全文获取类型
收费全文 | 8848篇 |
免费 | 531篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 121篇 |
儿科学 | 161篇 |
妇产科学 | 152篇 |
基础医学 | 1110篇 |
口腔科学 | 862篇 |
临床医学 | 686篇 |
内科学 | 1993篇 |
皮肤病学 | 199篇 |
神经病学 | 655篇 |
特种医学 | 251篇 |
外科学 | 903篇 |
综合类 | 23篇 |
一般理论 | 4篇 |
预防医学 | 1004篇 |
眼科学 | 160篇 |
药学 | 684篇 |
中国医学 | 97篇 |
肿瘤学 | 353篇 |
出版年
2023年 | 83篇 |
2022年 | 229篇 |
2021年 | 353篇 |
2020年 | 249篇 |
2019年 | 291篇 |
2018年 | 350篇 |
2017年 | 230篇 |
2016年 | 249篇 |
2015年 | 323篇 |
2014年 | 454篇 |
2013年 | 479篇 |
2012年 | 679篇 |
2011年 | 819篇 |
2010年 | 380篇 |
2009年 | 316篇 |
2008年 | 544篇 |
2007年 | 550篇 |
2006年 | 397篇 |
2005年 | 401篇 |
2004年 | 312篇 |
2003年 | 293篇 |
2002年 | 245篇 |
2001年 | 164篇 |
2000年 | 145篇 |
1999年 | 121篇 |
1998年 | 40篇 |
1997年 | 39篇 |
1996年 | 33篇 |
1995年 | 17篇 |
1994年 | 15篇 |
1993年 | 16篇 |
1992年 | 44篇 |
1991年 | 65篇 |
1990年 | 50篇 |
1989年 | 41篇 |
1988年 | 33篇 |
1987年 | 38篇 |
1986年 | 35篇 |
1985年 | 39篇 |
1984年 | 29篇 |
1983年 | 29篇 |
1982年 | 17篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1979年 | 17篇 |
1978年 | 11篇 |
1973年 | 14篇 |
1970年 | 13篇 |
1968年 | 10篇 |
1966年 | 13篇 |
排序方式: 共有9418条查询结果,搜索用时 15 毫秒
81.
82.
Genetic Analysis of PARK2 and PINK1 Genes in Brazilian Patients with Early-Onset Parkinson's Disease
Karla Cristina Vasconcelos Moura Mário Campos Junior Ana Lúcia Zuma de Rosso Denise Hack Nicaretta Jo?o Santos Pereira Delson José Silva Flávia Lima dos Santos Fabíola da Costa Rodrigues Cíntia Barros Santos-Rebou?as Márcia Mattos Gon?alves Pimentel 《Disease markers》2013,35(3):181-185
Parkinson''s disease is the second most frequent neurodegenerative disorder in the world, affecting 1-2% of individuals over the age of 65. The etiology of Parkinson''s disease is complex, with the involvement of gene-environment interactions. Although it is considered a disease of late manifestation, early-onset forms of parkinsonism contribute to 5–10% of all cases. In the present study, we screened mutations in coding regions of PARK2 and PINK1 genes in 136 unrelated Brazilian patients with early-onset Parkinson''s disease through automatic sequencing. We identified six missense variants in PARK2 gene: one known pathogenic mutation, two variants of uncertain role, and three nonpathogenic changes. No pathogenic mutation was identified in PINK1 gene, only benign polymorphisms. All putative pathogenic variants found in this study were in heterozygous state. Our data show that PARK2 point mutations are more common in Brazilian early-onset Parkinson''s disease patients (2.9%) than PINK1 missense variants (0%), corroborating other studies worldwide. 相似文献
83.
T.C.A. Ferrari M.A.P. Xavier P.V.T. Vidigal N.S. Amaral P.A. Diniz A.P. Resende D.M. Miranda A.C. Faria A.S. Lima L.C. Faria 《Brazilian journal of medical and biological research》2014,47(11):990-994
Estimates of occult hepatitis B virus (HBV) infection prevalence varies among
different studies depending on the prevalence of HBV infection in the study
population and on the sensitivity of the assay used to detect HBV DNA. We
investigated the prevalence of occult HBV infection in cirrhotic patients undergoing
liver transplantation in a Brazilian referral center. Frozen liver samples from 68
adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The
specificity of the amplified HBV sequences was confirmed by direct sequencing of the
amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females
with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed
in three (4.4%) patients. The etiologies of the underlying chronic liver disease in
these cases were alcohol abuse, HBV infection, and cryptogenic cirrhosis. Two of the
patients with cryptic HBV infection also presented hepatocellular carcinoma. Markers
of previous HBV infection were available in two patients with occult HBV infection
and were negative in both. In conclusion, using a sensitive nested polymerase chain
reaction assay to detect HBV DNA in frozen liver tissue, we found a low prevalence of
occult HBV infection in cirrhotic patients undergoing liver transplant, probably due
to the low prevalence of HBV infection in our population. 相似文献
84.
85.
One‐year follow‐up of titanium/zirconium alloy X commercially pure titanium narrow‐diameter implants placed in the molar region of the mandible: a randomized controlled trial
下载免费PDF全文
![点击此处可从《Clinical oral implants research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
86.
