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基于Living Library的高校图书馆服务模式探析 预览
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作者 袁聪 赵瑜璋 +1 位作者 余成斌 李梅 《河南图书馆学刊》 2019年第6期40-42,共3页
近年来,图书馆界逐渐兴起一种全新的服务模式--Living Library。文章介绍了Living Library在国内外的发展概况,分析了我国高校图书馆开展Living Library服务的可行性及面临的困难,并提出了相应的对策,以期使高校图书馆不断创新服务模式... 近年来,图书馆界逐渐兴起一种全新的服务模式--Living Library。文章介绍了Living Library在国内外的发展概况,分析了我国高校图书馆开展Living Library服务的可行性及面临的困难,并提出了相应的对策,以期使高校图书馆不断创新服务模式,提高服务质量,满足读者的信息需求。 展开更多
关键词 LIVING LIBRARY 服务模式 高校图书馆
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大学生拖延现象的分析 预览
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作者 郭政 郑雨露 +1 位作者 侯海峰 杨春贵 《医学信息》 2019年第17期32-34,38共4页
拖延是一种在大学生群体中日益普遍的现象,对大学生的学习表现和身心健康均会造成严重影响。本文对拖延症的定义、拖延的分类、大学生拖延现象、拖延症的原因、拖延症的危害和应对措施等方面研究进行综述,旨在探讨大学生拖延现状,寻求... 拖延是一种在大学生群体中日益普遍的现象,对大学生的学习表现和身心健康均会造成严重影响。本文对拖延症的定义、拖延的分类、大学生拖延现象、拖延症的原因、拖延症的危害和应对措施等方面研究进行综述,旨在探讨大学生拖延现状,寻求拖延形成原因,从而最大限度避免拖延现象发生。 展开更多
关键词 大学生 拖延 学习 生活
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Achievements and Outlook of China's Multidimensional Poverty Reduction 预览
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作者 陈燕凤 夏庆杰 《中国经济学人:英文版》 2019年第2期39-51,共13页
Since the founding of the People’s Republic of China in 1949,the Chinese government has made great achievements in reducing poverty through human capital development(education,healthcare,gender equality,maternal and ... Since the founding of the People’s Republic of China in 1949,the Chinese government has made great achievements in reducing poverty through human capital development(education,healthcare,gender equality,maternal and infant health,and prevention and treatment of iodine deficiency),infrastructure construction(transportation,electric power,ICT application and access to safe drinking water),improvement of living conditions(toilet hygiene,stove renovation and resettlement)and rural social security(“five-guarantees” system,subsistence allowance,rural pension insurance,natural disaster relief and agricultural insurance).Since the 18th CPC National Congress in 2012,the Chinese government has made remarkable progress in eradicating poverty and enhancing village governance.However,serious challenges will still exist after China’s poverty eradication in 2020 and may lead to re-impoverishment. 展开更多
关键词 MULTIDIMENSIONAL POVERTY REDUCTION POVERTY REDUCTION THROUGH human CAPITAL POVERTY REDUCTION THROUGH infrastructure construction POVERTY REDUCTION THROUGH improvement of living conditions POVERTY REDUCTION THROUGH social security
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论余华《在细雨中呼喊》的悲剧意识 预览
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作者 王玲丽 《嘉兴学院学报》 2019年第4期32-36,共5页
《在细雨中呼喊》是余华的第一部长篇小说,讲述了一位江南少年成长过程中孤独、恐惧与忧伤的经历,也叙述了那个时代发生在少年周围人身上的各种生死挣扎、美好破灭的悲剧。《在细雨中呼喊》的悲剧意识体现在生存与死亡的挣扎、人性与道... 《在细雨中呼喊》是余华的第一部长篇小说,讲述了一位江南少年成长过程中孤独、恐惧与忧伤的经历,也叙述了那个时代发生在少年周围人身上的各种生死挣扎、美好破灭的悲剧。《在细雨中呼喊》的悲剧意识体现在生存与死亡的挣扎、人性与道德的沦丧两个方面,其悲剧意识的价值则表现在对苦难生命的关怀、对美好人性的呼唤上。探求小说蕴含的悲剧意识及其价值,能更好地把握余华文学创作的价值追求。 展开更多
关键词 余华 《在细雨中呼喊》 悲剧意识 生存 人性
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Halogen effects on phenylethynyl palladium(Ⅱ) complexes for living polymerization of isocyanides
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作者 Xinhua Wan 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第7期883-886,共4页
Polyisocyanides belong to one of the most important artificial helical polymers. The rigid-rod helical conformation makes them to exhibit wide potential applications in chiral recognition, enantioseparation, asymmetri... Polyisocyanides belong to one of the most important artificial helical polymers. The rigid-rod helical conformation makes them to exhibit wide potential applications in chiral recognition, enantioseparation, asymmetrical catalysis, and liquid crystals [1]. Up to now, quite a few metal-promoted polymerization methods have been developed to synthesize polyisocyanides. Especially, it is a great challenge for synthetic chemists to synthesize polyisocyanides in living/controllable fashion that afford well-defined and high isotactic helical polymers. 展开更多
关键词 living POLYMERIZATION ISOCYANIDES CHIRAL recognition
