全文获取类型
收费全文 | 250篇 |
免费 | 13篇 |
专业分类
263篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 11篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 15篇 |
2015年 | 24篇 |
2014年 | 30篇 |
2013年 | 21篇 |
2012年 | 25篇 |
2011年 | 12篇 |
2010年 | 10篇 |
2009年 | 4篇 |
2008年 | 12篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 7篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有263条查询结果,搜索用时 0 毫秒
91.
Sérgio Ricardo Fernandes Araújo Sarra Elisabeth Jamieson Kathryn Margaret Dupnik Glória Regina Monteiro Maurício Lisboa Nobre Márcia Sousa Dias Pedro Bezerra Trindade Neto Maria do Carmo Palmeira Queiroz Carlos Eduardo Maia Gomes Jenefer Mary Blackwell Selma Maria Bezerra Jeronimo 《Memórias do Instituto Oswaldo Cruz》2014,109(2):182-188
Leprosy remains prevalent in Brazil. ErbB2 is a receptor for leprosy bacilli entering
Schwann cells, which mediates Mycobacterium leprae-induced
demyelination and the ERBB2 gene lies within a leprosy
susceptibility locus on chromosome 17q11-q21. To determine whether
polymorphisms at the ERBB2 locus contribute to this linkage peak,
three haplotype tagging single nucleotide polymorphisms (tag-SNPs) (rs2517956,
rs2952156, rs1058808) were genotyped in 72 families (208 cases; 372 individuals) from
the state of Pará (PA). All three tag-SNPs were associated with leprosy per se [best
SNP rs2517959 odds ratio (OR) = 2.22; 95% confidence interval (CI) 1.37-3.59; p =
0.001]. Lepromatous (LL) (OR = 3.25; 95% CI 1.37-7.70; p = 0.007) and tuberculoid
(TT) (OR = 1.79; 95% CI 1.04-3.05; p = 0.034) leprosy both contributed to the
association, which is consistent with the previous linkage to chromosome 17q11-q21 in
the population from PA and supports the functional role of ErbB2 in disease
pathogenesis. To attempt to replicate these findings, six SNPs (rs2517955, rs2517956,
rs1810132, rs2952156, rs1801200, rs1058808) were genotyped in a population-based
sample of 570 leprosy cases and 370 controls from the state of Rio Grande do Norte
(RN) and the results were analysed using logistic regression analysis. However, none
of the associations were replicated in the RN sample, whether analysed for leprosy
per se, LL leprosy, TT leprosy, erythema nodosum leprosum or reversal reaction
conditions. The role of polymorphisms at ERBB2 in controlling
susceptibility to leprosy in Brazil therefore remains unclear. 相似文献
92.
93.
Isabella Coimbra Magda Maruza Maria de Fátima Pessoa Milit?o Albuquerque Joanna D’Arc Lyra Batista Maria Cynthia Braga Líbia Vilela Moura Demócrito Barros Miranda-Filho Ulisses Ramos Montarroyos Heloísa Ramos Lacerda Laura Cunha Rodrigues Ricardo Arraes de Alencar Ximenes 《PloS one》2014,9(4)
Background
The challenge of diagnosing smear-negative pulmonary TB (tuberculosis) in people living with HIV justifies the use of instruments other than the smear test for diagnosing the disease. Considering the clinical-radiological similarities of TB amongst HIV-infected adults and children, the proposal of this study was to assess the accuracy of a scoring system used to diagnose smear-negative pulmonary TB in children and adolescents, in HIV-infected adults suspected of having smear-negative pulmonary TB.Methods
A Phase III validation study aiming to assess the diagnostic accuracy of a scoring system for diagnosing smear-negative pulmonary TB in HIV-infected adults. The study assessed sensitivity, specificity, positive and negative likelihood ratios, and positive and negative predictive values of the scoring system. Three versions of the scoring system were tested.Results
From a cohort of 2,382 (HIV-infected adults), 1276 were investigated and 128 were diagnosed with pulmonary TB. Variables associated with the diagnosis of TB were: coughing, weight loss, fever, malnutrition, chest X-ray, and positive tuberculin test. The best diagnostic performance occurred with the scoring system with new scores, with sensitivity = 81.2% (95%-CI 74.5% –88%), specificity = 78% (75.6% –80.4%), PPV = 29.2% (24.5% –33.9%) and NPV = 97.4% (96.4% –98.4%), LR+ = 3.7 (3.4–4.0) and LR− = 0.24 (0.2–0.4).Conclusion
The proposed scoring system (with new scores) presented a good capacity for discriminating patients who did not have pulmonary TB, in the studied population. Further studies are necessary in order to validate it, thus permitting the assessment of its use in diagnosing smear-negative pulmonary TB in HIV-infected adults. 相似文献94.
