全文获取类型
收费全文 | 5749篇 |
免费 | 388篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 89篇 |
妇产科学 | 48篇 |
基础医学 | 620篇 |
口腔科学 | 42篇 |
临床医学 | 284篇 |
内科学 | 572篇 |
皮肤病学 | 53篇 |
神经病学 | 208篇 |
特种医学 | 74篇 |
外科学 | 162篇 |
综合类 | 654篇 |
预防医学 | 2462篇 |
眼科学 | 31篇 |
药学 | 484篇 |
7篇 | |
中国医学 | 253篇 |
肿瘤学 | 179篇 |
出版年
2024年 | 3篇 |
2023年 | 63篇 |
2022年 | 89篇 |
2021年 | 188篇 |
2020年 | 189篇 |
2019年 | 158篇 |
2018年 | 151篇 |
2017年 | 181篇 |
2016年 | 196篇 |
2015年 | 186篇 |
2014年 | 274篇 |
2013年 | 473篇 |
2012年 | 302篇 |
2011年 | 381篇 |
2010年 | 280篇 |
2009年 | 284篇 |
2008年 | 311篇 |
2007年 | 344篇 |
2006年 | 285篇 |
2005年 | 217篇 |
2004年 | 175篇 |
2003年 | 205篇 |
2002年 | 129篇 |
2001年 | 114篇 |
2000年 | 107篇 |
1999年 | 89篇 |
1998年 | 54篇 |
1997年 | 63篇 |
1996年 | 52篇 |
1995年 | 55篇 |
1994年 | 78篇 |
1993年 | 62篇 |
1992年 | 72篇 |
1991年 | 55篇 |
1990年 | 40篇 |
1989年 | 26篇 |
1988年 | 29篇 |
1987年 | 36篇 |
1986年 | 22篇 |
1985年 | 26篇 |
1984年 | 37篇 |
1983年 | 23篇 |
1982年 | 32篇 |
1981年 | 19篇 |
1980年 | 18篇 |
1979年 | 23篇 |
1978年 | 16篇 |
1977年 | 14篇 |
1976年 | 10篇 |
1971年 | 2篇 |
排序方式: 共有6246条查询结果,搜索用时 15 毫秒
1.
2.
目的:通过文献探析中医治疗多囊卵巢综合征(PCOS)的证型分布及临床用药规律。方法:检索2003年至2018年1月1日中国期刊全文数据库(CNKI)、万方、维普3个中文数据库中相关中医治疗PCOS的临床研究文献,建立中医治疗PCOS的整体证型及临床用药数据库,并对数据进行处理、分析。结果:①共纳入符合标准的文献252篇,方剂284首;②涉及证型共37种,其中常见证型为肾虚血瘀证、痰湿证、肾虚痰瘀证,共占43.31%;③涉及病位要素以肾为主,其次为肝、脾;涉及病性要素以血瘀、痰、湿为主;④涉及药物193味,按功效共分为16类,补虚药占41.44%,活血化瘀药占16.20%,化痰祛湿药占14.90%;⑤中医治疗PCOS药性以温、平为主,药味以甘为主,辛、苦次之。结论:PCOS病因病机复杂,以肾虚为本,血瘀、痰湿为标,治疗以补肾活血、化湿祛痰为主。 相似文献
3.
Li Bai Saeha Shin Richard T. Burnett Jeffrey C. Kwong Perry Hystad Aaron van Donkelaar Mark S. Goldberg Eric Lavigne Scott Weichenthal Randall V. Martin Ray Copes Alexander Kopp Hong Chen 《International journal of cancer. Journal international du cancer》2020,146(9):2450-2459
Lung and female breast cancers are highly prevalent worldwide. Although the association between exposure to ambient fine particulate matter (PM2.5) and lung cancer has been recognized, there is less evidence for associations with other common air pollutants such as nitrogen dioxide (NO2) and ozone (O3). Even less is known about potential associations between these pollutants and breast cancer. We conducted a population-based cohort study to investigate the associations of chronic exposure to PM2.5, NO2, O3 and redox-weighted average of NO2 and O3 (Ox) with incident lung and breast cancer, using the Ontario Population Health and Environment Cohort (ONPHEC), which includes all long-term residents aged 35–85 years who lived in Ontario, Canada, 2001–2015. Incident lung and breast cancers were ascertained using the Ontario Cancer Registry. Annual estimates of exposures were assigned to the residential postal codes of subjects for each year during follow-up. We used Cox proportional-hazards models adjusting for personal- and neighborhood-level covariates. Our cohorts for lung and breast cancer analyses included ~4.9 million individuals and ~2.5 million women, respectively. During follow-up, 100,146 incident cases of lung cancer and 91,146 incident cases of breast cancer were diagnosed. The fully adjusted analyses showed positive associations of lung cancer incidence with PM2.5 (hazard ratio [HR] = 1.02 [95% CI: 1.01–1.05] per 5.3 μg/m3) and NO2 (HR = 1.05 [95% CI: 1.03–1.07] per 14 ppb). No associations with lung cancer were observed for O3 or Ox. Relationships between PM2.5 and NO2 with lung cancer exhibited a sublinear shape. We did not find compelling evidence linking air pollution to breast cancer. 相似文献
4.
