检索结果-南通市图书馆

A Comparative Study of the Power-law Relationship between the Pulse width and Energy of Precursor and Main Burst

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第3期24卷 144-168页

作者： Hui-Ying Deng Zhao-Yang Peng Jia-ming {1. Dan Zhu College of Physics and Electronic Information Yunnan Normal UniversityKunming 650500China

In gamma-ray burst prompt emission,there is still no consistent conclusion if the precursor and main burst share the same *** this paper,we try to study this issue based on the relationship between pulse width and energy of the precursor and main *** systematically search the light curve data observed by Swift/BAT and Fermi/GBM,and find 1. long bursts with well-structured precursors and main *** fitting the precursor light curve of each different energy channel with the Norris function,we find that there is not only a power-law relationship between precursor width and energy,but also a power-law relationship between the ratio of the rising width to the decaying width and *** comparing the relationship between the precursors and the main burst pulses,we find that the distribution of the precursors and the relationship between the power-law indices are roughly the same as those of the main *** addition,it is found that the precursor width distribution as well as the upper limit of the pulse width ratio does not exceed 1.and both are asymmetric,which are also consistent with the main *** indicate that the precursor and the main burst are indistinguishable,and the precursor and the main burst may have the same physical origin.

关键词： methods data analysis-(stars) gamma-ray burst general-shock waves

Minimizing the ratio of ionizable lipid in lipid nanoparticles for in vivo base editing

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第6期11卷 285-293页

作者： Qiubing chen Xuebin Wang Yizhou Zhang {1. Tian Junyi Duan Ying Zhang Hao Yin Departments of Urology and Laboratory Medicine Frontier Science Center for Immunology and Metabolism Medical Research InstituteZhongnan Hospital of Wuhan UniversityWuhan University State Key Laboratory of Virology Tai Kang Center for Life and Medical Sciences Tai Kang Medical SchoolWuhan University Department of Rheumatology and Immunology Zhongnan Hospital of Wuhan UniversityWuhan University Wuhan Research Center for Infectious Diseases and Cancer Chinese Academy of Medical Sciences RNA Institute Wuhan University

Lipid nanoparticles(LNPs) have gained clinical approval as carriers for both siRNA and mRNA. Among the crucial components of LNPs, ionizable lipids play a pivotal role in determining the efficiency of RNA delivery. In this study, we synthesized a series of ionizable lipids, denoted as HTO, with a higher count of hydroxyl groups compared to SM-1.2. Remarkably, LNPs based on HTO1. lipid demonstrated comparable mRNA delivery efficiency and biosafety to those based on SM-1.2. However, the former reduced the ratio of ionizable lipid/total lipids to mRNA in LNPs by 2.5 times compared to SM-1.2. The HTO1. LNP efficiently encapsulated adenine base editor mRNA and sgRNA targeting Pcsk9, leading to substantial gene editing within the liver of mice and effective reduction of the target protein. Our study underscores that ionizable lipids with multiple hydroxyl groups may facilitate an improved lipid-to-mRNA ratio to minimize the dosage of ionizable lipids for in vivo delivery.

关键词： ionizable lipid lipid nanoparticle mRNA delivery base editor delivery Pcsk9

Intelligent geochemical interpretation of mass chromatograms:Based on convolution neural network

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 752-764页

作者： Kai-ming Su Jun-Gang Lu Jian Yu Zi-Xing Lu Shi-Jia {1. Hubei Key Laboratory of Petroleum Geochemistry and Environment Wuhan430100HubeiChina College of Resources and Environment Yangtze UniversityWuhan430100HubeiChina School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500SichuanChina Changqing Oilfield Company PetroChinaXi'an710021ShaanxiChina

Gas chromatography-mass spectrometry(GC-MS)is an extremely important analytical technique that is widely used in organic *** is the only approach to capture biomarker features of organic matter and provides the key evidence for oil-source correlation and thermal maturity ***,the conventional way of processing and interpreting the mass chromatogram is both timeconsuming and labor-intensive,which increases the research cost and restrains extensive applications of this *** overcome this limitation,a correlation model is developed based on the convolution neural network(CNN)to link the mass chromatogram and biomarker features of samples from the Triassic Yanchang Formation,Ordos Basin,*** this way,the mass chromatogram can be automatically *** research first performs dimensionality reduction for 1. biomarker parameters via the factor analysis and then quantifies the biomarker features using two indexes(*** and PMI)that represent the organic matter thermal maturity and parent material type,***,training,interpretation,and validation are performed multiple times using different CNN models to optimize the model structure and hyper-parameter setting,with the mass chromatogram used as the input and the obtained MI and PMI values for supervision(label).The optimized model presents high accuracy in automatically interpreting the mass chromatogram,with R2values typically above 0.85 and0.80 for the thermal maturity and parent material interpretation results,*** significance of this research is twofold:(i)developing an efficient technique for geochemical research;(ii)more importantly,demonstrating the potential of artificial intelligence in organic geochemistry and providing vital references for future related studies.

