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Remote copper-catalyzed enantioselective substitution of yne-thiophene carbonates

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Science China Chemistry 2024年第4期67卷 1175-1180页

作者： Hao-dong Qian xiang Li Tingrui Yin wei-Feng Qian Chunhui Zhao Cuiju Zhu Hao Xu CCNU-uOttawa Joint Research Centre Key Laboratory of Pesticides&Chemical Biology of Ministry of EducationInternational Joint Research Center for Intelligent Biosensing Technology and HealthCollege of ChemistryCentral China Normal UniversityWuhan 430079China

Here,we describe a strategy for the copper-catalyzed asymmetric heteroarylation of yne-thiophene carbonates with indoles via remote *** key to the success of this strategy lies in the design of the alkynyl group at the ortho-position of the heterocycle thiophene,enabling the formation of a triarylmethane moiety via very remote ***,the concept of remote copper-catalyzed asymmetric transformation extends not only to yne-allylic esters but also to yne-aryl *** reaction readily provides a diverse array of chiral triarylmethanes with high efficiency,enantioselectivity,and excellent functional group ***,facile follow-up transformations underscore their potential utility in the synthesis of various enantioenriched building *** mechanistic studies support the plausibility of the remote substitution pathway.

关键词： remote substitution copper catalyst asymmetric catalysis triaryl methanes

L-cystine-Assisted Growth and Mechanism of CuInS_(2) Nanocrystallines via Solvothermal Process

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Chinese Physics Letters 2011年第5期28卷 245-248页

作者： LIU Hai-Tao ZHONG Jia-Song LIU Bing-Feng LIANG Xiao-Juan YANG Xin-Yu JIN Huai-dong YANG Fan xiang wei-dong College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035 College of Materials Science and Engineering Tongji UniversityShanghai 100092

L-cystine is successfully used as a kind of sulfur source to grow CuInS_(2) nanocrystallines at 200℃ for 18 h in a mixed solution made of 20mL ethylenediamine and 20mL distilled *** diameter of the CuInS_(2) nanocrystallines ranges from 300 to 500 *** structure of nanocrystallines is determined to be of the tetragonal phase of CuInS_(2).A reasonable possible mechanism for the growth of CuInS_(2) nanocrystallines is *** as-obtained CuInS_(2) products are examined using diverse techniques including x-ray powder diffraction,xray photoelectron spectroscopy,field-emission scanning electron microscopy,transmission electron microscopy,selected-area electron diffraction and high-resolution transmission electron microscopy.

关键词： tetragonal photoelectron sulfur

Computed tomography-based radiomics to predict early recurrence of hepatocellular carcinoma post-hepatectomy in patients background on cirrhosis

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World Journal of Gastroenterology 2024年第15期30卷 2128-2142页

作者： Gui-xiang Qian Zi-Ling Xu Yong-Hai Li Jian-Lin Lu xiang-Yi Bu Ming-Tong wei wei-dong Jia Department of Hepatic Surgery Anhui Provincial HospitalThe First Affiliated Hospital of USTCDivision of Life Science and MedicineUniversity of Science and Technology of ChinaHefei 230001Anhui ProvinceChina Department of Hepatic Surgery Anhui Provincial Hospital Affiliated to Anhui Medical UniversityAnhui Medical UniversityHefei 230001Anhui ProvinceChina Department of Anorectal Surgery the First People’s Hospital of HefeiHefei 230001Anhui ProvinceChina

BACKGROUND The prognosis for hepatocellular carcinoma(HCC)in the presence of cirrhosis is unfavourable,primarily attributable to the high incidence of *** To develop a machine learning model for predicting early recurrence(ER)of posthepatectomy HCC in patients with cirrhosis and to stratify patients’overall survival(OS)based on the predicted risk of *** In this retrospective study,214 HCC patients with cirrhosis who underwent curative hepatectomy were *** feature selection was conducted using the least absolute shrinkage and selection operator and recursive feature elimination ***-radiologic features were selected through univariate and multivariate logistic regression *** machine learning methods were used for model comparison,aiming to identify the optimal *** model’s performance was evaluated using the receiver operating characteristic curve[area under the curve(AUC)],calibration,and decision curve ***,the Kaplan-Meier(K-M)curve was used to evaluate the stratification effect of the model on patient *** Within this study,the most effective predictive performance for ER of post-hepatectomy HCC in the background of cirrhosis was demonstrated by a model that integrated radiomics features and clinical-radiologic *** the training cohort,this model attained an AUC of 0.844,while in the validation cohort,it achieved a value of *** K-M curves illustrated that the combined model not only facilitated risk stratification but also exhibited significant discriminatory ability concerning patients’*** The combined model,integrating both radiomics and clinical-radiologic characteristics,exhibited excellent performance in HCC with *** K-M curves assessing OS revealed statistically significant differences.

