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   4397篇
  免费   195篇
  国内免费   15篇
耳鼻咽喉   105篇
儿科学   196篇
妇产科学   229篇
基础医学   680篇
口腔科学   31篇
临床医学   262篇
内科学   973篇
皮肤病学   69篇
神经病学   384篇
特种医学   72篇
外科学   189篇
综合类   28篇
预防医学   394篇
眼科学   112篇
药学   583篇
中国医学   15篇
肿瘤学   285篇
  2024年   2篇
  2023年   24篇
  2022年   153篇
  2021年   303篇
  2020年   104篇
  2019年   134篇
  2018年   143篇
  2017年   130篇
  2016年   153篇
  2015年   158篇
  2014年   203篇
  2013年   286篇
  2012年   367篇
  2011年   378篇
  2010年   202篇
  2009年   150篇
  2008年   240篇
  2007年   312篇
  2006年   279篇
  2005年   257篇
  2004年   189篇
  2003年   190篇
  2002年   152篇
  2001年   16篇
  2000年   9篇
  1999年   6篇
  1998年   7篇
  1997年   10篇
  1996年   6篇
  1995年   4篇
  1992年   3篇
  1991年   4篇
  1990年   2篇
  1986年   1篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1981年   2篇
  1980年   1篇
  1978年   3篇
  1977年   2篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1972年   4篇
  1971年   2篇
  1970年   1篇
  1969年   2篇
  1967年   1篇
  1935年   1篇
排序方式: 共有4607条查询结果,搜索用时 15 毫秒
71.
Right classification of diabetes is important clinical issue. The aim of present study was to compare clinical, biochemical and immunological features, to analyze their practical use and to establish new decision tree which make the distinction between diabetes type 1, LADA, diabetes type 2 and MODY. We studied 97 not obese (mean BMI 26.3 +/- 4.9 kg/m2) patients aged 14 to 70 years, mean age 43 +/- 11.7 years, 53 women, 44 men. Mean duration of diabetes--2.3 +/- 4.3 years. We measured basal and stimulated C-peptide (6 minutes after 1 mg i.v. glucagon) (ELISA) and antibodies titers to glutamic acid decarboxylase--antiGAD65, tyrosine phosphatase-like molecule--IA2 and insulin--IAA (RIA). Autoimmune diabetes (LADA, type 1) was diagnosed with presence of one or more islet antigen antibodies. The highest frequencies had anti-GAD antibodies 33/97 (34%). The most complicated was to sort out group of patients with LADA. Comparison between this group and patients with diabetes type 2 have shown that BMI, co-existence of autoimmune disease, autoimmune markers and basal and stimulated C-peptide level measured at entry for the classification were useful in differentiation. Moreover we observed significantly lower C-peptide basal, stimulated and over basal level in group with MODY diabetes in comparison to diabetes type 2 patients. In the studied group were 5 patients with diabetes type 2 and obesity, in relatively young age. At the end there was one case of ADM (atypical diabetes mellitus). Clinical criteria for the classification of diabetes not always correlated with diagnosis. Autoimmune markers, basal and stimulated C-peptide were useful specially in differentiation between LADA and diabetes type 2 or diabetes type 1. Autoimmune diabetes co-existe with autoimmune disease. Proposed diagnostic scheme take for consideration presence of autoantibodies as well as C-peptide criteria.  相似文献   
72.
