Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
1.
Br Poult Sci ; : 1-9, 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39399982

RESUMO

1. Dietary electrolyte balance (DEB) has been used to minimise problems in broiler chickens raised in warm climates. However, there is a need to determine the most appropriate DEB levels in these animals2. This study evaluated the influence of five DEB levels (110, 175, 240, 305 and 370 mEq/kg) on water intake (WI), zootechnical performance (feed intake, weight gain and feed conversion ratio), tibiotarsus bone variables (fresh bone weight, dry bone weight, bone length, mineral matter, Seedor index and bone strength) and intestinal histomorphometry (villus height (VH) and width (VW), crypt height (CH) and width (CW), internal and external muscularis) on broilers in two developmental phases (1-21 and 22-42 d of age). Additionally, the haematological profile (blood count and serum biochemistry), carcass yield, cuts and abdominal fat were assessed.3. Applying 370 mEq/kg DEB increased WI, VW in the jejunum and ileum and number of haemocytes at 21 d, while WI and VW in the duodenum and ileum at 42 d. In contrast, 110 mEq/kg increased chlorine concentrations at 21 d and leukocyte and heterophil numbers at 42 d.4. In summary, the 370 mEq/kg level was the most appropriate for broiler homoeostasis raised under natural heat stress, as the best results were found on WI and VW variables. Therefore, this DEB level was recommended in broilers aged 21 or 42 d.

2.
Inorg Chem ; 62(31): 12392-12402, 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37478498

RESUMO

The influence of manganese modification on the spectroscopic features of manganese-doped CeO2 systems synthesized by the microwave-assisted hydrothermal route and their correlation with the presence of O defective structures were verified, focusing on their interaction with poisonous atmospheres. Raman and electron paramagnetic resonance studies confirmed the presence of defective clusters formed by dipoles and/or quadrupoles. The number of paramagnetic species was found to be inversely proportional to the doping concentration, resulting in an increase in the Mn2+ signal, likely due to the reduction of Mn3+ species after the interaction with CO. X-ray photoelectron spectroscopy data showed the pure system with 33% of its cerium species in the Ce3+ configuration, with an abrupt decrease to 19%, after the first modification with Mn, suggesting that 14% of the Ce3+ species are donating one electron to the Mn2+ ions, thus becoming nonparamagnetic Ce4+ species. On the contrary, 58% of the manganese species remain in the Mn2+ configuration with five unpaired electrons, corroborating the paramagnetic feature of the samples seen in the electron paramagnetic resonance study.

3.
Community Dent Health ; 39(4): 267-274, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36314645

RESUMO

BACKGROUND: The Brazilian federal government issued Ministerial Ordinance No. 718 in 2010 to expand the funding of orthodontic treatment provided by Brazilian municipalities via the Unified Health System (SUS in Portuguese). AIM: To identify social and structural factors associated with Brazilian municipalities that provide fixed orthodontic appliance therapy and interceptive orthodontic therapy. METHODS: Official Brazilian government databases were used for data collection. Poisson regression with robust variance was used for statistical analysis. RESULTS: Municipalities hosting Dental Specialty Centers (DSCs) with greater installed capacity (type III DSC with 7 dental chairs or over), which employed dentists specializing in pediatric dentistry and orthodontics, were more likely to offer orthodontic services via SUS. CONCLUSIONS: Federal, state, and municipal managers need to review the funding of orthodontic services via SUS, which can be used for creating DSCs and hiring professionals with expertise in orthodontics.


Assuntos
Ortodontia , Criança , Humanos , Brasil , Ortodontia Interceptora , Assistência Odontológica , Odontopediatria
4.
Physica A ; 569: 125773, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33495669

RESUMO

We study the spreading of SARS-CoV-2 in Brazil based on official data available since March 22, 2020. Calculations are done via an adaptive susceptible-infected-removed (SIR) model featuring dynamical recuperation and propagation rates. We are able reproduce the number of confirmed cases over time with less than 5% error and also provide with short- and long-term predictions. The model can also be used to account for the epidemic dynamics in other countries with great accuracy.

