63 results on '"Shan Xiao"'
Search Results
2. Balancing free and confined metallic Ni for an active and stable catalyst—A case study of CO methanation over Ni/Ni–Al2O3
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Yong-Shan Xiao, Zhao-Tie Liu, Shi Xianying, Chang Liu, Yong-Hong Song, Zhong-Wen Liu, Min-Li Zhu, and Han-Qing Ge
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Materials science ,Non-blocking I/O ,Energy Engineering and Power Technology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Methane ,0104 chemical sciences ,Catalysis ,Metal ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Chemical engineering ,Methanation ,visual_art ,Electrochemistry ,visual_art.visual_art_medium ,0210 nano-technology ,Dispersion (chemistry) ,Mesoporous material ,Energy (miscellaneous) ,Space velocity - Abstract
We propose a new strategy to make an active and stable Ni-based catalyst which can be operated in a wide range of reaction temperatures. The ordered mesoporous alumina (OMA) with confined Ni in the pore wall (Ni-OMA) was prepared via the one-pot evaporation induced self-assembly method. By using the incipient impregnation method, different amounts of free Ni were loaded over Ni-OMA (Ni/Ni-OMA) at a fixed total NiO content of 15 wt%. Characterization results confirmed the formation of well-structured Ni-OMA, and the ordered structure was still well preserved even after impregnating NiO at a content of as high as 12 wt%. The catalysts were evaluated for the CO methanation as a model reaction under varied conditions. Importantly, the activity and stability of Ni/Ni-OMA for the titled reaction were significantly regulated by simply changing the ratio of the confined to free Ni. Over the optimum catalyst of NiO (2 wt%)/NiO (13 wt%)-OMA, the high activity at a temperature of as low as 300 °C was achieved with the space-time yield of methane over 7.6 g gcat−1 h−1 while a long-term stability for a time-on-stream of 400 h was confirmed without an observable deactivation under the conditions of 600 °C and an extremely high gas hourly space velocity of 120,000 mL g−1 h−1. The results were well explained as the integrated merits of the free Ni for a high dispersion and the confined Ni in OMA for the anti-sintering property.
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- 2020
3. Amorphous silica-alumina composite with regulated acidity for efficient production of hydrogen via steam reforming of dimethyl ether
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Yong-Hong Song, Shan-Shan Wang, Zhong-Wen Liu, Qijian Zhang, Chang Liu, Yong-Hua Zhao, Zhao-Tie Liu, and Yong-Shan Xiao
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Hydrogen ,chemistry.chemical_element ,Amorphous silica-alumina ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Bifunctional catalyst ,Steam reforming ,chemistry.chemical_compound ,Hydrolysis ,chemistry ,Dimethyl ether ,0210 nano-technology ,Space velocity ,Nuclear chemistry - Abstract
In this work, we demonstrate that the amorphous silica-alumina composite (ASA) is an efficient solid acid for the steam reforming of dimethyl ether (SRD). Thus, a series of ASA with different Si/Al molar ratios was synthesized via the modified hydrolytic method by using Al(NO3)3·9H2O and/or NaAlO2 as Al precursor and tetraethoxysilane as Si precursor, respectively. Irrespective of the synthesis conditions, all of ASA composites were in an amorphous nature. However, both the acidity and the surface area were significantly affected by the synthesis conditions, the extent of which depends on the specific precursor and Si/Al molar ratios. The ASA physically mixed with a commercial Cu/ZnO/Al2O3 was investigated as a bifunctional catalyst for SRD under the conditions of P=0.1 MPa and gas hourly space velocity of 4000 h−1. Results indicate that both the conversion of dimethyl ether (DME) and the hydrogen yield were strongly dependent on the acidic property of ASA and the ASA to Cu/ZnO/Al2O3 ratios. Following the two-step consecutive mechanism of SRD, the catalytic results were well explained based on the acidic property of ASA, and the synergetic effect between the two catalytic functions was found to play a crucial role in determining the activity and stability of the bifunctional catalyst. Moreover, the DME hydrolysis was revealed to be the rate-limiting step for SRD reactions in the case of ASA as an acidic catalyst. By optimizing the synthesis conditions of ASA and the composition of the bifunctional catalyst, greater than 99% of DME conversion and hydrogen yield was achieved, and was kept for a time on stream of 66 h without an observable decrease. Thus, ASA is a very efficient solid acid for SRD.
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- 2020
4. Diverse RNA Viruses Discovered in Three Parasitoid Wasps of the Rice Weevil Sitophilus oryzae
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Bo Yuan, Gongyin Ye, Shan Xiao, Qisheng Song, Jiao Zhang, Fang Wang, Fei Wang, Qi Fang, and Wenxi Jia
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Dicistroviridae ,Genetics ,0303 health sciences ,biology ,030306 microbiology ,Weevil ,Sitophilus ,viruses ,fungi ,RNA ,food and beverages ,biology.organism_classification ,Microbiology ,QR1-502 ,03 medical and health sciences ,chemistry.chemical_compound ,chemistry ,Iflaviridae ,RNA polymerase ,Picornavirales ,Molecular Biology ,human activities ,Virus classification ,030304 developmental biology - Abstract
In this study, many virus-like fragments were obtained from transcriptomes of three wasp species, including Anisopteromalus calandrae (8), Lariophagus distinguendus (3), and Theocolax elegans (18), which can parasitize and control rice weevil Sitophilus oryzae, a serious insect pest of farm-stored grains. By further bioinformatic analysis and sequencing, we identified six novel RNA viruses with complete genomes and named them WWPSRV-1, WWPSRV-2, AcPSRV-1, AcNSRV-1, AcNSRV-2, and LdNSRV-1. PCR-based detection revealed that WWPSRV-1 and WWPSRV-2 had the possibility of interspecies virus transmission, especially WWPSRV-2, which was also present in the rice weevil adults. Phylogenetically, three out of these six viruses appeared to be members of order Picornavirales: WWPSRV-1 belonged to unassigned virus families of this order, whereas WWPSRV-2 and AcPSRV-1 belonged to families Iflaviridae and Dicistroviridae, respectively. The conserved picornavirus-typical domains helicase, protease, and RNA-dependent RNA polymerase could be found in the nonstructural protein encoded by the three viruses, whose genomes consisted of the different numbers of open reading frames (ORFs). The other three RNA viruses could be classified to order Mononegavirales: AcNSRV-1 and AcNSRV-2 belonged to family Lispiviridae, whereas LdNSRV-1 belonged to a big family Rhabdoviridae The genomes of the three viruses contained at least five ORFs, encoding deduced proteins in the following order: 3'-N-P-M-G-L-5'. All the ORFs were separated by conserved intergenic sequences which likely regulated the transcription termination and initiation. Our findings enhance the understanding of RNA viruses in weevil wasps and set the foundation for the future study of the association among weevils, weevil wasps, and RNA viruses.IMPORTANCE The enormous diversity of RNA viruses in insects is continuously validated. Parasitoid wasps, as biocontrol insects which are widely used against insect pests in agroecosystems, may also carry many "good" RNA viruses. Some RNA viruses in parasitoid wasps have been reported to affect the host wasps or the wasps' host. Here, six novel RNA viruses with complete genomes were identified in three parasitoid wasps of the rice weevil. One of these viruses was also detected in the rice weevil adults. Phylogenetically, WWPSRV-1 was the first unambiguous detection of Nora-like virus in insect parasitoids. WWPSRV-2 and AcPSRV-1 belong to families Iflaviridae and Dicistroviridae, some viruses of which can result in lethal infections in silkworms and honeybees. The other three RNA viruses belong to order Mononegavirales, which comprises many well-known insect-associated viruses.
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- 2021
5. The RNA N6-methyladenosine modification landscape of human fetal tissues
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Shuo Cao, Qi-tao Huang, Yuan Li, Mengtian Yang, Weishi Wang, Junfang Shi, Sun Liu, Shan Xiao, Qizhi Luo, Guiru Jia, Mingqiang Deng, Laixin Xia, Kaifen Tan, Linjian Xia, Xiaona Liu, Chunjiang He, Mei Zhong, and Haoran Zhu
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0303 health sciences ,RNA ,Single-nucleotide polymorphism ,Cell Biology ,Computational biology ,Biology ,Cell biology ,Gene expression profiling ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,chemistry ,030220 oncology & carcinogenesis ,Gene expression ,N6-Methyladenosine ,Enhancer ,Gene ,030304 developmental biology ,Epigenomics - Abstract
A single genome gives rise to diverse tissues through complex epigenomic mechanisms, including N6-methyladenosine (m6A), a widespread RNA modification that is implicated in many biological processes. Here, to explore the global landscape of m6A in human tissues, we generated 21 whole-transcriptome m6A methylomes across major fetal tissues using m6A sequencing. These data reveal dynamic m6A methylation, identify large numbers of tissue differential m6A modifications and indicate that m6A is positively correlated with gene expression homeostasis. We also report m6A methylomes of long intergenic non-coding RNA (lincRNA), finding that enhancer lincRNAs are enriched for m6A. Tissue m6A regions are often enriched for single nucleotide polymorphisms that are associated with the expression of quantitative traits and complex traits including common diseases, which may potentially affect m6A modifications. Finally, we find that m6A modifications preferentially occupy genes with CpG-rich promoters, features of which regulate RNA transcript m6A. Our data indicate that m6A is widely regulated by human genetic variation and promoters, suggesting a broad involvement of m6A in human development and disease.
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- 2019
6. Counteranion‐ and Solvent‐Mediated Chirality Transfer in the Supramolecular Polymerization of Luminescent Platinum(II) Complexes
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Chi-Ming Che, Kam-Hung Low, Wei Lu, Xin-Shan Xiao, Wai-Pong To, Qingyun Wan, and Yong Chen
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Supramolecular chirality ,010405 organic chemistry ,Intermolecular force ,Supramolecular chemistry ,Cationic polymerization ,General Chemistry ,General Medicine ,Photochemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Solvent ,chemistry.chemical_compound ,Monomer ,chemistry ,Polymerization ,Chirality (chemistry) - Abstract
The chirality of supramolecular polymeric materials is subtly affected by a delicate balance among various non-covalent interactions, the details of which are inadequately understood. Now, a fine balance of intermolecular interactions, including closed-shell metal-metal, dispersive and electrostatic interactions, is used to direct the delicate orientation of monomeric building blocks, thereby achieving the successful preparation of different nanostructures with distinct supramolecular chirality. Moreover, kinetically trapped and thermodynamically stable aggregates were monitored over time in the supramolecular polymerization of cationic PtII complexes. The dynamic self-assembly process can be successfully controlled by modifying the counteranion and solvent composition. A chiral doping approach can also be used to induce the chirality of an achiral PtII complex at the supramolecular level.
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- 2018
7. Clinical Characteristics of Patients With Progressive and Non-progressive Coronavirus Disease 2019: Evidence From 365 Hospitalised Patients in Honghu and Nanchang, China
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Yanpei Zhang, Lu-shan Xiao, Pu Li, Hongbo Zhu, Chenyi Hu, Wen-Feng Zhang, Qing-can Sun, Meng-ying Shen, Shan-shan Liu, Wan-li Zhang, Han-yi Zeng, Mengchun Gong, Li Liu, Yu-Lin He, and Hong Zhu
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medicine.medical_specialty ,medicine.drug_class ,Disease ,Anorexia ,030204 cardiovascular system & hematology ,creatinine kinase ,C-reactive protein ,coronavirus disease 2019 ,03 medical and health sciences ,chemistry.chemical_compound ,disease progression ,0302 clinical medicine ,Internal medicine ,medicine ,030212 general & internal medicine ,Original Research ,lcsh:R5-920 ,Creatinine ,bilateral patchy shadowing ,biology ,business.industry ,Incidence (epidemiology) ,creatinine ,General Medicine ,medicine.disease ,chemistry ,biology.protein ,Coinfection ,Medicine ,Corticosteroid ,medicine.symptom ,lcsh:Medicine (General) ,business ,Progressive disease ,severe acute respiratory syndrome coronavirus 2 - Abstract
Background: Coronavirus disease (COVID-19) has swept around the globe and led to a worldwide catastrophe. Studies examining the disease progression of patients with non-severe disease on admission are scarce but of profound importance in the early identification of patients at a high risk of deterioration. Objectives: To elucidate the differences in clinical characteristics between patients with progressive and non-progressive COVID-19 and to determine the risk factors for disease progression. Study design: Clinical data of 365 patients with non-severe COVID-19 from 1 January 2020 to 18 March 2020 were retrospectively collected. Patients were stratified into progressive and non-progressive disease groups. Univariate and multivariate logistic regression analyses were performed to determine the independent risk factors for disease progression. Results: Compared with patients with non-progressive disease, those who progressed to severe COVID-19 were older and had significantly decreased lymphocyte and eosinophil counts; increased neutrophil and platelet counts; lower albumin levels; higher levels of lactate dehydrogenase, C-reactive protein (CRP), creatinine, creatinine kinase, and urea nitrogen; and longer prothrombin times. Hypertension, fever, fatigue, anorexia, bacterial coinfection, bilateral patchy shadowing, antibiotic and corticosteroid administration, and oxygen support had a significantly higher incidence among patients with progressive disease. A significantly longer duration of hospital stay was also observed in patients with progressive disease. Bilateral patchy shadowing (OR = 4.82, 95% CI: 1.33–17.50; P = 0.017) and elevated levels of creatinine (OR =6.24, 95% CI: 1.42–27.40; P = 0.015), and CRP (OR = 7.28, 95% CI: 2.56–20.74; P < 0.001) were independent predictors for disease progression. Conclusion: The clinical characteristics of patients with progressive and non-progressive COVID-19 were significantly different. Bilateral patchy shadowing and increased levels of creatinine, and CRP were independent predictors of disease progression.
