全文获取类型
收费全文 | 130903篇 |
免费 | 7575篇 |
国内免费 | 846篇 |
专业分类
耳鼻咽喉 | 1258篇 |
儿科学 | 3934篇 |
妇产科学 | 3040篇 |
基础医学 | 17824篇 |
口腔科学 | 4489篇 |
临床医学 | 11860篇 |
内科学 | 30752篇 |
皮肤病学 | 3191篇 |
神经病学 | 12610篇 |
特种医学 | 3335篇 |
外国民族医学 | 1篇 |
外科学 | 14015篇 |
综合类 | 458篇 |
一般理论 | 56篇 |
预防医学 | 11487篇 |
眼科学 | 2054篇 |
药学 | 8818篇 |
中国医学 | 463篇 |
肿瘤学 | 9679篇 |
出版年
2024年 | 99篇 |
2023年 | 1120篇 |
2022年 | 2120篇 |
2021年 | 4318篇 |
2020年 | 2719篇 |
2019年 | 3658篇 |
2018年 | 4188篇 |
2017年 | 3183篇 |
2016年 | 3747篇 |
2015年 | 4097篇 |
2014年 | 5406篇 |
2013年 | 7213篇 |
2012年 | 10855篇 |
2011年 | 11263篇 |
2010年 | 6185篇 |
2009年 | 5293篇 |
2008年 | 9127篇 |
2007年 | 9029篇 |
2006年 | 8297篇 |
2005年 | 7854篇 |
2004年 | 7063篇 |
2003年 | 6280篇 |
2002年 | 5713篇 |
2001年 | 774篇 |
2000年 | 570篇 |
1999年 | 803篇 |
1998年 | 982篇 |
1997年 | 828篇 |
1996年 | 699篇 |
1995年 | 617篇 |
1994年 | 571篇 |
1993年 | 481篇 |
1992年 | 430篇 |
1991年 | 314篇 |
1990年 | 312篇 |
1989年 | 270篇 |
1988年 | 246篇 |
1987年 | 223篇 |
1986年 | 229篇 |
1985年 | 176篇 |
1984年 | 204篇 |
1983年 | 183篇 |
1982年 | 204篇 |
1981年 | 150篇 |
1980年 | 163篇 |
1979年 | 111篇 |
1978年 | 96篇 |
1977年 | 91篇 |
1975年 | 67篇 |
1974年 | 79篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
H. Hall S. B. Ross Maria Sällemark 《Journal of neural transmission (Vienna, Austria : 1996)》1984,59(1):9-23
Summary The dependence of intact noradrenergic and serotonergic nerve terminals for the decrease in the number of-adrenoceptors and 5-HT2 binding sites in the cerebral cortex produced by long-term treatment of rats with antidepressant drugs was examined. Noradrenergic nerve terminals were destroyed with the selective noradrenaline neurotoxin DSP4, and serotonergic nerve terminals were destroyed with p-chloroamphetamine (PCA). It was found that lesioning of the noradrenergic nerve terminals abolished the decrease in-adrenoceptors produced by desipramine, mianserin and zimeldine and partially antagonized that of the-adrenoceptor agonist clenbuterol. PCA pretreatment did not antagonize the long-term effects on the-adrenoceptor produced by these compounds.Lesioning of serotonergic nerve terminals affected the down-regulation of 5-HT2 binding sites produced by long-term treatment with mianserin, desipramine and amiflamine. DSP4 pretreatment partially abolished the down-regulation of 5-HT2 binding sites produced by long-term treatment with desipramine, while the effects of mianserin and amiflamine were unaffected by pretreatment with DSP4. 相似文献
992.
A new metabolite of the diuretic drug bumetanide, the 4-[(4-hydroxy)-phenoxy] analog (7), was identified in incubation mixtures of rat liver microsomes. Phenobarbital and clofibrate pretreatment to induce microsomal enzymes changed the relative amounts of the six metabolites formed. Compound 7was the most prevalent metabolite after clofibrate pretreatment. 相似文献
993.
994.
995.
