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   244篇
  免费   16篇
  国内免费   1篇
  2024年   1篇
  2023年   2篇
  2022年   2篇
  2021年   11篇
  2020年   6篇
  2019年   3篇
  2018年   7篇
  2017年   8篇
  2016年   11篇
  2015年   14篇
  2014年   14篇
  2013年   17篇
  2012年   19篇
  2011年   17篇
  2010年   15篇
  2009年   11篇
  2008年   10篇
  2007年   16篇
  2006年   8篇
  2005年   9篇
  2004年   8篇
  2003年   19篇
  2002年   8篇
  2001年   3篇
  2000年   9篇
  1999年   5篇
  1998年   1篇
  1996年   1篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1985年   1篇
  1982年   1篇
  1969年   1篇
排序方式: 共有261条查询结果,搜索用时 15 毫秒
61.
62.
A rare complication of circumcision: concealed penis   总被引:2,自引:0,他引:2  
  相似文献   
63.
A total of 1,173 specimens of Stomatopoda were captured in 27 localities at different depths (20 to 73 m) during three oceanographic cruises in the Mexican Pacific along the continental shelf of the states of Oaxaca and Chiapas. Seven species were identified of the families Eurysquillidae, Lysiosquillidae and Squillidae. Squilla hancocki and Squilla parva were the most abundant species and the most frequently found together. The relationships between total length and carapace length were obtained for these species, which show that males of S. hancocki have a longer carapace length than females having the same total length, whereas for S. parva the opposite occurs. Larger sizes than previously reported were obtained for Lysiosquilla panamica and Squilla mantoidea. Squilla bigelowi was recorded for the first time in the Gulf of Tehuantepec. All the species were found in the intermediate platform (25-60 m); E. veleronis, S. hancocki and S. parva extended their distributions to the external platform (60-120 m), and S. hancocki and S. parva reached the circalittoral zone (10-25 m).  相似文献   
64.
Vasoactive intestinal peptide (VIP) has potent protective activity against sepsis and increases the survival rate of septic rats and mice. The present study was planned to evaluate the effect of VIP on mast cell activity, histamine and methylhistamine levels and oxidative stress in the liver and kidneys of septic rats. The effect of VIP was compared to that of nitric oxide synthesis inhibition, previously tested extensively in septic shock models, with doubtful benefit. The present study showed that endotoxic shock did not lead to oxidative stress in either liver or kidney of the rats. On the other hand, mast cells, based on their location, displayed functional heterogeneity to the septic insults. VIP possibly modulated the specific reactions of the tissues to mediators released from mast cells during septic shock. The most prominent effect of VIP as compared to nitric oxide synthesis inhibition was related to mast cells. In conclusion, the prevention of mast cell reactivity by VIP could be a potential therapeutic strategy in controlling septic shock.  相似文献   
65.
Knowledge about the origin and identity of the microbial products recognized by the innate immune system is important for understanding the pathogenesis of inflammatory diseases. We investigated the potential role of Salmonella enterica serotype Typhimurium fimbriae as pathogen-associated molecular patterns (PAMPs) that may stimulate innate pathways of inflammation. We screened a panel of 11 mutants, each carrying a deletion of a different fimbrial operon, for their enteropathogenicity using the calf model of human gastroenteritis. One mutant (csgBA) was attenuated in its ability to elicit fluid accumulation and GROalpha mRNA expression in bovine ligated ileal loops. The mechanism by which thin curled fimbriae encoded by the csg genes contribute to inflammation was further investigated using tissue culture. The S. Typhimurium csgBA mutant induced significantly less IL-8 production than the wild type in human macrophage-like cells. Purified thin curled fimbriae induced IL-8 expression in human embryonic kidney (HEK293) cells transfected with Toll-like receptor (TLR) 2/CD14 but not in cells transfected with TLR5, TLR4/MD2/CD14 or TLR11. Fusion proteins between the major fimbrial subunit of thin curled fimbriae (CsgA) and glutathione-S-transferase (GST) elicited IL-8 production in HEK293 cells transfected with TLR2/CD14. Proteinase K treatment abrogated IL-8 production elicited in these cells by GST-CsgA, but not by synthetic lipoprotein. GST-CsgA elicited more IL-6 production than GST in bone marrow-derived macrophages from TLR2+/+ mice, while there was no difference in IL-6 secretion between GST-CsgA and GST in macrophages from TLR2-/- mice. These data suggested that CsgA is a PAMP that is recognized by TLR2.  相似文献   
66.