Ricardo Arraes de Alencar Ximenes Celina Maria Turchi Martelli Marcos Amaku Ana Marli C. Sartori Patricia Coelho de Soárez Hillegonda Maria Dutilh Novaes Leila Maria Moreira Beltr?o Pereira Regina Célia Moreira Gerusa Maria Figueiredo Raymundo Soares de Azevedo for the Hepatitis Study Group 《PloS one》2014,9(5)
Background
This study aimed to identify the transmission pattern of hepatitis A (HA) infection based on a primary dataset from the Brazilian National Hepatitis Survey in a pre-vaccination context. The national survey conducted in urban areas disclosed two epidemiological scenarios with low and intermediate HA endemicity.Methods
A catalytic model of HA transmission was built based on a national seroprevalence survey (2005 to 2009). The seroprevalence data from 7,062 individuals aged 5–69 years from all the Brazilian macro-regions were included. We built up three models: fully homogeneous mixing model, with constant contact pattern; the highly assortative model and the highly assortative model with the additional component accounting for contacts with infected food/water. Curves of prevalence, force of infection (FOI) and the number of new infections with 99% confidence intervals (CIs) were compared between the intermediate (North, Northeast, Midwest and Federal District) and low (South and Southeast) endemicity areas. A contour plot was also constructed.Results
The anti- HAV IgG seroprevalence was 68.8% (95% CI, 64.8%–72.5%) and 33.7% (95% CI, 32.4%–35.1%) for the intermediate and low endemicity areas, respectively, according to the field data analysis. The models showed that a higher force of infection was identified in the 10- to 19-year-old age cohort (∼9,000 infected individuals per year per 100,000 susceptible persons) in the intermediate endemicity area, whereas a higher force of infection occurred in the 15- to 29-year-old age cohort (∼6,000 infected individuals per year per 100,000 susceptible persons) for the other macro-regions.Conclusion
Our findings support the shift of Brazil toward intermediate and low endemicity levels with the shift of the risk of infection to older age groups. These estimates of HA force of infection stratified by age and endemicity levels are useful information to characterize the pre-vaccination scenario in Brazil. 相似文献95.
96.
Background
Chagas'' disease is an important neglected public health problem in many Latin American countries, but population-based epidemiological data are scarce. Here we present a nationwide analysis on Chagas-associated mortality, and risk factors for death from this disease.Methodology/Principal Findings
We analyzed all death certificates of individuals who died between 1999 and 2007 in Brazil, based on the nationwide Mortality Information System (a total of 243 data sets with about 9 million entries). Chagas'' disease was mentioned in 53,930 (0.6%) of death certificates, with 44,537 (82.6%) as an underlying cause and 9,387 (17.4%) as an associated cause of death. Acute Chagas'' disease was responsible for 2.8% of deaths. The mean standardized mortality rate was 3.36/100.000 inhabitants/year. Nationwide standardized mortality rates reduced gradually, from 3.78 (1999) to 2.78 (2007) deaths/year per 100,000 inhabitants (−26.4%). Standardized mortality rates were highest in the Central-West region, ranging from 15.23 in 1999 to 9.46 in 2007 (−37.9%), with a significant negative linear trend (p = 0.001; R2 = 82%). Proportional mortality considering multiple causes of death was 0.60%. The Central-West showed highest proportional mortality among regions (2.17%), with a significant linear negative trend, from 2.28% to 1.90% (−19.5%; p = 0.001; R2 = 84%). There was a significant increase in the Northeast of 38.5% (p = 0.006; R2 = 82%). Bivariable analysis on risk factors for death from Chagas'' disease showed highest relative risks (RR) in older age groups (RR: 10.03; 95% CI: 9.40–10.70; p<0.001) and those residing in the Central-West region (RR: 15.01; 95% CI: 3.90–16.22; p<0.001). In logistic regression analysis, age ≥30 years (adjusted OR: 10.81; 95% CI: 10.03–10.65; p<0.001) and residence in one of the three high risk states Minas Gerais, Goiás or the Federal District (adjusted OR: 5.12; 95% CI: 5.03–5.22, p<0.001) maintained important independent risk factors for death by Chagas'' disease.Conclusions/Significance
This is the first nationwide population-based study on Chagas mortality in Brazil, considering multiple causes of death. Despite the decline of mortality associated with Chagas'' disease in Brazil, the disease remains a serious public health problem with marked regional differences. 相似文献97.
