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C-H…X-C bonds in alkyl halides drive reverse selectivities in confined spaces

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Chinese Chemical Letters 2023年第5期34卷 237-240页

作者： Manuel Petroselli Yong-Qing Chen Ming-Kai Zhao Julius Rebek jr. Yang Yu Center for Supramolecular Chemistry and Catalysis and Department of Chemistry College of ScienceShanghai UniversityShanghai 200444China Skaggs Institute for Chemical Biology and Department of Chemistry The Scripps Research InstituteLa JollaCA 92037United States

Binding of non-activated alkyl halides(2-20)in water-soluble cavitand(1)through supramolecular forces is here reported,with emphasis on the role of size and polarizability of the halogen atom in the formation of intra... 详细信息

关键词： Water-soluble cavitand Host-guest complex Molecular recognition C-H hydrogen bond Alkyl halides

Current interventional options for palliative care for patients with advanced-stage cholangiocarcinoma

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World Journal of Clinical Oncology 2024年第3期15卷 381-390页

作者： Maryam Makki Malak Bentaleb Mohammed Abdulrahman Amal Abdulla Suhool Salem Al Harthi Marcelo AF Ribeiro jr Department of Surgery Division of TraumaCritical Care and Acute Care SurgerySheikh Shakhbout Medical CityAbu Dhabi 11001United Arab Emirates Department of Surgery College of Medicine and Health SciencesKhalifa UniversityAbu Dhabi 11001United Arab Emirates Department of Surgery Division of Hepato-Pancreato-Biliary(HPB)SurgerySheikh Shakhbout Medical CityAbu Dhabi 91888United Arab Emirates

Primary biliary tract tumors are malignancies that originate in the liver,bile ducts,or *** tumors often present with jaundice of unknown etiology,leading to delayed diagnosis and advanced ***,several palliative treatment options are available for primary biliary tract *** include percutaneous transhepatic biliary drainage(PTBD),biliary stenting,and surgical interventions such as biliary *** therapy is also commonly used for the palliative treatment of primary biliary tract *** involves the administration of chemotherapy drugs,such as gemcitabine and cisplatin,which have shown promising results in improving overall survival in patients with advanced biliary tract *** is another palliative treatment option for patients with unresectable or inoperable malignant biliary *** stenting can also be used as a palliative treatment option to alleviate symptoms in patients with unresectable or inoperable malignant biliary *** interventions,such as biliary diversion,have traditionally been used as palliative options for primary biliary tract ***,biliary diversion only provides temporary relief and does not remove the *** biliary tract tumors often present in advanced stages,making palliative treatment the primary option for improving the quality of life of patients.

关键词： Cholangiocarcinoma Palliative care Endoscopic treatment Surgery Complications Interventional radiology

亚热带森林植物的叶片和根系功能性状部分耦合但具有不同的群落性状分布格局

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Journal of Plant Ecology 2024年第1期17卷 94-110页

作者： Wenqi Luo Oscar J Valverde-Barrantes Monique Weemstra James F Cahill jr.Zi Wang Dong He Yongfa Chen Chengjin Chu Youshi Wang State Key Laboratory of Biocontrol School of Life Sciences/School of EcologySun Yat-sen UniversityGuangzhou 510275China International Center for Tropical Botany Department of Biological SciencesFlorida International UniversityMiamiFL 33199USA Department of Biological Sciences University of AlbertaEdmontonABT6G 2E9Canada School of Ecology and the Environment Xinjiang UniversityUrumqi 830046China

植物的生态过程依赖于叶片和根系的功能运行,但少有研究同时关注这两类性状在群落中的分布格局(CTD)。本文测定了广东亚热带森林44种共生木本植物的16个叶片和根系性状,旨在检验类比的叶片和根系性状是否耦合,是否沿类似的功能性状谱变... 详细信息

