全文获取类型
收费全文 | 13278篇 |
免费 | 975篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 104篇 |
儿科学 | 380篇 |
妇产科学 | 225篇 |
基础医学 | 2218篇 |
口腔科学 | 304篇 |
临床医学 | 1183篇 |
内科学 | 3006篇 |
皮肤病学 | 306篇 |
神经病学 | 1655篇 |
特种医学 | 275篇 |
外科学 | 1287篇 |
综合类 | 60篇 |
一般理论 | 9篇 |
预防医学 | 1023篇 |
眼科学 | 139篇 |
药学 | 998篇 |
中国医学 | 48篇 |
肿瘤学 | 1102篇 |
出版年
2024年 | 19篇 |
2023年 | 133篇 |
2022年 | 326篇 |
2021年 | 625篇 |
2020年 | 341篇 |
2019年 | 437篇 |
2018年 | 494篇 |
2017年 | 389篇 |
2016年 | 438篇 |
2015年 | 466篇 |
2014年 | 570篇 |
2013年 | 700篇 |
2012年 | 1090篇 |
2011年 | 1158篇 |
2010年 | 653篇 |
2009年 | 534篇 |
2008年 | 837篇 |
2007年 | 875篇 |
2006年 | 755篇 |
2005年 | 738篇 |
2004年 | 704篇 |
2003年 | 575篇 |
2002年 | 547篇 |
2001年 | 82篇 |
2000年 | 64篇 |
1999年 | 78篇 |
1998年 | 107篇 |
1997年 | 104篇 |
1996年 | 67篇 |
1995年 | 69篇 |
1994年 | 50篇 |
1993年 | 38篇 |
1992年 | 36篇 |
1991年 | 29篇 |
1990年 | 30篇 |
1989年 | 14篇 |
1988年 | 17篇 |
1987年 | 7篇 |
1986年 | 14篇 |
1985年 | 17篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 13篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
61.
Ewa Surmacz Marina A. Guvakova Mary K. Nolan Roberto F. Nicosia Laura Sciacca 《Breast cancer research and treatment》1998,47(3):255-267
Experimental evidence suggests an important role of the type I IGF receptor (IGF-IR) in breast cancer development. Breast tumors and breast cancer cell lines express the IGF-IR. IGF-IR levels are higher in cancer cells than in normal breast tissue or in benign mammary tumors. The ligands of the IGF-IR are potent mitogens promoting monolayer and anchorage-independent growth of breast cancer cells. Interference with IGF-IR activation, expression, or signaling inhibits growth and induces apoptosis in breast cancer cells. In addition, recent studies established the involvement of the IGF-IR in the regulation of breast cancer cell motility and adhesion. We have demonstrated that in MCF-7 cells, overexpression of the IGF-IR promotes E-cadherin-dependent cell aggregation, which is associated with enhanced cell proliferation and prolonged survival in three-dimensional culture.The expression or function of the IGF-IR in breast cancer cells is modulated by different humoral factors, such as estrogen, progesterone, IGF-II, and interleukin-1. The IGF-IR and the estrogen receptor (ER) are usually co-expressed and the two signaling systems are engaged in a complex functional cross-talk controlling cell proliferation.Despite the convincing experimental evidence, the role of the IGF-IR in breast cancer etiology, especially in metastatic progression, is still not clear. The view emerging from cellular and animal studies is that abnormally high levels of IGF-IRs may contribute to the increase of tumor mass and/or aid tumor recurrence, by promoting proliferation, cell survival, and cell-cell interactions. However, in breast cancer, except for the well established correlation with ER status, the associations of the IGF-IR with other prognostic parameters are still insufficiently documented. 相似文献
62.
63.
