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1.
Int J Biometeorol ; 68(3): 427-434, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38147120

RESUMO

The aim of this study was to determine effects of parity (primiparous vs. multiparous), seasonal heat stress at calving (summer vs. winter), and time postpartum on some parameters associated with colostrum quality in Holstein cows reared in the Sonoran Desert ecosystem. Forty-seven cows (11 primiparous and 36 multiparous) expected to calve during summer, and 46 cows during winter (14 primiparous and 32 multiparous) were randomly selected. Management and feeding before and after parturition were similar for cows in both seasons. After parturition, colostrum from all cows was evaluated for volume, weight, temperature, density, and content of fat, protein, solids non-fat (SNF), and immunoglobulins (IGG). Data were analyzed with a model that included effects of parity status, calving season, and time postpartum, as well as all interactions. Colostrum produced in summer was warmer (P < 0.01) by almost 6 °C than winter colostrum, while colostrum from multiparous was warmer (P = 0.02) by 1.2 °C than that produced by primiparous cows. Colostrum volume and weight were not impacted by parity, calving season or time postpartum. Density, protein, and SNF content in colostrum were higher (P < 0.01) in multiparous vs. primiparous cows, as well as at parturition (0 h postpartum) than at 12 h postpartum (P < 0.01). At calving (0 h), spring colostrum had higher fat content (P < 0.01) and lower (P < 0.01) IGG concentration than that collected in summer, and no difference (P > 0.05) between seasons was observed for these components at 12 h postpartum. Multiparous cows produced colostrum with higher (P < 0.01) IGG concentrations than primiparous cows. In conclusion, only 0-h colostrum and that from multiparous cows was categorized as "Excellent," meanwhile the colostrum produced under summer heat stress was characterized as "Good" with reduced fat content. While the lacteal secretion collected at 12 post-partum still classified as colostrum, substantially lower contents of IGG, protein, fat, and SNF decreased its classification to "Poor" from the classification of "Excellent" at 0 h postpartum.


Assuntos
Colostro , Lactação , Gravidez , Feminino , Humanos , Bovinos , Animais , Estações do Ano , Leite , Ecossistema , Período Pós-Parto , Imunoglobulina G
2.
J Dairy Sci ; 106(10): 7177-7190, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37210353

RESUMO

Inferring causal effects between variables when utilizing observational data is challenging due to confounding factors not controlled through a randomized experiment. Propensity score matching can decrease confounding in observational studies and offers insights about potential causal effects of prophylactic management interventions such as vaccinations. The objective of this study was to determine potential causality and impact of vaccination with an Escherichia coli J5 bacterin on the productive performance of dairy cows applying propensity score matching techniques to farm-recorded (e.g., observational) data. Traits of interest included 305-d milk yield (MY305), 305-d fat yield (FY305), 305-d protein yield (PY305), and somatic cell score (SCS). Records from 6,418 lactations generated by 5,121 animals were available for the analysis. Vaccination status of each animal was obtained from producer-recorded information. Confounding variables considered were herd-year-season groups (56 levels), parity (5 levels: 1, 2, 3, 4, and ≥5), and genetic quartile groups (4 levels: top 25% through bottom 25%) derived from genetic predictions for MY305, FY305, PY305, and SCS, as well as for the genetic susceptibility to mastitis. A logistic regression model was applied to estimate the propensity score (PS) for each cow. Subsequently, PS values were used to form pairs of animals (1 vaccinated with 1 unvaccinated control), depending on their PS similarities (difference in PS values of cows within a match required to be <20% of 1 standard deviation of the logit of PS). After the matching process, 2,091 pairs of animals (4,182 records) remained available to infer the causal effects of vaccinating dairy cows with the E. coli J5 bacterin. Causal effects estimation was performed using 2 approaches: simple matching and a bias-corrected matching. According to the PS methodology, causal effects of vaccinating dairy cows with a J5 bacterin on their productive performance were identified for MY305. The simple matched estimator suggested that vaccinated cows produced 163.89 kg more milk over an entire lactation when compared with nonvaccinated counterparts, whereas the bias-corrected estimator suggested that such increment in milk production was of 150.48 kg. Conversely, no causal effects of immunizing dairy cows with a J5 bacterin were identified for FY305, PY305, or SCS. In conclusion, the utilization of PS matching techniques applied to farm-recorded data was feasible and allowed us to identify that vaccination with an E. coli J5 bacterin relates to an overall milk production increment without compromising milk quality.


