Morphological dependent exciton dynamics and thermal transport in MoSe2 films.

Thermal transport and exciton dynamics of semiconducting transition metal dichalcogenides (TMDCs) play an immense role in next-generation electronic, photonic, and thermoelectric devices. In this work, we synthesize distinct morphologies (snow-like and hexagonal) of a trilayer MoSe2 film over the SiO2/Si substrate via the chemical vapor deposition (CVD) method and investigated their morphological dependent exciton dynamics and thermal transport behaviour for the first time to the best of our knowledge. Firstly, we studied the role of spin-orbit and interlayer couplings both theoretically as well as experimentally via first-principles density functional theory and photoluminescence study, respectively. Further, we demonstrate morphological dependent thermal sensitive exciton response at low temperatures (93-300 K), showing more dominant defect-bound excitons (EL) in snow-like MoSe2 compared to hexagonal morphology. We also examined the morphological-dependent phonon confinement and thermal transport behaviour using the optothermal Raman spectroscopy technique. To provide insights into the nonlinear temperature-dependent phonon anharmonicity, a semi-quantitative model comprising volume and temperature effects was used, divulging the dominance of three-phonon (four-phonon) scattering processes for thermal transport in hexagonal (snow-like) MoSe2. The morphological impact on thermal conductivity (ks) of MoSe2 has also been examined here by performing the optothermal Raman spectroscopy, showing ks ∼ 36 ± 6 W m-1 K-1 for snow-like and ∼41 ± 7 W m-1 K-1 for hexagonal MoSe2. Our research will contribute to the understanding of thermal transport behaviour in different morphologies of semiconducting MoSe2, finding suitability for next-generation optoelectronic devices.

Bacteriological profile of paediatric skin and soft tissue infections and their antibiogram at a tertiary care teaching hospital in north India.

The increasing complexity of wound care in pediatric patients along with delay in the initiation of treatment predisposes these patients to many complications such as pressure ulcers, non-healing surgical wounds and skin damage. A retrospective study was conducted over a period of five years to gain insight into the etiology of pediatric wound infection. A total of 2819 wound culture positive cases were included. Most samples were from the burn ward (30.15%) followed by the general surgery ward (20.46%). Overall, the most common isolate was Staphylococcus aureus (39.73%) followed by Pseudomonas spp (19.12%). The prevalence of MRSA (Methicillin resistant S. aureus), CRE (Carbapenem-resistant Enterobacteriaceae), CRP (Carbapenem resistant Pseudomonas), CRAB (Carbapenem resistant Acinetobacter baumannii) was 47.3%, 62.5%, 70.5%, 96.4%, respectively. The high degree of resistance in children highlights the importance of regular surveillance for identification of common pathogens and optimization of antimicrobial treatment for multidrug resistant organisms.