全文获取类型
收费全文 | 1433471篇 |
免费 | 132001篇 |
国内免费 | 4309篇 |
专业分类
耳鼻咽喉 | 21220篇 |
儿科学 | 44577篇 |
妇产科学 | 39529篇 |
基础医学 | 203575篇 |
口腔科学 | 45016篇 |
临床医学 | 126889篇 |
内科学 | 286569篇 |
皮肤病学 | 37194篇 |
神经病学 | 119683篇 |
特种医学 | 56988篇 |
外国民族医学 | 440篇 |
外科学 | 224231篇 |
综合类 | 35350篇 |
现状与发展 | 10篇 |
一般理论 | 465篇 |
预防医学 | 98308篇 |
眼科学 | 32932篇 |
药学 | 107514篇 |
37篇 | |
中国医学 | 5188篇 |
肿瘤学 | 84066篇 |
出版年
2019年 | 18738篇 |
2018年 | 21413篇 |
2017年 | 20335篇 |
2016年 | 21916篇 |
2015年 | 23465篇 |
2014年 | 28311篇 |
2013年 | 37738篇 |
2012年 | 39001篇 |
2011年 | 40828篇 |
2010年 | 30100篇 |
2009年 | 26269篇 |
2008年 | 37219篇 |
2007年 | 39362篇 |
2006年 | 39764篇 |
2005年 | 38094篇 |
2004年 | 36893篇 |
2003年 | 35929篇 |
2002年 | 35264篇 |
2001年 | 64914篇 |
2000年 | 66502篇 |
1999年 | 55950篇 |
1998年 | 14846篇 |
1997年 | 13612篇 |
1996年 | 13075篇 |
1995年 | 12344篇 |
1992年 | 42855篇 |
1991年 | 41343篇 |
1990年 | 40619篇 |
1989年 | 39613篇 |
1988年 | 37019篇 |
1987年 | 36466篇 |
1986年 | 34948篇 |
1985年 | 33165篇 |
1984年 | 24893篇 |
1983年 | 21104篇 |
1982年 | 12736篇 |
1981年 | 11619篇 |
1979年 | 23957篇 |
1978年 | 17091篇 |
1977年 | 14853篇 |
1976年 | 13408篇 |
1975年 | 15284篇 |
1974年 | 18100篇 |
1973年 | 17585篇 |
1972年 | 16819篇 |
1971年 | 15728篇 |
1970年 | 14921篇 |
1969年 | 14351篇 |
1968年 | 13470篇 |
1967年 | 12020篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
K.-C. Sung D.-C. Seo S.-J. Lee M.-Y. Lee S.H. Wild C.D. Byrne 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(5):489-495
Background and aims
It is not known whether non alcoholic fatty liver disease (NAFLD) is a risk factor for diabetes in non obese, non centrally-obese subjects. Our aim was to investigate relationships between fatty liver, insulin resistance and a biomarker score for liver fibrosis with incident diabetes at follow up, in subjects who were neither obese nor centrally-obese.Methods and results
As many as 70,303 subjects with a body mass index (BMI) < 25 kg/m2 and without diabetes were followed up for a maximum of 7.9 years. At baseline, fatty liver was identified by liver ultrasound, insulin resistance (IR) by homeostatic model assessment of insulin resistance (HOMA-IR) ≥2.0, and central obesity by waist circumference (waist circumference ≥90 cm (men) and ≥85 cm (women). The Fibrosis-4 (FIB-4 score) was used to estimate extent of liver fibrosis. Cox proportional hazards models adjusted for confounders were used to estimate hazard ratios (aHRs) for incident diabetes. As many as 852 incident cases of diabetes occurred during follow up (median [IQR] 3.71 [2.03] years). Mean ± SD BMI was 22.8 ± 1.8 and 21.7 ± 2.0 kg/m2 in subjects with and without diabetes at follow up. In subjects without central obesity and with fatty liver, aHRs (95% CI) for incident diabetes at follow up were 2.17 (1.56, 3.03) for men, and 2.86 (1.50,5.46) for women. Similar aHRs for incident diabetes occurred with fatty liver, IR and the highest quartile of FIB-4 combined, in men; and there was a non significant trend toward increased risk in women.Conclusions
In normal weight, non-centrally obese subjects NAFLD is an independent risk factor for incident diabetes. 相似文献103.
104.
105.
106.
