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   17239篇
  免费   1082篇
  国内免费   54篇
耳鼻咽喉   206篇
儿科学   524篇
妇产科学   420篇
基础医学   3295篇
口腔科学   331篇
临床医学   1480篇
内科学   3505篇
皮肤病学   725篇
神经病学   1367篇
特种医学   789篇
外国民族医学   2篇
外科学   2441篇
综合类   116篇
一般理论   9篇
预防医学   1063篇
眼科学   223篇
药学   1034篇
中国医学   12篇
肿瘤学   833篇
  2021年   221篇
  2020年   145篇
  2019年   184篇
  2018年   218篇
  2017年   223篇
  2016年   295篇
  2015年   278篇
  2014年   383篇
  2013年   559篇
  2012年   660篇
  2011年   683篇
  2010年   390篇
  2009年   463篇
  2008年   642篇
  2007年   653篇
  2006年   659篇
  2005年   623篇
  2004年   573篇
  2003年   550篇
  2002年   609篇
  2001年   559篇
  2000年   522篇
  1999年   495篇
  1998年   235篇
  1997年   219篇
  1996年   225篇
  1995年   168篇
  1994年   179篇
  1993年   153篇
  1992年   294篇
  1991年   314篇
  1990年   306篇
  1989年   316篇
  1988年   304篇
  1987年   268篇
  1986年   271篇
  1985年   260篇
  1984年   198篇
  1983年   172篇
  1982年   123篇
  1980年   120篇
  1979年   197篇
  1978年   141篇
  1977年   128篇
  1976年   118篇
  1975年   153篇
  1974年   153篇
  1973年   143篇
  1972年   140篇
  1971年   126篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Luckscheiter  A.  Lohs  T.  Fischer  M.  Zink  W. 《Der Anaesthesist》2020,69(3):170-182
Die Anaesthesiologie - Das Management des schwierigen Atemwegs ist eine präklinische Schlüsselqualifikation. Für Notärzte mit hohem Erfahrungsgrad im Atemwegsmanagement sind...  相似文献   
5.
Radiolabeled octreotide analogs (Oct) and metaiodobenzylguanidine (MIBG) offer 2 different approaches for imaging and targeting metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NET). Despite successful establishment of the revised World Health Organization (WHO) classification, which distinguishes between low- and high-grade malignant GEP-NET, there is a lack of scintigraphic studies comparing uptake behavior on the basis of this categorization. This study aims to define predisposing factors of tracer uptake for both imaging principles implementing the updated tumor criteria of the current WHO classification. METHODS: Fifty-seven consecutive patients with histologically confirmed metastatic GEP-NET evaluated with both 111In-pentetreotide and 123I/131I-MIBG scintigraphy were included in this study. Intensity of tracer uptake was graded according to the different metastatic regions. Patients were classified as overall positive when avid uptake in the clinically relevant tumor lesions was present. Correlation was tested between the proportion of positive patients and tumor origin, function, and malignancy. RESULTS: Overall, 52 patients (91.2%) were Oct positive and 28 patients (49.1%) were MIBG positive. The proportion of tracer-positive patients was significantly higher (P < 0.05) in low-grade malignant tumors for both tracers and in functioning as well as in gastroenteral NET for MIBG. Five patients were negative for both tracers. None of the Oct-negative patients proved to be MIBG positive. CONCLUSION: Oct affinity is observed with high frequency throughout the subgroups of metastatic GEP-NET, whereas corresponding MIBG uptake is overall less prevalent and more group dependent. Tumor differentiation significantly impacts both Oct and MIBG uptake, whereas functionality predisposes only for MIBG accumulation. Though clearly inferior to Oct-based radioimaging in most GEP-NET, MIBG achieves a remarkable rate of radioligand accumulation in functioning midgut enterochromaffin cell metastases (>80% of patients positive). These results may have implications for patient management and potentially for selection and performance of targeted therapy.  相似文献   
6.
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating.  相似文献   
7.
8.
The Authors examine the correlation between hypertensive disorders of pregnancy and fetal growth. The results of a study of 342 pregnancies, confirm a significant correlation between hypertension and fetal growth retardation. These findings, so evident in moderate and severe hypertension, have also been confirmed in cases of mild hypertension. The medical treatment also in the pregnancies with mild hypertension, and a larger utilisation of operative deliveries, determined a decrease in perinatal mortality and morbidity.  相似文献   
9.
Fifteen cases of microtuboplasty were done as outpatient procedures at low cost and with increased patient convenience. Advances in outpatient surgery at free-standing surgery centers have allowed many new patient care innovations, and microsurgery should now be considered an outpatient procedure for gynecologic patients. Outpatient microtuboplastic surgery is not only feasible but perhaps preferable to that done as an inpatient procedure.  相似文献   
10.
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