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   13149篇
  免费   578篇
  国内免费   70篇
耳鼻咽喉   197篇
儿科学   133篇
妇产科学   208篇
基础医学   1461篇
口腔科学   615篇
临床医学   913篇
内科学   3128篇
皮肤病学   426篇
神经病学   770篇
特种医学   484篇
外科学   2175篇
综合类   53篇
预防医学   463篇
眼科学   399篇
药学   795篇
中国医学   31篇
肿瘤学   1546篇
  2022年   100篇
  2021年   208篇
  2020年   146篇
  2019年   166篇
  2018年   204篇
  2017年   157篇
  2016年   176篇
  2015年   180篇
  2014年   252篇
  2013年   312篇
  2012年   579篇
  2011年   568篇
  2010年   376篇
  2009年   286篇
  2008年   621篇
  2007年   621篇
  2006年   589篇
  2005年   596篇
  2004年   630篇
  2003年   558篇
  2002年   562篇
  2001年   458篇
  2000年   569篇
  1999年   494篇
  1998年   185篇
  1997年   124篇
  1996年   113篇
  1995年   115篇
  1994年   87篇
  1993年   80篇
  1992年   260篇
  1991年   282篇
  1990年   277篇
  1989年   321篇
  1988年   295篇
  1987年   247篇
  1986年   220篇
  1985年   227篇
  1984年   141篇
  1983年   119篇
  1979年   145篇
  1978年   99篇
  1977年   90篇
  1976年   72篇
  1975年   63篇
  1974年   97篇
  1973年   74篇
  1972年   73篇
  1970年   62篇
  1969年   65篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
991.
OBJECTIVE: The purpose of our study was to investigate a possible difference in ovarian metastasis between squamous cell carcinoma and adenocarcinoma of the uterine cervix and to confirm clinicopathological variables associated with the metastases. METHODS: Clinical and pathological variables of 1064 patients with invasive squamous cell carcinoma and 240 with adenocarcinoma were studied. RESULTS: Ovarian metastasis was found in 14 patients (1.3%) with squamous cell carcinoma and 15 (6.3%) with adenocarcinoma. The mean age of patients with ovarian metastasis of squamous cell carcinoma was 57.4 years, compared to 50.2 years for adenocarcinoma. Ovarian metastasis of adenocarcinoma was more likely to be visible (40.0%) and present in both ovaries (66.7%), while these two characteristics occurred in only 21.4 and 36.7% of patients with squamous cell carcinoma. A logistic regression analysis with clinical variables indicated that clinical stage beyond IIb was a significant variable of squamous cell carcinoma, and more than 30-mm tumor size was significant in adenocarcinoma. CONCLUSION: The incidence of ovarian metastasis of adenocarcinoma of the uterine cervix was significantly higher than that of squamous cell carcinoma. The incidence of adenocarcinoma was associated more closely with tumor size than clinical stage, whereas it was more associated with clinical stage in squamous cell carcinoma. The results thus suggested that the differences in ovarian metastases were caused by the different characteristics of the two types of carcinoma.  相似文献   
992.
We describe a rare case of esophageal metastasis from hepatocellular carcinoma. Esophagoscopy showed an oozing semipedunculated polypoid mass. Endoscopic ultrasound showed a mosaic pattern, and angiography and computed tomography showed tumor staining similar to that of the primary tumor in the liver. The present patient underwent superselective transcatheter arterial infusion of anticancer agents and permanent hemostasis was achieved.  相似文献   
993.
994.
Adrenomedullin (AM) inhibits vascular smooth muscle cell proliferation stimulated by fetal calf serum and platelet-derived growth factor in vitro. In this study, an adenovirus expressing AM (AxCAAM) was created to examine the in vivo action of AM. Femoral arteries of Wistar rats were wrapped with a silicone cuff and treated with adenovirus expressing Escherichia coli beta-galactosidase (AxCALacZ) or AxCAAM. Immunoreactivity for endothelial nitric oxide synthase (eNOS) was reduced in the endothelium of cuff-injured arteries and was associated with increased local DNA synthesis. Consequently, the intimal formation measured by the intimal-to-medial ratio was significantly increased at 14 and 28 days after the cuff placement. AxCAAM-infected arteries increased the expression of eNOS in the endothelium and inducible NOS in the media and the adventitia. AxCAAM significantly decreased the intimal-to-medial ratio by 40% at 14 days and 51% at 28 days, whereas AxCALacZ showed no changes compared with cuff-injured control arteries. AM overexpression effectively limits intimal hyperplasia by reducing cell proliferation through a nitric oxide-dependent pathway of eNOS. Our findings suggest the possibility of a therapeutic use of the AM gene for the prevention of vascular proliferative disorders.  相似文献   
995.
