几种含笑属(木兰科)植物的花粉形态

含笑属 ( Michelia) 4种花粉光镜下形态相似。SEM下观察 ,黄兰 ( M.champaca)和金叶含笑 ( M.foveolata)表面雕纹为小穿孔 ,苦梓含笑 ( M.balansae)为小穴 ,野含笑 ( M.skinner-iana)为细皱纹 ,较粗糙。 TEM下观察 ,4种花粉外壁均可分为覆盖层、柱状层和基层。其中黄兰的柱状层结构较原始 ,金叶含笑的较进化。花粉形态在一定程度上可反映类群的系统演化。     

东北杜鹃花科4属植物花粉形态的研究

利用光学显微镜和扫描的电子显微镜的对东北杜鹃花科甸属（Ｃｈａｍａｅｄａｐｈｎｅ Ｍｏｅｎｃｈ．）、杜香属（Ｌｅｄｕｍ Ｌｉｎｎ．）、松毛翠属（Ｐｈｙｌｌｏｄｏｃｅ Ｓａｌｉｓｂ．）、越橘属（Ｖａｃｃｉｎｉｕｍ Ｌｉｎｎ．）４属６种,１变种的花粉形态进行了观察和比较研究。以上４属花粉粒均为四合花粉。四合花粉呈正四面体排列。花粉粒近球形。每粒花粉均具３沟,在四合花粉粒上,相邻花粉粒上的沟相接,有些种可     

国产蔷薇科李亚科的花粉形态

本文报道了国产李亚科（Ｐｒｕｎｏｉｄｅａｅ）１０属１１种植物花粉形态。花粉近球形至长球形,极轴２０００～４４１２μｍ,赤道轴１７８５～３６９５μｍ。极面观三裂圆形,赤道面观椭圆形至圆形。具三孔沟,内孔常为长方形。沟较长,两端较窄。但在Ｓｉｎｏｐｌａｇｉｏｓｐｅｒｍｕｍｕｎｉｆｌｏｒａ中除了３孔沟外,还有周孔沟。花粉外壁明显分化为覆盖层和柱状层,在光学显微镜下表面常模糊,扫描电镜下外壁纹饰均为条纹状。孢粉学结合形态学和细胞学证据说明本亚科为一单系发生的类群。Ｐｒｉｎｓｅｐｉａｕｔｉｌｉｓ和Ｓｉｎｏｐｌａｇｉｏｓｐｅｒｍｕｍｕｎｉｆｌｏｒａ（Ｐｒｉｎｓｅｐｉａｕｎｉｆｌｏｒａ）这两个种在花粉特征和外壁纹饰上差异很大,从而支持将Ｐｒｉｎｓｅｐｉａ和Ｓｉｎｏｐｌａｇｉｏｓｐｅｒｍｕｍ分别处理为两个属但不支持将广义的Ｐｒｉｎｃｅｐｉａ（含Ｐｒｉｎｃｅｐｉａ和Ｓｉｎｏｐｌａｇｉｏｓｐｅｒｍｕｍ）独立为亚科。此外,由于Ｅｘｏｃｈｏｒｄａ的外壁纹饰同Ｐｒｕｎｏｉｄｅａｅ中较原始的类群（如Ｌａｕｒｏｃｅｒａｓｕｓ）相近,结合细胞学和形态学证据,支持将Ｅｘｏｃｈｏｒｄａ移置至Ｐｒｕｎｏｉｄｅａｅ之下     

合果木属和观光木属的花粉形态

合果木属合果木（Ｐａｒａｍｉｃｈｅｌｉａｂａｉｌｌｏｎｉｉ（Ｐｉｅｒｒｅ）Ｈｕ）和观光木属观光木（ＴｓｏｏｎｇｉｏｄｅｎｄｒｏｎｏｄｏｒｕｍＣｈｕｎ）的花粉,在光镜和扫描电镜下形态较相似。但在透射电镜下,两者差异较大：合果木花粉外壁的覆盖层、往状层和基层的分化不明显,柱状层小柱极少,虽有颗粒分化但数量不多;观光木花粉外壁三层的分化较明显,柱状层中已出现较多典型的颗粒和小柱。据此,合果木的花粉壁在木兰科中应属较原始的类型,而观光木的则属该科中较进化的类型。两者在花粉壁结构上的差异可为二属的分立提供花粉学上的证据。     

中国北部绣线菊属的花粉形态及分类学意义

本文用光学显微镜和扫描电镜观察了中国北部绣线菊属ＳｐｉｒａｅａＬ．２１种及６个变种的花粉形态,描述了外壁纹饰的形态特征,指出了外壁纹饰特征在分类上的意义。绣线菊属的花粉为球形至长球形,外壁纹饰为条网状至条纹状。外壁纹饰类型不具有属内分组意义,但对一些种类具有一定的分类价值。花粉形态支持将曲枣绣线菊Ｓ．ｆｌｅｘｕｏｓａＦｉｓｃｈ。并入石蚕叶绣线菊Ｓ．ｃｈａｍｏｅｄｒｙｆｏｌｉａＬ．的观点［Ｍａｘｉｍｏｗｉｃｚ,Ｃ．Ｊ．（１８７９）、Ｒｅｈｄｅｒ,Ａｉ．（１９４０）］,不同意将蒙古绣线菊毛枝变种Ｓ．ｍｏｎｇｏｌｉｃａＭａｘｉｍ．ｖａｒ．ｔｏｍｅｎｔｕｌｏｓａＹｕ提升为贺兰山绣线菊Ｓ．ｔｏｍｅｎｔｕｌｏｓａ（Ｙｕ）Ｙ．Ｚ．Ｚｈａｏ［赵一之（１９８７）］。     

