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Ventricular arrhythmias, consisting of single ectopic beats (sEB), multiple EB (mEB), and torsades de pointes (TdP, defined as ≥5 beats with QRS vector twisting around isoelectric line) can be induced in the anesthetized chronic atrioventricular block (CAVB) dog by dofetilide (IKr blocker). The interplay between temporal dispersion of repolarization, quantified as short-term variability (STV), and spatial dispersion of repolarization (SDR) in the initiation and perpetuation of these arrhythmias remains unclear. Five inducible (≥3 TdPs/10 min) CAVB dogs underwent one mapping experiment and were observed for 10 min from the start of dofetilide infusion (0.025 mg/kg, 5 min). An intracardiac decapolar electrogram (EGM) catheter and 30 intramural cardiac needles in the left ventricle (LV) were introduced. STVARI was derived from 31 consecutive activation recovery intervals (ARIs) on the intracardiac EGM, using the formula: [Formula: see text]. The mean SDR3D in the LV was determined as the three-dimensional repolarization time differences between the intramural cardiac needles. Moments of measurement included baseline (BL) and after dofetilide infusion before first 1) sEB (occurrence at 100 ± 35 s), 2) mEB (224 ± 96 s), and 3) non-self-terminating TdP (454 ± 298 s). STVARI increased from 2.15 ± 0.32 ms at BL to 3.73 ± 0.99 ms* before the first sEB and remained increased without further significant progression to mEB (4.41 ± 0.45 ms*) and TdP (5.07 ± 0.84 ms*) (*P < 0.05 compared with BL). SDR3D did not change from 31 ± 11 ms at BL to 43 ± 13 ms before sEB but increased significantly before mEB (68 ± 7 ms*) and to TdP (86 ± 9 ms*+) (+P < 0.05 compared with sEB). An increase in STV contributes to the initiation of sEB, whereas an increase in SDR is important for the perpetuation of non-self-terminating TdPs.NEW & NOTEWORTHY This study compared two well-established electrophysiological parameters, being temporal and spatial dispersion of repolarization, and provided new insights into their interplay in the arrhythmogenesis of torsades de pointes arrhythmias. Although it confirmed that an increase in temporal dispersion of repolarization contributes to the initiation of single ectopic beats, it showed that an increase in spatial dispersion of repolarization is important for the perpetuation of non-self-terminating torsades de pointes arrhythmias.
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Bloqueio Atrioventricular/fisiopatologia , Modelos Cardiovasculares , Torsades de Pointes/fisiopatologia , Potenciais de Ação , Animais , Bloqueio Atrioventricular/complicações , Cães , Feminino , Masculino , Tempo de Reação , Torsades de Pointes/etiologiaRESUMO
BACKGROUND: Patients with cardiac sarcoidosis (CS) are at increased risk of life-threatening ventricular arrhythmias (VA). Current approaches to risk stratification have limited predictive value. OBJECTIVES: To assess the utility of spatial dispersion analysis of late gadolinium enhancement cardiac magnetic resonance (LGE-CMR), as a quantitative measure of myocardial tissue heterogeneity, in risk stratifying patients with CS for VA and death. METHODS: Sixty two patients with CS underwent LGE-CMR. LGE images were segmented and dispersion maps of the left and right ventricles were generated as follows. Based on signal intensity (SI), each pixel was categorized as abnormal (SI ≥3SD above the mean), intermediate (SI 1-3 SD above the mean) or normal (SI <1SD above the mean); and each pixel was then assigned a value of 0 to 8 based on the number of adjacent pixels of a different category. Average dispersion score was calculated for each patient. The primary endpoint was VA during follow up. The composite of VA or death was assessed as a secondary endpoint. RESULTS: During 4.7 ± 3.5 years of follow up, six patients had VA, and five without documented VA died. Average dispersion score was significantly higher in patients with VA versus those without (0.87 ± 0.08 vs. 0.71 ± 0.16; p = .002) and in patients with events versus those without (0.83 ± 0.08 vs. 0.70 ± 0.16; p = .003). Patients at higher tertiles of dispersion score had a higher incidence of VA (p = .03) and the composite of VA or death (p = .01). CONCLUSIONS: Increased substrate heterogeneity, quantified by spatial dispersion analysis of LGE-CMR, may be helpful in risk-stratifying patients with CS for adverse events, including life-threatening arrhythmias.
