全文获取类型
收费全文 | 2551篇 |
免费 | 295篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 70篇 |
妇产科学 | 21篇 |
基础医学 | 465篇 |
口腔科学 | 107篇 |
临床医学 | 242篇 |
内科学 | 575篇 |
皮肤病学 | 36篇 |
神经病学 | 245篇 |
特种医学 | 137篇 |
外科学 | 285篇 |
综合类 | 63篇 |
一般理论 | 2篇 |
预防医学 | 190篇 |
眼科学 | 24篇 |
药学 | 114篇 |
中国医学 | 2篇 |
肿瘤学 | 269篇 |
出版年
2021年 | 33篇 |
2020年 | 21篇 |
2019年 | 30篇 |
2018年 | 33篇 |
2017年 | 27篇 |
2016年 | 45篇 |
2015年 | 37篇 |
2014年 | 50篇 |
2013年 | 80篇 |
2012年 | 83篇 |
2011年 | 124篇 |
2010年 | 77篇 |
2009年 | 82篇 |
2008年 | 92篇 |
2007年 | 116篇 |
2006年 | 88篇 |
2005年 | 89篇 |
2004年 | 83篇 |
2003年 | 91篇 |
2002年 | 66篇 |
2001年 | 78篇 |
2000年 | 81篇 |
1999年 | 93篇 |
1998年 | 52篇 |
1997年 | 59篇 |
1996年 | 59篇 |
1995年 | 49篇 |
1994年 | 41篇 |
1993年 | 38篇 |
1992年 | 66篇 |
1991年 | 59篇 |
1990年 | 56篇 |
1989年 | 62篇 |
1988年 | 53篇 |
1987年 | 59篇 |
1986年 | 45篇 |
1985年 | 34篇 |
1984年 | 44篇 |
1983年 | 27篇 |
1982年 | 26篇 |
1981年 | 28篇 |
1980年 | 20篇 |
1979年 | 28篇 |
1978年 | 29篇 |
1977年 | 32篇 |
1976年 | 24篇 |
1975年 | 22篇 |
1974年 | 19篇 |
1973年 | 18篇 |
1922年 | 22篇 |
排序方式: 共有2858条查询结果,搜索用时 15 毫秒
1.
2.
3.
Miriam Stewart Linda Reutter Edward Makwarimba Irving Rootman Deanna Williamson Kim Raine Doug Wilson Janet Fast Rhonda Love Sharon McFall Deana Shorten Nicole Letourneau Karen Hayward Jeff Masuda William Rutakumwa 《Revue canadienne de recherche en sciences infirmières》2005,37(3):104-131
Poverty influences health status, life expectancy, health behaviours, and use of health services. This study examined factors influencing the use of health-related services by people living in poverty. In the first phase, 199 impoverished users of health-related services in 2 large Canadian cities were interviewed by their peers. In the second phase, group interviews with people living in poverty (n = 52) were conducted. Data were analyzed using thematic content analysis. Diverse health-related services were used to meet basic and health needs, to maintain human contact, and to cope with life's challenges. Use of services depended on proximity, affordability, convenience, information, and providers' attitudes and behaviours. Use was impeded by inequities based on income status. To promote the health of people living in poverty, nurses and other health professionals can enhance the accessibility and quality of services, improve their interactions with people living in poverty, provide information about available programs, offer coordinated community-based services, collaborate with other sectors, and advocate for more equitable services and policies. 相似文献
4.
5.
6.
Lawrence Watkins Richard Hayward Unday Andar William Harkness 《Child's nervous system》1994,10(2):87-90
A prospective study was undertaken of all children referred to the Hospital for Sick Children with a provisional diagnosis of shunt blockage over a 5-month period. Fifty-two admissions were recorded, relating to 45 children, 5 of whom had multiple admissions. Only 19 of the 52 admissions led to a final diagnosis of shunt malfunction. No source of referral, whether by the child's general practitioner or from another hospital, was found to be more accurate than direct referral by the parents to the neurosurgical ward. Headache, vomiting and irritability were not significant indicators as to whether the child's shunt was actually blocked, and nor was the duration of the symptoms. Drowsiness was a significant, but not definite, indicator of shunt blockage, while pyrexia made it more likely that the patient had an alternative diagnosis. In 35 of the admissions a computed tomographic scan was performed: a normal scan, unchanged from previous scans, did not reliably exclude the diagnosis of shunt blockage. Percutaneous manometry via the reservoir of the shunt system was performed during 26 admissions: this investigation produced no false positives nor false negatives, but was equivocal in 5 cases, all of which were found at surgery to have a definite shunt blockage. The accuracy of the diagnosis of shunt blockage made prior to referral to a neurosurgical unit is discussed, together with the implications for resource use. 相似文献
7.
