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   875篇
  免费   63篇
  国内免费   24篇
耳鼻咽喉   1篇
儿科学   31篇
妇产科学   17篇
基础医学   72篇
口腔科学   19篇
临床医学   126篇
内科学   238篇
皮肤病学   41篇
神经病学   59篇
特种医学   105篇
外科学   65篇
综合类   72篇
预防医学   37篇
眼科学   20篇
药学   27篇
中国医学   1篇
肿瘤学   31篇
  2021年   5篇
  2018年   5篇
  2017年   6篇
  2016年   12篇
  2015年   12篇
  2014年   21篇
  2013年   61篇
  2012年   7篇
  2011年   16篇
  2010年   34篇
  2009年   30篇
  2008年   13篇
  2007年   39篇
  2006年   18篇
  2005年   15篇
  2004年   16篇
  2003年   14篇
  2002年   14篇
  2001年   15篇
  2000年   16篇
  1999年   20篇
  1998年   53篇
  1997年   48篇
  1996年   38篇
  1995年   28篇
  1994年   33篇
  1993年   36篇
  1992年   9篇
  1991年   10篇
  1990年   15篇
  1989年   38篇
  1988年   20篇
  1987年   25篇
  1986年   22篇
  1985年   9篇
  1984年   11篇
  1983年   8篇
  1982年   9篇
  1981年   12篇
  1980年   10篇
  1977年   5篇
  1976年   7篇
  1975年   6篇
  1966年   4篇
  1965年   4篇
  1963年   6篇
  1962年   5篇
  1960年   5篇
  1955年   4篇
  1941年   11篇
排序方式: 共有962条查询结果,搜索用时 0 毫秒
41.
维生素K3粉末降解动力学   总被引:1,自引:0,他引:1  
在温度为50~90℃,相对湿度为50~93%范围内,维生素K3的变色速率方程为—dR/dt=kRR,降解速率方程为d(Co—c)/dt=kC(co—c)1/2,光解速率方程为—dR/dt=kP(Ro—R)-1。kRC与热力学温度T和相对湿度RH的关系通式为k=k′exp(—EA/RT)exp(m′RH)。在实验温度和湿度范围内,变色和降解的表观活化能平均值分别为105.51和130.72 kJ/mol。  相似文献   
42.
Head injury in child abuse: evaluation with MR imaging   总被引:3,自引:0,他引:3  
To evaluate the usefulness of magnetic resonance (MR) imaging in the diagnosis of head injury in child abuse, the authors compared the findings at head MR imaging and computed tomography (CT) in 19 abused children. Subdural hematomas (15 cases), cortical contusions (six cases), and shearing injuries (five cases) were demonstrated to particular advantage with MR imaging. CT remained superior in the detection of subarachnoid hemorrhage. MR imaging appears to be valuable in the assessment of patients with suspected intracranial injury due to child abuse.  相似文献   
43.
44.
The Ben Lewin film The Sessions has drawn attention again to the potential role for sexual surrogate partners and sex workers in enabling persons with disabilities and impairments to give expression to their sexual needs and desires. However, away from the big screen, the ethics of registered health practitioners in themselves engaging in such therapies are highly problematic. Difficult too is the role of such practitioners in being ‘the therapist’ responsible for enabling or brokering sexual contact between their patients and those offering such services for financial reward. In some jurisdictions, arrangements involving sexual surrogate therapy (especially where the therapist benefits from it financially) may not be lawful. Further, in spite of many assertions one way and the other, there are no data enabling evaluation of the success rates of the interventions of sexual surrogates or sex workers. Whether positive outcomes to such interactions are likely in most circumstances, given that the provision of services is predicated upon idealised attachments, is questionable. It is also unclear whether sexual surrogates’ adherence to an ethical code effectively ameliorates the potential for counter-therapeutic consequences from the commodification of intimacy, and it is far from straightforward to identify what steps should be taken by the referring health practitioner to select a suitable provider of sexual services to their patient or client, and then to monitor whether the arrangement is achieving its objectives.  相似文献   
45.
46.
Arguably, Australia's most significant judicial pronouncement on the human rights of those with mental illnesses was made in 2009 by Justice Bell, the then President of the Victorian Civil and Administrative Tribunal (“VCAT”). The decision is an exhaustive analysis of the application of the Charter of Human Rights and Responsibilities Act 2006 (Vic) to the involuntary status of a person subject to a community treatment order in Victoria. It occurred in the context of delays in the conduct of reviews of the status of a mentally ill person by Victoria's Mental Health Review Board (“the Board”). The outcome of the hearing was a declaration that the Board had breached the person's human rights to a fair hearing, even though the person's involuntary status on a community treatment order was not disturbed by VCAT. Whilst some important aspects of Justice Bell's decision concerning the general methodology to be applied when analysing human rights were overturned in the subsequent Court of Appeal decision of R v Momcilovic [2010] VSCA 50, the latter decision did not concern mental health and so leaves Kracke as the most detailed articulation and analysis of human rights within this difficult sphere.  相似文献   
47.
K-Ⅱ系k阿片激动剂U-50488的同类物。通过部分离体和整体实验比较了K-Ⅱ与U-50488的药理作用。实验发现,K-Ⅱ抑制电刺激兔输精管收缩的IC50值为0.42 nmol/L,U-50488为26.5 nmol/L;K-Ⅱ抑制小鼠运动功能(横筛法)的ED50值为1.7 mg/g,U-50488为15.3 mg/kg;K-Ⅱ的小鼠LD50值为152.5 mg/kg,U-50488为118.4 mg/g;K-Ⅱ明显降低小鼠自发活动的作用比U-50488强5倍。结果表明,K-Ⅱ是一个药理作用较U-50488强的k受体激动剂。  相似文献   
48.
49.
The recent Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC) reiterated long-standing recommendations that Stage 1 hypertension (BP ≥ 140/90 mm Hg) without comorbidity should be treated initially with diuretics (DI) or beta blockers (BB). Yet market research suggests that many physicians prefer to use other drug classes, such as calcium channel blockers and ACE inhibitors.
OBJECTIVES: To explore the determinants of therapeutic choice in hypertension.
METHODS: We surveyed by mail a stratified random sample of 10,000 U.S. cardiologists, internists, and family/general practitioners. Physicians were queried about their practice environment and their knowledge, attitudes, and practices regarding antihypertensive therapy, including their choice of drugs to treat patients with specified clinical profiles. The probability that physicians would follow JNC guidelines Stage 1 hypertension was analyzed using multiple logistic regression with stepwise backward elimination to select variable with p < 0.001.
RESULTS: Completed surveys were received from 1,023 physicians. 86.7% prescribe drug therapy for Stage 1 hypertension, and 19.5% (22.5% of drug prescribers) limit their choices to DI and BB. Guideline conformity was higher among physicians who: practice in academic medical centrers; are older; are general practitioners (versus general internists); have smaller caseloads; have fewer hypertensive patients; have higher proportions of HMO, Medicaid, and uninsured patients; and experience more formulary restrictions. Cardiologists and family practitioners were less likely than internists to follow guidelines.
CONCLUSION: JNC guidelines are better accepted by academic physicians, older physicians who have more expenence using DI and BB, physicians with smaller caseloads and hence more time for follow-up and therapy adjustment, and physicians who face drug reimbursement constraints.  相似文献   
50.
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