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   4718篇
  免费   317篇
  国内免费   17篇
耳鼻咽喉   100篇
儿科学   297篇
妇产科学   161篇
基础医学   493篇
口腔科学   105篇
临床医学   488篇
内科学   861篇
皮肤病学   105篇
神经病学   407篇
特种医学   170篇
外科学   838篇
综合类   56篇
一般理论   1篇
预防医学   349篇
眼科学   123篇
药学   246篇
中国医学   16篇
肿瘤学   236篇
  2024年   2篇
  2023年   48篇
  2022年   79篇
  2021年   165篇
  2020年   88篇
  2019年   170篇
  2018年   173篇
  2017年   152篇
  2016年   159篇
  2015年   201篇
  2014年   233篇
  2013年   324篇
  2012年   388篇
  2011年   386篇
  2010年   222篇
  2009年   148篇
  2008年   334篇
  2007年   344篇
  2006年   288篇
  2005年   276篇
  2004年   230篇
  2003年   190篇
  2002年   167篇
  2001年   39篇
  2000年   37篇
  1999年   35篇
  1998年   16篇
  1997年   16篇
  1996年   16篇
  1995年   9篇
  1994年   5篇
  1993年   15篇
  1992年   12篇
  1991年   10篇
  1990年   8篇
  1989年   4篇
  1988年   3篇
  1987年   4篇
  1986年   7篇
  1985年   6篇
  1984年   7篇
  1983年   3篇
  1982年   3篇
  1981年   2篇
  1980年   4篇
  1979年   3篇
  1978年   5篇
  1977年   3篇
  1966年   2篇
  1947年   2篇
排序方式: 共有5052条查询结果,搜索用时 437 毫秒
1.
2.
3.
4.
Purpose of the study: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design.

Material and methods: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility.

Results: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔO2Hb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as “Working Memory” and “Verbal Fluency Tasks”.

Conclusions: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar.  相似文献   

5.
6.
The region is characterized by diversity in cultural, political, economic and health conditions. Blindness in the region varies from 6.4% to 0.2% with cataract ranking highly as an underlying cause. There is a need to develop national policies to deliver affordable, technically suitable, and cost effective management plans to reduce cataract. Economic, demographic, health, and manpower statistics are essential information to be considered in formulating such policies.  相似文献   
7.
IR, 1H NMR and mass spectrometric studies showed that cetirizine dihydrochloride interacted strongly with diclofenac sodium, even when the latter was metal bound, forming high molecular weight stable adducts. These new formations were unaffected by the possible steric constraints that may exist because of coordination yet did not have the power to break the formed coordinate bonds. The formed ionic bond took place between the carbonyl ion of diclofenac and the positively charged piperazine ring of cetirizine, forming a ternary compound in the case of the divalent metal clusters (Ca{(dic)2.2H2O}, Mg{(dic)2.2H2O}, Zn{(dic)2.2H2O}) and a quaternary one with the trivalent iron cluster (Fe{dic}3.3H2O). IR bands assigned to nuNH, deltaNH and nuC-N were shifted to lower frequency values in the spectra of the complexes; thus showing that coordination took place at the NH of the diphenylamine. TG and elemental analysis confirmed these results.  相似文献   
8.
OBJECTIVE: The purpose of this study was to assess and compare cognitive functioning in adults with unilateral hemispheric injury due to either congenital damage or an ischemic event in young adulthood. METHOD: Adults with cerebral palsy resulting from left hemispheric brain damage were compared with adults who had a unilateral stroke in either the left or the right hemisphere. Our primary interest was to determine the impact on hemispheric dominance as revealed by dichotic listening, a task that assesses the bias for preferential listening and processing of sounds. Performance also was determined on a language-related task (word finding) and a spatial task (dot localization). RESULTS: Scores on the Quick Neurological Screening Test indicated that all participants demonstrated significant neuromotor deficits, whereas scores on the Barthel Index indicated that the participants were functional in basic activities of daily living. On cognitive assessments, healthy control participants demonstrated a pronounced left-hemisphere dominance and right-ear advantage; participants with injury to the left hemisphere showed a strong shift toward a right-hemisphere and left-ear dominance. In particular, injury of congenital origin appeared to foster this neural reorganization and localization of language-related functions into the healthy hemisphere. This shift was associated with a deterioration of performance on both the language and the spatial tasks. CONCLUSION: The importance of appreciating subtle deficits after unilateral injury is important in therapy. The dichotic listening test may provide a simple and useful means for evaluating persistent unilateral brain dysfunction in the clinical setting.  相似文献   
9.
Extracorporeal septoplasty is a radical solution for the severely deviated nose. The major problems associated with this procedure are fixation of the septal cartilage graft and dorsal irregularities. Extracorporeal septoplasty was performed in combination with open rhinoplasty in 17 patients with severe nasal deformities. In this technique septum was totally removed through the columellar incision of open rhinoplasty, corrected outside, and replaced as a free ``L' shaped cartilage graft. The cartilage graft was fixated to the upper lateral cartilages to restore the natural relations of the anatomical structures. Additional rhinoplastic manipulations were also performed. The follow-up period was up to 18 months. The overall result was successful in all patients. Nasal deviation did not recur and secondary revisions were not needed for any patient during follow-up.  相似文献   
10.
Esthesioneuroblastoma is an uncommon malignant neoplasm that arises from olfactory mucosa, often with intracranial extension.A case report of the youngest victim in the literature (2-year-old boy) is presented.  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