Schrewe Brett Martimianakis Maria Athina 《Advances in health sciences education : theory and practice》2022,27(3):847-861
Advances in Health Sciences Education - Professional identity formation has emerged as a key topic for medical education research, with contributions from perspectives of psychological development... 相似文献
996.
Rosa C. Villegas-Valle Unhee Lim Gertraud Maskarinec Adrian A. Franke Thomas Ernst Bo Fan Gerardo Álvarez-Hernández Maria del Carmen Candia-Plata Rolando Giovanni Díaz-Zavala Lynne R. Wilkens Kristine R. Monroe Mauro E. Valencia Loïc Le Marchand John A. Shepherd 《Obesity research & clinical practice》2021,15(3):227-234
ObjectiveTo determine if visceral adipose tissue (VAT) area measured through MRI can be used opportunistically to assess the presence of cardiometabolic risk factors and compare its performance to simpler adiposity measures.MethodsA cross-sectional analysis was carried out on a subset of 1683 participants (856 women) from the Adiposity Phenotype Study (mean age = 69.2y; range 59.9–77.4). The association of total VAT area (sum of four cross sections, L1–L2, L2–L3, L3–L4, L4–L5) and each location, as well as BMI and body fat % (per SD) with the metabolic syndrome (MetSx) or its components was evaluated through logistic regression analysis.ResultsTotal VAT can be accurately predicted using all sites evaluated (R2 range = 0.82?0.96). In men, VAT did not show a superior association to MetSx compared to BMI in men. However, in women, VAT was consistently superior to BMI and body fat % in its association to MetSx, independent of ethnicity [odds ratio for BMI, body fat %and total VAT area = 2.25 (95% CI: 1.93–2.62); 1.66 (95% CI: 1.36–2.03); 6.20 (95% CI: 4.69–8.21) respectively in all women]. Ethnic-specific odds ratios to MetSx in women ranged from 5.38 to 8.63 for total VAT area and 2.12–4.08 for BMI.ConclusionTotal VAT area can be accurately predicted from individual VAT regions in men and women and offers superior association to BMI for MetSx in women but not in men for five ethnicities. Therefore, opportunistic screening for elevated VAT area in women may be warranted across multiple ethnic groups. 相似文献
997.
Pedro Guimarães de Azevedo Luana Reis Miranda Eduardo Souza Nicolau Rayane Benfica Alves Maria Aparecida Camargos Bicalho Patrícia Pereira Couto Adauto Versiani Ramos Renan Pedra de Souza Rafael Longhi Eitan Friedman Luiz De Marco Luciana Bastos-Rodrigues 《Obesity research & clinical practice》2021,15(4):334-338
BackgroundObesity has reached epidemic proportions worldwide, affecting life quality and span. Susceptibility to obesity is partly mediated by genetic differences. Indeed, several genes from the clock gene family have already been shown to be intimately associated with obesity in diverse ethnic groups. In the present study, an association between BMI and the rs707467, rs228697 and rs228729 PER3 (Period Circadian Clock 3) polymorphisms in subjects with class II (BMI ≥ 35.0–39.9 kg/m2) and class III obesity (>40 kg/m2, extreme obesity) were carried out using TaqMan real-time PCR. Overall, 259 Brazilian adults were genotyped, of whom 122 had class II or III obesity (BMI ≥ 35.0 kg/m2) and 137 were controls having normal weight (BMI > 18.5 and <24.9 kg/m2).ResultsPER3 tag SNP (rs228729) shows a significant association with extreme obesity (1000 permutation p = 0.03 and p = 0.04), for genotype and allele frequency respectively) and a haplotype among the three assessed SNPs (alleles G/T/A, rs228697, rs228729, and rs707467, respectively, 1000 permutation p = 0.03) was significantly more prevalent in the group with obesity.ConclusionThis exploratory association study suggests that PER3 rs228729 may be associated with extreme obesity in Brazilian adults, however, replication is needed. 相似文献
998.
