全文获取类型
收费全文 | 4700篇 |
免费 | 306篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 154篇 |
妇产科学 | 100篇 |
基础医学 | 833篇 |
口腔科学 | 146篇 |
临床医学 | 453篇 |
内科学 | 820篇 |
皮肤病学 | 95篇 |
神经病学 | 662篇 |
特种医学 | 122篇 |
外科学 | 389篇 |
综合类 | 26篇 |
一般理论 | 2篇 |
预防医学 | 314篇 |
眼科学 | 184篇 |
药学 | 284篇 |
中国医学 | 23篇 |
肿瘤学 | 348篇 |
出版年
2024年 | 14篇 |
2023年 | 42篇 |
2022年 | 56篇 |
2021年 | 84篇 |
2020年 | 78篇 |
2019年 | 104篇 |
2018年 | 95篇 |
2017年 | 120篇 |
2016年 | 118篇 |
2015年 | 134篇 |
2014年 | 140篇 |
2013年 | 228篇 |
2012年 | 387篇 |
2011年 | 354篇 |
2010年 | 213篇 |
2009年 | 208篇 |
2008年 | 322篇 |
2007年 | 359篇 |
2006年 | 325篇 |
2005年 | 298篇 |
2004年 | 308篇 |
2003年 | 272篇 |
2002年 | 259篇 |
2001年 | 47篇 |
2000年 | 30篇 |
1999年 | 60篇 |
1998年 | 64篇 |
1997年 | 61篇 |
1996年 | 42篇 |
1995年 | 22篇 |
1994年 | 21篇 |
1993年 | 17篇 |
1992年 | 12篇 |
1991年 | 18篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1978年 | 9篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1961年 | 2篇 |
排序方式: 共有5032条查询结果,搜索用时 15 毫秒
21.
In the current study we examined the combination of SAHA and SBE13 in cancer and non-cancer cells. HeLa cells displayed a synergistically reduced cell proliferation, which was much weaker in hTERT-RPE1 or NIH-3T3 cells. Cell cycle distribution differed in HeLa, hTERT-RPE1 and NIH-3T3 cells. SAHA-treated HeLa cells showed slightly increasing cell numbers in G2/M phase, but after combination with SBE13 strongly elevated cell numbers in G2/M and S phase, accompanied by decreasing G0/G1 percentages. hTERT-RPE1 and NIH-3T3 cells showed strongly enriched cell numbers in G0/G1 phase. Western blot and quantitative real time analyses revealed reduced Plk1 mRNA and protein in all cells. p21 protein was strongly induced in cancer, but not in non-cancer cells, corresponding to a different localization in immunofluorescence studies. Additionally, these revealed an abundantly present pRb protein in HeLa cells after any treatment but almost completely vanished pRb staining in treated hTERT-RPE1 cells. These differences could be approved in Western blots against Parp and Caspase 3, which were activated in HeLa, but not in hTERT-RPE1 cells. Thus, we observed for the first time a differential effect of cancer versus non-cancer cells after treatment with SAHA and SBE13, which might be due to the dual role of p21. 相似文献
22.
Matthias Schulz Christoph Bührer Birgit Spors Hannes Haberl Ulrich-Wilhelm Thomale 《Child's nervous system》2013,29(5):771-779
Objective
Neuroendoscopic procedures became essential in neurosurgical treatment of disturbed cerebrospinal fluid dynamics. While a vast number of papers report on the neuroendoscopic experience for adults and children, no series so far reported on techniques and indications for neonate infants. We present our experience for the feasibility of neuroendoscopic procedures in preterm and term newborn infants.Methods
All preterm and term infants who underwent an endoscopic neurosurgical intervention prior to the 28th day after the previously estimated date of delivery were identified by retrospective review. Surgical procedures and techniques, complications, and further follow-up data are reported.Results
During the study period, 14 infants (median age at surgery, 36+2/7 weeks of gestation) underwent 20 endoscopic procedures. The performed procedures included endoscopic septostomy (n?=?3), endoscopic shunt placement for multiloculated hydrocephalus (n?=?4), endoscopic transaqueductal stenting for isolated fourth ventricle (n?=?3), and endoscopic lavage for ventriculitis (n?=?4) or for intraventricular hemorrhage (n?=?6). No severe complications were seen, while two patients necessitating unexpected interventions during further follow-up (10 %).Conclusions
Despite the fragility of preterm and term newborn infants, neuroendoscopic procedures may play an important role in the treatment of disturbed cerebrospinal fluid (CSF) dynamics also in this patient population. The neuroendoscopic approach may be curative in conditions like isolated lateral ventricle, may facilitate simplified and effective CSF diversion in multiloculated hydrocephalus or isolated fourth ventricle, and may be beneficial in the course of ventriculitis and intraventricular hemorrhage. Further studies must verify our experience with a bigger cohort of patients and on a multicenter basis. 相似文献23.
