全文获取类型
收费全文 | 81582篇 |
免费 | 5619篇 |
国内免费 | 2566篇 |
专业分类
耳鼻咽喉 | 832篇 |
儿科学 | 1956篇 |
妇产科学 | 1135篇 |
基础医学 | 10340篇 |
口腔科学 | 1574篇 |
临床医学 | 6891篇 |
内科学 | 12439篇 |
皮肤病学 | 2538篇 |
神经病学 | 5970篇 |
特种医学 | 1615篇 |
外国民族医学 | 6篇 |
外科学 | 5015篇 |
综合类 | 11334篇 |
现状与发展 | 7篇 |
预防医学 | 6421篇 |
眼科学 | 989篇 |
药学 | 12492篇 |
35篇 | |
中国医学 | 4092篇 |
肿瘤学 | 4086篇 |
出版年
2024年 | 154篇 |
2023年 | 1241篇 |
2022年 | 2908篇 |
2021年 | 3212篇 |
2020年 | 2586篇 |
2019年 | 2613篇 |
2018年 | 2634篇 |
2017年 | 2573篇 |
2016年 | 2465篇 |
2015年 | 2622篇 |
2014年 | 4611篇 |
2013年 | 5199篇 |
2012年 | 4473篇 |
2011年 | 5053篇 |
2010年 | 4076篇 |
2009年 | 3963篇 |
2008年 | 3983篇 |
2007年 | 3849篇 |
2006年 | 3378篇 |
2005年 | 3167篇 |
2004年 | 2775篇 |
2003年 | 2427篇 |
2002年 | 2040篇 |
2001年 | 1710篇 |
2000年 | 1566篇 |
1999年 | 1426篇 |
1998年 | 1143篇 |
1997年 | 1152篇 |
1996年 | 1019篇 |
1995年 | 986篇 |
1994年 | 861篇 |
1993年 | 660篇 |
1992年 | 649篇 |
1991年 | 617篇 |
1990年 | 485篇 |
1989年 | 471篇 |
1988年 | 466篇 |
1987年 | 405篇 |
1986年 | 368篇 |
1985年 | 536篇 |
1984年 | 498篇 |
1983年 | 398篇 |
1982年 | 444篇 |
1981年 | 351篇 |
1980年 | 314篇 |
1979年 | 269篇 |
1978年 | 212篇 |
1977年 | 157篇 |
1976年 | 150篇 |
1975年 | 127篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
O. JOHNSTON J. CRAWFORD H. SHORT T. RAYMOND SMYTH J. MOLLER 《Journal of paediatrics and child health》1987,23(3):157-161
A simple standardized screening test (South Australian Motor Co-ordination Screening Test, SAM Test) was developed to screen for poor co-ordination in 5 year olds; This SAM Test, which can be used by teachers, nurses and doctors, has explicit pass/fail criteria and has classified correctly 90% of children. The McCarthy Motor Scales, which are time consuming and limited to use by psychologists, were used to categorize 60 poorly co-ordinated and 60 normal children. The 120 children thus selected were tested on 19 items covering gross and fine motor skills. Statistical analysis to determine which items best discriminated between the two groups found the following five gross motor items to be most effective: one leg balancing, hopping, heel-toe walking on line, jumping Over ribbon and dropping ball and catching. 相似文献
52.
