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Electrochemical Mono-Deuterodefluorination of Trifluoromethyl Aromatic Compounds with Deuterium Oxide

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CCS Chemistry 2024年第1期6卷 230-240页

作者： Jie Sheng xu cheng Institute of Chemistry and Biomedical Sciences Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023 State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 30071

The deuterodifluoromethyl group CF_(2)D combines the structural features of CF_(3) and CD_(3) groups,finding wide applications in diverse pharmaceutical entities.In this work,the electrochemical monodeuterodefluorination of Ar-CF_(3) to Ar-CF_(2)D is achieved with an unreported deuterium atom transfer-coupled electron transfer pathway using D_(2)O as the only D source for the first time.A series of Ar-CF_(3) substances,including commercial pharmaceuticals,were converted to corresponding CF_(2)D products in up to 91% yield and 97% D-incorporation.A variety of functional groups,including pyridine,pyrrole,furan,thiophene,borate,thio ether,amine,amide,sulfonamide,and halide,are well tolerated in this protocol.t-BuOLi was an essential reagent to achieve chemoselective mono-defluorination.

关键词： electrochemistry C-F activation fluorinecontaining drugs deuterated drugs deuterium oxide

Vision-based docking system for an aromatic-hydrocarbon-inspired reconfigurable robot

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Science China Technological Sciences 2024年第6期67卷 1798-1816页

作者： XING FangYi xu cheng LIU JinGuo xuE ZhiHui State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of Sciences School of Automation and Electrical Engineering Shenyang Ligong University Institutes for Robotics and Intelligent Manufacturing Chinese Academy of Sciences University of Chinese Academy of Sciences

Aromatic hydrocarbons generally refer to compounds containing benzene rings. Many types of isomers can be formed by replacing hydrogen atoms on the benzene ring. In this paper, an aromatic-hydrocarbon-inspired modular robot(AHIMR) is proposed.The robot can be reassembled into different configurations suitable for various task requirements. A vision-based docking system is designed for the AHIMR. The system primarily consists of two stages: a remote guidance stage and a precise docking stage.During the remote guidance stage, an object module is identified using an illumination adaptive target recognition algorithm,and then the active module moves to the docking area through communication with ZigBee. In the precise docking stage, the active module calculates the relative pose with the object module using a perspective-n-point method and dynamically adjusts its posture to dock. In this process, a Kalman filter is used to reduce target occlusion and jitter interference. In addition, the docking system feasibility is verified via several simulation experiments. The module docking accuracy is controlled within 0.01 m, which meets the reconfiguration task requirements of the AHIMR. In the AHIMR submodule docking experiment, the active module accurately moves to the expected position with a docking success rate of 95%.

关键词： modular robot reconfiguration aromatic hydrocarbon autonomous docking visual identification

Microstructure and property of laser additive manufactured alloy Ti–6Al–2V–1.5Mo–0.5Zr–0.3Si after aged at different temperatures

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Rare Metals 2024年第5期43卷 2275-2281页

作者： Guo-Chao Li xu cheng Hua-Ming Wang National Engineering Laboratory of Additive Manufacturing for Large Metallic Components and Engineering Research Center ofMinistry of Education on Laser Direct Manufacturing for Large Metallic Components School of Materials Science and Engineering Beihang University

The solid solution and aging treatment for conventional manufacturing processes might not be suitable for laser additive manufactured titanium alloys due to the different lamellar microstructures. In this study, the influence of aging temperatures (600, 700 and 800°C) on microstructure and mechanical properties of titanium alloy Ti–6Al–2V–1.5Mo–0.5Zr–0.3Si was investigated. The results indicate that after solid solution treatment at 970°C followed by water quenching, the alloy mainly consists of coarsening lamellar a phase in martensite a'matrix. Aging at 600°C will not change the size of primary lamellar a phase but lead to huge amount of secondary a phases (as)generating with very fine microstructure. By increasing the aging temperature, the number of asdecreases but with coarsened microstructures. When aged at 800°C, the width of the asphase reaches 350 nm, almost 7 times wider than that aged at 600°C. The changing size of asobviously influences the property of the alloy. The fine asleads to high strength and microhardness but low plasticity, and specimen aged at 700°C with suitable assize has the best comprehensive properties.

关键词： α + β titanium alloy Laser additive manufacturing Solid solution and aging treatment Microstructure Room temperature tensile property

Biomaterials and tissue engineering in traumatic brain injury:novel perspectives on promoting neural regeneration

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Neural Regeneration Research 2024年第10期19卷 2157-2174页

作者： Shihong Zhu Xiaoyin Liu Xiyue Lu Qiang Liao Huiyang Luo Yuan Tian xu cheng Yaxin Jiang Guangdi Liu Jing Chen Department of Neurosurgery West China HospitalWest China Medical SchoolSichuan UniversityChengduSichuan ProvinceChina National Engineering Research Center for Biomaterials College of Biomedical EngineeringSichuan UniversityChengduSichuan ProvinceChina Department of Anesthesiology West China HospitalWest China Medical SchoolSichuan UniversityChengduSichuan ProvinceChina Department of Pharmacy West China HospitalWest China Medical SchoolSichuan UniversityChengduSichuan ProvinceChina Out-patient Department West China HospitalWest China Medical SchoolSichuan UniversityChengduSichuan ProvinceChina Department of Respiratory and Critical Care Medicine West China HospitalWest China Medical SchoolSichuan UniversityChengduSichuan ProvinceChina

Traumatic brain injury is a serious medical condition that can be attributed to falls, motor vehicle accidents, sports injuries and acts of violence, causing a series of neural injuries and neuropsychiatric symptoms. However, limited accessibility to the injury sites, complicated histological and anatomical structure, intricate cellular and extracellular milieu, lack of regenerative capacity in the native cells, vast variety of damage routes, and the insufficient time available for treatment have restricted the widespread application of several therapeutic methods in cases of central nervous system injury. Tissue engineering and regenerative medicine have emerged as innovative approaches in the field of nerve regeneration. By combining biomaterials, stem cells, and growth factors, these approaches have provided a platform for developing effective treatments for neural injuries, which can offer the potential to restore neural function, improve patient outcomes, and reduce the need for drugs and invasive surgical procedures. Biomaterials have shown advantages in promoting neural development, inhibiting glial scar formation, and providing a suitable biomimetic neural microenvironment, which makes their application promising in the field of neural regeneration. For instance, bioactive scaffolds loaded with stem cells can provide a biocompatible and biodegradable milieu. Furthermore, stem cells-derived exosomes combine the advantages of stem cells, avoid the risk of immune rejection, cooperate with biomaterials to enhance their biological functions, and exert stable functions, thereby inducing angiogenesis and neural regeneration in patients with traumatic brain injury and promoting the recovery of brain function. Unfortunately, biomaterials have shown positive effects in the laboratory, but when similar materials are used in clinical studies of human central nervous system regeneration, their efficacy is unsatisfactory. Here, we review the characteristics and properties of various bioactive materials, followed by the

关键词： bioactive materials biomaterials exosomes neural regeneration scaffolds stem cells tissue engineering traumatic brain injury

Gut-targeted therapies for type 2 diabetes mellitus: A review

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World Journal of Clinical Cases 2024年第1期12卷 1-8页

作者： Tian-cheng xu Yun Liu Zhi Yu Bin xu Key Laboratory of Acupuncture and Medicine Research of Ministry of Education Nanjing University of Chinese MedicineNanjing 210023Jiangsu ProvinceChina

