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   570篇
  免费   32篇
  国内免费   8篇
儿科学   30篇
妇产科学   3篇
基础医学   51篇
口腔科学   7篇
临床医学   52篇
内科学   184篇
皮肤病学   5篇
神经病学   12篇
特种医学   86篇
外科学   54篇
综合类   10篇
预防医学   29篇
眼科学   6篇
药学   33篇
肿瘤学   48篇
  2022年   1篇
  2021年   6篇
  2020年   1篇
  2019年   7篇
  2018年   11篇
  2017年   5篇
  2016年   6篇
  2015年   8篇
  2014年   8篇
  2013年   23篇
  2012年   20篇
  2011年   17篇
  2010年   24篇
  2009年   19篇
  2008年   21篇
  2007年   20篇
  2006年   16篇
  2005年   19篇
  2004年   14篇
  2003年   14篇
  2002年   10篇
  2001年   11篇
  2000年   17篇
  1999年   25篇
  1998年   27篇
  1997年   29篇
  1996年   30篇
  1995年   22篇
  1994年   25篇
  1993年   18篇
  1992年   10篇
  1991年   7篇
  1990年   15篇
  1989年   15篇
  1988年   9篇
  1987年   14篇
  1986年   12篇
  1985年   5篇
  1984年   4篇
  1983年   4篇
  1982年   4篇
  1981年   9篇
  1980年   7篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1976年   10篇
  1975年   3篇
排序方式: 共有610条查询结果,搜索用时 15 毫秒
31.

Background

Late or inadequate therapeutic management increases the risk of mortality associated with HIV/AIDS. The aim of this study was to analyze the proportion and factors associated with loss of follow-up in HIV patients who receiving antiretroviral therapy at Conakry.

Methods

A retrospective cohort study was conducted in HIV patients aged over 15 years and who receiving antiretroviral therapy. Between August 1, 2008 and July 31, 2015, all patients managed by the ambulatory treatment center of the Guinean Women Association against AIDS and sexually and transmissible infection were included. Loss of follow-up was defined as no follow-up visit within 3 months. Kaplan–Meier curves and multivariate Cox regression models were used to analyze factors associated with loss of follow-up. Analyses were performed by using Stata 13 software.

Results

614 patients aged 36.3 ± 11.2 years, mainly females (68.4%) and living in Conakry (80.5%) were included. Among them, 104 were loss to follow-up, corresponding to a proportion rate of 16.9% (95% CI: 14.2–19.7%) or 5.79/100 person-years. The results of multivariate analyses showed that factors independently associated with loss of follow-up were malnutrition (AHR = 7.05; 95% CI: 2.05–24.27; P = 0.002) and CD4 cells account at the initiation of AHR (2.35; 95% CI: 1.61–6.39; P = 0.016) in patients with 201–350 CD4/μL and 5.83 (95% CI: 2.85–11.90; P < 0.001) in patients with less than 150 CD4/μL.

