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   467篇
  免费   41篇
  国内免费   1篇
耳鼻咽喉   10篇
儿科学   21篇
妇产科学   5篇
基础医学   79篇
口腔科学   5篇
临床医学   85篇
内科学   54篇
皮肤病学   2篇
神经病学   79篇
特种医学   21篇
外科学   61篇
综合类   16篇
预防医学   22篇
眼科学   5篇
药学   22篇
中国医学   1篇
肿瘤学   21篇
  2021年   7篇
  2018年   5篇
  2017年   5篇
  2016年   6篇
  2015年   9篇
  2014年   4篇
  2013年   7篇
  2012年   11篇
  2011年   18篇
  2010年   13篇
  2009年   5篇
  2008年   11篇
  2007年   15篇
  2006年   19篇
  2005年   14篇
  2004年   21篇
  2003年   19篇
  2002年   12篇
  2001年   19篇
  2000年   18篇
  1999年   22篇
  1998年   20篇
  1997年   16篇
  1996年   17篇
  1995年   9篇
  1994年   4篇
  1993年   12篇
  1992年   15篇
  1991年   12篇
  1990年   12篇
  1989年   13篇
  1988年   8篇
  1987年   10篇
  1986年   8篇
  1985年   7篇
  1984年   4篇
  1983年   8篇
  1982年   7篇
  1981年   7篇
  1978年   5篇
  1977年   4篇
  1976年   6篇
  1975年   4篇
  1974年   9篇
  1973年   2篇
  1972年   2篇
  1969年   2篇
  1966年   2篇
  1875年   6篇
  1871年   3篇
排序方式: 共有509条查询结果,搜索用时 15 毫秒
51.
Aims and objectives. This element of the larger Scottish evaluation aimed to explore differences between access routes, cohorts and higher education institutes (HEI) (universities and colleges) in levels of self‐efficacy, student support and self‐reported competence in a nationally representative sample of student nurses and midwives. Background. This paper reports findings from the National Review of Pre‐Registration Nursing and Midwifery Programmes in Scotland. Fitness for practice curricula have been the heart of many recent developments in nurse and midwifery education. Fitness for practice set out to map out the future direction of preregistration nursing and midwifery education with the aim of ensuring fitness for practice based on healthcare need. There have been no national evaluations of the effectiveness of this strategic objective. Previous major evaluations in the 1990s suggested that students may not have had the skills needed to be fit for practice. Design. The study design was a cross‐sectional survey of a stratified random sample of student nurses and midwives (n = 777). Data collected included demographic information, generalised perceived self‐efficacy, student support and self‐reported competency. Results. Students reported high levels of self‐reported competency. There were no significant differences between two cohorts or between students with different access routes. Students rated support from family and friends highest and support from HEI lowest. There was a significant difference in support levels between HEI. Self‐efficacy scores were similar to other population means and showed small‐moderate correlations with self‐report competence. Similarly, self‐reported competency appears to be at the higher end of the spectrum, although older students may have a more realistic perception of their competence. However, support from HEI was seen as less satisfactory and varied from one institution to another. Conclusions. This study portrays a relatively positive picture of preregistration fitness for practice curricula. Questions are raised about the relative value students place on support from educationalists and mentors and whether support from family and friends and from peers needs to feature more prominently in curricula. The study provides modest support for social cognitive theory. Relevance to clinical practice. The major drivers for changes in preregistration curricula stemmed from fears about the competence of students. This study did not provide support for this viewpoint, and students’ self‐reports suggest that curricula are, in this respect, meeting their objectives. Nevertheless support from mentors and from educational institutes may need to be improved.  相似文献   
52.
The aims of this study were, through secondary data analysis, to establish consultation rates for self‐neglect by 100 000 of the Scottish population and by deprivation and to identify the main comorbidities associated with self‐neglect. Data from a national dataset recording consultations in general practices where a self‐neglect diagnoses was made were analysed. Rates of self‐neglect in patients who consulted a Practice Nurse or General Medical Practitioners vary over time. Self‐neglect is more common in the 75 years and over group but is found across the age spectrum. It is more common in males and is linked to higher levels of deprivation. Self‐neglect is recorded as a diagnosis relatively infrequently in general practice. A wide range of comorbid conditions are found coexisting with self‐neglect. Nurse interventions generally focus on comorbidities and not self‐neglect. Self‐neglect does present in primary care. Nurses need to be aware of its varied presentations. Practice Nurse interventions suggest we need to develop self‐management interventions rather than respond to associated comorbid conditions.  相似文献   
53.
