全文获取类型
收费全文 | 17209篇 |
免费 | 1115篇 |
国内免费 | 329篇 |
专业分类
耳鼻咽喉 | 317篇 |
儿科学 | 790篇 |
妇产科学 | 344篇 |
基础医学 | 1905篇 |
口腔科学 | 595篇 |
临床医学 | 1848篇 |
内科学 | 2317篇 |
皮肤病学 | 315篇 |
神经病学 | 553篇 |
特种医学 | 742篇 |
外科学 | 1741篇 |
综合类 | 1774篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 3049篇 |
眼科学 | 212篇 |
药学 | 1407篇 |
9篇 | |
中国医学 | 242篇 |
肿瘤学 | 491篇 |
出版年
2024年 | 20篇 |
2023年 | 249篇 |
2022年 | 348篇 |
2021年 | 1088篇 |
2020年 | 716篇 |
2019年 | 639篇 |
2018年 | 616篇 |
2017年 | 616篇 |
2016年 | 649篇 |
2015年 | 701篇 |
2014年 | 1133篇 |
2013年 | 1360篇 |
2012年 | 1061篇 |
2011年 | 1082篇 |
2010年 | 909篇 |
2009年 | 859篇 |
2008年 | 687篇 |
2007年 | 747篇 |
2006年 | 673篇 |
2005年 | 571篇 |
2004年 | 535篇 |
2003年 | 419篇 |
2002年 | 378篇 |
2001年 | 313篇 |
2000年 | 258篇 |
1999年 | 245篇 |
1998年 | 204篇 |
1997年 | 192篇 |
1996年 | 142篇 |
1995年 | 139篇 |
1994年 | 109篇 |
1993年 | 87篇 |
1992年 | 86篇 |
1991年 | 73篇 |
1990年 | 62篇 |
1989年 | 77篇 |
1988年 | 60篇 |
1987年 | 67篇 |
1986年 | 58篇 |
1985年 | 78篇 |
1984年 | 48篇 |
1983年 | 32篇 |
1982年 | 53篇 |
1981年 | 28篇 |
1980年 | 30篇 |
1979年 | 30篇 |
1978年 | 25篇 |
1977年 | 19篇 |
1976年 | 26篇 |
1975年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的:通过对颈椎病患者上下终板弧形高度、椎间隙高度与椎间隙后骨赘的影像学测量,研究其相关性及其临床应用价值。方法:收集2017年9月至2018年9月颈椎病手术108例患者的临床资料,男48例,年龄30~72岁,平均52岁,女60例,年龄37~79岁,平均54岁。其中C2,3 6例,C3,4 15例,C4,5 32例,C5,6 42例,C6,7 13例。术前及术后摄颈椎X线片,利用PACS(Picture Archiving and Communication Systems)调阅影像,测量椎间隙的下上终板弧形高度(L1,L2),椎间隙高度(L3)及后方骨赘的宽度(L4)。利用Spearman分析它们之间的相关性。结果:L1与L4对比(r=-0.34,P<0.05),L3与L4对比(r=-0.36,P<0.05),存在负相关。L1与L3对比(r=0.38,P<0.05),L2与L3对比(r=0.48,P<0.05),存在正相关。L1与L2对比(P>0.05),L2与L4对比(P>0.05),差异无统计学意义。结论:下终板弧形高度与椎间隙后缘骨赘宽度呈负相关,通过其测量可明确颈椎退变程度,对颈椎病的早期防治有指导意义。 相似文献
2.
Purpose: To describe how central venous access devices (CVADs) are utilized for ambulatory oncology patients and to evaluate the rate of complications. Method: Single institution retrospective study of oncology patients with CVADs who received systemic treatment at the Walker Family Cancer Centre (WFCC) between 1 January and 31 December 2018. Results: A total of 480 CVADS were placed in 305 patients, of which 408 (85%) were peripherally inserted central catheters (PICCs) and 72 (15%) were implanted vascular access devices (PORTs). The incidence of early and late complications was 9% and 24%, respectively. For the entire cohort, the rate of venous thromboembolism (VTE) was 16%, of which 9% were CVAD-related thrombosis (CRTs) and 7% were distant VTE. The CRT rates were similar for PICCs and PORTs (9% vs. 7%). A total of 6% of CVADs were complicated by infection (i.e., localized infections and bacteremia), with a total infection rate of 0.43 and 0.26 per 1000 indwelling days for PICCs and PORTs, respectively. The incidence of central line associated bloodstream infections (CLABSI) was greater for PICCs than PORTs, at a rate of 0.22 compared with 0.08 per 1000 indwelling days, respectively. The premature catheter removal rate was 26% for PICCs and 18% for PORTs. PORTs required more additional hospital visits. Conclusions: PICCs were utilized more frequently than PORTs and had a higher rate of premature removal. The rates of VTE and CRT were similar for both CVAD types. PORTs had a lower rate of infection per 1000 indwelling days. However, the management of PORT related complications required more visits to the hospital and oncology clinic. 相似文献
3.
