全文获取类型
收费全文 | 217176篇 |
免费 | 11060篇 |
国内免费 | 650篇 |
专业分类
耳鼻咽喉 | 3080篇 |
儿科学 | 6953篇 |
妇产科学 | 5401篇 |
基础医学 | 29754篇 |
口腔科学 | 6889篇 |
临床医学 | 15223篇 |
内科学 | 51396篇 |
皮肤病学 | 6855篇 |
神经病学 | 18444篇 |
特种医学 | 5073篇 |
外国民族医学 | 30篇 |
外科学 | 26496篇 |
综合类 | 1203篇 |
一般理论 | 85篇 |
预防医学 | 21591篇 |
眼科学 | 4236篇 |
药学 | 14808篇 |
1篇 | |
中国医学 | 877篇 |
肿瘤学 | 10491篇 |
出版年
2023年 | 1489篇 |
2022年 | 2325篇 |
2021年 | 5522篇 |
2020年 | 3006篇 |
2019年 | 5340篇 |
2018年 | 7342篇 |
2017年 | 4681篇 |
2016年 | 4669篇 |
2015年 | 5034篇 |
2014年 | 6631篇 |
2013年 | 9365篇 |
2012年 | 14730篇 |
2011年 | 15453篇 |
2010年 | 8173篇 |
2009年 | 6704篇 |
2008年 | 12287篇 |
2007年 | 12816篇 |
2006年 | 12118篇 |
2005年 | 11897篇 |
2004年 | 10659篇 |
2003年 | 10025篇 |
2002年 | 9414篇 |
2001年 | 6070篇 |
2000年 | 6603篇 |
1999年 | 5259篇 |
1998年 | 1412篇 |
1997年 | 1046篇 |
1996年 | 935篇 |
1995年 | 819篇 |
1994年 | 646篇 |
1993年 | 618篇 |
1992年 | 2324篇 |
1991年 | 2123篇 |
1990年 | 1909篇 |
1989年 | 1651篇 |
1988年 | 1479篇 |
1987年 | 1417篇 |
1986年 | 1343篇 |
1985年 | 1209篇 |
1984年 | 917篇 |
1983年 | 767篇 |
1979年 | 799篇 |
1978年 | 551篇 |
1975年 | 610篇 |
1974年 | 693篇 |
1973年 | 741篇 |
1972年 | 638篇 |
1971年 | 635篇 |
1970年 | 611篇 |
1969年 | 600篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Melatonin reduces oxidative stress and improves vascular function in pulmonary hypertensive newborn sheep
下载免费PDF全文
![点击此处可从《Journal of pineal research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Flavio Torres Alejandro González‐Candia Camilo Montt Germán Ebensperger Magdalena Chubretovic María Serón‐Ferré Roberto V. Reyes Aníbal J. Llanos Emilio A. Herrera 《Journal of pineal research》2015,58(3):362-373
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN. 相似文献
43.
Maria Gonzalez-Cao Cristina Carrera Juan Francisco Rodriguez Moreno Pedro Rodríguez-Jiménez Mónica Antoñanzas Basa Rosa Feltes Ochoa Teresa Puertolas Eva Muñoz-Couselo José Luis Manzano Ivan Marquez-Rodas Juan Martín-Liberal Ainara Soria Pilar Lopez Criado Almudena Garcia-Castaño Aram Boada Pablo Ayala de Miguel Susana Puig Guillermo Crespo Alfonso Berrocal 《Journal of the American Academy of Dermatology》2021,84(5):1412-1415
44.
目的 收集藿香正气汤的主要活性成分,通过分子对接及网络药理学探讨其防控新型冠状病毒肺炎(COVID-19)的有效成分及治疗机制。方法 通过基于配体-蛋白质相互作用的计算方法,以瑞德西韦为对照,探索藿香正气汤潜在治疗COVID-19的成分,并选出对接较好成分进行药理学机制预测,初探其药理学机制。结果 本研究筛选出5种与新冠病毒3CLpro结合能力强于瑞德西韦的小分子成分。网络药理学初步预测抗病毒途径可能是通过PI3K-Akt 信号通路影响病毒复制。结论 成分C1-C5与3CLpro结合良好,推测其可能是潜在的3CLpro的抑制剂,为抗病毒天然药物的开发提供了理论依据。 相似文献
45.
46.
47.
José Antonio Pereira Miguel Pera Manuel López-Cano Marta Pascual Sandra Alonso Silvia Salvans Marta Jiménez-Toscano Alba González-Martín Luis Grande-Posa 《Cirugía espa?ola》2019,97(1):20-26
Objectives
To determine the incidence of incisional hernia (IH) in the extraction incision (EI) in colorectal resection for cancer. To analyze whether the location of the incision has any relationship with the incidence of hernias and whether mesh could be useful for prevention in high-risk patients.Methods
Retrospective review of the colon and rectal surgery database from January 2015 to December 2016. Data were classified into 2 groups, transverse (TI) and midline incision (MI), and the latter was divided into 2 subgroups (mesh [MIM] and suture [MIS]). Patients were classified using the HERNIAscore. Hernias were diagnosed by clinical and/or CT examination.Results
A total of 182 out of 210 surgical patients were included. After a median follow-up of 13.0 months, 39 IH (21.9%) were detected, 23 of which (13.4%) were in the EI; their frequency was lower in the TI group (3.4%) and in the MIM group (5.9%) than in the MIS group (29.5%; p = 0.007). The probability of developing IH in the MIS group showed an OR = 11.7 (95%CI: 3.3-42.0) compared to the TI group and 4.3 (IC 95%: 1.1-16.3) versus the MIM group.Conclusions
The location of the incision is relevant to avoid incisional hernias. Transverse incisions should be used as the first option. When a midline incision is needed, a prophylactic mesh could be considered in high risk patients because it is safe and associated with low morbidity. 相似文献48.
49.
50.
Lorena Martin-Morales Sara Manzano Maria Rodrigo-Faus Adrian Vicente-Barrueco Victor Lorca Gonzalo Núñez-Moreno Paloma Bragado Almudena Porras Trinidad Caldes Pilar Garre Alvaro Gutierrez-Uzquiza 《International journal of cancer. Journal international du cancer》2023,152(2):283-297
Matrix metalloproteinase-11 (MMP11) is an enzyme with proteolytic activity against matrix and nonmatrix proteins. Although most MMPs are secreted as inactive proenzymes and are later activated extracellularly, MMP11 is activated intracellularly by furin within the constitutive secretory pathway. It is a key factor in physiological tissue remodeling and its alteration may play an important role in the progression of epithelial malignancies and other diseases. TCGA colon and colorectal adenocarcinoma data showed that upregulation of MMP11 expression correlates with tumorigenesis and malignancy. Here, we provide evidence that a germline variant in the MMP11 gene (NM_005940: c.232C>T; p.(Pro78Ser)), identified by whole exome sequencing, can increase the tumorigenic properties of colorectal cancer (CRC) cells. P78S is located in the prodomain region, which is responsible for blocking MMP11's protease activity. This variant was detected in the proband and all the cancer-affected family members analyzed, while it was not detected in healthy relatives. In silico analyses predict that P78S could have an impact on the activation of the enzyme. Furthermore, our in vitro analyses show that the expression of P78S in HCT116 cells increases tumor cell invasion and proliferation. In summary, our results show that this variant could modify the structure of the MMP11 prodomain, producing a premature or uncontrolled activation of the enzyme that may contribute to an early CRC onset in these patients. The study of this gene in other CRC cases will provide further information about its role in CRC development, which might improve patient treatment in the future. 相似文献