Koji Tomobe Hajime Fujii Buxiang Sun Hiroshi Nishioka Okezie I Aruoma 《Biomedicine & Pharmacotherapy》2007,61(7):427-434
Oligonol is produced from the oligomerization of polyphenols (typically proanthocyanidin from a variety of fruits such as lychees, grapes, apples, persimmons, etc.) and contains catechin-type monomers and oligomers of proanthocyanidins. The ability of Oligonol to affect infection-dependent eye inflammation, locomotion and longevity in senescence-accelerated prone mice (SAMP8) (a model of senescence acceleration and geriatric disorders with increased oxidative stress and neuronal deficit) was investigated. Oligonol (60mg/kg) significantly modulated the extent of inflammation scores in the eye of SAMP8 mice. Examination of the mice indicated infection with mouse hepatitis virus and pinworm (Syphacia obvelata) in both males and females and with the intestinal protozoa (trichomonad) in males. A comparison of the two groups (using log-rank test) and the difference in the mean life span between groups (using Student's t-test) indicated significant differences in survival (p=0.043) and the mean life span (p=0.033) in male SAMP8 mice. Oligonol increased the mean life span and this was statistically significant. In the open-field locomotive test, the 7-week-old SAMP8 mice crossed more than 40 partitioned lines in 1min. At 48-week-old control untreated male SAMP8 crossed 2 lines. The Oligonol-treated 48-week-old male SAMP8 mice crossed 17 lines however. The improved locomotive activity was statistically significant even after 36weeks in the Oligonol-treated male SAMP8 but this was not the case throughout the time course of the study in the Oligonol-treated female SAMP8. Thus Oligonol treatment to SAMP8 mice modulated the severity of infection-dependent inflammation, prolonged life-span and significantly improved locomotive activity indicating potential benefit to aging-associated diseases such as Alzheimer's or Parkinson's diseases. This presents potential for further research to define infection-dependent inflammation associated with degenerative conditions and the molecular mechanism of dietary antioxidant protection. 相似文献
53.
硬膜外腔阻滞对胸部手术应激反应的影响 总被引:33,自引:1,他引:32
目的 观察硬膜外腔阻滞对胸部手术应激激素和细胞因子的影响。方法20例食管癌手术病人,随机分为两组,每组10例,即全麻复令硬膜外腔阻滞(GEA)组和全麻(GA)组,分别测定麻醉诱导前、手术2h、手术4h、术毕、术后1d及术后3d的血浆去甲肾上腺素、肾上腺素、血清促肾上腺皮质激素(ACTH)、皮质醇、C-反应蛋白、IL-6及IL-10的水平。结果 血浆去甲肾上腺素和血清皮质醇GEA组术中术后无显著改变,但GA组术毕和术后1d显著升高(P<0.05),术后3d恢复至术前水平,组间比较前者有显著差异(P<0.05)。两组血浆肾上腺素、IL-10术中术后均无显著变化。两组血清ACTH、IL-6及CRP术中术后均显著升高(P<0.05),组间比较无显著差异。结论 硬膜外腔阻滞可以减轻胸部手术的应激反应。IL-6是较CRP更灵敏的反映组织损伤的炎性指标。 相似文献
54.
葡萄糖筛选试验在妊娠期糖尿病诊断及治疗中的价值 总被引:5,自引:1,他引:4
目的 探讨 5 0 g葡萄糖筛选试验 (GCT)在妊娠期糖尿病 (GDM )诊断及治疗中的价值。 方法 选择 2 0 0 0年 1月~ 2 0 0 3年 6月在我院行产前检查并分娩的 5 0 gGCT异常的孕妇 36 8例 ,按血糖值分为 5组 :≥7.8~ <8.0mmol/L为Ⅰ组 ,≥ 8.0~ <9.0mmol/L为Ⅱ组 ,≥ 9.0~ <10 .0mmol/L为Ⅲ组 ,≥ 10 .0~ <11.0mmol/L为Ⅳ组 ,≥ 11.0mmol/L为Ⅴ组。比较 5组 75 g口服葡萄糖耐量试验 (OGTT)异常的比例及需用胰岛素治疗的病例数的差异。结果 5组GDM的发生率分别为 6 .9%、8.5 %、2 1.3%、4 7.8%和 85 .0 % ,75 gOGTT异常的发生率分别为 19.0 %、2 4 .2 %、5 1.1%、87.0 %和 90 .0 % ,且用胰岛素治疗的病例数随 5 0 gGCT血糖值的上升而增加。结论 5 0 gGCT在GDM的诊断及治疗方案的预测方面均有重要价值。 相似文献
55.
