全文获取类型
收费全文 | 279448篇 |
免费 | 7018篇 |
国内免费 | 663篇 |
专业分类
耳鼻咽喉 | 2155篇 |
儿科学 | 9972篇 |
妇产科学 | 5409篇 |
基础医学 | 31657篇 |
口腔科学 | 5477篇 |
临床医学 | 21886篇 |
内科学 | 54464篇 |
皮肤病学 | 3426篇 |
神经病学 | 26442篇 |
特种医学 | 11189篇 |
外国民族医学 | 1篇 |
外科学 | 37835篇 |
综合类 | 2709篇 |
一般理论 | 51篇 |
预防医学 | 28621篇 |
眼科学 | 4442篇 |
药学 | 16755篇 |
中国医学 | 1053篇 |
肿瘤学 | 23585篇 |
出版年
2024年 | 124篇 |
2023年 | 1049篇 |
2022年 | 2279篇 |
2021年 | 3725篇 |
2020年 | 2336篇 |
2019年 | 3153篇 |
2018年 | 24857篇 |
2017年 | 19627篇 |
2016年 | 22108篇 |
2015年 | 4323篇 |
2014年 | 5332篇 |
2013年 | 6695篇 |
2012年 | 15830篇 |
2011年 | 29963篇 |
2010年 | 23526篇 |
2009年 | 15590篇 |
2008年 | 26512篇 |
2007年 | 28665篇 |
2006年 | 7351篇 |
2005年 | 8488篇 |
2004年 | 9030篇 |
2003年 | 9345篇 |
2002年 | 7021篇 |
2001年 | 811篇 |
2000年 | 785篇 |
1999年 | 757篇 |
1998年 | 990篇 |
1997年 | 849篇 |
1996年 | 646篇 |
1995年 | 552篇 |
1994年 | 521篇 |
1993年 | 411篇 |
1992年 | 331篇 |
1991年 | 275篇 |
1990年 | 318篇 |
1989年 | 251篇 |
1988年 | 228篇 |
1987年 | 184篇 |
1986年 | 183篇 |
1985年 | 148篇 |
1984年 | 159篇 |
1983年 | 154篇 |
1982年 | 181篇 |
1981年 | 115篇 |
1980年 | 166篇 |
1979年 | 76篇 |
1978年 | 86篇 |
1977年 | 77篇 |
1976年 | 75篇 |
1974年 | 77篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Najat MA Farsi 《BMC oral health》2007,7(1):15
Background
This study aimed to investigate the signs of oral dryness in relation to different salivary variables and to correlate subjective complaints of oral dryness with salivary flow rate. 相似文献83.
84.
85.
Luigi Paolo Badano Maria C Albanese Paola De Biaggio Patrizia Rozbowsky Daniela Miani Claudio Fresco Paolo M Fioretti 《Journal of the American Society of Echocardiography》2004,17(3):253-261
Prevalence of isolated left ventricular (LV) diastolic dysfunction has been reported to be as high as one-third of all heart failure (HF) cases, with an increasing prevalence in the elderly population. However, there is a paucity of prospective data about the prevalence and prognosis of isolated LV diastolic dysfunction in an unselected population of patients hospitalized with HF. Therefore, we prospectively evaluated 179 consecutive patients discharged from our hospital with HF to assess the prevalence of systolic versus diastolic LV dysfunction among patients hospitalized with HF and to compare their demographics, clinical features, self-perceived quality of life (QOL), and 6-month readmission rate and mortality. Among them, 133 (59% men, median age 74 years) showed in sinus rhythm and had no significant primary valvular disease. LV diastolic dysfunction was diagnosed on the basis of the European Study Group on Diastolic HF echocardiographic criteria. QOL was assessed at hospital discharge and 6-month follow-up visit using the Minnesota Living with HF questionnaire. Survival of patients with HF was compared with that of age- and sex-matched general population. In all, 29 patients (22%) had isolated LV diastolic dysfunction and 102 (78%) had prevalent LV systolic dysfunction (ie, LV ejection fraction = 45%). There was no difference in age, sex, or New York Heart Association functional class between patients with LV diastolic or systolic dysfunction. QOL scores were similar between the 2 patient groups with HF both at discharge (39.4 and 34) and at 6-month visit (10.4 and 10.4). Both 6-month readmission rate (48% and 48%) and median inhospital length-of-stay during readmissions (10 days and 10 days) were similar between the 2 patient groups with HF. Finally, 6-month survival, adjusted for age and sex, was similar between patients with LV diastolic or systolic dysfunction (hazard ratio 0.68; 95% confidence interval 0.20-2.35). Using standardized echocardiographic criteria, isolated LV diastolic dysfunction among unselected patients hospitalized with HF was less than previously reported. Patients with HF and isolated diastolic dysfunction showed similar clinical symptoms, self-perceived QOL, readmission rate, and 6-month mortality to patients with prevalent LV systolic dysfunction. 相似文献
86.
87.
88.
Atopy may be associated with a reduced T-cell function early in life, particularly regarding maturation of Th1 responses. The T-cell surface molecules CD2 and CD28 are involved in important T-cell activation pathways. Stimulation via the CD2 receptor increases the responsiveness to interleukin (IL)-12, which is a potent inducer of Th1 responses, whereas CD28 stimulation is critical for Th2 differentiation. Our aim was to prospectively study the expression of the cell-surface markers CD2 and CD28 on T-cells in relation to development of atopic disease. Children (n = 172) were followed from birth to 18 months and the cumulative history of atopic disease was recorded. Blood samples were obtained at birth and at 18 months, and in a subgroup of 78 infants also at 3, 6 and 12 months. Flow cytometry was used to analyze the T-cell markers CD2 and CD28, the latter also within the subsets of T-helper (CD4+) and T-cytotoxic (CD8+) cells. At 18 months, 31 children had and 118 did not have atopic symptoms. At this age, skin prick test (SPT) positive children with atopic symptoms with or without an atopic family history (AFH) showed a lower expression of CD2 mode fluorescence intensity (FI) as well as a lower proportion of CD2+ cells, as compared with non-sensitized children with neither atopic symptoms nor AFH. This was accompanied by a higher expression of CD28 FI on CD2+CD8+CD28+ cells. No significant differences were seen at time points before 18 months, although the proportion of CD2+ tended to be low also earlier in life. In conclusion, the observed reduced expression of CD2 in atopic infants may support previous findings that atopy is associated with a reduced CD2 function. The high CD28 FI in SPT positive children with atopic symptoms may possibly be a consequence of a TH2-skewed immune system. 相似文献
89.
90.
Hybrid tumours of the salivary glands. A report of two cases involving the palate and a review of the literature 总被引:1,自引:0,他引:1
Luz María Ruíz-Godoy R Adalberto Mosqueda-Taylor Lourdes Suárez-Roa Adela Poitevin Esther Bandala-Sánchez Abelardo Meneses-García 《European archives of oto-rhino-laryngology》2003,260(6):312-315
Hybrid tumours are very rare salivary gland lesions composed of two or more different tumoural entities in a single neoplasm that arise within a definite topographical region. In most cases adenoid cystic carcinoma has been the predominant component in these lesions. In this study we describe two patients with hybrid tumours located in the palate, one in a 49-year-old woman and one in a 71-year-old man. The first case involved adenoid cystic carcinoma and mucoepidermoid carcinoma, and the patient in the second case exhibited adenoid cystic carcinoma and epithelial-myoepithelial carcinoma. Both patients were treated with surgery and radiotherapy, and there has been no evidence of recurrence after 13 and 36 months of follow-up, respectively. The recognition of the histologic component with the higher grade of malignancy in every case of hybrid tumour of the salivary glands is a necessary step to determine the biological behaviour and, consequently, to determine the proper therapeutic approach. 相似文献