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Inhibitory Effects of Saponins From Anemarrhena asphodeloides Bunge on the Growth of Vascular Smooth Muscle Cells

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Biomedical and Environmental Sciences 2006年第3期19卷 185-191页

作者： SHANG-ZHI XIAO MING-EN xu ya-kun GE GUI-FENG XIAO Department of Biomedical Engineering Zhejiang University （Yuquan Campus） Hangzhou 310027 Zhejiang China

Objective To investigate the effects of saponins from Anemarrhena asphodeloides Bunge （SAaB）（Botanical Name： Anemarrhena Asphodeloidis Rhizoma） on the growth of vascular smooth muscle cells （VSMCs）. Methods Cell proliferation was measured by a newly developed cell proliferation reagent, WST-1. Cell apoptosis was assayed by flow cytometry through detecting annexin V. Nitric oxide production was evaluated using confocal laser scanning microscopy with diaminofluorescein diacetate （DAF-2, DA）. Cell aldose reductase （AR） activity, as well as the effect of Epalrestat and interleukin-1β were also explored. Results WST assay showed that cell proliferation induced by serum was significantly inhibited by SAaB （P〈0.01）. Flow cytometry analysis revealed that SAaB could enhance apoptotic rate of VSMCs （P〈0.01）. Nitric oxide production was significantly enhanced after administration of SAaB and interleukin-Iβ Moreover, AR activity of VSMCs was also remarkably inhibited by both SAaB and Epalrestat （P〈 0.01）. Conclusion SAaB can inhibit proliferation and enhance apoptosis of VSMCs. It may protect vascular cells by inhibiting VSMC proliferation and augmenting apoptotic rate of VSMCs via NO-dependent pathway.

关键词： Anemarrhena asphodeloides Bunge Saponins Vascular smooth muscle cells Proliferation

Quantifying soil nitrous oxide emissions in spring freezing-thawing period over different vegetation types in Northeast China

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Journal of Mountain Science 2022年第7期19卷 1919-1930页

作者： WU Bin MU Chang-cheng LIU Hui xu ya-kun ZHANG Yue yaNG Jia-shuo xu Wen-nian Hubei Key Laboratory of Construction and Management in Hydropower Engineering China Three Gorges UniversityYichang443002China College of Hydraulic&Environmental Engineering China Three Gorges UniversityYichang443002China Ministry of Education Key Laboratory of Sustainable Forest Ecosystem Management Northeast Forestry UniversityHarbin150040China Survey Planning and Design Institute of DaxinganlingNational Forestry and Grassland AdministrationDaxinganling165100China Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region Ministry of EducationChina Three Gorges UniversityYichang443002China State Key Laboratory of Forest and Soil Ecology Institute of Applied EcologyChinese Academy of SciencesShenyang110016China Hubei Key Laboratory of Disaster Prevention and Mitigation China Three Gorges UniversityYichang443002China Key Laboratory of Geological Hazards on Three Gorges Reservoir Area Ministry of EducationYichang443002China

Environmental changes significantly alter the structure,diversity and activity of soil microbial communities during spring freezing-thawing period,leading to changes in the soil microbial nitrogen *** in N_(2)O fluxes after land use conversion from primary forest to secondary forest,Korean pine plantation and cropland in northeast China have not been *** experiments were conducted to measure soil N_(2)O fluxes in a primary forest,two secondary forests,a Korean pine plantation,and one maize field in a temperate region in northeast China from 2017-03-06 to *** the experimental period,the soil was exclusively a nitrogen source for all land *** found that N_(2)O emissions ranged from 15.63 to 68.74μg m^(-2) h^(-1),and cumulative N_(2)O emissions ranged from 0.33 to 2.10 kg ha^(-1) during the *** N_(2)O emissions from the maize field were significantly higher than that from primary forest,Korean pine plantation,hardwood forest,and Betula platyphylla forest by 262.1% to 536.4%.Compared with other ecosystems in similar studies,the N_(2)O emission rates of all ecosystem types in this study were low during the spring thaw *** multiple linear regression indicated that there were significant correlations between N_(2)O emissions and environmental factors(air temperature and soil temperature,soil water content,soil p H,NH_(4)^(+)-N,NO_(3)^(-)-N,and soil organic carbon).The results showed that conversion of land use from primary forest to hardwood forest,Korean pine plantation or maize field greatly increased soil N_(2)O emissions during spring freezing-thawing period,and N_(2)O emissions from primary forest were almost the same as those from Betula platyphylla forest.