《Vaccine》2020,38(42):6508-6516
BackgroundPneumococcal conjugate vaccine (PCV) effectiveness against radiographic pneumonia in South Asia is unknown. Bangladesh introduced PCV10 in 2015 using a three dose primary series (3 + 0). We sought to measure PCV10 effectiveness for two or more vaccine doses on radiographic pneumonia among vaccine-eligible children in rural Bangladesh.MethodsWe conducted a matched case-control study over two years from 2015 to 2017 using clinic and community controls in three subdistricts of Sylhet, Bangladesh. Cases were vaccine eligible 3–35 month olds at Upazila Health Complex outpatient clinics with World Health Organization-defined radiographic primary endpoint pneumonia (radiographic pneumonia). Clinic controls were matched to cases within a one week time window by age, sex, and clinic and had an illness unlikely to be Streptococcus pneumoniae; community controls were healthy and similarly matched within a one week time window by age and sex, and distance from the clinic. We estimated adjusted vaccine effectiveness (aVE) using conditional logistic regression.ResultsWe matched 1262 cases with 2707 clinic and 2461 community controls. Overall, aVE using clinic controls was 21.4% (95% confidence interval, −0.2%, 38.4%) for ≥2 PCV10 doses and among 3–11 month olds was 47.3% (10.5%, 69.0%) for three doses. aVE increased with higher numbers of doses in clinic control sets (p = 0.007). In contrast, aVE using community controls was 7.6% (95% confidence interval, −22.2%, 30.0%) for ≥2 doses. We found vaccine introduction in the study area faster and less variable than expected with 75% coverage on average, which reduced power. Information bias may also have affected community controls.ConclusionsClinic control analyses show PCV10 prevented radiographic pneumonia in Bangladesh, especially among younger children receiving three doses. While both analyses were underpowered, community control enrollment – compared to clinic controls – was more difficult in a complex, pluralistic healthcare system. Future studies in comparable settings may consider alternative study designs. 相似文献
4.
《Gaceta sanitaria / S.E.S.P.A.S》2016,30(3):208-214
ObjectiveTo measure incidence and main risk factors related to sexually transmitted infections (STIs) in Daroca Prison (Zaragoza, Spain).MethodA retrospective cohort study (2005-2013) to measure the incidence of STI and a cross-sectional study to measure risk factors.ResultsOf the 203 inmates, 79 developed an STI, 37 had a previous STI, 55.2% lacked knowledge on STI prevention, and 28.9% showed behaviours unfavourable for STI prevention. The incidence rate was 6.5 STIs per 1,000 inmates-year. The most frequent STIs were hepatitis B (39.7%), Ureaplasma urealyticum (19.1%), herpes simplex (16.2%) and HIV (8.8%). The risk (hazard ratio, HR) of acquiring a new STI was significantly higher in inmates with a history of previous STI (HR = 2.61; 95%CI: 1.01 to 6.69), and was at the limit of significance for non-preventive behaviour (HR = 2.10; 95%CI: 0.98 to 4.53), but not in knowledge related to STIs (HR = 1.33; 95%CI: 0.58 to 3.07).ConclusionThe most important risk factors in prison are behaviours related to STIs and previous history of STIs. Other factors are being a repeat offender, injecting drug use, or being in a methadone programme. Health personnel and peer education can facilitate prevention and control. 相似文献
5.
《Anais brasileiros de dermatologia》2021,96(1):85-87
There have been several clinical manifestations associated with SARS-CoV-2 infection since 2019, including dermatological signs and symptoms. In this article, the authors report a case of a previously healthy patient with COVID-19 who was mistakenly diagnosed with dengue fever due to a skin rash. By the time the patient's investigation was initiated, Joinville (Santa Catarina, Brazil) had approximately 5,000 confirmed cases of dengue fever and 1,700 cases of COVID-19 in 2020. Thus, the authors emphasize that in endemic regions such as Brazil, the two diseases must be considered until proven otherwise. Finally, the authors warn of the possibility of co-infection with these two viruses in regions that are facing both epidemics at the same time. 相似文献
6.