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Arritmias Cardíacas/diagnóstico por imagem , Arritmias Cardíacas/etiologia , Imageamento por Ressonância Magnética/métodos , Sarcoidose/complicações , Sarcoidose/diagnóstico por imagem , Meios de Contraste , Feminino , Gadolínio , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Medição de RiscoRESUMO
BACKGROUND: Visceral leishmaniasis (VL) is becoming endemic in São Paulo state, in the southeastern region of Brazil. Unusual manifestations with non-specific signs and symptoms may make diagnosis difficult and delay treatment, increasing the risk of severity and death, particularly in new endemic areas. There are few studies on patients with these characteristics in Brazil. We describe a case series of unusual manifestations of VL in children and its spatial dispersion in the western region of São Paulo state. CASES PRESENTATION: From 2009 to 2014, five clinical cases involving children treated in the Regional Hospital of Presidente Prudente (RH) were selected. Two patients had multiple relapses requiring liposomal amphotericin B; one patient had VL-cytomegalovirus-dengue co-infection and liver injury; one patient was diagnosed with X-linked agammaglobulinemia, a primary immunodeficiency; and one patient was diagnosed with VL-human immunodeficiency virus/acquired immunodeficiency syndrome (VL-HIV/AIDS) co-infection. Primary or secondary immunodeficiencies were found in four children, and associated viral infections were found in three children. Three patients were referred from other hospitals to RH. With regard to the geographic spread of VL, more cases were found in the northern area, in the epicenter of the infection where the first cases were registered, flowing south; a spatial-temporal occurrence was found. CONCLUSIONS: Primary and secondary immunodeficiencies and viral co-infectious should be considered among unusual manifestations of VL, especially in those with multiple relapses. Spatial-temporal occurrence was found. Thus, integrated actions and effective monitoring of the disease are needed to complement curative practices to stem the tide of the epidemic.
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Síndromes de Imunodeficiência/etiologia , Leishmaniose Visceral/etiologia , Síndrome da Imunodeficiência Adquirida/etiologia , Agamaglobulinemia/etiologia , Anfotericina B/uso terapêutico , Animais , Antiprotozoários/uso terapêutico , Brasil/epidemiologia , Criança , Pré-Escolar , Coinfecção/etiologia , Infecções por Citomegalovirus/etiologia , Cães , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/etiologia , Humanos , Lactente , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/epidemiologia , MasculinoRESUMO
The invasive larger grain borer (Prostephanus truncatus) and the maize weevil (Sitophilus zeamais) co-occur in many regions of the world. While competition between these 2 species has been studied extensively, there is little information on spatial dispersion patterns in bulk storage of grain. To evaluate potential overlap in realized niche, we evaluated the short-term spatial dispersion behavior of P. truncatus and S. zeamais in monolayers of maize alone or together for 1 day compared to 7 days. We evaluated competition under three different densities, namely 10-20, 75-150, and 150-300 insects/kg for P. truncatus and S. zeamais. The monolayers were equally divided into 24 zones to track location the abundance of insects and damage to maize. We found that both species generally aggregated together and were correlated to the same location as heterospecifics. After 1 day, most of the insects for both species were near the top of the monolayer, but by 7 days, most individuals were at the bottom of the monolayers. In monolayers, when alone, P. truncatus created a clear path of destruction to the bottom of the monolayer, but when S. zeamais was present, damage was lessened and shifted upwards in the grain column. In an olfactometer assay, P. truncatus preferred maize odors, while S. zeamais exhibited no preference among maize, conspecifics, and heterospecifics. In evaluating relative emissions, each of these treatments emitted unique odors but with significant overlap. These data may improve targeting of chemical control tactics by identifying the position of these insects in the grain mass.