Intercellular adhesion molecule-1 (ICAM-1) is 1 of the possible factors linking obesity and diabetes with cardiovascular disease, however, the mechanism of the increase in ICAM-1 concentration in obesity remains unclear. Therefore, the aim of the present study was to assess plasma soluble ICAM-1 (sICAM-1) levels in obese subjects with normal glucose tolerance and to evaluate whether those levels may be related to insulin resistance and tumor necrosis factor-alpha (TNFalpha) system activity. The study was performed in 8 lean and 15 obese subjects. Anthropometric and biochemical parameters were measured, and insulin sensitivity was evaluated using the euglycemic hyperinsulinemic clamp technique (insulin infusion, 50 mU x kg(-1) x h(-1)). Obese subjects were markedly more hyperinsulinemic and insulin resistant and had higher plasma soluble TNF receptor 2 (sTNFR2) and sICAM-1 levels. sICAM-1 was related positively to body mass index (BMI), waist-to-hip ratio (WHR), percent of body fat, glycated hemoglobin (HbA(1c)), plasma insulin and triglycerides (TG), TNFalpha, and sTNFR2 and negatively to insulin sensitivity. Multiple regression analysis showed that only sTNFR2 and insulin sensitivity were independent predictors of sICAM-1 concentrations and were responsible for 66% of sICAM-1 variability. We conclude that an increase in plasma sICAM-1 concentration in obesity is related to TNFalpha system activation and insulin resistance.  相似文献   
73.
Dermatomyositis (DM) is a connective tissue disease characterized by specific inflammatory lesions in muscle biopsy. It is caused by vasculitis determined by humoral factors with subsequent inflammatory cell accumulation, mainly T CD4+ and B cells, which infiltrate myocytes leading to its vacuolization and degeneration (mainly in the skeletal muscles, rarely in the smooth muscles). The incidence of DM is estimated at 1-10 per million in adults and at 1-3.2 per million in children. The autoimmune mechanism of disease induction is not fully recognized. Several lines of evidence showed the link between DM and neoplastic disease. The first report of dermatomyositis associated with stomach cancer, by Stertz, comes from 1916. In the same time, Kankeleit reported DM associated with breast cancer. Presumably, it is the result of immune reaction against antigens common for muscle and neoplastic cells or some paraneoplastic syndrome underlying mechanism. The report presents the case of a 52-year-old woman with DM (diagnosed according to the Bohan and Peter criteria) and with coexistent squamous lung cancer in situ. The left upper lobectomy was performed. No complications in postoperative period were observed. During more than 2 years of follow-up after the surgery, the patient remained in good condition, without DM symptoms, or cancer relapse. Considering that DM may be associated with lung cancer; extensive diagnostic work-up to exclude neoplastic lesions should be performed. Patients aged 40 years or more should be particularly screened.  相似文献   
74.
The objective of the paper was compare the effects and tolerability of combined therapy of multiple intravenous infusions of anti-tumour necrosis factor-alfa (TNF-alfa) monoclonal antibody (Remicade) with methotrexate versus treatment with sodium aurothiomalate and intramuscular depot methylprednisolone in rheumatoid arthritis (RA). We investigate also the interval necessary to obtain the improvement in both treatment groups. 36 patients commencing intramuscular sodium aurothiomalate therapy with intramuscular depot methylprednisolone acetate at weeks 0, 4, 8 and 12 in addition to chrysotherapy were compared in retrospective analysis with 32 patients starting with multiple intravenous infusions of infliximab, anti-TNF-alfa monoclonal antibody (Remicade) and methotrexate at a stable dose. Patients were assessed by composite clinical score (DAS 28) and C-reactive protein during 22 weeks of therapy. At week 2 and 6 a significantly greater percentage of infliximab-treated than gold-treated RA patients achieved improvement in each clinical measurement of disease activity. At 22 week of treatment moderate and good response according to EULAR criteria was achieved in 91% of infliximab-treated patients and 58% gold treated patients (p < 0.001). Adverse events were more frequently observed in infliximab-treated patients, but only gold-treated patients discontinued treatment because adverse events (2 patients due to proteinuria, 2 patients due to mucocutaneous changes and one patient due to leucopenia). The higher percentage of adverse events in infliximab-treated patients was caused mainly by the occurrence of infusion reactions (23 reactions out of 160 infusions); most of them were mild (somnolentia and headache) and transient. Viral infections (including herpes simplex and zoster) were more common in patients treated with infliximab and methotrexate. Combination therapy of infliximab and methotrexate is more effective in reducing clinical and biochemical disease activity than gold with methylprednisolone treatment in RA patients during 22 weeks of treatment, especially in the first 6 weeks.  相似文献   
75.
