全文获取类型
收费全文 | 15999篇 |
免费 | 1107篇 |
国内免费 | 129篇 |
专业分类
耳鼻咽喉 | 140篇 |
儿科学 | 470篇 |
妇产科学 | 456篇 |
基础医学 | 2480篇 |
口腔科学 | 278篇 |
临床医学 | 1324篇 |
内科学 | 3771篇 |
皮肤病学 | 380篇 |
神经病学 | 2244篇 |
特种医学 | 435篇 |
外科学 | 1455篇 |
综合类 | 31篇 |
一般理论 | 1篇 |
预防医学 | 921篇 |
眼科学 | 177篇 |
药学 | 1121篇 |
中国医学 | 32篇 |
肿瘤学 | 1519篇 |
出版年
2024年 | 29篇 |
2023年 | 205篇 |
2022年 | 439篇 |
2021年 | 735篇 |
2020年 | 400篇 |
2019年 | 494篇 |
2018年 | 648篇 |
2017年 | 471篇 |
2016年 | 540篇 |
2015年 | 604篇 |
2014年 | 740篇 |
2013年 | 973篇 |
2012年 | 1391篇 |
2011年 | 1394篇 |
2010年 | 782篇 |
2009年 | 710篇 |
2008年 | 1171篇 |
2007年 | 1060篇 |
2006年 | 961篇 |
2005年 | 856篇 |
2004年 | 782篇 |
2003年 | 692篇 |
2002年 | 528篇 |
2001年 | 56篇 |
2000年 | 41篇 |
1999年 | 59篇 |
1998年 | 105篇 |
1997年 | 67篇 |
1996年 | 46篇 |
1995年 | 40篇 |
1994年 | 44篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 17篇 |
1990年 | 17篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 12篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Journal of Public Health - This study aimed at assessing emergency medical service (EMS) use by patients with acute myocardial infarction (AMI), factors associated with EMS use, and outcomes in the... 相似文献
102.
Francesca Snchez-Martínez Silvia Brugueras Gemma Serral Sara Valmayor Olga Jurez María Jos Lpez Carles Ariza 《Nutrients》2021,13(2)
Childhood obesity has increased worldwide over the past four decades. This quasi-experimental study aimed to assess the effectiveness of a multicomponent and multilevel school-based intervention (POIBA) at 3 years of follow-up. The nutrition intervention focused on food groups, food pyramid, nutrients, portions, and balanced menus. In total, 3624 children participated in the study. Anthropometric measurements and information on food frequency and behavior, physical activity, and daily screen use were collected in the intervention (IG) and comparison group (CG). Positive unadjusted changes toward adherence to recommendations were found for water, meat, sweets, and fried potato consumption, proper breakfast, not having dinner in front of the TV, out-of-school physical activity, and daily screen use. Three scores were used to calculate the proportion of children making more than one change to improve healthy habits regarding physical activity (global Activity score), nutrition (global Nutrition score), and both (global score). Students exposed to the intervention had a significantly better global Activity score (16.2% IG vs. 11.9% CG; p = 0.012) and Global score (63.9% IG vs. 58.5% CG; p = 0.025). Intervention effects on obesity incidence at 3-year follow-up lost significance but maintained the positive trend. In conclusion, school-based interventions including a family component could be useful to address the childhood obesity problem. 相似文献
103.
Chiara Di Lorenzo Francesca Colombo Simone Biella Creina Stockley Patrizia Restani 《Nutrients》2021,13(1)
Polyphenols are a group of phytochemicals with potential health-promoting effects. They are classified as flavonoid (flavonols, flavanols, flavones, flavanones, isoflavones, and anthocyanins) and non-flavonoid molecules (phenolic acids, hydroxycinnamic acids, lignans, stilbenes, and tannins). Although an increasing number of trials have shown a correlation among polyphenol consumption and a reduction in risk factors for chronic diseases, discrepancies in explaining their positive effects have been found in terms of the bioavailability. In fact, polyphenols show a low bioavailability due to several factors: interaction with the food matrix, the metabolic processes mediated by the liver (phase I and II metabolism), intestine and microbiota. On the other hand, the biological activities of phenol compounds may be mediated by their metabolites, which are produced in vivo, and recent studies have confirmed that these molecules may have antioxidant and anti-phlogistic properties. This review discusses the studies performed in vivo, which consider the polyphenol bioavailability and their different food sources. Factors influencing the biological effects of the main classes of polyphenols are also considered. 相似文献
104.
