Differential metabolism of alprazolam by liver and brain cytochrome (P4503A) to pharmacologically active metabolite

Cytochrome P450 (P450) is a superfamily of enzymes which mediates metabolism of xenobiotics including drugs. Alprazolam, an anti-anxiety agent, is metabolized in rat and human liver by P4503A1 and P4503A4 respectively, to 4-hydroxy alprazolam (4-OHALP, pharmacologically less active) and α-hydroxy alprazolam (α-OHALP, pharmacologically more active). We examined P450 mediated metabolism of alprazolam by rat and human brain microsomes and observed that the relative amount of α-OHALP formed in brain was higher than liver. This biotransformation was mediated by a P450 isoform belonging to P4503A subfamily, which is constitutively expressed in neuronal cells in rat and human brain. The formation of larger amounts of α-OHALP in neurons points to local modulation of pharmacological activity in brain, at the site of action of the anti-anxiety drug. Since hydroxy metabolites of alprazolam are hydrophilic and not easily cleared through blood-CSF barrier, α-OHALP would potentially have a longer half-life in brain

Partnership of obstetrician and neonatologist to improve neonatal outcome in peri-viable and premature babies: a cross sectional survey

Background: Collaboration between obstetricians and paediatricians/Neonatologists provides the best quality care to infants and their mothers. Present study was conducted to evaluate the practices of obstetricians and neonatologists’ partnership to improve neonatal outcome.Methods: Present cross-sectional, observational study was conducted on 50 Obstetricians and 50 paediatricians/ neonatologists during October 2021 to evaluate the practices of obstetricians and neonatologists’ partnership to improve neonatal outcome.Results: In present study, among 50 obstetricians and 50 pediatricians/ neonatologists, all i.e., 100 (100%) feel that partnership of obstetrician and neonatologist in managing pre-viable pregnancy improves neonatal outcome. Among 50 obstetricians, all i.e., 50 (100%) said that they will explain the need for caesarean section and if necessary classical caesarean section. All said they will explain the need and advantages of steroids. Among 50 pediatricians/ neonatologists, majority i.e., 44 (88%) said that they will explain the need for caesarean section and if necessary classical caesarean section. All said they will explain the need and advantages of steroids. Among 50 obstetricians, majority i.e., 45 (90%) said that they will explain thoroughly the risk to the baby, survival, short term complications and disability, 30 (60%) each said that they will explain thoroughly the risk of RDS, need of resuscitation, need of NICU for baby, uncertainty of hospital stay and outcome. Among 50 pediatricians/ neonatologists, all i.e., 50 (100%) each said that they will explain thoroughly the risk to the baby, survival, short term complications and disability, the risk of RDS, need of resuscitation, need of NICU for baby, uncertainty of hospital stay and outcome. Expressions of pediatricians/ neonatologists were significantly different on counselling aspects of mother and baby.Conclusions: In present study, majority of obstetricians and pediatricians/ neonatologists were of opinion that partnership between them surely improves neonatal outcome in peri viable and preterm babies. 

Quasinormal Spectrum and Quantization of Charged Black Holes

Black-hole quasinormal modes have been the subject of much recent attention, with the hope that these oscillation frequencies may shed some light on the elusive theory of quantum gravity. We study {\it analytically} the asymptotic quasinormal spectrum of a {\it charged} scalar field in the (charged) Reissner-Nordstr\"om spacetime. We find an analytic expression for these black-hole resonances in terms of the black-hole physical parameters: its Bekenstein-Hawking temperature $T_{BH}$, and its electric potential $\Phi$. We discuss the applicability of the results in the context of black-hole quantization. In particular, we show that according to Bohr's correspondence principle, the asymptotic resonance corresponds to a fundamental area unit $\Delta A=4\hbar\ln2$.Comment: 4 page

CHANGES IN VELOCITY OF FISHER GLACIER, EAST ANTARCTICA USING PIXEL TRACKING METHOD

Glacier movement is a crucial factor for assessing cryospheric climate change. Traditional methods of field surveys for studying glacier movement and velocity are often not possible owing to inaccessibility and harsh terrains. Furthermore, as it is not feasible to physically monitor and survey many glaciers around the globe, these traditional methods are limited in their global coverage. Remote sensing is an ideal tool to study such phenomena on a global scale. Optical remote sensing employs techniques such as feature tracking and pixel tracking, whereas, microwave remote sensing uses intensity tracking, speckle tracking, Interferometric SAR and Differential InSAR (DInSAR). This study focuses on estimation of glacier velocity and its seasonal variations using the image-matching technique for optical images for the Fisher glacier, a tributary glacier of the Amery ice shelf in Antarctica. The tool used in this study is the COSI-Corr module embedded in ENVI which provides the velocity in both azimuth and range resolution. The principle of estimating velocity using this tool is pixel tracking wherein similar pixels on two images are tracked where one is the master image and the other is a slave. This technique correlates the master and slave images over a time period and generates three outputs: displacements in the East-West and North-South directions and signal-to-noise ratio (SNR) image. Landsat 8 image pairs were used for cross correlation over a time span of four years spanning 2013–2017. With a resolution of 15 m, the panchromatic band (Band 8) was the ideal choice for pixel tracking as the resolution of other bands is coarser. The initial window size for correlation was 64 while the final window size was 16. The resolution of the displacement images produced is dependent on the value assigned for the step size, which was set to 8. The resultant velocity was derived using the result of the two displacement images. The SNR image was used to remove all the pixels from the velocity output having the value of SNR less than 0.9, in order to reduce the effect of noise. The annual velocity of the Fisher glacier was estimated to be around 600 to 650 myr−1 near the tongue where it merges with the Amery Ice Shelf, which was reduced to 150 myr−1 as it recedes. The resultant velocity images have a resolution of 120 m. The seasonal variation in velocity for the year 2013–2014 is 1.8 myr−1, while in the succeeding year 2014-2015 it subdued to 1.7 myr−1. The seasonal variation for the year 2015–2016 was estimated to be 7.9 myr−1. The seasonal variation for 2016–2017 was 17.4 myr−1

Terahertz magneto-optical spectroscopy of two-dimensional hole and electron systems

We have used terahertz (THz) magneto-optical spectroscopy to investigate the cyclotron resonance in high mobility two-dimensional electron and hole systems. Our experiments reveal long-lived (~20 ps) coherent oscillations in the measured signal in the presence of a perpendicular magnetic field. The cyclotron frequency extracted from the oscillations varies linearly with magnetic field for a two-dimensional electron gas (2DEG), as expected. However, we find that the complex non-parabolic valence band structure in a two-dimensional hole gas (2DHG) causes the cyclotron frequency and effective mass to vary nonlinearly with the magnetic field, as verified by multiband Landau level calculations. This is the first time that THz magneto-optical spectroscopy has been used to study 2DHG, and we expect that these results will motivate further studies of these unique 2D nanosystems.Comment: 11 pages, 7 figure

Perturbative calculation of quasi-normal modes of Schwarzschild black holes

We discuss a systematic method of analytically calculating the asymptotic form of quasi-normal frequencies of a four-dimensional Schwarzschild black hole by expanding around the zeroth-order approximation to the wave equation proposed by Motl and Neitzke. We obtain an explicit expression for the first-order correction and arbitrary spin. Our results are in agreement with the results from WKB and numerical analyses in the case of gravitational waves.Comment: 11 pages; references added and a sign error corrected; to appear in CQ