全文获取类型
收费全文 | 9472篇 |
免费 | 863篇 |
国内免费 | 539篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 110篇 |
妇产科学 | 75篇 |
基础医学 | 697篇 |
口腔科学 | 178篇 |
临床医学 | 372篇 |
内科学 | 857篇 |
皮肤病学 | 131篇 |
神经病学 | 198篇 |
特种医学 | 86篇 |
外国民族医学 | 3篇 |
外科学 | 236篇 |
综合类 | 1574篇 |
现状与发展 | 2篇 |
预防医学 | 1021篇 |
眼科学 | 109篇 |
药学 | 2331篇 |
1篇 | |
中国医学 | 2445篇 |
肿瘤学 | 403篇 |
出版年
2024年 | 23篇 |
2023年 | 91篇 |
2022年 | 201篇 |
2021年 | 310篇 |
2020年 | 306篇 |
2019年 | 285篇 |
2018年 | 282篇 |
2017年 | 373篇 |
2016年 | 403篇 |
2015年 | 414篇 |
2014年 | 661篇 |
2013年 | 907篇 |
2012年 | 710篇 |
2011年 | 780篇 |
2010年 | 624篇 |
2009年 | 514篇 |
2008年 | 544篇 |
2007年 | 528篇 |
2006年 | 423篇 |
2005年 | 344篇 |
2004年 | 291篇 |
2003年 | 246篇 |
2002年 | 249篇 |
2001年 | 176篇 |
2000年 | 112篇 |
1999年 | 133篇 |
1998年 | 105篇 |
1997年 | 106篇 |
1996年 | 84篇 |
1995年 | 71篇 |
1994年 | 67篇 |
1993年 | 70篇 |
1992年 | 73篇 |
1991年 | 38篇 |
1990年 | 39篇 |
1989年 | 46篇 |
1988年 | 39篇 |
1987年 | 21篇 |
1986年 | 18篇 |
1985年 | 28篇 |
1984年 | 29篇 |
1983年 | 20篇 |
1982年 | 17篇 |
1981年 | 19篇 |
1980年 | 12篇 |
1979年 | 15篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1974年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
1.
Surgical Smoke and Biological Symptoms in Healthcare Professionals and Patients: A Systematic Review
《Journal of PeriAnesthesia Nursing》2022,37(1):130-136
PurposeThis study aimed to identify the evidence in the scientific literature between exposure to surgical smoke and biological symptoms in healthcare professionals and patients.DesignA systematic review.MethodsElectronic databases were searched, including vivo observational and experimental studies published until August 2020 in Portuguese, English, Spanish and French.FindingsWe identified 13 studies, with a predominance of cross-sectional (6; 46.15%), experimental laboratory (4; 30.76%) and cohort (3; 23.07%) studies. The main manifestations identified were related to respiratory tract and headache. There was identification of histopathological changes in the nasal mucosa of healthcare professionals and the presence of toxic substances from smoke identified in the urine of patients and healthcare professionals.ConclusionThe scientific literature on the biological symptoms of surgical smoke is mainly composed of observational studies with a reduced sample size, thus constituting aspects which limit a broader and long-term understanding of the biological effects of surgical smoke exposure in healthcare professionals and patients. 相似文献
2.
Vasundhara Sridharan Yuichi Shoda Jaimee L. Heffner Jonathan Bricker 《Substance use & misuse》2019,54(7):1086-1095
Background: Lay belief systems about the malleability of human attributes have been shown to impact behavior change in multiple domains. Addiction mindset—i.e., beliefs about the permanence (vs. malleability) of addiction — may affect cigarette smokers’ ability to quit, but this has never been examined. Objectives: The aims of the present research were to develop a measure of addiction mindset (study 1) and examine its associations with various psychological aspects of quitting smoking (study 2). Methods: In Study 1, using factor analysis of current smokers’ and nonsmokers’ (n?=?600) responses to 22 items designed to measure addiction mindset, we developed a reliable six-item Addiction Mindset Scale (AMS). In Study 2, adult smokers (n?=?200) completed the AMS, and measures of a number of psychological processes related to smoking. Results: Higher scores on the AMS, indicative of the belief that addiction is malleable (referred to as a growth mindset), were positively and significantly associated with greater motivation to quit, greater commitment to quitting, greater self-efficacy to abstain, less attribution of failure to lack of ability to change addiction, and fewer self-reported barriers to cessation (all p’s < .05). Conclusions: The results of this study show a relationship between the beliefs about the permanence of addiction and psychological processes relevant to quitting smoking. The findings underscore the potential of future research exploring how addiction mindsets relate to successful smoking cessation as well as other types of addictive behavior and how they can be applied to change people’s behavior. 相似文献
3.
