首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   76篇
  免费   2篇
妇产科学   17篇
基础医学   24篇
口腔科学   2篇
临床医学   4篇
内科学   16篇
神经病学   1篇
外科学   3篇
综合类   3篇
预防医学   3篇
药学   4篇
肿瘤学   1篇
  2021年   2篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2015年   3篇
  2014年   6篇
  2013年   2篇
  2012年   4篇
  2011年   4篇
  2010年   2篇
  2009年   4篇
  2008年   4篇
  2007年   6篇
  2006年   7篇
  2005年   5篇
  2004年   6篇
  2003年   1篇
  2002年   8篇
  2001年   4篇
  2000年   1篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
排序方式: 共有78条查询结果,搜索用时 0 毫秒
51.
52.
[目的]归纳卵巢颗粒细胞瘤的临床、病理和CT表现,以提高本病诊断水平。[方法]回顾性分析11例经手术病理证实的卵巢颗粒细胞瘤的临床、病理和CT表现。[结果]11例均为单发病灶,以囊实性为主;增强后轻度或中度强化。临床表现不规则阴道出血,CA125升高。镜下成人型颗粒细胞瘤可见典型的卡-埃小体。[结论]卵巢颗粒细胞瘤具有较为特征性的临床及影像表现,仔细分析有助于提高诊断准确率。  相似文献   
53.
Spermatozoa recovered from testicular biopsies can be used through intracytoplasmic sperm injection (ICSI) to achieve a pregnancy. To assess the likelihood of successful testicular sperm extraction (TESE) in men suffering from severe oligo- or azoospermia, bilateral biopsy specimens were obtained. Following semi-thin sectioning, the morphology of testicular samples was graded according to a modified Johnsen score. TESE was performed in parallel to this histological examination. The number of isolated spermatozoa was assessed in a semiquantitative way. From 103 patients investigated, 64 (62.1%) showed azoospermia in a preceding semen analysis and 29 (28.2%) patients had sperm concentrations between 0.1 and 1 x 10(6)/ml. In 10 patients who had higher sperm counts, most spermatozoa were non-motile. Spermatozoa could be detected after TESE in the testicular tissue of 49 (77%) azoospermic men. When follicle stimulating hormone (FSH) concentration was normal, most patients had detectable spermatozoa after TESE. Nearly one-third of patients with mildly elevated FSH had no spermatozoa. Thirty-nine percent of patients in whom FSH was elevated to more than twice normal and 50% of patients with grossly elevated FSH had no detectable spermatozoa. In all, 82.8% of men with sperm concentrations between 0.1 and 1x10(6)/ml in their ejaculate showed spermatozoa in the tissue sample after TESE. Our data demonstrate that, contrary to previous recommendations, infertile men with azoospermia and high FSH values should be reconsidered for testicular biopsy, provided that tissue samples can be cryopreserved for later TESE/ICSI treatment.   相似文献   
54.
Context: Endometriosis is an estrogen-dependent disease characterized by the presence of endometrial tissue outside of the uterine cavity, causing pelvic pain and infertility in 10% of reproductive-aged women. It is unclear why ectopic endometrium remains viable in only a subset of women. ERK1/2 plays key intracellular roles in activating cellular survival and differentiation processes. Objective: We sought to determine ERK1/2 activity in patients with endometriosis and its possible roles in regulating endometrial cell survival. Design: ERK1/2 phosphorylation and expression throughout the menstrual cycle were evaluated in vivo in normal and endometriotic human endometrium, and in vitro techniques assessed the steroidal regulation of ERK1/2 and its effect on endometrial cell survival. Results: Total ERK1/2 remained constant in normal and endometriotic endometrium throughout the menstrual cycle. Phospho-ERK1/2 was high in the late proliferative and secretory phases in normal endometrium (P < 0.05). In endometriotic glandular cells, there was no cyclical variation in phospho-ERK1/2. In endometriotic stromal cells, there was also a reduction in phospho-ERK1/2 variation, with higher levels in the early-mid secretory phase (P < 0.05). In cultured endometrial stromal cells (ESCs), estrogen plus progesterone increased ERK1/2 phosphorylation within 15 min (P < 0.05). Although estrogen alone did not induce ERK1/2 phosphorylation in normal ESCs, there was a significant response to estrogen in ESCs isolated from eutopic endometriotic endometrium (P < 0.05). ERK1/2 inhibition in ESCs reduced proliferation and increased apoptosis (P < 0.05). Conclusion: Abnormally high levels of ERK1/2 activity may be involved in endometriosis, possibly by stimulating endometrial cell survival.  相似文献   
55.
Vasculogenesis in the human placenta comprises differentiation and growth of newly forming blood vessels derived from hemangiogenic stem cells within the mesenchymal core of villi. In a second stage, angiogenesis leads to the expansion and remodeling of the already existing vessels. At present, relatively little is known about the regulatory mechanisms of vasculogenesis and angiogenesis during very early placentation. Using placental villous tissues from days 22 to 48 of pregnancy, we analyzed the spatial and temporal expression of Tie-1 and Tie-2 in parallel to vascular maturation in the human placenta. In immunohistochemistry both receptors, Tie-1 and Tie-2 show a cell and villous type specific expression during this early phase of placental development. Especially, cytotrophoblast and hemangiogenic cell cords in mesenchymal villi and Hofbauer cells in immature intermediate villi have the strongest immunoreactivities. Western blot analysis showed that no significant changes were detected for Tie-1 and Tie-2 as pregnancy advanced. Moreover, phospho-Tie-2 levels did not change significantly in parallel to pregnancy ages. We conclude that both receptors are involved in angiogenesis as well as vascular modulation of early vessels. Due to their spatial distribution we speculate on an additional role in regulation of villous and extravillous trophoblastic behavior.  相似文献   
56.
