Este artigo destina-se a apresentar sob uma perspectiva didática os detalhes e procedimentos matemáticos necessários para a construção da equação diferencial quântica, sob regime relativístico, ...denominada Equação de Klein-Gordon-Fock (EK-G-F), admitindo o sistema de coordenadas da frente de luz. Para tanto, inicialmente, destacamos algumas propriedades algébricas da Teoria da Relatividade Especial de Einstein assim como apresentamos resumidamente as coordenadas da frente de luz em termos das coordenadas cartesianas e do parâmetro de evolução temporal, isto é, do espaço de Minkowski, obtendo dessa forma a EK-G-F tanto em coordenadas usuais do espaço de Minkowski, quanto em coordenadas da frente de Luz. Em seguida, para essas últimas coordenadas, desenvolvemos detalhadamente a estrutura algébrica da EK-G-F para uma partícula quântica eletricamente carregada em regime de relatividade especial e sob influência de configurações de campos magnéticos clássicos. Além disso, obtemos a EK-G-F com estrutura algébrica similar a uma equação diferencial quântica de Schrödinger. Por fim, como aplicação imediata do uso dessas coordenadas, desenvolvemos os trâmites e passos algébricos necessários para obtenção do operador de aniquilação do tipo integral de movimento, o qual configura-se como estrutura matemática necessária para construção dos estados quânticos coerentes.
This article is intended to present, from a didactic perspective, the details and mathematical procedures necessary for the construction of the quantum differential equation, under a relativistic regime, called the Klein-Gordon-Fock Equation (KGFE), admitting the front coordinate system of light. To do so, initially, we highlight some algebraic properties of Einstein’s Special Theory of Relativity as well as briefly present the coordinates of the light front in terms of cartesian coordinates and the temporal evolution parameter, that is, of Minkowski space, thus obtaining the KGFE both in usual coordinates of Minkowski space and in coordinates of the light front. Then, for these last coordinates, we develop in detail the algebraic structure of KGFE for an electrically charged quantum particle in a special relativity regime and under influence of classical magnetic field configurations. Furthermore, we obtain the KGFE with an algebraic structure similar to a Schrödinger quantum differential equation. Finally, as an immediate application of the use of these coordinates, we developed the necessary algebraic procedures and steps to obtain the annihilation operator of the integral type of motion, which is configured as the necessary mathematical structure for the construction of coherent quantum states.
RESUMEN La rinitis alérgica (RA) es una de las enfermedades crónicas más frecuentes de la infancia. Sin embargo, permanece subdiagnosticada y subtratada. Su prevalencia ha aumentado en los últimos ...años y varía del 2 % al 25 %. Los síntomas de la RA incluyen estornudos, prurito, rinorrea y congestión nasal. Un correcto diagnóstico y tratamiento de la RA y sus comorbilidades, tales como rinosinusitis con o sin poliposis nasal, conjuntivitis, otitis media, asma bronquial e infecciones del tracto respiratorio, son importantes para reducir el impacto negativo en la afectación de la calidad de vida del paciente y sus familiares, y los gastos sanitarios que ocasiona. La inmunoterapia alérgeno específica, en pacientes correctamente seleccionados, previene nuevas sensibilizaciones y reduce la hiperreactividad bronquial asociada a la RA. Considerando todos estos factores, el Comité Nacional de Alergia de la Sociedad Argentina de Pediatría propone recomendaciones basadas en la evidencia actual.
•Identification of recoverable metallic elements in PCBs from printers is done.•Physical and hydrometallurgical processing of PCBs was developed.•Copper concentration on studied PCBs is 32.5wt.%.•The ...copper extraction was higher in oxidant media rather than in sulfuric one.
