睾丸支持细胞的功能、分离纯化及鉴定研究进展

支持细胞对维持精子形成过程中的微环境起决定作用,它可以通过分泌功能、细胞间连接形成的血睾屏障功能以及吞噬功能等来促进精子的形成过程,其发育异常会导致不同程度的雄性生殖缺陷。基于支持细胞在雄性动物生殖过程中的作用,体外培养高纯度支持细胞可成为研究睾丸两大核心功能-精子发生和性激素分泌功能相关调节机制重要的细胞模型。此外,体外培养睾丸支持细胞也可作为生殖毒理学等新兴热点领域的细胞模型,为评估和研究环境因素对雄性生殖的影响提供便利。因此,作者系统地归纳、总结了目前关于动物支持细胞生物功能的研究及常用的体外分离纯化、培养及鉴定方法,以期为利用动物支持细胞开展雄性生殖领域的研究提供参考。     

A pioneering survey of deep-diving and off-shore cetaceans in the northern South China Sea

A pioneering boat-based survey was conducted in 2019, to gather baseline information regarding the presence, composition, relative abundance, and spatial distribution of deep-diving and off-shore cetaceans in the northern South China Sea (SCS). A total of 27 sightings comprising at least 8 cetacean species were recorded during the 13-day survey, including 5 deep-diving species (i.e. Risso's dolphin [Grampus griseus], short-finned pilot whale [Globicephala macrorhynchus], sperm whale [Physeter macrocephalus], Cuvier's beaked whale [Ziphius cavirostris], and an unidentified beaked whale [either the ginkgo-toothed beaked whale, Mesoplodon ginkgodens, or Deraniyagala's beaked whale, Mesoplodon hotaula]), as well as 3 off-shore dolphins (i.e. pantropical spotted dolphin [Stenella attenuate], striped dolphin [Stenella coeruleoalba], and Fraser's dolphin [Lagenodelphis hosei]). With the exception of pantropical spotted dolphins, all other species were sighted and recorded at sea in the northern SCS for the first time. The pantropical spotted dolphin was the most frequently sighted species, comprising 30% of the total sightings. Deep-diving cetaceans were mainly sighted in the northern Xisha Archipelago, whereas off-shore dolphins were distributed across the survey area. The pantropical spotted dolphin was observed in aggregations of more than 100 individuals and nearly all encountered species included calves; these findings suggested that the survey area functions as an important feeding and calving ground for various cetacean species. This pioneering survey provides fundamental information regarding cetacean fauna in the northern SCS and highlights the need to strengthen research and conservation efforts concerning these species.     

基于线粒体DNA Cyt b研究城市化对上海金线侧褶蛙遗传结构的影响

城市化在全球范围内快速扩张,已经成为影响物种进化的重要力量。两栖动物的迁移能力较弱,城市化导致两栖类被完全或部分的隔离,丢失更多的遗传多样性。本研究对上海市的金线侧褶蛙(Pelophylax plancyi)的mtDNA Cyt b部分序列进行分析,共扩增出235条序列,获得61个单倍型。研究表明城市区域遗传多样性较低,上海市的金线侧褶蛙分化程度处于中低的水平(Max F_ST=0.296;Min F_ST=0.004),各种群之间遗传分化有限。黄浦江及其支流可能作为水上扩散通道,有助于基因交流,各城市公园之间的遗传分化差异并不显著;而长江阻碍了种群之间的交流,城市公园和郊区,以及岛屿种群之间的遗传分化显著。此外,单倍型网络和系统发育分析表明,上海的金线侧褶蛙并没有对应城市化程度形成相应的单系。     

温度对紫色辣椒新品系YN 99007萌发及某些生理指标的影响

用6种温度(40、35、30、25、20、15℃)处理紫色辣椒新品系YN 99007进行发芽试验(以日本天鹰椒作为对照),研究各温度下的发芽率、发芽势、发芽指数、芽长、脯氨酸(Pro)含量、丙二醛(MDA)含量及质膜透性(PMP)等指标.结果表明:紫色辣椒YN 99007的发芽适宜温度范围为20～35℃,40℃和15℃下发芽优于对照品种;抗逆温生理特性亦优于对照品种.     

