Contrasting the dynamics of elastic and non-elastic deformations across an experimental colloidal Martensitic transition

We present a framework to segregate the roles of elastic and non-elastic deformations in the examination of real-space experiments of solid-solid Martensitic transitions. The Martensitic transformation of a body-centred-tetragonal(BCT) to a body-centred-orthorhombic(BCO) crystal structure has been studied in a model system of micron-scale ionic microgel colloids. Non-affine fluctuations, i.e., displacement fluctuations that do not arise from purely elastic(affine) deformations, are detected in particle configurations acquired from the experiment. Tracking these fluctuations serves as a highly sensitive tool in signaling the onset of the Martensitic transition and precisely locating particle rearrangements occurring at length scales of a few particle diameters. Particle rearrangements associated with non-affine displacement modes become increasingly favorable during the transformation process. The nature of the displacement fluctuation modes that govern the transformation are shown to be different from those predominant in an equilibrium crystal. We show that BCO crystallites formed through shear may, remarkably, co-exist with those resulting from local rearrangements within the same sample

Electrorheological responses of soft ionic colloids

N-isopropyl poly acrylamide microgel colloids exhibit strong electric-field-induced phase transitions, suggesting the possibility of a strong electrorheological response. [1] Electrorheological (ER) fluids draw researchers’ attention due to their huge potential for applications in mechanical devices, switches, valves and microfluidic chips. Please click on the file below for full content

Deuterium NMR and rheology of microgel colloids at ambient and high pressure

Microgel colloids exhibit a polymer collapse transition resulting in a large reduction in colloid size at high temperatures or pressures. Our goal is to obtain a microscopic understanding of the internal structure and microscopic dynamics of microgels by examining the temperature and pressure dependence of the collapse transition. We have conducted a systematic study of how the nature of this collapse transition is affected by crosslink density (Cd). We used deuterium NMR (2H-NMR) to probe the microscopic dynamics of cross-linked poly-N-isopropylacrylamide (p-nipam) chains, in microgel colloids, as a function of temperature and pressure. Four differently crosslinked microgels colloids were synthesized with deuteron labels on the nipam backbone (d3- nipam). Corresponding macroscopic properties of unlabeled colloids having the same crosslink densities were characterized by dynamic light scattering (DLS) and rheology. Rheological characterization as a function of temperature (T) and particle concentration (c), and for 4 crosslink densities, showed that the microgel viscosity decreases as temperature is increased, and that in the high T/low c regime, there is a collapse of the viscosity as a function of T and c when plotted against volume fraction: this yields a measure of the water content in the particles as function of T. 2H-NMR spectra of the d3-nipam suspensions for all Cd indicated freely moving chains at low temperature and a nearly immobilized fraction above 35°C. This is consistent with DLS observations of a transition from swollen to collapsed colloids. 2H-NMR spectra for the dry powder indicated totally immobilized segments in the particle. Nipam segments in the collapse phase of the d3-nipam suspension were more mobile than those in the dry powder. This suggests significant amounts of water in the collapsed phase, a finding consistent with the rheology observations. For the highest two values of Cd, microgel spectra showed the presence of an immobilized fraction of segments even in the swollen phase. Variable pressure NMR (up to 90 MPa) showed a slight increase in transition temperature with pressure for all Cd values studied

Study of fetomaternal outcome in eclampsia

Background: Eclampsia is preventable and treatable cause of maternal mortality and morbidity with poor fetomaternal outcomes in developing countries. Poor knowledge, lack of education, malnutrition and lack of antenatal care major causative factors for increase in eclampsia in developing countries.Methods: This was a retrospective single center observational study including 106 pregnant women with eclampsia in antenatal, intranatal and postnatal period over period of one year in our institute.Results: 106 women included in this study. In present study mean age of the study population was 25.41 years. 1 maternal death reported during study period. Antepartum eclampsia was commonest type 78%. Most of the patients were referred. In this study LSCS most common mode of deliveries. Perinatal mortality rate was 152/1000 live birth.Conclusions: Eclampsia is important cause of maternal and Fetal mortality and morbidity. Prevention of eclampsia is not possible, whereas early diagnosis can be done through clinical signs and symptoms, so as to prevent complications leading to mortality and morbidity related to eclampsia. Improvement in antenatal care services quality, increasing patient awareness about warning symptoms, investigations timely delivery, intensive monitoring in intrapartum and postpartum period have potential to improve fetomaternal outcomes.