Assuntos
Doenças dos Bovinos , Infecções por Escherichia coli , Mastite Bovina , Gravidez , Feminino , Bovinos , Animais , Escherichia coli , Infecções por Escherichia coli/prevenção & controle , Infecções por Escherichia coli/veterinária , Pontuação de Propensão , Mastite Bovina/prevenção & controle , Mastite Bovina/metabolismo , Lactação , Vacinação/veterinária , Leite/metabolismo , Vacinas Bacterianas , Doenças dos Bovinos/metabolismo
3.
J Neuroinflammation ; 19(1): 292, 2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36482444

RESUMO

The hippocampus is a plastic brain area that shows functional segregation along its longitudinal axis, reflected by a higher level of long-term potentiation (LTP) in the CA1 region of the dorsal hippocampus (DH) compared to the ventral hippocampus (VH), but the mechanisms underlying this difference remain elusive. Numerous studies have highlighted the importance of microglia-neuronal communication in modulating synaptic transmission and hippocampal plasticity, although its role in physiological contexts is still largely unknown. We characterized in depth the features of microglia in the two hippocampal poles and investigated their contribution to CA1 plasticity under physiological conditions. We unveiled the influence of microglia in differentially modulating the amplitude of LTP in the DH and VH, showing that minocycline or PLX5622 treatment reduced LTP amplitude in the DH, while increasing it in the VH. This was recapitulated in Cx3cr1 knockout mice, indicating that microglia have a key role in setting the conditions for plasticity processes in a region-specific manner, and that the CX3CL1-CX3CR1 pathway is a key element in determining the basal level of CA1 LTP in the two regions. The observed LTP differences at the two poles were associated with transcriptional changes in the expression of genes encoding for Il-1, Tnf-α, Il-6, and Bdnf, essential players of neuronal plasticity. Furthermore, microglia in the CA1 SR region showed an increase in soma and a more extensive arborization, an increased prevalence of immature lysosomes accompanied by an elevation in mRNA expression of phagocytic markers Mertk and Cd68 and a surge in the expression of microglial outward K+ currents in the VH compared to DH, suggesting a distinct basal phenotypic state of microglia across the two hippocampal poles. Overall, we characterized the molecular, morphological, ultrastructural, and functional profile of microglia at the two poles, suggesting that modifications in hippocampal subregions related to different microglial statuses can contribute to dissect the phenotypical aspects of many diseases in which microglia are known to be involved.


Assuntos
Plasticidade Neuronal , Masculino , Animais , Camundongos
4.
Helminthologia ; 58(3): 315-322, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34934393

RESUMO

The tayra Eira barbara is a Neotropical mustelid considered as an endangered species by Mexican environmental authorities. Despite the considerable information available on the biology and ecology of E. barbara, little is known about its helminth fauna. Here, we provided new records of nematodes from a road-killed tayra in Calakmul, Campeche, Mexico. The species identification of nematodes was based on morphological studies and molecular analysis of fragments of the 28S gene. The tayra specimen was infected by three nematodes: Molineus sp., Physalopterinae gen. sp. and Angiostrongylus vasosum. To our knowledge, this study is the first to report the natural infection of E. barbara with Molineus sp. and Physalopterinae gen. sp. Our study provides the first nucleotide sequences of nematodes parasitizing E. barbara providing a starting point against which future studies may be compared.