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- 2020
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8. Gallium nitride catalyzed the direct hydrogenation of carbon dioxide to dimethyl ether as primary product
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Jia-Xin He, Ye Wang, Yong-Shan Xiao, Chun-Ran Chang, Zhao-Tie Liu, Jian Song, Yong-Hong Song, Jincan Kang, Han-Qing Ge, Zhong-Wen Liu, Chang Liu, and Zheng-Qing Huang
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Science ,General Physics and Astronomy ,Gallium nitride ,02 engineering and technology ,010402 general chemistry ,Photochemistry ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Catalysis ,chemistry.chemical_compound ,Chemical engineering ,Dimethyl ether ,Formate ,Heterogeneous catalysis ,Multidisciplinary ,Catalytic mechanisms ,General Chemistry ,021001 nanoscience & nanotechnology ,Product distribution ,0104 chemical sciences ,chemistry ,Density functional theory ,Methanol ,0210 nano-technology ,Selectivity - Abstract
The selective hydrogenation of CO2 to value-added chemicals is attractive but still challenged by the high-performance catalyst. In this work, we report that gallium nitride (GaN) catalyzes the direct hydrogenation of CO2 to dimethyl ether (DME) with a CO-free selectivity of about 80%. The activity of GaN for the hydrogenation of CO2 is much higher than that for the hydrogenation of CO although the product distribution is very similar. The steady-state and transient experimental results, spectroscopic studies, and density functional theory calculations rigorously reveal that DME is produced as the primary product via the methyl and formate intermediates, which are formed over different planes of GaN with similar activation energies. This essentially differs from the traditional DME synthesis via the methanol intermediate over a hybrid catalyst. The present work offers a different catalyst capable of the direct hydrogenation of CO2 to DME and thus enriches the chemistry for CO2 transformations., The conversion of CO2 to valuable chemicals is still challenged by catalyst developments. Herein, the authors found that GaN is an efficient catalyst for selective CO2 hydrogenation to dimethyl ether as the primary product, in contrast to the traditional methanol-intermediate route over hybrid catalysts.
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- 2020
9. Effects of catheter-based renal denervation on glycemic control and lipid levels: a systematic review and meta-analysis
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Xiaoping Chen, Shan Xiao, Zhipeng Zhang, and Kai Liu
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Blood Glucose ,medicine.medical_specialty ,Funnel plot ,Catheters ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,030209 endocrinology & metabolism ,Glycemic Control ,030204 cardiovascular system & hematology ,Kidney ,Gastroenterology ,Cohort Studies ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Endocrinology ,Internal medicine ,Diabetes mellitus ,Internal Medicine ,Medicine ,Humans ,Insulin ,Glycemic ,Randomized Controlled Trials as Topic ,Glycated Hemoglobin ,Triglyceride ,business.industry ,General Medicine ,Publication bias ,medicine.disease ,Lipid Metabolism ,Denervation ,Lipids ,Observational Studies as Topic ,chemistry ,Strictly standardized mean difference ,Meta-analysis ,Hypertension ,Catheter Ablation ,Insulin Resistance ,business - Abstract
As an emerging interventional technique to treat resistant hypertension, renal denervation (RDN) has also attracted considerable attention due to its potential beneficial effects on glucose and lipid metabolism. Given that inconsistent results were documented among studies, we aimed to perform a systematic review and meta-analysis to elaborate on this issue. The PubMed, EMBASE, Web of Science (SCI) and ClinicalTrials.gov databases were comprehensively searched from their inception date to June 18, 2020, for relevant clinical studies evaluating the efficacy of RDN on glucose and lipid levels. The outcomes of interest were changes in fasting glucose, insulin, C-peptide, hemoglobin A1C (HbA1C), homeostatic model assessment-insulin resistance (HOMA-IR), cholesterol and triglyceride (TG) levels before versus after RDN and also RDN versus the control group. The mean differences (MDs) of the outcomes measured before versus after RDN and RDN versus the control group were pooled by a randomized effects model. Heterogeneity was quantified with Chi-square (χ2) and inconsistency index (I2). Assessment of publication bias was performed by the funnel plot and Egger’s test. A total of 1600 studies were initially identified. Nineteen of the identified studies (six randomized controlled studies, one non-randomized controlled studies and 12 observational cohort studies) involving 2245 subjects were included in the final analysis. No significant change was observed after RDN in fasting glucose (weighted mean difference [WMD] − 0.19 mmol/L; 95% CI − 0.37, 0.00 mmol/L), insulin (standardized mean difference [SMD] − 0.01; 95% CI − 0.41, 0.39), C-peptide (SMD − 0.05; 95% CI − 0.30, 0.21), HbA1C (SMD − 0.05; 95% CI − 0.17, 0.07), HOMA-IR (SMD − 0.29; 95% CI − 0.72, 0.14), total cholesterol (TC) (WMD − 0.11 mmol/L; 95% CI − 0.37, 0.15 mmol/L), and low-density lipoprotein cholesterol (LDL-C) levels (WMD − 0.18 mmol/L; 95% CI − 0.59, 0.24 mmol/L) during follow-up. Changes in fasting glucose, insulin, HbA1C and TC levels in RDN groups were not significantly different from those in the control group. High-density lipoprotein cholesterol (HDL-C) and TG were slightly improved after RDN (WMD 0.07 mmol/L, 95% CI 0.01, 0.14 mmol/L; WMD − 0.26 mmol/l, 95% CI − 0.51, − 0.01 mmol/L, respectively). The funnel plot and Egger’s test demonstrated the absence of potential publication bias. Catheter-based RDN appeared to have no impact on glucose metabolism. There was a statistically significant but clinically negligible improvement in HDL-C and TG levels based on the current evidence. Future research with more rigorous designs is warranted to draw definitive conclusions. The protocol of this meta-analysis was registered on PROSPERO (CRD42020192805). ( https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=192805 )
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- 2020
10. Identifying defect-related quantum emitters in monolayer WSe$_2$
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Yunuan Wang, Shan Xiao, Kai Peng, Xin Xie, Longlong Yang, Xiulai Xu, Chenjiang Qian, Feilong Song, Shiyao Wu, Muhammad Rafiq, S. S. Sun, Yang Yu, Jingnan Yang, Jianchen Dang, and Can Wang
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Materials science ,Exciton ,FOS: Physical sciences ,02 engineering and technology ,01 natural sciences ,Molecular physics ,lcsh:Chemistry ,symbols.namesake ,chemistry.chemical_compound ,0103 physical sciences ,Monolayer ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,lcsh:TA401-492 ,Tungsten diselenide ,General Materials Science ,Spontaneous emission ,010306 general physics ,Zeeman effect ,Condensed Matter - Mesoscale and Nanoscale Physics ,business.industry ,Mechanical Engineering ,Exchange interaction ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Semiconductor ,chemistry ,lcsh:QD1-999 ,Mechanics of Materials ,Quantum dot ,symbols ,lcsh:Materials of engineering and construction. Mechanics of materials ,0210 nano-technology ,business ,Physics - Optics ,Optics (physics.optics) - Abstract
Monolayer transition metal dichalcogenides have recently attracted great interests because the quantum dots embedded in monolayer can serve as optically active single photon emitters. Here, we provide an interpretation of the recombination mechanisms of these quantum emitters through polarization-resolved and magneto-optical spectroscopy at low temperature. Three types of defect-related quantum emitters in monolayer tungsten diselenide (WSe$_2$) are observed, with different exciton g factors of 2.02, 9.36 and unobservable Zeeman shift, respectively. The various magnetic response of the spatially localized excitons strongly indicate that the radiative recombination stems from the different transitions between defect-induced energy levels, valance and conduction bands. Furthermore, the different g factors and zero-field splittings of the three types of emitters strongly show that quantum dots embedded in monolayer have various types of confining potentials for localized excitons, resulting in electron-hole exchange interaction with a range of values in the presence of anisotropy. Our work further sheds light on the recombination mechanisms of defect-related quantum emitters and paves a way toward understanding the role of defects in single photon emitters in atomically thin semiconductors., Comment: 14 pages, 4 Figures
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- 2020
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11. Atmospheric new particle formation from sulfuric acid and amines in a Chinese megacity
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Jianmin Chen, Markku Kulmala, Fuhai Geng, Xin Yang, Heikki Junninen, Bowen Zhang, Hangfei Chen, Douglas R. Worsnop, Lei Yao, Dongfang Wang, Jun Zheng, Olga Garmash, Tuukka Petäjä, Mikael Ehn, Mingyi Wang, Hongli Wang, Jenni Kontkanen, Li Li, Qingyan Fu, Mikko Sipilä, Xinke Wang, Chao Yan, Pauli Paasonen, Lin Wang, F. Bianchi, Veli-Matti Kerminen, Yiqun Lu, Stephany Buenrostro Mazon, Liping Qiao, Shan Xiao, Institute for Atmospheric and Earth System Research (INAR), Aerosol-Cloud-Climate -Interactions (ACCI), INAR Physics, and Polar and arctic atmospheric research (PANDA)
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010504 meteorology & atmospheric sciences ,NUMBER CONCENTRATIONS ,116 Chemical sciences ,Nucleation ,010501 environmental sciences ,114 Physical sciences ,01 natural sciences ,Ammonia ,chemistry.chemical_compound ,SIZE DISTRIBUTION ,Cluster (physics) ,EMISSIONS ,1172 Environmental sciences ,0105 earth and related environmental sciences ,AMMONIA ,Multidisciplinary ,Condensation ,Sulfuric acid ,TIME ,Aerosol ,OXIDIZED ORGANIC-MOLECULES ,Chemical engineering ,chemistry ,YANGTZE-RIVER DELTA ,13. Climate action ,GROWTH ,Particle ,AEROSOL NUCLEATION ,Sink (computing) ,CLUSTERS - Abstract
Atmospheric new particle formation (NPF) is an important global phenomenon that is nevertheless sensitive to ambient conditions. According to both observation and theoretical arguments, NPF usually requires a relatively high sulfuric acid (H2SO4) concentration to promote the formation of new particles and a low preexisting aerosol loading to minimize the sink of new particles. We investigated NPF in Shanghai and were able to observe both precursor vapors (H2SO4) and initial clusters at a molecular level in a megacity. High NPF rates were observed to coincide with several familiar markers suggestive of H2SO4-dimethylamine (DMA)water (H2O) nucleation, including sulfuric acid dimers and H2SO4-DMA clusters. In a cluster kinetics simulation, the observed concentration of sulfuric acid was high enough to explain the particle growth to similar to 3 nanometers under the very high condensation sink, whereas the subsequent higher growth rate beyond this size is believed to result fromthe added contribution of condensing organic species. These findings will help in understanding urban NPF and its air quality and climate effects, as well as in formulating policies to mitigate secondary particle formation in China.
