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981.
Embryo transfer (ET) is the last stage of extracorporal fertilization during which the embryo is placed in the uterine cavity with a medium-filled catheter 2–3 days after in vitro fertilization. While fertilization in the laboratory occurs at very high rates (>:90%), the overall success of the procedure (i.e., take home baby) is still very low (<25%) and assumed to be mainly due to implantation failure. A computational model was developed to simulate ET within the uterine cavity by a fluid-filled catheter inserted into a two-dimensional channel with oscillating walls. The results showed that the speed at which the embryos are injected from the catheter dominates the procedure and controls the velocity of their transport within the uterine cavity. ET at excessively high injection speeds may lead to ectopic pregnancies, while uterine peristalsis affects transverse dispersion only during injection at low injection speeds. The presence of the catheter within the uterus does not affect flow patterns downstream of its tip. The potential risks to implantation failure due to mechanical factors involved in the ET processes are discussed. © 2003 Biomedical Engineering Society. PAC2003: 8719-j, 8710+e  相似文献   
982.
Materials are distributed throughout the body of mammals by fractal networks of branching tubes. Based on the scaling laws of the fractal structure, the vascular tree is reduced to an equivalent one-dimensional, tube model. A dispersion–convection partial differential equation with constant coefficients describes the heterogeneous concentration profile of an intravascular tracer in the vascular tree. A simple model for the mammalian circulatory system is built in entirely physiological terms consisting of a ring shaped, one-dimensional tube which corresponds to the arterial, venular, and pulmonary trees, successively. The model incorporates the blood flow heterogeneity of the mammalian circulatory system. Model predictions are fitted to published concentration-time data of indocyanine green injected in humans and dogs. Close agreement was found with parameter values within the expected physiological range. © 2003 Biomedical Engineering Society. PAC2003: 8710+e, 8719Hh, 8719Uv  相似文献   
983.
为建立二核苷酸简单串联重复顺序(STR)多态位点个体鉴别技术系统,应用6个位于不同染色体呈共显性传递的二核苷酸STE多态位点进行中国汉族人个体鉴别研究,这6个位点是D1S103、D4S175、D5S107、D19S49、D6S89及D9S58。结果显示:(1)6个STR位点基因型数14~39个,等位片段数0~20个;(2)杂合度观察值及估测值分别为0.65~0.91及0.63~0.93.多态信息含量0.59~0.90;(3)6个位点均符合Hardy-Weinberg平衡;(4)6个位点15次配对分析中,未见非随机关联;(5)6个位点的亲子关系排除概率0.99;(6)普通群体中两个无亲缘关系随机个体间6个位点基因型完全一致的概率在1.7×10-12~9.2×10-33间。结果表明,应用这六个二核苷酸STR位点适于亦足以在中国汉族人中进行个体鉴别.故将此检测及数据处理系统,命名为DNA身份号码。  相似文献   
984.
The caecilians (Amphibia, Gymnophiona) constitute one of the least known groups of terrestrial vertebrates because most species live underground in quite inaccessible environments. Siphonops annulatus is an exclusively fossorial species and is the most extensively distributed caecilian in South America. Little is known of this order concerning circulating granulocytes, including their morphological and cytochemical structure and ultrastructure. This paper is part of a project covering the study of granulocytes in representative species of the order Amphibia. Blood extensions were carried out and submitted to Leishman, Toluidine Blue, Periodic acid Schiff, Sirius Red and hydrogen o-toluidine peroxide methods. Part of the samples was prepared for conventional transmission electron microscopy. Among granular leukocytes, mature and immature neutrophils and eosinophils were identified, plus basophils. The most frequent granulocyte encountered in S. annulatus peripheral blood is the neutrophil. This is a cell with a hyper-segmented nucleus and with a very clear cytoplasm when compared to the eosinophil, which presents large cytoplasmic acidophilic granules. On the other hand, the basophils present basophilic and metachromatic granules. Glycogen was detected in the cytoplasm of the neutrophils and eosinophils, while basic protein rich in amino acids was observed in the eosinophil’s granules. Myeloperoxidase activity was detected in the cytoplasm of the neutrophils and eosinophils. Neutrophils were ultrastructurally detected with three types of small granules: eosinophils with large and small spherical granules and basophils with large spherical granules with lamellate structures.  相似文献   
985.