Fluorescence imaging of Cu(Ⅰ) in endoplasmic reticulum of live cells and tissue
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作者 Xiaowen Yan X. Chris Le 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第7期887-888,共2页
Copper (Cu) is an essential element to living organisms. The redox activity of Cu gives rise to redox cycling reactions between Cu^2+ and Cu^+. Organisms harness this redox cap? ability for their biological functions ... Copper (Cu) is an essential element to living organisms. The redox activity of Cu gives rise to redox cycling reactions between Cu^2+ and Cu^+. Organisms harness this redox cap? ability for their biological functions by tightly regulating copper homeostasis in the processes of cellular uptake, intracellular transport, protein loading and storage [1]. 展开更多
关键词 endoplasmic reticulum Copper (Cu) LIVING ORGANISMS
Splenectomy in living donor liver transplantation and risk factors of portal vein thrombosis 预览
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作者 Nobuhiko Kurata Yasuhiro Ogura +3 位作者 Satoshi Ogiso Yasuharu Onishi Hideya Kamei Yasuhiro Kodera 《国际肝胆胰疾病杂志:英文版》 SCIE CAS CSCD 2019年第4期337-342,共6页
Background:Graft inflow modulation(GIM)during adult-to-adult living donor liver transplantation(LDLT)is a common strategy to avoid small-for-size syndrome,and some transplant surgeons attempt small size graft strategy... Background:Graft inflow modulation(GIM)during adult-to-adult living donor liver transplantation(LDLT)is a common strategy to avoid small-for-size syndrome,and some transplant surgeons attempt small size graft strategy with frequent GIM procedures,which are mostly performed by splenectomy,in LDLT.However,splenectomy can cause serious complications such as portal vein thrombosis and overwhelming postsplenectomy infection.Methods:Forty-eight adult-to-adult LDLT recipients were enrolled in this study and retrospectively reviewed.We applied the graft selection criteria,which routinely fulfill graft-to-recipient weight ratio≥0.8%,and consider GIM as a backup strategy for high portal venous pressure(PVP).Results:In our current strategy of LDLT,splenectomy was performed mostly due to hepatitis C and splenic arterial aneurysms,but splenectomy for GIM was intended to only one patient(2.1%).The final PVP values≤20 mmHg were achieved in all recipients,and no significant difference was observed in patient survival or postoperative clinical course based on whether splenectomy was performed or not.However,6 of 18 patients with splenectomy(33.3%)developed postsplenectomy portal vein thrombosis(PVT),while none of the 30 patients without splenectomy developed PVT after LDLT.Splenectomy was identified as a risk factor of PVT in this study(P<0.001).Our study revealed that a lower final PVP could be risk factor of postsplenectomy PVT.Conclusions:Using sufficient size grafts was one of the direct solutions to control PVP,and allowed GIM to be reserved as a backup procedure.Splenectomy should be avoided as much as possible during LDLT because splenectomy was found to be a definite risk factor of PVT.In splenectomy cases with a lower final PVP,a close follow-up is required for early detection and treatment of PVT. 展开更多
关键词 Living donor liver transplantation SPLENECTOMY Portal venous pressure Graft-to-recipient weight ratio Portal vein thrombosis
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Electro-selective interconversion of living cationic and radical polymerizations
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作者 Jiannan Zhu Xiang Hao Qiang Yan 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第8期1023-1029,共7页
