全文获取类型
收费全文 | 50795篇 |
免费 | 4350篇 |
国内免费 | 1483篇 |
专业分类
耳鼻咽喉 | 130篇 |
儿科学 | 698篇 |
妇产科学 | 1022篇 |
基础医学 | 7356篇 |
口腔科学 | 1350篇 |
临床医学 | 6163篇 |
内科学 | 6281篇 |
皮肤病学 | 409篇 |
神经病学 | 6803篇 |
特种医学 | 1126篇 |
外科学 | 4891篇 |
综合类 | 6018篇 |
一般理论 | 1篇 |
预防医学 | 4233篇 |
眼科学 | 518篇 |
药学 | 6524篇 |
29篇 | |
中国医学 | 2032篇 |
肿瘤学 | 1044篇 |
出版年
2024年 | 57篇 |
2023年 | 905篇 |
2022年 | 1222篇 |
2021年 | 2125篇 |
2020年 | 2353篇 |
2019年 | 1870篇 |
2018年 | 1775篇 |
2017年 | 2115篇 |
2016年 | 2161篇 |
2015年 | 2106篇 |
2014年 | 3648篇 |
2013年 | 4678篇 |
2012年 | 3221篇 |
2011年 | 3579篇 |
2010年 | 2817篇 |
2009年 | 2798篇 |
2008年 | 2853篇 |
2007年 | 2438篇 |
2006年 | 2178篇 |
2005年 | 1647篇 |
2004年 | 1504篇 |
2003年 | 1324篇 |
2002年 | 1009篇 |
2001年 | 882篇 |
2000年 | 716篇 |
1999年 | 548篇 |
1998年 | 482篇 |
1997年 | 420篇 |
1996年 | 355篇 |
1995年 | 296篇 |
1994年 | 278篇 |
1993年 | 215篇 |
1992年 | 240篇 |
1991年 | 207篇 |
1990年 | 208篇 |
1989年 | 184篇 |
1988年 | 154篇 |
1987年 | 122篇 |
1986年 | 122篇 |
1985年 | 154篇 |
1984年 | 130篇 |
1983年 | 77篇 |
1982年 | 87篇 |
1981年 | 70篇 |
1980年 | 65篇 |
1979年 | 63篇 |
1978年 | 46篇 |
1977年 | 32篇 |
1976年 | 30篇 |
1973年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Tebuconazole is a systemic follicular fungicide known to cause diverse problems in non-target organisms namely associated to the pure active ingredient. As such, the objective of this work was to evaluate developmental changes induced by a tebuconazole commercial formulation to a non-target animal model. Zebrafish embryos at ± 2 h post-fertilization were exposed to tebuconazole wettable powder concentrations (0.05, 0.5 and 5 mg L-1) for 96 h with developmental toxicity assessed throughout the exposure period and biochemical parameters evaluated at the end of the exposure. Behavioural assessment (spatial exploration and response to stimuli) was conducted 24 h after the end of the exposure. While no developmental and physiological alterations were observed, exposure to tebuconazole resulted in an increased generation of reactive oxidative species at the 0.05 and 0.5 mg L-1 concentrations and a decreased GPx activity at the 0.5 mg L-1 concentration suggesting a potential protection mechanism. There was also a change in the avoidance-escape behaviour supporting an anxiolytic effect suggesting possible alterations in the central nervous system development demanding further studies. 相似文献
2.
Microbeads and fragments have been widely studied, while glitter remains neglected by the literature although found in a variety product (e.g., body paints, nail polish, cosmetics, craft products). The main aim of this study was to assess the effects of different types and concentrations of glitter particles on Mytilus galloprovincialis after 7 days of exposure. The experiment was divided into a preliminary test and a confirmatory test. Our findings support the hypothesis for a link between concentration and type of glitter particles, percentage of recovery and oxidative stress in M. galloprovincialis. There was a significant correlation between particle length and percentage of particles recovered in water, suggesting that the digestive tract of M. galloprovincialis retains smaller particles more. In addition, we noted an increase in antioxidant defense induced by smaller particles. Moreover, certain types of glitter crumbled and shortened in length, resulting in higher levels of oxidative stress biomarkers. Finally, the star-shaped glitter particles had a different effect on oxidative stress biomarkers. Further studies are needed to clarify the toxic effects of glitter on aquatic organisms and to quantify its proportion to other microplastics in the environment. 相似文献
3.