植物的生态过程依赖于叶片和根系的功能运行,但少有研究同时关注这两类性状在群落中的分布格局(CTD)。本文测定了广东亚热带森林44种共生木本植物的16个叶片和根系性状,旨在检验类比的叶片和根系性状是否耦合,是否沿类似的功能性状谱变异,是否表现出类似的CTD,其CTD和群落加权平均性状值(CWM)是否沿环境梯度表现出类似的响应。研究结果表明,叶片和根系性状变异的第一轴均呈显出由资源获取向资源保守变异的经济学谱,但叶片变异的第二轴主要由叶片碳含量表征,而根系变异的第二轴主要由反映菌根协作程度的根系粗细表征。类比的叶片和根系化学性状整体正相关,但形态性状的耦合程度较低。在群落水平上,叶片和根系性状第一轴的CWM均随海拔升高而变得更保守,而第二轴的变化则不一致。随土壤磷含量的降低或钾含量的升高,根系变得更细和在养分性状上更保守,而叶片性状无显著变化。当整合多维性状轴时,叶片性状呈发散格局,且随海拔、土壤磷和钾含量的增加呈收敛趋势;而根系性状呈收敛格局,但沿上述环境梯度呈发散趋势。该研究强调,叶片和根系性状与环境互作的差异可能导致不同的性状分布格局;植物可通过多样的地上和地下功能设计应对环境异质性。

关键词：性状维度群落构建叶片性状根系性状植物经济谱群落性状结构亚热带森林

中国急性冠状动脉综合征患者治疗和预后的地区差异:来自国家胸痛中心的证据

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Science Bulletin 2024年第9期69卷 1302-1312页

作者：周书铎张岩董雪洁马郡雄李娜史红 Sidney C.Smith jr.金音子许铭向定成郑志杰霍勇 Department of Global Health Peking University School of Public HealthBeijing 100191China Institute for Global Health and Development Peking UniversityBeijing100871China Department of Cardiology Peking University First HospitalBeijing 100034China Chinese Medical Association Beijing 100052China Division of Cardiovascular Medicine School of MedicineUniversity of North Carolina at Chapel HillNorth Carolina 27599-3140USA Department of Cardiology General Hospital of Southern Theater Command of PLAGuangzhou 510010China

Regional variations in acute coronary syndrome(ACS) management and outcomes have been an enormous public health issue. However, studies have yet to explore how to reduce the variations. The National Chest Pain Center Program(NCPCP) is the first nationwide, hospital-based, comprehensive, continuous quality improvement program for improving the quality of care in patients with ACS in China. We evaluated the association of NCPCP and regional variations in ACS healthcare using generalized linear mixed models and interaction analysis. Patients in the Western region had longer onset-to-first medical contact(FMC) time and time stay in non-percutaneous coronary intervention(PCI) hospitals, lower rates of PCI for ST-elevation myocardial infarction(STEMI) patients, and higher rates of medication *** in Central regions had relatively lower in-hospital mortality and in-hospital heart failure *** in the door-to-balloon time(Dto B) and in-hospital mortality between Western and Eastern regions were less after accreditation(β =-8.82, 95% confidence interval(CI)-14.61 to-3.03;OR = 0.79, 95%CI 0.70 to 0.91). Similar results were found in differences in Dto B time, primary PCI rate for STEMI between Central and Eastern regions. The differences in PCI for higher-risk non-ST-segment elevation acute coronary syndrome(NSTE-ACS) patients among different regions had been ***, the differences in medication use between Eastern and Western regions were higher after accreditation. Regional variations remained high in this large cohort of patients with ACS from hospitals participating in the NCPCP in China. More comprehensive interventions and hospital internal system optimizations are needed to further reduce regional variations in the management and outcomes of patients with ACS.

