全文获取类型
收费全文 | 2043篇 |
免费 | 124篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 161篇 |
妇产科学 | 27篇 |
基础医学 | 225篇 |
口腔科学 | 51篇 |
临床医学 | 214篇 |
内科学 | 478篇 |
皮肤病学 | 25篇 |
神经病学 | 69篇 |
特种医学 | 488篇 |
外科学 | 154篇 |
综合类 | 28篇 |
预防医学 | 50篇 |
眼科学 | 13篇 |
药学 | 112篇 |
中国医学 | 3篇 |
肿瘤学 | 89篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 21篇 |
2020年 | 19篇 |
2019年 | 18篇 |
2018年 | 28篇 |
2017年 | 21篇 |
2016年 | 26篇 |
2015年 | 30篇 |
2014年 | 40篇 |
2013年 | 67篇 |
2012年 | 37篇 |
2011年 | 32篇 |
2010年 | 88篇 |
2009年 | 62篇 |
2008年 | 56篇 |
2007年 | 42篇 |
2006年 | 44篇 |
2005年 | 35篇 |
2004年 | 27篇 |
2003年 | 30篇 |
2002年 | 43篇 |
2001年 | 30篇 |
2000年 | 39篇 |
1999年 | 37篇 |
1998年 | 142篇 |
1997年 | 122篇 |
1996年 | 129篇 |
1995年 | 93篇 |
1994年 | 76篇 |
1993年 | 82篇 |
1992年 | 27篇 |
1991年 | 32篇 |
1990年 | 27篇 |
1989年 | 69篇 |
1988年 | 51篇 |
1987年 | 52篇 |
1986年 | 54篇 |
1985年 | 55篇 |
1984年 | 30篇 |
1983年 | 36篇 |
1982年 | 35篇 |
1981年 | 20篇 |
1980年 | 37篇 |
1979年 | 20篇 |
1978年 | 16篇 |
1977年 | 22篇 |
1976年 | 23篇 |
1975年 | 27篇 |
1969年 | 4篇 |
排序方式: 共有2193条查询结果,搜索用时 9 毫秒
101.
Sandra Trapani Paola Mariotti Massimo Resti Lido Nappini Maurizio de Martino Fernanda Falcini 《Rheumatology international》2010,30(10):1355-1359
Henoch Schonlein purpura (HSP) is a small-sized blood vessels vasculitis, resulting from immunoglobulin A-mediated inflammation.
It is the most common acute systemic vasculitis in childhood and mainly affects skin, gastrointestinal tract, joints and kidney.
Skin lesions, usually presenting as erythematous maculopapules, petechiae, and purpura, often involve lower extremities and
buttocks, but may also extend to the upper extremities, face and trunk. Conversely to adults, hemorrhagic bullous evolution
has been seldom described in childhood. The pressure is likely a factor into the pathogenesis of bullae. We report on three
new pediatric cases of HSP with hemorrhagic bullous skin lesions, and a review of the literature. Bullous evolution represents
an unusual, but well-recognized cutaneous manifestation that may be a source of diagnostic dilemma, but does not seem to have
any prognostic value in the outcome of HSP. 相似文献
102.
Antoniucci D Valenti R Migliorini A Moschi G Trapani M Buonamici P Cerisano G Bolognese L Santoro GM 《American heart journal》2002,144(2):315-322
Background The impact of abciximab therapy on mortality in unselected patients with acute myocardial infarction (AMI) undergoing routine primary infarct-related artery (IRA) stent implantation is not yet defined, and previous randomized studies have produced conflicting results. Methods A strategy of IRA stenting alone as opposed to IRA stenting plus abciximab was compared in a series of 561 consecutive unselected patients with AMI. Abciximab tretament was strongly encouraged for all patients. The contraindication for abciximab therapy was a high risk of major bleeding as assessed by the operator before mechanical intervention. Results Of 561 patients, 348 patients underwent abciximab therapy and 213 underwent primary IRA stenting alone. The 1-month overall mortality rate was 2.9% in the abciximab group and 10.8% in the stent alone group (P < .001). The relative reduction in mortality rate was 73% for patients overall, 77% in the subset of patients aged ≤70 years (mortality rate, 1.2% vs 5.2%, P = .020), 57% in patients aged >70 years (7.7% vs 18%, P = .043), 63% in patients with cardiogenic shock (17% vs 46%, P = .022), and 77% in patients without cardiogenic shock (1.3% vs 5.6%, P = .002). Multivariate analyses on the basis of all patients, and on the subset of patients aged ≤70 years, showed that abciximab therapy was independently related to the risk of death at 1 month. No differences were seen between groups in the procedural success rate (99.1% vs 98.1%) or in the incidence rates of nonfatal reinfarction (0.3% vs 1.9%) or repeat target vessel revascularization (1.7% vs 1.9%). Conclusion The results of this study strongly support the use of abciximab therapy in nonselected patients with AMI undergoing routine IRA stent implantation. The mechanism of the clinical benefit of abciximab was not related to the patency of the IRA. (Am Heart J 2002;144:315-22.) 相似文献
103.
