棉铃虫蛾复眼的形态及显微结构

棉铃虫[Heliothis armigera(Hubner)]蛾复眼的外形约为椭球体绕长轴等切的2/5。最前和最后小眼之间的夹角约为150°,而最上和最下小眼之间的夹角约为180°,一个复眼大约包括8,900个小眼。每个小眼有一套由角膜、晶锥细胞及晶锥所组成的屈光器和分布在不同水平面上的7-9个小网膜细胞。其周围被6个次虹膜细胞所包围。两个明显可见的区域性差异为:1)复眼不同区域内小眼长度不等,背部区域最短,侧、后、腹和前各区域相继增加。2)背部区域视杆中段的横切面为矩形,其它区域的视杆为放射形。本文将小眼及其周围,从远端到基部分13个层次进行了结构上的描述。     

母亲是18-三体携带者,能生育正常宝宝吗?

<正>答:18三体综合征又称Edward综合征,本病临床症状复杂,主要特征是生长发育障碍,智力低下,小眼,眼距宽。耳低位、畸形,先天性心脏病,有特殊握拳姿势等。本病最常见的染色体畸变是单纯18三体,即     

白薯天蛾的复眼结构及形态特征

白薯天蛾Herse convolvuli L.复眼的外部形状与棉铃虫蛾Heliothis armigera Hübner眼虽较相似但其结构却明显不同,大小也不等,其长为4.28毫米,宽为3.78毫米,整个复眼大约有27,000个小眼组成。小眼密度为1177.9/毫米,约为棉铃虫蛾小眼密度的1/3。复眼不同部位上的小眼长度不等,侧部最短,背、后、前、腹依次递增。视杆长度占小眼总长的比例明显地短于棉铃虫,其侧部小眼的视杆约占小眼总长的23%,而腹部视杆仅占小眼总长的18%左右。屏蔽色素移动的幅度也较小,当充分光适应色素带最宽时才仅占屈光器加透明区总长的35%左右,同样条件下棉铃虫蛾眼的色素带可宽达80%以上。网膜细胞在透明区基部膨大,细胞核大多数在此集中。本文对小眼及小眼间16个不同水平的横切面进行了形态上的描述并根据小眼结构上的某些特征讨论了与其功能和蛾子趋光行为之间相关的一些问题。     

北京萤火虫复眼的模型小眼设计与光线追迹

以实际的北京萤火虫复眼结构与生理参数与依据,基于已知的ＧＲＩＮ透镜特征,把小眼的整个光学系统分成几个部分被模型化。模型中,在晶体柱部分使用了一个径向梯度折射率透镜柱具有的抛物线轮廓折射率公式;在晶锥末端所接的半椭球ＧＲＩＮ透镜部分,使用了一个径向梯度和纵向梯度分布都存在的折射率公式．模型的尺寸与折射率的大小根据实际晶锥的测量值．通过对模型小眼的光线追迹,证明模型小眼基本上是一个平行光入射,年行光出射的望远镜系统．小眼光学系统的前半部分把入射的平行光束聚焦到中间焦点,而这个点的位置恰好位于实际晶锥的腰的部位,而光线再次经过晶锥近端以后又以大致平行光束从晶锥末端出射。此模型小眼的最大入射角为３０度,在这个入射角内其角放大率基本上是相同的。随着对平行入射光束与小眼光轴的角度的增加,所产生的中间像越来越远离晶锥光轴。     

复眼是由单眼组成的吗?

答:复眼的组成单位不是单眼,而是个眼或称小眼,或称类似单眼的小眼。个眼与单眼结构和功能都不同。个眼是由外为六角形个眼面内连感光细胞和神经。每个个眼可分为集光和感光两部分。集光部分包     

桃小食心虫复眼的外部形态及结构特征*

桃小食心虫(Carposina nipponensis Wals)蛾复眼的外部形态与棉铃虫(Heliothis armi-gera Hubner)蛾等较相似,但大小及结构明显不同,它的体长为o.54毫米,宽为o.50毫米,每只复眼大约有l500个小眼组成。 小眼密度为每平方毫米3301个。透明区占小眼总长的64%。网膜细胞多在远端膨大,细胞核也大都在此集中。本文对小眼及其周围分10个层次进行了描述和摄影。     

