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   1783878篇
  免费   123439篇
  国内免费   2575篇
耳鼻咽喉   25430篇
儿科学   54414篇
妇产科学   46967篇
基础医学   256102篇
口腔科学   51719篇
临床医学   158693篇
内科学   338881篇
皮肤病学   39090篇
神经病学   137267篇
特种医学   69647篇
外国民族医学   276篇
外科学   275917篇
综合类   36609篇
现状与发展   2篇
一般理论   476篇
预防医学   125371篇
眼科学   42060篇
药学   140994篇
  10篇
中国医学   4421篇
肿瘤学   105546篇
  2018年   18272篇
  2017年   14288篇
  2016年   16161篇
  2015年   18148篇
  2014年   24673篇
  2013年   36195篇
  2012年   49765篇
  2011年   52435篇
  2010年   30889篇
  2009年   29241篇
  2008年   49531篇
  2007年   52497篇
  2006年   53496篇
  2005年   51177篇
  2004年   49220篇
  2003年   47201篇
  2002年   45711篇
  2001年   96962篇
  2000年   99762篇
  1999年   82968篇
  1998年   20625篇
  1997年   18191篇
  1996年   18212篇
  1995年   17141篇
  1994年   15693篇
  1993年   14702篇
  1992年   62868篇
  1991年   60560篇
  1990年   59064篇
  1989年   56913篇
  1988年   51862篇
  1987年   50451篇
  1986年   47328篇
  1985年   45130篇
  1984年   32694篇
  1983年   27568篇
  1982年   14977篇
  1981年   13101篇
  1979年   29455篇
  1978年   19974篇
  1977年   17477篇
  1976年   15314篇
  1975年   17192篇
  1974年   20301篇
  1973年   19501篇
  1972年   18588篇
  1971年   17460篇
  1970年   16328篇
  1969年   15465篇
  1968年   13992篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Background Familial partial lipodystrophy (FPLD) is a monogenic form of diabetes characterised by a dominantly inherited disorder of adipose tissue associated with the loss of subcutaneous fat from the limbs and trunk, with excess fat deposited around the face and neck. The lipodystrophy causes severe insulin resistance, resulting in acanthosis nigricans, diabetes, dyslipidaemia, and increased risk of cardiovascular disease. Preliminary results from animals and man suggest that increasing subcutaneous fat by treatment with thiazolidinediones should improve insulin resistance and the associated features of this syndrome. Case report We report a 24-year-old patient with FPLD caused by a mutation in the LMNA gene (R482W) treated with 12 months of rosiglitazone. Subcutaneous fat increased following rosiglitazone treatment as demonstrated by a 29% generalised increase in skin-fold thickness. Leptin levels increased from 5.8 to 11.2 ng/ml. Compared with treatment on Metformin, there was an increase in insulin sensitivity (HOMA S% 17.2–31.6) but no change in glycaemic control. The lipid profile worsened during the follow-up period. Conclusion This initial case suggests that, for modification of cardiovascular risk factors, there are no clear advantages in treating patients with FPLD with rosiglitazone despite increases in subcutaneous adipose tissue. Larger series will be needed to identify moderate beneficial effects and treatment may be more effective in patients with generalised forms of lipodystrophy.  相似文献   
42.
The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis.  相似文献   
43.
44.
AIM: The intention was to investigate cerebrospinal fluid pressure (CSFP) and volume of cerebrospinal fluid (CSF) drained during and after thoracic- and thoracoabdominal aneurysm repair. The findings were related to the occurrence of postoperative neurologic deficits. METHODS: Twenty-nine patients (12 with thoracic and 17 with thoracoabdominal aortic aneurysm) were operated without shunting or extracorporeal circulation. For monitoring of CSFP an intrathecal catheter was placed in all patients. The volume of CSF withdrawn intraoperatively, on the day of operation as well as on the 1st and 2nd postoperative day was recorded. RESULTS: Twenty-six patients had no postoperative neurologic sequelae. One patient had postoperative paraplegia while 2 had paraparesis. The three patients with neurologic sequelae had higher CSFP intraoperatively than those without neurologic symptoms (P=0.04). Median CSFP during aortic cross-clamping was 19 mmHg and 10 mmHg and the median volumes of CSF drained on the day of operation 210 and 85 mL in the two groups, respectively. There was a significant positive correlation between CSFP and central venous pressure. CONCLUSIONS: A higher intraoperative CSFP was observed in patients with neurologic sequelae following thoracic- and thoracoabdominal aneurysm repair. Further, there was a tendency of higher volumes of CSF drained in this group of patients. Although, the series is too small to allow firm conclusions, it supports the view that CSFP monitoring and drainage is beneficial during thoracic- and thoracoabdominal aneurysm repair.  相似文献   
45.
46.
47.
48.
49.
PURPOSE: In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas. METHODS: Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output. RESULTS AND CONCLUSIONS: In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads.  相似文献   
50.
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