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   4847篇
  免费   261篇
  国内免费   30篇
耳鼻咽喉   44篇
儿科学   203篇
妇产科学   120篇
基础医学   606篇
口腔科学   129篇
临床医学   414篇
内科学   1042篇
皮肤病学   76篇
神经病学   375篇
特种医学   253篇
外科学   556篇
综合类   22篇
一般理论   1篇
预防医学   405篇
眼科学   66篇
药学   316篇
中国医学   10篇
肿瘤学   500篇
  2024年   6篇
  2023年   39篇
  2022年   78篇
  2021年   147篇
  2020年   113篇
  2019年   133篇
  2018年   133篇
  2017年   98篇
  2016年   124篇
  2015年   144篇
  2014年   188篇
  2013年   247篇
  2012年   405篇
  2011年   424篇
  2010年   218篇
  2009年   175篇
  2008年   313篇
  2007年   318篇
  2006年   287篇
  2005年   288篇
  2004年   268篇
  2003年   220篇
  2002年   178篇
  2001年   64篇
  2000年   45篇
  1999年   40篇
  1998年   33篇
  1997年   30篇
  1996年   16篇
  1995年   19篇
  1994年   23篇
  1993年   12篇
  1992年   23篇
  1991年   27篇
  1990年   20篇
  1989年   22篇
  1988年   17篇
  1987年   32篇
  1986年   18篇
  1985年   39篇
  1984年   18篇
  1983年   8篇
  1982年   9篇
  1979年   7篇
  1978年   5篇
  1971年   4篇
  1970年   4篇
  1969年   14篇
  1968年   8篇
  1967年   7篇
排序方式: 共有5138条查询结果,搜索用时 15 毫秒
41.
Amphetamines are commonly used to treat attention-deficit hyperactivity disorder, but are also widely abused. They are employed in schizophrenia-related animal models as they disrupt the prepulse inhibition (PPI) of the acoustic startle response. The behavioral effects of amphetamines have mainly been attributed to changes in dopamine transmission, but they also involve increases in the synaptic concentrations of norepinephrine (NE). alpha2-Adrenoceptors (alpha2-ARs) regulate the excitability and transmitter release of brain monoaminergic neurons mainly as inhibitory presynaptic auto- and heteroreceptors. Modulation of acoustic startle and its PPI by the alpha2A-AR subtype was investigated with mice lacking the alpha2A-AR (alpha2A-KO) and their wild-type (WT) controls, without drugs and after administration of the alpha2-AR agonist dexmedetomidine or the antagonist atipamezole. The interaction of D-amphetamine (D-amph) and the alpha2-AR-noradrenergic neuronal system in modulating startle reactivity and in regulating brain monoamine metabolism was assessed as the behavioral and neurochemical responses to D-amph alone, or to the combination of D-amph and dexmedetomidine or atipamezole. alpha2A-KO mice were supersensitive to both neurochemical and behavioral effects of D-amph. Brain NE stores of alpha2A-KO mice were depleted by D-amph, revealing the alpha2A-AR as essential in modulating the actions of D-amph. Also, increased startle responses and more pronounced disruption of PPI were noted in D-amph-treated alpha2A-KO mice. alpha2A-AR also appeared to be responsible for the startle-modulating effects of alpha2-AR drugs, since the startle attenuation after the alpha2-AR agonist dexmedetomidine was absent in alpha2A-KO mice, and the alpha2-AR antagonist atipamezole had opposite effects on the startle reflex in alpha2A-KO and WT mice.  相似文献   
42.
A young woman with microscopic polyangiitis (MPA) requiring hemodialysis showed repeated posterior reversible encephalopathy syndrome (PRES) with spatiotemporal multiple lesions over a period of two months. The first PRES episode with confusion and the second PRES episode with vertigo and nausea were caused by MPA, hypertension and renal failure. These symptoms were improved by the reinforcement of MPA treatment and blood pressure management. The third PRES episode with nausea, headache, seizure and visual changes was induced by rituximab infusion and hypertension. The PRES was improved with blood pressure and convulsant management. These conditions are challenging to diagnose and treat.  相似文献   
43.
Aim: To clarify the question of whether patients with Kawasaki disease suffer a higher mortality rate after the incidence of the disease in comparison with age-matched healthy individuals. Methods: Between July 1982 and December 1992, 52 collaborating hospitals collected data on all patients having a new, definite diagnosis of Kawasaki disease. Patients were followed up until 31 December 2001 or their death. The expected number of deaths was calculated from Japanese vital statistics data and compared with the observed number. Results: Of 6576 patients enrolled, 29 (20 males and 9 females) died. The standardized mortality ratio (SMR: the observed number of deaths divided by the expected number of deaths based on the vital statistics in Japan) was 1.15 (95% CI: 0.77-1.66). In spite of the high SMRs during the acute phase, the mortality rate was not high after the acute phase for the entire group of patients. Although the SMR after the acute phase was 0.75 for those without cardiac sequelae, six males (but none of the females) with cardiac sequelae died during this period; and the SMR for the male group with cardiac sequelae was 1.95 (95% CI: 0.71-4.25). The mortality from congenital anomalies of the circulatory system was elevated, but no increase in cancer deaths was observed.