Claudia Tonini Marco Segatto Francesca Martino Luisa Cigliano Martina Nazzaro Laura Barberio Maurizio Mandal Valentina Pallottini 《Nutrients》2021,13(1)
Background: A major problem of aging is the disruption of metabolic homeostasis. This is particularly relevant in the brain where it provokes neurodegeneration. Caloric restriction is a physiologic intervention known to delay the deleterious consequences of aging in several species ranging from yeast to mammals. To date, most studies on experimental models have started this dietary intervention from weaning, which is very difficult to be translated to human beings. Here, we study the effects of a more realistic dietary regimen in rats, starting at an advanced age and lasting for six months. Methods: we analyzed in the cortex and hippocampus, the proteins involved in the energetic balance of the cells, cholesterol metabolism, oxidative stress response, inflammation, synaptic impairment, and brain trophism. Results: our results suggest that caloric restriction in late life can revert only some age-related changes studied here. 相似文献
105.
Simone Baldi Marta Menicatti Giulia Nannini Elena Niccolai Edda Russo Federica Ricci Marco Pallecchi Francesca Romano Matteo Pedone Giovanni Poli Daniela Renzi Antonio Taddei Antonino S. Calabr Francesco C. Stingo Gianluca Bartolucci Amedeo Amedei 《Nutrients》2021,13(3)
Altered circulating levels of free fatty acids (FFAs), namely short chain fatty acids (SCFAs), medium chain fatty acids (MCFAs), and long chain fatty acids (LCFAs), are associated with metabolic, gastrointestinal, and malignant diseases. Hence, we compared the serum FFA profile of patients with celiac disease (CD), adenomatous polyposis (AP), and colorectal cancer (CRC) to healthy controls (HC). We enrolled 44 patients (19 CRC, 9 AP, 16 CD) and 16 HC. We performed a quantitative FFA evaluation with the gas chromatography–mass spectrometry method (GC–MS), and we performed Dirichlet-multinomial regression in order to highlight disease-specific FFA signature. HC showed a different composition of FFAs than CRC, AP, and CD patients. Furthermore, the partial least squares discriminant analysis (PLS-DA) confirmed perfect overlap between the CRC and AP patients and separation of HC from the diseased groups. The Dirichlet-multinomial regression identified only strong positive association between CD and butyric acid. Moreover, CD patients showed significant interactions with age, BMI, and gender. In addition, among patients with the same age and BMI, being male compared to being female implies a decrease of the CD effect on the (log) prevalence of butyric acid in FFA composition. Our data support GC–MS as a suitable method for the concurrent analysis of circulating SCFAs, MCFAs, and LCFAs in different gastrointestinal diseases. Furthermore, and notably, we suggest for the first time that butyric acid could represent a potential biomarker for CD screening. 相似文献
106.
107.
Francesca Oliviero Paola Galozzi Anna Scanu Francesca Galuppini Vanni Lazzarin Silvia Brocco Giampietro Ravagnan Paolo Sfriso Roberta Ramonda Paolo Spinella Leonardo Punzi Gianmaria Pennelli Roberto Luisetto 《Nutrients》2021,13(3)
Background: Polydatin is a stilbenoid with important antioxidant, anti-inflammatory, and immunomodulating properties. The aim of this study was to assess the anti-inflammatory preventive effect of polydatin in the mouse model of acute arthritis induced by calcium pyrophosphate (CPP) crystals. Methods: Acute arthritis was induced by the injection of a suspension of sterile CPP crystals into the ankle joint of Balb/c mice. Animals were randomized to receive polydatin or colchicine (the control drug) according to a prophylactic and a therapeutic protocol. The primary outcome was the variation of ankle swelling obtained after crystal injection and treatment, while histological parameters such as leukocyte infiltration, IL-1ß and CXCL1 levels and tissue expression were considered as secondary outcomes. Results: Prophylactic treatment with PD significantly diminished ankle swelling after 48 h from crystal injection. Secondary outcomes such as leukocyte infiltration, necrosis, edema, and synovitis were also decreased. PD caused a reduction in circulating levels of IL-1ß and CXCL1, as well as their tissue expression. By contrast, the therapeutic administration of PD did not have any beneficial effect. Conclusions: PD can effectively prevent acute inflammatory response to crystals in the mouse model of CPP crystal-induced arthritis. These results suggest that this bioactive compound might be used in the prevention of crystal-induced acute attacks in humans. 相似文献
108.