Orchestrating conflicting polymerization mechanisms in a single polymerization process through one external stimulus is a prerequisite to achieve in-situ selective synthesis of different monomers. Here we report an el... Orchestrating conflicting polymerization mechanisms in a single polymerization process through one external stimulus is a prerequisite to achieve in-situ selective synthesis of different monomers. Here we report an electrochemically controlled mechanism transformation that enables selective activation of living cationic or radical polymerization via an alternating voltage and dual electrocatalysts. Using identical mixed-monomer condition, a variety of desired block copolymer structures, including diblock, multiblock, random, and tapered copolymers can be obtained by simply varying the periods or phases of the alternating potential. Moreover, merging this electro-interconverted polymerization with a flow-chemistry technique can streamline preparation of functional polymer materials with complex multiblock structure. This study would offer a new vision on large-scale electrochemical synthesis of sequence-defined polymers. 展开更多
关键词 ELECTROCHEMISTRY LIVING polymerization mechanism INTERCONVERSION RADICAL CATION
Donor ductal anomaly is not a contraindication to right liver lobe donation 预览
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作者 Kenneth SH Chok James YY Fung +5 位作者 Wing Chiu Dai Sui Ling Sin Ka Wing Ma Albert CY Chan Tan To Cheung Chung Mau Lo 《国际肝胆胰疾病杂志:英文版》 SCIE CAS CSCD 2019年第4期343-347,共5页
Background:Data of living-donor liver transplantation(LDLT)suggested that donor ductal anomaly may contribute to postoperative biliary complications in recipients and in donors.This retrospective study aimed to determ... Background:Data of living-donor liver transplantation(LDLT)suggested that donor ductal anomaly may contribute to postoperative biliary complications in recipients and in donors.This retrospective study aimed to determine if the occurrence of postoperative biliary stricture in donors or recipients in rightlobe LDLT(RLDLT)is related to donor biliary anatomy type.Methods:We analyzed our RLDLT recipients’clinical data and those of their graft donors.The recipients were divided into 2 groups:with and without postoperative biliary stricture.The 2 groups were compared.The primary endpoints were donor biliary anatomy type and postoperative biliary complication incidence;the secondary endpoints were 1-,3-and 5-year graft and patient survival rates.Results:Totally 127 patients were included in the study;25(19.7%)of them developed biliary anastomotic stricture.In these 25 patients,16 had type A biliary anatomy,3 had type B,2 had type C,3 had type D,and 1 had type E.In the 127 donors,96(75.6%)had type A biliary anatomy,13(10.2%)had type B,6(4.7%)had type C,10(7.9%)had type D,and 2(1.6%)had type E.Biliary stricture was seen in 2 donors,who had type A biliary anatomy.None of the recipients or donors developed bile leakage.No association between the occurrence of postoperative biliary stricture and donor biliary anatomy type was found(P=0.527).Conclusions:The incidence of biliary stricture in donors or recipients after RLDLT was not related to donor biliary anatomy type.As postoperative complications were similar in whatever type of donor bile duct anatomy,donor ductal anomaly should not be considered a contraindication to donation of right liver lobe. 展开更多
关键词 Living donor liver transplantation Right liver donation Biliary complications Cholangiograms Ductal anomaly
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Pure three-dimensional laparoscopic full left hepatectomy of a living donor for an adolescent in China
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作者 Jiu-Lin Song Hong Wu Jia-Yin Yang 《中华医学杂志:英文版》 SCIE CAS CSCD 2019年第2期242-244,共3页
To the Editor:Living donor liver transplantation (LDLT) has expanded the donor pool in countries with low cadaveric organ donation rates.Generally, a left-side liver allograft is sufficient and safe for child and adol... To the Editor:Living donor liver transplantation (LDLT) has expanded the donor pool in countries with low cadaveric organ donation rates.Generally, a left-side liver allograft is sufficient and safe for child and adolescent recipients.[1] For the sake of the donor's cosmetic demands and for early functional rehabilitation, laparoscopic technology has been used in live hepatectomy since 2002.[2] Three-dimensional visualization provides better depth perception and tactile feedback than does conventional two-dimensional laparoscopy.[3] In this report, we presented a case of pure three-dimensional laparoscopic full left live hepatectomy. 展开更多
