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替米沙坦通过直接抑制Kv2.1通道促进离体大鼠的胰岛素分泌

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中国药理学通报 2024年第5期40卷 893-898页

作者：刘涛陈晓琴郭瑞旺崔丽娟刘师伟山西白求恩医院山西医科大学第三医院普通外科山西太原030032 山西医科大学基础医学院药理教研室山西太原030001 山西白求恩医院山西医科大学第三医院内分泌科山西白求恩医院内分泌科内分泌代谢病山西省重点实验室山西太原030032

目的研究替米沙坦促进大鼠胰岛素分泌作用相关的信号通路。方法(1)分离成年Wistar大鼠胰腺获得胰岛和胰岛细胞,通过胰岛素分泌实验观察药物对胰岛素分泌的影响,通过钙成像实验和全细胞膜片钳技术观察药物对β细胞内Ca^(2+)浓度的变化和... 详细信息

目的研究替米沙坦促进大鼠胰岛素分泌作用相关的信号通路。方法(1)分离成年Wistar大鼠胰腺获得胰岛和胰岛细胞,通过胰岛素分泌实验观察药物对胰岛素分泌的影响,通过钙成像实验和全细胞膜片钳技术观察药物对β细胞内Ca^(2+)浓度的变化和对离子通道的作用。(2)使用过表达电压门控性钾(voltage-gated potassium channel,Kv)通道2.1亚型(Kv2.1)的慢病毒转染中国仓鼠卵巢(Chinese hamster ovary,CHO)细胞构建CHO-Kv2.1细胞系,使用膜片钳技术观察替米沙坦对Kv2.1通道的直接作用。结果缬沙坦和厄贝沙坦无类似替米沙坦的高糖浓度下促胰岛素分泌、升高β细胞内Ca^(2+)浓度和抑制β细胞的Kv通道等作用。过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)阻断剂GW9662亦未阻断替米沙坦的上述作用。而替米沙坦可以浓度依赖性地抑制CHO-Kv2.1细胞的Kv2.1通道电流。结论替米沙坦的促胰岛素分泌作用可能与血管紧张素Ⅱ-1型(angiotensin II type 1,AT-1)受体和PPARγ无关,但至少与对Kv2.1通道的直接抑制作用有关。

关键词：替米沙坦 β细胞胰岛素分泌 AT-1受体 PPARγ Kv2.1通道

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职业本科人才培养方案制定现状、问题与路径探索——基于6校电子商务专业人才培养方案的实证调查

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职业教育研究 2024年第4期 25-31页

作者：肖云梅刘琼陈小芹袁旭宏湖南软件职业技术大学湖南湘潭411100

文章以我国6所典型职业本科大学电子商务专业为例,对其人才培养方案进行实证研究。研究发现,职业本科人才培养方案的制定应从产业出发,有机融合产业链、人才链,确定职业本科高层次人才培养目标和规格,构建“四突出”课程体系,构建“五... 详细信息

文章以我国6所典型职业本科大学电子商务专业为例,对其人才培养方案进行实证研究。研究发现,职业本科人才培养方案的制定应从产业出发,有机融合产业链、人才链,确定职业本科高层次人才培养目标和规格,构建“四突出”课程体系,构建“五共同”深度产教融合校企合作模式,打造职业本科“双师型”教学团队,建设多维立体化教学资源库,构建适合中国国情的本科层次职业教育人才培养方案,推动人才供给侧结构性改革。

关键词：职业本科人才培养方案课程体系产教融合

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Long-term straw return influenced ammonium ion retention at the soil aggregate scale in an Anthrosol with rice-wheat rotations in China

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Journal of Integrative Agriculture 2022年第2期21卷 521-531页

作者： ZHANG Wen-zhao chen xiao-qin WANG Huo-yan WEI Wen-xue ZHOU Jian-min Key Laboratory of Agro-ecological Processes in Subtropical Region and Taoyuan Station of Agro-Ecology Research Institute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125P.R.China State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008P.R.China