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- 2018
12. The distribution and function characterization of the i type lysozyme from Apostichopus japonicus
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Lina Cong, Shan Xiao, Jun Huang, Tingting Liu, Cheng Li, Jihui Wang, Qi Zhang, Bingnan Liu, Yu Zhao, Benkang Liu, and Han Wang
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0301 basic medicine ,Aquatic Science ,03 medical and health sciences ,chemistry.chemical_compound ,Animals ,Environmental Chemistry ,Coelomocyte ,chemistry.chemical_classification ,Isopeptide bond ,Innate immune system ,biology ,Gene Expression Profiling ,virus diseases ,04 agricultural and veterinary sciences ,General Medicine ,biology.organism_classification ,Immunity, Innate ,In vitro ,respiratory tract diseases ,Isopeptidase activity ,030104 developmental biology ,Gene Expression Regulation ,Biochemistry ,chemistry ,Stichopus ,Apostichopus japonicus ,040102 fisheries ,0401 agriculture, forestry, and fisheries ,Muramidase ,Lysozyme ,Bacteria - Abstract
Lysozyme is a very important component of the innate immune system and a key molecule that protects against bacterial infection. Sea cucumber i-type lysozyme (Aj-iLys) has been shown to possess multiple functions. In this study, we investigated the function and characterization of Aj-iLys in detail. Spatial distribution analysis showed that Aj-iLys was constitutively expressed in all tested tissues, with dominant expression in the tentacles and respiratory trees. Challenge with the pathogen V. splendidus and LPS stimulation both significantly up-regulated the mRNA expression of Aj-iLys. More importantly, inhibition of Aj-iLys expression by mRNA interference resulted in significant promotion of coelomocyte apoptosis during LPS challenge in vitro. The results indicated that Aj-iLys serves as an important innate immunity factor and plays a key defense role during host-pathogen interactions in sea cucumbers. From the radius of the antimicrobial zone, it was determined that the non-fusion Aj-iLys exerted a remarkable inhibitive effect on tested bacteria in vitro. Functional investigation revealed that Aj-iLys also exhibited isopeptidase activity based on its ability to hydrolyze l-Glutamic acid γ-(4-nitroanilide) in vitro to produce p-NA, which is an analogue of the isopeptide bond. The optimal catalytic conditions for the isopeptidase activity were 37 °C, pH 6.5, and the optimum ionic strength was about 0.050 mol/L.
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- 2018
13. Synthesis and Evaluation of a New Kind of Kinetic Hydrate Inhibitor
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An Shan Xiao, Zou Bing, Hong-Xing Zhang, Ke Le Yan, Ming Ma, and Ying Li
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Work (thermodynamics) ,Ethanol ,Stereochemistry ,Mechanical Engineering ,Clathrate hydrate ,Caprolactam ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Kinetic energy ,Subcooling ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,Chemical engineering ,Mechanics of Materials ,Precipitation polymerization ,General Materials Science ,0204 chemical engineering ,0210 nano-technology ,Hydrate - Abstract
A new kind of kinetic hydrate inhibitor (KHI) named KL-1 as the ramification of poly (N-vinyl caprolactam) (PVCap), was synthesized successfully by use of precipitation polymerization. The hydrate inhibition performance of KL-1 was assessed in a high pressure sapphire cell, and the onset time of hydrate formation and maximum subcooling were determined by the visual observation method and compared with the commercial KHIs, including Inhibex 501 and VC-713. Meanwhile, the synergic effect between ethanol and KL-1 developed was also studied in this work. The experimental results show that the onset time of KL-1 measured increases with the increase of the dosage and decrease of subcooling. Compared with the system without kinetic hydrate inhibitor, the morphological behavior of hydrate crystals in the systems containing KL-1 is different, and the hydrate crystals only grow to the gas phase with the hydrate formation. Additionally, based on the measurement of inhibition time, the inhibition performance of KL-1 is superior to Inhibex 501 and VC-713, and shows higher maximum subcooling at the similar conditions. Finally, we also demonstrated that ethanol can be used as synergist to improve the performance of KL-1 remarkably at suitable dosage.
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- 2017
14. Xanthophyllomyces dendrorhous-Derived Astaxanthin Regulates Lipid Metabolism and Gut Microbiota in Obese Mice Induced by A High-Fat Diet
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Shiwen Liu, Shan Xiao, Bingnan Liu, Cheng Li, Han Wang, Jihui Wang, and Ying Li
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obesity ,Firmicutes ,Pharmaceutical Science ,Gut flora ,Article ,law.invention ,03 medical and health sciences ,chemistry.chemical_compound ,Probiotic ,0302 clinical medicine ,Xanthophyllomyces dendrorhous ,Astaxanthin ,law ,Drug Discovery ,lipid metabolism ,medicine ,Food science ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) ,lcsh:QH301-705.5 ,030304 developmental biology ,0303 health sciences ,biology ,gut microbiota ,Cholesterol ,Lipid metabolism ,Akkermansia ,biology.organism_classification ,astaxanthin ,chemistry ,lcsh:Biology (General) ,030220 oncology & carcinogenesis ,medicine.symptom ,Weight gain - Abstract
Astaxanthin is an important antioxidant with many biological activities such as anti-tumor, anti-obesity, cardioprotective, and immuno-modulatory activities. Most of these biological activities are derived from (3S,3&prime, S)-astaxanthin, while the activities of (3R,3&prime, R)-astaxanthin are rarely reported. The purpose of this study was to investigate the effect of (3R,3&prime, R)-astaxanthin on lipid metabolism and gut microbiota in mice fed with a high-fat diet. In this work, 40 male C57BL/6 mice were divided into 8 groups fed a high-fat diet supplemented or not with (3R,3&prime, R)-astaxanthin or Xanthophyllomyces dendrorhous for 8 weeks. The weight gain, energy intake, fat index, plasma triacylglycerol and cholesterol, liver triacylglycerol and cholesterol, and gut microbiota were determined. The results showed that the addition of (3R,3&prime, R)-astaxanthin/X. dendrorhous to the high-fat diet as a supplement prevented weight gain, reduced plasma and liver triacylglycerol, and decreased plasma and liver total cholesterol. The addition of (3R,3&prime, R)-astaxanthin/X. dendrorhous also regulated the gut microbiota of the mice, which optimized the ratio of Bacteroides to Firmicutes and increased the content of Verrucomicrobia, especially Akkermansia. The changes in the gut microflora achieved a healthier structure, thus reducing the incidence of obesity. Thus (3R,3&prime, R)-Astaxanthin has the function of regulating lipid metabolism and gut microbiota to prevent obesity caused by a high-fat diet. The production strain of (3R,3&prime, R)-astaxanthin, X. dendrorhous, has the same function as astaxanthin in preventing obesity caused by a high-fat diet, which reflects its potential ability as a probiotic drug.
- Published
- 2019
15. Association of Elevated Plasma Homocysteine Level with Restenosis and Clinical Outcomes After Percutaneous Coronary Interventions: a Systemic Review and Meta-analysis
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Zhipeng Zhang, Shan Xiao, Xiaoping Chen, Runyu Ye, Xianjin Hu, and Changqiang Yang
- Subjects
0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Homocysteine ,medicine.medical_treatment ,Hyperhomocysteinemia ,030204 cardiovascular system & hematology ,Risk Assessment ,Coronary Restenosis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Percutaneous Coronary Intervention ,Restenosis ,Risk Factors ,Internal medicine ,Angioplasty ,medicine ,Humans ,Pharmacology (medical) ,Myocardial infarction ,Aged ,Pharmacology ,business.industry ,Percutaneous coronary intervention ,General Medicine ,Middle Aged ,medicine.disease ,Up-Regulation ,030104 developmental biology ,Treatment Outcome ,chemistry ,Relative risk ,Conventional PCI ,Cardiology ,Female ,Stents ,Cardiology and Cardiovascular Medicine ,business ,Mace ,Biomarkers - Abstract
We conducted this systemic review and meta-analysis to investigate the association between elevated plasma homocysteine (Hcy) levels and recurrent restenosis and clinical outcomes after percutaneous coronary intervention (PCI). PubMed, EMBASE, and Web of Science were systematically searched prior to May 2018. Studies evaluating the association between plasma Hcy levels and the occurrence of restenosis, major adverse cardiac events (MACE), all-cause mortality, cardiac death, non-fatal myocardial infarction (MI), and target lesion revascularization were identified. A total of 19 articles with 4340 participants were identified. Higher Hcy levels were not associated with an increased risk of restenosis (relative risk (RR) = 1.10, 95% CI 0.90–1.33). Hcy levels in the restenosis group were not significantly higher than in the non-restenosis group (weighted mean difference = 0.70, 95% CI − 0.23–1.63). Subgroup analysis revealed that higher Hcy levels were not associated with restenosis after stenting but appeared to increase the risk of restenosis after angioplasty. Elevated Hcy levels increased the risk of all-cause mortality by an average of 3.19-fold (RR = 3.19, 95% CI 1.90–5.34, P = 0.000), the risk of MACE by 1.51-fold (RR = 1.51, 95% CI 1.23–1.85, P = 0.000), and the risk of cardiac death by 2.76-fold (RR = 2.76, 95% CI 1.44–5.32, P = 0.000) but appeared not to increase the risk of non-fatal MI (RR = 1.36, 95% CI 0.89–2.09). Our meta-analysis suggests that although there is no clear association between higher Hcy levels and restenosis following stent implantation, higher Hcy levels appeared to increase the risk of restenosis after coronary angioplasty and also increased the risk of all-cause mortality, MACE, and cardiac death after PCI. The protocol of this meta-analysis was registered on PROSPERO (CRD42018096466). ( http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018096466 ).
- Published
- 2019
16. CVm6A: A Visualization and Exploration Database for m6As in Cell Lines
- Author
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Chunjiang He, Xinyang Zhang, Laixin Xia, Zhixiang Zuo, Xin Dong, Yujing Han, Shan Xiao, Shihan Zhang, Qidi Xu, Linjian Xia, Jing Feng, and Yuqi Miao
- Subjects
m6A ,Database ,N6-methyladenosine ,General Medicine ,cell line ,Biology ,computer.software_genre ,Visualization ,chemistry.chemical_compound ,chemistry ,lcsh:Biology (General) ,TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY ,N6-Methyladenosine ,computer ,Gene ,lcsh:QH301-705.5 ,Function (biology) ,visualization - Abstract
N6-methyladenosine (m6A) has been identified in various biological processes and plays important regulatory functions in diverse cells. However, there is still no visualization database for exploring global m6A patterns across cell lines. Here we collected all available MeRIP-Seq and m6A-CLIP-Seq datasets from public databases and identified 340,950 and 179,201 m6A peaks dependent on 23 human and eight mouse cell lines respectively. Those m6A peaks were further classified into mRNA and lncRNA groups. To better understand the potential function of m6A, we then mapped m6A peaks in different subcellular components and gene regions. Among those human m6A modification, 190,050 and 150,900 peaks were identified in cancer and non-cancer cells, respectively. Finally, all results were integrated and imported into a visualized cell-dependent m6A database CVm6A. We believe the specificity of CVm6A could significantly contribute to the research for the function and regulation of cell-dependent m6A modification in disease and development.
