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   2605篇
  免费   147篇
  国内免费   8篇
耳鼻咽喉   9篇
儿科学   72篇
妇产科学   29篇
基础医学   429篇
口腔科学   72篇
临床医学   140篇
内科学   553篇
皮肤病学   35篇
神经病学   241篇
特种医学   149篇
外科学   358篇
综合类   10篇
预防医学   108篇
眼科学   76篇
药学   184篇
中国医学   19篇
肿瘤学   276篇
  2023年   8篇
  2022年   11篇
  2021年   56篇
  2020年   36篇
  2019年   45篇
  2018年   88篇
  2017年   65篇
  2016年   63篇
  2015年   59篇
  2014年   69篇
  2013年   118篇
  2012年   173篇
  2011年   141篇
  2010年   79篇
  2009年   87篇
  2008年   140篇
  2007年   170篇
  2006年   147篇
  2005年   154篇
  2004年   140篇
  2003年   142篇
  2002年   162篇
  2001年   38篇
  2000年   32篇
  1999年   43篇
  1998年   54篇
  1997年   35篇
  1996年   32篇
  1995年   36篇
  1994年   27篇
  1993年   28篇
  1992年   32篇
  1991年   30篇
  1990年   38篇
  1989年   37篇
  1988年   20篇
  1987年   23篇
  1986年   11篇
  1985年   14篇
  1984年   13篇
  1983年   8篇
  1982年   7篇
  1981年   6篇
  1980年   6篇
  1979年   6篇
  1978年   5篇
  1977年   4篇
  1970年   2篇
  1969年   3篇
  1966年   2篇
排序方式: 共有2760条查询结果,搜索用时 15 毫秒
1.
2.
In order to treat fistulated esophageal cancer using a flexible stent, a covered flexible stent was constructed by wrapping a nitinol stent with a thin sheet of Gore-Tex, preserving the stents original advantages of flexibility and a low-profile introducer system. This stent was used to perform standard radiotherapy in a case of fistulated esophageal cancer.  相似文献   
3.
4.
Carbon fibers with fibrin glue were used as electrodes for diaphragm pacing. The electrodes were applied to three mongrel dogs and the effectiveness was tested. The carbon leads were glued to phrenic nerves by means of the fibrinogen and thrombin bilaterally. The tidal volumes and threshold current level for stimulation were measured at various time up to 9 weeks after implantation. Effective contraction of diaphragm were observed for 9 weeks. By using this electrode, the exfoliation of the nerve is not necessary, the nerve can be maintained in an intact state, and the risk of the implanting operation can be minimized.  相似文献   
5.
Purpose Reelin is important in the guidance of neuronal stem cells in the central nervous system during normal development. We wished to determine whether reelin is expressed in the retina and cornea after injury. Methods Mice underwent laceration of their retina as well as corneal epithelial debridement. The mice were sacrificed at 3 days, and eyes were fixed and stained for reelin expression and reelin messenger ribonucleic acid (mRNA). Results In normal eyes, reelin was expressed only at very low levels in the ganglion cell layer of the retina and the endothelial cell layer of the cornea. In injured eyes, there was marked expression in reelin immunoreactivity in the retina and cornea. Reelin gene expression was seen in the retina and cornea. Conclusions Reelin is expressed during normal retinogenesis. This study shows that reelin is also upregulated following injury to the retina and cornea. The expression of reelin following injury suggests that reelin may play an important role in regulating stem cell trafficking in neuronal and nonneuronal tissues following injury similar to its role in normal organogenesis. For consideration of publication in Graefe’s Archive for Clinical and Experimental Ophthalmology.  相似文献   
6.
A case of early gastric carcinoma accompanied by Dieulafoy ulcer is presented. The patient, a 26‐year‐old female, visited our emergency room with chief complaints of massive hematemesis and tarry stool. The initial endoscopic examination revealed a superficial depressed lesion with a faded color accompanied by a tiny ulcer with converging folds at the anterior wall of the middle gastric body. Although no active bleeding vessel was found at that time, the patient was admitted to our hospital for further check‐ups and treatment. On the 6th hospital day, she developed massive hematemesis resulting in shock. Urgent endoscopy, this time, disclosed an exposed bleeding vessel at the small ulcer floor previously mentioned, and endoscopic hemostasis was achieved. Since, however, a biopsy at initial examination from the surrounding depressed area proved carcinoma, a partial distal gastrectomy was subsequently carried out. Histological examination of the resected specimen confirmed the diagnosis of carcinoma limited to the mucosa and submucosa along with findings consistent with Dieulafoy ulcer. This is a rare case of combination of early cancer and Dieulafoy ulcer particularly in such a young patient. A review of the literature is also presented.  相似文献   
7.
We reported three cases of spontaneous rupture which were surgically treated with direct suture method. One patient was operated on within eight hours after rupture with good results. In two patients diagnoses were made more than two days after rupture. One had esophageal fistula, but completely recovered after cervical oesophageal fistula, and another died of multiple organ failure. In this syndrome, early diagnosis and surgical treatment are essential for acceptable results. For early diagnosis, we emphasized on the presence of roentgenologic mediastinal and cervical emphysema. In patients for whom diagnosis was delayed and post-operative leakage at the oesophageal suture line occurred, temporarily fistulation of the cervical oesophagus proved to be effective in exclusion and diversion of the ruptured segment.  相似文献   
8.
9.
The effect of vitamin E on halothane-induced liver damage was studied in guinea pig halothane hepatitis. Twenty animals were divided into 3 groups, consisting of a control group, a halothane group and a vitamin E + halothane (H) group. The animals in the control group (n = 6) were allowed to inhale air only. The animals in the halothane group (n = 6) and the vitamin E + H group (n = 8) were allowed to inhale 1% halothane with air. Animals in the vitamin E + H group were additionally injected with 30 mg kg-1 of vitamin E 30 minutes prior to inhalation of halothane. Blood was aspirated from the heart immediately after sacrificing to measure the serum activity of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT). A microsomal suspension was prepared from the excised liver. Then the amount of thiobarbituric acid (TBA) reactive products in the microsomes were measured. The amount of tissue TBA-reactive products was increased by inhalation of halothane. The increase in the amount of TBA-reactive product was inhibited by the administration of vitamin E. The serum GPT activity was increased by halothane inhalation. Increased serum GOT and GPT activity were inhibited by the administration of vitamin E. These results demonstrated that vitamin E suppressed halothane-induced liver damage in the guinea pig by inhibiting lipid peroxidation.  相似文献   
10.
Summary To study the effects of family history and reproductive, anthropometric, and dietary factors on the risk of breast cancer among low risk populations, we conducted a hospital-based case-control study involving 908 patients with breast cancer and their matched controls, in Japan. A positive family history of breast cancer significantly increased the risk of breast cancer (odds ratio = 1.52, 95% confidence interval: 1.14–2.03). The risk further increased with increasing number of family members affected. Obesity, single marital status, fewer births, a late childbirth, and less consumption of green-yellow vegetables and dairy products were also associated with an increased risk of breast cancer. These associations were independent in multivariate analyses. There was no increase in risk associated with consumption of high fat foods. When analyzed by menopausal status, the association with family history of breast cancer, especially in the first degree of relatives, was more evident for premenopausal breast cancer. The associations with obesity and lower consumption of dairy products were more pronounced for postmenopausal breast cancer, while those with lower parity and single marital status were stronger for premenopausal breast cancer.  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