307 results on '"Yuyuan Zhang"'
Search Results
152. Gas-liquid dual phase inhibition method for explosion accident of wet Al dust collection system based on KH2PO4
- Author
-
Bo Liu, Kaili Xu, Yuyuan Zhang, and Ji Ge
- Subjects
Mechanics of Materials ,General Chemical Engineering - Published
- 2022
153. A Novel Immune Classification Reveals Distinct Immune Escape Mechanism and Genomic Alterations: Implications for Immunotherapy in Hepatocellular Carcinoma
- Author
-
Zhenqiang Sun, Kaihao Xu, Zaoqu Liu, Xueliang Zhou, Yuyuan Zhang, Shi Chengcheng, Xinwei Han, and Dechao Jiao
- Subjects
0301 basic medicine ,Sorafenib ,Carcinoma, Hepatocellular ,ARID1A ,Hepatocellular carcinoma ,medicine.medical_treatment ,lcsh:Medicine ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Molecular subtype ,03 medical and health sciences ,Phosphatidylinositol 3-Kinases ,0302 clinical medicine ,Immune system ,CDKN2A ,medicine ,Tumor Microenvironment ,Humans ,PI3K/AKT/mTOR pathway ,Immune escape ,Research ,lcsh:R ,Liver Neoplasms ,General Medicine ,Immunotherapy ,Genomics ,Phenotype ,Tumor antigen ,030104 developmental biology ,030220 oncology & carcinogenesis ,Cancer research ,Tumor immunological microenvironment ,medicine.drug - Abstract
Background The tumor immunological microenvironment (TIME) has a prominent impact on prognosis and immunotherapy. However, the heterogeneous TIME and the mechanisms by which TIME affects immunotherapy have not been elucidated in hepatocellular carcinoma (HCC). Methods A total of 2195 eligible HCC patients from TCGA and GEO database were collected. We comprehensively explored the different heterogeneous TIME phenotypes and its clinical significance. The potential immune escape mechanisms and what genomic alterations may drive the formation of different phenotypes were further investigated. Results We identified three phenotypes in HCC: TIME-1, the “immune-deficiency” phenotype, with immune cell depletion and proliferation; TIME-2, the “immune-suppressed” phenotype, with enrichment of immunosuppressive cells; TIME-3, the “immune-activated phenotype”, with abundant leukocytes infiltration and immune activation. The prognosis and sensitivity to both sorafenib and immunotherapy differed among the three phenotypes. We also underlined the potential immune escape mechanisms: lack of leukocytes and defective tumor antigen presentation capacity in TIME-1, increased immunosuppressive cells in TIME-2, and rich in immunoinhibitory molecules in TIME-3. The different phenotypes also demonstrated specific genomic events: TIME-1 characterized by TP53, CDKN2A, CTNNB1, AXIN1 and FOXD4 alterations; TIME-2 characterized by significant alteration patterns in the PI3K pathway; TIME-3 characterized by ARID1A mutation. Besides, the TIME index (TI) was proposed to quantify TIME infiltration pattern, and it was a superior prognostic and immunotherapy predictor. A pipeline was developed to classify single patient into one of these three subtypes and calculated the TI. Conclusions We identified three TIME phenotypes with different clinical outcomes, immune escape mechanisms and genomic alterations in HCC, which could present strategies for improving the efficacy of immunotherapy. TI as a novel prognostic and immunotherapeutic signature that could guide personalized immunotherapy and clinical management of HCC.
- Published
- 2020
154. EGCG Promotes Neurite Outgrowth through the Integrin
- Author
-
Yuyuan, Zhang, Mengguo, Han, Xiaoxue, Sun, Guojun, Gao, Guoying, Yu, Liong, Huang, and Ying, Chen
- Subjects
food and beverages ,sense organs ,cardiovascular diseases ,complex mixtures ,nervous system diseases ,Research Article - Abstract
The abnormal neurites have long been regarded as the main player contributing to the poor outcome of patients with subarachnoid hemorrhage (SAH). (-)-Eigallocatechin-3-gallate (EGCG), the major biological component of tea catechin, exhibited strong neuroprotective effects against central nervous system diseases; however, the role of EGCG-mediated neurite outgrowth after SAH has not been delineated. Here, the effect of reactive oxygen species (ROS)/integrin β1/FAK/p38 pathway on neurite outgrowth was investigated. As expected, oxyhemoglobin- (OxyHb-) induced excessive ROS level was significantly reduced by EGCG as well as antioxidant N-acetyl-l-cysteine (NAC). Consequently, the expression of integrin β1 was significantly inhibited by EGCG and NAC. Meanwhile, EGCG significantly inhibited the overexpression of phosphorylated FAK and p38 to basal level after SAH. As a result, the abnormal neurites and cell injury were rescued by EGCG, which eventually increased energy generation and neurological score after SAH. These results suggested that EGCG promoted neurite outgrowth after SAH by inhibition of ROS/integrin β1/FAK/p38 signaling pathway. Therefore, EGCG might be a new pharmacological agent that targets neurite outgrowth in SAH therapy.
- Published
- 2020
155. Intermolecular Hydrogen Bonding Modulates O-H Photodissociation in Molecular Aggregates of a Catechol Derivative
- Author
-
Christopher Grieco, Yuyuan Zhang, Forrest R. Kohl, Lluís Blancafort, Bern Kohler, Sangeetha Natarajan, and Ministerio de Economía y Competitividad (Espanya)
- Subjects
Semiquinone ,Chemistry ,Hydrogen bond ,Photochemistry ,Photodissociation ,Intermolecular force ,02 engineering and technology ,General Medicine ,Hydrogen atom ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Dissociation (chemistry) ,Photobiology ,0104 chemical sciences ,Homolysis ,Fotobiologia ,Fotoquímica ,Molecule ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
The catechol functional group plays a major role in the chemistry of a wide variety of molecules important in biology and technology. In eumelanin, intermolecular hydrogen bonding between these functional groups is thought to contribute to UV photoprotective and radical buffering properties, but the mechanisms are poorly understood. Here, aggregates of 4-t-butylcatechol are used as model systems to study how intermolecular hydrogen bonding influences photochemical pathways that may occur in eumelanin. Ultrafast UV-visible and mid-IR transient absorption measurements are used to identify the photochemical processes of 4-t-butylcatechol monomers and their hydrogen-bonded aggregates in cyclohexane solution. Monomer photoexcitation results in hydrogen atom ejection to the solvent via homolytic O-H bond dissociation with a time constant of 12 ps, producing a neutral semiquinone radical with a lifetime greater than 1 ns. In contrast, intermolecular hydrogen bonding interactions within aggregates retard O-H bond photodissociation by over an order of magnitude in time. Excited state structural relaxation is proposed to slow O-H dissociation, allowing internal conversion to the ground state to occur in hundreds of picoseconds in competition with this channel. The semiquinone radicals formed in the aggregates exhibit spectral broadening of both their electronic and vibrational transitions. LB acknowledges financial support from the Spanish Ministerio de Economía y Competitividad (CTQ2015-69363-P) and computational time from Consorci de Serveis Universitarisde Catalunya
- Published
- 2020
156. Impact of Abdominal Obesity on Thyroid Auto-Antibody Positivity: Abdominal Obesity Can Enhance the Risk of Thyroid Autoimmunity in Men
- Author
-
Li Han, Yanrong Ma, Yanying Guo, Bei Xing, Suli Li, Jazyra Zynat, Yuyuan Zhang, Fuhui Ma, and Xinling Wang
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Waist ,Article Subject ,Endocrinology, Diabetes and Metabolism ,030209 endocrinology & metabolism ,Overweight ,Diseases of the endocrine glands. Clinical endocrinology ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Thyroid peroxidase ,medicine ,Risk factor ,Abdominal obesity ,biology ,Endocrine and Autonomic Systems ,Obstetrics ,business.industry ,Thyroid ,medicine.disease ,RC648-665 ,Obesity ,Anti-thyroid autoantibodies ,030104 developmental biology ,medicine.anatomical_structure ,biology.protein ,medicine.symptom ,business ,Research Article - Abstract
Background. The interrelation between obesity and autoimmune thyroid diseases is complex and has not been confirmed. The aim of the present study was to observe the relationship between thyroid autoimmunity and obesity, especially abdominal obesity, in a large population. Methods. A total of 2253 residents who had lived in Xinjiang for more than 3 years were enrolled. Serum thyroid hormone concentration, thyroid autoantibodies, lipid parameters, Weight, height, and waist and hip circumference were measured. Results. The prevalence of thyroid peroxidase antibody (TPOAb) and/or thyroglobulin antibody (TgAb) positive was 32.1% (21.2% in men and 37% in women, P<0.01). Compared with women, men had significantly higher TG levels, waist circumference, and hip circumference levels (P<0.01), while women showed higher TSH, TPOAb, and TgAb levels (P<0.01). The prevalence of overweight and obesity was 71.1% in men and 63.5% in women. Men had a higher prevalence of abdominal obesity than women (56.6% in men and 47.6% in women, P<0.01). TPOAb correlates positively with waist circumference (r = 0.100, P<0.05) in men. Binary logistic analysis showed that TPOAb positivity had increased risks of abdominal obesity in men, and the OR was 1.1044 (95% CI 1.035, 1.151, P<0.05). Conclusion. Our results indicate that men had higher lipid levels, thicker waist circumference, and higher prevalence of overweight, obesity, and abdominal obesity. Abdominal obesity is a risk factor for TPOAb positivity in men, suggesting that abdominal obesity can enhance the risk of thyroid autoimmunity in men.
- Published
- 2020
157. Graphene-assisted construction of electrocatalysts for carbon dioxide reduction
- Author
-
Yugang Huang, Hong Zhao, Yinlei Lin, Yuyuan Zhang, Huawen Hu, Dongchu Chen, Jian Zhen Ou, Minghui He, Xuejun Xu, and Lifang Deng
- Subjects
Materials science ,Graphene ,General Chemical Engineering ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Redox ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,law.invention ,Catalysis ,Reaction rate ,chemistry ,law ,Specific surface area ,Environmental Chemistry ,0210 nano-technology ,Carbon ,Electrochemical reduction of carbon dioxide - Abstract
The electrochemical conversion of the greenhouse gas, carbon dioxide (CO2), to energy fuels and value-added chemicals presents one of the most valuable approaches to harvest pollutants and produce renewable energy. However, the stable molecular structure of CO2 and the sluggish reaction kinetics make CO2 reduction reaction (CO2RR) formidably challenging to achieve reaction rate and selectivity practical in industry. Graphene and its derivatives have been considered a group of intriguing materials to develop advanced CO2RR electrocatalysts due to their large specific surface area, remarkable electron transfer ability, superior stability, and easy tunability of the structure and surface properties. Herein, we comprehensively discuss the state-of-the-art electrocatalysts constructed with graphene and derivatives for active and selective CO2RR within the recent five years, mainly including the electrocatalysts with both metal-based (e.g., noble, non-noble, or combined thereof) and non-metal (e.g., doped, modified, defected, or composited) catalytic sites. To present the versatile, high-performance metal-based CO2RR electrocatalysts constructed with graphene, we further subdivide them according to the sizes, oxidation states, metal species synergies, dimensionalities, and versatility. Finally, we provide the challenges and perspectives in this emerging area of utilising CO2 to produce various carbon-based fuels and chemicals via graphene chemistry.
