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   26536篇
  免费   1657篇
  国内免费   120篇
耳鼻咽喉   295篇
儿科学   893篇
妇产科学   594篇
基础医学   2953篇
口腔科学   513篇
临床医学   2198篇
内科学   5709篇
皮肤病学   366篇
神经病学   1609篇
特种医学   773篇
外科学   4915篇
综合类   802篇
一般理论   19篇
预防医学   1789篇
眼科学   680篇
药学   2331篇
中国医学   249篇
肿瘤学   1625篇
  2023年   212篇
  2022年   598篇
  2021年   974篇
  2020年   621篇
  2019年   765篇
  2018年   917篇
  2017年   622篇
  2016年   600篇
  2015年   752篇
  2014年   1047篇
  2013年   1345篇
  2012年   1911篇
  2011年   1906篇
  2010年   1093篇
  2009年   856篇
  2008年   1453篇
  2007年   1498篇
  2006年   1419篇
  2005年   1297篇
  2004年   1190篇
  2003年   1064篇
  2002年   878篇
  2001年   638篇
  2000年   569篇
  1999年   464篇
  1998年   184篇
  1997年   137篇
  1996年   138篇
  1995年   154篇
  1994年   96篇
  1993年   106篇
  1992年   248篇
  1991年   235篇
  1990年   194篇
  1989年   209篇
  1988年   170篇
  1987年   173篇
  1986年   144篇
  1985年   155篇
  1984年   127篇
  1983年   101篇
  1982年   66篇
  1981年   81篇
  1979年   110篇
  1978年   73篇
  1977年   76篇
  1975年   63篇
  1974年   57篇
  1973年   61篇
  1972年   56篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
41.
Intravenous Pyogenic Granuloma of the Hand   总被引:1,自引:0,他引:1  
BACKGROUND: Intravenous pyogenic granuloma is the intravasal counterpart of cutaneous pyogenic granuloma. This rare, benign lesion appears clinically as a subcutaneous nodule usually located in the upper extremity or neck in middle-aged people. It is hard to make an exact diagnosis on clinical basis, and there is a risk of recurrence because of undertreatment. OBJECTIVE: To report a case of an intravenous pyogenic granuloma located in the hand and to describe the clinical and histopathologic features of this rare vascular tumor. METHODS: An operation was performed on a 58-year-old female who presented with a small, painless mass in the right palm, and the pathologic examination revealed an intravenous pyogenic granuloma. CONCLUSION: This rare lesion should be differentiated from a regular pyogenic granuloma and should be excised with the vein segment to avoid recurrence.  相似文献   
42.
There are few records detailing the techniques and tribulations of early American surgeons who dared venture into the treacherous recess of the human orbit. The authors present a recently discovered letter written by a young woman who in 1841 underwent an orbital operation performed by the prominent New York City surgeon, Willard Parker. The letter details the patient's experiences in an era without anesthesia or antibiotics, and her subsequent development of conjunctival adhesions.  相似文献   
43.
Mixed-panic disorder patients (16/60, 27%) randomly assigned to receive blind placebo during a 40-week treatment study were defined as placebo responders based on combined criteria of Hamilton Anxiety Scale score percentage decreases below the median point (-42%), moderate to marked improvement on both clinician and patient Clinical Global Impressions scores, and panic-free at final treatment visit. These criteria applied separately also resulted in a similar clinical grouping and pattern of response. Differential patterns of response between responders and nonresponders occurred across most clinical measures of panic/anxiety. Responders experienced early improvement within the first week of double-blind treatment. This response progressed during treatment and tended to persist during taper and at followup 1 month later. Post-hoc analysis of demographic and clinical features at entrance into the study failed to characterize this stringently defined group of placebo responders.  相似文献   
44.
Coats'-type retinitis pigmentosa   总被引:3,自引:0,他引:3  
Coats'-like changes (i.e., retinal telangiectasia and/or exudative detachment) have been reported in as many as 1.2 to 3.6 percent of patients with retinitis pigmentosa. In severe cases this disorder may progress to total retinal detachment and visual loss in the context of longstanding retinitis pigmentosa. Forty-six cases of Coats'-type retinitis pigmentosa gathered from the literature are reviewed. Historical and epidemiological features, hereditary factors, clinical features, histopathological findings, pathogenesis, differential diagnosis, prognosis and possible treatment are discussed.  相似文献   
45.
