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Ni-catalyzed highly regio- and stereo-selective diborylative cyclization of 1,6-enynes with diboron reagent

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Science China Chemistry 2024年第3期67卷 981-989页

作者： Qitao Guan zhen Shen Yiqiang Tian Genping Huang Chun zhang Institute of Molecular Plus Tianjin Key Laboratory of Molecular Optoelectronic ScienceDepartment of ChemistrySchool of SciencesTianjin UniversityTianjin 300072China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China

The Ni-catalyzed highly selective diborylative cyclization of 1,6-enynes with diboron reagent has been developed. When pinB-Bdan was used, multiple types of boron-containing functional groups could be installed into organic molecule with great chemoselectivity and regioselectivity though this reaction. Meanwhile, if B_2pai_2 was employed, the asymmetric diborylative cyclization could be well induced by using strategy of dynamic kinetic resolution. Importantly, the above reactions could afford desired product with 100% atomic economy, and could be compatible with different series of substituents. The studies of further transformation well illustrated that different type products could serve diverse synthetic strategy. Notably, the reaction mechanism was intensively studied by density functional theory(DFT) calculations, which could reveal the mechanism of regio- and enantio-selective control.

关键词： nickel-catalyzed organoboron cyclization regioselectivity enantioselectivity

SDCC: software-defined collective communication for distributed training

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Science China(Information Sciences) 2024年第9期67卷 105-125页

作者： Xin JIN zhen zhang Yunshan JIA Yun MA Xuanzhe LIU School of Computer Science Peking University Department of Computer Science and Technology Johns Hopkins University

Communication is crucial to the performance of distributed training. Today's solutions tightly couple the control and data planes and lack flexibility, generality, and performance. In this study, we present SDCC, a software-defined collective communication framework for distributed training. SDCC is based on the principle of modern systems design to effectively decouple the control plane from the data *** abstracts the operations for collective communication in distributed training with dataflow operations and unifies computing and communication with a single dataflow graph. The abstraction, together with the unification, is powerful: it enables users to easily express new and existing collective communication algorithms and optimizations, simplifies the integration with different computing engines(e.g., Py Torch and Tensor Flow) and network transports(e.g., Linux TCP and kernel bypass), and allows the system to improve performance by exploiting parallelism exposed by the dataflow graph. We further demonstrate the benefits of SDCC in four use cases.

关键词： machine learning systems distributed training deep learning collective communication software-defined networking

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Clinical significance of peripheral blood immune cells in patients with gastric cancer after surgery

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2521-2527页

作者： Qian-Wen Wang jie-Wen Zhu Ling-zhen Gong Department of Clinical Laboratory Huangshi Central Hospital(Affiliated Hospital of Hubei Polytechnic University)Huangshi 435000Hubei ProvinceChina Hubei Key Laboratory of Kidney Disease Pathogenesis and Intervention Huangshi 435000Hubei ProvinceChina Huangshi Tumor Molecular Diagnosis and Treatment Key Laboratory Huangshi 435000Hubei ProvinceChina

BACKGROUND Gastric cancer is one of the most common malignant tumors worldwide,and surgical resection is one of the main ways to treat gastric ***,the immune status of postoperative patients is crucial for prognosis and survival,and immune cells play an important role in this ***,it is helpful to understand the immune status of postoperative patients by evaluating the levels of peripheral blood immune cells,especially total T cells(CD3+),helper T cells(CD3+CD4+),and suppressor T cells(CD3+CD8+),and its relationship to *** To analyzed the immune cells in peripheral blood of patients with gastric cancer after surgery,detect the levels of total T cells,helper T cells and suppressor T *** A total of 58 patients with gastric cancer who received surgical treatment were included in the retrospective *** cytometry was used to detect the level of peripheral blood immune cells and analyze the correlation between total T cells,helper T cells and inhibitory T *** explore the relationship between these immune markers and patient *** The results showed that the levels of total T cells,helper T cells,and suppressor T cells changed in patients after gastric cancer *** was a significant positive correlation between total T cells,helper T cells and suppressor T cells(r=0.35,P<0.01;r=0.56,P<0.01).However,there was a negative correlation between helper T cells and suppressor T cells(r=-0.63,P<0.01).Follow-up showed that the survival rate of patients in the high-level total T cell group was significantly higher than that in the low-level group(28.87±24.98 months vs 18.42±16.21 months).The survival curve shows that the curve of patients in the high-level group is shifted to the upper right,and that of the low-level group is shifted *** was no significant difference between the levels of helper T cells and suppressor T cells and patient survival *** By detecting peripheral blood immune c

