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   344篇
  免费   14篇
  国内免费   2篇
耳鼻咽喉   4篇
儿科学   8篇
妇产科学   11篇
基础医学   42篇
口腔科学   10篇
临床医学   22篇
内科学   115篇
皮肤病学   13篇
神经病学   23篇
特种医学   4篇
外科学   40篇
预防医学   21篇
眼科学   8篇
药学   30篇
中国医学   3篇
肿瘤学   6篇
  2023年   4篇
  2022年   9篇
  2021年   18篇
  2020年   10篇
  2019年   13篇
  2018年   11篇
  2017年   8篇
  2016年   6篇
  2015年   5篇
  2014年   12篇
  2013年   15篇
  2012年   23篇
  2011年   24篇
  2010年   15篇
  2009年   10篇
  2008年   13篇
  2007年   23篇
  2006年   27篇
  2005年   32篇
  2004年   22篇
  2003年   15篇
  2002年   16篇
  2001年   1篇
  2000年   4篇
  1998年   4篇
  1997年   2篇
  1996年   1篇
  1993年   2篇
  1991年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1982年   2篇
  1975年   1篇
  1974年   1篇
  1973年   3篇
  1971年   1篇
  1965年   3篇
排序方式: 共有360条查询结果,搜索用时 609 毫秒
61.
Introduction: Management of patients with opioid use disorder (OUD) commonly includes opioid agonist therapy (OAT) as a part of an integrated treatment plan. These interventions are associated with proven benefits to the individual and society.

Areas covered: The use of methadone and buprenorphine within an integrated treatment plan in the management of patients with OUD: this work provides consensus recommendation on pharmacotherapy in OUD to assist clinicians with practical decision making in this field.

Expert opinion: Pharmacotherapy is recommended as part of an integrated OUD treatment approach with psychosocial interventions, with the goal of reducing risks of illicit opioid use, overdose mortality, infection with HIV or HCV, improving health, psychological and social outcomes. Access to OAT should be prioritised in the treatment of OUD. Treatment choices in OUD pharmacotherapy should be based on the needs of the individual and characteristics of medications. Recommendations for choices of OAT are based on clinical efficacy, safety, patient preference, side effects, pharmacological interactions, quality of life, dose titration potential and outcomes (control craving, ongoing opioids consumption or other drugs, and potentially psychiatric comorbidities). Special groups, pregnant women, prisoners, patients with mental health problems have specific needs which must be addressed with expert input.  相似文献   

62.
Obstructive sleep apnea is a risk factor for pulmonary embolism, although its association with pulmonary embolism severity is unknown. Our objective was to study if obstructive sleep apnea is associated with worse pulmonary embolism severity scores and greater extent of arterial obstruction. In consecutive pulmonary embolism patients, we performed respiratory polygraphy and recorded sleep characteristics, classical risk factors for pulmonary embolism and physical activity 6–12 months after the pulmonary embolism episode. Simplified Geneva Prognostic Score and Pulmonary Embolism Severity Index were calculated at the time of the pulmonary embolism diagnosis. The Pulmonary Artery Obstruction Index and the right ventricle to left ventricle diameter ratio were measured by computed tomography pulmonary angiography. We included 120 patients, of whom 45.8% had moderate‐severe obstructive sleep apnea (apnea–hypopnea index > 15 hr?1). There was a larger proportion of moderate‐severe obstructive sleep apnea patients in the third and fourth Pulmonary Artery Obstruction Index quartiles and in the III‐V Pulmonary Embolism Severity Index levels compared with apnea–hypopnea index < 15 hr?1 group. However, no differences were found between the proportion of patients with or without moderate‐severe obstructive sleep apnea in their stratification by simplified Geneva Prognostic Score. The mean adjusted values of the simplified Geneva Prognostic Score, Pulmonary Embolism Severity Index and Pulmonary Artery Obstruction Index scores were higher in the apnea–hypopnea index > 15 hr?1 group (p < .05). Multiple linear regression analysis identified apnea–hypopnea index as the only independent factor related to Pulmonary Artery Obstruction Index and Pulmonary Embolism Severity Index, whereas desaturation index was associated with simplified Geneva Prognostic Score. Patients with pulmonary embolism and moderate‐severe obstructive sleep apnea had greater pulmonary artery obstruction as well as more pulmonary embolism severity, assessed by both the simplified Geneva Prognostic Score and the Pulmonary Embolism Severity Index, compared with patients with apnea–hypopnea index ≤ 15 hr?1. Moreover, these prognostic indices were independently related to sleep parameters.  相似文献   
63.
Estradiol protects dopamine neurons of the substantia nigra from toxic insults. Such neurons succumb in Parkinson's disease; one strategy for restoring dopamine deficiency is cell therapy with neurons differentiated from embryonic stem cells. We investigated the effects of 17β-estradiol on dopaminergic induction of embryonic stem cells using the 5-stage protocol. Cells were incubated with different steroid concentrations during the proliferation (stage 4) or differentiation (stage 5) phases. Estradiol added at nM concentrations only during stage 4 increases the proliferation of dopaminergic precursors expressing Lmx1a, inducing a higher proportion of dopamine neurons at stage 5. These actions were mediated by activation of estrogen receptors, because co-incubation of cells with estradiol and ICI 182,780 completely abolished the positive effect on both proliferation of committed precursors, and subsequent differentiation to dopaminergic neurons. Our results suggest that estradiol should be useful in producing higher proportions of dopamine neurons from embryonic stem cells aimed for treating Parkinson's disease.  相似文献   
64.

