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   1091篇
  免费   37篇
  国内免费   10篇
耳鼻咽喉   15篇
儿科学   111篇
妇产科学   74篇
基础医学   90篇
口腔科学   46篇
临床医学   101篇
内科学   199篇
皮肤病学   25篇
神经病学   105篇
特种医学   22篇
外科学   140篇
综合类   20篇
预防医学   45篇
眼科学   24篇
药学   30篇
中国医学   2篇
肿瘤学   89篇
  2023年   8篇
  2022年   20篇
  2021年   32篇
  2020年   16篇
  2019年   23篇
  2018年   41篇
  2017年   42篇
  2016年   37篇
  2015年   33篇
  2014年   46篇
  2013年   57篇
  2012年   72篇
  2011年   76篇
  2010年   56篇
  2009年   43篇
  2008年   79篇
  2007年   88篇
  2006年   82篇
  2005年   70篇
  2004年   59篇
  2003年   43篇
  2002年   50篇
  2001年   13篇
  2000年   2篇
  1999年   4篇
  1998年   3篇
  1997年   7篇
  1996年   8篇
  1995年   9篇
  1994年   2篇
  1993年   3篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1985年   1篇
  1981年   2篇
  1980年   1篇
  1968年   1篇
排序方式: 共有1138条查询结果,搜索用时 0 毫秒
991.
Thrombocytopenia represents a major problem in the management of acute myeloid leukaemia (AML). The data regarding the alterations of endogenous thrombopoietin (TPO) regulation during the clinical course of AML are limited. The aim of this study was to investigate endogenous TPO dynamics in association with platelets during the clinical course of AML. We serially measured both TPO and platelets concurrently over the entire treatment period of newly diagnosed patients receiving both remission induction and consolidation chemotherapies. The median concentration of TPO in AML patients at the initial diagnosis was 469.71 pg/ml and increased significantly during the aplastic period due to remission induction chemotherapy (median: 1085.33 pg/ml) but then decreased to a level (median: 45.26 pg/ml) encountered in the healthy control subjects (median: 56.90 pg/ml). In the cytopenic period due to consolidation treatment, TPO level again increased significantly to a high level (median: 891.38 pg/ml) during the platelet nadir, but decreased toward normal (median: 100.75 pg/ml) after the thrombocytopenic period had elapsed. In conclusion, endogenous TPO levels exhibit an inverse fluctuation in relation to platelet counts during the clinical course of AML. Pharmacological stimulation of thrombopoiesis in AML with novel molecules, including the recombinant thrombopoietins and the small peptide agonists, should be based on a critical administration strategy that must consider the endogenous levels of TPO. TPO levels in distinct AML disease states may explain the unsuccessful recombinant TPO trials and could help to design better strategies for 'pharmacological stimulation of thrombopoiesis' in AML.  相似文献   
992.
The aim of this study was to compare health related quality of life (HRQoL) and assess functional and psychological status in rheumatoid arthritis (RA), fibromyalgia syndrome (FS) patients and controls (each 30 subjects). Demographic characteristics, pain and sleep disturbance by Visual Analog Scale, depression by Beck Depression Inventory (BDI), disease impact by fibromyalgia impact questionnaire, DAS-28, and HRQoL by SF-36 were gathered. The FS group scored significantly worser than the RA group with respect to physical role, social functioning and bodily pain subscales of SF-36. The scores of all SF-36 subscales were significantly lower in FS and RA patients than controls except mental health score. All of the subscales of SF-36 were negatively correlated with BDI scores in FS patients. In RA group, the DAS-28 scores were inversely correlated with all of SF-36 subscales. In conclusion, presence of comorbid depression must be taken into account when determining HRQoL in FS and RA. Essentials improving the HRQoL are management of depression in FS and control of disease activity in RA.  相似文献   
993.
Behcet's disease (BD) is a chronic, multisystem inflammatory disorder of unknown etiology, which is characterized by recurrent aphthous ulcers of the mouth and genitalia, uveitis with hypopyon, and a diffuse vasculitis that involves the arterial and venous systems.
From January 1968 to July 1993, 66 of 844 patients with BD seen at the Hacettepe University Hospital, Ankara, Turkey, experienced a vascular complication other than peripheral thrombophlebitis. The vascular complication in each case was identified based upon a combination of clinical data, digital subtraction angiography, CT, and ultrasonography findings. Six of these 66 (9.1%) had cavernous transformation of the portal vein. Five of these six had additional large vein involvement resulting in the Budd-Chiari syndrome with or without inferior vena caval obstruction.
Based upon this experience, it can be concluded that portal vein thrombosis is not a rare complication of BD. When patients with BD are found to have or develop splenomegaly, portal vein thrombosis should be suspected and investigated. If hepatomegaly and ascites are detected, Budd-Chiari syndrome due to hepatic vein thrombosis should be suspected. Finally, if hepato-splenomegaly, ascites, and dependent edema of the lower body are present, thrombosis of the inferior vena cava should be suspected.  相似文献   
994.
