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   325篇
  免费   22篇
  2023年   4篇
  2022年   5篇
  2021年   6篇
  2020年   7篇
  2019年   5篇
  2018年   8篇
  2017年   8篇
  2016年   18篇
  2015年   8篇
  2014年   21篇
  2013年   20篇
  2012年   27篇
  2011年   28篇
  2010年   16篇
  2009年   10篇
  2008年   17篇
  2007年   31篇
  2006年   27篇
  2005年   16篇
  2004年   14篇
  2003年   9篇
  2002年   7篇
  2001年   5篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1996年   3篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1991年   2篇
  1990年   7篇
  1989年   2篇
  1988年   2篇
  1986年   1篇
  1985年   4篇
  1971年   1篇
  1965年   1篇
排序方式: 共有347条查询结果,搜索用时 31 毫秒
61.
62.
63.
64.
Stuffed mussel is a traditional food that sold by street venders in various countries. In the present study, samples of stuffed mussels were collected from various places in Ankara. The mussels were analyzed to show the microbiological risks for human health. Thirty samples (600 stuffed mussels in total) were collected periodically and microbiological analyses were performed by standard procedures for Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella sp., Clostridium sp. In terms of Salmonella sp., approximately 50% of samples were not suitable for consumption. Besides, in accordance with Turkish Food Codex Microbiological Criteria Announcement in terms of E. coli 30%, in terms of B. cereus 80%, in terms of S. aureus 76.6%, in terms of Clostridium perfringens 13.3% of these samples were not suitable for consumption. The aim of this study is to discuss the microbiological quality of stuffed mussels as a ready-to-eat food according to Turkish Food Codex (TFC). The result of this investigation indicates that stuffed mussels as a street food may constitute a potential health hazard, depending on contamination level and lack of sanitary practices, and therefore, handling practices should require more attention and improvement.  相似文献   
65.
Arıcı OF  Cetin N 《Regulatory peptides》2011,166(1-3):139-142
Recent data indicate that ghrelin has protective effects in different organs and cell types including the pancreas, heart, and gastrointestinal tract. The purpose of this study was to determine whether ghrelin plays a protective role against CCl4-induced coagulation disturbances in rats.Fourty male Sprague–Dawley rats were equally divided into four groups including group 1 (1 ml physiological saline s.c., for 5 days), group 2 (CCl4, i.p., single dose of 1.6 g/kg), group 3 (ghrelin, s.c., 10 nmol/kg/day, for 5 days) and group 4 (ghrelin, 10 nmol/kg/day, for 5 days plus CCl4, i.p., single dose of 1.6 g/kg on the 5th day). Fibrinogen level, activated partial thromboplastin time (aPTT), prothrombin time (PT), platelet counts and alanine transaminase (ALT) activity were evaluated. The values of PT, aPTT and ALT activity were increased (p < 0.05), while fibrinogen level was decreased (p < 0.05) due to CCl4 treatment alone. Pre-treatment with ghrelin prior to the administration of CCl4 reduced (p < 0.05) PT, aPTT and ALT values and increased (p < 0.05) fibrinogen level when compared with CCl4-treated only group. The results of this study suggest that exogenously administered ghrelin may play a protective role against CCl4-induced coagulation disturbances in rats.  相似文献   
66.
The tetrameric tumor suppressor p53 plays a pivotal role in the control of the cell cycle and provides a paradigm for an emerging class of oligomeric, multidomain proteins with structured and intrinsically disordered regions. Many of its biophysical and functional properties have been extrapolated from truncated variants, yet the exact structural and functional role of certain segments of the protein is unclear. We found from NMR and X-ray crystallography that the DNA-binding domain (DBD) of human p53, usually defined as residues 94-292, extends beyond these domain boundaries. Trp91, in the hinge region between the disordered proline-rich N-terminal domain and the DBD, folds back onto the latter and has a cation-π interaction with Arg174. These additional interactions increase the melting temperature of the DBD by up to 2 °C and inhibit aggregation of the p53 tetramer. They also modulate the dissociation of the p53 tetramer. The absence of the Trp91/Arg174 packing presumably allows nonnative DBD-DBD interactions that both nucleate aggregation and stabilize the interface. These data have important implications for studies of multidomain proteins in general, highlighting the fact that weak ordered-disordered domain interactions can modulate the properties of proteins of complex structure.  相似文献   
67.
Hydroxyamide‐based ligands have occupied a considerable place in asymmetric synthesis. Here we report the synthesis of seven β‐hydroxyamide‐based ligands from the reaction of 2‐hydroxynicotinic acid with chiral amino alcohols and test their effect on the enantioselective reduction of aromatic prochiral ketones with borane in tetrahydofuran (THF). They produce the corresponding secondary alcohols with up to 76% enantiomeric excess (ee) and good to excellent yields (86‐99%). Chirality 26:21–26, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   
68.
69.
70.
Ovarian cancer is the most common cause of death among all gynecologic malignancies and a result of complex interaction of multiple oncogenes and tumor suppressor genes. The aim of this study was to evaluate expression of HER-2/neu (c-erbB2), survivin and cycline D1 biomarkers in serous ovarian neoplasms and their correlations with clinicopathological variables in serous ovarian cancers. We analyzed pathological specimens of 62 patients with benign (n = 25), borderline (n = 14) and malignant (n = 23) serous ovarian neoplasms. Immunohistochemical analysis was performed on formalin-fixed paraffin-embedded specimens. Significantly more immunoreactivity with HER-2/neu was detected in malignant tumors (100 %) compared to borderline (78.6 %) and benign tumors (48 %) (P < 0.01). Survivin expression was significantly higher in malignant tumors (91.3 %) than those found in borderline (71.4 %) and benign tumors (24 %) (P < 0.001). Similarly, higher cyclin D1 expression was observed in malignant tumors (95.6 %) compared to borderline (85.7 %) and benign tumors (48 %) (P < 0.001). Expression of all biomarkers analyzed significantly and gradually increased from benign to borderline and borderline to malignant serous tumors. In terms of clinicopathological variables, only tumor grade was associated with the expression of all biomarkers others exhibited different correlations in serous ovarian cancers. The expressions of HER-2/neu (c-erbB2), survivin and cycline D1 are positively correlated with the malignant potential of serous ovarian neoplasms.  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