海洋芽孢杆菌（Bacillus marinus）B-9987菌株抑制病原真菌机理的研究

摘要：【目的】：探讨海洋芽孢杆菌（Bacillus marinus）B-9987菌株的代谢产物BMME-1,对植物病原真菌茄链格孢菌的抑菌作用机理。【方法】分别使用分光光法、气相色谱-质谱GC-MS联用技术、红外光谱法等,检测了BMME-1处理病原真菌后,菌体渗透性、细胞壁及细胞膜成份的变化。【结果】BMME-1对茄链格孢菌的抑菌中浓度（MIC50）为6.2 mg/L,最小杀菌浓度（MFC）为50 mg/L,在MIC50浓度或高于此浓度处理靶标菌,将导致菌体蛋白质、核酸等大分子物质的外流;处理菌株葡聚糖结     

RETRACTED ARTICLE: Circ-NUP214 Promotes Papillary Thyroid Carcinoma Tumorigenesis by Regulating HK2 Expression Through miR-15a-5p

Biochemical Genetics -     

A green and effective method for the determination of metalaxyl enantiomers in tobacco and soil by supercritical fluid chromatography–tandem mass spectrometry

We reported a new methodology for the stereoselective determination of metalaxyl enantiomers in tobacco and soil. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used for the extraction and clean-up of the tobacco and soil samples. Separation of the metalaxyl enantiomers was performed on an ACQUITY UPC2 Trefoil CEL1 chiral column coupled with supercritical fluid chromatography with tandem mass spectrometry (SFC-MS/MS), and the run time was only 5 minutes. Under the optimized conditions, the recoveries for the enantiomers were between 78.2% and 93.3% with intraday relative standard deviations (RSDs) ranging from 1.1% to 5.4%. The limit of detection (LOD) for the enantiomers in tobacco and soil varied from 0.005 to 0.007 mg/kg, and the limit of quantitation (LOQ) ranged from 0.017 to 0.020 mg/kg. In this method, only a small amount of methanol was consumed to obtain a rapid stereoselective separation. This proposed method showed good accuracy and precision and might be suitable for fast enantioselective determination of metalaxyl in food and environmental samples. The developed method was further validated by application to the analysis of authentic samples.     

Study on fibroin heavy chain of the silkwormBombyx mori by fluorescencein situ hybridization (FISH)

The sericulture industry plays a very important role in our national economy. Silkworm (Bombyx mori) is always regarded as a model animal and biological reactor. There have been detailed studies on the structure, expression and control and molecular evolution of silk genes. However, few, if any, reports are available on the localization of structural genes in silkworm by molecular cytogenetics. The present experiment has tentatively localized theFib-H gene at the distal end of the 25th linkage group, namely at the 25-0.0 position, and verified thatFib-H has only one locus, thus providing a temporary solution to the problem about its localization.     

小鼠胎肝细胞透明质酸3D培养体系的建立

目的 利用透明质酸建立小鼠胎肝细胞3D培养体系。 方法 分离获得胚胎12-14天胎肝细胞,利用KM培养基进行初步2D肝干/祖细胞的筛选培养,并利用透明质酸及KM培养基配制水凝胶建立3D细胞培养体系。 结果 胎肝细胞在2D体系中呈现克隆状生长。分离培养获得的肝干/祖细胞克隆在透明质酸建立的3D培养体系保持增殖活性,并进一步获得肝细胞功能特性,表现为3D培养上清中白蛋白合成和尿素水平显著增加。Q-PCR结果显示随着3D培养时间的延长,其肝细胞干性标志如AFP、CK19、EpCAM、Prox1等表达水平都大幅度降低且接近成年小鼠肝脏表达水平。 结论 本研究成功建立基于透明质酸的小鼠胎肝细胞的3D无血清培养体系,并可促进小鼠胎肝细胞肝细胞功能进一步成熟。     

水分胁迫对甘薯叶肉细胞光合电子传递的影响

水分胁迫降低了甘薯叶肉细胞的光合能力。在有解偶联剂存在时,水分胁迫对叶肉细胞的光合电子传递没有影响,但在无解偶联剂存在下,水分胁迫促进了甘薯叶肉细胞的光合电子传递,表现出明显的解偶联效应。水分胁迫伤害了甘薯叶绿体偶联因子结构,使ATP合成受阻,叶肉细胞的光合滞后期加长。     

