The Ordos Cretaceous Groundwater Basin, located in an arid-semiarid area in northwestern China, is a large-style groundwater basin. SO4^2- is one of the major harmful components in groundwater. Dissolved SO4^2- concen...The Ordos Cretaceous Groundwater Basin, located in an arid-semiarid area in northwestern China, is a large-style groundwater basin. SO4^2- is one of the major harmful components in groundwater. Dissolved SO4^2- concentrations, and δ^34S-SO4^2- and δ^18O-SO4^2- in groundwater from 14 boreholes and in gypsum from aquifer were analyzed. Results show that SO4^2- in shallow groundwaters originates from precipitation, sulfide oxidation, and dissolution of stratum sulphate, with a big range of δ^34S values, from -10.7‰ to 9.2‰, and addition of SO4^2- in deep groundwater results from dissolution of stratum sulphate, with bigger δ^34S values, from 7.8‰ to 18.5‰, compared with those in shallow groundwater. This research also indicates that three types of sulphate are present in the strata, and characterized by high δ^34S values and high δ^18O values-style, high δ^34S values and middle δ^18O valuesstyle, middle δ^34S values and low δ^18O values-style, respectively. The δ^34S-SO4^2- and δ^18O-SO4^2- in groundwater have a good perspective for application in distinguishing different groundwater systems and determining groundwater circulation and evolution in this area.展开更多
In this paper we further study the delay differential equation N .(t)=-δN(t)+pN(t-τ)e -aN(t-τ) , t0(*) used in describing the dynamics of Nicholson’s blowflies. When p】δ ,we establish new su...In this paper we further study the delay differential equation N .(t)=-δN(t)+pN(t-τ)e -aN(t-τ) , t0(*) used in describing the dynamics of Nicholson’s blowflies. When p】δ ,we establish new sufficient conditions for the positive equilibrium N * of (*) which is a global attractor.展开更多
Discrete high energy y-rays in~5-10MeV region were produced utilizing a~105/s Am-Be neutron source through the radiation capture process.The device can be conveniently used for energy calibration and relative efficien...Discrete high energy y-rays in~5-10MeV region were produced utilizing a~105/s Am-Be neutron source through the radiation capture process.The device can be conveniently used for energy calibration and relative efficiency determination forγ-detectors.展开更多
背景:帕金森病是全球第二大神经退行性疾病,其运动症状和非运动症状都严重影响患者日常生活,最近研究发现外泌体及其携带的物质参与帕金森病病理发生发展,且还介导细胞通讯可作为帕金森病的潜在生物标志物。目的:探讨外泌体介导细胞通...背景:帕金森病是全球第二大神经退行性疾病,其运动症状和非运动症状都严重影响患者日常生活,最近研究发现外泌体及其携带的物质参与帕金森病病理发生发展,且还介导细胞通讯可作为帕金森病的潜在生物标志物。目的:探讨外泌体介导细胞通讯作为帕金森病的潜在生物标志物的类型及其发生作用的机制,用以寻找新的早期诊疗靶点,以期减缓帕金森病的发病进程并为其诊疗提供新思路。方法:应用计算机检索1987年1月至2022年8月PubMed、中国知网、万方数据、维普、Web of Science、EMBASE、Cochrane、EBSCO和SinoMed数据库收录的相关文献,最终纳入76篇英文文献和2篇中文文献进行归纳分析。结果与结论:(1)外泌体通过胞吞胞吐膜融合方式输送物质至受体细胞或膜表面携带信号因子,释放在细胞间隙等方式在细胞间通讯进行物质交换。(2)外泌体可通过介导细胞间通讯和信息交流以及物质运输参与帕金森病的病理进展,因此其可作为帕金森病的早期生物标志物,协助提供新的诊疗靶点,并可作为将来帕金森病的诊疗载体。(3)外泌体通过细胞间传递和物质运输扩散介导参与帕金森病病理发展机制,其主要生物标志物与病理作用途径的关系为:外泌体α突触核蛋白介导神经毒性、神经炎症、氧化应激及细胞自噬等过程,外泌体微小RNA可以靶向帕金森病相关基因并参与氧化应激,外泌体DJ-1蛋白调控细胞的氧化应激水平并影响细胞毒性,外泌体富含亮氨酸的重复激酶2介导路易体形成和堆积造成神经毒性,以上外泌体及其携带物质均可作为帕金森病的早期生物标志物。(4)目前外泌体的帕金森病生物标志物相关研究较少,但其中最具代表性和应用最多的是外泌体α突触核蛋白,由于外泌体微小RNA种类多数量大,在帕金森病中表达和作用不尽相同,近两年成为了研究热点。(5)目前相关研究缺少相应的临床验证,因此可做为未来研究方向,研究前景广阔,因此更需深入验证和研究更多的潜在生物标志物及其作用机制,为帕金森病的早期诊断提供诊疗新靶点。(6)外泌体在临床诊断帕金森病中的应用仍有很大的研究空间和发展前景,基于临床试验开展外泌体介导细胞通讯在帕金森病诊治中的应用是未来研究的重点和亟待突破点。展开更多
