全文获取类型
收费全文 | 718篇 |
免费 | 38篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 9篇 |
妇产科学 | 12篇 |
基础医学 | 111篇 |
口腔科学 | 77篇 |
临床医学 | 54篇 |
内科学 | 136篇 |
皮肤病学 | 22篇 |
神经病学 | 80篇 |
特种医学 | 13篇 |
外科学 | 88篇 |
综合类 | 2篇 |
预防医学 | 44篇 |
眼科学 | 8篇 |
药学 | 53篇 |
中国医学 | 7篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 19篇 |
2021年 | 28篇 |
2020年 | 18篇 |
2019年 | 14篇 |
2018年 | 33篇 |
2017年 | 18篇 |
2016年 | 16篇 |
2015年 | 32篇 |
2014年 | 26篇 |
2013年 | 37篇 |
2012年 | 67篇 |
2011年 | 72篇 |
2010年 | 41篇 |
2009年 | 45篇 |
2008年 | 40篇 |
2007年 | 40篇 |
2006年 | 27篇 |
2005年 | 29篇 |
2004年 | 26篇 |
2003年 | 28篇 |
2002年 | 23篇 |
2001年 | 15篇 |
2000年 | 14篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 5篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1973年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有757条查询结果,搜索用时 15 毫秒
1.
2.
3.
Lima JO dos Santos JK Pereira JF de Resende ML de Araújo EF de Queiroz MV 《Current genetics》2003,42(4):236-240
Protoplasts of the pathogenic plant fungus, Crinipellis perniciosa, were transformed to hygromycin B resistance using the pAN7-1 plasmid, which contains the Escherichia coli hph gene under the control of Aspergillus nidulans regulatory sequences. The pAN7-1 plasmid was introduced by PEG/CaCl(2) treatment. Transformation frequencies of 1.6-2.5 transformants/microg of DNA were achieved. About 54% of the transformants were abortive and 40 analyzed transformants were mitotically stable and showed different hygromycin B resistance levels. The presence of the hph gene was checked by PCR in five transformants and the integration of multiple plasmid copies into different genome sites was observed by Southern analysis. This is the first report of a C. perniciosa transformation system and represents an important step for further research into genetic manipulation of this fungal plant pathogen. 相似文献
4.
Sputum Cytokine Levels in Patients with Pulmonary Tuberculosis as Early Markers of Mycobacterial Clearance 下载免费PDF全文
Rodrigo Ribeiro-Rodrigues Tatiana Resende Co John L. Johnson Fabiola Ribeiro Moises Palaci Ricardo T. S Ethel L. Maciel Fausto E. Pereira Lima Valderio Dettoni Zahra Toossi W. Henry Boom Reynaldo Dietze Jerrold J. Ellner Christina S. Hirsch 《Clinical and Vaccine Immunology : CVI》2002,9(4):818-823
Sputum and serum from patients with active pulmonary tuberculosis (TB), healthy purified protein derivative-positive adults, and patients with bacterial pneumonia were collected to simultaneously assess local immunity in the lungs and peripheral blood. To determine whether cytokine profiles in sputum from TB patients and control subjects were a reflection of its cellular composition, cytospin slides were prepared in parallel and assessed for the presence of relative proportions of epithelial cells, neutrophils, macrophages, and T cells. Gamma interferon (IFN-γ) in sputum from TB patients was markedly elevated over levels for both control groups. With anti-TB therapy, IFN-γ levels in sputum from TB patients decreased rapidly and by week 4 of treatment were comparable to those in sputum from controls. Further, IFN-γ levels in sputum closely followed mycobacterial clearance. Although detected at fourfold-lower levels, IFN-γ immunoreactivities in serum followed kinetics in sputum. TNF-α, interleukin 8 (IL-8) and IL-6 also were readily detected in sputum from TB patients at baseline and responded to anti-TB therapy. In contrast to IFN-γ, however, TNF-α and IL-8 levels also were elevated in sputum from pneumonia controls. These data indicate that sputum cytokines correlate with disease activity during active TB of the lung and may serve as potential early markers for sputum conversion and response to anti-TB therapy. 相似文献
5.
Resende JG 《Jornal de pediatria》1994,70(6):354-358
We developed a new device for respiratory revival in order to do it better than by using the auto inflating reanimation purse, which is common in this emergency situation. This is a portable equipment, handly operated, that controls a continuous flow of gas with until 100% of oxygen, that permits to define both peak inspiratory pressure and positive end expiratory pressure. Both inspiratory and expiratory time can be controlled by the operator during the revive process. All process can be effected using endotracheal tube or mask. 相似文献
6.
The results of a research project into the level of satisfaction/dissatisfaction of 158 first-time patients attending by an University hospital, Brazil, are presented. The interviews were carried out by first year medical students as part of a comprehensive project concerned with the restructuring of the Medical Curriculum. Its prime objective was to expose the students to patients/consumers as early as possible in their studies. After an introductory training program, the students asked the patients arriving at the hospital out-patient clinic for permission to observe them throughout the attendance given. A questionnaire was used which covered the various aspects of the consumers relationship with a medical institution (socio-economic variables, "art of care", outcome of the medical encounter and suggestions for improvement). Both patients and students were able to perceive the different problems that patients confront in the course of their dealings with a medical institution (reception, registration, nursing, social service and medical attention). The data showed a difference of opinion between students and patients regarding several aspects of the satisfaction/dissatisfaction items, partly because of their different social class status and party due to the different expectations regarding medical care. 相似文献
7.