目的探讨无创正压通气(NIPPV)在急性加重期慢性阻塞性肺疾病(AECOPD)合并重度二氧化碳潴留患者中的应用效果。方法选取2010年4月至2014年9月凉山州第一人民医院收治的AECOPD合并重度二氧化碳潴留患者138例作为研究对象,在常规治疗的基础上采用NIPPV治疗,分析治疗前后患者心率(HR)、呼吸(R)、氢离子浓度指数(pH)、血氧饱和度(SaO2)、氧分压(PaO2)和二氧化碳分压(PaCO2)改善情况。结果本次研究中气管插管率为21.01%(29/138),病死率为5.80%(8/138),NIPPV有效率为81.88%(113/138)。HR和R在治疗2h后虽有一定下降,但与治疗前比较差异无统计学意义(P0.05)。治疗24h后HR和R均有较大幅度下降,与治疗前及治疗后2h比较,差异有统计学意义(P0.05)。SaO2、pH和PaO2在治疗2h后及24h后增高均较为明显,而PaCO2在治疗2h后及24h后下降均较明显,不同时点间的比较差异均有统计学意义(P0.05)。结论 NIPPV对合并重度二氧化碳潴留的AECOPD患者有良好的治疗效果,血气指标能够得到迅速改善。  相似文献   
57.
When Fas ligand (FasL) interacts with the Fas receptor, it induces apoptosis through autocrine and/or paracrine signalling. Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine. VEGF plays a role during remodelling of the endometrium following menstruation. We hypothesized that, by regulating FasL expression, VEGF may play a role in endometrial stromal cell survival by decreasing autocrine apoptotic signalling. We aimed to determine the expression of FasL in cultured endometrial stromal cells and its modulation by VEGF. VEGF induced a decrease in both FasL-positive cell number and FasL intensity as determined by immunocytochemistry and western blot respectively (P < 0.05). These effects of VEGF were observed in a concentration-dependent manner (10-42%; P < 0.05). Anti-VEGF neutralizing antibody alone resulted in an increase in the FasL expression. When combined with VEGF, anti-VEGF reversed the VEGF-induced decrease in FasL level up to 100% (P < 0.05). In addition, western blot analysis showed that FasL expression in endometrial stromal cells demonstrated a cyclic change every 12 h during 48 h of incubation. These results suggest that down-regulation of FasL by VEGF may affect endometrial stromal cell survival in an autocrine or paracrine manner. The decrease in FasL level may be due to a stimulation of its degradation. Our results show that FasL in endometrial stromal cells in culture has a cyclic expression model, suggesting that there may be a regulation at the translation level.  相似文献   
58.
59.
In the present study, we present the ultrastructural and immunohistochemical properties of the sural nerves of two patients, one of whom was diagnosed as having multiple sclerosis with involvement of the peripheral nervous system (PNS), and the other as having hereditary motor sensory neuropathy type-I with involvement of the central nervous system (CNS). Expression of several extracellular matrix (ECM) proteins (fibronectin, laminin, and collagen type-IV), intermediate filaments (vimentin) and S-100 protein (marker for the axon-Schwann cell interface) was investigated by means of immunohistochemical methods. In addition, the tissue samples were evaluated ultrastructurally. Immunohistochemical staining revealed increased expression of the ECM molecules mentioned above in relation with the sural nerves of the patients. We hypothesize that this enhanced expression is due to Schwann cell-axon interactions. Vimentin expression was different in Schwann cells and S-100 immunostaining was decreased near the Schwann cell-axon interface. Myelin fragmentation, axon vacuolization, onion bulbs, tomoculous formation, axonal degeneration were found to occur. These results suggest that there is active ECM reorganization in the sural nerve of these patients, and some ultrastructural changes are similar in the damaged axonal organization and in Schwann cells although the changes are not completely the same in the two patients. In conclusion, our study demonstrates that there is an association between the demyelinization process in the CNS and the PNS even though they are affected by different mechanisms.  相似文献   
60.
Blood vessel growth and regression in human endometrium are regulated throughout the menstrual cycle. We sought a direct role of ovarian steroids on human endometrial endothelial cell (HEEC) proliferation and vascularization. To investigate the HEEC angiogenicity of sex steroids, we developed a reliable method for the isolation of HEEC, which allowed us to investigate the angiogenic effects of sex steroids using immunohistochemistry, immunocytochemistry, Western blot, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt proliferation, and vascular tube formation analyses. We were able to obtain 95-99% pure HEEC with our isolation technique. HEEC expressed predominantly estrogen receptor beta, minimally expressed estrogen receptor alpha, and but did not express progesterone (P(4)) receptors A and B in vivo and in vitro. Estradiol (E(2); 10(-10)-10(-8) m) and P(4) (10(-12)-10(-8) m), alone or in combination, induced HEEC proliferation compared with control values after 48 h of treatment (P < 0.05). Furthermore, after 8 d of treatment, there were significantly more angiogenic patterns in E(2) (10(-8) m), P(4) (10(-10) m), and E(2) plus P(4) (10(-8) and 10(-10) m) treatment groups compared with the control group (angiogenic scores, 2.95 +/- 0.16, 3.26 +/- 0.16, 3.06 +/- 0.17, and 1.93 +/- 0.15, respectively; P < 0.01). In conclusion, our results suggest that there are direct effects of E(2) and P(4) on HEEC and provide a new understanding of the physiological role of sex steroids in the regulation of endometrial events such as angiogenesis.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号