全文获取类型
收费全文 | 1408篇 |
免费 | 74篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 45篇 |
妇产科学 | 30篇 |
基础医学 | 154篇 |
口腔科学 | 86篇 |
临床医学 | 118篇 |
内科学 | 301篇 |
皮肤病学 | 71篇 |
神经病学 | 70篇 |
特种医学 | 162篇 |
外国民族医学 | 1篇 |
外科学 | 130篇 |
综合类 | 70篇 |
预防医学 | 101篇 |
眼科学 | 18篇 |
药学 | 77篇 |
中国医学 | 1篇 |
肿瘤学 | 38篇 |
出版年
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 13篇 |
2016年 | 13篇 |
2015年 | 26篇 |
2014年 | 15篇 |
2013年 | 29篇 |
2012年 | 23篇 |
2011年 | 33篇 |
2010年 | 36篇 |
2009年 | 49篇 |
2008年 | 24篇 |
2007年 | 20篇 |
2006年 | 19篇 |
2005年 | 16篇 |
2004年 | 34篇 |
2003年 | 16篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 10篇 |
1999年 | 20篇 |
1998年 | 64篇 |
1997年 | 69篇 |
1996年 | 70篇 |
1995年 | 51篇 |
1994年 | 57篇 |
1993年 | 55篇 |
1992年 | 19篇 |
1991年 | 17篇 |
1990年 | 25篇 |
1989年 | 24篇 |
1988年 | 36篇 |
1987年 | 33篇 |
1986年 | 33篇 |
1985年 | 17篇 |
1984年 | 10篇 |
1983年 | 18篇 |
1982年 | 26篇 |
1980年 | 14篇 |
1979年 | 13篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1959年 | 34篇 |
1958年 | 38篇 |
1957年 | 55篇 |
1956年 | 51篇 |
1955年 | 48篇 |
1954年 | 58篇 |
1949年 | 21篇 |
1948年 | 23篇 |
排序方式: 共有1491条查询结果,搜索用时 15 毫秒
31.
R. A. F. CRAWFORD J. C. HEALY R. H. REZNEK R. R. PHILLIPS P. ARMSTRONG & J. H. SHEPHERD 《International journal of gynecological cancer》1997,7(4):267-272
The objective of this study was to determine whether magnetic resonance imaging (MRI) could reliably demonstrate fistulas and any associated mass and to see whether these findings were beneficial in the management of the fistula. Twelve consecutive patients presenting with suspected vaginal fistulas were examined prospectively with MRI, using a combination of sequences, for the presence, extent and configuration of fistulas and any associated mass. Comparison was made with CT when available. All patients underwent examination under anesthesia (EUA) and the findings compared. Of the 12 women presenting, seven had vesico-vaginal fistulas (VVF) and seven had recto-vaginal fistulas (RVF). Four women had both types of fistulas. The underlying pathology was cervical cancer (seven cases), colonic cancer (three cases), breast cancer (one case) and ovarian cancer (one case). Vaginal fistulas were unequivocally seen on MRI in eight of 10 cases with fistulas. In the two cases with a difference between the MRI and EUA findings, the MRI was interpreted as showing more than was found at EUA. In the seven women with VVF, MRI detected five of the cases. In the seven women with RVF, MRI detected all seven cases. Magnetic resonance imaging was correct in determining the presence of recurrent disease in the pelvis when an associated mass was seen (seven cases). Computer-assisted tomography was compared in 10 cases and in six cases, the results were comparable and in four cases, more information was obtained from the MRI. Magnetic resonance imaging appears to be accurate in detecting and defining complex gynecologic fistulas and should be considered the investigation of choice to aid the planning of restorative, salvage or palliative surgery. 相似文献
32.
Kangaroo Care with a ventilated preterm infant 总被引:4,自引:0,他引:4
33.
