全文获取类型
收费全文 | 1129篇 |
免费 | 113篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 69篇 |
妇产科学 | 24篇 |
基础医学 | 151篇 |
口腔科学 | 27篇 |
临床医学 | 133篇 |
内科学 | 317篇 |
皮肤病学 | 31篇 |
神经病学 | 111篇 |
特种医学 | 103篇 |
外科学 | 85篇 |
综合类 | 23篇 |
预防医学 | 50篇 |
眼科学 | 5篇 |
药学 | 55篇 |
肿瘤学 | 53篇 |
出版年
2023年 | 9篇 |
2022年 | 7篇 |
2021年 | 21篇 |
2020年 | 14篇 |
2019年 | 31篇 |
2018年 | 27篇 |
2017年 | 11篇 |
2016年 | 23篇 |
2015年 | 26篇 |
2014年 | 31篇 |
2013年 | 36篇 |
2012年 | 41篇 |
2011年 | 52篇 |
2010年 | 64篇 |
2009年 | 47篇 |
2008年 | 49篇 |
2007年 | 49篇 |
2006年 | 37篇 |
2005年 | 41篇 |
2004年 | 31篇 |
2003年 | 37篇 |
2002年 | 32篇 |
2001年 | 26篇 |
2000年 | 28篇 |
1999年 | 26篇 |
1998年 | 32篇 |
1997年 | 38篇 |
1996年 | 38篇 |
1995年 | 32篇 |
1994年 | 24篇 |
1993年 | 20篇 |
1992年 | 12篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 20篇 |
1988年 | 21篇 |
1987年 | 24篇 |
1986年 | 16篇 |
1985年 | 13篇 |
1984年 | 6篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1979年 | 15篇 |
1978年 | 6篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1974年 | 8篇 |
1971年 | 7篇 |
1970年 | 8篇 |
排序方式: 共有1247条查询结果,搜索用时 15 毫秒
961.
JB Austin G Russell MG Adam D Mackintosh S Kelsey DF Peck 《Archives of disease in childhood》1994,71(3):211-216
To establish the prevalence of asthma and wheeze in 12 year old children in a region with low background pollution levels, a population of children resident in the Highland Region of Scotland was studied by questionnaire supported by objective data. A respiratory questionnaire was distributed to the parents of 1919 children aged from 12-13 years and attending secondary schools in the educational divisions of Lochaber, Ross and Cromarty, and Inverness including Skye in Highland Region to ascertain history of wheeze and parental awareness of a diagnosis of asthma. Peak expiratory flow (PEF) measurements were carried out before and after a standardised exercise test. Ozone levels were noted. Questionnaires were completed by 1825 parents (95% of those invited) and 1702 (93%) of those returning questionnaires took part in the exercise test. The overall prevalence of reported asthma was 14% and wheeze 25%. Defined as a fall in PEF of more than 15% with exercise, the overall prevalence of exercise induced bronchospasm was 9%. In Skye the prevalence of reported asthma was 17%, wheeze 28%, and exercise induced bronchospasm 30%. There were no significant differences between areas for reported asthma or wheeze. There was, however, a highly significant difference between areas for exercise induced bronchospasm, most of which was accounted for by the very high incidence in Skye, which is one of the most rural of the areas studied. The results of this study do not support the hypothesis that asthma is commoner in urban than rural areas, whether we compare the Highlands with the rest of the UK or areas within the Highlands, or whether we examine reported symptoms or exercise induced bronchospasm. The results do not support an association between atmospheric pollution and the prevalence of asthma. 相似文献
962.
Between 1982 and 1992, 22 patients were treated with colonic strictures in the course of necrotizing enterocolitis (NEC). Fourteen newborns in whom a primary enterostomy and, when necessary, resection of necrotic bowel was performed developed strictures in the diverted colon. The strictures were detected by colon contrast enema study performed on average 3 months after the first intervention. Eight additional children suffered from an ileus due to primary strictures after conservatively treated NEC, which was surgically managed by enterostomy. Closure of the enterostomy and resection of the stenotic part of the colon was performed thereafter in all 22 children as a single stage procedure. There was no insufficiency of the anastomosis nor any late stricture at follow-up 2.7 years after NEC in our patients. It is concluded therefore that reanastomosis of the enterostomy and resection of an intestinal stricture can be performed as a single stage procedure without any risk after an interval of 3 months between onset of acute NEC and reevaluation. During this interval, a close monitoring and an appropriate management of adequate supplement of electrolytes and bicarbonates is necessary. Most of our babies could be nursed at home and showed a good weight gain during this period, despite the enterostomy. 相似文献
963.
