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   682篇
  免费   27篇
  国内免费   12篇
耳鼻咽喉   5篇
儿科学   7篇
妇产科学   28篇
基础医学   73篇
口腔科学   17篇
临床医学   58篇
内科学   180篇
皮肤病学   2篇
神经病学   19篇
特种医学   42篇
外科学   138篇
预防医学   8篇
眼科学   4篇
药学   56篇
中国医学   10篇
肿瘤学   74篇
  2023年   3篇
  2022年   6篇
  2021年   10篇
  2020年   7篇
  2019年   11篇
  2018年   5篇
  2017年   5篇
  2016年   10篇
  2015年   12篇
  2014年   12篇
  2013年   18篇
  2012年   17篇
  2011年   39篇
  2010年   15篇
  2009年   8篇
  2008年   36篇
  2007年   50篇
  2006年   23篇
  2005年   19篇
  2004年   34篇
  2003年   33篇
  2002年   29篇
  2001年   14篇
  2000年   21篇
  1999年   17篇
  1998年   10篇
  1997年   11篇
  1996年   10篇
  1995年   9篇
  1994年   11篇
  1993年   8篇
  1992年   17篇
  1991年   12篇
  1990年   18篇
  1989年   18篇
  1988年   25篇
  1987年   17篇
  1986年   19篇
  1985年   9篇
  1984年   10篇
  1983年   7篇
  1982年   3篇
  1980年   6篇
  1979年   6篇
  1978年   4篇
  1974年   5篇
  1972年   7篇
  1970年   4篇
  1969年   3篇
  1967年   4篇
排序方式: 共有721条查询结果,搜索用时 15 毫秒
1.
The authors describe two surgically cured cases of symptomatic subependymomas located in the lateral ventricle and septum pellucidum with emphasis on magnetic resonance imaging study. Both computed tomography and MRI revealed a calcified mass with repeated intratumoral hemorrhages. Cerebral angiograms disclosed rather hypovascular lesions. The histologic diagnosis was proven to be of subependymoma. The pertinent literature of surgically treated subependymomas is reviewed, and the characteristic biologic features are also discussed.  相似文献   
2.
The immunohistochemical distribution of CA19-9 in normal and tumor tissue of the kidney was investigated. CA19-9 was detected in the cytoplasm and apical surface of renal proximal tubules, distal tubules and uroepithelium of the renal pelvis. Eight of 28 renal cell carcinomas (29%) expressed CA19-9. CA19-9 was also detected in 2 cases of transitional cell carcinoma and 1 of 4 cases of Wilm's tumor, but not in angiomyolipoma. As the measurement of CA19-9 is widely used to detect gastrointestinal carcinoma, the expression of CA19-9 in normal and neoplastic kidney tissue might have some clinical significance.  相似文献   
3.
We carried out electron microscopic studies on renal tissues from 9 patients with IgA nephropathy. Electron dense deposits were present in the mesangial area in all cases, subendothelial deposits in 4, and subepithelial deposits in only one. In basement membrane, segmental swelling and rarefaction of basement membrane substance were observed. In some cases the degenerated basement membrane substance protruded through the dilated endothelial fenestration into capillary lumina. Focal splitting, attenuation, mouse eaten appearance, and herniation of basement membrane were seen in a high incidence. Mesangial cells possessed well developed rough endoplasmic reticulums and polysomes. In the peripheral areas of mesangial cell cytoplasm, there was accumulation of electron dense substance and this was occasionally continuously present in the mesangial matrix. There was segmental swelling of endothelial cell cytoplasm, resulting in loss of fenestration. Epithelial cells had well developed rough endoplasmic reticulums and polysomes. Segmental foot process fusion was seen, and these processes, regardless of fusion, became electron denser in the area close to the basement membrane. Multivesiculated bodies were present in all cases in the epithelial cells and in 7 cases in the endothelial cells. Spherical microparticles were present in 3 cases in the urinary space or between the basement membrane and the epithelial cells.  相似文献   
4.
5.
Abstract Cilostazol is a selective inhibitor of phosphodiesterase III with anti-platelet-aggregatory and vasodilating properties. Randomised, double-blind, placebo-controlled trials in 2702 patients with intermittent claudication demonstrated that cilostazol significantly increased walking distances compared with placebo. Furthermore, the agent has beneficial effects on the serum lipid profile and fatty acid composition in plasma. Consequently, cilostazol may be useful to prevent atherosclerosis from progressing by ameliorating lipid and fatty acid metabolism.  相似文献   
6.
A case of a 41 years old Japanese woman with widely disseminated primary lung cancer (adenocarcinoma) metastasizing to renal cell carcinoma (hypernephroma) is presented together with a brief review of the literature.  相似文献   
7.
