全文获取类型
收费全文 | 271994篇 |
免费 | 21334篇 |
国内免费 | 8656篇 |
专业分类
耳鼻咽喉 | 1847篇 |
儿科学 | 4770篇 |
妇产科学 | 3633篇 |
基础医学 | 31217篇 |
口腔科学 | 4039篇 |
临床医学 | 24284篇 |
内科学 | 29759篇 |
皮肤病学 | 2493篇 |
神经病学 | 29553篇 |
特种医学 | 12829篇 |
外国民族医学 | 8篇 |
外科学 | 29273篇 |
综合类 | 40382篇 |
现状与发展 | 25篇 |
一般理论 | 9篇 |
预防医学 | 18715篇 |
眼科学 | 3252篇 |
药学 | 33870篇 |
99篇 | |
中国医学 | 16348篇 |
肿瘤学 | 15579篇 |
出版年
2024年 | 262篇 |
2023年 | 3646篇 |
2022年 | 5051篇 |
2021年 | 10496篇 |
2020年 | 9674篇 |
2019年 | 9026篇 |
2018年 | 9002篇 |
2017年 | 10034篇 |
2016年 | 10272篇 |
2015年 | 9793篇 |
2014年 | 13124篇 |
2013年 | 18243篇 |
2012年 | 14592篇 |
2011年 | 16951篇 |
2010年 | 12110篇 |
2009年 | 11913篇 |
2008年 | 13445篇 |
2007年 | 14470篇 |
2006年 | 13675篇 |
2005年 | 12386篇 |
2004年 | 10427篇 |
2003年 | 9446篇 |
2002年 | 7483篇 |
2001年 | 6740篇 |
2000年 | 5570篇 |
1999年 | 4681篇 |
1998年 | 3611篇 |
1997年 | 3657篇 |
1996年 | 3232篇 |
1995年 | 3000篇 |
1994年 | 2854篇 |
1993年 | 2328篇 |
1992年 | 2153篇 |
1991年 | 1941篇 |
1990年 | 1698篇 |
1989年 | 1429篇 |
1988年 | 1361篇 |
1987年 | 1222篇 |
1986年 | 1197篇 |
1985年 | 1672篇 |
1984年 | 1398篇 |
1983年 | 1013篇 |
1982年 | 1098篇 |
1981年 | 933篇 |
1980年 | 881篇 |
1979年 | 636篇 |
1978年 | 404篇 |
1977年 | 351篇 |
1976年 | 330篇 |
1975年 | 231篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
IntroductionHip displacement is common in cerebral palsy (CP) and is related to the severity of neurological and functional impairment. It is a silent, but progressive disease, and can result in significant morbidity and decreased quality of life, if left untreated. The pathophysiology of hip displacement in CP is a combination of hip flexor-adductor muscle spasticity, abductor muscle weakness, and delayed weight-bearing, resulting in proximal femoral deformities and progressive acetabular dysplasia. Due to a lack of symptoms in the early stages of hip displacement, the diagnosis is easily missed. Awareness of this condition and regular surveillance by clinical examination and serial radiographs of the hips are the key to early diagnosis and treatment.Hip surveillance programmesSeveral population-based studies from around the world have demonstrated that universal hip surveillance in children with CP allows early detection of hip displacement and appropriate early intervention, with a resultant decrease in painful dislocations. Global hip surveillance models are based upon the patients’ age, functional level determined by the Gross Motor Function Classification system (GMFCS), gait classification, standardized clinical exam, and radiographic indices such as the migration percentage (MP), as critical indicators of progressive hip displacement.ConclusionDespite 25 years of evidence showing the efficacy of established hip surveillance programmes, there is poor awareness among healthcare professionals in India about the importance of regular hip surveillance in children with CP. There is a need for professional organizations to develop evidence-based guidelines for hip surveillance which are relevant to the Indian context. 相似文献
82.
Zongzhang Huang Qigu Yao Jianping Zhu Ying He Yanghao Chen Feng Wu Teng Hua 《Diagnostic and interventional imaging》2021,102(5):279-285
PurposeThe purpose of this study was to make a systematic review and meta-analysis to determine the stent diameter (8 mm vs. 10 mm) that conveys better safety and clinical efficacy for transjugular intrahepatic portosystemic shunt (TIPS).Materials and methodsFour databases were used to identify clinical trials published from inception until March 2020. Data were extracted to estimate and compare one-year and three-year overall survivals, hepatic encephalopathy, variceal rebleeding, and shunt dysfunction rates between patients with 8 mm covered stents and those with 10 mm covered stents.ResultsFive eligible studies were selected, which included 489 patients (316 men, 173 women). The 8 mm covered stent group had higher efficacy regarding one-year or three-year overall survival (odds ratio [OR], 2.88; P = 0.003) and (OR, 1.81; P = 0.04) and lower hepatic encephalopathy (OR, 0.69; P = 0.04) compared with 10 mm covered stent group. There were no significant differences in variceal rebleeding rate (OR 0.80; P = 0.67). However, shunt dysfunction was lower in 10 mm covered stent group (OR, 2.26; P = 0.003).ConclusionsOur results suggest that the use of 8 mm covered stents should be preferred to that of 10 mm covered stents for TIPS placement when portal pressure is frequently monitored. 相似文献
83.
84.