Soil aggregates are an important controlling factor for the physico-chemical and biological processes such as ammonium(NH;) retention. Straw return to the field is increasingly recommended to promote soil carbon(C) sequestration and improve crop yields. However, the effects of straw return on NH;retention at soil aggregate level in agricultural soils have seldom been investigated. This study aimed to evaluate the influences of long-term straw return on NH;adsorption and fixation in microaggregates(<0.25 mm) with or without soil organic carbon(SOC) oxidization. Soil samples were collected from plots of three treatments, i.e., no fertilizer(CK), inorganic NPK fertilizers(NPK), and inorganic NPK fertilizers with rice straw return(NPKS), from a 20-year-old field trial with rice-wheat rotations in Taihu Lake Region, China. Soil aggregates were separated using wet-sieving method. The SOC of microaggregates was oxidized by H;O;. The results showed that longterm straw return significantly increased SOC and NH;adsorption, but inhibited NH;fixation in microaggregates. NH;adsorption potential and strength-obtained from adsorption isotherms-increased, but NH;fixation decreased along with increasing SOC in microaggregates, indicating the important role of SOC in NH;adsorption and fixation. This was verified by the SOC oxidization test that showed a relative decrease in NH;adsorption potential for the NPKS treatment and an increase in NH;fixation in all three treatments. Therefore, long-term straw return influences NH;adsorption and fixation by enhancing SOC content and could improve N availability for crop uptake and minimize applied N fertilizer losses in rice-wheat cropping systems.

关键词： soil organic carbon microaggregates NH4+ adsorption fixation

Experimental and numerical investigation of the impacts of rotor tip-rake on excitation forces of pump-jet propulsors

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Journal of Hydrodynamics 2024年第1期36卷 142-157页

作者： Xue-qin Ji xiao-song Zhang chen-jun Yang xiao-qian Dong State Key Laboratory of Ocean Engineering Marine Numerical Experiment CentreSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China CSSC Shanghai Marine Energy Saving Technology Co. Ltd.Shanghai200011China China Ship Scientific Research Center Shanghai Branch Shanghai200011China

The tip-clearance flow in a pump-jet propulsor exerts great impacts on the fluctuating pressures and resultant unsteady forces,which are important sources of structural vibrations and radiated noise *** blade geometry close to the tip is an important factor determining the vortex strength in the tip-clearance *** the open-water condition,the effects of raking the rotor tips on the duct-surface fluctuating pressures and the resultant unsteady forces acting on different components of the propulsor are investigated via physical model experiments and the numerical solution of Reynolds-averaged Navier-Stokes(RANS)equations coupled with the SST k-ωturbulence *** measured and simulated results of hydrodynamic pressures are consistent to each other,and the simulated flows help better understand why the fluctuating pressures change with the tip *** strong fluctuations of duct-surface pressures are caused by intensive tip separation *** duct-surface pressure fluctuations are effectively reduced by using the rake distribution near the tip towards blade back side and,for the combination of the five-bladed rotor and the seven-bladed stator,the resultant unsteady horizontal(and vertical)forces acting on the duct and stator are also reduced;while increasing rake leads to negative effect on pressure fluctuations and unsteady horizontal(and vertical)forces acting on all the components of the propulsor.

关键词： Pump-jet tip-clearance tip-rake fluctuating pressures excitation forces

Kinetics of Phosphate Release from Three Phosphate-Treated Soils

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Pedosphere 2005年第4期15卷 518-525页

作者： LI Shou-Tian ZHOU Jian-Min WANG Huo-Yan DU Chang-Wen chen xiao-qin Institute of Soil Science Chinese Academy of Sciences P. O. Box 821 Nanjing 210008 （China）.