5.
Neurobiol Dis ; 120: 139-150, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30201312

RESUMO

An increasing number of rare mutations linked to autism spectrum disorders have been reported in genes encoding for proteins involved in synapse formation and maintenance, such as the post-synaptic cell adhesion proteins neuroligins. Most of the autism-linked mutations in the neuroligin genes map on the extracellular protein domain. The autism-linked substitution R451C in Neuroligin3 (NLGN3) induces a local misfolding of the extracellular domain, causing defective trafficking and retention of the mutant protein in the endoplasmic reticulum (ER). The activation of the unfolded protein response (UPR), due to misfolded proteins accumulating in the ER, has been implicated in pathological and physiological conditions of the nervous system. It was previously shown that the over-expression of R451C NLGN3 in a cellular system leads to the activation of the UPR. Here, we have investigated whether this protective cellular response is detectable in the knock-in mouse model of autism endogenously expressing R451C NLGN3. Our data showed up-regulation of UPR markers uniquely in the cerebellum of the R451C mice compared to WT littermates, at both embryonic and adult stages, but not in other brain regions. Miniature excitatory currents in the Purkinje cells of the R451C mice showed higher frequency than in the WT, which was rescued inhibiting the PERK branch of UPR. Taken together, our data indicate that the R451C mutation in neuroligin3 elicits UPR in vivo, which appears to trigger alterations of synaptic function in the cerebellum of a mouse model expressing the R451C autism-linked mutation.


Assuntos
Transtorno Autístico/metabolismo , Moléculas de Adesão Celular Neuronais/metabolismo , Cerebelo/metabolismo , Modelos Animais de Doenças , Ácido Glutâmico/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Resposta a Proteínas não Dobradas/fisiologia , Animais , Transtorno Autístico/genética , Moléculas de Adesão Celular Neuronais/genética , Cerebelo/patologia , Proteínas de Membrana/genética , Camundongos , Camundongos da Linhagem 129 , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Transmissão Sináptica/fisiologia
6.
Epidemiol Infect ; 145(11): 2287-2295, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28689507

RESUMO

The house mouse (Mus musculus) and the black rat (Rattus rattus) are reservoir hosts for zoonotic pathogens, several of which cause neglected tropical diseases (NTDs). Studies of the prevalence of these NTD-causing zoonotic pathogens, in house mice and black rats from tropical residential areas are scarce. Three hundred and two house mice and 161 black rats were trapped in 2013 from two urban neighbourhoods and a rural village in Yucatan, Mexico, and subsequently tested for Trypanosoma cruzi, Hymenolepis diminuta and Leptospira interrogans. Using the polymerase chain reaction we detected T. cruzi DNA in the hearts of 4·9% (8/165) and 6·2% (7/113) of house mice and black rats, respectively. We applied the sedimentation technique to detect eggs of H. diminuta in 0·5% (1/182) and 14·2% (15/106) of house mice and black rats, respectively. Through the immunofluorescent imprint method, L. interrogans was identified in 0·9% (1/106) of rat kidney impressions. Our results suggest that the black rat could be an important reservoir for T. cruzi and H. diminuta in the studied sites. Further studies examining seasonal and geographical patterns could increase our knowledge on the epidemiology of these pathogens in Mexico and the risk to public health posed by rodents.


Assuntos
Doença de Chagas/veterinária , Himenolepíase/veterinária , Leptospirose/veterinária , Camundongos , Ratos , Doenças dos Roedores/epidemiologia , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Reservatórios de Doenças/microbiologia , Reservatórios de Doenças/parasitologia , Meio Ambiente , Himenolepíase/epidemiologia , Himenolepíase/parasitologia , Hymenolepis diminuta/isolamento & purificação , Leptospira interrogans/isolamento & purificação , Leptospirose/epidemiologia , Leptospirose/microbiologia , México/epidemiologia , Prevalência , Doenças dos Roedores/microbiologia , Doenças dos Roedores/parasitologia , Roedores , Trypanosoma cruzi/isolamento & purificação , Zoonoses/epidemiologia , Zoonoses/microbiologia , Zoonoses/parasitologia
7.
J Oral Rehabil ; 44(2): 81-88, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27973713

RESUMO

The presence of body posture changes among patients with temporomandibular disorders (TMD) has been a controversial topic in dentistry. Based on that, the aim of this study was to assess postural features of pain-free subjects with internal derangement of the temporomandibular joint (TMJ), viz. disc displacement, when compared to subjects with normal disc position. A total of 21 subjects with unilateral, pain-free TMJ disc displacement (DD) and 21 subjects without any TMD signs of symptoms were assessed for body posture changes by means of posturographic evaluation of several body segments and postural balance reactions through the centre of mass during jaw movements using a balance platform. Posturographic measurements showed the absence of any significant differences between the two groups in any of the outcome parameters. Similarly, all balance platform responses to mandibular movements were not different between groups. There are no significant differences in body posture between subjects with and without unilateral disc displacement in the temporomandibular joint. Such observations, indicating a well-preserved postural balance in the presence of TMJ internal derangement, put into serious question the potential influence of TMJ disorders on whole body posture and viceversa.


Assuntos
Dor Facial/fisiopatologia , Cabeça/anatomia & histologia , Má Oclusão/fisiopatologia , Postura/fisiologia , Transtornos da Articulação Temporomandibular/fisiopatologia , Análise de Variância , Estudos de Casos e Controles , Oclusão Dentária , Feminino , Humanos , Masculino , Côndilo Mandibular/fisiopatologia , Músculos da Mastigação/fisiopatologia , Reprodutibilidade dos Testes , Adulto Jovem
8.
Nanotechnology ; 27(23): 235502, 2016 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-27125568

RESUMO

The measurement of local temperature in nanoscale volumes is becoming a technological frontier. Photoluminescent nanoparticles and nanocolloids are the natural choice for nanoscale temperature probes. However, the influence of a surrounding liquid on the cryogenic behavior of oxidized Si-nanocrystals (Si-NCs) has never been investigated. In this work, the photoluminescence (PL) of oxidized Si-NCs/alcohol based nanocolloids is measured as a function of the temperature and the molecule length of monohydric alcohols above their melting-freezing point. The results unveil a progressive blue shift on the emission peak which is dependent on the temperature as well as the dielectric properties of the surrounding liquid. Such an effect is analyzed in terms of thermal changes of the Si-NCs bandgap, quantum confinement and the polarization effects of the embedding medium; revealing an important role of the dielectric constant of the surrounding liquid. These results are relevant because they offer a general insight to the fundamental behavior of photoluminescent nanocolloids under a cooling process and moreover, enabling PL tuning based on the dielectric properties of the surrounding liquid. Hence, the variables required to engineer PL of nanofluids are properly identified for use as temperature sensors at the nanoscale.

9.
J Chem Phys ; 144(23): 234511, 2016 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-27334183

RESUMO

Theoretical results for the absorption spectrum and electric properties of the enol and keto tautomeric forms of anil derivatives in the gas-phase and in solution are presented. The electronic properties in chloroform, acetonitrile, methanol, and water were determined by carrying out sequential Monte Carlo simulations and quantum mechanics calculations based on the time dependent density functional theory and on the second-order Møller-Plesset perturbation theory method. The results illustrate the role played by electrostatic interactions in the electronic properties of anil derivatives in a liquid environment. There is a significant increase of the dipole moment in solution (20%-100%) relative to the gas-phase value. Solvent effects are mild for the absorption spectrum and linear polarizability but they can be particularly important for first hyperpolarizability. A large first hyperpolarizability contrast between the enol and keto forms is observed when absorption spectra present intense lowest-energy absorption bands. Dynamic results for the first hyperpolarizability are in qualitative agreement with the available experimental results.

10.
J Chem Phys ; 143(23): 234503, 2015 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-26696062

RESUMO

We present theoretical results for the dipole moment, linear polarizability, and first hyperpolarizability of the urea and thiourea molecules in solid phase. The in-crystal electric properties were determined by applying a supermolecule approach in combination with an iterative electrostatic scheme, in which the surrounding molecules are represented by point charges. It is found for both urea and thiourea molecules that the influence of the polarization effects is mild for the linear polarizability, but it is marked for the dipole moment and first hyperpolarizability. The replacement of oxygen atoms by sulfur atoms increases, in general, the electric responses. Our second-order Møller-Plesset perturbation theory based iterative scheme predicts for the in-crystal dipole moment of urea and thiourea the values of 7.54 and 9.19 D which are, respectively, increased by 61% and 58%, in comparison with the corresponding isolated values. The result for urea is in agreement with the available experimental result of 6.56 D. In addition, we present an estimate of macroscopic quantities considering explicit unit cells of urea and thiourea crystals including environment polarization effects. These supermolecule calculations take into account partially the exchange and dispersion effects. The results illustrate the role played by the electrostatic interactions on the static second-order nonlinear susceptibility of the urea crystal.

