全文获取类型
收费全文 | 359篇 |
免费 | 28篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 20篇 |
妇产科学 | 4篇 |
基础医学 | 55篇 |
口腔科学 | 28篇 |
临床医学 | 32篇 |
内科学 | 79篇 |
皮肤病学 | 11篇 |
神经病学 | 5篇 |
特种医学 | 57篇 |
外科学 | 47篇 |
综合类 | 9篇 |
预防医学 | 8篇 |
药学 | 17篇 |
1篇 | |
肿瘤学 | 13篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 21篇 |
2014年 | 17篇 |
2013年 | 18篇 |
2012年 | 13篇 |
2011年 | 8篇 |
2010年 | 22篇 |
2009年 | 12篇 |
2008年 | 7篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2001年 | 9篇 |
2000年 | 1篇 |
1999年 | 6篇 |
1998年 | 20篇 |
1997年 | 19篇 |
1996年 | 29篇 |
1995年 | 15篇 |
1994年 | 21篇 |
1993年 | 13篇 |
1992年 | 3篇 |
1991年 | 2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 | 3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388条查询结果,搜索用时 15 毫秒
101.
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
102.
Yano T; Sander CA; Andrade RE; Gauwerky CE; Croce CM; Longo DL; Jaffe ES; Raffeld M 《Blood》1993,82(6):1813-1819
103.
Dexamethasone was administered to 51 donors prior to filtration leukapheresis. The results of this maneuver, including the consequences of transfusion, were contrasted with results in 52 donors who did not receive the steroid. Yields of polymorphonuclear leukocytes, the posttransfusion increments in recipients, themorphologic polymorphonuclear leukocytes obtained, and the incidence of donor and recipient reactions were all beneficially influenced by this manipulation. Possible mechanisms responsible for these observations are discussed. It is recommended that dexamethasone stimulation be used in filtration leukapheresis when circumstances do not otherwise contraindicate such a maneuver. 相似文献
104.
105.
Alim Hirji Alessandra Bernasconi Brian W McCrindle Elizabeth Dunn Rebecca Gurofsky Cedric Manlhiot Steven ES Miner John CP Kingdom Edgar T Jaeggi Glen Van Arsdell Lynne E Nield 《The Canadian journal of cardiology》2010,26(1):e1-e6
OBJECTIVES:
To assess outcomes of prenatally diagnosed tetralogy of Fallot and determine factors associated with the choice to undergo a valve-sparing repair versus transannular patch, and the use of prostaglandins at birth.METHODS:
All cases at The Hospital for Sick Children (Toronto, Ontario) with a fetal diagnosis of tetralogy of Fallot from 1998 to 2006, were reviewed for demographic and fetal echocardiographic data to determine factors associated with the valve-sparing repair and need for perinatal support.RESULTS:
Sixty-four fetuses met inclusion criteria (median gestational age 22 weeks) with 47 live births. Twenty-six underwent valve-sparing repair (median age 5.7 months) and 14 underwent transannular patch repair (median age 4.5 months). There were seven deaths before surgery and one post-transannular patch repair. One patient required a transannular patch repair after the initial valve-sparing repair. Twelve of 29 (41%) patients received prostaglandins at birth. Type of surgical repair, use of prostaglandins and postnatal death were among the outcomes investigated. The mean pulmonary valve (PV) z-score was −3.0±2.0 and the mean PV/aortic valve (AoV) ratio was 0.65±0.10. Lower PV z-score (P=0.04), smaller PV/AoV ratio (P=0.04) and the presence of nonantegrade arterial duct flow (P=0.02) were associated with prostaglandin use. A higher PV/AoV ratio was associated with valve-sparing repair (P=0.04). Fetal z-scores of the PV, AoV and right pulmonary artery at 29 to 32 weeks gestational age correlated with respective postnatal z-scores (P=0.01).CONCLUSION:
Fetal echocardiographic variables were associated with the use of prostaglandins and valve-sparing repair in fetuses with tetralogy of Fallot, and at 29 weeks, correlated with postnatal valve diameters. 相似文献106.