67.
68.
In the field of orthopaedics, treatment of extremity deformities can be realised by means of external fixators. However, control of such biomedical system is very difficult. Some different mathematical models have been developed to improve quality of this service. Most of the parameters, which are used in these models, have been obtained from two orthogonal X-ray images: one from anteroposterior, AP, direction and the other from a lateral, L, direction. The quality of the results of this model is dependent on the accuracy of the input parameters. Measuring these parameters is a time-consuming issue, and the accuracy of the results is also low. To increase the quality of the measurement, the reference points should be chosen from the edges of the biomedical system, and it is important to find the edges without noise. To achieve this purpose, Sobel edge detector, binary large object analysis, thresholding and inverting are applied as image processing steps. The results are compared with manual measurement values which have been obtained earlier. The results show that semi-automatic measurement of the parameters is more accurate and faster than manual measurement. It shows that the efficiency of the fixator method has been improved.  相似文献   
69.
One strategy in cancer immunotherapy is to capitalize on the key immunoregulatory and antigen presenting capabilities of dendritic cells (DCs). This approach is dependent on efficient delivery of tumor specific antigens to DCs, which subsequently induce an anti-tumor T-cell mediated immune response. Human adenovirus serotype 5 (HAdV5) has been used in human studies for gene delivery, but has limited infection in DCs, which lack the proper receptors. Addition of the porcine fiber knob (PK) from porcine adenovirus type 4 to HAdV5 allows the virus to deliver genetic material via binding to glycosylated surface proteins and bypasses the coxsackie-and-adenovirus receptor required by wild-type HAdV5. In this study we explored the potential therapeutic applications of an adenovirus with PK-based tropism against cancers expressing mesothelin. Infectivity and gene transfer assays were used to compare Ad5-PK to wild-type HAdV5. Mouse models were used to demonstrate peptide specificity and T-cell responses. We show that the PK modification highly augmented infection of DCs, including the CD141+ DC subset, a key subset for activation of naïve CD8+ T-cells. We also show that Ad5-PK increases DC infectivity and tumor specific antigen expression. Finally, vaccination of mice with the Ad5-PK vector resulted in enhanced T-cell-mediated interferon gamma (IFN-γ) release in response to both mesothelin peptide and a tumor line expressing mesothelin. Ad5-PK is a promising tool for cancer immunotherapy as it improves infectivity, gene transfer, protein expression, and subsequent T-cell activation in DCs compared to wild-type HAdV5 viruses.  相似文献   
70.
The uterosacral ligaments are an important part of the pelvic support system. The objective of this study was to compare the expression of collagen type I and collagen type III in the uterosacral ligament biopsies from women with and without pelvic organ prolapse (POP). The uterosacral ligament biopsies were obtained from women with POP (n = 29) and non-POP subjects (n = 35). Immunohistochemistry for collagen type I and collagen type III was performed on formalin-fixed and paraffin-embedded sections. The two groups were matched for age, body mass index, parity and postmenopausal status. The expression of collagen type I (p < 0.001) and collagen type III (p < 0.0001) differed between women with POP and non-POP subjects. There was decreased expression of collagen type I and increased expression of collagen type III in uterosacral ligaments of women with POP compared with non-POP subjects. This difference indicates a possible relationship between POP and the immunohistochemical expression of collagen type I and collagen type III in uterosacral ligaments.  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