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   9651篇
  免费   786篇
  国内免费   185篇
耳鼻咽喉   11篇
儿科学   387篇
妇产科学   75篇
基础医学   701篇
口腔科学   230篇
临床医学   604篇
内科学   1687篇
皮肤病学   83篇
神经病学   519篇
特种医学   94篇
外科学   446篇
综合类   612篇
现状与发展   1篇
预防医学   3761篇
眼科学   27篇
药学   563篇
  5篇
中国医学   260篇
肿瘤学   556篇
  2024年   12篇
  2023年   185篇
  2022年   891篇
  2021年   1061篇
  2020年   507篇
  2019年   415篇
  2018年   380篇
  2017年   331篇
  2016年   345篇
  2015年   399篇
  2014年   573篇
  2013年   809篇
  2012年   446篇
  2011年   416篇
  2010年   360篇
  2009年   320篇
  2008年   371篇
  2007年   328篇
  2006年   267篇
  2005年   238篇
  2004年   204篇
  2003年   199篇
  2002年   164篇
  2001年   110篇
  2000年   126篇
  1999年   98篇
  1998年   95篇
  1997年   95篇
  1996年   74篇
  1995年   66篇
  1994年   58篇
  1993年   58篇
  1992年   69篇
  1991年   54篇
  1990年   43篇
  1989年   39篇
  1988年   48篇
  1987年   38篇
  1986年   39篇
  1985年   45篇
  1984年   36篇
  1983年   31篇
  1982年   30篇
  1981年   28篇
  1980年   27篇
  1979年   17篇
  1978年   22篇
  1977年   12篇
  1975年   7篇
  1974年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Atopic dermatitis (AD) is today the most common, chronic inflammatory skin disease among children in developed countries. Its cumulative prevalence varies from 20% in northern Europe and the USA to approximately 5% in Mediterranean countries. As a chronic disease it puts a special demand on treatment. There is no curative therapy, but competent guidance on treatment principles can control the disease in most, if not all children. This article summarizes the evidence-based knowledge that relates to the treatment of atopic eczema. It also gives advice and opinions on prophylactic measures as these are the focus of interest from most parents. LEARNING OBJECTIVE: This article should enable you to give advice and guidance to parents of children with AD, including what is necessary for diagnosis, what is of value and importance considering allergies and allergological investigations, allergen exposure, prophylactic measures, diets and indoor environment. Finally, you should be able to explain the diversity of treatment principles for parents.  相似文献   
32.
The aim of the study was to compare salivary variables in a group of vegetarians with a group of omnivores. Twenty-nine vegetarians, 19 women and 10 men, mean age 35 yr, and 28 omnivores, 20 women and 8 men, mean age 35 yr, were compared in terms of salivary secretion rate, pH, buffer capacity, mutans streptococci and lactobacilli. The vegetarians had a significantly higher secretion rate, but there were no other significant differences regarding the salivary variables. The difference in secretion rate may have been caused by some lifestyle factor(s) differing between vegetarians and omnivores which probably mainly include nutrient(s), texture and roughness of the food.  相似文献   
33.
本文通过荤食组、常食组、素食组与胆石症发病率关系的调查,发现荤食组的发病率14/35(40%)比其它两组8/35(22.85%)、2/35(5.71%)更高。同时发现与病人的高血脂水平呈正相关。荤食组的胆固醇和甘油三酯水平分别为5.4±0.85和1.88±1.02,并且比常食组5.08±1.18,1.76±0.62和素食组4.88±0.41,1.67±0.36更高。结果提示:限制大量的胆固醇和脂肪饮食可降低胆石症的发病率。  相似文献   
34.