关键词： Machine learning Radiomics Hepatocellular carcinoma Cirrhosis Early recurrence Overall survival Computed tomography Prognosis Risk factor Delta-radiomics

Improved Approximation Schemes for Early Work Scheduling on Identical Parallel Machines with a Common Due Date

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Journal of the Operations Research Society of China 2024年第2期12卷 341-350页

作者： wei-dong Li School of Mathematics and Statistics Yunnan UniversityKunming650504YunnanChina

We study the early work scheduling problem on identical parallel machines in order to maximize the total early work,i.e.,the parts of non-preemptive jobs that are executed before a common due *** preprocessing and constructing an auxiliary instance which has several good properties,for any desired accuracy,we propose an efficient polynomial time approximation scheme with running time O(f(1/ε)n),where n is the number of jobs and f(1/ε)is exponential in 1/ε,and a fully polynomial time approximation scheme with running time O(1/ε^(2m+1)+n)when the number of machines is fixed.

关键词： Scheduling Early work Polynomial time approximation scheme Effcient polynomial time approximation scheme Fully polynomial time approximation scheme

Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy

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China Foundry 2024年第1期21卷 11-19页

作者： Wen-ning Liu wei Zhang Peng-yue Wang Yi-xian Liu xiang-yi Jiao Ao-xiang Wan Cheng-gang Wang Guo-dong Tong Shou-mei Xiong School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Tsinghua UniversityBeijing 100084Beijing China FAW Group Co. Ltd.Changchun 130013China China FAW Foundry Co. Ltd.Changchun 130013China

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg *** AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg *** elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-*** a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and *** an increase in slow shot speed,the size and number of ESCs and porosities significantly *** addition,the distribution of ESCs is more dispersed and the net-shrinkage *** tensile property is greatly improved by adopting a higher slow shot *** ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%).

关键词： hypoeutectic Al-Si alloy high pressure die casting porosity externally solidified crystal tensile property

Robot-Oriented 6G Satellite-UAV Networks: Requirements, Paradigm Shifts, and Case Studies

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China Communications 2024年第2期21卷 74-84页

作者： Peng wei wei Feng Yunfei Chen Ning Ge wei xiang Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Department of Engineering University of DurhamDH13LEDurhamUK School of Computing Engineering and Mathematical SciencesLa Trobe UniversityMelbourneVIC 3086Australia

Networked robots can perceive their surroundings, interact with each other or humans,and make decisions to accomplish specified tasks in remote/hazardous/complex environments. Satelliteunmanned aerial vehicle(UAV) networks can support such robots by providing on-demand communication services. However, under traditional open-loop communication paradigm, the network resources are usually divided into user-wise mostly-independent links,via ignoring the task-level dependency of robot collaboration. Thus, it is imperative to develop a new communication paradigm, taking into account the highlevel content and values behind, to facilitate multirobot operation. Inspired by Wiener’s Cybernetics theory, this article explores a closed-loop communication paradigm for the robot-oriented satellite-UAV network. This paradigm turns to handle group-wise structured links, so as to allocate resources in a taskoriented manner. It could also exploit the mobility of robots to liberate the network from full coverage,enabling new orchestration between network serving and positive mobility control of robots. Moreover,the integration of sensing, communications, computing and control would enlarge the benefit of this new paradigm. We present a case study for joint mobile edge computing(MEC) offloading and mobility control of robots, and finally outline potential challenges and open issues.

关键词： closed-loop communication mobility control satellite-UAV network structured resource allocation

Zinc-based metal-organic frameworks as efficient carriers for anticancer drug to reduce toxicity and increase efficacy

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Rare Metals 2024年第10期43卷 5152-5163页

作者： dong-wei Ma Jing-Sheng Lu xiang-Xin Cao Yan-wei Cheng Gang Wang Zi-Qian Zhang Bo-Cheng Chen Ning Lin Qing Chen College of Pharmacy Guangxi Scientific Research Center of Traditional Chinese MedicineGuangxi University of Chinese Medicine Guangxi Zhuang Yao Medicine Center of Engineering and Technology

