A study of effect of delayed and early umbilical cord clamping on neonatal haemoglobin status

Background: Delayed cord clamping has been supported by physician because it allows for physiological transfer of blood from placenta to the infant and thus permits placenta to newborn transfusion and results in an increased neonatal blood volume at birth. At present there is no standard definition of delayed cord clamping. Clamping time varies significantly between studies and a wide range of parameters were used for clamping of cord.Methods: This was an observational study conducted in a public hospital among 200 uncomplicated full-term pregnancies where 100 each were present in early cord clamping (ECC) and delayed cord clamping (DCC) groups respectively and neonatal haematological parameters studied according to different cord clamping times.Results: There was a significant increase of mean haemoglobin level from 14.8 to 16.0 g/dl from 15 secs to 60 secs and gradual increase of mean haemoglobin level from 16.2 to 16.8 g/dl from 60 secs to 180 secs. There was a highly significant difference between ECC and DCC groups regarding mean haemoglobin level and MCH values. MCV and MCH values were also significantly different in both the groups.Conclusions: We concluded in this study that delayed cord clamping, resulted in improved haemoglobin and other haematocrit levels specially when cord was clamped after first 60 secs. Delayed clamping also reduced the prevalence of neonatal anaemia at 2 days of age. In terms of maternal outcomes, delayed umbilical cord clamping did not increase the risk of postpartum haemorrhage or the need for blood transfusion

Including many-body effects into the Wannier-interpolated quadratic photoresponse tensor

We present a first-principles scheme for incorporating many-body interactions into the unified description of the quadratic optical response to light of noncentrosymmetric crystals. The proposed method is based on time-dependent current-density response theory and includes the electron-hole attraction \textit{via} a tensorial long-range exchange-correlation kernel, which we calculate self-consistently using the bootstrap method. By bridging with the Wannier-interpolation of the independent-particle transition matrix elements, the resulting numerical scheme is very general and allows resolving narrow many-body spectral features at low computational cost. We showcase its potential by inspecting the second-harmonic generation in the benchmark zinc-blende semiconductor GaAs, the layered graphitic semiconductor BC$_{2}$N and the Weyl semimetal TaAs. Our results show that excitonic effects can give rise to large and sharply localized one- and two-photon resonances that are absent in the independent-particle approximation. We find overall good agreement with available experimental measurements, capturing the magnitude and peak-structure of the spectrum as well as the angular dependence at fixed photon energy. The implementation of the method in Wannier-based code packages can serve as a basis for performing accurate theoretical predictions of quadratic optical properties in a vast pool of materials.Comment: 15 pages, 6 figure

A complete description of the magnetic ground state in spinel vanadates

Capturing the non-collinear magnetic ground state of the spinel vanadates AV$_2$O$_4$ (A= Mn, Fe and Co) remains an outstanding challenge for state-of-the-art ab-initio methods. We demonstrate that both the non-collinear spin texture, as well as the magnitude of local moments, are captured by a single value of the on-site Hubbard $U$ of 2.7~eV in conjunction with the local spin density approximation (LSDA+$U$), provided the source term (i.e., magnetic monopole term) is removed from the exchange-correlation magnetic field ${\bf B}_{XC}$. We further demonstrate that the magnetic monopole structure in ${\bf B}_{XC}$ is highly sensitive to the value of $U$, to the extent that the interplay between on-site localization and local moment magnitude is qualitatively different depending on whether the source term is removed or not. This suggests that in treating strongly correlated magnetic materials within the LSDA+$U$ formalism, subtraction of the unphysical magnetic monopole term from the exchange-correlation magnetic field is essential to correctly treat the magnetic ground state.Comment: 4 pages, 3 figure

Synthesis and characterization of new thiazole involving isatin for studying their antimicrobial activity

485-4871-(Substituted-1-ylmethyl)indoline-2,3-dione 1a-c have been synthesized from different types of secondary amine with isatin and formaldehyde in alcohol. The compound 1 have then been converted to the respective compound 2a-g (Z)3-(4-subsitutedphenylimino)-1-(substituted-1-ylmethyl)indolin-2-one by treatment with different types of primary amines. Interaction of compound 2 with thioglycolic acid and chloro acetyl chloride results in cyclization to give compound spiro isatin derivatives compounds 3a-g. The anti-microbial activity screening of novel spiro isatin substituted compounds have also been carried out

Understanding the large shift photocurrent of WS2_{2} nanotubes: A comparative analysis with monolayers

We study the similarities and differences in the shift photocurrent contribution to the bulk photovoltaic effect between transition-metal dichalcogenide monolayers and nanotubes. Our analysis is based on density functional theory in combination with the Wannier interpolation technique for the calculation of the shift photoconductivity tensor. Our results show that for nanotube radii of practical interest $r>60$~\AA, the shift photoconductivity of a single-wall nanotube is well described by that of the monolayer. Additionally, we quantify the shift photocurrent generated under realistic experimental conditions like device geometry and absorption capabilities. We show that a typical nanotube can generate a photocurrent of around 10 nA, while the monolayer only attains a maximum of 1 nA. This enhancement is mainly due to the larger conducting cross section of a nanotube in comparison to a monolayer. Finally, we discuss our results in the context of recent experimental measurements on WS$_{2}$ monolayer and nanotubes[Zhang et al., Nature 570, 349 (2019)].Comment: 11 pages, 9 figure