检索结果-南通市图书馆

Anomeric configuration-dependence of the Lattrell-Dax epimerization from D-glucose to synthetically useful D-allose derivatives

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2020年第10期18卷 723-728页

作者： NING Yun-Zhan QIN Chun-jun SUN wen-Bin FU jun-Jie HU Jing yin Jian Key Laboratory of Carbohydrate Chemistry and Biotechnology Ministry of EducationSchool of BiotechnologyJiangnan UniversityWuxi 214122China Wuxi School of Medicine Jiangnan UniversityWuxi 214122China

D-Allose and its derivatives play important roles in the field of health care and food nutrition. Pure and well-defined Dallose derivatives can facilitate the elucidation of their structure-activity relationship as an essential step for drug design. The LattrellDax epimerization, refers to the triflate inversion using nitrite reagent, is known as valuable method for the synthesis of rare D-allose derivatives. Here, the influence of protecting group patterns on the transformation efficiency of D-glucose derivatives into synthetically useful D-alloses and D-allosamines via the Lattrell-Dax epimerization was studied. For C3 epimerization of D-glucose derivatives bearing O2-acyl group, an anomeric configuration-dependent acyl migration from O2 to O3 was found. In addition, a neighbouring group participation effect-mediated SN1 nucleophilic substitution of the D-glucosamine bearing C2 trichloroacetamido(TCA) group in the Lattrell-Dax epimerization was dependent upon anomeric configuration. Thus, the effect of anomeric configuration on the LattrellDax epimerization of D-glucose suggests that β-D-glucosides with low steric hindrance at C2 should be better substrates for the synthesis of D-allose derivatives. Significantly, the efficient synthesis of the orthogonally protected D-allose 13 and D-allosamine 18 will serve well for further assembly of complex glycans.

关键词： D-allose D-allosamine Epimerization Anomeric configuration Acyl migration

Factors predicting occurrence and prognosis of hepatitis-B-virus-related hepatocellular carcinoma

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2011年第38期17卷 4258-4270页

作者： Yi-Fang Han jun Zhao Li-Ye Ma Jian-Hua yin wen-jun Chang Hong-Wei Zhang Guang-wen Cao Department of Epidemiology Second Military Medical University Shanghai 200433 China Department of Hepatobiliary Surgery the 3rd Affiliated Hospital Second Military Medical University Shanghai200433 China Department of General Surgery the 1st Affiliated Hospital Second Military Medical University Shanghai200433 China

Primary liver cancer is an important cause of cancer death, and hepatocellular carcinoma （HCC） accounts for 70%-85% of total liver cancer worldwide. Chronic hepatitis B virus （HBV） infection contributes to 〉 75% of HCC cases. High serum viral load is the most reliable indicator of viral replication in predicting development of HCC. HBV genotype C is closely associated with HCC in cirrhotic patients aged 〉 50 years, whereas genotype B is associated with development of HCC in non-cirrhotic young patients and postoperative relapse of HCC. Different HBV subgenotypes have distinct patterns of mutations, which are clearly associated with increased risk of HCC. Mutations accumulate during chronic HBV infection and predict occurrence of HCC. Chronic inflammation leads to increased frequency of viral mutation via cellular cytidine deaminase induction. Mutations are negatively selected by host immunity, whereas some immuno-escaped HBV mutants are active in hepatocarcinogenesis. Inflammatory pathways contribute to the inflammation-necrosis-regeneration process, ultimately HCC. Their hallmark molecules can predict malignancy in HBV-infected subjects. Continuing inflammation is involved in hepatocarcinogenesis and closely related to recurrence and metastasis. HBV load, genotype C, viral mutations and expression of inflammatory molecules in HBV-related HCC tissues are significantly associated with poor prognosis. Imbalance between intratumoral CD8^＋T cells and regulatory T cells or Thl and Th2 cytokines in peritumoral tissues can predict prognosis of HBV-related HCC. These factors are important for developing active prevention and surveillance of HBV-infected subjects who are more likely to develop HCC, or for tailoring suitable treatment to improve survival or postpone postoperative recurrence of HCC.

关键词： Hepatitis B virus Hepatocellular carcinoma Viral load Genotype Mutation Immune cells Signal-ing pathway Cytokine Prognosis

Study on The Method of Quantitative Analysis of Serum Ferritin and Soluble Transferrin Receptor with Protein Microarray Technology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2012年第4期25卷 430-439页

作者： yin Ji Yong SUN Jing HUANG Jian LI wen Xian HUO jun Sheng Institute for Nutrition and Food Safety Chinese Center for Disease Control and PreventionBeijing 100050China

Objective To establish and evaluate a protein serum ferritin （SF） and soluble transferrin receptor microarray method for combined measurement of （sTfR）. Methods Microarrayer was used to print both anti-SF antibodies I and anti-sTfR antibodies I on each protein microarray. Anti-SF antibodies II and anti-sTfR antibodies II were used as detection antibodies and goat antibodies coupled to Cy3 were used as antibodies Ill. The detection conditions of the quantitative analysis method for simultaneous measurement of SF and sTfR with protein microarray were optimized and evaluated. The protein microarray was compared with commercially available traditional tests with 26 serum samples. Results By comparison experiment, mouse monoclonal antibodies were chosen as the probes and contact printing was chosen as the printing method. The concentrations of SF and sTfR probes were 0.5 mg/mL and 0.5 mg/mL respectively, while those of SF and sTfR detection antibodies were 5 μg/mL and 0.36 μg/mL respectively. Intra- and inter-assay variability was between 3.26% and 18.38% for all tests. The regression coefficients comparing protein microarray with traditional test assays were better than 0.81 for SF and sTfR. Conclusion The present study has established a protein microarray method for combined measurement of SF and sTfR.

关键词： Protein microarray Optimization Combined measurement conditions Serum ferritin Soluble transferrin receptor.

Human-induced pluripotent stem cell-derived neural stem cell exosomes improve blood-brain barrier function after intracerebral hemorrhage by activating astrocytes via PI3K/AKT/MCP-1 axis

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 518-532页

作者： Conglin Wang Fangyuan Cheng Zhaoli Han Bo Yan Pan Liao Zhenyu yin Xintong Ge Dai Li Rongrong Zhong Qiang Liu Fanglian Chen Ping Lei Department of Geriatrics Tianjin Medical University General HospitalTianjinChina School of Medicine Nankai UniversityTianjinChina Tianjin Neurological Institute TianjinChina

Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor ***-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system *** this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying *** results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral ***,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory *** sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier *** with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these *** summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.

关键词： AKT astrocyte blood-brain barrier cerebral edema exosomes human-induced pluripotent stem cells intracerebral hemorrhage neural stem cells neuroinflammation PI3K

Contribution of fungal biomass to persistent soil carbon across natural ecosystems

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年

作者： Xiang WANG Guang-Hui YU Yakov KUZYAKOV Bo-Hao yin Andreas KAPPLER Cong-Qiang LIU Bohai Coastal Critical Zone National Observation and Research Station Institute of Surface-Earth System Science School of Earth System Science Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim Tianjin University Department of Soil Science of Temperate Ecosystems Department of Agricultural Soil Science University of G?ttingen Agro-Technological Institute Peoples Friendship University of Russia (RUDN University) Geomicrobiology Center for Applied Geosciences University of Tübingen Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infection University of Tübingen

Fungi are known to be crucial in the formation and stabilization of soil organic matter through their exudates and dead residues (necromass). Yet, it remains unclear how fungi contribute to the persistence of carbon in soils over millennial scales across biomes. Here, this study fills the knowledge gap by linking fungal carbon stocks with minerals-associated carbon stocks across major biomes. A strong correlation between fungal biomass and reactive mineral-associated carbon stocks in soils across six biomes supports the substantial role of fungi in soil carbon persistence at the global level. High spatial resolution nanoscale secondary ion mass spectrometry revealed that fungi may stabilize carbon by forming organo-mineral associations through their close physical connection to reactive minerals and weathered nanoparticles. We propose a conceptual model that emphasizes the dualistic role of hypha-mineral interactions:(i) fungi accelerate organic matter decomposition by producing reactive oxygen species on the hypha-mineral interfaces, and (ii) fungi stabilize their residues on mineral surfaces, leading to millennial scale persistence of soil C. Concluding, fungi play a fundamental role in ecosystems that extends beyond the decomposition of persistent carbon. They are crucial in stabilizing carbon on mineral surfaces, thereby facilitating the long-term removal of carbon from rapid biotic cycling.

关键词：

Simulation of the f-d transitions of lanthanide ions in YPO_4 using quantum-chemical calculations

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2012年第1期21卷 471-475页

作者： Hu Liu-Sen wen jun yin Min Xia Shang-Da Department of Physics University of Science and Technology of ChinaHefei 230026China

We constructed an effective one-electron Hamiltonian by using the 4f/5d energies and eigenvectors obtained from the first-principles calculation with the relativistic self-consistent discrete variational Slater software package （DV-Xα）. From the effective Hamiltonian, we obtained the crystal-field and spin-orbit interaction parameters for the 4f and 5d electrons of lanthanide ions （Ce^3＋, Pr^3＋, Nd^3＋ and Eu^3＋） doped in YPO4, and these parameters were used to calculate the 4fN-4fN- 15d transition. Comparison with experiments shows that the obtained parameters are reasonable and the excitation spectra can be well predicted.