Phosphate release from three selected soils after treatments of 1.6 and 2.4 mmol L-1 P was investigated using sequential extractions and fitted using six kinetic models, including zero order (Z), first order (F), second order (S), parabolic diffusion (PD), two constant rate (TC), and Elovich type (ET) equations. The results showed that the rate of P release was initially rapid and then gradually declined with time. Also, P release increased with added P. Total P release followed the order: paddy soil with 2.4 mmol L-1 P > red soil with 2.4 mmol L-1 P > paddy soil with 1.6 mmol L-1 P > fluvo-aquic soil with 2.4 mmol L-1 P > fluvo-aquic with 1.6 mmol L-1 P > red soil with 1.6 mmol L-1 P. For the two P treatments P release from the paddy soils in the first extraction was 44.3% and 45.6% of total released P, respectively, which were higher than those from red and fluvo-aquic soils. The ratio of P release at the end of release time was 14.0% and 13.1% in the paddy soil treated with 1.6 and 2.4 mmol L-1 P, respectively, but only 5.1% and 9.2% in the red soil and 7.0% and 5.2% in the fluvo-aquic soil, respectively. Comparison of the coefficients of determination (R2) indicated that ET, TC, and PD equations could describe the P release data better than Z, F, and S equations.

关键词： fluvo-aquic soil paddy soil phosphate red soil release kinetics

Minimum Data Set for Assessing Soil Quality in Farmland of Northeast China

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Pedosphere 2013年第5期23卷 564-576页

作者： chen Yu-Dong WANG Huo-Yan ZHOU Jian-Min XING Lu ZHU Bai-Shu ZHAO Yong-Cun chen xiao-qin Institute of Soil Science Chinese Academy of Science University of Chinese Academy of Sciences Southwest University College of Resources and Environment

Soil quality assessment provides a tool for agriculture managers and policy makers to gain a better understanding of how various agricultural systems affect soil resources. Soil quality of Hailun County, a typical soybean （Glycine max L. Merill） growing area located in Northeast China, was evaluated using soil quality index （SQI） methods. Each SQI was computed using a minimum data set （MDS） selected using principal components analysis （PCA） as a data reduction technique. Eight MDS indicators were selected from 20 physical and chemical soil measurements. The MDS accounted for 74.9% of the total variance in the total data set （TDS）. The SQI values for 88 soil samples were evaluated with linear scoring techniques and various weight methods. The results showed that SQI values correlated well with soybean yield （r = 0.658＊＊） when indicators in MDS were weighted by the regression coefficient computed for each yield and index. Stepwise regression between yield and principal components （PCs） indicated that available boron （AvB）, available phosphorus （AvP）, available potassium （AvK）, available iron （AvFe） and texture were the main factors limiting soybean yield. The method used to select an MDS could not only appropriately assess soil quality but also be used as a powerful tool for soil nutrient diagnosis at the regional level.

关键词： norm value principal component analysis soil quality index stepwise regression

Influence of Humic Acid on Interaction of Ammonium and Potassium Ions on Clay Minerals

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Pedosphere 2013年第4期23卷 493-502页

作者： ZHANG Wen-Zhao chen xiao-qin ZHOU Jian-Min LIU Dai-Huan WANG Huo-Yan DU Chang-Wen State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Key Laboratory of Agro-Ecological Processes in Subtropical Region Institue of Subtropical Agriculture Chinese Academy of Sciences

Interaction of ammonium (NH+4) and potassium (K+) is typical in field soils. However, the effects of organic matter on interaction of NH+4 and K+have not been thoroughly investigated. In this study, we examined the changes in major physicochemical properties of three clay minerals (kaolinite, illite, and montmorillonite) after humic acid (HA) coating and evaluated the influences of these changes on the interaction of NH+4 and K+on clay minerals using batch experiments. After HA coating, the cation exchange capacity (CEC) and specific surface area (SSA) of montmorillonite decreased significantly, while little decrease in CEC and SSA occurred in illite and only a slight increase in CEC was found in kaolinite. Humic acid coating significantly increased cation adsorption and preference for NH+4, and this effect was more obvious on clay minerals with a lower CEC. Results of Fourier transform infrared spectrometry analysis showed that HA coating promoted the formation of H-bonds between the adsorbed NH+4 and the organo-mineral complexes. HA coating increased cation fixation capacity on montmorillonite and kaolinite, but the opposite occurred on illite. In addition, HA coating increased the competitiveness of NH+4 on fixation sites. These results showed that HA coating affected both the nature of clay mineral surfaces and the reactions of NH+4 and K+with clay minerals, which might influence the availability of nutrient cations to plants in field soils amended with organic matter.