Effects of Cultivars,Organic Cropping Management,and Environment on Antioxidants in Whole Grain Rice

Whole grain rice contains functional antioxidants such as phenolics, flavonoids (including proanthocyanidins), vitamin E homologs (tocopherols and tocotrienols), and γ‐oryzanol that have positive effects on human health. These antioxidants are secondary metabolites in plants that can be induced under external stress. The objectives of this study were to quantify the effects of cultivars, crop management method (organic and conventional), and growing environment on the concentrations of these antioxidants in whole grain rice. Cultivars and environment contributed to a higher percentage of variation in the concentrations of these antioxidants than did crop management method. Cultivars accounted for a greater proportion of the variation than environment for all traits except total tocotrienols and γ‐oryzanol. Cultivars that are high in concentrations of these antioxidants were identified, but no one cultivar contained the highest concentration of all antioxidants evaluated. These cultivar differences indicate that improvement for phytochemical and antioxidant traits can be accomplished through traditional breeding. Because of the limited effect of crop management on these antioxidants, choice of cultivar should be the focus for organic production of whole grain rice high in these antioxidants.     

现代鸟害防治技术及其特点

随着人类爱鸟意识的增强以及鸟类粮食的丰富,鸟类种群数量逐渐增大,然而,鸟类有时候会为人类生产、生活带来不可估量的损失,尤其是在航空安全以及农业生产中的损失。因此,越来越多的鸟害防治技术被应用到了这些领域。对鸟类益害的评定方式、驱鸟的意义、常见的驱鸟方式及其特点进行了简单介绍。     

覆膜防沙治沙方法

沙漠、沙尘暴和沙化问题已经成为威胁人类生存的头号敌人，如何根治沙漠、沙尘暴和沙化是摆在人类面前的十分紧迫的任务。覆膜防沙治沙方法的研究和提出，成功地解决了人类面临的重大防沙治沙难题。为人类征服自然，征服沙漠树立了信心。介绍了覆膜防沙治沙的技术方式、方法、原理和覆膜栽培技术，供防沙治沙工程参考和推广。     

高效节水灌溉管道流量计算原则初探

对于管网优化及投资分析来说,最不利情况下的水力条件不是普遍条件,不能够完全代表管网应当有的优化假定条件。通过管道控制灌溉面积来确定管道的流量,按照满足在一天内,管道控制的所有灌水器都灌溉一次的原则确定,并给出公式。让管道的流量这一重要参数,在高效节水灌溉工程优化和设计计算中变得简单并容易计算。     

地温空调井抽回灌效果影响关键因子识别

为了探析引起地温空调井抽回灌效果的主要制约因素,通过单相关系数分析、主成分绝对得分的源解析模型、拟合度检验和多元线性回归的方法分析影响单井回灌效率的影响因素。结果表明:井径、滤水管孔隙率及抽回灌井数比与单井回灌效率的相关性和拟合度较好,故将井径、滤水管孔隙率及抽回灌井数比作为影响单井回灌效率的关键因子,同时分析了单井回灌效率与关键因子的之间的拟合方程及多元线性回归方程,得到了单井回灌效率与关键因子之间的定量关系。     

拖拉机自动转向系统设计及仿真

以TN654拖拉机为平台,基于原车液压转向系统,设计一套比例方向电磁阀组和电控单元(ECU),构建了能响应程序控制的自动转向系统。通过建立阀控缸动力系统数学模型,利用Mat Lab对该系统PD控制性能进行仿真分析。仿真结果显示:系统最大迟滞0.24、1.8s内均能达到平衡点,表明系统具有良好的控制精度和响应性,符合拖拉机自动驾驶作业需求。