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Besouros , Gorgulhos , Humanos , Animais , Grão Comestível , Odorantes , Zea maysRESUMO
Ultrashort optical pulses are integral to probing various physical, chemical, and biological phenomena and feature in a whole host of applications, not least in data communications. Super- and subluminal pulse propagation and dispersion management (DM) are two of the greatest challenges in producing or counteracting modifications of ultrashort optical pulses when precise control over pulse characteristics is required. Progress in modern photonics toward integrated solutions and applications has intensified this need for greater control of ultrafast pulses in nanoscale dimensions. Metamaterials, with their unique ability to provide designed optical properties, offer a new avenue for temporal pulse engineering. Here an epsilon-near-zero metamaterial is employed, exhibiting strong nonlocal (spatial dispersion) effects, to temporally shape optical pulses. The authors experimentally demonstrate, over a wide bandwidth of tens of THz, the ability to switch from sub to superluminal and further to "backward" pulse propagation (±c/20) in the same metamaterial device by simply controlling the angle of illumination. Both the amplitude and phase of a 10 ps pulse can be controlled through DM in this subwavelength device. Shaping ultrashort optical pulses with metamaterials promises to be advantageous in laser physics, optical communications, imaging, and spectroscopy applications using both integrated and free-standing devices.
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The level of energy green consumption is an essential factor influencing China's economy's high-quality development. In this paper, we select relevant panel data from 2010 to 2019 for 28 cities in Beijing-Tianjin-Hebei and surrounding areas, and use the DPSIR model and spatial econometric model to analyze the spatial divergence characteristics and driving factors of the energy green consumption index based on the construction of the energy green consumption level evaluation index system and index measurement. The results of this research are as follows: (1) The energy green consumption index has a distribution pattern of "high in the east and low in the west, high in the north, and low in the south," and the driving force (D) and response force (I) are the key factors influencing the spatial variation of the energy green consumption index. (2) The measurement results show that GDP per capita and built-up green coverage have a considerable positive effect on the energy green consumption index, whereas non-domestic energy structure has a significant inhibitory effect. (3) In terms of spatial spillover effects, greening coverage of built-up areas, industrial structure, and domestic energy structure, all have positive effects on neighboring regions' energy green consumption indexes, with positive spatial spillover effects, whereas GDP per capita, urbanization level, and non-domestic energy structure, all have negative spatial spillover effects. In light of the issues at hand, this paper suggests making good efforts to create and put into practice laws and policy norms, cultivate green energy-saving markets, vigorously promote the use and promotion of energy-saving technologies, and lower energy consumption in secondary industry and domestic consumption. The study's findings can help advance the modernization of the region's industrial structure and the growth of a green economy by providing the local government with a reference point for timely policy adjustments.
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Indústrias , Urbanização , Cidades , Pequim , Desenvolvimento Econômico , ChinaRESUMO
Background: An electrical storm of Torsade de Pointes arrhythmias (TdP) can be reproducibly induced in the anesthetized chronic AV-block (CAVB) dog by infusion of the IKr-blocker dofetilide. Earlier studies showed that these arrhythmias 1) arise from locations with high spatial dispersion in repolarization (SDR) and 2) can be suppressed by high-rate pacing. We examined whether suppression of TdP by high-rate pacing is established through a decrease in SDR in the CAVB dog. Methods: Dofetilide (25 µg/kg in 5 min) was administered to 5 anesthetized CAVB dogs to induce TdP arrhythmias. During the experiments, animals were continuously paced from the right ventricular apex at 50 beats/minute (RVA50). Upon TdP occurrence and conversion, RVA pacing was consecutively set to 100, 80 and 60 beats/minute for 2 min, referred to as pacing blocks. To determine the additional anti-arrhythmic effects of HRP over defibrillation alone, the number of arrhythmic events and SDR at RVA100 were compared to data from three previously conducted experiments, in which dogs underwent the same experimental protocol but were paced at RVA60 upon TdP occurrence (RVA60retro). In all experiments, recordings included surface electrocardiogram and mapping by 56 intramural needles, each recording four electrograms, evenly inserted into the ventricular walls and septum. For each pacing block, the number of ectopic beats (EB), and TdP severity were scored. SDR was quantified as the average difference in repolarization time within four squared needles (SDRcubic). Results: In 4 out of 5 animals, pacing at RVA100 suppressed TdP occurrence. One dog could not be converted by defibrillation after the initial TdP. Compared to RVA50, pacing at RVA100, but not RVA80 and RVA60, significantly reduced the TdP score (78 ± 33 vs. 0 ± 0, p < 0.05 and vs. 12.5 ± 25 and 25 ± 50, both p > 0.05). The reduction in TdP score was reflected by a significant decrease in SDRcubic (125 ± 46 ms before TdP vs. 49 ± 18 ms during RVA100, p < 0.05), and SDR was smaller than in the RVA60retro animals (101 ± 52 ms, p < 0.05 vs. RVA100). Conclusion: In CAVB dogs, high-rate pacing effectively suppresses TdP, which, at least in part, results from a spatial homogenization of cardiac repolarization, as reflected by a decrease in SDR.