Conclusion

Despite efforts of health care workers and free antiretroviral therapy, many patients were loss to follow-up. Multivariate analysis showed that malnutrition and low CD4 account were independently associated with loss to follow-up.  相似文献   
32.
BACKGROUND Polyethylene(PE) particles produced by wear of the acetabular insert are thought to cause osteolysis and thereby aseptic loosening of the implant in total hip arthroplasty(THA). As highly cross-linked polyethylene(HXLPE) is presumed to give lower wear rates, in vivo studies are needed to confirm this.AIM To compare the wear of REXPOL, a HXPLE, with conventional PE within the first five years after implantation using Roentgen stereophotogrammetric analysis(RSA).METHODS Patients were randomised to receive either a HXLPE(REXPOL) or a conventional PE insert during primary THA. RSA images were obtained directly postoperative and after 6 wk, 12 wk, 6 mo, 12 mo, 24 mo and five years. Functional outcomes were assessed using the Hip Injury and Osteoarthritis Outcome Score and Harris Hip Score at baseline and five years after surgery.RESULTS The HXLPE(REXPOL) showed less wear in the latero-medial direction. Significant wear rates of conventional PE were seen in the latero-medial and center-proximal direction and in volume and corrected volume, whereas the REXPOL did not show these outcomes over time. Improvement from baseline in functional outcome did not significantly differ.CONCLUSION Total 3 D wear is less in THAs inserted with a REXPOL inlay than a conventional PE inlay after five years. This study confirms, for the first, that the REXPOL HXLPE inlay is preferred to standard PE.  相似文献   
33.
BackgroundThe BALAD score and BALAD-2 class derived from bilirubin, albumin, AFP, AFP-L3, and des-gamma-carboxyprothrombin (DCP) are effective in predicting mortality in HCC, but have not been validated in North America.Methods148 HCC patients from 2000 to 2015 who had all five biomarkers tested at diagnosis were included. Hazard ratios (HR) were calculated.Results75 patients died during a median follow-up of 21.9 months. 1-and 3-year survival rates were 70.8% and 47.6%. 114 (77%) had cirrhosis. The HR (95%CI) for death were 1.24 (0.42–3.67), 1.79 (0.61–5.26), 2.83 (0.95–8.38), and 7.19 (2.26–22.91) for BALAD scores 1, 2, 3, and 4 vs. BALAD 0. The HR (95%CI) for death were 1.25 (0.65–2.40), 1.75 (0.94–3.23), and 6.20 (3.29–11.68) for BALAD-2 classes 2, 3, and 4 vs. BALAD-2 class 1. A multivariate model incorporating maximal tumor diameter, tumor number, neutrophil-lymphocyte ratio, and BALAD had HR of 1.43 (1.14–1.81) per increase of 1 BALAD score. A similar model with BALAD-2 had HR of 1.50 (1.18–1.90) per increase of 1 BALAD-2 class.ConclusionBALAD models at diagnosis can predict the survival of HCC patients in North America. AFP, AFP-L3, and DCP reflect tumor progression and metastasis of HCC and distinguish the BALAD model from other predictive models.  相似文献   
34.
We have used the long-term bone marrow culture (LTBMC) system to analyze hematopoiesis in three patients with dyskeratosis congenita (DC), two of whom had aplastic anemia, and the third had a normal blood count (apart from mild macrocytosis) and normal BM cellularity. Hematopoiesis was severely defective in all three patients, as measured by a low incidence of colony-forming cells and a low level of hematopoiesis in LTBMC. The function of the marrow stroma was normal in its ability to support the growth of hematopoietic progenitors from normal marrows seeded onto them in all three cases, but the generation of hematopoietic progenitors from patients marrow cells inoculated onto normal stromas was reduced, thus suggesting the defect to be of stem cell origin. The parents and unaffected brother of one of the families have also been studied in LTBMC and all showed normal hematopoietic and stromal cell function. From this study we speculate that there are some similarities between DC and the defect in the W/Wv mouse.  相似文献   
35.
CALLA-positive myeloma: an aggressive subtype with poor survival   总被引:5,自引:0,他引:5  
Durie  BG; Grogan  TM 《Blood》1985,66(1):229-232
Detailed immunotyping was carried out on 21 direct myeloma bone marrow aspirates and eight human myeloma cell lines. Four previously untreated common acute lymphoblastic leukemia antigen (CALLA)-positive myeloma patients were identified and six of eight cell lines (75%) were also positive. CALLA positivity, as part of an immature B phenotype, was found to correlate with very aggressive clinical disease: median survival six months v 56 months for the CALLA-negative group.  相似文献   
36.
