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   376篇
  免费   20篇
  国内免费   12篇
儿科学   43篇
妇产科学   3篇
基础医学   24篇
口腔科学   10篇
临床医学   42篇
内科学   87篇
皮肤病学   6篇
神经病学   9篇
特种医学   70篇
外科学   21篇
综合类   17篇
预防医学   17篇
药学   37篇
肿瘤学   22篇
  2020年   3篇
  2019年   5篇
  2018年   8篇
  2017年   9篇
  2016年   3篇
  2015年   6篇
  2014年   11篇
  2013年   17篇
  2012年   13篇
  2011年   5篇
  2010年   21篇
  2009年   16篇
  2008年   4篇
  2007年   7篇
  2006年   13篇
  2005年   8篇
  2004年   7篇
  2003年   12篇
  2002年   3篇
  2001年   5篇
  2000年   7篇
  1999年   14篇
  1998年   30篇
  1997年   24篇
  1996年   26篇
  1995年   19篇
  1994年   18篇
  1993年   13篇
  1992年   5篇
  1991年   2篇
  1990年   6篇
  1989年   8篇
  1988年   5篇
  1987年   7篇
  1986年   8篇
  1985年   5篇
  1984年   4篇
  1983年   4篇
  1982年   4篇
  1981年   4篇
  1980年   1篇
  1979年   4篇
  1977年   3篇
  1976年   2篇
  1975年   1篇
  1972年   1篇
  1959年   2篇
  1958年   1篇
  1957年   1篇
  1950年   1篇
排序方式: 共有408条查询结果,搜索用时 15 毫秒
41.
Megaloblastic anaemia is uncommon in Hong Kong. Eighty-four consecutive Chinese patients with megaloblastic anaemia were studied. There were 48 males and 36 females, with a median age at presentation of 67 years. Vitamin B12 deficiency was found in all cases, with none of the patients showing folate deficiency. The frequency of pernicious anaemia in our patients was higher than in other south-east Asian series but comparable with western ones. When compared with patients in the West, our cases showed the following main differences: virtual absence of folate deficiency, even in alcoholics; absence of associated gastric malignancies; and a high frequency of tuberculosis.  相似文献   
42.
Resting neutrophils may be "primed" to augmented effector function, eg, superoxide (O2-) production in the respiratory burst, upon a second stimulation with a variety of soluble agonists including formylated methionyl-leucyl-phenylalanine (FMLP) and phorbol myristate acetate (PMA). At priming concentrations of FMLP (5 x 10(-9) mol/L) that did not initiate O2- generation, two metabolic activities were noted: (1) approximately a threefold increase in the baseline intracellular calcium (Ca++i) level, that was not dependent on extracellular Ca++, and (2) a rapid rise in intracellular pH that was blocked by 5-(N,N- dimethyl) amiloride (DA), that had no effect on the Ca++i response to priming. Furthermore, there were no significant increases in inositol metabolites in cells primed and stimulated with FMLP compared with cells receiving the stimulating dose of FMLP alone and pretreatment with pertussis toxin (PT) (before the addition of the priming -5 x 10(- 9) mol/L dose of FMLP), whereas abolishing the response to FMLP during the second stage of stimulation, had (1) no effect on FMLP-primed cells subsequently stimulated with PMA, and (2) only partially ablated the rise in Ca++i initiated with FMLP. That FMLP priming involved distinctive processes to those of the well characterized FMLP-coupled Ca++-dependent activation cascade was shown by the full priming effect attained in a Ca++-free buffer, which did not sustain an O2- response to a second-stage FMLP stimulation, but sustained a primed response to PMA. These data demonstrate that FMLP primes human neutrophils by a Ca++-independent and PT-insensitive pathway, offering a functional model for studying heterogeneous FMLP receptor-coupled reactions.  相似文献   
43.
44.
Dyspepsia is most optimally defined as pain or discomfort centred in the upper abdomen. The symptom complex may be caused by peptic ulcer disease, gastro-oesophageal reflux, or gastric cancer but is most often due to functional (or non-ulcer) dyspepsia. While upper endoscopy is the method of choice to determine the underlying cause of dyspepsia, it is expensive. A more pragmatic approach is needed in the Asia-Pacific region where health services are limited. A detailed treatment algorithm is given for managing patients presenting with new-onset dyspepsia and documented functional dyspepsia after endoscopy, and evidence to support this approach is reviewed. Prompt endoscopy is recommended for patients with alarm features. In patients without alarm features, treatment for 2–4 weeks with an empirical anti-secretory or prokinetic agent, followed by investigation using non-invasive Helicobacter pylori testing and treatment for patients who do not respond or relapse, is recommended. Trials of management strategies are now needed to establish the efficacy and cost-effectiveness of the approaches recommended.  相似文献   
45.

