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Photonic and electronic properties exist inherently in ferroelectric barium titanate (BaTiO3); severe luminescence quenching also exists due to the insufficient confinement of excitons. In this sense, high optical emission can only be achieved by its chemical and structural modification. Thin BaTiO3 and Er:BaTiO3 films were grown by the spin coating method on a glass substrate at room temperature. Self-trapping of excitons in the thin BaTiO3 film and its structural modification due to the doping with Er3+ ions (Er:BaTiO3) are verified using scanning confocal fluorescence microscopy (SCFM), where self-trapping excitons never occured in its pure state. By thermal treatment and doping (BaTiO3 and Er:BaTiO3) we obtained localization of the excitons, which would further induce lattice strain around the surface defects, to accommodate the self-trapped excitons. With such a self-trapped state, the structure of BaTiO3 generates broadband emission of several overlapping bands between 1.95 and 2.65 eV at room temperature, while the structure Er:BaTiO3 showed defined emission bands at 2.24 and 2.35 eV, with very weak contributions of the emission due to the self-trapping state. The influence of the variation of the excitation wavelength using 1PE and 2PE on the emission bands of BaTiO3 and Er:BaTiO3 is also investigated. The results of enhanced emission bands suggest a clear dependence of the emission intensity on the excitation energy, where a â¼3 fold enhancement in emission has been demonstrated under Er3+ (1.55 eV) excitation, which can be attributed to effective energy transfer between the Er3+ ions. As a result, it is concluded that the developed BaTiO3 and Er:BaTiO3 can pave the way for future photonic devices.
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AIMS: The AGT1 gene encodes for a general α-glucoside-H+ symporter required for efficient maltotriose fermentation by Saccharomyces cerevisiae. In the present study, we analysed the involvement of four charged amino acid residues present in this transporter that are required for maltotriose consumption and fermentation by yeast cells. METHODS AND RESULTS: By using a knowledge-driven approach based on charge, conservation, location, three-dimensional (3D) structural modelling and molecular docking analysis, we identified four amino acid residues (Glu-120, Asp-123, Glu-167 and Arg-504) in the AGT1 permease that could mediate substrate binding and translocation. Mutant permeases were generated by site-directed mutagenesis of these charged residues, and expressed in a yeast strain lacking this permease (agt1∆). While mutating the Arg-504 or Glu-120 residues into alanine totally abolished (R504A mutant) or greatly reduced (E120A mutant) maltotriose consumption by yeast cells, as well as impaired the active transport of several other α-glucosides, in the case of the Asp-123 and Glu-167 amino acids, it was necessary to mutate both residues (D123G/E167A mutant) in order to impair maltotriose consumption and fermentation. CONCLUSIONS: Based on the results obtained with mutant proteins, molecular docking and the localization of amino acid residues, we propose a transport mechanism for the AGT1 permease. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results present new insights into the structural basis for active α-glucoside-H+ symport activity by yeast transporters, providing the molecular bases for improving the catalytic properties of this type of sugar transporters.
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Aminoácidos/química , Proteínas de Transporte de Monossacarídeos/química , Proteínas de Saccharomyces cerevisiae/química , Simportadores/química , Trissacarídeos/metabolismo , Transporte Biológico Ativo , Fermentação , Simulação de Acoplamento Molecular , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Simportadores/genética , Simportadores/metabolismoRESUMO
What are the necessary ingredients for log-periodicity to appear in the dynamics of a random walk model? Can they be subtle enough to be overlooked? Previous studies suggest that long-range damaged memory and negative feedback together are necessary conditions for the emergence of log-periodic oscillations. The role of negative feedback would then be crucial, forcing the system to change direction. In this paper we show that small-amplitude log-periodic oscillations can emerge when the system is driven by positive feedback. Due to their very small amplitude, these oscillations can easily be mistaken for numerical finite-size effects. The models we use consist of discrete-time random walks with strong memory correlations where the decision process is taken from memory profiles based either on a binomial distribution or on a delta distribution. Anomalous superdiffusive behavior and log-periodic modulations are shown to arise in the large time limit for convenient choices of the models parameters.
