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   679篇
  免费   40篇
  国内免费   14篇
耳鼻咽喉   1篇
儿科学   21篇
妇产科学   10篇
基础医学   83篇
口腔科学   6篇
临床医学   62篇
内科学   187篇
皮肤病学   15篇
神经病学   92篇
特种医学   32篇
外科学   56篇
综合类   1篇
预防医学   39篇
眼科学   2篇
药学   53篇
中国医学   3篇
肿瘤学   70篇
  2024年   2篇
  2023年   8篇
  2022年   16篇
  2021年   33篇
  2020年   13篇
  2019年   16篇
  2018年   22篇
  2017年   16篇
  2016年   21篇
  2015年   22篇
  2014年   30篇
  2013年   41篇
  2012年   53篇
  2011年   32篇
  2010年   22篇
  2009年   16篇
  2008年   57篇
  2007年   42篇
  2006年   38篇
  2005年   37篇
  2004年   24篇
  2003年   31篇
  2002年   27篇
  2001年   2篇
  2000年   6篇
  1999年   12篇
  1998年   10篇
  1997年   9篇
  1996年   3篇
  1995年   4篇
  1994年   3篇
  1993年   2篇
  1992年   4篇
  1991年   3篇
  1990年   6篇
  1989年   5篇
  1988年   8篇
  1987年   4篇
  1986年   7篇
  1985年   2篇
  1983年   1篇
  1982年   1篇
  1981年   4篇
  1980年   3篇
  1979年   9篇
  1978年   3篇
  1975年   2篇
  1970年   1篇
排序方式: 共有733条查询结果,搜索用时 31 毫秒
31.

Background

Renal disease is an increasingly recognized noninfectious comorbidity associated with human immunodeficiency virus (HIV) infection.

Methods

Our retrospective, cross-sectional study evaluated prevalence of nephropathy among HIV-infected patients followed up in our outpatient clinic during the year 2011. Renal dysfunction and chronic kidney disease (CKD) were defined as estimated glomerular filtration rate (eGFR) <90 ml/min per 1.73 m2 and as renal damage or eGFR <60 ml/min per 1.73 m2 over a 3-month or greater period, respectively.

Results

We enrolled 894 HIV-infected patients with a mean age of 44.2 years and a mean current CD4 lymphocyte count of 508 cells/mm3. The prevalence of renal dysfunction and CKD was 27.4 and 21.3 %, respectively. Older age, male gender, hypertension, diabetes, proteinuria, hypertriglyceridemia, lower nadir CD4 cell count, current use of tenofovir or tenofovir plus a ritonavir-boosted protease inhibitor were independently associated with renal dysfunction.

