全文获取类型
收费全文 | 46297篇 |
免费 | 3717篇 |
国内免费 | 2892篇 |
专业分类
耳鼻咽喉 | 363篇 |
儿科学 | 682篇 |
妇产科学 | 627篇 |
基础医学 | 5671篇 |
口腔科学 | 724篇 |
临床医学 | 6052篇 |
内科学 | 7503篇 |
皮肤病学 | 485篇 |
神经病学 | 2881篇 |
特种医学 | 1408篇 |
外国民族医学 | 17篇 |
外科学 | 5091篇 |
综合类 | 6916篇 |
现状与发展 | 5篇 |
一般理论 | 7篇 |
预防医学 | 2741篇 |
眼科学 | 1249篇 |
药学 | 4525篇 |
45篇 | |
中国医学 | 1927篇 |
肿瘤学 | 3987篇 |
出版年
2025年 | 37篇 |
2024年 | 730篇 |
2023年 | 902篇 |
2022年 | 1786篇 |
2021年 | 2334篇 |
2020年 | 1735篇 |
2019年 | 1638篇 |
2018年 | 1609篇 |
2017年 | 1407篇 |
2016年 | 1315篇 |
2015年 | 1939篇 |
2014年 | 2401篇 |
2013年 | 2166篇 |
2012年 | 3242篇 |
2011年 | 3475篇 |
2010年 | 2073篇 |
2009年 | 1702篇 |
2008年 | 2361篇 |
2007年 | 2384篇 |
2006年 | 2250篇 |
2005年 | 2251篇 |
2004年 | 1539篇 |
2003年 | 1480篇 |
2002年 | 1250篇 |
2001年 | 1106篇 |
2000年 | 1129篇 |
1999年 | 1228篇 |
1998年 | 654篇 |
1997年 | 714篇 |
1996年 | 531篇 |
1995年 | 479篇 |
1994年 | 412篇 |
1993年 | 300篇 |
1992年 | 365篇 |
1991年 | 321篇 |
1990年 | 270篇 |
1989年 | 239篇 |
1988年 | 219篇 |
1987年 | 188篇 |
1986年 | 168篇 |
1985年 | 123篇 |
1984年 | 70篇 |
1983年 | 78篇 |
1982年 | 47篇 |
1981年 | 53篇 |
1980年 | 29篇 |
1979年 | 45篇 |
1978年 | 20篇 |
1977年 | 17篇 |
1974年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
Tang Su-en唐素恩 Kang Ying-qu康映蕖Departments of Pathology Obstetrics Gynecology First Hospital. Beijing Medical University Beijing. 《中华医学杂志(英文版)》1986,99(6):464-469
Eight cases of malignant and 12 0f benign Bren-
ner tumor are reported, patient ages ranged 31
69 and 39-53 years. The malignant tumor was
bilateral in 6 0f 8 cases, and the benign in l of 12.
The greatest diameter of the malignant tumors
averaged around 11 cm, and the benign 10. Six of
the malignant Brenner tumor patients died, one was
lost to follow up, and one survived for 10 years.
Pathologic and microscopic findings were pre-
sented in some detail. Based on the analysis of the
association between the histologic features and type
of Mullerian epithelium, we believe that the so called
Brenner tumor is in effect a tumor arising from the
Mullerian epithelium with a tendency to differentiate
into vaginocervical type epithelium. 相似文献
13.
BACKGROUND: Reduced Th1 and elevated Th2 cytokine responses are considered to be a principal mechanism in the generation of the inflammation leading to the manifestations of atopic disease in the skin of atopic dermatitis and in the airways of asthma. If reduced Th1 and elevated Th2 responses are principal determinants of the manifestation of atopic disease it might be expected that subjects with established disease would exhibit differences in their cytokine profiles as compared with atopic patients without clinical disease. OBJECTIVE: To determine whether asymptomatic atopic children exhibit a cytokine imbalance similar to that seen in patients with established atopic disease or if they behave like non-atopic controls. Cytokine responses in a group of children with elevated IgE but no clinical manifestations of disease, atopic children with established disease and non-atopic controls were compared. METHODS: We examined allergen-induced (house dust mite, HDM, rye grass pollen and RYE) cytokine responses in parallel with polyclonal (staphylococcal enterotoxin B, SEB) cytokine responses in a group of children with elevated serum IgE levels without current or past evidence of atopic disease (median age 6.6 years) and compared these with a non-atopic control group (median age 6.5 years) and a group of children with atopic disease (median age 6.7 years). RESULTS: Symptomatic atopic children had reduced SEB-induced IFN-gamma and increased SEB-induced IL-4 and IL-5 as compared with non-atopic controls. In contrast, SEB-induced IFN-gamma, IL-4 and IL-5 production in asymptomatic atopics was not significantly different from the non-atopic control subjects. Allergen-induced Th1 (IFN-gamma) and Th2 (IL-5 and IL-13) cytokine production was increased in both symptomatic atopics and asymptomatic atopics when compared with non-atopic controls. CONCLUSION: The defect in polyclonally induced IFN-gamma production was associated with the clinical manifestation of atopic disease but not the atopic stateper se. This suggests that the global reduction in IFN-gamma is the key determinant of the development of overt atopic disease. In contrast, elevated allergen-induced Th2 cytokine responses in children related to the atopic state per se irrespective of the presence of clinical atopic disease. 相似文献
14.
