以龙胆紫染硫酸酯多醣类的组织化学意义

甲、方法:1)固定于任何固定液皆可,但以酒精为最合适。石蜡切片,厚3微来。切片脱蜡,降酒精,至蒸馏水。2)以龙胆紫(gentian violet)水溶液1∶250,000或1∶1,280,000染色24小时(即0.25毫升0.1%龙胆紫贮存液加入100毫升蒸馏水内;或以0.1毫升0.1%龙胆紫液加入128毫升蒸馏水内)。3)滤纸吸干切片,然后在亚尼林二甲苯(anilinc-xylene)1∶1或1∶2液内脱色及脱水约5分钟(或稍长),直至紫色不再从切片上脱下为止。以二甲苯洗2—3次,用树胶封片。若染透明质酸(hyaluronic anid)可以甘油封片。     

念珠藻的制片方法

取材普通念珠藻(Nostoc Commune)生于潮湿的土壤或草地上,在春、夏多雨季节里很容易采到.它形似木耳,俗称“地木耳”或“地皮菜”,可食用.发状念珠藻(Nostoc flagelliforme)形如发丝,俗称发菜,是重要的食用蓝藻,可从商店购得.取其中任何一种材料泡在水中,使其胶质鞘膨胀,用小毛笔刷净泥砂杂物,剪成3毫米左右长的小块(或段).选平整的材料置于载片中央,用另一张载片将材料压薄,用棉线捆紧两张载片. 固定将捆好的两张载片投入FAA固定液中24小时,松开棉线,分开载片.由于材料本身的胶质,它能粘贴在两张或其中的一张载片上(通常两张载片各粘一部分).将此材料染色和脱水. 洗涤与初染将固定好的材料用50％酒精洗涤2—3次,每次10分钟.再经40％→30％→20％→10％酒精洗,每级10分钟.最后经蒸馏水浸洗2次,每次2分钟.媒染用4％铁明矾1小时,蒸馏水洗2次后用海氏苏木精染色1小时.蒸馏水洗去浮色,1％铁明矾分色.边分色边显微镜检,至细胞内含物呈黑色,其它部分浅灰色或无色时为止.立即倒掉分色液,蒸馏水洗2—3次后,将材料浸泡于自来水中,使其变蓝     

胞间连丝玻片的制备

将柿子或黑枣的种子浸于温水中24小时,剥去种皮,将胚乳切成薄切片并于I—KI溶液(I 1克,KI 1.25克,蒸馏水100毫升)中固定3—5分钟,移入5％H_2SO_4溶液中3—5分钟。将切片置载片中央滴一滴结晶紫染色,3分钟后用50％酒精洗1—2     

小肠腺三色染色法

我们采用三色染色的方法对小肠肠腺细胞进行染色,杯状细胞、潘氏细胞、胞质和肠腺基膜呈现三种不同的颜色。细胞形态清晰,对比鲜艳,收到了理想效果。材料和方法1·材料人小肠为手术切除新鲜标本。10%甲醛固定24-48h,常规脱水,石蜡包埋。2·方法石蜡切片厚4-6μm,切片脱蜡,蒸馏水洗2m in,复合染液染3-5m in,70%乙醇分色,蒸馏水洗1m in,阿利新蓝染5m in,蒸馏水轻洗;0·2%光绿复染胞质、肠腺基膜20s;70%盐酸乙醇分色;梯度乙醇脱水;二甲苯透明;中性树胶封固。3·染液配制(1)复合染液:1%伊红(1g伊红,70%乙醇100m l)40m l,2%偶氮桃红(2g偶氮桃红甲…     

观察有丝分裂方法的改进

在观察植物细胞的有丝分裂实验中,通常的步骤为:将取下的根尖在固定液中固定15—30分钟,然后用95％酒精洗净醋酸,移入70％酒精中,再水洗后转入1N盐酸中60℃下水解10分钟,之后水洗1—2次,压片,用醋酸洋红染色10分钟。整个过程约需35—50分钟,耗时长,且操作繁琐。近年来,我们采用了一种较为简便的方法,具体如下:     

小型昆虫整体玻片标本的简便制法

1.处死固定将蚊、蚜等置于70%酒精中杀死固定. 2.脱脂将材料装人试管中注入适量70%的氢氧化钾或氢氧化钠溶液加热脱脂,待水开后,再用文火维持15分钟左右. 3.清水漂洗:脱脂后用纱布过滤碱液,用蒸馏水或清水漂洗2-3次,再用蒸馏水将材料浸泡半小时左右. 4.染色用75%酒精、酸性品红饱和液染     

对Бильшовский-Γросс氏浸渍法的一些应用上的意见

著者建议一种简单的染周围神经系及末梢的浸渍改良方法,操作如下:标本在5%硫酸镁(Mag·sulphate)液中约洗5—40分钟,并以15%中性甲醛固定,固定时间不少于7天(可保存甲醛中数月),水洗,冰冻切片。切片浸于10%硝酸银5—30分钟,移入20%酸性甲醛,在此液中勿超过5秒,迅速通过蒸馏水。切片放在2张滤纸间吸干(此步重要!),入10%硝酸银     

肺血管注射石蜡切片

通过卡红明胶液进行血管注射,而不经过其他染色方法,直接石蜡切片,可清楚地显示毛细血管在泡壁上的分布及其毗邻关系。卡红明胶液的配制 1.取卡红6克加入50毫升蒸馏水中,逐渐滴加氨水,直至完全溶解,过滤备用。 2.取精制明胶20克与200毫升蒸馏水混合,过夜,置水浴锅中滆水加热溶解。随即取卡红液入明胶液中,搅拌混合,逐步滴加醋酸,至     

对弹性组织的选择性染色 (俄西印——新复红法)

1)切片脱蜡,入100%酒精.2)以俄西印——新复红(orcinol-new fuchsin)液于37℃染15分钟。染液配法为:新复红(new fuchsin)(C.I.,No.678)2克俄西印(orcinol)4克蒸馏水 200毫升上液煮佛5分钟,加37.2%三氯化铁溶液(ferricchloride)25毫升,再煮5分钟,待凉,过滤,其沉淀收集于滤约上,并须洗净晾干,将沉淀溶于95%酒精100     

植物维管束透明法

1.选幼嫩蚕豆一株连根拔出,用清水洗净根、茎表面污物备用。 2.将根部浸入碱性洋红溶液(配制:取0.5克碱性洋红溶解于2毫升95%酒精中后,用自来水稀释至150毫升)中染色12小时左右,待细小叶脉染为红色后,取出,用清水漂洗数分钟。     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various