Urinary incontinence (UI) is a common health problem and negatively affects the quality of life of women who are afflicted. The aim of the study is to explore the prevalence and risk factors of UI among climacteric Turkish women and to examine the effects of UI on their quality of life. This cross‐sectional study was conducted with 258 women aged 40–64 years who visited the outpatient clinic in Ankara, Turkey, between 15 June 2012 and 15 January 2013. The data were collected using the International Consultation on Incontinence Questionnaire Short Form and the Incontinence Quality of Life Questionnaire. This paper reveals that the overall prevalence of UI was 45.3%. Stress UI, mixed UI, and urge UI were reported by 54.7%, 22.2%, and 10.3% of the subjects, respectively. The proportion of women suffering from UI who seek medical treatment was low despite mild or moderate negative effect impacts on their quality of life. Increasing women's awareness of UI and protective measures is essential, and standard UI assessment should be added to all patient examinations.  相似文献   
995.
Background: Failure to decrease blood pressure (BP) normally during nighttime, which is called non-dipper, in hypertensive individuals is associated with higher cardiovascular morbidity and mortality. In addition, non-dipper BP leads to structural changes in the left ventricle; however, the influences of non-dipper BP on aortic elastic properties and left ventricular diastolic function have not been studied yet. Methods: In this study, we evaluated aortic elastic properties and left ventricular diastolic function of 22 subjects with non-dipper hypertension, and 15 subjects with dipper hypertension using transthoracic second harmonic standard and tissue Doppler echocardiography (Acuson Sequoia C256®). None of the subjects had any systemic disease or coronary risk factor except hypertension. Results: Age, gender, body mass index, lipids, and standard echocardiographic findings including left ventricular mass index were similar between the groups. Office BP recordings were similar between non-dipper and dipper groups (147.9±6.1/93.9±4.3 vs. 144.0±8.0/93.0±3.7). Daytime and 24-h ambulatory BP measurements were similar within the groups, but nighttime BPs were significantly greater in non-dipper group than those were in dipper group. Left ventricular diastolic parameters obtained by both standard and tissue Doppler did not differ between the non-dipper and dipper groups. However, aortic distensibility was found to be slightly lower (4.1±2.4 vs. 4.9±1.9, p=0.08), and aortic stiffness index (6.3±0.5 vs. 6.1±0.4, p=0.08) and elastic modulus (6.2±2.5 vs. 4.8±2.3, p=0.08; groups non-dipper and dipper respectively) higher in non-dipper group than in dipper group. However, these differences were not statistically significant. Conclusion: Left ventricular remodeling and diastolic function were similar in patients with non-dipper and dipper hypertension. However, aortic elastic properties were slightly impaired in non-dipper hypertensives than those were in dipper ones, but these differences did not reach statistically significance.  相似文献   
996.
Hemostatic changes due to vascular endothelial damage are seen during the course of hematopoietic stem cell transplantation (HSCT). The fibrinolytic response to ongoing hemostatic activation in HSCT remains to be elucidated. Global fibrinolytic capacity (GFC) is a novel method, which reflects the amount of generated D-dimer when fibrinolysis of a freeze-dried fibrin clot is stopped by introducing aprotinin. GFC is sensitive to all the factors involved in the process of fibrinolysis. The aim of this study was to serially assess GFC at certain critical time points (days -1, +7, +14, +21 prior to and following stem cell infusion) during the course of HSCT. The study group comprised 16 patients with hematological malignancies (11 women, five men; median age 32+/-9 years) in whom HSCT had been performed. Thirty healthy adults (21 women, nine men; median age 31+/-7 years) served as controls. In this study, global fibrinolytic response, as reflected by GFC, was unchanged despite ongoing hemostatic activation, as indicated by D-dimer, moreover GFC remained stable, despite the development of thrombocytopenia associated with HSCT prior to platelet engraftment. Our results indicate that a global fibrinolytic response was impaired as a compensatory response to endothelial activation and to other hemostatic changes seen in HSCT. Further studies in larger HSCT populations are warranted to better understand the implications of these findings.  相似文献   
997.