98.
Francisco S A Cavalcante Satoru Ito Kelly Brewer Hiroaki Sakai Adriano M Alencar Murilo P Almeida José S Andrade Arnab Majumdar Edward P Ingenito Béla Suki 《Journal of applied physiology》2005,98(2):672-679
Collagen and elastin are thought to dominate the elasticity of the connective tissue including lung parenchyma. The glycosaminoglycans on the proteoglycans may also play a role because osmolarity of interstitial fluid can alter the repulsive forces on the negatively charged glycosaminoglycans, allowing them to collapse or inflate, which can affect the stretching and folding pattern of the fibers. Hence, we hypothesized that the elasticity of lung tissue arises primarily from 1) the topology of the collagen-elastin network and 2) the mechanical interaction between proteoglycans and fibers. We measured the quasi-static, uniaxial stress-strain curves of lung tissue sheets in hypotonic, normal, and hypertonic solutions. We found that the stress-strain curve was sensitive to osmolarity, but this sensitivity decreased after proteoglycan digestion. Images of immunofluorescently labeled collagen networks showed that the fibers follow the alveolar walls that form a hexagonal-like structure. Despite the large heterogeneity, the aspect ratio of the hexagons at 30% uniaxial strain increased linearly with osmolarity. We developed a two-dimensional hexagonal network model of the alveolar structure incorporating the mechanical properties of the collagen-elastin fibers and their interaction with proteoglycans. The model accounted for the stress-strain curves observed under all experimental conditions. The model also predicted how aspect ratio changed with osmolarity and strain, which allowed us to estimate the Young's modulus of a single alveolar wall and a collagen fiber. We therefore identify a novel and important role for the proteoglycans: they stabilize the collagen-elastin network of connective tissues and contribute to lung elasticity and alveolar stability at low to medium lung volumes. 相似文献
99.
100.
Emerson Dechechi Chambó Newton Tavares Escocard de Oliveira Regina Conceição Garcia Maria Claudia Colla Ruvolo-Takasusuki Vagner Alencar Arnaut de Toledo 《Arthropod-Plant Interactions》2017,11(4):613-621
Understanding specific meteorological factors that affect the foraging activity of pollinator insects can provide valuable information to ensure appropriate levels of pollination of crops. This research was carried out to verify the spectrum of pollinating insects and their foraging behavior in relation to specific meteorological variables in the Brassica napus (rapeseed) crop. Data collected consisted of the following observations: number of visits by each pollinator, floral resources collected by Africanized honeybee Apis mellifera L., number of flowers visited by Africanized honeybees in 1 min, number of flowers visited by Africanized honeybees in one specific plant during the timed observation of 1 min, and the time taken by the honeybees to visit each flower. In this study the analyses were made through different generalized linear models. The Africanized honeybees were the most abundant pollinating insects (88%) and most visitors were observed collecting nectar (90%). The Africanized honeybees visited a total of 12.9?±?1.40 flowers in 1 min and 2.96?±?1.09 flowers of a single plant in 1 min. The time the honeybees spent on the rapeseed flowers was 4.2?±?1.6 s. The number of floral visitors correlated closely to the variation of abiotic factors, especially temperature, relative humidity, wind speed, and solar radiation. Africanized honeybees were more active at different times of the day as compared to the other floral visitors and they foraged more intensely on the Hyola 433 hybrid than on the Hyola 61 hybrid. The Hyola 61 hybrid was more attractive to Diabrotica speciosa and Lepidoptera. 相似文献