目的:建立UPLC-MS/MS分析方法同时测定玳玳果黄酮降脂提取物效应组分新橙皮苷和柚皮苷在大鼠10种脏器组织中含量,分布规律及特征。方法:采用UPLC-MS/MS技术建立提取物效应组分新橙皮苷及柚皮苷在大鼠心、肝、脾、肺、肾、脑、胃、小肠、脂质、肌肉组织中的定量分析方法;大鼠给药后分别于0.33,0.67,1,4,8 h的5个时间点,分别摘取以上10种脏器组织,测定脏器组织及血液中效应组分的质量浓度,采用DAS(V 2.0)药动学软件对各样本的药物浓度-时间数据进行房室拟合,并计算不同组织效应组分的药-时曲线下面积(AUC)及平均滞留时间(MRT)。结果:所建立的UPLC-MS/MS定量分析方法具备良好的专属性、标准曲线及线性范围良好、方法准确度与精密度、定量下限均符合有关规定;玳玳果黄酮降脂提取物效应组分在血液中的分布符合一室模型,除肾脏及脑组织外,其余脏器中提取物效应组分的房室特征多为静脉注射的二室模型,柚皮苷在肾脏中的拟合结果为非静脉注射的二室模型,新橙皮苷在脑组织拟合结果为静脉注射的三室模型,给药后8 h各组织中效应组分新橙皮苷及柚皮苷AUC值大小顺序均为小肠 > 胃 > 肾 > 脂质 ≈ 脾脏 > 肺 > 肌肉 > 肝 > 心 > 脑,效应组分在各脏器中均无明显蓄积;效应组分在血液、肾脏、肝脏中的滞留时间较长,MRT均大于2 h,脂质最短,MRT不足1 h;各脏器中新橙皮苷的药-时曲线下面积约是柚皮苷的3倍,而心、肝、肾中则是3.5,2.1和3.4倍。结论:玳玳果黄酮降脂提取物效应组分在大鼠组织中分布迅速,达峰时间早于血液;效应组分在肠道内消除缓慢,给药8 h后在各脏器中的含量均显著下降且无特异的蓄积部位。研究结果揭示玳玳果黄酮降脂提取物效应组分在大鼠体内的分布特征及规律,为进一步理解玳玳果黄酮降脂提取物在体内的作用靶点及机制奠定了基础。 相似文献
4.
If cigarette design was exogenous, inefficiencies arising from smoking could be addressed either with a tax per packet or with an ad valorem tax. However, it is well known that the consequences of these two instruments differ when product characteristics are endogenous. We consider three such characteristics: nicotine, tar, and flavor. Implementation of the first‐best social optimum typically requires the capacity to tax or regulate harmful ingredients. Without such a capacity, the next‐best policy often combines a per‐unit tax on cigarettes with an ad valorem subsidy. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
5.
艾灸作为中医学最古老的疗法之一,作用多样,应用广泛,疗效显著。随着科技的发展,人们对灸法的认识逐渐深入,其中艾烟的相关研究也硕果累累,其安全性广受关注。通过对艾烟作用和安全性评价研究中取得的成果进行归纳分析,以期为艾灸临床安全应用提供指导。 相似文献
6.
7.
Seulkee Heo 《International journal of environmental health research》2015,25(3):330-348
In this study, we estimated the disease burdens attributable to environmental tobacco smoke (ETS) exposure in Korean adults in 2010 and analyzed the trend of that from 2005 to 2010. We obtained information on the study population from the 2010 Cause of Death Statistic and estimated the ETS-attributable fraction using data from the Korean Community Health Survey and the Korean National Health and Nutrition Examination Survey. The numbers of ETS-attributable deaths in female and male non-smokers were estimated to be 4.1 and 69.6?% of the numbers of deaths attributable to current smoke, respectively. The deaths attributable to ETS were larger in female than in male non-smokers (710 vs. 420). The ETS-attributable deaths increased slightly in 2005–2008 but decreased in 2009–2010. The number of potential years of life lost from ETS was 9077.24?years in 2010. If there were no exposure to ETS in adult non-smokers, we would expect to see 1130 fewer deaths (9.9?% of the deaths from current smoke). The results suggest that ETS poses considerable disease burdens for non-smokers, especially women, in Korea. 相似文献
8.
9.
Kimberly M. Avallone 《The Journal of asthma》2015,52(5):498-504
Objective: Despite its negative effects, smoking is more common among individuals with asthma compared to those without. Anxiety sensitivity (fear of arousal-related sensations) is associated with both smoking and asthma; however, no research, to date, has examined the interplay between these three factors. Thus, the purpose of the current study was to evaluate the mediating role of anxiety sensitivity in the association between asthma diagnosis and smoking status. Methods: The current study was a secondary analysis of data from three existing datasets of non-smokers and smokers with and without asthma (n?=?433; 56.3% female, Mage?=?34.01 years, SD?=?13.9). Participants provided information on their asthma diagnosis status and smoking status and completed self-report measures. Results: As hypothesized, after controlling for gender, race and age, there was a significant indirect effect of asthma diagnosis on smoking status through anxiety sensitivity (95% CI?=?0.07–0.48). Conclusions: These results indicate that the association between asthma diagnosis and smoking status appears to be driven, in part, by anxiety sensitivity and suggest that anxiety sensitivity may serve as an important target for prevention and intervention efforts for smokers with asthma. 相似文献
10.
The antiproliferative, cytotoxic and apoptogenic activities of Bufo melanostictus (Indian common toad) skin extract (TSE) on U937 and K562 leukemic cell line has been investigated. TSE significantly (P<0.001) reduced the time-dependent cell proliferation and decreased MTT values in U937 and K562 cells. TSE (IC50 doses) suppressed the proliferating cell nuclear antigen expression in both the cells. It was demonstrated that, TSE (IC50 doses) primarily arrested the U937 and K562 cells at G1 phase of the cell cycle. Confocal microscopy showed the altered fragmented nuclei and apoptotic bodies formation in TSE (IC50 doses) treated U937 and K562 cells. Membrane blebbing, cell surface shrinkage and perforation were observed through scanning electron microscope. TSE-induced DNA fragmentation in U937 and K562 cells was reflected in single-cell gel electrophoresis. TSE significantly (P<0.001) increase the length-width ratio of DNA mass as compared to control in comet assay. The flow cytometric analysis of annexin-V binding to the cancer cells further supported the apoptotogenic activity of TSE. The effect of TSE on normal human peripheral blood mononuclear cells viability and cytotoxicity was studied in culture and found to be less cytotoxic than on the U937 and K562 cells. The findings from the present study suggested that TSE might possess potent antineoplastic agent having antiproliferative, cytotoxic and apoptogenic activity against U937 and K562 myeloid leukemic cells. 相似文献