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Open cast mining - a predominant method of coal production in India (94.46% of total coal production) - has been found to be a major factor which is responsible for the emission of dust particles and gaseous pollutants, leading to the deterioration of air quality in the coal mining area. Considering the health concerns and environmental impacts of these pollutants, the inhabited villages of Ib valley coalfield area of Orisha, India, were selected for this study. In this regard, various researchers have performed the analysis of air quality data and modeling for the dispersion of pollutants. However, a long-term study on spatial and seasonal variations of air pollutants and their relationship with meteorological parameters were missing in the literature. Accordingly, the spatial and seasonal variations of air pollutants in the area were assessed for a period of six years (2014 - 2020), and concentrations of PM2.5, PM10, and SPM were found to be above the annual national ambient air quality standards (NAAQS) for all the three seasons. The overall mean concentrations of NOx, PM10, PM2.5, SPM, and SO2 during this period were found to be 17.2 ± 9.28, 152.5 ± 99.7, 53.27 ± 37.70, 268.5 ± 158.2, and 12.58 ± 7.47 µg/m3, respectively. The analysis of meteorological parameters showed a strong and significant negative correlation of relative humidity with PM2.5 (r = - 0.30, p-value = 5.659 × 10-10), PM10 (r = - 0.36, p-value = 1.97 × 10-13), and SPM (r = - 0.45, p-value = 2.2 × 10-16). Furthermore, the spatial distribution of pollutants was performed using the geographic information system (GIS) and inverse distance weighting (IDW) method, wherein the seasonal distribution of pollutants was shown through the bivariate polar plots. Therefore, the analyses and recommendations provided in this study can help the policymakers in developing a long-term air quality improvement strategy around a coal mining area, including the spatial and seasonal variations of air pollutants and their relationship with meteorological parameters.
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Poluentes Atmosféricos , Poluição do Ar , Minas de Carvão , Poluentes Ambientais , Material Particulado/análise , Estações do Ano , Poluentes Ambientais/análise , Monitoramento Ambiental/métodos , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Dióxido de Enxofre/análise , Índia , Carvão Mineral/análiseRESUMO
This work is a first approach to investigate the role of spatial dispersion in photonic hypercrystals (PHCs). The scope of the presented analysis is focused on exploiting nonlocality, which can be controlled by appropriate design of the structure, to obtain new light generation effects in a distributed feedback (DFB) laser based on PHC, which are not observable under weak spatial dispersion. Here, we use effective medium approximation and our original model of threshold laser generation based on anisotropic transfer matrix method. To unequivocally identify nonlocal generation phenomena, the scope of our analysis includes comparison between local and nonlocal threshold generation spectra, which may be obtained for different geometries of PHC structure. In particular, we have presented that, in the presence of strong spatial dispersion, it is possible to obtain spectrally shifted Bragg wavelengths of TE- and TM-polarization spectra, lowered generation threshold levels for both light polarizations, generation of light of selected light polarization (TE or TM), or simultaneous generation of TE- and TM-polarized waves at different frequencies with controllable spectral separation, instead of single mode operation anticipated with local approach.
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Hereby, we present an optical isolator (optical diode) based on a hyperbolic metamaterial (HMM). We demonstrate that a grating-free planar linear non-magnetic HMM structure deposited on a high-index substrate, which, due to presence of strong spatial dispersion (non-locality), reveals asymmetrical transmittance and reflectance characteristics for light of arbitrary polarization within a wide angular and spectral range. The presented device may be efficiently utilized to completely block backward and enforce unidirectional propagation in free space and integrated systems without the use of magnetooptical or non-linear effects.