David Antoniucci Renato Valenti Guia Moschi Angela Migliorini Maurizio Trapani Giovanni Maria Santoro Leonardo Bolognese Giampaolo Cerisano Piergiovanni Buonamici Emilio Vincenzo Dovellini 《The American journal of cardiology》2002,89(2):121-125
It is unknown if collateral circulation (CC) has a beneficial effect on outcomes of patients who undergo mechanical intervention in the first hours after onset of acute myocardial infarction (AMI). This study analyzes the relation between CC and outcome in patients with AMI who underwent primary angioplasty or stenting within 6 hours of symptom onset. The analysis was performed in a series of 1,164 consecutive patients. The contribution of clinical, angiographic, and procedural variables to the angiographic and clinical outcomes was evaluated by multivariate logistic regression analysis and the Cox proportional hazard model, respectively. Of 1,164 patients, 264 (23%) had angiographic evidence of CC. Patients with CC had a lower incidence of diabetes (11% vs 16%, p = 0.033), anterior AMI (41% vs 55%, p <0.001), cardiogenic shock (9% vs 14%, p = 0.029), anterograde TIMI grade flow >1 (10% vs 21%, p <0.001), and a greater incidence of preinfarction angina (43% vs 32%, p = 0.001), multivessel disease (59% vs 47%, p = 0.001), and total chronic occlusion (20% vs 10%, p <0.001). At 6 months, the mortality rate was lower in patients with CC compared with patients without CC (4% vs 9%, p = 0.011), whereas there were no differences in the incidence of reinfarction, target vessel revascularization, and angiographic restenosis. After multivariate analysis, CC did not emerge as a significant variable in relation to 6-month clinical and angiographic outcomes. CC does not exert a protective effect in patients who undergo mechanical intervention in the first 6 hours of AMI onset. 相似文献
104.
Coronary heart disease is less prevalent in pre-menopausal women than in men, but increases at the onset of menopause. This delay is due to estrogen protective effects. The rise of cholesterolemia is one of the main risk factors for coronary disease. Since 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is the rate-limiting enzyme of the cholesterol biosynthetic pathway, it plays a pivotal role in cholesterol homeostasis maintenance. Aim of this study is to investigate whether HMGR is involved in the cholesterolemia increase that occurs during aging, and to consider its potential role as a target for estrogen protective effects. “In vivo” studies have been performed using the livers of 12-month-old female rats (whose estrogen level decrease is comparable to the one detected at the occurrence of human menopause), 12-month-old female rats treated with 17-β-estradiol, and 3-month-old untreated male and female rats. The results indicated hypercholesterolemic status and a significant increase of HMGR activity according to a reduced activation of AMPK detected in treated rats compared to controls. Furthermore, 17-β estradiol treatment reduced HMGR activity restoring AMPK activation. These findings highlight the correlation between estrogen and HMGR short-term regulation, and suggest the presence of another mechanism underlying the protective role of estrogen in age-related diseases. 相似文献
105.
R Rubio O Serrano J Carmena V Asensi S Echevarría J Flores E Ribera M Zarraga A Ocampo B De La Fuente MA Sepúlveda AI Mario C Minguez R Vicent JA Cartn B Moyano H Esteban B Mahillo L Serrano J Gonzlez‐García 《HIV medicine》2010,11(9):545-553
Background
Atazanavir (ATV) boosted with ritonavir (ATV/r) is a potent, well‐tolerated, once‐daily protease inhibitor (PI). Few data are available on this agent as a treatment simplification option for patients taking other PIs.Objective
The aim of the study was to determine the effectiveness and safety of ATV‐containing regimens in patients who have simplified their antiretroviral treatment.Methods
SIMPATAZ was a multicentre, prospective, noninterventional study in patients who had undetectable HIV RNA on their current PI‐containing therapy and who were switched to an ATV/r‐based regimen. Patients underwent a routine physical examination, and data were collected on HIV RNA levels, CD4 cell counts, liver function, lipid parameters, adverse reactions, adherence to treatment and patient satisfaction.Results
A total of 183 patients were enrolled in the study and included in the analysis (80% were male, 29% had AIDS, and 52% were coinfected with HIV and hepatitis B virus or hepatitis C virus). The median baseline CD4 count was 514 cells/μL. Median exposure to previous HIV therapy was 8 years, and 32% of patients had a history of PI failures. Lopinavir boosted with ritonavir was the most frequent PI replaced (62%) and tenofovir+lamivudine /emtricitabine the backbone most used during the study (29%). The study drug was discontinued early by 25 patients (14%), two of whom discontinued as a result of adverse events (Hodgkin lymphoma and vomiting). Two patients died (lung cancer and myocardial infarction). At month 12, 93% of the study population had an undetectable HIV RNA viral load. Hyperbilirubinaemia >3 mg/dL and increased alanine aminotransferase levels>200 IU/L were observed in 38.5% and 4.4% of patients, respectively. Median changes from baseline to month 12 in total cholesterol, triglycerides and low‐density lipoprotein cholesterol were ?13 mg/dL (?7%; P<0.0001), ?19 mg/dL (?13%; P<0.0001) and ?7 mg/dL (?6%; P=0.021), respectively.Conclusions
In a real‐world setting, switching from other PIs to ATV/r is a well‐tolerated and safe option for improving the lipid profile and for retaining virological response in controlled pretreated patients.106.
