102 research outputs found
Spectral Theory for Non-linear Superconducting Microwave Systems: Extracting Relaxation Rates and Mode Hybridization
The accurate modeling of mode hybridization and calculation of radiative
relaxation rates have been crucial to the design and optimization of
superconducting quantum devices. In this work, we introduce a spectral theory
for the electrohydrodynamics of superconductors that enables the extraction of
the relaxation rates of excitations in a general three-dimensional distribution
of superconducting bodies. Our approach addresses the long-standing problem of
formulating a modal description of open systems that is both efficient and
allows for second quantization of the radiative hybridized fields. This is
achieved through the implementation of finite but transparent boundaries
through which radiation can propagate into and out of the computational domain.
The resulting spectral problem is defined within a coarse-grained formulation
of the electrohydrodynamical equations that is suitable for the analysis of the
non-equilibrium dynamics of multiscale superconducting quantum systems.Comment: 21 pages, 12 figures, journal pape
Negative electrohydrostatic pressure between superconducting bodies
Despite being largely limited to bulk phenomena, well-known theoretical
models of superconductivity like the Bardeen-Cooper-Schrieffer and
Ginzburg-Landau theories have played a key role in the development of
superconducting quantum devices. In this letter, we present a hydrodynamic
non-relativistic scalar electrodynamic theory capable of describing systems
comprising superconducting materials of arbitrary shape and apply it to predict
the existence of a negative (attractive) pressure between planar
superconducting bodies. For conventional superconductors with London
penetration depth , the pressure
reaches tens of at angstrom separations.Comment: 9 pages, 1 figur
Tuning spatial entanglement in interacting few-electron quantum dots
Confined geometries such as semiconductor quantum dots are promising
candidates for fabricating quantum computing devices. When several quantum dots
are in proximity, spatial correlation between electrons in the system becomes
significant. In this article, we develop a fully variational action integral
formulation for calculating accurate few-electron wavefunctions in
configuration space, irrespective of potential geometry. To evaluate the
Coulomb integrals with high accuracy, a novel numerical integration method
using multiple Gauss quadratures is proposed. Using this approach, we
investigate the confinement of two electrons in double quantum dots, and
evaluate the spatial entanglement. We investigate the dependence of spatial
entanglement on various geometrical parameters. We derive the two-particle
wavefunctions in the asymptotic limit of the separation distance between
quantum dots, and obtain universal saturation values for the spatial
entanglement. Resonances in the entanglement values due to avoided
level-crossings of states are observed. We also demonstrate the formation of
electron clusters, and show that the entanglement value is a good indicator for
the formation of such clusters. Further, we show that a precise tuning of the
entanglement values is feasible with applied external electric fields
The Vietnamese Version of the Brief Illness Perception Questionnaire and the Beliefs about Medicines Questionnaire:Translation and Cross-cultural Adaptation
OBJECTIVE: To translate and cross-culturally adapt the Brief Illness Perception Questionnaire (BIPQ) and the Beliefs about Medicines Questionnaire (BMQ) into Vietnamese. METHODS: We followed the guideline by Beaton et al. (2000 & 2007). Stage I: two translators (informed and uninformed) translated the questionnaires. Stage II: the translations were synthesized. Stage III: back translation was performed by two translators fluent in both Vietnamese and English but naïve to the outcome measurement. Stage IV: seven experts reached consensus on the pre-final Vietnamese version (BIPQ-V and BMQ-V). Stage V: field test of the questionnaires on 16 twelve-year-old students and 31 Vietnamese patients. In addition, we determined the internal consistency and test-retest reliability of the questionnaires in 34 Vietnamese patients with acute coronary syndrome. RESULTS: All experts agreed that there was semantic, idiomatic, experiential, and conceptual equivalence between the original and pre-final Vietnamese versions of the BIPQ and BMQ. Cronbach's alpha coefficients of the internal consistency were acceptable for the BMQ-V Specific-Necessity (0.64), BMQ-V Specific-Concerns (0.62), and BMQ-V General-Harm (0.60), with the exception of BMQ-V General-Overuse (0.27). Intra-class correlation coefficients of the test-retest reliability was acceptable for the subscales of BMQ-V (range: 0.77-0.86), and BIPQ-V items (range: 0.62-0.85) with the exception of BIPQ-V 1 (0.44, 95% CI -014-0.72) and BIPQ-V 4 (0.57, 95% CI 0.22-0.81). CONCLUSIONS: The Vietnamese version of BIPQ and BMQ are reliable tools to assess illness perceptions and beliefs about medicines of patients with acute coronary syndrome. Psychometric properties of these questionnaires should be tested in different patient populations
Petrographic Characteristics and Depositional Environment Evolution of Middle Miocene Sediments in the Thien Ung - Mang Cau Structure of Nam Con Son Basin