目的:比较不同性别BALB/c小鼠采用高脂饮食建立肥胖模型的差异。方法:32只4周龄无特定病原体级BALB/c小鼠(雌雄各半)随机分为雌性对照组、雌性高脂组、雄性对照组和雄性高脂组,每组8只。雌性对照组和雄性对照组采用普通饮食,雌性高脂组和雄性高脂组采用高脂饲料喂养,喂养12周后测量小鼠体重、内脏脂肪比、空腹血糖、葡萄糖耐量、血脂、代谢相关激素水平,并采用16S rRNA测序检测小鼠粪便菌群构成。结果:高脂饮食干预导致雄性小鼠体重和内脏脂肪比明显增加,病理表现为单个脂肪面积明显增大,肝脏脂肪滴堆积,总胆固醇、空腹血糖、口服糖耐量试验时间-血糖曲线下面积以及血清胰岛素水平明显上升(均P<0.05),并出现明显胰岛素抵抗(P<0.01)。而雌性高脂组体重、内脏脂肪比、血清胰岛素和瘦素水平与雌性对照组差异均无统计学意义(均P>0.05)。高脂干预后小鼠肥胖相关肠道菌群相对丰度显著变化并存在性别差异,其中雄性高脂组肥胖相关菌属(如布劳特菌)相对丰度明显增加,菌群结构变化更明显。结论:高脂饮食喂养12周4周龄BALB/c雄性小鼠可稳定建立以内脏脂肪堆积、代谢功能紊乱和肠道菌群变...  相似文献   
35.
The role of dietary factors in patients with type 1 (insulin-dependent) diabetes is reviewed by examining three different aspects: the effect of an acute protein load, the effect of dietary protein restriction on the progression of nephropathy and the metabolic effects of low-protein diets. After an acute protein load some impairment of the renal functional reserve may be observed only in patients with type 1 diabetes and overt nephropathy. However, the renal functional reserve is not able to give useful indications of the extent of renal damage and the prognosis of the disease. Both short-term and long-term dietary protein restriction are followed by a significant decrease in glomerular filtration rate (GFR) and albuminuria in type 1 diabetics with incipient nephropathy. In patients with overt nephropathy the long-term administration of a low-protein diet is followed by significant reductions in the rate of decline of GFR and in urinary protein excretion only when started at GFR values higher than 45 ml/min. The rate of functional deterioration when dietary treatment is prescribed seems critical in modulating the effects of a low-protein diet. In addition, low-protein diets may exert important metabolic and clinical effects beyond their supposed effect on progression. Clearly, an adequate dietary regimen is only part of the medical treatment in patients with diabetic nephropathy.  相似文献   
36.
A study has been carried out in the apolipoprotein (apo) E-deficient mouse to investigate the activity of lacidipine (a calcium antagonist with antioxidant properties) in inhibiting the development of atherosclerotic lesions; of particular interest were changes in the susceptibility of low-density lipoproteins (LDL) to oxidation. Mice receiving a Western-type diet to accelerate the development of atherosclerosis were treated orally with vehicle or lacidipine at 3 or 10 mg/kg/day for 8 weeks. Lacidipine treatment (at 3 or 10 mg/kg) had no effect on the plasma lipid profile. However, a significant (P < 0.01) dose-related reduction of 43 and 50% of the aortic lesion area in respect to vehicle-treated mice was observed. Moreover, the resistance of mouse plasma LDL to undergo lipid peroxidation was significantly (P < 0.01) increased in apo E-deficient mice treated with lacidipine. The native LDL-like particle, derived from apo E-deficient mice treated with lacidipine, contained significantly lower concentrations of malonyldialdehyde than the vehicle-treated control group (P < 0.01). After exposure to human umbilical vein endothelial cells, LDL-like particle vitamin E levels (expressed as area under the curve; AUC), were significantly higher (P < 0.01) in both the 3 and 10 mg/kg lacidipine-treated groups, in comparison with the vehicle-treated control animals. We conclude that lacidipine reduced the extent of the atherosclerotic area in hypercholesterolaemic apo E-deficient mice, and that this reduction may be associated with the capacity of the drug to decrease the susceptibility of LDL to oxidation.  相似文献   
37.