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In this work, we study the effect of spatial dispersion on propagation properties of planar waveguides with the core layer formed by hyperbolic metamaterial (HMM). In our case, the influence of spatial dispersion was controlled by changing the unit cell's dimensions. Our analysis revealed a number of new effects arising in the considered waveguides, which cannot be predicted with the help of local approximation, including mode degeneration (existence of additional branch of TE and TM high-ß modes), power flow inversion, propagation gap, and plasmonic-like modes characterized with long distance propagation. Additionally, for the first time we reported unusual characteristic points appearing for the high-ß TM mode of each order corresponding to a single waveguide width for which power flow tends to zero and mode stopping occurs.
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This protocol focuses on the quantitative description of the angioarchitecture of experimental tumor xenografts. This semiautomatic analysis is carried out on functional vessels and microvessels acquired by confocal imaging and processed into progressively reconstructed angioarchitectures following a caliber-classification step. The protocol can be applied also to the quantification of pathological angioarchitectures other than tumor grafts as well as to the microvasculature of physiological tissue samples.
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Microscopia Confocal/métodos , Microvasos/patologia , Neoplasias/patologia , Neovascularização Patológica/patologia , Animais , Xenoenxertos/patologia , Humanos , CamundongosRESUMO
Magnetoplasmonics based on composite nanostructures is widely used in many biomedical applications. Nanostructures, consisting of a magnetic core and a gold shell, exhibit plasmonic properties, that allow the concentration of electromagnetic energy in ultra-small volumes when used, for example, in imaging and therapy. Magnetoplasmonic nanostructures have become an indispensable tool in nanomedicine. The gold shell protects the core from oxidation and corrosion, providing a biocompatible platform for tumor imaging and cancer treatment. By adjusting the size of the core and the shell thickness, the maximum energy concentration can be shifted from the ultraviolet to the near infrared, where the depth of light penetration is maximum due to low scattering and absorption by tissues. A decrease in the thickness of the gold shell to several nanometers leads to the appearance of the quantum effect of spatial dispersion in the metal. The presence of the quantum effect can cause both a significant decrease in the level of energy concentration by plasmon particles and a shift of the maxima to the short-wavelength region, thereby reducing the expected therapeutic effect. In this study, to describe the influence of the quantum effect of spatial dispersion, we used the discrete sources method, which incorporates the generalized non-local optical response theory. This approach made it possible to account for the influence of the nonlocal effect on the optical properties of composite nanoparticles, including the impact of the asymmetry of the core-shell structure on the energy characteristics. It was found that taking spatial dispersion into account leads to a decrease in the maximum value of the concentration of electromagnetic energy up to 25%, while the blue shift can reach 15 nm.
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AIMS: This study investigated the contribution of the regulator of G-protein signaling 5 (Rgs5) knockout to the alteration of the action potential duration (APD) restitution and repolarizing dispersion in ventricle. METHODS AND RESULTS: The effects of Rgs5-/- were investigated by QT variance (QTv) and heart rate variability analysis of Rgs5-/- mice. Monophasic action potential analysis was investigated in isolated Rgs5-/- heart. Rgs5-/- did not promote ventricular remodeling. The 24-h QTv and QT variability index (QTVI) of the Rgs5-/- mice were higher than those of wild-type (WT) mice (P < 0.01). In WT mice, a positive correlation was found between QTv and the standard deviation of all NN intervals (r = 0.62; P < 0.01), but not in Rgs5-/- mice (R = 0.01; P > 0.05). The absence of Rgs5 resulted in a significant prolongation of effective refractory period and APD in isolated ventricle. In addition, compared with WT mice, the knockout of Rgs5 significantly deepened the slope of the APD recovery curve at all 10 sites of the heart (P < 0.01) and increased the spatial dispersions of Smax (COV-Smax) (WT: 0.28 ± 0.03, Rgs5-/-: 0.53 ± 0.08, P < 0.01). Compared with WT heart, Rgs5-/- increased the induced S1-S2 interval at all sites of heart and widened the window of vulnerability of ventricular tachyarrhythmia (P < 0.05). CONCLUSION: Our findings indicate that Rgs5-/- is an important regulator of ventricular tachyarrhythmia in mice by prolonging ventricular repolarization and increasing spatial dispersion in ventricle.
