全文获取类型
收费全文 | 3079篇 |
免费 | 182篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 73篇 |
妇产科学 | 50篇 |
基础医学 | 511篇 |
口腔科学 | 67篇 |
临床医学 | 334篇 |
内科学 | 698篇 |
皮肤病学 | 41篇 |
神经病学 | 285篇 |
特种医学 | 80篇 |
外科学 | 331篇 |
综合类 | 19篇 |
预防医学 | 251篇 |
眼科学 | 43篇 |
药学 | 174篇 |
中国医学 | 3篇 |
肿瘤学 | 310篇 |
出版年
2024年 | 8篇 |
2023年 | 44篇 |
2022年 | 55篇 |
2021年 | 86篇 |
2020年 | 69篇 |
2019年 | 94篇 |
2018年 | 92篇 |
2017年 | 83篇 |
2016年 | 86篇 |
2015年 | 84篇 |
2014年 | 153篇 |
2013年 | 179篇 |
2012年 | 226篇 |
2011年 | 283篇 |
2010年 | 150篇 |
2009年 | 138篇 |
2008年 | 236篇 |
2007年 | 227篇 |
2006年 | 175篇 |
2005年 | 172篇 |
2004年 | 131篇 |
2003年 | 121篇 |
2002年 | 95篇 |
2001年 | 16篇 |
2000年 | 17篇 |
1999年 | 28篇 |
1998年 | 25篇 |
1997年 | 24篇 |
1996年 | 19篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 13篇 |
1992年 | 13篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1977年 | 3篇 |
1975年 | 4篇 |
1973年 | 3篇 |
1969年 | 4篇 |
1955年 | 2篇 |
排序方式: 共有3284条查询结果,搜索用时 15 毫秒
101.
102.
Zoe Giannousi Evangelos C. Karademas Georgia Dimitraki 《Journal of behavioral medicine》2016,39(1):85-93
The aim was to examine the impact of the dyadic, interaction and dissimilarity effects of the illness representations on the psychological health of recently diagnosed cancer patients and spouses in Greece. The sample consisted of 298 individuals nested in 149 couples. Effects were examined with the Actor–Partner Interdependence Model. Both actor (i.e., within person) and partner (i.e., between partners) effects were detected for both patients’ and spouses’ psychological symptoms. The negative association of patients’ psychological symptoms with their representations of illness coherence was weak at the higher and medium levels, and stronger at the lower levels of spouse corresponding representations. Patient–partner discrepancy in perceived illness consequences was associated with more psychological symptoms in patients. Adaptation to cancer is a dyadic process within the context of which patient and partner psychological well-being is affected by each other’s understanding of illness. Thus, the parallel examination of the illness representations of both partners is needed from the early phases of the illness trajectory. 相似文献
103.
Acute stressful experience enhances subsequent learning in males and impairs learning in females. These sex differences emerge soon after puberty in adulthood. Whether these opposite effects of stress on learning extend into older age is unknown. To examine this, young adult (2-3 months) and middle aged (17-18 months) Fischer 344 rats of both sexes were exposed to an acute stressor of brief tailshocks and trained 24 h later with classical eyeblink conditioning using a trace paradigm. Whereas stressful experience enhanced conditioning in adult males and impaired conditioning in adult females, it had no effect whatsoever on conditioning in the aging animals of either sex. There was no effect of aging itself on acquisition of the conditioned response, suggesting that trace conditioning is not necessarily compromised during this period of life. Together, these data indicate that associative learning in the aging animal is resistant to both the negative and positive consequences of stressful experience. 相似文献
104.
Multiple studies suggest that prospective KIR typing may be beneficial for the outcome of bone marrow transplants, but to date no practical high-resolution KIR typing system has been developed. Here we propose a comprehensive high-resolution typing approach that provides allele level KIR typing. Based on the low-resolution typing obtained by SSO, the 14 KIR loci are divided in groups according to the level of polymorphism in exons coding for extracellular Ig-like domains and cytoplasmic tail. The first group is typed by sequence-specific oligonucleotide only; the second is typed by sequence-based typing (SBT) based on the amplification of a fragment coding the Ig-like domains; and the third is typed by SBT based on amplification of a fragment coding the cytoplasmic tail. SBT for the fourth group includes both the Ig-like and cytoplasmic domains. Because of a considerable number of polymorphisms scattered throughout all nine KIR exons, SBT results may still produce a number of ambiguities, which can be resolved by sequence-specific primers. This combined high-resolution approach was applied to the complete KIR typing of 205 Caucasian hematopoietic stem cell donors in support of the National Marrow Donor Program High-resolution KIR Typing Pilot Project. High-resolution typing of several KIR loci produced numerous novel alleles, whereas some loci demonstrated very limited polymorphism. Several of the novel alleles appeared in more than four donors, suggesting that these alleles are not rare. Our results showed that the comprehensive KIR typing approach presented here provides the balance of high-resolution typing and cost effectiveness. 相似文献
105.