Retrospective record based study of maternal and fetal outcome in induction of labour at 40 and 41 weeks of gestation in uncomplicated primigravida women

Background: The objective of the study was to compare maternal and foetal outcome after induction in two groups: women who were induced at 40-weeks and at 41-weeks.Methods: This was a retrospective study conducted over period of one year from 1 January 2018 to 31 December 2018 in the obstetrics and gynaecology department. A total of 200 uncomplicated primigravida women were included in the study. The data was collected and comparative analysis was done between two groups: control group (group A), women with induction at 40 weeks; study group (group B), women with induction at 41 weeks. The outcome was then analysed in terms of mode of delivery, oligohydramnios, meconium-stained liquor, Apgar score, need of NICU, perinatal death. The data was collected, analysed and statistical analysis was done using the Chi square test.Results: Out of total 200 women, 104 women were of 40 weeks and 96 women had completed 41 weeks. The LSCS rate was reduced from 25.96% to 17.7%, when the labour was induced at 41 weeks, the instrumental delivery rate was low in the study group compared to the control group. Even though the meconium staining of liquor was high but NICU admission and perinatal mortality was comparatively lower in the study group.Conclusions: Induction of labour done at 41weeks is associated with reduced maternal morbidity and no adverse effect on the perinatal outcome as compare to induction at 40 weeks

Field-directed assembly of responsive colloids

Field-directed self-assembly (DSA) has recently moved into the focus of the soft-matter and nanotechnology community. It employs the basic principles of self-assembly through carefully chosen building blocks, but the underlying self-assembly process is then aided or modulated using external fields. Here we demonstrate how we can apply a combination of responsive nanoparticles and external electromagnetic fields in order to modulate the intrinsic interparticle interactions and tune the subtle balance between thermal motion and the action of interparticle forces, and thus generate novel self-assembled structures. We will show in particular how we can use field-driven self-assembly to induce phase transitions, cycle through various equilibrium and non-equilibrium phases, and study the micro-structural changes and the underlying kinetic mechanisms of these phase transitions in-situ and in real time. Moreover, we will demonstrate the effect of particle anisotropy in field-driven assembly. References [1] J. J. Crassous, A. M. Mihut, E. Wernersson, P. Pfleiderer, J. Vermant, P. Linse, and P. Schurtenberger, Nature Communications 5 (2014) 5516. [2] P. S. Mohanty, P. Bagheri, S. Nöjd, A. Yethiraj and P. Schurtenberger, Phys. Rev. X 5 (2015) 011030

Predicting risk of airflow obstruction in primary care: Validation of the lung function questionnaire (LFQ)

Summary: The Lung Function Questionnaire (LFQ) is being developed as a case finding tool to identify patients who are appropriate for spirometry testing to confirm the diagnosis of chronic obstructive pulmonary disease (COPD). The cross-sectional study reported herein was conducted to validate the LFQ, to identify item-response scales associated with the best accuracy, and to determine the impact on accuracy of the addition of another item on activity limitations (AL). Patients ≥ 40 years old seen at 2 primary care offices completed the LFQ, a demographic questionnaire followed by spirometry. Of the 837 evaluable patients, 18.6% had airflow obstruction (forced expiratory volume in 1 s/forced vital capacity [FEV1/FVC] p 1/FVC 1/FVC

The Association of Knowledge and Behaviours Related to Salt with 24-h Urinary Salt Excretion in a Population from North and South India

Global Alliance for Chronic Disease through the National Health and Medical Research Council (NHMRC) of Australia (APP1040179). C.J. is supported by a National Health and Medical Research Council postgraduate scholarship (APP1074678). J.W. is supported by a National Health and Medical Research Council/National Heart Foundation Career Development Fellowship (APP1082924). B.N. is supported by a National Health and Medical Research Council of Australia Principal Research Fellowship (APP1106947). He also holds an NHMRC Program Grant (APP1052555). P.K.M. is an Intermediate Career Fellow of the WT/DBT India Alliance. R.S. is supported by a Wellcome Trust Capacity Strengthening Strategic Award Extension phase to the Public Health Foundation of India and a consortium of UK universities (WT084754/Z/08/A)

Cardiovascular risk prediction in India: Comparison of the original and recalibrated Framingham prognostic models in urban populations.

Introduction: Cardiovascular diseases (CVDs) are the leading cause of death in India. The CVD risk approach is a cost-effective way to identify those at high risk, especially in a low resource setting. As there is no validated prognostic model for an Indian urban population, we have re-calibrated the original Framingham model using data from two urban Indian studies. Methods: We have estimated three risk score equations using three different models. The first model was based on Framingham original model; the second and third are the recalibrated models using risk factor prevalence from CARRS (Centre for cArdiometabolic Risk Reduction in South-Asia) and ICMR (Indian Council of Medical Research) studies, and estimated survival from WHO 2012 data for India. We applied these three risk scores to the CARRS and ICMR participants and estimated the proportion of those at high-risk (&gt;30% 10 years CVD risk) who would be eligible to receive preventive treatment such as statins. Results: In the CARRS study, the proportion of men with 10 years CVD risk &gt; 30% (and therefore eligible for statin treatment) was 13.3%, 21%, and 13.6% using Framingham, CARRS and ICMR risk models, respectively. The corresponding proportions of women were 3.5%, 16.4%, and 11.6%. In the ICMR study the corresponding proportions of men were 16.3%, 24.2%, and 16.5% and for women, these were 5.6%, 20.5%, and 15.3%. Conclusion: Although the recalibrated model based on local population can improve the validity of CVD risk scores our study exemplifies the variation between recalibrated models using different data from the same country. Considering the growing burden of cardiovascular diseases in India, and the impact that the risk approach has on influencing cardiovascular prevention treatment, such as statins, it is essential to develop high quality and well powered local cohorts (with outcome data) to develop local prognostic models.</ns4:p