Strength, durability, and microstructure of self-compacting geopolymer concrete produced with copper slag aggregates.

Lack of vibrations on fresh concrete negatively influences the compaction and thus the quality of concrete. This is particularly concerning with geopolymer concrete (GPC) containing sodium silicate (Na2SiO3), which is viscous in nature. In this study, self-compacting geopolymer concrete (SCGC) containing fly ash (FA) and ultrafine slag (UFS) with copper slag aggregates (CSA) was proposed and investigated. CSA were used as a substitute to sand (by weight) in SCGC at different percentages up to 60%. In the fresh state, slump, T500 slump flow, V-funnel, L-box, U-box, and sieve aggregation ratio tests were performed to investigate flowability, passing ability, and viscosity. At the hardened state, the compressive strength, water absorption, chloride ion resistance and sorptivity tests were examined. The flowability of SCGC improved when CSA were added, and the highest slump of 735 mm was achieved for the mix with 60% CSA. Substitution of up to 20% of CSA enhanced the properties of SCGC at all ages. Mix having 20% CSA (20CSA-SCGC) was superior to other mixes, exhibiting the highest compressive strength (47 MPa) at 365 days while possessing the lowest water absorption, sorptivity, and the highest chloride ion resistance. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analyses also confirmed the improved microstructure of Mix 20CSA-SCGC. Meanwhile, X-ray diffraction (XRD) analysis confirmed the presence of quartz and calcium silicate hydrate (CSH) products, which were the main contributors to properties enhancement.

Performance of Fetal Medicine Foundation algorithm for first trimester preeclampsia screening in an indigenous south Asian population.

BACKGROUND: To evaluate the performance of the Fetal Medicine Foundation (FMF) preterm preeclampsia (PE) screening algorithm in an indigenous South Asian population. METHODS: This was a prospective observational cohort study conducted in a tertiary maternal fetal unit in Delhi, India over 2 years. The study population comprised of 1863 women carrying a singleton pregnancy and of South Asian ethnicity who were screened for preterm pre-eclampsia (PE) between 11 and 14 weeks of gestation using Mean Arterial Pressure (MAP), transvaginal Mean Uterine Artery Pulsatility Index (UtAPI) and biochemical markers - Pregnancy Associated Plasma Protein-A (PAPP-A) and Placental Growth Factor.. Absolutemeasurements of noted biomarkers were converted to multiples of the expected gestational median (MoMS) which were then used to estimate risk for preterm PE < 37 weeks using Astraia software. Women with preterm PE risk of ≥1:100 was classified as as high risk. Detection rates (DR) at 10% false positive rate were calculated after adjusting for prophylactic aspirin use (either 75 or 150 mg). RESULTS: The incidence of PE and preterm PE were 3.17% (59/1863) and 1.34% (25/1863) respectively. PAPP-A and PlGF MoM distribution medians were 0.86 and 0.87 MoM and significantly deviated from 1 MoM. 431 (23.1%) women had a risk of ≥1:100, 75 (17.8%) of who received aspirin. Unadjusted DR using ≥1:100 threshold was 76%.Estimated DRs for a fixed 10% FPR ranged from 52.5 to 80% depending on biomarker combination after recentering MoMs and adjusting for aspirin use. CONCLUSION: The FMF algorithm whilst performing satisfactorily could still be further improved to ensure that biophysical and biochemical markers are correctly adjusted for indigenous South Asian women.

Elective Fetal Reduction in Dichorionic Diamniotic Twin Pregnancies on Parental Request: A Single-Centre Experience.