- Published
- 2021
158. PAN dust explosion inhibition mechanisms of NaHCO3 and Al(OH)3
- Author
-
Kaili Xu, Yuyuan Zhang, Bo Liu, Ji Ge, and Yansong Zhang
- Subjects
Materials science ,Control and Systems Engineering ,General Chemical Engineering ,Pressure increase ,Analytical chemistry ,Energy Engineering and Power Technology ,Management Science and Operations Research ,Safety, Risk, Reliability and Quality ,Dust explosion ,Pyrolysis ,Industrial and Manufacturing Engineering ,Food Science - Abstract
We investigate the PAN dust explosion inhibition behaviors of NaHCO3 and Al(OH)3 in a 20 L spherical explosion system and a transparent pipe explosion propagation test system. The results show that, in the standard 20 L spherical explosion system, the highest PAN dust explosion concentration is 500 g/m3, the maximum explosion pressure is 0.661 MPa, and the maximum explosion pressure increase rate is 31.64 MPa/s; adding 50% NaHCO3 and 60% Al(OH)3 can totally inhibit PAN dust explosion. In the DN0.15 m transparent pipe explosion propagation test system, for 500 g/m3 PAN dust, the initial explosion flame velocity is 102 m/s, the initial pressure is 0.46 MPa, and the initial temperature is 967 °C; adding 60% NaHCO3 and 70% Al(OH)3 can totally inhibit PAN dust explosion flames. Through FTIR and TG analyses, we obtain the explosion products and pyrolysis patterns of the explosion products of PAN dust, NaHCO3, and Al(OH)3. On this basis, we also summarize the PAN dust explosion inhibition mechanisms of NaHCO3 and Al(OH)3.
- Published
- 2021
159. Hydrogen inhibition in wet dust removal systems by using L-aspartic: A feasible way of hydrogen explosion control measures
- Author
-
Ben Wang, Xinyue Pei, Bo Liu, Jiahuan Li, Kaili Xu, Yuyuan Zhang, and Mengyuan Li
- Subjects
Materials science ,Hydrogen ,General Chemical Engineering ,technology, industry, and agriculture ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Langmuir adsorption model ,Management Science and Operations Research ,Industrial and Manufacturing Engineering ,law.invention ,Chemical kinetics ,symbols.namesake ,Adsorption ,chemistry ,Chemical engineering ,Control and Systems Engineering ,law ,Dust collector ,Monolayer ,symbols ,Molecule ,Safety, Risk, Reliability and Quality ,Food Science ,Hydrogen production - Abstract
Alloy dust generated from automobile wheel hub grinding, after entering the wet dust collector, will react with water to produce hydrogen, thus exposing the entire ventilation and dust removal system to potential hydrogen explosion. In this paper, the inhibition mechanism and kinetic characteristics of different concentrations of L-Aspartic acid (L-Asp) on the reaction of Al0.9Mg0.1 alloy with water were studied with respect to adsorption morphology, chemical kinetic modeling and molecular dynamics (MD), using L-Asp as the environmentally-safe hydrogen inhibitor. The results show that within a given temperature interval, the hydrogen production rate of Al0.9Mg0.1 alloy dust decreases with increasing L-Asp concentration. When the L-Asp concentration exceeds 1.0g/L, the hydrogen evolution rate is almost zero. The calculated results of chemical kinetics agree with the Langmuir adsorption model, confirming that L-Asp is an ideal monolayer physical adsorption system on the surface of alloy particles. The FTIR and MD simulation results show that –NH2 and –COOH groups in L-Asp molecules contribute greatly to the adsorption. The research results of this paper can help fundamentally avoid hydrogen generation in wet dust collectors and guarantee intrinsic safety.
- Published
- 2021
160. Low-cost carbonyl polymer design for high-performance lithium-organic battery cathodes
- Author
-
Da Wang, Caiting Li, Qingguang Zeng, Chunhui Duan, Yangfan Zhang, Tao Wang, Xi Liu, Yuyuan Zhang, John Haozhong Xin, Hui Yu, Zhiling He, Yongtang Jia, and Fei Huang
- Subjects
chemistry.chemical_classification ,Materials science ,Sulfide ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Organic radical battery ,Polymer ,Electrolyte ,chemistry ,Chemical engineering ,Polymerization ,Electrochemical reaction mechanism ,Lithium ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Amination - Abstract
Carbonyl polymers, such as poly(anthraquinonyl sulfide) (PAQS) and poly(benzoquinonyl sulfide) (PBQS), are typically selected as cathode materials for lithium-organic batteries (LOBs) because of their inherent high theoretical capacity and low solubility in the electrolyte. However, their commercialization is hindered by their relatively complex synthesis routes, low yields, and high cost. Herein, a carbonyl polymer poly(piperazine-alt-benzoquinone) (NP2), obtained from the polymerization of vanillin and piperazine with oxidative amination at the theoretical production cost of US $0.48 per gram, exhibits a high reversible capacity of 257 mAh g−1, leading to a cost performance of US $0.19 per 100 mAh, which is superior to the reported carbonyl polymers. Furthermore, ex situ X-ray photoelectron spectroscopy and ex situ and in situ Fourier-transform infrared measurements release the reversible electrochemical reaction mechanism of NP2 based on carbonyl redox chemistry. This study demonstrates a simple and effective strategy to synthesize low-cost carbonyl polymers, which will pave the way for their future application in high-performance LOBs.
- Published
- 2021
161. High temperature thermochromic polydiacetylenes: Design and colorimetric properties
- Author
-
Zhibo Zhu, Ting Fan, Zhudong Hu, Guozhang He, Bangyun Xiong, Shi-He Luo, Zhihao Yang, Jing-Pei Huo, Hong Chen, Dongchu Chen, Yuyuan Zhang, Xiufang Ye, Li Yanli, Min Zhang, Xiaxiao Hong, Zhao-Yang Wang, and Yubo Zhang
- Subjects
Thermochromism ,Thermogravimetric analysis ,Materials science ,Analytical chemistry ,General Physics and Astronomy ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Photochemistry ,01 natural sciences ,Fluorescence spectroscopy ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electrophoretic deposition ,symbols.namesake ,Polymerization ,symbols ,Naked eye ,0210 nano-technology ,Raman spectroscopy ,Polydiacetylenes - Abstract
Three novel polydiacetylenes (PDAs) are synthesized through the self-assembly followed by the topochemical polymerization via controllable electrophoretic deposition. All the samples could undergo a multi-step thermochromic process, turning purple and red successively over a wide range from room temperature to above 250 °C. Resulting PDAs are studied by UV–vis, IR, Raman spectroscopies, and chromoisomerism by naked eye visualization; their stabilities by thermogravimetric method, and emission behavior by fluorescence spectroscopy. To study the mechanism of the thermochromic response, temperature-dependent UV–vis spectra, the results of which successfully highlighted the close relationship between chromatic transitions and the conformational changes.
- Published
- 2017
162. In situ N-, P- and Ca-codoped biochar derived from animal bones to boost the electrocatalytic hydrogen evolution reaction
- Author
-
Yuyuan Zhang, Yufeng Wu, Haoran Yuan, Lifang Deng, Yazhuo Wang, and Yong Chen
- Subjects
Economics and Econometrics ,Tafel equation ,Materials science ,Electrolysis of water ,Hydrogen ,0211 other engineering and technologies ,chemistry.chemical_element ,Exchange current density ,02 engineering and technology ,010501 environmental sciences ,Overpotential ,01 natural sciences ,Catalysis ,chemistry ,Chemical engineering ,Biochar ,021108 energy ,Waste Management and Disposal ,Carbon ,0105 earth and related environmental sciences - Abstract
The development of highly efficient and inexpensive carbon-based catalysts for the production of hydrogen from water electrolysis is a considerable challenge in the field of sustainable energy transformation. Herein, an in situ N-, P- and Ca-codoped biochar was successfully fabricated from animal bone by thermal treatment at 800 °C. This in situ N-, P- and Ca-codoped catalyst exhibits high atomic contents with synergistic effects of N, P and Ca, a large electrochemically active surface area, a low charge-transfer resistance, high conductivity, and a large specific area. These characteristics lead to an outstanding hydrogen evolution reaction (HER) activity and good stability in a H2SO4 acidic solution, with an onset potential of 80±3 mV, an overpotential of 162±3 mV at a current density of 10 mA/cm2, a Tafel slope of 80 mV/dec, and an exchange current density of 52.5 µA/cm2, which are comparable to or even better than those of synthetic heteroatom-doped or transition metal-doped carbon-based catalysts. These findings demonstrate that animal bone is a useful material for the preparation of N-, P- and Ca-codoped carbon materials as effective electrocatalysts for the HER.
- Published
- 2021
163. Template-free scalable synthesis of TiO2 hollow nanoparticles for excellent photoelectrochemical applications
- Author
-
Min Zhang, Menglei Chang, Liangpeng Wu, Xinjun Li, Yuyuan Zhang, Huawen Hu, Wei Hongyang, and Dongchu Chen
- Subjects
Ostwald ripening ,Anatase ,Materials science ,business.industry ,Mechanical Engineering ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Crystallinity ,symbols.namesake ,Semiconductor ,Mechanics of Materials ,law ,symbols ,General Materials Science ,Calcination ,Nyquist plot ,0210 nano-technology ,business ,Visible spectrum - Abstract
With the energy crisis and resource depletion nowadays, novel, highly performing, and cost-effective semiconductors are in urgent demand for efficiently harvesting solar energy for photoelectrochemical applications. Herein, this study presents low-cost anatase TiO2 hollow nanoparticles as prepared by a critical liquid-phase deposition (LPD) processing combined with a hydrothermal reaction and calcination processing, without involving any templates. The additional LPD processing not only makes the resulting samples more visible light responsive, but also results in hollowing the TiO2 nanoparticles (nanosheets vs. hollow nanoparticles). Importantly, commercial TiO2 powder is employed as the starting material to achieve the final synthesis of TiO2 hollow nanoparticles, making it scalable and cost-effective for production and applications. As a by-product, the fluoride, formed during the preparation process, is assumed to play a significant role in hollowing through chemically induced self-transformation and Ostwald ripening, in addition to enhancing the crystallinity. The beneficial structural evolution to the hollow nanoparticles enables the improvement of the photoelectrochemical performance through impressive inhibition of the recombination of the photoelectrons and holes, which is well evidenced by I ph and EIS (Nyquist plot), as well as by I–V curve and electron lifetime evaluations as for the assembled DSSCs with the prepared TiO2 hollow nanoparticles under simulated sunlight illumination (50 mW/cm2).