Global generation of waste electrical and electronic equipment (WEEE) is about 40 million tons per year. Constant increase in WEEE generation added to international legislations has improved the development of processes for materials recovery and sustainability of electrical and electronic industry. This paper describes a new hydrometallurgical route (leaching process) to recycle printed circuit boards (PCBs) from printers to recover copper. Methodology included PCBs characterization and a combined route of physical and hydrometallurgical processing. Magnetic separation, acid digestion and chemical analysis by ICP-OES were performed. On leaching process were used two stages: the first one in a sulfuric media and the second in an oxidant media. The results showed that the PCBs composition was 74.6wt.% of non-magnetic material and 25.4wt.% of magnetic one. The metallic fraction corresponded to 44.0wt.%, the polymeric to 28.5wt.% and the ceramic to 27.5wt.%. The main metal was copper and its initial content was 32.5wt.%. On sulfuric leaching 90wt.% of Al, 40wt.% of Zn and 8.6wt.% of Sn were extracted, whereas on oxidant leaching tests the extraction percentage of Cu was 100wt.%, of Zn 60wt.% and of Al 10wt.%. At the end of the hydrometallurgical processing was obtained 100% of copper extraction and the recovery factor was 98.46%, which corresponds to a 32kg of Cu in 100kg of PCB.
An evanescent wave fiber optic sensor for detection of Escherichia coli (E. coli) outer membranes proteins (EcOMPs) using long period gratings (LPGs) as a refractometric platform is presented. The ...sensing probes were attained by the functionalization of LPGs inscribed in single mode fiber using two different methods of immobilization; electrostatic assembly and covalent binding. The resulting label-free configuration enabled the specific recognition of EcOMPs in water by monitoring the resonance wavelength shift due to refractive index changes induced by binding events. The sensors displayed linear responses in the range of 0.1nM to 10nM EcOMPs with sensitivities of −0.1563±0.005nmdecade−1 EcOMP, M (electrostatic method) and −0.1597±0.004nmdecade−1 EcOMP, M (covalent method). The devices could be regenerated (under low pH conditions) with a deviation less than 0.1% for at least three subsequent detection events. The sensors were also applied to spiked environmental water samples.
•Label-free remote evanescent wave fiber optic sensor.•The system uses regular telecommunication optical fiber in a simple and robust configuration.•Accurate quantification of E. coli proteins concentration down to 10nM in less than 1h.•Reusable sensor with a deviation less than 0.1% for subsequent detection events.•Preliminary alarm system for the detection of E. coli in environmental waters.
Abstract
The SARS-CoV-2 pandemic triggered substantial economic and social disruptions. Mitigation policies varied across countries based on resources, political conditions, and human behavior. In ...the absence of widespread vaccination able to induce herd immunity, strategies to coexist with the virus while minimizing risks of surges are paramount, which should work in parallel with reopening societies. To support these strategies, we present a predictive control system coupled with a nonlinear model able to optimize the level of policies to stop epidemic growth. We applied this system to study the unfolding of COVID-19 in Bahia, Brazil, also assessing the effects of varying population compliance. We show the importance of finely tuning the levels of enforced measures to achieve SARS-CoV-2 containment, with periodic interventions emerging as an optimal control strategy in the long-term.
Scorpion venom causes renal injury and affects vascular ion-channels function. Centruroides margaritatus scorpion is found in Colombia and is frequently the cause of envenomation accidents; however, ...its renal impact has never been investigated.
To evaluate the effects of C. margaritatus venom (CmV) on renal parameters using isolated rat kidney and renal cell culture models.
Wistar rats (n = 5, weighing 240-300 g) were first perfused with Krebs-Henseleit solution containing 6 g 100 mL-1 bovine serum albumin. After 30 minutes, the kidneys were perfused with CmV to a final concentration of 10 μgmL-1; evaluation was performed by measuring Perfusion Pressure (PP), Renal Vascular Resistance (RVR), Urinary Flow (UF), Glomerular Filtration Rate (GFR), and percentage of electrolyte tubular transport. Moreover, kidney histological analyses and cell cytotoxicity in renal tubule epithelial cells (MDCK) and proximal tubular cells (LLC-MK2) were assessed.
CmV increased PP and RVR 60 min after perfusion. On the other hand, UF, GFR, and the percentages of sodium, potassium and chloride tubular transport decreased after experimental envenomation. UF dropped after 120 min, while GFR and percentage of electrolyte tubular transport diminished after 60, 90 and 120 min. CmV was not toxic to MDCK cell line but reduced the viability of LLC-MK2 cells at concentrations ranging from 6.25 to 200 μgmL-1. Histological analyses disclosed hydropic degeneration, edema, and protein deposits. Flow cytometry disclosed that cell death occurred predominantly by necrosis.
