麻雀视网膜的组织学研究

1、麻雀(passev,montanus)视网膜结构可分为十层.视网膜中有大量的视杆,视锥细胞,视锥细胞可分为单锥(SC)和双维(DC)两大类.视细胞密度在中失区较高,在周边区较低,视杆与视维数之比约为1.66:1,视细胞与神经节细胞数之比约为1.66:1.2、神经节细胞密度可分为4级.在视网膜中央区神经节细胞的密度较高.细胞的直经较小,细胞排列规则,离中央区越远,神经节细胞密度越低,细胞的直经越大,排列不规则.     

乌梢蛇视网膜的显微结构观察

采用光镜观察了乌梢蛇(Zoacys dhumnades)视网膜的结构,测量并比较了外核层、内核层与节细胞层的细胞数量,分析了视细胞的分布特征,研究了其视网膜结构与生活习性的关系.结果表明,乌梢蛇视网膜中央区分布着大量的视锥细胞,外核层与节细胞层的细胞数量相当,色素上皮层的细胞有许多突起伸向视杆视锥层内,说明乌梢蛇是一种昼行性蛇类.视网膜盲部接近视部处有椭圆形突起,该突起呈连续分布而形成一圈,突起内可见血窦及丰富的红细胞,该突起可能与锥状突和/或栉膜具有同源关系.     

视神经损伤引起斑马鱼视网膜神经细胞凋亡的研究

用石蜡连续切片苏木精染色法,通过定量分析研究夹伤和切断视神经后,斑马鱼视网膜神经节细胞、视杆和视锥细胞密度的变化。结果发现,在损伤视神经7～21d后,上述3种细胞的细胞核密度均呈减少趋势,节细胞减少的比率大于感光细胞,而感光细胞中视锥细胞所受影响比视杆细胞更为明显;在夹伤和切断视神经两种情况中,后者引起视网膜神经节细胞核密度的减少更为显著。上述结果表明,损伤视神经不但影响与其相连的神经节细胞,而且可逆向跨神经元地影响感光细胞的变化。由上述结果推测,由于损伤视神经使视网膜神经节细胞失去靶组织而引起的各种神经细胞密度减少是视网膜中神经细胞凋亡的表现。     

斑马鱼（Branchydaniorerio）视网膜正常结构的定量研究

本文采用半薄切片甲苯胺蓝染色方法，对斑马鱼视网膜正常结构进行了形态学观察，并对视网膜各层厚度，特别是神经节细胞层中细胞核的大小和密度进行了定量分析。结果表明：斑马鱼视网膜正常结构象大多数脊椎动物的一样分为１０层，其总厚度为１６７．５±１２．５μｍ、除外、内界膜外、其余各层由外向内分别为：色素上皮层约２９．６±５．９μｍ，视杆视锥层２５．４±３．４μｍ，外核层８．９±ｌ．４μｍ，外网状层８．９±２．０μｍ，内核层２９．５±４．８μｍ，内网状层３７．８±５．６μｍ，神经节细胞层与视神经纤维层一起共２５．９±３．７μｍ，其中神经节细胞核长轴平均约８．０±１．２μｍ，，短轴约７．３±１．１μｍ，每ｍｍ长度中约含１２５．８±４０．０个神经节细胞核。这些数据可为以后更深入的科研工作提供参考价值。同时讨论了斑马鱼视网膜具有典型的光照条件好，白昼活动型的结构特点。     

斑马鱼视网膜正常结构的定理研究

本采用半薄切片甲苯胺蓝染色方法，对斑马鱼视网膜正常结构进行了形态学观察，并对视网膜各层厚度，特别是神经节细胞层中细胞核的大小和密度进行了定量分析。结果表明：斑马鱼视网膜正常结构象大多数脊椎动物的一样分为１０层，其总厚度为１６７．５±１２．５μｍ、除外、内界膜外、其余各层由外向内分别为：色素上皮层约２９．６±５．９μｍ，视杆视锥层２５．４±３．４μｍ，外核层８．９±１．４μｍ，外网状层８．９±２．     

