首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7298篇
  免费   650篇
  国内免费   156篇
耳鼻咽喉   26篇
儿科学   193篇
妇产科学   37篇
基础医学   709篇
口腔科学   161篇
临床医学   579篇
内科学   1515篇
皮肤病学   34篇
神经病学   435篇
特种医学   482篇
外科学   689篇
综合类   750篇
现状与发展   1篇
预防医学   1190篇
眼科学   68篇
药学   704篇
  1篇
中国医学   351篇
肿瘤学   179篇
  2024年   14篇
  2023年   101篇
  2022年   164篇
  2021年   561篇
  2020年   292篇
  2019年   247篇
  2018年   263篇
  2017年   240篇
  2016年   250篇
  2015年   295篇
  2014年   426篇
  2013年   523篇
  2012年   372篇
  2011年   419篇
  2010年   329篇
  2009年   299篇
  2008年   308篇
  2007年   300篇
  2006年   223篇
  2005年   245篇
  2004年   182篇
  2003年   182篇
  2002年   169篇
  2001年   159篇
  2000年   138篇
  1999年   123篇
  1998年   127篇
  1997年   108篇
  1996年   93篇
  1995年   95篇
  1994年   90篇
  1993年   85篇
  1992年   85篇
  1991年   73篇
  1990年   62篇
  1989年   70篇
  1988年   42篇
  1987年   48篇
  1986年   35篇
  1985年   32篇
  1984年   48篇
  1983年   37篇
  1982年   35篇
  1981年   28篇
  1980年   18篇
  1979年   22篇
  1978年   11篇
  1977年   6篇
  1976年   8篇
  1973年   7篇
排序方式: 共有8104条查询结果,搜索用时 15 毫秒
71.
Energy drinks containing significant quantities of caffeine, taurine and sugar are increasingly consumed, particularly by adolescents and young adults. The putative effects of chronic ingestion of either standard energy drink, MotherTM (ED), or its sugar-free formulation (sfED) on metabolic syndrome were determined in wild-type C57BL/6J mice, in comparison to a soft drink, Coca-Cola (SD), a Western-styled diet enriched in saturated fatty acids (SFA), and a combination of SFA + ED. Following 13 weeks of intervention, mice treated with ED were hyperglycaemic and hypertriglyceridaemic, indicating higher triglyceride glucose index, which was similar to the mice maintained on SD. Surprisingly, the mice maintained on sfED also showed signs of insulin resistance with hyperglycaemia, hypertriglyceridaemia, and greater triglyceride glucose index, comparable to the ED group mice. In addition, the ED mice had greater adiposity primarily due to the increase in white adipose tissue, although the body weight was comparable to the control mice receiving only water. The mice maintained on SFA diet exhibited significantly greater weight gain, body fat, cholesterol and insulin, whilst blood glucose and triglyceride concentrations remained comparable to the control mice. Collectively, these data suggest that the consumption of both standard and sugar-free forms of energy drinks induces metabolic syndrome, particularly insulin resistance.  相似文献   
72.
Background: Low energy availability results in physiological adaptations which contribute to unfavourable health outcomes. Little information exists on perceptions of nutritional advice to eat more food to maintain health and enhance performance. The aim of this study was to explore athletes’ and coaches’ perceptions towards advice to athletes to eat larger than their current quantities of food and to explore how nutritionists could deliver this advice. Methods: Semi-structured interviews (~20 min in length) were conducted using online communication technology, audio-recorded, and transcribed verbatim. The interview explored perceptions of the nutritional advice provided, its role in health and performance, and the challenges to eating larger amounts of food. Data were analysed using NVIVO 1.2 using an inductive thematic approach. Results: Nine elite athletes (female = 6; males = 3) and nine high-performance coaches (female = 3; male = 6) completed the semi-structured interviews. Athletes reported improved training consistency, fewer injuries and illnesses, and improved resilience when consuming adequate energy and nutrients to meet their needs. Lack of time and meal preparation difficulties were the main challenges faced to fuelling. Conclusions: Although education about under-fuelling is important, motivating, enabling, and supporting athletes to change behaviour is pivotal to increasing athlete self-awareness and to make long-term nutritional changes.  相似文献   
73.
Increasing sugar-sweetened beverages (SSB) consumption and associated health impacts warrant health-policy action. We assessed associations of socioeconomic and lifestyle variables with adolescents’ consumption of regular soda (RSD), sport (SD), and energy (ED) drinks. Cross-sectional study of 3930 Spanish adolescents (2089 girls, 1841 boys) aged 13–18 years). We compared frequency of consuming each SSB type (European Food Safety Authority questionnaire) with sociodemographic and lifestyle variables (standardized questions). RSD, SD, and ED were consumed at least weekly by 72.7%, 32.3%, and 12.3% of participants, respectively, and more frequently (p < 0.001) by boys, compared to girls. Multivariate ordinal logistic regression showed inverse association between RSD, SD, and ED consumption and parental occupation-based socioeconomic status (p < 0.01). Daily smoking was associated (p < 0.001) with higher ED (OR 3.64, 95% CI 2.39–5.55) and RSD (OR 2.15, 95% CI 1.56–2.97) consumptions. SD intake was associated inversely with smoking (OR 0.60, 95% CI 0.40–0.89, p = 0.012) and directly with physical activity (OR 2.93, 95% CI 2.18–3.95, p < 0.001). School performance was lower among ED (OR 2.14, 95% CI, 1.37–3.35, p = 0.001) and RSD (OR 1.81, 95% CI 1.24–2.64, p = 0.002) consumers, compared to SD. Maleness and low socioeconomic status predicted SSB consumption. Smoking and low school performance were associated with higher ED and RSD intakes.  相似文献   
74.
Obesity is a complex and multifactorial chronic disease with genetic, environmental, physiological and behavioural determinants that requires long-term care. Obesity is associated with a broad range of complications including type 2 diabetes, cardiovascular disease, dyslipidaemia, metabolic associated fatty liver disease, reproductive hormonal abnormalities, sleep apnoea, depression, osteoarthritis and certain cancers. An algorithm has been developed (with PubMed and Medline searched for all relevant articles from 1 Jan 2000–1 Oct 2021) to (i) assist primary care physicians in treatment decisions for non-pregnant adults with obesity, and (ii) provide a practical clinical tool to guide the implementation of existing guidelines (summarised in Appendix 1) for the treatment of obesity in the Australian primary care setting.Main recommendations and changes in managementTreatment pathways should be determined by a person’s anthropometry (body mass index (BMI) and waist circumference (WC)) and the presence and severity of obesity-related complications. A target of 10–15% weight loss is recommended for people with BMI 30–40 kg/m2 or abdominal obesity (WC > 88 cm in females, WC > 102 cm in males) without complications. The treatment focus should be supervised lifestyle interventions that may include a reduced or low energy diet, very low energy diet (VLED) or pharmacotherapy. For people with BMI 30–40 kg/m2 or abdominal obesity and complications, or those with BMI > 40 kg/m2 a weight loss target of 10–15% body weight is recommended, and management should include intensive interventions such as VLED, pharmacotherapy or bariatric surgery, which may be required in combination. A weight loss target of > 15% is recommended for those with BMI > 40 kg/m2 and complications and they should be referred to specialist care. Their treatment should include a VLED with or without pharmacotherapy and bariatric surgery.  相似文献   
75.
ObjectiveInsufficient and poor-quality sleep among young adults is closely related to obesity and may impact metabolic processes. The mobilization and use of endogenous substrates during sleep, especially fat oxidation, is essential for energy metabolism. This study investigated whether there are differences in sleep structure, metabolic rate, substrate oxidation, and the respiratory quotient (RQ) between young males with normal weight and obesity according to sleep stages and overnight sleep.MethodsFifteen young males with normal weight and fifteen with obesity posited electrodes of polysomnography (PSG) and slept in the metabolic chamber for estimation of sleep structure, sleep metabolic rate (SMR), carbohydrate oxidation (CHOO), fat oxidation (FATO), and RQ. Fat-free mass (FFM) was measured by bioelectrical impedance analysis.ResultsThe sleep period time (p = 0.038) and total sleep time (p = 0.032) were significantly shorter in the obesity group than in the normal-weight group. The obesity group also had a longer sleep latency (p = 0.034) and more sleep-turning events (p = 0.018). CHOO/FFM and the RQ were higher in the obesity group while FATO/FFM was significantly higher in the normal-weight group. FATO/FFM was also higher in the normal-weight group in each sleep stage whereas the RQ was higher in the obesity group (p < 0.05).ConclusionsYoung males with obesity showed lower fat oxidation and more dominant carbohydrate-derived fuel oxidation than normal-weight during sleep and experienced shorter sleep periods and total sleep time.  相似文献   
76.