- Published
- 2019
17. Association of hospital admission for bronchiectasis with air pollution: A province-wide time-series study in southern China
- Author
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Jinzhen Zheng, Shan Xiao, Huajing Yang, Xinwang Wang, Sha Liu, Pixin Ran, Yongbo Zhang, Nanshan Zhong, Heshen Tian, Xianzhong Duan, Xiaoliang Huang, Longhui Tang, Wei Hu, Fan Wu, Zhishan Deng, Chenghao Liao, Min Xie, Shiliang Liu, Zihui Wang, Ming Luo, Long Wang, Yubo Ou, Jieqi Peng, Yumin Zhou, and Yijia Zheng
- Subjects
China ,Ozone ,Nitrogen Dioxide ,Air pollution ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Interquartile range ,Air Pollution ,Environmental health ,medicine ,Humans ,Sulfur Dioxide ,Nitrogen dioxide ,030212 general & internal medicine ,Risk factor ,0105 earth and related environmental sciences ,Air Pollutants ,Bronchiectasis ,business.industry ,Public Health, Environmental and Occupational Health ,Environmental Exposure ,medicine.disease ,Hospitals ,Hospitalization ,chemistry ,Relative risk ,Hospital admission ,Female ,Particulate Matter ,business - Abstract
The relation of acute fluctuations of air pollution to hospital admission for bronchiectasis remained uncertain, and large-scale studies were needed. We collected daily concentrations of particulate matter (PM), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and daily hospitalizations for bronchiectasis for 21 cities across Guangdong Province from 2013 through 2017. We examined their association using two-stage time-series analysis. Our analysis was stratified by specific sub-diagnosis, sex and age group to assess potential effect modifications. Relative risks of hospitalization for bronchiectasis were 1.060 (95%CI 1.014-1.108) for PM10 at lag0-6, 1.067 (95%CI 1.020-1.116) for PM2.5 at lag0-6, 1.038 (95%CI 1.005-1.073) for PMcoarse at lag0-6, 1.058 (95%CI 1.015-1.103) for SO2 at lag0-4, 1.057 (95%CI 1.030-1.084) for NO2 at lag0 and 1.055 (95%CI 1.025-1.085) for CO at lag0-6 per interquartile range increase of air pollution. Specifically, acute fluctuations of air pollution might be a risk factor for bronchiectasis patients with lower respiratory infection but not with hemoptysis. Patients aged ≥65 years, and female patients appeared to be particularly susceptible to air pollution. Acute fluctuations of air pollution, particularly PM may increase the risk of hospital admission for bronchiectasis exacerbations, especially for the patients complicated with lower respiratory infection. This study strengthens the importance of reducing adverse impact on respiratory health of air pollution to protect vulnerable populations.
- Published
- 2021
18. Linoelaidic acid enhances adipogenic differentiation in adipose tissue-derived stromal cells through suppression of Wnt/β-catenin signaling pathway in vitro
- Author
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Luyang Jian, Jingwei Zhang, Han Wang, Yuan Liang, Shan Xiao, Shuai Liang, Bingnan Liu, and Jihui Wang
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Linolenic acid ,Cellular differentiation ,Linoleic acid ,Clinical Biochemistry ,Down-Regulation ,Adipose tissue ,Linoleic Acid ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,3T3-L1 Cells ,Internal medicine ,Lipid droplet ,medicine ,Animals ,Wnt Signaling Pathway ,Cells, Cultured ,Triglycerides ,beta Catenin ,Cell Nucleus ,Adipogenesis ,Wnt signaling pathway ,Cell Differentiation ,Cell Biology ,030104 developmental biology ,Linolelaidic acid ,Endocrinology ,Adipose Tissue ,chemistry ,Stromal Cells - Abstract
Obesity has become a major health problem which is related with high-trans fatty acids diet. Adipogenic differentiation of adipose tissue-derived stromal cells (ADSCs) plays an important role in the development of adipose tissue. In order to determine the effect of trans fatty acids on adipogenic differentiation in ADSCs, cells were treated with linoelaidic acid, as well as linoleic acid and linolenic acid. We found that linoelaidic acid significantly increased the lipid droplet formation and triglyceride content compared with linoleic acid and linolenic acid. Linoelaidic acid also down-regulated the levels of β-catenin in cells and inhibited the accumulation of β-catenin in cell nuclei. Lithium chloride, an activator of Wnt/β-catenin pathway, antagonized the enhancement of linoelaidic acid on adipogenesis and up-regulated the levels of β-catenin in ADSCs. These results indicated that linoelaidic acid could enhance the adipogenic differentiation in ADSCs in vitro, which is partly due to the suppression of Wnt/β-catenin pathway.
- Published
- 2016
19. Sensitivity enhancement of pH indicator and its application in the evaluation of fish freshness
- Author
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Han Wang, Shan Xiao, Jihui Wang, Liang Feng, Wen Sun, and Hui Li
- Subjects
Detection limit ,Color transition ,Chromatography ,genetic structures ,Colorimetric sensor array ,Bromophenol blue ,HSL and HSV ,Hydrogen-Ion Concentration ,Ethylenediamines ,Perciformes ,Analytical Chemistry ,Color model ,chemistry.chemical_compound ,chemistry ,Limit of Detection ,pH indicator ,Food Quality ,Solvents ,Animals ,Colorimetry ,Hydrochloric Acid ,Hue - Abstract
The sensitivity of pH indicators is always confined in acidic solvents used during the immobilization because of the large deviation from their color transition points. By regulating the pH of indicators using organic acid or base, the color transition points of indicators could be readily achieved and the sensitivity could be greatly enhanced. In this study, bromophenol blue was selected as an example to interpret this improvement. And Hue, Saturation and Value (HSV) color model was applied to obtain digital color information of pH indicators. In addition, other two kinds of pH indicators were chosen and regulated to their color transition points as well. The resultant indicators together with the original ones were composed to a colorimetric sensor array and utilized to determine fish freshness. Compared with the original indicators, much higher sensitivity in the detection of fish freshness was obtained by the pH regulated indicators.
- Published
- 2015
20. Production of astaxanthin at moderate temperature in Xanthophyllomyces dendrorhous using a two‐step process
- Author
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Shan Xiao, Bingnan Liu, Jihui Wang, Han Wang, Shiwen Liu, and Ying Li
- Subjects
0106 biological sciences ,0301 basic medicine ,Environmental Engineering ,Two step ,Bioengineering ,01 natural sciences ,Continuous production ,Moderate temperature ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Astaxanthin ,010608 biotechnology ,Yield (chemistry) ,Astaxanthin synthesis ,Xanthophyllomyces dendrorhous ,Fermentation ,Food science ,Research Articles ,Biotechnology - Abstract
In order to achieve continuous industrial production of astaxanthin in Xanthophyllomyces dendrorhous, a moderate temperature (25–37°C) fermentation process was needed. In this study, a two‐step process with a 20°C pre‐culture for 18 h and a 30°C culture for 30 h was performed to achieve the astaxanthin yields of 116.42 μg g(−1) dry cell weight, which was lower than that in the normal process (20°C, 96 h). However, cell yield (Y(X/S)) and product yield (Y(P/S)) showed no significant differences between the two processes, suggesting that moderate temperature did not affect the productivity of astaxanthin. The transcriptional levels of genes involved in astaxanthin synthesis were compared in different culture times and a negative correlation between temperature and expression of carotenogenic genes was found. This work provided a potential method for continuous production of astaxanthin using X. dendrorhous at moderate temperature throughout the year.
- Published
- 2018
21. Strand-Biased Formation of G-Quadruplexes in DNA Duplexes Transcribed with T7 RNA Polymerase
- Author
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Zheng Tan, Shan Xiao, Jiaquan Liu, and Yu-hua Hao
- Subjects
Base pair ,RNA polymerase II ,Catalysis ,Viral Proteins ,chemistry.chemical_compound ,Transcription (biology) ,Nucleic Acids ,medicine ,T7 RNA polymerase ,heterocyclic compounds ,Polymerase ,Transcription bubble ,Base Sequence ,General transcription factor ,biology ,DNA ,DNA-Directed RNA Polymerases ,General Medicine ,General Chemistry ,Molecular biology ,Cell biology ,G-Quadruplexes ,chemistry ,biology.protein ,medicine.drug - Abstract
G-quadruplex-forming sequences are enriched near transcription start sites (TSSs) in animal genes. They readily form G-quadruplexes in transcription, which in turn regulate transcription. Therefore, the control of G-quadruplex formation is important for their functionality. It is now shown that G-quadruplexes form efficiently on the non-template, but hardly on the template DNA strand in the downstream vicinity of TSSs in DNA duplexes when they are transcribed by the T7 RNA polymerase (RNAP). Structural analysis reveals that the T7 RNAP causes distortion in a DNA duplex both inside and in front of the enzyme. This structural distortion leads to strand-biased G-quadruplex formation when a G-quadruplex-forming sequence is partially fed into the T7 RNAP to a position about seven nucleotides away from the front of RNA synthesis. Based on these facts, we propose a model for the strand-biased formation of G-quadruplexes in transcribed DNA duplexes.
- Published
- 2015
22. Central carbon metabolism influences cellulase production in Bacillus licheniformis
- Author
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Han Wang, Ying Li, Shiwen Liu, Shan Xiao, Jihui Wang, Bingnan Liu, and Cheng Li
- Subjects
0301 basic medicine ,030106 microbiology ,Malic enzyme ,Cellulase ,Pentose phosphate pathway ,Applied Microbiology and Biotechnology ,Pentose Phosphate Pathway ,03 medical and health sciences ,chemistry.chemical_compound ,Bacterial Proteins ,Malate Dehydrogenase ,Metabolic flux analysis ,Bacillus licheniformis ,chemistry.chemical_classification ,biology ,Glucanase ,biology.organism_classification ,Carbon ,030104 developmental biology ,Enzyme ,Biochemistry ,chemistry ,biology.protein ,Anaplerotic reactions ,NADP - Abstract
Bacillus licheniformis which can produce cellulase including endo glucanase and glucosidase is an important industrial microbe for cellulose degradation. The purpose of this research was to assess the effect of endo glucanase gene bglC and glucosidase gene bglH on the central metabolic flux in B. licheniformis. bglC and bglH were knocked out using homologous recombination method, respectively, and the corresponding knockout strains were obtained for 13C metabolic flux analysis. A significant change was observed in metabolic fluxes after 13C metabolic flux ratio analysis. In both of the knockout strains, the increased fluxes of the pentose phosphate pathway and malic enzyme reaction enabled an elevated supply of NADPH which provided enough reducing power for the in vivo synthesis reactions. The fluxes through tricarboxylic acid cycle and anaplerotic reactions increased fast in the two knockout strains, which meant more energy generated. The changed fluxes in central carbon metabolism provided a holistic view of the physiological status in B. licheniformis and possible targets for further strain engineering. This article is protected by copyright. All rights reserved.
- Published
- 2017
23. Heavy Metals Induce Decline of Derivatives of 5-Methycytosine in Both DNA and RNA of Stem Cells
- Author
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Shan Xiao, Laixin Xia, Jun Xiong, Bi-Feng Yuan, Qing-Yun Cheng, Yu-Qi Feng, and Xiaona Liu
- Subjects
0301 basic medicine ,Biology ,Tandem mass spectrometry ,01 natural sciences ,Biochemistry ,Epigenesis, Genetic ,03 medical and health sciences ,chemistry.chemical_compound ,Cytosine ,Mice ,Tandem Mass Spectrometry ,Metals, Heavy ,Animals ,Epigenetics ,Cytotoxicity ,Carcinogen ,Cells, Cultured ,Stem Cells ,010401 analytical chemistry ,RNA ,General Medicine ,DNA ,DNA Methylation ,Molecular biology ,0104 chemical sciences ,030104 developmental biology ,chemistry ,DNA methylation ,5-Methylcytosine ,Molecular Medicine ,Stem cell - Abstract
Toxic heavy metals have been considered to be harmful environmental contaminations. The molecular mechanisms of heavy-metals-induced cytotoxicity and carcinogenicity are still not well elucidated. Previous reports showed exposures to toxic heavy metals can cause a change of DNA cytosine methylation (5-methylcytosine, 5-mC). However, it is still not clear whether heavy metals have effects on the recently identified new epigenetic marks in both DNA and RNA, i.e., 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-foC), and 5-carboxylcytosine (5-caC). Here, we established a chemical labeling strategy in combination with liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS) analysis for highly sensitive detection of eight modified cytidines in DNA and RNA. The developed method allowed simultaneous detection of all eight modified cytidines with improved detection sensitivities of 128-443-fold. Using this method, we demonstrated that the levels of 5-hmC, 5-foC, and 5-caC significantly decreased in both the DNA and RNA of mouse embryonic stem (ES) cells while exposed to arsenic (As), cadmium (Cd), chromium (Cr), and antimony (Sb). In addition, we found that treatments by heavy metals induced a decrease of the activities of 10-11 translocation (Tet) proteins. Furthermore, we revealed that a content change of metabolites occurring in the tricarboxylic acid cycle may be responsible for the decline of the derivatives of 5-mC. Our study shed light on the epigenetic effects of heavy metals, especially for the induced decline of the derivatives of 5-mC in both DNA and RNA.