关键词： Gastric cancer surgery Peripheral blood immune cells Flow cytometry Survival analysis Immune monitoring

Novel process for facile preparation of mesoporous silica-based materials with controllable pore structure from coal fly ash Author links open overlay panel

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Particuology 2024年第8期91卷 128-137页

作者： Jian-ming Gao zhen Li Shujia Ma Yuanyuan zhang Fangqin Cheng Institute of Resources and Environment Engineering State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste ResourcesShanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related WastesShanxi UniversityTaiyuan 030006China

Extraction of silica from fly ash to produce mesoporous silica materials is one of the most important utilization *** silica could not be synthesized on a large-scale by conventional sol-gel *** this paper,facile preparation of mesoporous silica with controllable pore structure from fly ash by the template-free process via two steps of mineral phase transformation and selective acid etching was *** influence of crystalline structure and acid etching degree on structure of as-synthesized mesoporous silica materials was revealed,as well as mechanism of crystalline structure transformation and pore structure *** results show that mullite and quartz could be transformed into acid-soluble kaliophilite when fly ash reacted with K_(2)CO_(3)at temperature of 800-1100℃.The hexagonal kaliophilite would be transformed into orthorhombic KAlSiO_(4)-O1 phase when the temperature is controlled at 1100℃.Mesoporous silica with specific surface area of 475.93 m^(2)/g and 642.57 m^(2)/g could be synthesized from activated fly ash with kaliophilite and KAlSiO_(4)-O1 phase crystalline *** controlling the degree of acid etching,mesoporous silica materials with different pore structures can be *** paper provides a cost-effective and large-scale process for the preparation of mesoporous silica materials with controllable pore structure from solid waste fly ash.

关键词： Fly ash Mesoporous silica Crystal transformation Acid etching Controllable pore structure

The Effect of Blending Ratio on the Structure and Properties of the PPR/PS In situ Fiber Reinforced System Prepared by Multi-Flow Vibration Injection Molding

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Chinese Journal of Polymer Science 2024年第6期42卷 851-863页

作者： Yan-Jiang Li Meng-Long Hu Jun-Wen zhang Qiang Fu jie zhang College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China

To enhance the mechanical properties of polypropylene random copolymer(PPR),polystyrene(PS)with four different contents were added to the PPR matrix through melt ***,using the Multi-Flow Vibration Injection Molding(MFVIM)technology,PPR/PS in situ microfiber composites(MFC)with different blending ratios were *** results indicated that blending ratio had a great impact on the phase morphology and crystal structure of MFVIM samples,which was different from those of conventional injection molding(CIM)*** ultrafine fibers could be formed under the shear field and could absorb the PPR molecular chains to form hybrid shish-kebab ***,the PPR matrix could also form shish-kebab structures under the effect of strong *** the PS content reached 20%,under the combined action of PS in situ microfibers and highly oriented crystal structure,the tensile strength and Young’s modulus of the sample were obviously improved and the impact strength remained at a relatively high *** a strong and tough balanced PPR based material was *** results provide valuable insights for expanding the industrial and daily-life applications of PPR and show promising development prospects.

关键词： PPR MFVIM In situ microfibers Shearfield Hybrid shish-kebab structures

Piezoelectric fibers based on silk fibroin with excellent output performance

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Chinese Physics B 2024年第8期33卷 128-135页

作者：甄文强陈杰范苏娜张耀鹏 State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China

The self-powered tissue engineering scaffold with good biocompatibility is of great significance for stimulating nerve cell *** this study,silk fibroin(SF)-based fibers with regulatable structure and piezoelectric performance are fabricated by dry-spinning and *** concentration of SF and calcium ion in spinning dope and the post-treatment affect the conformation transition and crystallinity of *** a result,the SF fibers exhibit high piezoelectric coefficient d_(33)(3.24 pm/V)and output voltage(~27 V).Furthermore,these piezoelectric fibers promote the growth of PC-12 cells,demonstrating the promising potential for nerve repair and other energy harvester.