关键词： Acute coronary syndromes Quality improvement Regional variations Quality metrics

Self-assembled hexameric capsule:A highlyβ-selective O-glycosylation reaction enabled via proton wire mechanism

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绿色合成与催化(英文) 2023年第1期4卷 7-9页

作者： Kuppusamy Kanagaraj Julius Rebek jr. Yang Yu Center for Supramolecular Chemistry&Catalysis and Department of Chemistry College of ScienceShanghai UniversityShanghai200444China The Skaggs Institute for Chemical Biology and Department of Chemistry The Scripps Research InstituteLa JollaCA 92037United States

A simple methodology has been developed for the synthesis of highlyβ-selective O-glycosylation scaffolds of wider substrate scope under mild conditions using a self-assembled hexameric *** reaction conditions are compatible with a wide range of functional *** control experiments and theoretical studies established that the reaction takes place inside the capsule *** substrates are activated via a proton wire as seen in some enzymes,and the reactions follow an SN2 pathway through a loose transition *** advantages of this methodology are selectivity,high yields and scalability;the catalyst is readily recovered and *** methodology was adapted to the synthesis of mesomorphic glycosides and anti-tumour agents in short synthetic routes.

关键词： Capsule Self-assembly β-Selective glycosylation Synthetic receptor Proton wire mechanism

Functionally graded structure of a nitride-strengthened Mg_(2)Si-based hybrid composite

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Journal of Magnesium and Alloys 2024年第3期12卷 1239-1256页

作者： Jeongho Yang Woongbeom Heogh Hogi Ju Sukhyun Kang Tae-Sik Jang Hyun-Do Jung Mohammad Jahazi Seung Chul Han Seong Je Park Hyoung Seop Kim Susmita Bose Amit Bandyopadhyay Martin Byung-Guk Jun Young Won Kim Dae-kyeom Kim Rigoberto CAdvincula Clodualdo Aranas jr.Sang Hoon Kim School of Mechanical Engineering Pusan National UniversityBusan 46241Republic of Korea Department of Mechanical Design Engineering Hanyang UniversitySeoul 04763Republic of Korea Process Research 3 Team LG Display Co.Ltd.PajuGyeonggi-do 10845Republic of Korea Department of Materials Science and Engineering Chosun UniversityGwangju 61452Republic of Korea Institute of Well-Aging Medicare&Chosun University LAMP Center Chosun UniversityGwangju 61452Republic of Korea Division of Materials Science and Engineering Hanyang UniversitySeoul 04763Republic of Korea Department of Mechanical Engineering École de Technologie SupérieureMontrealQuebec H3C 1K3Canada Material&Component Convergence R&D Center Korea Construction Equipment Technology InstituteGunsanJeollabuk-do 54002Republic of Korea School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore Graduate Institute of Ferrous&Eco Materials Technology Pohang University of Science and TechnologyPohangGyeongsangbuk-do 37673Republic of Korea Advanced Institute for Materials Research Tohoku UniversitySendai 980-8577Japan Institute for Convergence Research and Education in Advanced Technology Yonsei UniversitySeoul 03722Republic of Korea School of Mechanical and Materials Engineering Washington State UniversityPullmanWashington 99164USA School of Mechanical Engineering Purdue UniversityWest LafayetteIndiana 47907USA Research Institute of Advanced Manufacturing Technology Korea Institute of Industrial TechnologyIncheon 21999Republic of Korea Department of Macromolecular Science and Engineering Case Western Reserve UniversityClevelandOhio 44106USA Department of Chemical and Biomolecular Engineering and Joint Institute for Advanced Materials University of TennesseeKnoxvilleTennessee 37996USA Center for Nanophase Materials and Sciences Oak Ridge National LaboratoryOak RidgeTennessee 37830USA Department of Mechanical Engineering University of New BrunswickFrederictonNew Brunswick E3B 5A3Cana