5.
Eur Arch Paediatr Dent ; 22(4): 553-559, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32897533

RESUMO

PURPOSE: This study aimed to evaluate parents' perceptions of the oral health status of children enrolled in public preschools and associated factors. METHODS: This was a cross-sectional study with data collected via self-administered questionnaire. A total of 474 questionnaires were distributed in public preschools in the city of Canoas, Rio Grande do Sul, the southernmost state of Brazil. Poisson regression models were used in the multivariate analysis (p < 0.05). RESULTS: The study included 171 (36%) valid questionnaires. The prevalence of parents who perceived the oral health status of their children as negative was 29.8% (n = 51). Mother being unemployed (vs employed) increased by 16% the likelihood of parents perceiving the oral health status of their children as negative (prevalence ratio [PR] 1.16; 95% confidence interval [CI] 1.02-1.31. Parents having (vs having not) observed difficulties in the child's ability to eat increased by 27% the likelihood of perceiving the child's oral health status as negative (PR 1.27; 95% CI 1.08-1.48), while child's tooth brushing 1-2 (vs 3 or more) times a day and family income up to 2 (vs 3 or more) minimum wages increased it by 14% (PR 1.14; 95% CI 1.03-1.27 for both). Current or past use (vs no use) of pacifiers increased by 12% the likelihood of parents' negative perceptions (PR 1.12; 95% CI 1.00-1.25). CONCLUSION: We can conclude that unemployed mothers, low-income families, parents having observed child's feeding difficulties, child's tooth brushing 1-2 times a day, and current or past use of pacifiers contributed significantly to parents' negative perception of the child's oral health status. These factors are essential for the planning, implementation, monitoring, and evaluation of actions aimed at controlling the oral health of children enrolled in public preschools.


Assuntos
Saúde Bucal , Pais , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Percepção , Inquéritos e Questionários
6.
Sci Rep ; 10(1): 8620, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32451399

RESUMO

Besides technical and tactical aspects, basketball matches involve high aerobic and anaerobic capacities, conferring the final performance of a team. Thus, the evaluation of physical and technical responses is an effective way to predict the performance of athletes. Field and laboratory tests have been used in sports. The first involving high ecological validity and low cost, and the second, greater control and accuracy but not easy application, considering the different preparation phases in a season. This study aimed, through complex networks analysis, to verify whether centrality parameters analysed from significant correlations behave similarly in distinct scenarios (laboratory and on-court), emphasizing aerobic and anaerobic physical parameters and technical performances. The results showed that, in a compelling  analysis involving basketball athletes, the studied centralities (degree, betweenness, eigenvector and pagerank) revealed similar responses in both scenarios, which is widely attractive considering the greater financial economy and lower time when applying tests in the field.

7.
Carbohydr Polym ; 218: 343-354, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31221339

RESUMO

Taxifolin possesses gastroprotective property but is characterized by low water solubility, is instabile in alkaline medium, and is degraded by the intestinal bacteria flora. The purpose of the work was therefore to produce a gastroadhesive formulation to prolong taxifolin residence time and release in the stomach. We first demonstrated that taxifolin is stable in simulated gastric fluid with or without pepsin and mucus, and is able to cross pig gastric mucus layer and stomach mucosa. Next, gastromucoadhesive microparticles composed of Syloid® AL-1 mesoporous silica, chitosan and HPMC were produced using spray-drying. Microparticles were characterized by a spherical shape and a mean volume-equivalent diameter around 12 µm. The optimized microparticles were able to release taxifolin and to adhere to pig stomach mucosa for 5 h.


Assuntos
Quitosana/química , Portadores de Fármacos/química , Fármacos Gastrointestinais/química , Quercetina/análogos & derivados , Adesividade , Animais , Liberação Controlada de Fármacos , Excipientes/química , Mucosa Gástrica/metabolismo , Microtecnologia , Mimusops/química , Tamanho da Partícula , Permeabilidade , Quercetina/química , Sementes/química , Dióxido de Silício/química , Suínos
8.
Arq. bras. med. vet. zootec. (Online) ; 71(3): 990-996, May-June 2019. tab
Artigo em Português | VETINDEX | ID: vti-25614

