检索结果-南通市图书馆

An Unconventional trans-exo-Selective Cyclization of Alkyne-Tethered Cyclohexadienones Initiated by Rhodium(III)-Catalyzed C-H Activation via Insertion Relay

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CCS Chemistry 2021年第5期3卷 1582-1595页

作者： Yun-Xuan Tan Xing-Yu Liu Shuo-Qing Zhang pei-pei xie Xin Wang Kai-Rui Feng Shao-Qian Yang Zhi-Tao He Xin Hong Ping Tian Guo-Qiang Lin The Research Center of Chiral Drugs Innovation Research Institute of Traditional Chinese MedicineShanghai University of Traditional Chinese MedicineShanghai 201203 CAS Key Laboratory of Synthetic Chemistry of Natural Substances Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032 Department of Chemistry Zhejiang UniversityHangzhou 310027 Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong UniversityShanghai 200240

Different from the established trans-endo-selective cyclization of alkyne-tethered electrophiles that involve an E/Z isomerization process,herein,the authors present a novel strategy to allow trans-exo-selective arylative cyclization of 1,*** initiation of rhodium(III)-catalyzed C-H activation,a diverse range of N-heterocyclic directing groups,including pyridine,pyrazole,imidazo[1,2-a]pyridine,benzoxazole,benzothiazole,and purine,was feasible for the cascade transformation,exhibiting high efficiency(up to 92%yield),broad substrate scope,and excellent functional group ***,the modification of natural products and pharmaceutical compounds was also demonstrated to showcase its synthetic *** on density functional theory(DFT)calculations,a key three-membered ring intermediate through the insertion relay,rather than the direct E/Z isomerization of alkenyl rhodium species,controlled the stereochemical outcome for this trans-exo-selective *** subsequent ring-opening protonation of the more favored rotamer led to exclusive trans-exo-selectivity.

关键词： rhodium catalysis insertion relay alkyne-tethered cyclohexadienones trans-exoselective stereochemistry-determining protonation

无染色剂下视网膜内界膜剥离联合笛针吸引治疗特发性黄斑裂孔

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

国际眼科杂志 2020年第3期20卷 544-546页

作者：谢培培齐绍文尚亚南胡长娥中国人民解放军联勤保障部队第九八九医院平顶山分院眼科

目的:探讨玻璃体切割(PPV)联合无染色剂下视网膜内界膜剥离(ILMP)、笛针吸引、空气填充术治疗特发性黄斑裂孔(IMH)的临床疗效。方法:回顾性非随机对照研究。选取2018-01/2019-01在我院确诊的IMH患者76例76眼,按手术方式分为两组,其中38... 详细信息

目的:探讨玻璃体切割(PPV)联合无染色剂下视网膜内界膜剥离(ILMP)、笛针吸引、空气填充术治疗特发性黄斑裂孔(IMH)的临床疗效。方法:回顾性非随机对照研究。选取2018-01/2019-01在我院确诊的IMH患者76例76眼,按手术方式分为两组,其中38眼行PPV联合无染色剂下ILMP、空气填充术(A组),38眼行PPV联合无染色剂下ILMP、笛针吸引、空气填充术(B组)。术后随访6mo以上,观察两组患者黄斑裂孔闭合、最佳矫正视力(BCVA)及并发症发生情况。结果:术后6mo,A组患者黄斑裂孔闭合率和BCVA提高率均显著低于B组(84%vs 100%,76%vs 95%,均P<0.05)。随着术后时间的推移,两组患者BCVA逐渐改善,且术后7、14d,1、3、6mo B组患者BCVA优于A组(均P<0.05)。术后随访期间,两组患者均未出现严重并发症。结论:无染色剂下ILMP联合笛针吸引治疗IMH临床疗效确切,在裂孔闭合率及BCVA改善方面明显优于单纯ILMP组。

关键词：裂孔特发性黄斑裂孔内界膜剥离笛针吸引空气充填染色剂

Nucleophile-Dependent Z/E-and Regioselectivity in the Palladium-Catalyzed Asymmetric Allylic C-H Alkylation of 1,4-Dienes

在线全文

学校读者我要写书评

暂无评论

Nucleophile-Dependent Z/E-and Regioselectivity in the Pallad...

