全文获取类型
收费全文 | 264628篇 |
免费 | 8083篇 |
国内免费 | 727篇 |
专业分类
耳鼻咽喉 | 4285篇 |
儿科学 | 9902篇 |
妇产科学 | 7515篇 |
基础医学 | 34228篇 |
口腔科学 | 8118篇 |
临床医学 | 20103篇 |
内科学 | 51467篇 |
皮肤病学 | 6845篇 |
神经病学 | 17631篇 |
特种医学 | 12096篇 |
外国民族医学 | 98篇 |
外科学 | 37909篇 |
综合类 | 1620篇 |
一般理论 | 37篇 |
预防医学 | 23173篇 |
眼科学 | 5693篇 |
药学 | 18392篇 |
2篇 | |
中国医学 | 613篇 |
肿瘤学 | 13711篇 |
出版年
2021年 | 3008篇 |
2020年 | 1558篇 |
2019年 | 2595篇 |
2018年 | 6374篇 |
2017年 | 5576篇 |
2016年 | 4808篇 |
2015年 | 6460篇 |
2014年 | 6846篇 |
2013年 | 7115篇 |
2012年 | 14897篇 |
2011年 | 10298篇 |
2010年 | 5385篇 |
2009年 | 6366篇 |
2008年 | 6063篇 |
2007年 | 6919篇 |
2006年 | 6838篇 |
2005年 | 14873篇 |
2004年 | 15969篇 |
2003年 | 11303篇 |
2002年 | 6350篇 |
2001年 | 5898篇 |
2000年 | 3478篇 |
1999年 | 7185篇 |
1998年 | 1007篇 |
1992年 | 7266篇 |
1991年 | 7409篇 |
1990年 | 7648篇 |
1989年 | 7180篇 |
1988年 | 6711篇 |
1987年 | 6449篇 |
1986年 | 6155篇 |
1985年 | 5447篇 |
1984年 | 3722篇 |
1983年 | 3038篇 |
1982年 | 1138篇 |
1979年 | 3963篇 |
1978年 | 2474篇 |
1977年 | 1845篇 |
1976年 | 1636篇 |
1975年 | 2534篇 |
1974年 | 3199篇 |
1973年 | 2816篇 |
1972年 | 2830篇 |
1971年 | 2820篇 |
1970年 | 2628篇 |
1969年 | 2534篇 |
1968年 | 2302篇 |
1967年 | 2230篇 |
1966年 | 1935篇 |
1965年 | 1159篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Ignasi Esteban Carmen Pastor-Quiones Lorena Usero Montserrat Plana Felipe García Lorna Leal 《Viruses》2021,13(3)
Over 36 million people worldwide are infected with HIV. Antiretroviral therapy (ART) has proven to be highly effective to prevent HIV-1 transmission, clinical progression and death. Despite this success, the number of HIV-1 infected individuals continues increasing and ART should be taken for life. Therefore, there are two main priorities: the development of preventive vaccines to protect from HIV acquisition and achieve an efficient control of HIV infection in the absence of ART (functional cure). In this sense, in the last few years, there has been a broad interest in new and innovative approaches such as mRNA-based vaccines. RNA-based immunogens represent a promising alternative to conventional vaccines because of their high potency, capacity for rapid development and potential for low-cost manufacture and safe administration. Some mRNA-based vaccines platforms against infectious diseases have demonstrated encouraging results in animal models and humans. However, their application is still limited because the instability and inefficient in vivo delivery of mRNA. Immunogens, design, immunogenicity, chemical modifications on the molecule or the vaccine delivery methods are all crucial interventions for improvement. In this review we, will present the current knowledge and challenges in this research field. mRNA vaccines hold great promises as part of a combined strategy, for achieving HIV functional cure. 相似文献
22.
Focal hyperhidrosis secondary to eccrine naevus successfully treated with botulinum toxin type A
下载免费PDF全文
![点击此处可从《Clinical and experimental dermatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Eccrine naevus (EN) is a rare skin hamartoma included in the organoid group of epidermal naevi, histologically defined as focal hyperplasia and/or hypertrophy of eccrine glands. Clinically, EN usually presents as hyperhidrotic patches with no visible skin changes, frequently located on the forearms. The decision to treat EN or not usually depends on the grade of hyperhidrosis, but there is no therapeutic consensus because of the rarity of this condition. We present a case diagnosed as EN in an adult patient with severe localized hyperhidrosis, which was successfully treated with botulinum toxin. 相似文献
23.
Enrique Luengo Izaskun Buendia Cristina Fernndez‐Mendívil Paula Trigo‐Alonso Pilar Negredo Patrycja Michalska Borja Hernndez‐García Cristina Snchez‐Ramos Juan A. Bernal Tsuneya Ikezu Rafael Len Manuela G. Lpez 《Journal of pineal research》2019,67(1)
Alterations in autophagy are increasingly being recognized in the pathogenesis of proteinopathies like Alzheimer's disease (AD). This study was conducted to evaluate whether melatonin treatment could provide beneficial effects in an Alzheimer model related to tauopathy by improving the autophagic flux and, thereby, prevent cognitive decline. The injection of AAV‐hTauP301L viral vectors and treatment/injection with okadaic acid were used to achieve mouse and human ex vivo, and in vivo tau‐related models. Melatonin (10 μmol/L) impeded oxidative stress, tau hyperphosphorylation, and cell death by restoring autophagy flux in the ex vivo models. In the in vivo studies, intracerebroventricular injection of AAV‐hTauP301L increased oxidative stress, neuroinflammation, and tau hyperphosphorylation in the hippocampus 7 days after the injection, without inducing cognitive impairment; however, when animals were maintained for 28 days, cognitive decline was apparent. Interestingly, late melatonin treatment (10 mg/kg), starting once the alterations mentioned above were established (from day 7 to day 28), reduced oxidative stress, neuroinflammation, tau hyperphosphorylation, and caspase‐3 activation; these observations correlated with restoration of the autophagy flux and memory improvement. This study highlights the importance of autophagic dysregulation in tauopathy and how administration of pharmacological doses of melatonin, once tauopathy is initiated, can restore the autophagy flux, reduce proteinopathy, and prevent cognitive decline. We therefore propose exogenous melatonin supplementation or the development of melatonin derivatives to improve autophagy flux for the treatment of proteinopathies like AD. 相似文献
24.
25.
26.
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
27.
28.
Attachment is a behavioral and physiological system, which enables individual’s dynamic adaptation to its environment. Attachment develops in close interaction between an infant and his/her mother, plays an important role in the development of the infant’s brain, and influences the quality of interpersonal relationships throughout life.Security of attachment is believed to influence individual response to stress, exposing insecurely organized individuals to deregulated autonomic nervous system and exaggerated hypothalamic-pituitary-adrenal activity, which, in turn, produces increased and prolonged exposure to stress-hormones. Such stress responses may have considerable implications for the development of diverse health-risk conditions, such as insulin resistance and hyperlipidemia, shown by numerous studies.Although the mechanisms are not yet fully understood, there is compelling evidence highlighting the role of psychological stress in the development of type 1 diabetes (T1D). One of the possible contributing factors for the development of T1D may be the influence of attachment security on individual stress reactivity. Thus, the suggestion is that insecurely attached individuals are more prone to experience increased and prolonged influence of stress hormones and other mechanisms causing pancreatic beta-cell destruction.The present paper opens with a short overview of the field of attachment in children, the principal attachment classifications and their historic development, describes the influence of attachment security on individual stress-reactivity and the role of the latter in the development of T1D. Following is a review of recent literature on the attachment in patients with T1D with a conclusion of a proposed role of attachment organization in the etiology of T1D. 相似文献
29.
Torbj?rn Karlsson 《Upsala journal of medical sciences》2015,120(4):257-262
Background. Haemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterized by fever, hepatosplenomegaly, cytopenia, and progressive multiple-organ failure. HLH in adults is often secondary to autoimmune diseases, cancer, or infections in contrast to familial HLH. Treatment of secondary HLH is directed against the triggering disease in addition to immunosuppressive therapy, the latter commonly according to the HLH-2004 protocol.Methods. We conducted a retrospective study to identify triggering diseases, disease-specific and immunosuppressive therapy administered, and prognosis in adult patients with secondary HLH. Patient data were collected from October 2010 to January 2015.Results. Ten adult patients with secondary HLH were identified. Seven were men, and the median age at diagnosis was 62 years. Five cases were triggered by malignant disease and five by infection. The median patient fulfilled five of the eight HLH-2004 diagnostic criteria. All patients fulfilled the criteria fever, cytopenia, and ferritin >500 µg/L. Median time from hospital admission to HLH diagnosis was 20 days. Four patients received immunosuppressive therapy according to the HLH-2004 protocol. The prognosis was dismal, especially for the patients with malignancy-associated HLH, of whom all died.Conclusion. HLH should be suspected in patients who present with fever, cytopenia, and ferritin >500 µg/L. Secondary HLH has a dismal prognosis. None of the patients with HLH triggered by malignancy survived. Achieving remission of the triggering disease seems to be important for a favourable outcome as, in all surviving patients, the haemophagocytic syndrome resolved after remission of the underlying infection. 相似文献
30.
Sania Amr Magdy Garas Dina N. K. Boulos Doa’a A. Saleh Irene A. Jillson Christopher A. Loffredo 《Journal of substance use》2019,24(3):341-345
Background: Egyptian street youth use substances including tobacco, illicit drugs, and pharmaceutical drugs. To understand the circumstances, including adverse childhood experiences, that place adolescents at risk for engaging in substance use, we conducted in-depth interviews among a sample of Egyptian street children. Methods: From youth residing at or attending Caritas, a non-profit organization, which provides shelter and education to street youth, seven girls and twelve boys, aged 12–18 years, participated in open-ended, in-depth interviews. Results: Eight out of the 19 participants reported family history (early exposure) to substance use; and seven of them were initiated by either a family member (sibling), friend or coworker. Most of the participants reported a history of conflict with or abuse (verbal or physical) by their parents or siblings, or stressful situations at home; they used substance(s) to alleviate their stress. Few attended school, and some were forced to work and help their family. Conclusions: Among Egyptian youth, adverse childhood experiences, such as poverty, child abuse, and family substance use, challenge somewhat susceptible youths and lead them to the path of substance use and addiction. Prevention intervention should be multifaceted, culturally adaptable, and primarily targeting the social environment during childhood. 相似文献