An in situ hybridization technique has been developed for the detection of immunoglobulin light chain mRNA in routine pathology specimens. The method detects kappa or lambda constant region sequences using a cocktail of synthetic oligonucleotide probes labelled with biotin or fluorescein 5-isothiocyanate (FITC) reporter molecules. The probes were labelled at flanking sites chemically by primary amine directed acylation and by 'homopolymer tailing' with terminal deoxynucleotidyl transferase using non-radioactive nucleotide analogues. The mRNA was unmasked in the formalin-fixed tissue sections by digestion with varying concentrations of proteinase K, and the hybrids were demonstrated using alkaline phosphatase with either a streptavidin/biotin based four-stage system or an anti-FITC antibody based detection system. Alkaline phosphatase was visualized using a Fast Red naphthol-capture method and the sections were counterstained with haematoxylin. The results confirm that the method is specific for kappa or lambda mRNA and show that specific mRNAs can be detected in routine formalin-fixed sections using non-radioactive techniques with retention of good morphology. The method reliably detects light chain mRNA in cells expressing secretory immunoglobulin. The protocol can also be applied to tissue rich in endogenous biotin by using hapten-labelled probes.  相似文献   
54.
In situ hybridization techniques were used to detect immunoglobulin light chain messenger RNA (mRNA) in 28 formalin-fixed, paraffin-embedded samples of Hodgkin's disease. Cocktails of biotinylated oligonucleotide probes specific for the constant regions of kappa and lambda light chain mRNA were used. None of the Reed-Sternberg cells or their variants in any of the cases studied showed positive staining with either probe, in contrast to normal plasma cells which showed strong staining in the same sections. It was concluded, therefore, that the cytoplasmic immunoglobulin frequently detected within these cells by immunocytochemistry is present not as a result of synthesis, but as a result of some other mechanism.  相似文献   
55.
56.
BACKGROUND AND PURPOSE: Hitherto, treatment of acute cerebral hemorrhage with intravenous glycerol has not been evaluated in rigorous clinical studies with sufficient patient numbers. METHODS: We undertook a double-blind, stratified and randomized, placebo-controlled clinical trial. Only patients with a first stroke admitted to the hospital within 24 hours after onset of symptoms were recruited, provided computed tomography confirmed hemorrhage and informed consent was obtained. After stratification into alert, semicoma, and coma subgroups using the Glasgow Coma Scale, 107 patients received active treatment (500 ml of 10% glycerol in saline by intravenous infusion over 4 hours on 6 consecutive days) and 109 were given corresponding saline treatment. Using a variety of objective scoring systems, patients were followed up for up to 6 months. RESULTS: At follow-up, all measures of outcome in the treated and control groups were very similar. At 6 months, respective mortality rates were 37 of 107 and 33 of 109. Corresponding mean +/- SD improvements in Scandinavian Stroke Study Group scores were 8.35 +/- 16.9 versus 11.55 +/- 15.6 (long-term) and 0.64 +/- 7.3 versus 2.40 +/- 6.9 (prognostic), and improvements in the Barthel Index ratings were 10.72 +/- 24.7 versus 13.95 +/- 23.3, respectively. Glasgow Coma Scale score improvements in the survivors were 0.81 +/- 1.5 and 1.16 +/- 1.7 in the treated and control groups, respectively. Hemolysis (generally subclinical) was the only adverse effect of glycerol noted. CONCLUSIONS: In the absence of any clinically or statistically significant difference in outcome between the treated and control groups, this trial provides no justification for glycerol therapy following acute cerebral hemorrhage.  相似文献   
57.
Mantle zone lymphoma—is it an entity?   总被引:1,自引:0,他引:1  
  相似文献   
58.