Recombinant human erythropoietin (rhEPO) treatment of hemodialyzed (HD) patients normalizes the altered phenotype of CD4+ lymphocytes and restores the balance of Th1/Th2 cytokines. We decided to test how the presence of rhEPO in cell culture modulates cytokine production of CD4+ lymphocytes in HD patients with stable hemoglobin level and expression of activation antigens of stimulated CD4+ lymphocytes similar to those observed in healthy individuals. We also tested whether the presence of rhEPO in cell culture protects stimulated CD4+ lymphocytes of HD patients from apoptosis. Peripheral blood mononuclear cells (PBMC) of HD patients were stimulated with an immobilized anti-CD3 antibody with or without addition of rhEPO. The percentage of apoptotic CD4+ lymphocytes and the level of Th1/Th2 cytokines in culture supernatants were measured with flow cytometry. HD patients showed a decrease in the percentage of apoptotic CD4+ cells after stimulation with the anti-CD3 antibody combined with rhEPO. The level of IFN-γ and IL-10 was increased while the level of TNF-α was decreased in the presence of rhEPO in cell culture from HD patients. These results confirm the role of rhEPO signaling in T lymphocytes of HD patients.  相似文献   
76.
One of the basic rules of transfusion is to prevent alloimmunisation by highly immunogenic RhD antigen and not to transfuse RhD negative individuals with RhD positive blood. In some cases the expression of this antigen is so weak that it is undetectable in routine serological tests. The paper presents an algorithm for mass DNA testing with the purpose of identifying donors with low RhD expression. The screening is based on RHD gene detection (absent in RhD negative Caucasians) in DNA isolated from pools of 96 plasma samples from blood donors identified as RhD negative by the routine serological methods in Blood Transfusion Centers. Such procedure substantially reduces the costs. Plasma samples can be brought from the territory of the whole country, stored and accumulated for testing in one selected center. The cost would amount to approximately 25 PLN per donor. The test is performed once for each RhD negative individual. It is estimated that such persons will represent approximately 0.2% of RhD negative donors.  相似文献   
77.
Bruton's tyrosine kinase (BTK) is a central mediator of B-cell receptor (BCR) signaling essential for normal B-cell development. Ibrutinib is an oral BTK inhibitor that induces apoptosis and inhibits migration and adhesion of malignant B-cells. Updated results of this international, multicenter, phase 2 study of single agent ibrutinib in relapsed or refractory MCL will be presented.Ibrutinib 560 mg PO QD was administered continuously until disease progression. Tumor response was assessed every 2 cycles (one cycle = 28 days). The study enrolled 115 patients (65 bortezomib-naïve, 50 bortezomib-exposed); 111 patients were treated; 110 were evaluable for response. Baseline characteristics included: median age 68 years, time since diagnosis 42 months, number of prior treatments 3; bulky disease (>10 cm) 13%, prior stem cell transplant 10%, high risk MIPI 49%.Median time on treatment was 9.2 months; 53% of patients remain on therapy. Median PFS was 13.9 months and DOR has not yet been reached. Responses increased with longer treatment: comparing to previous data described at ASH 2011, the CR rate increased from 16% to 39%, and the ORR increased from 69% to 75%.  相似文献   
78.
IntroductionThe aim of the study was to evaluate the correlation between the nutritional status of patients with anorexia nervosa (AN) and levels of vaspin (VASP), neuropeptide B (NPB), neuropeptide W (NPW) and total antioxidant status (TAS).Material and methodsNinety serum samples collected from 30 teenage female patients during the acute stage of AN and 30 healthy persons (CONTR) were subjected to biochemical analysis; patients with AN were examined at the beginning of the study (AN-I) and after hospitalization (AN-II), as a result of which partial stabilization of anthropometric measurements was achieved (an increase of body mass index (BMI) by 3.5 kg/m2).ResultsVaspin levels dropped at the end of the hospitalization (compared to AN-I, p < 0.05), achieving values comparable to the CONTR; moreover there was a positive correlation between VASP level and the achieved body weight in AN-II (p < 0.05). Positive correlations were also noted with regard to VASP vs. NPB in AN-I (p < 0.02) (and AN-II, p < 0.013), as well as in the case of VASP vs. NPW in the same groups (p < 0.02 and p < 0.015, respectively). NPB concentration was higher in AN-I (p < 0.05) and AN-II (p < 0.018) than in CONTR, whereas there were no differences (p > 0.05) with regard to levels of VASP, NPW, or TAS.ConclusionsThe high level of NPB despite treatment and normalization of VASP level may suggest that there are chronic neuroendocrine disorders at play in anorexia nervosa.  相似文献   
79.