Genaro G Ortiz Miguel Huerta H ctor A Gonz lez-Usigli Erandis D Torres-S nchez Daniela LC Delgado-Lara Ferm n P Pacheco-Mois s Mario A Mireles-Ram rez Blanca MG Torres-Mendoza Roxana I Moreno-Cih Irma E Vel zquez-Brizuela 《World journal of diabetes》2022,13(4):319-337
Insulin, a key pleiotropic hormone, regulates metabolism through several signaling pathways in target tissues including skeletal muscle, liver, and brain. In the brain, insulin modulates learning and memory, and impaired insulin signaling is associated with metabolic dysregulation and neurodegenerative diseases. At the receptor level, in aging and Alzheimer’s disease (AD) models, the amount of insulin receptors and their functions are decreased. Clinical and animal model studies suggest that memory improvements are due to changes in insulin levels. Furthermore, diabetes mellitus (DM) and insulin resistance are associated with age-related cognitive decline, increased levels of β-amyloid peptide, phospho rylation of tau protein; oxidative stress, pro-inflammatory cytokine production, and dyslipidemia. Recent evidence shows that deleting brain insulin receptors leads to mild obesity and insulin resistance without influencing brain size and apoptosis development. Conversely, deleting insulin-like growth factor 1 receptor (IGF-1R) affects brain size and development, and contributes to behavior changes. Insulin is synthesized locally in the brain and is released from the neurons. Here, we reviewed proposed pathophysiological hypotheses to explain increased risk of dementia in the presence of DM. Regardless of the exact sequence of events leading to neurodegeneration, there is strong evidence that mitochondrial dysfunction plays a key role in AD and DM. A triple transgenic mouse model of AD showed mitochondrial dysfunction, oxidative stress, and loss of synaptic integrity. These alterations are comparable to those induced in wild-type mice treated with sucrose, which is consistent with the proposal that mitochondrial alterations are associated with DM and contribute to AD development. Alterations in insulin/IGF-1 signaling in DM could lead to mitochondrial dysfunction and low antioxidant capacity of the cell. Thus, insulin/IGF-1 signaling is important for increased neural processing and systemic metabolism, and could be a specific target for therapeutic strategies to decrease alterations associated with age-related cognitive decline. 相似文献
964.
de Latour RP Mary JY Salanoubat C Terriou L Etienne G Mohty M Roth S de Guibert S Maury S Cahn JY Socié G;French Society of Hematology;French Association of Young Hematologists 《Blood》2008,112(8):3099-3106
The natural history of paroxysmal nocturnal hemoglobinuria (PNH) clinical subcategories (classic PNH and aplastic anemia [AA]/PNH syndrome) is still unknown. We retrospectively studied 460 PNH patients diagnosed in 58 French hematologic centers from 1950 to 2005. The median (SE) follow-up time was 6.8 (0.5) years. The median survival time (SE) was 22 (2.5) years. We identified 113 patients with classic PNH, 224 patients with AA-PNH syndrome, and 93 (22%) intermediate patients who did not fit within these 2 categories. At presentation, classic PNH patients were older, with more frequent abdominal pain and displayed higher levels of GPI-AP-deficient granulocytes. A time-dependent improved survival was observed. In classic PNH, diagnoses before 1986 (hazard ratio [HR]: 3.6; P = .01) and increasing age (P < .001) were associated with worse survival prognoses, whereas use of androgens within the first year after diagnosis was protective (HR, 0.17; P = .01). Transfusions before 1996 (HR, 2.7; P = .007) led to lower survival rates in patients with AA-PNH syndrome, whereas immunosuppressive treatment was associated with better outcomes (HR, 0.33; P = .03). Evolution to thrombosis affected survival in both subcategories (classic PNH: HR, 7.8 [P < .001]; AA-PNH syndrome: HR, 33.0 [P < .001]). Evolution to bicytopenia or pancytopenia for classic PNH (HR, 7.3, P < .001) and malignancies for AA-PNH syndrome (HR, 48.8; P < .001) were associated with worse outcomes. Although clinical presentation and prognosis factors are different, classic PNH and AA-PNH syndrome present roughly similar outcomes, affected mainly by complications. 相似文献
965.
966.
Bishop JF; McGrath K; Wolf MM; Matthews JP; De Luise T; Holdsworth R; Yuen K; Veale M; Whiteside MG; Cooper IA 《Blood》1988,71(2):383-387
To determine the relative importance of clinical factors on the efficacy of platelet transfusions, 941 pooled platelet transfusions from HLA-unmatched donors were studied prospectively in 133 patients with bone marrow failure. Multiple linear regression analyses identified the major factors influencing one-hour-corrected increments (CI) as prior splenectomy, bone marrow transplantation, disseminated intravascular coagulation, concurrent intravenous amphotericin B, splenomegaly, and HLA antibody grade. The relative impact of these factors on CI has been quantitated by using a formula developed from these data. A linear relationship was demonstrated between increasing percentage of HLA antibody grade and decreasing CI. A number of other factors were less important in the linear regression model than the aforementioned major factors. These included platelet-specific antibodies, concurrent antibacterial antibiotics, clinical bleeding grade, and temperature. Factors that did not influence CI included the number of prior platelet transfusions, prior granulocyte transfusions, prior red cell transfusions, infection, age, blood group, diagnosis, sex, pretransfusion platelet count, prior pregnancies, and concurrent antineoplastic drugs. This study identified major clinical factors that significantly influenced CI and were major causes of refractoriness to pooled platelet transfusions. 相似文献
967.
Similar outcome of allogeneic stem cell transplantation after myeloablative and sequential conditioning regimen in patients with refractory or relapsed acute myeloid leukemia: A study from the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire 下载免费PDF全文
Justine Decroocq Raphaël Itzykson Stéphane Vigouroux Mauricette Michallet Ibrahim Yakoub‐Agha Anne Huynh Florence Beckerich Felipe Suarez Patrice Chevallier Stéphanie Nguyen‐Quoc Marie‐Pierre Ledoux Laurence Clement Yosr Hicheri Gaëlle Guillerm Jérôme Cornillon Nathalie Contentin Martin Carre Natacha Maillard Mélanie Mercier Mohamad Mohty Yves Beguin Jean‐Henri Bourhis Amandine Charbonnier Charles Dauriac Jacques‐Olivier Bay Didier Blaise Eric Deconinck Charlotte Jubert Nicole Raus Regis Peffault de Latour Nathalie Dhedin 《American journal of hematology》2018,93(3):416-423
Patients with acute myeloid leukemia (AML) in relapse or refractory to induction therapy have a dismal prognosis. Allogeneic hematopoietic stem cell transplantation is the only curative option. In these patients, we aimed to compare the results of a myeloablative transplant versus a sequential approach consisting in a cytoreductive chemotherapy followed by a reduced intensity conditioning regimen and prophylactic donor lymphocytes infusions. We retrospectively analyzed 99 patients aged 18‐50 years, transplanted for a refractory (52%) or a relapsed AML not in remission (48%). Fifty‐eight patients received a sequential approach and 41 patients a myeloablative conditioning regimen. Only 6 patients received prophylactic donor lymphocytes infusions. With a median follow‐up of 48 months, 2‐year overall survival was 39%, 95% confidence interval (CI) (24‐53) in the myeloablative group versus 33%, 95% CI (21‐45) in the sequential groups (P = .39), and 2‐year cumulative incidence of relapse (CIR) was 57% versus 50% respectively (P = .99). Nonrelapse mortality was not higher in the myeloablative group (17% versus 15%, P = .44). In multivariate analysis, overall survival, CIR and nonrelapse mortality remained similar between the two groups. However, in multivariate analysis, sequential conditioning led to fewer acute grade II‐IV graft versus host disease (GVHD) (HR for sequential approach = 0.37; 95% CI: 0.21‐0.65; P < .001) without a significant impact on chronic GVHD (all grades and extensive). In young patients with refractory or relapsed AML, myeloablative transplant and sequential approach offer similar outcomes except for a lower incidence of acute GvHD after a sequential transplant. 相似文献
968.