Maria Ruiz-Castell Gwenaëlle Le Coroller Jean-Francois Landrier Djedgiga Kerkour Bernard Weber Guy Fagherazzi Brice M. R. Appenzeller Michel Vaillant Torsten Bohn 《Nutrients》2021,13(1)
Metabolic syndrome (MetS) characteristics include chronic inflammation and elevated oxidative stress. This study assessed associations between circulating concentrations of micronutrients/phytochemicals and inflammatory/oxidative stress markers with MetS and MetS components. Adults (N = 606) from the European Health Examination Survey in Luxembourg (2013–2015) were randomly selected. We performed a multivariable logistic regression model using the least absolute shrinkage and selection operator to identify MetS-associated variables. Participants with MetS had higher concentrations of C-reactive protein (CRP), 8-iso-prostaglandin F2α, leptin, insulin, and vitamins E/A, but lower concentrations of adiponectin, beta-carotene, and oxidized low-density lipoprotein. A one-unit increase in log-CRP was associated with 51% greater odds of MetS (OR = 1.51 (95% CI: 1.16, 1.98)). Adults with a one-unit increase in log-leptin were 3.1 times more likely to have MetS (3.10 (2.10, 4.72)). Women with a one-unit increase in vitamin A were associated with 3% increased odds of MetS (1.03 (1.01, 1.05)), while those with a one-unit increase in log-adiponectin were associated with 82% decreased odds (0.18 (0.07, 0.46)). Chronic inflammation best characterized adults with MetS, as CRP, adiponectin, and leptin were selected as the main MetS determinants. Micronutrients did not seem to affect MetS, except for vitamin A in women. 相似文献
999.
Magdalena Hoffmann Christine Maria Schwarz Stefan Fürst Christina Starchl Elisabeth Lobmeyr Gerald Sendlhofer Marie-Madlen Jeitziner 《Nutrients》2021,13(1)
Critically ill patients in the intensive care unit (ICU) have a high risk of developing malnutrition, and this is associated with poorer clinical outcomes. In clinical practice, nutrition, including enteral nutrition (EN), is often not prioritized. Resulting from this, risks and safety issues for patients and healthcare professionals can emerge. The aim of this literature review, inspired by the Rapid Review Guidebook by Dobbins, 2017, was to identify risks and safety issues for patient safety in the management of EN in critically ill patients in the ICU. Three databases were used to identify studies between 2009 and 2020. We assessed 3495 studies for eligibility and included 62 in our narrative synthesis. Several risks and problems were identified: No use of clinical assessment or screening nutrition assessment, inadequate tube management, missing energy target, missing a nutritionist, bad hygiene and handling, wrong time management and speed, nutritional interruptions, wrong body position, gastrointestinal complication and infections, missing or not using guidelines, understaffing, and lack of education. Raising awareness of these risks is a central aspect in patient safety in ICU. Clinical experts can use a checklist with 12 identified top risks and the recommendations drawn up to carry out their own risk analysis in clinical practice. 相似文献
1000.
Type 2 diabetes mellitus (T2DM) represents a major health burden for the elderly population, affecting approximately 25% of people over the age of 65 years. This percentage is expected to increase dramatically in the next decades in relation to the increased longevity of the population observed in recent years. Beyond microvascular and macrovascular complications, sarcopenia has been described as a new diabetes complication in the elderly population. Increasing attention has been paid by researchers and clinicians to this age-related condition—characterized by loss of skeletal muscle mass together with the loss of muscle power and function—in individuals with T2DM; this is due to the heavy impact that sarcopenia may have on physical and psychosocial health of diabetic patients, thus affecting their quality of life. The aim of this narrative review is to provide an update on: (1) the risk of sarcopenia in individuals with T2DM, and (2) its association with relevant features of patients with T2DM such as age, gender, body mass index, disease duration, glycemic control, presence of microvascular or macrovascular complications, nutritional status, and glucose-lowering drugs. From a clinical point of view, it is necessary to improve the ability of physicians and dietitians to recognize early sarcopenia and its risk factors in patients with T2DM in order to make appropriate therapeutic approaches able to prevent and treat this condition. 相似文献