关键词： N_(2)O emission Land use change Environmental factors Nitrogen cycle

Introducing urea into tirapazamine derivatives to enhance anticancer therapy

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National Science Review 2024年第4期11卷 245-253页

作者： yajun xu Jianlin Lv Chaoying Kong ya Liu kun Wang Zhaohui Tang xuesi Chen Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Applied Chemistry and Engineering University of Science and Technology of China

Tirapazamine（TPZ） has been approved for multiple clinical trials relying on its excellent anticancer ***,as a typical hypoxia-activated prodrug（HAP）,TPZ did not exhibit survival advantages in Phase Ⅲ clinical trials when used in combination therapy due to the insufficient hypoxia levels in patients' *** this study,to improve the therapeutic effects of TPZ,we first introduced urea to synthesize a series of urea-containing derivatives of *** urea-containing TPZ derivatives showed increased hypoxic cytotoxicity（9.51-30.85-fold） compared with TPZ,while maintaining hypoxic ***,one of these derivatives,showed 20-fold higher cytotoxicity than TPZ while maintaining a similar hypoxic cytotoxicity *** highly efficiently deliver TPZP to the tumors and reduce its side effects on healthy tissues,we further prepared TPZP into a nanodrug with fibrin-targeting ability:***4-NPs,a vascular disrupting agent,was used to increase the fibrin level within tumors and exacerbate tumor *** being combined with CA4-NPs,FT11-TPZP-NPs can accumulate in the hypoxia-aggravated tumors and activate sufficiently to kill tumor *** a single-dose treatment,FT11-TPZP-NPs+CA4-NPs showed a high inhibition rate of 98.1% against CT26 tumor models with an initial volume of ～480 mm3and four out of six tumors were completely eliminated;it thereby exerted a significant antitumor *** study provides a new strategy for improving the therapeutic effect of TPZ and other HAPs in anticancer therapy.

关键词： tirapazamine vascular disrupting agent hypoxia-activated prodrug combretastatin A4 urea

Current and Potential Roles of Ferroptosis in Bladder Cancer

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Current Medical Science 2024年第1期44卷 51-63页

作者： Wen-xin AN Radheshyam Gupta kun ZHAI ya-ru WANG Wan-hai xu yan CUI Department of Urology Harbin Medical University Cancer HospitalHarbin 150081China Department of Internal Medical Oncology Harbin Medical University Cancer HospitalHarbin 150081China

Ferroptosis,a type of regulated cell death driven by iron-dependent lipid peroxidation,is mainly initiated by extramitochondrial lipid peroxidation due to the accumulation of iron-dependent reactive oxygen *** is a prevalent and primitive form of cell *** cellular metabolic processes regulate ferroptosis,including redox homeostasis,iron regulation,mitochondrial activity,amino acid metabolism,lipid metabolism,and various disease-related signaling *** plays a pivotal role in cancer therapy,particularly in the eradication of aggressive malignancies resistant to conventional *** studies have explored the connection between ferroptosis and bladder cancer,focusing on its incidence and treatment *** biomolecules and tumor-associated signaling pathways,such as p53,heat shock protein 1,nuclear receptor coactivator 4,RAS-RAF-MEK,phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin,and the Hippo-tafazzin signaling system,exert a moderating influence on ferroptosis in bladder *** inducers,including erastin,artemisinin,conjugated polymer nanoparticles,and quinazolinyl-arylurea derivatives,hold promise for enhancing the effectiveness of conventional anticancer medications in bladder cancer *** conventional therapeutic drugs and treatment methods related to ferroptosis offers a promising approach for the treatment of bladder *** this review,we analyze the research on ferroptosis to augment the efficacy of bladder cancer treatment.

关键词： ferroptosis bladder cancer ferroptosis-associated tumor signaling pathway ferroptosis inducer

A froth velocity measurement method based on improved U-Net++semantic segmentation in flotation process

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1816-1827页

作者： Yiwei Chen Degang xu kun Wan School of Automation Central South UniversityChangsha 410083China

During flotation,the features of the froth image are highly correlated with the concentrate grade and the corresponding working *** static features such as color and size of the bubbles and the dynamic features such as velocity have obvious differences between different working *** extraction of these features is typically relied on the outcomes of image segmentation at the froth edge,making the segmentation of froth image the basis for studying its visual ***,the absence of scientifically reliable training data with label and the necessity to manually construct dataset and label make the study difficult in the mineral *** solve this problem,this paper constructs a tungsten concentrate froth image dataset,and proposes a data augmentation network based on Conditional Generative Adversarial Nets(cGAN)and a U-Net++-based edge segmentation *** performance of this algorithm is also evaluated and contrasted with other algorithms in this *** the results of semantic segmentation,a phase-correlationbased velocity extraction method is finally suggested.

关键词： froth flotation froth segmentation froth image data augmentation velocity extraction image features

Dielectric Constant Calculation of Poly(vinylidene fluoride)Based on Finite Field and Density Functional Theory

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Chinese Journal of Polymer Science 2024年第5期42卷 655-662,I0009页

作者： Yong-Zhi Lin Lu-kun Feng ya-Dong Li Chao-Fan Chang Cai-Zhen Zhu Ming-Liang Wang Jian xu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen518055China Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu610041China

In this study,we proposed a novel method that integrates density functional theory(DFT)with the finite field method to accurately estimate the polarizability and dielectric constant of *** approach effectively accounts for the influence of electronic and geometric conformation changed on the dielectric *** validated our method using polyethylene(PE)and polytetrafluoroethylene(PTFE)as benchmark materials,and found that it reliably predicted their dielectric ***,we explored the impact of conformation variations in poly(vinylidene fluoride)(PVDF)on its dielectric constant and *** resulting dielectric constants ofα-andγ-PVDF(3.0)showed excellent agreement with crystalline PVDF in *** findings illuminate the relationship between PVDF’s structural properties and its electrical behavior,offering valuable insights for material design and applications.