Luigi Barrea Giovanna Muscogiuri Gabriella Pugliese Chiara Graziadio Maria Maisto Francesca Pivari Andrea Falco Gian Carlo Tenore Annamaria Colao Silvia Savastano 《Nutrients》2021,13(5)
Individual differences in the chronotype, an attitude that best expresses the individual circadian preference in behavioral and biological rhythms, have been associated with cardiometabolic risk and gut dysbiosis. Up to now, there are no studies evaluating the association between chronotypes and circulating TMAO concentrations, a predictor of cardiometabolic risk and a useful marker of gut dysbiosis. In this study population (147 females and 100 males), subjects with the morning chronotype had the lowest BMI and waist circumference (p < 0.001), and a better metabolic profile compared to the other chronotypes. In addition, the morning chronotype had the highest adherence to the Mediterranean diet (p < 0.001) and the lowest circulating TMAO concentrations (p < 0.001). After adjusting for BMI and adherence to the Mediterranean diet, the correlation between circulating TMAO concentrations and chronotype score was still kept (r = −0.627, p < 0.001). Using a linear regression analysis, higher chronotype scores were mostly associated with lower circulating TMAO concentrations (β = −0.479, t = −12.08, and p < 0.001). Using a restricted cubic spline analysis, we found that a chronotype score ≥59 (p < 0.001, R2 = −0.824) demonstrated a more significant inverse linear relationship with circulating TMAO concentrations compared with knots <59 (neither chronotype) and <41 (evening chronotype). The current study reported the first evidence that higher circulating TMAO concentrations were associated with the evening chronotype that, in turn, is usually linked to an unhealthy lifestyle mostly characterized by low adherence to the MD. 相似文献
109.
Michele Torre Vittorio Guerriero Luca Ramenghi Francesca Rizzo Annalisa Gallizia Oliviero Sacco 《Journal of pediatric surgery》2021,56(4):700-705
Background/PurposeMany studies on ex-preterm babies were conducted to evaluate their respiratory sequelae, but, to our knowledge, the condition described in this paper was never reported before and is not included in the classifications of thoracic anomalies proposed so far.MethodsClinical data and images of a novel thoracic deformity observed in the last 10 years are shown. This anomaly is characterized by an indentation of the ribs on both (less frequently one) anterolateral parts of the chest wall. All our patients with this condition were ex-preterm babies. We named this novel thoracic anomaly as “postprematurity thoracic dysplasia” (PPTD). Possible etiopathogenetic mechanisms and treatment options are discussed.ResultsWe observed 8 patients with variable range of respiratory symptoms. In 2 cases the malformation caused a severe functional restriction of lung volumes and surgery was performed to improve respiratory symptoms; in other cases the symptoms were mild or absent and the malformation was a matter of concern only for cosmesis.ConclusionsPPTD is a novel thoracic anomaly typical of ex-preterms. Clinical relevance is variable. In severe cases surgery can be considered.Level of evidenceIV. 相似文献
110.
Giulia Leanza Francesca Fontana Seung-Yon Lee Maria S. Remedi Céline Schott Mathieu Ferron Malcolm Hamilton-Hall Yael Alippe Rocky Strollo Nicola Napoli Roberto Civitelli 《Journal of bone and mineral research》2021,36(7):1403-1415
High fracture rate and high circulating levels of the Wnt inhibitor, sclerostin, have been reported in diabetic patients. We studied the effects of Wnt signaling activation on bone health in a mouse model of insulin-deficient diabetes. We introduced the sclerostin-resistant Lrp5A214V mutation, associated with high bone mass, in mice carrying the Ins2Akita mutation (Akita), which results in loss of beta cells, insulin deficiency, and diabetes in males. Akita mice accrue less trabecular bone mass with age relative to wild type (WT). Double heterozygous Lrp5A214V/Akita mutants have high trabecular bone mass and cortical thickness relative to WT animals, as do Lrp5A214V single mutants. Likewise, the Lrp5A214V mutation prevents deterioration of biomechanical properties occurring in Akita mice. Notably, Lrp5A214V/Akita mice develop fasting hyperglycemia and glucose intolerance with a delay relative to Akita mice (7 to 8 vs. 5 to 6 weeks, respectively), despite lack of insulin production in both groups by 6 weeks of age. Although insulin sensitivity is partially preserved in double heterozygous Lrp5A214V/Akita relative to Akita mutants up to 30 weeks of age, insulin-dependent phosphorylated protein kinase B (pAKT) activation in vitro is not altered by the Lrp5A214V mutation. Although white adipose tissue depots are equally reduced in both compound and Akita mice, the Lrp5A214V mutation prevents brown adipose tissue whitening that occurs in Akita mice. Thus, hyperactivation of Lrp5-dependent signaling fully protects bone mass and strength in prolonged hyperglycemia and improves peripheral glucose metabolism in an insulin independent manner. Wnt signaling activation represents an ideal therapeutic approach for diabetic patients at high risk of fracture. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). 相似文献