- Published
- 2017
24. Formation of DNA:RNA Hybrid G-Quadruplexes of Two G-Quartet Layers in Transcription: Expansion of the Prevalence and Diversity of G-Quadruplexes in Genomes
- Author
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Xiang Zhou, Renyi Wu, Yu-hua Hao, Jia-yu Zhang, Jun Wu, Zheng Tan, Ye Xia, Shan Xiao, and Ke-wei Zheng
- Subjects
Genome ,Chemistry ,Oligonucleotide ,Oligonucleotides ,RNA ,General Medicine ,DNA ,General Chemistry ,G-quadruplex ,Molecular biology ,Catalysis ,Footprinting ,G-Quadruplexes ,chemistry.chemical_compound ,Biochemistry ,Transcription (biology) ,Prevalence ,Humans ,Human genome - Abstract
G-quadruplexes are implicated in important cellular processes. Previous studies mostly focused on intramolecular G-quadruplexes of three or more G-quartets. Those composed of two G-quartets were only shown to form in single-stranded oligonucleotides. On the basis of electrophoresis, DMS footprinting, fluorescence labeling, and photo-cross-linking, we detected the formation of DNA:RNA hybrid G-quadruplexes (HQs) of two G-quartets during the transcription of DNA duplexes. These HQs have a lifetime on the minute scale and are stabilized by a stabilizing ligand. They are far shorter-lived than the HQs of three G-quartets, which last for hours. The occurrence of putative formation motifs of such HQs shows a transcription-dependent strand-biased selection, thus supporting their formation and function in genomes. They are present in almost all human genes in large amounts. We speculate that the two-G-quartet HQs may be a distinct type of G-quadruplexes that may play a role in timely responsive processes and for purposes of fine-tuning.
- Published
- 2014
25. Nascent RNA transcripts facilitate the formation of G-quadruplexes
- Author
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Shan Xiao, Prakash Shrestha, Hanbin Mao, Zheng Tan, and Soma Dhakal
- Subjects
Genetics ,education.field_of_study ,Transcription, Genetic ,General transcription factor ,Population ,RNA ,DNA ,Biology ,G-quadruplex ,Cell biology ,G-Quadruplexes ,Kinetics ,Natural sequence ,chemistry.chemical_compound ,chemistry ,Transcriptional regulation ,Thermodynamics ,Human genome ,education ,Molecular Biology - Abstract
Recent discovery of the RNA/DNA hybrid G-quadruplexes (HQs) and their potential wide-spread occurrence in human genome during transcription have suggested a new and generic transcriptional control mechanism. The G-rich sequence in which HQ may form can coincide with that for DNA G-quadruplexes (GQs), which are well known to modulate transcriptions. Understanding the molecular interaction between HQ and GQ is, therefore, of pivotal importance to dissect the new mechanism for transcriptional regulation. Using a T7 transcription model, herein we found that GQ and HQ form in a natural sequence, (GGGGA)4, downstream of many transcription start sites. Using a newly-developed single-molecular stalled-transcription assay, we revealed that RNA transcripts helped to populate quadruplexes at the expense of duplexes. Among quadruplexes, HQ predominates GQ in population and mechanical stabilities, suggesting HQ may serve as a better mechanical block during transcription. The fact that HQ and GQ folded within tens of milliseconds in the presence of RNA transcripts provided justification for the co-transcriptional folding of these species. The catalytic role of RNA transcripts in the GQ formation was strongly suggested as the GQ folded >7 times slower without transcription. These results shed light on the possible synergistic effect of GQs and HQs on transcriptional controls.
- Published
- 2014
26. Extraction Kinetics and Mechanism of La(III) by P204-Kerosine from Phosphoric Acid
- Author
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Ying Zhang, Ya Gu Dang, Yun Shan Xiao, and De Jun Fei
- Subjects
chemistry.chemical_compound ,Reaction mechanism ,Chromatography ,Reaction rate constant ,Chemistry ,Diffusion ,Extraction (chemistry) ,General Engineering ,Analytical chemistry ,Rate equation ,Activation energy ,Phosphoric acid ,Chemical reaction - Abstract
The extraction kinetics and mechanism of La (III) by P204-kerosine from phosphoric acid were investigated by constant interfacial cell with laminar flow. The effects of stirring speed, temperature, specific interface area on extraction rate were studied. The results indicated that a plateau region is appeared at the stirring speed of over 115r/min. The extraction apparent activation energy was calculated to be-13.40kJ/mol and the extraction process is controlled by a mixed mechanism of diffusion and chemical reaction. The rate equation of extraction was deduced. Under conditions of 25°C and interfacial area 19.64cm2, the extraction rate constant was 2.08×10-6 m·s-1·. Through the derivation of the reaction mechanism the reaction zone is at the liquid-liquid interface.
- Published
- 2014
27. Pediococcus acidilactici AS185 attenuates early atherosclerosis development through inhibition of lipid regulation and inflammation in rats
- Author
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Shan Xiao, Zijian Zhao, Gao Lei, Han Wang, Duan Cuicui, Jihui Wang, Shengyu Li, Yujuan Zhao, and Chao Wang
- Subjects
0301 basic medicine ,Vitamin ,CD36 ,Medicine (miscellaneous) ,Inflammation ,Pharmacology ,Probiotic ,law.invention ,03 medical and health sciences ,chemistry.chemical_compound ,0404 agricultural biotechnology ,law ,Medicine ,TX341-641 ,Pediococcus acidilactici ,030109 nutrition & dietetics ,Nutrition and Dietetics ,biology ,Nutrition. Foods and food supply ,business.industry ,food and beverages ,Interleukin ,04 agricultural and veterinary sciences ,Atherosclerosis ,medicine.disease ,biology.organism_classification ,040401 food science ,Lipid profile ,Interleukin 10 ,chemistry ,biology.protein ,medicine.symptom ,business ,Dyslipidemia ,Food Science - Abstract
Pathophysiologic mechanisms underlying atherosclerosis (AS) development are linked to dyslipidemia and inflammation. Pediococcus acidilactici AS185, a probiotic, was isolated from traditional farmers’ soybean paste (Yanji, China). This study aimed to assess P. acidilactici AS185 anti-atherosclerotic effects and elucidate molecular mechanisms of action using an early AS model of SD rats fed a high-fat diet with intraperitoneal vitamin D3 (VD3) injections. For 8 weeks, model rats received P. acidilactici AS185 via gavage once/day. Post-treatment serum levels of inflammatory mediators, lipids, adhesion molecules, aortic histopathological characteristics and AS-related aortic protein expression levels were assessed. P. acidilactici AS185 administration markedly increased serum HDL-C and IL-10 levels, while reducing serum TG, LDL-C, TC, Ox-LDL, ICAM-1, VCAM-1, TNF-α, IFN-γ, IL-1β, and IL-6 levels. Notably, P. acidilactici AS185 inhibited p-p38 and ERK1/2 MAPK pathways and decreased Ox-LDL and CD36 expression to attenuate early AS by altering lipid profiles and MAPK-signaling-based inflammation.
- Published
- 2019
28. Induction of apoptosis by c9, t11-CLA in human endometrial cancer RL 95-2 cells via ERα-mediated pathway
- Author
-
Xiao Liu, Shuhong Ye, Jing Liu, Han Wang, Jihui Wang, Shan Xiao, Xiaojuan Zhang, and Hongzhou Chen
- Subjects
medicine.medical_specialty ,Conjugated linoleic acid ,Estrogen receptor ,Antineoplastic Agents ,Apoptosis ,Biochemistry ,Flow cytometry ,Endometrium ,chemistry.chemical_compound ,Annexin ,Cell Line, Tumor ,Internal medicine ,medicine ,Humans ,Linoleic Acids, Conjugated ,Molecular Biology ,Protein kinase B ,integumentary system ,medicine.diagnostic_test ,Chemistry ,Organic Chemistry ,Estrogen Receptor alpha ,food and beverages ,Cell Biology ,In vitro ,Endometrial Neoplasms ,Endocrinology ,Cancer cell ,Cancer research ,Female ,lipids (amino acids, peptides, and proteins) ,Signal Transduction - Abstract
Numerous studies have shown that conjugated linoleic acid (CLA) can inhibit cancer cells growth and induce apoptosis in vitro and in vivo. The aim of the present study was to investigate the effects of CLA, including cis9, trans11-conjugated linoleic acid (c9, t11-CLA) and trans10, cis12-conjugated linoleic acid (t10, c12-CLA), on apoptosis of human endometrial cancer RL 95-2 cells and its related mechanisms. The MTT analysis was used to evaluate the effect of CLA isomers on the viability of endometrial cancer RL 95-2 cells. We then estimated the apoptosis by Morphological observation and Annexin V-FITC/PI staining and flow cytometry. We also used Western blot analysis to assess the expression of caspase-3, Bax, Bcl-2 proteins and the activation of Akt/p-Akt and ERα/p-ERα. Propylpyrazole-triol (PPT), a selective ERα agonist was used to confirm the induction of apoptosis by c9, t11 CLA may relate to ERα-mediated pathway. In CLA-treated RL 95-2 cells, we found that c9, t11-CLA inhibited viability and trigged apoptosis, as judged from nuclear morphology and flow cytometric analysis. The expression of caspase-3 and the ratio of Bax/Bcl-2 were significant increased, but no obvious change was observed about Akt and p-Akt in c9, t11-CLA-treated cells. However, the expression of total ERα level in RL 95-2 cells-treated with c9, t11-CLA was unchanged, while in the concentration of 80 mM, c9, t11-CLA down-regulated the protein expression level of p-ERα. Then PPT has the antagonistic action on growth inhibitory effect in RL 95-2 cells incubated with c9, t11-CLA. This study demonstrated that c9, t11- CLA could induce apoptosis in RL 95-2 cells, and may involve in ERα-mediated pathway. These results indicated that c9, t11- CLA could induce apoptosis of endometrial cancer cells and may be potential agents for the treatment of endometrial cancer.
- Published
- 2013
29. Induction of apoptosis and inhibition of invasion in choriocarcinoma JEG-3 cells by α-calendic acid and β-calendic acid
- Author
-
Jihui Wang, Xiao Liu, Yuping Xie, Shuhong Ye, Qian Li, Han Wang, and Shan Xiao
- Subjects
Pyridines ,Linolenic acid ,alpha-Tocopherol ,Clinical Biochemistry ,Apoptosis ,Biology ,medicine.disease_cause ,p38 Mitogen-Activated Protein Kinases ,Lipid peroxidation ,chemistry.chemical_compound ,Cell Movement ,Cell Line, Tumor ,Malondialdehyde ,medicine ,Humans ,bcl-2-Associated X Protein ,chemistry.chemical_classification ,Reactive oxygen species ,Imidazoles ,Stereoisomerism ,Cell Biology ,Glutathione ,Antineoplastic Agents, Phytogenic ,Acetylcysteine ,Gene Expression Regulation, Neoplastic ,Calendic acid ,Oxidative Stress ,bcl-2 Homologous Antagonist-Killer Protein ,chemistry ,Biochemistry ,Caspases ,Fatty Acids, Unsaturated ,Female ,Lipid Peroxidation ,Reactive Oxygen Species ,Oxidative stress ,Signal Transduction - Abstract
Alfa-calendic acid and β-calendic acid, geometric and positional isomers of linolenic acid were previously shown to possess potent anticancer properties. In this study, we found that α-calendic acid and β-calendic acid could induce apoptosis and suppress invasion of human choriocarcinoma JEG-3 cells in vitro. Treatment with α-calendic acid and β-calendic acid significantly increased oxidative stress in human choriocarcinoma JEG-3 cells detected by the level of reactive oxygen species (ROS), lipid peroxidation production malondialdehyde (MDA), glutathione (GSH) and the effects of antioxidants NAC and α-tocopherol. Furthermore, oxidative stress activated the phosphorylation of p38MAPK. SB203580, a selective p38MAPK inhibitor, blocked the apoptosis induced by α-calendic acid and β-calendic acid by upregulating Bcl-2/Bax ratio and inhibition of the activation of Caspase-3 and Caspase-9. SB20350 also partially abrogated the cell invasion effects of α-calendic acid and β-calendic acid. These results suggested that α-calendic acid and β-calendic acid induced apoptosis and inhibited invasion in JEG-3 cells by activation of oxidative stress pathways and subsequent activation of P38MAPK.