关键词： Dielectric constant PVDF Finite field DFT

Electrochemical radical-polar crossover:a radical approach to polar chemistry

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Science China Chemistry 2024年第2期67卷 450-470页

作者： Zhoumei Tan Haonan Zhang kun xu Chengchu Zeng Faculty of Environment and Life Beijing University of TechnologyBeijing100124China

Radical-polar crossover(RPC) reaction bridges the gap between one-and two-electron reactivities,thus providing an ideal solution to overcome the limitations of both radical and polar *** this manifold,organic electrochemistry provides a uniquely facile strategy to access a diverse array of radical intermediates,thus broadening the chemical space of the RPC *** review highlights the synthetic advances in the field of electrochemical RPC reactions since 2020,with an emphasis on the substrate scope,reaction limitation and mechanistic *** related RPC reactions are categorized as netoxidative,net-reductive,or redox neutral transformations.

关键词： electrosynthesis radical-polar crossover radical chemistry polar chemistry alkene functionalization

Improving the accuracy of precipitation estimates in a typical inland arid area of China using a dynamic Bayesian model averaging approach

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Journal of Arid Land 2024年第3期16卷 331-354页

作者： xu Wenjie DING Jianli BAO Qingling WANG Jinjie xu kun College of Geography and Remote Sensing Sciences Xinjiang UniversityUrumqi 830017China Key Laboratory of Smart City and Environment Modelling of Higher Education Institute Xinjiang UniversityUrumqi 830017China

Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water *** and integrating precipitation datasets from different sources to accurately characterize precipitation patterns has become a challenge to provide more accurate and alternative precipitation information for the region,which can even improve the performance of hydrological *** study evaluated the applicability of widely used five satellite-based precipitation products(Climate Hazards Group InfraRed Precipitation with Station(CHIRPS),China Meteorological Forcing Dataset(CMFD),Climate Prediction Center morphing method(CMORPH),Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record(PERSIANN-CDR),and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA))and a reanalysis precipitation dataset(ECMWF Reanalysis v5-Land Dataset(ERA5-Land))in Xinjiang using ground-based observational precipitation data from a limited number of meteorological *** on this assessment,we proposed a framework that integrated different precipitation datasets with varying spatial resolutions using a dynamic Bayesian model averaging(DBMA)approach,the expectation-maximization method,and the ordinary Kriging interpolation *** daily precipitation data merged using the DBMA approach exhibited distinct spatiotemporal variability,with an outstanding performance,as indicated by low root mean square error(RMSE=1.40 mm/d)and high Person's correlation coefficient(CC=0.67).Compared with the traditional simple model averaging(SMA)and individual product data,although the DBMA-fused precipitation data were slightly lower than the best precipitation product(CMFD),the overall performance of DBMA was more *** error analysis between DBMA-fused precipitation dataset and the more advanced Inte

关键词： precipitation estimates satellite-based and reanalysis precipitation dynamic Bayesian model averaging streamflow simulation Ebinur Lake Basin Xinjiang

Characteristics and geological significance of the stress state of the lithosphere in the Qinghai-Tibetan Plateau and its neighboring areas

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Science China Earth Sciences 2024年第6期67卷 1836-1855页

作者： Qianwen ZHANG ya xu Wei CHU Shupeng LU Key Lab of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The present-day lithospheric stress state of the Qinghai-Tibetan Plateau and neighboring areas is controlled by both the lithosphere itself and the underlying *** other words,the stress is affected by the gravitational potential energy(GPE)difference caused by the change in the density distribution within the lithosphere and the drag force on the base of the lithosphere caused by mantle *** study of the lithospheric stress state plays an important role in further understanding the dynamic background and mechanism for the evolution of the Qinghai-Tibetan *** this study,the Crust1.0 crustal density model combined with the S40RTS mantle shear wave velocity variation model was used to calculate the *** EGM2008gravity field model was used to calculate the drag force from mantle convection at the base of the *** lithospheric and joint stress fields of the two sources were obtained by solving the force balance under the thin sheet *** way,we could comprehensively analyze the characteristics of the stress state within the *** regions were classified according to the GPE stress field,mantle drag force stress field,the relative magnitude of the two stress fields,and correlation between the two stress fields and surface *** lithospheric stress fields of the Tarim Basin and other stable blocks are mainly controlled by the GPE *** lithospheric stress field in the collision zone between the Indian Plate and the QinghaiTibetan Plateau is predominantly controlled by the deep mantle drag *** lithospheric stress field in the interior of the Plateau is controlled by both GPE and mantle *** correlation between the lithospheric stress field and surface deformation at the southeast margin of the Qinghai-Tibetan Plateau is *** is hypothesized that the presence of lower crustal flow with lower effective viscosity leads to crust-mantle decoupling,and the mantle drag force has a weaker influe

关键词： Qinghai-Tibetan Plateau Gravitational potential energy Mantle convection Lithospheric deviatoric stress field GPS strain rate field