Jeroen M. van de Pol Jurjen G. Geljon Svetlana V. Belitser Geert W.J. Frederix Anke M. Hövels Marcel L. Bouvy 《Research in social & administrative pharmacy》2019,15(1):70-76
Introduction
The nature of community pharmacy is changing, shifting from the preparation and distribution of medicines to the provision of cognitive pharmaceutical services (CPS); however, often the provision of traditional services leaves little time for innovative services. This study investigated the time community pharmacists spend on the tasks and activities of daily practice and to what extent they are able to implement CPS-related services in daily practice.Methods
Self-reporting work sampling was used to register the activities of community pharmacists. A smartphone application, designed specifically for this purpose, alerted participants to register their current activity five times per working day for 6 weeks. Participants also completed an online survey about baseline characteristics.Results
Ninety-one Dutch community pharmacists provided work-sampling data (7848 registered activities). Overall, 51.5% of their time was spent on professional activities, 35.4% on semi-professional activities, and 13.1% on non-professional activities. The proportion of time devoted to CPS decreased during the workweek, whereas the time spent on traditional task increased.Discussion and conclusion
This study shows it is feasible to collect work-sampling data using smartphone technology. Community pharmacists spent almost half of their time on semi-professional and non-professional activities, activities that could be delegated to other staff members. In practice, the transition to CPS is hampered by competing traditional tasks, which prevents community pharmacists from profiling themselves as pharmaceutical experts in daily practice. 相似文献107.
108.
Marie Warrer Petersen Tine Sylvest Meyhoff Marie Helleberg Maj-Brit Nørregaard Kjær Anders Granholm Carl Johan Steensen Hjortsø Thomas Steen Jensen Morten Hylander Møller Peter Buhl Hjortrup Mik Wetterslev Gitte Kingo Vesterlund Lene Russell Vibeke Lind Jørgensen Klaus Tjelle Thomas Benfield Charlotte Suppli Ulrik Anne Sofie Andreasen Thomas Mohr Morten H. Bestle Lone Musaeus Poulsen Mette Friberg Hitz Thomas Hildebrandt Lene Surland Knudsen Anders Møller Christoffer Grant Sølling Anne Craveiro Brøchner Bodil Steen Rasmussen Henrik Nielsen Steffen Christensen Thomas Strøm Maria Cronhjort Rebecka Rubenson Wahlin Stephan Jakob Luca Cioccari Balasubramanian Venkatesh Naomi Hammond Vivekanand Jha Sheila Nainan Myatra Christian Gluud Theis Lange Anders Perner 《Acta anaesthesiologica Scandinavica》2020,64(9):1365-1375
Introduction
Severe acute respiratory syndrome coronavirus-2 has caused a pandemic of coronavirus disease (COVID-19) with many patients developing hypoxic respiratory failure. Corticosteroids reduce the time on mechanical ventilation, length of stay in the intensive care unit and potentially also mortality in similar patient populations. However, corticosteroids have undesirable effects, including longer time to viral clearance. Clinical equipoise on the use of corticosteroids for COVID-19 exists.Methods
The COVID STEROID trial is an international, randomised, stratified, blinded clinical trial. We will allocate 1000 adult patients with COVID-19 receiving ≥10 L/min of oxygen or on mechanical ventilation to intravenous hydrocortisone 200 mg daily vs placebo (0.9% saline) for 7 days. The primary outcome is days alive without life support (ie mechanical ventilation, circulatory support, and renal replacement therapy) at day 28. Secondary outcomes are serious adverse reactions at day 14; days alive without life support at day 90; days alive and out of hospital at day 90; all-cause mortality at day 28, day 90, and 1 year; and health-related quality of life at 1 year. We will conduct the statistical analyses according to this protocol, including interim analyses for every 250 patients followed for 28 days. The primary outcome will be compared using the Kryger Jensen and Lange test in the intention to treat population and reported as differences in means and medians with 95% confidence intervals.Discussion
The COVID STEROID trial will provide important evidence to guide the use of corticosteroids in COVID-19 and severe hypoxia.109.
Solid-state reactions between sodium hydride and sodium hydroxide are unusual among hydride-hydroxide systems since hydrogen can be stored reversibly. In order to understand the relationship between hydrogen uptake/release properties and phase/structure evolution, the dehydrogenation and hydrogenation behavior of the Na-O-H system has been investigated in detail both ex- and in-situ. Simultaneous thermogravimetric-differential thermal analysis coupled to mass spectrometry (TG-DTA-MS) experiments of NaH-NaOH composites reveal two principal features: Firstly, an H2 desorption event occurring between 240 and 380 °C and secondly an additional endothermic process at around 170 °C with no associated weight change. In-situ high-resolution synchrotron powder X-ray diffraction showed that NaOH appears to form a solid solution with NaH yielding a new cubic complex hydride phase below 200 °C. The Na-H-OH phase persists up to the maximum temperature of the in-situ diffraction experiment shortly before dehydrogenation occurs. The present work suggests that not only is the inter-phase synergic interaction of protic hydrogen (in NaOH) and hydridic hydrogen (in NaH) important in the dehydrogenation mechanism, but that also an intra-phase Hδ+… Hδ– interaction may be a crucial step in the desorption process. 相似文献
110.