11.
ScientificWorldJournal ; 2015: 394956, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26247057

RESUMO

A novel cross-layer optimized video adaptation driven by perceptual semantics is presented. The design target is streamed live video to enhance situational awareness in challenging communications conditions. Conventional solutions for recreational applications are inadequate and novel quality of experience (QoE) framework is proposed which allows fully controlled adaptation and enables perceptual semantic feedback. The framework relies on temporal/spatial abstraction for video applications serving beyond recreational purposes. An underlying cross-layer optimization technique takes into account feedback on network congestion (time) and erasures (space) to best distribute available (scarce) bandwidth. Systematic random linear network coding (SRNC) adds reliability while preserving perceptual semantics. Objective metrics of the perceptual features in QoE show homogeneous high performance when using the proposed scheme. Finally, the proposed scheme is in line with content-aware trends, by complying with information-centric-networking philosophy and architecture.

12.
S Afr J Surg ; 53(3 and 4): 45-47, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28240483

RESUMO

BACKGROUND: The parotid tissue can give rise to a large variety of benign and malignant neoplasms. The objective of this study was to describe the management and outcome of parotid gland tumours over a 15-year period. METHOD: The records of consecutive patients treated by parotid gland excision from January 1995 to December 2008 were reviewed retrospectively. Data recorded were age, gender, history, physical findings, surgical procedure, fine-needle aspiration biopsy (FNAB), final pathological diagnosis and complications. RESULTS: The vast majority of patients (306) had benign neoplasms, and 14 patients had malignant neoplasms. Overall, pleomorphic adenoma contributed to 76% of the lesions, and Warthin's tumour to 17%. The sensitivity and specificity of FNAB was 79% and 100%, respectively. There were 15 cases of marginal mandibular transitory paresis and 12 cases of seroma. Marginal mandibular definitive paralysis was observed in three cases with malignant tumour. CONCLUSION: Standardised parotidectomy is a safe operation, with a low complication rate.

13.
J Chem Phys ; 139(9): 094502, 2013 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-24028122

RESUMO

We investigate the nuclear isotropic shielding constants σ((13)C) and σ((17)O) of isomers of retinoic acid and retinal in gas-phase and in chloroform, acetonitrile, methanol, and water solutions via Monte Carlo simulation and quantum mechanics calculations using the GIAO-B3LYP∕6-311++G(2d,2p) approach. Electronic solute polarization effects due to protic and aprotic solvents are included iteratively and play an important role in the quantitative determination of oxygen shielding constants. Our MP2∕6-31G+(d) results show substantial increases of the dipole moment of both retinal derivatives in solution as compared with the gas-phase results (between 22% and 26% in chloroform and between 55% and 99% in water). For the oxygen atoms the influence of the solute polarization is mild for σ((17)O) of hydroxyl group, even in protic solvents, but it is particularly important for σ((17)O) of carbonyl group. For the latter, there is a sizable increase in the magnitude with increasing solvent polarity. For the carbon atoms, the solvent effects on the σ((13)C) values are in general small, being more appreciable in carbon atoms of the polyene chain than in the carbon atoms of the ß-ionone ring and methyl groups. The results also show that isomeric changes on the backbones of the polyene chains have marked influence on the (13)C chemical shifts of carbon atoms near to the structural distortions, in good agreement with the experimental results measured in solution.