关键词 LIVING DONOR LIVER transplantation expanded LIVER
Outcomes of adult patients adopting small-for-size grafts in living donor liver transplantation: A systematic review and meta-analysis 预览
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作者 Yue Yan Dao-Feng Zheng +1 位作者 Jun-Liang Pu Zhong-Jun Wu 《国际肝胆胰疾病杂志:英文版》 SCIE CAS CSCD 2019年第3期206-213,共8页
Background: Small-for-size graft(SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation(LDLT) as a certain graft size is related to recipients’ prognosis. Graftto-recipi... Background: Small-for-size graft(SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation(LDLT) as a certain graft size is related to recipients’ prognosis. Graftto-recipient weight ratio(GRWR)≥0.8% was considered as a threshold to conduct LDLT. However, this also has been challenged over decades as a result of technique refinements. For a better understanding of SFSG in practice, we conducted this meta-analysis to compare the perioperative outcomes and long-term outcomes between patients adopting the grafts with a lower volume(GRWR < 0.8%, SFSG group) and sufficient volume(GRWR ≥ 0.8%, non-SFSG group) in adult-to-adult LDLT. Data sources: The studies comparing recipients adopting graft with a GRWR < 0.8% and ≥ 0.8% were searched by three authors independently in Pub Med, Web of Science, Embase, the Cochrane Library, MEDLINE and Google Scholar databases until September 2018 and data were analyzed by RevMan 5.3.5. Results: Sixteen studies with a total of 3272 subjects were included in this meta-analysis. In terms of small-for-size syndrome(SFSS), no significant difference was found in subjects enrolled after year 2010(before 2010, OR = 3.00, 95% CI: 1.69–5.35, P = 0.0002;after 2010, OR = 1.23, 95% CI: 0.79–1.90, P = 0.36;P for interaction: 0.02). There was no significant difference in operative duration, blood loss, cold ischemia time, biliary complications, acute rejection, postoperative bleeding, hospitalization time, perioperative mortality, and 1-, 3-and 5-year overall survival rates between two groups. Conclusions: This meta-analysis suggested that adopting SFSG in adult LDLT has comparable outcomes to those with non-SFSG counterparts since 2010. 展开更多
关键词 LIVING DONOR liver transplantation Graft-to-recipient WEIGHT ratio Small-for-size GRAFT
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Living systems allometric scaling laws 预览
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作者 Pierre Bricage 《资源与环境经济(英文)》 2019年第2期57-70,共14页
The spatial and temporal structuring and functioning of living systems are associated with scaling independent qualitative characteristics (gauge invariance) and quantitative laws (power laws). This is allowed by the ... The spatial and temporal structuring and functioning of living systems are associated with scaling independent qualitative characteristics (gauge invariance) and quantitative laws (power laws). This is allowed by the emergence of new blueprints through the systems merging into ‘Associations for the Reciprocal and Mutual Sharing of Advantages and Dis-Advantages’(ARMSADA). The local actors become more and more mutually integrated into their new global Whole. Then they are more and more independent from their previous local situations of emergence. Reversely (systemic constructal law), the global Whole is more and more integrating local parceners. The relationship between actors within a living system was described using allometric laws, e.g. the metabolic rate of a lot of species was supposed to be proportional to its mass according to a 3/4 exponent power-law (Kleiber’s law). But, according to the gauge invariance paradigm, an other explanation of the invariant scaling of living systems is proposed with a 2/3 power-law. Whatever its level of organization, a living system,‘system of systems’ emerging by embedments and juxtapositions of previous ones, effectively functions in 4 dimensions (VA: the Adult system Volume, and tg: the time of generation, the duration that is necessary to acquire the capacity of reproduction). Looking at the gauge invariance paradigm as a ‘factual’ system, from the quantum of Planck to the Universe as a Whole, a meta-analysis of a database of the systems internal (endophysiotope) and external (ecoexotope) interactions can allow to quantify 45-18 allometric relationships. This allows to evidence a ‘grammar’: 1. Invariant independent processes (power-laws with exponent e= 0);2. Simultaneous limiting interactions regulation processes (e=+1);3. Feedback (e=-1);4. Competition between actors (e= 1/2);5. Optimal exchanges flow (e= 2/3) processes. Brownian motion is the basic fundamental process that governs all functions. From the Monera to the ecosystem levels the increasing o 展开更多
关键词 living systems ALLOMETRIC SCALING SYSTEMIC CONSTRUCTAL LAW POWER-LAWS Pieron’s LAW
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生活化的广东漆:“广州十三行”
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作者 张景 《中国生漆》 2019年第2期22-28,共7页
广东漆工艺在浩瀚的历史长河中发展与传承了几千年,经历了由辉煌到低谷的历史演变。当下,随着传统工艺的振兴和人民对美好生活的向往,让广东漆艺重新回到人们的日常生产与生活中,满足人们对漆艺的实用与精神需求,同时以"广州十三行... 广东漆工艺在浩瀚的历史长河中发展与传承了几千年,经历了由辉煌到低谷的历史演变。当下,随着传统工艺的振兴和人民对美好生活的向往,让广东漆艺重新回到人们的日常生产与生活中,满足人们对漆艺的实用与精神需求,同时以"广州十三行"构建的广东漆艺品牌,将传统技艺与现代创意设计理念相融合,开发富含地域及民族特色的漆艺产品,积极推动漆艺文化创意产业发展。 展开更多
关键词 广东漆艺 生活化 广州十三行 品牌
Peculiar Living Shrines and Yuan Governance as Background to Ming Populism
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作者 Sarah Schneewind 《中国历史学前沿:英文版》 2019年第2期243-275,共33页
Although post-mortem apotheosis and secular honor in temples have received more attention,shrines to living men were also ordinary institutions from Han times onwards in Chinese history.Previous scholarship so far on ... Although post-mortem apotheosis and secular honor in temples have received more attention,shrines to living men were also ordinary institutions from Han times onwards in Chinese history.Previous scholarship so far on pre-mortem shrines in Tang and Song relates them to pre-mortem commemoration in inscribed records of local commendation on the one hand and Neo-Confucian Daoxue Shrines to Local Worthies on the other.That scholarly work suggests that Tang and Song premortem shrines when political were basically elite institutions;and that when common people were involved their motivations were religious rather than political.In Ming times,by contrast,premortem shrines were normatively established by commoners and const^uted a venue for popular political participation,while the steles commemorating the shrines explicitly argued that non-el让e people had the right to political speech.This article speculates,as a hypothesis awaiting further research,that both Yuan modes of government generally,and creative uses of premortem enshrinement in Yuan times specifically,may have contributed to Ming populism. 展开更多
关键词 dezheng bei qusi bei sheng ci LIVING shrine commemorative STELE YUAN government Yuan-Ming transition pre-mortem shrine
传统体育生活化的空间延伸——基于太极拳习练者群体的考察
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作者 罗湘林 邱芬 《北京体育大学学报》 CSSCI 北大核心 2019年第4期150-156,共7页
我国传统体育源起于久远的农耕文明,在现代城市文化的冲击中逐渐远离了当下的民众生活。传统体育如何在现代社会生活当中,重新融入民众的日常,不仅占据一定的休闲时间,而且延伸其社会空间,是关乎传统体育焕发生机的核心所在。本文基于... 我国传统体育源起于久远的农耕文明,在现代城市文化的冲击中逐渐远离了当下的民众生活。传统体育如何在现代社会生活当中,重新融入民众的日常,不仅占据一定的休闲时间,而且延伸其社会空间,是关乎传统体育焕发生机的核心所在。本文基于一个陈氏太极拳习练者群体的考察,以空间分析的视角,探求其习练活动的空间分野,分析其社会空间的内、外延伸和相互转化。研究认为:传统体育因其独有的文化特质,不仅能够融入日常生活,同时还能摆脱日常的乏味与重复;既不离日常,又超越日常,其缘由在于"感知空间"与"构想空间"等多个空间的伸展和超越;由此探寻传统体育生活化的空间特点、延伸路径和内在机制,进而挖掘其延续于现代社会的内在活力。 展开更多
关键词 传统体育 太极拳习练者 生活化 融入 超越 空间延伸
Toxicity and mechanisms of action of titanium dioxide nanoparticles in living organisms
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作者 Jing Hou Luyao Wang +4 位作者 Chunjie Wang Songlin Zhang Haiqiang Liu Shiguo Li Xiangke Wang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第1期40-53,共14页