目的探讨对前列腺癌患者采用一体化管理老年综合评估(CGA)护理模式对其心理因素和生活质量的影响。方法选取2020年3月至2021年3月在南京市第一医院就诊,确诊为前列腺癌,且首次行腹腔镜下前列腺癌根治术的患者96例,随机分为对照组、观察1组、观察2组,各32例。对照组为住院后采用常规护理模式进行护理,观察1组为入院后行CGA干预组,观察2组为一体化管理的CGA干预组。三组患者分别在干预前、出院时,进行焦虑自评量表(SAS)、抑郁自评量表(SDS)测评;在干预前、术后30 d,进行生活质量核心量表QLQ-C30(V3.0)和前列腺癌特异性补充量表QLQ-PR25测评。结果出院时,观察2组SAS、SDS评分显著优于对照组及观察1组(P<0.05);术后30 d,观察2组生活质量QLQ-C30、QLQ-PR25评分显著优于对照组及观察1组(P<0.05)。结论一体化管理CGA护理模式可有效改善前列腺癌患者的心理状态,提高其术后生活质量。 相似文献
4.
5.
6.
《The Journal for Nurse Practitioners》2022,18(2):245-247
Transient stress hyperglycemia in the setting of acute myocardial infarction is a frequent phenomenon. Its transient nature should not dissuade the clinician from management of elevated blood glucose in a patient after an ST-elevation myocardial infarction. This case presents an adult patient after an ST-elevation myocardial infarction with transient stress hyperglycemia and the evidence used to identify optimal pharmacologic management and secondary prevention. 相似文献
7.
8.
《Saudi Pharmaceutical Journal》2022,30(11):1572-1588
Non-alcoholic fatty liver disease (NAFLD) is one of the most common complications of a metabolic syndrome caused by excessive accumulation of fat in the liver. Orthosiphon stamineus also known as Orthosiphon aristatus is a medicinal plant with possible potential beneficial effects on various metabolic disorders. This study aims to investigate the in vitro inhibitory effects of O. stamineus on hepatic fat accumulation and to further use the computational systems pharmacology approach to identify the pharmacokinetic properties of the bioactive compounds of O. stamineus and to predict their molecular mechanisms against NAFLD. Methods: The effects of an ethanolic extract of O. stamineus leaves on cytotoxicity, fat accumulation and antioxidant activity were assessed using HepG2 cells. The bioactive compounds of O. stamineus were identified using LC/MS and two bioinformatics databases, namely the Traditional Chinese Medicine Integrated Database (TCMID) and the Bioinformatics Analysis Tool for the Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM). Pathway enrichment analysis was performed on the predicted targets of the bioactive compounds to provide a systematic overview of the molecular mechanism of action, while molecular docking was used to validate the predicted targets. Results: A total of 27 bioactive compounds corresponding to 50 potential NAFLD-related targets were identified. O. stamineus exerts its anti-NAFLD effects by modulating a variety of cellular processes, including oxidative stress, mitochondrial β-oxidation, inflammatory signalling pathways, insulin signalling, and fatty acid homeostasis pathways. O. stamineus is significantly targeting many oxidative stress regulators, including JNK, mammalian target of rapamycin (mTOR), NFKB1, PPAR, and AKT1. Molecular docking analysis confirmed the expected high affinity for the potential targets, while the in vitro assay indicates the ability of O. stamineus to inhibit hepatic fat accumulation. Conclusion: Using the computational systems pharmacology approach, the potentially beneficial effect of O. stamineus in NAFLD was indicated through the combination of multiple compounds, multiple targets, and multicellular components. 相似文献
9.
10.
《Health & place》2022
Low-income communities and communities of color face multiple, cumulative environmental and social burdens. Methods development in environmental justice research has largely focused on spatial and quantitative approaches. Less attention has been paid to developing methodologies that help collect information on everyday stressors and quality of life experiences for residents in overburdened communities. Mixed methods approaches can be one way to structure study designs that help consider how residents experience environmental and socioeconomic impacts in a localized community context. In neighborhoods burdened by cumulative stressors, traditional cross-sectional epidemiological research designs can also be challenging, as well as limited or narrow in their application. However, repeat sampling of measures within a vulnerable population can approach a quasi-experimental design and help consider variations within residents in a single neighborhood as well as better parse relationships between exposures and outcomes. Through a community-academic partnership with university partners, local community partners, and a local promotores de salud (community health workers) network, we pilot tested a novel mobile daily diary approach in both English and Spanish in an urban, predominantly immigrant community in South Los Angeles as a potential method to collect information on daily stress, environmental quality, and health status/symptoms. We collected resident responses via a once per day 7-day SMS/text messaging survey. We sought to gather granular data on daily resident experiences of air pollution and environmental hazards. Residents reported acute health symptoms and stressors, with repeat measures demonstrating how residents might rank, categorize, or cope with stressors. We find that residents in environmental justice communities record variation in their daily diary responses and document changes in environmental quality, stressors, and odors. Refining this type of method could enable a more rigorous examination of co-occurrences of environmental quality and acute health symptoms. This approach supports the inclusion of residents in the research process and helps more systematically integrate open-ended environmental health relevant data in environmental justice efforts. Used with measured data such as air monitoring or health measures, mixed methods generated data can help support efforts that aim to alleviate sources of daily stress, alongside efforts to reduce overall pollution burdens. Mobile daily diaries can be one way to capture variable responses to environmental quality, acute health symptoms, and stressors. 相似文献