三角帆蚌外套膜细胞的超微结构

用透射电镜观察了三角帆蚌(Hyriopsis cumingii Lea)外套膜细胞的超徽结构。外套膜内表皮细胞中,有具纤毛的柱状细胞,顶端具小分泌泡的杯状细胞,胞质中含大分泌泡以及线粒体聚集成群的柱状细胞四类。各类表皮细胞的细胞质电子密度和内含物均有差异。细胞核呈椭圆或棒形。线粒体和高尔基体多分布在细胞核上方细胞的游离端。各类细胞游离表面都密生微绒毛,其中内表皮的柱状细胞还着生有纤毛,但无分泌泡。其余几种表皮细胞在细胞顶部都具有大小不等,电子密度不同的分泌泡。在外表皮中只观察到一般的柱状表皮细胞和胞质中具有成群线粒体的细胞两类。另外,外表皮细胞中具有较多的溶酶体。从三角帆蚌外套膜表皮细胞超微结构来看,内、外表皮都具有分泌和吸收机能。内表皮的纤毛柱状细胞有运动功能,而外表皮细胞有较强的消化吸收功能。     

褶爪沪蚖假眼的电镜观察

褶爪沪蚖(Huhentomon plicatunguis Yin)假眼为梨形隆起,表面具纵向条纹和沟缝;内、外表皮之间形成假眼腔,腔的后半部有一条由内表皮突出形成的龙骨;假眼下有3个感觉细胞,各伸出一条纤毛树突,经假眼后端的通道进入假眼腔,逐渐伸展成片层状,其末端与沟缝相通。观察结果表明其假眼结构与华山夕蚖假眼甚为接近。     

褶爪沪蚖假眼的电镜观察

褶爪沪蚖(Huhentomon plicatunguis Yin)假眼为梨形隆起,表面具纵向条纹和沟缝;内、外表皮之间形成假眼腔,腔的后半部有一条由内表皮突出形成的龙骨;假眼下有3个感觉细胞,各伸出一条纤毛树突,经假眼后端的通道进入假眼腔,逐渐伸展成片层状,其末端与沟缝相通.观察结果表明其假眼结构与华山夕蚖假眼甚为接近.     

鳜鳃部寄生河鲈锚首吸虫的扫描电镜观察

河鲈锚首吸虫头器表面分布着形状各异的孔状结构,每个中央头瓣上有两个随着器囊,而每个外侧头瓣上只有一个。口腔位于头器下方的腹面中线上,口腔表皮与周围的表皮无异。生殖孔在口腔正下方,阴道开口于虫体背侧面,周围有微纤毛的分布。交接器位于生殖孔左下方,交接管表面波纹状,辅助交配器表面布满疣状突起,后随着器的中央锚钩上具一凹槽,边缘小钩的钩尖弯向基部。虫体表面至少分布着两类可能的感受器末端,一类呈单纤毛状散布于体表,纤毛从体表凹坑中伸出,或在其基部围一环状领襟;另一类呈乳突状,位于外侧头瓣的顶部。在部分河鲈锚首吸虫体表可见车轮虫的超寄生。     

冰川退缩地15种丛藓科植物茎的比较结构学观察

应用石蜡切片和扫描电镜方法对一号冰川退缩地生长的15种丛藓科植物茎的结构及表面微形态特征进行观察,结果表明：该地区的15种丛藓科植物的茎分为具中轴和无中轴两类,其细胞壁均有不同程度的加厚。而具中轴的丛藓科植物的茎又分为表皮、皮部、中轴三部分,茎表皮细胞短,1层,细胞壁大多向外突出,表面粗糙,表面纹饰多为颗粒状;皮部所占面积最大,大部分有内、外皮部的分化,大多数种的细胞壁由外向内逐渐变薄,细胞由小到大整齐排列;中轴所占的面积也不同,其细胞壁多具角隅加厚;而没有中轴分化的种类,其各自细胞壁加厚的程度基本一致。     

玉吊钟多细胞根毛的发育及其超微结构研究

玉吊钟气生不定根根尖区域的部分表皮细胞经分裂可形成多细胞根毛。根毛长０．０３ｍｍ左右,具单列细胞、双列细胞和叉状分枝类型,由基细胞和毛体细胞二部分组成。电镜显示,基细胞内部结构与表皮细胞相似。组成毛体的细胞都有分泌功能。在分泌活动期,细胞内形成大量内质网,并膨大成囊泡状或溢出囊泡,分泌停止,内质网即消失;其细胞结构的变化及主要由内质网参与分泌活动与蜜腺细胞在分泌活动中的结构变化类似。故推测多细胞根     

意大利工蜂咽下腺结构观察

通过研究意大利蜜蜂Apis mellifera工蜂咽下腺的结构及形态,为蜜蜂形态学和蜜蜂生理学以及王浆分泌生理提供新知识采用光学显微镜、扫描电镜、HE染色石蜡切片和透射电镜,从形态学和细胞学水平对意大利工蜂咽下腺的结构和功能做了详尽探究和分析.意大利工蜂咽下腺由多个卵圆形腺泡组成,每个腺泡的直径约为120×180 μm,腺泡之间有微气管相连,腺泡外侧有神经细胞,神经细胞的胞体直径约为12μm.每个腺泡是由多细胞构成,最外层有0.1 ～0.2 μm的结缔组织膜,内部有壁细胞、酶原细胞和王浆分泌细胞,其中王浆分泌细胞分布较多,细胞直径约为16 ～ 18 μm,细胞核直径约为6μm. 由咽下腺的形态结构和细胞类型推断,意大利工蜂咽下腺主要分泌王浆,也具有分泌消化酶的功能,同时了解到分泌消化酶和王浆的途径.     

森林革蜱雌蜱唾液腺的结构与变化(英文)

森林革蜱 (DermacentorsilvarumOlenev)雌蜱唾液腺由唾液腺管和大量的腺泡组成。从假头基到唾液腺末端 ,唾液腺管分为三部分 ,即中央腺管、主分支腺管和小叶管。球状的腺泡分布在各级腺管上。气管和中央腺管并行。腺泡呈圆形或近圆形 ,表面呈褶皱状 ,并有细小的气管分布。饥饿雌蜱唾液腺长度短 (5 4 7 3 3 μm) ;吸血后长度增加 ,吸血后 3天达到最大值 (1 1 0 9 40 μm)。从吸血后 3天到饱血后前 3 天 ,无明显变化 ,饱血后 4天明显缩短 (5 0 0 0 0 μm)。饥饿雌蜱的腺泡直径短 (45 2 4 μm) ,吸血期逐渐增大 ,吸血后 5天达到最大值 (74 1 0 μm)。饱血后腺泡逐渐萎缩并于饱血后 4天退化。     

中国水韭属植物的孢子形态特征

利用扫描电镜观察了中国现存5种水韭属Isētes植物孢子的表面纹饰,并统计分析了孢子的大小(n=30).结果显示:高寒水韭上hypsophila大孢子表面光滑无突起纹饰,平均极面直径358 μm,小孢子具脑回状纹饰,平均长度22μm;云贵水韭Lyunguiensis大孢子表面具脊条-网络状纹饰,纹饰突起较低,近极面较稀疏且不连成完全的网络,平均极面直径390 μm,小孢子具疣状小颗粒至近于光滑的表面纹饰,平均长度22μm;台湾水韭L taiwanensis大孢子表面具瘤状突起,平均极面直径312μm,小孢子表面具刺棘状突起,平均长度24μm;中华水韭I sinensis大孢子表面具脊条状突起,平均极面直径409 μm,小孢子表面具刺棘状突起,平均长度28 μm;东方水韭I orientalis大孢子表面具脊条-网络状纹饰,纹饰突起较高,近极面的网络较完整,平均极面直径420 μm,小孢子表面具矮刺状-瘤状突起,平均长度34 μm.比较类群间的孢子形态特征与染色体数目表明:5个类群的孢子表面纹饰区别明显,同时,孢子的大小可反映类群的倍性,孢子较小的高寒水韭、云贵水韭和台湾水韭是二倍体(2n=22),孢子较大的中华水韭(2n=44)和东方水韭(2n=66)为多倍体.孢子的形态特征在中国水韭属植物物种的鉴定与分类中具有重要意义.     

蟹累枝虫的光镜及电镜观察

利用活体观察、蛋白银染色及电镜技术对蟹累枝虫(Epistylis eriocheiri)的形态学、表膜下纤维及超微结构进行了较为系统的描述,研究发现:(1)光镜下该种群体双叉分支,活体时虫体表膜柔软,完全伸展时呈长筒状;大核马蹄形,呈横位;伸缩泡单个,斜卧口围缘下方。口围缘纤维上连细密的环状纤维,下接两端较为粗壮,中间细长的纵长纤维,构成了连续的表膜下纤维系。(2)电镜下该种表面具沟、嵴、横纹结构,沟嵴相互交错;口围纤毛花瓣状;虫体表膜层呈齿状,具嵴状突起、泡间微管、表膜孔,胞质层包括内含胞器单一的致密原生质层和富含胞器的疏松原生质层。研究对该种的上述特征在虫体的收缩机制及与其他相似种之间的关系等方面进行了讨论。       

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).