Bo S Bertino E Trapani A Bagna R De Michieli F Gambino R Ghione F Fabris C Pagano GF 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2007,17(10):741-747
AimsTo evaluate cross-sectional associations between dietary magnesium intake and the metabolic pattern of very-low-birth-weight (VLBW, <1500 g) pre-term children, in pre-school years (>2 and < 6 years).Methods and resultsFifty-eight Italian children without major congenital malformations/conditions were enrolled; dietary intakes, clinical and (in 34 cases) laboratory characteristics were evaluated. Subjects with lower magnesium intake showed significantly higher fasting glucose, insulin and Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) levels. At simple regression analysis, fasting glucose was significantly associated with magnesium intake (inversely) and catch-up growth (CUG). Fasting insulin and HOMA-IR values were inversely associated with intakes of magnesium and fibres, and directly with Body Mass Index (BMI) and CUG. In a multiple regression model, after adjusting for multiple confounders and fibre intake, magnesium intake was inversely associated with glucose (β = − 0.018; 95%CI −0.026 to −0.010), but not with insulin or HOMA-IR levels. In the same model, dietary fibres remained inversely associated with insulin (β = − 0.075; −0.14 to −0.008) and HOMA-IR levels (β = − 0.06; −0.11 to −0.01).ConclusionThese results suggest a significant association between reduced magnesium intake and fasting glucose, and between reduced fibre intake and insulin resistance and this is present even in earlier childhood, and independently of BMI and growth characteristics. 相似文献
107.
Retrovirally marked CD34-enriched peripheral blood and bone marrow cells contribute to long-term engraftment after autologous transplantation 总被引:16,自引:17,他引:16
Dunbar CE; Cottler-Fox M; O'Shaughnessy JA; Doren S; Carter C; Berenson R; Brown S; Moen RC; Greenblatt J; Stewart FM 《Blood》1995,85(11):3048-3057
We report here on a preliminary human autologous transplantation study of retroviral gene transfer to bone marrow (BM) and peripheral blood (PB)-derived CD34-enriched cells. Eleven patients with multiple myeloma or breast cancer had cyclophosphamide and filgrastim-mobilized PB cells CD34-enriched and transduced with a retroviral marking vector containing the neomycin resistance gene, and CD34-enriched BM cells transduced with a second marking vector also containing a neomycin resistance gene. After high-dose conditioning therapy, both transduced cell populations were reinfused and patients were followed over time for the presence of the marker gene and any adverse effects related to the gene-transfer procedure. All 10 evaluable patients had the marker gene detected at the time of engraftment, and 3 of 9 patients had persistence of the marker gene for greater than 18 months posttransplantation. The marker gene was detected in multiple lineages, including granulocytes, T cells, and B cells. The source of the marking was both the transduced PB graft and the BM graft, with a suggestion of better long-term marking originating from the PB graft. The steady- state levels of marking were low, with only 1:1000 to 1:10,000 cells positive. There was no toxicity noted, and patients did not develop detectable replication-competent helper virus at any time posttransplantation. These results suggest that mobilized PB cells may be preferable to BM for gene therapy applications and that progeny of mobilized peripheral blood cells can contribute long-term to engraftment of multiple lineages. 相似文献
108.
Antisickling effects of 2,3-diphosphoglycerate depletion 总被引:2,自引:0,他引:2
Elevation of 2,3-bisphosphoglycerate (2,3-DPG) in sickle erthrocytes (SS RBCs) and concomitant acidification of the cell interior promote polymerization by decreasing the solubility (csat) of deoxyhemoglobin S. The antisickling effect of 2,3-DPG depletion was evaluated after activation of the 2,3-DPG phosphatase activity of bisphosphoglycerate mutase by glycolate-2-phosphate, leading to rapid loss of intracellular 2,3-DPG. To ensure its maximal reduction in a physiologic medium, isosmotic CO2/bicarbonate-buffered saline, pH 7.0, was used. Substitution of K+ for Na+ as the major extracellular cation suppressed K:Cl cotransport, prevented cell shrinkage, and allowed demonstration of the full antisickling effect of 2,3-DPG depletion. The modest effect on solubility per se of removing intraerythrocytic 2,3-DPG (delta Csat = 1.6 g/dL) was amplified into a much larger antisickling effect by interaction with three other cellular variables affecting solubility and polymer content (intracellular pH, O2 saturation, and mean cell hemoglobin concentration). Acting in concert, these four antisickling effects (three solubilizing, one osmotic) reduced polymer fraction of glycolate-treated SS RBCs by 32% to 63%, with a concomitant decrease in sickling of 46% to 95% at the nominal pO2 of the microcirculation (20 mm Hg). A decrement in sickling of this magnitude should significantly ameliorate the vasoocclusive severity of sickle cell disease. 相似文献
109.
Analysis of optimal conditions for retroviral-mediated transduction of primitive human hematopoietic cells 总被引:7,自引:4,他引:7
We sought to define optimal conditions for retroviral-mediated transduction of long-lived human hematopoietic progenitors from bone marrow and peripheral blood. CD34+ cells were transduced by the LN and G2 retroviral vectors in the presence or absence of stromal support and with or without cytokine addition. After transduction, a portion of the cells was plated in methylcellulose colony-forming assay, with or without G418, to assess the extent of gene transfer into committed progenitors. The remaining cells from each experiment were transplanted into immunodeficient mice to allow analysis of transduction of long- lived progenitors. Human colony-forming cells contained within the murine bone marrow were analyzed after engraftment periods of 2 to 11 months. Cells were plated in a human-specific colony-forming assay with and without G418 to assess the extent of transduction of primitive progenitors. Individual human colonies were also analyzed by polymerase chain reaction for the presence of provirus. Bone marrow progenitors were efficiently transduced only when stroma was present, whereas mobilized peripheral blood progenitors were effectively transduced in the presence of either stroma or cytokines. Inclusion of the cytokines interleukin-3, interleukin-6, and stem cell factor did not further augment the extent of gene transfer in the presence of a stromal support layer. Additionally, human CD34+ progenitors from bone marrow or mobilized peripheral blood that had been transduced for 3 days in the absence of stroma failed to produce sustained, long-term engraftment of bnx mice. Mice transplanted with the same pools of human progenitors that had been transduced in the presence of stroma for 3 days had significant levels of human cell engraftment at the same timepoints, 7 to 11 months after transplantation. Our data show loss of long-lived human progenitors during 3-day in vitro transduction periods in the absence of stromal support. Therefore, the presence of bone marrow stroma has dual benefits in that it increases gene transfer efficiency and is essential for survival of long-lived human hematopoietic progenitors. 相似文献
110.
Corzo D; Yunis JJ; Salazar M; Lieberman JA; Howard A; Awdeh Z; Alper CA; Yunis EJ 《Blood》1995,86(10):3835-3840
Genes of the major histocompatibility complex (MHC) have been associated with susceptibility to drug-induced adverse reactions. We previously found that clozapine-induced agranulocytosis (CA) is associated with the HLA-DRB1*0402, DRB4*0101, DQB1*0302, DQA1*0301 haplotype in Ashkenazi Jewish patients and with the HLA-DRB1*1601, DRB5*02, DQB1*0502, DQA1*0102 haplotype in non-Jewish patients. In the present study, we tested the hypothesis that the variants of the heat- shock protein 70 (HSP-70) encoded by the HSP-70 loci located within the MHC region and known to be involved in apoptosis and regulation of cell proliferation could play an important role in molecular mechanisms of CA. First, we analyzed HSP70-2 polymorphism in risk-associated haplotypes from HLA homozygous cells and normal individuals and confirmed that the HSP70-2 9-kb variant was associated invariably with DR4 (HLA-DRB1*0402, DQB1*0302) and DR2 (HLA-DRB1*01601, DQB1*0502, DQA1*0102 and HLA-DRB1*1501, DQB1*0602) haplotypes, which were the haplotypes found increased in Jewish and non-Jewish patients with CA, respectively. The 9.0-kb variant was also found to be associated with HLA-B44, DRB1*0401 and HLA-B44, DRB1*07 haplotypes. Second, in patients with CA (12 Ashkenazi Jewish and 20 non-Jewish patients), HSP70-1 A and HSP70-2 9.0-kb variants were associated with the MHC haplotypes found by us to be markers of susceptibility to CA. The clozapine-treated control group had an excess number of HSP70-1 C and HSP70-2 8.5-kb variants, consistent with genetic resistance to CA associated with those variants. This finding supports our hypothesis that a dominant gene within the MHC region (marked by HSP70-1 and HSP70-2), but not necessarily HLA, is associated with CA in two different ethnic groups. 相似文献