Introduction: Research on Coronavirus Disease-2019 (COVID19) seroprevalence in children and adolescent population across the globe is quite limited. In India, there is a dearth of data on COVID-19 ...seropositivity, especially in unvaccinated paediatric population, particularly in the Himalayan region. Aim: To estimate the seroprevalence of COVID-19 in children presenting in a tertiary care health institution. Materials and Methods: A hospital-based cross-sectional serosurvey was conducted on 500 children, from October 2021 to March 2022 in paediatric age group, attending Indira Gandhi Medical College Shimla, Himachal Pradesh, India, for various health related concerns such as fever, cough, loose stools, vomiting and fast breathing using convenience sampling. Socio-demographic profile was recorded and blood sample was drawn for COVID-19 antibody titre estimation. Chi-squared and Fisher’s-exact tests for proportions was used for testing statistical significance. Results: A total of 500 children, age ranged from 12 hours to 17 years 7 months were enrolled with maximum children belonging to 01-05 years age group and there was slight male preponderance. Seropositivity in males (27.3%) was significantly higher than females (8.3%). Highest (42.3%) seropositivity was seen in age group of 06 months to 01 year. About 10.8% of cases were positive for Immunoglobulin (Ig) G antibody, 4.4% were positive for IgM antibody, while about 6.6% cases were positive for both antibodies. Conclusion: The seroprevalence status of children and adolescents is quite low in this region, revealing the high susceptibility of children to SARS-CoV-2 in the study region. It further emphasises benefits of serological testing in children for SARS-CoV-2 as well as the need of safe and effective vaccination for the unimmunised, unprotected and vulnerable paediatric age group.
The present study aimed to compare clinical features, management, and outcomes between children and adolescents admitted as cases of multi-system inflammatory syndrome in children (MIS-C) in Indira ...Gandhi Medical College (IGMC), Shimla.
We conducted a cross-sectional study for MIS-C from January to July 2021, in the pediatric ward of IGMC in Himachal Pradesh. All children admitted with a diagnosis of MIS-C were included in the study. Data regarding socio-demographic factors, clinical features, and treatment modalities were extracted and analyzed using Epi Info V7 software.
A total of 31 children diagnosed as cases of MIS-C were included. The mean age was 7.12 ± 4.78 years. 71% were in group 0-10 years, followed by 29% in 11-18 years. Although the duration of hospital stay, mortality, and Kawasaki disease cases were more in children as compared to adolescents, the difference was not significant. Similarly, fever, rash, cough, hematemesis, tachypnea, respiratory distress, hypotension, vomiting, bleeding diathesis, hematuria, seizure, encephalopathy, hepatomegaly, splenomegaly, and lymphadenopathy were greater in children as compared to adolescents but were not significant. Likewise, abnormalities in various biochemical, hematological, inflammatory, and cardiac markers were deranged to a greater extent in children as compared to adolescents, but there was no significant difference. The need for various treatment modalities such as IVIG, methylprednisolone, low-molecular weight heparin, aspirin, respiratory Support, O
, ventilatory support, and inotropic support was more in children as compared to an adolescent, but there was no significant difference.
There was no significant difference in socio-demographic factors, clinical presentation, diagnostic test, mode of treatment, duration of stay, and mortality among children and adolescents.
Pain during the developmental period may adversely affect developing neuronal pathways and result in adverse neurodevelopmental, cognitive, and behavioral effects in later life. Immunizations, e.g., ...hepatitis B vaccine (HBV), administered at birth are painful experiences to which neonates are universally subjected.
Here we aimed to study and compare the effectiveness of various nonpharmacological pain management methods in newborns to enable the development of safe and effective analgesic methods for newborns.
This prospective study was conducted at a tertiary care hospital in the Himalayan region. Three hundred term healthy neonates were divided into 6 groups of 50 each. Groups 1-5 were intervention groups, patients of which received a nonpharmacological intervention (breastfeeding, nonnutritive sucking, rocking, 25% sucrose, or distilled water) before the intramuscular HBV, while patients in group 6 received no intervention. The pain response in each group after the HBV injection was assessed and compared using cry duration and Douleur Aigue Nveau-ne (DAN) score, a behavioral acute pain rating scale for newborns.
Cry duration was decreased in all intervention groups, significantly so in the sucrose (19.90 seconds), breastfeeding (31.57 seconds), and nonnutritive sucking (36.93 seconds) groups compared with controls (52.86 seconds). DAN scores decreased significantly (P<0.05) at one or more points i.e. 30, 60, or 120 seconds in the breastfeeding and 25% sucrose intervention groups compared with controls.