Malnutrition is a core symptom of the frailty cycle in older adults. The purpose of this study was to investigate whether dysphagia influences nutrition or frailty status in community-dwelling older adults. The study participants were 320 Japanese community-dwelling older adults aged ≥65 years. All participants completed a questionnaire survey that included items on age, sex, family structure, self-rated health, nutritional and frailty status, and swallowing function. Nutritional status was categorized as malnourished, at risk of malnutrition, and well-nourished based on the Mini Nutrition Assessment-Short Form. The participants were then classified into a malnutrition (malnourished/at risk) or a well-nourished group (well-nourished). Frailty was assessed using the Cardiovascular Health Study criteria. The participants were then divided into a frailty (frail/pre-frail) or a non-frailty group (robust). Dysphagia was screened using the 10-item Eating Assessment Tool. Multiple logistic regression analysis was conducted to determine whether dysphagia was associated with nutritional or frailty status. The results revealed that dysphagia influenced both nutrition (odds ratio [OR]: 4.0; 95% confidence interval [CI]: 1.9–8.2) and frailty status (OR: 2.3; 95% CI: 1.0–5.2); therefore, the swallowing function would be an important factor for community-dwelling older adults on frailty prevention programs.  相似文献   
8.
Five cases of alveolar soft part sarcoma, 5 cases of granular cell tumor, and 6 cases of paraganglioma were investigated immunohistochemically to examine the expression of tissue-specific intermediate filaments (cytokeratin, vimentin, desmin, and glial fibrillary acidic protein (GFAP], actin, myoglobin, and nervous tissue markers (S-100 protein, neuron-specific enolase, and Leu-7). In alveolar soft part sarcomas, some of the tumor cells were positive for desmin, but negative for nervous tissue markers. The tumor cells of granular cell tumors were stained with anti-S-100 protein antibody, but not with anti-neuron-specific enolase antibody. In contrast, the tumor cells of paragangliomas were positive for neuron-specific enolase, but not for S-100 protein except for stellate cells surrounding the tumor cell nests. This immunohistochemical approach was valuable for the differential diagnosis of these three tumors. Furthermore, the complete absence of cytokeratin in all of the tumor cells may be helpful in distinguishing these three tumors from metastatic carcinoma in soft tissue. The histogenesis of alveolar soft part sarcoma is a matter of controversy. The result that besides desmin actin was also demonstrated in some of the tumor cells may support the myogenic origin of this tumor.  相似文献   
9.
An 18-year-old male was admitted to our Emergency Department with a traumatic abdominal wall hernia (TAWH) of the left lower quadrant (LLQ) after suffering hypogastric blunt injury and urogenital lacerations in a motorcycle accident. Upright chest X-ray showed a small amount of right infradiaphragmatic free air, and a computed tomographic (CT) scan demonstrated an abdominal wall hernia. At surgery, no impairment was found in the digestive tract, and an abdominal herniorrhaphy was performed. It is suggested that the free air had passed through a connection between the scrotal laceration and the contralateral abdominal defect via the subcutaneous space and was palpated as emphysema. This is a new type of TAWH, which suggests that blunt abdominal trauma may result in negative pressure in the subcutaneous and peritoneal cavity, and this could reflect the pathophysiology of TAWH.  相似文献   
10.
It has been controversial whether cancer cells harboring loss or inactivation of the tumor suppressor p53 are resistant or sensitive to DNA-damaging agents including cisplatin and doxorubicin. Overexpression of mdm2 oncoprotein, a negative regulator of p53, is assumed to be an alternative to p53 dysfunction. Archival urothelial carcinoma specimens obtained from 60 patients prior to cisplatin-based chemotherapy were immunohistochemically studied for overexpression of p53 and mdm2. Thirty-two patients (group I) were treated with chemotherapy in the neoadjuvant setting, while 28 patients (group II) underwent chemotherapy for distant metastases or inoperable locoregional tumors. In group I, the responsiveness was correlated with staining status of p53 ( P =0.0225) and the combination of p53 and mdm2 ( P =0.0497). Negative staining of p53 and negative for both p53 and mdm2 could have predicted favorable response to chemotherapy in 16 of 18 (88.9%) and in 12 of 13 (92.3%) tumors, respectively. On the other hand, p53-positive and p53 and/or mdm2-positive staining could have predicted poor response only in 7 of 14 (50.0%) and 8 of 19 (42.1%) tumors, respectively. Disease-specific survival of the p53-negative group was significantly superior to that of the p53-positive group ( P =0.0086). Difference in survival did not become more significant when overexpression of mdm2 was taken into consideration ( P =0.0456). In contrast, in group II, there was no correlation of responsiveness to chemotherapy or survival with p53- or p53/mdm2-staining status. The patients with urothelial carcinomas negative for overexpression of p53 will benefit from neoadjuvant chemotherapy. From clinical viewpoint, however, p53 status alone or the combination of p53 and mdm2 status is not enough to identify those patients who will not benefit from the treatment.  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