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   755篇
  免费   58篇
  国内免费   20篇
耳鼻咽喉   5篇
儿科学   19篇
妇产科学   27篇
基础医学   94篇
口腔科学   15篇
临床医学   59篇
内科学   133篇
皮肤病学   8篇
神经病学   84篇
特种医学   111篇
外科学   83篇
综合类   36篇
预防医学   47篇
眼科学   9篇
药学   65篇
中国医学   1篇
肿瘤学   37篇
  2021年   7篇
  2019年   8篇
  2018年   6篇
  2017年   6篇
  2016年   7篇
  2015年   20篇
  2014年   22篇
  2013年   26篇
  2012年   27篇
  2011年   27篇
  2010年   27篇
  2009年   24篇
  2008年   32篇
  2007年   37篇
  2006年   37篇
  2005年   32篇
  2004年   27篇
  2003年   18篇
  2002年   21篇
  2001年   25篇
  2000年   22篇
  1999年   16篇
  1998年   24篇
  1997年   23篇
  1996年   16篇
  1995年   8篇
  1994年   12篇
  1993年   17篇
  1992年   13篇
  1991年   15篇
  1990年   9篇
  1989年   15篇
  1988年   14篇
  1987年   19篇
  1986年   12篇
  1985年   14篇
  1984年   11篇
  1983年   13篇
  1982年   9篇
  1979年   10篇
  1978年   9篇
  1977年   8篇
  1976年   4篇
  1975年   4篇
  1974年   14篇
  1973年   4篇
  1972年   7篇
  1971年   7篇
  1969年   5篇
  1961年   4篇
排序方式: 共有833条查询结果,搜索用时 31 毫秒
1.
2.
3.
Obstructed voiding is a well recognized complication following a suburethral sling procedure. Current methods of transvaginal and transabdominal urethrolysis have had variable success rates in relieving the obstruction, and do not restabilize the urethra to prevent potential postoperative stress incontinence. We report on a procedure used in 4 cases which addresses both of these issues. All patients had persistent urinary retention beyond 8 weeks after a suburethral sling procedure. An oupatient procedure consisting of sling incision and associated tissue interposition (vaginal wall in three cases and fascia lata in one) was successful in relieving the obstruction. Continence status was maintained in 3 of the 4 patients. There were no major complications of this outpatient procedure.  相似文献   
4.
This paper reports a survey of program evaluation and service monitoring activity in 49 Victorian community health centres. Centres generally have not made evaluation and monitoring an important part of their operations despite the rhetoric of health services policy makers and administrators. Reasons for this include a lack of staff in centres who are trained in evaluation methods; the reluctance of centre staff to divert time and resources from service provision to evaluation; and insufficient assistance to centres from the Health Commission of Victoria. “The assumptions that operating a service is equivalent to rendering service and that both are equivalent to rendering quality service are no longer being honoured as inherently valid.”1  相似文献   
5.
The actions of the neurotoxic amino acids folate and kainate have been compared on ortho-and antidromic responses evoked in CA1, CA3 and the dentate gyrus of slices of rat hippocampus maintained in vitro. Both in CA1 and the dentate gyrus superfusion of these acids caused an increase in amplitude of the population spike discharging from an excitatory postsynaptic potential which either remained unaffected or was reduced. In the CA3 region kainate and folate had broadly similar actions to enhance the probability of cell firing to synaptic excitation, and also caused epileptiform discharges to occur spontaneously or in response to electrical stimulation. Spontaneous and evoked population bursts in CA3 did not persist in low calcium/high magnesium medium indicating their dependence on intact synaptic transmission; spontaneously occurring bursts in CA1 were eliminated with the latter treatment or when the axonal connections between it and CA3 were cut. Following folate superfusion the commissural-evoked response in CA3 showed large and variable shifts of the latency which were dependent on the stimulus intensity and its timing after a spontaneous population discharge. Although all of the effects of folate were reproduced by bicuculline, no evidence for a decreased recurrent inhibition in CA1 was obtained although this was observed with kainate. The finding that folate and kainate produced their effects in the absence of a detectable effect on the antidromic population spike suggests a mechanism of action other than neuronal depolarization. The implications of these data for the neurotoxic mechanism(s) and the receptor homologies of folate and kainate are discussed.  相似文献   
6.
