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   2291篇
  免费   214篇
  国内免费   29篇
耳鼻咽喉   14篇
儿科学   40篇
妇产科学   12篇
基础医学   299篇
口腔科学   43篇
临床医学   238篇
内科学   774篇
皮肤病学   105篇
神经病学   109篇
特种医学   47篇
外科学   342篇
综合类   10篇
预防医学   59篇
眼科学   9篇
药学   137篇
中国医学   5篇
肿瘤学   291篇
  2024年   5篇
  2023年   65篇
  2022年   103篇
  2021年   166篇
  2020年   87篇
  2019年   92篇
  2018年   123篇
  2017年   103篇
  2016年   93篇
  2015年   120篇
  2014年   122篇
  2013年   149篇
  2012年   222篇
  2011年   206篇
  2010年   103篇
  2009年   74篇
  2008年   126篇
  2007年   105篇
  2006年   96篇
  2005年   96篇
  2004年   93篇
  2003年   58篇
  2002年   45篇
  2001年   5篇
  2000年   5篇
  1999年   8篇
  1998年   11篇
  1997年   5篇
  1996年   8篇
  1994年   3篇
  1993年   2篇
  1992年   4篇
  1991年   2篇
  1989年   2篇
  1988年   3篇
  1985年   1篇
  1984年   3篇
  1983年   2篇
  1982年   2篇
  1981年   5篇
  1980年   2篇
  1977年   2篇
  1972年   1篇
  1970年   1篇
  1968年   1篇
  1967年   1篇
  1966年   1篇
  1961年   2篇
排序方式: 共有2534条查询结果,搜索用时 486 毫秒
241.
We report here a 35-year-old man with isolated chronic cough associated with sputum eosinophilia in which Humicola fuscoatra (H. fuscoatra) antigen was an etiologic agent. He was admitted for the diagnosis and the treatment of his severe nonproductive cough. Although 80% of the nucleated cells in his induced sputum were eosinophils, he did not have bronchial hyperresponsiveness to methacholine or heightened bronchomotor tone. Bronchodilator therapy was not effective against his coughing. His cough worsened on his return home, suggesting the existence of some etiologic agent in his house. H. fuscoatra was isolated from his house, and the bronchoprovocation test with H. fuscoatra antigen was positive: i.e., development of coughing and decrease in capsaicin cough threshold (capsaicin concentration causing five or more coughs) from the prechallenge value of 31.3 microM to 1.95 microM at 6 and 48 hr, respectively, after the challenge. In addition, repeated environmental survey for fungi was suggestive of the importance of H. fuscoatra in the sputum eosinophilia. This is the first report concerning chronic cough with sputum eosinophilia caused by allergic reaction to H. fuscoatra antigen.  相似文献   
242.
243.
BACKGROUND: Aggressive early rehabilitation is recommended after reconstruction of the anterior cruciate ligament (ACL) using a patellar tendon-bone graft. However, rehabilitation after reconstruction of ACL using the multistranded hamstring is controversial. In this study, we compared the clinical results of 3-day immobilization after reconstruction of ACL using the multistranded hamstring, with those of 2-week immobilization prospectively. METHODS: A total of 30 consecutive patients with ruptured ACL underwent single-socket ACL reconstruction. 10 male and 5 female patients (mean age of 29.2+/-10.0 years) were prospectively randomized for a 3-day immobilization period, and 6 male and 9 female patients (mean age of 27.3+/-10.9 years) were randomized for a 2-week immobilization period. We measured the anterior laxity with a KT-2000 arthrometer, joint position sense, and thigh muscle strength at 3, 6 and 12 months after surgery. RESULTS AND CONCLUSIONS: There were no statistically significant differences between the two groups. We concluded that the post-operative 3-day immobilization period is preferable to the longer 2-week period in our rehabilitation program from the viewpoint of psychological load to the patients and the duration of hospitalization after ACL reconstruction using multistranded hamstring tendons.  相似文献   
244.
Journal of Neuro-Oncology - Lower grade gliomas with 1p/19q codeletion are often responsive to chemotherapy, and several of these have been treated using upfront chemotherapy and subsequent...  相似文献   
245.
