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   19545篇
  免费   1270篇
  国内免费   123篇
耳鼻咽喉   207篇
儿科学   274篇
妇产科学   270篇
基础医学   2630篇
口腔科学   456篇
临床医学   1791篇
内科学   3899篇
皮肤病学   511篇
神经病学   2232篇
特种医学   1235篇
外科学   3665篇
综合类   112篇
一般理论   8篇
预防医学   666篇
眼科学   213篇
药学   1231篇
中国医学   13篇
肿瘤学   1525篇
  2023年   172篇
  2022年   273篇
  2021年   506篇
  2020年   344篇
  2019年   457篇
  2018年   523篇
  2017年   433篇
  2016年   523篇
  2015年   651篇
  2014年   789篇
  2013年   890篇
  2012年   1517篇
  2011年   1616篇
  2010年   979篇
  2009年   913篇
  2008年   1362篇
  2007年   1376篇
  2006年   1302篇
  2005年   1220篇
  2004年   1098篇
  2003年   1010篇
  2002年   944篇
  2001年   214篇
  2000年   170篇
  1999年   218篇
  1998年   166篇
  1997年   178篇
  1996年   97篇
  1995年   101篇
  1994年   80篇
  1993年   56篇
  1992年   87篇
  1991年   71篇
  1990年   62篇
  1989年   67篇
  1988年   62篇
  1987年   38篇
  1986年   43篇
  1985年   38篇
  1984年   35篇
  1983年   22篇
  1982年   31篇
  1981年   12篇
  1980年   16篇
  1979年   23篇
  1978年   20篇
  1977年   15篇
  1975年   18篇
  1974年   14篇
  1973年   11篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
61.
62.
Chronic renal failure triggered by calcineurin inhibitor (CNI)-based immunosuppression is a common complication after cardiac transplantation. Sirolimus and mycophenolate mofetil (MMF) are 2 newer immunosuppressive agents with no documented nephrotoxic side effects. This case report describes a patient with ongoing chronic renal failure 10 months after cardiac transplantation on cyclosporine-based immunosuppressive therapy. Conversion of the immunosuppressive regimen from cyclosporine to sirolimus and MMF resulted in freedom from acute rejection, excellent cardiac graft function and consistently improved renal function. This case illustrates the beneficial potential of sirolimus and MMF as CNI-free and safe long-term immunosuppression in a patient with chronic renal failure after heart transplantation.  相似文献   
63.
Sepsis continues to be a major clinical problem that is difficult to treat, as the pathophysiology of the disease is still unclear. Despite promising experimental strategies, therapeutic interventions have been largely unsuccessful. There is now increasing evidence that the disturbance of innate immunity during sepsis and multiorgan dysfunction syndrome (MODS) may be linked to uncontrolled activation of the complement system. Especially, the powerful anaphylatoxin C5a seems to play a key role in the development of immune paralysis. In this review, we describe our present understanding of the role of complement in the inflammatory response during sepsis and MODS.  相似文献   
64.
65.
Volume expansion in the presence of elevated aldosterone availabilityis a hallmark of normal pregnancy. Intravascular volume depletioncharacterizes severe pregnancy-associated disease conditionssuch as intra-uterine growth retardation, chronic hypertensionor pre-eclampsia [1]. Two hypotheses have been forwarded toexplain volume depletion in pregnancy: the first hypothesischarges inappropriate sensing of vascular ‘overfilling’,resulting in an increased transendothelial loss of fluid tothe extravascular compartment. In contrast, the second hypothesisfocuses on vascular ‘underfilling’ due to inappropriatelylow aldosterone levels. The second hypothesis is based on theassumption that a compensatory increase in the circulating fluidvolume is required in normal pregnancy to support fetal substratedelivery. According to the second concept, maternal blood pressureincreases due to counter-regulatory mechanisms when placentalblood supply is reduced [2]. In support of the ‘underfilling’hypothesis are observations that a  相似文献   
66.
67.
Polyunsaturated fatty acids (PUFAs) are components of cell membranes and may play an immunomodulating role in the pathogenesis of atopic dermatitis (AD). The goal was to determine the impact of PUFAs on AD by dietary supplementation of infants. Based on the parents' decision on their babies' primary feeding, mothers and newborns were randomized to the supplementation with gamma-linolenic acid (GLA) or placebo for up to 6 months. Breastfed infants received GLA by supplementing their mothers. Formula diet was commercial whey hydrolysate unsupplemented with PUFAs. Of 131 eligible infants, 24 developed AD within the first year of life. Of these, nine belonged to the exclusively breastfed group (n = 58), 14 to the combined-fed group (n = 53), and one to the never breastfed group (n = 20). We could not find an influence of GLA on the development of AD. In subjects with AD, at 1 yr of age the serum-immunoglobulin E (IgE) was the lowest in the GLA-supplemented group A-subjects. In the GLA-supplemented group, GLA-levels in breast milk were similar in atopic and non-atopic infants. In the non-supplemented group the GLA-content of breast milk was 0.07% of total fatty acids in atopic infants vs. 0.17% in non-atopic infants (p < 0.01). Dietary GLA-supplementation could not prevent AD. Interestingly, the number of infants developing AD was the lowest in never breastfed children. In infants suffering from AD, GLA-supplementation seemed to reduce total IgE in the first year of life.  相似文献   
68.
69.
In the past decade laparoscopic surgery replaced many open operations in general surgery. Apart from therapeutic uses in cholecystectomy, appendectomy, hernia surgery, gastric fundoplication, and increasingly also large intestine surgery, it is indicated diagnostically first of all for unclear abdominal findings and for staging of intra-abdominal malignancies. To date laparoscopy has been used occasionally for diagnosis and therapy of mesenteric ischemia. Patients suffering from mesenteric ischemia are usually old and have comorbid conditions. Quick diagnosis and therapy are necessary due to the pathogenesis of the disease. The low rate of morbidity as well as the easy availability of laparoscopy in principle favor the employment of laparoscopy also for mesenteric ischemia. Against the background of increasing experience in the area of laparoscopic surgery, this study gives an overview of the present value of laparoscopy for mesenteric ischemia.  相似文献   
70.
Valproic acid (VPA) is a broad-spectrum antiepileptic drug and is usually well-tolerated. Rare serious complications may occur in some patients, including haemorrhagic pancreatitis, bone marrow suppression, VPA-induced hepatotoxicity and VPA-induced encephalopathy. The typical signs of VPA-induced encephalopathy are impaired consciousness, sometimes marked EEG background slowing, increased seizure frequency, with or without hyperammonemia. There is still no proof of causative effect of VPA in patients with encephalopathy, but only of an association with an assumed causal relation. We report 19 patients with VPA-associated encephalopathy in Germany from the years 1994 to 2003, none of whom had been published previously.  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