Essential role of Skp2-mediated p27 degradation in growth and adaptive expansion of pancreatic beta cells 下载免费PDF全文
Zhong L Georgia S Tschen SI Nakayama K Nakayama K Bhushan A 《The Journal of clinical investigation》2007,117(10):2869-2876
Diabetes results from an inadequate mass of functional beta cells, due to either beta cell loss caused by immune assault or the lack of compensation to overcome insulin resistance. Elucidating the mechanisms that regulate beta cell mass has important ramifications for fostering beta cell regeneration and the treatment of diabetes. We report here that Skp2, a substrate recognition component of Skp1-Cul1-F-box (SCF) ubiquitin ligase, played an essential and specific role in regulating the cellular abundance of p27 and was a critical determinant of beta cell proliferation. In Skp2(-/-) mice, accumulation of p27 resulted in enlarged polyploid beta cells as a result of endoreduplication replacing proliferation. Despite beta cell hypertrophy, Skp2(-/-) mice exhibited diminished beta cell mass, hypoinsulinemia, and glucose intolerance. Increased insulin resistance resulting from diet-induced obesity caused Skp2(-/-) mice to become overtly diabetic, because beta cell growth in the absence of cell division was insufficient to compensate for increased metabolic demand. These results indicate that the Skp2-mediated degradation pathway regulating the cellular degradation of p27 is essential for establishing beta cell mass and to respond to increased metabolic demand associated with insulin resistance. 相似文献
106.
107.
Sarah Bonk MD Martina Kluth PhD Kristina Jansen MD Claudia Hube-Magg PhD Georgia Makrypidi-Fraune PhD Doris Höflmayer MD Sören Weidemann MD Katharina Möller MD Ria Uhlig MD Franziska Büscheck MD Andreas M. Luebke MD Eike Burandt MD Till S. Clauditz MD Stefan Steurer MD Thorsten Schlomm MD Hartwig Huland MD Hans Heinzer MD Guido Sauter MD Ronald Simon PhD David Dum MD 《The Prostate》2020,80(13):1097-1107
108.
109.
Theodoros Eleftheriadis Georgios Pissas Maria Remoundou Georgios Filippidis Georgia Antoniadi Niki Oustampasidou Vassilios Liakopoulos Ioannis Stefanidis 《International urology and nephrology》2014,46(1):161-167
Purpose
Disturbed iron homeostasis contributes to resistance to recombinant human erythropoietin (rHuEpo) in hemodialysis (HD) patients. Increased hepcidin, which downregulates the iron exporter ferroportin, has been incriminated. However, other factors also control ferroportin expression in mononuclear phagocyte system. Ferroportin in monocytes, as well as serum hepcidin, interleukin-6 (IL-6) and common markers of iron status were measured and correlations with rHuEpo resistance index (ERI) were evaluated.Methods
After a 4-week washout period from iron treatment, 34 HD patients and 20 healthy volunteers enrolled in the study. Ferroportin was assessed by means of western blotting, whereas hepcidin and IL-6 with enzyme-linked immunosorbent assay. Hemoglobin, serum iron, ferritin and transferrin saturation (TSAT) were also measured.Results
Ferroportin in monocytes of HD patients was decreased. Serum hepcidin and IL-6 were increased, whereas serum iron and TSAT were decreased. ERI was negatively correlated with ferroportin and all the markers of iron adequacy, but not with hepcidin.Conclusion
Decreased ferroportin in monocytes of HD patients accompanies increased hepcidin, inflammation, decreased iron availability and is correlated with resistance to rHuEpo treatment. 相似文献110.
Childhood Bone Mineral Content Is Associated With Methylation Status of the RXRA Promoter at Birth 下载免费PDF全文
Keith M Godfrey Cameron McLean Emma Garratt Georgia Ntani Lucy Davies Robert Murray Hazel M Inskip Peter D Gluckman Mark A Hanson Cyrus Cooper 《Journal of bone and mineral research》2014,29(3):600-607
Maternal vitamin D deficiency has been associated with reduced offspring bone mineral accrual. Retinoid‐X receptor‐alpha (RXRA) is an essential cofactor in the action of 1,25‐dihydroxyvitamin D (1,25[OH]2‐vitamin D), and RXRA methylation in umbilical cord DNA has been associated with later offspring adiposity. We tested the hypothesis that RXRA methylation in umbilical cord DNA collected at birth is associated with offspring skeletal development, assessed by dual‐energy X‐ray absorptiometry, in a population‐based mother‐offspring cohort (Southampton Women's Survey). Relationships between maternal plasma 25‐hydroxyvitamin D (25[OH]‐vitamin D) concentrations and cord RXRA methylation were also investigated. In 230 children aged 4 years, a higher percent methylation at four of six RXRA CpG sites measured was correlated with lower offspring bone mineral content (BMC) corrected for body size (β = ?2.1 to ?3.4 g/SD, p = 0.002 to 0.047). In a second independent cohort (n = 64), similar negative associations at two of these CpG sites, but positive associations at the two remaining sites, were observed; however, none of the relationships in this replication cohort achieved statistical significance. The maternal free 25(OH)‐vitamin D index was negatively associated with methylation at one of these RXRA CpG sites (β = ?3.3 SD/unit, p = 0.03). Thus, perinatal epigenetic marking at the RXRA promoter region in umbilical cord was inversely associated with offspring size–corrected BMC in childhood. The potential mechanistic and functional significance of this finding remains a subject for further investigation. © 2014 American Society for Bone and Mineral Research. 相似文献