全文获取类型
收费全文 | 16567篇 |
免费 | 1001篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 132篇 |
儿科学 | 425篇 |
妇产科学 | 418篇 |
基础医学 | 2618篇 |
口腔科学 | 662篇 |
临床医学 | 1375篇 |
内科学 | 3665篇 |
皮肤病学 | 341篇 |
神经病学 | 1960篇 |
特种医学 | 450篇 |
外科学 | 1456篇 |
综合类 | 41篇 |
一般理论 | 5篇 |
预防医学 | 1012篇 |
眼科学 | 274篇 |
药学 | 1349篇 |
中国医学 | 57篇 |
肿瘤学 | 1409篇 |
出版年
2024年 | 18篇 |
2023年 | 171篇 |
2022年 | 394篇 |
2021年 | 592篇 |
2020年 | 361篇 |
2019年 | 477篇 |
2018年 | 574篇 |
2017年 | 451篇 |
2016年 | 522篇 |
2015年 | 649篇 |
2014年 | 738篇 |
2013年 | 936篇 |
2012年 | 1469篇 |
2011年 | 1563篇 |
2010年 | 775篇 |
2009年 | 741篇 |
2008年 | 1166篇 |
2007年 | 1087篇 |
2006年 | 1015篇 |
2005年 | 925篇 |
2004年 | 829篇 |
2003年 | 753篇 |
2002年 | 641篇 |
2001年 | 77篇 |
2000年 | 54篇 |
1999年 | 69篇 |
1998年 | 106篇 |
1997年 | 94篇 |
1996年 | 60篇 |
1995年 | 57篇 |
1994年 | 42篇 |
1993年 | 30篇 |
1992年 | 19篇 |
1991年 | 16篇 |
1990年 | 12篇 |
1989年 | 23篇 |
1988年 | 15篇 |
1987年 | 22篇 |
1986年 | 14篇 |
1985年 | 14篇 |
1984年 | 11篇 |
1983年 | 15篇 |
1982年 | 13篇 |
1981年 | 12篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1975年 | 3篇 |
1973年 | 6篇 |
1961年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
71.
Lymphatic vessel density and epithelial D2-40 immunoreactivity in pre-invasive and invasive lesions of the uterine cervix 总被引:3,自引:0,他引:3
Longatto-Filho A Pinheiro C Pereira SM Etlinger D Moreira MA Jubé LF Queiroz GS Baltazar F Schmitt FC 《Gynecologic oncology》2007,107(1):45-51
OBJECTIVE: We sought to determine the significance of lymphatic vessel density (LVD) in pre-malignant lesions and carcinomas of the uterine cervix and to evaluate the prognostic value of lymphatic invasion and D2-40 positivity in tumor cells in the three histological types of invasive lesions. The correlation of LVD, lymphatic invasion and D2-40 positivity in tumor cells with EGFR and COX-2 expressions was also evaluated. METHODS: We studied 50 cervicitis, 50 low-grade squamous intraepithelial lesions (LSIL) (CIN1), 51 high-grade squamous intraepithelial lesions (HSIL) (CIN2/CIN3), 49 invasive squamous cells carcinomas (SCC), 43 adenocarcinomas (AC) and 30 adenosquamous cells carcinomas (ASC). The immunoreaction assay was performed using the monoclonal antibody D2-40. RESULTS: Significant differences in LVD were found among all categories of pre-invasive and invasive lesions (p=0.001 and p<0.001, respectively). LVD in invasive lesions was significantly greater than in pre-invasive lesions (p<0.001) and no significant association was found between LVD in invasive lesions and both lymph node invasion and/or metastasis. D2-40 positivity in tumor cells was associated with a better prognosis in ASC cases. EGFR and COX-2 expressions in invasive lesions were not associated with LVD; however, they correlated with both lymphatic invasion and D2-40 positivity in tumor cells. CONCLUSIONS: Lymphatic neovascularization begins early in intraepithelial lesions and continues to increase towards malignancy. Both lymphatic invasion and decrease in D2-40 expression in tumor cells appear to have a prognostic value. 相似文献
72.
73.