Although Y‐box binding protein‐1 (YB‐1) is known to be overexpressed in prostate cancer, especially castration‐resistant prostate cancer (CRPC), the mechanism of its overexpression remains unclear. We aimed to elucidate the mechanism of YB‐1 overexpression in CRPC. Gene amplification in CRPC cells and tissues was examined by public database analysis, and digital PCR. The significance of YB‐1 amplification for the YB‐1/androgen receptor (AR) axis and prognosis was examined by public database analysis and immunohistochemistry. YB‐1 amplification was mainly observed in CRPC tissues by public database analysis and confirmed in CRPC cells and tissues by digital PCR. Expression of YB‐1 was increased in CRPC tissues compared with treatment‐naïve tissues. Furthermore, YB‐1 and phosphorylated YB‐1 levels were associated with AR and AR V7 expression levels. Finally, YB‐1 amplification was associated with poor outcomes in CRPC. Taken together, the present findings suggest that YB‐1 amplification contributes to progression to CRPC through regulation of AR and AR V7 expressions, and that YB‐1 is a promising therapeutic target in CRPC.  相似文献   
246.
247.
248.
Protrusion of scaffold struts is related with local coronary flow dynamics that can promote scaffold restenosis and thrombosis. That fact has prompted us to investigate in vivo the protrusion status of different types of scaffolds and their relationship with endothelial shear stress (ESS) distributions. Six Absorb everolimus-eluting Bioresorbable Vascular Scaffolds (Absorb, Abbott Vascular) and 11 Mirage sirolimus-eluting Bioresorbable Microfiber Scaffolds (Mirage, Manli Cardiology) were implanted in coronaries of eight mini pigs. Optical coherence tomography (OCT) was performed post-scaffold implantation and obtained images were fused with angiographic data to reconstruct the three dimensional coronary anatomy. Blood flow simulation was performed and ESS distribution was estimated for each scaffold. Protrusion distance was estimated using a dedicated software. Correlation between OCT-derived protrusion and ESS distribution was assessed for both scaffold groups. A significant difference was observed in the protrusion distances (156?±?137 µm for Absorb, 139?±?153 µm for Mirage; p?=?0.035), whereas difference remained after adjusting the protrusion distances according to the luminal areas. Strut protrusion of Absorb is inversely correlated with ESS (r?=??0.369, p?<?0.0001), whereas in Mirage protrusion was positively correlated with EES (r?=?0.192, p?<?0.0001). Protrusion distance was higher in Absorb than in Mirage. The protrusion of the thick quadratic struts of Absorb has a tendency to lower shear stress in the close vicinity of struts. However, circular shape of the less thick struts of Mirage didn’t show this trend in creating zone of recirculation around the struts. Strut geometry has different effect on the relationship between protrusion and shear stress in Absorb and Mirage scaffolds.  相似文献   
249.
A deoxyribonucleic acid preparation which showed infectivity and tumorigenic activity in domestic rabbits was isolated from the papillomatous tissue of wild cottontail rabbits by phenolic deproteinization procedure. The activity of the preparation could be completely abolished by its exposure to a minute amount (0.02 µg/ml) of DNAase. Antisera against Shope papilloma virus did not block the tumorigenic activity of the preparation, and trypsin and chymotrypsin had no effect on it. The extraction with phenol of a partially purified virus preparation also yielded extracts with tumorigenic potency. Extracts obtained from the domestic rabbit papilloma and submitted to phenolic deproteinization also proved infective and tumorigenic in rabbits of this sort, although the level of "tumorigenicity" was much lower than that of the cottontail preparations. Tests for intact virus, carried out with half of the extracts yielded wholly negative findings.  相似文献   
250.
The activation of antitumor cytotoxic T-lymphocytes (CTLs) depends on how efficiently the relevant tumor antigen peptides are delivered into the major histocompatibility complex (MHC) class I presentation pathway in antigen presenting cells (APCs). An elegant approach to promote the peptide-MHC class I association has been described for enhanced peptide transportation into the endoplasmic reticulum (ER) by adding an ER insertion signal sequence (Eriss). Nevertheless, this approach does not appear potent enough to induce in vivo tumor protective immunity. Herein, we present a novel peptide-vaccine strategy based on the combined utilization of Eriss and fusogenic liposomes (FLs) capable of directly introducing encapsulated CTL-epitope peptides into the MHC class I pathway of APCs. APCs pulsed with free peptides, FL-encapsulated peptides, or FL-encapsulated Eriss-conjugated peptides exhibited comparable levels of antigen-presenting activity at early phases after pulsing. Interestingly, whereas in the first two methods the APC ability began to decline 40 to 60 h after pulsing, FL-encapsulated Eriss(+) peptides allowed APCs to retain peptide-presentation activity for at least 140 h. This advantage of FL-encapsulated Eriss(+) peptides correlated with the induction of more potent antitumor immunity compared with soluble Eriss(+) or Eriss(-) peptides or FL-encapsulated Eriss(-) peptides when they were administered in vivo. Thus, Eriss-conjugated CTL-epitope peptides encapsulated in FLs provide a highly efficient tumor-vaccine to enhance the induction of in vivo tumor immunity.  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