- Published
- 2013
30. Bioinformatic analysis reveals an evolutional selection for DNA:RNA hybrid G-quadruplex structures as putative transcription regulatory elements in warm-blooded animals
- Author
-
Shan Xiao, Ke-wei Zheng, Jia-yu Zhang, Zheng Tan, and Yu-hua Hao
- Subjects
Genetics ,Computational Biology ,RNA ,Promoter ,Genomics ,DNA ,Biology ,G-quadruplex ,Evolution, Molecular ,G-Quadruplexes ,chemistry.chemical_compound ,chemistry ,Transcription (biology) ,Coding strand ,Transcriptional regulation ,Animals ,Regulatory Elements, Transcriptional ,Selection, Genetic ,Transcription Initiation Site ,Gene - Abstract
Recently, we reported the co-transcriptional formation of DNA:RNA hybrid G-quadruplex (HQ) structure by the non-template DNA strand and nascent RNA transcript, which in turn modulates transcription under both in vitro and in vivo conditions. Here we present bioinformatic analysis on putative HQ-forming sequences (PHQS) in the genomes of eukaryotic organisms. Starting from amphibian, PHQS motifs are concentrated in the immediate 1000-nt region downstream of transcription start sites, implying their potential role in transcription regulation. Moreover, their occurrence shows a strong bias toward the non-template versus the template strand. PHQS has become constitutional in genes in warm-blooded animals, and the magnitude of the strand bias correlates with the ability of PHQS to form HQ, suggesting a selection based on HQ formation. This strand bias is reversed in lower species, implying that the selection of PHQS/HQ depended on the living temperature of the organisms. In comparison with the putative intramolecular G-quadruplex-forming sequences (PQS), PHQS motifs are far more prevalent and abundant in the transcribed regions, making them the dominant candidates in the formation of G-quadruplexes in transcription. Collectively, these results suggest that the HQ structures are evolutionally selected to function in transcription and other transcription-mediated processes that involve guanine-rich non-template strand.
- Published
- 2013
31. 4,4′-Bipyridine-aided synthesis and characterization of Zn(II) and Cd(II) 2-sulfoterephthalate complexes
- Author
-
Xin-Xin Li, Tian-Jing Jia, Xiang-Jun Zheng, Lin-Pei Jin, and Shan-Shan Xiao
- Subjects
chemistry.chemical_classification ,Stereochemistry ,Condensed Matter Physics ,Fluorescence ,Electronic, Optical and Magnetic Materials ,4,4'-Bipyridine ,Coordination complex ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Chemical preparation ,Hydrothermal synthesis ,Physical and Theoretical Chemistry ,Luminescence ,Chirality (chemistry) - Abstract
Six d10 complexes, [Zn1.5(stp)(bpy)0.5(H2O)2]·0.5H2O (1), Cd1.5(stp)(bpy)0.5(H2O)2 (2), [Cd1.5(stp)(bpy)(H2O)]·H2O (3), [Zn0.5(bpy)0.5(H2O)2][Zn(stp)(bpy)(H2O)]·0.5H2O (4), Cd3(stp)2(bpy)3(H2O)3 (5), Hbpy·[Zn0.5(bpy)(H2O)2][Zn0.5(stp)(H2O)]·H2O (6) based on 2-sulfoterephthalate (stp3−) and 4,4′-bipyridine (bpy) have been synthesized under hydro/solvo-thermal conditions and structurally characterized. Complex 1 exhibits a three-fold interpenetrated 3D porous architecture. Complexes 2 and 3 possess helices with different chirality arranging alternately. 4 and 6 are addition compounds, which compose of complex cation and complex anion. Complex 5 features a 3D layer-pillar framework in which a (4, 4) grid layer is constructed by stp3− ligands and Cd(II) ions, and the layers are further connected by bpy pillars. The solid-state luminescent properties of the coordination polymers have also been investigated.
- Published
- 2013
32. Co-transcriptional formation of DNA:RNA hybrid G-quadruplex and potential function as constitutional cis element for transcription control
- Author
-
Ke-wei Zheng, Shan Xiao, Yu-hua Hao, Jia-yu Zhang, Zheng Tan, and Jiaquan Liu
- Subjects
Transcription, Genetic ,Response element ,E-box ,Biology ,Trans-regulatory element ,chemistry.chemical_compound ,Structural Biology ,Transcription (biology) ,Genetics ,Humans ,heterocyclic compounds ,Regulatory Elements, Transcriptional ,Gene ,General transcription factor ,Genome, Human ,Promoter ,DNA ,Cell biology ,G-Quadruplexes ,HEK293 Cells ,chemistry ,RNA ,Transcriptome ,Plasmids - Abstract
G-quadruplex formation in genomic DNA is considered to regulate transcription. Previous investigations almost exclusively focused on intramolecular G-quadruplexes formed by DNA carrying four or more G-tracts, and structure formation has rarely been studied in physiologically relevant processes. Here, we report an almost entirely neglected, but actually much more prevalent form of G-quadruplexes, DNA:RNA hybrid G-quadruplexes (HQ) that forms in transcription. HQ formation requires as few as two G-tracts instead of four on a non-template DNA strand. Potential HQ sequences (PHQS) are present in >97% of human genes, with an average of 73 PHQSs per gene. HQ modulates transcription under both in vitro and in vivo conditions. Transcriptomal analysis of human tissues implies that maximal gene expression may be limited by the number of PHQS in genes. These features suggest that HQs may play fundamental roles in transcription regulation and other transcription-mediated processes.
- Published
- 2013
33. Beta-eleostearic acid induce apoptosis in T24 human bladder cancer cells through reactive oxygen species (ROS)-mediated pathway
- Author
-
Zhongyan Sun, Shuhong Ye, Wenwen Wang, Shan Xiao, Xiao Liu, Jing Liu, Jihui Wang, Dandan Jiang, and Han Wang
- Subjects
Linolenic Acids ,Cell Survival ,Physiology ,Down-Regulation ,Apoptosis ,Biology ,Biochemistry ,Antioxidants ,Polyethylene Glycols ,Flow cytometry ,chemistry.chemical_compound ,Annexin ,Tumor Cells, Cultured ,medicine ,Humans ,Viability assay ,Cytotoxicity ,Pharmacology ,chemistry.chemical_classification ,Reactive oxygen species ,medicine.diagnostic_test ,Caspase 3 ,Cell Biology ,Glutathione ,Catalase ,Caspase Inhibitors ,Molecular biology ,Acetylcysteine ,PPAR gamma ,Urinary Bladder Neoplasms ,chemistry ,Cancer cell ,Reactive Oxygen Species - Abstract
Beta-eleostearic acid (β-ESA, 9E11E13E-18:3), a linolenic acid isomer with a conjugated triene system, is a natural and biologically active compound. Herein, we investigated effects of β-eleostearic acid on T24 human bladder cancer cells. In this study, results showed that β-eleostearic acid had strong cytotoxicity to induce cell apoptosis, which was mediated by reactive oxygen species (ROS) in T24 cells. The cell viability assay results showed that incubation with β-eleostearic acid concentrations of 10-80μmol/L caused a dose- and time-dependent decrease of T24 cell viability, and the IC(50) value was 21.2μmol/L at 24h and 13.1μmol/L at 48h. Annexin V/PI double staining was used to assess apoptosis with flow cytometry. Treatment with β-eleostearic acid caused massive ROS accumulation and GSH decrease, which lead to activation of caspase-3 and down-regulation of Bcl-2 indicating induction of apoptosis. Subsequently, N-acetyl-l-cysteine (NAC) and PEG-catalase effectively blocked the ROS elevated effect of β-eleostearic acid, which suggested that β-eleostearic acid-induced apoptosis involved ROS generated. Additionally, we found that treating T24 cells with β-eleostearic acid induced activation of PPARγ. A PPARγ-activated protein kinase inhibitor was able to partially abrogate the effects of β-eleostearic acid. These results suggested that β-eleostearic acid can induce T24 cells apoptosis via a ROS-mediated pathway which may be involved PPARγ activation.
- Published
- 2012
34. Homoleptic gold(i) N-heterocyclic allenylidene complexes: excited-state properties and lyotropic chromonics
- Author
-
Chi-Ming Che, Xin-Shan Xiao, Xiangguo Guan, Chen Yang, Wei Lu, and Chao Zou
- Subjects
010402 general chemistry ,Photochemistry ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Heterocyclic Compounds ,Lyotropic ,Ultrafast laser spectroscopy ,Materials Chemistry ,Molecule ,Homoleptic ,Aqueous solution ,Molecular Structure ,010405 organic chemistry ,Metals and Alloys ,Water ,General Chemistry ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Alkadienes ,Solutions ,Crystallography ,chemistry ,Excited state ,Ceramics and Composites ,Chromonic ,Gold ,Phosphorescence ,Organogold Compounds - Abstract
A series of phosphorescent Au(i) bis(N-heterocyclic allenylidene) complexes, namely [Au(=C=C=CR(1)R(2))2](+)X(-), were synthesized and structurally characterized. These organometallic complexes exhibit panchromatic transient absorption upon electronic photo-excitation and can self-organize into lyotropic chromonic mesophases in aqueous solutions.
- Published
- 2016
35. Optimal culture conditions for producing conjugated linoleic acid in skim-milk by co-culture of different Lactobacillus strains
- Author
-
Lin Li, Tian Yu, Shuhong Ye, Shan Xiao, Jihui Wang, Hong Yang, and Han Wang
- Subjects
Streptococcus thermophilus ,food.ingredient ,biology ,Conjugated linoleic acid ,food and beverages ,biology.organism_classification ,Applied Microbiology and Biotechnology ,chemistry.chemical_compound ,Hydrolysis ,Lactobacillus acidophilus ,food ,chemistry ,Biochemistry ,Lactobacillus ,Skimmed milk ,Food science ,Response surface methodology ,Co-Culture - Abstract
The ability of different Lactobacillus strains to produce conjugated linoleic acid (CLA) was determined. Three species—Lactobacillus plantarum (Lp), Lactobacillus acidophilus (La) and Streptococcus thermophilus (St)—were co-cultured in a medium containing skim-milk supplemented with hydrolyzed safflower oil. This study was aimed at future applications in dairy products. The optimal operation parameters were established by response surface methodology. More CLA was produced by co-culture than by single strain culture. The CLA produced by co-culture of La and Lp (La–Lp) was more than that produced by La and St (La–St). Maximum CLA production of 316.52 μg/mL was obtained with La–Lp co-culture using a substrate concentration of 5.0 %, inoculum size of 5.0 %, an initial medium pH of 6.4 and a temperature of 36.4 °C for 48 h. To our knowledge, this is the first report in the literature of the use of co-cultures of La–St and La–Lp to produce CLA.
- Published
- 2012
36. Calcium carbonate phase transformations during the carbonation reaction of calcium heavy alkylbenzene sulfonate overbased nanodetergents preparation
- Author
-
Min Zhao, Feng Chen, Shan Xiao, Zhaocong Chen, Dongzhong Chen, and Jianglin Fang
- Subjects
Calcite ,chemistry.chemical_classification ,Base (chemistry) ,Surface Properties ,Carbonation ,Detergents ,Inorganic chemistry ,chemistry.chemical_element ,Calcium ,Phase Transition ,Amorphous calcium carbonate ,Calcium Carbonate ,Nanostructures ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Sulfonate ,Calcium carbonate ,Alkanesulfonic Acids ,chemistry ,Vaterite ,Particle Size - Abstract
The preparation and application of overbased nanodetergents with excess alkaline calcium carbonate is a good example of nanotechnology in practice. The phase transformation of calcium carbonate is of extensive concern since CaCO(3) serves both as an important industrial filling material and as the most abundant biomineral in nature. Industrially valuable overbased nanodetergents have been prepared based on calcium salts of heavy alkylbenzene sulfonate by a one-step process under ambient pressure, the carbonation reaction has been monitored by the instantaneous temperature changes and total base number (TBN). A number of analytical techniques such as TGA, DLS, SLS, TEM, FTIR, and XRD have been utilized to explore the carbonation reaction process and phase transformation mechanism of calcium carbonate. An enhanced understanding on the phase transformation of calcium carbonate involved in calcium sulfonate nanodetergents has been achieved and it has been unambiguously demonstrated that amorphous calcium carbonate (ACC) transforms into the vaterite polymorph rather than calcite, which would be of crucial importance for the preparation and quality control of lubricant additives and greases. Our results also show that a certain amount of residual Ca(OH)(2) prevents the phase transformation from ACC to crystalline polymorphs. Moreover, a vaterite nanodetergent has been prepared for the first time with low viscosity, high base number, and uniform particle size, nevertheless a notable improvement on its thermal stability is required for potential applications.