关键词： Organic geochemistry Biomarker Mass chromatographic analysis Automated interpretation Convolution neural network Machine learning

A PET probe targeting polyamine transport system for precise tumor diagnosis and therapy

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Pharmaceutical Sciences 2024年第3期19卷 146-159页

作者： ming Zhou Xiaoqin Yin Bei {1. Shuo Hu Wenhu Zhou Department of Nuclear Medicine Xiangya HospitalCentral South UniversityChangsha 410008China Xiangya School of Pharmaceutical Sciences Central South UniversityChangsha 410013China Key Laboratory of Biological Nanotechnology of National Health Commission Changsha 410008China National Clinical Research Center for Geriatric Disorders(Xiangya) Changsha 410008China

Polyamine metabolism dysregulation is a hallmark of many cancers,offering a promising avenue for early tumor *** study presents the development of a nuclear probe derived from spermidine(SPM)for dual-purpose tumor PET imaging and internal radiation *** probe,radiolabeled with either[68Ga]Ga for diagnostic applications or[1.7Lu]Lu for therapeutic use,was synthesized with exceptional purity,stability,and specific *** testing involving 1. different tumor cell lines revealed remarkable specificity towards B1. melanoma cells,showcasing outstanding tumor localization and target-to-non-target *** investigations employing polyamines,non-labeled precursor,and polyamine transport system(PTS)inhibitor,consistently affirmed the probe?s targetability through recognition of the ***,while previous reports indicated PTS upregulation in various tumor types for targeted therapy,this study observed no positive signals,highlighting a concentration-dependent discrepancy between targeting for therapy and ***,when labeled with[1.7Lu],the probe demonstrated its therapeutic potential by effectively controlling tumor growth and extending mouse *** into biodistribution,excretion,and biosafety in healthy humans laid a robust foundation for clinical *** study introduces a versatile SPM-based nuclear probe with applications in precise tumor theranostics,offering promising prospects for clinical implementation.

关键词： PET imaging Polyamine metabolism Spermine Radiopharmaceutical Melanoma

Genetic Engineered Ultrasound-Triggered Injectable Hydrogels for Promoting Bone Reconstruction

在线全文

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 431-447页

作者： Zhenyu Zhao Huitong Ruan Aopan chen Wei Xiong {1.zhu Zhang {1. Cai Wenguo Cui Department of Orthopaedics Shanghai Tenth People's HospitalSchool of MedicineTongji University No.301 Middle Yanchang RoadShanghai 200072China Department of Orthopaedics Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint DiseasesShanghai Institute of Traumatology and OrthopaedicsRuijin HospitalShanghai Jiao Tong University Schoolof Medicine197 Rujin 2nd RoadShanghai 200025China Department of Foot and Ankle Surgery Beijing Tongren HospitalCapital Medical University1 Dongjiao MinxiangBeijing 100730China

Genetic engineering technology can achieve specific gene therapy for a variety of diseases, but the current strategy still has some flaws, such as a complex system, single treatment, and large implantation trauma. Herein, the genetic engineering injectable hydrogels were constructed by ultrasonic technology for the first time to realize in vivo ultrasound-triggered in situ cross-linking and cell gene transfection, and finally complete in situ gene therapy to promote bone reconstruction. First, ultrasound-triggered calcium release was used to activate transglutaminase and catalyze the transamidation between fibrinogen. Simultaneously, liposome loaded with Zinc-finger E-box-binding homeobox 1.(ZEB1. gene plasmid (Lip-ZEB1. was combined to construct an ultrasound-triggered in situ cross-linked hydrogels that can deliver Lip-ZEB1. Second, ultrasound-triggered injectable hydrogel introduced ZEB1.gene plasmid into endothelial cell genome through Lip-ZEB1.sustained release, and then acted on the ZEB1.Notch signal pathway of cells, promoting angiogenesis and local bone reconstruction of osteoporosis through genetic engineering. Overall, this strategy provides an advanced gene delivery system through genetic engineered ultrasound-triggered injectable hydrogels.

关键词： sustained release linking

Wellbore-heat-transfer-model-based optimization and control for cooling downhole drilling fluid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1955-1968页

作者： Chao Wang He Liu Guo-Wei Yu chen Yu Xian-{1. Liu Peng Huang Yangtze University Jingzhou434023HubeiChina State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China CNPC Bohai Drilling Engineering Co. LtdTianjin300280China Exploration Development and Construction Engineering Division of PetroChina Jidong Oilfield Company Tangshan63200HebeiChin Henan University of Urban Construction Pingdingshan467036HenanChina

To address the two critical issues of evaluating the necessity of implementing cooling techniques and achieving real-time temperature control of drilling fluids underground in the current drilling fluid cooling technology,we first established a temperature and pressure coupled downhole heat transfer model,which can be used in both water-based and oil-based drilling ***,fourteen factors,which could affect wellbore temperature,were *** on the standard deviation of the downhole temperature corresponding to each influencing factor,the influence of each factor was *** influencing factors that can be used to guide the drilling fluid's cooling technology were drilling fluid thermal conductivity,drilling fluid heat capacity,drilling fluid density,drill strings rotation speed,pump rate,viscosity,ROP,and injection *** nondominated sorting genetic algorithm was used to optimize these six parameters,but the optimization process took 1.2 *** these eight parameters'influence rules with the nondominated sorting genetic algorithm can reduce the optimization time to 1.8 ***,the downhole temperature has been demonstrated to increase with the inlet temperature increasing linearly under quasi-steady *** this law and PID,the downhole temperature can be controlled,which can reduce the energy for cooling the surface drilling fluid and can ensure the downhole temperature reaches the set value as soon as possible.

