Imaging of vertical surface-breaking cracks in concrete members using ultrasonic shear wave tomography.

Surface-breaking cracks in concrete pose a significant threat to the durability of built structures. They create pathways for an accelerated moisture intrusion, and the transport of environmental and chemical agents such as chloride ions, which in turn, exacerbate reinforced concrete deterioration. Estimating the extent of crack propagation beneath the surface helps in determining the safety, durability and reliability of a structure. This information can be used to devise appropriate repair methodologies. Developments in Dry Point Contact (DPC)-based ultrasonic arrays have enabled the detection and localization of defects in concrete through high-resolution imaging. This work proposes the use of Half-Skip travel modes in the time-domain pulse-echo data to be deployed for imaging vertical cracks in concrete. In contrast to the standard Synthetic Aperture Focusing Technique (SAFT), which is widely used for ultrasonic imaging of concrete, the Half-Skip Total Focusing Method (HSTFM) configuration uses the target-scattered signals after a reflection from the back wall. The technique has been evaluated on both simulated and experimentally measured ultrasonic data on specimens fabricated with notches and cracks of different depths. Crack sizes were estimated by measuring the length of thresholded reflection signatures obtained in the images. The presented solution using half-skip modes serves as a supplementary technique to standard SAFT, in order to estimate the depth of surface-breaking cracks in concrete.

Does route of delivery affect maternal and perinatal outcome in women with eclampsia? A randomized controlled pilot study.

OBJECTIVE: The route of delivery in eclampsia is controversial. We hypothesized that adverse maternal and perinatal outcomes may not be improved by early cesarean delivery. STUDY DESIGN: This was a randomized controlled exploratory trial carried out in a rural teaching institution. In all, 200 eclampsia cases, carrying ≥34 weeks, were allocated to either cesarean or vaginal delivery. Composite maternal and perinatal event rates (death and severe morbidity) were compared by intention-to-treat principle. RESULTS: Groups were comparable at baseline with respect to age and key clinical parameters. Maternal event rate was similar: 10.89% in the cesarean arm vs 7.07% for vaginal delivery (relative risk, 1.54; 95% confidence interval, 0.62-3.81). Although the neonatal event rate was less in cesarean delivery-9.90% vs 19.19% (relative risk, 0.52; 95% confidence interval, 0.25-1.05)-the difference was not significant statistically. CONCLUSION: A policy of early cesarean delivery in eclampsia, carrying ≥34 weeks, is not associated with better outcomes.

Randomized controlled study comparing effect of magnesium sulfate with placebo on fetal umbilical artery and middle cerebral artery blood flow in mild preeclampsia at ≥ 34 weeks gestational age.

AIMS: The aim of this study was to evaluate whether prophylactic magnesium sulfate given in women with mild preeclampsia or gestational hypertension brings any significant change in umbilical artery and fetal middle cerebral artery pulsatility index. MATERIAL AND METHODS: Forty-eight women with gestational age greater than 34 weeks with mild preeclampsia or gestational hypertension were randomly assigned to receive either magnesium sulfate or placebo. Pre- and post-magnesium sulfate pulsatility index of umbilical and fetal middle cerebral artery were compared by Mann-Whitney U-test between the groups. Within-group comparison was conducted using Wilcoxon's signed rank test. RESULTS: There was a significant reduction in the post-magnesium sulfate umbilical artery pulsatility index in the intervention group (median 0.88 [0.82-1.03]) when compared to the placebo group (median 1.00 [0.89-1.10]). Post-magnesium sulfate fetal middle cerebral artery pulsatility index in the intervention group (median 1.78 [1.63-1.98]) did not show a significant change compared to the placebo group (median 1.65 [1.42-1.91]). Within-group comparison showed change in both variables after treatment in the intervention group. CONCLUSION: Magnesium sulfate produces a significant decrease in fetal umbilical artery and middle cerebral artery pulsatility index.

Role of Hayman technique and its modification in recurrent puerperal uterine inversion.

Acute puerperal uterine inversion is a rare and fatal complication after delivery. The first priority is its rapid management and prevention of postpartum hemorrhage. On rare occasions, there may be recurrence of inversion after reduction. We applied Hayman technique to two cases of recurrent uterine inversion.

Comparison of neonatal outcome in women with severe pre-eclampsia undergoing caesarean section under spinal or general anaesthesia.

Ideal method of anaesthesia during caesarean section in women with severe pre-eclampsia is difficult to decide. The aim and objective of the study were to compare neonatal outcome in women with severe pre-eclampsia, undergoing caesarean section in intrapartum period, either under general or spinal anaesthesia. Women with severe pre-eclampsia, undergoing caesarean section in intrapartum period, were included in the study. Diastolic blood pressure was kept below 100mm Hg by giving parenteral labetalol pre-operatively. All women received prophylactic magnesium sulphate (5g IV and 10g IM). Maternal blood- gas parameters were measured. Scalp blood pH estimation was done in all cases. Women undergoing caesarean section were randomised into two groups and received either spinal or general anaesthesia. Umbilical arterial catheterisation was done for collecting blood for estimating neonatal blood- gas parameters. Complete data was available in 82 women. Both the groups were comparable in terms of general demographic data, except that percentage of women having an induced labour was significantly more in the general anaesthesia group. Induction of anaesthesia and delivery interval was prolonged for the spinal group. Mean dose of phenylephrine was significantly higher for the spinal anaesthesia group. Preoperative maternal blood-gas parameters and foetal scalp blood pH were comparable in between groups. Difference in neonatal umbilical artery base deficit in between groups was not statistically significant (p = 0.99). Correlation coefficient between maternal base deficit and foetal base deficit was 0.414 (p = 0.01) and 0.06 (p > 0.1) respectively for general and spinal anaesthesia. Subgroup analysis in the population with pre-operative scalp blood pH < 7.2, neonatal umbilical artery base deficit was significantly higher in general anaesthesia group. Five minutes APGAR score was comparable but resuscitation at birth was more common in the general anaesthesia group. Correlation coefficient between maternal base deficit and foetal base deficit in this subgroup was 0.42 (p = 0.05) and -0.57 (p < 0.05) respectively for general and spinal anaesthesia.

Knowledge, attitude and practices of emergency contraception among beneficiaries and providers.

In the new millennium emergency contraceptives have become one of the effective methods for control of global population. It can avert many unwanted pregnancies. In the present study the authors have tried to evaluate the knowledge, attitude and practice of different methods of contraceptive techniques available at present and also about the emergency contraceptive which is recently available amongst 140 healthcare providers and 480 beneficiaries. In one of the teaching institution of Kolkata, RG Kar Medical College and in the district of 24 Parganas (N), the participants in the study were evaluated by preset questionnaires which were separate for providers and for beneficiaries. The results were analysed subsequently.