全文获取类型
收费全文 | 1494篇 |
免费 | 82篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 40篇 |
妇产科学 | 34篇 |
基础医学 | 164篇 |
口腔科学 | 115篇 |
临床医学 | 149篇 |
内科学 | 279篇 |
皮肤病学 | 42篇 |
神经病学 | 129篇 |
特种医学 | 187篇 |
外科学 | 129篇 |
综合类 | 22篇 |
预防医学 | 122篇 |
眼科学 | 14篇 |
药学 | 105篇 |
中国医学 | 17篇 |
肿瘤学 | 64篇 |
出版年
2023年 | 16篇 |
2022年 | 36篇 |
2021年 | 49篇 |
2020年 | 30篇 |
2019年 | 44篇 |
2018年 | 38篇 |
2017年 | 35篇 |
2016年 | 37篇 |
2015年 | 73篇 |
2014年 | 81篇 |
2013年 | 119篇 |
2012年 | 89篇 |
2011年 | 100篇 |
2010年 | 66篇 |
2009年 | 46篇 |
2008年 | 46篇 |
2007年 | 68篇 |
2006年 | 45篇 |
2005年 | 63篇 |
2004年 | 46篇 |
2003年 | 29篇 |
2002年 | 38篇 |
2001年 | 24篇 |
2000年 | 20篇 |
1999年 | 17篇 |
1998年 | 25篇 |
1997年 | 25篇 |
1996年 | 23篇 |
1995年 | 23篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1992年 | 15篇 |
1991年 | 19篇 |
1990年 | 13篇 |
1989年 | 21篇 |
1988年 | 19篇 |
1987年 | 10篇 |
1986年 | 12篇 |
1985年 | 10篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1976年 | 11篇 |
1975年 | 4篇 |
1971年 | 4篇 |
1968年 | 5篇 |
1949年 | 4篇 |
1947年 | 6篇 |
排序方式: 共有1630条查询结果,搜索用时 0 毫秒
1.
Talita da Silva Mendes de Farias Ariclécio Cunha de Oliveira Sandra Andreotti Fernanda Gaspar do Amaral Patrícia Chimin André Ricardo Alves de Proença Francisco Leonardo Torres Leal Rogério Antonio Laurato Sertié Amanda Baron Campana Andressa Bolsoni Lopes Arnaldo Henrique de Souza José Cipolla‐Neto Fabio Bessa Lima 《Journal of pineal research》2015,58(3):251-261
Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals. 相似文献
2.
Henyse G V Silva Rosangela P Tórtora Maria Lucia F Farias 《Gynecological endocrinology》2005,21(3):174-179
To evaluate the impact of pregnancy on bone, we studied bone turnover at the first (T1) and third (T3) trimester of gestation in 58 adolescents and 28 healthy adolescents who had never been pregnant. Total body (TB) and lumbar spine (LS) bone mineral density (BMD) and body composition were evaluated by dual-energy X-ray absorptiometry in all control patients (C) and after parturition in 28 pregnant patients (G). Paired and unpaired t tests, Mann-Whitney and Pearson correlation tests were used. Bone turnover markers were above the reference range for adult women in more than 80% of the adolescents, with no difference between C and G patients at T1. Increase in urinary N-telopeptide crosslinks of type I collagen and serum bone-specific alkaline phosphatase, markers of bone turnover, was seen during pregnancy ( p < 0.0001). Body composition did not differ between groups, but LS BMD, percentage of expected LS BMD, LS Z-score, percentage of expected TB BMD and TB Z-score were lower in G than C patients ( p < 0.05). TB BMD was positively correlated with LS BMD (r2 = 0.52). The inverse correlations between bone markers and LS BMD suggest that the increased bone turnover during pregnancy probably explains the low bone density after parturition. The impact on future peak bone mass must be studied. 相似文献
3.
Deborah A Cahn-Weiner Sarah Tomaszewski Farias Laura Julian Danielle J Harvey Joel H Kramer Bruce R Reed Dan Mungas Margaret Wetzel Helena Chui 《Journal of the International Neuropsychological Society》2007,13(5):747-757
Impaired ability to conduct daily activities is a diagnostic criterion for dementia and a determinant of healthcare services utilization and caregiver burden. What predicts decline in instrumental activities of daily living (IADLs) is not well understood. This study examined measures of episodic memory, executive function, and MRI brain volumes in relation to baseline IADLs and as predictors of rate of IADL change. Participants were 124 elderly persons with cognitive function between normal and moderate dementia both with and without significant small vessel cerebrovascular disease. Random effects modeling showed that baseline memory and executive function (EXEC) were associated with baseline IADL scores, but only EXEC was independently associated with rate of change in IADLs. Whereas hippocampal and cortical gray matter volumes were significantly associated with baseline IADL scores, only hippocampal volume was associated with IADL change. In a model including cognitive and neuroimaging predictors, only EXEC independently predicted rate of decline in IADL scores. These findings indicate that greater executive dysfunction at initial assessment is associated with more rapid decline in IADLs. Perhaps executive function is particularly important with respect to maintaining IADLs. Alternatively, executive dysfunction may be a sentinel event indicating widespread cortical involvement and poor prognosis. 相似文献
4.
Rechtsanwalt Dr. iur. Matthias Dann LL.M. 《MedR Medizinrecht》2007,25(11):638-643
Ohne Zusammenfassung 相似文献
5.
J. KRØLL 《Scandinavian journal of immunology》1983,17(S10):171-173
6.
J. KRØLL 《Scandinavian journal of immunology》1983,17(S10):165-169
7.
J. KRØLL 《Scandinavian journal of immunology》1983,17(S10):135-139
8.
9.
10.
Mahadevaiah SK; Odorisio T; Elliott DJ; Rattigan A; Szot M; Laval SH; Washburn LL; McCarrey JR; Cattanach BM; Lovell-Badge R; Burgoyne PS 《Human molecular genetics》1998,7(4):715-727
An RNA-binding motif (RBM) gene family has been identified on the human Y
chromosome that maps to the same deletion interval as the 'azoospermia
factor' (AZF). We have identified the homologous gene family (Rbm) on the
mouse Y with a view to investigating the proposal that this gene family
plays a role in spermatogenesis. At least 25 and probably >50 copies of
Rbm are present on the mouse Y chromosome short arm located between Sry and
the centromere. As in the human, a role in spermatogenesis is indicated by
a germ cell-specific pattern of expression in the testis, but there are
distinct differences in the pattern of expression between the two species.
Mice carrying the deletion Yd1, that maps to the proximal Y short arm, are
female due to a position effect resulting in non-expression of Sry ;
sex-reversing such mice with an Sry transgene produces males with a high
incidence of abnormal sperm, making this the third deletion interval on the
mouse Y that affects some aspect of spermatogenesis. Most of the copies of
Rbm map to this deletion interval, and the Yd1males have markedly reduced
Rbm expression, suggesting that RBM deficiency may be responsible for, or
contribute to, the abnormal sperm development. In man, deletion of the
functional copies of RBM is associated with meiotic arrest rather than
sperm anomalies; however, the different effects of deletion are consistent
with the differences in expression between the two species.
相似文献