基金supported by the China Geological Survey(grant No.1212010331302)National Science and Technology Project(grant No. 2006BAB01A10)International Atomic Energy Agency(grant No.CPR8012,CPR8017)
文摘The Ordos Cretaceous Groundwater Basin, located in an arid-semiarid area in northwestern China, is a large-style groundwater basin. SO4^2- is one of the major harmful components in groundwater. Dissolved SO4^2- concentrations, and δ^34S-SO4^2- and δ^18O-SO4^2- in groundwater from 14 boreholes and in gypsum from aquifer were analyzed. Results show that SO4^2- in shallow groundwaters originates from precipitation, sulfide oxidation, and dissolution of stratum sulphate, with a big range of δ^34S values, from -10.7‰ to 9.2‰, and addition of SO4^2- in deep groundwater results from dissolution of stratum sulphate, with bigger δ^34S values, from 7.8‰ to 18.5‰, compared with those in shallow groundwater. This research also indicates that three types of sulphate are present in the strata, and characterized by high δ^34S values and high δ^18O values-style, high δ^34S values and middle δ^18O valuesstyle, middle δ^34S values and low δ^18O values-style, respectively. The δ^34S-SO4^2- and δ^18O-SO4^2- in groundwater have a good perspective for application in distinguishing different groundwater systems and determining groundwater circulation and evolution in this area.
文摘In this paper we further study the delay differential equation N .(t)=-δN(t)+pN(t-τ)e -aN(t-τ) , t0(*) used in describing the dynamics of Nicholson’s blowflies. When p】δ ,we establish new sufficient conditions for the positive equilibrium N * of (*) which is a global attractor.
文摘Discrete high energy y-rays in~5-10MeV region were produced utilizing a~105/s Am-Be neutron source through the radiation capture process.The device can be conveniently used for energy calibration and relative efficiency determination forγ-detectors.
文摘背景:帕金森病是全球第二大神经退行性疾病,其运动症状和非运动症状都严重影响患者日常生活,最近研究发现外泌体及其携带的物质参与帕金森病病理发生发展,且还介导细胞通讯可作为帕金森病的潜在生物标志物。目的:探讨外泌体介导细胞通讯作为帕金森病的潜在生物标志物的类型及其发生作用的机制,用以寻找新的早期诊疗靶点,以期减缓帕金森病的发病进程并为其诊疗提供新思路。方法:应用计算机检索1987年1月至2022年8月PubMed、中国知网、万方数据、维普、Web of Science、EMBASE、Cochrane、EBSCO和SinoMed数据库收录的相关文献,最终纳入76篇英文文献和2篇中文文献进行归纳分析。结果与结论:(1)外泌体通过胞吞胞吐膜融合方式输送物质至受体细胞或膜表面携带信号因子,释放在细胞间隙等方式在细胞间通讯进行物质交换。(2)外泌体可通过介导细胞间通讯和信息交流以及物质运输参与帕金森病的病理进展,因此其可作为帕金森病的早期生物标志物,协助提供新的诊疗靶点,并可作为将来帕金森病的诊疗载体。(3)外泌体通过细胞间传递和物质运输扩散介导参与帕金森病病理发展机制,其主要生物标志物与病理作用途径的关系为:外泌体α突触核蛋白介导神经毒性、神经炎症、氧化应激及细胞自噬等过程,外泌体微小RNA可以靶向帕金森病相关基因并参与氧化应激,外泌体DJ-1蛋白调控细胞的氧化应激水平并影响细胞毒性,外泌体富含亮氨酸的重复激酶2介导路易体形成和堆积造成神经毒性,以上外泌体及其携带物质均可作为帕金森病的早期生物标志物。(4)目前外泌体的帕金森病生物标志物相关研究较少,但其中最具代表性和应用最多的是外泌体α突触核蛋白,由于外泌体微小RNA种类多数量大,在帕金森病中表达和作用不尽相同,近两年成为了研究热点。(5)目前相关研究缺少相应的临床验证,因此可做为未来研究方向,研究前景广阔,因此更需深入验证和研究更多的潜在生物标志物及其作用机制,为帕金森病的早期诊断提供诊疗新靶点。(6)外泌体在临床诊断帕金森病中的应用仍有很大的研究空间和发展前景,基于临床试验开展外泌体介导细胞通讯在帕金森病诊治中的应用是未来研究的重点和亟待突破点。