关键词： Drilling Cooling Influencing factors Analysis Optimization Control

A Stable Copper-based Metal-Azolate Framework for Efficient Electroreduction of CO_(2)to C_(2+)Products

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2024年第4期40卷 664-669页

作者： LIU Yuan-Yuan ZHU Hao-Lin LIAO Pei-Qin chen Xiao-{1. Key Laboratory of Bioinorganic and Synthetic Chemistry Ministry of EducationGBRCE for Functional Molecular EngineeringSchool of ChemistryIGCMESun Yat-sen UniversityGuangzhou510275P.R.China Chemistry and Chemical Engineering Guangdong Laboratory Shantou515031P.R.China

Driven by renewable or excess electrical energy,electrochemical CO_(2)reduction reaction(eCO_(2)RR)represents a promising carbon-neutral approach to generating valuable low-carbon fuels by consuming CO_(2)and H_(2)O.C_(2+)products are one of the most economically valuable products among the reduction species of eCO_(2)RR,but there are still some challenges,such as low selectivity or low current *** this work,we showed that a copper-based metal-azolate framework(MAF),denoted as MAF-203,exhibits the high performance of eCO_(2)RR to yield C_(2+)products with the Faradaic efficiency(C_(2+))of 52.5%and a current density of 660 mA/cm^(2)at-1.2 V *** in a flow cell device under alkaline *** experiment,in situ infrared spectroscopy and the density functional theory(DFT)calculations showed that the electron donating effect of methyl substituents on organic ligands of the copper-based MAF could enhance the ligand field and activation of key intermediates(*CO and*CHO species),thus promoting the coupling of*CO and*CHO for yielding C_(2+)products.

关键词： Metal-organic framework Carbon dioxide Electroreduction C_(2+)product Metal-azolate framework

Ultrahigh spatiotemporal resolution beam signal reconstruction with bunch phase compensation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第5期35卷 99-108页

作者： You-ming Deng Yong-Bin Leng Xing-Yi Xu Jian {1. Yi-Mei Zhou Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of the Chinese Academy of Sciences Beijing 100049China Shanghai Synchrotron Radiation Facility Chinese Academy of SciencesShanghai 201204China University of Science and Technology of China Hefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

Various electromagnetic signals are excited by the beam in the acceleration and beam-diagnostic elements of a particle *** is important to obtain time-domain waveforms of these signals with high temporal resolution for research,such as the study of beam–cavity interactions and bunch-by-bunch parameter ***,a signal reconstruction algorithm with ultrahigh spatiotemporal resolution and bunch phase compensation based on equivalent sampling is proposed in this *** with traditional equivalent sampling,the use of phase compensation and setting the bunch signal zero-crossing point as the time reference can construct a more accurate reconstructed *** basic principles of the method,simulation,and experimental comparison are also *** on the beam test platform of the Shanghai Synchrotron Radiation Facility(SSRF)and the method of experimental verification,the factors that affect the reconstructed signal quality are analyzed and discussed,including the depth of the sampled data,quantization noise of analog-to-digital converter,beam transverse oscillation,and longitudinal *** results of the beam experiments show that under the user operation conditions of the SSRF,a beam excitation signal with an amplitude uncertainty of 2%can be reconstructed.

关键词： Turn-by-turn bunch phase compensation technique Equivalent sampling Signal reconstruction algorithm Ultrahigh spatiotemporal resolution SSRF

Microstructure recognition of steels by machine learning based on visual attention mechanism

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第4期31卷 909-923页

作者： Xing-yu chen Lin cheng cheng-yang Hu Yu-peng Zhang Kai-ming Wu The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyCollaborative Center on Advanced SteelsWuhan University of Science and TechnologyWuhan 430081HubeiChina Metals Valley and Band(Foshan)Metallic Composite Materials Co. Ltd.Foshan 528000GuangdongChina

U-Net has achieved good performance with the small-scale datasets through skip connections to merge the features of the low-level layers and high-level layers and has been widely utilized in biomedical image segmentation as well as recent microstructure image segregation of the *** representative visual attention mechanism modules,named as squeeze-and-excitation networks,convolutional block attention module,and extended calibration algorithm,were intro-duced into the traditional U-Net architecture to further improve the prediction *** is found that compared with the original U-Net architecture,the evaluation index of the improved U-Net architecture has been significantly improved for the microstructure segmentation of the steels with the ferrite/martensite composite microstructure and pearlite/ferrite composite microstructure and the complex martensite/austenite island/bainite microstructure,which demonstrates the advantages of the utilization of the visual attention mechanism in the microstructure *** reasons for the accuracy improvement were discussed based on the feature maps analysis.

关键词： Microstructure recognition-Steel Machine learning Visual attention mechanism Visualization