全文获取类型
收费全文 | 2055篇 |
免费 | 165篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 58篇 |
妇产科学 | 55篇 |
基础医学 | 333篇 |
口腔科学 | 21篇 |
临床医学 | 224篇 |
内科学 | 400篇 |
皮肤病学 | 54篇 |
神经病学 | 199篇 |
特种医学 | 46篇 |
外科学 | 148篇 |
综合类 | 11篇 |
一般理论 | 2篇 |
预防医学 | 240篇 |
眼科学 | 22篇 |
药学 | 237篇 |
中国医学 | 2篇 |
肿瘤学 | 166篇 |
出版年
2023年 | 27篇 |
2022年 | 20篇 |
2021年 | 96篇 |
2020年 | 69篇 |
2019年 | 76篇 |
2018年 | 92篇 |
2017年 | 68篇 |
2016年 | 62篇 |
2015年 | 82篇 |
2014年 | 89篇 |
2013年 | 142篇 |
2012年 | 188篇 |
2011年 | 198篇 |
2010年 | 96篇 |
2009年 | 84篇 |
2008年 | 105篇 |
2007年 | 111篇 |
2006年 | 119篇 |
2005年 | 110篇 |
2004年 | 94篇 |
2003年 | 89篇 |
2002年 | 59篇 |
2001年 | 13篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1992年 | 5篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1978年 | 5篇 |
1971年 | 3篇 |
1955年 | 2篇 |
1954年 | 3篇 |
1932年 | 2篇 |
1930年 | 2篇 |
1929年 | 2篇 |
1927年 | 2篇 |
1921年 | 2篇 |
排序方式: 共有2226条查询结果,搜索用时 140 毫秒
31.
‘Young carers’ are children who take on adult responsibility in response to familial illness. South Africa’s high disease burden, limited health care capacity and cultural notions of children’s familial duty suggest a large population of ‘young carers’ in this country. This study aims to explore the nature of responsibility among children affected by illness in deprived South African communities. A total of 349 children and adolescents aged 10–18 years in illness-affected households in the Western Cape province were recruited via community- and school-based convenience sampling. Data about their daily life, responsibilities and the impact of familial illness were collected via semi-structured interviews. Caring tasks involving intimate contact and medical treatments were relatively common among children in the sample, and nearly all children were engaged in some type of responsibility, from caring tasks to housework, childcare and earning money. Children frequently indicated their responsibilities constituted a substantial burden. Responses suggested a tension between duty to care and appropriateness of intimate contact between parents and children required for some caring responsibilities. Children often linked their tasks burden to familial illness, though further quantitative research is needed to identify the drivers of child responsibility. 相似文献
32.
Melissa Sharer Lucie Cluver Joseph Shields 《Vulnerable children and youth studies》2015,10(2):141-152
This research explored the biological and social support relationship between youth orphaned due to AIDS and his/her caregiver to identify protective factors that are related to positive mental health outcomes. These youth have significantly higher levels of depression, anxiety, and post-traumatic stress (PTS) symptoms compared to those orphaned due to other causes and non-orphans. Using a 2009 cross-sectional data-set from South Africa, 254 youth orphaned due to AIDS were purposively selected from the overall sample of 732 to further examine this caregiver relationship. Caregiver relation was analyzed in several combinations to determine if it was significantly related to mental health outcomes, with only anxiety showing significance. Those living with a biological parent had significantly higher anxiety symptoms than those living with a grandparent, other kin, or non-kin. Anxiety was also significantly related to an increased age, lower levels of emotional support, and lower levels of instrumental/financial support (R2 = .153). Age was the only significant variable from the model that was related to depression symptoms (R2 = .111). PTS symptoms were related to increases in age, lower levels of emotional support, instrumental/financial support, and satisfaction with the caregiver (R2 = .194). Gender and age were related to suicidal tendencies, specifically boys were 2.26 times more likely to exhibit suicidal tendencies compared to girls, and every yearly increase in age results in the youth being 1.22 times more likely to exhibit suicidal tendencies. Strengthening the caregiver’s ability to provide social support for the child is critical, irrespective of any biological kin relationship. 相似文献
33.