OBJECTIVES: Our study aimed to examine a subset of electively reduced twins and compare their outcomes with those of expectantly managed twins, along with a cohort of singleton pregnancies. The secondary aim was to ascertain the procedure-related miscarriage risks. METHODS: A retrospective cohort analysis was performed at Apollo Centre for Fetal Medicine, New Delhi, comparing pregnancy outcomes in dichorionic diamniotic twin pregnancies which were reduced to singletons (group 1) with that of women with dichorionic twins managed expectantly (group 0) and women with a singleton pregnancy (group 2). Comparison of continuous and categorical variables was conducted using standard statistical tests. RESULTS: We analysed 35 twins which were reduced to singletons, 421 expectantly managed dichorionic twins and 1915 women with a singleton pregnancy. In the reduction group, the rate of procedure related pregnancy loss<24 weeks was lower, compared to the expectantly managed twins, although the difference was not statistically significant (5.71% [2/35] vs. 7.13% [30/421]; p = 1.000). The median gestational age at delivery was significantly higher in reduced twins compared to expectantly managed twin pregnancies (38.0 vs. 35.4 weeks respectively, p < 0.001) with a higher mean birth weight at delivery, both of which were comparable to that among the singleton pregnancies (38.3 weeks). The rates of preterm birth <32 weeks and <34 weeks in the expectantly managed twins were significantly higher at 19.8% (66/334) and 25.7% (86/334) compared to the reduced twins, all of whom delivered beyond 34 weeks. The rates of preterm births <32 weeks, <34 weeks, and the late preterm births in the reduced twins were comparable to those in the singleton cohort. CONCLUSIONS: The obstetric and perinatal outcomes after reduction of a dichorionic twin are better than an expectantly managed twin without an associated increase in pregnancy loss rates. Fetal reduction of dichorionic twin to a singleton appears to be a safe procedure in expert hands.

First-Trimester Crown-Rump Length (CRL) and Nuchal Translucency (NT) Discordance in Monochorionic Twins: An Ominous Sign or a Benign Feature?

BACKGROUND: This study aimed to evaluate the usefulness of the first-trimester crown-rump length (CRL) and nuchal translucency (NT) discordance in monochorionic diamniotic twins (MCDA) for the prediction of complications-twin-twin transfusion syndrome (TTTS), selective fetal growth restriction (sFGR) or intrauterine fetal demise (IUFD). METHODS: Intertwin discordance in the CRL and NT was calculated as a percentage of the larger CRL and NT, respectively. The performance of inter twin discordance (CRL ≥ 10% and NT≥ 20%) for predicting complications was analysed using standard statistical screening test methods. RESULTS: Fifty-eight MCDA twin pregnancies were studied. Out of them, 19 (32%) pregnancies resulted in one of the complications studied (4 TTTS, 10 sFGR, 5 IUFD). CRL and NT discordance showed an increased probability of developing complications positive likelihood ratio (LR+) {95% confidence interval}: 2.05 {0.46-9.23} and 1.88 {1.03-3.45}, respectively. NT discordance showed a sensitivity of 57%. CONCLUSIONS: Although discordant first-trimester CRL and NT in monochorionic twins are poor screening tools for early prediction, if positive, they increase the risk of developing complications.

Graphene nanoplatelet/graphitized nanodiamond-based nanocomposite for mediator-free electrochemical sensing of urea.

Urea is well-known to offer tremendous scope for sensing/diagnosing such as adulteration in dairy products or diseases in human body. This study was organized to describe and validate a new mediator-free, unsophisticated, and direct current voltage (IV)-based sensor for facile detection of urea using nanocomposites made of urease-immobilized graphene nanoplatelets and graphitized nanodiamonds. This nanocomposite displayed sensitive and direct signal in the form of current at 0 V without the need of any complex chemical reaction. This platform was highly sensitive (limit of detection of 5 µg/mL) far superior to the comparable systems introduced recently. The incorporation of graphitized nanodiamonds within the graphene nanoplatelets layers helped improve the sensitivity by a factor of three (up to 806.3 µA (mg mL-1)-1 cm-2) with 20 s response time. As such, the use of this nanocomposite was helpful in improving sensing performances with enhanced enzyme loading capacity.

Vitamin D Status in Mothers and Their Newborns and Its Association with Pregnancy Outcomes: Experience from a Tertiary Care Center in Northern India.

OBJECTIVE: Study was planned to know vitamin D status in mothers and their newborns and effect of vitamin D deficiency on pregnancy outcome. