44 results on '"Pan, Han"'
Search Results
2. Synthesis of Dibenzosiloles through Electrocatalytic Sila‐Friedel‐Crafts Reaction
- Author
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Jundan Yi, Mengyun Yin, Haiqiong Li, Pan Han, Linhai Jing, and Bang-Guo Wei
- Subjects
Chemistry ,Organic chemistry ,General Chemistry ,Friedel–Crafts reaction - Published
- 2021
3. A Facile and Efficient Synthesis of Diaryl Amines or Ethers under Microwave Irradiation at Presence of KF/Al2O3 without Solvent and Their Anti-Fungal Biological Activities against Six Phytopathogens
- Author
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Tao Zhang, Zhen-Ting Du, Ying-Meng Xu, You-Qiang Li, Liang-Zhu Huang, and Pan Han
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microwave-assisted organic synthesis ,diaryl amine ,diaryl ether ,KF/Al2O3 ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
A series of diaryl amines, ethers and thioethers were synthesized under microwave irradiation efficiently at presence of KF/Al2O3 in 83%–96% yields without any solvent. The salient characters of this method lie in short reaction time, high yields, general applicability to substrates and simple workup procedure. At the same time, their antifungal biological activities against six phytopathogen were evaluated. Most of the compounds (3b, 3c, 3g–o) are more potent than thiophannate-methyl against to Magnaporthe oryzae. This implies that diaryl amine or ether moiety may be helpful in finding a fungicide against Magnaporthe oryzae.
- Published
- 2013
- Full Text
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4. Posttreatment of Maresin1 Inhibits NLRP3 inflammasome activation via promotion of NLRP3 ubiquitination
- Author
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Yu Hao, Minqi Ma, Sisi Zheng, Hui Li, Shengwei Jin, Zhongwang Li, and Pan-Han Fu
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Lipopolysaccharides ,Male ,0301 basic medicine ,Proteasome Endopeptidase Complex ,Docosahexaenoic Acids ,Lipopolysaccharide ,Inflammasomes ,Biochemistry ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Ubiquitin ,In vivo ,Sepsis ,NLR Family, Pyrin Domain-Containing 3 Protein ,Genetics ,medicine ,Animals ,Secretion ,Molecular Biology ,Mice, Knockout ,integumentary system ,biology ,Chemistry ,Kinase ,Ubiquitination ,Inflammasome ,Lipid signaling ,Cell biology ,Enzyme Activation ,030104 developmental biology ,biology.protein ,Signal transduction ,030217 neurology & neurosurgery ,Biotechnology ,medicine.drug - Abstract
Maresin1 is a potent lipid mediator exhibiting potential anti-inflammatory activity in a variety of inflammatory diseases, however, the underlying mechanisms remain poorly understood. Excessive activation of NLRP3 inflammasome has been established in multiple inflammatory diseases. Here, we show that Maresin1 dose-dependently inhibited the NLRP3 inflammasome activation and subsequent caspase-1 activation and IL-1β secretion. This inhibitory effect could be reversed by KH7 and H89, the inhibitors of the cAMP-PKA signaling pathway. Activation of PKA kinase induced by Maresin1 led to the K63-linked ubiquitination of NLRP3 in macrophages. Maresin1 attenuated serum IL-1β secretion through inhibition of NLRP3 inflammasome in vivo using Nlrp3-deficient mouse models of lipopolysaccharide (LPS)-induced sepsis. Maresin1 also repressed MSU-induced peritonitis. This study suggests that Maresin1 is an inhibitor of NLRP3 inflammasome activation and can be used clinically in the treatment of NLRP3 inflammasome-driven inflammatory diseases.
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- 2020
5. One new spirocyclic lactone and one new benzopyran derivative from Aspergillus terreus
- Author
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Pan Han, Chunmei Chen, Zhaodi Wu, Yongji Lai, Dongyan Li, Hucheng Zhu, Jieru Guo, Qingyi Tong, and Yonghui Zhang
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Pharmacology ,chemistry.chemical_classification ,Natural product ,biology ,010405 organic chemistry ,Stereochemistry ,Organic Chemistry ,Pharmaceutical Science ,General Medicine ,Ring (chemistry) ,biology.organism_classification ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Benzopyran ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,Complementary and alternative medicine ,chemistry ,Drug Discovery ,Molecular Medicine ,Aspergillus terreus ,Derivative (chemistry) ,Human cancer ,Lactone - Abstract
One new spirocyclic lactone, terreinlactone C (1), and one new benzopyran derivative, 2,2-dimethyl-3-hydroxychroman-6-aldehyde (2), were discovered from the fungus Aspergillus terreus. The chemical structures of compounds 1 and 2 were elucidated by detailedly analyzing NMR and HRESIMS data. Compound 1 is the first natural product with a 1-oxaspiro[4.5]decan-2-one ring system and a possible biogenetic pathway is proposed. Two compounds were tested for their cytotoxic activities against five human cancer cell lines.[Formula: see text].
- Published
- 2020
6. Synthesis of Amide Enol Carbamates and Carbonates through Cu(OTf)2-Catalyzed Reactions of Ynamides with t-Butyl Carbamates/Carbonates
- Author
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Pan Han, Zhuo-Ya Mao, Chang-Mei Si, Bang-Guo Wei, Guo-Qiang Lin, and Ming Li
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chemistry.chemical_compound ,chemistry ,010405 organic chemistry ,Amide ,Organic Chemistry ,Regioselectivity ,010402 general chemistry ,01 natural sciences ,Enol ,Medicinal chemistry ,0104 chemical sciences ,Catalysis - Abstract
A highly regioselective approach to access amide enol carbamates and carbonates 5a-5c', 7a-7h, and 9 was developed through Cu(OTf)2-catalyzed reactions of ynamides 4 with t-butyl carbamates 2 and 8 and t-butyl carbonates 6. Moreover, this strategy was successfully applied to generate amide enol carbamates 11a-11s and 14a-14f from imides 10 and 13 with ynamides through an N-Boc cleavage-addition ring-opening process. A range of substituents was amenable to this transformation, and the desired amide enol carbamates and carbonates were obtained in moderate to good yields.