IntroductionImmunoglobulin A nephropathy (IgAN) may lead to end stage renal disease and severely affect patient functioning and wellbeing. The aim of the study was to evaluate health-related quality of life (HRQoL) in children and adolescents with IgAN, and compare HRQoL in relation to the disease course, social status and psychological factors, such as expressing anger and perceived personal competence.Material and methodsThe multicentre cross-sectional study included 51 patients ≥ 8 years from 7 paediatric nephrology centres in Poland. Psychometric analysis was performed using the Kidscreen-52 questionnaire to evaluate HRQoL, the Anger Expression Scale to evaluate the severity of anger and the Personal Competence Scale to measure general perception of personal competence.ResultsMean age of patients was 14.54 ±3.69 years; duration since the diagnosis of IgAN was 4.98 ±3.9 years. Patients with IgAN rated their psychological wellbeing as significantly worse compared to healthy peers (p < 0.05). The presence of proteinuria was associated with significantly worse physical wellbeing (58.72 ±18.45 vs. 74.44 ±22.97; p < 0.05). Current therapy (steroids/immunosuppressive drugs) had no effect on HRQoL in the study group. Perceived personal competence was rated high by 49% of children in the study group. Children with IgAN were characterized by lower intensity of expressed anger (p < 0.001) and significantly higher intensity of suppressed anger (p < 0.01) compared to reference ranges. Severity of expressed anger correlated positively with the parent relations and school environment dimensions of HRQoL.ConclusionsWe found lower HRQoL in regard to physical and psychological wellbeing in a group of Polish children with IgAN compared to healthy peers. HRQoL should be monitored in this patient group.  相似文献   
80.
IntroductionIn inflammatory bowel diseases (IBD), osteopenia and osteoporosis constitute a significant medical problem. Cytokines, especially IL-17, play an important role in the pathogenesis of IBD and osteoporosis. Vitamin D is a regulator of bone metabolism, and helps maintain immune system homeostasis.Material and methodsThe research sample consisted of 208 persons: 83 patients (age 35 ±11.99 years) with Crohn’s disease (CD); 86 patients (age 39.58 ±14.74 years) with ulcerative colitis (UC); and 39 persons (age 30.74 ±8.63 years) in the control group (CG). Clinical data on bone mineral density of the lumbar spine (L2-L4), bone mineral density of the femoral neck (FN), and body mass index (BMI) were collected. 25OHD and IL-17 serum concentrations were also measured.ResultsBody mass index (kg/m2) results: in CD, 21.51 ±3.68; in UC, 23.31 ±4.38; and in CG, 24.57 ±3.45 (p < 0.01). Densitometry results for L2–L4 T-score SD: in CD –0.83 ±1.45; in UC –0.47 ±1.15; in CG 0.09 ±0.70. Densitometry results for FN T-score SD: in CD –0.62 ±1.26; in UC –0.29±1.17; in CG 0.41 ±1.03 25OHD (ng/ml) serum concentrations: in CD, 21.33±12.50; in UC, 22.04±9.56; in CG, 21.56±9.11 (ns). IL-17 (pg/ml) serum concentrations: in CD, 8.55±10.99; in UC, 11.67±12.97; in CG, 5.16±9.11 (ns).ConclusionsInflammatory bowel diseases patients and persons from the CG did not differ in vitamin D or IL-17 levels. Patients with a mild course of the disease had a higher vitamin D concentration and bone mineral density. In UC, higher vitamin D concentrations were associated with lower IL-17 concentrations. The IBD patients with a severe course of the disease had a lower body mass than those in the CG and the patients with a mild course of the disease.  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