全文获取类型
收费全文 | 27776篇 |
免费 | 2070篇 |
国内免费 | 717篇 |
专业分类
耳鼻咽喉 | 192篇 |
儿科学 | 1296篇 |
妇产科学 | 786篇 |
基础医学 | 2166篇 |
口腔科学 | 309篇 |
临床医学 | 2505篇 |
内科学 | 5189篇 |
皮肤病学 | 257篇 |
神经病学 | 996篇 |
特种医学 | 1213篇 |
外国民族医学 | 2篇 |
外科学 | 2733篇 |
综合类 | 2564篇 |
现状与发展 | 2篇 |
预防医学 | 4207篇 |
眼科学 | 227篇 |
药学 | 3717篇 |
7篇 | |
中国医学 | 988篇 |
肿瘤学 | 1207篇 |
出版年
2024年 | 89篇 |
2023年 | 591篇 |
2022年 | 1317篇 |
2021年 | 1642篇 |
2020年 | 1342篇 |
2019年 | 1397篇 |
2018年 | 1262篇 |
2017年 | 1027篇 |
2016年 | 925篇 |
2015年 | 943篇 |
2014年 | 1956篇 |
2013年 | 1926篇 |
2012年 | 1531篇 |
2011年 | 1841篇 |
2010年 | 1463篇 |
2009年 | 1482篇 |
2008年 | 1463篇 |
2007年 | 1455篇 |
2006年 | 1092篇 |
2005年 | 968篇 |
2004年 | 782篇 |
2003年 | 580篇 |
2002年 | 456篇 |
2001年 | 414篇 |
2000年 | 326篇 |
1999年 | 284篇 |
1998年 | 224篇 |
1997年 | 218篇 |
1996年 | 200篇 |
1995年 | 159篇 |
1994年 | 137篇 |
1993年 | 115篇 |
1992年 | 98篇 |
1991年 | 117篇 |
1990年 | 98篇 |
1989年 | 73篇 |
1988年 | 67篇 |
1987年 | 48篇 |
1986年 | 54篇 |
1985年 | 69篇 |
1984年 | 60篇 |
1983年 | 53篇 |
1982年 | 48篇 |
1981年 | 38篇 |
1980年 | 30篇 |
1979年 | 33篇 |
1978年 | 24篇 |
1977年 | 10篇 |
1976年 | 12篇 |
1973年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Alberti MB Pinzauti S Moneti G Agati G Giannellini V Coran SA Vincieri FF 《Journal of pharmaceutical and biomedical analysis》1984,2(3-4):409-415
The medicinally important quaternary ammonium salts benzyldimethyltetradecylammonium chloride (BDTA), cetylpyridinium chloride and benzethonium chloride, all afford, under fast atom bombardment (FAB) mass spectrometric conditions, abundant and persistent [M---Cl]+ species usefully amenable to quantitative analysis with the aid of thioglycerol as a liquid FAB matrix. The use of BDTA as an internal standard allowed a direct, precise and accurate determination of cetylpyridinium and benzethonium chlorides, either as pure samples or in dosage forms, in the concentration range 0.05–2 mg/ml. 相似文献
72.
目的 探讨儿童青少年肌肉质量与心血管疾病危险因素的关系,为心血管疾病的早期预防提供理论依据。方法 采用现况研究设计,以整群抽样的方法于2017—2020年抽取宁夏银川市12~17岁儿童青少年共1 622名为研究对象。对所有参与测试者进行问卷调查、体格测量、实验室检查、体成分检查。结果 总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)与肌肉质量指数(SMMI)呈负相关(r=-0.105,-0.094,P<0.001);甘油三酯(TG)与全身肌肉质量(SMM)呈负相关(r=-0.067,P<0.01)。高SMMI者患高血压、高TC、高TG分别是低SMMI者的0.60(95%CI: 0.37~0.97)、0.54(95%CI: 0.33~0.89)倍和0.53(95%CI: 0.32~0.87)倍(P<0.05);SMMI良好、充足患高脂血症的风险分别是SMMI严重不足的0.32(95%CI:0.15~0.70)、0.23(95%CI: 0.08~0.65)倍(P<0.05)。SMMI良好患血脂异常的风险是SMMI严重不足的0.44(95%CI:0.22~0.89)倍(P<0.05)。结论 儿童青少年肌肉质量与心血管疾病危险因素关系密切,低肌肉质量为高血压、高脂血症的危险因素。 相似文献
73.
