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   4671篇
  免费   318篇
  国内免费   28篇
耳鼻咽喉   105篇
儿科学   147篇
妇产科学   91篇
基础医学   584篇
口腔科学   185篇
临床医学   458篇
内科学   1008篇
皮肤病学   77篇
神经病学   531篇
特种医学   155篇
外科学   685篇
综合类   52篇
一般理论   1篇
预防医学   270篇
眼科学   44篇
药学   203篇
中国医学   8篇
肿瘤学   413篇
  2023年   46篇
  2022年   105篇
  2021年   163篇
  2020年   103篇
  2019年   129篇
  2018年   144篇
  2017年   87篇
  2016年   145篇
  2015年   126篇
  2014年   171篇
  2013年   203篇
  2012年   336篇
  2011年   340篇
  2010年   183篇
  2009年   171篇
  2008年   267篇
  2007年   253篇
  2006年   254篇
  2005年   220篇
  2004年   222篇
  2003年   207篇
  2002年   183篇
  2001年   59篇
  2000年   66篇
  1999年   52篇
  1998年   35篇
  1997年   34篇
  1996年   42篇
  1995年   29篇
  1994年   32篇
  1993年   32篇
  1992年   46篇
  1991年   44篇
  1990年   34篇
  1989年   34篇
  1988年   29篇
  1987年   26篇
  1986年   32篇
  1985年   25篇
  1984年   29篇
  1983年   30篇
  1982年   21篇
  1981年   24篇
  1980年   18篇
  1979年   15篇
  1978年   16篇
  1977年   16篇
  1975年   15篇
  1974年   12篇
  1972年   17篇
排序方式: 共有5017条查询结果,搜索用时 15 毫秒
101.
Objective: To independently validate the predictive value of the intensive care requirement score (IRS) in unselected poisoned patients.

Design: Retrospective chart review.

Patients and methods: Five hundred and seventeen out of 585 admissions for acute intoxications could be analyzed. Eleven were excluded for a condition already requiring intensive care unit (ICU) support at admission (e.g., preclinical intubation). A further 57 admissions were excluded due to missing data. The IRS was calculated using a point-scoring system including age, Glasgow Coma Scale, heart rate, type of intoxication, and preexisting conditions. It was then compared to a composite endpoint indicating an ICU requirement (death in hospital, vasopressors, need for ventilation). The endpoint and the point-scoring system were identical to the original publication of the score.