The PET tracer [11C]5-hydroxytryptophan ([11C]5-HTP), which is converted to [11C]5-hydroxytryptamine ([11C]5-HT) by aromatic amino acid decarboxylase (AADC), is thought to measure 5-HT synthesis rates. But can we measure these synthesis rates by kinetic modeling of [11C]5-HTP in rat? Male rats were scanned with [11C]5-HTP (60 minutes) after different treatments. Scans included arterial blood sampling and metabolite analysis. 5-HT synthesis rates were calculated by a two-tissue compartment model (2TCM) with irreversible tracer trapping or Patlak analysis. Carbidopa (inhibitor peripheral AADC) dose-dependently increased [11C]5-HTP brain uptake, but did not influence 2TCM parameters. Therefore, 10 mg/kg carbidopa was applied in all subsequent study groups. These groups included treatment with NSD 1015 (general AADC inhibitor) or p-chlorophenylalanine (PCPA, inhibitor of tryptophan hydroxylase, TPH). In addition, the effect of a low-tryptophan (Trp) diet was investigated. NSD 1015 or Trp depletion did not affect any model parameters, but PCPA reduced [11C]5-HTP uptake, and the k3. This was unexpected as NSD 1015 directly inhibits the enzyme converting [11C]5-HTP to [11C]5-HT, suggesting that trapping of radioactivity does not distinguish between parent tracer and its metabolites. As different results have been acquired in monkeys and humans, [11C]5-HTP-PET may be suitable for measuring 5-HT synthesis in primates, but not in rodents.  相似文献   
37.
Background Appropriate pricing for medical services of not‐for‐profit hospital is necessary. The prices should be fair to the public and should be high enough to cover the operative costs of the organization. Objective The purpose of this study was to determine the cost and unit cost of medical services performed at the Mohs and Dermasurgery Unit (MDU), Department of Dermatology, The University of Texas – MD Anderson Cancer Center, Houston, TX from the healthcare provider’s perspective. Methods MDU costs were retrieved from the Financial Department for fiscal year 2006. The patients’ statistics were acquired from medical records for the same period. Unit cost calculation was based on the official method of hospital accounting. Results The overall unit cost for each patient visit was $673.99 United States dollar (USD). The detailed unit cost of nurse visit, new patient visit, follow‐up visit, consultation, Mohs and non‐Mohs procedure were, respectively, $368.27, $580.09, $477.82, $585.52, $1,086.12 and $858.23 USD. With respect to a Mohs visit, the unit cost per lesion and unit cost per stage were $867.89 and $242.30 USD respectively. Conclusions Results from this retrospective study provide information that may be used for pricing strategy and resource allocation by the administrative board of MDU.  相似文献   
38.
Ursodeoxycholic acid (UDCA) is a safe and effective medical therapy for most patients with primary biliary cirrhosis (PBC), but some patients show an incomplete response. Silymarin is a potent antioxidant with immunomodulatory and antifibrotic properties. The aim of this study was to evaluate the safety and assess the efficacy of silymarin in patients with PBC who had shown a suboptimal response to UDCA. Twenty-seven patients with PBC who had been on UDCA (13-15 mg/kg/day) therapy for 7 to 221 months and had shown a persistent elevation of alkaline phosphatase activity at least 2 times the upper limit of normal for more than 6 months were enrolled. Oral silymarin, 140 mg 3 times daily was given for 1 year, and patients continued on the same dosage of UDCA. No significant changes in serum alkaline phosphatase activity (897 +/- 84 vs. 876 +/- 95, P =.5), total bilirubin (0.9 +/- 0.1 vs. 1 +/- 0.1, P =.07), aspartate transaminase (AST) (58 +/- 5 vs. 56 +/- 6, P =.4), albumin (4.0 +/-.06 vs. 4.1 +/-.06, P =.4), or Mayo risk score (3.82 +/- 0.2 vs. 3.88 +/- 0.2, P =.4) were noted after 1 year of treatment with combination therapy. Transitory gastrointestinal adverse events occurred in 2 patients. In conclusion, although silymarin was well tolerated, this medication did not provide benefit to patients with PBC responding suboptimally to UDCA. The results of this pilot study would seem to discourage further controlled trials of silymarin in patients with PBC.  相似文献   
39.
We report the case of a 9-year-old boy with a spinal cord meningioma whose only manifestations were recurrent episodes of chest pain lasting for 2 years. This case shows that spinal cord meningioma should be considered among the possible causative factors of chronic chest pain in childhood. Chest pain, meningioma, spinal tumors  相似文献   
40.
Clinical evaluation of biomarkers in Gaucher disease   总被引:1,自引:0,他引:1  
Novel or candidate biomarkers require thorough evaluation to establish their utility in a clinical setting. This paper describes an evaluation of several established enzyme markers of Gaucher disease and a newly-described chemokine, pulmonary and activation-regulated chemokine (PARC). The ability of the biomarkers to rank patients with Gaucher disease in order of disease severity and organ bulk, and to reflect changes in key clinical parameters in response to enzyme replacement therapy were evaluated. PARC concentrations were found to be reliably correlated with visceral disease and with key clinical responses to enzyme replacement in an unbiased manner. Unlike chitotriosidase and serum angiotensin-converting enzyme activity, genetic variation in serum PARC did not appear to influence its utility as a biomarker.
Conclusion: For each new candidate biomarker of lysosomal storage diseases, a similar clinical evaluation will be required, though the approach will need to be modified according to the clinical features and natural history of each disorder.  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