关键词： silk fibroin piezoelectric fiber dry-spinning conformation transition

Absence of ultrasonic-vibration-induced plasticity in metallic glacial glasses

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Rare Metals 2024年第7期43卷 3422-3429页

作者： Zhe Chen Shuai Ren Jian Zhu jie Shen Xin Li He-Ting zhang Hong-Ji Lin Sajad Sohrabi Wen-Qing Ruan zhen-Xuan zhang Xiong Liang Jiang Ma Jun Shen Shenzhen Key Laboratory of High Performance Nontraditional Manufacturing College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Mechanical Electrical and Information EngineeringShandong UniversityWeihai 264209China

Metallic glasses (MGs) have been found to exhibit unexpected ultrasonic-vibration-induced plasticity (UVIP),which provides a promising way to realize room temperature processing and molding of ***,whether all MGs poss... 详细信息

关键词： glasses metallic plasticity

FPGA implementation of 500-MHz high-count-rate high-time-resolution real-time digital neutron-gamma discrimination for fast liquid detectors

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Nuclear Science and Techniques 2024年第8期35卷 101-113页

作者： Hui‑Yin Shen Jing‑Long zhang jie zhang Jian‑Hang Zhou College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059China Southwestern Institute of Physics P.O.Box 432Chengdu 610041China

Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as *** this study,real-time neutron and gamma discrimination was implemented on a self-developed 500-Msps,12-bit digitizer,and the neutron and gamma spectra were calculated directly on an FPGA.A fast neutron flux measurement system with BC-501A and EJ-309 liquid scintillator detectors was developed and a fast neutron measurement experiment was successfully performed on the HL-2 M tokamak at the Southwestern Institute of Physics,*** experimental results demonstrated that the system obtained the neutron and gamma spectra with a time accuracy of 1 *** count rates of up to 1 Mcps,the figure of merit was greater than 1.05 for energies between 50 keV and 2.8 MeV.

关键词： Neutron-gamma discrimination Liquid scintillation detector Real-time spectrum analyzer

Succinylation modification:a potential therapeutic target in stroke

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Neural Regeneration Research 2024年第4期19卷 781-787页

作者： jie Lian Wenwu Liu Qin Hu Xiaohua zhang Department of Neurosurgery Ren Ji HospitalShanghai Jiao Tong University School of Medicine Department of Diving and Hyperbaric Medicine Naval Medical CenterNaval Medical University

Stroke is a leading cause of mortality and disability *** cell death triggered by the compromised supply of blood oxygen and glucose is one of the major pathophysiology of strokeinduced brain *** mitochondrial energy metabolism is observed minutes after stroke and is closely associated with the progression of ***,a new type of posttranslational modification,known as lysine succinylation,has been recognized to play a significant role in mitochondrial energy metabolism after ***,the role of succinylation modification in cell metabolism after stroke and its regulation are not well *** aimed to review the effects of succinylation on energy metabolism,reactive oxygen species generation,and neuroinflammation,as well as Sirtuin 5 mediated desuccinylation after *** also highlight the potential of targeting succinylation/desuccinylation as a promising strategy for the treatment of *** succinylation level is dynamically regulated by the nonenzymatic or enzymatic transfer of a succinyl group to a protein on lysine residues and the removal of succinyl catalyzed by *** evidence has suggested that succinylation can regulate the metabolic pathway through modulating the activity or stability of metabolic ***,especially Sirtuin 5,are characterized for their desuccinylation activity and have been recognized as a critical regulator of metabolism through desuccinylating numerous metabolic *** between succinylation and desuccinylation has been implicated in the pathophysiology of *** agents that enhance the activity of Sirtuin 5 have been employed to promote desuccinylation and improve mitochondrial metabolism,and neuroprotective effects of these agents have been observed in experimental stroke ***,their therapeutic efficacy in stroke patients should be validated.

关键词： mitochondria metabolism neuroprotection sirtuin 5 stroke succinylation modification