Our results suggest that C. margaritatus venom can trigger renal impairment, mainly in the proximal kidney tubule.
OBJETIVO: Comparar a pressão arterial pelos métodos do flush, da oximetria de pulso e da oscilometria utilizando o Doppler em neonatos. MÉTODOS: Foram realizadas medidas de pressão arterial não ...invasiva utilizando três métodos distintos (flush, oximetria de pulso e oscilometria automática) em três grupos de recém-nascidos selecionados por sorteio: 15 a termo e normais, 16 prematuros estáveis e 14 doentes. Todas as medidas foram filmadas, editadas separadamente, codificadas e analisadas independentemente por três neonatologistas. RESULTADOS: Realizaram-se 57 medidas por cada método. Os métodos do flush e da oximetria de pulso mostraram melhor correlação com o Doppler do que a oscilometria (coeficiente de correlação 0,89, 0,85 e 0,71, respectivamente, p < 0,01). A diferença entre as médias das medidas, seus respectivos desvios padrão e o intervalo de confiança de 95% quando comparados com Doppler foram: -5,2±7,9 (-21,1:10,7) mmHg com o método do flush; 0,4±8,9 (-17,5:18,2) mmHg com a oximetria de pulso; e 6,4±16,1 (-25,8:8,6) mmHg com a oscilometria. O método do flush mostrou melhor concordância com o Doppler para diagnóstico de hipotensão do que os métodos da oximetria e da oscilometria. CONCLUSÕES: Os métodos do flush e da oximetria de pulso mostraram-se úteis para medir a pressão arterial sistólica de recém-nascidos, sendo que o método oscilométrico mostrou-se o menos concordante com o Doppler para detectar hipotensão.
We present a portable and low-cost system for interrogation of long-period fiber gratings (LPFGs) costing around a 30th of the price of a typical setup using an optical spectrum analyzer and a ...broadband light source. The unit is capable of performing real-time monitoring or as a stand-alone data-logger. The proposed technique uses three thermally modulated fiber-coupled laser diodes, sweeping a few nanometers around their central wavelength. The light signal is then modulated by the LPFG and its intensity is acquired by a single photo-detector. Through curve-fitting algorithms the sensor transmission spectrum is reconstructed. Testing and validation were accomplished by inducing variations in the spectral features of an LPFG through changes either in external air temperature from 22 to 425 °C or in refractive index (RI) of the surrounding medium from 1.3000 to 1.4240. A dynamic resolution between 3.5 and 1.9 °C was achieved, in temperatures from 125 to 325 °C. In RI measurements, maximum wavelength and optical power deviations of 2.75 nm and 2.86 dB, respectively, were obtained in the range from 1530 to 1570 nm. The worse RI resolution obtained was 3.47 × 10 - 3 . The interrogation platform was then applied in the detection of iron corrosion, expressing wavelength peak values within 1.12 nm from the real value in the region between 1530 and 1570 nm.
COVID-19 is affecting healthcare resources worldwide, with lower and middle-income countries being particularly disadvantaged to mitigate the challenges imposed by the disease, including the ...availability of a sufficient number of infirmary/ICU hospital beds, ventilators, and medical supplies. Here, we use mathematical modelling to study the dynamics of COVID-19 in Bahia, a state in northeastern Brazil, considering the influences of asymptomatic/non-detected cases, hospitalizations, and mortality. The impacts of policies on the transmission rate were also examined. Our results underscore the difficulties in maintaining a fully operational health infrastructure amidst the pandemic. Lowering the transmission rate is paramount to this objective, but current local efforts, leading to a 36% decrease, remain insufficient to prevent systemic collapse at peak demand, which could be accomplished using periodic interventions. Non-detected cases contribute to a ∽55% increase in R
. Finally, we discuss our results in light of epidemiological data that became available after the initial analyses.
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