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INTRODUCTION: Torsade de pointes arrhythmias (TdP) in the chronic atrioventricular block (CAVB) dog model result from proarrhythmic factors, which trigger TdP and/or reinforce the arrhythmic substrate. This study investigated electrophysiological and arrhythmogenic consequences of severe bradycardia for TdP. METHODS: Dofetilide (25 µg/kg per 5 min) was administered to eight anesthetized, idioventricular rhythm (IVR) remodeled CAVB dogs in two serial experiments: once under 60 beats per minute (bpm), right ventricular apex paced (RVA60) conditions, once under more bradycardic IVR conditions. Recordings included surface electrocardiogram and short-term variability (STV) of repolarization from endocardial unipolar electrograms. TdP inducibility (three or more episodes within 10 min after start of dofetilide) and arrhythmic activity scores (AS) were established. Mapping experiments in 10 additional dogs determined the effect of lowering rate on STV and spatial dispersion of repolarization (SDR) in baseline. RESULTS: IVR-tested animals had longer baseline RR-interval (1,403 ± 271 ms) and repolarization intervals than RVA60 animals. Dofetilide increased STV similarly under both rhythm strategies. Nevertheless, TdP inducibility and AS were higher under IVR conditions (6/8 and 37 ± 27 vs. 1/8 and 8 ± 12 in RVA60, respectively, both p < 0.05). Mapping: Pacing from high (128 ± 10 bpm) to middle (88 ± 10 bpm) to experimental rate (61 ± 3 bpm) increased all electrophysiological parameters, including interventricular dispersion, due to steeper left ventricular restitution curves, and intraventricular SDR: maximal cubic dispersion from 60 ± 14 (high) to 69 ± 17 (middle) to 84 ± 22 ms (p < 0.05 vs. high and middle rate). CONCLUSION: In CAVB dogs, severe bradycardia increases the probability and severity of arrhythmic events by heterogeneously causing electrophysiological instability, which is mainly reflected in an increased spatial, and to a lesser extent temporal, dispersion of repolarization.
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The spread of H5 highly pathogenic avian influenza viruses poses serious threats to the poultry industry, wild bird ecology and human health. Circulation of H5 viruses between poultry and wild birds is a significant public health threat in China. Thus, viral migration networks in this region need to be urgently studied. Here, we conducted molecular genetic analyses of the hemagglutinin genes of H5 highly pathogenic avian influenza viruses in multiple hosts from 2000 to 2018 in China. Our aim was to clarify the roles of different hosts in the evolution of H5 viruses. We used a flexible Bayesian statistical framework to simulate viral space diffusion and continuous-time Markov chains to infer the dynamic evolutionary process of spatiotemporal dissemination. Bayesian phylogeographic analysis of H5 viruses showed for the first time that H5 viruses in poultry and wild birds were present in Guangdong Province. Furthermore, Guangdong, Jiangsu, Shanghai and Hunan acted as the epicenters for the spread of various H5 subtypes viruses in poultry, and Henan, Shanghai, Hong Kong and Inner Mongolia acted as epicenters for the spread of various H5 subtypes viruses in wild birds. Thus, H5 viruses exhibited distinct evolutionary dynamics in poultry and wild birds. Our findings extend our understanding of the transmission and spread of highly pathogenic H5 avian influenza viruses in China.
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Vírus da Influenza A , Influenza Aviária , Animais , Teorema de Bayes , China , Hong Kong , Humanos , Filogenia , Filogeografia , Aves DomésticasRESUMO
Annual influenza B virus epidemics and outbreaks cause severe influenza diseases in humans and pose a threat to public health. China is an important epidemic area of influenza B viruses. However, the spatial, temporal transmission pathways and the demography history of influenza B viruses in China remain unknown. We collected the haemagglutinin gene sequences sampled of influenza B virus in China between 1973 and 2018. A Bayesian Markov chain Monte Carlo phylogeographic discrete approach was used to infer the spatial and temporal phylodynamics of influenza B virus. The Bayesian phylogeographic analysis of influenza B viruses showed that the North subtropical and South subtropical zones are the origins of the Victoria and Yamagata lineage viruses, respectively. Furthermore, the South temperate and North subtropical zones acted as transition nodes in the Victoria lineage virus dispersion network and that the North subtropical and Mid subtropical zones acted as transition nodes in the Yamagata lineage virus dispersion network. Our findings contribute to the knowledge regarding the spatial and temporal patterns of influenza B virus outbreaks in China.
