全文获取类型
收费全文 | 8236篇 |
免费 | 492篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 97篇 |
儿科学 | 214篇 |
妇产科学 | 171篇 |
基础医学 | 1185篇 |
口腔科学 | 572篇 |
临床医学 | 636篇 |
内科学 | 1857篇 |
皮肤病学 | 155篇 |
神经病学 | 768篇 |
特种医学 | 128篇 |
外科学 | 838篇 |
综合类 | 32篇 |
一般理论 | 2篇 |
预防医学 | 765篇 |
眼科学 | 114篇 |
药学 | 529篇 |
中国医学 | 55篇 |
肿瘤学 | 647篇 |
出版年
2023年 | 74篇 |
2022年 | 161篇 |
2021年 | 350篇 |
2020年 | 201篇 |
2019年 | 316篇 |
2018年 | 364篇 |
2017年 | 199篇 |
2016年 | 227篇 |
2015年 | 282篇 |
2014年 | 386篇 |
2013年 | 438篇 |
2012年 | 723篇 |
2011年 | 776篇 |
2010年 | 396篇 |
2009年 | 361篇 |
2008年 | 522篇 |
2007年 | 499篇 |
2006年 | 460篇 |
2005年 | 371篇 |
2004年 | 318篇 |
2003年 | 303篇 |
2002年 | 280篇 |
2001年 | 94篇 |
2000年 | 57篇 |
1999年 | 77篇 |
1998年 | 30篇 |
1997年 | 33篇 |
1996年 | 20篇 |
1995年 | 32篇 |
1994年 | 22篇 |
1993年 | 19篇 |
1992年 | 33篇 |
1991年 | 39篇 |
1990年 | 41篇 |
1989年 | 14篇 |
1988年 | 20篇 |
1987年 | 12篇 |
1986年 | 13篇 |
1985年 | 18篇 |
1984年 | 16篇 |
1983年 | 11篇 |
1979年 | 13篇 |
1978年 | 10篇 |
1975年 | 9篇 |
1974年 | 8篇 |
1973年 | 14篇 |
1972年 | 8篇 |
1971年 | 11篇 |
1968年 | 10篇 |
1967年 | 8篇 |
排序方式: 共有8765条查询结果,搜索用时 31 毫秒
1.
Selwyn Arlington Headley Nayara Emily Viana Mariana de Mello Zanim Michelazzo Ana Aparecida Correa Xavier Cícero Júlio Silva Costa Felipe Hideki Ogo de Pinho Marcelo Diniz dos Santos 《Transboundary and Emerging Diseases》2020,67(Z2):49-59
Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish‐eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH‐induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus‐2 (CPV‐2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH‐induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV‐2. 相似文献
2.
3.
Caio Henrique de Carvalho Assuno Júlio Csar Trabanco Raquel Fornaziero Gomes Renata Rodrigues Moreira Alessandra Giannella Samelli 《La Medicina del lavoro》2019,110(4):304
Objective:The present study evaluates a training program for fitting different hearing protection devices (HPDs) based on personal attenuation rating (PAR) before, immediately after, and six months after training.Methods:A total of 67 workers from a public university in the city of São Paulo, Brazil, were invited to participate in the measurement of PARs for foam and silicone protectors through the 3M™ E-A-Rfit Validation System. Two evaluations were performed for each protector at each sampling date: one after reading printed material (the package instructions) and another after being trained by an audiologist. The same procedures were repeated after six months. The final sample consisted of 30 individuals. ANOVA was used for statistical analysis.Results:Larger PAR values were observed after training by the audiologist, and smaller values were observed after six months. Then, after re-training, the values increased again. There were no statistically significant differences in PAR among the HPDs tested. Even after the two training sessions, 23 to 27% of the subjects did not obtain adequate PAR values.Conclusion:These findings emphasize the need for continual worker training in the correct fit of earplug HPDs and the importance of longitudinal PAR monitoring. In addition, some workers, despite the training provided, did not adapt to the HPDs used. Therefore, it is essential that other protection methods and/or other HPD types are made available to these individuals.Key words: Hearing, noise-induced hearing loss, occupational health, personal protective equipment, hearing protection devices 相似文献
4.