Marina Cuttini Veronica Casotto Marcello Orzalesi & THE EURONIC STUDY GROUP 《Acta paediatrica (Oslo, Norway : 1992)》2006,95(S452):42-46
An international project (EURONIC) was carried out to explore the end-of-life decision-making process in a large, representative sample of neonatal intensive care units (NICUs) in eight western European countries: France, Germany, Great Britain, Italy, Luxembourg, the Netherlands, Spain and Sweden. Structured questionnaires were used to record data on NICU organization and policies, and to survey staff views and practices regarding ethical decision-making. One hundred and twenty-two NICUs were recruited by census or random sampling (response rate 86%); 1235 physicians and 3115 nurses completed the staff questionnaire (response rates 89 and 85%, respectively). This paper focuses on the physicians' answers. In all countries but Italy, most physicians reported having been involved at least once in setting limits to intensive care because of a baby's incurable condition and/or poor neurological prognosis. Adopted strategies varied between countries. Practices such as the continuation of current treatment without intensifying it and the withholding of emergency manoeuvres appeared widespread. In contrast, the frequency of doctors reporting withdrawal of mechanical ventilation was highest in the Netherlands (93%), Sweden (91%) and the Great Britain (88%), intermediate in France and Germany, and lowest in Spain and Italy (34 and 21%, respectively).
Conclusion: Ethically problematic clinical cases are approached differently in the various countries. The findings of this study may provide an opportunity for physicians to review their practices critically, in light of how other colleagues proceed, and foster an open discussion about these difficult issues. 相似文献
Conclusion: Ethically problematic clinical cases are approached differently in the various countries. The findings of this study may provide an opportunity for physicians to review their practices critically, in light of how other colleagues proceed, and foster an open discussion about these difficult issues. 相似文献
64.
65.
Lajos Pusztai Savitri Krishnamurti Jorge Perez Cardona Nour Sneige Francisco J. Esteva Marina Volchenok Patricia Breitenfelder Shu-Wan Kau Shin Takayama Stanislaw Krajewski John C. Reed Robert C. Bast Jr. Gabriel N. Hortobagyi 《Cancer investigation》2005,22(2):248-256
It has been suggested that expression of anti-apoptotic proteins such as Bcl-2 or BAG-1 may confer cellular resistance to chemotherapy. A corollary of this hypothesis is that expression of these proteins may predict clinical response to treatment and that Bcl-2- or BAG-1-positive cells may selectively be enriched in postchemotherapy tissue specimens. The goal of this exploratory pilot study was to assess these two predictions by using immunohistochemistry in 29 paired pre- and postchemotherapy breast tissue specimens obtained from patients who underwent preoperative doxorubicin-based chemotherapy. All breast cancers expressed BAG-1 protein, and, in individual tumors, 40-100% of neoplastic cells stained positive for this protein. Homogenous cytoplasmic staining was typically observed, though neoplastic cells also showed nuclear staining in many specimens. We found no correlation between prechemotherapy expression of BAG-1 and subsequent pathological response to cytotoxic therapy. Paired pre- and posttreatment specimens showed similar levels of BAG-1 expression when residual tumor could be assessed. Bcl-2 was expressed in 55% of cancers and was localized to the cytoplasm. Absence of Bcl-2 expression in prechemotherapy specimens was associated with more frequent complete pathological response (58% vs. 20%; p = 0.04). However, similar to BAG-1, no difference between pre- and posttherapy expression of Bcl-2 was observed in neoplastic cells in paired tissue specimens. These observations suggest that BAG-1 contributes an important cellular function to breast epithelial cells, which is reflected by its ubiquitous expression in these tissues. However, it does not appear to determine response to doxorubicin-based chemotherapy. In contrast, lack of Bcl-2 expression was associated with a higher probability of complete pathological response to doxorubicin-based chemotherapy. 相似文献
66.