This paper introduces the petrographic characteristics and depositional environment of Middle Miocene rocks of the Thien Ung - Mang Cau structure in the central area of Nam Con Son Basin based on the results of analyzing thin sections and structural characteristics of core samples. Middle Miocene sedimentary rocks in the studied area can be divided into three groups: (1) Group of terrigenous rocks comprising greywacke sandstone, arkosic sandstone, lithic-quartz sandstone, greywacke-lithic sandstone, oligomictic siltstone, and bitumenous claystone; (2) Group of carbonate rocks comprising dolomitic limestone and bituminous limestone; (3) Mixed group comprising calcareous sandstone, calcarinate sandstone, arenaceous limestone, calcareous claystone, calcareous silty claystone, dolomitic limestone containing silt, and bitumen. The depositional environment is expressed through petrographic characteristics and structure of the sedimentary rocks in core samples. The greywacke and arkosic sandstones are of medium grain size, poor sorting and roundness, and siliceous cement characterizing the alluvial and estuarine fan environment expressed by massive structure of core samples. The mixed calcareous limestone, arenaceous dolomitic limestone, and calcareous and bituminous clayey siltstone in the core samples are of turbulent flow structure characterizing shallow bay environment with the action of bottom currents. The dolomitic limestones are of relatively homogeneous, of microgranular and fine-granular texture, precipitated in a weakly reducing, semi-closed, and relatively calm bay environment
Drug-Related Problems in Prescribing for Pediatric Outpatients in Vietnam
BACKGROUND: Our study was conducted to determine the prevalence of drug-related problems (DRPs) in outpatient prescriptions, the impact of DRPs on treatment efficacy, safety, and cost, and the determinants of DRPs in prescribing for pediatric outpatients in Vietnam. METHODS: A retrospective cross-sectional study was conducted on pediatric outpatients at a pediatric hospital in Can Tho, Vietnam. DRPs were classified according to the Pharmaceutical Care Network Europe classification (PCNE) of 2020. The study determined prevalence of DRPs and their impacts on efficacy, safety, and cost. Multivariate regression was used to identify the determinants of DRPs. RESULTS: The study included 4339 patients (mean age 4.3, 55.8% male), with a total of 3994 DRPs, averaging 0.92 DRP/prescription. The proportion of prescriptions with at least one DRP was 65.7%. DRPs included inappropriate drug selection (35.6%), wrong time of dosing relative to meals (35.6%), inappropriate dosage form (9.3%), inappropriate indication (7.1%), and drug-drug interactions (0.3%). The consensus of experts was average when evaluating each aspect of efficiency reduction, safety reduction, and treatment cost increase, with Fleiss' coefficients of 0.558, 0.511, and 0.541, respectively (p < 0.001). Regarding prescriptions, 50.1% were assessed as reducing safety. The figures for increased costs and decreased treatment effectiveness were 29.0% and 23.9%, respectively. Patients who were ≤2 years old were more likely to have DRPs than patients aged 2 to 6 years old (OR = 0.696; 95% CI = 0.599-0.809) and patients aged over 6 years old (OR = 0.801; 95% CI = 0.672-0.955). Patients who had respiratory system disease were more likely to have DRPs than patients suffering from other diseases (OR = 0.715; 95% CI = 0.607-0.843). Patients with comorbidities were less likely to have DRPs than patients with no comorbidities (OR = 1.421; 95% CI = 1.219-1.655). Patients prescribed ≥5 drugs were more likely to have DRPs than patients who took fewer drugs (OR = 3.677; 95% CI = 2.907-4.650). CONCLUSION: The proportion of prescriptions in at least one DRP was quite high. Further studies should evaluate clinical significance and appropriate interventions, such as providing drug information and consulting doctors about DRPs
Analytical study of the sth-order perturbative corrections to the solution to a one-dimensional harmonic oscillator perturbed by a spatially power-law potential Vper(x) = λxα
In this work, we present a rigorous mathematical scheme for the derivation of the sth-order perturbative corrections to the solution to a one-dimensional harmonic oscillator perturbed by the potential V-per(x) = lambda x(alpha), where alpha is a positive integer, using the non-degenerate time-independent perturbation theory. To do so, we derive a generalized formula for the integral I = integral(+infinity)(-infinity)x(alpha)exp(-x(2))H-n(x)H-m(x)d(x), where H-n(x) denotes the Hermite polynomial of degree n, using the generating function of orthogonal polynomials. Finally, the analytical results with alpha = 3 and alpha = 4 are discussed in detail and compared with the numerical calculations obtained by the Lagrange-mesh method
The ecological dynamics of fecal contamination and Salmonella Typhi and Salmonella Paratyphi A in municipal Kathmandu drinking water
One of the UN sustainable development goals is to achieve universal access to safe and
affordable drinking water by 2030. It is locations like Kathmandu, Nepal, a densely populated
city in South Asia with endemic typhoid fever, where this goal is most pertinent. Aiming
to understand the public health implications of water quality in Kathmandu we subjected
weekly water samples from 10 sources for one year to a range of chemical and bacteriological
analyses. We additionally aimed to detect the etiological agents of typhoid fever and
longitudinally assess microbial diversity by 16S rRNA gene surveying. We found that the
majority of water sources exhibited chemical and bacterial contamination exceeding WHO
guidelines. Further analysis of the chemical and bacterial data indicated site-specific pollution,
symptomatic of highly localized fecal contamination. Rainfall was found to be a key
driver of this fecal contamination, correlating with nitrates and evidence of S. Typhi and S.
Paratyphi A, for which DNA was detectable in 333 (77%) and 303 (70%) of 432 water samples,
respectively. 16S rRNA gene surveying outlined a spectrum of fecal bacteria in the
contaminated water, forming complex communities again displaying location-specific temporal
signatures. Our data signify that the municipal water in Kathmandu is a predominant
vehicle for the transmission of S. Typhi and S. Paratyphi A. This study represents the first
extensive spatiotemporal investigation of water pollution in an endemic typhoid fever setting and implicates highly localized human waste as the major contributor to poor water quality
in the Kathmandu Valley
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