5.
Del Lama Rafael Silva Candido Raquel Mariana Chiari-Correia Natália Santana Nogueira-Barbosa Marcello Henrique de Azevedo-Marques Paulo Mazzoncini Tinós Renato 《Journal of digital imaging》2022,35(3):446-458
Journal of Digital Imaging - Vertebral Compression Fracture (VCF) occurs when the vertebral body partially collapses under the action of compressive forces. Non-traumatic VCFs can be secondary to... 相似文献
6.
Samira Marín-Romero Teresa Elías-Hernández María Isabel Asensio-Cruz Rocío Ortega-Rivera Raquel Morillo-Guerrero Javier Toral Emilio Montero Verónica Sánchez Elena Arellano José María Sánchez-Díaz Macarena Real-Domínguez Remedios Otero-Candelera Luis Jara-Palomares 《Archivos de bronconeumología》2019,55(12):619-626
IntroductionScales for predicting venous thromboembolism (VTE) recurrence are useful for deciding the duration of the anticoagulant treatment. Although there are several scales, the most appropriate for our setting has not been identified. For this reason, we aimed to validate the DASH prediction score and the Vienna nomogram at 12 months.MethodsThis was a retrospective study of unselected consecutive VTE patients seen between 2006 and 2014. We compared the ability of the DASH score and the Vienna nomogram to predict recurrences of VTE. The validation was performed by stratifying patients as low-risk or high-risk, according to each scale (discrimination) and comparing the observed recurrence with the expected rate (calibration).ResultsOf 353 patients evaluated, 195 were analyzed, with an average age of 53.5 ± 19 years. There were 21 recurrences in 1 year (10.8%, 95% CI: 6.8%-16%). According to the DASH score, 42% were classified as low risk, and the rate of VTE recurrence in this group was 4.9% (95% CI: 1.3%-12%) vs. the high-risk group that was 15% (95% CI: 9%-23%) (p <.05). According to the Vienna nomogram, 30% were classified as low risk, and the rate of VTE recurrence in the low risk group vs. the high risk group was 4.2% (95% CI:0.5%-14%) vs. 16.2% (95% CI: 9.9%-24.4%) (p <.05).ConclusionsOur study validates the DASH score and the Vienna nomogram in our population. The DASH prediction score may be the most advisable, both because of its simplicity and its ability to identify more low-risk patients than the Vienna nomogram (42% vs. 30%). 相似文献
7.
Objective
The aim of this paper is to study the opportunity costs (OC) that are involved in being a caregiver and to compare them with the direct costs assumed by the State and the families. We evaluate direct cost (those that imply a payment-out-of-pocket) and indirect cost (those that imply a dedication in time). We hypothesized that costs increase with the severity of the dementia, with the educational level and active occupational situation of caregiver. They are greater if the caregiver is male, but if the patient and caregiver cohabit they are reduced.Method
778 surveys were analyzed. Data was collected using a questionnaire specifically designed for the purpose, with the collaboration of Alzheimer's Diseases Associations in Andalusia (Spain). For the indirect cost, we used the reveal preferences method. For the comparison between groups an ANOVA and a MANOVA was done.Results
The hypotheses were confirmed. The OC exponentially increases with severity. More than 55% of costs are assumed by families. Occupied people have higher educational level and incomes and contract more external support. Costs are significantly higher for male caregivers. Cohabiting reduces all kinds of costs.Conclusions
The relationship between educational level and employment situation lead to think that if these variables are greater more people will seek professional support. Cultural reasons still maintain women as main caregivers for all educational levels. The existence of these informal caregivers as the main care providers is a saving for the State, and a brake for the development of professional supply. 相似文献8.
9.
Modena Débora Aparecida Oliveira Miranda Ana Carolina Godoy Grecco Clovis Liebano Richard Eloin Cordeiro Raquel Cristina Tancsik Guidi Renata Michelini 《Lasers in medical science》2020,35(4):797-806
Lasers in Medical Science - Using light sources in phototherapy has presented promising results regarding several types of facial and body skin affections for centuries. The neodymium-doped yttrium... 相似文献
10.