EZH2 expression is a prognostic factor in childhood intracranial ependymoma: A Canadian Pediatric Brain Tumor Consortium study 下载免费PDF全文
Amanda M. Li MD MSc Christopher Dunham MD Uri Tabori MD Anne‐Sophie Carret MD P. Daniel McNeely MD Donna Johnston MD Lucie Lafay‐Cousin MD Beverly Wilson MD David D. Eisenstat MD MA Nada Jabado MD PhD Shayna Zelcer MD Mariana Silva MD Katrin Scheinemann MD MSc Christopher Fryer MD Glenda Hendson MB BCh Abbas Fotovati PhD Cynthia Hawkins MD PhD Stephen Yip MD PhD Sandra E. Dunn PhD Juliette Hukin MBBS 《Cancer》2015,121(9):1499-1507
34.
Dominika Pa?esová Barbora Volfová Kate?ina ?ervená Lucie Hejnová Ji?í Novotny Zdeňka Bendová 《British journal of pharmacology》2015,172(14):3638-3649
Background and Purpose
Opioids affect the circadian clock and may change the timing of many physiological processes. This study was undertaken to investigate the daily changes in sensitivity of the circadian pacemaker to an analgesic dose of morphine, and to uncover a possible interplay between circadian and opioid signalling.Experimental Approach
A time-dependent effect of morphine (1 mg·kg−1, i.p.) applied either during the day or during the early night was followed, and the levels of phosphorylated ERK1/2, GSK3β, c-Fos and Per genes were assessed by immunohistochemistry and in situ hybridization. The effect of morphine pretreatment on light-induced pERK and c-Fos was examined, and day/night difference in activity of opioid receptors was evaluated by [35S]-GTPγS binding assay.Key Results
Morphine stimulated a rise in pERK1/2 and pGSK3β levels in the suprachiasmatic nucleus (SCN) when applied during the day but significantly reduced both kinases when applied during the night. Morphine at night transiently induced Period1 but not Period2 in the SCN and did not attenuate the light-induced level of pERK1/2 and c-Fos in the SCN. The activity of all three principal opioid receptors was high during the day but decreased significantly at night, except for the δ receptor. Finally, we demonstrated daily profiles of pERK1/2 and pGSK3β levels in the rat ventrolateral and dorsomedial SCN.Conclusions and Implications
Our data suggest that the phase-shifting effect of opioids may be mediated via post-translational modification of clock proteins by means of activated ERK1/2 and GSK3β.Tables of LinksTARGETS | |
---|---|
GPCRsa1997 | Enzymesc1997 |
δ receptor | Akt (PKB) |
κ receptor | Clock |
μ receptor | ERK1/2 |
Nuclear hormone receptorsb1997 | GSK3β |
Rev-Erb-α |
LIGANDS | |
---|---|
Arginine vasopressin | GDP |
cAMP | GTPγS |
DADLE | Morphine |
DAMGO | Neuropeptide Y |
Enkephalin | Thiopental |
GABA | U-50488 |
Gastrin | UTP |
35.
Hana Bártíková Lenka Skálová Lucie Stuchlíková Ivan Vokřál Tomáš Vaněk 《Drug metabolism reviews》2015,47(3):374-387
Many various xenobiotics permanently enter plants and represent potential danger for their organism. For that reason, plants have evolved extremely sophisticated detoxification systems including a battery of xenobiotic-metabolizing enzymes. Some of them are similar to those in humans and animals, but there are several plant-specific ones. This review briefly introduces xenobiotic-metabolizing enzymes in plants and summarizes present information about their action toward veterinary drugs. Veterinary drugs are used worldwide to treat diseases and protect animal health. However, veterinary drugs are also unwantedly introduced into environment mostly via animal excrements, they persist in the environment for a long time and may impact on the non-target organisms. Plants are able to uptake, transform the veterinary drugs to non- or less-toxic compounds and store them in the vacuoles and cell walls. This ability may protect not only plant themselves but also other organisms, predominantly invertebrates and wild herbivores. The aim of this review is to emphasize the importance of plants in detoxification of veterinary drugs in the environment. The results of studies, which dealt with transport and biotransformation of veterinary drugs in plants, are summarized and evaluated. In conclusion, the risks and consequences of veterinary drugs in the environment and the possibilities of phytoremediation technologies are considered and future perspectives are outlined. 相似文献
36.