Conclusion: Although it was not statistically significant, the mortality rate among males with cardiac sequelae due to Kawasaki disease appeared to be higher than in the general population. On the other hand, the mortality rates for females with the sequelae and both males and females without sequelae were not elevated.  相似文献   
44.
45.
46.
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are common therapeutic agents for EGFR mutation-positive advanced non-small-cell lung cancer. There has been no report of rhabdomyolysis caused by an overdose of EGFR-TKIs. We herein review the existing literature on the subject and report a rare case of rhabdomyolysis due to an overdose of gefitinib, an EGFR-TKI.  相似文献   
47.
Recently, we have demonstrated a decreased level of iso-branched-chain fatty acids (iso-BCFAs) in patients with excessive weight. However, it is still unclear whether BCFAs may influence lipid metabolism and inflammation in lipogenic tissues. To verify this, human visceral adipocytes were cultured with three different concentrations of selected iso-BCFA (14-methylpentadecanoic acid) and anteiso-BCFA (12-methyltetradecanoic acid), and then the expression of genes associated with lipid metabolism (FASN—fatty acid synthase; SREBP1—sterol regulatory element-binding protein 1; SCD1—stearoyl-CoA desaturase; ELOVL4—fatty acid elongase 4; ELOVL6—fatty acid elongase 6; FADS2—fatty acid desaturase 2; FADS1–fatty acid desaturase 1) and inflammation (COX-2—cyclooxygenase 2; ALOX-15—lipoxygenase 15; IL-6—interleukin 6) were determined. This study demonstrates for the first time that incubation with iso-BCFA decreases the expression of adipocyte genes that are associated with lipid metabolism (except FASN) and inflammation. These findings suggest that changes in the iso-BCFA profile in obese patients may contribute to adipose inflammation and dyslipidemia. Further studies should evaluate whether iso-BCFA supplementation in obese patients would be beneficial.  相似文献   
48.
Background: The importance of maintaining good mental health with overall well-being has recently drawn attention from various spheres of academics and the working population. Amino acid intake has been reported to reduce depression symptoms and other mental health problems. However, the effectiveness of amino acid intake (i.e., single or combined) remains unknown. In this study, we assessed a combination of five amino acids (serine, alanine, glutamate, aspartate, and tyrosine; SAGAT) reported to regulate mental health. Methods: A randomized, double-blind, placebo-controlled exploratory trial was conducted. Participants, aged between 20 and 65 years with fatigue sensation, were randomized to receive either SAGAT or the placebo and ingested them for four weeks. A transient mental work was loaded at day 0 and after four weeks of intervention. As the primary outcomes, the fatigue sensation was assessed. The mood status, cognitive function, work efficiency, and blood marker were also measured as secondary outcomes. Results: The number of participants analyzed for the efficacy evaluation were 20 in SAGAT and 22 in the placebo. There were no significant differences in the primary outcomes. However, as the secondary outcomes, the SAGAT group showed a significant improvement in motivation and cognitive function in the recovery period after mental work loaded in a four-week intervention compared to the placebo. Conclusion: The current findings suggest that SAGAT contributes to maintaining proper motivation and cognitive function. Clinical Trial Registration: University Hospital Medical Information Network Clinical Trial Registry (ID: UMIN 000041221).  相似文献   
49.
Five cases with primary Budd-Chiari syndrome due to membranous obstruction of the hepatic segment of the inferior vena cava were examined by CT. In all cases, CT demonstrated caudate lobe enlargement, reticular low density within the liver parenchyma, splenomegaly, and collaterals via the ascending lumbar veins and azygous system. Pathological study revealed liver cirrhosis or fibrosis in all cases. In two cases, calcification was shown in the region of the hepatic segment of the inferior vena cava. Our results suggested that the CT appearance of primary Budd-Chiari syndrome was rather characteristic and useful in diagnosis, although membranous obliteration could not be shown directly on CT.  相似文献   
50.
Although hyperfunctioning mediastinal parathyroid lesions that require median sternotomy or thoracotomy for removal are occasionally present, the majority are located in the anterior mediastinum closely associated with the thymus. Only eight cases of ectopic hyperfunctioning parathyroid tumors in the middle mediastinum have been reported. We experienced two cases of either persistent or recurrent hyperparathyroidism in which abnormal parathyroid tissue was located in the aorticopulmonary window. One of the patients had a parathyroid adenoma and the other had metastatic lesions of parathyroid carcinoma. In both cases, thallium scanning proved useful in identifying the lesions while computed tomography scan was effective for mediastinal three-dimensional localization. In one case, single photon emission computed tomography imaging with thallium proved beneficial for both identification and localization of the middle mediastinal lesion. The surgical approach used in both cases was different. In one case, left thoracotomy was performed, after which the ligamentum arteriosum was divided, and an adenoma anterior to the left main bronchus and posterior to the left pulmonary artery removed. In the other case, two metastatic tumors of parathyroid carcinoma anterior to the right main bronchus and posterior to the right pulmonary artery were resected through a median sternotomy and opening of the pericardium.  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