辽宁太子河大型水生植物的群落特征及其与环境的关系

采用样方法对太子河3条支流大型水生植物群落结构与生物量的研究表明：太子河北支大型水生植物的优势种为小眼子菜（Potamogeton pusillus）、菹草（P.crispus）和马来眼子菜（P.malaianus）,主要群落类型为小眼子菜＋菹草群落;细河大型水生植物的优势种为菹草、马来眼子菜和轮叶黑藻（Hydrilla verticillata）,主要群落类型为菹草＋轮叶黑藻群落;海城河大型水生植物的优势种为轮叶黑藻、小眼子菜、五刺金鱼藻（Ceratophyllum oryze-torum）和菹草,主要群落类型为轮叶黑藻＋小眼子菜＋菹草群落。从定量生长型谱来看,太子河北支以小眼子菜型为主要类型,细河以大眼子菜型为主要类型,海城河以大眼子菜型、小眼子菜型、金鱼藻型和伊乐藻型为主要类型;从生活型谱来看,3条支流都是以沉水植物为主要生活型。大型水生植物群落相似性聚类分析表明3条支流水生植物群落组成差异显著。3条支流大型水生植物沿河流纵向分布格局均为间断的斑块状,沿水深的垂直分布格局不明显。太子河北支大型水生植物从上游到下游均有出现;细河大型水生植物主要分布在下游;海城河大型水生植物主要分布在中下游。大型水生植物生产力（湿重）：海城河（644 g/m2）﹥太子河北支（586.8 g/m2）﹥细河（151.1 g/m2）。大型水生植物与环境因子的相关性分析表明：大型水生植物的物种数与氨态氮、水温、pH和电导率显著正相关（p〈0.05）;与溶解氧、底质指数和海拔显著负相关（p〈0.01）;优势种小眼子菜的生物量与水深显著正相关（p〈0.01）,与电导率和总氮显著负相关（p〈0.05）。     

海州湾秋季小眼绿鳍鱼摄食习性的空间异质性

研究海州湾小眼绿鳍鱼摄食习性的空间异质性,对于海州湾食物网构建和资源保护具有重要意义。根据2011及2013-2016年秋季在海州湾海域进行的渔业资源底拖网调查数据,结合小眼绿鳍鱼（Chelidonichthys spinosus）的空间分布特征及其胃含物样品的分析结果,研究了海州湾小眼绿鳍鱼的摄食热点海域及其摄食习性的空间异质性。结果表明,小眼绿鳍鱼是海州湾秋季底层鱼类群落中的优势鱼种,且各年均主要分布在海州湾35 °N附近及以北海域。细螯虾（Leptochela gracilis）、戴氏赤虾（Metapenaeopsis dalei）和疣背宽额虾（Latreutes planirostris）是小眼绿鳍鱼最重要的三种饵料生物。研究发现,海州湾小眼绿鳍鱼的摄食热点海域主要集中在30 m等深线附近,且尚未呈现出明显的年间变化趋势。根据各站位小眼绿鳍鱼食物组成的相似性,将调查海域划分为两个区域,即近岸区和远岸区,近岸区小眼绿鳍鱼的体长和体重均显著小于远岸区（P < 0.05）,小眼绿鳍鱼在近岸区主要摄食细螯虾和疣背宽额虾,在远岸区则主要摄食戴氏赤虾。近岸区小眼绿鳍鱼的空胃率显著小于远岸区（P < 0.05）,条件指数显著大于远岸区（P < 0.05）,平均胃饱满指数大于远岸区,但尚未呈现出显著差异（P > 0.05）,表明海州湾秋季小眼绿鳍鱼的摄食习性存在明显的空间异质性。     

棉铃虫夜眼反射光斑的研究

利用一个圆弧投光器,使点光源在90°范围内绕眼移动,对棉铃虫暗适应眼的反射光斑进行了研究。主要结果为:1.投射在眼上,并且与光斑垂直轴在背腹方向上构成的夹角不超过20°—23°的全部光线,对于引起光斑的反射光都是有效的。2.在眼的不同区域中,光斑的明亮度不等。以腹部区域最亮,而背部区域最不亮。3.有效投射光线依照其投射角,由光斑的不同部位进入眼中。平行于光斑垂直轴的光线,由整个光斑中的小眼面进入。具有较大投射角的光线,由同侧更边缘的小眼面进入。否则它们无助于被观察的光斑的亮度。4.在直径约为光斑直径1/2的中央部分,其反射光的来源是由两部分组成的,一部分是从该中央部分进入又反射出来,另一部分是从眼的其余部分进入而从该中央部分反射出来。起源于其余部分进眼的光线的总反射光,远强于起源于从该中央部分进眼的光线的总反射光。     

眼蛇毒伤27例治疗及文献复习

眼蛇毒伤是两广地区餐馆内较常发生的眼部损伤,如果处理不当,常常发生严重的全身及眼部损害。我院从1998年至今共治疗27例眼蛇毒伤病人,取得了一定的经验,现报告如下。1临床资料1·1一般资料27例病人均为我科住院或留观病人,均为男性,3例为儿童,其余为成年人。21人在餐馆工作受     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78?µg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell line.