Electron microscopy has been the ‘gold standard’ of spatial resolution for studying the structure of the cell nucleus. Electron spectroscopic imaging (ESI) offers advantages over conventional transmission electron microscopy by eliminating the need for heavy-atom contrast agents. ESI also provides mass-dependent and element-specific information at high resolution, permitting the distinguishing of structures that are primarily composed of protein, DNA, or RNA. The technique can be applied to understand the structural consequences of epigenetic modifications, such as modified histones, on chromatin fiber morphology. ESI can also be applied to elucidate the multifunctional behavior of subnuclear ‘organelles’ such as the nucleolus and promyelocytic leukemia nuclear bodies. The authors dedicate this paper to the memory of Ying Ren (1961–2007). We all benefited from knowing her. Our research advanced through the technical creativity she provided.  相似文献   
986.
987.
冷冻浓缩腹水回输在治疗顽固性肝硬化腹水中的应用   总被引:4,自引:0,他引:4  
目的 探讨冷冻浓缩腹水回输治疗顽固性肝硬化腹水的疗效。方法 采用透析机对32例顽固性肝硬化腹水患者的腹水进行超滤浓缩,置-18℃环境中冷冻2~3天,37℃温育溶解后静脉回输。结果 冷冻浓缩腹水回输前后,血清总蛋白为(59.1±5.6)g/L和(66.3±4.7)g/L,白/球比值为0.8±0.3和1.1±0.5,腹水总蛋白为(15.2±6.8)g/L和(55.6±8.4)g/L;腹围为(91.3±9.5)cm和(80.8±9.2)cm,腹压为(3.5±0.43)kPa和(2.4±0.32)kPa,24 h尿量为(615.0±185.5)ml和(1 240.0±255.0)ml;治疗前后相比,差异有高度显著性(P<0.01)。血清钾为(3.5±1.1)mmol/L和(4.0±1.3)mmol/L,腹水钾(3.6±0.9)mmol/L和(4.1±1.0)mmol/L;血清钠为(122.2±4.0)mmol/L和(126.5±4.3)mmol/L,腹水钠为(120.8±4.5)mmol/L和(123.3±4.7)mmol/L;血清氯为(90.3±6.2)mmol/L和(95.1±5.7)mmol/L,腹水氯为(92.0±5.9)mmol/L和(96.4±50.5)mmol/L;治疗前后相比,血清钠、腹水钠、腹水钾、血清氯、腹水氯差异均有显著性(P<0.05,P<0.01),血清钾差异无显著性(P>0.05)。冷冻浓缩腹水回输后,除2例出现一过性发热外,未发生低血压、肝昏迷、消化道出血现象,未出现蛋白凝集、堵塞管腔;未出现电解质紊乱现象。结论 冷冻浓缩腹水回输可大量回收腹水  相似文献   
988.
[目的 ]探讨非手术方法治疗腰椎间盘突出症的疗效 .[方法 ]将 98例腰椎间盘突出症患者分成腰痛组和腿痛组 ,前者采用骶管阻滞加严氏椎间隙阻滞法 ,后者采用骶管阻滞加腰大肌肌沟阻滞法 .[结果 ]两组治疗前后分值相比较均有显著性差异 ,其优良率分别为 88%和 84% .[结论 ]采用骶管阻滞加严氏椎间隙阻滞或腰大肌肌沟阻滞法治疗腰椎间盘突出症具有疗效  相似文献   
989.
5-氨基水杨酸灌肠对大鼠免疫性结肠炎的影响   总被引:5,自引:0,他引:5  
目的 探讨5-氨基水杨酸(5-ASA)灌肠对大鼠三硝基苯磺酸(TNBS)诱导的结肠炎的作用.方法用TNBS诱发大鼠结肠炎.造模7天后,用不同剂量的5-ASA(25、50、100mg·kg-1·d-1)开始灌肠.观察大鼠粪隐血(OB)反应强度、结肠大体形态和组织学改变,并检测肠黏膜髓过氧化物酶(MPO)活性.结果 5-ASA灌肠可明显降低结肠黏膜损伤指数(CMDI)、OB反应强度、MPO活性及组织学评分(HS),各剂量组间有一定的量效关系.结论 5-ASA灌肠对TNBS诱导的大鼠结肠炎有保护作用,且与剂量有一定关系.  相似文献   
990.
小儿病毒性肺炎的病毒病原学分析   总被引:9,自引:1,他引:8  
目的:探讨小儿病毒性肺炎的病毒病原学。方法:对1998年至1999年二次拟诊为病毒性肺炎的2岁以下小儿采用免疫法进行咽拭子检查,证实为病毒感染后,再进行血酶联免疫抗体法检测,结果相一致的判断为该种病毒感染。结果:呼吸道合胞病毒(RSV),腺病毒(ADV),柯萨奇病毒(DBV)是引起2岁以下小儿肺炎的主要病原。结论:提示黑龙江省地区RSV,ADV是引起小儿感染的主要病原,CBV亦为应引起注意的病原。冬春季应给以早期发现。治疗。/  相似文献   
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