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An envelope-based machine learning workflow for locating earthquakes in the southern Sichuan Basin

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Earthquake Research Advances 2024年第2期4卷 45-54页

作者： Kang Wang jie zhang ji zhang zhangyu Wang Ziyu Li School of Earth and Space Sciences University of Science and Technology of ChinaHefei230026China

The development of machine learning technology enables more robust real-time earthquake monitoring through automated implementations. However, the application of machine learning to earthquake location problems faces challenges in regions with limited available training data. To address the issues of sparse event distribution and inaccurate ground truth in historical seismic datasets, we expand the training dataset by using a large number of synthetic envelopes that closely resemble real data and build an earthquake location model named ENVloc. We propose an envelope-based machine learning workflow for simultaneously determining earthquake location and origin time. The method eliminates the need for phase picking and avoids the accumulation of location errors resulting from inaccurate picking results. In practical application, ENVloc is applied to several data intercepted at different starting points. We take the starting point of the time window corresponding to the highest prediction probability value as the origin time and save the predicted result as the earthquake location. We apply ENVloc to observed data acquired in the southern Sichuan Basin, China, between September 2018 and March 2019. The results show that the average difference with the catalog in latitude, longitude, depth, and origin time is 0.02°,0.02°, 2 km, and 1.25 s, respectively. These suggest that our envelope-based method provides an efficient and robust way to locate earthquakes without phase picking, and can be used in earthquake monitoring in near-real time.

关键词： Waveform envelope Earthquake location Local seismicity Synthetic data Sparse stations

Mannitol inhibits the proliferation of neural stem cell by a p38 mitogen-activated protein kinase-dependent signaling pathway

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Chinese Journal of Traumatology 2024年第1期27卷 42-52页

作者： Hai-Zhen Duan Xin Zhou Quan Hu Meng-Long Liu Shu-Hong Wang ji zhang Xu-Heng jiang Tian-Xi zhang An-Yong Yu Department of Emergency Affiliated Hospital of Zunyi Medical UniversityZunyi563000Guizhou provinceChina Dazhou Vocational College of Chinese Medicine Dazhou635000Sichuan provinceChina Dachuan District Traditional Chinese Medicine Hospital Dazhou635000Sichuan provinceChina

Purpose:Mannitol is one of the first-line drugs for reducing cerebral edema through increasing the extracellular osmotic pressure.However,long-term administration of mannitol in the treatment of cerebral edema triggers damage to neurons and astrocytes.Given that neural stem cell(NSC)is a subpopulation of main regenerative cells in the central nervous system after injury,the effect of mannitol on NSC is still elusive.The present study aims to elucidate the role of mannitol in NSC proliferation.Methods:C57 mice were derived from the animal house of Zunyi Medical University.A total of 15 pregnant mice were employed for the purpose of isolating NSCs in this investigation.Initially,mouse primary NSCs were isolated from the embryonic cortex of mice and subsequently identified through immunofluorescence staining.In order to investigate the impact of mannitol on NSC proliferation,both cell counting kit-8 assays and neurospheres formation assays were conducted.Thein vitro effects of mannitol were examined at various doses and time points.In order to elucidate the role of Aquaporin 4(AQP4)in the suppressive effect of mannitol on NSC proliferation,various assays including reverse transcription polymerase chain reaction,western blotting,and immunocytochemistry were conducted on control and mannitol-treated groups.Additionally,the phosphorylated p38(p-p38)was examined to explore the potential mechanism underlying the inhibitory effect of mannitol on NSC proliferation.Finally,to further confirm the involvement of the p38 mitogen-activated protein kinase-dependent(MAPK)signaling pathway in the observed inhibition of NSC proliferation by mannitol,SB203580 was employed.All data were analyzed using SPSS 20.0 software(SPSS,Inc.,Chicago,IL).The statistical analysis among multiple comparisons was performed using one-way analysis of variance(ANOVA),followed by Turkey’’s post hoc test in case of the data following a normal distribution using a Shapiro-Wilk normality test.Comparisons between 2 groups were determined using Student’s t-te

关键词： Mannitol Cerebral edema Neural stem cell Proliferation AQP4 p38 MAPK signaling pathway

Five quinolizidine alkaloids with anti-tobacco mosaic virus activities from two species of Sophora

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Chinese Chemical Letters 2024年第6期35卷 380-384页