关键词： adsorption illite kaolinite montmorillonite organo-mineral complex

Enhancement of Phosphorus Solubility by Humic Substances in Ferrosols

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Pedosphere 2008年第4期18卷 533-538页

作者： HUA Quan-Xian LI Jian-Yun ZHOU Jian-Min WANG Huo-Yan DU Chang-Wen chen xiao-qin Zhengzhou University Zhengzhou 450001 （China） State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） Zhengzhou Institute of Aeronautical Industry Management Zhengzhou 450015 （China）

An investigation was conducted to study the effect of humic substance (HS) on the phosphorus (P) solubility in acidic soil. The soil (2.5 g), HS (0, 0.5, and 2.5 g), and P as monocalcium phosphate (0.31 and 1.25 g P kg-1 soil) were mixed with 50 mL distilled water and two different sequences of adding HS and P were used. The results indicated that the P concentration in water and 0.01 mol L-1 CaCl2 solution increased with increasing amounts of humic substance. The concentrations of Fe and Al were also increased. However, Olsen P decreased with increasing amount of humic substance. Water-soluble P concentrations from P rates at 0.31 and 1.25 g P kg-1 soil in the treatment with 0.5 g (2.5 g) humic substance addition were 360% and 70% (500% and 90%) higher, respectively, than those in the treatment with no humic substance addition. P extracted by 0.01 mol L-1 CaCl2 in the treatments with 0.5 and 2.5 g humic substance addition was increased by 400% and 540%, respectively, compared with that in the treatment without humic substance at the rate of 0.31 g P kg-1 soil, while the corresponding P concentrations were increased by 80% and 90% at the rate of 1.25 g P kg-1 soil. The order of mixing humic substance and phosphate did not significantly affect desorbed P and labile P extracted with CaCl2.

关键词： aluminium Ferrosols humic substance iron phosphorus

Effect of Nitrogen Fertilizers on Movement and Transformation of Phosphorus in an Acid Soil

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Pedosphere 2005年第4期15卷 424-431页

作者： DU Zhen-Yu ZHOU Jian-Min WANG Huo-Yan DU Chang-Wen chen xiao-qin State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing210008 （China）.

The effects of two different nitrogen fertilizers （urea and NH4C1） with monocalcium phosphate （MCP） on the movement and transformation of fertilizer P in soil microsites along with soil pH changes at different distances from the fertilizer application site were studied in an incubation experiment. A highly acidic red soil （Ultisol, pH 4.57） from south China with MCP fertilizer alone or in combination with NH4C1 or urea was added to the surface of soil cylinders and packed in wax blocks. After 7 and 28 days, the extraction and analysis of each 2 mm layer from the interface of the soil and fertilizer showed that added NH4C1 or urea did not change the movement distance of fertilizer P. However, P transformation was significantly affected （P 〈 0.05）. After 7 days, at 0-8 mm distance from the fertilizer site the addition of urea significantly decreased the water-extractable P concentration; however, after 28 days the effect of N addition had disappeared. Also,at limited distances close to the fertilizer site NH4Cl application with MCP significantly increased acid-extractable P and available P, while with the addition of urea they significantly decreased. Compared with application of MCP alone,addition of urea significantly increased soil pH in fertilizer microsites, whereas the addition of NH4Cl significantly decreased soil pH.

关键词： NH4Cl P movement P transformation red soil urea