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   20613篇
  免费   1059篇
  国内免费   199篇
耳鼻咽喉   161篇
儿科学   422篇
妇产科学   218篇
基础医学   2315篇
口腔科学   371篇
临床医学   1368篇
内科学   6517篇
皮肤病学   418篇
神经病学   1283篇
特种医学   696篇
外科学   3330篇
综合类   75篇
一般理论   3篇
预防医学   464篇
眼科学   488篇
药学   1455篇
中国医学   42篇
肿瘤学   2245篇
  2023年   174篇
  2022年   334篇
  2021年   583篇
  2020年   329篇
  2019年   450篇
  2018年   506篇
  2017年   397篇
  2016年   492篇
  2015年   521篇
  2014年   673篇
  2013年   804篇
  2012年   1346篇
  2011年   1510篇
  2010年   880篇
  2009年   660篇
  2008年   1148篇
  2007年   1317篇
  2006年   1260篇
  2005年   1240篇
  2004年   1166篇
  2003年   1081篇
  2002年   1107篇
  2001年   337篇
  2000年   307篇
  1999年   306篇
  1998年   245篇
  1997年   216篇
  1996年   188篇
  1995年   150篇
  1994年   133篇
  1993年   115篇
  1992年   170篇
  1991年   166篇
  1990年   157篇
  1989年   153篇
  1988年   113篇
  1987年   121篇
  1986年   96篇
  1985年   104篇
  1984年   81篇
  1983年   75篇
  1982年   38篇
  1981年   48篇
  1980年   45篇
  1979年   73篇
  1978年   41篇
  1977年   46篇
  1974年   34篇
  1971年   40篇
  1969年   37篇
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
101.
102.
To investigate cholecalciferol (vitamin D) metabolism disorders in hepatic osteodystrophy (HOD) and the effects of vitamin D, its metabolites, and calcium (Ca) on HOD, an experimental HOD model in rats was developed using carbon tetrachloride. In the serum level of 25-hydroxycholecalciferol, 1,25-dihydroxycholecalciferol, and 24R,25-dihydroxycholecalciferol, there were no significant differences between normal and control cirrhotic rats. Vitamin D supplementation significantly inhibited the atrophy of intestinal villi, reduction of bone calcium content, elevation of bone resorption, reduction of osteoid volume, and reduction of bone volume. Ca supplementation significantly increased the serum free Ca index and inhibited the elevation of bone resorption, the reduction of bone ash and Ca content, and the reduction of bone volume. This experimental study demonstrates that: (1) no marked vitamin D hydroxylation disorder was found in HOD; (2) vitamin D supplementation was effective in inhibiting HOD; and (3) sufficient Ca supplementation was also effective in inhibiting HOD.A portion of this work was presented at the 13th Annual Meeting of the Japanese Society for Bone and Mineral Research, July 1995, Fukuoka, Japan.  相似文献   
103.
104.
105.
106.
The intravenous secretin injection test (secretin test) has been used for the differential diagnosis of gastrinoma. In this study we report that the intraoperative secretin test (IOS test) is also useful for determining the extent of curability in patients with Zollinger-Ellison syndrome (ZES). Twelve patients with ZES underwent surgical exploration and the IOS test. The results of the IOS test were obtained by rapid radioimmunoassay of the serum gastrin level (IRG) within 60 minutes. The test was diagnosed as negative when the maximum increase of serum IRG was less than 80 pg/ml and also less than 20% of the basal serum IRG level. Three of the twelve patients underwent pancreatoduodenectomy (PD), and two patients underwent distal pancreatectomy. Extirpation of duodenal tumors with dissection of regional lymph nodes was performed in seven patients. In two of the seven patients the IOS test remained positive after extirpation of the duodenal tumors and the dissection of regional lymph nodes. In one patient PD was performed on the basis of the positive results, and the IOS test became negative after PD. In the other patient, two tiny metastatic liver tumors were identified and were resected, but the IOS test did not become negative. We closed the abdomen in 11 patients when we obtained negative results from the IOS test. The results of the IOS test were almost identical to the data obtained by the standard assay postoperatively. The serum IRG levels of all but one patient fell to the normal level, and the secretin test became negative postoperatively. The IOS test is thus useful and indispensable for curative resection of microgastrinomas in patients with ZES.  相似文献   
107.
