Photo-Physical Characteristics of Janus Green B in Different Solvents and its Interaction Mechanism with Silver Nanoparticles.

This work explores the effects of solvent polarity on Janus Green B (JGB) photophysical properties. The Lippert-Mataga, Billot, and Ravi equations were utilized to calculate the singlet-state excited dipole moments (µe) and ground state dipole moments (µg) using absorption and fluorescence spectra analyses. The results showed an increase in the former, which is suggestive of electronic structural alterations upon excitation. Analysis of fluorescence quantum yield values revealed that JGB's environment had an impact on its emission characteristics; it was particularly sensitive to silver nanoparticles, suggesting possible interactions. While simulations of electron density, electrostatic potential, and energy gap (Eg) helped to understand the electronic structure of JGB, theoretical absorption spectra produced by Time Dependent Density Function Theory (TD-DFT) calculations offered insights into electronic transitions during absorption. To sum up, the present study contributes to our comprehension of the molecular behavior of JGB in various solvents by elucidating the intricate relationship among solvent polarity, molecular environment, and interactions with silver nanoparticles. Additionally, theoretical computations support the interpretation of experimental results.

Development and validation of a French questionnaire that assesses knowledge, attitude, and practices toward Marburg diseases in sub-Saharan African countries.

OBJECTIVES: Marburg virus, previously referred to as Marburg hemorrhagic fever, is a highly severe and frequently fatal illness that affects humans. This study aimed to develop and validate a French questionnaire to assess knowledge, attitude, and practice toward Marburg virus disease (FKAP-MVD). STUDY DESIGN: An anonymous online survey was used, which was distributed through various platforms and emails. Data were collected from Burkina Faso, Guinea, the Democratic Republic of Congo, and Senegal. METHODS: To conduct the study, an anonymous online survey was used, which was distributed through various platforms such as Facebook, Twitter, WhatsApp, and emails. The survey was uploaded onto a Google form to facilitate data collection. Data were collected from Burkina Faso, Guinea, the Democratic Republic of Congo, and Senegal. RESULTS: Of the total sample of 510 participants, 60.0% were male, their mean age was 28.41 ± 6.32 years, 38.0% were married, 86.6% resided in urban areas and 64.1% had a university education. The questionnaire had good internal consistency; Cronbach's alpha was 0.87. The correlation between knowledge and attitude was 0.002, the correlation between knowledge and practice was 0.204, and the correlation between practice and attitude was relatively weak and negative at -0.060. This indicates the divergent validity of the questionnaire. The KMO value of 0.91 indicates a high level of adequacy, suggesting that the data are suitable for factor analysis. The Bartlett test of Sphericity yielded an approximate χ2 value of 4016.890 with 300 degrees of freedom and a P-value of 0.0001. The confirmatory factor analysis revealed 25 questions in three domains. The normed chi-square value is 1.224. The goodness of Fit Index (GFI) is 0.902, the Comparative Fit Index (CFI) is 0.982, the Root Mean Square Error of Approximation (RMSEA) is 0.033, and the Root Mean Square Residual (RMR) is 0.062. These values indicate a good fit of the model to the data. CONCLUSIONS: In general, the developed questionnaire has significant potential to inform public health initiatives and interventions related to MVD.

Structure, optical properties, TD-DFT simulations for nanosecond and continuous laser irradiation of vanadium antimony borate glass doped with nickel ferrite.

Borate antimony glass doped with vanadium oxide V2O5 encoded into a [BSV glass system] was prepared with the traditional melt quenching technique. The Nickel ferrite [NiFe2O4] was prepared using Flash auto-combustion and mixed at a fixed ratio of 0.05 gm into the glass matrix to form a BSV- composite glass system [BSV / NiFe2O4], which was also prepared using the traditional melt quenching technique. The X-Ray diffraction pattern was used to characterize the glass samples and indicated their amorphous structure, with different structure phases for different levels of V2O5 content. Ranging from 200 to 1100 nm, UV-Vis spectroscopy was used to study the optical properties of the samples. The glass was found to absorb electromagnetic waves with wavelengths lower than 500 nm, while the energy gap decreased from 2.46 eV for 0.1 mol% V2O5 to 2.39 eV for 0.5 wt% V2O5. The Urbach energy also had the same behavior, and decreasing from 0.226 to 0.217 eV. On the other hand, the refractive index increased when V2O5 was added. The thermal characteristics of a [BSV / NiFe2O4] system, such as, glass transition temperature [Formula: see text], onset temperature [Formula: see text], crystallization temperature [Formula: see text] and melting temperature [Formula: see text] were studied using a Differential Scanning Calorimeter. Using continuous and pulsed laser radiation, a [BSV-0.1 V2O5 / NiFe2O4] sample was exposed to laser irradiation to observe its effect on the optical features of the glass. Laser irradiation significantly changed the absorbance spectrum, while the energy gap decreased as time increased. The pulsed laser was found to have a more power-full and uniform effect compared to continuous laser. Time-dependent density function theory was used to optimize the geometrical structure of the glass and study the effect of the formation of 4- coordinate boron atoms on its properties.