The ex-situ incorporation of the secondary SiC reinforcement,along with the in-situ incorporation of the tertiary and quaternary Mg_(3)N_(2) and Si_(3)N_(4) phases,in the primary matrix of Mg_(2)Si is employed in order to provide ultimate wear resistance based on the laser-irradiation-induced inclusion of N_(2) gas during laser powder bed *** is substantialized based on both the thermal diffusion-and chemical reactionbased metallurgy of the Mg_(2)Si–SiC/nitride hybrid *** study also proposes a functional platform for systematically modulating a functionally graded structure and modeling build-direction-dependent architectonics during additive *** strategy enables the development of a compositional gradient from the center to the edge of each melt pool of the Mg_(2)Si–SiC/nitride hybrid ***,the coefficient of friction of the hybrid composite exhibits a 309.3%decrease to–1.67 compared to–0.54 for the conventional nonreinforced Mg_(2)Si structure,while the tensile strength exhibits a 171.3%increase to 831.5 MPa compared to 485.3 MPa for the conventional *** outstanding mechanical behavior is due to the(1)the complementary and synergistic reinforcement effects of the SiC and nitride compounds,each of which possesses an intrinsically high hardness,and(2)the strong adhesion of these compounds to the Mg_(2)Si matrix despite their small sizes and low concentrations.

关键词： Laser powder bed fusion Mg_(2)Si-SiC/nitride hybrid composite Both the thermal diffusion-and chemical reaction-based metallurgy Functionally graded structure Compositional gradient Wear resistance.

The Paleoarchean Northern Mundo Novo Greenstone Belt,São Francisco Craton:Geochemistry,U-Pb-Hf-O in zircon and pyriteδ^(34)S-Δ^(33)S-Δ^(36)S signatures

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Geoscience Frontiers 2022年第5期13卷 190-206页

作者： Guilherme S.Teles Farid Chemale jr. Janaína N.Ávila Trevor R.Ireland Unidade Acadêmica de Mineração e Geologia Universidade Federal de Campina GrandeCampina GrandeBrazil Programa de Pós-Graduação em Geologia Universidade de BrasíliaBrasíliaBrazil Programa de Pós-Graduação em Geologia Universidade do Vale do Rio dos SinosSão LeopoldoBrazil Research School of Earth Sciences The Australian National UniversityCanberraACT 2601Australia Griffith Centre for Social and Cultural Research Griffith UniversityNathanQueensland 4111Australia

Greenstone belts contain several clues about the evolutionary history of primitive ***,we describe the volcano-sedimentary rock association exposed along the eastern margin of the Gavião Block,named the Northern Mundo Novo Greenstone Belt(N-MNGB),and present data collected with different techniques,including U–Pb–Hf–O isotopes of zircon and multiple sulfur isotopes(^(32)S,^(33)S,^(34)S,and ^(36)S)of pyrite from this supracrustal sequence.A pillowed metabasalt situated in the upper section of the N-MNGB is 3337±25 Ma old and has zircon with ε_(Hf)(t)=2.47 to1.40,Hf model ages between 3.75 Ga and 3.82 Ga,and δ^(18)O=+3.6‰to+7.3‰.These isotopic data,together with compiled whole-rock trace element data,suggest that the mafic metavolcanic rocks formed in a subduction-related setting,likely a back-arc basin juxtaposed to a continental *** this context,the magma interacted with older Eoarchean crustal components from the Gavião *** zircons from the overlying quartzites of the Jacobina Group are sourced from Paleoarchean rocks,in accordance with previous studies,yielding a maximum depositional age of 3353±22 *** detrital zircons have ε_(Hf)(t)=5.40 to0.84,Hf model ages between 3.66 Ga and 4.30 Ga,and δ^(18)O=+4.8‰to+6.4‰.The pyrite multiple sulfur isotope investigation of the 3.3 Ga supracrustal rocks from the N-MNGB enabled a further understanding of Paleoarchean sulfur *** samples have diverse isotopic compositions that indicate sulfur sourced from distinct ***,they preserve the signal of the anoxic Archean atmosphere,expressed by MIF-S signatures(Δ^(33)S between1.3‰to+1.4‰)and a Δ^(36)S/Δ^(33)S slope of0.81 that is indistinguishable from the so-called Archean array.A BIF sample has a magmatic origin of sulfur,as indicated by the limited Δ^(34)S range(0 to+2‰),Δ^(33)S~0‰,and Δ^(36)S~0‰.A carbonaceous schist shows positive Δ^(34)S(2.1‰–3.5‰)and elevated Δ^(33)S(1.2‰–1.4‰)values,with corresponding negative Δ^(36)S