- Published
- 2017
164. Alfalfa Leaf-Derived Porous Heteroatom-Doped Carbon Materials as Efficient Cathodic Catalysts in Microbial Fuel Cells
- Author
-
Lifang Deng, Yuyuan Zhang, Ying Chen, Yong Yuan, Haoran Yuan, Yazhuo Wang, and Yong Chen
- Subjects
Materials science ,Microbial fuel cell ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,Heteroatom ,Limiting current ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Cathode ,0104 chemical sciences ,Catalysis ,law.invention ,chemistry ,Chemical engineering ,law ,Botany ,Environmental Chemistry ,0210 nano-technology ,Porosity ,Carbon - Abstract
Heteroatom-doped lamellar-structured carbon with a high surface area synthesized from alfalfa leaves is utilized as a cathode catalyst in this study to improve the power output of microbial fuel cells (MFCs). Different chemical activation agents are used to treat alfalfa leaf-derived carbon (ALC). It is found that chemical activation agents substantially affect the catalytic activities of the alfalfa leaf-derived carbon materials in the power output of MFCs and the oxygen reduction reaction (ORR). ALC materials activated by KOH (ALC-K) exhibit the best electrochemical activity compared with those of materials activated by FeCl3 (ALC-Fe) or ZnCl2 (ALC-Zn). A high limiting current density and excellent long-term stability can be seen with ALC-K as the cathode catalyst, which gives superior results to those of Pt/C. Moreover, a maximum power density of approximately 1328.9 mW/m2 is obtained from an MFC equipped with an ALC-K cathode, offering performance characteristics comparable to those of a Pt/C cathode ...
- Published
- 2017
165. Non-uniform doping outperforms uniform doping for enhancing the photocatalytic efficiency of Au-doped TiO 2 nanotubes in organic dye degradation
- Author
-
Huawen Hu, Min Zhang, Menglei Chang, Dongchu Chen, Yuyuan Zhang, Liangpeng Wu, and Xinjun Li
- Subjects
Materials science ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Condensed Matter::Materials Science ,Condensed Matter::Superconductivity ,Phase (matter) ,Materials Chemistry ,Physics::Chemical Physics ,Deposition (law) ,Dopant ,Process Chemistry and Technology ,Doping ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,chemistry ,Ceramics and Composites ,Photocatalysis ,Degradation (geology) ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology ,Dispersion (chemistry) ,Platinum - Abstract
Uniform doping is usually recognized as an efficient method for enhancing photocatalysis of TiO 2 , while non-uniform doping is generally supposed to be inefficient because of the inhomogeneous dispersion of dopants. However, in this study, we present the first example of non-uniform doping (with Au)-better enhanced photocatalysis of TiO 2 nanotubes, as compared to uniform doping, in terms of the photocatalytic organic dye degradation. The extent to which the non-uniform doping (achieved by liquid phase deposition (LPD)) can enhance photocatalysis is evaluated, along with a comparison with uniform doping. There exists an additional positive effect in the non-uniform doping system, that is, as generated interfaces between pure phase TiO 2 and Au-doped TiO 2 , in contrast to the uniform doping system leading to a positive “platinum island” effect. Such double beneficial effects contribute to the highest performance in the photocatalytic organic dye degradation for the Au-non-uniformly doped TiO 2 nanotubes as compared to other samples involved in this study. Both the “platinum island” and interfacial separation effects are helpful to isolate the photo-generated electrons and holes, resulting in enhanced photocatalytic activities.
- Published
- 2017
166. Core-shell-core heterostructural engineering of Y2O3:Eu3+/MCM-41/YVO4:Eu3+ for enhanced red emission and tunable, broadened-band response to excitation
- Author
-
Yuyuan Zhang, Dongchu Chen, Menglei Chang, Huawen Hu, Min Chen, Hong Hu, and Xiufang Ye
- Subjects
010302 applied physics ,Materials science ,Analytical chemistry ,Inner core ,Heterojunction ,Phosphor ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Outer core ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Electron diffraction ,Transmission electron microscopy ,0103 physical sciences ,Electrical and Electronic Engineering ,0210 nano-technology ,Luminescence - Abstract
For the first time, a hierarchical phosphor Y2O3:Eu3+/MCM-41/YVO4:Eu3+, with a core–shell-core heterostructure, is presented in this study. Synergistically bridging the phosphors Y2O3:Eu3+ (as an inner core) and YVO4:Eu3+ (as an outer core) by amorphous SiO2, i.e., MCM-41 (with ordered mesoporous channels) leads to the generation of the core–shell-core heterostructure with enhanced red emission and tunable, broadened-band response to excitation. The novel structure of the core–shell-core hierarchical material is clarified through various characterization methods including X-ray diffraction analysis, transmission electron microscopy, selected-area electron diffraction and N2 adsorption–desorption measurements. Significantly, through temperature-dependent fluorescence investigation, it is found that our core–shell phosphor (Y2O3:Eu3+/MCM-41) exhibits impressive fluorescence stability against temperature variation (27–227 °C) due to the protective effect resulting from MCM-41. By contrast, lowered stability can be noted for the core–shell-core phosphor (Y2O3:Eu3+/MCM-41/YVO4:Eu3+), especially when the temperature is higher than 100 °C, owing to the outer core (YVO4:Eu3+ nanoparticles) that is directly exposed to heat. Such a kind of luminescent materials holds substantial promise for labeling the organisms that are vulnerable to short-wavelength UV light irradiation. Additionally, potential intelligent systems can be expected to be designed on the basis of the fluorescence mutation as triggered by the temperature of 100 °C.
- Published
- 2017
167. Architecture of CoNx single clusters on nanocarbon as excellent oxygen reduction catalysts with high-efficient atomic utilization
- Author
-
Yulai Lei, Yi Zhang, Xiao-Juan Wang, Ting He, Hui Xue, Yuyuan Zhang, Rujuan Shen, Juan Xiang, and Shuanghua He
- Subjects
Materials science ,Single cluster ,Rational design ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,Thermal treatment ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Oxygen reduction ,0104 chemical sciences ,Catalysis ,Metal ,chemistry ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,0210 nano-technology ,Cobalt ,Pyrolysis - Abstract
A new strategy to fabricate CoNx single cluster supported nanocarbon catalysts (C/P/2Co600) with enhanced atomic utilization towards the oxygen reduction reaction (ORR) is reported. N-Coordination protection and low-temperature pyrolysis are the two key factors for the formation of CoNx single clusters on nanocarbon supports. Morphological and structural identification confirmed the simultaneous anchoring of homo-dispersed CoNx single clusters and N-doping on the nanocarbon under relatively mild thermal treatment conditions. Expectedly, the obtained single cluster catalyst with a trace amount of metal atoms exhibited excellent ORR performance including a positive half-wave potential (0.846 V), a high mass activity (0.98 A mgCo−1, ampere per milligram of cobalt) and outstanding chemical durability after 8000 potential cycles. We believe that our findings provide a new route for the rational design of low-cost and highly active ORR catalytic materials.
- Published
- 2017
168. Explosion Characteristics and Flame Propagation Behavior of Mixed Dust Cloud of Coal Dust and Oil Shale Dust
- Author
-
Bo Liu, Yansong Zhang, Huifeng Su, Junfeng Wang, Yuyuan Zhang, and Jinshe Chen
- Subjects
Control and Optimization ,020209 energy ,Energy Engineering and Power Technology ,Mineralogy ,02 engineering and technology ,Coal dust ,Combustion ,lcsh:Technology ,law.invention ,020401 chemical engineering ,law ,0202 electrical engineering, electronic engineering, information engineering ,Coal ,Char ,0204 chemical engineering ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,Renewable Energy, Sustainability and the Environment ,business.industry ,lcsh:T ,flame propagation ,Autoignition temperature ,Ignition system ,Minimum ignition energy ,oil shale and coal dust ,explosion mechanism ,Environmental science ,ignition sensitivity ,business ,Oil shale ,Energy (miscellaneous) - Abstract
Coal and oil shale are often mined and utilized together, and mixed dust is easily formed in these processes. In order to ensure safe production in these processes, the explosion characteristics of mixed dust were studied. Using a Godbert-Greenwold (G-G) Furnace experimental device, Hartmann tube experimental device, and 20 L explosion vessel, the oil shale and coal mixed dust ignition sensitivity experiment, flame propagation experiment, and explosion characteristics experiment were carried out. The minimum ignition temperature (MIT), minimum ignition energy (MIE), maximum explosion pressure (Pmax), maximum rate of pressure rise ((dp/dt)max), and explosibility index (KSt) parameters and the flame propagation behavior of the mixed dust were analyzed in detail. A scanning electron microscope (SEM) analysis of the coal and oil shale dust before and after the explosion was carried out to study the changes in the microscopic morphology of the dust particles. The results show that due to the oil shale having a high volatile content and low moisture content, in the mixture, the greater the percentage of oil shale, the more likely the dust cloud is to be ignited and the faster the explosion flame is propagated, the greater the percentage of oil shale, the greater the (dP/dt)max and KSt will be and, under a high dust concentration, a greater Pmax will be produced. During explosion, coal dust will experience particle pyrolysis and the gas phase combustion of the volatile matter, followed by solid phase combustion of coal char, whereas oil shale dust will only experience particle pyrolysis and the gas phase combustion of the volatile matter.
- Published
- 2019
169. Electronic Structure of Liquid Methanol and Ethanol from Polarization-Dependent Two-Photon Absorption Spectroscopy
- Author
-
Yuyuan Zhang, Dhritiman Bhattacharyya, Christopher G. Elles, and Stephen E. Bradforth
- Subjects
010304 chemical physics ,Absorption spectroscopy ,Chemistry ,Electronic structure ,010402 general chemistry ,01 natural sciences ,Two-photon absorption ,Molecular physics ,Spectral line ,0104 chemical sciences ,Ab initio quantum chemistry methods ,Excited state ,0103 physical sciences ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Ionization energy ,Spectroscopy - Abstract
Two-photon absorption (2PA) spectra of liquid methanol and ethanol are reported for the energy range 7-10 eV from the first electronic excitation to close to the liquid-phase ionization potential. The spectra give detailed information on the electronic structures of these alcohols in the bulk liquid. The focus of this Article is to examine the electronic structure change compared with water on substitution of a hydrogen by an alkyl group. Continuous 2PA spectra are recorded in the broadband pump-probe fashion, with a fixed pump pulse in the UV region and a white-light continuum as a probe. Pump pulses of two different energies, 4.6 and 6.2 eV, are used to cover the spectral range up to 10 eV. In addition, theoretical 2PA cross sections for both molecules isolated in the gas phase are computed by the equation-of-motion coupled-cluster method with single and double substitutions (EOM-CCSD). These computational results are used to assign both the experimental 2PA and literature one-photon linear absorption spectra. The most intense spectral features are due to transitions to the Rydberg states, and the 2PA spectra are dominated by the totally symmetric 3pz ← 2pz transition in both alcohols. The experimental 2PA spectra are compared with the simulated 2PA spectra based on ab initio calculations that reveal a general blue shift of the excited transitions upon solvation. The effective 2PA thresholds in methanol and ethanol decrease to 6.9 eV compared with 7.8 eV for water. The analysis of the 2PA polarization ratio leads us to conclude that the excited states of ethanol deviate more markedly from water in the lower energy region compared with methanol. The polarization dependence of the 2PA spectra reveal the symmetries of the excited states within the measured energy range. Natural transition orbital calculations are performed to visualize the nature of the transitions and the orbitals participating during electronic excitation.