张艳 《中国儿童保健杂志》2022,30(9):1005-1009
目的 分析8~11岁儿童体成分和尿酸的含量以及不同年龄、性别、体重指数(BMI)之间的差异,分析血尿酸与体成分各指标的相关性。方法 以2020年4—12月在太原市妇幼保健院营养科体检的306例8~11岁儿童为研究对象,检测身高、体重及体成分各项指标,并检测血清尿酸的水平,分析该年龄段儿童体成分特征及其与尿酸的相关性。结果 男童和女童体成分各指标相比,男童的BMI显著高于女童,差异具有统计学意义(t=2.253,P<0.05),其余各指标差异均无统计学意义(P>0.05);BMI和体脂百分比(PBF)在女童中判断肥胖的一致性较高(Kappa值=0.642),而在男童中的一致性较低(Kappa值=0.438);男童中9岁年龄组一致性最高(Kappa值=0.669),女童中11岁年龄组一致性最高(Kappa值=0.761);Person相关性分析显示,尿酸与体成分各指标均呈正相关,男童中,BMI与血尿酸的相关性最大(r=0.579,P<0.001);女童中,BMI(r=0.706,P<0.001)、体脂肪含量(r=0.705,P<0.001)与血尿酸的相关性最大,多重线性回归分析显示,BMI对8~11岁儿童血清尿酸影响最大(P<0.05)。结论 太原市8~11岁儿童身体状况与全国水平较为接近;体成分PBF与BMI筛查8~11岁儿童肥胖率具有较高的一致性;体成分各指标与血清尿酸水平均有相关性,对于BMI较高的儿童,应注意预防早期高尿酸血症。 相似文献
74.
肾间质纤维化(RIF)是由多种病因导致慢性肾脏疾病的主要病理特征,结合中医“络病学说”“癥瘕理论”与现代医学肾脏病理特征,“肾虚络瘀,肾络癥瘕”是RIF的主要病机,正气亏虚,累及肾气,肾虚气化不利,痰热瘀毒等实邪阻滞肾络,相互胶结,形成癥瘕,积聚于肾络导致了RIF。自噬是细胞体内将受损或衰老的细胞器、变性的蛋白质等代谢产物进行降解与重吸收的过程,自噬参与了RIF发生的诸多环节,与RIF发生发展关系密切,将自噬与中医学结合研究发现,机体内生痰热瘀毒等实邪的代谢与自噬降解和重吸收功能相关,自噬在一定程度上是消除痰热瘀毒等实邪的方式,正气不足,累及肾气,肾虚气化不利,自噬功能不足,会引起痰热瘀毒等实邪累积,瘀阻肾络则易形成肾络癥瘕造成RIF,肾虚络瘀是自噬不足的基础,肾络癥瘕是自噬不足的微观病理表现,自噬不足与肾络癥瘕形成具有相同的病机演变,该文就RIF“肾虚络瘀,肾络癥瘕”病机,结合RIF-自噬病理机制,深入探讨“肾虚络瘀-自噬不足-肾络癥瘕”在RIF的相关性,全面诠释“肾虚络瘀,肾络癥瘕”病机的科学内涵,以期从中医理论阐述自噬在RIF中的作用研究奠定基础,为RIF的治疗及其机制研究提供新... 相似文献
75.
Weight change adjusted equations for assessing resting metabolic rate in overweight and obese adults
Moran Nachmani Yair Lahav Aviva Zeev Liza Grosman-Rimon Sigal Eilat-Adar 《Obesity research & clinical practice》2021,15(3):221-226
BackgroundAlthough over one hundred equations have been developed to predict the energy expenditure of individuals, none are sensitive to weight change in assessment of resting metabolic rate (RMR) before and after weight loss.ObjectiveTo formulate adjusted equations for overweight and obese individuals and to compare their accuracy with existing prediction RMR equations before and after weight loss.Subjects/materialsThis is historical prospective study. Participants included 39 overweight and obese men and women before and after losing 10–20% from baseline weight on a diet and physical activity regimen for at least three months. Pre and post weight loss measured RMR results were compared to estimated RMR using several existing prediction equations: Harris and Benedict, Ravussin and Bogardus, and Mifflin et al. To improve the accuracy of these prediction equations, we suggest new equations adjusted for weight loss, based on measured RMR and evaluated their accuracy.ResultsPre and post weight loss data indicated: significant fat reduction in both genders; reduction in free-fat mass only in men, and a significant decrease in measured RMR only in women. Our suggested equations were the most accurate and closest to measured RMR in both genders, in comparison to the Harris and Benedict, Ravussin and Bogardus, and Mifflin et al equation results. Estimated RMR using the latter equations was significantly lower than measured RMR in both genders at pre and post weight loss (P < 0.01).ConclusionsThis study highlights the need for adjusting RMR equations before and after weight loss in overweight and obese individuals. Further research is needed to validate our suggested equations. 相似文献
76.
《Disability and health journal》2021,14(4):101121
BackgroundObesity is a growing global health concern, and those with a developmental disorder are at particular risk. Elevated levels of childhood trauma, placement breakdowns and obesity have been documented in the developmental disorder population, yet their relative associations remain unclear.ObjectiveA previous study (Morris et al., 2020) highlighted a high prevalence of adverse childhood experiences (ACEs) and obesity in adolescents with developmental disorders residing in a secure inpatient setting. The current cross-sectional study sought to further explore the prevalence of placement breakdowns and its relationship with Body Mass Index (BMI) in this sample.MethodsSecondary analysis was conducted on existing data for 34 adolescents, aged 10–17 years at admission, held in a secure mental health hospital developmental disorder service in the United Kingdom (UK) under the Mental Health Act.ResultsAlmost half of participants had experienced a placement breakdown (47.1%), the majority of whom typically experienced multiple breakdowns (M = 3.94, SD = 2.14). Placement breakdowns significantly predicted BMI and had a predictive effect that was independent to and above that of ACEs.ConclusionsPlacement breakdowns significantly contribute to risk for obesity, above that explained by early adversity. Those who have experienced placement breakdowns have a greater risk for obesity, irrespective of their level of exposure to ACEs. A history of previous placement breakdowns may act as a red flag for obesity. 相似文献
77.
