ABSTRACT
In this study, we have synthesized pristine and [0.5,1.5, and 2.5] M% samarium (Sm)-incorporating α-MoO3 2D-layered nanoplates utilizing a facile hydrothermal process, and investigated the physical properties along with antibacterial effectiveness. X-ray diffraction (XRD) patterns confirmed the single-phase, stable orthorhombic polycrystalline structure of the as-prepared samples. The crystallite size, lattice strain, and dislocation density were measured using both Debye-Scherrer (D-S) and Williamson-Hall (W-H) techniques. Both pristine and Sm-incorporating α-MoO3 samples showed two-dimensional (2D) layered nanoplate-type surface morphology, revealed by field emission scanning electron microscopy (FE-SEM) images. Energy dispersive X-ray spectroscopy (EDS) confirmed the presence of Sm contents in the α-MoO3 matrix. After Sm incorporation in α-MoO3, the different functional groups as well as vibrational groups were observed by Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy analyses, respectively. The optical band gaps were measured from UV-vis diffuse reflectance spectroscopy (DRS) by employing the Kubelka-Munk formula and interestingly it is found that the bandgap energy (E g) gradually decreased from 2.96 to 2.83 eV with the increment of Sm content. When compared to pristine α-MoO3, the Sm-incorporating samples experienced a steady improvement in room temperature ferromagnetic (RTFM) behavior as Sm content increased, as measured by hysteresis loops. The antibacterial activities of both samples were assessed against Gram-positive: Staphylococcus aureus (S. aureus), and Gram-negative: Escherichia coli (E. coli) and Salmonella enteritidis (S. enteritidis) bacteria by the agar well diffusion method and enhanced antibacterial activity was observed as the Sm concentration increased, compared to pristine nanoplates. The obtained results suggest that the synthesized Sm-incorporating α-MoO3 2D-layered nanoplate could be a potential antibacterial agent.
ABSTRACT
Fifty eight neonates who survived birth asphyxia were prospectively studied in the department of Paediatrics, Dhaka Medical College Hospital, to see the incidence of long term neurodevelopmental sequelae among them and also to identify possible risk factors. All of them had been admitted in the Neonatal Unit of this hospital and were born between July 1997 & December 1999. After discharge from the hospital, the study infants were followed up at the Child Neurology Clinic of this hospital. They were seen at 6 weeks. at 3 months & then every 3 months upto 2 years of age for evaluation of growth and development (age corrected for prematurity for preterm babies) 69% of them were boys and 31% were girls. 74% of the babies were inborn in the same hospital & the rest were out born. Prolonged labour (24%) and PET (18.96%) were the most common obstetric factors & respiratory distress (38%) and neonatal convulsion (35%) were the important neonatal complications. Of the 58 enlisted study cases, 30 (51.7%) responded to complete 2 years follow up and the rest were lost. Normal growth and developments were observed in 12 (40%) cases, 7 (23.33%) had mild handicap, 6 (20%) moderate & 5 (16.6%) were left with severe neurodevelopmental handicaps at 2 years of age. 61% of the handicapped children had suffered from neonatal seizure for varying periods. It may be concluded that the response to follow up unsatisfactory, the number of severe handicap was alarmingly high and post asphyxiated seizure was associated with poor outcome. So prevention of perinatal asphyxia should be targeted. Further long term follow up study is required.