Adenophora polysaccharides (AP), is an active principle extracted from the root of Adenophorae Potaninii Korsh originated in Gansu Province and isolated with boiling water(1). AP is isolated and purified from the crude drug by DEAE-cellulose and Sephadex G-200 column, with a white powder and mean molecular weight of 8.3 × 104 , and [α]D20of AP is 68(1). AP is only composed of glucose judging from the analysis of it with patina chromatography (PC) and gas chromatography-mass spectrometer (GC-MS) methods.The methylation analysis showed that AP is composed of (1→6) linked glucose residues. The measure of nuclear magnetic resonance imaging (NMR) 1H NMR and 14C NMR techniques further proved that AP is α(l→6) linked by Dglucose. The structure of AP is as follows: -[→6]α-D-Glu(1-)n→ (2). 相似文献
15.
OBJECTIVE: To study the expression of S100 in oral submucose fibrosis(OSF). METHODS: Immunohistochemistry assay was performed on 10 cases of OSF, 10 cases of oral epithelial dysplasia (OED) and 8 cases of normal oral epithelium using monoclonal antibody against S100 protein. RESULTS: S100 did not express in the normal oral muscosal epithelium. The S100 positive nuclear staining was found in 50% of the OSF and OED cases, which was significantly higher than that in the normal oral epithelium (P < 0.05). But the positive staining in the OSF and OED cases had no difference (P > 0.05). CONCLUSION: S100 expression is closely related to the development of OSF and OED. The positive staining expression in the OSF and OED cases is the same. 相似文献
16.
17.
Twenty patients with major depressive disorder were studied with evoked potential (EP) topographic mapping after receiving placebo, imipramine, or amoxapine for 2 days in a random-assignment, double-blind design. Patients performed the Continuous Performance Test (CPT), a visual vigilance test. The stimuli were the digits 0-9, with 0 a target to be responded to with a button press. EPs were recorded from 32 channels and were averaged separately for detected and undetected targets and for false positives and correctly identified nontargets (no button press). Twenty-one normal controls were also tested. Amoxapine enhanced N120 amplitude in midline parietal and right parietal cortex where selective attention effects have been found to be greatest in studies of normal controls. Both amoxapine and imipramine enhanced differences in P200 between target and nontarget stimuli in comparison to placebo, with amoxapine differences again being greatest over midline parietal locations. CPT performance was significantly better on amoxapine than placebo. 相似文献
18.
From Jan. to Oct. 1989, we investigated the role of various life style and dietary factors in areas of high and low incidences of cervical carcinoma, as well as infection with types 16 and 33 of human papillomavirus (HPV) in populations. The polymerase chain reaction (PCR) technique was used to detect the infection with HPV 16/33. The result showed that the infection rate of HPV was about 17.9% (Guangyuan, area of high incidence of cervical cancer), and the infection rate about 3.4% (Mian Zhu, area of low incidence of cervical cancer). It was clear that Guangyuan was 5-fold as the infection rate of HPV 16/33 as Mian Zhu. Strong and statistically significant associations were found to between infection rate of Guangyuan and Mian Zhu (P < 0.001). Other risk factors of cervical carcinoma, such as cigarette smoker, Vegetable intake, genital hygiene, personal hygiene etc, were also discussed and analysed in the article. 相似文献
19.
穿透性角膜移植术后角膜内皮细胞之命运 总被引:1,自引:0,他引:1
地2组猴行5。5→5.0mm穿透性角膜移植术,异种组4只,同种组4只,术前用冷冻创伤^3H-TdR标记法标记受生角膜内皮细胞,术后14周摘除眼球,用放射自显影法显示银颗粒的分布。 相似文献
20.