Titanium dioxide nanoparticles(TiO2 NPs) are one of the most widely used nanomaterials in the consumer products, agriculture, and energy sectors. Their large demand and widespread applications will inevitably cause da... Titanium dioxide nanoparticles(TiO2 NPs) are one of the most widely used nanomaterials in the consumer products, agriculture, and energy sectors. Their large demand and widespread applications will inevitably cause damage to organisms and ecosystems. A better understanding of TiO2 NP toxicity in living organisms may promote risk assessment and safe use practices of these nanomaterials. This review summarizes the toxic effects of TiO2 NPs on multiple taxa of microorganisms, algae, plants, invertebrates, and vertebrates. The mechanism of TiO2 NP toxicity to organisms can be outlined in three aspects: The Reactive Oxygen Species(ROS)produced by TiO2 NPs following the induction of electron–hole pairs; cell wall damage and lipid peroxidation of the cell membrane caused by NP-cell attachment by electrostatic force owing to the large surface area of TiO2 NPs; and TiO2 NP attachment to intracellular organelles and biological macromolecules following damage to the cell membranes. 展开更多
关键词 TiO2 nanoparticles PARTICLE size EXPOSURE OXIDATIVE stress LIVING ORGANISMS
Sensing carboxylesterase 1 in living systems by a practical and isoformspecific fluorescent probe
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作者 Lele Ding Zhenhao Tian +8 位作者 Jie Hou Tongyi Dou Qiang Jin Dandan Wang Liwei Zou Yadi Zhu Yunqing Song Jingnan Cui Guangbo Ge 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第3期558-562,共5页
Carboxylesterase 1(CES1), one of the most abundant serine hydrolases in mammals, has drawn much attentions in recent years, owing to this enzyme involves in many physiological processes via hydrolysis of both endogeno... Carboxylesterase 1(CES1), one of the most abundant serine hydrolases in mammals, has drawn much attentions in recent years, owing to this enzyme involves in many physiological processes via hydrolysis of both endogenous esters and xenobiotic esters.Herein, to real-time monitor the activities of CES1 in various biological systems, a practical and iso form-specific fluorescent probe was developed on the basis of the substrate preference of CES1, as well as the structural and optical properties of BODIPY dyes.After screening of a panel of BODIPY ester derivatives, probe 1 displayed the best combination of specificity,sensitivity, enzymatic kinetics and applicability for monitoring CES1 activities in real samples.This probe was successfully used to detect CESl activities in several biological systems including tissue preparations,living cells, tissue slices and zebrafish.Furthermore, the biomedical applications of probe 1 for screening of CES1 inhibitors were also demonstrated using tissue preparations or living cells as enzyme sources.In summary, a practical and broadly applicable tool for real-time monitoring CES1 in biological systems was developed and well-characterized, which held great promise for further investigations on CES1-associated drug discovery, clinical practice and fundamental research. 展开更多
关键词 CARBOXYLESTERASE 1 FLUORESCENT probe Biological imaging LIVING cells based INHIBITORS screening BODIPY DYES
To Look Life in the Face: Characterization of the Novel The Hours 预览
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作者 雷筱 《海外英语》 2019年第8期220-223,共4页
Michael Cunningham's The Hours involves one day of three women of different times in different places. Studying on the characterization in it, it concludes women's dreary living condition and their consciousne... Michael Cunningham's The Hours involves one day of three women of different times in different places. Studying on the characterization in it, it concludes women's dreary living condition and their consciousness is in a crisis. Along with their struggle against time-consuming life, they still are faced up with dilemma and troubles, they have to make choices and compromises in their life to a certain degree. Pressure and disillusion behind their comfortable and carefree life penetrate their life. 展开更多
关键词 MICHAEL Cunningham The Hours CHARACTERIZATION LIVING CONDITION
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Synthesis of Alkyne-functionalized Polymers via Living Anionic Polymerization and Investigation of Features during the Post-“thiol-yne” Click Reaction