虎纹蛙视觉器官组织学研究

用光镜和电镜观察了虎纹蛙（Rana rugulosa）眼球的组织结构,同时测量了其眼球的一些视参数。虎纹蛙眼球呈圆球形。角膜内未见前界膜;虹膜内可见少量括约肌,但未见扩瞳肌纤维;虹膜的内侧面有许多突起;巩膜有完整的半球形软骨;晶状体环垫薄,因而视觉调节能力很弱。视网膜中视细胞由视杆细胞、视锥细胞组成,其中视杆细胞占多数,视细胞与神经节细胞数量之比为3.68:1,以上表明虎纹蛙的眼球组织结构与其弱光视觉和捕食习性相适应。     

褪黑激素受体Mel1a在无蹼壁虎视网膜的空间差异性表达

为探讨褪黑激素对视网膜功能的调节机制,本实验运用免疫组织化学方法(ABC法)观察了褪黑激素受体Mel1a在无蹼壁虎视网膜的表达与分布.发现褪黑激素受体Mel1a免疫阳性结果主要位于光感受器细胞层的内节和内网状层的细胞突起.在外网状层、内核层和神经节细胞层,部分细胞的胞体或突起Mel1a免疫染色呈阳性.统计表明,视网膜中央区光感受器层阳性内节线密度(3.3532±0.6941/mm)较周边区(颞或鼻侧)(21.0186±1.5023/mm)明显小(P＜0.001);光感受器细胞阳性内节面积占内节总面积的百分率中央区(15.8579±2.2908%)较周边区(43.8575±5.3839%)明显低(P＜0.001).褪黑激素受体Mel1a在无蹼壁虎视网膜的分布特点,提示褪黑激素可能通过Mel1a的介导对无蹼壁虎视网膜生理功能的调节不同区域存在差异性.     

视网膜向大脑传输抑制信号

正一直以来,生物学家们都认为,眼睛和大脑只靠一条信息通路进行"交流"。但一项于2020年4月30日发表在Science上的研究却发现,视网膜上的一部分神经元会选择一条此前从未发现的新路径向大脑传送信息。和视锥细胞等光感受细胞一样,视网膜神经节细胞(RGC)也能将光信号传送至大脑。但与光感受细胞不同的是,神经节细胞大多不参与视觉成像,而是调解昼夜节律等与光线有关的非成像行为。在新发现     

赤点石斑鱼视觉特性

组织学研究表明:赤点石斑鱼(Epinephelus akaara)的视网膜具有视杆和视锥两种光感受系统。但ERG研究未发现混合视网膜典型特性:该种鱼的明视和颜色背景光下S_λ曲线峰值均未发生明显位移,强光明适应时未出现R型变化,暗适应曲线没有平台和转折,而且视锥细胞视色素在较强光下极易漂白,强光漂白后的暗适应进程非常缓慢甚至阈值难以恢复到暗视水平。因此,我们认为该种鱼的视锥在某种程度上退化,适应于弱光视觉,无辨色能力。这可能是与其长期生活于近海底层岩礁,洞穴中的环境相适应。     

Q：为什么看红色的物体太久后再转向看其他的东西，发现周围是绿色呢？

A：这是由于视网膜上负责感受颜色的视锥细胞的变化造成的。我们的视锥细胞中存在3种类型的视锥细胞，分别感受红色、绿色和蓝色3种颜色的光。这3种物质各自感受到的信号强度被组合在一起传递给视神经，我们据此就能判断所看到的是什么颜色。当我们持续凝视红色后，由于红色视物质兴奋时间过长，引起疲劳，由它负责收集的红色光的信号强度就“被削弱了”，而此时绿色视物质处于兴奋状态会“趁虚而入”。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with