Routine childhood immunization in Sub-Saharan Africa: addressing parental vaccine hesitancy.

OBJECTIVES: Parental vaccine hesitancy (VH) is a major barrier to childhood vaccination. We aimed to identify the determinants of parental VH towards routine childhood immunization in 12 Sub-Saharan African countries. STUDY DESIGN: A cross-sectional study was conducted from November 1 to December 15, 2022. METHODS: Parents of children aged 19 months to 6 years and residing in the Sub-Saharan Africa were included. An anonymous online survey and face-to-face interviews were conducted. The Parent Attitude about Childhood Vaccine Scale was used to identify vaccine-hesitant parents. Multivariate regression and mediating analysis were performed. RESULTS: Across the 5032 participants, 21.2% were hesitant towards routine childhood immunization. Urban residents (adjusted odds ratio [AOR] = 1.32, 95% confidence interval [CI]: 1.10-1.58), non-first-born children (AOR = 1.54, 95% CI: 1.19-1.98), and chronically ill children (AOR = 2.00, 95% CI: 1.69-2.37) increased the likelihood of parental VH. Mothers with higher education, attending at least one antenatal care (ANC) visit (AOR = 0.25, 95% CI: 0.19-0.32), and had a healthcare facility-based delivery (AOR = 0.55, 95% CI: 0.44-0.70) decreased the odds of parental VH. Parental VH mediated the effect of ANC and mothers' age on vaccination uptake. ANC increased the odds of vaccination uptake (odds ratio [OR] = 12.49, 95% CI: 9.68-16.13). Parental VH mediated the association between ANC and vaccination uptake, decreasing the likelihood of vaccination uptake (OR = 0.12, 95% CI: 0.10-0.14). Each additional year of the mother's age decreased the odds of vaccination uptake (OR = 0.95, 95% CI: 0.95-0.96). The indirect effect of mother's age on vaccination through parental VH decreased the odds of vaccination uptake (OR = 0.45, 95% CI: 0.44-0.45). Parental VH continued to be a mediator of the combined effect of mother's age and ANC on vaccination uptake, decreasing the likelihood of vaccination uptake (OR = 0.0017, 95% CI: 0.00166-0.00168). CONCLUSIONS: Context-specific interventions are needed to address parental VH and improve vaccine acceptance and coverage.

Structural, optical, and cytotoxicity studies of laser irradiated ZnO doped borate bioactive glasses.

Borate glasses (BG) doped with different amounts of ZnO (0-0.6 mol%) were formed by the traditional melt quenching technique. The different glasses so made were characterized using different characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and UV-Vis absorption optical properties. The XRD patterns showed an amorphous structure with one broad peak at 2θ = 29°, while the phonons bands were studied in terms of the FTIR bands. Optical properties of the glasses were studied using UV-Vis absorption spectra in the range 190-1100 nm, in which the prominent band lies at about 261.5 nm of peak position, from which the bandgab (Eg) was calculated from its edge using Tauc's plot, with Eg ~ 3.5 eV. The laser irradiation showed no significant changes in the absorption bands, despite a significant change observed in the amorphous behavior in the XRD pattern. The cell viability was performed for two samples of the BG and 0.6 mol% ZnO doped using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay method. The result showed better cell viability and low toxicity. So, ZnO doped BG can be used in various biomedical applications.

Experimental studies on the determination of the dipole moments of some different laser dyes.

In this paper we used the Stokes shift phenomena to determine the difference in the dipole moments of the excited state micro(e) and ground state micro(g) to be (micro(e)-micro(g)), and the polarizability alpha. In this paper, we studied six different laser dyes belonging to four different classes of laser dyes which are diolefin 2,5-Distyryl pyrazine (DSB); 1,4-Bis (-pyridyl-2-vinyl) benzene (P2VB) and p-Bis-(o-methylstyryl)-benzene (Bis-MSB) with (micro(e)-micro(g)) equal to 6.40, 6.70 and 2.98 Debye, respectively; anthracene class includes 10(4-acetoxyphenyl)-2-methyl-9-acetoxy anthracene (APMAA) with (micro(e)-micro(g)) value of 7.25 Debye; Rhodamine B (RB) with (micro(e)-micro(g)) value of 5.33 Debye; and Coumarin 120 (C120) with the value 3.97 Debye for (micro(e)-micro(g)). In addition the value of both polarizability alpha and the radius r of each investigated laser dye molecule are determined. Therefore, the ratio alpha/r(3) for each dye is calculated to be 0.93, 0.79, 0.39, 0.37, 0.67 and 0.76 for DSP, P2VB, Bis-MSB, APMAA, RB and C120, respectively. The values of r are 4.83, 4.83, 4.90, 5.34, 5.75 and 4.11 A for the above consequence laser dyes. These dyes are studied in a large number of different solvents. The values obtained of (micro(e)-micro(g)) for these selected dyes are positive, which means that the excited state is more polar than the ground state.