I. Ibarrola M. L. Sanz† P. M. Gamboa‡ A. Mir§ D. Benahmed§ A. Ferrer¶ M. C. Arilla A. Martínez J. A. Asturias 《Clinical and experimental allergy》2004,34(2):303-309
BACKGROUND: Allergoids are widely used in specific immunotherapy (SIT) for the treatment of IgE-mediated allergic diseases, but all techniques for standardization of conventional allergic extracts may not be appropriate for standardization of a glutaraldehyde (GA)-modified extract because of the unique characteristics of these extracts. OBJECTIVE: To assess an accurate methodology for standardization of chemically modified extracts. METHODS: GA-modified extracts from Parietaria judaica pollen were purified by diafiltration. Biochemical properties were investigated by determination of amino groups, chromatography, and SDS-PAGE. The IgE-binding activity was determined by skin prick test, enzyme allergosorbent test inhibition, basophil activation, and histamine release tests. Peripheral blood mononuclear cells (PBMCs) from P. judaica pollen-allergic subjects were stimulated with either native or allergoid extracts, and proliferation was measured. RESULTS: Biochemical data indicated a high degree of allergen polymerization resulting in extract components higher than 100 kDa. IgE-binding activity, both in vivo and in vitro, was reduced by more than 99.8%. Both allergen and allergoid induced PBMC proliferation and synthesis of blocking IgG antibodies at similar rates. Moreover, no evidence of introduction of new determinants by chemical modification was found. CONCLUSIONS: The preparation of GA-modified extracts by diafiltration is faster and more reliable than previous chromatographic methods. These modified extracts have drastically reduced their allergenicity while maintaining their immunogenicity, and therefore they can be used in safer and shortened schedules of SIT. 相似文献
56.
J Dissemond D Haberer T Franckson U Hillen 《Journal of the European Academy of Dermatology and Venereology》2004,18(5):611-613
The Van der Woude syndrome is a rare autosomal dominant developmental malformation usually associated with bilateral lower lip pits. These congenital lip pits appear clinically as a malformation in the vermilion border of the lip, with or without excretion. As a genetic defect has been identified as a microdeletion of chromosome bands 1q32-q41, genetic counselling of patients may be considered. A nonsense mutation in the interferon regulatory factor-6 (IRF-6) is discussed as a pathogenic relevant factor. Therapeutic intervention is generally not necessary, although surgical excision is especially indicated in patients with recurrent inflammation. Physicians should be aware of the Van der Woude syndrome because it has been reported to be associated with a variety of malformations or other congenital disorders. 相似文献
57.
P. Botas E. Delgado G. Castaño C. Díaz de Greñu J. Prieto F. J. Díaz-Cadórniga 《Diabetic medicine》2003,20(11):904-908
AIMS: To estimate the prevalence of diabetes mellitus with three diagnostic criteria (WHO-1985 and 1999 and ADA-1997), evaluate their concordance and analyse the sensitivity and specificity of the different screening strategies for diabetes. METHODS: A cross-sectional population study with two-step sampling. One thousand and 34 people were selected randomly. A 75-g oral glucose tolerance test (OGTT) was performed and venous blood samples were obtained fasting and at 2 h. RESULTS: The prevalence of known Type 2 diabetes mellitus (DM-2) is 4%[95% confidence interval (CI) 2.8, 5.1]. By WHO-1985 criteria the prevalence of unknown DM-2 is 5.9% (4.5, 7.4); by ADA-1997 criteria 3.5% (2.5, 4.6) and by WHO-1999 criteria 7.3% (5.8, 8.8). Diagnostic overlap and statistical concordance (coefficient K) are WHO-1985/ADA-1997 29.3%, K=0.42; WHO-1985/WHO-1999 80%, K=0.88; ADA-1997/WHO-1999 48%, K=0.63. If only fasting glucose was used (following ADA-1997), 36.3% of those with diabetes (2-h glucose > or =11.1 mmol/l) would be diagnosed. If OGTT was performed (i) in those with a fasting glucose between 6.1 mmol/l and 6.9 mmol/l (9.8% of the population) we would diagnose 66.6%, and (ii) in all those between 5.7 mmol/l and 6.9 mmol/l (18.9% of the population) 81.8% would be diagnosed. CONCLUSIONS: The ADA criteria decrease the prevalence of DM in the adult population of Asturias by 2.4% and concordance with the classical criteria (WHO-1985) was only 29.3%. Using fasting glucose only (ADA-1997) diagnoses 36.3% of those with diabetes. The recent recommendations of the WHO-1999 increases this to 66.6%. To improve the diagnostic strategy for diabetes and detect up to 81.8% of patients, we propose the use of OGTT for all those with a fasting glucose between 5.7 mmol/l and 6.9 mmol/l. 相似文献
58.
