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   400篇
  免费   27篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   21篇
妇产科学   4篇
基础医学   55篇
口腔科学   28篇
临床医学   38篇
内科学   107篇
皮肤病学   11篇
神经病学   4篇
特种医学   58篇
外科学   36篇
综合类   9篇
预防医学   10篇
眼科学   1篇
药学   30篇
  1篇
肿瘤学   13篇
  2022年   1篇
  2021年   3篇
  2020年   2篇
  2019年   1篇
  2018年   3篇
  2017年   4篇
  2016年   6篇
  2015年   19篇
  2014年   16篇
  2013年   17篇
  2012年   13篇
  2011年   15篇
  2010年   22篇
  2009年   10篇
  2008年   5篇
  2007年   19篇
  2006年   8篇
  2005年   11篇
  2004年   8篇
  2003年   8篇
  2002年   4篇
  2001年   10篇
  2000年   2篇
  1999年   9篇
  1998年   22篇
  1997年   21篇
  1996年   30篇
  1995年   15篇
  1994年   21篇
  1993年   13篇
  1992年   3篇
  1991年   3篇
  1990年   5篇
  1989年   4篇
  1988年   14篇
  1987年   4篇
  1986年   6篇
  1985年   10篇
  1984年   5篇
  1983年   8篇
  1982年   3篇
  1981年   2篇
  1980年   3篇
  1979年   3篇
  1978年   1篇
  1977年   7篇
  1976年   4篇
  1975年   3篇
  1963年   1篇
  1961年   1篇
排序方式: 共有428条查询结果,搜索用时 15 毫秒
91.
BACKGROUND: Bilirubin and albumin may act as antioxidants. Their circulating levels are lower in those patients with ischemic heart disease (IHD) and could be further reduced by more extensive atherosclerosis, i.e. peripheral vascular disease (PVD). METHODS: Serum bilirubin and albumin were measured in 456 patients classified into 3 groups: 1) no clinically evident cardiovascular disease (CVD), 2) IHD present and 3) PVD present. Smoking status and gender (which affect bilirubin and albumin levels in healthy individuals) were considered separately. RESULTS: Bilirubin was lower in smoking men without CVD or with PVD than in non-smokers (p=0.02 and p=0.04, respectively) in the same groups. Non-smoking women without CVD had significantly (p=0.004) lower bilirubin levels than the corresponding group of men. Frequency analysis of male non-smokers revealed significantly (p=0.04) more patients with a lower bilirubin (<6.5 mmol/l) in the PVD compared with the no CVD group. Albumin levels showed the same trends. CONCLUSIONS: Prospective studies should consider smoking and gender when assessing the relevance of bilirubin and/or albumin levels in patients with vascular disease. Our findings support those of other studies that show that low serum bilirubin and albumin levels are associated with the presence of vascular disease.  相似文献   
92.
Two xanthones, 2-hydroxyethoxy-6-(5-tetrazoyl) (BW A440C) and 2-ethoxy- 6-(5-tetraozyl) (BW A827C), are members of a chemical series tested in vitro as potential additives to citrate-phosphate-dextrose-adenine (CPDA-1) medium for blood storage. P50 was maintained in the presence of these compounds during 42 days' storage by a partial maintenance of 2,3 diphosphoglycerate (2,3 DPG) and by a direct effect on hemoglobin previously reported for BW A827C. Red cell 2,3 DPG levels for BW A440C (n = 5), BW A827C (n = 5), and control (n = 6), respectively, were 3.38 +/− 0.47, 3.44 +/− 0.25, and 1.20 +/− 0.10 mM +/− SEM on day 7; 1.16 +/− 0.13, 1.52 +/− 0.37, and 0.16 +/− 0.02 mM on day 21; and 0.67 +/− 0.09, 0.61 +/− 0.08, and 0.06 +/− 0.006 mM on day 42. Red cell adenine triphosphate levels at the same time intervals were 1.84 +/− 0.09, 1.46 +/− 0.18, and 2.11 +/− 0.04 mM; 2.10 +/− 0.05, 2.07 +/− 0.17, and 2.13 +/− 0.05 mM; and 1.42 +/− 0.13, 1.37 +/− 0.13, and 1.38 +/− 0.06 mM, respectively. The degree of hemolysis was less with the addition of the compounds, and the methemoglobin formation, plasma Na+ and K+, and lactate production were unaffected by the compounds.  相似文献   
93.
94.
Growth retardation is common in children with chronic renal failure (CRF). To investigate the efficacy and safety of recombinant human growth hormone treatment in such children and in children after renal transplantation, 43 prepubertal children with CRF, and 30 prepubertal and 25 pubertal patients with a renal transplant were studied. Data are reported for 31, 26 and 17 of these patients, respectively. Median height velocity increased from 4.2 to 9.8 cm/year during the first year of treatment, and to 6.8 cm/year during the second year of treatment in the patients with CRF. In the prepubertal transplant group, median height velocity changed from 3.5 to 8.4 cm/year during the first year and to 5.4 cm/year during the second year. In the pubertal transplant group, median height velocity increased from 3.2 to 6.6 cm/year during the first year and was 4.5 cm/year during the second year. The gain in height SDS for the prepubertal children in both the CRF and transplant groups was approximately 1 SD over 2 years. Treatment was well tolerated, and renal function did not change significantly in any group.  相似文献   
95.
