Resuscitation of extremely preterm infants - controversies and current evidence

Despite significant advances in perinatal medicine, the management of extremely preterm infants in the delivery room remains a challenge. There is an increasing evidence for improved outcomes regarding the resuscitation and stabilisation of extremely preterm infants but there is a lack of evidence in the periviable (gestational age 23-25 wk) preterm subgroup. Presence of an experienced team during the delivery of extremely preterm infant to improve outcome is reviewed. Adaptation from foetal to neonatal cardiorespiratory haemodynamics is dependent on establishing an optimal functional residual capacity in the extremely preterm infants, thus enabling adequate gas exchange. There is sufficient evidence for a gentle approach to stabilisation of these fragile infants in the delivery room. Evidence for antenatal steroids especially in the periviable infants, delayed cord clamping, strategies to establish optimal functional residual capacity, importance of temperature control and oxygenation in delivery room in extremely premature infants is reviewed in this article

Antiseptic use in the neonatal intensive care unit - a dilemma in clinical practice: An evidence based review

Infants in the neonatal intensive care unit are highly susceptible to healthcare associated infections (HAI), with a substantial impact on mortality, morbidity and healthcare costs. Effective skin disinfection with topical antiseptic agents is an important intervention in the prevention or reduction of HAI. A wide array of antiseptic preparations in varying concentrations and combinations has been used in neonatal units worldwide. In this article we have reviewed the current evidence of a preferred antiseptic of choice over other agents for topical skin disinfection in neonates. Chlorhexidine (CHG) appears to be a promising antiseptic agent; however there exists a significant concern regarding the safety of all agents used including CHG especially in preterm and very low birth weight infants. There is substantial evidence to support the use of CHG for umbilical cord cleansing and some evidence to support the use of topical emollients in reducing the mortality in infants born in developing countries. Well-designed large multicentre randomized clinical trials are urgently needed to guide us on the most appropriate and safe antiseptic to use in neonates undergoing intensive care, especially preterm infants

Higher Moments and Prediction Based Estimation for the COGARCH(1,1) model

COGARCH models are continuous time version of the well known GARCH models of financial returns. They are solution of a stochastic differential equation driven by a L\'evy process. The first aim of this paper is to show how the method of Prediction-Based Estimating Functions (PBEFs) can be applied to draw statistical inference from a discrete sample of observations of a COGARCH(1,1) model as far as the higher order structure of the process is clarified. Motivated by the search for an optimal PBEF, a second aim of the paper is to provide recursive expressions for the joint moments of any fixed order of the process, whenever they exist. Asymptotic results are given and a simulation study shows that the method of PBEF outperforms the other available estimation methods

Studying the properties of the radio emitter in LS 5039

LS 5039 is an X-ray binary that presents non-thermal radio emission. The radiation at $\sim 5$ GHz is quite steady and optically thin, consisting on a dominant core plus an extended jet-like structure. There is a spectral turnover around 1 GHz, and evidence of variability at timescales of 1 yr at 234 MHz. We investigate the radio emitter properties using the available broadband radio data, and assuming two possible scenarios to explain the turnover: free-free absorption in the stellar wind, or synchrotron self-absorption. We use the relationships between the turnover frequency, the stellar wind density, the emitter location, size and magnetic field, and the Lorentz factor of the emitting electrons, as well as a reasonable assumption on the energy budget, to infer the properties of the low-frequency radio emitter. Also, we put this information in context with the broadband radio data. The location and size of the low-frequency radio emitter can be restricted to \ga few AU from the primary star, its magnetic field to $\sim 3\times 10^{-3}-1$ G, and the electron Lorentz factors to $\sim 10-100$. The observed variability of the extended structures seen with VLBA would point to electron bulk velocities \ga 3\times 10^8 cm s$^{-1}$, whereas much less variable radiation at 5 GHz would indicate velocities for the VLBA core \la 10^8 cm s$^{-1}$. The emission at 234 MHz in the high state would mostly come from a region larger than the dominant broadband radio emitter. We suggest a scenario in which secondary pairs, created via gamma-ray absorption and moving in the stellar wind, are behind the steady broadband radio core, whereas the resolved jet-like radio emission would come from a collimated, faster, outflow.Comment: accepted for publication in A&A, 5 pages, 2 figures, 1 tabl

Low frequency radio spectrum and spectral turnover of LS 5039

LS 5039, a possible black hole x-ray binary, was recently observed with Giant Meterwave Radio Telescope. The observed spectrum presented here shows that the spectrum is inverted at the low frequency. When combined with the archival data with orbital phase similar to the present observations, it shows a clear indication of a spectral turnover. The combined data are fitted with a broken power-law and the break frequency signifies a possible spectral turnover of the spectrum around 964 MHz. Truly simultaneous observations in radio wavelength covering a wide range of frequencies are required to fix the spectrum and the spectral turn over which will play a crucial role in developing a deeper understanding of the radio emitting jet in LS 5039.Comment: Accepted for publication in MNRAS Letter

DEVELOPMENT OF SPECTROPHOTOMETRIC AND FLUOROMETRIC METHODS FOR ESTIMATION OF DARUNAVIR USING QBD APPROACH

Objective: The main objective of the present study is to develop newer simple, precise spectrophotometric and fluorometric methods of estimation for Darunavir using coupling agent O-pthaladehyde.Methods: The experimental work was designed for both spectroscopic and fluorometric method development and validation. The method is based on formation complex of Darunavir with O-pthaladehyde. QbD approach was applied by varying different parameters. These parameters were designed into Ishikawa diagram.Results: The complex Darunavir-Phthalaldehyde in methanol with 0.1 N HCl showed linearity for both spectrophotometric and fluorometric methods. The calibration curve by spectrophotometry is linear in concentration range of 2-22 µg/ml with regression coefficient (R2) = 0.998 at 355 nm and for fluorometry it is linear in concentration range of 0.5-5.0 ng/ml with regression coefficient (R2) = 0.999. This method was found to be rugged and robust in different testing criteria with % RSD less than 2. The limit of detection and limit of quantification was found to be 0.2 μg/ml and 0.8 μg/ml for a spectrophotometric method and 0.12 μg/ml and 0.43 μg/ml for fluorometric method respectively.Conclusion: Both methods were found to be precise with % RSD of less than 2. The % recovery of the spectrophotometric and fluorometric methods was found to be 101.04 %, 98.15 % respectively. In this way, the results of all validation parameter were within the limits as per International Conference on Harmonization guideline.Â

Search for TeV γ\gamma -rays from H1426+428 during 2004-07 with the TACTIC telescope

The BL Lac object H1426+428 ($z\equiv 0.129$) is an established source of TeV $\gamma$-rays and detections of these photons from this object also have important implications for estimating the Extragalactic Background Light (EBL) in addition to the understanding of the particle acceleration and $\gamma$-ray production mechanisms in the AGN jets. We have observed this source for about 244h in 2004, 2006 and 2007 with the TACTIC $\gamma$-ray telescope located at Mt. Abu, India. Detailed analysis of these data do not indicate the presence of any statistically significant TeV $\gamma$-ray signal from the source direction. Accordingly, we have placed an upper limit of $\leq1.18\times10^{-12}$ $photons$ $cm^{-2}$ $s^{-1}$ on the integrated $\gamma$-ray flux at 3$\sigma$ significance level.Comment: 11 pages, 5 figures accepted for publication in Journal of Physics G: Nuclear and Particle Physic