- Published
- 2019
170. Isotopic substitution affects excited state branching in a DNA duplex in aqueous solution
- Author
-
Yuyuan Zhang, Forrest R. Kohl, Kimberly de La Harpe, and Bern Kohler
- Subjects
inorganic chemicals ,Models, Molecular ,Dna duplex ,Base pair ,010402 general chemistry ,Branching (polymer chemistry) ,01 natural sciences ,Catalysis ,Materials Chemistry ,A-DNA ,Deuterium Oxide ,Base Pairing ,Aqueous solution ,Base Sequence ,010405 organic chemistry ,Chemistry ,Metals and Alloys ,General Chemistry ,DNA ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Solvent ,Solutions ,Chemical physics ,Duplex (building) ,Excited state ,Ceramics and Composites ,Solvents ,Quantum Theory - Abstract
Changing the solvent from H2O to D2O dramatically affects the branching of the initial excited electronic states in an alternating G·C DNA duplex into two distinct decay channels. The slower, multisite PCET channel that deactivates more than half of all excited states in D2O becomes six times weaker in H2O.
- Published
- 2019
171. Self-Ordered Orientation of Crystalline Hexagonal Boron Nitride Nanodomains Embedded in Boron Carbonitride Films for Band Gap Engineering
- Author
-
Yin Hong, Li Yujing, Dehe Zhao, Fei Wang, Yuyuan Zhang, and Gao Wei
- Subjects
BCN ,growth mechanism ,Materials science ,Band gap ,optoelectronics ,Doping ,chemistry.chemical_element ,Surfaces and Interfaces ,Substrate (electronics) ,orientation ,Surfaces, Coatings and Films ,Characterization (materials science) ,Orientation (vector space) ,bandgap-engineering ,chemistry ,Chemical physics ,lcsh:TA1-2040 ,Materials Chemistry ,Perpendicular ,hexagonal boron nitride ,Ternary operation ,lcsh:Engineering (General). Civil engineering (General) ,Carbon - Abstract
Boron carbonitride (BCN) films containing hybridized bonds involving elements B, C, and N over wide compositional ranges enable an abundant variety of new materials, electronic structures, properties, and applications, owing to their semiconducting properties with variable band gaps. However, it still remains challenging to achieve band gap-engineered BCN ternary with a controllable composition and well-established ordered structure. Herein, we report on the synthesis and characterization of hybridized BCN materials, consisting of self-ordered hexagonal BN (h-BN) crystalline nanodomains, with its aligned basal planes preferentially perpendicular to the substrate, depending on the growth conditions. The observation of the two sets of different band absorptions suggests that the h-BN nanodomains are distinguished enough to resume their individual band gap identity from the BCN films, which decreases as the carbon content increases in the BCN matrix, due to the doping and/or boundary effect. Our results reveal that the structural features and band gap of this form of hybrid BCN films are strongly correlated with the kinetic growth factors, making it a great system for further fundamental physical research and for potential in the development of band gap-engineered applications in optoelectronics.
- Published
- 2019
- Full Text
- View/download PDF
172. The electronic properties and band-gap discontinuities at the cubic boron nitride/diamond hetero-interface
- Author
-
Yuyuan Zhang, Wei Gao, Dehe Zhao, Li Yujing, and Hong Yin
- Subjects
Materials science ,Band gap ,General Chemical Engineering ,Binding energy ,Diamond ,General Chemistry ,engineering.material ,Molecular physics ,Band offset ,chemistry.chemical_compound ,Atomic orbital ,chemistry ,Boron nitride ,Density of states ,engineering ,Electronic band structure - Abstract
Clarifying the electronic states and structures of the c-BN/diamond interface is of extreme importance for bundling these two different wide-band gap materials in order to synthesize hybrid structures with new functional properties. In this work, the structural optimization and property determinations were carried out on (100) and (111) c-BN/diamond hetero-interface by using first principles total energy calculations. A 12-layers c-BN above the diamond was found to be energetically reasonable for the calculations of the properties of the hetero-interface. Based on the calculation of the chemical potentials for the c-BN/diamond interface, the hetero-interface with the C–B configuration is the most energetically favorable structure under the (111) and (100) surfaces of diamond, respectively. The calculations of band structure and density of states for C–N bond configuration indicate that the main contribution to the density of the interface states near the EF is from the N 2s 2p, B 2p and C 2p orbitals while that for C–B bond configuration is mainly from the B 2p, N 2p and C 2p orbitals. The electron density difference, binding energy and band offset were also calculated, demonstrating that the C–B bond was found to be remarkably stronger than other adjacent bonds. Furthermore, a band offset of 0.587 eV for the (111) c-BN/diamond hetero-interface with the C–N bond configuration has been obtained, which is in good agreement with the previous experimental result (0.8 eV), suggestting that the C–N bond may exist in synthesized c-BN/diamond epitaxy using different growth methods. This should allow the design of a hybrid structure of c-BN/diamond thereby opening a new pathway towards high temperature electronics, UV photonics and (bio-) sensor applications.
- Published
- 2019
173. Association and Interaction Analysis of Lipid Accumulation Product with Impaired Fasting Glucose Risk: A Cross-Sectional Survey
- Author
-
Yuhong Jiang, Huaiquan Gao, Xuesen Wu, Jing Mi, Xue Chen, Jian Song, Yingying Zhao, and Yuyuan Zhang
- Subjects
Blood Glucose ,Male ,medicine.medical_specialty ,China ,Article Subject ,Cross-sectional study ,Endocrinology, Diabetes and Metabolism ,Logistic regression ,lcsh:Diseases of the endocrine glands. Clinical endocrinology ,Body Mass Index ,Prediabetic State ,Endocrinology ,Risk Factors ,Internal medicine ,Surveys and Questionnaires ,Glucose Intolerance ,Medicine ,Humans ,Obesity ,Aged ,lcsh:RC648-665 ,Receiver operating characteristic ,business.industry ,Absolute risk reduction ,Fasting ,Middle Aged ,Impaired fasting glucose ,medicine.disease ,Cross-Sectional Studies ,Quartile ,Female ,business ,Lipid Accumulation Product ,Body mass index ,Biomarkers ,Research Article - Abstract
Aims. Lipid accumulation product (LAP) is put forward as a powerful marker showing the accumulation of visceral fat. The present study is aimed at (i) analyzing the predictive performances of LAP in the identification of impaired fasting glucose (IFG) in Chinese population and (ii) exploring the potentially interactive effect between LAP and other factors on IFG risk. Methods. Analysis was conducted on the data obtained from a community-based cross-sectional survey in Chinese population, and all the participants enrolled were required to complete a face-to-face questionnaire survey and related health checks. Then, for the purpose of comparing predictive values between LAP and conventional obesity indices for IFG, relevant analysis was carried out on the receiver operating characteristic (ROC) curve. The assessment of interactive effects was conducted by employing the three indicators as follows: (1) RERI (the relative excess risk due to interaction), (2) AP (attributable proportion due to interaction), and (3) SI (synergy index). Results. A total of 1777 participants (748 males and 1029 females) were involved in the final analysis. It was finally obtained that the prevalence rate of IFG was 14.1% in total, 15.5% for males and 13.1% for females, respectively. In logistic regression analysis, individuals with LAP levels in the fourth quartile had a significant higher risk of getting IFG in comparison with that of the lowest quartile (crude OR: 4.58, 95% CI: 3.01-6.98; adjusted OR: 3.81, 95% CI: 2.33-6.23). In addition, it was indicated by the ROC curve analysis that LAP showed a better performance in discriminating IFG risk than BMI in both males (Z=2.20, P=0.028) and females (Z=2.13, P=0.033). However, LAP displayed a higher predictability in comparison with WC only in females (Z=2.07, P=0.038), but not in males (Z=0.18, P=0.860). Furthermore, LAP and family history of diabetes were able to impose significant synergistic interaction on the risk of IFG, which was indicated by all the parameters in females (RERI: 2.52, 95% CI: 0.19-4.84; AP: 0.47, 95% CI: 0.20-0.74; SI: 2.39, 95% CI: 1.17-4.87) and males (RERI: 2.18, 95% CI: 0.08-4.73; AP: 0.43, 95% CI: 0.07-0.79; SI: 2.15, 95% CI: 1.03-5.45). However, none of the indicators showed significant interaction between LAP and smoking on the risk of IFG in females (RERI: 0.92, 95% CI: -2.79-4.63; AP: 0.20, 95% CI: -0.50-0.92; SI: 1.37, 95% CI: 0.42-4.52). Meanwhile, there was also no significant interaction between LAP and smoking on the risk of IFG in males as indicated by the value of SI (2.22, 95% CI: 0.80-6.21). Conclusion. It was concluded that LAP was significantly related to a higher risk of IFG in Chinese population, and its performance was superior to that of conventional obesity indices, especially in females. Apart from that, LAP with family history of diabetes may have an interactive effect that can impose a great influence on the development of IFG.
- Published
- 2019
- Full Text
- View/download PDF
174. Experimental Study on Multiple Explosions during the Development and Utilization of Oil Shale Dust
- Author
-
Jinshe Chen, Yuyuan Zhang, Yansong Zhang, Xiangbao Meng, and Bo Liu
- Subjects
Explosive material ,Article Subject ,020209 energy ,Mechanical Engineering ,Mineralogy ,02 engineering and technology ,Fragmentation (weaponry) ,Geotechnical Engineering and Engineering Geology ,Condensed Matter Physics ,Microstructure ,lcsh:QC1-999 ,Pressure rise ,Minimum ignition energy ,020401 chemical engineering ,Mechanics of Materials ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,0204 chemical engineering ,Dust explosion ,Oil shale ,lcsh:Physics ,Civil and Structural Engineering ,Maximum rate - Abstract
Oil shale is a kind of high-combustion heat mineral; in the process of exploitation, storage, and utilization, oil shale dust has the risk of explosion. The explosion characteristics and flame propagation behavior of oil shale dust are worth studying. The difference between the multiple explosion behaviors of oil shale dust was investigated with the use of a 20 L explosive spherical tank and a dust MIE experimental device. The explosion characteristics and microstructure changes of the explosive products in multiple explosions were examined. The experimental results show that the maximum explosion pressure (Pmax) dropped, and simultaneously, the minimum ignition energy (MIE), the explosion time (t), and the maximum rate of pressure rise (dp/dtmax) increased as the explosions continued. Furthermore, the oil shale continued exploding until the third explosion. Some original oil shale dust (OOSD) and explosive residues were analyzed using a scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) spectrometer. The SEM images of the explosive residues indicate a high fragmentation degree and well-developed pore structure during the entire multiexplosion process. Oxygen-containing functional groups, the aliphatic C-H bond, and the aromatic C-H bond in oil shale dust all participated in the oil shale dust explosion process.
- Published
- 2019
- Full Text
- View/download PDF
175. [Effect of phosphatase and tensin homolog deleted on chromosome ten on the neurological function induced by cadmium of mice]
- Author
-
Yuyuan, Zhang, Xue, Chen, Jing, Yang, Yunli, Zhao, and Yun, Wang
- Subjects
Mice ,Mice, Inbred ICR ,Tensins ,PTEN Phosphohydrolase ,Animals ,Brain ,Nervous System ,Chromosomes ,Cadmium - Abstract
To explore the effect of cadmium on nerve function and whether the phosphatase and tensin homolog deleted on chromosome ten(PTEN)was involved in its toxicity.The healthy adult ICR mice were randomly divided into4 groups which included CdCl_20, 0. 5, 1. 0 and 2. 0 mg/kg, all the mice were intraperitoneally injected administration every day for 14 days. 15-point disease score scale were used to assess neurological function, after the elevation, all the brain were removed and harvested, the level of MDA, CAT, GSH and T-SOD were elevated. qRT-PCR and western blotting were used to detected the expression of PTEN. SPSS 20. 0 was used to analyze the data.The body weight in CdCl_22. 0 mg/kg group was(-0. 6±0. 9)g, was significant lower than the others(F=9. 211, P0. 05);the level of MDA in2. 0 mg/kg was increased[(19. 3±3. 7)nmol/mg pro](F=4. 123, P0. 05)and GSH[(81. 1±8. 2)mg/g pro]decreased compared with the blank(F=7. 644, P0. 05);the level of CAT in 1. 0 mg/kg[(56. 0±8. 5)U/mg pro]was decreased compared with the blank and 0. 5 mg/kg(F=3. 542, P0. 05);the level of p-PTEN(Ser380)was significantly improved in western blotting(F=389. 2, P0. 05).Cadmium cause the damage to the nervous system at least partially by activating the lipid phosphatase activity of PTEN.
- Published
- 2018
176. [Combined treatment with myo-inositol and luteolin selectively suppresses growth of human lung cancer A549 cells possibly by suppressing activation of PDK1 and Akt]
- Author
-
Yun, Wang, Yuyuan, Zhang, Xue, Chen, Yun, Hong, and Zhengdong, Wu
- Subjects
Lung Neoplasms ,基础研究 ,A549 Cells ,Cell Movement ,Cell Survival ,Vitamin B Complex ,Humans ,Pyruvate Dehydrogenase Acetyl-Transferring Kinase ,Protein Serine-Threonine Kinases ,Luteolin ,Proto-Oncogene Proteins c-akt ,Inositol ,Cell Proliferation - Abstract
OBJECTIVE: To study the effects of myo-inositol and luteolin on human lung cancer A549 cells and explore the possible mechanisms. METHODS: A549 cells were treated with different concentrations of myo-inositol and luteolin, either alone or in combination, and the cell viability was examined using MTT assay. A549 cells and human bronchial epithelial Beas-2B cells were treated for 48 h with 10 mmol/L myo-inositol and 20 μmol/L luteolin, alone or in combination, and the cell proliferation was detected using MTT assay; the colony formation and migration of the cells were examined with colony formation assay and wound healing assay, respectively. The protein expression levels in A549 cells were detected using Western blotting. RESULTS: Both myo-inositol and luteolin could dose-dependently inhibit the viability of A549 cells. Treatments with 10 mmol/L myo-inositol, 20 μmol/L luteolin, and both for 48 h caused significant reduction in the cell viability (92%, 83% and 70% of the control level, respectively) and colony number (79%, 73% and 43%, respectively), and significantly lowered the wound closure rate (24.61%, 13.08% and 8.65%, respectively, as compared with 29.99% in the control group). Similar treatments with myoinositol and luteolin alone or in combination produced no significant inhibitory effect on the growth, colony formation or migration of Beas-2B cells. The expressions of p-PDK1 and p-Akt in myo-inositol-treated A549 cells and the expression of pPDK1 in luteolin-treated cells were significantly decreased (P < 0.05), and the decrements were more obvious in the combined treatment group (P < 0.05). CONCLUSION: Luteolin combined with myo-inositol can selectively inhibit the proliferation and migration of A549 cells, and these effects are probably mediated, at least in part, by suppressing the activation of PDK1 and Akt.
- Published
- 2018
177. Geometric dimension assisted absolute phase recovery in 3D shape measurement with digital fringe projection
- Author
-
Shenzhen Lv, Jian Wang, Qiang Sun, Lei Jing, Yuyuan Zhang, and Ying Liu
- Subjects
Optics ,Dimension (vector space) ,business.industry ,Computer science ,Absolute phase ,Applied Mathematics ,Surface measurement ,business ,Optical metrology ,Instrumentation ,Engineering (miscellaneous) ,Phase unwrapping ,Structured-light 3D scanner - Abstract
A novel method of geometric dimension assisted absolute phase recovery in 3D shape measurement is presented. This method mainly includes two steps: (a) using the window Fourier filter-quality guided phase unwrapping algorithm to obtain the relative phase distribution of the tested object; (b) using the geometric dimension of the object as a clue to convert the relative phase distribution to the absolute phase distribution. This method is convenient, and only three fringe image acquisitions are needed to recover the absolute phase. In addition, there is no limit to the depth range of the tested object. The correctness of this method is verified by several experiments.
- Published
- 2021
178. Quadrangular resection versus chordal replacement for degenerative posterior mitral leaflet prolapse
- Author
-
Hongxiang Wu, Zhao Chen, Bin Xie, Liangzheng Fang, Peijian Wei, Ximeng Yao, Tong Tan, Huanlei Huang, Huiming Guo, Yuyuan Zhang, Yanjun Liu, Jimei Chen, Jian Zhuang, Jiexu Ma, and Jian Liu
- Subjects
Mitral regurgitation ,medicine.medical_specialty ,Proportional hazards model ,business.industry ,Hazard ratio ,General Medicine ,030204 cardiovascular system & hematology ,Confidence interval ,Surgery ,Resection ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,030228 respiratory system ,Mitral valve ,medicine ,Minimally invasive cardiac surgery ,Original Article ,Risk factor ,business - Abstract
BACKGROUND: The aims of the present study was to compare midterm results of quadrangular leaflet resection versus chordal replacement for the repair of degenerative posterior mitral leaflet (PML) prolapse, and to explore the risk factors for recurrent severe mitral regurgitation (MR). METHODS: From January 2012 to December 2018, 1,423 consecutive patients underwent mitral valve (MV) repair. A total of 317 had degenerative PML prolapse and constituted the study population. Of these, 74 (23.3%) underwent quadrangular leaflet resection, and 243 (76.7%) underwent chordal replacement. Outcomes were compared by using unadjusted data and propensity score-matched analyses. RESULTS: Patients with multiple leaflet prolapse were more likely to undergo chordal replacement (18.4% vs. 41.9%, P0.05). Multivariate Cox regression indicated that dilated left ventricular end-systolic diameter (LVESD) was an independent risk factor for recurrent severe MR [40 mm, hazards ratio (HR): 3.17, 95% confidence interval (CI): 1.20–8.39, P=0.020]; however, surgical technique was not (resection vs. neochordae, HR: 0.31, 95% CI: 0.07–1.37, P=0.122). CONCLUSIONS: Chordal replacement for the repair of degenerative posterior MV prolapse yields similar satisfactory outcomes when compared with quadrangular resection, and is promising in minimally invasive cardiac surgery for various lesions. However, it is also associated with more recurrent severe MR, albeit non-significant, for which patients with dilated LVESD are at high risk.
- Published
- 2021
179. Optical properties of multicolor, hierarchical nanocomposite films based on anodized aluminum oxide
- Author
-
Yuyuan Zhang, Xiufang Ye, Hongyang Wei, Menglei Chang, Wu Wen, Li Zhiqiang, Meifeng Wang, Dongchu Chen, and Huawen Hu
- Subjects
Materials science ,Nanostructure ,Oxide ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,Inorganic Chemistry ,chemistry.chemical_compound ,law ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Spectroscopy ,Electrolysis ,Nanocomposite ,business.industry ,Anodizing ,Organic Chemistry ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry ,6063 aluminium alloy ,Optoelectronics ,0210 nano-technology ,business ,Layer (electronics) ,Visible spectrum - Abstract
With three distinct layers, multicolor, hierarchical nanocomposite films based on anodized aluminum oxide (AAO) were fabricated on the 6063 aluminum alloy surface by anodizing and alternating current electrodeposition. The impact of the electrolysis time on the nanostructures and optical properties of the as-grown film was investigated. It was found that with the extension of electrolysis time, the sample color could be varied from gray, yellow, red, blue, to green, realizing almost full-spectrum colors of the AAO-based films in the visible light range. The nanostructure characterizations and the UV–Vis reflectance spectroscopy of the AAO-based films showed that the thickness of the bottom one (i.e., layer 3) of the three layers was dictated by the electrolysis time over the range of 55–145 s, corresponding to the thickness from 135 to 264 nm. Additionally, the optical pathway of the AAO-based film with hierarchical composite nanostructures was analyzed. An increase in the layer 3 thickness would cause a shift in the peak wavelength in the corresponding reflectance spectra, conforming to the Bragg-Snell formula. The colors of AAO films were speculated to originate from constructive interference between the light reflected from the layer 1-layer 2 interface and the light reflected from the layer 3-aluminum alloy substrate interface.
- Published
- 2021
180. Upcycling biomass tar into highly porous, defective and pyridinic-n-enriched graphene nanohybrid as efficient bifunctional catalyst for Zn-air battery
- Author
-
Huibing Chen, Jizhang Yang, Denian Li, Yuyuan Zhang, Haoran Yuan, and Yong Chen
- Subjects
Materials science ,Graphene ,Annealing (metallurgy) ,General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Nitrogen ,0104 chemical sciences ,Bifunctional catalyst ,Catalysis ,law.invention ,Ammonia ,chemistry.chemical_compound ,Upcycling ,chemistry ,Chemical engineering ,law ,Electrochemistry ,0210 nano-technology ,Porosity - Abstract
With quite limited use, biomass tar has been a long-standing issue that strongly impaired the cost-efficiency of biomass gasification. Here, a facile activation-annealing route for upcycling biomass tar into graphene nanohybrids with developed porosity and enriched pyridinic nitrogen was reported, whilst the metal-free product revealed with superior catalytic activities to the benchmark Pt/C and RuO2 catalysts toward oxygen reduction reaction (ORR) and evolution reaction (OER). By associating the dual functionalities with products’ physiochemical properties, it was unveiled that those pyridinic-N and defects were accounted for the promoted oxygen reduction and evolution, respectively. Together with reinforced electric conductivity and hierarchical porosity and enlarged interface via ammonia annealing, the heterogeneously structured carbon catalyst finally endowed an assembled primary Zn-air battery with maximum energy density of 121 mW/cm−2, in addition to robust stability against long-term running. This work highlights the great potential of biomass tar for advanced carbon materials, and therefore a novel strategy to address the tar-related challenges faced by gasification technologies.