Type 2 diabetes mellitus (T2DM) represents a major health burden for the elderly population, affecting approximately 25% of people over the age of 65 years. This percentage is expected to increase dramatically in the next decades in relation to the increased longevity of the population observed in recent years. Beyond microvascular and macrovascular complications, sarcopenia has been described as a new diabetes complication in the elderly population. Increasing attention has been paid by researchers and clinicians to this age-related condition—characterized by loss of skeletal muscle mass together with the loss of muscle power and function—in individuals with T2DM; this is due to the heavy impact that sarcopenia may have on physical and psychosocial health of diabetic patients, thus affecting their quality of life. The aim of this narrative review is to provide an update on: (1) the risk of sarcopenia in individuals with T2DM, and (2) its association with relevant features of patients with T2DM such as age, gender, body mass index, disease duration, glycemic control, presence of microvascular or macrovascular complications, nutritional status, and glucose-lowering drugs. From a clinical point of view, it is necessary to improve the ability of physicians and dietitians to recognize early sarcopenia and its risk factors in patients with T2DM in order to make appropriate therapeutic approaches able to prevent and treat this condition. 相似文献
78.
Dorota Skrzypczak Alicja Ewa Ratajczak Aleksandra Szymczak-Tomczak Agnieszka Dobrowolska Piotr Eder Iwona Krela-Ka
mierczak 《Nutrients》2021,13(2)
Sarcopenia is a disorder characterized by a loss of muscle mass which leads to the reduction of muscle strength and a decrease in the quality and quantity of muscle. It was previously thought that sarcopenia was specific to ageing. However, sarcopenia may affect patients suffering from chronic diseases throughout their entire lives. A decreased mass of muscle and bone is common among patients with inflammatory bowel disease (IBD). Since sarcopenia and osteoporosis are closely linked, they should be diagnosed as mutual consequences of IBD. Additionally, multidirectional treatment of sarcopenia and osteoporosis including nutrition, physical activity, and pharmacotherapy should include both disorders, referred to as osteosarcopenia. 相似文献
79.
Heterogeneities in Consumer Diet Quality and Health Outcomes of Consumers by Store Choice and Income
Obesity and other diet-related health conditions have received much attention in the public health literature over the past two decades. This study investigates the relationship between household food budget shares at different food outlets with diet quality and weight-related health outcomes in the United States. Our analysis used event-level food purchase data from the national household food acquisition and purchases survey (FoodAPS). We find that, after controlling for observables, food purchase location is significantly associated with diet quality and body mass index (BMI). Our findings indicate that larger food budget shares at convenience stores and restaurants are linked with poor diet quality based on the healthy eating index-2015 (HEI-2015) scores and higher BMI. We further explored potential heterogeneity on outcomes of interest across income groups. Results suggest heterogeneous effects may exist across income groups: low-income households, who spent a larger share of their food budget at convenience stores and fast-food restaurants are related to poor diet quality and more likely to be obese. Our findings will help improve understanding of the causes of diet-related health problems and may illuminate potential avenues of intervention to address obesity. 相似文献
80.
Marlene Fabiola Escobedo-Monge María Carmen Torres-Hinojal Enrique Barrado María Antonieta Escobedo-Monge Jos Manuel Marugn-Miguelsanz 《Nutrients》2021,13(4)
Background: Zinc is an essential trace element for the normal growth and development of human beings. The main objective was to evaluate the nutritional status of zinc and its association with nutritional indicators in a series of children with chronic diseases. Methods: The prevalence of patients with dietary zinc deficiency or deficit zinc intake (<80% DRI: dietary reference intake) was analyzed through prospective 72 h dietary surveys, and serum zinc deficiency or hypozincemia (≤70 µg/dL in children under 10 years of age in both sexes and in females older than 10 years and <74 μg/dL in males older than 10 years) was measured through atomic absorption spectrophotometry. The participants were classified according to their nutritional status by body mass index (BMI). Results: Mean serum zinc level in obese (87 µg/dL), undernourished (85 µg/dL), and eutrophic children (88 µg/dL) were normal, but in the undernutrition (60% DRI) and eutrophic (67% DRI) groups the mean dietary zinc intake was low compared to that in the obesity group (81% DRI). There were different associations between nutritional parameters, dietary zinc intake, and serum zinc. All patients with hypozincemia had dietary zinc deficiency. Conclusions: In the whole series, 69% of participants showed a zinc intake lower than recommended and might be at high risk of zinc deficiency. 相似文献