Kyle M. Walsh Veryan Codd Terri Rice Christopher P. Nelson Ivan V. Smirnov Lucie S. McCoy Helen M. Hansen Edward Elhauge Juhi Ojha Stephen S. Francis Nils R. Madsen Paige M. Bracci Alexander R. Pico Annette M. Molinaro Tarik Tihan Mitchel S. Berger Susan M. Chang Michael D. Prados Robert B. Jenkins Joseph L. Wiemels ENGAGE Consortium Telomere Group Nilesh J. Samani John K. Wiencke Margaret R. Wrensch 《Oncotarget》2015,6(40):42468-42477
Telomere maintenance has emerged as an important molecular feature with impacts on adult glioma susceptibility and prognosis. Whether longer or shorter leukocyte telomere length (LTL) is associated with glioma risk remains elusive and is often confounded by the effects of age and patient treatment. We sought to determine if genotypically-estimated LTL is associated with glioma risk and if inherited single nucleotide polymorphisms (SNPs) that are associated with LTL are glioma risk factors. Using a Mendelian randomization approach, we assessed differences in genotypically-estimated relative LTL in two independent glioma case-control datasets from the UCSF Adult Glioma Study (652 patients and 3735 controls) and The Cancer Genome Atlas (478 non-overlapping patients and 2559 controls). LTL estimates were based on a weighted linear combination of subject genotype at eight SNPs, previously associated with LTL in the ENGAGE Consortium Telomere Project. Mean estimated LTL was 31bp (5.7%) longer in glioma patients than controls in discovery analyses (P = 7.82×10-8) and 27bp (5.0%) longer in glioma patients than controls in replication analyses (1.48×10-3). Glioma risk increased monotonically with each increasing septile of LTL (O.R.=1.12; P = 3.83×10-12). Four LTL-associated SNPs were significantly associated with glioma risk in pooled analyses, including those in the telomerase component genes TERC (O.R.=1.14; 95% C.I.=1.03-1.28) and TERT (O.R.=1.39; 95% C.I.=1.27-1.52), and those in the CST complex genes OBFC1 (O.R.=1.18; 95% C.I.=1.05-1.33) and CTC1 (O.R.=1.14; 95% C.I.=1.02-1.28). Future work is needed to characterize the role of the CST complex in gliomagenesis and further elucidate the complex balance between ageing, telomere length, and molecular carcinogenesis. 相似文献
37.
Lucie Broc Josie Bernicot Thierry Olive Monik Favart Judy Reilly Pauline Quémart Joël Uzé 《Research in developmental disabilities》2013,34(10):3253-3266
The goal of this study was to compare the lexical spelling performance of children and adolescents with specific language impairment (SLI) in two contrasting writing situations: a dictation of isolated words (a classic evaluative situation) and a narrative of a personal event (a communicative situation). Twenty-four children with SLI and 48 typically developing children participated in the study, split into two age groups: 7–11 and 12–18 years of age. Although participants with SLI made more spelling errors per word than typically developing participants of the same chronological age, there was a smaller difference between the two groups in the narratives than in the dictations. Two of the findings are particularly noteworthy: (1) Between 12 and 18 years of age, in communicative narration, the number of spelling errors of the SLI group was not different from that of the typically developing group. (2) In communicative narration, the participants with SLI did not make specific spelling errors (phonologically unacceptable), contrary to what was shown in the dictation. From an educational perspective or that of a remediation program, it must be stressed that the communicative narration provides children—and especially adolescents—with SLI an opportunity to demonstrate their improved lexical spelling abilities. Furthermore, the results encourage long-term lexical spelling education, as adolescents with SLI continue to show improvement between 12 and 18 years of age. 相似文献
38.
39.
40.