全文获取类型
收费全文 | 2904篇 |
免费 | 167篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 168篇 |
妇产科学 | 43篇 |
基础医学 | 294篇 |
口腔科学 | 60篇 |
临床医学 | 290篇 |
内科学 | 551篇 |
皮肤病学 | 68篇 |
神经病学 | 140篇 |
特种医学 | 200篇 |
外科学 | 371篇 |
综合类 | 65篇 |
预防医学 | 141篇 |
眼科学 | 284篇 |
药学 | 186篇 |
中国医学 | 16篇 |
肿瘤学 | 192篇 |
出版年
2024年 | 2篇 |
2023年 | 27篇 |
2022年 | 44篇 |
2021年 | 116篇 |
2020年 | 69篇 |
2019年 | 92篇 |
2018年 | 100篇 |
2017年 | 80篇 |
2016年 | 96篇 |
2015年 | 91篇 |
2014年 | 126篇 |
2013年 | 143篇 |
2012年 | 227篇 |
2011年 | 234篇 |
2010年 | 151篇 |
2009年 | 111篇 |
2008年 | 197篇 |
2007年 | 188篇 |
2006年 | 165篇 |
2005年 | 153篇 |
2004年 | 141篇 |
2003年 | 114篇 |
2002年 | 98篇 |
2001年 | 24篇 |
2000年 | 35篇 |
1999年 | 32篇 |
1998年 | 12篇 |
1997年 | 13篇 |
1996年 | 13篇 |
1995年 | 13篇 |
1994年 | 11篇 |
1993年 | 17篇 |
1992年 | 15篇 |
1991年 | 13篇 |
1990年 | 18篇 |
1989年 | 11篇 |
1988年 | 23篇 |
1987年 | 9篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 5篇 |
1965年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有3085条查询结果,搜索用时 31 毫秒
1.
Nurse perceptions of the Nursing Delirium Screening Scale in two palliative care inpatient units: a focus group study
下载免费PDF全文
![点击此处可从《Journal of clinical nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
2.
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.3.
4.
Drishty Satpati Ketaki Bapat Archana Mukherjee Sharmila Banerjee Kanchan Kothari Meera Venkatesh 《Applied radiation and isotopes》2006,64(8):888-892
Studies on the development of imaging agents for targeting neuroreceptors is an area of considerable interest owing to the limited availability of specific as well as selective radiolabeled agents. Therefore, with an aim of developing a receptor-specific agent, iminodiacetic acid (IDA) derivative of 5-hydroxy tryptamine viz., HTIDA has been synthesized. HTIDA could be radiolabeled with the synthon [(99m)Tc(CO)(3)(H(2)O)(3)](+) in >98% yield. The biodistribution studies in normal Swiss mice showed that the (99m)Tc(CO)(3)-HTIDA crosses the blood-brain barrier successfully with a brain uptake of 0.5%ID/g at 5min post injection. The other relevant observations from biodistribution studies included no significant uptake in any other organ and fast clearance from blood, lungs and liver. 相似文献
5.
6.
7.
8.
Leeta Alison Green Khoi Nguyen Bijan Berenji Meera Iyer Eileen Bauer Jorge R Barrio Mohammad Namavari Nagichettiar Satyamurthy Sanjiv S Gambhir 《Journal of nuclear medicine》2004,45(9):1560-1570
Reporter probe 9-(4-18F-fluoro-3-[hydroxymethyl]butyl)guanine (18F-FHBG) and reporter gene mutant herpes simplex virus type 1 thymidine kinase (HSV1-sr39tk) have been used for imaging reporter gene expression with PET. Current methods for quantitating the images using the percentage injected dose per gram of tissue do not distinguish between the effects of probe transport and subsequent phosphorylation. We therefore investigated tracer kinetic models for 18F-FHBG dynamic microPET data and noninvasive methods for determining blood time-activity curves in an adenoviral gene delivery model in mice. METHODS: 18F-FHBG (approximately 7.4 MBq [approximately 200 microCi]) was injected into 4 mice; 18F-FHBG concentrations in plasma and whole blood were measured from mouse heart left ventricle (LV) direct sampling. Replication-incompetent adenovirus (0-2 x 10(9) plaque-forming units) with the E1 region deleted (n = 8) or replaced by HSV1-sr39tk (n = 18) was tail-vein injected into mice. Mice were dynamically scanned using microPET (approximately 7.4 MBq [approximately 200 microCi] 18F-FHBG) over 1 h; regions of interest were drawn on images of the heart and liver. Serial whole blood 18F-FHBG concentrations were measured in 6 of the mice by LV sampling, and 1 least-squares ratio of the heart image to the LV time-activity curve was calculated for all 6 mice. For 2 control mice and 9 mice expressing HSV1-sr39tk, heart image (input function) and liver image time-activity curves (tissue curves) were fit to 2- and 3-compartment models using Levenberg-Marquardt nonlinear regression. The models were compared using an F statistic. HSV1-sr39TK enzyme activity was determined from liver samples and compared with model parameter estimates. For another 3 control mice and 6 HSV1-sr39TK-positive mice, the model-predicted relative percentage of metabolites was compared with high-performance liquid chromatography analysis. RESULTS: The ratio of 18F-FHBG in plasma to whole blood was 0.84 +/- 0.05 (mean +/- SE) by 30 s after injection. The least-squares ratio of the heart image time-activity curve to the LV time-activity curve was 0.83 +/- 0.02, consistent with the recovery coefficient for the partial-volume effect (0.81) based on independent measures of heart geometry. A 3-compartment model best described 18F-FHBG kinetics in mice expressing HSV1-sr39tk in the liver; a 2-compartment model best described the kinetics in control mice. The 3-compartment model parameter, k3, correlated well with the HSV1-sr39TK enzyme activity (r2 = 0.88). CONCLUSION: 18F-FHBG equilibrates rapidly between plasma and whole blood in mice. Heart image time-activity curves corrected for partial-volume effects well approximate LV time-activity curves and can be used as input functions for 2- and 3-compartment models. The model parameter k3 from the 3-compartment model can be used as a noninvasive estimate for HSV1-sr39TK reporter protein activity and can predict the relative percentage of metabolites. 相似文献
9.
B Denise Raynor Elizabeth A Bonney Kyung T Jang Wendy Coto Meera S Garcia 《Hypertension in pregnancy》2004,23(2):129-134
Several parallels exist between preeclampsia and atherosclerosis. Both are multifactorial diseases that share risk factors such as obesity, insulin resistance, lipid abnormalities, and elevated serum homocysteine. There are also similarities in the biochemical changes seen in both diseases, including elevated serum triglycerides, decreased HDL cholesterol and enhanced formation of small, dense LDL particles as well as vascular atherosclerotic lesions. Chronic infection with Chlamydia pneumoniae has been linked to coronary artery disease. This study evaluated a possible link between the incidence of preeclampsia and infection with C. pneumoniae by examining the rate of seropositivity in 81 women with preeclampsia, and 206 women with normal pregnancies. Although our data confirmed well-known risk factors for preeclampsia such as obesity, diabetes, and hypertension, we found no difference in the rate of seropositivity between preeclampsia and normal pregnancy. On the contrary, the presence of chlamydial antibodies was lower in preeclampsia. Multiparous women with preeclampsia showed a significantly lower rate of seropositivity than multiparous normal women and nulliparous preeclamptics. In addition, women with a history of preeclampsia who developed preeclampsia in the current pregnancy also had a significantly lower rate of seropositivity. 相似文献
10.