- Published
- 2011
37. Lipid and Protein Oxidation of Chicken Breast Rolls as Affected by Dietary Oxidation Levels and Packaging
- Author
-
Chang Wei Ma, Wangang Zhang, Dong U. Ahn, Shan Xiao, and Eun Joo Lee
- Subjects
Antioxidant ,Vacuum ,medicine.medical_treatment ,Protein oxidation ,Thiobarbituric Acid Reactive Substances ,Hexanal ,Antioxidants ,Fats ,chemistry.chemical_compound ,Lipid oxidation ,medicine ,TBARS ,Animals ,Vitamin E ,Cooking ,Food science ,Volatile Organic Compounds ,Chemistry ,Food Packaging ,Broiler ,Proteins ,Lipid metabolism ,Lipid Metabolism ,Animal Feed ,Diet ,Meat Products ,Dietary Supplements ,Chickens ,Oxidation-Reduction ,Food Science - Abstract
The objective of this study was to determine the effects of dietary treatment and packaging on the oxidative stability of breast rolls. A total of 120 4-wk-old broiler chickens were randomly assigned to control, oxidized diet (5% oxidized oil, PV = 100), or antioxidants-added diet (500 IU vitamin E + 200 ppm BHA) and fed for 2 wk. Breast muscles were separated from the carcasses and breast rolls were prepared. The rolls were cooked in a smoke house (85 °C) to an internal temperature of 74 °C, cooled, sliced to 2-cm thick pieces, individually packaged in oxygen permeable bags or vacuum-packaged in oxygen impermeable bags, and stored in a 4 °C cold room for 7 d. Lipid, protein oxidation and volatiles were determined at 1, 4, and 7 d of storage. Dietary supplementation of antioxidants significantly reduced lipid oxidation (TBARS) and protein oxidation (carbonyls) in breast rolls, and the effect of dietary antioxidants on lipid oxidation was more pronounced than protein oxidation. Chicken breast rolls from antioxidants treatment group produced significantly lower amounts of hexanal and pentanal than those from control and oxidized oil treatments (P < 0.05). However, dietary oxidized oil did not increase lipid and protein oxidation in breast rolls. Vacuum-packaging significantly delayed the onset of lipid oxidation and protein oxidation in chicken rolls during 7-day refrigerated storage (P < 0.05). Therefore, it is suggested that appropriate use of dietary supplementation of antioxidants in combination with packaging could minimize lipid oxidation in chicken breast rolls.
- Published
- 2011
38. Consumption of Oxidized Oil Increases Oxidative Stress in Broilers and Affects the Quality of Breast Meat
- Author
-
Eun Joo Lee, Dong U. Ahn, Shan Xiao, and Wangang Zhang
- Subjects
medicine.medical_specialty ,Meat ,SERCA ,medicine.medical_treatment ,Biology ,Protein oxidation ,medicine.disease_cause ,Antioxidants ,Lipid peroxidation ,chemistry.chemical_compound ,Animal science ,Lipid oxidation ,Internal medicine ,medicine ,Animals ,Plant Oils ,Vitamin E ,Glycolysis ,Muscle, Skeletal ,Broiler ,General Chemistry ,Hydrogen-Ion Concentration ,Dietary Fats ,Diet ,Oxidative Stress ,Endocrinology ,chemistry ,Food Technology ,Lipid Peroxidation ,General Agricultural and Biological Sciences ,Chickens ,Oxidation-Reduction ,Oxidative stress - Abstract
A total of 120 4-week-old broiler chickens were allotted to 12 pens and fed one of three diets including control, oxidized diet (5% oxidized oil), or antioxidant-added diet (500 IU vitamin E) for 2 weeks. Blood samples were collected at the end of feeding trial, and breast muscles were sampled immediately after slaughter. Breast meats were also collected 24 h after slaughter and used for meat quality measurements. Oxidative stress in blood, lipid and protein oxidation, and sarcoplasmic reticulum Ca²(+)-ATPase (SERCA) activity of breast muscle were determined. The oxidized diet increased oxidative stress in blood and increased carbonyl content in breast meat compared with the other two dietary treatments (P < 0.05). Lipid oxidation of breast muscles with the antioxidant-supplemented diet was lower than that with the oxidized and control diet groups (P < 0.05). Meat from birds fed the oxidized diet showed higher drip loss after 1 and 3 days of storage and greater 0-1 h post-mortem pH decline (P < 0.05). Significant differences in specific SERCA activity in breast muscles from birds fed control and oxidized diets (P < 0.05) were detected. This suggested that dietary oxidized oil induced oxidative stress in live birds and increased lipid and protein oxidation in breast muscle. Decrease in SERCA activity in breast muscles due to oxidative stress in live animals accelerated post-mortem glycolysis, which sped the pH drop after slaughter and increased drip loss, indicating that oxidation of diet can cause PSE-like (pale, soft, and exudative) conditions in broiler breast muscles.
- Published
- 2010
39. Improving functional value of meat products
- Author
-
Eun Joo Lee, Himali Samaraweera, Shan Xiao, Wangang Zhang, and Dong U. Ahn
- Subjects
Meat ,Curing (food preservation) ,Food Handling ,Linoleic acid ,Vegetable Proteins ,Health Promotion ,Health benefits ,Biology ,chemistry.chemical_compound ,Functional Food ,Animals ,Humans ,Food science ,Carcass composition ,Marketing ,business.industry ,Animal production ,food and beverages ,Consumer Behavior ,Animal Feed ,Biotechnology ,Meat Products ,chemistry ,Food, Fortified ,Food processing ,Fermentation ,business ,Food Science - Abstract
In recent years, much attention has been paid to develop meat and meat products with physiological functions to promote health conditions and prevent the risk of diseases. This review focuses on strategies to improve the functional value of meat and meat products. Value improvement can be realized by adding functional compounds including conjugated linoneleic acid, vitamin E, n3 fatty acids and selenium in animal diets to improve animal production, carcass composition and fresh meat quality. In addition, functional ingredients such as vegetable proteins, dietary fibers, herbs and spices, and lactic acid bacteria can be directly incorporated into meat products during processing to improve their functional value for consumers. Functional compounds, especially peptides, can also be generated from meat and meat products during processing such as fermentation, curing and aging, and enzymatic hydrolysis. This review further discusses the current status, consumer acceptance, and market for functional foods from the global viewpoints. Future prospects for functional meat and meat products are also discussed.
- Published
- 2010
40. Changes of hormone-sensitive lipase (HSL), adipose tissue triglyceride lipase (ATGL) and free fatty acids in subcutaneous adipose tissues throughout the ripening process of dry-cured ham
- Author
-
Jiankun Lei, Yong Yang, Wangang Zhang, Min Du, Xiang Li, Dong U. Ahn, Shan Xiao, and Changwei Ma
- Subjects
Triglyceride lipase ,biology ,Chemistry ,Linoleic acid ,food and beverages ,Adipose tissue ,Hormone-sensitive lipase ,General Medicine ,Analytical Chemistry ,Palmitic acid ,chemistry.chemical_compound ,Biochemistry ,Adipose triglyceride lipase ,biology.protein ,Lipolysis ,lipids (amino acids, peptides, and proteins) ,Food science ,Lipase ,Food Science - Abstract
Changes in adipose triglyceride lipase (ATGL) and hormone-sensitive lipases (HSL) in subcutaneous adipose tissue of Xuanwei ham at different ripening stages were studied. Green hams were salted for 40 d and then ripened in a ventilated chamber for 15 months. Adipose triglyceride lipase and HSL could be detected during the whole ripening period of Xuanwei ham, but their protein levels decreased as the ripening time increased. The decrease of lipase proteins could be attributed to the decrease in protein synthesis as ripening time progressed. The level of free fatty acids (FFAs) increased at the first stage but HSL protein remained constant indicating that HSL was more important than ATGL for adipose tissues lipolysis. The main FFAs produced during the ripening period of Xuanwei ham were oleic acid, linoleic acid and palmitic acid, suggesting that the triacylglycerols containing these three FFAs were preferential substrates for ATGL and HSL.
- Published
- 2010
41. Synchrotron Radiation Vacuum Ultraviolet Photoionization and Photodissociation of Diethylzinc
- Author
-
Zhang Guo-Bin, Du Qi, Sheng Liu-Si, Shan Xiao-Bin, Liu Fu-Yi, Han Ju-Guang, and Yang Guang-Tao
- Subjects
Vacuum ultraviolet ,chemistry.chemical_compound ,Materials science ,chemistry ,Photodissociation ,Synchrotron radiation ,Photoionization ,Physical and Theoretical Chemistry ,Atomic physics ,Diethylzinc - Published
- 2008
42. Characterization of flavonoids in the extract of Sophora flavescens Ait. by high-performance liquid chromatography coupled with diode-array detector and electrospray ionization mass spectrometry
- Author
-
Xiaohui Chen, Lei Zhang, Jian Liang, Shan-Shan Xiao, Qing Li, Qiong-Feng Liao, Kaishun Bi, and Liang Xu
- Subjects
Spectrometry, Mass, Electrospray Ionization ,Time Factors ,Sophoraflavanone G ,Electrospray ionization ,Clinical Biochemistry ,Pharmaceutical Science ,Mass spectrometry ,Sensitivity and Specificity ,High-performance liquid chromatography ,Analytical Chemistry ,chemistry.chemical_compound ,Chromatography detector ,Drug Discovery ,Chromatography, High Pressure Liquid ,Spectroscopy ,Flavonoids ,Sophora flavescens ,Chromatography ,Molecular Structure ,biology ,Plant Extracts ,Flavanonol ,biology.organism_classification ,chemistry ,Sophora ,Flavanone - Abstract
A method coupling high-performance liquid chromatography (HPLC) with diode-array detector (DAD) and electrospray ionization mass spectrometry (ESI) was established for the separation and characterization of flavonoids in Sophora flavescens Ait. Based on the chromatographic separation of most flavonoids present in S. flavescens Ait., a total of 24 flavonoids were identified. Fourteen compounds were unambiguously identified comparing experimental data for retention time (t(R)), UV and MS spectra with those of the authentic compounds: 3',7-dihydroxy-4'-methoxy-isoflavone (13), trifolirhizin (14), kurarinol (18), formononetin (19), 7,4'-dihydroxy-5-methoxy-8-(gamma,gamma-dimethylallyl)-flavanone (22), maackiain (21), isoxanthohumol (23), kuraridine (26), kuraridinol (27), sophoraflavanone G (30), xanthohumol (31), isokurarinone (33), kurarinone (35) and kushenol D (38), and additional 10 compounds were tentatively identified as kushenol O (10), trifolirhizin-6''-malonate (15), sophoraisoflavanone A (20), norkurarinol/kosamol Q (24), kushenol I/N (25), kushenol C (28), 2'-methoxykurarinone (29), kosamol R (32), kushecarpin A (34) and kushenol A (37) by comparing experimental data for UV and MS spectra with those of literature. Furthermore, fragmentation pathways in positive ions mode of 24 flavonoid compounds of types of flavanone, flavanonol, flavonol, chalcone, isoflavone, isoflavanone and ptercocarpane were summarized. Some common features, such as CH(3)., H(2)O, CO, CO(2), C(3)O(2) and C(2)H(2)O losses, together with Retro-Diels-Alder fragmentations were observed in the prenylated flavonoids in S. flavescens Ait. The loss of the lanandulyl chain was their characteristic fragmentation, which might help deducing the structure of unknown flavonoid compounds. The present study provided an approach to rapidly characterize bioactive constituents in S. flavescens Ait.
