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   13922篇
  免费   721篇
  国内免费   95篇
耳鼻咽喉   89篇
儿科学   290篇
妇产科学   130篇
基础医学   2222篇
口腔科学   97篇
临床医学   1393篇
内科学   3125篇
皮肤病学   371篇
神经病学   1344篇
特种医学   590篇
外科学   2077篇
综合类   48篇
一般理论   2篇
预防医学   674篇
眼科学   227篇
药学   982篇
中国医学   42篇
肿瘤学   1035篇
  2023年   63篇
  2022年   91篇
  2021年   264篇
  2020年   159篇
  2019年   225篇
  2018年   325篇
  2017年   206篇
  2016年   238篇
  2015年   276篇
  2014年   381篇
  2013年   531篇
  2012年   929篇
  2011年   1054篇
  2010年   616篇
  2009年   546篇
  2008年   892篇
  2007年   1027篇
  2006年   923篇
  2005年   968篇
  2004年   893篇
  2003年   876篇
  2002年   851篇
  2001年   145篇
  2000年   128篇
  1999年   157篇
  1998年   218篇
  1997年   170篇
  1996年   172篇
  1995年   114篇
  1994年   113篇
  1993年   113篇
  1992年   105篇
  1991年   73篇
  1990年   57篇
  1989年   73篇
  1988年   69篇
  1987年   56篇
  1986年   56篇
  1985年   44篇
  1984年   55篇
  1983年   56篇
  1982年   46篇
  1981年   38篇
  1980年   44篇
  1979年   37篇
  1978年   29篇
  1977年   29篇
  1974年   34篇
  1973年   26篇
  1972年   26篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
142.

OBJECTIVE

To assess the long‐term outcome of forearm free‐flap phalloplasty in transsexuals, as obtaining a satisfying neophallus in female‐to‐male transsexuals is a surgical challenge.

PATIENTS AND METHODS

We analysed retrospectively 56 transsexuals who had a phalloplasty using a radial forearm free‐flap in our department from 1986 to 2002. The complication rate was assessed by regular examination. Patient satisfaction was evaluated by a questionnaire about cosmetic aspects, sexual life and overall satisfaction.

RESULTS

The mean follow up was 110 months; 53 of the 56 patients (95%) currently have a neophallus, after a mean of six surgical procedures. Satisfaction was assessed in 53 patients using a specific questionnaire: 51 (93%) of the patients reported that the phalloplasty allowed them to accord their physical appearance with their feeling of masculinity. There were flap complications in 14 patients (25%); three (5%) flaps were lost, with one each due to early haematoma, cellulitis and late arterial thrombosis. The other 11 flap complications were all transitory, e.g. infection, haematomas and vascular thrombosis. There were prosthesis complications in 11 of 38 patients (29%). Moreover, seven of 19 patients (37%) who had a urethroplasty presented with complex strictures and fistulae that led to perineal urethrostomy.

