小鼠视网膜胆碱能无长突细胞出生后的密度分析

为了研究小鼠出生后视网膜胆碱能无长突细胞密度和空间分布的发育变化,使用免疫组织化学的方法对不同天龄小鼠视网膜的胆碱能无长突细胞进行免疫荧光标记,并对用激光共聚焦显微镜采集的数据进行统计学分析.结果表明,小鼠视网膜胆碱能无长突细胞的密度随天龄增长而降低,这个结果与通过眼球直径预测的变化一致.     

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.     

N-甲基-N-亚硝脲诱导的视网膜变性大鼠模型的形态学和功能改变

目的:观察N-甲基-N-亚硝脲(N-m ethyl-N-n itrosourea,MNU)对SD大鼠视网膜光感受器细胞的毒性作用。方法:出生后50 d的SD大鼠84只,随机抽取4只作为正常对照组,余下80只分为4组,每组20只,分别按体质量一次性腹腔注射MNU 80、60、40和30 mg/kg。各组每次4只分别于12 h、24 h、48 h、72 h、120 h行右眼闪光视网膜电图检查(ERG),并于造模后1 d、2 d、3 d、5 d、7 d处死动物,取眼球做组织学检查。结果:1)显示正常对照组的大鼠ERG波形清晰,a、b波振幅正常。MNU 80、60、40和30 mg/kg剂量组a波消失时间分别为3 h、12 h、24 h、120 h;b波消失时间分别为12 h、24 h、72 h、168 h。2)形态学检查测到正常组大鼠中心视网膜的外视网膜厚度为(98.4±1.8)μm。MNU处理后5 d和7 d,80、60、40和30 mg/kg剂量组外视网膜厚度分别为0μm、(9.5±2.3)μm、(42.8±2.7)μm、(71.3±2.4)μm和0μm、0μm、(20.8±2.5)μm、(62.9±2.0)μm,其损伤程度和剂量及时间成正比。结论:MNU可选择性地诱导视网膜光感受器细胞发生凋亡,该作用呈剂量和时间依赖性。     

GAP-43在锦鲤荒漠沙蜥和雉鸡视网膜内分布的免疫组化研究

GAP-43具有多种功能,主要与神经元轴突的生长、再生、神经递质的释放及膜泡的吞噬有关.本研究用免疫组织化学的方法观察了正常成年锦鲤、荒漠沙蜥和雉鸡视网膜内GAP-43分布.结果显示GAP-43主要分布在内网层,另外,在内核层、外网层、光感受器细胞层因动物不同也呈现不同的分布特点,而在节细胞层中3种动物均未发现GAP-43阳性染色.在锦鲤视网膜中GAP-43主要分布在内网层和内核层的无长突细胞;在荒漠沙蜥视网膜中GAP-43主要分布在内网层和外网层,在雉鸡视网膜中GAP-43主要分布在内网层、外网层、外核层和光感受器外节,其中在雉鸡视网膜外核层和光感受器外节中发现阳性分布是在脊椎动物此层发现GAP-43的首次报道.     

光损伤视网膜片培养上清液诱导大鼠骨髓间充质干细胞为视网膜样细胞的研究

目的:探讨大鼠视网膜片光损伤后诱导体外培养的大鼠骨髓间充质干细胞(MSCs)成视网膜细胞的可能性。方法:实验研究。采用贴壁筛选法分离、培养SD大鼠骨髓MSC细胞,经流式细胞仪鉴定后,用大鼠视网膜片光损伤后的上清液与10%FBS的LG-DMEM以2:3混合成的条件培养液诱导MSC细胞7～8d。用免疫细胞化学染色和RT-PCR观察诱导后的细胞是否表达视紫红质、GFAP、NSE。结果:第3代MSC细胞经诱导后有(36.64±7.84)%表达rhodopsin,(20.21±6.47)%表达GFAP,(21.83±2.98)%表达NSE。RT-PCR鉴定结果分析示GFAP、NSE、Rhodopsin mRNA均有表达。结论:光损伤SD大鼠视网膜片培养上清液可诱导MSCs分化为视网膜样细胞。     

老年黄斑变性频域光学相干断层图像分割研究

提出了一种分割老年黄斑变性视网膜频域光学相干断层图像的方法.该方法通过如下技术在保持高精度的同时减少计算时间:首先采用费舍尔判别分析方法对视网膜各层分界面进行粗分割,其次采用曲率计算方法对玻璃膜疣进行检测,最后使用卡尔曼滤波优化分割效果.该方法对20卷体数据中220幅老年黄斑变性图像的三层分界面进行分割验证,在平均绝对误差小于3.29μm的同时,每幅平均处理时间小于42ms.与代表当前最好水平的文献相比,本文所提出的算法能在保持精度的基础上将处理时间缩短40倍,因而能更好地适应于临床需求.     

