30 research outputs found
Change in the room temperature magnetic property of ZnO upon Mn doping
We present in this paper the changes in the room temperature magnetic
property of ZnO on Mn doping prepared using solvo-thermal process. The zero
field cooled (ZFC) and field cooled (FC) magnetisation of undoped ZnO showed
bifurcation and magnetic hysteresis at room temperature. Upon Mn doping the
magnetic hysteresis at room temperature and the bifurcation in ZFC-FC
magnetization vanishes. The results seem to indicate that undoped ZnO is
ferromagnetic while on the other hand the Mn doped ZnO is not a ferromagnetic
system. We observe that on addition of Mn atoms the system shows
antiferromagnetism with very giant magnetic moments.Comment: 5 figure
Photoelectrochemical behaviour of pulse plated CdS films
Cadmium sulphide (CdS) films were deposited
by the pulse plating technique at room temperature and at
different duty cycles in the range of 6–50% using AR grade
0.25 M cadmium sulphate and 0.30 M sodium thiosulphate
at a deposition potential of -0.75 V (SCE). The total
deposition time was kept constant at 1 h. The thickness of
the films were around 2.0 lm. X-ray diffraction (XRD)
studies indicate the formation of polycrystalline films with
the cubic structure. The crystallite size increased from 23.0
to 27.5 nm as the duty cycle increased from 10 to 50%.
Optical absorption studies indicated a direct band gap in
the range of 2.40–2.80 eV as the duty cycle is decreased.
XPS studies indicated the formation of CdS. Photoelectrochemical
(PEC) cell measurements made with the
photoelectrodes deposited at 50% duty cycle have exhibited
higher conversion efficiency compared to earlier
reports
Pulse plated cadmium telluride films and their characteristics
Cadmium telluride thin films were deposited on
conducting glass and titanium substrates by the pulse plating
technique at different duty cycles in the range 10–50%. The
films were characterised by X-ray diffraction and were found
to possess single phase cubic structure. Optical studies
indicated a direct band gap of 1.45 eV. Surface morphology
of the films indicated that the crystallite size increases with
increase of duty cycle. X-ray photoelectron spectroscopy
studies confirmed the formation of CdTe. Electron-dispersive
X-ray studies were made to estimate the composition. Crossplane
resistivity measurements indicated that the resistivity
decreases with increase of duty cycle
Pulse plated cadmium telluride films and their characteristics
Cadmium telluride thin films were deposited on
conducting glass and titanium substrates by the pulse plating
technique at different duty cycles in the range 10–50%. The
films were characterised by X-ray diffraction and were found
to possess single phase cubic structure. Optical studies
indicated a direct band gap of 1.45 eV. Surface morphology
of the films indicated that the crystallite size increases with
increase of duty cycle. X-ray photoelectron spectroscopy
studies confirmed the formation of CdTe. Electron-dispersive
X-ray studies were made to estimate the composition. Crossplane
resistivity measurements indicated that the resistivity
decreases with increase of duty cycle
Clindamycin Resistance Detection among MRSA at a Tertiary Care Hospital: A Cross-sectional Study
Introduction: Antimicrobial resistance is on the rise, posing a global threat to the success of modern surgical procedures. A common and notorious superbug causing community and hospital-acquired infections is Methicillin-resistant Staphylococcus aureus (MRSA). Its potential for easy and rapid spread leads to increased mortality in hospitals. Clindamycin, a relatively inexpensive and effective drug, is empirically prescribed for the treatment of MRSA infections. Due to the risk of misidentifying clindamycin resistance as susceptibility, leading to treatment failure, its judicious use after D-test is advocated.
Aim: To isolate Staphylococcus aureus (S.aureus) from various clinical specimens and to identify MRSA using cefoxitin disc (30 μg), further determining the incidence of inducible clindamycin resistance among MRSA by the disc diffusion method (D-test).
Materials and Methods: The present cross-sectional study was conducted in the Department of Microbiology, Government Mohan Kumaramangalam Medical College Hospital (GMKMCH), Salem, Tamil Nadu, India, from June 2023 to August 2023. Study was conducted using 185 S.aureus isolates collected from samples received from patients of all genders treated at the present study hospital. Various clinical samples such as pus, sputum, blood, urine and fluids collected from patients treated at the study Institute Salem during the study period were included. A cefoxitin disc (30 μg) was used to detect MRSA among the 185 S.aureus isolates by disc diffusion method as per Clinical and Laboratory Standards Institute (CLSI) guidelines, which were further tested for clindamycin resistance using clindamycin (2 μg) with erythromycin (15 μg) discs by the D-test. The data of the study were analysed using Statistical Package for the Social Sciences (SPSS) software version 21.0. Further descriptive statistics and a chi-square test with a level of significance, p-value ≤0.005 (statistically significant), were used.
Results: Among 185 S.aureus isolates, 130 (70.27%) were Methicillin-sensitive S.aureus (MSSA) and 55 (29.7%) were MRSA. Inducible clindamycin resistance was observed in 22 (40%) isolates, while 17 (30.9%) isolates showed constitutive resistance, 9 (16.36%) showed the MS phenotype, and the remaining 7 (12.72%) showed the susceptible phenotype. Among the clindamycin resistance patterns in MRSA, inducible clindamycin resistance was reported predominantly.
Conclusion: The majority of S.aureus was isolated from pus samples, highlighting its importance as a pyogenic microorganism. The current study records a high rate of MRSA resistance among S.aureus isolates. The present study reports a higher rate of inducible clindamycin resistance among MRSA isolates when compared to other phenotypes of clindamycin resistance. Therefore, routine D-testing must be implemented to identify inducible resistance to clindamycin in MRSA to avoid treatment failure
Pulse plated CdSxTe1-x films and their properties
CdSxTe1-x films were deposited on titanium and conducting glass substrates at room temperature using 0.25 M cadmium sulphate, the concentration of sodium thiosulphate and TeO2 dissolved in sodium hydroxide was varied in the range of 0.01–0.05 M. The as deposited films exhibited hexagonal structure irrespective of the composition. The FWHM maximum of the x-ray diffraction peaks were found to decrease with increase of duty cycle. The optical energy gap values are in the range of 1.54–2.32 eV for films of different composition, it is observed that the band gap shifts towards CdS side as the concentration of CdS in the films increase. XPS studies indicated the formation
of CdSTe solid solution. The grain size increases from 11.54 to 99.40 nm as the value of x increases from 0.2 to 0.8. The surface roughness is found to increase from 0.22 to 2.50 nm as the value of ‘x’ increases from 0.2 to 0.8. The resistivity is found to vary from 53 to 8 ohm cm as the ‘x’ value decreases from 1 to 0