Type 2 diabetes mellitus(T2DM)is a chronic metabolic disorder characterized by hyperglycemia and insulin resistance.The global prevalence of T2DM has reached epidemic proportions,affecting approximately 463 million adults worldwide in 2019.Current treatments for T2DM include lifestyle modifications,oral antidiabetic agents,and insulin therapy.However,these therapies may carry side effects and fail to achieve optimal glycemic control in some patients.Therefore,there is a growing interest in the role of gut microbiota and more gut-targeted therapies in the management of T2DM.The gut microbiota,which refers to the community of microorganisms that inhabit the human gut,has been shown to play a crucial role in the regulation of glucose metabolism and insulin sensitivity.Alterations in gut microbiota composition and diversity have been observed in T2DM patients,with a reduction in beneficial bacteria and an increase in pathogenic bacteria.This dysbiosis may contribute to the pathogenesis of the disease by promoting inflammation and impairing gut barrier function.Several gut-targeted therapies have been developed to modulate the gut microbiota and improve glycemic control in T2DM.One potential approach is the use of probio-tics,which are live microorganisms that confer health benefits to the host when administered in adequate amounts.Several randomized controlled trials have demonstrated that certain probiotics,such as Lactobacillus and Bifidobacterium species,can improve glycemic control and insulin sensitivity in T2DM patients.Mechanisms may include the production of short-chain fatty acids,the improvement of gut barrier function,and the reduction of inflammation.Another gut-targeted therapy is fecal microbiota transplantation(FMT),which involves the transfer of fecal material from a healthy donor to a recipient.FMT has been used successfully in the treatment of Clostridioides difficile infection and is now being investigated as a potential therapy for T2DM.A recent randomized controlled trial showed that FMT from lea

关键词： Type 2 diabetes mellitus Gastroenterology Bacteria Implanted device

Image Recognition Model of Fraudulent Websites Based on Image Leader Decision and Inception-V3 Transfer Learning

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China Communications 2024年第1期21卷 215-227页

作者： Shengli Zhou cheng xu Rui xu Weijie Ding Chao Chen Xiaoyang xu Information Department of Zhejiang Police College Hangzhou 310053China Hangzhou Dianzi University Hangzhou 310018China Big Data Laboratory of Zhejiang Police College Hangzhou 310053China Hangzhou Public Security Bureau Hangzhou 310002China

The fraudulent website image is a vital information carrier for telecom fraud.The efficient and precise recognition of fraudulent website images is critical to combating and dealing with fraudulent websites.Current research on image recognition of fraudulent websites is mainly carried out at the level of image feature extraction and similarity study,which have such disadvantages as difficulty in obtaining image data,insufficient image analysis,and single identification types.This study develops a model based on the entropy method for image leader decision and Inception-v3 transfer learning to address these disadvantages.The data processing part of the model uses a breadth search crawler to capture the image data.Then,the information in the images is evaluated with the entropy method,image weights are assigned,and the image leader is selected.In model training and prediction,the transfer learning of the Inception-v3 model is introduced into image recognition of fraudulent websites.Using selected image leaders to train the model,multiple types of fraudulent websites are identified with high accuracy.The experiment proves that this model has a superior accuracy in recognizing images on fraudulent websites compared to other current models.

关键词： fraudulent website image leaders telecom fraud transfer learning

Unraveling the enigma:A comprehensive review of solid pseudopapillary tumor of the pancreas

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 614-629页

作者： Ye-cheng xu De-Liang Fu Feng Yang Department of Pancreatic Surgery Pancreatic Disease InstituteHuashan HospitalFudan UniversityShanghai 200040China

Solid pseudopapillary tumor of the pancreas(SPTP)is a rare neoplasm predom-inantly observed in young females.Pathologically,CTNNB1 mutations,β-catenin nuclear accumulation,and subsequent Wnt-signaling pathway activation are the leading molecular features.Accurate preoperative diagnosis often relies on imaging techniques and endoscopic biopsies.Surgical resection remains the mainstay treatment.Risk models,such as the Fudan Prognostic Index,show promise as predictive tools for assessing the prognosis of SPTP.Establishing three types of metachronous liver metastasis can be beneficial in tailoring individu-alized treatment and follow-up strategies.Despite advancements,challenges persist in understanding its etiology,establishing standardized treatments for unresectable or metastatic diseases,and developing a widely recognized grading system.This comprehensive review aims to elucidate the enigma by consolidating current knowledge on the epidemiology,clinical presentation,pathology,molecular characteristics,diagnostic methods,treatment options,and prognostic factors.

