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   1026篇
  免费   43篇
  国内免费   2篇
耳鼻咽喉   10篇
儿科学   27篇
妇产科学   8篇
基础医学   150篇
口腔科学   22篇
临床医学   89篇
内科学   188篇
皮肤病学   12篇
神经病学   49篇
特种医学   143篇
外科学   121篇
综合类   7篇
预防医学   39篇
眼科学   18篇
药学   18篇
肿瘤学   170篇
  2023年   14篇
  2022年   18篇
  2021年   30篇
  2020年   12篇
  2019年   16篇
  2018年   20篇
  2017年   25篇
  2016年   23篇
  2015年   18篇
  2014年   26篇
  2013年   32篇
  2012年   48篇
  2011年   58篇
  2010年   37篇
  2009年   30篇
  2008年   43篇
  2007年   53篇
  2006年   43篇
  2005年   38篇
  2004年   40篇
  2003年   41篇
  2002年   44篇
  2001年   28篇
  2000年   33篇
  1999年   25篇
  1998年   9篇
  1997年   9篇
  1996年   7篇
  1995年   6篇
  1994年   5篇
  1992年   12篇
  1991年   11篇
  1990年   9篇
  1989年   12篇
  1988年   23篇
  1987年   19篇
  1986年   13篇
  1985年   10篇
  1982年   7篇
  1979年   6篇
  1977年   8篇
  1974年   18篇
  1973年   12篇
  1972年   7篇
  1971年   5篇
  1970年   7篇
  1969年   11篇
  1968年   7篇
  1966年   11篇
  1965年   4篇
排序方式: 共有1071条查询结果,搜索用时 15 毫秒
41.
42.
43.
Infection with Helicobacter pylori is linked to inflammation and is the main cause of peptic ulcer, gastritis, and gastric malignancies. To examine associations between gastric cancer risk and the erythrocyte composition of docosahexaenoic acid (DHA), a fatty acid with anti-inflammatory and apoptosis-inducing effects, here we conducted a case-control study of 179 incident gastric cancer cases and 357 noncancer controls (matched by age, sex, and season of sample collection). Dietary information and blood samples were collected from all subjects, and erythrocyte fatty acid levels were measured using accelerated solvent extraction and gas-liquid chromatography. Gastric cancer risk did not seem to be directly associated with dietary intake of fish and n-3 highly unsaturated fatty acids (HUFAs), such as DHA, derived from fish. However, risk was inversely associated with erythrocyte compositions of n-3 HUFAs [the highest to the lowest tertile, odds ratio (OR), 0.39; 95% confidence interval (95% CI), 0.23-0.68; P(trend)<0.005] and DHA (OR, 0.47; 95% CI, 0.28-0.79; P(trend)<0.01). Particularly strong associations were noted for well-differentiated type lesions and n-3 HUFAs (OR, 0.10; 95% CI, 0.03-0.35; P(trend)=0.0005) as well as DHA (OR, 0.20; 95% CI, 0.07-0.58; P(trend)<0.01) values. In conclusion, the erythrocyte composition of DHA was found to be negatively linked to risk of gastric cancer, especially of well-differentiated adenocarcinoma. Further studies are needed to investigate mechanisms of action of DHA relevant to antitumor effects in the stomach.  相似文献   
44.
45.
The number of airborne methicillin-resistant Staphylococcus aureus (MRSA) before, during and after bedmaking was investigated. Air was sampled with an Andersen air sampler in the rooms of 13 inpatients with MRSA infection or colonization. Sampling of surfaces, including floors and bedsheets, was performed by stamp methods. MRSA-containing particles were isolated on all the sampler stages-stage 1 (>7 microm diameter) to stage 6 (0.65-1.1 microm). The MRSA-containing particles were mostly 2-3 microm diameter before bedmaking and >5 microm during bedmaking. The number was significantly higher 15 min after bedmaking than during the resting period, but the differences in counts after 30 and 60 min were not significant. MRSA was detected on many surfaces. The results suggest that MRSA was recirculated in the air, especially after movement. To prevent airborne transmission, healthcare staff should exercise great care to disinfect inanimate environments. Further studies will be needed to confirm the level of MRSA contamination of air during bedmaking and establish measures for prevention of airborne transmission.  相似文献   
46.
Eighteen elderly patients aged 76 years or older with small cell lung cancer were treated with carboplatin (AUC = 4 mg/ml.min, i.v. day 1) and etoposide (70 mg/m2 i.v. day 1-3) and 17 patients were evaluable. The median age of the study population was 77 years (range: 76-81). Eight patients had limited disease (LD) and nine did extensive disease (ED). The overall response rate was 88% for LD patients and 67% for ED patients. Median survival time was 219 days for LD patients and 158 days for ED patients. Grade 3 and 4 leukopenia, neutropenia, thrombocytopenia and anemia occurred in 41%, 76%, 24% and 6% of patients, respectively. There was one treatment-related death due to pneumonitis.  相似文献   
47.
PURPOSE: Most patients with pancreatic cancer are unresectable because of local invasion and liver metastasis at the time of diagnosis. To date, no treatment has had a significant impact on this disease. To deliver a high concentration of drug to the cancer, intra-arterial chemotherapy with GEM was performed in two patients with unresectable advanced cancer. PATIENTS AND METHODS: One patient, a 70-year-old man with liver metastasis, was treated with arterial infusion of GEM 1,000 mg/body. Another patient, a 55-year-old woman with local invasion and distant metastatic lymphadenopathy, was given intra-arterial infusion of GEM 400 mg and intra-venous infusion of GEM 1,000 mg/body. The patients were given GEM weekly for 3 weeks followed by a week of rest. RESULTS: In the first patient, the pain went away and CEA was decreased for 6 months. After that, the patient died due to intra-abdominal dissemination within 4 months. In the other patient, the pain went away. Tumor markers, such as CEA and CA19-9, were normalized and primary pancreatic cancer was reduced locally. The patient currently has a metastatic liver tumor, but she has had a significant improvement in performance status. CONCLUSION: Intra-arterial chemotherapy with GEM may be tolerated in patients with unresectable pancreatic cancer.  相似文献   
48.
PURPOSE: We report 2 patients with refractory liver metastatic tumor after esophagectomy for advanced esophageal cancer, who responded markedly to locoregional cellular immunotherapy by repeated intraarterial infusions of autologous tumor cell-activated T lymphocytes (AuTL), even after they failed the standard chemotherapy of cisplatin (CDDP) and 5-fluorouracil (5-FU). METHODS: AuTL administrations were made through the hepatic artery via a subcutaneous reservoir located at the right upper leg. Six injections were administered to both patients, repeated at 2-week intervals. The total number of administered T cells reached 2.4 x 10(9) and 3.1 x 10(9), respectively. RESULTS: A 39% and 51% regression in each infused field, compared with the size of liver tumor before treatment, was observed by computed tomography (CT) scan in patient 1 and 2, respectively. The responses continued up to the 10th and 11th month after the intraarterial infusion, confirmed by follow-up CT scan. The adverse effects of intraarterial immunotherapy were tolerable, with grade 1-2 fever and nausea in each patient. CONCLUSIONS: Clinical regression of liver metastases of esophageal cancer was observed in both patients who received this intraarterial cellular immunotherapy. Liver metastases of esophageal cancer may be controlled effectively and safely by repeating the intraarterial AuTL infusion as a locoregional immunotherapy over a long period.  相似文献   
49.
Biopsy     
We reviewed the current devices, techniques, guiding images, indications and complications of needle biopsy with CT guidance. The development of new devices such as automated cutting needle has enabled radiologists to obtain tissue specimens of good quality at biopsy. Techniques such as the tandem or coaxial method ensure more a more accurate biopsy route. And helical CT and CT fluoroscopy have markedly shortened the time required for needle biopsy. However, we sometimes encounter minor complications, and rarely major ones, during and after needle biopsy. Some of these complications may be caused by malpractice. Therefore it is important always to pay attention to the possibility of complications of needle biopsy and to minimize radiation exposures from CT fluoroscopy.  相似文献   
50.
A 67-year-old woman was referred with an abnormal finding on an abdominal echogram but presented with no symptoms; a pancreatic tail tumor was detected by ultrasonography. Biochemical examinations showed slight elevation of serum carcinoembryonic antigen level. The lesion was resected by tail and body pancreatectomy and her postoperative course was uneventful. Seven years and 4 months after the initial operation, however, her serum level of carbohydrate antigen 19-9 was found to be elevated, and a recurrence of pancreatic cancer was suspected. Examinations revealed a mass in the head of the remnant pancreas. The lesion was radically resected by total remnant pancreatectomy. Histological examinations showed that the initial tumor was a well differentiated tubular adenocarcinoma, while the second tumor was characterized as a moderately differentiated tubular adenocarcinoma. The surgical margins of the distal pancreatectomy specimen were free of atypical cells. Therefore, the position of the second lesion diminished the likelihood that it had developed by intrapancreatic metastasis. This suggests that the second carcinoma in the head of the pancreas may have been a second primary lesion. Received for publication on June 1, 1999; accepted on Sept. 20, 1999  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