Background  

Antigen exposure is one of the major exogenous factors modulating human immunocompetence acquisition. Decline in family size and improvements in public health and hygiene in developed countries, may deprive the immune system of appropriate antigen input by diminishing infectious stimuli. Probiotics are a large group of microorganisms defined by their beneficial effects on human health and with stimulating effects on different functions of the immune system.  相似文献   
65.
Class 3 Semaphorins are a subfamily of chemotropic molecules implicated in the projection of dopaminergic neurons from the ventral mesencephalon and in the formation of the nigrostriatal pathway (NSP) during embryonic development. In humans, loss of mesencephalic dopaminergic neurons leads to Parkinson's disease (PD). Cell replacement therapy with dopaminergic neurons generated from embryonic stem cells (ES‐TH+) is being actively explored in models of PD. Among several requisites for this approach to work are adequate reconstruction of the NSP and correct innervation of normal striatal targets by dopaminergic axons. In this work, we characterized the response of ES‐TH+ neurons to semaphorins 3A, 3C, and 3F and compared it with that of tyrosine hidroxylase‐positive neurons (TH+) obtained from embryonic ventral mesencephalon (VM‐TH+). We observed that similar proportions of ES‐TH+ and VM‐TH+ neurons express semaphorin receptors neuropilins 1 and 2. Furthermore, the axons of both populations responded very similarly to semaphorin exposure: semaphorin 3A increased axon length, and semaphorin 3C attracted axons and increased their length. These effects were mediated by neuropilins, insofar as addition of blocking antibodies against these proteins reduced the effects on axonal growth and attraction, and only TH+ axons expressing neuropilins responded to the semaphorins analyzed. The observations reported here show phenotypic similarities between VM‐TH+ and ES‐TH+ neurons and suggest that semaphorins 3A and 3C could be employed to guide axons of grafted ES‐TH+ in therapeutic protocols for PD. © 2009 Wiley‐Liss, Inc.  相似文献   
66.
67.
Cyclospora spp. is a protozoan parasite responsible for significant gastrointestinal disease in patients infected with the human immunodeficiency virus. We report the clinical features of two patients with chronic diarrhea and intestinal cyclosporosis caused by Cyclospora cayetanensis. The average value for CD4 count in these patients was lower than or equal to 100 cells/mm3. The oocysts were detected in smears from stool samples stained with modified acid-fast or safranin technique. Light microscopy revealed parasites in the enterocytes and these parasites were associated with villous atrophy. Cyclospora cayetanensis infection might be an important cause of diarrhea in patients with AIDS in Argentina.  相似文献   
68.
69.
70.

Background

Online haemodiafiltration (OL-HDF) is currently the most effective dialysis technique that also improves survival. To date, high permeability membranes with low albumin loss, such as polysulfone, polyamide and polyacrylonitrile membranes have been the most widely used. However, the initially restricted use of cellulose triacetate (CTA) membranes in OL-HDF has expanded. The aim of the study was to ascertain whether the latest generation asymmetric CTA membranes are more effective in obtaining high convective transport.

Patients and methods

A total of 16 patients (10 males and 6 females) undergoing OL-HDF were studied. Each patient underwent 4 different sessions, with haemodialysis or OL-HDF, and/or with CTA or asymmetric CTA 1.9 m2 membranes. Each session was assigned in a randomised order. Serum levels of urea, creatinine, β2-microglobulin, myoglobin, prolactin, α1-microglobulin, α1-acid glycoprotein and albumin where measured at the beginning and end of each session to obtain the reduction rate. The loss of solutes and albumin was quantified from the dialysate.

Results

A significantly greater replacement volume in OL-HDF (32.1 ± 3.1 vs. 19.7 ± 4.5 l, P<.001) was obtained by using asymmetrical CTA membranes compared to conventional CTA membranes. Regarding uraemic toxin removal, both membranes obtained similar results for small molecules, whereas asymmetric CTA membranes achieved better results for large molecules, increasing the reduction ratio by 29% for β2-microglobulin, 27.7% for myoglobin, 19.5% for prolactin, 49% for α1-microglobulin and double for α1-acid glycoprotein (P<0.001 in all situations). The loss of albumin was less than 2 g for all treatment sessions.

Conclusion

Latest-generation asymmetric CTA have proven to be effective in attaining OL-HDF objectives without increased albumin loss.  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