Patch-Based Dark Channel Prior Dehazing for RS Multi-spectral Image

中国化学会·第十三届全国物理有机化学学术会议

作者： Hua-Chen Lin pei-pei xie Zhen-Yao Dai Shuo-Qing Zhang Pu-Sheng Wang Yu-Gen Chen Tian-Ci Wang Xin Hong Liu-Zhu Gong Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of China Department of Chemistry Zhejiang University Collaborative Innovation Center of Chemical Science and Engineering

The asymmetric allylic alkylation（AAA）, which features employing active allylic substrates, has historical significance in organic synthesis. The allylic C-H alkylation is principally more atom-and step-economic than the classical allylic functionalizations and thus can be considered a transformative variant. However, asymmetric allylic C-H alkylation reactions are still scarce and yet underdeveloped. Herein, we have found that Z/E-and regioselectivities in the Pd-catalyzed asymmetric allylic C-H alkylation of 1,4-dienes are highly dependent on the type of nucleophiles. A highly stereoselective allylic C-H alkylation of 1,4-dienes with azlactones has been established by palladium-chiral phosphoramidite catalysis. The protocol proceeds under mild conditions and can accommodate a wide scope of substrates, delivering structurally divergent α,α-disubstituted α-amino acid surrogates in high yields and excellent levels of diastereo-, Z/E-, regio-, and enantioselectivities. Notably, this method provides key chiral intermediates for an efficient synthesis of lepadiformine marine alkaloids. Experimental and computational studies on the reaction mechanism suggest a novel concerted proton and two-electron transfer process for the allylic C-H cleavage and reveal that the Z/E-and regioselectivities are governed by the geometry and coordination pattern of nucleophiles.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2015年第3期24卷 573-578页

作者： WANG Lixia xie Weixin pei Jihong ATR Key Laboratory of National Defense Technology College of Information Engineering Shenzhen University

Remote sensing(RS) multi-spectral images are usually suffered from cloud and fog cover, which can lead to analysis troubles and application limitations. A novel patch-based dark channel prior dehaze method is proposed for solving this problem. An Atmospheric light(AL) curved surface hypothesis, instead of globally invariable plane, is applied to describe AL distribution, and a patch-based approach is given to estimate curved *** using AL curved surface estimation, a new recovering model for RS multi-spectral images is given to obtain dehaze-free images. Comparative experiments are conducted, those results illustrate that the proposed method can produces visually impressive restored images, and the proposed method is superior to other relative methods in terms of image quality evaluations.

关键词： RS multi-spectral images Dehaze Cloud and fog removal Dark channel prior AL curved surface

Continuous, homogeneous and rapid synthesis of 4-bromo-3-methylanisole in a modular microreaction system

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 Journal of Chemical Engineering 2020年第8期28卷 2092-2098页

作者： pei xie Kai Wang Jian Deng Guangsheng Luo The State Key Laboratory of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

4-Bromo-3-methylanisole is mainly used to synthesize black fluorane dye(2-anilino-3-methyl-6-dibutylaminofluorane, ODB-2), which is one of the most important heat and pressure-sensitive dyes in the manufacture of thermal papers. Compared to the industrial heterogeneous batch process, a continuous homogeneous bromination technology in a modular microreaction system has been developed, and 4-bromo-3-methylanisole has been successfully prepared through high-selective mono-bromination of 3-methylanisole with Br2 solution in CHCl3. In optimal conditions, the content of bis-brominated byproducts can be controlled less than 0.5%,which is superior to the industrial standard with 99.5% 3-methylanisole conversion at very short residence time and mild reaction temperature.

关键词： 4-bromo-3-methylanisole bromination continuous synthesis modular microreaction system mixing enhancement

History and progress of hypotheses and clinical trials for Alzheimer’s disease

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2019年第1期4卷 412-433页

作者： pei-pei Liu Yi xie Xiao-Yan Meng Jian-Sheng Kang Clinical Systems Biology Laboratories The First Affiliated Hospital of Zhengzhou UniversityZhengzhou450052 HenanChina

Alzheimer’s disease(AD)is a neurodegenerative disease characterized by progressive memory loss along with neuropsychiatric symptoms and a decline in activities of daily *** main pathological features are cerebral atrophy,amyloid plaques,and neurofibrillary tangles in the brains of *** are various descriptive hypotheses regarding the causes of AD,including the cholinergic hypothesis,amyloid hypothesis,tau propagation hypothesis,mitochondrial cascade hypothesis,calcium homeostasis hypothesis,neurovascular hypothesis,inflammatory hypothesis,metal ion hypothesis,and lymphatic system ***,the ultimate etiology of AD remains *** this review,we discuss the main hypotheses of AD and related clinical *** puzzles and lessons have made it possible to develop explanatory theories and identify potential strategies for therapeutic interventions for *** combination of hypometabolism and autophagy deficiency is likely to be a causative factor for *** further propose that fluoxetine,a selective serotonin reuptake inhibitor,has the potential to treat AD.

关键词： Alzheimer metabolism clinical

Variation of cyanobacteria with different environmental conditions in Nansi Lake,China

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 Environmental Sciences 2012年第8期24卷 1394-1402页

作者： Chang Tian Haiyan pei Wenrong Hu Jun xie School of Environmental Science and Engineering Shandong UniversityJinan 250061China Shandong Provincial Engineering Center on Environmental Science and Technology Jinan 250061China Shandong Environmental Monitoring Central Station Jinan 250013China

Nansi Lake is located on the east line of the South-to-North Water Diversion Project in China. A comprehensive study was carried out to investigate the spatial and temporal distribution of cyanobacteria in the lake from June 2008 to May 2011 based on monthly sample monitoring from five stations. The effect of environmental factors on cyanobacterial abundance was also evaluated. The eyanobaeterial community contained 15 genera and 23 species. The cyanobacterial abundance of each monitoring station ranged from 0 to 1.53x 107 cells/L with an average of 1.45~ 106 cells/L, which accounted for 11.66% of the total phytoplankton abundance. The dominant species of cyanobacteria were Pseudanabaena （32.94%） and Merismopedia （19.85%）, not the bloom-forming algae such as Microcystis and Anabaena. In addition, the cyanobacterial community structure and water quality variables changed substantially over the survey period. Redundancy analysis （RDA） suggested that temperature and phosphorus were important environmental factors that affected cyanobacteria. Temperature was the most important factor affecting cyanobacterial abundance. The effect of phosphorus on cyanobacterial abundance was more notable in warm periods than in periods with low temperature.

关键词： cyanobacteria Nansi Lake cyanobacterial bloom South-to-North Water Diversion Project

Traditional Chinese medicine in the treatment of Helicobacter pylorirelated gastritis:The mechanisms of signalling pathway regulations

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2025年第3期31卷 11-28页

作者： pei-pei Zhang Liang Li Hao-Yu Qu Guang-Yu Chen Meng-Zhou xie Yan-Kun Chen School of Traditional Chinese Medicine Hunan University of Chinese MedicineChangsha 410200Hunan ProvinceChina Hunan Engineering Technology Research Center for Medicinal and Functional Food Hunan University of Chinese MedicineChangsha 410200Hunan ProvinceChina Key Laboratory of Traditional Chinese Medicine Heart and Lung Syndrome Differentiation and Medicated Diet and Dietotherapy Hunan University of Chinese MedicineChangsha 410200Hunan ProvinceChina School of Informatics Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina Precision Medicine Research and Development Center Zhuhai Institute of Advanced TechnologyChinese Academy of SciencesZhuhai 519000Guangdong ProvinceChina

Helicobacter pylori-associated gastritis(HPAG)is a common condition of the gastrointestinal ***,extensive and long-term antibiotic use has resulted in numerous adverse effects,including increased resistance,gastrointestinal dysfunction,and increased recurrence *** these concerns develop,traditional Chinese medicine(TCM)may have *** is based on the concept of completeness and aims to eliminate pathogens and strengthen the *** has the potential to prevent this condition while also boosting the rate of Helicobacter pylori *** review elaborates on the mechanism of TCM treatment for HPAG based on cellular signalling pathways,which reflects the flexibility of TCM in treating diseases and the advantages of multi-level,multipathway,and multi-target treatments for HPAG.

关键词： Helicobacter pylori Helicobacter pylori-associated gastritis Traditional Chinese medicine Signalling pathway Eliminate pathogens Strengthen the body

Self-assembled nanoformulations of paclitaxel for enhanced cancer theranostics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2023年第8期13卷 3252-3276页

作者： Qing pei Bowen Jiang Dengyuan Hao Zhigang xie State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Chemotherapy has occupied the critical position in cancer therapy,especially towards the post-operative,advanced,recurrent,and metastatic ***(PTX)-based formulations have been widely used in clinical practice,while the therapeutic effect is far from satisfied due to off-target toxicity and drug *** caseless multi-components make the preparation technology complicated and aggravate the concerns with the excipients-associated *** self-assembled PTX nanoparticles possess a high drug content and could incorporate various functional molecules for enhancing the therapeutic *** this work,we summarize the self-assembly strategy for diverse nanodrugs of ***,the advancement of nanodrugs for tumor therapy,especially emphasis on monochemotherapy,combinational therapy,and theranostics,have been ***,the challenges and potential improvements have been briefly spotlighted.

关键词： Paclitaxel Self-assembly Homodimeric prodrug Heterodimeric prodrug Poly-prodrug Chemotherapy Combinational therapy Theranostics