Results and conclusion: Twenty-three out of 517 patients had a complicated clinical course as defined by meeting the endpoint definition. Twenty-one out of 23 complicated courses had a positive IRS (defined as greater or equal 6 points), as compared to 255/494 patients with an uncomplicated clinical course (p?相似文献   
102.
103.
Highly pathogenic avian influenza (H5N8) virus, like the recently described H5N8 strain from Korea, was detected in November 2014 in farmed turkeys and in a healthy common teal (Anas crecca) in northeastern Germany. Infected wild birds possibly introduced this virus.  相似文献   
104.
105.
The psychotomimetic effect of the N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine is thought to arise from a functional modulation of the brain''s fronto-striato-thalamic (FST) circuits. Animal models suggest a pronounced effect on ventral ‘limbic'' FST systems, although recent work in patients with psychosis and high-risk individuals suggests specific alterations of dorsal ‘associative'' FST circuits. Here, we used functional magnetic resonance imaging to investigate the effects of a subanesthetic dose of ketamine on measures of functional connectivity as indexed by the temporal coherence of spontaneous neural activity in both dorsal and ventral FST circuits, as well as their symptom correlates. We adopted a placebo-controlled, double-blind, randomized, repeated-measures design in which 19 healthy participants received either an intravenous saline infusion or a racemic mixture of ketamine (100 ng/ml) separated by at least 1 week. Compared with placebo, ketamine increased functional connectivity between the dorsal caudate and both the thalamus and midbrain bilaterally. Ketamine additionally increased functional connectivity of the ventral striatum/nucleus accumbens and ventromedial prefrontal cortex. Both connectivity increases significantly correlated with the psychosis-like and dissociative symptoms under ketamine. Importantly, dorsal caudate connectivity with the ventrolateral thalamus and subthalamic nucleus showed inverse correlation with ketamine-induced symptomatology, pointing to a possible resilience role to disturbances in FST circuits. Although consistent with the role of FST in mediating psychosis, these findings contrast with previous research in clinical samples by suggesting that acute NMDAR antagonism may lead to psychosis-like experiences via a mechanism that is distinct from that implicated in frank psychotic illness.  相似文献   
106.
We report the case of a 68-year old woman complaining of disorders of memory and persistent headaches in whom the diagnosis of Waldenstr?m's macroglobulinaemia (WM) was made. Computerized tomography of the brain showed a butterfly-shaped hyperdensity in the splenium of the corpus callosum, with ventricular dilatation. Magnetic resonance imaging displayed high-intensity signals on T2-weighted sequences. Protein immunoelectrophoresis elicited an IgM kappa peak. The CSF was found to contain proteins and lymphocytes in excess, and immunohistochemical staining confirmed the predominance of anti-kappa and the presence of intrathecal IgM secretion. Chemotherapy was temporarily effective on the memory disorders, but the patient died 26 months after the beginning of treatment. Central nervous system manifestations are seldom observed in WM, and they are now grouped under the name of Bing-Neel syndrome. Psychic disorders are rarely reported. It is suggested that IgM secretion plays a predominant role in the pathogenesis of leucoencephalitis, and this is supported by the finding of intrathecal IgM synthesis.  相似文献   
107.
Sport Sciences for Health - The generalized joint hypermobility (GJH) syndrome is a condition characterized by a connective tissue disorder that may negatively affect the muscle function and muscle...  相似文献   
108.
Thoracoscopic surgery in elderly lung cancer patients   总被引:10,自引:0,他引:10  
Age is a recognized risk factor for death after thoracotomy in elderly patients with lung cancer. Among other factors, the genesis of this risk is the physiologic debilitation that occurs after division of the intrathoracic respiratory muscles during thoracotomy, as well as the loss of lung tissue after lung resection. Recent advances in video-assisted thoracic surgery (VATS) techniques provide an alternative to standard thoracotomy in elderly lung cancer patients, resulting in decreased recovery times and fewer perioperative complications. Likewise, smaller lung resections (VATS-guided limited wedge resection versus lobectomy with thoracotomy) can be adequate oncologic procedures in patients with a limited life expectancy but resectable disease. We studied these alternative procedures in a cohort of thoracic surgical patients at the Brigham and Women's Hospital in Boston, MA. Proposed investigations of the psychosocial implications of thoracic surgery in the elderly, irrespective of the safety of these maneuvers, are addressed.  相似文献   
109.
Nasal provocation tests with normal saline and methacholine (MC) were performed in 25 atopic and 27 nonatopic subjects in an effort to assess the sources of protein in induced airway secretions. Nasal lavages obtained at baseline and after provocation were analyzed for albumin, total protein, secretory IgA (sIgA), and total IgA. Compared with baseline levels or saline provocation, MC provocation increased the secretion of albumin (p less than 0.025), total protein (p less than 0.001), sIgA (p less than 0.025), and total IgA (p less than 0.025), but did not significantly affect the relative proportions of albumin-to-total protein (albumin percent) or sIgA-to-total IgA (sIgA/total IgA ratio). Nasal pretreatment with atropine significantly inhibited MC-induced secretion of all 4 proteins, again without affecting the albumin percent or the sIgA/total IgA ratio. Because MC is known to stimulate atropine-inhibitable secretion of glandular products, these data suggest that sIgA and albumin may accompany glandular secretions. Immunohistochemical analyses of nasal turbinates confirmed that secretory component was found only on serous cells within submucous glands. Thus, it appears that cholinergic stimulation may regulate sIgA secretion and thereby participate in local nasal (and possibly respiratory tract) immunity.  相似文献   
110.
Transient and permanent neonatal diabetes mellitus (TNDM and PNDM) are rare conditions occurring in around 1 per 300,000 live births. In TNDM, growth-retarded infants develop diabetes in the first few weeks of life, only to go into remission after a few months with possible relapse to permanent diabetes usually around adolescence or in adulthood. In PNDM, insulin secretory failure occurs in the late fetal or early postnatal period. The very recently elucidated mutations in KCNJ11 and ABCC8 genes, encoding the Kir6.2 and SUR1 subunits of the pancreatic K(ATP) channel involved in regulation of insulin secretion, account for a third to a half of the PNDM cases. Molecular analysis of chromosome 6 anomalies and the KCNJ11 and ABCC8 genes encoding Kir6.2 and SUR1 provides a tool for distinguishing transient from permanent neonatal diabetes mellitus in the neonatal period. Some patients (those with mutations in KCNJ11 and ABCC8) may be transferred from insulin therapy to sulphonylureas.  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