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101.
目的 观察应用引导管芯做引导,更换经口气管内导管的临床效果。方法 随机选择26例已完成气管内插管的病人,将引导管芯插入气管导管内至隆突水平,并拔出气管导管;将欲更换的气管导管套在引导管芯外,在管芯引导下将气管导管插入气管内,完成换置;结果 全部病例均顺利完成更换导管,换管过程中病人氧合良好,术后未发生与更换导管相关并发症;结论 应用引导管芯更换气管内导管,方法安全,简便易行,可替代传统换管方法。  相似文献   
102.
Fabian MR  Na H  Ray D  White KA 《Virology》2003,313(2):567-580
The plus-strand RNA genome of tomato bushy stunt virus (TBSV) contains a 351-nucleotide (nt)-long 3'-untranslated region. We investigated the role of the 3'-proximal 130 nt of this sequence in viral RNA accumulation within the context of a TBSV defective interfering (DI) RNA. Sequence comparisons between different tombusviruses revealed that the 3' portion of the 130-nt sequence is highly conserved and deletion analysis confirmed that this segment is required for accumulation of DI RNAs in protoplasts. Computer-aided sequence analysis and in vitro solution structure probing indicated that the conserved sequence consists of three stem-loop (SL) structures (5'-SL3-SL2-SL1-3'). The existence of SLs 1 and 3 was also supported by comparative secondary structure analysis of sequenced tombusvirus genomes. Formation of the stem regions in all three SLs was found to be very important, and modification of the terminal loop sequences of SL1 and SL2, but not SL3, decreased DI RNA accumulation in vivo. For SL3, alterations to an internal loop resulted in significantly reduced DI RNA levels. Collectively, these data indicate that all three SLs are functionally relevant and contribute substantially to DI RNA accumulation. In addition, secondary structure analysis of other tombusvirus replicons and related virus genera revealed that a TBSV satellite RNA and members of the closely related genus Aureusvirus (family Tombusviridae) share fundamental elements of this general structural arrangement. Thus, this secondary structure model appears to extend beyond tombusvirus genomes. These conserved 3'-terminal RNA elements likely function in vivo by promoting and/or regulating minus-strand synthesis.  相似文献   
103.
104.
The lingual papillae and their connective tissue cores (CTC) from Reeves’ muntjac deers (herbivorous artiodactyla) were studied using light and scanning electron microscopy and then compared to those of other mammalian species. At the posterior portion of the tongue, the Reeves’ muntjac has a lingual prominence on which large conical papillae are distributed. On the dorsal surface of the anterior tongue, numerous filiform papillae were found. Externally, each filiform papilla consists of a rod-shaped main process and several small accessory processes. Their CTCs consist of 10 or more rod-shaped processes arranged in a horseshoe pattern and several posterior processes forming a small circular pattern. This structure is a common characteristic of artiodactyla, through which Reeves’ muntjac deer can be categorized in a position in the artiodactyla class lying between the bighorn sheep and the East African bongo. Fungiform papillae are distributed among the filiform papillae on the anterior portion of the tongue. Large fungiform papillae are also sparsely distributed on the lingual prominence and have several taste buds in the epithelium on the surface. Ten or more vallate papillae are distributed at the postero-lateral area of the lingual prominence and numerous taste buds are distributed in the epithelium of their side.  相似文献   
105.
Summary The yeast Saccharomyces cerevisiae has been engineered to synthesize and secrete desulfato-hirudin (hirudin), a thrombin inhibitor from the leech Hirudo medicinalis. The synthetic gene coding for hirudin was expressed constitutively under the control of four size-variants of the yeast glyceraldehyde-3-phosphate dehydrogenase promoter (GAP) and cloned into a 2 based multicopy yeast vector. The constitutive action of the four promoter variants was confirmed by demonstrating that the expression and secretion of hirudin is growth-related. The different efficiencies of the promoter variants not only affected hirudin expression but also led to changes in several cellular parameters, such as cell growth, average plasmid copy number and plasmid stability. The observed changes show that yeast cells establish a specific equilibrium for each promoter variant. We conclude, that the adjustment of cellular parameters in response to the expression levels of a heterologous protein is regulated by two counteracting selective forces: (1) the need for complementation of the auxotrophic host marker by the plasmid-encoded selection gene which, in the case of dLEU2, requires several plasmid copies; and (2) a selective advantage of cells with a lower copy number enabling them to escape the burden of heterologous protein production.  相似文献   
106.
Light microscopic examination of the renal tubular epithelium of a female with a rapid progressive glomerulonephritis revealed in several areas the presence of cells bearing ciliumlike structures.

At transmission electron microscopy, normal tubular cells appeared to be partially replaced by epithelial cells showing numerous 9×2 cilia and a normally developed basal apparatus. The cilia showed several ultra-structural details (i.e., outer dynein arms, spokes) such as observed in kinocilia of the respiratory epithelium. In addition, a number of poorly differentiated cells showing cilia with a 9 + 0 pattern and at the same time cilia with a 9 + 2 pattern of microtubular arrangement were also seen.

The possible biologic significance of these cilia is discussed.  相似文献   
107.
108.
关于我院图书馆中外文期刊利用状况的调研   总被引:2,自引:0,他引:2  
目的 :明确图书馆专业期刊资源对科研活动的文献保障状况 ,初步制订出我馆的专业核心期刊表 ,以形成特色馆藏。方法 :应用流通统计法确定本馆的期刊文献利用情况 ,在此基础上 ,采用引文分析法确定我馆的核心期刊。结果 :本院研究生和教研人员引用文献的来源主要集中在 188种外文期刊和 69种中文期刊中 ,故这 188种外文期刊和 69种中文期刊可初步定为我馆的核心期刊。结论 :调研结果可作为图书馆确定藏书建设方向和特色的依据。  相似文献   
109.
目的 :探讨螺旋CT辅以LeksellG定向仪在微电极引导脑立体定向术中的应用。方法 :对治疗组和对照组帕金森病病人进行CT定位和手术靶点定位 ,比较AC PC层面与体表标志间的关系以及进行定位结果分析。结果 :对照组和治疗组AC PC层面与外耳孔上缘之间的距离无显著差异 ,距离为 ( 4 7.75± 0 .6 2 )mm ;AC PC层面与GI线之间没有确定的关系 ,与听眶线的夹角为 ( 1.0± 1.5 )° ;与外耳孔上方中点联线的夹角为 ( 0 .5± 1.0 )°。结论 :螺旋CT辅以LeksellG定向仪可以较好地满足临床定位要求 ,以听眶线为扫描基线更易掌握  相似文献   
110.
目的 为了探讨前列腺基底细胞的免疫组化特征。方法 采用常规HE染色及免疫组化En Vision两步法,用高分子角蛋白34βE12、广谱CK、Vim、PSA、PsAP、S-100、SMA7种标记物对37例良性前列腺增生(BTH)的基底细胞进行检测观察。结果 所有37例BPH的基底细胞对高分子角蛋白34βE12均呈胞质阳性反应,阳性率100%;大部分基底细胞(71%)对广谱CK表达阳性;PsAP及PSA在基底细胞中的阳性率均为35%;S-100蛋白阳性率较低,仅13.5%;而Vim及SMA则均呈阴性反应。结论 高分子角蛋白34βE12是前列腺基底细胞的特异性标记物;前列腺基底细胞具有向前列腺腺泡上皮分化的能力,也可引起局部自身增殖,故其在前列腺的生长、增生甚至疾病的发生中起着一定的作用;前列腺基底细胞与肌上皮细胞是不同的,但其是否具有向肌上皮分化或化生仍有待进一步探讨。  相似文献   
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