全文获取类型
收费全文 | 170641篇 |
免费 | 7321篇 |
国内免费 | 488篇 |
专业分类
耳鼻咽喉 | 2491篇 |
儿科学 | 5075篇 |
妇产科学 | 3835篇 |
基础医学 | 23029篇 |
口腔科学 | 5223篇 |
临床医学 | 10984篇 |
内科学 | 41905篇 |
皮肤病学 | 4873篇 |
神经病学 | 13980篇 |
特种医学 | 4579篇 |
外国民族医学 | 7篇 |
外科学 | 21084篇 |
综合类 | 934篇 |
一般理论 | 46篇 |
预防医学 | 16672篇 |
眼科学 | 3678篇 |
药学 | 11705篇 |
7篇 | |
中国医学 | 752篇 |
肿瘤学 | 7591篇 |
出版年
2024年 | 445篇 |
2023年 | 1081篇 |
2022年 | 1321篇 |
2021年 | 3920篇 |
2020年 | 1986篇 |
2019年 | 3826篇 |
2018年 | 7290篇 |
2017年 | 4335篇 |
2016年 | 3533篇 |
2015年 | 3792篇 |
2014年 | 4737篇 |
2013年 | 6925篇 |
2012年 | 11495篇 |
2011年 | 12183篇 |
2010年 | 6379篇 |
2009年 | 4915篇 |
2008年 | 9905篇 |
2007年 | 10437篇 |
2006年 | 9754篇 |
2005年 | 9728篇 |
2004年 | 8802篇 |
2003年 | 8307篇 |
2002年 | 7851篇 |
2001年 | 4901篇 |
2000年 | 5588篇 |
1999年 | 4265篇 |
1998年 | 951篇 |
1997年 | 626篇 |
1996年 | 613篇 |
1995年 | 512篇 |
1994年 | 414篇 |
1993年 | 386篇 |
1992年 | 1764篇 |
1991年 | 1454篇 |
1990年 | 1367篇 |
1989年 | 1125篇 |
1988年 | 960篇 |
1987年 | 966篇 |
1986年 | 917篇 |
1985年 | 805篇 |
1984年 | 592篇 |
1983年 | 458篇 |
1979年 | 491篇 |
1975年 | 392篇 |
1974年 | 441篇 |
1973年 | 484篇 |
1972年 | 420篇 |
1971年 | 434篇 |
1970年 | 391篇 |
1969年 | 378篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Megan L. Robbins Robert C. Wright Ana María López Karen Weihs 《Journal of psychosocial oncology》2019,37(2):160-177
AbstractObjectives: This study examined word use as an indicator of interpersonal positive reframing in daily conversations of couples coping with breast cancer and as a predictor of stress.Design: The Electronically Activated Recorder (EAR) and Linguistic Inquiry and Word Count (LIWC) were used to examine naturally occurring word use conceptually linked to positive reframing (positive emotion, negative emotion, and cognitive processing words).Sample: Fifty-two couples coping with breast cancer.Methods: Couples wore the EAR, a device participants wear, that audio-recorded over one weekend (>16,000 sound files), and completed self-reports of positive reframing (COPE) and stress (Perceived Stress Scale). LIWC, a software program, measured word use.Findings: Both partners’ word use (i.e., positive emotion and cognitive processing words) was associated with their own reported positive reframing, and spouses’ word use was also indicative of patients’ positive reframing. Results also revealed that, in general, words indicating positive reframing predicted lower levels of stress.Conclusions: Findings supported the hypothesis that partners—and particularly spouses of breast cancer patients—may assist each other’s coping by positively reframing the cancer experience and other negative experiences in conversation. 相似文献
2.
María Cabrerizo Gloria Trallero María José Pena Amaia Cilla Gregoria Megias Carmen Mu?oz-Almagro Eva Del Amo Diana Roda Ana Isabel Mensalvas Antonio Moreno-Docón Juan García-Costa Nuria Rabella Manuel Ome?aca María Pilar Romero Sara Sanbonmatsu-Gámez Mercedes Pérez-Ruiz María José Santos-Mu?oz Cristina Calvo And the study group of “Enterovirus parechovirus infections in children under ?years-old Spain” PI- 《European journal of pediatrics》2015,174(11):1511-1516
3.
4.
J. Rodríguez-Carrio A. Martínez-Zapico I. Cabezas-Rodríguez L. Benavente Á.I. Pérez-Álvarez P. López J.B. Cannata-Andía M. Naves-Díaz A. Suárez 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(2):135-143
Background and aims
Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.Methods and results
In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.Conclusion
SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE. 相似文献5.
Mariana Spitz Alexandre Aluízio Costa Machado Rodrigo do Carmo Carvalho Fernanda Martins Maia Monica Santoro Haddad Dagoberto Calegaro Milberto Scaff Egberto Reis Barbosa 《Movement disorders》2006,21(9):1520-1522
We report on 3 patients with pseudoathetosis, which are involuntary, slow, writhing movements due to loss of proprioception. 相似文献
6.
7.
8.
9.
Mariela Dutra Gontijo Moura Soraya de Mattos Camargo Grossmann Linaena Méricy da Silva Fonseca Maria Inês Barreiros Senna Ricardo Alves Mesquita 《Journal of oral pathology & medicine》2006,35(6):321-326
BACKGROUND: Oral hairy leukoplakia (OHL) may be an indicator of the progression of Human Immunodeficiency Virus (HIV)-induced immuno-depression, and the evaluation of risk factors leading to OHL is important in the management of these HIV-infected patients. However, there are few studies that analyze risk factors leading to OHL in the Brazilian population. The aim of this case-control study is to present data about prevalence rates and risk factors leading to OHL in a sample of HIV-infected adults in Brazil. METHODS: This case-control study included 111 HIV-infected patients treated at a clinic for sexually transmitted diseases and HIV. In the initial examinations with dentists, variables were collected from all patients. Diagnosis of OHL was performed in accordance with the International Classification System and cytological features. The Fisher and the chi-squared tests were used for statistical analysis. The proportional prevalence and odds ratio were estimated. RESULTS: Outcome presented a positive, statistically significant association among the presence of OHL and viral load of 3000 copies/mul or greater (P = 0.0001; odds ratio (OR) = 5.8), presence of oral candidiasis (P = 0.0000; OR = 11.1), previous use of fluconazole (P = 0.0000; OR = 24.6), and use of systemic acyclovir (P = 0.032; OR = 4.3). Antiretroviral medication presented a negative, statistically significant association with the presence of OHL (P = 0.002; OR = 8.4). CONCLUSIONS: Prevalence of OHL was 28.8%. Viral load, oral candidiasis, previous use of fluconazole, and systemic acyclovir were determined to be risk factors for OHL. Antiretroviral medication proved to be protective against the development of OHL. 相似文献
10.
Effect of leptin on the regulation of placental hormone secretion in cultured human placental cells.
Raquel Coya Pedro Martul Jaime Algorta Ma Angeles Aniel-Quiroga Ma Angeles Busturia Rosa Se?arís 《Gynecological endocrinology》2006,22(11):620-626
Placenta is an important source of leptin during pregnancy that contributes to the high plasma leptin levels in pregnant women. Leptin and its functional receptors are synthesized in trophoblast cells that, in turn, secrete gestational hormones supporting a paracrine or autocrine role for leptin in the endocrine activity of the placenta. In the present study we examined the effect of leptin on in vitro release of gestational hormones (human chorionic gonadotropin (hCG), human placental lactogen (hPL), progesterone, estrogens and testosterone) by human term placental cells in culture. Placentas at term were obtained immediately after delivery from mothers with uncomplicated pregnancies. Progesterone, hCG, hPL, estradiol, estrone, estriol and testosterone levels were measured by different assays in culture media of cells maintained in monolayer culture after incubation for 12, 24, 48 or 72 h with leptin or placebo. Incubation with leptin did not modify hCG, hPL, progesterone, estriol and estrone secretion for any of the doses and times assayed. However, leptin led to a dose-dependent decrease in estradiol release. This effect was observed when treatment with recombinant human leptin spanned from 12 to 72 h. At this time an increase in testosterone levels was observed in leptin-treated cells versus placebo. These results indicate that leptin can be considered a gestational hormone implied in the endocrine function of the placenta, with an important role in control of the production of steroid reproductive hormones in placental cells in vitro. 相似文献