- Published
- 2020
7. Protectin conjugates in tissue regeneration 1 restores lipopolysaccharide-induced pulmonary endothelial glycocalyx loss via ALX/SIRT1/NF-kappa B axis
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Xin-Yu Li, Hong-xia Mei, Shengwei Jin, Yu Hao, Hui Li, Xin-Yang Wang, Cheng-Hua Wu, Fang Chen, Yu-Qiang Gong, and Pan-Han Fu
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0301 basic medicine ,Lipopolysaccharides ,Male ,PCTR1 ,Lipopolysaccharide ,Docosahexaenoic Acids ,Anti-Inflammatory Agents ,Inflammation ,Respiratory Mucosa ,Lung injury ,Pharmacology ,Glycocalyx ,Umbilical vein ,Proinflammatory cytokine ,03 medical and health sciences ,chemistry.chemical_compound ,Diseases of the respiratory system ,Mice ,0302 clinical medicine ,SIRT1 ,Sirtuin 1 ,In vivo ,medicine ,Human Umbilical Vein Endothelial Cells ,Animals ,Humans ,EXT-1 ,Adaptor Proteins, Signal Transducing ,RC705-779 ,Research ,NF-kappa B ,030104 developmental biology ,chemistry ,HPA ,030220 oncology & carcinogenesis ,Tumor necrosis factor alpha ,medicine.symptom - Abstract
Background Endothelial glycocalyx loss is integral to increased pulmonary vascular permeability in sepsis-related acute lung injury. Protectin conjugates in tissue regeneration 1 (PCTR1) is a novel macrophage-derived lipid mediator exhibiting potential anti-inflammatory and pro-resolving benefits. Methods PCTR1 was administrated intraperitoneally with 100 ng/mouse after lipopolysaccharide (LPS) challenged. Survival rate and lung function were used to evaluate the protective effects of PCTR1. Lung inflammation response was observed by morphology and inflammatory cytokines level. Endothelial glycocalyx and its related key enzymes were measured by immunofluorescence, ELISA, and Western blot. Afterward, related-pathways inhibitors were used to identify the mechanism of endothelial glycocalyx response to PCTR1 in mice and human umbilical vein endothelial cells (HUVECs) after LPS administration. Results In vivo, we show that PCTR1 protects mice against lipopolysaccharide (LPS)-induced sepsis, as shown by enhanced the survival and pulmonary function, decreased the inflammatory response in lungs and peripheral levels of inflammatory cytokines such as tumor necrosis factor-α, interleukin-6, and interleukin-1β. Moreover, PCTR1 restored lung vascular glycocalyx and reduced serum heparin sulphate (HS), syndecan-1 (SDC-1), and hyaluronic acid (HA) levels. Furthermore, we found that PCTR1 downregulated heparanase (HPA) expression to inhibit glycocalyx degradation and upregulated exostosin-1 (EXT-1) protein expression to promote glycocalyx reconstitution. Besides, we observed that BAY11-7082 blocked glycocalyx loss induced by LPS in vivo and in vitro, and BOC-2 (ALX antagonist) or EX527 (SIRT1 inhibitor) abolished the restoration of HS in response to PCTR1. Conclusion PCTR1 protects endothelial glycocalyx via ALX receptor by regulating SIRT1/NF-κB pathway, suggesting PCTR1 may be a significant therapeutic target for sepsis-related acute lung injury.
- Published
- 2021
8. Alveolar size effects on nanoparticle deposition in rhythmically expanding-contracting terminal alveolar models
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Mohamed Talaat, Xiuhua April Si, Jinxiang Xi, Pan Han, Shaokuan Zheng, and Haibo Dong
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0301 basic medicine ,Aerosols ,Chemistry ,Respiration ,Health Informatics ,Models, Biological ,Computer Science Applications ,Pulmonary Alveoli ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Lagrangian model ,Breathing ,Biophysics ,Humans ,Nanoparticles ,Allometry ,Nanoparticle deposition ,Diffusion (business) ,Particle Size ,Deposition (chemistry) ,Lung ,030217 neurology & neurosurgery ,Particle deposition - Abstract
Significant differences in alveolar size exist in humans of different ages, gender, health, and among different species. The effects of alveolar sizes, as well as the accompanying breathing frequencies, on regional and local dosimetry of inhaled nanoparticles have not been sufficiently studied. Despite a well-accepted qualitative understanding of the advection-diffusion-sedimentation mechanism in the acinar region, a quantitative picture of the interactions among these factors remains inchoate. The objective of this study is to quantify the effects of alveolar size on the regional and local deposition of inhaled nanoparticles in alveolar models of varying complexities and to understand the dynamic interactions among different deposition mechanisms. Three different models were considered that retained 1, 4, and 45 alveoli, respectively. For each model, the baseline geometry was scaled by ¼, ½, 2, 4, and 8 times by volume. Temporal evolution and spatial distribution of particle deposition were tracked using a discrete-phase Lagrangian model. Lower retentions of inhaled nanoparticles were observed in the larger alveoli under the same respiration frequency, while similar retentions were found among different geometrical scales if breathing frequencies allometrically matched the alveolar size. Dimensional analysis reveals a manifold deposition mechanism with tantamount contributions from advection, diffusion, and gravitational sedimentation, each of which can become dominant depending on the location in the alveoli. Results of this study indicate that empirical correlations obtained from one sub-population cannot be directly applied to others, nor can they be simply scaled as a function of the alveolar size or respiration frequency due to the regime-transiting deposition mechanism that is both localized and dynamic.
- Published
- 2020
9. 3-Carboxamide oxindoles as 1,3-C,N-bisnucleophiles for the highly diastereoselective synthesis of CF3-containing spiro-δ-lactam oxindoles featuring acyl at the ortho-position of spiro carbon atom
- Author
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Linhai Jing, Hongcai Zhao, Wenhua Lu, Pan Han, Zhengbing Zhang, and Wei Wang
- Subjects
Ortho position ,Trifluoromethyl ,Carbon atom ,medicine.drug_class ,Stereochemistry ,Organic Chemistry ,Carboxamide ,Biochemistry ,chemistry.chemical_compound ,chemistry ,Cascade reaction ,Drug Discovery ,medicine ,Lactam - Abstract
A simple and efficient strategy has been established for the synthesis of δ-lactam fused oxindoles via the Michael/N-hemiketalization cascade reaction of 3-carboxamide oxindoles and α,β-unsaturated trifluoromethyl ketones. A wide range of structurally novel CF3-containing spiro-δ-lactam oxindoles featuring acyl at the ortho-position of spiro carbon atoms were obtained in moderate to good yields with excellent diastereoselectivities under mild conditions. This work represents the first example of a systematic study of 3-carboxamide oxindoles as 1,3-C,N bisnucleophiles.
- Published
- 2021
10. Asymmetric synthesis of epohelmins A, B and 3-epi ent-epohelmin A
- Author
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Pan Han, Chang-Mei Si, Zhuo-Ya Mao, Yi-Wen Liu, Zhen-Ting Du, and Bang-Guo Wei
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chemistry.chemical_classification ,Natural product ,010405 organic chemistry ,Stereochemistry ,Organic Chemistry ,Imine ,Enantioselective synthesis ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Aldehyde ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Intramolecular force ,Drug Discovery ,Pyrrolizidine ,Malic acid ,Divergent synthesis - Abstract
An efficient method for asymmetric synthesis of epohelmins A (3), B (4) and their isomer 24 is detailed in this report. The key feature in this divergent synthesis includes the SmI2-induced cross-coupling of N-tert-butanesulfinyl imine 10 with chiral aldehyde 9 derived from d -malic acid. A cascade cyclization to the pyrrolizidine skeleton is achieved in our synthetic route for epohelmins. In addition, an interesting intramolecular oxa-Michael addition was observed for epohelmin A (3).
- Published
- 2016
11. Studies toward asymmetric synthesis of hoiamides A and B
- Author
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Juan Xiong, Jin-Feng Hu, Pan Han, Chang-Mei Si, Zhuo-Ya Mao, Ming Li, Wen Zhou, and Bang-Guo Wei
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010405 organic chemistry ,Stereochemistry ,Chemistry ,Organic Chemistry ,Enantioselective synthesis ,Cyclic depsipeptide ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,Stereocenter ,Polyketide ,Drug Discovery - Abstract
A convenient method for diastereoselective synthesis of the key intermediate 5 from triheterocyclic fragment and polyketide 6 for hoiamides A (1) and B (2) was developed. The main feature is the successive construction of four stereogenic centers from C33 to C36 for hoiamides A (1) through the well-established Oppolzer’s anti-aldol and Paterson’s anti-aldol methodology. Furthermore, asymmetric allylation was also utilized as a key step to form the stereogenic center at C32 for hoiamides A (1).