OBJECTIVE: To determine the effectiveness of medical history and physical examination in predicting electrodiagnostic outcome in patients with suspected cervical radiculopathy. METHODS: Data on 183 subjects prospectively collected at five different electrodiagnostic laboratories were analyzed (96 cervical radiculopathies, 45 normal studies, and 42 abnormal electrodiagnostic findings other than radiculopathy). The sensitivity, specificity, positive predictive value, negative predictive value, and odds ratios were determined for symptoms and neurologic signs. RESULTS: Symptoms of numbness, weakness, and tingling were associated with twice the probability of having abnormal electrodiagnostic study results in general, yet were not helpful in identifying a cervical radiculopathy. All single and combined physical examination components had poor sensitivities, with the exception of weakness, but much higher specificities. Patients with either weakness or reduced reflexes on physical examination were up to five times more likely to have abnormal electrodiagnostic findings. In subjects with any abnormal neurologic sign, the sensitivity improved to 84%, the positive predictive value was 79%, but the specificity was low (44%). Of those subjects with normal physical examination results, almost one half had an abnormal electrodiagnostic study result (negative predictive value 52%). CONCLUSIONS: In a population of patients with suspected cervical radiculopathy, medical history and physical examination are helpful yet not sufficient to predict the electrodiagnostic outcome.  相似文献   
59.
Interleukin-8 (IL-8) is a chemoattractant cytokine involved in chemotaxis and activation of neutrophils. Because in vivo administration of IL-8 induces mobilization of hematopoietic stem cells in mice, we assessed the mobilizing properties of IL-8 in rhesus monkeys. Recombinant human IL-8 was administered as a single intravenous injection at doses of 10, 30, and 100 micrograms/kg to rhesus monkeys (age, 2 to 3 years; weight, 2.5 to 4.5 kg). Venous blood samples were obtained at time intervals ranging from 1 to 480 minutes after IL-8 administration. Cell counts, colony-forming unit-Mix assays, and fluorescence-activated cell sorter analysis were performed. Plasma was harvested to assess IL-8 levels. A time-controlled bolus intravenous injection of 100 micrograms IL-8 per kilogram of body weight resulted in peak IL-8 plasma levels up to 5 micrograms/mL. The calculated half-time life of free IL-8 was 9.9 +/- 2.2 minutes. IL-8 injection resulted in instant neutropenia that was due to pulmonary sequestration, as shown using 99mTc-labeled leukocytes. Within 30 minutes after IL-8 injection, neutrophilia developed with counts up to 10-fold greater than baseline levels. The numbers of hematopoietic progenitor cells (HPCs) increased from 45 +/- 48/mL to 1,382 +/- 599/mL of blood at 30 minutes after injection of 100 micrograms IL-8 per kilogram of bodyweight (mean +/- SD, n = 8). Individual animals showed 10- to 100-fold increase in numbers of circulating HPCs that returned to almost pretreatment values (92 +/- 52 CFU/mL) at 240 minutes after the injection of IL-8. Immunophenotyping showed no significant changes in lymphocyte (sub)populations. A second bolus injection of IL-8 with an interval of 72 hours resulted in similar numbers of mobilized stem cells as observed after the first injection, showing that no tachyphylaxis had occurred. We conclude that IL-8 induces mobilization of HPCs from the bone marrow of rhesus monkeys in a rapid and reproducible fashion. Therefore, IL-8 may be a potentially useful cytokine in the setting of blood stem cell transplantation.  相似文献   
60.
The prognosis for patients with hepatocellular carcinoma (HCC) is poor because of the low chance of curative treatment. To increase the chance of intervention and to improve survival, early detection of subclinical HCC (SCHCC) by alpha-fetoprotein (AFP) and/or ultrasonography (USG) screening is implemented in many countries. Three hundred six Chinese patients with HCC diagnosed between January 1995 and December 1997 were recruited. They were categorized into two groups: 142 patients (group 1) had SCHCC diagnosed by screening (AFP and/or USG), and 164 patients (group 2) presented with symptomatic HCC. The tumor size was significantly smaller in group 1 compared with that of group 2 (3.5 cm vs. 8.1 cm; P <.0001). A significantly higher proportion of patients had bilobar involvement, multifocal HCC, diffuse-type HCC, portal vein infiltration, and distant metastasis in group 2 when compared with group 1. Operability and feasibility of treatment by transcatheter intra-arterial chemoembolization (TACE) in group 1 patients (26.8% and 45.1%, respectively) were significantly better than in group 2 patients (7.9% and 32.3%, P <.0001 and P =.03, respectively). The cumulative survival rate was significantly higher in group 1 than in group 2 (P <.0001). For those who had surgical resection and those who had TACE, group 1 patients had a higher cumulative survival rate compared with that of group 2 patients (P =.04 and P =.0003, respectively). Screening for HCC by AFP and/or USG can identify tumors at an early stage, resulting in a higher chance of receiving treatment. Whether it can improve survival requires a further prospective, randomized study.  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