全文获取类型
收费全文 | 182490篇 |
免费 | 17293篇 |
国内免费 | 11808篇 |
专业分类
耳鼻咽喉 | 1633篇 |
儿科学 | 1920篇 |
妇产科学 | 2428篇 |
基础医学 | 21898篇 |
口腔科学 | 3259篇 |
临床医学 | 23964篇 |
内科学 | 26725篇 |
皮肤病学 | 2208篇 |
神经病学 | 9509篇 |
特种医学 | 6462篇 |
外国民族医学 | 97篇 |
外科学 | 18593篇 |
综合类 | 29596篇 |
现状与发展 | 39篇 |
一般理论 | 22篇 |
预防医学 | 12231篇 |
眼科学 | 4768篇 |
药学 | 19708篇 |
191篇 | |
中国医学 | 10975篇 |
肿瘤学 | 15365篇 |
出版年
2024年 | 733篇 |
2023年 | 2986篇 |
2022年 | 7789篇 |
2021年 | 9798篇 |
2020年 | 7368篇 |
2019年 | 6340篇 |
2018年 | 6623篇 |
2017年 | 6078篇 |
2016年 | 5689篇 |
2015年 | 8730篇 |
2014年 | 10584篇 |
2013年 | 9786篇 |
2012年 | 14266篇 |
2011年 | 15411篇 |
2010年 | 9842篇 |
2009年 | 7573篇 |
2008年 | 10054篇 |
2007年 | 9528篇 |
2006年 | 9139篇 |
2005年 | 8875篇 |
2004年 | 5682篇 |
2003年 | 5146篇 |
2002年 | 4261篇 |
2001年 | 3604篇 |
2000年 | 3795篇 |
1999年 | 3851篇 |
1998年 | 2288篇 |
1997年 | 2340篇 |
1996年 | 1782篇 |
1995年 | 1731篇 |
1994年 | 1512篇 |
1993年 | 910篇 |
1992年 | 1279篇 |
1991年 | 1115篇 |
1990年 | 896篇 |
1989年 | 842篇 |
1988年 | 761篇 |
1987年 | 623篇 |
1986年 | 458篇 |
1985年 | 396篇 |
1984年 | 190篇 |
1983年 | 162篇 |
1982年 | 93篇 |
1981年 | 123篇 |
1980年 | 79篇 |
1979年 | 108篇 |
1978年 | 52篇 |
1977年 | 51篇 |
1976年 | 42篇 |
1974年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 1 毫秒
41.
神经肽Y(NPY)是广泛分布于中枢神经系统和外周神经各部位的神经肽类物质。本实验观察NPY在体外对几种免疫细胞活性的直接作用。结果表明,NPY对小鼠T淋巴细胞丝裂原反应性和NK细胞的杀伤活性均无明显影响(P>0.05),对巨噬细胞分泌溶菌酶有明显抑制作用(P<0.05);而对B淋巴细胞丝裂原反应性则有明显的促进作用(P<0.05)。上述结果提示,NPY对部分免疫细胞功能的影响因细胞种类而异。 相似文献
42.
43.
在蟾蜍离体坐骨神经-缝匠肌制备的肌细胞终板进行细胞内记录,研究了雌酮对神经-肌接头传递的影响。结果表明:雌酮加于浸浴液能增加10μg筒箭毒处理组和10mmol/L MgCl2处理组制备的终板电位振幅,但前者的增加更显著;雌酮加入浸浴液30分钟后引起小终板电位的振幅和频率明显增加,但波形不改变,静息膜电位也不改变。这些结果提示,雌酮能增加神经-肌接头传递,且主要通过突触前机理的作用。 相似文献
44.
Amrik Sahota Min Yang Sujuan Gao Siu L. Hui Olusegun Baiyewu Oyewusi Gureje Steven Oluwole Adesola Ogunniyi Kathleen S. Hall Hugh C. Hendrie 《Annals of neurology》1997,42(4):659-661
As a part of our ongoing study on Alzheimer's disease (AD) in elderly African Americans, we obtained clinical assessment and apolipoprotein E (ApoE) genotype data on 288 individuals (including 60 with AD). The ApoE σ4 allele frequency was significantly increased in AD patients compared with controls. The age-adjusted odds ratio (OR) for AD in σ4 homozygotes was 4.83 (95% confidence interval [CI], 1.71–13.64) compared with the σ3/σ3 genotype, but the OR for AD with the σ3/σ4 genotype did not reach significance (1.20; 95% CI, 0.58–2.45). These findings suggest that the association between ApoE σ4 and AD is weaker in African Americans than in whites. 相似文献
45.
Lyme disease presenting as urinary retention 总被引:1,自引:0,他引:1
We report a case of Lyme disease that presented with urinary retention. The individual then experienced lower extremity paralysis. Paralysis and urinary retention resolved with intravenous ceftriaxone antibiotic. To our knowledge this is the first report of a urological manifestation as the initial clinical presentation of Lyme disease. Recognition of clinical symptoms and urological complications of Lyme disease also are discussed. 相似文献
46.
47.
T J Yang 《In vivo (Athens, Greece)》1987,1(5):297-302
Canine cyclic hematopoiesis (CH) was first described in Gray Collies as the lethal gray syndrome, and was subsequently shown to be a counterpart of human cyclic neutropenia (CN). The disease is characterized by a recurrent cyclic change in the levels of neutrophils and other blood elements at approximately 12-day intervals. It is caused by an autosomally recessive gene with pleiotropic effects or a CH gene which is closely linked to a gray color gene. The infectious insult on affected animals is periodic but its clinical and pathologic effects are continual and cumulative Affected dogs die after weaning and rarely survive over 6 months of age. There is evidence of immunoregulatory defects in these dogs. Reciprocal bone marrow transplantation indicates that the defect resides in the bone marrow, but the actual site and mechanism of the defect has not been established. The disease in Gray Collies represents a unique model system for studying the mechanism of cyclic hematopoiesis and hematopoietic regulation. Studies of the disease have made conceptual contributions toward understanding and treatment of human cyclic neutropenia. 相似文献
48.
49.
关木通引起慢性间质性肾炎7例报告 总被引:3,自引:0,他引:3
目的 观察关木通所致慢性肾损伤的临床和病理改变特点。方法 本组 7例中 ,男 5例 ,女 2例。 3例服关木通汤药 ,4例服含关木通成药。分析服用时间、累积总量与肾损害首发症状及症状出现时间、肾功能和肾病理改变的关系。结果 汤药组 :服药时间平均 3 3 3个月 ,累积总量平均 82 9 3 g ,首发症状为乏力 3例 ,夜尿增多 2例 ,平均时间为 8 3个月 ,Cr平均 40 2 μmol/L。肾病理 :3例均为重度寡细胞性肾间质纤维化 ,肾小管广泛萎缩。成药组 :服药时间平均 7 5个月 ,累积总量平均 13 6g ,乏力 3例 ,夜尿增多 1例 ,恶心呕吐、头痛头晕 1例 ,平均18 8个月 ,Cr 3 62 8μmol/L。肾病理为重度寡细胞性间质纤维化和灶状纤维化各 2例 ,肾小管灶状萎缩 3例 ,广泛萎缩 1例。结论 汤药组关木通积累大 ,发病时间早 ,肾病理改变重。提示关木通所致肾损其临床表现、病理改变与服用关木通时间、剂量相关。 相似文献
50.
BACKGROUND AND PURPOSE: Health-related quality of life (HRQOL) is primarily an assessment of how domains of life are affected by health. This study investigated the factors influencing HRQOL of Taiwanese patients with bronchial asthma. METHODS: A cross-sectional study was conducted to assess the factors influencing HRQOL. The sample consisted of 242 outpatients with bronchial asthma. The Chinese language version of the St. George's Respiratory Questionnaire was used to measure HRQOL. Data were analyzed using simple regression and multiple regression. RESULTS: Age, marital status, level of education, asthma severity, peak expiratory flow, and previous hospital admissions were found to be predictors of HRQOL. Gender, duration of disease, and history of emergency visits were not correlated with HRQOL. The variables entered in the HRQOL model accounted for 17.4% of the total variance (adjusted R(2)). The regression coefficients indicated that the mean scores increased 7.68 in patients with moderate to severe disease severity, and increased 7.34 in patients with a history of hospital admissions. The mean scores decreased 7.60 in married patients. CONCLUSION: This study found that marital status, asthma severity, and history of hospital admissions were major predictors of HRQOL in Taiwanese patients with bronchial asthma. 相似文献