关键词： crystal field spectroscopic YPO4 ab initio

Probing hydroxyl radical generation from H2O2 upon plasmon excitation of gold nanorods using electron spin resonance： Molecular oxygen-mediated activation

在线全文

学校读者我要写书评

暂无评论

Nano Research 2016年第6期9卷 1663-1673页

作者： Tao wen Hui Zhang Yu Chong Wayne G. Wamer jun-Jie yin Xiaochun Wu ing I O0190 China Division of Analytical Chemistry Office of Regulatory Science Center for Food Safety and Applied Nutrition US Food and Drug Administration College Park MD 20740 USA Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100005 China Division of Bioanalytical Chemistry Office of Regulatory Science Center for Food Safety and Applied Nutrition US Food and Drug Administration College Park MD 20740 USA

Gold nanostructures are among the noble metal nanomaterials being intensely studied due to their good biocompatibility, tunable localized surface plasmon resonance （SPR）, and ease of modification. These properties give gold nano- structures many potential chemical and biomedical applications. Herein, we demonstrate the critical role of oxygen activation during the decomposition of hydrogen peroxide （H202） in the presence of photoexcited gold nanorods （AuNRs） by using electron spin resonance （ESR） techniques. Upon SPR excitation, 02 is activated first, and the resulting reactive intermediates further activate H202 to produce ,OH. The reactive intermediates exhibit singlet oxygen-like （102-1ike） reactivity, indicated by 102-specific oxidation reaction, quenching behaviors, and the lack of the typical 102 ESR signal. In addition, by using the antioxidant sodium ascorbate （NaA） as an example, we show that hydroxyl radicals from H202 activation can induce much stronger NaA oxidation than that in the absence of H202. These results may have significant biomedical implications. For example, as oxidative stress levels are known to influence tumorigenesis and cancer progression, the ability to control redox status inside tumor microenvironments using noble metal nanostructures may provide new strategies for regulating the metabolism of reactive oxygen species and new approaches for cancer treatment.

关键词： gold nanorod oxygen activation hydroxyl radicalplasmon catalysis electron spin resonance

Retrofitting low-performance units to abate sewer overflow pollution based on mathematical model and Sobol algorithm

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2023年第4期35卷 770-781页

作者： Zhi-chao Zhao Xiao-min Huang Hai-long yin jun-bo wen Xiao-wei Fu Changjiang Institute of Survey PlanningDesign and ResearchWuhan430010China Key Laboratory of Yangtze River Water Environment Ministry of EducationTongji UniversityShanghai200092China State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai200092China Hubei Provincial Engineering Research Center for Comprehensive Water Environment Treatment in the Yangtze River Basin Wuhan430010China Key Laboratory of Urban Water Supply Water Saving and Water Environment Governance in the Yangtze River Delta of Ministry of Water ResourcesShanghai200092China

Optimal retrofit of low-performance units(LPUs)is promising to abate overflow pollutant mass loading of sewer systems during *** study presents a combination of mathematical model and Sobol algorithm to help identify LPUs of sewer systems and design retrofitting ***,the solution to minimize the overflow pollutant mass loading from sewers systems can be efficiently *** developed method was demonstrated at a catchment served by one wastewater treatment plant in the Chaohu City,Anhui Province of China,with five pumping stations and a total sewer length of 58.3 *** the catchment,there are three rivers and a small lake to receive overflows from the sewer *** them,one river that was mostly polluted was selected as the object of overflow pollution abatement during wet weather *** identifying the LPUs of the sewer system and developing retrofitting strategies using Sobol sequence,the mitigation of overflow pollution during wet weather period was *** show that the mass loading of chemical oxygen demand(COD)discharged into the target river could be reduced by 40.6%,by implementing optimal retrofit strategy of LPUs,i.e.,increasing the conveyance capacities of two pumping stations by 2.5–3.2 times and augmenting the diameters of 12 sewers by 1.25–1.29 *** further coordinate the abatement of overflow pollution and retrofit investment,Sobol sensitivity analysis was conducted to screen the dominant LPUs to update the optimal retrofit *** applying the updated strategy,the overflow COD mass loading per overflow event was close to that of non-updated strategy,while the retrofitting length of sewers was reduced by 40%.Therefore,on the basis of the presented method,decision-makers can flexibly develop retrofitting strategies of sewer system to abate overflow pollution during wet weathers in a cost-effective way.

关键词： Urban sewer system low-performance units Sobol sensitivity analysis sewer overflow optimal retrofit strategy

Greedy Randomized Adaptive Search Procedure with Path-Relinking for the Vertex p-Center Problem

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2017年第6期32卷 1319-1334页

作者： Ai-Hua yin Tao-Qing Zhou jun-wen Ding Qing-Jie Zhao Zhi-Peng Lv School of Software and Communication Engineering Jiangxi University of Finance and Economics Nanchang 330013 China School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China Department of Computer Science School of Information Engineering Zhejiang Agriculture and Forestry University Hangzhou 311300 China

The p-center problem consists of choosing a subset of vertices in an undirected graph as facilities in order to minimize the maximum distance between a client and its closest facility. This paper presents a greedy randomized adaptive search procedure with path-relinking （GRASP/PR） algorithm for the p-center problem, which combines both GRASP and path-relinking. Each iteration of GRASP/PR consists of the construction of a randomized greedy solution, followed by a tabu search procedure. The resulting solution is combined with one of the elite solutions by path-relinking, which consists in exploring trajectories that connect high-quality solutions. Experiments show that GRASP/PR is competitive with the state-of-the-art algorithms in the literature in terms of both solution quality and computational efficiency. Specifically, it virtually improves the previous best known results for 10 out of 40 large instances while matching the best known results for others.

关键词： p-center problem tabu search path-relinking facility location