关键词： Pancreas Solid pseudopapillary tumor β-catenin Endoscopic ultrasound Surgery Recurrence Liver metastasis Prognostic prediction

A synthesis of the Cretaceous wildfire record related to atmospheric oxygen levels?

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Journal of Palaeogeography 2024年第1期13卷 149-164页

作者： Da-Wei Lü Wen-xu Du Zhi-Hui Zhang Yuan Gao Tian-Tian Wang Jin-cheng xu Ao-Cong Zhang cheng-Shan Wang Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals College of Earth Sciences and EngineeringShandong University of Science and TechnologyQingdao 266590Shandong ProvinceChina School of Earth Sciences and Resources China University of GeosciencesBejing 100083China Institute of Earth Sciences China University of Geosciences(Bejing)Beijing 100083China

The Cretaceous was a significant greenhouse period in Earth's history with higher atmospheric CO_(2) levels and temperatures than today. Although evidence of combustion has been widely described from the Cretaceous deposits, our understanding of the spatiotemporal diversification pattern and process of the Cretaceous wildfires is still limited. In this study, we comprehensively synthesize a total of 271 published Cretaceous wildfire occurrences based on the by-products of burning, including fossil charcoal, pyrogenic inertinite(fossil charcoal in coal), and pyrogenic polycyclic aromatic hydrocarbons(PAHs). Spatially, the dataset shows a distinctive distribution of reported wildfire evidence characterized by high concentration in the middle latitudinal areas of the Northern Hemisphere(30°N-60°N) over the Cretaceous. Temporally, an overall increasing trend of the reported wildfire data from the Early Cretaceous to the Late Cretaceous is coincident with higher atmospheric O_(2) levels. However, the spatial and temporal patterns may result from many types of factors, such as taphonomy, preservation, and researcher biases, instead of a real picture of the Cretaceous wildfire evolution. To better understand the spatiotemporal diversification of the Cretaceous wildfire, more investigations on the record of wildfire occurrences during this period would be necessary in the future.

关键词： Wildfire Cretaceous Atmospheric oxygen Taphonomy Charcoal

Generation,bonding and reactivity of transient zinc-substituted silylenes

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Science China Chemistry 2024年第4期67卷 1256-1262页

作者： cheng xu Thayalan Rajeshkumar Laurent Maron xuebing Leng Yaofeng Chen State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China Spin-X Institute School of Chemistry and Chemical EngineeringState Key Laboratory of Luminescent Materials and DevicesGuangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional MaterialsSouth China University of TechnologyGuangzhou 510641China LPCNO CNRS&INSAUniversitéPaul SabatierToulous 31077France

The metal-substituted silylenes are of high interest,as the theoretical studies indicated that the silylenes with electropositive substituents have a small ΔE_(S-T)(singlet-triplet energy gap)or even the ground-state triplets.However,such compounds are highly unstable,and only two transient alkali metal-substituted silylenes M(^(t)Bu_(3)Si)Si:(M=Li,K)were generated by photoextrusion of the alkali metal-substituted silacyclopropenes and merely studied by spectroscopic method(EPR)at low temperature(14 to 50 K).Herein,we report the generation of transient zinc-substituted silylenes from zinc silacyclopropanyl complexes under very mild and convenient conditions.The generated transient zinc-substituted silylenes are highly reactive and undergo intermolecular cycloaddition with alkenes for the synthesis of zinc-substituted Si-heterocyclic compounds.If there is no substrate,the zinc-substituted silylenes attack the C-C bonds of the β-diketiminato ligands and break the C-C bonds.DFT studies further highlight the silylene nature of the zinc-substituted silylene and a very small ΔE_(S-T)(4.4 kcal/mol).

关键词： zinc complex silylene C-C bond cleavage cycloaddition DFT calculations