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Clima , Surtos de Doenças/estatística & dados numéricos , Vírus da Influenza B/classificação , Influenza Humana/epidemiologia , Influenza Humana/transmissão , Filogenia , Teorema de Bayes , China/epidemiologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza B/patogenicidade , Influenza Humana/virologia , Filogeografia , Análise Espaço-TemporalRESUMO
Nanostructure porous films with arrays of gold nanoparticles (Au NPs) have been produced by pulsed laser deposition. Dispersion properties of surface plasmons have been studied by the modulation-polarization spectroscopy technique. The dispersion relations for radiative modes and two types of non-radiative modes of localized and propagating surface plasmons were obtained. The branches of propagating modes were characterized by negative group velocity caused by spatial dispersion of dielectric function. The propagating modes are caused by dipole-dipole interactions between adjacent Au NPs. The frequencies and relaxation parameters of surface plasmon resonances and the plasma frequencies for Αu NPs were obtained. The relation between the surface plasmon's properties and formation conditions of films with arrays of Αu NPs is discussed.
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Periodic repolarisation dynamics (PRD) refers to low-frequency (≤0.1Hz) modulations of cardiac repolarisation instability. Spontaneous PRD can be assessed non-invasively from 3D high-resolution resting ECGs. Physiological and experimental studies have indicated that PRD correlates with efferent sympathetic nerve activity, which clusters in low-frequency bursts. PRD is increased by physiological provocations that lead to an enhancement of sympathetic activity, whereas it is suppressed by pharmacological ß-blockade. Electrophysiological studies revealed that PRD occurs independently from heart rate variability. Increased PRD under resting conditions is a strong predictor of mortality in post-myocardial infarction (post-MI) patients, yielding independent prognostic value from left-ventricular ejection fraction (LVEF), heart rate variability, the Global Registry of Acute Coronary Events score and other established risk markers. The predictive value of PRD is particularly strong in post-MI patients with preserved LVEF (>35 %) in whom it identifies a new high-risk group of patients. The upcoming Implantable Cardiac Monitors in High-Risk Post-Infarction Patients with Cardiac Autonomic Dysfunction and Moderately Reduced Left Ventricular Ejection Fraction (SMART-MI) trial will test prophylactic strategies in high-risk post-MI patients with LVEF 36-50 % identified by PRD and deceleration capacity of heart rate (NCT02594488).
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To investigate the causes of the remarkable similarity of emergent assemblage properties that has been demonstrated across disparate intertidal seagrass sites and assemblages, this study examined whether their emergent functional-group metrics are scale related by testing the null hypothesis that functional diversity and the suite of dominant functional groups in seagrass-associated macrofauna are robust structural features of such assemblages and do not vary spatially across nested scales within a 0.4 ha area. This was carried out via a lattice of 64 spatially referenced stations. Although densities of individual components were patchily dispersed across the locality, rank orders of importance of the 14 functional groups present, their overall functional diversity and evenness, and the proportions of the total individuals contained within each showed, in contrast, statistically significant spatial uniformity, even at areal scales <2 m(2). Analysis of the proportional importance of the functional groups in their geospatial context also revealed weaker than expected levels of spatial autocorrelation, and then only at the smaller scales and amongst the most dominant groups, and only a small number of negative correlations occurred between the proportional importances of the individual groups. In effect, such patterning was a surface veneer overlying remarkable stability of assemblage functional composition across all spatial scales. Although assemblage species composition is known to be homogeneous in some soft-sediment marine systems over equivalent scales, this combination of patchy individual components yet basically constant functional-group structure seems as yet unreported.