Although the prevention of unintended adolescent pregnancy is a primary goal of the American Academy of Pediatrics and society, many adolescents continue to become pregnant. Since the last statement on adolescent pregnancy was issued by the Academy in 1989, new observations have been recorded in the literature. The purpose of this new statement is to review current trends and issues on adolescent pregnancy to update practitioners on this topic.  相似文献   
96.
97.
98.
Summary. Background and objectives: Thrombin activatable fibrinolysis inhibitor (TAFI) attenuates fibrinolysis and may therefore contribute to the pathophysiology of arterial thrombosis. The aim of the present study was to elucidate the pathogenetic role of TAFI levels and genotypes in young patients with arterial thrombosis. Patients and methods: In a case–control study, 327 young patients with a recent first‐ever event of coronary heart disease (CHD subgroup) or cerebrovascular disease (ischemic stroke subgroup) and 332 healthy young controls were included. TAFI levels [intact TAFI, activation peptide (TAFI‐AP) and (in)activated TAFI (TAFIa(i)] and TAFI activity were measured and genetic variations in the TAFI gene (?438G/A, 505G/A and 1040C/T) were determined. Results: In the total group of patients, TAFIa(i) levels were higher (145.1 ± 37.5%) than in controls (137.5 ± 31.3%, P = 0.02). Plasma levels of intact TAFI, TAFI‐AP and TAFI activity were similar in patients and controls. In the CHD subgroup (n = 218), intact TAFI levels were higher (109.4 ± 23.0%) than in controls (102.8 ± 20.7%, P = 0.02). In 325Ile/Ile homozygotes, lower TAFI levels and a decreased risk of arterial thrombosis were observed (OR 0.58, 95% CI 0.34–0.99) compared with patients with the common 325Thr/Thr genotype. This association was most evident in CHD patients (OR 0.48, 95% CI 0.26–0.90). Haplotype analyses supported a role for the Thr325Ile polymorphism. Conclusions: TAFIa(i) levels were higher in patients with cardiovascular disease. Furthermore, the TAFI 325Thr/Ile polymorphism was associated with lower TAFI levels and with the risk of cardiovascular disease in young patients, especially in CHD.  相似文献   
99.
As the diversity in clinical presentation of American tegumentary leishmaniasis (ATL) is determined mainly by the immune response of host, our aim was to evaluate the in situ expression of Foxp3 [marker of regulatory T (Treg) cell] in lesions of the different clinical forms of ATL. Foxp3+ cells were observed in 39·5% (32/81) of the samples and the number of positive cells was low in all the clinical forms. Even presenting a significantly lower number of CD4+ T cells, diffuse cutaneous leishmaniasis (DCL) showed a higher expression of Foxp3 when compared with localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL). In LCL and MCL, the number of Foxp3+ cells correlated positively with the number of apoptotic cells (active caspase-3+ cells). A positive correlation was also observed between the expression of active caspase-3 and FasL in these clinical forms. Our data suggest that increased number of Treg cells may be associated to the hyporesponsiveness observed in DCL and also indicate that the apoptosis may be a possible mechanism of action of Foxp3+ Treg cell in LCL and MCL. However, further studies are required to better understand the mechanism of action of Treg cell.  相似文献   
100.
Sparano  JA; Wiernik  PH; Strack  M; Leaf  A; Becker  N; Valentine  ES 《Blood》1993,81(10):2810-2815
Fourteen patients with poor-prognosis intermediate- to high-grade non- Hodgkin's lymphoma (NHL) associated with human immunodeficiency virus (HIV) infection (12 patients) or human T-cell leukemia virus type I (HTLV-I) infection (two patients) received cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, and etoposide 240 mg/m2 administered as a continuous intravenous (IV) infusion over 4 days (infusional CDE); treatment was repeated every 28 or more days for up to six cycles. All HIV-positive patients had at least one poor prognostic feature, which included either extranodal disease (10 patients), Karnofsky performance status less than 70% (six patients), a CD4 count less than 100/microL (six patients), or a prior history of acquired immunodeficiency syndrome (AIDS; one patient). Both HTLV-I-positive patients had an elevated serum lactate dehydrogenase (LDH) level, a poor prognostic feature in that setting. Complete response (CR) occurred in 10 patients (71%; 95% confidence interval, 48% to 95%) and partial response (PR) occurred in three patients (21%), yielding an overall objective response rate of approximately 93%. The estimated Kaplan-Meier median survival was 17.4 months; seven of 12 HIV-positive patients are alive and disease-free with a median follow-up of 15 months (range, 7 to 24 months). Hospitalization was required after 19% of treatment cycles due to fever associated with granulocytopenia. Documented or suspected opportunistic infection occurred in five patients (36%), bacteremia occurred in three patients (21%), and candidemia occurred in one patient (7%). There was one treatment-related death attributable to disseminated aspergillosis. This pilot study suggests that infusional CDE may be a highly active regimen capable of producing durable remissions in a high proportion of patients with HIV-related NHL. Further study is required to confirm this observation.  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