INTRODUCTION

The preliminary results of a pyrocarbon interpositional radiocarpal implant in a small cohort of patients were reviewed. As it is currently only a limited release product, we describe to potential users early complications and negative outcomes.

METHODS

Patients were assessed using pain levels, ranges of motion, grip strength, type of and time to return to work as well as pre-operative and post-operative DASH (Disabilities of the Arm, Shoulder and Hand) scores. Radiographs were taken and patient satisfaction was recorded.

RESULTS

All six patients were contacted. One was not satisfied. Three had reduced motion. None experienced squeaking. There were no immediate or late post-operative complications. There was one early volar displacement of an implant.

CONCLUSIONS

Although our early results are somewhat encouraging, further and longer studies are warranted before supporting the use of this particular pyrocarbon implant as a primary procedure.  相似文献   
46.
Understanding and identifying new ways of mounting an effective CD8+ T cell immune response is important for eliminating infectious pathogens. Although upregulated programmed death-1 (PD1) in chronic infections (such as HIV-1 and tuberculosis) impedes T cell responses, blocking this PD1/PD-L pathway could functionally rescue the “exhausted” T cells. However, there exists a number of PD1 spliced variants with unknown biological function. Here, we identified a new isoform of human PD1 (Δ42PD1) that contains a 42-nucleotide in-frame deletion located at exon 2 domain found expressed in peripheral blood mononuclear cells (PBMCs). Δ42PD1 appears to function distinctly from PD1, as it does not engage PD-L1/PD-L2 but its recombinant form could induce proinflammatory cytokines. We utilized Δ42PD1 as an intramolecular adjuvant to develop a fusion DNA vaccine with HIV-1 Gag p24 antigen to immunize mice, which elicited a significantly enhanced level of anti-p24 IgG1/IgG2a antibody titers, and important p24-specific and tetramer+CD8+ T cells responses that lasted for ≥7.5 months. Furthermore, p24-specific CD8+ T cells remain functionally improved in proliferative and cytolytic capacities. Importantly, the enhanced antigen-specific immunity protected mice against pathogenic viral challenge and tumor growth. Thus, this newly identified PD1 variant (Δ42PD1) amplifies the generation of antigen-specific CD8+ T cell immunity when used in a DNA vaccine.  相似文献   
47.
48.
亚太地区炎症性肠病处理共识意见(一)   总被引:24,自引:0,他引:24  
虽然目前亚太地区尚无炎症性肠病(IBD)的大规模流行病学资料,但一系列研究显示其发病率和患病率呈上升趋势。与西方国家相比仍呈滞后现象。溃疡性结肠炎(UC)的发病率仍较克罗恩病(CD)高。除地域差异外。在一些多民族国家中,IBD尚可见种族差异。亚太地区IBD的遗传背景有异于西方国家。如据报道该地区CD患者未检出NOD2/CARDI5变异。一般而言,该地区IBD患者的临床过程似不如西方国家严重。 亚太地区IBD的诊断存在一些特殊问题。如缺乏IBD诊断金标准。存在多种小肠结肠炎,与IBD临床表现相似,使鉴别诊断特别困难。迄今为止,亚太地区IBD的诊断标准多采用西方国家的诊断标准。诊断必须逐步排除非IBD的小肠结肠炎。确诊应有典型的组织学表现。某些患者需借助随访和诊断性治疗才能确诊。进一步研究IBD发病机制将有助于开发更好的诊断标记物。 亚太地区IBD的治疗亦存在特殊问题。由于诊断困难。IBD患者常未能及时接受适当的药物治疗,但该地区仍广泛采用药物治疗方案。结合西方指南和本地经验可制定类似的处理原则。以利诱导缓解和维持缓解。提倡逐级使用基于病变范围、活动性和严重度的阶梯式治疗方案。对不同病例采用综合性、个体化的方法。随着对IBD发病机制和亚太地区IBD独特性的深入理解。合理、实用的药物治疗指南和应用生物制剂治疗将改善该地区IBD的治疗前景。  相似文献   
49.
Erythromycin treatment for gastrointestinal dysmotility in preterm infants   总被引:3,自引:0,他引:3  
To report our clinical experience on the use of oral erythromycin for the treatment of severe gastrointestinal dysmotility in preterm infants.

Methodology:


A case series study of seven preterm infants (six were very low birthweight) with severe intestinal dysmotility in a tertiary neonatal centre.

Results:


All responded favourably without adverse effects and tolerated full enteral feeding within 1–2 weeks of the commencement of the drug.

Conclusions:


As prolonged total parenteral nutrition carries significant risk of complications, this therapy could be considered in selected preterm infants who fail to establish enteral feeding after an extended period, and in whom an anatomically obstructive lesion of the gastrointestinal tract has been excluded. Meanwhile, we would caution against the widespread implementation of this therapeutic approach until formal evaluation by randomized controlled trials have established the exact role of erythromycin, or its analogues, in the treatment of intestinal dysmotility in preterm infants.  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