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作者 Lin-Can Yang Li Han +5 位作者 Hong-Wei Ma Pi-Bo Liu He-Yu Shen Chao Li Song-Bo Zhang Yang Li 《高分子科学:英文版》 SCIE CAS CSCD 2019年第9期841-850,共10页
"Thiol-yne" click reaction has already been widely applied in synthesis and modification of new polymer structures or novel materials due to its specific features. However, in most studies, only chain-end st... "Thiol-yne" click reaction has already been widely applied in synthesis and modification of new polymer structures or novel materials due to its specific features. However, in most studies, only chain-end strategy was employed when using the di-addition feature of thiol-yne reaction, thus the in-chain di-addition strategy could endow us with a broader space to develop the synthesis of advanced polymers. Therefore, in this paper, the features of in-chain mono and di-addition were investigated when modifying the alkynefunctionalized polymers to prepare grafted polymers via thiol-yne click reaction. The results showed that it is almost impossible to obtain the in-chain di-adducts even under excess feeding of chain-end thiol-functionalized grafts, while only the in-chain mono-adducts could be obtained efficiently. Further researches investigated that the controlled grafting could be encountered when carrying out the thiol-yne click reaction between chain-end alkyne-functionalized polystyrenes and chain-end thiol-functionalized polystyrenes under proper feedings. Therefore, the effect of steric?hindrance might be the primary reason for the alternative grafting via thiol-yne click reaction between in-chain and chain-end alkyne-functionalized polymers. 展开更多
关键词 Alkyne-functionalized polymers In-chain di-addition Thiol-yne CLICK reaction Living ANIONIC polymerization
A User-friendly Living Cationic Polymerization: Degenerative Chaintransfer Polymerization of Vinyl Ethers by Simply Using Mixtures of Weak and Superstrong Protonic Acids
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作者 Mineto Uchiyama Masataka Sakaguchi +1 位作者 Kotaro Satoh Masami Kamigaito 《高分子科学:英文版》 SCIE CAS CSCD 2019年第9期851-857,共7页
Mixtures of a weak protonic acid and a trace amount of superstrong protonic acid were used for the simple control of the cationic polymerization of vinyl ethers via a degenerative chain-transfer mechanism, in which th... Mixtures of a weak protonic acid and a trace amount of superstrong protonic acid were used for the simple control of the cationic polymerization of vinyl ethers via a degenerative chain-transfer mechanism, in which the former acid works as a precursor of the chain transfer agent (CTA) or the dormant species and the latter works as a source of the cationic propagating species. The addition of mixtures of phosphoric acid dibutyl ester ((n=BuO)2PO2H) or 1 -octanethiol (n-C8H17SH) and a trace amount of trifluoromethanesulfonic acid (TfOH) to a solution of isobutyl vinyl ether (IBVE) at -78℃ resulted in polymers with controlled molecular weights, which were basically determined by the feed ratio of IBVE to the weak protonic acid, and narrow molecular weight distributions (Mw/Mn≈ 1.1). These results were almost the same as those obtained using their prepared adducts of IBVE as CT As in the presence of a trace amount of TfOH under similar conditions. Methanesulfonic acid (CH3SO3H), whose adduct of IBVE has not been isolated due to instability, was similarly used in conjunction with trace TfOH to result in controlled molecular weights but slightly broader MWDs (Mw/Mn = 1.2-1.8). These results indicate that the sulfoxonium ion is also an effective intermediate in the cationic DT polymerization in addition to the phosphonium and sulfonium intermediates derived from (n=BuO)2PO2H and C8H17SH, respectively. The simple living cationic polymerization was thus achieved by using a combination of a weak protonic acid and a trace amount of TfOH, which are both easily available, low cost, free from metal, and easy to handle, without need for preparation of the initiator. 展开更多
关键词 Living CATIONIC POLYMERIZATION DEGENERATIVE chain transfer RAFT POLYMERIZATION Metal free VINYL ETHER
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