Yang PY Almofti MR Lu L Kang H Zhang J Li TJ Rui YC Sun LN Chen WS 《第二军医大学学报》2006,27(6):637-637
Polygonum multiflorum stilbeneglycoside (PMS) is a water-soluble fraction of Polygonum multiflorum Thunb. , one of the most famous tonic traditional Chinese medicines, that has protective effects on the cardiovascular system. The purpose of the present study is to elucidate the effects of PMS on macrophage-derived foam cell functions and the reduction of severity of atherosclerosis in hypercholesterolemic New Zealand White (NZW) rabbits. NZW rabbits were fed for 12 weeks with a normal diet, a high cholesterol diet, or a high cholesterol diet associated with irrigation with different doses of PMS (25, 50, or 100 mg/kg). Treatment of NZW rabbits fed with high cholesterol diet with 100 mg/kg PMS attenuated the increase in plasma cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and plasma triglyceride. Treatment with 50 and 100 mg/kg PMS caused 43% and 60% decrease in atherosclerotic lesioned area ratio to total surface area, respectively. In U937 foam cells, PMS could decrease the high expression of intercellular adhesion molecule (ICAM)-1 protein and the vascular endothelial growth factor (VEGF) protein levels in the medium induced by oxidized lipoprotein when analyzed by flow cytometry. The results proved that PMS is a powerful agent against atherosclerosis and that PMS action could possibly be through the inhibition of the expression of ICAM-1 and VEGF in foam cells. 相似文献
34.
35.
A Khaled A Sellami B Fazaa M Kharfi F Zeglaoui MR Kamoun 《Journal of the European Academy of Dermatology and Venereology》2010,24(7):781-788
Background Erythroderma is a severe syndrome and prognostic studies are rare in the literature. Objectives Through a retrospective study of erythroderma in adults, we have analysed epidemiological and clinical data and precised the relevant aetiologies and survival in our patients. Methods This study was performed at the Department of Dermatology of Charles Nicolle Hospital of Tunis (1995–2007) including 82 cases of acquired erythroderma (>16 years). We have recorded epidemio‐clinical, biological and histological data, treatment and outcome. Clinical–histological correlation was analysed [kappa coefficient (κ)]. Follow‐up time and disease‐free survival time were calculated as were Kaplan–Meier estimates of overall survival and relapse‐free survival for some aetiologies. Results Erythroderma represented 0.44‰ of all dermatoses with an age of 55.13 ± 18.16 and no sex predilection. Psoriasis was the predominant aetiology (32.9%) with a median duration of 6.75 years and previous one or more episodes of erythroderma. Psoriasis was significantly associated with pruritus (P = 0.0001), pachyonychia (P = 0.00001), palmoplantar keratoderma (P = 0.0001) and hypereosinophilia (P = 0.008). The latter is then not specific for drug induced erythroderma (P = 0.004). Carbamazepine (27.8%) and penicillin (22.2%) were the most implicated drugs. Positive Clinical–histological correlation was found in 77% of cases (κ = 0.753). Relapse was seen in all aetiologies, but drug reactions and had occurred in the first 3 years in 90% of them. Mortality rate was 11.3 per 1000 patients‐years. Conclusions Our study illustrates the severity of erythroderma. It alters heavily the quality of life of patients which is initially altered by the pre‐existent dermatosis. It may be life threatening as mortality rate is high. 相似文献
36.
G. SUTHERLAND G. EDWARDS C. TAYLOR G. T. PHILLIPS M. R. GOSSOP 《Addiction (Abingdon, England)》1988,83(7):755-760
Two papers have appeared in the literature recently reporting the use of the Severity of Opiate Dependence Questionnaire (SODQ) with American and British samples of opiate addicts. This paper presents the findings of a third study. The SODQ was completed by a further 126 subjects attending the original New York Clinic and the results largely confirmed our earlier findings: first the four main sections of the SODQ each give a strong first factor and secondly when these are combined a strong overall factor emerges. These results are again at variance with those found in the British sample and possible reasons briefly discussed. 相似文献
37.