7.
《Health & place》2019
The objective of this paper was to assess the link between premature mortality and a combination of neighbourhood contextual (environmental and health) and compositional (socioeconomic and demographic) characteristics. We statistically and spatially examined six environmental variables (ultrafine particles, carcinogenic and non-carcinogenic pollutants, pollution released to air, tree cover, and walkability index), six health service indicators (number health providers, breast, colorectal and cervical cancer screening uptake rates, student nutrition program uptake rates, and healthy food index), and eight socioeconomic indicators (total income, Gini coefficient, two age categories – below and above 40 years, proportion of females to males, visible minorities, Indigenous peoples, education, less than grade 9) among 140 neighbourhoods of the City of Toronto in Ontario (Canada). We applied principal component analysis to identify patterns and to reduce the number of explanatory variables into combined component axes that represent unique variation in these confounded and overlapping factors. We then applied regression analysis to model the relationship between the indices of enviro-health and socioeconomics and their potential relationship with premature mortality. Residual spatial analysis was used to investigate any remaining spatial structure (such as neighbourhoods with higher residual premature mortality rates). Neighbourhood Equity Index was correlated with our enviro-health and socioeconomic indices. Premature mortality within neighbourhoods was predicted by poor cancer screenings, pollution, lack of tree canopy, increased uptake of student nutrition programs and high walkability index. A negative association between premature mortality and pollution was associated low walkability index and presence of visible minorities within neighbourhoods. There was some unexplained residual spatial variation in our model of premature mortality - especially along the shores of Lake Ontario and in neighbourhoods with major highways or road corridors: premature mortality in Toronto neighbourhoods was higher than expected along highway-corridor neighbourhoods and shorelines. Our analysis revealed a significant relationship between neighbourhood contextual features – both environmental and health – and premature mortality, suggesting that these contextual components of neighbourhoods can predict rates of urban premature mortality in Toronto. 相似文献
8.
Microorganisms thrive in well-organized biofilm ecosystems. Biofilm-associated cells typically show increased resistance to antibiotics and contribute significantly to treatment failure. This has prompted investigations aimed at developing advanced and novel antimicrobial approaches that could effectively overcome the shortcomings associated with conventional antibiotic therapy. Studies are ongoing to develop effective curative strategies ranging from the use of peptides, small molecules, nanoparticles to bacteriophages, sonic waves, and light energy targeting various structural and physiological aspects of biofilms. In photodynamic therapy, a light source of a specific wavelength is used to irradiate non-toxic photosensitizers such as tetrapyrroles, synthetic dyes or, naturally occurring compounds to generate reactive oxygen species that can exert a lethal effect on the microbe especially by disrupting the biofilm. The photosensitizer preferentially binds to and accumulates in the microbial cells without causing any damage to the host tissue. Currently, photodynamic therapy is increasingly being used for the treatment of oral caries and dental plaque, chronic wound infections, infected diabetic foot ulcers, cystic fibrosis, chronic sinusitis, implant device-associated infections, etc. This approach is recognized as safe, as it is non-toxic and minimally invasive, making it a reliable, realistic, and promising therapeutic strategy for reducing the microbial burden and biofilm formation in chronic infections. In this review article, we discuss the current and future potential strategies of utilizing photodynamic therapy to extend our ability to impede and eliminate biofilms in various medical conditions. 相似文献
9.
10.
Takahiro Namiki Chika Takano Ryoji Aoki Quang Duy Trinh Ichiro Morioka Satoshi Hayakawa 《Congenital anomalies》2022,62(1):38-41
Congenital rubella syndrome (CRS) results from maternal rubella virus infection in early pregnancy. Abnormal neuroimaging findings have been analyzed in a small number of CRS patients in the past; however, their clinical significance has been poorly addressed. Therefore, we have investigated the neuroimaging findings of 31 patients with CRS from previous studies. The most common finding was parenchymal calcification, which was observed in 18 of 31 patients (58.1%). A multivariable logistic regression model showed that it was associated with psychomotor or mental retardation (p = 0.018), suggesting that parenchymal calcification in CRS could be a prognostic factor. 相似文献