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The study investigated whether chronic TMD patients with disc displacement with reduction (DDR), performing non-assisted maximum jaw movements, presented any changes in their mandibular kinematics with respect to an age-matched control group. Moreover, it was examined whether jaw kinematics and a valid clinic measure of oro-facial functional status have significant associations. Maximum mouth opening, mandible protrusion and bilateral laterotrusions were performed by 20 patients (18 women, 2 men; age, 18-34 years) and 20 healthy controls (17 women, 3 men; age, 20-31 years). The three-dimensional coordinates of their mandibular interincisor and condylar reference points were recorded by means of an optoelectronic motion analyser and were used to quantitatively assess their range of motion, velocity, symmetry and synchrony. Three functional indices (opening-closing, mandibular rototranslation, laterotrusion - right and left - and protrusion) were devised to summarise subject's overall performance, and their correlation with the outcome of a clinical protocol, the oro-facial myofunctional evaluation with scores (OMES), was investigated. TMD patients were able to reach maximum excursions of jaw movements comparable to healthy subjects' performances. However, their opening and closing mandibular movements were characterised by remarkable asynchrony of condylar translation. They had also reduced jaw closing velocity and asymmetric laterotrusions. The functional indices proved to well summarise the global condition of jaw kinematics, highlighting the presence of alterations in TMD-DDR patients, and were linearly correlated with the oro-facial functional status. The jaw kinematic alterations seem to reflect both oro-facial motor behaviour adaptation and a DDR-related articular impairment.
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Imageamento Tridimensional , Côndilo Mandibular/fisiopatologia , Transtornos da Articulação Temporomandibular/fisiopatologia , Articulação Temporomandibular/fisiopatologia , Adolescente , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Côndilo Mandibular/diagnóstico por imagem , Radiografia , Amplitude de Movimento Articular , Articulação Temporomandibular/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Adulto JovemRESUMO
We develop an approach for performing scaling analysis of N-step random walks (RWs). The mean square end-to-end distance, ãR[over â]_{N}^{2}ã, is written in terms of inner persistence lengths (IPLs), which we define by the ensemble averages of dot products between the walker's position and displacement vectors, at the jth step. For RW models statistically invariant under orthogonal transformations, we analytically introduce a relation between ãR[over â]_{N}^{2}ã and the persistence length, λ_{N}, which is defined as the mean end-to-end vector projection in the first step direction. For self-avoiding walks (SAWs) on 2D and 3D lattices we introduce a series expansion for λ_{N}, and by Monte Carlo simulations we find that λ_{∞} is equal to a constant; the scaling corrections for λ_{N} can be second- and higher-order corrections to scaling for ãR[over â]_{N}^{2}ã. Building SAWs with typically 100 steps, we estimate the exponents ν_{0} and Δ_{1} from the IPL behavior as function of j. The obtained results are in excellent agreement with those in the literature. This shows that only an ensemble of paths with the same length is sufficient for determining the scaling behavior of ãR[over â]_{N}^{2}ã, being that the whole information needed is contained in the inner part of the paths.