59.
Inflammatory biomarkers in blood of patients with acute brain ischemia 总被引:11,自引:0,他引:11
S. Sotgiu B. Zanda B. Marchetti M. L. Fois G. Arru G. M. Pes F. S. Salaris A. Arru A. Pirisi G. Rosati 《European journal of neurology》2006,13(5):505-513
Although many failed surrogate markers are provided in the literature, inflammation may contribute to the outcome of ischemic stroke. In 50 consecutive patients with acute ischemic stroke, in the absence of symptoms and signs of concomitant infection, we evaluated a panel of biomarkers reported to be variably associated with brain ischemia, and correlate their serum level with the brain lesion volume and clinical outcome. Infarct size was calculated on computed tomography (CT) scans by means of the Cavalieri's method. Neurological impairment was scored by using the Glasgow Coma Scale, Glasgow Outcome Scale and National Institutes of Health (NIH) scales at stroke onset and 3-month follow-up. Some markers showed a direct significant correlation with both initial and final NIH scale and with infarct size, particularly tumor necrosis factor alpha (TNF-alpha) (P=0.002), intercellular adhesion molecule-1 (P<0.01) and matrix metalloproteinase-2/9 (P=0.001). In contrast to previous reports, interleukin-6 (IL-6) serum level showed a significant inverse correlation with both final neurological impairment and infarct size (P<0.001). This novel finding allows us suggesting that IL-6, in the context of a complex pro-inflammatory network occurring during stroke, is associated with neuroprotection rather than neurotoxicity in patients with ischemic brain injury. 相似文献
60.
Measurements of respiratory mechanics are frequently made in ventilated infants and children. Esophageal pressure measurements (Pes using a balloon on a catheter have been used to partition the respiratory mechanics into lung and chest wall components. Appropriate positioning of this balloon is crucial to obtain accurate estimates of pleural pressure. Traditionally, in spontaneously breathing subjects the balloon position is assessed with an occlusion test. In ventilated subjects, it is not always possible to perform an occlusion test prior to paralysis, and even if such a test is performed it may not be relevant under conditions of positive pressure ventilation. We have assessed a positive pressure occlusion test that is suitable for paralyzed subjects. By occluding the airway opening and applying gentle pressure to the abdomen or rib cage, positive swings in pressure can be measured by both Pes and airway opening pressure (Pao). We compared traditional occlusion tests measured in 16 spontaneously breathing puppies to the positive pressure occlusion test performed after paralysis. In 2 pups we were unable to obtain a reasonable traditional occlusion test (>15% difference between Pes and Pao) but we obtained 10 traditional occlusion tests in each of the remaining 14 pups (2.1–14 kg). In 11 of these animals Ape, was within 10% of Pao. This compared well to positive pressure occlusion test using abdominal pressure performed after paralysis, where Apes was within 10% of ΔPao in 10 animals. In 9 of these pups occlusion tests were also performed by applying pressure on the rib cage, where ΔPes was within 10% of ΔPao in 6 animals. These results suggest that it is possible to perform accurate occlusion tests in paralyzed subjects by abdominal or rib cage compression with the airway occluded. Pediatr Pulmonol. 1994; 17:56–62. © 1994 Wiley-Liss, Inc. 相似文献