作者： ji zhang Tong zhang Qiao An Peng zhang Cai-Yan Tian Chun-Mao Yuan Ping Yi Zhan-Xing Hu Xiao-jiang Hao State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical UniversityGuiyang 550014China Natural Products Research Center of Guizhou Province Guiyang 550014China School of Pharmaceutical Sciences Guizhou Medical UniversityGuiyang 550025China School of Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of ScienceKunming 650201China Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical SciencesKunming 650201China

Three novel matrine-type alkaloids(1-3)and two unprecedented aloperine-type alkaloids(4 and 5)were isolated from the root of Sophora tonkinensis and the seeds of Sophora alopecuroides respectively.Notably,compound 1 possessed an unprecedented 6/5/6 tricyclic skeleton,while compounds 2 and 3 characterized by rare 6/6/5/6 tetracyclic system and 6/6/6/6/6 pentacyclic system respectively.Moreover,compound 4 possessed an unprecedented 6/7/6/6 tetracyclic core,and compound 5 characterized by rare 6/6/6/6tetracyclic skeleton.Their structures were elucidated by comprehensive spectroscopic data analysis and electronic circular dichroism(ECD)calculations.Biological tests indicated that compound 5 displayed significant anti-tobacco mosaic virus(TMV)activity compared with the positive control ningnanmycin.

关键词： Matrine-type alkaloids Aloperine-type alkaloids Sophora tonkinensis Sophora alopecuroides Anti-tobacco mosaic virus

Threshold Selection and Resource Allocation for Quantized Identification

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Journal of Systems Science & Complexity 2024年第1期37卷 204-229页

作者： WANG Ying LI Xin ZHAO Yanlong zhang ji-Feng Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

This paper is concerned with the optimal threshold selection and resource allocation problems of quantized identification, whose aims are improving identification efficiency under limited resources. Firstly, the first-order asymptotically optimal quantized identification theory is extended to the weak persistent excitation condition. Secondly, the characteristics of time and space complexities are established based on the Cramér-Rao lower bound of quantized systems. On these basis, the optimal selection methods of fixed thresholds and adaptive thresholds are established under aperiodic signals, which answer how to achieve the best efficiency of quantized identification under the same time and space complexity. In addition, based on the principle of maximizing the identification efficiency under a given resource, the optimal resource allocation methods of quantized identification are given for the cases of fixed thresholds and adaptive thresholds, respectively, which show how to balance time and space complexity to realize the best identification efficiency of quantized identification.

关键词： Quantized output resource allocation system identification threshold selection.

Candidate reference measurement procedure for serum 17-hydroxyprogesterone quantification via isotope dilution liquid chromatography–tandem mass spectrometry

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iLABMED 2024年第2期2卷 98-107页

作者： ji zhang Yang jiang Ting Liu Xiongwei Liu Hui Huang Yanxiang Cheng jieyan Li Bangning Cheng Chungen Qian Xufu Xiang Jun-Fa Xu Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics Department of Clinical ImmunologyInstitute of Laboratory MedicineSchool of Medical TechnologyGuangdong Medical UniversityDongguanGuangdongChina Shenzhen YHLO Biotech Co. Ltd.ShenzhenGuangdongChina Shenzhen Longgang Central Hospital Clinical Laboratory ShenzhenGuangdongChina The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory Systems Biology ThemeDepartment of Biomedical EngineeringCollege of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanHubeiChina

Background:Accurate quantification of 17-hydroxyprogesterone(17-OHP)in serum is vital for clinical and research applications.However,inter-laboratory variability in test results exists owing to the lack of a standardized reference measurement procedure(RMP).Therefore,in this study,we developed a highly accurate,cost-effective,and user-friendly candidate RMP(cRMP)for analyzing 17-OHP in serum.Methods:We quantified 17-OHP in serum using a one-step liquid–liquid extraction method with the addition of 17-OHP-13C3,followed by liquid chromatography–tandem mass spectrometry.The ability of these methods to suppress interference was evaluated by chromatographic analysis.We assessed accuracy,specificity,the lower limit of quantitation,linearity,and matrix effects by following the standards specified by the Clinical and Laboratory Standards Institute.The consistency between the developed cRMP and the chemiluminescence method was evaluated through experiments with 120 clinical samples.Results:The developed cRMP required only 8 min for accurate quantification of serum 17-OHP without bias from matrix effects or interference from 19 metabolites added as potential interferents.The method exhibited favorable measurement performance,with a quantitation limit of 0.086 ng/mL,linear range of 0.1–400 ng/mL,a total imprecision of≤2.90%,spike recovery of 100.1%–100.6%,and relative deviations from assigned target values(RfB Institution)of−2.91%to 1.10%.The cRMP demonstrated good consistency with the conventional assay(chemiluminescence method),with a correlation coefficient R of 0.96977.Conclusion:A cRMP with high accuracy,cost-effectiveness,and convenient operation was developed for quantifying 17-OHP in serum.Its simplicity and robust performance make it an invaluable addition to the arsenal of analytical tools available for laboratories.This method can enhance the accuracy and reliability of 17-OHP measurements across various laboratories.