The rational design of a specific co-drug delivery platform that can address the unavoidable resistance, toxic side effects and low targeting efficiency of traditional cancer treatments is of great ***, Zn-based MOF-zeolitic imidazole framework-90(ZIF-90) was selected as the drug delivery carrier, with the cancer therapeutic drug mercaptopurine(6-MP) and glucose oxidase(GOD) as the drug models, hyaluronic acid(HA) was used for protection and targeted delivery, which designed and fabricated an intelligent drug delivery platform(6-MP@ZIF-90@GOD@HA). This platform aims to reduce the toxic side effects of 6-MP and enhance its efficacy while improving the targeting ability of GOD,thereby further enhancing the treatment outcome. Notably,results from both in vitro and in vivo experiments demonstrate that the targeted synergistic chemo/reactive oxygen species(ROS)-mediated/starvation therapy inhibited the cancer cell growth while reducing the chemotherapy toxicity, which provides new possibilities for the development of more precise and effective treatment strategies.

关键词： Cancer treatment Combination therapy Drug delivery Metal-organic framework Reduced toxicity

Inter-stage performance and energy characteristics analysis of electric submersible pump based on entropy production theory

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Petroleum Science 2024年第2期21卷 1354-1368页

作者： Hui Wang Yang Yang Bin Xi wei-dong Shi Chuan Wang Lei-Lei Ji xiang-Yu Song Zhao-Ming He College of Hydraulic Science and Engineering Yangzhou UniversityYangzhou225009JiangsuChina College of Electrical and Mechanical Engineering Nanchang Institute of TechnologyNanchang330044JiangxiChina College of Mechanical Engineering Nantong UniversityNantong226019JiangsuChina National Research Center of Pumps Jiangsu UniversityZhenjiang212013JiangsuChina Zhejiang Zhenxing Petrochemical Machinery Co. Ltd.Ruian325204ZhejiangChina Department of Mechanical Engineering of Texas Tech University Lubbock79411TXUSA

The electric submersible pump(ESP) is a crucial apparatus utilized for lifting in the oil extraction *** lifting capacity is enhanced by the multi-stage tandem structure, but variations in energy characteristics and internal flow across stages are also introduced. In this study, the inter-stage variability of energy characteristics in ESP hydraulic systems is investigated through entropy production(EP) analysis,which incorporates numerical simulations and experimental validation. The EP theory facilitates the quantification of energy loss in each computational subdomain at all ESP stages, establishing a correlation between microscopic flow structure and energy dissipation within the system. Furthermore, the underlying causes of inter-stage variability in ESP hydraulic systems are examined, and the advantages and disadvantages of applying the EP theory in this context are evaluated. Consistent energy characteristics within the ESP, aligned with the distribution of internal flow structure, are provided by the EP theory, as demonstrated by our results. The EP theory also enables the quantitative analysis of internal flow losses and complements existing performance analysis methods to map the internal flow structure to hydraulic losses. Nonetheless, an inconsistency between the energy characterization based on EP theory and the traditional efficiency index when reflecting inter-stage differences is identified. This inconsistency arises from the exclusive focus of the EP theory on flow losses within the flow field, disregarding the quantification of external energy input to the flow field. This study provides a reference for the optimization of EP theory in rotating machinery while deeply investigating the energy dissipation characteristics of multistage hydraulic system, which has certain theoretical and practical significance.

关键词： Electric submersible pump(ESP) Entropy production theory Energy characteristics Inter-stage differences

PARP1-DNA co-condensation:the driver of broken DNA repair

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Signal Transduction and Targeted Therapy 2024年第6期9卷 2351-2353页

作者： xiang wei Fangfang Zhou Long Zhang Life Sciences Institute The Second Affiliated Hospital of the Zhejiang University School of MedicineThe MOE Key Laboratory of Biosystems Homeostasis&Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell BiologyZhejiang UniversityHangzhouChina The First Affiliated Hospital the Institutes of Biology and Medical SciencesSuzhou Medical CollegeSoochow UniversitySuzhouJiangsu 215123China

A recent study published by Simon Alberti1 in Cell has revealed that DNA double-strand break(DSB)sites that prevent the disjunction of broken DNA ends are formed through poly(ADPribose)(PAR)polymerase 1(PARP1)-DNA co-condensation.1(Fig.1).Here,a comprehensive and novel model was provided for the ordered assembly of PARP1-DNA condensates,which can rationally make clear broken DNA end synapses and how repair effectors are recruited to repair DSB.

关键词： PARP1 repair rational