Conclusion

Renal dysfunction is a frequent comorbidity among HIV-infected persons and requires a careful clinical and laboratory monitoring of renal function.  相似文献   
32.
33.
In women of fertile age, iron loss consequent to excessive menstrual discharge is by far the most frequent cause of iron-deficient anemia. However, the relationship between menstrual discharge and iron loss is poorly understood. In this prospective study, total menstrual and iron losses were assayed in a large cohort of non-anemic women and women with excessive menstrual blood losses (menorrhagia) in order to provide data useful for intervention. One hundred and five Caucasian women aged 20–45 years were recruited. Blood cell count and serum ferritin (SF) levels were determined in each case before menses. Menstrual fluid losses (MFL) were determined using a standardized pads’ weight method. Hematin concentration was assayed by a variant of the Alkaline Hematin Method from which iron concentration was calculated. Mean SF levels were 36.2 (range 8.6–100) ng/ml in healthy women and 6.4 (range 5–14) ng/ml in patients with menorrhagia. Median values of iron lost/cycle were 0.87 mg in healthy women and 5.2 mg in patients with menorrhagia (ranges 0.102–2.569 and 1.634–8.665 mg, respectively, p?<?0.001). In women with menorrhagia, iron lost/cycle strongly correlated (0.789, p?<?0.001) with MFL. In conclusion, healthy women with normal menses lose, on average, 1 mg iron/cycle. Average iron losses in patients with menorrhagia are, at least in our cohort, on average, five-to-six times higher than normal. Most women with menorrhagia had totally depleted iron stores. Indirect, quantitative evaluation of iron lost with menses may be useful to assess the risk of developing iron-deficient anemia in individual patients.  相似文献   
34.
Portal vein thrombosis (PVT) is a well-known and relatively common complication of liver cirrhosis. In the past, PVT was considered as a contraindication for liver transplantation (LT). To characterize prevalence, risk factors, perioperative management and outcome of PVT in the setting of LT, the English literature published between 1991 and 2011 was reviewed.Of 6807 articles, 280 were selected, and 39 experiences were analyzed in detail (methodology, type and duration of treatments, peri-operative management, strategy to avoid recurrence, strengths and weaknesses, Oxford evidence level, citations). 3/39 studies were prospective; 9/39 were based on prospectively recorded databases; no studies of 1, 2a, 3a level of evidence were present; 5/39 were recognized as level 2b, 23/39 as level 3b, and 8/39 as level 4.High complication rate has been reported with consequent effect on graft and patient survival. Overall, PVT presents today good results similar to those obtained in patients without PVT undergoing LT even if they require a higher transfusion number and a longer ICU/hospital stay.Reported cases were retrospectively stratified according to Yerdel classification. Grade 1–2 patients (76%) do well with eversion thromboendovenectomy, resection of damaged vein and porto-portal anastomosis. Results of patients with grade 3–4 (24%) are inferior, however data on outcome in this subsets are fragmented and do not allow a reliable analysis. Moreover, results obtained in grade 3–4 cases are better in transplant centers with large specific experience. The small number of reports suggests caution.The role of anticoagulant treatment is still debated. Although in cirrhotics with PVT LT remains a demanding procedure, PVT should not be considered a contraindication anymore.  相似文献   
35.
Abdominal Radiology - Erectile dysfunction (ED) is defined as the persistent inability to achieve and/or maintain an erection for a satisfactory sexual activity. It is secondary to several organic,...  相似文献   
36.
37.
38.
The present paper assesses petrographic, mineralogical, chemical, and technological features of different zeolitic tuff samples from various western USA districts of the Basin and Range Province containing mainly erionite, mordenite, clinoptilolite/heulandite and phillipsite. The aim of this characterization is to evaluate the pozzolanic activity of these samples according to European normative UNI-EN 196/5 (Fratini test) to program a possible use as addition for blended cements. Petrographic and mineralogical results show that the two phillipsite-bearing tuffs have a higher theoretical Cation Exchange Capacity (CEC) than the other samples; technological characterization shows a pozzolanic behavior for all the samples but higher for the tuff samples containing phillipsite, which shows a higher reactivity with CaO. All the samples could be thus advantageously employed for the preparation of blended cements, potentially reducing CO2 emissions by 70–90%.  相似文献   
39.
Introduction: The gut liver axis is an operative unit that works to protect the human body against potentially harmful substances and microorganisms, maintaining the homeostasis of the immune system. Liver cirrhosis profoundly alters this complex system. The intestine becomes more permeable allowing the translocation of bacteria, bacterial products and fragments into the portal circulation, triggering an abnormal local and systemic inflammatory response and a condition of perpetual immunologic alarm. This immune-inflammatory disorder related to dysbiosis is involved in the development of liver damage and liver cirrhosis complications and increases intestinal permeability in a vicious circle.

Areas covered: The most relevant studies on bacterial translocation, the mechanism of intestinal barrier dysfunction and its consequences in patients with liver cirrhosis have been revised through a PubMed search. Data have been discussed with particular regard to their significance in clinical practice.

Expert commentary: The assessment of bacterial translocation and intestinal permeability is not currently used in clinical practice but may be useful to stratify patients’ prognosis.  相似文献   

40.
Recent studies estimated an incidence of 4–25% of disease rebound after withdrawal of fingolimod (FTY) for any reason, but specific data on disease reactivation after FTY withdrawal due to pregnancy are limited. The aim of the study was to evaluate the frequency and predictors of disease reactivation in patients who stopped FTY for pregnancy. A multicentre retrospective cohort study was conducted in four Italian MS centres in 2013–2019. Both planned and unplanned pregnancies were included. The annualized relapse rate (ARR) was calculated before FTY treatment, during FTY treatment, during pregnancy and during the year after delivery. In total, 27 patients (mean age 29 years) were included. The ARR 1 year before FTY treatment was 1.3. Patients were exposed to FTY for a median of 2.9 years. The ARR was 0.04 during the last year before conception (p < 0.001 compared with the ARR before FTY treatment). Eleven patients became pregnant after a mean of 88 days following FTY discontinuation, whereas 16 patients stopped FTY after pregnancy confirmation. Relapses were observed in 22% of patients during pregnancy and in 44% in the postpartum period. ARR increased both during pregnancy (0.49; p = 0.027) and in the first year after delivery (0.67; p < 0.001) compared to the last year before pregnancy. Compared with radiological assessment before pregnancy, more patients showed new or enlarging T2 lesions (63% vs 30%; p = 0.02) and gadolinium-enhancing lesions (44% vs 0; p = 0.0001) on brain Magnetic Resonance Imaging. Relapses during pregnancy were the only significant predictor for postpartum relapses (OR 1.9, 95% CI 1.11–3.1). One case of spontaneous abortion and no cases of abnormal foetal development were observed. Despite adequate and prolonged control of disease activity, women who discontinue FTY because of pregnancy are at risk for disease reactivation. In patients who relapsed during pregnancy, the initiation of high-efficacy disease modifying drugs (DMDs) soon after delivery is advisable to prevent postpartum relapses.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13311-021-01106-6.  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