目的验证JOA X-线骨质疏松诊断标准的可靠性.方法47名女性病人(年龄65.3±7.2岁)行腰椎常规X-线检查和第三腰椎正、侧位DEXA骨密度测量.用t检验验证X-线骨质疏松等级间骨密度的差异性,用Spearman相关性分析法检验X-线骨质疏松等级与骨密度值的相关性.结果X-线骨质疏松等级间骨密度具有显著性差异(P<0.01),X-线骨质疏松等级与第三腰椎侧位骨密度值之间相关性最高(r=0.714).结论通过腰椎X-线片按照JOA标准划分骨质疏松等级,可以作为粗略检查腰椎骨质疏松的方法.  相似文献   
77.
目的:探讨高胆汁酸血症单一因素对肝脏能量代谢的影响。方法:经Wistar大鼠颈内静脉持续给阳外源性胆汁酸,升高其外周血清中胆汁酸浓度,模拟阻塞性黄疸患者外周血清中胆汁酸的变化规律。观察腹腕动脉酮体比值及肝组织能荷变化,时间一周。结果:随外周血清中胆法 酸浓度的升高,腹腔动脉血酮体比值,肝组织能荷均呈进行性下降,结论:高胆汁酸血症时肝脏能量代谢受损,表明在阻塞性黄疸患者肝功能损害中高胆汁酸血症起了重要作用。  相似文献   
78.
Implant wear and corrosion have been associated with adverse tissue reactions that can lead to implant failure. Wear and corrosion products are therefore of great clinical concern. For example, Co2+ and Cr3+ originating from CoCrMo‐based implants have been shown to induce a proinflammatory response in macrophages in vitro. Previous studies have also shown that the polarization of macrophages by some proinflammatory stimuli is associated with a hypoxia‐inducible factor‐1α (HIF‐1α)‐dependent metabolic shift from oxidative phosphorylation (OXPHOS) towards glycolysis. However, the potential of Co2+ and Cr3+ to induce this metabolic shift, which plays a determining role in the proinflammatory response of macrophages, remains largely unexplored. We recently demonstrated that Co2+, but not Cr3+, increased oxidative stress and decreased OXPHOS in RAW 264.7 murine macrophages. In the present study, we analyzed the effects of Co2+ and Cr3+ on glycolytic flux and HIF‐1α stabilization in the same experimental model. Cells were exposed to 6 to 24 ppm Co2+ or 50 to 250 ppm Cr3+. Glycolytic flux was determined by analyzing extracellular flux and lactate production, while HIF‐1α stabilization was analyzed by immunoblotting. Results showed that Co2+, and to a lesser extent Cr3+, increased glycolytic flux; however, only Co2+ acted through HIF‐1α stabilization. Overall, these results, together with our previous results showing that Co2+ increases oxidative stress and decreases OXPHOS, suggest that Co2+ (but not Cr3+) can induce a HIF‐1α‐dependent metabolic shift from OXPHOS towards glycolysis in macrophages. This metabolic shift may play an early and pivotal role in the inflammatory response induced by Co2+ in the periprosthetic environment.  相似文献   
79.
疲劳是亚健康的典型表现,会导致身体发生一系列的生理变化。长期疲劳如不及时缓解,可诱发心血管功能障碍、精神障碍等严重病理反应。中药为防治疲劳、减缓继发性疾病提供了可靠的临床实践,具有抗疲劳作用的天然药物种类丰富,为开发利用新型抗疲劳药物提供崭新领域。通过对疲劳的认识、中药与天然药物防治疲劳的复杂机制进行综述,为揭示中药干预疲劳提供理论依据,也为开发具有抗疲劳潜力的新产品提供指导。  相似文献   
80.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号