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   2616篇
  免费   147篇
  国内免费   10篇
耳鼻咽喉   10篇
儿科学   92篇
妇产科学   13篇
基础医学   364篇
口腔科学   78篇
临床医学   160篇
内科学   700篇
皮肤病学   25篇
神经病学   132篇
特种医学   129篇
外科学   481篇
综合类   8篇
预防医学   94篇
眼科学   27篇
药学   172篇
中国医学   3篇
肿瘤学   285篇
  2023年   44篇
  2022年   76篇
  2021年   115篇
  2020年   62篇
  2019年   69篇
  2018年   75篇
  2017年   50篇
  2016年   67篇
  2015年   69篇
  2014年   78篇
  2013年   86篇
  2012年   124篇
  2011年   159篇
  2010年   95篇
  2009年   70篇
  2008年   97篇
  2007年   95篇
  2006年   86篇
  2005年   112篇
  2004年   117篇
  2003年   107篇
  2002年   116篇
  2001年   66篇
  2000年   61篇
  1999年   57篇
  1998年   33篇
  1997年   26篇
  1996年   26篇
  1995年   25篇
  1994年   27篇
  1993年   17篇
  1992年   39篇
  1991年   24篇
  1990年   35篇
  1989年   41篇
  1988年   37篇
  1987年   24篇
  1986年   37篇
  1985年   24篇
  1984年   20篇
  1983年   15篇
  1981年   11篇
  1980年   11篇
  1979年   11篇
  1976年   13篇
  1975年   13篇
  1974年   12篇
  1970年   13篇
  1969年   16篇
  1967年   10篇
排序方式: 共有2773条查询结果,搜索用时 15 毫秒
81.
Kasabach–Merritt syndrome (KMS) is characterized by hemangioma associated with life‐threatening thrombocytopenia, and is a consumptive coagulopathy. Although treatments available include corticosteroids, α‐interferon, vincristine, and surgery, response may be unsatisfactory, and the mortality rate remains at approximately 30%. Although radiotherapy has been used effectively for KMS, it may cause growth retardation and secondary malignancy. We report a case of KMS in which hemangioma of the left thigh was successfully treated with low‐dose radiotherapy (6 Gy in six fractions, weekly) after failure of corticosteroid therapy. No significant late effects due to the radiotherapy were noted at 5 year follow up. Thus, low‐dose radiotherapy remains an important treatment method for KMS when patients fail to respond to other treatments.  相似文献   
82.
83.

Background

The prevention of relapse and infection complications during remission maintenance therapy is required to improve the prognosis of patients with microscopic polyangiitis (MPA) showing rapidly progressive glomerulonephritis (RPGN). The clinicopathological characteristics of patients with ANCA-positive MPA were examined to determine the risk factors for relapse or infectious complications after remission induction therapy.

Patients and methods

The study population consisted of 52 patients diagnosed as ANCA-positive MPA showing RPGN from 2002 to 2012, after publication of the Japanese guideline for RPGN. The clinicopathological findings were examined between the presence and absence of relapse or infectious complications.

Results

The value of vasculitis damage index (VDI) was high for the relapse group and VDI value was identified as the leading factor associated with relapse [hazard ratio (HR) 3.36, 95 % confidence interval (CI) 1.58–7.12, P < 0.01]. On the other hand, the values of Birmingham Vasculitis Activity Score, clinical grade category of RPGN at diagnosis, and VDI at remission were high in the infectious group. Furthermore, clinical grade category of RPGN was the leading factor associated with infectious complications (HR 5.30, 95 % CI 1.41–19.9, P = 0.01).