- Published
- 2020
181. Subnanosecond Emission Dynamics of AT DNA Oligonucleotides
- Author
-
Yuyuan Zhang, Bern Kohler, Ashley A. Beckstead, David J. Skowron, Jacob M. Remington, and Madison Strawn
- Subjects
Time Factors ,Ultraviolet Rays ,010405 organic chemistry ,Chemistry ,Relaxation (NMR) ,Oligonucleotides ,DNA ,010402 general chemistry ,Photochemistry ,Excimer ,01 natural sciences ,Molecular physics ,Atomic and Molecular Physics, and Optics ,Photon counting ,0104 chemical sciences ,Picosecond ,Excited state ,Ultrafast laser spectroscopy ,Thermodynamics ,Physical and Theoretical Chemistry ,Time-resolved spectroscopy ,Ground state - Abstract
UV radiation creates excited electronic states in DNA that can decay to mutagenic photoproducts. When excited states return to the electronic ground state, photochemical injury is avoided. Understanding of the available relaxation pathways has advanced rapidly during the past decade, but there has been persistent uncertainty, and even controversy, over how to compare results from transient absorption and time-resolved emission experiments. Here, emission from single- and double-stranded AT DNA compounds excited at 265 nm was studied in aqueous solution using the time-correlated single photon counting technique. There is quantitative agreement between the emission lifetimes ranging from 50 to 200 ps and ones measured in transient absorption experiments, demonstrating that both techniques probe the same excited states. The results indicate that excitations with lifetimes of more than a few picoseconds are weakly emissive excimer and charge transfer states. Only a minute fraction of excitations persist beyond 1 ns in AT DNA strands at room temperature.
- Published
- 2016
182. UV-Induced Proton-Coupled Electron Transfer in Cyclic DNA Miniduplexes
- Author
-
Yuyuan Zhang, Xi Bo Li, Bern Kohler, Anita M. Orendt, Cynthia J. Burrows, Aaron M. Fleming, Ashley A. Beckstead, and Jordan Dood
- Subjects
Guanine ,Ultraviolet Rays ,Base pair ,Stacking ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Catalysis ,Nucleobase ,Electron Transport ,Electron transfer ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Tetramer ,Base Pairing ,DNA ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Crystallography ,chemistry ,Cyclization ,Excited state ,Nucleic Acid Conformation ,Protons ,Proton-coupled electron transfer ,0210 nano-technology - Abstract
The excited-state dynamics of two cyclic DNA miniduplexes, each containing just two base pairs, are investigated using time-resolved infrared spectroscopy. As in longer DNA duplexes, intrastrand electron transfer induced by UV excitation triggers interstrand proton transfer in the alternating miniduplex containing two out-of-phase G·C base pairs. The resulting excited state decays on a time scale of several tens of picoseconds. This state is absent when one of the two G residues is substituted by 8-oxo-7,8-dihydroguanine, a modification that is suggested to disrupt base stacking, while maintaining base pairing. These findings demonstrate that a nucleobase tetramer arranged as two stacked base pairs accurately captures the interplay between intrastrand and interstrand decay channels. The similar signals seen in the miniduplexes and longer sequences suggest that excited states in the latter rapidly localize on two adjacent base pairs.
- Published
- 2016
183. Excited-State Dynamics of DNA Duplexes with Different H-Bonding Motifs
- Author
-
Bern Kohler, Yuyuan Zhang, Ashley A. Beckstead, Roberto Improta, Kimberly de La Harpe, and Lara Martínez-Fernández
- Subjects
Spectrophotometry, Infrared ,Ultraviolet Rays ,010405 organic chemistry ,Base pair ,Hydrogen bond ,Radical ,Kinetics ,Hydrogen Bonding ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Crystallography ,Electron transfer ,Models, Chemical ,chemistry ,Duplex (building) ,Excited state ,DNA, Z-Form ,General Materials Science ,Physical and Theoretical Chemistry ,DNA, B-Form ,Base Pairing ,DNA - Abstract
The excited-state dynamics of three distinct forms of the d(GC)9·d(GC)9 DNA duplex were studied by combined time-resolved infrared experiments and quantum mechanical calculations. In the B- and Z-forms, bases on opposite strands form Watson-Crick (WC) base pairs but stack differently because of salt-induced changes in backbone conformation. At low pH, the two strands associate by Hoogsteen (HG) base pairing. Ultraviolet-induced intrastrand electron transfer (ET) triggers interstrand proton transfer (PT) in the B- and Z-forms, but the PT pathway is blocked in the HG duplex. Despite the different decay mechanisms, a common excited-state lifetime of ∼ 30 ps is observed in all three duplex forms. The ET-PT pathway in the WC duplexes and the solely intrastrand ET pathway in the HG duplex yield the same pair of π-stacked radicals on one strand. Back ET between these radicals is proposed to be the rate-limiting step behind excited-state deactivation in all three duplexes.
- Published
- 2016
184. Photoinduced long-lived charge transfer excited states in AT-DNA strands
- Author
-
Ashley A. Beckstead, Roberto Improta, Yuyuan Zhang, Lara Martínez-Fernández, Kimberly de La Harpe, and Bern Kohler
- Subjects
010405 organic chemistry ,Chemistry ,Adenine ,General Physics and Astronomy ,Infrared spectroscopy ,Charge (physics) ,DNA ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Marcus theory ,Electron Transport ,chemistry.chemical_compound ,Transfer (computing) ,Excited state ,Animals ,Humans ,Transient (oscillation) ,Physical and Theoretical Chemistry ,Atomic physics ,Thymine ,Single strand - Abstract
The IR spectrum of a charge transfer (CT) excited electronic state in DNA has been computed for the first time, enabling assignment of the long-lived component of the transient IR spectrum of a d(AT)9 single strand to an A → T CT state. Experimentally, the CT state lifetime is much shorter than in the double strand, and our calculations explain this result using Marcus Theory.
- Published
- 2016
185. Life in the light: nucleic acid photoproperties as a legacy of chemical evolution
- Author
-
Bern Kohler, Yuyuan Zhang, Ashley A. Beckstead, and Mattanjah S. de Vries
- Subjects
Excited electronic state ,Ultraviolet Rays ,General Physics and Astronomy ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Nucleobase ,Electron Transport ,chemistry.chemical_compound ,Molecule ,Physical and Theoretical Chemistry ,Photolysis ,Nucleotides ,RNA ,DNA ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemical evolution ,chemistry ,Excited state ,Nucleic acid ,0210 nano-technology - Abstract
Photophysical investigations of the canonical nucleobases that make up DNA and RNA during the past 15 years have revealed that excited states formed by the absorption of UV radiation decay with subpicosecond lifetimes (i.e.,10(-12) s). Ultrashort lifetimes are a general property of absorbing sunscreen molecules, suggesting that the nucleobases are molecular survivors of a harsh UV environment. Encoding the genome using photostable building blocks is an elegant solution to the threat of photochemical damage. Ultrafast excited-state deactivation strongly supports the hypothesis that UV radiation played a major role in shaping molecular inventories on the early Earth before the emergence of life and the subsequent development of a protective ozone shield. Here, we review the general physical and chemical principles that underlie the photostability, or "UV hardiness", of modern nucleic acids and discuss the possible implications of these findings for prebiotic chemical evolution. In RNA and DNA strands, much longer-lived excited states are observed, which at first glance appear to increase the risk of photochemistry. It is proposed that the dramatically different photoproperties that emerge from assemblies of photostable building blocks may explain the transition from a world of molecular survival to a world in which energy-rich excited electronic states were eventually tamed for biological purposes such as energy transduction, signaling, and repair of the genetic machinery.
- Published
- 2016
186. A method of depth extension in 3D shape measurement by geometric constraints
- Author
-
Yuyuan Zhang, Qiang Sun, Jian Wang, and Shenzhen Lv
- Subjects
Physics ,Optics ,business.industry ,Absolute phase ,Extension (predicate logic) ,business ,Optical metrology ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Abstract
In this paper a new method to extend the measurement depth limited by geometric constraints for objects with large depth variances is presented. This method mainly includes the following steps: (1) using the watershed image segmentation algorithm to extract the correct part of the discontinuous absolute phase distribution obtained by geometric constraints, and making a binary mask of the correspondent region; (2) using the window Fourier filter-quality guided phase unwrapping algorithm to obtain the relative phase distribution of the tested object; (3) using the binary mask to get the difference between the relative and the absolute phases; (4) converting the relative phase distribution to absolute phase distribution by referring to their phase difference in the mask region. The experimental results prove the effectiveness and correctness of the proposed method.
- Published
- 2020
187. Ultrafast excited state dynamics of silver ion-mediated cytosine–cytosine base pairs in metallo-DNA
- Author
-
Yuyuan Zhang, Lara Martínez-Fernández, Bern Kohler, Forrest R. Kohl, and Aaron P. Charnay
- Subjects
Models, Molecular ,Circular dichroism ,Silver ,Materials science ,Base pair ,General Physics and Astronomy ,Crystal structure ,010402 general chemistry ,01 natural sciences ,Ion ,Cytosine ,chemistry.chemical_compound ,0103 physical sciences ,Ultrafast laser spectroscopy ,Physical and Theoretical Chemistry ,Spectroscopy ,Base Pairing ,010304 chemical physics ,Circular Dichroism ,DNA ,Cations, Monovalent ,0104 chemical sciences ,Silver nitrate ,Crystallography ,chemistry ,Excited state - Abstract
To better understand the nexus between structure and photophysics in metallo-DNA assemblies, the parallel-stranded duplex formed by the all-cytosine oligonucleotide, dC20, and silver nitrate was studied by circular dichroism (CD), femtosecond transient absorption spectroscopy, and time-dependent-density functional theory calculations. Silver(I) ions mediate Cytosine–Cytosine (CC) base pairs by coordinating to the N3 atoms of two cytosines. Although these silver(I) mediated CC base pairs resemble the proton-mediated CC base pairs found in i-motif DNA at first glance, a comparison of experimental and calculated CD spectra reveals that silver ion-mediated i-motif structures do not form. Instead, the parallel-stranded duplex formed between dC20 and silver ions is proposed to contain consecutive silver-mediated base pairs with high propeller twist-like ones seen in a recent crystal structure of an emissive, DNA-templated silver cluster. Femtosecond transient absorption measurements with broadband probing from the near UV to the near IR reveal an unusually long-lived (>10 ns) excited state in the dC20 silver ion complex that is not seen in dC20 in single-stranded or i-motif forms. This state is also absent in a concentrated solution of cytosine–silver ion complexes that are thought to assemble into planar ribbons or sheets that lack stacked silver(I) mediated CC base pairs. The large propeller twist angle present in metal-mediated base pairs may promote the formation of long-lived charged separated or triplet states in this metallo-DNA.
- Published
- 2020
188. Photocatalytic degradation of methyl orange by Ag/TiO2/biochar composite catalysts in aqueous solutions
- Author
-
Bo Luo, Jing Gu, Lili Lu, Haoran Yuan, Rui Shan, Yong Chen, and Yuyuan Zhang
- Subjects
010302 applied physics ,chemistry.chemical_classification ,Aqueous solution ,Materials science ,Mechanical Engineering ,Electron donor ,02 engineering and technology ,Electron acceptor ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Mineralization (biology) ,law.invention ,Catalysis ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,law ,0103 physical sciences ,Biochar ,Methyl orange ,General Materials Science ,Calcination ,0210 nano-technology ,Nuclear chemistry - Abstract
One set of biochar-coupled Ag and TiO2 composites were successfully fabricated by mixing, calcination, and photodeposition method to remove methyl orange (MO). It was found that all catalysts modified with Ag showed better photocatalytic degradation performance (the highest decolorization efficiency and mineralization efficiency were 97.48% and 85.38%, respectively) than single TiO2 because of the synergy of Ag, TiO2 and biochar. Characterization results indicated that Ag as well as TiO2 acted as electron donor and biochar acted as electron acceptor, which could effectively promote the separation of photogenerated electron hole pairs. In addition, the catalyst exhibited high stability up to 5 cycles and the loss of activity was negligible. And the catalytic degradation process was consistent with the pseudo-first-order kinetic (PFOK) model with the degradation rate constant of 6.29 × 10−2 min−1.
- Published
- 2020
189. Reactivity and deactivation mechanisms of toluene reforming over waste peat char-supported Fe/Ni/Ca catalyst
- Author
-
Shuxiao Wang, Yuyuan Zhang, Haoran Yuan, Rui Shan, Jing Gu, Jun Zhang, Yong Chen, and Bo Luo
- Subjects
Peat ,Chemistry ,020209 energy ,General Chemical Engineering ,Organic Chemistry ,Energy Engineering and Power Technology ,Tar ,02 engineering and technology ,Toluene ,Catalysis ,chemistry.chemical_compound ,Fuel Technology ,020401 chemical engineering ,Catalytic reforming ,Chemical engineering ,0202 electrical engineering, electronic engineering, information engineering ,Char ,0204 chemical engineering ,Pyrolysis ,Syngas - Abstract
The pyrolysis char from waste peat with impregnated metal (Fe/Ni/Ca) were investigated for catalytic reforming of toluene in a laboratory dual-stage reactor. The prepared catalysts were examined in microstructure and textural characterization to analyze catalytic performance and stability. The results indicated that under the optimized conditions, the toluene conversions are greater than 92.7% for three types of peat char-supported catalysts, and the maximum molar ratio of syngas (CO + H2) can reach up to 94.7% using Ni/peat char catalyst. The promising results demonstrated that the H2 and CO are favored for Fe/peat char and Ni/peat char catalysts while the H2 and CH4 are favored for Ca/peat char catalyst. After 320 min of experiment, the mol% of syngas decreased by less than 30% for three types of peat char catalysts. Significantly, peat char (C-SiO2) as a carrier can enhance the performance of catalyst through interaction with the metal, and it can be used as an adsorption carrier to absorb unreacted toluene. Such peat char-supported catalysts are thus promising for tar conversion and useful syngas production.
- Published
- 2020
190. Co-pyrolysis of xylan and high-density polyethylene: Product distribution and synergistic effects
- Author
-
Haoran Yuan, Honggang Fan, Yazhuo Wang, Yuyuan Zhang, Yong Chen, and Jing Gu
- Subjects
Reaction mechanism ,Hydrogen ,020209 energy ,General Chemical Engineering ,Organic Chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,Decomposition ,Product distribution ,Thermogravimetry ,Fuel Technology ,020401 chemical engineering ,chemistry ,Yield (chemistry) ,0202 electrical engineering, electronic engineering, information engineering ,Dehydrogenation ,0204 chemical engineering ,Fourier transform infrared spectroscopy ,Nuclear chemistry - Abstract
The thermal weight-loss characteristics and product distribution of the co-pyrolysis between xylan from corn cob (XC) and high-density polyethylene (HP) were investigated by thermogravimetry coupled with fourier transform infrared spectroscopy and mass spectrometry (TG-FTIR-MS) and pyrolysis gas chromatography/mass spectroscopy (Py-GC/MS). Moreover, the synergistic effects in the co-pyrolysis process were explored. The co-pyrolysis of XC and HP occurs in two stages. The first stage (220–350 °C) was the decomposition of XC, and the second stage (440–525 °C) was mainly attributed to the decomposition of HP. Co-pyrolysis caused the blends to decompose more easily. The synergistic effect was confirmed during the co-pyrolysis process. The co-pyrolysis process promoted the release of hydrocarbons (CH4, C2H2, C2H6, C3H6, and C3H8) and aldehyde derivatives (CH3CHO and CHO+) and decreased the production of H2 and H2O. Moreover, co-pyrolysis suppressed the generation of CO2 only when the content of HP was 75%. The Py-GC/MS results showed that the yield of oxygen-containing compounds decreased, and the yield of alkenes and alkanes increased. The increase in alkenes was greatest when the ratio of XC to HP was 1:3. This phenomenon could be attributed to the release of hydrogen radicals from mono-molecular and bi-molecular dehydrogenation reactions during the decomposition of HP. Thus, HP could be a hydrogen donor, providing hydrogen for xylan-derived oxygenates, which served as acceptors. A reaction mechanism for the co-pyrolysis of XC and HP was also proposed.
- Published
- 2020
191. An aerogel adsorbent with bio-inspired interfacial adhesion between graphene and MoS2 sheets for water treatment
- Author
-
Ting Fan, Wuqing Zhu, Weibin Zhang, Wanwen Kang, Yinlei Lin, Dongchu Chen, Haiyan Quan, Li Zhiqiang, Yuyuan Zhang, Wang Kun, Menglei Chang, Hu Huawen, Min Zhang, and Wei Hongyang
- Subjects
Materials science ,Graphene ,Composite number ,General Physics and Astronomy ,Langmuir adsorption model ,Aerogel ,Environmental pollution ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Adhesion ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,law.invention ,symbols.namesake ,Adsorption ,Chemical engineering ,law ,Specific surface area ,symbols ,0210 nano-technology - Abstract
The increasing environmental pollution calls for the development of stable functional materials for efficiently binding contaminants, while they can be synthesized and recycled easily. Herein, a three-dimensional (3D) aerogel is constructed by bio-inspired adhesion of graphene and MoS2 sheets with polydopamine (PDA) through a one-step hydrothermal route for the adsorption of the water-soluble organic contaminants. The impact of the bio-inspired interfacial adhesion on the resulting composite aerogel is thoroughly investigated, e.g., the interfacial PDA layer renders the composite aerogel considerably more porous, together with the much higher specific surface area and pore volume, as well as strikingly smaller average pore size and superior stability upon exposure to air, relative to the counterpart without the bio-inspired adhesion. The 3.2 wt% PDA composition is adequate to yield a composite structure with small MoS2 nanocrystallites uniformly dispersed over the modified graphene surface without aggregation. The adsorption of methylene green onto such a 3D composite architecture is spontaneous and endothermic and obeys the Langmuir isotherm model and pseudo-second-order kinetics, with the maximum adsorption capacities over 200 mg/g at all the operating temperatures and the satisfactory recycling properties without significant degradation after 5 cycles.
- Published
- 2020
192. High-efficiency removal of Cr(VI) by modified biochar derived from glue residue
- Author
-
Hong Jiang, Yuyuan Zhang, Lili Lu, Rui Shan, Haoran Yuan, Yong Chen, and Yueyue Shi
- Subjects
Renewable Energy, Sustainability and the Environment ,Chemistry ,020209 energy ,Strategy and Management ,05 social sciences ,Chemical modification ,Sorption ,02 engineering and technology ,Building and Construction ,Industrial and Manufacturing Engineering ,Residue (chemistry) ,Adsorption ,X-ray photoelectron spectroscopy ,Biochar ,050501 criminology ,0202 electrical engineering, electronic engineering, information engineering ,GLUE ,Pyrolysis ,0505 law ,General Environmental Science ,Nuclear chemistry - Abstract
A series of cost-effective, high-efficiency and sustainable adsorbent for Cr(VI) were prepared from waste glue residue. Considering that chemical modification has great influence on the properties of biochar, several modifiers (HCl, KOH, and ZnCl2) were used to improve the adsorption capacity of biochar. Besides that, the effect of prepare conditions (i.e., pyrolysis temperature and impregnation ratio of modifier and glue residue) were also investigated. Emission scanning electron microscopy, transmission electron microscopy, X-ray diffractometer, X-ray photoelectron spectroscopy and Autosorb1-MP Quantachrome were used to characterize the physicochemical properties of waste glue residue biochar. Reaction time, solution pH, adsorbent dosage, and initial adsorbate concentration on contaminant removal were also examined. The maximum sorption capacity of ZnCl2 modified glue residue biochar reached 325.54 mg/g, which is higher than previous reported adsorbents. The recycling experiment demonstrated that the removal efficiency of the optimal biochar was 90% after six cycles. Hence, waste glue residue exhibits a great potential in Cr(VI) contaminated water’s management.
- Published
- 2020
193. Pyrolysis char derived from waste peat for catalytic reforming of tar model compound
- Author
-
Rui Shan, Yuyuan Zhang, Haoran Yuan, Tao Lu, Shuxiao Wang, and Yong Chen
- Subjects
Chemistry ,020209 energy ,Mechanical Engineering ,Tar ,02 engineering and technology ,Building and Construction ,Management, Monitoring, Policy and Law ,Fluid catalytic cracking ,Catalysis ,General Energy ,Adsorption ,020401 chemical engineering ,Catalytic reforming ,Chemical engineering ,0202 electrical engineering, electronic engineering, information engineering ,Char ,0204 chemical engineering ,Pyrolysis ,Syngas - Abstract
The pyrolysis char derived from solid waste peat was used in the removal of biomass tar. A laboratory dual-stage reactor was designed to obtain a cost-effective and eco-friendly tar removal approach using peat pyrolysis char-based catalyst. Rich pore structure of pyrolysis char can enhance the adsorption and removal performance of tar, the KOH and CO2 activation method were used to increase the pore structure of pyrolysis char. Toluene was chosen as the model compound of biomass tar for basic research. The effects of pyrolysis char and transition metal Fe on toluene removal were studied. The investigated reforming parameters were reaction temperature (700–900 °C), residence time (0.3–0.8 s) and steam-to-carbon ratio (1.5:1–4:1). The results indicated that the peat pyrolysis char-based Fe catalysts showed excellent catalytic performance (toluene conversion >89%) and gas selectivity, especially the catalyst that activated by CO2 had the best selectivity for syngas (88.1 mol%), and the waste peat catalyst was compared with other waste pyrolysis char-based catalysts. Textural characterization showed that the excellent catalytic activity and stability of the catalysts are due to the presence of FeC and FeSiO3 structures. Such the peat pyrolysis char can as a carrier be used to remove tar and produce high content syngas in pyrolysis process.
