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   21706篇
  免费   1363篇
  国内免费   67篇
耳鼻咽喉   278篇
儿科学   839篇
妇产科学   528篇
基础医学   3143篇
口腔科学   932篇
临床医学   1922篇
内科学   4637篇
皮肤病学   451篇
神经病学   2036篇
特种医学   552篇
外科学   2396篇
综合类   125篇
一般理论   9篇
预防医学   2004篇
眼科学   366篇
药学   1488篇
中国医学   118篇
肿瘤学   1312篇
  2023年   171篇
  2022年   136篇
  2021年   600篇
  2020年   399篇
  2019年   595篇
  2018年   731篇
  2017年   498篇
  2016年   535篇
  2015年   650篇
  2014年   857篇
  2013年   1158篇
  2012年   1619篇
  2011年   1742篇
  2010年   1020篇
  2009年   843篇
  2008年   1376篇
  2007年   1396篇
  2006年   1278篇
  2005年   1250篇
  2004年   1084篇
  2003年   1027篇
  2002年   958篇
  2001年   310篇
  2000年   320篇
  1999年   304篇
  1998年   161篇
  1997年   123篇
  1996年   97篇
  1995年   119篇
  1994年   117篇
  1993年   89篇
  1992年   161篇
  1991年   126篇
  1990年   111篇
  1989年   106篇
  1988年   97篇
  1987年   80篇
  1986年   76篇
  1985年   74篇
  1984年   74篇
  1983年   70篇
  1982年   53篇
  1981年   44篇
  1980年   44篇
  1979年   46篇
  1978年   47篇
  1976年   35篇
  1975年   38篇
  1974年   34篇
  1973年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Odontology - The purpose of this study was to investigate whether the root perforation repair with mineral aggregate-based cements affects the retention of customized fiberglass posts to bovine...  相似文献   
2.
3.
4.
IntroductionNerve compression by anomalous masses located at the wrist and distal forearm is an infrequent condition. They may compress underlying structures in the carpal tunnel region, causing pain and paresthesias, which leads to the wrong diagnosis of carpal tunnel syndrome.Clinical casesWe present three cases of patients with symptomatology and clinical tests compatible with compression of the median nerve in the carpal tunnel but whose physical examination showed a soft mass in the distal region of the forearm which was compressing the median nerve, as demonstrated by ultrasound evaluation.DiscussionThe reported cases of accessory muscles or lipomas described in the literature as causes of median nerve compression clinic are mainly described only after the surgical decompression of the carpal tunnel, due to the maintenance of residual symptoms.ConclusionCareful examination with an ultrasound evaluation prior to surgery may help to identify these cases and help planning surgical treatment.  相似文献   
5.
BackgroundContrast associated-acute kidney injury (CA-AKI) has been associated with adverse outcomes after ST-segment elevation myocardial infarction (STEMI). However, early markers of CA-AKI are still needed to improve risk stratification. We investigated the association between elevated serum uric acid (eSUA) and CA-AKI in patients with STEMI treated with primary percutaneous coronary intervention (pPCI).Methods and resultsSerum creatinine (Scr) was measured at admission and 24, 48 and 72 h after pPCI. CA-AKI was defined as an increase of 25% (CA-AKI 25%) or 0.5 mg/dl (CA-AKI 0.5) of Scr level above the baseline after 48 h following contrast administration. Multivariable analyses to investigate CA-AKI predictors were performed by binary logistic regression and multivariable backward logistic regression model.In the 3023 patients considered, CA-AKI was more frequent among patients with eSUA as compared with patients with normal SUA levels, considering both CA-AKI definitions (CA-AKI25%: 20.8% vs 16.2%, p < 0.012; CA-AKI 0.5: 10.1% vs 5.8%, p < 0.001). The association between eSUA and CA-AKI was confirmed at multivariable analyses (CA-AKI 25%: odd ratio 1.32, 95% CI 1.03–1.69, p = 0.027; CA-AKI 0.5: odd ratio 1.76, 95% CI 1.11–2.79, p = 0.016).ConclusionElevated serum uric acid is associated with CA-AKI after reperfusion in patients with STEMI treated with pPCI.  相似文献   
6.

Background

Limited data exist on the clinical behavior of pediatric non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) with distant metastases at onset, and a clear standard of care has not yet been defined.

Methods

This cohort study reports on pediatric adult-type metastatic NRSTS enrolled in two concurrent prospective European studies, i.e., the randomized BERNIE study and the single-arm MTS 2008 study developed by the European paediatric Soft tissue sarcoma Study Group. Treatment programs were originally designed for patients with metastatic rhabdomyosarcoma, i.e., nine courses of multidrug chemotherapy (with or without bevacizumab in the BERNIE study), followed by 12 cycles of maintenance therapy, whereas radiotherapy and/or surgery (on primary tumor and/or metastases) were delayed until after seven courses of chemotherapy had been administered.