Zi-Qi Shao Shan-Shan Dou Jun-Ge Zhu Hui-Qing Wang Chun-Mei Wang Bao-Hua Cheng Bo Bai 《中国神经再生研究》2021,16(6):1044
Apelin-13 is a novel endogenous ligand for an angiotensin-like orphan G-protein coupled receptor, and it may be neuroprotective against cerebral ischemia injury. However, the precise mechanisms of the effects of apelin-13 remain to be elucidated. To investigate the effects of apelin-13 on apoptosis and autophagy in models of cerebral ischemia/reperfusion injury, a rat model was established by middle cerebral artery occlusion. Apelin-13(50 μg/kg) was injected into the right ventricle as a treatment. In addition, an SH-SY5 Y cell model was established by oxygen-glucose deprivation/reperfusion, with cells first cultured in sugar-free medium with 95% N2 and 5% CO2 for 4 hours and then cultured in a normal environment with sugar-containing medium for 5 hours. This SH-SY5 Y cell model was treated with 10–7 M apelin-13 for 5 hours. Results showed that apelin-13 protected against cerebral ischemia/reperfusion injury. Apelin-13 treatment alleviated neuronal apoptosis by increasing the ratio of Bcl-2/Bax and significantly decreasing cleaved caspase-3 expression. In addition, apelin-13 significantly inhibited excessive autophagy by regulating the expression of LC3 B, p62, and Beclin1. Furthermore, the expression of Bcl-2 and the phosphatidylinositol-3-kinase(PI3 K)/Akt/mammalian target of rapamycin(mTOR) pathway was markedly increased. Both LY294002(20 μM) and rapamycin(500 nM), which are inhibitors of the PI3 K/Akt/mTOR pathway, significantly attenuated the inhibition of autophagy and apoptosis caused by apelin-13. In conclusion, the findings of the present study suggest that Bcl-2 upregulation and mTOR signaling pathway activation lead to the inhibition of apoptosis and excessive autophagy. These effects are involved in apelin-13-induced neuroprotection against cerebral ischemia/reperfusion injury, both in vivo and in vitro. The study was approved by the Animal Ethical and Welfare Committee of Jining Medical University, China(approval No. 2018-JS-001) in February 2018. 相似文献
85.
86.
87.
胆胰肠结合部(CPDJ)医源性损伤发生隐匿,易漏诊与误诊,可导致严重并发症。近年来,随着胆石病发病率的不断增高、胆胰手术的普遍开展以及内镜和胆道镜等技术的深入推广,CPDJ医源性损伤发生逐渐增多。损伤处理方式和时机选择仍存在一定争议,治疗方案因人、因时而异。目前,多以“损伤控制性外科”理念为原则,继而进行“个体化”分期手术治疗。但二次手术治疗成本高、风险大、病人预后不佳,因此,防胜于治,全面而细致的防治思维可为病人提供更好的治疗效果。而对于CPDJ医源性损伤的监测及诊断技术有待进一步优化。 相似文献
88.
George Haddad Malte Klling Urs A. Wegmann Angela Dettling Harald Seeger Roland Schmitt Inga Soerensen-Zender Hermann Haller Andreas D. Kistler Anne Dueck Stefan Engelhardt Thomas Thum Thomas F. Mueller Rudolf P. Wüthrich Johan M. Lorenzen 《Journal of the American Society of Nephrology : JASN》2021,32(2):323
89.
《Clinical neurophysiology》2021,132(2):315-322
ObjectivePrevious studies have demonstrated voluntary movement alterations as well as motor cortex excitability and plasticity changes in patients with mild cognitive impairment (MCI). To investigate the pathophysiology of movement abnormalities in MCI, we tested possible relationships between movement abnormalities and primary motor cortex alterations in patients.MethodsFourteen amnestic MCI (aMCI) patients and 16 healthy controls were studied. Cognitive assessment was performed using clinical scales. Finger tapping was recorded by a motion analysis system. Transcranial magnetic stimulation was used to test the input/output curve of motor evoked potentials, intracortical inhibition, and short-latency afferent inhibition. Primary motor cortex plasticity was probed by theta burst stimulation. We investigated correlations between movement abnormalities, clinical scores, and cortical neurophysiological parameters.ResultsMCI patients showed less rhythmic movement but no other movement abnormalities. Cortical excitability measures were normal in patients, whereas plasticity was reduced. Movement rhythm abnormalities correlated with frontal dysfunction scores.ConclusionOur study in MCI patients demonstrated abnormal voluntary movement and plasticity changes, with no correlation between the two. Altered rhythm correlated with frontal dysfunction.SignificanceOur results contribute to the understanding of pathophysiological mechanisms of motor impairment in MCI. 相似文献
90.
《Human brain mapping》2021,42(7):1945
Having the means to share research data openly is essential to modern science. For human research, a key aspect in this endeavor is obtaining consent from participants, not just to take part in a study, which is a basic ethical principle, but also to share their data with the scientific community. To ensure that the participants'' privacy is respected, national and/or supranational regulations and laws are in place. It is, however, not always clear to researchers what the implications of those are, nor how to comply with them. The Open Brain Consent (https://open-brain-consent.readthedocs.io) is an international initiative that aims to provide researchers in the brain imaging community with information about data sharing options and tools. We present here a short history of this project and its latest developments, and share pointers to consent forms, including a template consent form that is compliant with the EU general data protection regulation. We also share pointers to an associated data user agreement that is not only useful in the EU context, but also for any researchers dealing with personal (clinical) data elsewhere. 相似文献