ObjectiveThere are few reports about the direct toxic effects of hyperhomocysteinemia on the liver. We investigated oxidative and nitrosative stresses and apoptotic and necrotic changes in the liver of rats fed a high-methionine (HM) diet (2%, w/w) for 6 mo. We also investigated whether taurine, an antioxidant amino acid, is protective against an HM-diet–induced toxicity in the liver.MethodsLipid peroxide levels, nitrotyrosine formation, and non-enzymatic and enzymatic antioxidants were determined in livers of rats fed an HM diet. In addition, apoptosis-related proteins, proapoptotic Bax and antiapoptotic B-cell lymphoma-2 expressions, apoptotic cell count, histopathologic appearance in the liver, and alanine transaminase and aspartate transaminase activities in the serum were investigated.ResultsPlasma homocysteine levels and serum alanine transaminase and aspartate transaminase activities were increased after the HM diet. This diet resulted in increases in lipid peroxide and nitrotyrosine levels and decreases in non-enzymatic and enzymatic antioxidants in liver homogenates in rats. Bax expression increased, B-cell lymphoma-2 expression decreased, and apoptotic cell number increased in livers of rats fed an HM diet. Inflammatory reactions, microvesicular steatosis, and hepatocyte degeneration were observed in the liver after the HM diet. Taurine (1.5%, w/v, in drinking water) administration and the HM diet for 6 mo was found to decrease serum alanine transaminase and aspartate transaminase activities, hepatic lipid peroxide levels, and nitrotyrosine formation without any change in serum homocysteine levels. Decreases in Bax expression, increases in B-cell lymphoma-2 expression, decreases in apoptotic cell number, and amelioration of histopathologic findings were observed in livers of rats fed with the taurine plus HM diet.ConclusionOur results indicate that taurine has protective effects on hyperhomocysteinemia-induced toxicity by decreasing oxidative and nitrosative stresses, apoptosis, and necrosis in the liver.  相似文献   
998.
Untreated asymptomatic bacteriuria has been associated with acute pyelonephritis, which may have a role in many maternal and fetal complications. Acute pyelonephritis in pregnancy is related to anemia, septicemia, transient renal dysfunction, and pulmonary insufficiency. A randomized study was conducted to assess the clinical and microbiological efficacy of a single dose of fosfomycin trometamol for the treatment of asymptomatic bacteriuria in the second trimester of pregnancy compared with a 5-day regimen of cefuroxime axetyl. Forty-four women received fosfomycin trometamol and 40 women received cefuroxime axetyl. There were no statistically significant differences between both groups regarding the mean age and mean duration of pregnancy. Therapeutic success was achieved in 93.2% of the patients treated with fosfomycin trometamol vs 95% of those treated with cefuroxime axetyl. A single dose of fosfomycin trometamol is a safe and effective alternative in the treatment of asymptomatic urinary tract infections in the second trimester of pregnancy.  相似文献   
999.
The presence of estrogen and progesterone-receptor-positive stroma is well known in renal mixed epithelial and stromal tumor, cystic nephroma, and angiomyolipoma with epithelial cysts. It has been suggested that the hormone receptor positivity in mixed epithelial and stromal tumor may be etiologically related to exogenous hormone intake-a phenomenon that has become more frequent in recent years. In the past few years, we have observed such stroma in some non-neoplastic kidneys, as well as in tumor-bearing kidneys away from the tumor. Herein we present our experience with 10 such cases. In a prospective manner, whenever we noted stroma resembling that in ovaries or müllerian organs (endometrial or cervical-like) in kidneys removed for any cause, immunohistochemical stains for estrogen and progesterone receptors were performed. There were eight males and two females among the group, with ages ranging from 11 months to 71 years. In six cases, the nephrectomies were performed for a non-functional kidney, and in three for tumors (one each of chromophobe, clear cell, and acquired cystic disease-associated renal cell carcinoma). One case was a partial nephrectomy for vesico-ureteric reflux, with upper pole hydronephrosis. Such stroma was present in nine cases as a non-mass forming proliferation around dilated, frequently inflamed pelvicalyceal system and collecting ducts. In one it was present at the periphery of an acquired cystic disease-associated renal cell carcinoma, as well as around non-tumorous cysts. The only common finding in all cases was a generalized or segmental hydronephrosis, or tumor compression-related focal obstruction. The stroma was positive for estrogen receptors in all 10 cases, and for progesterone receptors in seven. Thus, estrogen- and progesterone receptor-positive stroma can be present in the kidney, not only as a component of certain tumors, but also in association with non-neoplastic conditions. Its association with obstructive changes suggests that it may represent a metaplastic change in the renal interstitial cells surrounding these obstructed epithelial structures.  相似文献   
1000.
Spinocerebellar ataxia type 2 is a neurodegenerative disease caused by a CAG repeat expansion in the ataxin-2 gene. Gain-of-toxic effects caused by expanded polyglutamine tracts are important for the disease pathogenesis and there is an inverse relationship between the number of CAG repeats and the age of onset and clinical severity. Previously, we reported an extended Turkish family with spinocerebellar ataxia type 2 with several affected members in three generations. Two sisters in this generation showed an earlier age of onset (5 and 7years, respectively) than their father (30years). In this paper, we present a further interesting finding regarding the disease onset and manifestation in the two sisters. Interestingly, the age of onset was delayed and the clinical severity of the disease was milder in the child who had more CAG repeats (84 vs. 70). This finding suggests that there are other factors contributing to the age of onset and clinical severity in spinocerebellar ataxia type 2 other than the increased CAG repeat.  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