关键词： 17-hydroxyprogesterone isotope dilution liquid chromatography-tandem mass spectrometry reference measurement procedure serum

Monotropein Induced Apoptosis and Suppressed Cell Cycle Progression in Colorectal Cancer Cells

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Chinese Journal of Integrative Medicine 2024年第1期30卷 25-33页

作者： GAO Quan LI Lin zhang Qi-man SHENG Qin-song zhang ji-liang jiN Li-jun SHANG Rui-yan School of Pharmacy and Department of Medical Oncology the Affiliated Hospital of Hangzhou Normal UniversityHangzhou Normal UniversityHangzhou(311121)China Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines Engineering Laboratory of Development and Application of Traditional Chinese MedicinesCollaborative Innovation Center of Traditional Chinese Medicines of Zhejiang ProvinceHangzhou Normal UniversityHangzhou(311121)China Department of Colorectal Surgery the First Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhouChina Beijing Tong Ren Tang Chinese Medicine Co. Ltd.Beijing(100000)China Department of Traditional Chinese Medicine Hangzhou Shangcheng District People's HospitalHangzhou(310006)China Department of Gynecology Hangzhou Women's HospitalHangzhou(310008)China

Objective: To determine whether monotropein has an anticancer effect and explore its potential mechanisms against colorectal cancer(CRC) through network pharmacology and molecular docking combined with experimental verification. Methods: Network pharmacology and molecular docking were used to predict potential targets of monotropein against CRC. Cell counting kit assay, plate monoclonal assay and microscopic observation were used to investigate the antiproliferative effects of monotropein on CRC cells HCT116, HT29 and LoVo. Flow cytometry and scratch assay were used to analyze apoptosis and cell cycle, as well as cell migration, respectively in HCT116, HT29, and LoVo cells. Western blotting was used to detect the expression of proteins related to apoptosis, cell cycle, and cell migration, and the expression of proteins key to the Akt pathway. Results: The Gene Ontology and Reactome enrichment analyses indicated that the anticancer potential of monotropein against CRC might be involved in multiple cancer-related signaling pathways. Among these pathways, RAC-beta serine/threonine-protein kinase(Akt1, Akt2), cyclin-dependent kinase 6(CDK6), matrix metalloproteinase-9(MMP9), epidermal growth factor receptor(EGFR), cell division control protein 42 homolog(CDC42) were shown as the potential anticancer targets of monotropein against CRC. Molecular docking suggested that monotropein may interact with the 6 targets(Akt1, Akt2, CDK6, MMP9, EGFR, CDC42). Subsequently, cell activity of HCT116, HT29 and LoVo cell lines were significantly suppressed by monotropein(P<0.05). Furthermore, our research revealed that monotropein induced cell apoptosis by inhibiting Bcl-2 and increasing Bax, induced G_1–S cycle arrest in colorectal cancer by decreasing the expressions of CyclinD1, CDK4 and CDK6, inhibited cell migration by suppressing the expressions of CDC42 and MMP9(P<0.05), and might play an anticancer role through Akt signaling pathway. Conclusions: Monotropein exerts its antitumor effects primarily by arresting the cell cycle,

关键词： monotropein Chinese medicine anticancer activity colorectal cancer cells network pharmacology

Deployment of SMP Miura-ori sheet and its application:Aerodynamic drag and RCS reduction

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Chinese Journal of Aeronautics 2022年第8期35卷 121-131页

作者： ji zhang Changguo WANG Lamei zhang National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Center for Composite Materials and Structures Harbin Institute of TechnologyHarbin 150001China Department of Information Engineering Harbin Institute of TechnologyHarbin 150001China

Origami,such as Miura-ori,is the art of folding two-dimensional materials into complex,elaborate,and multifunctional three-dimensional objects.In this paper,SMP MO sheet are prepared,and the accuracy of deployable process is verified by experiments.The folding and deployable process of SMP MO sheet is divided into 4 stages,and each stage is described in detail.The stiffness of smart deployable stage is characterized by an exponential decline at the beginning and a gradual decrease to 0,and this is similar to the theoretical shear equivalent modulus in the Y direction.The effects of various parameters on strain and stress are also explored.The purpose of studying these mechanical characteristics is to provide driving force reference in application;In terms of application,the flow field and electromagnetic characteristics of MO sheet in different directions are studied.The aerodynamic drag and RCS reduction of MO unit cell and graded MO sheet during the deployable process are evaluated.When the dihedral fold angle is about 45°,the RCS reduction and drag reduction characteristics of MO sheet are relatively optimal,which is most beneficial to morphing aircraft.