We report on an individual with trimethyl-aminuria, Prader-Willi syndrome, and del(15) (q11q13). To our knowledge, such an association has never been reported. Skin sores secondary to choline-rich foods and amenable to dietary control have not been described in trimethylaminuria, although they are seen in some patients with Prader-Willi syndrome. Pathogenesis, clinical diagnosis, and management of reported cases with trimethylaminuria are reviewed. Serious social and behavioral problems may result from strong body odor. Amelioration of the “fish odor” by dietary choline restriction makes trimethylaminuria detection important. Association of trimethylaminuria with Prader-Willi syndrome and del(15) (q11q13) in this patient is of particular interest. It may represent a contiguous gene syndrome, or deletion of the normal allele leading to expression of a single recessive trimethylaminuria gene, or an unrelated association, such as in Noonan syndrome. However, recent development of mapping of flavin-containing monooxygenase 2 (FMO2), the likely enzyme that is defective in fish odor syndrome, to chromosome 1q probably excludes pathogenetic association of fish odor syndrome with the Prader-Willi syndrome. © 1993 Wiley-Liss, Inc.  相似文献   
38.
Bovine spongiform encephalopathy (BSE) clearly originated in the UK, where there have now been more than 180 000 cases. However, through the exportation of cattle and cattle-feed additives from the UK, BSE also became established to a lesser extent in other European countries. There is current concern that BSE might have been distributed more widely as a result of the exportation of cattle or BSE-infected feed or foodstuff not only from the UK but also from other European countries that later became affected. It is now recognized that the transmissible agent that causes BSE also causes a new variant form of Creutzfeldt–Jakob disease (vCJD) in humans, and the evidence for this is presented. This probably resulted from dietary exposure to the bovine agent, and the potential role of mechanically recovered meat is discussed. There is a brief discussion on the controversial issue of the nature of the causal agents of diseases like BSE and vCJD. Whether or not sheep or goats could have become infected with BSE, and whether they represent a human health hazard, is also debated. Finally, the question of the control of BSE, and consequently vCJD, is discussed with regard to the rigorous application of the relevant regulations.  相似文献   
39.
High-fat diet-feeding increases body weight and adiposity in Syrian hamsters (Mesocricetus auratus), effects due in part to decreased energy expenditure. The effects of voluntary exercise- or cold exposure-induced increases in energy expenditure were examined in fat- or chow-fed, female Syrian hamsters. In Experiment 1, voluntary exercise (10 weeks) caused a moderate hyperphagia and actually increased body weight in both diet groups through increases in lean body mass. Carcass lipid was not affected by by exercise in chow-fed hamsters and only slightly reduced in fat-fed animals. In Experiment 2, chronic (8 weeks) cold exposure (5 degrees C) increased energy intake to the same extent in both dietary groups relative to the warm-exposed (23 degrees C) controls. High-fat diet-induced obesity was largely prevented by cold exposure. Cold exposure reduced lean body mass in chow-fed hamsters, but this carcass component was spared by fat-feeding. These results indicate that the increased metabolic demands of cold exposure were more effective in preventing this form of diet-induced obesity than those of voluntary exercise (80% and 17% reductions in carcass lipid, respectively). These results are discussed in terms of possible beneficial effects of eating a lipid-rich diet prior to winter.  相似文献   
40.
A number of studies have demonstrated that physiological andbehavioral cardiovascular disease (CVD) risk factors aggregatewithin families. This fact, and the potential mediating rolethat the family plays in behavior change, have led to the developmentof family-based CVD risk reduction programs, including the SanDiego Family Health Project. The aggregation of behavioral,physiological, and cognitive changes within families was assessedduring a 1-year intervention. We found evidence of modest butsignificant aggregation of change. There was more aggregationof change in behavioral variables than in physiological or cognitivevariables. More significant correlations were found among 3-dayfood record measures than among 24-hour recall dietary measures,suggesting an influence of assessment method. Aggregation ofchange within families was stronger within generations thanacross generations. These data point to the importance of involvingall age groups in health promotion programs.  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