CONCLUSION

Our study shows that phalloplasty with a forearm free‐flap leads to good results in term of flap survival and patient satisfaction. However, there was a high rate of complications. Patients must be clearly informed that the procedure can seldom be achieved in one stage.  相似文献   
143.
Many patients undergoing total hip resurfacing arthroplasty present with reduced anterior femoral neck concavity as a part of the degenerative process. Painful hip impingement may develop or persist after hip resurfacing when the retained femoral neck abuts against the metallic acetabular component or the anterior acetabular bony wall. We report on two cases of painful postoperative hip impingement after hip resurfacing, in one of whom anterior neck-contouring osteoplasty restored pain-free range of motion (ROM). To restore natural hip ROM, surgeons performing hip total hip resurfacing arthroplasty should aim to reproduce the normal femoral head-neck offset ratio. Femoral head-neck offset restoration can be achieved by proper femoral component positioning (especially optimal translation), by femoral neck osteoplasty or by increasing femoral component head size appropriately.  相似文献   
144.
Apelin is a vasoactive peptide identified as the endogenous ligand of an orphan G protein-coupled receptor called APJ. Apelin and its receptor have been found in the brain and the cardiovascular system. Here we show that the apelin receptor mRNA is highly expressed in the glomeruli while its level of expression is lower in all nephron segments including collecting ducts that express vasopressin V2 receptors. Intravenous injection of apelin 17 into lactating rats induced a significant diuresis. Apelin receptor mRNA was also found in endothelial and vascular smooth muscle cells of glomerular arterioles. Apelin administration caused vasorelaxation of angiotensin II-preconstricted efferent and afferent arterioles as shown by an increase in their diameter. Activation of endothelial apelin receptors caused release of nitric oxide which inhibited angiotensin II-induced rise in intracellular calcium. In addition, it appears that apelin had a direct receptor-mediated vasoconstrictive effect on vascular smooth muscle. These results show that apelin has complex effects on the pre- and post glomerular microvasculature regulating renal hemodynamics. Its role on tubular function (if any) remains to be determined.  相似文献   
145.
An inverse relationship between arterial calcifications and bone activity has been documented in patients with ESRD. Calcium overload is associated with arterial calcification, which is associated with arterial stiffening. Whether bone activity interacts with calcium load, aortic stiffness, or arterial calcification is unknown. This study assessed the impact of bone activity on the relationships between the dosage of calcium-containing phosphate binders and aortic stiffness (measured by pulse wave velocity) or abdominal aorta calcification score. Aortic stiffness and calcification were both positively associated with calcium load and negatively associated with bone activity. A significant interaction was found between dosage of calcium-containing phosphate binders and bone activity such that calcium load had a significantly greater influence on aortic calcifications and stiffening in the presence of adynamic bone disease. Independent of any other factor, including dosage of calcium-containing phosphate binders, adynamic bone was associated with greater aortic stiffening, suggesting cross-talk between the bone and arterial walls.  相似文献   
146.
PURPOSE: To compare multidetector CT scan (MDCT) results with intraoperative findings in the detection of an inferior-pole pedicle crossing the ureteropelvic junction. PATIENTS AND METHODS: Over the 2-year study period, 35 patients receiving laparoscopic pyeloplasty underwent preoperative investigation with a novel MDCT protocol in order to detect crossing vessels. Postprocessing, including maximum intensity projection, volume-rendering technique, and multiplanar reconstruction, was used in addition to standard axial views. RESULTS: All the arteries found during laparoscopic surgery were detected by MDCT, but one radiologic false-positive was noted at the beginning of the series. Seven veins were not detected with MDCT. In the only case featuring an isolated inferior-pole vein, the aberrant vessel was identified by MDCT. CONCLUSION: Multidetector CT scanning is a highly accurate way of providing all the information necessary preoperatively concerning renal parenchymal anomalies, urinary stones, and collecting system and vessel anatomy. It helps physicians make appropriate therapeutic decisions and gives surgeons information about what they can expect during laparoscopic procedures.  相似文献   
147.
BACKGROUND: The true relevance of allosensitization in patients benefiting from left ventricular assist device (LVAD) as bridge to transplant (BTT) is still debated. Available registry data referred to numerous devices precluding LVAD-specific analysis. Therefore, we studied all patients with Novacor LVAD prior to transplantation. METHODS: From 1985 to 2006, 37 Novacor LVADs were implanted as BTT, with 30 patients surviving to transplantation (81%). Post-LVAD sensitization was determined for anti-HLA-class I and class II IgGs. Study endpoints were overall survival and/or graft loss, > or =3A cellular rejection and chronic allograft vasculopathy (CAV). The results from LVAD patients were compared to non-LVAD primary heart transplant recipients (n=318). RESULTS: After LVAD insertion, 5 out of 27 patients available for analysis developed anti-HLA antibodies (18.5%). The mean anti-HLA titer after Novacor LVAD implantation was 14% [SD 31]. Actuarial 5- and 10-year patient/graft survival for LVAD and non-LVAD transplant recipients were 73% and 55%, and 70% and 55%, respectively (p=NS). Overall prevalence of rejection > or =3A was 23.3 % (LVAD group) and 18.9% (non-LVAD group) (p=NS). At follow-up, the respective incidence of CAV was 8% (LVAD group) and 32.4% (non-LVAD group) (p<0.01). However, mean follow-up was significantly different for LVAD and non-LVAD patients, 46 vs 90 months (p<0.001). CONCLUSION: In this study, allosensitization occurred infrequently after Novacor LVAD implantation. Secondly, analysis of outcome variables shows that Novacor-LVAD BTT patients can anticipate similar survival to non-LVAD patients, thus minimizing the impact of allosensitization after LVAD implantation.  相似文献   
148.
Chylothorax     
PHYSIOLOGY: Chylothorax corresponds to the intrathoracic presence of chyle. Chyle is a lymph of intestinal origin containing the product of digested fat. This lymph joins the blood circulation through the thoracic duct. The thoracic duct receives a part of the lymphatic drainage from the viscera below the diaphragm, from the diaphragm and from the sterno-costal wall. PHYSIOPATHOLOGY: Intrapleural chyle issue is explained by an acquired or spontaneous lesion of the thoracic duct or of one of its collaterals in the thorax. The iatrogenic or spontaneous lesions of the collaterals suggest that the latter are incontinent and have lost their valve capacity, and hence provoke a reflux of chyle from the thoracic duct. The anatomy of the chylothorax (occasionally pathological) can be specified by a pedal lymphography. FROM A THERAPEUTIC POINT OF VIEW: Treatment, essentially medical, can be completed by surgery. The medical treatment is based on re-nutrition and a diet excluding fat, supplemented by medium chain triglycerides. Surgery consists in pleural symphysis and/or suture of the damaged collaterals, or ligature of the thoracic duct. The indications depend on the severity of the chyle leakage and the type of original lesion. The indications therefore depend on the etiology and clinical evolution of each case. These different treatments, isolated or combined, lead to the regression of the effusion in nearly all cases.  相似文献   
149.
150.
BACKGROUND: The introduction of composite graft repair of aortic root aneurysm by Hugh Bentall in 1968 promised Marfan patients the choice for a normal life expectancy. We performed our first Bentall composite graft procedure in 1976 and herein report our 24-year experience with 271 Marfan patients. METHODS: Between September 1976 and August 2000, 232 Marfan patients had a composite graft replacement of the aortic root, 15 patients received a homograft, and 24 had a valve-sparing procedure. RESULTS: Two hundred thirty-five Marfan patients underwent elective aortic root replacement with no 30-day mortality. Two early deaths occurred among 36 patients who underwent urgent or emergent operation. Eighty-three percent of patients in this series are currently alive. The actuarial freedom from thromboembolism, endocarditis, and reoperation on the residual aorta 20 years postoperatively was 93%, 90%, and 74%. Twenty-four patients have undergone valve-sparing procedures with encouraging results. CONCLUSIONS: Elective aortic root replacement for Marfan patients can be performed with low operative risk. Elective repair before the aortic root reaches 6 cm in diameter is recommended to minimize risk of dissection and rupture.  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