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   15763篇
  免费   1116篇
  国内免费   42篇
耳鼻咽喉   208篇
儿科学   470篇
妇产科学   483篇
基础医学   2221篇
口腔科学   555篇
临床医学   1534篇
内科学   2590篇
皮肤病学   623篇
神经病学   1596篇
特种医学   655篇
外科学   2319篇
综合类   193篇
一般理论   3篇
预防医学   1054篇
眼科学   332篇
药学   1025篇
中国医学   42篇
肿瘤学   1018篇
  2021年   225篇
  2020年   159篇
  2019年   233篇
  2018年   284篇
  2017年   236篇
  2016年   297篇
  2015年   346篇
  2014年   441篇
  2013年   545篇
  2012年   803篇
  2011年   865篇
  2010年   532篇
  2009年   516篇
  2008年   817篇
  2007年   896篇
  2006年   920篇
  2005年   844篇
  2004年   774篇
  2003年   704篇
  2002年   720篇
  2001年   391篇
  2000年   331篇
  1999年   326篇
  1998年   179篇
  1997年   153篇
  1996年   123篇
  1995年   129篇
  1994年   121篇
  1993年   121篇
  1992年   235篇
  1991年   183篇
  1990年   233篇
  1989年   219篇
  1988年   218篇
  1987年   203篇
  1986年   190篇
  1985年   176篇
  1984年   144篇
  1983年   126篇
  1982年   81篇
  1981年   83篇
  1979年   124篇
  1978年   102篇
  1977年   87篇
  1975年   94篇
  1974年   94篇
  1973年   96篇
  1971年   86篇
  1970年   86篇
  1969年   80篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz -  相似文献   
3.
Journal of Neuro-Oncology - Evidence supporting routine postoperative antiepileptic drug (AED) prophylaxis following oncologic neurosurgery is limited, and actual practice patterns are largely...  相似文献   
4.
ABSTRACT

Objectives: The consequences of polypharmacy (intake of ≥ 5 drugs) are diverse, including drug interactions, rising costs and side effects. Risk groups for polypharmacy are multimorbid and chronically ill people, such as patients with multiple sclerosis (MS). MS is the most common neuroimmunological disease in young adults worldwide. We aimed to provide a systematic overview of the current research status regarding frequency and predictors of polypharmacy in MS patients.

Methods: A systematic literature search in the databases PubMed, Cochrane Library and Scopus was carried out according to the PRISMA guidelines. English and German original research articles were included.

Results: Seven studies fulfilled the inclusion criteria of this review, while the research objectives and methods were very heterogenous. The polypharmacy rates in these studies ranged from 15% to 59%. Polypharmacy correlated with comorbidities, increased disability, cognitive deficits, increased hospitalization, higher relapse rate and lower quality of life.

Conclusions: In MS patients, polypharmacy is common and closely associated with health issues. There is a great need for research in this area, especially regarding longitudinal changes in drug utilization. Effective networks between physicians and pharmacists are needed to optimize medication management for patients and to achieve the best possible therapy results.  相似文献   
5.
6.
Klawitter  Felix  Walter  Uwe  Axer  Hubertus  Ehler  Johannes 《Der Anaesthesist》2023,72(8):543-554
Die Anaesthesiologie - Die Intensive Care Unit-Acquired Weakness (ICUAW) stellt eine der häufigsten neuromuskulären Komplikationen in der Intensivmedizin dar. Besonders bei...  相似文献   
7.
Many pregnant women rely on their health professional for nutrition information during routine antenatal visits. This review offers information to assist health professionals with advising pregnant women of the important nutrition considerations during pregnancy. The roles of some of the key nutrients are discussed, including folic acid, iodine, iron, calcium, and vitamin D. Recommendations for each of the key nutrients are covered and examples of how these can be achieved are presented. The review also details additional nutritional considerations that should be discussed during antenatal consults, including energy balance and weight gain recommendations, the importance of food safety during pregnancy, the recommended safe levels of consumption of vitamin A, caffeine, and fish, and the importance of abstaining from alcohol. Educating and supporting women during pregnancy to make healthy food choices to fulfil their needs and the needs of their growing fetus, will help to promote a healthy start to life.  相似文献   
8.

Background and purpose

Evidence of pre-operative resting state functional magnetic resonance (RS-fMRI) validation by correlating it with clinical pre-operative status in brain tumor patients is scarce. Our aim was to validate the functional relevance of RS-fMRI by investigating the association between RS-fMRI and pre-operative motor and language function performance in patients with brain tumor.

Materials and methods

Sixty-nine patients with brain tumors were prospectively recruited. Patients with tumors near precentral gyrus (n?=?49) underwent assessment for apparent (paresis) and subtle (finger tapping) deficits. Patients with left frontal tumors in the vicinity of the inferior frontal gyrus (n?=?29) underwent assessment for gross (aphasia) and mild language (phonological verbal fluency) deficits. RS-fMRI results were extracted by spatial independent component analysis (ICA).

Results

Motor group: paretic patients showed significantly (P?=?0.01) decreased BOLD signal in ipsilesional precentral gyrus when compared to contralesional one. Significantly (P?<?0.01) lower BOLD signal was also observed in ipsilesional precentral gyrus of paretics when compared with the non-paretics. In asymptomatic patients, a strong positive correlation (r?=?0.68, P?<?0.01) between ipsilesional motor cortex BOLD signal and contralesional finger tapping performance was observed. Language group: patients with aphasia showed significantly (P?=?0.01) decreased RS-fMRI BOLD signal in left BA 44 when compared with non- aphasics. In asymptomatic patients, a strong positive correlation (r?=?0.72, P?<?0.01) between BA 44 BOLD signal and phonological fluency performance was observed.

Conclusions

Our results showed that RS-fMRI BOLD signal of motor and language networks were significantly affected by the tumors implying the usefulness of the method for assessment of the underlying functions in brain tumors patients.  相似文献   
9.
The central complex (CX) comprises a group of midline neuropils in the insect brain, consisting of the protocerebral bridge (PB), the upper (CBU) and lower division (CBL) of the central body and a pair of globular noduli. It receives prominent input from the visual system and plays a major role in spatial orientation of the animals. Vertical slices and horizontal layers of the CX are formed by columnar, tangential, and pontine neurons. While pontine and columnar neurons have been analyzed in detail, especially in the fruit fly and desert locust, understanding of the organization of tangential cells is still rudimentary. As a basis for future functional studies, we have studied the morphologies of tangential neurons of the CX of the desert locust Schistocerca gregaria. Intracellular dye injections revealed 43 different types of tangential neuron, 8 of the PB, 5 of the CBL, 24 of the CBU, 2 of the noduli, and 4 innervating multiple substructures. Cell bodies of these neurons were located in 11 different clusters in the cell body rind. Judging from the presence of fine versus beaded terminals, the vast majority of these neurons provide input into the CX, especially from the lateral complex (LX), the superior protocerebrum, the posterior slope, and other surrounding brain areas, but not directly from the mushroom bodies. Connections are largely subunit- and partly layer-specific. No direct connections were found between the CBU and the CBL. Instead, both subdivisions are connected in parallel with the PB and distinct layers of the noduli.  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