Dusse LM Carvalho Md Bragança WF Paiva SG Godoi LC Guimarães DA Fernandes AP 《European journal of obstetrics, gynecology, and reproductive biology》2007,134(1):20-23
OBJECTIVE: The aim of the present study was to compare the distribution of G1691A, G20210A and C677T mutations in pre-eclamptic Brazilian women and in matched control women with an uncomplicated normal pregnancy. STUDY DESIGN: these mutations were investigated by PCR-RFLP in 83 normal pregnancies (control group) and in 30 pre-eclamptic pregnant women (severe form). RESULTS: G1691A mutation was detected neither in the control group nor in pre-eclamsia women. G20210A mutation was detected in heterozygosis in 3 (3.61%) control subjects, but not in pre-eclampsia group. C677T mutation was detected in homozygosis in 6 (7.23%) control subjects and 2 (6.67%) pre-eclamptic women and in heterozygosis in 31 (37.3%) control subjects and 12 (40%) pre-eclamptic women. Differences in the mutation frequencies detected in the two groups were not statistically significant. CONCLUSION: No correlation was observed between pre-eclampsia and presence of G1691A, G20210A and C677T mutations in Brazilian women. 相似文献
74.
75.
76.
Agic A Xu H Altgassen C Noack F Wolfler MM Diedrich K Friedrich M Taylor RN Hornung D 《Reproductive sciences (Thousand Oaks, Calif.)》2007,14(5):486-497
The authors demonstrate expression of the vitamin D receptor (VDR) and its hydroxylases in the endometrium and ovaries of women with and without endometriosis and endometrial or ovarian cancer. Immunohistochemistry showed strong staining of the VDR in endometriosis and endometrial cancer, with the most intense staining in epithelial cells. The VDR mRNA was significantly increased in patients with endometrial and ovarian cancer compared to the control group. There was a significantly higher 1 alpha-hydroxylase expression in the endometrium of patients with endometriosis compared to healthy controls. The observed differences in VDR and 1 alpha -hydroxylase mRNA levels were maintained at the protein level. The authors found no differences in 25-OH vitamin D levels between the serum of patients with endometriosis (25.7 +/- 2.1 ng/mL, n = 46) and healthy controls (22.6 +/- 2.0 ng/mL, n = 33, P = .31). They hypothesize that vitamin D might influence the local activity of immune cells and cytokines thought to play important pathogenic roles in the development and maintenance of endometriosis. 相似文献
77.
78.
Daniela Campaniello Maria Rosaria Corbo Milena Sinigaglia Barbara Speranza Angela Racioppo Clelia Altieri Antonio Bevilacqua 《Nutrients》2022,14(12)
Gut microbiota plays a significant role in the maintenance of physiological homeostasis, contributing to human health. Nevertheless, some factors (sex, age, lifestyle, physical activity, drug-based therapies, diet, etc.) affect its composition and functionality, linked to pathologies and immunological diseases. Concerning diet, it interacts with microorganisms, leading to beneficial or detrimental outcomes for the health of host. On the other hand, physical activity is known to be useful for preventing and, sometimes, treating several diseases of cardiovascular, neuroendocrine, respiratory, and muscular systems. This paper focuses on diet and physical activity presenting the current knowledge about how different diets (Western, ketogenic, vegan, gluten free, Mediterranean) as well as different types of exercise (intensive, endurance, aerobic) could shape gut microbiota. 相似文献
79.
Daniela Gerges Sebastian Kapps Esperanza Hernndez-Carralero Raimundo Freire Monika Aiad Sophie Schmidt Wolfgang Winnicki Thomas Reiter Sahra Pajenda Alice Schmidt Gere Sunder-Plassmann Ludwig Wagner 《Viruses》2022,14(6)
SARS-CoV-2 variants of concern (VOCs) have caused a significant increase in infections worldwide. Despite high vaccination rates in industrialized countries, the fourth VOC, Omicron, has outpaced the Delta variant and is causing breakthrough infections in individuals with two booster vaccinations. While the magnitude of morbidity and lethality is lower in Omicron, the infection rate and global spread are rapid. Using a specific IgG multipanel-ELISA with the spike protein’s receptor-binding domain (RBD) from recombinant Alpha, Gamma, Delta, and Omicron variants, sera from health-care workers from the Medical University of Vienna were tested pre-pandemic and post-vaccination (BNT162b2; ChAdOx1 nCoV-19). The cohort was continuously monitored by SARS-CoV-2 testing and commercial nucleocapsid IgG ELISA. RBD IgG ELISA showed significantly lower reactivity against the Omicron-RBD compared to the Alpha variant in all individuals (p < 0.001). IgG levels were independent of sex, but were significantly higher in BNT162b2 recipients <45 years of age for Alpha, Gamma, and Delta (p < 0.001; p = 0.040; p = 0.004, respectively). Pre-pandemic cross-reactive anti-Omicron IgG was detected in 31 individuals and was increased 8.78-fold after vaccination, regardless of vaccine type. The low anti-RBD Omicron IgG level could explain the breakthrough infections and their presence could also contribute to a milder COVID-19 course by cross-reactivity and broadening the adaptive immunity. 相似文献
80.