Sérgio Aparecido TORRES Odila Pereira da Silva ROSA Mitsue Fujimaki HAYACIBARA Maria do Carmo Machado GUIMAR?ES Roberto M. HAYACIBARA Walter Ant?nio BRETZ 《Journal of applied oral science : revista FOB》2010,18(3):297-302
Objectives
The aim of this study was to analyze the periodontal parameters of patients with chronic renal failure.Material and Methods
The periodontal status of 16 Brazilian patients aged 29 to 53 (41.7±7.2) years with chronic renal failure (CRF) and another matched group of 14 healthy controls with periodontitis was assessed clinically and microbiologically. Probing pocket depth (PPD), gingival recession (GR), dental plaque index (PLI), gingival index (GI), and dental calculus index (CI) were the clinical parameters recorded for the entire dentition (at least 19 teeth), while the anaerobic periodontopathogen colonization in four sites with the highest PPD was evaluated using the BANA test (“PerioScan”; Oral B).Results
The results for the CRF group and control group, respectively were: PPD: 1.77±0.32 and 2.65±0.53; GR: 0.58±0.56 and 0.51±0.36; PLI: 1.64±0.56 and 1.24±0.67; GI: 0.64±0.42 and 0.93±0.50; CI: 1.17±0.54 and 0.87±0.52. Comparison between groups using the "t" test revealed a significantly increased PPD (p<0.001) in the control group. Comparison of the other clincial parameters by the Mann-Whitney test showed differences only for PLI, which was significantly higher (p<0.05) in the CRF group. Spearman''s test applied to each group showed a positive correlation among all clinical parameters, except for GR (p<0.05). None of the groups showed any correlation between GR and GI, while a significant negative correlation between GR and PPD was observed for the CRF group. The percentage of BANA-positive sites was 35.9% for the CRF group and 35.7% for the control group. The BANA test correlated positively with PPD only in the control group and with GR only in the CRF group.Conclusions
In spite of a higher PLI and dense anaerobic microbial population even in shallow PPD, patients with CRF exhibited better periodontal conditions than periodontitis patients, which is an evidence of altered response to local irritants. 相似文献107.
EL Scotter CE Goodfellow ES Graham M Dragunow M Glass 《British journal of pharmacology》2010,160(3):747-761
Background and purpose:
The therapeutic potential of cannabinoids in Huntington''s disease (HD) has been investigated by several groups with complex and sometimes contrasting results. We sought to examine key points of intersection between cannabinoid receptor 1 (CB1) signalling, survival and the formation of mutant huntingtin aggregates in HD.Experimental approach:
Using a simplified pheochromocytoma (PC12) cell model of HD expressing exon 1 of wild-type or mutant huntingtin, we assayed cell death and aggregate formation using high-throughput cytotoxicity and image-based assays respectively.Key results:
CB1 activation by HU210 conferred a small but significant level of protection against mutant huntingtin-induced cell death. Pertussis toxin uncoupled HU210 from the inhibition of cAMP, preventing rescue of cell death. Phosphorylation of extracellular signal-regulated kinase (ERK) was also critical to CB1-mediated rescue. Conversely, treatments that elevated cAMP exacerbated mutant huntingtin-induced cell death. Despite opposing effects on HD cell survival, both HU210 and compounds that elevated cAMP increased the formation of mutant huntingtin aggregates. The increase in aggregation by HU210 was insensitive to Pertussis toxin and UO126, suggesting a G-protein alpha subtype s (Gs)-linked mechanism.Conclusions and implications:
We suggest that the CB1 receptor, through G-protein alpha subtype i/o (Gi/o)-linked, ERK-dependent signal transduction, is a therapeutic target in HD. However the protective potential of CB1 may be limited by promiscuous coupling to Gs, the stimulation of cAMP formation and increased aggregate formation. This may underpin the poor therapeutic efficacy of cannabinoids in more complex model systems and suggest that therapies that are selective for the Gi/o, ERK pathway may be of most benefit in HD.This article is part of a themed issue on Cannabinoids. To view the editorial for this themed issue visit http://dx.doi.org/10.1111/j.1476-5381.2010.00831.x 相似文献108.
血管内皮生长因子(VEGF)和可溶性VEGF受体2(sVEGFR-2)由VEGF通路抑制因子所调控,化疗、VEGFR抑制剂或两者联合治疗是否可引起细胞因子和血管生成因子(CAFs)的改变,而这些改变是否又能预示临床获益? 相似文献
109.
C David L. Thomas Paul M. Mayhew Jon Power Kenneth ES Poole Nigel Loveridge John G. Clement Chris J. Burgoyne Jonathan Reeve 《Journal of bone and mineral research》2009,24(11):1808-1818
Hip fracture risk rises 100‐ to 1000‐fold over six decades of age, but only a minor part of this increase is explained by declining BMD. A potentially independent cause of fragility is cortical thinning predisposing to local crushing, in which bone tissue's material disintegrates at the microscopic level when compressed beyond its capacity to maintain integrity. Elastic instability or buckling of a much thinned cortex might alternatively occur under compression. In a buckle, the cortex moves approximately at right angles to the direction of load, thereby distorting its microstructure, eventually to the point of disintegration. By resisting buckling movement, trabecular buttressing would protect the femoral neck cortex against this type of failure but not against crushing. We quantified the effect of aging on trabecular BMD in the femoral neck and assessed its contribution to cortical elastic stability, which determines resistance to buckling. Using CT, we measured ex vivo the distribution of bone in the midfemoral necks of 35 female and 33 male proximal femurs from cases of sudden death in those 20–95 yr of age. We calculated the critical stress σcr, at which the cortex was predicted to buckle locally, from the geometric properties and density of the cortical zone most highly loaded in a sideways fall. Using long‐established engineering principles, we estimated the amount by which stability or buckling resistance was increased by the trabecular bone supporting the most stressed cortical sector in each femoral neck. We repeated these measurements and calculations in an age‐ and sex‐matched series of femoral necks donated by women who had suffered intracapsular hip fracture and controls, using histological measurements of cortical thickness to improve accuracy. With normal aging, trabecular BMD declined asymmetrically, fastest in the supero‐lateral one‐half (in antero‐posterior projection) of the trabecular compartment. When viewed axially with respect to the femoral neck, the most rapid loss of trabecular bone occurred in the posterior part of this region (supero‐posterior [S‐P]), amounting to a 42% reduction in women (34% in men) over five decades of adult age. Because local cortical bone thickness declined comparably, age had no significant effect on the relative contributions of cortical and trabecular bone to elastic stability, and trabecular bone was calculated to contribute 40% (in men) and 43% (in women) to the S‐P cortex of its overall elastic stability. Hip fracture cases had reduced elastic stability compared with age‐matched controls, with a median reduction of 49% or 37%, depending on whether thickness was measured histologically or by CT (pQCT; p < 0.002 for both). This effect was because of reduced cortical thickness and density. Trabecular BMD was similar in hip fracture cases and controls. The capacity of the femur to resist fracture in a sideways fall becomes compromised with normal aging because cortical thickness and trabecular BMD in the most compressed part of the femoral neck both decline substantially. This decline is relatively more rapid than that of femoral neck areal BMD. If elastic instability rather than cortical crushing initiates the fracture event, interventions that increase trabecular bone in the proximal femur have great potential to reduce fracture risk because the gradient defining the increase in elastic stability with increasing trabecular BMD is steep, and most hip fracture cases have sufficient trabecular bone for anabolic therapies to build on. 相似文献
110.
F. P. CARNEIRO A. V. DE MAGALHÃES M. DE JESUS ABREU ALMEIDA COUTO A. L. BOCCA M. I. MUNIZ-JUNQUEIRA & R. N. RIBEIRO SAMPAIO 《Parasite immunology》2009,31(10):646-651
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