Marina Gonzalez-Ramirez Rocio Sanchez-Carrera Angela Cejudo-Lopez Mauricio Lozano-Navarrete Elena Salamero Snchez-Gabriel M. Alfonso Torres-Bengoa Manuel Segura-Balbuena Maria J. Sanchez-Cordero Mercedes Barroso-Vazquez Francisco J. Perez-Barba Ana M. Troncoso M. Carmen Garcia-Parrilla Ana B. Cerezo 《Nutrients》2022,14(10)
Promoting a healthy diet is a relevant strategy for preventing non-communicable diseases. This study aims to evaluate the impact of an innovative tool, the SAlBi educa nutrition app, in primary healthcare dietary counseling to improve dietary profiles as well as adherence to the Mediterranean diet. A multi-center randomized control trial comprising 104 participants was performed. Both control (n = 49) and intervention (n = 55) groups attended four once-weekly sessions focusing on healthy eating habits and physical activity, over one month. As well as attending the meetings, the intervention group used the app, which provides self-monitoring and tailored dietary advice based on the Mediterranean diet model. In a second intervention (one arm trial), the potential of SAlBi educa was evaluated for three months during the COVID-19 pandemic. At 4 weeks, the intervention group had significantly increased their carbohydrate intake (7.7% (95% CI: 0.16 to 15.2)) and decreased their total fat intake (−5.7% (95% CI: −10.4 to −1.15)) compared to the control group. Significant differences were also found for carbohydrates (3.5% (95% CI: −1.0 to 5.8)), total fats (−5.9% (95% CI: −8.9 to −3.0)), fruits and vegetables (266.3 g/day (95% CI: 130.0 to 402.6)), legumes (7.7g/day (95% CI: 0.2 to 15.1)), starchy foods (36.4 g/day (95% CI: 1.1 to 71.7)), red meat (−17.5 g/day (95% CI: −34.0 to −1.1)), and processed meat (−6.6 g/day (95% CI: −13.1 to −0.1)) intakes during the COVID-19 pandemic. SAlBi educa is a useful tool to support nutrition counseling in primary healthcare, including in special situations such as the COVID-19 pandemic. Trial registration: ISRCTN57186362. 相似文献
67.
68.
Gabriela de Freitas Laiber Pascoal Marina Vilar Geraldi Mrio Roberto Marstica Jr. Thomas Prates Ong 《Nutrients》2022,14(10)
Infertility is a growing public health problem. Consumption of antioxidant bioactive food compounds (BFCs) that include micronutrients and non-nutrients has been highlighted as a potential strategy to protect against oxidative and inflammatory damage in the male reproductive system induced by obesity, alcohol, and toxicants and, thus, improve spermatogenesis and the fertility parameters. Paternal consumption of such dietary compounds could not only benefit the fathers but their offspring as well. Studies in the new field of paternal origins of health and disease show that paternal malnutrition can alter sperm epigenome, and this can alter fetal development and program an increased risk of metabolic diseases and breast cancer in adulthood. BFCs, such as ascorbic acid, α-tocopherol, polyunsaturated fatty acids, trace elements, carnitines, N-acetylcysteine, and coenzyme Q10, have been shown to improve male gametogenesis, modulate epigenetics of germ cells, and the epigenetic signature of the offspring, restoring offspring metabolic health induced by stressors during early life. This indicates that, from a father’s perspective, preconception is a valuable window of opportunity to start potential nutritional interventions with these BFCs to maximize sperm epigenetic integrity and promote adequate fetal growth and development, thus preventing chronic disease in adulthood. 相似文献
69.
Eline Lima Borges Gilmara Lopes Amorim Marina Barcelos de Miranda Flaviano dos Santos Martins Antnio Carlos Martins Guedes Kinulpe Honorato Sampaio Josimare Aparecida Otoni Spira Lucíola da Silva Barcelos 《Acta cirúrgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia》2022,37(3)
70.
Identification
of RAD51–BRCA2 Inhibitors Using N-Acylhydrazone-Based
Dynamic Combinatorial Chemistry
Greta Bagnolini Beatrice Balboni Fabrizio Schipani Dario Gioia Marina Veronesi Francesca De Franco Cansu Kaya Ravindra P. Jumde Jose Antonio Ortega Stefania Girotto Anna K. H. Hirsch Marinella Roberti Andrea Cavalli 《ACS medicinal chemistry letters》2022,13(8):1262
RAD51 is an ATP-dependent recombinase, recruited by BRCA2 to mediate DNA double-strand breaks repair through homologous recombination and represents an attractive cancer drug target. Herein, we applied for the first-time protein-templated dynamic combinatorial chemistry on RAD51 as a hit identification strategy. Upon design of N-acylhydrazone-based dynamic combinatorial libraries, RAD51 showed a clear templating effect, amplifying 19 N-acylhydrazones. Screening against the RAD51–BRCA2 protein–protein interaction via ELISA assay afforded 10 inhibitors in the micromolar range. Further 19F NMR experiments revealed that 7 could bind RAD51 and be displaced by BRC4, suggesting an interaction in the same binding pocket of BRCA2. These results proved not only that ptDCC could be successfully applied on full-length oligomeric RAD51, but also that it could address the need of alternative strategies toward the identification of small-molecule PPI inhibitors. 相似文献