The function of the normal conformational isoform of prion protein, PrP(C), remains unclear although lines of research have suggested a role in the cellular response to oxidative stress. Here we investigate the expression of PrP(C) in hypoxic brain tissues to examine whether PrP(C) is in part regulated by neuronal stress. Cases of adult cerebral ischemia and perinatal hypoxic-ischemic injury in humans were compared with control tissues. PrP(C) immunoreactivity accumulates within neuronal processes in the penumbra of hypoxic damage in adult brain, and within neuronal soma in cases of perinatal hypoxic-ischemic injury, and in situ hybridization analysis suggests an up-regulation of PrP mRNA during hypoxia. Rodents also showed an accumulation of PrP(C) in neuronal soma within the penumbra of ischemic lesions. Furthermore, the infarct size in PrP-null mice was significantly greater than in the wild type, supporting the proposed role for PrP(C) in the neuroprotective adaptive cellular response to hypoxic injury.  相似文献   
7.
A peripheral blood smear from a patient with probable splenic lymphoma with villous lymphocytes (SLVL) showed clumping of lymphoma cells. The clumping was not seen in films made from unanticoagulated blood, and has not been previously described in lymphomas. The patient also had metastatic prostatic adenocarcinoma for 30 months before lymphoma was diagnosed and the clumped cells posed diagnostic problems.  相似文献   
8.
L Gasmi  A G McLennan    S W Edwards 《Immunology》1997,90(1):154-159
The diadenosine polyphosphates diadenosine 5',5"'-P1,P3-triphosphate (Ap3A), diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A), diadenosine 5',5"'-P1,P5-pentaphosphate (Ap5A) and diadenosine 5',5"'-P1,P6-hexaphosphate (Ap6A) all stimulated increases in intracellular Ca2+ in human neutrophils. Maximal increases in intracellular Ca2+ of 650 nM were obtained at dinucleotide concentrations of 500-700 microM. These increases in intracellular, Ca2+ were completely abolished by pre-treatment of the neutrophils with pertussis toxin and were hardly affected when the extracellular buffer was devoid of Ca2+. On the other hand, adenosine triphosphate (ATP) could stimulate much greater increases in intracellular Ca2+ (up to 1.1 microM) at much lower concentrations (half maximal responses obtained at around 5 microM ATP). Receptor de-sensitization experiments indicate that human neutrophils may possess two types of P2-purinoceptors. The first of these may bind ATP (but not the dinucleotides) with high affinity whilst the second may bind the dinucleotides with lower affinity and also bind ATP.  相似文献   
9.
Confusion still exists about the roles and functions of social workers in the mental health care system. The authors discuss this role ambiguity and its effects. They then present and discuss the findings of a study that explored the current role of the social worker in Ontario psychiatric hospitals with the following objectives: to document social workers' major roles and activities; to assess role satisfaction; to assess involvement in decision making; and to identify major types of therapy used.  相似文献   
10.
Most of the biological actions of the circulating (a.k.a., the systemic or blood-borne) renin-angiotensin system require the generation of the octapeptide angiotensin (ANG) II from the decapeptide ANG I. In the case of circulating ANG I, the lungs are generally considered the major site for this conversion. The present experiments explored the possibility that under conditions of marked elevations of blood-borne ANG I, the generation of ANG II takes place within brain-associated target tissues, most notably circumventricular organs (CVOs) that lack a blood-brain barrier. The first important result of these experiments demonstrates that intracerebroventricular (i.c.v.) infusion of the converting enzyme inhibitor, captopril, completely blocks the drinking response and significantly attenuates the pressor response produced by systemically infused ANG I. This result indicates that under physiological/pathophysiological conditions associated with large elevations of circulating ANG I, an important part of the biological responses derived from blood-borne ANG may result from local conversion of ANG I to ANG II within specific brain target tissues which have high concentrations of converting enzyme. This local conversion process provides an important mechanism that would act to reinforce the "classic" conversion process which takes place in the lungs thereby delivering more ANG II immediately to central target receptors. The second important finding from these studies showed that drinking produced by systemically infused ANG II was not attenuated by an i.c.v. dose of captopril which was effective in blocking a comparable dipsogenic response induced by i.v. ANG I. This observation suggests that drinking induced by systemic ANG II does not require an intact metabolic cascade within the brain for the formation of ANG II (or ANG II-like effector peptide) from ANG I.  相似文献   
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