Caroline Louise Diniz Pereira Joelma Carvalho Santos Raissa Melo Arruda Milena Lima Rodrigues Eduardo Sampaio Siqueira Roberto Souza Lemos Andrea Dória Batista Ana Lúcia Coutinho Domingues Edmundo Pessoa Lopes 《Ultrasound in medicine & biology》2021,47(5):1235-1243
In patients with Mansoni schistosomiasis, it is fundamental to evaluate the disease morbidity, which is reflected by the severity of periportal fibrosis (PPF) and parameters of portal hypertension, as analyzed by ultrasonography (US). This study aimed to evaluate the morbidity of schistosomiasis by hepatic and splenic point shear-wave elastography (pSWE) and relate this to US parameters. The PPF pattern, the diameter of the portal and splenic veins and the size of the spleen were evaluated by US. Then, liver and spleen pSWEs were assessed in 74 patients using the same equipment. As the PPF pattern progressed, the splenic pSWE values significantly increased. Significant correlations between splenic pSWE, the longitudinal and transverse lengths of the spleen and the diameters of the portal and splenic veins were observed. These findings, however, were not observed through hepatic pSWE. In conclusion, the splenic pSWE has the potential for assessing morbidity in schistosomiasis mansoni. 相似文献
87.
Regina Sordi Octávio Menezes‐de‐Lima Ana M. Della‐Justina Edir Rezende Jamil Assreuy 《International journal of experimental pathology》2013,94(2):144-155
The aim of the present work is to provide a better comprehension of the pneumonia‐induced sepsis model through temporal evaluation of several parameters, and thus identify the main factors that determine mortality in this model. Klebsiella pneumoniae was inoculated intratracheally in anesthetized Swiss male mice. Inflammatory and cardiovascular parameters were evaluated 6, 24 and 48 h after the insult. The results show that severity of infection and the mortality correlated with the amount of bacteria. Six, 24 and 48 h after inoculation, animals presented pathological changes in lungs, increase in cell number in the bronchoalveolar lavage, leukopenia, increase in TNF‐α and IL‐1β levels, hypotension and hyporesponsiveness to vasoconstrictors, the two latter characteristics of severe sepsis and septic shock. Significant numbers of bacteria in spleen and heart homogenates indicated infection spreading. Interestingly, NOS‐2 expression appeared late after bacteria inoculation, whereas levels of NOS‐1 and NOS‐3 were unchanged. The high NOS‐2 expression coincided with an exacerbated NO production in the infection focus and in plasma, as judging by nitrate + nitrite levels. This study shows that K. pneumoniae inoculation induces a systemic inflammatory response and cardiovascular alterations, which endures at least until 48 h. K. pneumoniae‐induced lung infection is a clinically relevant animal model of sepsis and a better understanding of this model may help to increase the knowledge about sepsis pathophysiology. 相似文献
88.
Rosimar Costa Penido Myriam Lima Isaac 《Revista brasileira de otorrinolaringologia (English ed.)》2013,79(4):429-433
Auditory neuropathy spectrum disorder (ANSD) is characterized by impairment of the auditory nerve associated with preservation of outer hair cell function.ObjectiveTo establish the prevalence of ANSD in subjects with sensorineural hearing loss (SNHL).MethodThis retrospective study was carried out between 2010 and 2012 and included the charts of 2,292 individuals with SNHL. Data from otolaryngological and audiological examinations based on pure-tone and speech audiometry, impedance tests, otoacoustic emissions (OAEs), and brainstem auditory evoked potentials (BAEPs) were collected. Inclusion criteria: presence of OAEs and/or cochlear microphonic (CM); absent or altered BAEPs, and normal MRI scans of the brain.ResultsTwenty-seven (1.2%) of the 2,292 subjects with SNHL had ANSD (37% males; 63% females). Mild SNHL was seen in 29.6% of the individuals with ANSD; 55.5% had moderate SNHL; 7.4% had severe SNHL; and 7.5% had profound SNHL. In terms of age, 14.8% were aged between zero and 20 years, 44.1% were 41 to 60 years old, and 7.4% were above the age of 60.ConclusionANSD was seen in 1.2% of the individuals with SNHL included in this study. 相似文献
89.
Fernanda Neves de Carvalho Carolina Toniolo Zenatti Danila Cassia Reis Santana Juliana Maria da Silva Juliane Cristina Oliveira dos As Katia Kisielow dos Anjos Jessica Sigari Cassia de Lima Santos Marcelle Guerra Olivia Pereira Barros Tomaz Cochemore Roberto Camargo Narciso Mario Lucio Baptista Filho 《The Brazilian journal of infectious diseases》2018
90.
Veruska Lima Moura Brasil Mariana Bitu Ramos Pinto Roberta Ferreti Bonan Luiz Paulo Kowalski Danyel Elias da Cruz Perez 《Journal of oral pathology & medicine》2018,47(7):641-651
Humans may be exposed to pesticides such as fungicides, herbicides, and insecticides, during occupational and non‐occupational activities. Pesticides could be related to cancer development mainly because of their effects on the endocrine and immune systems and their cumulative effect. The present review evaluated in current literature evidence of an association between exposure to pesticides and the occurrence of head and neck cancer (HNC). A literature search for cohort studies was conducted in the PubMed, Web of science, and Cochrane databases. Methodological quality of each study was rated with the Scottish Intercollegiate Guidelines Network (SIGN) checklist. One thousand one hundred and thirty‐two studies were identified. Thirty‐two were included. Most of the studies found addressed occupational exposure to pesticides and were conducted in Europe and North America. Eleven high‐quality studies were found. Most of them found no association between exposure to pesticides and increased risk of HNC. Two studies found some evidence of a positive association between pesticide (malathion and atrazine) exposure and thyroid cancer. The literature review does not support a clear evidence for association between pesticides exposure and HNC. Only limited evidence points to a positive association between exposure to some pesticides and thyroid cancer. Further standardized studies based on appropriate designs are required to clarify the effect of pesticides on the genesis of HNC, considering dose, length of exposure, and type of pesticide. 相似文献