Seulbi Lee Hyesook Park Soontae Kim Eun-Kyung Lee Jiyoung Lee Young Sun Hong Eunhee Ha 《International journal of hygiene and environmental health》2019,222(3):533-540
Background
It has been reported that particulate matter (PM) is associated with cardiovascular diseases (CVD) while metabolic syndrome is also an important risk factor for CVD. However, few studies have investigated the epidemiological association between PM and metabolic syndrome.Objective
To investigate the association between one-year exposure to PM with an aerodynamic diameter <2.5?μm (PM2.5) and the risk of metabolic syndrome in Korean adults without CVD.Methods
Exposure to PM2.5 was assessed using a Community Multiscale Air Quality (CMAQ) model. Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III. Andersen and Gill model with time-varying covariates, considering recurrent events, was used to investigate the association between one-year average PM2.5 and the risk of incident metabolic syndrome in 119,998 adults from the national health screening cohort provided by Korea National Health Insurance from 2009 to 2013.Results
Higher risk of metabolic syndrome, waist-based obesity, hypertension, hypertriglyceridemia, low HDL cholesterol, and hyperglycemia were significantly associated with a 10-μg/m3 increase in PM2.5 [adjusted hazard ratio (HR): 1.070, 1.510, 1.499, 1.468, 1.627 and 1.380, respectively]. In addition, the risk of metabolic syndrome associated with PM2.5 exposure was significant in the consistently obese group (obese at baseline and endpoint).Conclusion
Exposure to one-year average PM2.5 is associated with an increased risk of metabolic syndrome and its components in adults without CVD. These associations are particularly prominent in the consistently obese group (obese at baseline and endpoint). Our findings indicate that PM2.5 affects the onset of MS and its components which may lead to increase the risk of CVD. 相似文献5.
Chien-Hua Tseng Ben-Jei Tsuang Chun-Ju Chiang Kai-Chen Ku Jeng-Sen Tseng Tsung-Ying Yang Kuo-Hsuan Hsu Kun-Chieh Chen Sung-Liang Yu Wen-Chung Lee Tsang-Wu Liu Chang-Chuan Chan Gee-Chen Chang 《Journal of thoracic oncology》2019,14(5):784-792
Introduction
For never-smokers (smoked <100 lifetime cigarettes), lung cancer (LC) has emerged as an important issue. We aimed to investigate the effects of prevalence changes in tobacco smoking and particulate matter (PM) 2.5 (PM2.5) levels on LC in Taiwan, in relation to contrasting PM2.5 levels, between Northern Taiwan (NT) and Southern Taiwan (ST).Methods
We reviewed 371,084 patients with LC to assess smoking prevalence and correlations between the incidence of adenocarcinoma lung cancer (AdLC) and non-AdLC. Two subsets were selected to assess different AdLC stage trends and the effect of PM2.5 on survival of patients with AdLC.Results
From 1995 to 2015, the proportion of male adult ever-smokers decreased from 59.4% to 29.9% whereas the female smoking rate remained low (3.2% to 5.3%). AdLC incidence in males and females increased from 9.06 to 23.25 and 7.05 to 24.22 per 100,000 population, respectively. Since 1993, atmospheric visibility in NT improved (from 7.6 to 11.5 km), but deteriorated in ST (from 16.3 to 4.2 km). The annual percent change in AdLC stages IB to IV was 0.3% since 2009 (95% confidence interval [CI]: -1.9%–2.6%) in NT, and 4.6% since 2007 (95% CI: 3.3%–5.8%) in ST; 53% patients with LC had never smoked. Five-year survival rates for never-smokers, those with EGFR wild-type genes, and female patients with AdLC were 12.6% in NT and 4.5% in ST (hazard ratio: 0.79, 95% CI: 0.70–0.90).Conclusions
In Taiwan, greater than 50% of patients with LC had never smoked. PM2.5 level changes can affect AdLC incidence and patient survival. 相似文献6.
Kristina Shkirkova Krista Lamorie-Foote Michelle Connor Arati Patel Giuseppe Barisano Hans Baertsch 《Journal of toxicology and environmental health. Part B, Critical reviews》2020,23(7):319-350
ABSTRACT Fine and ultra-fine particulate matter (PM) are major constituents of urban air pollution and recognized risk factors for cardiovascular diseases. This review examined the effects of PM exposure on vascular tissue. Specific mechanisms by which PM affects the vasculature include inflammation, oxidative stress, actions on vascular tone and vasomotor responses, as well as atherosclerotic plaque formation. Further, there appears to be a greater PM exposure effect on susceptible individuals with pre-existing cardiovascular conditions. 相似文献
7.