- Published
- 2016
12. Stereoselective Synthesis of Pyrido- and Pyrrolo[1,2- c][1,3]oxazin-1-ones via a Nucleophilic Addition-Cyclization Process of N, O-Acetal with Ynamides
- Author
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Zhu Zhou, Chang-Mei Si, Bang-Guo Wei, Guo-Qiang Lin, Zhuo-Ya Mao, and Pan Han
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chemistry.chemical_compound ,Nucleophilic addition ,Nucleophile ,chemistry ,010405 organic chemistry ,Organic Chemistry ,Acetal ,Stereoselectivity ,Piperidine ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences - Abstract
An efficient asymmetric approach to access functionalized pyrido- and pyrrolo[1,2- c][1,3]oxazin-1-ones has been developed through a nucleophilic addition-cyclization process of N, O-acetal with ynamides. A number of substituted ynamides 8a-8o and 3-silyloxypyrrolidine or piperidine N, O-acetals 6a, 7 were amenable to this transformation, and the desired products 9a-9o, 10a-10m were obtained with excellent regioselectivities and outstanding diastereoselectivities. Moreover, chiral ynamides 14a-14f could also experience this addition-cyclization process to afford products 15a-15f in excellent yields.
- Published
- 2018
13. Synthesis of high performance mordenite membranes from fluoride-containing dilute solution under microwave-assisted heating
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Ye Zhao, Jiaxuan Wang, Jinqu Wang, Jinming Lu, Jiajia Li, Jianhua Yang, Liangqing Li, Dehong Yin, Pan Han, and Yan Zhang
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Aqueous solution ,Chemistry ,Inorganic chemistry ,Filtration and Separation ,02 engineering and technology ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,medicine.disease ,01 natural sciences ,Biochemistry ,Mordenite ,0104 chemical sciences ,chemistry.chemical_compound ,Acetic acid ,Membrane ,medicine ,General Materials Science ,Dehydration ,Pervaporation ,Physical and Theoretical Chemistry ,0210 nano-technology ,Fluoride - Abstract
High performance mordenite membranes were successfully prepared in a short synthesis time from fluoride-containing dilute solution without organic template under microwave-assisted heating. The effects of crystallization temperature, fluoride ion and aluminum source on the membrane morphology and separation performance for dehydration of acetic acid by pervaporation were systematically investigated. High performance mordenite membranes with a thickness about 5 µm could be prepared from dilute solution with composition of SiO 2 : 0.06Al 2 O 3 :0.24Na 2 O:0.3NaF:120H 2 O at 165 °C for 4 h using various aluminum sources. These mordenite membranes exhibited high fluxes of 0.87±0.06 kg m −2 h −1 and excellent selectivities, that is only pure water was detected in the permeate side for dehydration of 90 wt% acetic acid aqueous mixtures at 75 °C. The reproducibility of mordenite membranes was high, using the fluoride-containing dilute solution under microwave-assisted heating, which forebodes a promising prospect for industrial applications in preferential separation of water from acetic acid aqueous solutions.
- Published
- 2016
14. Three-dimensional beehive-like hierarchical porous polyacrylonitrile-based carbons as a high performance supercapacitor electrodes
- Author
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Junhe Yang, Long Yao, Pan Han, Guangzhi Yang, and Zhihong Tang
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Supercapacitor ,chemistry.chemical_classification ,Materials science ,Renewable Energy, Sustainability and the Environment ,Carbonization ,Polyacrylonitrile ,Energy Engineering and Power Technology ,Emulsion polymerization ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Specific surface area ,Lithium ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,0210 nano-technology ,Porosity - Abstract
Three-dimensional beehive-like hierarchical porous carbons (HPCs) have been prepared by a facile carbonization of polymethylmethacrylate (PMMA)/polyacrylonitrile (PAN) core-shell polymer particle followed by KOH activation. The all-organic porogenic core-shell precursor was synthesized by a simple and green surfactant-free emulsion polymerization. The as-obtained HPCs show favorable features for electrochemical energy storage such as high specific surface area of up to 2085 m 2 g −1 , high volume of pores up to 1.89 cm 3 g −1 , hierarchical porosity consisting of micro, meso, and macropores, turbostratic carbon structure, uniform pore size and rich oxygen-doping (21.20%). The supercapacitor performance of HPCs exhibit a high specific capacitance 314 F g −1 at a current density of 0.5 A g −1 and 237 F g −1 at a current density of 20 A g −1 , ultra-high rate capability with 83% retention rate from 1 to 20 A g −1 and outstanding cycling stability with 96% capacitance retention after 2000 cycles. The facile, efficient and green synthesis strategy for novel HPCs from polymer sources could find use in supercapacitors, lithium ion batteries, fuel cells and sorbents.
- Published
- 2016
15. A divergent approach for asymmetric syntheses of (+)-spicigerine, (+)-cassine and their 3-epimers
- Author
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Zhen-Ting Du, Chang-Mei Si, Pan Han, Bang-Guo Wei, Zhuo-Ya Mao, and Hai-Tong Li
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chemistry.chemical_classification ,Aldimine ,010405 organic chemistry ,Stereochemistry ,Organic Chemistry ,Enantioselective synthesis ,Total synthesis ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Nucleophile ,Bromide ,Yield (chemistry) ,Intramolecular force ,Drug Discovery ,Aminal - Abstract
An efficient approach for asymmetric synthesis of (+)-spicigerine, (+)-cassine and their 3-epimers has been developed through the intramolecular diastereoselective tandem addition/cyclisation process of α-chiral aldimine 9 with methylmagnesium bromide and the asymmetric addition of nucleophilic reagents to aminal 14. Moreover, the first asymmetric synthesis of (+)-spicigerine has been achieved in this manuscript. In this synthetic strategy, the asymmetric syntheses of (+)-spicigerine and (+)-cassine was achieved in a 14% overall yield and nine steps and an 18% overall yield and seven steps from cheap α-chiral aldimine 9, respectively.
- Published
- 2016
16. Asymmetric syntheses of epohelmins A and B by In-mediated allylation
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Zhuo-Ya Mao, Bang-Guo Wei, Wen Zhou, Yi-Wen Liu, Chang-Mei Si, and Pan Han
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chemistry.chemical_classification ,Aldimine ,Allyl bromide ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Organic Chemistry ,Sulfonium Compounds ,Stereoisomerism ,Bridged Bicyclo Compounds, Heterocyclic ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Pyrrolidinones ,0104 chemical sciences ,Stereocenter ,Allyl Compounds ,chemistry.chemical_compound ,Sulfinamide ,Moiety ,Physical and Theoretical Chemistry - Abstract
A diastereoselective new approach for the synthesis of trans-4-hydroxy-5-allyl-2-pyrrolidinone 9 has been developed through In-mediated allylation of α-chiral aldimine 8 with allyl bromide. The stereochemistry at the C-2 stereogenic center of 9 was controlled by both the α-OTBS substitution and the sulfinamide moiety. The utility of this asymmetric allylation is demonstrated by the asymmetric syntheses of epohelmins A (4) and B (10).
- Published
- 2016
17. Regio- and Stereoselective Cascades via Aldol Condensation and 1,3-Dipolar Cycloaddition for Construction of Functional Pyrrolizidine Derivatives
- Author
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Zhuo-Ya Mao, Guo-Qiang Lin, Yi-Wen Liu, Han-Qing Dong, Chang-Mei Si, Pan Han, and Bang-Guo Wei
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chemistry.chemical_classification ,Tandem ,010405 organic chemistry ,Organic Chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,Aldehyde ,Cycloaddition ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Pyrrolizidine ,1,3-Dipolar cycloaddition ,Acetone ,Stereoselectivity ,Aldol condensation ,Physical and Theoretical Chemistry - Abstract
An efficient and step-economical approach to access functionalized pyrrolizidine derivatives by a one-pot tandem sequence, including an aldol condensation and subsequent 1,3-dipolar cycloaddition process, has been developed, starting from acetone, aldehyde, and proline. A number of substituted aromatic aldehydes were amenable to this transformation, and the desired products, racemic 7a–7w and chiral 9a–9m, were obtained with excellent regioselectivities and outstanding diastereoselectivities. Moreover, in situ NMR studies revealed MgSO4 could effectively promote the aldol condensation pathway in this tandem process.
