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   7038篇
  免费   320篇
  国内免费   37篇
耳鼻咽喉   180篇
儿科学   156篇
妇产科学   262篇
基础医学   774篇
口腔科学   70篇
临床医学   507篇
内科学   2155篇
皮肤病学   53篇
神经病学   586篇
特种医学   291篇
外科学   827篇
综合类   46篇
一般理论   1篇
预防医学   348篇
眼科学   122篇
药学   568篇
中国医学   3篇
肿瘤学   446篇
  2024年   5篇
  2023年   47篇
  2022年   252篇
  2021年   439篇
  2020年   120篇
  2019年   203篇
  2018年   246篇
  2017年   164篇
  2016年   169篇
  2015年   212篇
  2014年   285篇
  2013年   354篇
  2012年   596篇
  2011年   591篇
  2010年   317篇
  2009年   214篇
  2008年   374篇
  2007年   425篇
  2006年   470篇
  2005年   409篇
  2004年   427篇
  2003年   370篇
  2002年   313篇
  2001年   42篇
  2000年   45篇
  1999年   60篇
  1998年   30篇
  1997年   23篇
  1996年   18篇
  1995年   17篇
  1994年   12篇
  1993年   16篇
  1992年   14篇
  1991年   14篇
  1990年   7篇
  1989年   12篇
  1988年   7篇
  1987年   4篇
  1986年   12篇
  1985年   9篇
  1984年   4篇
  1983年   4篇
  1981年   5篇
  1980年   3篇
  1979年   6篇
  1974年   3篇
  1973年   6篇
  1972年   3篇
  1967年   2篇
  1966年   4篇
排序方式: 共有7395条查询结果,搜索用时 35 毫秒
101.
102.
Background: Myocardial ischemia during coronary spasm may generate malignant ventricular arrhythmias. The J‐wave pattern was suggested to be a marker of a disorder associated with life‐threatening arrhythmias. Results: We report the case of a patient with vasospastic angina and J‐wave pattern in inferior and lateral leads associated with polymorphic ventricular tachycardia which was effectively treated only with quinidine—vasodilating drugs were not able to prevent the arrhythmia although they were effective in preventing ischemic events. Conclusion: The J‐wave pattern in inferolateral leads may be a sign of electrical vulnerability to lethal ventricular arrhythmia in patients suffering from vasospastic angina—quinidine can effectively prevent such arrhythmias in these patients.  相似文献   
103.
104.
105.
106.
107.
The effect of melatonin on glucose metabolism in the presence and absence of insulin has been investigated in the primary cultures of renal tubules grown in a defined medium. In the absence of glucose in the medium containing 5 microg/mL of insulin and 2 mm alanine + 5 mm glycerol + 0.5 mm octanoate, 100 nm melatonin stimulated both glucose and lactate synthesis, while in the medium devoid of insulin melatonin action was negligible. Melatonin-induced increase in glucose and lactate synthesis was accompanied by an enhancement of alanine and glycerol consumption. In view of measurements of [U-14C]L-alanine and [U-14C]L-glycerol incorporation into glucose, it is likely that melatonin increased alanine utilization for glucose production, while accelerated lactate synthesis was because of an enhanced glycerol consumption. As (i) 10 nm luzindole attenuated the stimulatory action of melatonin on glucose formation and (ii) the indole induced a decrease in intracellular cAMP level, it seems likely that in renal tubules melatonin binds to ML1 membrane receptor subtype. In view of a decline of intracellular fructose-1,6-bisphosphate content accompanied by a significant rise in hexose-6-phosphate and glucose levels, melatonin might result in an acceleration of flux through fructose-1,6-bisphosphatase probably because of an increase in the active, dephosphorylated form of this enzyme. Thus, the administration of melatonin in combination with insulin might be beneficial for diabetic therapy because of protection against hypoglycemia.  相似文献   
108.
Cedars-Sinai's approach to the automation of gated perfusion single photon emission computed tomography (SPECT) imaging is based on the identification of key procedural steps (processing, quantitation, reporting), each of which is then implemented, in completely automated fashion, by use of mathematic algorithms and logical rules combined into expert systems. Our current suite of software applications has been designed to be platform- and operating system-independent, and every algorithm is based on the same 3-dimensional sampling scheme for the myocardium. The widespread acceptance of quantitative software by the nuclear cardiology community (QGS alone is used at over 20,000 locations) has provided the opportunity for extensive validation of quantitative measurements of myocardial perfusion and function, in our opinion, helping to make nuclear cardiology the most accurate and reproducible modality available for the assessment of the human heart.  相似文献   
109.
AIMS: Anaemia is common in chronic heart failure (CHF) and associated with worse outcome. This randomized, double-blind, placebo-controlled study evaluated the effect of two darbepoetin alfa dosing regimens on haemoglobin (Hb) rate of rise and clinical effects in patients with CHF and anaemia. METHODS AND RESULTS: Patients with CHF (>or=3 months), left ventricular ejection fraction (LVEF) 相似文献   
110.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inheritant disease with an autosomal dominant mode of transmission with incomplete penetrance and variable expression. Linkage analysis in affected families succeeds in identifying 9 loci determining 9 subtypes of the disease. Genotype phenotype correlation is unclear and the influence of various environmental factors is discussed. OBJECTIVES: Genotype phenotype correlation in 2 pairs of monozygotic twins with ARVC and the role of environmental factors are analyzed. PATIENTS AND METHODS: Among 40 pts with ARVC and their 195 relatives there were 2 pairs of monozygotic twins: brothers, age 47 y; and sisters, age 48 y. History, ECG, Holter monitoring, 2D and Doppler Echo, and MRI were analyzed. RESULTS: Twin brothers: ARVC was diagnosed in the proband after the episode of VT with LBBB morphology (enlarged right ventricle, focal hypokinesia of apex, MR evidence of adipose tissue in RV wall). Identical morphology of RV was seen in asymptomatic twin brother. The patient presenting arrhythmia has been rowing for 4 years. Twin sisters: diagnosis was done during family screening. Both were asymptomatic. RV morphology typical for ARVC was found discrete in one of them (bulges adipose tissue in the RV apex); the latter showed changes suggesting RV abnormality (mild segmental dilatation of infundibulum, adipose tissue in a free wall of the RV). No differences in previous viral infections and sports involvement were observed. CONCLUSIONS: 1. Clinical picture of ARVC in monozygotic twins is not identical. 2. Strenuous effort may be a factor triggering the arrhythmia in pts with ARVC.  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