收费全文 | 2531篇 |
免费 | 210篇 |
国内免费 | 11篇 |
耳鼻咽喉 | 5篇 |
儿科学 | 146篇 |
妇产科学 | 36篇 |
基础医学 | 351篇 |
口腔科学 | 31篇 |
临床医学 | 187篇 |
内科学 | 514篇 |
皮肤病学 | 44篇 |
神经病学 | 296篇 |
特种医学 | 212篇 |
外科学 | 294篇 |
综合类 | 29篇 |
预防医学 | 164篇 |
眼科学 | 103篇 |
药学 | 135篇 |
肿瘤学 | 205篇 |
2021年 | 26篇 |
2019年 | 45篇 |
2018年 | 33篇 |
2017年 | 24篇 |
2016年 | 32篇 |
2015年 | 33篇 |
2014年 | 56篇 |
2013年 | 80篇 |
2012年 | 100篇 |
2011年 | 99篇 |
2010年 | 73篇 |
2009年 | 62篇 |
2008年 | 108篇 |
2007年 | 104篇 |
2006年 | 112篇 |
2005年 | 105篇 |
2004年 | 104篇 |
2003年 | 80篇 |
2002年 | 99篇 |
2001年 | 79篇 |
2000年 | 103篇 |
1999年 | 77篇 |
1998年 | 53篇 |
1997年 | 44篇 |
1996年 | 28篇 |
1995年 | 29篇 |
1994年 | 24篇 |
1993年 | 29篇 |
1992年 | 59篇 |
1991年 | 57篇 |
1990年 | 61篇 |
1989年 | 73篇 |
1988年 | 59篇 |
1987年 | 39篇 |
1986年 | 48篇 |
1985年 | 45篇 |
1984年 | 40篇 |
1983年 | 31篇 |
1982年 | 22篇 |
1981年 | 23篇 |
1980年 | 20篇 |
1979年 | 22篇 |
1978年 | 17篇 |
1977年 | 19篇 |
1976年 | 16篇 |
1975年 | 16篇 |
1974年 | 18篇 |
1973年 | 19篇 |
1969年 | 20篇 |
1968年 | 18篇 |
Methods: Infertile women trying to conceive, and specialist nurses were recruited across 6 European countries. In total 18 patients and 19 nurses took part in the testing, which included both nurse-patient pairings and in-depth interviews. A standardized list of expected and pre-defined critical steps according to the Instructions for Use (IFU), was used to assess the correct handling of the pen.
Results: During the user experience testing, no critical errors, related to the use of the pen, which could affect the success of the injection process were identified. In general, both nurses and patients found the pen very easy to learn, use and would be confident using the pen for self-injection. Nurses also found the pen very easy to train the patients.
Conclusions: The study provides valuable information on the pen from both patient and nurse perspectives in different simulated scenarios reflecting standard practice. 相似文献
Aneurysm occlusion rate after clipping is higher than after endovascular treatment. However, a certain percentage of incompletely clipped aneurysms remains. Presurgical selection of the proper aneurysm clips could potentially reduce the rate of incomplete clippings caused by inadequate clip geometry. The aim of the present study was to assess whether preoperative 3D image-based simulation allows for preoperative selection of a proper aneurysm clip for complete occlusion in individual cases. Patients harboring ruptured or unruptured cerebral aneurysms prior to surgical clipping were analyzed. CT angiography images were transferred to a 3D surgical-planning station (Dextroscope®) with imported models of 58 aneurysm clips. Intracranial vessels and aneurysms were segmented and the virtual aneurysm clips were placed at the aneurysm neck. Operating surgeons had information about the selected aneurysm clip, and patients underwent clipping. Intraoperative clip selection was documented and aneurysm occlusion rate was assessed by postoperative digital subtraction angiography. Nineteen patients were available for final analysis. In all patients, the most proximal clip at the aneurysm neck was the preselected clip. All aneurysms except one were fully occluded, as assessed by catheter angiography. One aneurysm had a small neck remnant that did not require secondary surgery and was occluded 15 months after surgery. 3D image-based preselection of a proper aneurysm clip can be translated to the operating room and avoids intraoperative clip selection. The associated occlusion rate of aneurysms is high.
相似文献Rationale
Autism spectrum disorders (ASDs) affect 1 % of children, having significant impact on health and social outcomes. Psychotropic medication use by individuals with ASD in the USA increased over time, and polypharmacy occurred in >50 % of those prescribed. In the UK, no psychotropic drugs are approved in ASDs, and little is known about patterns of pharmacological treatment in the ASD population and associated co-morbidities.Methods
We used The Health Improvement Network, a nationally representative primary care database, to assess the prevalence of ASD diagnoses, psychotropic drug prescribing and neuropsychiatric co-morbidities of 0–24 year olds between 1992 and 2008.Results
ASD prevalence increased 65-fold from 0.01 % (1992) to 0.50 % (2008). Psychotropic drugs were prescribed to 29 % (1,619/5,651) of the ASD cohort; the most prescribed drugs were sleep medication (9.7 % of prescribed patients), psychostimulants (7.9 %) and antipsychotics (7.3 %). More patients were given psychostimulants and sleep medications over time from 1.5–6.3 % and 2.2–5.9 % respectively. Thirty-seven per cent of the cohort had ≥1 record of a neuropsychiatric co-morbidity, the most common being developmental difficulties and learning disabilities (12.6 %), behavioural, conduct and personality disorders (11.1 %) and attention deficit hyperactivity disorder (7.5 %).Conclusions
British physicians are more conservative in prescribing practice than American colleagues. However, use of psychostimulants and antipsychotics is much higher in those with ASD than in the general population. Polypharmacy was seen in 34 % of prescribed patients in 2008. Additional studies examining use, efficacy, and long-term safety of antipsychotics and psychostimulants in autistic individuals are warranted. 相似文献Grandparents play a vital role in providing childcare to families. Qualitative research and evidence from parents raise concerns that it is grandparents who are socio-economically disadvantaged who provide grandchild care more regularly, perform more intensive tasks, and care out of financial necessity. However, no European studies have investigated these issues at population level. This study is based on grandparents aged 50+ who looked after grandchildren. Data are from wave 8 of the nationally representative English Longitudinal Study of Ageing (2016/2017). We exploit newly collected information on frequency of grandchild care, activities, and reasons for care. Using multinomial regressions, we first examined the extent to which grandparents’ socio-economic characteristics (wealth and education) are associated with frequency of grandchild care. Second, using logistic regressions, we investigated whether wealth and education are associated with activities and reasons for grandchild care. Overall, grandparents from disadvantaged socio-economic backgrounds were more likely to provide more regular childcare. Similarly, grandparents in the lowest wealth quartile were more involved in hands-on activities (cooking, taking/collecting grandchildren to/from school), whereas highly educated grandparents were more likely to help grandchildren with homework. Finally, better-off grandparents were more likely to look after grandchildren to help parents and provide emotional support and less likely to report difficulty in refusing to provide care. Our findings show that grandparental childcare varies by socio-economic status with more intensive childcare activities falling disproportionately on those with fewer resources, and this may act to exacerbate existing socio-economic inequalities in later life.
相似文献