Effect of pravastatin on coronary plaque volume   总被引:2,自引:0,他引:2  
A volumetric analysis by 3-dimensional intravascular ultrasound revealed that lipid-lowering therapy with pravastatin significantly reduced coronary plaque volume. The changes in plaque volume were inversely correlated with the changes in plasma levels of high-density lipoprotein cholesterol but not with changes in levels of total cholesterol or low-density lipoprotein cholesterol.  相似文献   
996.
We herein report a case of postoperative fecal fistula following an appendectomy which was successfully treated by the use of autologous fibrin glue. An 82-year-old man had acute appendicitis and underwent an appendectomy. Later, a fecal fistula developed and he underwent drainage treatment twice. After 4 weeks of drainage and during the third recurrence, the remaining fistula was successfully treated using autologous fibrin glue, instead of surgery, due to potential complications and the risks of associated with advanced age. No recurrence has been observed for 5 months. In conclusion, autologous fibrin gluing for fecal fistula was found to be a safe, economical, and effective treatment. A search of Medline from 1980 until 2002 revealed no other report of this treatment for postoperative fecal fistula following an appendectomy.  相似文献   
997.
998.
The molecular mechanism of Bcl-2 phosphorylation and its relationship to Bax is largely unknown. Here we show that the phosphorylation of Bcl-2 is involved in the intracellular translocation of Bax from cytosol to mitochondria in NO-induced neuronal apoptosis. We examined how the phosphorylation of Bcl-2 is regulated during the apoptosis and found it to be mediated by the activation of p38 and ERK, members of the MAPK superfamily. Furthermore, we investigated whether Bcl-2 phosphorylation affected Bax translocation, using mutant Bcl-2 expression vectors. Cortical neuronal cells overexpressing the Bcl-2 mutant S70A (which cannot be phosphorylated) prevented the translocation of Bax. In contrast, transfection with Bcl-2 (S70D), a constitutively active Bcl-2 mutant, enhanced the translocation. Our results suggested that Bcl-2 phosphorylated at Ser-70 plays a critial role in the translocation of Bax from the cytosol to the mitochondria, and this may regulate NO-induced neuronal apoptosis.  相似文献   
999.
1000.
OBJECTIVE: The purpose of the study was to examine the oncological and functional outcomes of multimodality therapy for patients with advanced malignant maxillary sinus tumors that invaded the orbit. STUDY DESIGN: Retrospective study. METHODS: The medical records of 26 patients with orbital invasion were retrospectively analyzed. The patient group consisted of 16 men and 10 women, with a median age of 58 years. The mean follow-up period was 73 months. The most common disease was squamous cell carcinoma. Seven patients had nodal disease. All patients underwent simultaneous combined therapy consisting of conservative surgery through a sublabial incision, radiotherapy, and regional chemotherapy. Patients with nodal disease were treated with either irradiation or selective neck dissection. RESULTS: The 5- and 10-year overall survival rates were 68% and 51%, respectively. The 5- and 10-year local control rates were 66% and 51%, respectively. Overall survival rates and local control rates were significantly worse in patients with disease other than squamous cell carcinoma. Local control rates were significantly worse in patients with orbital apex disease than in patients without orbital apex disease. All 26 patients, despite orbital involvement, retained their orbital contents. Nineteen of these patients demonstrated adequate ocular function. CONCLUSIONS: Combined therapy with conservative surgery, radiotherapy, and regional chemotherapy is an effective method for local control and preservation of ocular function. However, performing orbital conservation procedure in patients with disease other than squamous cell carcinoma and with orbital apex disease must be considered carefully.  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