A series of novel, highly potent and selective agonists for the kappa-opioid receptor. 总被引:4,自引:4,他引:0
下载免费PDF全文
![点击此处可从《British journal of pharmacology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A. G. Hayes P. J. Birch N. J. Hayward M. J. Sheehan H. Rogers M. B. Tyers D. B. Judd D. I. Scopes A. Naylor 《British journal of pharmacology》1990,101(4):944-948
1. This paper describes the opioid receptor pharmacology and in vivo activity of several novel benzene-acetamidopiperidine and benzeneacetamidopiperazine analogues. 2. These compounds all showed potent, naloxone-reversible, full agonist activity in the field-stimulated rabbit vas deferens, indicating that they are kappa-opioid agonists; but showed very little activity in the rat or hamster vas deferens, indicating good selectivity with regard to mu- and delta-opioid receptors. 3. They were all potent antinociceptive agents, the most potent compound, GR 103545, having an ED50 value in the mouse abdominal constriction test of 0.25 micrograms kg-1 s.c. The compounds also produced sedation and diuresis, but had little effect on respiration rate or gastrointestinal motility. 4. It is concluded that the seven novel compounds described are all potent and selective agonists for the kappa-opioid receptor. 相似文献
8.
Premature fusion of cranial sutures in craniosynostosis has been thought to lead to craniostenosis, which in turn may lead to increased intracranial pressures. In 41 consecutive patients with craniosynostosis, intracranial pressure and intracranial volume were measured. Of the 41 patients, 38 (92.6%) had raised intracranial pressure but only 4 (9.7%) had a decreased skull volume. In the present study, there is no correlation between intracranial volume and intracranial pressure. This study confirms that the measurement of intracranial volume, a non invasive procedure, cannot be used to assess intracranial pressure and to avoid an invasive procedure. 相似文献
9.
Fifty-seven schizophrenic patients were initially assessed after admission to hospital, at which time their parents completed a Camberwell Family Interview, generating "expressed emotion" (EE) scores. Relapse over the next nine months was not predicted by household EE status or by individual EE scales. Multivariate analyses suggested that a poor course after hospitalization was best predicted by a poor course before admission and by living in a one-parent household. High household EE status was a predictor only in one multivariate analysis after course of illness and one-parent household status had been entered, suggesting an interaction effect. We query the causal proposition linking high EE and relapse and suggest instead that a poor illness course may elicit high EE in relatives, particularly in one-parent households, and, thus, may make the principal contribution to the proposed link. 相似文献
10.
Studies of proteins that inhibit tissue factor activity have generally been conducted using either an extracted tissue homogenate ("thromboplastin") or tissue factor protein reconstituted into phospholipid vesicles rather than with tissue factor expressed in cell membranes (its physiological environment). In the present study, a human fibroblast cell strain was used to evaluate the effects of lipoprotein associated coagulation inhibitor (LACI), placental anticoagulant protein (PAP), and apolipoprotein A-II (apo A-II) on human tissue factor in cell membranes. LACI was tested from 7.8 to 500 pmol/L on fibroblasts cultured at cell densities ranging from 3,500 to 9,925 cells/well, and caused a progressive inhibition of tissue factor activity. PAP was tested from 3.9 nmol/L to 1 mumol/L at cell densities ranging from 4,500 to 15,400 cells/well and caused up to 83% inhibition of tissue factor activity. Inhibition by these proteins appeared to be influenced by cell density as well as whether the cells were intact or disrupted. Apo A-II, up to 1 mumol/L, did not inhibit the tissue factor activity of intact or disrupted fibroblasts at any cell density examined even though it did inhibit the activity of tissue factor in phospholipid vesicles. Of these inhibitors of tissue factor-dependent activation of factor X, LACI was the most effective in suppressing the generation of factor Xa activity. The effects obtained with apo A-II are clearly dependent on the nature of the tissue factor preparation with which it is tested. The disparity between the inhibitory effect of apo A-II on the activity of tissue factor reconstituted into lipid vesicles and the absence of effect on the activity of tissue factor remaining in cell membranes serves to reemphasize the necessity of reexamining results obtained with model systems using as nearly physiological reagents as possible. 相似文献