首页 | 官方网站   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   379篇
  免费   36篇
  国内免费   3篇
医药卫生   418篇
  2023年   2篇
  2022年   3篇
  2021年   2篇
  2020年   6篇
  2019年   3篇
  2018年   10篇
  2017年   12篇
  2016年   12篇
  2015年   11篇
  2014年   10篇
  2013年   16篇
  2012年   19篇
  2011年   18篇
  2010年   16篇
  2009年   14篇
  2008年   26篇
  2007年   13篇
  2006年   19篇
  2005年   24篇
  2004年   24篇
  2003年   22篇
  2002年   12篇
  2001年   26篇
  2000年   15篇
  1999年   21篇
  1998年   8篇
  1997年   2篇
  1996年   1篇
  1995年   6篇
  1992年   5篇
  1991年   7篇
  1990年   5篇
  1989年   3篇
  1988年   3篇
  1987年   1篇
  1986年   3篇
  1983年   1篇
  1978年   3篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
  1965年   1篇
  1955年   1篇
  1952年   1篇
  1951年   2篇
  1950年   1篇
  1948年   1篇
  1947年   1篇
  1942年   1篇
  1940年   2篇
排序方式: 共有418条查询结果,搜索用时 31 毫秒
11.
We compared the efficacy of the Medoff sliding plate (MSP) with 3 other screw-plate systems for fixation of unstable intertrochanteric fractures in a randomized multicenter trial of 569 elderly patients. The MSP has biaxial dynamic capacity along both the neck and the shaft of the femur unlike the other systems, which lack dynamic capacity along the shaft. 268 fractures were operated on with the MSP, and 301 with the dynamic hip screw (DHS), with or without a trochanteric stabilizing plate (DHS/TSP) or with the dynamic condylar screw (DCS). The MSP had recently been shown to the surgeons.The patients in the groups were similar as regards age, domestic situation, preinjury walking ability and type of fracture. We followed the patients clinically and radiographically for at least 1 year. There was no significant difference in walking ability at follow-up or rate of return to home. Fixation failure occurred in 18/268 fractures operated on with the MSP, in 8/238 with the DHS, in 3/49 with the DHS/TSP and in 1/14 with the DCS. The difference in the rate of fixation failure was not statistically significant when the MSP group was compared to the 3 other groups. In 14 of the 18 fixation failures in the MSP group, the biaxial dynamic capacity of the MSP had not been used due to technical errors by surgeons, unfamiliar with the new method. No selection bias was found regarding fracture types in the 2 subgroups of patients with correct or inadequate biaxial dynamization. Extramedullary fixation of unstable intertrochanteric fractures with these implants showed a low failure rate. When using the MSP, biaxial dynamization must be correctly performed.  相似文献   
12.
The risk of Borrelia burgdorferi infection and the value of antibiotic prophylaxis after tick bite are controversial. In this study, performed in two areas of southwestern Germany, ticks were collected from 730 patients and examined by the polymerase chain reaction (PCR) for B. burgdorferi. To assess whether transmission of B. burgdorferi occurred, the patients were clinically and serologically examined after tick removal and during follow-up examinations. Data from all tick bites gave a total transmission rate of 2.6% (19 patients). Eighty-four ticks (11.3%) were PCR positive. Transmission occurred to 16 (26.7%) of 60 patients who were initially seronegative and could be followed up after the bite of an infected tick. These results indicate that the transmission rate from infected ticks in Europe is higher than previously assumed. Examination of ticks and antibiotic prophylaxis in the case of positivity appears to be indicated.  相似文献   
13.
14.
INTRODUCTION: There is controversy regarding tumor control of incidental prostate cancer (PC). We evaluated in a large cohort if we can recommend radical prostatectomy after TURP. MATERIAL AND METHOD: In 52 (4.3%) from a total of 1207 patients undergoing radical prostatectomy the diagnosis had been made by TURP. In a retrospective analysis we evaluated morbidity, histopathological results, and tumor control of pT1a/b tumors. RESULTS: The number of incidentally detected PC decreased with time. In 5.8% in the TURP group and in 0.5% of the needle biopsy group, there was no residual tumor found (p<0.001). Morbidity was similar +/- TURP with the exception of operation time (206 vs 188 min) and catheter duration (19.3 vs 17.3 days). Postoperative continence was identical. There was no difference in tumor control for local recurrence-free survival and PSA-free survival with and without TURP. CONCLUSIONS: The rate of incidentally detected PC by TURP decreases over time, but in almost all cases we found clinically relevant cancer. TURP is not an adverse prognostic factor and morbidity is similar compared with patients who were diagnosed by needle biopsy. Our data confirm that we should recommend radical prostatectomy to patients who are candidates for further curative therapy.  相似文献   
15.
16.
Approximately 15% of malignant diseases are caused by infectious agents. Human papilloma viruses (HPV) can be frequently found in oral carcinomas, especially tonsillar cancer. A group of HPV-infected tumors shows clear signs for a virally induced transformation process: high-risk HPVs can be detected in all tumor cells, the viral oncogenes E6 and E7 are constantly expressed and lead to upregulation of cellular p16(INK4a), a cyclin-dependent kinase inhibitor. The patients frequently lack typical risk factors associated with head and neck cancers such as drinking and smoking. Epstein-Barr viruses (EBV) are associated with lymphoproliferative disorders and cause nasopharyngeal carcinoma (NPC). NPC has a high incidence in some East Asian countries. In this review, the molecular pathogenesis of HPV- and EBV-associated malignancies are described and the clinical relevance of the presented findings is discussed.  相似文献   
17.
In a pilot study the effect of palliative chemotherapy on the detection rates of circulating tumour cells in peripheral venous blood of stage IV colorectal cancer patients was investigated. The results indicate a recruitment of tumour cells during chemotherapy and suggest a poorer survival for tumour cell positive patients. Circulating tumour cells have been shown to be a potential prognostic factor in patients who undergo curative resection for colorectal cancer. The effect of chemotherapy on the detection rates of disseminated tumour cells in blood has not yet been adequately investigated. Objective of this pilot-study was to analyze circulating tumour cells in peripheral venous blood of colorectal cancer patients undergoing chemotherapy in order to evaluate its potential value as a surrogate-marker for predicting clinical outcome after chemotherapy. Our hypothesis was that chemotherapy results in a reduction of the detection rates of circulating tumour cells in colorectal cancer patients. Forty-two Stage IV patients were examined at three different time points before and during palliative chemotherapy for the presence of disseminated tumour cells, using a previously described RT-PCR-assay for cytokeratin 20. 80.1% of the patients showed disseminated tumour cells at least once. Before chemotherapy, patients with multi-organ metastases were positive in 62.5%, patients with locally limited disease in only 14.3%. After the first chemotherapy, the detection rates in the latter group increased to 62.5%, for all patients in the same time from 46.3% to 57.5%. Clinical therapy responders showed an increase in the detection rates from 28.5% before to 71.4% after chemotherapy. In contrast, chemotherapy had no effect on tumour cell detection rates of patients with progressive disease (57% before vs. 60% after therapy). Patients with detected circulating tumour cells showed a shorter overall survival than patients without circulating tumour cells (83 vs. 53 weeks). Clinical therapy responders on average lived only 3 weeks longer than non-responders. In contrast to the original hypothesis, our data suggest a recruiting of circulating tumour cells during chemotherapy in advanced colorectal cancer. Further investigations are needed to clarify the potential role of circulating tumour cells for monitoring chemotherapy in these patients.  相似文献   
18.
19.
Chemotherapy and radiation therapy for cancer often have severe side effects that limit their efficacy. Glucocorticoids (GCs) are frequently used as cotreatment because they may have potent proapoptotic properties and reduce nausea, hyperemesis, and acute toxicity on normal tissue. In contrast to the proapoptotic effect of GCs in lymphoid cells, resistance toward cancer therapy-mediated apoptosis was induced in solid tumors of human cervix and lung carcinomas. Filter hybridization, expression data, as well as functional assays identified multiple core apoptosis molecules, which are regulated by GCs in a pro- or antiapoptotic manner. Both antiapoptotic genes such as FLIP and members of the Bcl-2 and IAP family as well as proapoptotic elements of the death receptor and mitochondrial apoptosis pathways were down-regulated in carcinomas resulting in a decreased activity of caspase-8, caspase-9, and caspase-3. In contrast, death receptor and mitochondrial apoptosis signaling as well as caspase activity was enhanced by dexamethasone in lymphoid cells. To restore apoptosis sensitivity in dexamethasone-treated carcinomas, caspase-8 and caspase-9 were transfected. This resensitized tumor cells in vitro and xenografts in vivo to cisplatin induced cell death. These data therefore raise concern about the widespread combined use of GCs with antineoplastic drugs or agents in the clinical management of cancer patients.  相似文献   
20.
AWD 131-138 [1-(4-chlorophenyl)-4-morpholino-imidazolin-2-one], a new low-affinity partial benzodiazepine receptor agonist with potent anticonvulsant and anxiolytic properties in rodent models, was studied in squirrel monkeys trained to discriminate intramuscular (i.m.) injections of midazolam (0.3 mg/kg) from injections of vehicle. Diazepam produced midazolam-like responding at cumulative doses of 1.0 and 3.0 mg/kg i.m. and decreased rates of responding at 3.0 mg/kg (plasma levels of about 400 ng/ml). In contrast, AWD 131-138 did not produce midazolam-like responding or alter response rates at cumulative doses up to 18.0 mg/kg i.m. (plasma levels over 2100 ng/ml). Other monkeys were trained to intravenously (i.v.) self-administer cocaine (56.0 microg/kg/injection). When AWD 131-138 (10-100 microg/kg/injection) was studied by substitution, responding declined to vehicle substitution levels within three sessions. At the dose of 100 microg/kg i.v. AWD 131-138, sufficient drug was self-administered during the first session (about 3.5 mg/kg) to produce plasma levels above 1000 ng/ml, yet responding over the next two sessions dropped to vehicle levels. The failure of AWD 131-138 to produce benzodiazepine-like discriminative effects and the absence of drug self-administration behavior when substituted for cocaine suggest that its abuse liability is low.  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-23

京公网安备 11010802026262号