- Published
- 2018
18. Asymmetric Synthesis of Rupestonic Acid and Pechueloic Acid
- Author
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Chang-Mei Si, Xian-Yi Sha, Zheng-Yi Gu, Pan Han, Bang-Guo Wei, Zhu Zhou, and Guo-Qiang Lin
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chemistry.chemical_classification ,010405 organic chemistry ,Organic Chemistry ,Saponin ,Enantioselective synthesis ,Glycoside ,010402 general chemistry ,Metathesis ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,chemistry ,Physical and Theoretical Chemistry ,Rupestonic acid ,Lactone - Abstract
In this report, the originally proposed rupestonic acid (5) and pechueloic acid (3) were efficiently synthesized. The chiral lactone 13, recycled from the degradation of saponin glycosides, was utilized to prepare the key chiral fragment 11. During the exploration of this convergent assembly strategy, the ring-closing metathesis (RCM), SmI2-prompted intermolecular addition, and [2,3]-Wittig rearrangement proved to be effective transformations for the synthesis of subunits.
- Published
- 2017
19. Heterocyclic aromatic amines in meat products consumed in China
- Author
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Pan Han, Ni Na, Dequan Zhang, Zhenyu Wang, and Haitao Guo
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Chemistry ,food and beverages ,Food science ,Applied Microbiology and Biotechnology ,Heterocyclic Aromatic Amines ,Food Science ,Biotechnology - Abstract
Heterocyclic aromatic amines (HAAs) formed in cooked muscle foods are recognized as mutagenic and carcinogenic compounds. A total of 9 nine HAAs were analyzed in 34 meat products consumed in China. The total HAAs content in all meat products ranged from 4.14 to 108.80 ng/g. Dry and sauced meats contained higher concentration of total HAAs than other kinds of meat products. Samples from East and Northwest China showed higher concentrations of total HAAs than samples from other regions. The most common specific HAAs, harman and norharman, were detected in all meat samples at levels of 1.09–63.97 and 1.19–62.30 ng/g, respectively. Concentrations of MeIQx, PhIP, 4, 8-DiMeIQx, and AαC were much lower. MeAαC (n=8), IQ (n=15), and Trp-P-2 (n=23) were detected in some samples.
- Published
- 2014
20. Sialic acid and anti-ganglioside antibody levels in children with autism spectrum disorders
- Author
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Xiaolei Yang, Lin Wang, Xi-Tao Jiang, Yanqiu Hao, Lijie Wu, Shuang Liang, Jianli Wang, and Pan-Pan Han
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0301 basic medicine ,Male ,Future studies ,Brain development ,Autism Spectrum Disorder ,Severity of Illness Index ,Antibodies ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,mental disorders ,Medicine ,Humans ,Child ,Molecular Biology ,Gangliosidosis, GM1 ,biology ,business.industry ,General Neuroscience ,medicine.disease ,N-Acetylneuraminic Acid ,Sialic acid ,030104 developmental biology ,chemistry ,ROC Curve ,Ganglioside antibody ,Child, Preschool ,Immunology ,Etiology ,biology.protein ,Autism ,Neural cell adhesion molecule ,Female ,Neurology (clinical) ,Antibody ,business ,030217 neurology & neurosurgery ,Developmental Biology - Abstract
Autism spectrum disorders (ASD) may result from a combination of genetic and environmental factors, and impact neurological functions and behaviors. Sialic acid (SA) is an indispensable nutrient for early brain development, and its polymer polySia (PSA) can modify neural cell adhesion molecules (NCAM), thereby indirectly mediating neuronal outgrowth, synaptic connectivity and memory formation. To investigate the association between SA and ASD, we conducted a case-control study.The study sample included 82 autistic children and 60 healthy children. We measured the levels of plasma SA and serum anti-gangliosides M1 antibodies (anti-GM1 antibodies) in the ASD and control groups. We also examined the severity of autistic children.The level of plasma SA in the control group was significantly higher than that in the ASD group (p .01). Autistic children had higher positive rates of anti-GM1 antibodies (37.8%) than controls (21.67%, P = .04). However, there was no correlation between autistic severity and the levels of SA. SA may be as a biomarker for diagnosis of ASD with a positive predictive value of 84.42%, a negative predictive value of 73.85% and an area under the ROC curve value of 0.858.These results indicate that SA and anti-GM1 antibodies are associated with ASD. Our data suggested that future studies to explore the function of SA in the etiology of ASD may be needed.
- Published
- 2017
21. Effects of traditional chinese cooking methods on formation of heterocyclic aromatic amines in lamb patties
- Author
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Zhenyu Wang, Li Chen, Xin Li, Weili Rao, Dequan Zhang, Pan Han, Haitao Guo, and Gao Yuan
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Indole test ,chemistry.chemical_compound ,Seasoning ,Chemistry ,Cooking methods ,Pyridine ,Organic chemistry ,Food science ,Applied Microbiology and Biotechnology ,Heterocyclic Aromatic Amines ,Food Science ,Biotechnology ,Roasting - Abstract
Different amounts of the potent mutagenic and/or carcinogenic heterocyclic aromatic amines (HAAs) are formed in muscle-based foods under different cooking methods. HAAs (9 varieties) in lamb patties cooked using traditional Chinese cooking methods (roasting, frying, panfrying, and stewing in seasonings) were investigated. The total HAAs contents in roasted, fried, pan-fried, and stewed patties were 4.39-123.15 ng/g, 3.59-43.24 ng/g, 0.71-10.05 ng/g, and 51.07-120.32 ng/g, respectively. Amounts of HAAs increased as cooking time increased. 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) was the dominant HAAs in deep roasted and fried samples, while 1-methyl- 9H-pyrido [3,4-b] indole (Harman) and 9H-pyrido [3,4-b] indole (Norharman) were the main HAAs in pan-fried and stewed samples. Types and contents of HAAs formed at different cooking times using different methods are unique. Stewing in seasoning generated a higher HAAs content than the high-temperature cooking methods roasting, frying, and pan-frying.
- Published
- 2014
22. Gel properties and molecular forces of lamb myofibrillar protein during heat induction at different pH values
- Author
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Zhenyu Wang, Dequan Zhang, Qiang Wang, Xin Li, Linchen Wang, Pan Han, Fan He, and Ni Na
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Crystallography ,Chemistry ,Biophysics ,Bioengineering ,Myofibril ,Microstructure ,Applied Microbiology and Biotechnology ,Biochemistry - Abstract
The gel properties and molecular forces of the Aohan Merino lamb myofibrillar protein (MP) were investigated during heat induction at different pH levels. The effects of pH values (from 5.0 to 8.5) on the lamb MP gel textures and water-holding capacities were analyzed. The protein gels had the lowest water-holding capacity and a disordered microstructure at pH 5.5 (P
- Published
- 2014
23. Simultaneous determination of nine heterocyclic aromatic amines in mutton products by solid phase extraction-high performance liquid chromatography
- Author
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Li Chen, Zhenyu Wang, Dequan Zhang, Pan Han, and Haitao Guo
- Subjects
Indole test ,Chromatography ,General Chemical Engineering ,Organic Chemistry ,Extraction (chemistry) ,Quinoline ,Biochemistry ,High-performance liquid chromatography ,Analytical Chemistry ,chemistry.chemical_compound ,Quinoxaline ,chemistry ,Chromatography detector ,Electrochemistry ,Solid phase extraction ,Triethylamine - Abstract
A method was established for the simultaneous determination of nine heterocyclic aromatic amines (HAAs) in mutton products by solid phase extraction-high performance liquid chromatography (SPE-HPLC). As a result, the sample was prepared by ultrasound in 2 mol/L NaOH, and dichloromethane was selected as the extraction solvent. The extract was purified and concentrated with an MCX SPE column. The chromatographic separation was achieved on a reverse-phase C18 column by gradient elution using 0.01 mol/L phosphoric acid (adjusted to pH 3.6 by triethylamine) and acetonitrile, detected with a diode array detector (DAD) at 228 nm for 2-amino-9H-pyrido [ 2,3-b] indole (AaC) and 2-amino-3-methyl-9H-pyrido [ 2,3-b] indole (MeAaC); 253 nm for 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 1-methyl-9H-pyrido[3, 4-b] indole (Harman), 9H-pyrido[3,4-b] indole (Norharman); 263 nm for 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo [4,5-f] quinoxaline (4, 8-DiMeIQx), 3-amino-1-methyl-5H-pyrido [4,3-b] indole (Trp-p-2); 321 nm for 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP). The results showed that the nine HAAs can be separated efficiently. The recoveries (n = 6) of the nine HAAs spiked in meat were between 50.27% and 94.77% with the relative standard deviations of 0.08%-4.42%. The limits of detection of this method were 1.6 -41.0 microg/L for the nine HAAs. The method is simple, accurate, rapid and repeatable. It can be used for the simultaneous determination of the nine HAAs in mutton products.
- Published
- 2013
24. A Facile and Efficient Synthesis of Diaryl Amines or Ethers under Microwave Irradiation at Presence of KF/Al2O3 without Solvent and Their Anti-Fungal Biological Activities against Six Phytopathogens
- Author
-
Ying-Meng Xu, Zhen-Ting Du, Tao Zhang, Pan Han, You-Qiang Li, and Liang-Zhu Huang
- Subjects
Antifungal ,Antifungal Agents ,Magnaporthe ,medicine.drug_class ,Anti fungal ,Ether ,Article ,Catalysis ,lcsh:Chemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,medicine ,Moiety ,Organic chemistry ,Amines ,Physical and Theoretical Chemistry ,Microwaves ,lcsh:QH301-705.5 ,Molecular Biology ,Spectroscopy ,diaryl amine ,biology ,microwave-assisted organic synthesis ,diaryl ether ,KF/Al2O3 ,Chemistry ,Organic Chemistry ,General Medicine ,biology.organism_classification ,Computer Science Applications ,Solvent ,lcsh:Biology (General) ,lcsh:QD1-999 ,Microwave irradiation ,Solvents ,Amine gas treating ,Ethers - Abstract
A series of diaryl amines, ethers and thioethers were synthesized under microwave irradiation efficiently at presence of KF/Al2O3 in 83%–96% yields without any solvent. The salient characters of this method lie in short reaction time, high yields, general applicability to substrates and simple workup procedure. At the same time, their antifungal biological activities against six phytopathogen were evaluated. Most of the compounds (3b, 3c, 3g–o) are more potent than thiophannate-methyl against to Magnaporthe oryzae. This implies that diaryl amine or ether moiety may be helpful in finding a fungicide against Magnaporthe oryzae.
- Published
- 2013
25. Adsorption of congo red using ethylenediamine modified wheat straw
- Author
-
Zhanwu Wang, Yubin Jiao, Dan Ma, Runping Han, Chanchan Dou, and Pan Han
- Subjects
Langmuir ,Aqueous solution ,Ion exchange ,Chemistry ,Inorganic chemistry ,Langmuir adsorption model ,Ocean Engineering ,Straw ,Pollution ,Congo red ,chemistry.chemical_compound ,symbols.namesake ,Adsorption ,symbols ,Freundlich equation ,Water Science and Technology - Abstract
The natural wheat straw (NWS) was modified by ethylenediamine and the modified wheat straw (MWS) was used as adsorbent for removal of congo red (CR) from aqueous solution. Analysis of FTIR and nitrogen element showed that amino group was introduced to NWS. A batch system was applied to study the behavior of CR adsorption on MWS. Experiments were carried out as function of pH, adsorbent dosage, contact time and dye concentration. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Redlich–Peterson models and Koble-Corrigan. Redlich–Peterson and Koble-Corrigan models provided the best correlation. The adsorption capacities from Langmuir model were 68.6 mg g–1 at 293 K. Adsorption kinetic data were fitted using the pseudo-first-order kinetic model, pseudo-second-order kinetic model, Elovish model and intraparticle diffusion model. The results showed that the Elovish model was best to fit the kinetic process, which suggested that ion exchange was one of main mechanism. The effective diffusi...
- Published
- 2011
26. Reuse of Spent Natural Zeolite for Methylene Blue Adsorption by Microwave Irradiation
- Author
-
Yu Wang, Ya Li Liu, Run Ping Han, Pan Han, and Jie Yang
- Subjects
chemistry.chemical_compound ,Aqueous solution ,Adsorption ,Materials science ,chemistry ,Microwave heating ,Microwave power ,Microwave irradiation ,General Engineering ,Reuse ,Zeolite ,Methylene blue ,Nuclear chemistry - Abstract
Microwave heating was efficient and the regeneration time was shortened compared to conventional thermal heating. Experiments were conducted to demonstrate that spent zeolite can be regenerated for reuse by microwave irradiation. The spent zeolite tested was prepared from the aqueous solutions of methylene blue. The effects of microwave irradiation time, microwave power on the regeneration efficiency were presented. The results show that microwave irradiation time and microwave power played significant role on the regeneration efficiency. It was concluded that microwave irradiation may be effective method for dye-loaded zeolite reuse.
- Published
- 2011
27. Equilibrium, kinetic and mechanism study for the adsorption of neutral red onto rice husk
- Author
-
Runping Han, Weihua Zou, Xiaotian He, Yinli Li, Pan Han, and Xin Liu
- Subjects
Langmuir ,Aqueous solution ,Chemistry ,Diffusion ,Thermodynamics ,Langmuir adsorption model ,Ocean Engineering ,Pollution ,Husk ,symbols.namesake ,Adsorption ,symbols ,Freundlich equation ,Equilibrium constant ,Water Science and Technology - Abstract
Adsorption of neutral red (NR) onto rice husk from aqueous solutions was investigated. Experiments were carried out as a function of pH, adsorbent dosage, contact time and dye concentration. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Redlich–Peterson models using nonlinear regressive analysis. The results indicated that the Langmuir and Redlich–Peterson models provided the best correlation of the experimental data. The adsorption capacities of NR adsorption onto rice husk from Langmuir model were 25.16, 29.15, 32.37 mg/g at 288, 308, 318 K, respectively. Adsorption kinetic data were fitted using the pseudo-first-order kinetic model and pseudo-second-order kinetics. It was shown that the pseudo-first-order and second-order kinetic equations could describe the adsorption kinetics. The process mechanism was found to be complex, consisting of both surface adsorption and pore diffusion. The effective diffusion parameter Di values estimated in the order of 10-9 cm2/s indicated that t...
- Published
- 2009
28. Study of equilibrium, kinetic and thermodynamic parameters about methylene blue adsorption onto natural zeolite
- Author
-
Pan Han, Mingsheng Tang, Zhenhui Zhao, Yuanfeng Wang, Runping Han, and Jingjing Zhang
- Subjects
Langmuir ,Chromatography ,Chemistry ,General Chemical Engineering ,Thermodynamics ,General Chemistry ,Kinetic energy ,Endothermic process ,Industrial and Manufacturing Engineering ,Nonlinear system ,Adsorption ,Approximation error ,Environmental Chemistry ,Freundlich equation ,Zeolite - Abstract
Adsorption equilibrium and kinetic of methylene blue (MB) onto natural zeolite was studied in a batch system. Variables of the system include contact time, pH, salt concentration, temperature, and initial MB concentration. The increase in temperature resulted in a higher MB loading per unit weight of the zeolite. Langmuir, Freundlich, Redlich–Peterson, Koble–Corrigan and Temkin isotherm models were applied to experimental equilibrium data of MB adsorption depending on temperature. The effect of contact time at different temperatures and initial concentration were fitted to pseudo-second-order kinetic model. Linear regressive method and nonlinear regressive method were used to obtain the relative parameters. The error analysis was conducted to find whether linear method or nonlinear method was better to predict the experimental results and which model was better to fit the experimental data. Both methods were suitable to obtain the parameters. The Redlich–Peterson equation was best to fit the equilibrium data. The pseudo-second-order kinetic model can be used to describe the adsorption behavior. The nonlinear method may be better with the absolute error as limited condition. The adsorption process was spontaneous and endothermic.
- Published
- 2009
29. Kinetics and isotherms of Neutral Red adsorption on peanut husk
- Author
-
Pan Han, Mingsheng Tang, Zhaohui Cai, Zhenhui Zhao, and Runping Han
- Subjects
Neutral red ,Langmuir ,Time Factors ,Environmental Engineering ,Chromatography ,Aqueous solution ,Arachis ,Chemistry ,Diffusion ,Kinetics ,General Medicine ,Hydrogen-Ion Concentration ,Husk ,chemistry.chemical_compound ,Adsorption ,Chemical engineering ,Neutral Red ,Environmental Chemistry ,Freundlich equation ,Coloring Agents ,Water Pollutants, Chemical ,General Environmental Science - Abstract
Adsorption of Neutral Red (NR) onto peanut husk in aqueous solutions was investigated at 295 K. Experiments were carried out as function of pH, adsorbent dosage, contact time, and initial concentration. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, and Toth isotherm models. The results indicated that the Toth and Langmuir models provided the best correlation of the experimental data. The adsorption capacity of peanut husk for the removal of NR was determined with the Langmuir and found to be 37.5 mg/g at 295 K. The adsorption kinetic data were modeled using the pseudo-first order, pseudo-second order, and intra-particle diffusion kinetic equations. It was seen that the pseudo-first order and pseudo-second order kinetic equations could describe the adsorption kinetics. The intraparticle diffusion model was also used to express the adsorption process at the two-step stage. It was implied that peanut husk may be suitable as adsorbent material for adsorption of NR from aqueous solutions.
- Published
- 2008
30. [In vitro autotetraploid induction and analysis on DNA methylation diversity of Platycodon grandiflorum]
- Author
-
Zeng-Xu Xiang, Hong-juan Wang, and Pan-Pan Han
- Subjects
Platycodon ,Polymorphism, Genetic ,DNA, Plant ,Genetic Variation ,Platycodon grandiflorus ,Methylation ,Biology ,DNA Methylation ,biology.organism_classification ,Molecular biology ,In vitro ,Chromosomes, Plant ,Tetraploidy ,chemistry.chemical_compound ,genomic DNA ,Complementary and alternative medicine ,chemistry ,DNA methylation ,Colchicine ,Pharmacology (medical) ,Epigenetics ,General Pharmacology, Toxicology and Pharmaceutics ,Ploidy - Abstract
In order to investigate the epigenetic variations between diploid and autotetraploid of Platycodon grandiflorus. The diploid buds of P. grandiflorus were soaked in the mixture of different concentration colchicines and 0.002 g•mL ⁻¹ dimethyl sulphoxide (DMSO).The identification of autotetraploid plants were based on morphological characteristics, chromosome number and flow cytometry. And then the level and pattern of DNA methylation explored by using the technology of methylation sensitive amplified polymorphism (MSAP).The result demonstrated that the buds soaked in 0.2% colchicines and 0.002 g•mL ⁻¹ DMSO solution for 12 h was ideal conditions to induce autotetraploid of P. grandiflorus, with induction rate of 32.0%.The diploid and tetraploid plants existed distinctly differences in morphological indexes.Totally,1 586 bands were amplified by 20 pairs of selective primers, of which 764 and 822 bands were detected in diploid and autotetraploid respectively. The total methylation ratio,full methylation ratio and hemimethylated ratio were 91.25%,61.25% and 30.65% in diploid of P. grandiflorus,respectively.However,the total methylation ratio,full methylation ratio and hemimethylated ratio of autotetraploid of P. grandiflorus were 86.13%,54.38% and 31.75%, respectively. Compared with diploid, the genomic DNA total methylate ratio and full methylation ratio of autotetration plants decreased by 6.02% and 7.14%.But the hemimethylated ratio of autotetraploid was higher than that of diploid, which more than 1.6%. All this results indicated that DNA methylation patterns have adjusted during the polyploidy process..
- Published
- 2015
31. ChemInform Abstract: Synthesis of Heterocycles via Palladium-Catalyzed C-H Activation/Cyclization of Diazonium Salts. Part 3. Phenanthridin-6-(5H)-ones
- Author
-
Ke Chen, Congcong Zhang, Zhen-Ting Du, Pan Han, and Jing Zhou
- Subjects
Chemistry ,chemistry.chemical_element ,Organic chemistry ,General Medicine ,Catalysis ,Palladium - Published
- 2015
32. Batteries: Nano-Copper-Assisted Immobilization of Sulfur in High-Surface-Area Mesoporous Carbon Cathodes for Room Temperature Na-S Batteries (Adv. Energy Mater. 12/2014)
- Author
-
Zhuo Han, Hui-Juan Zhang, Shiyou Zheng, Peng Li, Junhe Yang, and Pan Han
- Subjects
Nano copper ,Materials science ,Renewable Energy, Sustainability and the Environment ,Inorganic chemistry ,chemistry.chemical_element ,Nanoparticle ,Sulfur ,Cathode ,law.invention ,chemistry ,Mesoporous carbon ,Chemical engineering ,law ,High surface area ,General Materials Science ,Nanoarchitectures for lithium-ion batteries - Published
- 2014
33. High Performance C/S Composite Cathodes with Conventional Carbonate-Based Electrolytes in Li-S Battery
- Author
-
Hui-Juan Zhang, Shiyou Zheng, Zhuo Han, Pan Han, Junhe Yang, and Zhihong Tang
- Subjects
Battery (electricity) ,Multidisciplinary ,Materials science ,Electrolyte ,Conductivity ,Electrochemistry ,Article ,Cathode ,law.invention ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,law ,Carbonate ,Polysulfide ,Faraday efficiency - Abstract
High stable C/S composites are fabricated by a novel high-temperature sulfur infusion into micro-mesoporous carbon method following with solvent cleaning treatment. The C/S composite cathodes show high Coulombic efficiency, long cycling stability and good rate capability in the electrolyte of 1.0 M LiPF6 + EC/DEC (1:1 v/v), for instance, the reversible capacity of the treated C/S-50 (50% S) cathode retains around 860 mAh/g even after 500 cycles and the Coulombic efficiency is close to 100%, which demonstrates the best electrochemical performance of carbon-sulfur composite cathodes using the carbonate-based electrolyte reported to date. It is believed that the chemical bond of C-S is responsible for the superior electrochemical properties in Li-S battery, that is, the strong interaction between S and carbon matrix significantly improves the conductivity of S, effectively buffers the structural strain/stress caused by the large volume change during lithiation/delithiation, completely eliminates the formation of high-order polysulfide intermediates, and substantially avoids the shuttle reaction and the side reaction between polysulfide anions and carbonate solvent, and thus enables the C/S cathode to use conventional carbonate-based electrolytes and achieve outstanding electrochemical properties in Li-S battery. The results may substantially contribute to the progress of the Li-S battery technology.
- Published
- 2014
34. ChemInform Abstract: A Metal-Free Oxidation of Benzo[c]chromes to Benzo[c]chromen-6-ones by t-Butyl Hydroperoxide in the Presence of Potassium Iodide
- Author
-
Jing Zhou, Pan Han, Tao Zhang, Ying-Meng Xu, and Zhen-Ting Du
- Subjects
chemistry ,chemistry.chemical_element ,Organic chemistry ,General Medicine ,Iodine ,Medicinal chemistry - Published
- 2014
35. Fraction of Macroporous Resin from Smilax china L. Inhibits Testosterone Propionate–Induced Prostatic Hyperplasia in Castrated Rats
- Author
-
Pan Han, Jing Chen, Shan-Shan Song, Chaomei Xiong, and Jinlan Ruan
- Subjects
Gastric gavage ,Testosterone propionate ,Male ,medicine.medical_specialty ,Macroporous resin ,Prostatic Hyperplasia ,Medicine (miscellaneous) ,Andrology ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Random Allocation ,Internal medicine ,Medicine ,Animals ,Castration ,Testosterone ,Nutrition and Dietetics ,biology ,business.industry ,Plant Extracts ,Smilax china ,Prostate ,Dihydrotestosterone ,Hyperplasia ,biology.organism_classification ,medicine.disease ,Rats ,Testosterone Propionate ,Endocrinology ,chemistry ,Finasteride ,Smilax ,business ,Full Communications ,Resins, Plant ,Rhizome ,medicine.drug ,Phytotherapy - Abstract
The present study was conducted to evaluate the effect of a fraction of macroporous resin (FMR), a bioactive component of Smilax china L., on benign prostatic hyperplasia (BPH) in castrated rats induced by testosterone propionate. Rats were randomly divided into five groups: the negative control group (sham-operated), the model group, two FMR-treated groups (at doses of 300 mg/kg and 600 mg/kg of body weight), and the positive control group (treated with finasteride at the dose of 3 mg/kg). Drugs were administered once a day for three consecutive weeks by gastric gavage. Prostates were weighed, testosterone and dihydrotestosterone (DHT) levels in serum were determined, and histopathological examinations were carried out. FMR treatment inhibited prostatic hyperplasia, reducing the DHT level in serum and improving the prostate gland morphology compared with the model group. The overall results of this study suggest that FMR is effective at inhibiting experimentally induced prostate enlargement, and it presents a valuable resource for the treatment of human BPH.
- Published
- 2012
36. Notice of Retraction: Removal of Congo Red by Fixed Bed of Modified Wheat Straw: Effect of Flow Rate
- Author
-
Xiurong Zhao, Ya Li Liu, Runping Han, Congli Gao, and Pan Han
- Subjects
chemistry.chemical_compound ,Adsorption ,Chromatography ,Aqueous solution ,chemistry ,Fixed bed ,Analytical chemistry ,Ethylenediamine ,Straw ,Isothermal process ,Volumetric flow rate ,Congo red - Abstract
The congo red (CR) adsorption from aqueous solutions has been investigated by means of a fixed bed of ethylenediamine modified wheat straw (MWS). Isothermal column experiments were performed under a constant inlet concentration and bed depth, and different flow rates. The experimental data confirmed that the flow rate affected the shape of breakthrough curves. The Yan model was applied to the experimental results by nonlinear regressive analysis. The predicted breakthrough curves have been obtained, and they are in agreement with the corresponding experimental data. When the flow rate is 4 ml/min and the influent concentration of CR was 50 mg/l, the adsorption quantity reached 55.1 mg/g according to Yan model. It is concluded that the MWS column can remove CR from solution.
- Published
- 2011
37. Adsorption of Congo Red from Solution by Rice Husk in Batch Mode
- Author
-
Pan Han, Jiyun Song, Yinli Li, Chen Song, and Runping Han
- Subjects
Langmuir ,Aqueous solution ,Chemistry ,Environmental engineering ,Langmuir adsorption model ,Husk ,Endothermic process ,Congo red ,symbols.namesake ,chemistry.chemical_compound ,Adsorption ,symbols ,Freundlich equation ,Nuclear chemistry - Abstract
Rice husk, an agriculture byproduct, was used to adsorb congo red (CR) from aqueous solutions. Variables of the system, including contact time, pH, salt concentration, and equilibrium CR concentration, were adopted to study their effect on CR adsorption. The results showed that when the equilibrium concentration of CR increased, quantity of CR adsorption onto rice husk increased correspondingly. The equilibrium data was fitted well by the Langmuir and freundlich isotherm model. The process was spontaneous and endothermic in nature.
- Published
- 2010
38. Characterization of Manganese Oxide and the Adsorption of Copper(II) and Lead(II) Ions from Aqueous Solutions
- Author
-
Ke Li, Runping Han, Pan Han, Weihua Zou, and Jinghua Zhang
- Subjects
Aqueous solution ,General Chemical Engineering ,Inorganic chemistry ,lcsh:QD450-801 ,Ionic bonding ,chemistry.chemical_element ,Sorption ,lcsh:Physical and theoretical chemistry ,Surfaces and Interfaces ,General Chemistry ,Manganese ,Copper ,Metal ,Adsorption ,chemistry ,Ionic strength ,visual_art ,visual_art.visual_art_medium - Abstract
The characterization and sorption properties of manganese oxide towards Cu(II) and Pb(II) ions from aqueous solution were investigated. Scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared (IR) analyses were used to characterize the manganese oxide. Parameters affecting the adsorption of Cu(II) and Pb(II) ions, such as the adsorbent dosage, the ionic strength of the solution, the contact time, the solution pH, the initial metal ion concentration and the temperature, were investigated. The binding of Cu(II) and Pb(II) ions to manganese oxide was highly dependent on the pH of the solution, with the extent of adsorption increasing as the pH of the system increased. The uptake of both Cu(II) and Pb(II) ions was found to increase with temperature. Furthermore, the removal efficiency of Cu(II) and Pb(II) ions from aqueous solution increased with increasing adsorbent dosage and decreased with ionic strength. The adsorption equilibrium and adsorption kinetics of Cu(II) and Pb(II) ions onto manganese oxide were studied. The adsorption process was spontaneous and exothermic, with the order of affinity being Pb(II) > Cu(II). The same behaviour was observed during competitive adsorption, viz. adsorption from a binary solution of the ions concerned.
- Published
- 2009
39. Removal of methylene blue from aqueous solution by chaff in batch mode
- Author
-
Jian Yang, Runping Han, Pan Han, Yong-sen Lu, Jie Shi, and Yuanfeng Wang
- Subjects
Langmuir ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,Analytical chemistry ,Industrial Waste ,Endothermic process ,Waste Disposal, Fluid ,Water Purification ,Chaff ,Adsorption ,Water Pollution, Chemical ,Environmental Chemistry ,Freundlich equation ,Waste Management and Disposal ,Triticum ,Chromatography ,Aqueous solution ,Chemistry ,Biosorption ,Temperature ,Water ,Sorption ,Agriculture ,Hydrogen-Ion Concentration ,Pollution ,Methylene Blue ,Kinetics ,Models, Chemical ,Thermodynamics ,Water Pollutants, Chemical - Abstract
A new adsorbent system for removing methylene blue (MB) from aqueous solutions has been investigated. This new adsorbent is cereal chaff, an agriculture product in middle-west region in China. Variables of the system, including biosorption time, chaff dose, pH, salt concentration and initial MB concentration, were adopted to study their effects on MB removal. The results showed that as the dose of chaff increased, the percentage of MB sorption increased accordingly. There was no significant difference in the dye concentration remaining when the pH was increased from 4.0 to 11.0. The salt concentration has negative effect on MB removal. At the experimental range of MB concentration, the amount of MB adsorbed onto per unit mass of chaff ( q e ) is direct ratio to MB initial concentration ( c 0 ). The equilibrium data were analyzed using five equilibrium models, the Langmuir, the Freundlich, the Redlich–Peterson, the Koble–Corrigan and the Temkin isotherms. The results of non-linear regressive analysis are that the isotherms of Langmuir, Redlich–Peterson and Koble–Corrigan are better fit than the isotherms of Freundlich and Temkin at different temperatures according to the values of determined coefficients ( R 2 ) and Chi-square statistic ( χ 2 ). The maximum equilibrium capacities of chaff from Langmuir models are 20.3, 25.3 and 26.3 mg g −1 at 298, 318 and 333 K, respectively. Using the equilibrium concentration constants obtained at different temperatures, various thermodynamic parameters, such as Δ G 0 , Δ H 0 and Δ S 0 , have been calculated. The thermodynamics parameters of MB/chaff system indicate spontaneous and endothermic process. It was concluded that an increase in temperature results in a bigger MB loading per unit weight of the chaff.
- Published
- 2006
40. Nano-Copper-Assisted Immobilization of Sulfur in High-Surface-Area Mesoporous Carbon Cathodes for Room Temperature Na-S Batteries
- Author
-
Zhuo Han, Hui-Juan Zhang, Pan Han, Junhe Yang, Shiyou Zheng, and Peng Li
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,Fossil fuel ,chemistry.chemical_element ,Nanotechnology ,Environmental pollution ,Organic radical battery ,Cathode ,law.invention ,chemistry ,law ,General Materials Science ,Nanoarchitectures for lithium-ion batteries ,Lithium ,Grid energy storage ,Electronics ,business - Abstract
Rechargeable batteries have attracted increasing attention as power technologies for emerging electric vehicles and grid energy storage, which are expected to mitigate the environmental pollution caused by the use of fossil fuels. Although graphite/lithium transition-metal-oxides (LiCoO 2 , LiNiO 2 , and LiMn 2 O 4 , etc.) and lithium-ion batteries have been the dominant power sources for portable electronics and are used in hybrid electric vehicles, the limited ore resources of these materials make durative rising price. Most crucially, the limitations of potential energy density of these metal-oxide cathode materials are a main restriction in terms of large-scale applications of batteries, particularly in electric vehicles and hybrid electric vehicles. [ 1,2 ] Therefore, it has become urgent to search for alternative energy-storage systems that could complement the existing lithium-ion batteries and that simultaneously have high energy density and long cycle life, in addition to safety and low cost. Alternatively, sodium-sulfur (Na-S) batteries offer low cost, high capacity and high safety, showing great promissing for grid-scale applications. [ 2 ] Both Na and S are abundant and nontoxic elementals on the earth, providing larger availability and lower material cost over the conventional lithium-ion batteries.
- Published
- 2014
41. Synthesis of Heterocycles via Palladium-Catalyzed C-H Activation/Cyclization of Diazonium Salts (Part III): Phenanthridin-6-(5H)-ones
- Author
-
Ke Chen, Congcong Zhang, Zhen-Ting Du, Jing Zhou, and Pan Han
- Subjects
Pharmacology ,Part iii ,Chemistry ,Organic Chemistry ,chemistry.chemical_element ,Medicinal chemistry ,Analytical Chemistry ,Catalysis ,Palladium - Published
- 2014
42. Near-infrared fluorescent detection of glutathione via reaction-promoted assembly of squaraine-analyte adducts
- Author
-
Shiguo Sun, Yongqian Xu, Benhao Li, Yi Pang, and Pan Han
- Subjects
Analyte ,Spectroscopy, Near-Infrared ,Chemistry ,Cationic polymerization ,Glutathione ,Buffer solution ,Photochemistry ,Biochemistry ,Fluorescence ,Analytical Chemistry ,Adduct ,chemistry.chemical_compound ,Förster resonance energy transfer ,Phenols ,Fluorescence Resonance Energy Transfer ,Electrochemistry ,Environmental Chemistry ,Cyclobutanes ,Spectroscopy ,Fluorescent Dyes ,Cysteine - Abstract
The first "off-on" dual-output fluorescent assay based on reaction-promoted self-assembly approach for glutathione recognition in near infrared region over other relative thiols including cysteine and homocysteine was constructed with high selectivity and large Stocks shift (about 220 nm). The fluorescence enhancement is attributed to the intermolecular interaction, which manipulates the squaraine's aggregates and results in FRET for NIR emission. The sensitivity of the sensing ensemble was further improved in buffer solution containing cationic surfactant.
- Published
- 2013
43. A Metal-Free Oxidation of Benzo[c]chromen to Benzo[c]chromen-6-ones by t-Butyl Hydroperoxide in the Presence of Potassium Iodide
- Author
-
Tao Zhang, Jing Zhou, Ying-Meng Xu, Zhen-Ting Du, and Pan Han
- Subjects
Pharmacology ,chemistry ,Organic Chemistry ,chemistry.chemical_element ,Iodine ,Medicinal chemistry ,Analytical Chemistry - Published
- 2013
44. The mechanism of foam devolatilization in partially filled screw devolatilizers
- Author
-
Hso-Pan Han and Chang Dae Han
- Subjects
Materials science ,Aqueous solution ,Polymers and Plastics ,Polyacrylamide ,Flow channel ,General Chemistry ,Flow pattern ,Physics::Fluid Dynamics ,Mechanism (engineering) ,chemistry.chemical_compound ,chemistry ,Free surface ,Polymer solution ,Materials Chemistry ,Streamlines, streaklines, and pathlines ,Composite material - Abstract
An experimental investigation was conducted into elucidating the mechanism of foam devolatilization. For the investigation, we have constructed two separate apparatuses of Plexiglas—one simulating the partially filled flow channel in a single-screw devolatilizer, and the other simulating the partially filled, closed-chamber (often referred to as the “C-chamber),” in a twin-screw devolatilizer. The test fluids employed were aqueous solutions of polyacrylamide having various concentrations. During the preparation of the test fluids, we controlled the amount of air entrapped in the liquid phase by varying the level of vacuum applied. The entrapped air stayed as fine gas bubbles dispersed in the polymer solution, and mixtures of the polymer solution and air bubbles were subjected to devolatilization experiments. In the use of a single-screw devolatilizer, we have observed that: 1. The streamlines show circulatory flow patterns forming a singular point at a position slightly below the free surface, where small gas bubbles are trapped initially and become stationary, and 2. The small gas bubbles trapped at the stationary position coalesce later to form large gas bubbles, which then move slowly toward the free surface and are removed under vacuum from the system. In the use of twin-screw devolatilizers, we have found that the degree of fill, the rotational direction of the screws, and the degree of intermeshing, (i. e., partially or fully intermeshing) greatly influence the amount of free surface available for the removal of volatiles, as well as the flow patterns in the liquid pool, and thus the devolatilization efficiency.
- Published
- 1986
Catalog
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