Socorro Vanesca Frota Madeira Angela de Castro Resende Dayane Teixeira Ognibene Marcelo Augusto Vieira de Sousa Roberto Soares de Moura 《Pharmacological research》2005,52(4):321-327
An alcohol-free grape-skin extract (GSE) obtained from skins of Vitis labrusca has significant anti-hypertensive, antioxidant and vasodilator effects. According to our previous results, the vasodilator effect of GSE in the isolated mesenteric vascular bed (MVB) of the rat is dependent on endothelium and partially dependent on nitric oxide (NO). In the MVB of the rat pre-contracted with norepinephrine (NE), bolus injections of GSE induced a long-lasting dose-dependent vasodilation that is significantly reduced after the treatment with 1H-[1,2,3] oxadiazolo [4,4-a] quinoxalin-1-one (ODQ). Additionally, in vessels pre-contracted with norepinephrine and depolarized with KCl (25 mM) or treated with Ca(2+)-dependent K(+)-channel blockers charybdotoxin (ChTx) plus apamin, the vasodilator effect of GSE was significantly reduced and almost abolished by ChTx plus apamin plus L-NAME. However, the vasodilator effect of GSE was unaffected by D-Arg[Hyp(3),Thi(5),D-Tic(7),Oic(8)]bradykinin (HOE-140), atropine, yohimbine, pyrilamine and 4-aminopyridine (4-AP). The vasoconstriction response elicited by bolus injection of KCl was not affected by GSE, whereas the vasoconstrictor response induced by NE was dose-dependently and completed inhibited by GSE in the presence but not in the absence of endothelium. However, NE-induced vasoconstriction in calcium-free condition or without endothelium was not reduced by GSE. The present results demonstrate that GSE induces a vasodilator effect in the rat MVB, which is dependent on NO in combination with endothelium-derived hyperpolarizing factor (EDHF). Additionally, our results indicated that extracellular Ca(2+) has an important role on the endothelium-dependent vasodilator effect induced by GSE. 相似文献
8.
Virgínia Carla de Oliveira Tatsuya Nagata Felipe C. Guimarães Fernanda A. Ferreira Elliot Watanabe Kitajima Cícero Nicolini Renato de Oliveira Resende Alice Kazuko Inoue-Nagata 《Virus genes》2013,46(1):190-194
A tymovirus was isolated in Brazil from tomato plants with severe symptoms of leaf mosaic and blistering. The virus was mechanically transmissible to solanaceous indicator host species. The infected plants contained icosahedral particles and chloroplasts with membrane deformations which are typical cytopathic effects caused by tymoviruses. Its coat protein amino acid sequence shares the maximum of 64 % identity with the tymovirus Chiltepin yellow mosaic virus, which suggested that it can be considered as a distinct member of the genus Tymovirus. In a phylogenetic tree, this tymovirus was clustered with other solanaceous-infecting tymoviruses. It was tentatively named as Tomato blistering mosaic virus (ToBMV). 相似文献
9.
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
10.
Ana Dorcas de Melo Inagaki Cristina Gardonyi Carvalheiro Rosana Cipolotti Ricardo Queiroz Gurgel Dayse Alves Rocha Kariny Souza Pinheiro Raquel Melo Araújo Dorothy Ribeiro Resende Lima Jacques Leon Winandy Marisa Márcia Mussi‐Pinhata 《Tropical medicine & international health : TM & IH》2012,17(11):1349-1355
Objectives To estimate, by neonatal screening, the birth prevalence of congenital toxoplasmosis among live‐born infants in Sergipe state, Brazil, and to investigate the clinical features of affected infants. Methods Dried blood spot specimens obtained from 15 204 neonates were assayed for the presence of anti‐T. gondii IgM antibodies. Duplicate retesting was done in infants with positive and borderline results. Confirmatory testing in peripheral blood samples consisted of testing for anti‐T. gondii IgG and IgM in infants and mothers. Those with possible congenital toxoplasmosis were evaluated and followed up to a median age of 20 months. Congenital infection was confirmed in the presence of persisting anti‐T. gondii IgG antibodies beyond 12 months of age. All infants with confirmed infection were treated with pyrimethamine, sulfadiazine and folinic acid for 1 year. Results Fifty‐three infants had detectable IgM in dried blood spot specimens. Confirmatory testing was reactive in 39/50, of which, 38 completed follow‐up. Six of 15 204 newborns were diagnosed with congenital toxoplasmosis, resulting in an estimated birth prevalence of four per 10 000 [CI 95% 1.4–8.0]. Four infants (67%) showed signs of congenital toxoplasmosis in their first year of life; three (75%) had retinochoroidal scars, and one had cerebral calcifications. Two infants remained asymptomatic until 20 months of age. Conclusions The birth prevalence of congenital toxoplasmosis is high in the Brazilian state of Sergipe, with most of the infants showing ocular lesions. Preventive measures are strongly warranted. 相似文献