Oral sucrose and nonnutritive sucking are simple yet underutilized nonpharmacological interventions that effectively reduce pain in newborns.
Ternary chalcopyrites, having general formula AIBIIIC2, are of considerable research interest due to their optoelectronic applications as solar energy converters, nonlinear optical devices, light ...emitting diodes and detectors. In this study, an attempt has been made to correlate optoelectronic properties of CuTiX2 (X = S, Se and Te) with computed Density Functional Theory based electronic descriptors. The ground state configurations and low lying isomers of CuTiX2 (X = S, Se and Te) are analyzed invoking electronic structure theory. Our computed HOMO-LUMO energy gap (2.405 eV–3.197 eV) signifies CuTiX2 as potential candidate for solar cell applications. CuTiS2 and CuTiTe2 exhibit the maximum and the minimum energy gap respectively. HOMO-LUMO energy gap maintains an expected trend with DFT based global descriptors. A close agreement between our computed results and experimental data establishes the importance of present study.
•Chalcopyrite semiconductor CuTiX2 (X = S, Se, Te) is studied using electronic structure calculation.•The rectangular structure of CuTiS2 is favorable with maximum HOMO-LUMO energy gap of 3.197 eV.•Reactivity of compound is predicted in terms of DFT based descriptors.
The structure, electronic and optical properties of chalcopyrite-type semiconductor material AgTiX2 (X = S, Se, Te) are investigated invoking Density Functional Theory (DFT). The computed Highest ...Occupied Molecular Orbital (HOMO)-Lowest Unoccupied Molecular Orbital (LUMO) energy gap of AgTiX2 molecule with and without 4f function on Ag is in the range of 2.319 eV – 3.211 eV and 2.092 eV – 3.056 eV respectively. It establishes that AgTiX2 can be used as potential candidate for optoelectronic and photovoltaic applications, especially in solar cells. Result analysis reveals that AgTiS2, having a rectangular geometry with C2v point group and doublet spin multiplicity, is the most stable system with maximum HOMO-LUMO gap. Our calculated DFT based global descriptors and spectral analysis transpires that HOMO-LUMO energy gap, harmonic frequency and intensity of IR and Raman spectra decreases from AgTiS2 to AgTiSe2 to AgTiTe2. A strong correlation is established between DFT based global descriptors and HOMO-LUMO gap from this analysis.
In this paper, we have performed electronic and optical investigations for ternary bulk chalcopyrite's ZnGa2X4 (X = S, Se) to explore their utility as solar cell materials. The electronic structure ...computations presented over here, revealed direct band gap for these compounds. Detailed analysis of these structural results is performed using total and partial density of states. The optical investigations such as absorption spectra, dielectric tensors, refractivity, reflectivity, energy loss and conductivity of both compounds are performed to validate their applicability for solar photovoltaic and other optoelectronic applications. The intense nature of absorption curves observed in the solar energy region (0–5 eV), supports the possible utilization of these materials for the same. All the computations are performed using the different exchange and correlation functions namely, Wu-Cohen generalized gradient approximation (WC-GGA), Perdew et al. (PBE-sol) and the most accurate modified Becke and Johnson (mBJ) potentials within the frame work of density functional theory.
•Most accurate electronic & optical properties of ZnGa2X4 (X = S, Se) are computed.•First ever optical properties of ZnGa2X4 (X = S, Se) using mBJ within FP-LAPW.•The origin of complex dielectric functions is explained using energy bands.•Utility in Solar cell and photovoltaic is discussed in terms of absorption coefficients.
In recent years, lead‐free double perovskite materials have attracted much attention due to their probable applications in photovoltaic and optoelectronic devices. In this work, the electronic and ...optical properties of lead‐free double perovskites A2BCl6 (A = Rb, Cs; B = Si, Ge, and Sn) are studied using density functional theory (DFT) methodology. The result shows that the highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO‐LUMO) energy gaps of these compounds vary between 0.524 and 0.919 eV, which agrees with the previously reported data. HOMO‐LUMO gap for Rb2SiCl6 is observed as 0.919 eV, which falls in the optimal energy gap range, that is, 0.9 to 1.6 eV for double perovskite material. Conceptual DFT‐based descriptors—molecular hardness, softness, electronegativity, electrophilicity index, and dipole moment of these compounds—are studied. The tolerance factor of A2BCl6 is observed in the range of 1.00 to 1.26. Rb2SnCl6 is almost a perfect fit with a value of 1.00. Cs2SiCl6 shows the maximum value of the refractive index and dielectric constant. Optical electronegativity is found between 0.178 and 0.246 eV. The suitable band gap and high value of the refractive index and dielectric constant make double perovskites A2BCl6 effective for solar cells and optoelectronic devices.
In this report, we have studied lead‐free perovskite materials A2BCl6 (A = Rb, Cs; B = Si, Ge, Sn) using the DFT technique. DFT‐based global descriptors of perovskite materials are computed and analyzed. Our results reveal that Rb2SiCl6 is the most suitable material among the studied compounds for solar cell applications. Other parameters, namely, tolerance factor, optical properties, and IR and Raman spectra of A2BCl6, are also reported.
Lead‐free double perovskite materials A2BI6 (A = Cs, K, Rb; B = Pt and Sn) have been studied and analyzed invoking density functional theory (DFT). Computed values of the HOMO–LUMO gap for lead‐free ...double perovskites material A2BI6 are found in the range of 1.062–2.811 eV. The energy gaps of K2PtI6, K2SnI6, and Rb2SnI6 are in the optimal energy gap range (0.9 to 1.6 eV) required for a lead‐free double perovskite system. Conceptual DFT‐based descriptors, viz., molecular hardness, softness, electronegativity, electrophilicity index, dipole moment, and polarizability, are computed. The result reveals that K2PtI6 shows high efficacy towards electron injection and may show the maximum electron driving force. The optical properties—refractive index and dielectric constant—of these perovskites are also computed. The maximum value of refractive index and dielectric constant is found for K2PtI6. Our computed results are in good agreement with the available experimental and other theoretical data. Perovskite materials K2PtI6, K2SnI6, and Rb2SnI6 display a suitable energy gap as well as a high refractive index and dielectric constant, which makes them suitable for photovoltaic applications.
Perovskite materials K2PtI6, K2SnI6, and Rb2SnI6 can be potential candidates for photovoltaic cells. System Cs2SnI6 shows maximum stability among the studied compounds. K2PtI6 with the least value of HOMO‐LUMO energy gap displays maximum value of the refractive index and dielectric constant.
Abstract
Lead‐free double perovskite materials A
2
BI
6
(A = Cs, K, Rb; B = Pt and Sn) have been studied and analyzed invoking density functional theory (DFT). Computed values of the HOMO–LUMO gap ...for lead‐free double perovskites material A
2
BI
6
are found in the range of 1.062–2.811 eV. The energy gaps of K
2
PtI
6
, K
2
SnI
6
, and Rb
2
SnI
6
are in the optimal energy gap range (0.9 to 1.6 eV) required for a lead‐free double perovskite system. Conceptual DFT‐based descriptors, viz., molecular hardness, softness, electronegativity, electrophilicity index, dipole moment, and polarizability, are computed. The result reveals that K
2
PtI
6
shows high efficacy towards electron injection and may show the maximum electron driving force. The optical properties—refractive index and dielectric constant—of these perovskites are also computed. The maximum value of refractive index and dielectric constant is found for K
2
PtI
6
. Our computed results are in good agreement with the available experimental and other theoretical data. Perovskite materials K
2
PtI
6
, K
2
SnI
6
, and Rb
2
SnI
6
display a suitable energy gap as well as a high refractive index and dielectric constant, which makes them suitable for photovoltaic applications.
Abstract
In recent years, lead‐free double perovskite materials have attracted much attention due to their probable applications in photovoltaic and optoelectronic devices. In this work, the ...electronic and optical properties of lead‐free double perovskites A
2
BCl
6
(A = Rb, Cs; B = Si, Ge, and Sn) are studied using density functional theory (DFT) methodology. The result shows that the highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO‐LUMO) energy gaps of these compounds vary between 0.524 and 0.919 eV, which agrees with the previously reported data. HOMO‐LUMO gap for Rb
2
SiCl
6
is observed as 0.919 eV, which falls in the optimal energy gap range, that is, 0.9 to 1.6 eV for double perovskite material. Conceptual DFT‐based descriptors—molecular hardness, softness, electronegativity, electrophilicity index, and dipole moment of these compounds—are studied. The tolerance factor of A
2
BCl
6
is observed in the range of 1.00 to 1.26. Rb
2
SnCl
6
is almost a perfect fit with a value of 1.00. Cs
2
SiCl
6
shows the maximum value of the refractive index and dielectric constant. Optical electronegativity is found between 0.178 and 0.246 eV. The suitable band gap and high value of the refractive index and dielectric constant make double perovskites A
2
BCl
6
effective for solar cells and optoelectronic devices.
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