- Published
- 2020
194. Monotonicity analysis of absolute phase unwrapping by geometric constraint in a structured light system
- Author
-
Jiang Yang, Shenzhen Lv, Jian Wang, Qiang Sun, and Yuyuan Zhang
- Subjects
Pixel ,business.industry ,Absolute phase ,Mathematical analysis ,Monotonic function ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010309 optics ,Constraint (information theory) ,Optics ,Discriminant ,0103 physical sciences ,Point (geometry) ,0210 nano-technology ,business ,Sign (mathematics) ,Mathematics ,Structured light - Abstract
The monotonicity of depth in a geometric constraint based absolute phase unwrapping is analyzed and a monotonic discriminant of Δ(uc,vc) is presented in this paper. The sign of the discriminant determines the distance selection for the virtual plane to create the artificial absolute phase map for a given structured light system. As Δ(uc,vc) ≥ 0 at an arbitrary point on the CCD pixel coordinates the minimum depth distance is selected for the virtual plane, and the maximum depth distance is selected as Δ(uc,vc) ≤ 0. Two structured light systems with different signs of the monotonic discriminant are developed and the validity of the theoretical analysis is experimentally demonstrated.
- Published
- 2020
195. Occupational health and occupational hazard control in coal mines: a comparative study
- Author
-
Yuyuan Zhang, Liyuan Cui, and Xuexiang Deng
- Subjects
business.industry ,Environmental health ,Control (management) ,Coal mining ,business ,complex mixtures ,Occupational safety and health ,respiratory tract diseases - Abstract
The occupational health efforts within Y Group are examined after analysis on current occupational health and occupational hazard control among coal mines in and outside China, covering a systematic investigation of dust hazard prevention in B Mine and an analytical research of heat hazard in Z Mine. The paper includes an innovative set of studies on the distributions of coal mine workers subject to different occupational hazards and the types of work among pneumoconiosis victims, the distribution of main heat sources underground and measures against heat hazards, as well as the number of dust-exposed workers per ten thousand tons of raw coal. Our findings will provide useful clues for successful occupational health and occupational hazard control in the coal sector.
- Published
- 2020
196. Projector distortion correction in 3D shape measurement using a structured-light system by deep neural networks
- Author
-
Shenzhen Lv, Liu Jianzhuo, Jian Wang, Jianbai Yang, Yang Jiang, Yuyuan Zhang, and Qiang Sun
- Subjects
Accuracy and precision ,Artificial neural network ,Computer science ,business.industry ,Flatness (systems theory) ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,law.invention ,010309 optics ,Optics ,Projector ,law ,0103 physical sciences ,Computer vision ,Artificial intelligence ,0210 nano-technology ,business ,Phase retrieval ,Test data ,Camera resectioning ,Structured light - Abstract
In a structured-light system, lens distortion of the camera and projector is the main source of 3D measurement error. In this Letter, a new approach, to the best of our knowledge, of using deep neural networks to address this problem is proposed. The neural network consists of one input layer, five densely connected hidden layers, and one output layer. A ceramic plate with flatness less than 0.005 mm is used to acquire the training, validation, and test data sets for the network. It is shown that the measurement accuracy can be enhanced to 0.0165 mm in the RMS value by this technique, which is an improvement of 93.52%. It is also verified that the constructed neural network is with satisfactory repeatability.
- Published
- 2019
197. [Effect of cadmium choride on oxidative damage and expression of NF-κB in brain tissue of mice]
- Author
-
Yuyuan, Zhang, Xue, Chen, Yun, Wang, and Chunhua, Wang
- Subjects
Mice ,Mice, Inbred ICR ,Oxidative Stress ,Cadmium Chloride ,Tumor Necrosis Factor-alpha ,NF-kappa B ,Animals ,Brain ,Cadmium ,Signal Transduction - Abstract
To investigate the oxidative damage induced by cadmium choride and the expression of nuclear factor κB( NF-κB), tumor necrosis factor-α( TNF-α) and intercellular cell adhesion molecule-1( ICAM-1) in brain tissue of mice.A total of 32 adult ICR mice were divided into 4 groups randomly including CdCl_2 2. 0, 1. 0 and 0. 5 mg/kg and NS control group, all mice were through intraperitoneally injected administration for 14 days, after the last exposure, open-field test were used and all mice were sacrificed by cervical dislocation, the expression of reactive oxygen species( ROS)was measured and the expression of TNF-α, ICAM-1 were observed by ELISA, the level of NF-κB P65 in the brain were detected by immunohistochemistry and western blot, the slices of the brain were stained with HE for histopathological examination.Thebody weight gain in CdCl_22. 0 mg/kg was significant lower than others( P0. 05), the number of crossing lattice in CdCl_2 2. 0 mg/kg was higher than the NS control group in the open field test. The expression of ROS increased in CdCl_2 2. 0 and 1. 0 mg/kg groups( P0. 05), the expression of TNF-α increased in CdCl_2 2. 0 mg/kg group( P0. 05), no obvious change was found among every group of ICAM-1, the expression of NF-κB P65 in the brain increased in cadmium 2. 0 mg/kg group. The neuropathological test showed that the cerebral cortex and hippocampal cells were more loose in 2. 0 mg/kg group than the control.The level of ROS in mouse brain tissue increased, NF-κB pathway was activated by ROS and the expression of inflammatory cytokine TNF-α was increased.
- Published
- 2018
198. iTRAQ-based analysis of the Arabidopsis proteome reveals insights into the potential mechanisms of anthocyanin accumulation regulation in response to phosphate deficiency
- Author
-
Lixiang Dong, Yuyuan Zhang, Zhan Qi Wang, Yueyue Chen, Jiena Guo, Xiulian Zhou, Lifang Wu, and Maojun Xu
- Subjects
0106 biological sciences ,0301 basic medicine ,Proteomics ,Proteome ,Mutant ,Quantitative proteomics ,Biophysics ,Arabidopsis ,Quantitative Structure-Activity Relationship ,01 natural sciences ,Biochemistry ,Phosphates ,Anthocyanins ,03 medical and health sciences ,chemistry.chemical_compound ,Gene Expression Regulation, Plant ,Arabidopsis thaliana ,Gene ,biology ,Arabidopsis Proteins ,fungi ,food and beverages ,biology.organism_classification ,Plants, Genetically Modified ,Alcohol Oxidoreductases ,030104 developmental biology ,Flavonoid biosynthesis ,chemistry ,Seedlings ,Anthocyanin ,010606 plant biology & botany ,Signal Transduction - Abstract
Phosphate (Pi) deficiency significantly limits plant growth in natural and agricultural systems. Accumulation of anthocyanins in shoots is a common response of Arabidopsis thaliana to Pi deficiency. To elucidate the mechanisms underlying Pi deficiency-induced anthocyanin accumulation, we employed a proteomic approach based on isobaric tags for relative and absolute quantification (iTRAQ) to investigate protein expression profiles of Arabidopsis thaliana seedlings subjected to Pi deficiency for 7 days. In total, 5,106 proteins were identified, of which 156 displayed significant changes in abundance upon Pi deficiency. Bioinformatics analysis indicated that flavonoid biosynthesis was the most significantly elevated metabolic process under Pi deficiency. We further examined the potential role of the flavonoid biosynthetic pathway using a dihydroflavonol 4-reductase (DFR) mutant (tt3) and quantitative RT-PCR (qRT-PCR) analysis, and found that the tt3 mutant was deprived of transcriptional up-regulation of three genes related to anthocyanin biosynthesis, modification and transport under Pi deficiency. These results showed that Pi deficiency probably enhances the anthocyanin accumulation by promoting the flavonoid biosynthesis. The exact functions of these proteins remain to be examined. Nevertheless, our study increases the understanding of the mechanisms implicated in the anthocyanin accumulation induced by Pi deficiency and adaptive responses of plants to Pi starvation.
- Published
- 2018
199. Excited-State Dynamics of a DNA Duplex in a Deep Eutectic Solvent Probed by Femtosecond Time-Resolved IR Spectroscopy
- Author
-
Kimberly de La Harpe, Yuyuan Zhang, Forrest R. Kohl, and Bern Kohler
- Subjects
Models, Molecular ,Aqueous solution ,Time Factors ,Spectrophotometry, Infrared ,Analytical chemistry ,Infrared spectroscopy ,02 engineering and technology ,DNA ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Excimer ,01 natural sciences ,0104 chemical sciences ,Deep eutectic solvent ,Solvent ,chemistry.chemical_compound ,chemistry ,Excited state ,Ionic liquid ,Solvents ,Nucleic Acid Conformation ,Quantum Theory ,Physical and Theoretical Chemistry ,0210 nano-technology ,Choline chloride - Abstract
To better understand how the solvent influences excited-state deactivation in DNA strands, femtosecond time-resolved IR (fs-TRIR) pump–probe measurements were performed on a d(AT)9·d(AT)9 duplex dissolved in a deep eutectic solvent (DES) made from choline chloride and ethylene glycol in a 1:2 mol ratio. This solvent, known as ethaline, is a member of a class of ionic liquids capable of solubilizing DNA with minimal disruption to its secondary structure. UV melting analysis reveals that the duplex studied here melts at 18 °C in ethaline compared to 50 °C in aqueous solution. Ethaline has an excellent transparency window that facilitates TRIR measurements in the double-bond stretching region. Transient spectra recorded in deuterated ethaline at room temperature indicate that photoinduced intrastrand charge transfer occurs from A to T, yielding the same exciplex state previously detected in aqueous solution. This state decays via charge recombination with a lifetime of 380 ± 10 ps compared to the 300 ± 10 ps...
- Published
- 2018
200. Surgical perspective on hybrid ablation for non-paroxysmal atrial fibrillation
- Author
-
Yuyuan Zhang and Hui-Ming Guo
- Subjects
Pulmonary and Respiratory Medicine ,education.field_of_study ,medicine.medical_specialty ,Arterial embolism ,business.industry ,medicine.medical_treatment ,Population ,Cardiac arrhythmia ,Atrial fibrillation ,Reentry ,medicine.disease ,Ablation ,medicine.anatomical_structure ,Editorial ,Internal medicine ,medicine ,Cardiology ,Erratum ,Atrium (heart) ,education ,business ,Stroke - Abstract
Atrial fibrillation (AF), the most common cardiac arrhythmia in the world, has an increasing incidence in general population (1). According to duration of episode, AF is divided into paroxysmal AF, persistent AF and long-standing persistent AF. To avoid stroke, arterial embolism and other critical complications, convert to normal sinus rhythm as soon as possible is the best strategy for AF management. Cox-Maze III procedure, also called as “cut and sew” Maze, is still the gold standard procedure of treating AF (2). Briefly, a series of scars were made by Cox-Maze III to interrupt or isolate reentry circuits by “cut and sew” of the atrium. Though the results of 5-year follow-up were very attractive (96.6–99% of patients free of AF), Cox-Maze III was replaced gradually by more simplified Cox-Maze IV due to development of new devices of ablation energy and procedure (2).
- Published
- 2017
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.