鹅掌楸属植物的多糖壁前体和花粉管的生长

本文观察描述了中国鹅掌楸（Ｌｉｒｉｏｄｅｎｄｒｏｎｃｈｉｎｅｎｓｅ）和北美鹅掌楸（Ｌ．ｔｕｌｉｐｉｆｅｒａ）花粉在异已柱头萌发和花粉管生长期间多糖壁前体的发生、形态结构和生理功能．１、多糖壁前体在形态上有Ｐ－粒子（Ｐｏｌｙｓａｃｃｈａｒｉｄｅｐａｒｔｉｃｌｅｓ）,被膜小泡（ｃｏａｔｅｄｖｅｓｉｃｌｅ）和小泡（ｖｅｓｉｃｌｅ）三种。２、Ｐ－粒子于单核花粉期已经发生,至花粉管延伸期为发生高峰。多糖壁前体是在高尔基体,内质网和线粒体的相继、连续作用下,由淀粉质体、蛋白体和脂滴降解形成．３、Ｐ－粒子的形态随不同发育时期而变化,早期为成群的电子透明小泡,或为蛋白质束缚的挤压成多面体形,后期为内含颗粒或微纤丝的无被膜粒子或具刺被膜粒子。４、Ｐ－粒子移至管端．或融合或单个通过周质内质网（ＣＥＲ）,释放内容物参与管端壁的形成,被膜小池和小泡移至花粉管次顶端区向质膜外分泌,参与花粉管壁内层的形成,或移至管端,提供膜片。最后讨论了亲和性与超微结构特征的关系．     

单性木兰属花粉形态观察

本文对单性木兰（ＫｍｅｒｉａｓｅｐｔｅｎｔｒｉｏｎａｌｉｓＤａｎｄｙ）的花粉形态和花粉壁的亚显微结构做了详细观察。花粉椭圆形,具单沟;外壁表面较粗糙,具皱波状间小穴纹饰;外壁分层明显,柱状层发育较好。     

我国北方地区裸胞壳属(Emericela)的种

对１４０２份来自于东北、华北及西北地区的土样进行裸胞壳属（Ｅｍｅｒｉｃｅｌａ）菌的分离。结合菌落形态及扫描电镜下子囊孢子的形态将各菌鉴定到种。结果表明我国北方地区分布有８个种,１个变种,分别是无冠裸胞壳（Ｅｍｅｒｉｃｅｌａａｃｒｉｓｔａｔａ）、皱折裸胞壳（４Ｅｍｅｒｉｃｅｌａｃｏｒｒｕｇａｔａ）、茴香裸胞壳（Ｅｍｅｒｉｃｅｌａｆｏｅｎｉｃｕｌｉｃｏｌａ）、宫治裸胞壳（Ｅｍｅｒｉｃｅｌａｍｉｙａｊｉ）、构巢裸胞壳（Ｅｍｅｒｉｃｅｌａｎｉｄｕｌａｎｓｖａｒ．ｎｉｄｕｌａｎｓ）、构巢裸胞壳宽脊变种（Ｅｍｅｒｉｃｅｌａｎｉｄｕｌａｎｓｖａｒ．ｌａｔａ）、四脊裸胞壳（Ｅｍｅｒｉｃｅｌａｑｕａｄｒｉｌｉｎｅａｔａ）、褶皱裸胞壳（Ｅｍｅｒｉｃｅｌａｒｕｇｕｌｏｓａ）及波状裸胞壳（Ｅｍｅｒｉｃｅｌａｕｎｄｕｌａｔａ）。除银川地区以Ｅｍｅｒｉｃｅｌａａｃｒｉｓｔａｔａ为优势菌外,各地区以Ｅｍｅｒｉｃｅｌａｎｉｄｕｌａｎｓ最为常见。文中对常见菌种进行了简要的概述,对在我国较少见的种进行了详细的描述和讨论     

延龄草属花粉形态的研究

对延龄草属（Ｔｒｉｌｌｕｍ Ｌ．）２３种进行了光镜和电镜的观察研究。其中１４种作了透射电镜的研究。研究结果表明,本属花粉的形状和大小在种间变化不大,但在外壁纹饰上却有较大的差异,大致可分为４个纹饰类型,即颗粒状纹饰（多数种类）,疣状纹饰,星状纹饰及刺状纹饰。外壁结构上,大多数种类结构层次模糊,无明显的复盖层和柱状层分化。但Ｔ．ｇｒａｎｄｉｆｌｏｒｕｍ和Ｔ．ｃａｔｅｓａｂｅｉ２个种则有较明显的复盖层     

湖榕和小叶榕花形态结构特征的研究

通过对湖榕（Ｆｉｃｕｓ　ｓｐ．）和小叶榕（Ｆｉｃｕｓ　ｍｉｃｒｏｃａｒｐａ　Ｌ．）花形态结构特征的比较研究表明：湖榕和小叶榕的花果形态结构有较显著的差别。湖榕雌花的萼片数多为４片,萼片顶部都有毛,花粉位为精园形,花粉壁较薄,其结实率较低,只有０．１％;小叶榕雌花的萼片数多为３片,萼片顶部光滑无毛,花粉粒为圆形而壁较厚,其结实率较高,为２９．１％。     

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     

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.     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

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).     

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.