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Complex regional pain syndrome type 1 (CRPS1) may be evoked by ischemia/reperfusion, eliciting acute and chronic pain that is difficult to treat. Despite this, the underlying mechanism of CRPS1 has not been fully elucidated. Therefore, the goal of this study is to evaluate the involvement of inflammation, oxidative stress, and the transient receptor potential ankyrin 1 (TRPA1) channel, a chemosensor of inflammation and oxidative substances, in an animal model of chronic post-ischemia pain (CPIP). Male Wistar rats were subjected to 3 h hind paw ischemia/reperfusion (CPIP model). Different parameters of nociception, inflammation, ischemia, and oxidative stress were evaluated at 1 (acute) and 14 (chronic) days after CPIP. The effect of a TRPA1 antagonist and the TRPA1 immunoreactivity were also observed after CPIP. In the CPIP acute phase, we observed mechanical and cold allodynia; increased levels of tumor necrosis factor-α (hind paw), ischemia-modified albumin (IMA) (serum), protein carbonyl (hind paw and spinal cord), lactate (serum), and 4-hydroxy-2-nonenal (4-HNE, hind paw and spinal cord); and higher myeloperoxidase (MPO) and N-acetyl-ß-D-glucosaminidase (NAGase) activities (hind paw). In the CPIP chronic phase, we detected mechanical and cold allodynia and increased levels of IMA (serum), protein carbonyl (hind paw and spinal cord), and 4-HNE (hind paw and spinal cord). TRPA1 antagonism reduced mechanical and cold allodynia 1 and 14 days after CPIP, but no change in TRPA1 immunoreactivity was observed. Different mechanisms underlie acute (inflammation and oxidative stress) and chronic (oxidative stress) phases of CPIP. TRPA1 activation may be relevant for CRPS1/CPIP-induced acute and chronic pain.
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Dor Aguda/metabolismo , Dor Crônica/metabolismo , Membro Posterior/irrigação sanguínea , Nociceptividade , Distrofia Simpática Reflexa/metabolismo , Canais de Cátion TRPC/antagonistas & inibidores , Acetilglucosaminidase/metabolismo , Dor Aguda/etiologia , Aldeídos/metabolismo , Animais , Dor Crônica/etiologia , Temperatura Baixa , Hiperalgesia/etiologia , Hiperalgesia/metabolismo , Ácido Láctico/sangue , Masculino , Estresse Oxidativo , Peroxidase/metabolismo , Carbonilação Proteica , Ratos , Ratos Wistar , Distrofia Simpática Reflexa/etiologia , Traumatismo por Reperfusão/complicações , Albumina Sérica/metabolismo , Canal de Cátion TRPA1 , Canais de Cátion TRPC/metabolismo , Fator de Necrose Tumoral alfa/sangueRESUMO
INTRODUCTION: Early lymphocyte recovery after allogeneic hematopoietic stem cell transplantation (HSCT) is related to the prevention of serious infections and the clearing of residual tumor cells. METHODS: We analyzed the absolute lymphocyte count at 20 (D+20) and 30 (D+30) days after HSCT in 100 patients with malignant hematologic diseases and correlated with the risk of transplant-related mortality, overall survival (OS), disease-free survival (DFS), nonrelapsed mortality (NRM), and risk of infection. RESULTS: Patients presenting with lymphocyte counts of <300 × 103/µL on D+30 have a 3.76 times greater risk of death in <100 days. Over a medium follow-up of 20 months OS, DFS, and NRM were similar between the groups. CONCLUSION: In our group of patients delayed lymphocyte recovery after HSCT was a predictor of early death post-HSCT.
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Transplante de Células-Tronco Hematopoéticas , Leucemia/sangue , Leucemia/terapia , Contagem de Linfócitos , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/terapia , Adolescente , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Leucemia/mortalidade , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/mortalidade , Valor Preditivo dos Testes , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Transplante Homólogo , Resultado do Tratamento , Adulto JovemRESUMO
We study a one-dimensional discrete-time non-Markovian random walk with strong memory correlations subjected to pauses. Unlike the Scher-Montroll continuous-time random walk, which can be made Markovian by defining an operational time equal to the random-walk step number, the model we study keeps a record of the entire history of the walk. This new model is closely related to the one proposed recently by Kumar, Harbola, and Lindenberg [Phys. Rev. E 82, 021101 (2010)], with the difference that in our model the stochastic dynamics does not stop even in the extreme limit of subdiffusion. Surprisingly, this small difference leads to large consequences. The main results we report here are exact results showing ultraslow diffusion and a stationary diffusion regime (i.e., localization). Specifically, the equations of motion are solved analytically for the first two moments, allowing the determination of the Hurst exponent. Several anomalous diffusion regimes are apparent, ranging from superdiffusion to subdiffusion, as well as ultraslow and stationary regimes. We present the complete phase diffusion diagram, along with a study of the persistence and the statistics in the regions of interest.
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Difusão , Cadeias de Markov , Modelos Biológicos , Modelos Químicos , Modelos Estatísticos , Reologia/métodos , Simulação por ComputadorRESUMO
For almost a decade the consensus has held that the random walk propagator for the elephant random walk (ERW) model is a Gaussian. Here we present strong numerical evidence that the propagator is, in general, non-Gaussian and, in fact, non-Lévy. Motivated by this surprising finding, we seek a second, non-Gaussian solution to the associated Fokker-Planck equation. We prove mathematically, by calculating the skewness, that the ERW Fokker-Planck equation has a non-Gaussian propagator for the superdiffusive regime. Finally, we discuss some unusual aspects of the propagator in the context of higher order terms needed in the Fokker-Planck equation.
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A espécie Garcinia brasiliensis Mart. (Clusiaceae), nativa da região Amazônica e cultivada em todo o território brasileiro, vem sendo bastante estudada devido seu potencial farmacológico, porém são escassos estudos que tratam da caracterização farmacobotânica desta espécie. Considerando as propriedades terapêuticas para tornar-se um medicamento fitoterápico, o presente trabalho teve como objetivos estudar a anatomia e histoquímica da folha e do pecíolo e elaborar dados macroscópicos e microscópicos que forneçam características marcantes para sua identificação além de dar subsídios para a análise farmacognóstica no controle de qualidade da droga vegetal. O material vegetal foi fixado e submetido às técnicas usuais de microscopia de luz e a testes histoquímicos. As folhas de G. brasiliensis são opostas, simples, descolores, forma elíptica com nervação peninérvia. As células epidérmicas, em vista frontal, apresentam contorno sinuoso e estômatos paracíticos somente na face abaxial. O mesofilo é dorsiventral, a nervura central apresenta contorno biconvexo e feixe vascular em forma de semi-arco fechado envolto por bainha esclerenquimática. Inclusões inorgânicas de cristais na forma de drusas e orgânicas representadas por compostos fenólicos e grãos de amidos estão dispersos ao longo de toda lâmina foliar e pecíolo. Observa-se com frequência a presença de canais secretores preenchidos por um conteúdo lipídico dispersos pelo parênquima fundamental e próximos aos feixes vasculares. Estes dados fornecem subsídios para o controle de qualidade da matéria-prima utilizada para a produção de fitoterápicos.
The Garcinia brasiliensis Mart. (Clusiaceae) species, native of the Amazon region and cultivated throughout the Brazilian territory, has been widely studied due to its pharmacological potential, but there are few studies dealing with the pharmacobotanic characterization of this species. Considering the therapeutic properties in order to become an herbal medicine, the present paper had the purpose of studying the anatomical and histochemical characterization of the leaf and petiole, as well as producing macroscopic and microscopic data that provide important characteristics for its identification, in addition to providing subsidies for the pharmacognostical analysis in order to offer elements for the quality assurance of the drug. The botanical material was prepared through the usual optical and histochemical microtechniques. The leaves of G. brasiliensis are simple, opposed, colorless, and they show an elliptical shape. As seen from the front, the epidermal cells have a sinuous contour, and paracytic stomata occur on the low surface. The leaves are hipostomatic and dorsiventral with heterogeneous mesophile. The mesophile is dorsiventral, the central midrib shows a biconvex contour and vascular system in a semi-closed arch shape surrounded by a sclerenchymatic sheath. Inorganic inclusions of crystals in the shape of druses, and organic inclusions represented by phenolic compounds and starch grains are found throughout the leaf blade and petiole. It is common to find secretory canals filled with a lipid content dispersed throughout the parenchyma and near the vascular bundles. These data support the quality assurance of the elements used to produce herbal medicines.