Actually, allogeneic hematopoietic stem cell transplantation (AHSCT) is the treatment of choice of malignant hemopathies and also benign hemopathies. AHSCT conditioning presented three main objectives: anti-tumoral effect, immunosuppression and recipient bone marrow elimination. The standard conditioning is homogeneous in intensity but is unfortunately linked to an important toxicity and remains therefore reserved only to young patients. Better understanding of anti-tumoral mechanisms lead to the appearance of non-myeloablative conditioning or reduced intensity conditioning. The reduced intensity conditioning presented a great diversity (lower dose chemotherapy +/- total body irradiation). Many studies showed feasibility, tolerance and efficacy of this type of conditioning. However, this day, none of this conditioning showed his superiority in comparison with the others. Toxicity reduction provides an opportunity to use this approach in more and more old populations who were contraindicated to AHSCT with myeloablative conditioning. 相似文献
969.
A S Rigaud L Traykov L Caputo J Coste F Latour R Couderc F Moulin F Boller F Forette 《Neuroepidemiology》2001,20(4):268-272
Apolipoprotein E (ApoE) phenotyping was determined in 42 subjects with Alzheimer's disease (AD), 49 with depression, including 26 with early-onset depression (EOD) and 23 with late-onset depression (LOD), and 49 controls. In the EOD group, the frequency of the ApoE epsilon4 allele was not different from the control frequency (p = 0.532) but was significantly lower than in AD (p < 0.001). In the LOD group, the ApoE epsilon4 frequency was significantly higher than in the controls (p = 0.034) but was not different from that in the AD group (p = 0.229). Individuals with ApoE epsilon4 were at greater risk of getting AD (odds ratio, OR = 5.5, 95% confidence interval, CI, 2.0-14.0) or LOD (OR = 6.1, 95% CI, 1.9-19.0) than of EOD (OR = 0.7, 95% CI, 0.2-2.5). These results suggest an association between the ApoE epsilon4 allele frequency and LOD. Patients with LOD could be at risk of developing AD by an epsilon4-dependent pathway. 相似文献
970.
Zhouji Chen Jeffrey E. Saffitz Mickey A. Latour Gustav Schonfeld 《The Journal of clinical investigation》1999,103(10):1419-1430
Apo B-100 of LDL can bind to both the LDL receptor and megalin, but the molecular interactions of apo B-100 with these 2 receptors are not completely understood. Naturally occurring mutant forms of apo B may be a source of valuable information on these interactions. Apo B-70.5 is uniquely useful because it contains the NH2-terminal portion of apo B-100, that includes only one of the two putative LDL receptor-binding sites (site A). The lipoprotein containing apo B-70. 5 (Lp B-70.5) was purified from apo B-100/apo B-70.5 heterozygotes by sequential ultracentrifugation combined with immunoaffinity chromatography. Cell culture experiments, ligand blot analysis, and in vivo studies all consistently showed that Lp B-70.5 is not recognized by the LDL receptor. The kidney was identified as a major organ in catabolism of Lp B-70.5 in New Zealand white rabbits. Autoradiographic analysis revealed that renal proximal tubular cells selectively removed Lp B-70.5. On ligand blotting of renal cortical membranes, Lp B-70.5 bound only to megalin. The ability of megalin to mediate cellular endocytosis of Lp B-70.5 was confirmed using retinoic acid/dibutyryl cAMP-treated F9 cells. This study suggests that the putative LDL receptor-binding site A on apo B-100 might not by itself be a functional binding domain and that the apo B-binding sites recognized by the LDL receptor and by megalin may be different. Moreover, megalin may play an important role in renal catabolism of apo B truncations, including apo B-70.5. 相似文献