Conclusion

The disease activity at diagnosis and severity of organ damage at remission were associated with relapse and infectious complications during remission maintenance therapy and infectious complication affected kidney survival and all-cause mortality in patients with ANCA-positive MPA exhibiting RPGN.
  相似文献   
84.
Retinoic acids (RAs), including all-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA), play fundamental roles in a variety of physiological events in vertebrates, through their specific nuclear receptors: retinoic acid receptor (RAR) and retinoid X receptor (RXR). Despite the physiological importance of RA, their functional significance under pathological conditions is not well understood. We examined the effect of ATRA on oxygen/glucose-deprivation/reperfusion (OGD/Rep)-induced neuronal damage in cultured rat hippocampal slices, and found that ATRA significantly reduced neuronal death. The cytoprotective effect of ATRA was observed not only in cornu ammonis (CA) 1 but also in CA2 and dentate gyrus (DG), and was attenuated by selective antagonists for RAR or RXR. By contrast, in the CA3 region, no protective effects of ATRA were observed. The OGD/Rep also increased phosphorylated forms of c-jun-N-terminal kinase (P-JNK) and p38 (P-p38) in hippocampus, and specific inhibitors for these kinases protected neurons. ATRA prevented the increases in P-JNK and P-p38 after OGD/Rep, as well as the decrease in NeuN and its shrinkage, all of which were inhibited by antagonists for RAR or RXR. These findings suggest that the ATRA signaling via retinoid receptors results in the inhibition of JNK and p38 activation, leading to the protection of neurons against OGD/Rep-induced damage in the rat hippocampus.  相似文献   
85.
European Journal of Orthopaedic Surgery & Traumatology - Combined anteversion (CA) technique (stem-first procedure) is generally accepted as the optimal technique to attain an appropriate CA...  相似文献   
86.
87.
88.
Severe aortic insufficiency (AI) after implantation of continuous-flow left ventricular-assist device (LVAD) affects device performance and outcomes. However, the mechanism for the occurrence and progression of AI has not been elucidated. We investigated the impact of nonphysiological retrograde blood flow in the aortic root on AI after LVAD implantation. Blood flow pattern was analyzed in patients with and without AI (n = 3 each) who underwent LVAD implantation, by computational fluid dynamics with patient-specific geometries, which were reproduced using electrocardiogram-gated 320-slice computed tomographic images. The total volume of retrograde blood flow during one cardiac cycle (716 ± 88 mL) was higher and the volume of slow blood flow (<0.1 cm/s) (0.16 ± 0.04 cm3) was lower in patients with AI than in those without AI (360 ± 111 mL, P = .0495, and 0.49 ± 0.08 cm3, P = .0495, respectively). No significant difference in wall shear stress on the aortic valve was observed between the groups. Patients with AI had a perpendicular anastomosis at the distal ascending aorta and the simulation in the modified anastomosis model of patients with AI showed that the retrograde blood flow pattern depended on the angle and position of anastomosis. Computational fluid dynamics revealed strong retrograde blood flow in the ascending aorta and aortic root in patients with AI after LVAD implantation. The angle and position of LVAD outflow anastomosis might impact retrograde blood flow and de novo AI after LVAD implantation.  相似文献   
89.
90.

Purpose

To evaluate the anatomical variations in the middle hepatic vein tributaries (V5/V8) for determining the reconstruction strategy in right lobe living donor liver transplantation (LDLT).

Methods

The V5/V8 variations were examined in 268 patients and were classified into three and two types, respectively. The reconstruction rate (RR), patency rate (PR) and clinical outcomes were retrospectively evaluated in 46 right lobe LDLT cases.

Results

In terms of V5 variations, the RR and PR were significantly higher for type 2 than type 3 (82.6 vs. 44.4 % and 73.7 vs. 25.0 %, respectively). The alanine aminotransferase level on postoperative day (POD) 5 in the V5 patent group was significantly lower than in the occluded group (123 vs. 191 IU/dL). Regarding V8 variations, the RR and PR were significantly higher for type 1 than type 2 (44.4 vs. 17.6 % and 75.0 vs. 33.3 %, respectively). The aspartate aminotransferase level on POD 3 was significantly lower in the V8 patent group than in the occluded group (50 vs. 121 IU/dL).

Conclusion

For right lobe grafts with single large V5 (type 2) or V8 (type 1) variations, reconstruction is necessary. Our new classification of the MHV tributaries is useful for determining the reconstruction strategy to use in right lobe LDLT.  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