- Published
- 2007
43. Strong atmospheric new particle formation in winter in urban Shanghai, China
- Author
-
Markku Kulmala, Mingyi Wang, Lei Yao, Jianmin Chen, Xiao-Qing Yang, Qingyan Fu, Lin Wang, Shan Xiao, Dongfang Wang, D. R. Worsnop, Bin Zhou, and Department of Physics
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,AEROSOL-SIZE DISTRIBUTION ,education ,Analytical chemistry ,Nucleation ,Mineralogy ,Nanoparticle ,UNITED-STATES ,010501 environmental sciences ,01 natural sciences ,114 Physical sciences ,lcsh:Chemistry ,Ammonia ,chemistry.chemical_compound ,Scanning mobility particle sizer ,SULFURIC-ACID CONCENTRATION ,NANOPARTICLES ,Cloud condensation nuclei ,ORGANIC AEROSOL ,0105 earth and related environmental sciences ,PARTICULATE AIR-POLLUTION ,Sulfuric acid ,lcsh:QC1-999 ,Aerosol ,lcsh:QD1-999 ,chemistry ,13. Climate action ,CLUSTER ACTIVATION ,GROWTH ,H2SO4 ,Particle size ,lcsh:Physics ,NUCLEATION - Abstract
Particle size distributions in the range of 1.34–615 nm were recorded from 25 November 2013 to 25 January 2014 in urban Shanghai, using a combination of one nano condensation nucleus counter system, one nano scanning mobility particle sizer (SMPS), and one long-SMPS. Measurements of sulfur dioxide by an SO2 analyzer with pulsed UV fluorescence technique allowed calculation of sulfuric acid proxy. In addition, concentrations of ammonia were recorded with a differential optical absorption spectroscopy. During this 62-day campaign, 13 new particle formation (NPF) events were identified with strong bursts of sub-3 nm particles and subsequent fast growth of newly formed particles. The observed nucleation rate (J1.34), formation rate of 3 nm particles (J3), and condensation sink were 112.4–271.0 cm−3 s−1, 2.3–19.2 cm−3 s−1, and 0.030–0.10 s−1, respectively. Subsequent cluster/nanoparticle growth (GR) showed a clear size dependence, with average values of GR1.35~1.39, GR1.39~1.46, GR1.46~1.70, GR1.70~2.39, GR2.39~7, and GR7~20 being 1.6±1.0, 1.4±2.2, 7.2±7.1, 9.0±11.4, 10.9±9.8, and 11.4±9.7 nm h−1, respectively. Correlation between nucleation rate (J1.34) and sulfuric acid proxy indicates that nucleation rate J1.34 was proportional to a 0.65±0.28 power of sulfuric acid proxy, indicating that the nucleation of particles can be explained by the activation theory. Correlation between nucleation rate (J1.34) and gas-phase ammonia suggests that ammonia was associated with NPF events. The calculated sulfuric acid proxy was sufficient to explain the subsequent growth of 1.34–3 nm particles, but its contribution became smaller as the particle size grew. Qualitatively, NPF events in urban Shanghai likely occur on days with low levels of aerosol surface area, meaning the sulfuric acid proxy is only a valid predictor when aerosol surface area is low.
- Published
- 2015
44. Vacuum Ultraviolet Photoionization and Photodissociation of Pentafluoroethane
- Author
-
Sheng Liu-Si, Hao Li-Qing, Yang Bin, Zhang Yun-Wu, Huang Chao-Qun, Yang Rui, Wei Li-Xia, Wang Si-Sheng, Wang Zhen-Ya, Wang Jing, Shan Xiao-Bin, Zhou Shi-Kang, and Qi Fei
- Subjects
Vacuum ultraviolet ,chemistry.chemical_compound ,Materials science ,chemistry ,Pentafluoroethane ,Photodissociation ,Photoionization ,Physical and Theoretical Chemistry ,Atomic physics - Published
- 2005
45. Conformational changes at the active site of bovine pancreatic RNase A at low concentrations of guanidine hydrochloride probed by pyridoxal 5′-phosphate
- Author
-
Gui-Shan Xiao and Jun-Mei Zhou
- Subjects
Protein Denaturation ,Conformational change ,Protein Conformation ,RNase P ,Stereochemistry ,Biophysics ,Fluorescence Polarization ,Guanidines ,Biochemistry ,chemistry.chemical_compound ,Structural Biology ,Animals ,Denaturation (biochemistry) ,Pyridoxal phosphate ,Guanidine ,Molecular Biology ,Pyridoxal ,Binding Sites ,biology ,Active site ,Ribonuclease, Pancreatic ,Kinetics ,Spectrometry, Fluorescence ,chemistry ,Molecular Probes ,Pyridoxal Phosphate ,biology.protein ,Tyrosine ,Cattle ,Fluorescence anisotropy - Abstract
The alpha-amino group of Lys-1 and the epsilon-amino groups of Lys-41 and Lys-7 were labeled with pyridoxal 5'-phosphate (PLP) separately. The effects of GdnHCl on the activities and the fluorescence properties of the derivatives were compared. Both the fluorescence intensity and anisotropy of the probe introduced at the active site Lys-41 decreased obviously during denaturation by low concentrations of GdnHCl indicating conformational change of the active site is a parallel event to the inactivation of the enzyme. Time-correlated fluorescence lifetime measurements revealed the existence of two conformational states of PLP-modified RNase A and a shift of the conformation in favor of the slow-decay component with increasing GdnHCl concentration. The decrease in activity of RNase A at low concentrations of GdnHCl is therefore due to partial unfolding of the molecule, particularly at the active site. The experimental results of this work support the suggestion that the conformation at the active site is more easily perturbed and hence more flexible than the molecule as a whole.
- Published
- 1996
46. Is palladium or palladium–ascorbic acid or palladium–magnesium nitrate a more universal chemical modifier for electrothermal atomic absorption spectrometry?
- Author
-
Shan Xiao-quan and Wen Bei
- Subjects
Detection limit ,Chemistry ,Stereochemistry ,Inorganic chemistry ,Chemical modification ,chemistry.chemical_element ,Ascorbic acid ,Analytical Chemistry ,law.invention ,Magnesium nitrate ,chemistry.chemical_compound ,law ,Charring ,Absorption (chemistry) ,Atomic absorption spectroscopy ,Spectroscopy ,Palladium - Abstract
A comprehensive comparison was made between the performances of Pd, Pd–ascorbic acid and Pd–Mg(NO3)2 for the determination of Ag, As, Au, Bi, Cd, Ga, Ge, Hg, In, Mn, Pb, Sb, Se, Sn, Te and Tl in terms of charring temperatures available, characteristic mass values, background absorption, permissible interference range, capability of improving the atomization signal shapes and relative standard deviations of the determinations of trace elements in real samples. Generally, the performances of Pd, Pd–ascorbic acid and Pd–Mg are similar, except that the background absorption of the Pd–Mg modifier is 1–2 orders of magnitude greater than that of the Pd and Pd–ascorbic acid modifiers. Therefore, the need for the addition of ascorbic acid appears to be matrix-dependent, while the addition of Mg(NO3)2 is not recommended.
- Published
- 1995
47. Effects of selected ionic liquids on lipid production by the oleaginous yeast Rhodosporidium toruloides
- Author
-
Shuhong Ye, Haibo Xie, Jihui Wang, Guojie Jin, Zongbao K. Zhao, Shan Xiao, Zhiwei Gong, Qian Wang, Qitian Huang, and Hongwei Shen
- Subjects
Environmental Engineering ,biology ,Renewable Energy, Sustainability and the Environment ,Rhodosporidium toruloides ,Biomass ,Lignocellulosic biomass ,Ionic Liquids ,Bioengineering ,Lipid metabolism ,General Medicine ,biology.organism_classification ,Lipid Metabolism ,Yeast ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Biotransformation ,Biofuels ,Yeasts ,Ionic liquid ,Organic chemistry ,Bioprocess ,Waste Management and Disposal - Abstract
Lignocellulosic biomass pretreatment with ionic liquids (ILs) has been emerged as a new technology, but the effects of residual ILs on the downstream biotransformation remain largely unknown. Here, three typical ILs were tested for their effects on lipid production by the oleaginous yeast Rhodosporidium toruloides AS 2.1389. When cultures were maintained at pH 6.0 in the presence of 30mM ILs, [Emim]Cl, [Emim][DEP], or [Emim][OAc], minor inhibition effects were observed. When cultures were performed in the presence of 60mM ILs or without pH control, inhibition was largely dependent on ILs. Detailed analysis indicated that the anion of [Emim][OAc] was assimilated, leading to a rapid alkaline-pH shift and enhanced inhibition on cell growth and lipid production. Our results demonstrated that R. toruloides is a robust lipid producer tolerating ILs at low concentrations, and that care should be taken in bioprocess control and data analysis when ILs are involved.
- Published
- 2012
48. Trace Metal Redistribution during Extraction of Model Soils by Acetic Acid/Sodium Acetate
- Author
-
Qian. Jin, Ni Zhe-ming, Tu Qiang, and Shan Xiao-quan
- Subjects
Pyrolusite ,chemistry.chemical_classification ,Chemistry ,Inorganic chemistry ,engineering.material ,complex mixtures ,Analytical Chemistry ,Metal ,Acetic acid ,chemistry.chemical_compound ,Adsorption ,visual_art ,engineering ,visual_art.visual_art_medium ,Humic acid ,Trace metal ,Redistribution (chemistry) ,Sodium acetate - Abstract
A number of model soils synthesized with various known amounts of natural minerals and humic acid were employed to study copper and lead redistribution during extraction by 1 M HOAc/NaOAc. The adsorption intensities of the individual constituent phases were measured from adsorption isotherms, and the redistribution behavior was studied by the standard additions method. Humic acid and pyrolusite are found to exhibit the highest binding affinity for Cu and Pb, respectively, and their relative importance relies upon both their binding ability and their abundance. The extractable concentrations of the metals and the extent of recovery depend largely upon the composition of the model soils, owing to different binding strength presented in the various systems investigated. The presence of dissolved humic acid during extraction has a significant influence on metal redistribution, as evidenced by the increase in the adsorption of Cu and decrease in the adsorption of Pb. In view of the diverse compositions and various competing reactions involved, it is recognized that redistribution behavior will vary widely among both natural soil systems and given metals.
- Published
- 1994
49. Evaluation of a sequential extraction procedure for the fractionation of amorphous iron and manganese oxides and organic matter in soils
- Author
-
Ni Zhe-ming, Shan Xiao-quan, and Tu Qiang
- Subjects
chemistry.chemical_classification ,Environmental Engineering ,Inorganic chemistry ,Extraction (chemistry) ,Trace element ,Iron oxide ,chemistry.chemical_element ,Manganese ,Fractionation ,Pollution ,Amorphous solid ,chemistry.chemical_compound ,chemistry ,Environmental Chemistry ,Organic matter ,Waste Management and Disposal ,Dissolution - Abstract
A commonly applied sequential extraction procedure was evaluated with special emphasis on the interaction of amorphous iron and manganese oxides and organic matter in two soil samples. The results show that the fractionation was obscured by significant uncertainty. It is suggested that reduction of manganese oxides and amorphous iron oxides by NH2OH · HCl is hindered by a covering or occlusion of organic matter. Due to the presence of these components partly as a combined phase rather than discrete phases, the selective dissolution of these entities in soils by the tested method is impossible and the nominated speciation of the associated trace metals, as outlined in the procedure, appears to give ambiguous information.
- Published
- 1994
50. Changes of Hormone Sensitive Lipase, Adipose Tissue Triglyceride Lipase, and Free Fatty Acids in Subcutaneous Adipose Tissues throughout the Ripening Process of Dry-cured Ham
- Author
-
Wangang Zhang, Dong U. Ahn, and Shan Xiao
- Subjects
Triglyceride lipase ,biology ,Linoleic acid ,food and beverages ,Adipose tissue ,Hormone-sensitive lipase ,White adipose tissue ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Adipose triglyceride lipase ,biology.protein ,Lipolysis ,lipids (amino acids, peptides, and proteins) ,Food science ,Lipase - Abstract
Changes in adipose triglyceride lipase (ATGL) and hormone sensitive lipases (HSL) in subcutaneous adipose tissue of Xuanwei ham at different ripening stages were studied. Green hams were salted for 40 d and then ripened in a ventilated chamber for 15 months. Adipose triglyceride lipase and HSL could be detected during the whole ripening period of Xuanwei ham, but their protein levels decreased as the ripening time increased. The decrease of lipase proteins could be attributed to the decrease in protein synthesis as ripening time progressed. The level of free fatty acids (FFAs) increased at the first stage but HSL protein remained constant indicating that HSL was more important than ATGL for adipose tissues lipolysis. The main FFAs produced during the ripening period of Xuanwei ham were oleic acid, linoleic acid and palmitic acid, suggesting that the triacylglycerols containing these three FFAs were preferential substrates for ATGL and HSL
- Published
- 2011
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