J. Shin J. Choi K.J. Kim 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(2):144-151
Background and aim
The associations of long-term exposure to particulate matter <10 μm in size (PM10), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), and ozone (O3) with cardiometabolic diseases (CMD) remain uncertain in the Korean population. Therefore, we sought to examine the associations between PM10, NO2, CO, SO2, and O3 and CMD using data collected from the Korean Community Health Survey.Methods and results
We selected 100,867 adults aged 19 years or older who had lived in the same domicile for ≥10 years and surveyed them to collect data on socioeconomic characteristics; health-related behaviors; obesity; and physician-diagnosed CMD history, including hypertension, diabetes mellitus, dyslipidemia, stroke, myocardial infarction, and ischemic heart disease. We calculated interquartile ranges for PM10, NO2, CO, SO2, and O3 from the 10 year average concentrations (2003–2012). Hypertension, diabetes mellitus, and dyslipidemia were positively associated with PM10, NO2, CO, SO2, and O3 after adjusting for confounding factors. Obesity was positively associated with PM10, NO2, SO2, and O3. On the other hand, we found no associations between stroke, myocardial infarction, and ischemic heart disease and exposure to PM10, NO2, CO, SO2, and O3 in these subjects. In subjects aged ≥65 years, the risk of dyslipidemia was markedly increased under exposure to NO2 and CO compared to subjects aged <65 years. The risk of obesity was also significantly increased under exposure to PM10 and NO2. However, sex differences in these associations were not found.Conclusion
Long-term exposure to PM10, NO2, CO, SO2, and O3 may be a risk factor of CMD in Korean adults. 相似文献8.
Skin surface is constantly exposed to environmental and secreted stressors such as UV, air pollution and peroxidized sebum. The current study aims to use reconstructed human skin equivalents to demonstrate topical stressor‐induced hyperpigmentation and evaluate bioactives’ potential protective effect. Given that polycyclic aromatic hydrocarbons are representative airborne particle‐bound organic compounds with known relevance to pigmentation pathways, benzo(a)pyrene was selected as surrogate environmental toxin. On the other hand, squalene monohydroperoxides are well‐characterized sebum peroxidation product under UV and pollutant exposure, thus are used as another representative skin stressor. With 3‐day continuous exposure, 30 pmol/cm2 of benzo(a)pyrene and 3.4 nmol/cm2 of squalene monohydroperoxides induced significant viability loss, inflammatory response, and approximately 10 shades of pigmentation increase in pigmented living skin equivalents. At the same time, pretreatment and co‐treatment with 12‐hydroxystearic acid (12‐HSA, 20 μmol/L) or niacinamide (5 mmol/L) ameliorated such stressor‐induced consequences. Niacinamide was particularly effective against benzo(a)pyrene damage, probably as a substrate for important NAD+ dependent detoxification pathways, while 12‐HSA was potent against squalene monohydroperoxides through barrier enhancing, anti‐inflammatory, and anti‐oxidative mechanisms. In summary, topical stressor‐induced hyperpigmentation was achieved in vitro, with known bioactives showing protective benefits. 相似文献
9.
新型冠状病毒肺炎属于中医学“疫病”范畴。疫情爆发以来,全国各省市卫生行政管理部门坚持中西医结合原则,陆续制定了各省市的中医药防治方案,三因制宜,分期分型辨证并不断完善。笔者全面收集并整理相关信息,基于病因病机分析了各省市中医药防治方案,认为此次疫病是外感疫气,病位主要在肺卫,病邪主要表现为“毒、湿、热、虚、寒”。此“毒”即为疫气,武汉遇暖冬,非其时而有其气而发疫,一气一病,播散流行,治疫必先治毒;“湿”邪之地在南北方各占一半,东西部均有,在南方源于季节和地域,在北方可由寒挟杂,治疗均应祛湿;“热”主要见于南方,为南方常见的病邪,亦可因湿毒入里,湿郁化热,而在北方热与湿同现,主要是因湿毒入里,湿郁化热,治热均以清为主;“虚”则主要在北方,北方冬季多寒,易伤正致虚,或邪正交争激烈,伤阳伤阴致虚,宜祛邪为标,扶正为本;“寒”见于北方和南方山区,寒气过甚,易伤阳伤正,故尤其要注重预防,且以补正气为主。中医防疫治疫应三因制宜,重视预防,与时俱进。 相似文献
10.
A growing body of evidence suggests that ambient air pollution could be associated with low birthweight (LBW). In this study, we examined pregnancy exposure to ambient PM2.5 and the risk of LBW in the State of Georgia. The study population consisted of 48,172 full-term live births between 1 January 2004 and 31 December 2004 in nine counties of Georgia, which was obtained from the national natality dataset. County-level air quality index data obtained from the U.S. Environmental Protection Agency was used to estimate exposure to ambient levels of PM2.5. Multivariate logistic regression revealed that infants with maternal exposure to PM2.5 falling within 75 to < 95th percentiles were at increased risk of LBW (OR: 1.36; 95 % CI: 1.03, 1.79), after adjusting for potential confounders. This study provided more evidence on the role of PM2.5 in LBW. Reducing exposure for pregnant women would be necessary to improve the health of infants. 相似文献