Assuntos
Acetonitrilas/química , Clorofórmio/química , Metanol/química , Retinaldeído/química , Água/química , Isótopos de Carbono , Campos Magnéticos , Simulação de Dinâmica Molecular , Método de Monte Carlo , Isótopos de Oxigênio , Teoria Quântica , Retinaldeído/análogos & derivados , Solventes/química , Tretinoína/química
15.
Braz J Biol ; 83: e271954, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37132743

RESUMO

Chenopodium quinoa Willd. it is an Andean cereal of great importance for human consumption due to its high nutritional value. In Colombia there is a high phenotypic and genotypic variability within quinoa crops, which has not been studied and has been maintained by the same farmers cycle after production cycle. The objective of this study was to carry out an interpopulation characterization of quinoa cultivated in different producing municipalities of the department of Boyacá, in Colombia, for which 19 morphological descriptors were used, which were evaluated in situ in nine municipalities and analyzed through descriptive statistics, principal component analysis, correlation and conglomerates. In the evaluation of the quantitative traits for all the populations, it was observed that the most variable descriptors were Number of teeth lower leaf (DHI), Lower leaf length (LHI), Width upper leaf (AHI) and Number of teeth upper leaf (DHS). Great segregation between and within individuals of Blanca de Jericó and Piartal was observed for panicle and leaf color and shape, stem color, presence of teeth, and axils on upper and lower leaves. A classification key is proposed that allows in the field to be able to morphologically differentiate the genotypes of Piartal and Blanca de Jericó. This research shows that among the most cultivated genotypes in the department of Boyacá, there is still an important phenotypic diversity given at the inter and intra-individual level, due to the phenological state and the agroclimatological conditions of the different producing regions.


Assuntos
Chenopodium quinoa , Humanos , Chenopodium quinoa/genética , Colômbia , Grão Comestível , Fenótipo , Genótipo
16.
bioRxiv ; 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-36993629

RESUMO

Neural circuit function is shaped both by the cell types that comprise the circuit and the connections between those cell types 1 . Neural cell types have previously been defined by morphology 2, 3 , electrophysiology 4, 5 , transcriptomic expression 6-8 , connectivity 9-13 , or even a combination of such modalities 14-16 . More recently, the Patch-seq technique has enabled the characterization of morphology (M), electrophysiology (E), and transcriptomic (T) properties from individual cells 17-20 . Using this technique, these properties were integrated to define 28, inhibitory multimodal, MET-types in mouse primary visual cortex 21 . It is unknown how these MET-types connect within the broader cortical circuitry however. Here we show that we can predict the MET-type identity of inhibitory cells within a large-scale electron microscopy (EM) dataset and these MET-types have distinct ultrastructural features and synapse connectivity patterns. We found that EM Martinotti cells, a well defined morphological cell type 22, 23 known to be Somatostatin positive (Sst+) 24, 25 , were successfully predicted to belong to Sst+ MET-types. Each identified MET-type had distinct axon myelination patterns and synapsed onto specific excitatory targets. Our results demonstrate that morphological features can be used to link cell type identities across imaging modalities, which enables further comparison of connectivity in relation to transcriptomic or electrophysiological properties. Furthermore, our results show that MET-types have distinct connectivity patterns, supporting the use of MET-types and connectivity to meaningfully define cell types.

17.
J Chem Phys ; 136(23): 234311, 2012 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-22779597

RESUMO

Using the Hartree-Fock (HF) and second-order Mo̸ller-Plesset perturbation theory (MP2) methods with the 6-31G(d) basis set, we have investigated the chain length dependence of the longitudinal dipole moment and longitudinal components of the static linear polarizability, first and second hyperpolarizabilities of fluorinated polyacetylene chains. It is found that geometry changes caused by the electron correlation (EC) effects imply in marked increases of the electric properties but to obtain a reliable description it is necessary to properly account for both geometric and electronic changes. Based on the fast convergence pattern presented by the MP2∕HF ratios and from the converged HF oligomeric results, we have estimated the MP2 electric properties of long chains. The asymptotic value for the MP2 second hyperpolarizability per unit cell is estimated in 1.9 × 10(8) a.u. This result is one order of magnitude larger than the corresponding result reported for the unsubstituted polyacetylene chains.