Farhan S Jarai R Tentzeris I Freynhofer MK Brozovic I Vogel B Kautzky-Willer A Wascher T Wojta J Huber K 《Clinical chemistry》2011,57(10):1456-1460
24.
Katia Keglberg Hrvig Kajsa Ugelvig Petersen Karin Srig Hougaard Christian Lindh Cecilia Hst Ramlau-Hansen Gunnar Toft Aleksander Giwercman Birgit Bjerre Hyer Esben Meulengracht Flachs Jens Peter Bonde Sandra Sgaard Tttenborg 《Environmental health perspectives》2022,130(10)
Background: Concerns remain about the human reproductive toxicity of the widespread per- and polyfluoroalkyl substances (PFAS) during early stages of development.Objectives: We examined associations between maternal plasma PFAS levels during early pregnancy and male offspring reproductive function in adulthood.Methods: The study included 864 young men (age range:18.9–21.2 y) from the Fetal Programming of Semen Quality (FEPOS) cohort established between 2017 and 2019. Plasma samples from their mothers, primarily from the first trimester, were retrieved from the Danish National Biobank and levels of 15 PFAS were measured. Seven PFAS had detectable levels above the limit of detection in of the samples and were included in analyses. Semen quality, testicular volume, and levels of reproductive hormones and PFAS were assessed in the young men. We used weighted quantile sum (WQS) regression to estimate the associations between combined exposure to maternal PFAS and reproductive function, and negative binomial regression to estimate the associations of single substances, while adjusting for a range of a priori–defined fetal and postnatal risk factors.Results: By a 1-unit increase in the WQS index, combined maternal PFAS exposure was associated with lower sperm concentration (; 95% CI: , ), total sperm count (; 95% CI: , ), and a higher proportion of nonprogressive and immotile sperm (5%; 95% CI: 1%, 8%) in the young men. Different PFAS contributed to the associations with varying strengths; however, perfluoroheptanoic acid was identified as the main contributor in the analyses of all three outcomes despite the low concentration. We saw no clear association between exposure to maternal PFAS and testicular volume or reproductive hormones.Discussion: In a sample of young men from the general Danish population, we observed consistent inverse associations between exposure to maternal PFAS and semen quality. The study needs to be replicated in other populations, taking combined exposure, as well as emerging short-chain PFAS, into consideration. https://doi.org/10.1289/ EHP10285相似文献
25.
26.
27.
28.
29.
30.
Florie E. van Beek Femke Jansen Rob J. Baatenburg de Jong Johannes A. Langendijk C. Ren Leemans Johannes H. Smit Robert P. Takes Chris H. J. Terhaard Jos A. E. Custers Judith B. Prins Birgit I. Lissenberg-Witte Irma M. Verdonck-de Leeuw 《Current oncology (Toronto, Ont.)》2022,29(5):3200
Background: To investigate associations between psychological problems and the use of healthcare and informal care and total costs among head and neck cancer (HNC) patients. Method: Data were used of the NETherlands QUality of Life and Biomedical Cohort study. Anxiety and depression disorder (diagnostic interview), distress, symptoms of anxiety and depression (HADS), and fear of cancer recurrence (FCR) and cancer worry scale (CWS) were measured at baseline and at 12-month follow-up. Care use and costs (questionnaire) were measured at baseline, 3-, 6-, 12-, and 24-month follow-up. Associations between psychological problems and care use/costs were investigated using logistic and multiple regression analyses. Results: Data of 558 patients were used. Distress, symptoms of anxiety or depression, FCR, and/or anxiety disorder at baseline were significantly associated with higher use of primary care, supportive care, and/or informal care (odds ratios (ORs) between 1.55 and 4.76). Symptoms of anxiety, FCR, and/or depression disorder at 12-month follow-up were significantly associated with use of primary care, supportive care, and/or informal care (ORs between 1.74 and 6.42). Distress, symptoms of anxiety, and FCR at baseline were associated with higher total costs. Discussion: HNC patients with psychological problems make more use of healthcare and informal care and have higher costs. This is not the result of worse clinical outcomes. 相似文献