关键词： Northern Mundo Novo Greenstone Belt Multiple sulfur isotopes Geochronology Paleoarchean Gavião Block São Francisco Craton

Near-infrared electroluminescence of AlGaN capped InGaN quantum dots formed by controlled growth on photoelectrochemical etched quantum dot templates

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Photonics Research 2022年第1期10卷 33-40页

作者： XIONGLIANG WEI SYED AHMED AL MUYEED HAOTIAN XUE ELIA PALMESE RENBO SONG NELSON TANSU JONATHAN J.WIERER,jr. Center for Photonics and Nanoelectronics Department of Electrical and Computer EngineeringLehigh UniversityBethlehemPennsylvania 18015USA School of Electrical and Electronic Engineering The University of AdelaideAdelaideSA 5005Australia Institute for Photonics and Advanced Sensing The University of AdelaideAdelaideSA 5005Australia

Near-infrared electroluminescence of InGaN quantum dots(QDs)formed by controlled growth on photoelectrochemical(PEC)etched QD templates is *** QD template consists of PEC InGaN QDs with high density and controlled sizes,an AlGaN capping layer to protect the QDs,and a GaN barrier layer to planarize the *** transmission electron microscopy(STEM)of Stranski-Krastanov(SK)growth on the QD template shows high-In-content InGaN QDs that align vertically to the PEC QDs due to localized strain.A highAl-content A1_(0.9)Ga_(0.1)N capping layer prevents the collapse of the SK QDs due to intermixing or decomposition during higher temperature GaN growth as verified by *** of low-temperature(830℃)p-type layers is used to complete the p-n junction and further ensure QD ***,electroluminescence shows a significant wavelength shift(800 nm to 500 nm),caused by the SK QDs’tall height,high In content,and strong polarization-induced electric fields.

关键词： AlGaN polarization template

Climate pledges versus commitment: Are policy actions of Middle-East and North African countries consistent with their emissions targets?

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Advances in Climate Change Research 2022年第4期13卷 612-621页

作者： Hermas ABUDU Presley K.WESSEH jr.Boqiang LIN School of Management China Institute for Studies in Energy PolicyCollaborative Innovation Center for Energy Economics and Energy PolicyXiamen UniversityFujian361005China Belt and Road Research Institute Xiamen UniversityFujian361005China

Carbon emission is inevitable,and changes with energy consumption and economic development,presents policy options toward sustainable development ***,there is little assurance from policymakers in committing to climate change pledges:taking the Middle-East and North African(MENA)region as a specific case with using 2019 as a cut-off *** conducted an interim assessment of the Paris Agreement to ascertain whether climate actions are in tandem with emissions reduction *** use of difference-in-difference technique as a quasiexperiment supported by fixed-effects and placebo treatment models,the results point to evidence of less than 1%effective CO_(2) emissions reduction as of 2019 compared to the 2015 *** current carbon emissions reduction commitment level is far-reaching contrary to the Nationally Determined Contributions(NDCs)pledged(16.43%on average by 2030 compared to the 2015 level).The analysis suggests that achieving NDCs commitments are currently major burden on policymakers since the economic development is highly linked with nonrenewable energy ***,a more comprehensive framework when accounting for all available renewable and clean energy projects shows reduction levels in the range of 30%-40%from 2020 to *** results suggest that the Paris Agreement in MENA countries may be more effective from 2020,thus underscore the importance of capturing ongoing projects(involving renewable and clean energy technologies)into interim policy *** shared implication is that greater efforts are demanded from the region and at country levels to further decrease emissions through the use of negative emissions technologies particularly in the electricity generation sector.

关键词： Paris Agreement Carbon emissions reduction potential Carbon effciency:Climate change policy quasi-experiment MENA climate change performance