Thirty cases of phyllodes tumour (cystosarcoma phyllodes) of the breast that presented to the Clinical Oncology Unit at Guy's Hospital were reviewed. Tumours were classified as benign, malignant or borderline according to the following histological criteria: mitotic rate, nuclear pleomorphism, stromal overgrowth and tumour margins. In 14 (46.5%) cases the tumours were considered histologically benign, in 11 (36.5%) malignant, and in five (17%) borderline. Recurrence was seen in a similar proportion of patients with tumours classified as benign (21 %) and malignant (18 %) according to histological criteria. Malignant lesions tended to recur earlier. Infiltrating tumour margins were noted in all patients and stromal overgrowth in all hut one in whom recurrence was observed. Risk of recurrence also appeared to he related to tumour size. Only one patient developed distant metastases and died of her disease. Because of treatment variation no conclusion can he made regarding optimal therapy but the importance of adequate clearance, either through wide excision or mastectomy, is emphasized for all phyllodes tumours irrespective of histological features.  相似文献   
46.
47.
Methods: Second primary cancers constitute approximately 9–10% of malignancies diagnosed in the United States. We aimed to show the risk and incidance of second primary tumor occuring associated to urologic tumors and show the distrubution of tumors in Tracia region. We retrospectively examined the patients' files with the diagnosis of malignant disease between the years 1985–2000. Hazard function analysis was performed to estimate the relative risk of secondary malignancy occuring. Age, sex and tumor number were examined to find out if they affect on mortality rate. Results: A total number of 25 MPMNs were diagnosed. In 52 percent of the cases the second primary neoplasm developed within six months. The relative risk of development of a second neoplasm is found as increasing 1.111 times per month. The incidence of secondary malignancy occuring in the patients with one tumor was found as 6.31%. Age (p < 0.001) and tumor number (p < 0.001) are found as statistically effective predictor on mortality rate where the sex is not. Conclusions: In the patients with a primary tumor not only the metastasis must be investigated but also second primary tumors should be taken in to consideration. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
48.
Although postoperative beta irradiation for prevention of pterygium recurrence is widely used, its complication rate has not been widely appreciated. Thirty-six patients underwent pterygium excision followed by irradiation with 90Sr to between 1600 and 5300 cGy (median 2400) in two to four fractions over 7 to 27 days. A median of three fields were used in each treatment course (range two to 10). Most patients had undergone previous treatment for their pterygia, including surgery alone (25 patients), or both surgery and irradiation (5 patients). Overall, recurrences developed in 10 eyes (28%). Recurrence occurred in one eye after re-irradiation (20%), compared to 9 of 31 (29%) previously non-irradiated eyes (p greater than 0.1). There was no association with number of excisions and recurrences, although all but 6 patients had undergone more than one excision. Thirteen patients (36%) developed complications including: epithelial defect or corneal thinning (3), symblepharon (5), cataract (4) and corneal ulceration (1). Complications developed in 4 of the 5 (80%) re-irradiated eyes compared to 9 of 31 (29%) previously non-irradiated eyes (p less than 0.05). The power of the statistical analysis was limited by sample size, but no significant association was observed between the development of complications or recurrences and total dose, number of abutting fields, number of previous surgical excisions or patient age, even when re-irradiated patients were excluded. Recently described calibration uncertainties with the 90Sr applicator may explain in part these complications. Alternatively, technical factors such as the number of fields or volume treated may play a role. Excessive complications and recurrences with the use of postoperative beta irradiation in this series emphasize the danger of re-treatment and the need for alternative safe and effective therapies.  相似文献   
49.
50.
Neuroleptic malignant syndrome (NMS) is the rarest and most serious of the neuroleptic-induced movement disorders. We describe a case of neuroleptic malignant syndrome (NMS) associated with the use of ziprasidone. Although conventional neuroleptics are more frequently associated with NMS, atypical antipsychotic drugs like ziprasidone may also be a cause. The patient is a 24-year-old male with a history of schizophrenia who developed signs and symptoms of NMS after 2 days of treatment with an 80-mg/day dose of orally administrated ziprasidone. This case is the earliest (second day of treatment) NMS due to ziprasidone reported in the literature.  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