Results

The study included 61 patients <21 years old treated from July 2008 to December 2016. The lung was the site of metastases in 75% of the cases. All patients received multi-agent chemotherapy, 44% had local therapy to primary tumor, and 18% had treatment of metastases. Median time to progression/relapse was 6 months. A high rate of tumor progression was observed during the initial part of the chemotherapy program. With a median follow-up of 41.5 months (range, 2–111 months), 3-year event-free survival and overall survival were 15.4% (95% confidence interval [CI], 7.6–25.7) and 34.9% (95% CI, 22.7–47.5), respectively. There were no statistically significant differences in outcome depending on the type of treatment administered.

Conclusions

The study confirmed the overall poor outcome for patients with metastatic NRSTS, whose treatment remains a challenge.

Plain Language Summary

  • Pediatric non-rhabdomyosarcoma soft tissue sarcomas form a heterogeneous group of rare tumors.
  • Although recent international studies have defined the standard of care for patients with localized disease, limited data are available on the clinical behavior of patients with distant metastases.
  • This study on 61 metastatic cases treated on two prospective European protocols confirms that the chances of survival of such patients are often dismal and a standard treatment is still lacking.
  相似文献   
7.
Trotula de Ruggiero is supposed to be one of the first female physician of the history, or at least the first who practiced, taught, and wrote medical texts inside the illustrious medieval Medical School of Salerno around the XI‐XII centuries. Here we retrace the steps of her fascinating history from historical cues to legendary anecdotes, through the analysis of the medical texts which were ascribed to her in the Middle Ages and that were very popular around Europe for several centuries, prevalently dealing with all the aspects of women's medical problems, with a focus on dermatology, cosmetic science, and obstetrics/gynecology.  相似文献   
8.
The development of patient‐specific induced pluripotent stem cells (iPSCs) offered interesting insights in modeling the pathogenesis of Charcot‐Marie‐Tooth (CMT) disease and thus we decided to explore the phenotypes of iPSCs derived from a single CMT patient carrying a mutant ATP1A1 allele (p.Pro600Ala). iPSCs clones generated from CMT and control fibroblasts, were induced to differentiate into neural precursors and then into post‐mitotic neurons. Control iPSCs differentiated into neuronal precursors and then into post‐mitotic neurons within 6‐8 days. On the contrary, the differentiation of CMT iPSCs was clearly defective. Electrophysiological properties confirmed that post‐mitotic neurons were less mature compared to the normal counterpart. The impairment of in vitro differentiation of CMT iPSCs only concerned with the neuronal pathway, because they were able to differentiate into mesendodermal cells and other ectodermal derivatives. ATP1A1 was undetectable in the few neuronal cells derived from CMT iPSCs. ATP1A1 gene mutation (p.Pro600Ala), responsible for a form of axonal CMT disease, is associated in vitro with a dramatic alteration of the differentiation of patient‐derived iPSCs into post‐mitotic neurons. Thus, the defect in neuronal cell development might lead in vivo to a decreased number of mature neurons in ATP1A1‐CMT disease.  相似文献   
9.
Introduction and objectivesChronic kidney disease has a high prevalence and economic impact, and an increased risk of hospitalization. Although there are public regional and country registries, we have not found references to estimate the impact of renal replacement therapy (RRT) on hospital admissions.MethodsWe obtained authorization from the ethics committee and health authorities to integrate the REMER [Madrid Kidney Disease Registry] (2013-2014) and Minimum Basic Data Set (2013-2015) databases and to analyze the admissions during the first year of RRT.Results767 patients started RRT in all the hospitals of our region across all RRT modalities. More than a third of the patients start dialysis during a hospital admission. This unplanned start, more common in HD than PD, shows relevant differences in patient profile or admission characteristics.Without considering this initial episode, almost 60% of patients were admitted during their first year. The hospitalization rate was 1.2 admissions/patient, higher in HD than in TX or PD; the mean length of stay was 8.6 days.The estimated cost of admissions during the first year is €12,006/patient. Our analysis ensures the exhaustive inclusion of all episodes and accurate estimation based on the discharge form.ConclusionThe impact of RRT on hospitals has been underestimated and is very relevant when calculating the total cost of RRT. Results from other countries cannot be extrapolated due to differences in the health system and patient profile. The integration of clinical databases could open up an opportunity that needs only institutional support for its development.  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