大鼠骨髓间充质干细胞视网膜下移植观察

观察了骨髓间充质干细胞(MSC)在视网膜下移植后的定位以及分化后的蛋白表达情况.将体外培养的雄性大鼠MSC移植于成年大鼠视网膜下,4周后取眼球做石蜡切片并用Y染色体鉴定;将MSC用重组腺相关病毒AAV-gfp感染后移植,4周后在荧光显微镜下观察眼球冰冻切片中绿色荧光蛋白(GFP)的表达;并用4',6-二脒-2-苯基吲哚(DAPI)标记的MSC进行视网膜下移植,分别于10,20,35和50 d后观察DAPI荧光分布,并在阳性的连续切片上做神经元核(Ne-uN),神经元特异性烯醇化酶(NSE),胶质纤维酸性蛋白(GFAP)和角蛋白(CK)免疫组化染色.结果显示,光学显微镜下Y染色体原位杂交观察,荧光显微镜下GFP观察及DAPI观察均发现来源于MSC的阳性细胞融入了原来的视网膜结构,这些细胞分布于视网膜色素上皮层、视细胞层、双极细胞层及节细胞层,细胞形态结构与周围视网膜相似;DAPI标记观察表明,移植后至50 d无细胞增生,50 d后阳性细胞数量和分布范围缩小.免疫组织化学染色发现阳性区域的细胞NeuN,NSE,GFAP和CK的表达与周围组织相同.3种标记方法检测到的视网膜结构完整,但某些区域的细胞排列不整齐.上述结果表明,MSC在视网膜下移植后可与原视网膜结构相融合,MSC具有分化为类视网膜结构的能力.     

大鼠不完全性视网膜缺血的组织学变化

采用双侧颈总动脉阻断血流（２ＶＯ）的方法，造成大鼠不完全性视网膜缺血，用组织学方法观察了不同缺血时间（３０、９０ｍｉｎ，４、７、３０ｄ）的缺血后再灌注与不再灌流对视网膜变化的影响。结果显示：缺血３０和９０ｍｉｎ再灌流４ｄ后，内炕网膜（包括外网层、内核层、内网层、节细胞层、神经纤维怪和内界膜）明显增厚；其他不再灌流的缺血组，厚度趋向减少。节细胞计数随缺血时间延长逐渐减少；缺血４ｄ后明显减少。提示不完     

视网膜神经节细胞非经典感受野及其方位倾向性的模型研究

建立了包含无长突细胞相互抑制网络的视网膜神经节细胞的三层网络模型,以验证李朝义等提出的非经典感受野可能源于无长突细胞相互抑制的假说,并探讨神经节细胞感受野的方位倾向性的可能机制．模拟结果表明,通过无长突细胞之间的相互抑制可以形成神经节细胞的非经典感受野．模型模拟了神经节细胞的中心区和大周边区的方位倾向性及其相互作用,结果提示神经节细胞的方位倾向性可能主要源于神经节细胞树突野的空间分布．     

新型肽VIP-TAT对NMDA诱导的大鼠视网膜损伤的神经保护作用

目的:研究新型肽VIP-TAT(血管活性肠肽重组肽)对NMDA(N-甲基-D-天门冬氨酸)诱导的大鼠视网膜损伤的神经保护作用.方法:向SD大鼠双眼玻璃体腔注射40nmol NMDA(2μL)建立视网膜损伤模型,治疗组向玻璃体腔注射2μL不同浓度(10 pmol/L、1 nmol/L、100 nmol/L、10μmol/L)的VIP-TAT,NMDA组用等体积生理盐水替代,正常对照组不作任何处理.分别于术后7天用黑白箱装置对其行为学进行检测,观察每组大鼠术后视觉行为的变化;采用视网膜电图评估每组大鼠视功能的差异;石蜡切片HE染色比较各组大鼠视网膜形态学的差异.结果:行为学检测显示,各组大鼠在暗室停留时间的无统计学差异(P0.05);视网膜电图检测结果表明浓度为1 nmol/L的VIP-TAT能够显著提高因NMDA损伤而降低的b波与明视负向反应(Ph NR)的振幅;HE染色显示:在NMDA诱导的青光眼模型中,浓度为1 nmol/L的VIP-TAT能有效增加NMDA诱导的青光眼模型视中视网膜神经节细胞的存活数目.结论:NMDA诱导的SD大鼠青光眼模型中,VIP-TAT对视网膜神经节细胞有保护作用.     

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.     

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.     

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.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.