Use of silicone fluids in studies of cellular amino acids

In numerous cellular studies, cells labeled with radioisotopes have been separated from the labeling medium by an aqueous solution in order to determine the quantity of internalized labels; however, the aqueous wash tends to remove significant labeling from the cells. Therefore, in order to preserve all of the internalized labels, non-aqueous medium such as silicone fluids may be used. The termination of the labeling is achieved in the silicone method when, upon centrifugation, the cells separate from the medium and enter the silicone fluid to sediment to the tube bottom. This sedimentation of cells placed above a layer of silicone fluid exhibits a critical dependence on the centrifugal force, and gives rise to an uncertainty of only 2 s in determining the time of separation of cells from the medium using General Electric F-50 silicone fluid and a modified Beckman J2-21 centrifuge. It is therefore possible to determine the kinetics of incorporation of labeled amino acids into intracellular pools and proteins. In particular, since this silicone wash method determines the size of the total pool and the aqueous wash method determines the size of the acid-extractable pool, the simultaneous measurements of the size of both pools leads to the determination of the kinetics of labeling of the free amino acid pool. Among many possible applications and extensions of these methods, the studies of formation of intracellular pools and relations among different pools of transported molecules, such as water and amino acids, appear promising.     

北京地区红隼的迁徙路线和活动区域

红隼(Falco tinnunculus)被列为国家二级重点保护野生动物,是能同时适应农村和城市环境的小型猛禽,对维持城市生态系统稳定具有重要意义。2022年4月至7月,为在北京救助的7只红隼佩戴了卫星追踪器,追踪其活动轨迹,依据追踪的动物活动位点数据,采用净平方位移-时间曲线依次对各红隼的迁徙模式进行了判别,深入分析了迁徙红隼的迁徙时间、距离和路线等,并采用核心密度法分别计算了迁徙及留居型红隼95%及50%活动区面积。研究结果表明,在北京地区红隼的迁徙模式为部分迁徙,追踪的7只红隼个体(N01 ~ N07)中,4只为留鸟,1只为迁徙鸟,2只居留类型无法准确判断。N01为迁徙红隼,其度夏地和越冬地分别在内蒙古锡林郭勒盟和河北廊坊,此红隼秋季迁徙速度明显高于春季,其春季迁徙距离551 km,历时25 d,平均迁徙速度为22 km/d,而秋季迁徙距离412 km,历时2 d,平均迁徙速度为203 km/d,河北承德滦平县是其春季迁徙的重要中途停歇地。不同红隼个体间95%及50%活动区面积均存在较大差异,迁徙红隼N01 95%、50%活动区面积在度夏区分别为93.10 km²、17.50 km²,在越冬区分别为7.03 km²、0.99 km²;留居型红隼95%、50%活动区面积均值分别为1 165.34 km²、178.71 km²(n = 4),其中最大95%、50%活动区面积分别为4 320.26 km²(N02)、648.22 km²(N02),最小95%、50%活动区面积分别为2.80 km²(N03)、0.29 km²(N03)。本研究揭示了北京地区红隼的迁徙模式、迁徙路线、重要停歇地及活动区状况,为红隼的针对性保护和管理提供了科学依据。     

全球啄木鸟濒危格局及研究现状

啄木鸟科物种作为初级洞巢者与蛀干害虫控制者,对森林高度依赖,是森林生态系统重要的伞护种和环境指示物种。自20世纪以来,由于全球范围的栖息地丧失和片段化,啄木鸟科物种的森林生境急剧萎缩,威胁着该类群物种的生存和繁衍。为探究啄木鸟科动物濒危情况和研究现状,本研究利用世界自然保护联盟濒危物种红色名录(IUCN Red List)和国际鸟盟(BirdLife International)在线数据库,检索并整理出1988年到2023年以下内容：(1)全球啄木鸟的物种数、濒危等级及其变化情况;(2)各大洲的啄木鸟物种数及其受威胁物种的比例;(3)啄木鸟的主要威胁因素;(4)通过Google学术搜索等方式检索并统计啄木鸟相关文章的研究内容。结果显示：(1)目前现存254种啄木鸟,33年间全球受威胁啄木鸟由7种增加至18种,受威胁物种数占当年已命名啄木鸟物种数的比例由3.4%上升至7.0%。(2)亚洲、南美洲和北美洲各分布了83种、93种和56种啄木鸟,受威胁物种占比分别为12.0%、6.4%、5.3%。非洲和欧洲分别分布了36种和11种啄木鸟,当前没有受威胁物种。(3)农业和生物资源利用以及放牧是啄木鸟的主要威胁因素。(4)共检索到研究啄木鸟的有关文章1 024篇,研究覆盖了140种啄木鸟,其中,文章数最多的物种是红顶啄木鸟(Leuconotopicus borealis)(162篇)。研究主要集中在巢相关特征(129篇)、生境选择特征(122篇)、取食行为(112篇)、繁殖行为(99篇)和种群状况(66篇)等基础生态学内容。这些研究为啄木鸟生物学、生态学积累了一定的基础,但物种覆盖程度还远远不够。在生物多样性急剧丧失的大背景下,亟需开展更为广泛和深入的研究。本研究对全球啄木鸟的濒危格局与研究现状进行了全面的分析,以期为后续啄木鸟的研究与保护工作提供参考。