关键词： Aerodynamic characteristics Deployment Miura-Ori Morphing aircraft RCS reduction SMP sheet

Pressure-induced instability and its coupled aeroelasticity of inflated pillow

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Chinese Journal of Aeronautics 2022年第2期35卷 1-7页

作者： ji zhang Changguo WANG jiaming GUO jiawei zhang National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Special Environments Harbin Institute of TechnologyHarbin 150080China b Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbin 150001China

A floating air weapon system(such as airborne floating mines)plays an important role in modern air defense operations.This paper focuses on aeroelastic characteristics of airborne floating mine named inflated pillow.Firstly,the dynamic deployable process of the pillow and characteristics of the local instability of the edge are studied,and the evolution mechanism of wrinkles and kinks is analyzed.Secondly,in the cruising stage,the fluid-structural-thermal coupling analysis is performed on the pillow,and the aeroelastic characteristics are studied.Thirdly,the shapepreserving effect of the inflated pillow during the“negative pressure”slow landing stage is evaluated.It is found that when the wind velocity is higher,the pillow has a collapsed instability(surface extrusion and contact),and when the wind velocity is lower,snap-through instability occurs.Finally,for the collapsed instability,a carbon fiber skeleton is added to discrete the large global collapsed fold into small local folds,thus achieving shape-preserving effect of pillow.For snapthrough instability,the critical internal pressure and different shape evolution under different wind velocity are evaluated.Through the analysis of the mechanical mechanism and control of the structural morphological evolution,it provides theoretical guidance for the application of the curved shell structure in floating air weapon system.

关键词： Aeroelastic analysis Fluid-structural-thermal coupling analysis Inflated pillow Kink Pressure-induced instability Wrinkle

Double-tract reconstruction is superior to esophagogastrostomy in controlling reflux esophagitis and enhancing quality of life after proximal gastrectomy:Results from a prospective randomized controlled clinical trial in China

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Chinese Journal of Cancer Research 2023年第6期35卷 645-659页

作者： Yinan zhang Hongtao zhang Yan Yan Ke ji Ziyu jia Heli Yang Biao Fan Anqiang Wang Xiaojiang Wu ji zhang jiafu ji Xin ji Zhaode Bu Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Gastrointestinal Cancer CenterPeking University Cancer Hospital&InstituteBeijing 100142China Guowen(Changchun)International Hospital Changchun 136199China State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers Beijing Key Laboratory of Carcinogenesis and Translational ResearchEndoscopy CenterPeking University Cancer Hospital&InstituteBeijing 100142China State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers Beijing Key Laboratory of Carcinogenesis and Translational ResearchGastrointestinal Cancer CenterPeking University Cancer Hospital&InstituteBeijing 100142China

Objective:The aim of this study was to prospectively compare double-tract reconstruction(DTR)and esophagogastrostomy(EG)after proximal gastrectomy(PG)regarding the incidence of reflux esophagitis,quality of life(QOL),nutritional status and surgical safety.Methods:This study was a randomized controlled trial.Patients eligible for PG were enrolled and randomly assigned to the EG group and DTR group.The characteristics of patients,parameters for surgical safety,incidence of reflux esophagitis,nutrition status and QOL were collected and compared between the two groups.Univariate analysis and multivariate analysis were performed to determine the significant factors affecting the incidence of reflux esophagitis after PG.Results:Thirty-seven patients of the EG group and 36 patients of the DTR group were enrolled.The incidence of reflux esophagitis was significantly lower in the DTR group than in the EG group(8.3%vs.32.4%,P=0.019).The DTR group demonstrated a more favorable QOL than the EG group after PG.The nutritional status was balanced within the EG group and the DTR group.The operation time was longer in the DTR group than in the EG group(191 min vs.221 min,P=0.001),while surgical safety was similar in the two groups.Conclusions:Our research demonstrated that DTR is superior to EG after PG in terms of the incidence of reflux esophagitis and provides a more satisfactory QOL without increasing surgical complications or sacrificing nutritional status.

关键词： Double-tract reconstruction proximal gastrectomy quality of life reflux esophagitis