RESUMO

Objetivou-se avaliar o efeito de complexos enzimáticos sobre a energia metabolizável e o coeficiente de digestibilidade de nutrientes do milheto para frangos de corte. Quinhentos e setenta e seis frangos machos foram distribuídos em 36 gaiolas, com três tratamentos: T1 - composição de milheto sem complexo enzimático; T2 - composição de milheto com complexo enzimático (CES) e T3 - composição de milheto com complexo enzimático (CEV). Os tratamentos foram definidos com base em seis dietas (três dietas referências e três dietas testes). As dietas testes foram obtidas pela substituição de 40% da dieta referência por milheto inteiro, e a adição de enzimas consistiu de dois complexos enzimáticos: CES, constituído pelas enzimas fitase, protease, xilanase, ß-glucanase, celulase, amilase e pectinase; e CEV. constituído pelas enzimas protease, celulase e amilase. Na fase de 11 a 20 dias, a suplementação com o CEV reduziu os valores de EMA, EMAn e CDPB. A suplementação com CES melhorou o CDPB, e não houve efeito significativo para CDMS e CDEB. Na fase de 21 a 30 dias, houve menor aproveitamento da energia e dos nutrientes com as suplementações CES e CEV. Na fase de 31 a 40 dias, as suplementações reduziram os valores de EMA, EMAn, e o complexo CEV foi efetivo em aumentar o valor de CDPB. A inclusão dos complexos enzimáticos CES (fitase, protease, xilanase, ß-glucanase, celulase, amilase e pectinase) e CEV (protease, celulase e amilase) não favoreceu a utilização da energia do milheto, no entanto melhorou o coeficiente de digestibilidade da proteína do milheto nos períodos de 11 a 20 e de 31 a 40 dias de idade.(AU)


The objective of this study was to evaluate the effect of enzymatic complexes on metabolizable energy and nutrient digestibility coefficient of millet for broilers chickens. 576 male chickens, were distributed in 36 cages with three treatments: T1 - millet composition without enzymatic complex; T2 - millet composition with enzymatic complex (ECS); and T3 - millet composition with enzymatic complex (ECV). The treatments were defined from six diets (3 reference diets and 3 test diets). The test diets were obtained from the substitution of 40% for reference diet by whole millet, and the enzyme addition consisted of two enzymatic complex, ECS constituted by phytase, protease, xylanase, ß-glucanase, cellulase, amylase and pectinase enzymes, and ECV constituted by protease, cellulase and amylase enzymes. In the 11 to 20 days phase, a supplementation with the ECV reduced the AME, AMEn and CDPB values, a ECS supplementation improved the CDPB, and there was no significant effect for CDMS and CDEB. In the 21 to 30 days phase, there were less profit of the energy and nutrients with ECS and ECV supplements. In the 31 to 40 days phase as supplements reduced the values of AME, AMEn, and the ECV complex was effective in increasing the value of CDPB. The inclusion of ECS enzymatic complexes, (phytase, protease, xylanase, ß-glucanase, cellulase, amylase and pectinase) and ECV (protease, cellulase and amylase), did not favor millet's energy utilization, however, favored the millet's protein digestibility coefficient on 11 to 20 and 31 to 40 periods.(AU)


Assuntos
Animais , Masculino , Galinhas , Enzimas , Milhetes , Ração Animal/análise , Digestão
9.
Arq. bras. med. vet. zootec. (Online) ; 71(3): 990-996, May-June 2019. tab
Artigo em Português | VETINDEX, LILACS | ID: biblio-1011324

RESUMO

Objetivou-se avaliar o efeito de complexos enzimáticos sobre a energia metabolizável e o coeficiente de digestibilidade de nutrientes do milheto para frangos de corte. Quinhentos e setenta e seis frangos machos foram distribuídos em 36 gaiolas, com três tratamentos: T1 - composição de milheto sem complexo enzimático; T2 - composição de milheto com complexo enzimático (CES) e T3 - composição de milheto com complexo enzimático (CEV). Os tratamentos foram definidos com base em seis dietas (três dietas referências e três dietas testes). As dietas testes foram obtidas pela substituição de 40% da dieta referência por milheto inteiro, e a adição de enzimas consistiu de dois complexos enzimáticos: CES, constituído pelas enzimas fitase, protease, xilanase, ß-glucanase, celulase, amilase e pectinase; e CEV. constituído pelas enzimas protease, celulase e amilase. Na fase de 11 a 20 dias, a suplementação com o CEV reduziu os valores de EMA, EMAn e CDPB. A suplementação com CES melhorou o CDPB, e não houve efeito significativo para CDMS e CDEB. Na fase de 21 a 30 dias, houve menor aproveitamento da energia e dos nutrientes com as suplementações CES e CEV. Na fase de 31 a 40 dias, as suplementações reduziram os valores de EMA, EMAn, e o complexo CEV foi efetivo em aumentar o valor de CDPB. A inclusão dos complexos enzimáticos CES (fitase, protease, xilanase, ß-glucanase, celulase, amilase e pectinase) e CEV (protease, celulase e amilase) não favoreceu a utilização da energia do milheto, no entanto melhorou o coeficiente de digestibilidade da proteína do milheto nos períodos de 11 a 20 e de 31 a 40 dias de idade.(AU)


The objective of this study was to evaluate the effect of enzymatic complexes on metabolizable energy and nutrient digestibility coefficient of millet for broilers chickens. 576 male chickens, were distributed in 36 cages with three treatments: T1 - millet composition without enzymatic complex; T2 - millet composition with enzymatic complex (ECS); and T3 - millet composition with enzymatic complex (ECV). The treatments were defined from six diets (3 reference diets and 3 test diets). The test diets were obtained from the substitution of 40% for reference diet by whole millet, and the enzyme addition consisted of two enzymatic complex, ECS constituted by phytase, protease, xylanase, ß-glucanase, cellulase, amylase and pectinase enzymes, and ECV constituted by protease, cellulase and amylase enzymes. In the 11 to 20 days phase, a supplementation with the ECV reduced the AME, AMEn and CDPB values, a ECS supplementation improved the CDPB, and there was no significant effect for CDMS and CDEB. In the 21 to 30 days phase, there were less profit of the energy and nutrients with ECS and ECV supplements. In the 31 to 40 days phase as supplements reduced the values of AME, AMEn, and the ECV complex was effective in increasing the value of CDPB. The inclusion of ECS enzymatic complexes, (phytase, protease, xylanase, ß-glucanase, cellulase, amylase and pectinase) and ECV (protease, cellulase and amylase), did not favor millet's energy utilization, however, favored the millet's protein digestibility coefficient on 11 to 20 and 31 to 40 periods.(AU)


Assuntos
Animais , Masculino , Galinhas , Enzimas , Milhetes , Ração Animal/análise , Digestão
10.
Phys Rev E ; 99(2-1): 022117, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30934307

RESUMO

We study the effects of spatially long-range correlated phase disorder on the Hadamard quantum walk on a line. The shift operator is built to exhibit an intrinsic disorder distribution featuring long-range correlations. To impose such, we resort to fractional Brownian motion with power-law spectrum 1/k^{2α} with α≥0 being the exponent that controls the degree of correlations. We discuss the scaling behavior of the walker's wave packet and report a localization-delocalization transition controlled by α. We unveil two intermediate dynamical regimes between exponential localization and full delocalization.

11.
Nutr Metab Cardiovasc Dis ; 28(9): 865-876, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30111493

RESUMO

AIMS: To determine whether oral antioxidant therapies, of various types and doses, are able to prevent or treat women with preeclampsia. DATA SYNTHESIS: The following databases were searched: MEDLINE, CENTRAL, LILACS, and Web of Science. Inclusion criteria were: a) randomized clinical trials; b) oral antioxidant supplementation; c) study in pregnant women; d) control group, treated or not with placebo. Papers were excluded if they evaluated antioxidant nutrient supplementation associated with other non-antioxidant therapies. Data were extracted and the risk of bias of each study was assessed. Heterogeneity was analyzed using the Cochran Q test, and I2 statistics and pre-specified sensitivity analyses were performed. Meta-analyses were conducted on prevention and treatment studies, separately. The primary outcome was the incidence of preeclampsia in prevention trials, and of perinatal death in treatment trials. Twenty-nine studies were included in the analysis, 19 for prevention and 10 for treatment. The antioxidants used in these studies were vitamins C and E, selenium, l-arginine, allicin, lycopene and coenzyme Q10, none of which showed beneficial effects on the prevention of preeclampsia (RR: 0.89, CI 95%: [0.79-1.02], P = 0.09; I2 = 39%, P = 0.04) and other outcomes. The antioxidants used in the treatment studies were vitamins C and E, N-acetylcysteine, l-arginine, and resveratrol. A beneficial effect was found in intrauterine growth restriction. CONCLUSIONS: Antioxidant therapy had no effects in the prevention of preeclampsia but did show beneficial effects in intrauterine growth restriction, when used in the treatment of this condition.


Assuntos
Anti-Hipertensivos/administração & dosagem , Antioxidantes/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Pré-Eclâmpsia/tratamento farmacológico , Pré-Eclâmpsia/prevenção & controle , Administração Oral , Adolescente , Adulto , Anti-Hipertensivos/efeitos adversos , Antioxidantes/efeitos adversos , Medicina Baseada em Evidências , Feminino , Retardo do Crescimento Fetal/prevenção & controle , Humanos , Incidência , Pré-Eclâmpsia/mortalidade , Pré-Eclâmpsia/fisiopatologia , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
12.
Phys Rev E ; 95(5-1): 052217, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28618533

RESUMO

We consider interacting electrons moving in a nonlinear Morse lattice. We set the initial conditions as follows: electrons were initially localized at the center of the chain and a solitonic deformation was produced by an impulse excitation on the center of the chain. By solving quantum and classical equations for this system numerically, we found that a fraction of electronic wave function was trapped by the solitonic excitation, and trapping specificities depend on the degree of interaction among electrons. Also, there is evidence that the effective electron velocity depends on Coulomb interaction and electron-phonon coupling in a nontrivial way. This association is explained in detail along this work. In addition, we briefly discuss the dependence of our results with the type of initial condition we choose for the electrons and lattice.

13.
Animal ; 11(12): 2184-2192, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28571587

RESUMO

The appropriate supply of nutrients in pregnant cows has been associated with the optimal development of foetal tissues, performance of their progeny and their meat quality. The aim of this study was to evaluate supplementation effects of grazing cows in different stages of gestation on skeletal muscle development and performance of the progeny. Thereby, 27 Nellore cows were divided into three groups (n=9 for each group) and their progeny as follows: UNS, unsupplemented during gestation; MID, supplemented from 30 to 180 days of gestation; LATE, supplemented from 181 to 281 days of gestation. The percentage composition of the supplement provided for the matrices was the following: ground corn (26.25%), wheat bran (26.25%) and soya bean meal (47.5%). The supplement was formulated to contain 30% CP. Supplemented matrices received 150 kg of supplement (1 and 1.5 kg/day for cows in the MID and LATE groups, respectively). After birth, a biopsy was performed to obtain samples of skeletal muscle tissue from calves to determine number and size of muscle fibres and for messenger RNA (mRNA) expression analysis. The percentage composition of the supplement provided for the progeny was the following: ground corn grain (30%), wheat bran (30%), soya bean meal (35%) and molasses (5%). The supplement was formulated to contain 25% CP and offered in an amount of 6 g/kg BW. Performance of the progeny was monitored throughout the suckling period. Means were submitted to ANOVA and regression, and UNS, MID and LATE periods of supplementation were compared. Differences were considered at P0.10). Similarly, no differences were observed between calves for nutrient intake (P>0.10). However, greater subcutaneous fat thickness (P=0.006) was observed in the calves of LATE group. The ribeye area (P=0.077) was greater in calves born from supplemented compared with UNS cows. The supplementation of pregnant cows did not affect the muscle fibre size of their progeny (P=0.208). On the other hand, calves born from dams supplemented at mid-gestation had greater muscle fibre number (P=0.093) compared with calves from UNS group. Greater mRNA expression of peroxysome proliferator-activated receptor α (P=0.073) and fibroblast growth factor 2 (P=0.003) was observed in the calves born from MID cows. Although strategic supplementation did not affect the BW of offspring, it did cause changes in carcass traits, number of myofibres, and mRNA expression of a muscle hypertrophy and lipid oxidation markers in skeletal muscle of the offspring.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Dieta/veterinária , Desenvolvimento Muscular/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Pré-Natal/efeitos dos fármacos , Animais , Suplementos Nutricionais/análise , Ingestão de Energia , Feminino , Gravidez , Estações do Ano
14.
Trop Anim Health Prod ; 49(5): 983-988, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28386840

RESUMO

A grazing trial was carried out to evaluate the inclusion of three feed additives in supplements (crude protein, CP 230 g/kg dry matter, DM) on the performance, voluntary intake, and digestibility of beef heifers grazing Brachiaria decumbens (CP 81 and neutral detergent fiber, NDF 615 g/kg DM). Thirty-five Nellore heifers (21 months of age and 383 ± 6.29 kg of body weight, BW) were used in a completely randomized design. The treatments were as follows: no supplement (control); supplement fed at 1 kg/animal/day without additives (S); supplement with monensin (S + M); supplement with yeast culture (S + YC); and supplement with enzyme complex (S + EC). All of the supplemented heifers had greater (P < 0.1) average daily gain (∼0.186 kg/day) compared to the control treatment (0.014 kg/day). Average daily gain and final BW were similar (P > 0.1) among supplemented heifers. Monensin inclusion in the supplement decreased (P < 0.1) forage DM (expressed as g/kg BW) and NDF intake (expressed as kg/day and as g/kg BW). All of the feed additive inclusions decreased (P < 0.1) NDF digestibility. In conclusion, the heifers' performance was improved by concentrate supplementation. However, the inclusion of additives did not enhance this effect.


Assuntos
Bovinos/fisiologia , Digestão/efeitos dos fármacos , Monensin/metabolismo , Fermento Seco/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Brachiaria , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Fibras na Dieta/metabolismo , Feminino , Herbivoria , Monensin/administração & dosagem , Nitrogênio/metabolismo , Distribuição Aleatória , Fermento Seco/administração & dosagem
15.
Epidemiol Infect ; 144(2): 355-62, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26112312

RESUMO

Human adenoviruses (HAdVs) are important respiratory pathogens, found in 2-27% of acute respiratory infection (ARI) cases. Few studies have analysed the diversity of species and types of HAdVs associated with ARI in Brazil. The purpose of this study was to determine the circulation patterns of the different HAdV species and respective types associated with ARI in children in the city of Fortaleza, northeastern Brazil. HAdVs were screened by an indirect immunofluorescence assay, and subsequently identified as species and types by PCR and sequencing of the hexon gene (HVR1-HVR6). Between 2001 and 2013, a total of 290 HAdV strains were detected, 190 of which were identified as belonging to the HAdV-B, -C and -E species. Seven types of HAdVs circulated in the studied population during the analysed period, with HAdV-3 being predominant.


Assuntos
Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/classificação , Adenovírus Humanos/isolamento & purificação , Infecções Respiratórias/epidemiologia , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/genética , Adolescente , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Hospitalização , Humanos , Lactente , Recém-Nascido , Masculino , Reação em Cadeia da Polimerase , Infecções Respiratórias/virologia , Análise de Sequência de DNA
16.
J Phys Condens Matter ; 27(17): 175401, 2015 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-25836635

RESUMO

In this work, we study the vibrational modes and energy spreading in a harmonic chain model with diluted second-neighbors couplings and correlated mass-spring disorder. While all nearest neighbor masses are coupled by an elastic spring, second neighbors springs are introduced with a probability pD. The masses are randomly distributed according to the site connectivity mi = m0 (1 + 1/n(α)(I), where ni is the connectivity of the site i and α is a tunable exponent. We show that maximum localization of the vibrational modes is achieved for α ≃ 3/4. The time-evolution of the energy wave-packet is followed after an initial localized excitation. While the participation number remains finite, the energy spread is shown to be sub-diffusive after a displacement and super-diffusive after an impulse excitation. These features are related to the development of a power-law tail in the wave-packet distribution. Further, we unveil that the spring dilution leads to the emergence of a resonant localized state which is signaled by a van Hove singularity in the density of states.