PURPOSE: The F-box protein S-phase kinase-associated protein 2 (Skp2) is one of the positive regulators of the cell cycle that promote ubiquitin-mediated proteolysis of the cyclin-dependent kinase inhibitor p27. In this study, we investigated the significance of Skp2 expression in human non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Clinicopathologic features and immunohistochemical expression of Skp2 and p27 proteins were studied in 138 patients with NSCLC. Survival analyses were performed using the Kaplan-Meier method and the Cox regression model. To analyze the role of Skp2 in vitro, NSCLC cells were transfected with an Skp2-expressing vector or small interfering RNA. RESULTS: Skp2 was overexpressed in males, smokers, patients with squamous cell carcinomas, and patients with poorly differentiated cancers (P = .034, < .0001, < .0001, and .002, respectively). The multivariant analysis revealed that Skp2 expression is an independent prognostic factor for survival in NSCLC. An inverse relationship of Skp2 with p27 expression was observed (P = .012), and patients with both a higher expression of Skp2 and a lower expression of p27 showed a significantly unfavorable prognosis (P = .0002). In vitro ectopic expression of Skp2 in NSCLC cells reduced the protein level of p27. Conversely, induction of Skp2 siRNA increased the protein level of p27, leading to growth inhibition in NSCLC cells. CONCLUSION: Skp2 overexpression is closely associated with the suppression of p27 and the aggressiveness in NSCLC. It also could be a therapeutic target in NSCLC.  相似文献   
108.
We report a 3-month-old girl with Costelio syndrome complicating fatal hypertrophic obstructive cardio-myopathy. She had typical findings of this syndrome, slight dyspnea and persistent wheezing. Doppler echocardiography revealed asymmetric septal hypertrophy and systolic anterior movement of the anterior mitral leaflet. There was grade 1 mitral regurgitation. Although once her heart failure had been controlled medically, she died suddenly following deterioration of her heart condition. Costelio syndrome can complicate fatal hypertrophic obstructive cardiomyopathy.  相似文献   
109.
A 74-year-old woman underwent total cystectomy with ureterostomy on March 1993 on a diagnosis of advanced bladder cancer. The pathological diagnosis was transitional carcinoma grade 3, pT3a pN0 pV1, pL2. Two courses of adjuvant chemotherapy with CDDP and MTX were added. Three years and 3 months later, she began to suffer from amnesia and hemiparalysis on her left side. Brain MRI examination revealed a solid tumor, 4 x 4 x 3 cm in size, in the right frontal lobe of the cerebrum. No other metastatic lesions were found. She underwent surgical resection of the tumor and subsequent irradiation to right frontal lobe in the cerebrum. Pathological examination confirmed its origin of bladder cancer. She has been enjoying a disease-free life for 3 years with minimal neurological symptoms.  相似文献   
110.
We report a case of Fournier's gangrene. An 83-year-old man underwent biopsy of left inguinal tumor as an outpatient. Pathological diagnosis was malignant lymphoma (diffuse large cell type). Three weeks later, he developed reddened scrotal swelling accompanied with high fever (> 39 degrees C). On admission, antibiotic chemotherapy was initiated. Although his general condition was improved, scrotal necrosis had developed. A computed tomography scan demonstrated thickened subcutaneous tissue over the left lumbar region. Excision of necrotic tissue and sequential irrigation using povidone iodine liquid were effective. The patient then underwent chemotherapy for malignant lymphoma at the internal department. Nine months after the operation, the scrotal skin had completely recovered.  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