18.
Sci Rep ; 12(1): 12030, 2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35835771

RESUMO

An array of spin torque nano-oscillators (STNOs), coupled by dipolar interaction and arranged on a ring, has been studied numerically and analytically. The phase patterns and locking ranges are extracted as a function of the number N, their separation, and the current density mismatch between selected subgroups of STNOs. If [Formula: see text] for identical current densities through all STNOs, two degenerated modes are identified an in-phase mode (all STNOs have the same phase) and a splay mode (the phase makes a 2[Formula: see text] turn along the ring). When inducing a current density mismatch between two subgroups, additional phase shifts occur. The locking range (maximum current density mismatch) of the in-phase mode is larger than the one for the splay mode and depends on the number N of STNOs on the ring as well as on the separation. These results can be used for the development of magnetic devices that are based on STNO arrays.

19.
Cytokine ; 50(3): 335-40, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20231101

RESUMO

Previously, we have shown that electroacupuncture (EA) in rats decreased eosinophil infiltration into the pulmonary tissue (PT) and in the bronchoalveolar lavage (BAL) in an experimental model of asthma. Th2 cytokines, leukotriene B4 (LTB4) and nitric oxide (NO) are involved in the asthma inflammatory process. The aim of this study was to verify the effects of EA on these asthma mediators. Male Wistar rats were divided into control (C), immobilized (I), sham acupuncture (SA), and acupuncture (A) groups. All rats were sensitized, and EA treatment using clinical acupuncture points was started 24h after antigen priming. EA was done every other day for 2weeks. Subsequently, animals were challenged by inhalation and sacrificed 24h later. At this time, the BAL and lungs were collected and used to analyze cytokine production, LTB4 and NO. The EA increased IL-1 and IFN-gamma and decreased IL-4, IL-10, NO and LTB4 in the BAL and PT compared to the C and SA groups. The presence of eosinophils in the BAL negatively correlated with IL-1 and IFN-gamma production and positively correlated with IL-4 and IL-10 production. Our results show that the beneficial anti-inflammatory action of EA on asthma is related to the balance of the Thl/Th2 response and the reduction of LTB4 and NO. These results suggest that EA therapy could be an important complementary treatment for asthma.


Assuntos
Asma/imunologia , Citocinas/imunologia , Eletroacupuntura , Inflamação/imunologia , Leucotrieno B4/imunologia , Óxido Nítrico/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Líquido da Lavagem Broncoalveolar/imunologia , Eosinófilos/imunologia , Humanos , Masculino , Ratos , Ratos Wistar , Células Th1/imunologia , Células Th2/imunologia
20.
J Chem Phys ; 133(14): 144103, 2010 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-20949983

RESUMO

The dipole moment (µ), linear polarizability (α), and first hyperpolarizability (ß(tot)) of the asymmetric unit of L-arginine phosphate (LAP) monohydrate crystal are investigated using the supermolecule approach in combination with an iterative electrostatic polarization scheme. Environment polarization effects are attained by assuring the convergence of the dipole moment of LAP embedded in the polarization field of the surrounding molecules whose atomic sites are treated as point charges. The results obtained show that in the presence of the embedding charges, the value of µ is increased by 9% but the static values of α and ß(tot) are decreased, respectively, by 3% and 13%, as compared with the isolated situation. The MP2/6-311+G(d) model predicts for the in-crystal dipole moment the converged value of 33 D, in good concordance with the available experimental result of 32 D. Our estimates for the converged results of α and ß(tot) are, respectively, 22.51×10(-24) and 5.01×10(-30) esu. Dispersion effects are found to have a small impact on the nonlinear optical responses of LAP in the visible region. In addition, MP2/6-311G results obtained for ß(tot) by using isolated and embedded LAP dimers show that crystal packing effects have a significant contribution of the electrostatic interactions. Our results suggest that the role of the crystal environment is to minimize the effects of the intermolecular interactions in the electric properties. That is, µ and ß(tot) gain a more additive character in the presence of the field of the embedding charges. This is specially marked for ß(tot).

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