Liu SC; Palek J; Yi SJ; Nichols PE; Derick LH; Chiou SS; Amato D; Corbett JD; Cho MR; Golan DE 《Blood》1995,86(1):349-358
Southeast Asian ovalocytosis (SAO) is an asymptomatic trait characterized by rigid, poorly deformable red cells that resist invasion by several strains of malaria parasites. The underlying molecular genetic defect involves simple heterozygous state for a mutant band 3 protein, which contains a deletion of amino acids 400 through 408, linked with a Lys 56-to-Glu substitution (band 3-Memphis polymorphism). To elucidate the contribution of the mutant SAO band 3 protein to increased SAO red blood cell (RBC) rigidity, we examined the participation of the mutant SAO band 3 protein in increased band 3 attachment to the skeleton and band 3 oligomerization. We found first that SAO RBC skeletons retained more band 3 than normal cells and that this increased retention preferentially involved the mutant SAO band 3 protein. Second, SAO RBCs contained a higher percentage of band 3 oligomer-ankyrin complexes than normal cells, and these oligomers were preferentially enriched by the mutant SAO protein. At the ultrastructural level, the increased oligomer formation of SAO RBCs was reflected by stacking of band 3-containing intramembrane particles (IMP) into longitudinal strands. The IMP stacking was not reversed by treating SAO RBCs in alkaline pH (pH 11), which is known to weaken ankyrin-band 3 interactions, or by removing the cytoplasmic domain of band 3 from SAO membranes with trypsin. Finally, we found that band 3 protein in intact SAO RBCs exhibited a markedly decreased rotational mobility, presumably reflecting the increased oligomerization and the membrane skeletal association of the SAO band 3 protein. We propose that the mutant SAO band 3 has an increased propensity to form oligomers, which appear as longitudinal strands of IMP and exhibit increased association with membrane skeleton. This band 3 oligomerization underlies the increase in membrane rigidity by precluding membrane skeletal extension, which is necessary for membrane deformation. 相似文献
38.
Red cell membrane stiffness in iron deficiency 总被引:3,自引:0,他引:3
The purpose of this study was to characterize red blood cell (RBC) deformability by iron deficiency. We measured RBC deformability to ektacytometry, a laser diffraction method for determining the elongation of suspended red cells subjected to shear stress. Isotonic deformability of RBC from iron-deficient human subjects was consistently and significantly lower than that of normal controls. In groups of rats with severe and moderate dietary iron deficiency, RBC deformability was also reduced in proportion to the severity of iron deficiency. At any given shear stress value, deformability of resealed RBC ghosts from both iron-deficient humans and rats was lower than that of control ghosts. However, increase of applied shear stress resulted in progressive increase in ghost deformation, indicating that ghost deformability was primarily limited by membrane stiffness rather than by reduced surface area-to-volume ratio. This was consistent with the finding that iron-deficient cells had a normal membrane surface area. In addition, the reduced mean corpuscular hemoglobin concentration (MCHC) and buoyant density of the iron-deficient rat cells indicated that a high hemoglobin concentration was not responsible for impaired whole cell deformability. Biochemical studies of rat RBC showed increased membrane lipid and protein crosslinking and reduced intracellular cation content, findings that are consistent with in vivo peroxidative damage. RBC from iron-deficient rats incubated in vitro with hydrogen peroxide showed increased generation of malonyldialdehyde, an end-product of lipid peroxidation, compared to control RBC. Taken together, these findings suggest that peroxidation could contribute in part to increased membrane stiffness in iron- deficient RBC. This reduced membrane deformability may in turn contribute to impaired red cell survival in iron deficiency. 相似文献
39.
40.
SHETTY H. G. M.; FRASER A. G.; PHILLIPS D. I. W.; LAZARUS J. H.; WILLIAMS B. D. 《Rheumatology (Oxford, England)》1988,27(4):321-323
We describe a 42-year-old man with Reiter's syndrome who developedcomplete heart block only 5 wee after the onset of his illness.He was also noted to have carotid sinus hypersensitivity andevidence sinoatrial disease. There were no clinical signs orechocardiographic findings to suggest involvement of tl aorticroot or aortic valve. His arrhythmias were treated successfullywith a physiological pacemaker. The combination of sinoatrialand atrioventricular node disease suggests that the inflammatoryprocess Reiter's syndrome can produce widespread involvementof the conducting system. KEY WORDS: Reiter's syndrome, Arthritis, Carotid sinus hypersensitivity, Stokes-Adams attacks 相似文献