17.
J Phys Condens Matter ; 27(3): 035104, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25564495

RESUMO

We investigate the electronic wavepacket dynamics in a finite segment of a DNA single-strand chain considering the electron-phonon coupling. Our theoretical approach makes use of an effective tight-binding Hamiltonian to describe the electron dynamics, together with a classical harmonic Hamiltonian to treat the intrinsic DNA vibrations. An effective time-dependent Schrödinger equation is then settled up and solved numerically for an initially localized wave-packet using the standard Dormand-Prince eighth-order Runge-Kutta method. Our numerical results indicate the presence of a sub-diffusive electronic wavepacket spread mediated by the electron-phonon interaction.


Assuntos
DNA de Cadeia Simples/química , Fônons , Difusão , Transporte de Elétrons
18.
Free Radic Res ; 49(2): 199-203, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25465091

RESUMO

INTRODUCTION: Cholesterol undergoes oxidation via both enzymatic stress- and free radical-mediated mechanisms, generating a wide range of oxysterols. In contrast to oxidative stress-driven metabolites, enzymatic stress-derived oxysterols are scarcely studied in their association with atherosclerotic disease in humans. METHODS: 24S-hydroxycholesterol (24S-HC), 25-hydroxycholesterol (25-HC), and 27-hydroxycholesterol (27-HC) were assessed in plasma and arteries with atherosclerotic plaques from 10 patients (54-84 years) with severe peripheral artery disease (PAD) as well as arteries free of atherosclerotic plaques from 13 individuals (45-78 years, controls). RESULTS: Plasma 25-HC was higher in PAD individuals than in controls (6.3[2] vs. 3.9[1.9] ng/mgCol; p = 0.004). 24S-HC and 27-HC levels were, respectively, five- and 20-fold higher in the arterial tissue of PAD individuals than in those of the controls (p = 0.016 and p = 0.001). Plasma C-reactive protein correlated with plasma 24-HC (r = 0.51; p = 0.010), 25-HC (r = 0.75; p < 0.001), 27-HC (r = 0.48; p = 0.015), and with tissue 24S-HC (r = 0.4; p = 0.041) and 27-HC (r = 0.46; p = 0.023). CONCLUSION: Arterial intima accumulation of 27-HC and 24S-HC is associated with advanced atherosclerotic disease and systemic inflammatory activity in individuals with severe PAD.


Assuntos
Artérias/química , Hidroxicolesteróis/sangue , Inflamação/sangue , Doença Arterial Periférica/sangue , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Artigo em Inglês | MEDLINE | ID: mdl-25353765

RESUMO

The Bose-Einstein condensation of noninteracting particles restricted to move on the sites of hierarchical diamond lattices is investigated. Using a tight-binding single-particle Hamiltonian with properly rescaled hopping amplitudes, we are able to employ an orthogonal basis transformation to exactly map it on a set of decoupled linear chains with sizes and degeneracies written in terms of the network branching parameter q and generation number n. The integrated density of states is shown to have a fractal structure of gaps and degeneracies with a power-law decay at the band bottom. The spectral dimension d(s) coincides with the network topological dimension d(f) = ln(2q)/ln(2). We perform a finite-size scaling analysis of the fraction of condensed particles and specific heat to characterize the critical behavior of the BEC transition that occurs for q > 2 (d(s) > 2). The critical exponents are shown to follow those for lattices with a pure power-law spectral density, with non-mean-field values for q < 8 (d(s) < 4). The transition temperature is shown to grow monotonically with the branching parameter, obeying the relation 1/T(c) = a + b/(q - 2).


Assuntos
Coloides/química , Cristalização/métodos , Partículas Elementares , Modelos Químicos , Modelos Moleculares , Simulação por Computador , Transição de Fase , Termodinâmica
20.
J Phys Condens Matter ; 26(41): 415401, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25244998

RESUMO

In our work, we consider the problem of electronic transport mediated by coupling with solitonic elastic waves. We study the electronic transport in a 1D unharmonic lattice with a cubic interaction between nearest neighboring sites. The electron-lattice interaction was considered as a linear function of the distance between neighboring atoms in our study. We numerically solve the dynamics equations for the electron and lattice and compute the dynamics of an initially localized electronic wave-packet. Our results suggest that the solitonic waves that exist within this nonlinear lattice can control the electron dynamics along the chain. Moreover, we demonstrate that the existence of a mobile electron-soliton pair exhibits a counter-intuitive dependence with the value of the electron-lattice coupling.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA