全文获取类型
收费全文 | 220145篇 |
免费 | 20302篇 |
国内免费 | 15484篇 |
专业分类
耳鼻咽喉 | 1901篇 |
儿科学 | 2207篇 |
妇产科学 | 2981篇 |
基础医学 | 26563篇 |
口腔科学 | 3697篇 |
临床医学 | 30854篇 |
内科学 | 33023篇 |
皮肤病学 | 2235篇 |
神经病学 | 12397篇 |
特种医学 | 8321篇 |
外国民族医学 | 138篇 |
外科学 | 21741篇 |
综合类 | 35411篇 |
现状与发展 | 55篇 |
一般理论 | 19篇 |
预防医学 | 13161篇 |
眼科学 | 6696篇 |
药学 | 22731篇 |
194篇 | |
中国医学 | 12348篇 |
肿瘤学 | 19258篇 |
出版年
2024年 | 698篇 |
2023年 | 3559篇 |
2022年 | 9200篇 |
2021年 | 11544篇 |
2020年 | 8597篇 |
2019年 | 7540篇 |
2018年 | 8036篇 |
2017年 | 7087篇 |
2016年 | 6658篇 |
2015年 | 10254篇 |
2014年 | 12560篇 |
2013年 | 10700篇 |
2012年 | 16006篇 |
2011年 | 17949篇 |
2010年 | 10528篇 |
2009年 | 8194篇 |
2008年 | 11114篇 |
2007年 | 11098篇 |
2006年 | 11230篇 |
2005年 | 11330篇 |
2004年 | 7004篇 |
2003年 | 6615篇 |
2002年 | 5504篇 |
2001年 | 4939篇 |
2000年 | 5345篇 |
1999年 | 5691篇 |
1998年 | 3547篇 |
1997年 | 3514篇 |
1996年 | 2824篇 |
1995年 | 2624篇 |
1994年 | 2155篇 |
1993年 | 1390篇 |
1992年 | 1895篇 |
1991年 | 1597篇 |
1990年 | 1293篇 |
1989年 | 1108篇 |
1988年 | 1029篇 |
1987年 | 908篇 |
1986年 | 740篇 |
1985年 | 538篇 |
1984年 | 339篇 |
1983年 | 242篇 |
1982年 | 152篇 |
1981年 | 152篇 |
1980年 | 116篇 |
1979年 | 145篇 |
1978年 | 54篇 |
1977年 | 61篇 |
1975年 | 65篇 |
1974年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Delta hepatitis virus infection in China 总被引:1,自引:0,他引:1
D Q Wang H H Cheng G Y Minuk L H Liu C M Anand T C Stowe H X Wang D C Ying Y R Tu K A Buchan 《International journal of epidemiology》1987,16(1):79-83
To assess the prevalence, epidemiological features and prognostic implications of hepatitis D (Delta) in Sichuan Province, The People's Republic of China, 649 sera (515 from HBsAg positive patients and 134 from HBsAg negative subjects) were tested by radioimmunoassay (RIA) for antibody to the hepatitis D virus (anti-HD). Forty-seven sera (7.2%) showed some degree of reactivity. Serial dilutions of these sera indicated that prozoning was not responsible for the equivocal results. Thirty-four of the 47 sera were submitted under code to a second laboratory for independent analysis. According to those results anti-HD antibodies were detected in four of these sera. The overall prevalence of anti-HD in the HBsAg positive patients therefore was 0.8% (4/515). On the basis of clinical, biochemical and histological data 427 HBsAg positive sera were further divided into acute Type B hepatitis, chronic Type B hepatitis, healthy carrier state and hepatocellular carcinoma (HCC) subgroups. Two of 65 (3.1%) anti-HD positive sera belonged to the acute Type B hepatitis group; one of 104 (0.9%), the chronic Type B hepatitis group and one of 246 (0.4%), the healthy carrier group. No antibody was detected in sera from 12 HBsAg positive HCC patients. All HBsAg negative patients were negative for anti-HD antibody. The results of this study indicate that despite a high prevalence of hepatitis B virus infection, positive serology for delta virus is uncommon in Sichuan Province, The People's Republic of China. 相似文献
62.
Population-based association studies are powerful tools for the genetic mapping of complex diseases. However, this method is sensitive to potential confounding by population structure. While statistical methods that use genetic markers to detect and control for population structure have been the focus of current literature, the utility of self-defined race/ethnicity in controlling for population structure has been controversial. In this study of 1334 individuals, who self-identified as either African American, European American or Hispanic, we demonstrated that when the true underlying genetic structure and the self-defined racial/ethnic groups were roughly in agreement with each other, the self-defined race/ethnicity information was useful in the control of population structure. 相似文献
63.
64.
目的 初步建立阴道粘膜上皮细胞体外培养方法,为阴道粘膜上皮研究提供实验模型.方法 取雌性新西兰大白兔阴道粘膜组织小块,胶原酶Ⅳ和胰蛋白酶联合消化分离法收集上皮细胞,接种于角朊细胞无血清培养液中静置培养、传代.动态观察细胞生长增殖情况,扫描和透射电镜观察超微结构,流式细胞仪测定细胞增殖周期,并进行免疫组织化学鉴定.结果 体外培养的阴道粘膜上皮细胞为二倍体细胞,增殖状态良好,细胞间可见桥粒连接,免疫组化角蛋白染色阳性.细胞的超微结构和免疫组化染色均具有上皮细胞特征.结论 在本实验条件下,体外培养的阴道粘膜上皮细胞具有较好的增殖能力,可作为阴道粘膜上皮研究的理想实验模型. 相似文献
65.
66.
目的:建立乳腺非典型增生病动物模型,探讨非典型增生与血管生成的关系。方法:采用灌服二甲基苯蒽+颈部枷具方法复制大鼠肝郁血瘀型乳腺非典型增生动物模型,并给予中药乳复汤治疗。常规染色观察大鼠乳腺组织病理组织形态.免疫组化方法检测MVD、VEGF和bFGF的表达。结果:病证模型组乳腺非典型增生率90%.较单纯造模组高.P=0.0415;中药乳复汤治疗组非典型增生率较病证模型组低.P=0.0459;随着一般增生到非典型增生程度加重,MVD计数增多,VEGF、bFGF的表达升高,P〈0.05。结论:病证结合造模更适合中医动物实验要求,中药乳复汤具有抑制血管生成作用。 相似文献
67.
The authors reviewed the radiographic manifestations of 17 cases of parosteal osteosarcoma, with pathologic correlation in 15. There were two types of parosteal osteosarcoma radiologically. The majority of cases were type I with uniformly dense masses which had regular borders. They often adhered to the cortex and showed no evidence of soft-tissue invasion which correlated with low-grade pathologic malignancy and a relatively benign clinical course. Type II involved the bone, soft-tissue and the medullary cavity. These lesions were poorly differentiated and frequently accompanied by metastatic lesions.
相似文献
68.
69.
随着社会经济的不断发展,由于交通及运动损伤引起的膝关节损伤目趋增多。交叉韧带是维持膝关节稳定的重要结构,韧带的断裂会引起关节不稳,若时间长会发展成创伤性关节炎,严重影响病人的工作与生活。膝交叉韧带重建术,尤其在关节镜监视下重建是近年来发展起来的一项新技术,通过手术能有效地恢复关节的稳定与功能,但手术的效果优劣在很大程度上取决于手术技术及术中医护配合的好坏。2000年7月-2003年7月,我院共行膝交叉韧带重建术236例,现将护理配合报告如下。 相似文献
70.
Fengxiu Ouyang Binyan Wang Lester M. Arguelles Xiping Xu Jianhua Yang Zhiping Li Liuliu Wang Xue Liu Genfu Tang Houxun Xing Craig Langman Xiaobin Wang 《Archives of osteoporosis》2007,2(1-2):29-43
Summary We prospectively examined bone growth patterns in 894 children aged 6–17 years at the baseline visit, with a 6-year follow-up.
Results show bone “tracking” over a six-year interval and sexual dimorphism of bone attained levels and timing of peak bone
growth. Our findings underscore childhood and adolescence as critical periods for building bone and developing gender differences.
Introduction Bone growth patterns were prospectively examined in 894 Chinese children (496 males), aged 6–17 yrs, from a population-based
twin cohort. Whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD) were measured by DEXA at
baseline and a 6-yr follow-up.
Methods Graphic smoothing plots and generalized estimating equations were used to model bone attained levels, growth, and “tracking”.
Results Attained levels of BMC and BA increased curvilinearly with age. Male attained levels were higher than females after age ∼15 yr,
but BMD was lower between 13–17 yrs (Tanner stage I to IV). In both genders, peak BMC and BMD growth lagged ∼2 yrs behind
peak BA growth, which lagged 2 yrs behind peak height growth. Peak bone growth occurred 1–3 yrs later in males. Over the 6-yr
follow-up, all bone measurements “tracked”, but “shifting” across ranks also occurred, and baseline tertile ranking influenced
bone growth. Females with early menarche had higher attained levels than females with late menarche at age 12–13 yrs.
Conclusion Our findings confirm and expand previous studies on peak bone growth conducted in Caucasian cohorts, particularly sexually
dimorphic and maturational effects. The significant “tracking” of bone measurements in this 6-yr follow-up study underscores
the importance that osteoporosis prevention should begin in childhood and adolescence.
Fengxiu Ouyang and Binyan Wang contributed equally to this article.
Source(s) of support: This study is supported in part by grant R01 HD049059, R01 HL0864619 and R01 AR045651 from the National
Institute of Health and by the Food Allergy Project. 相似文献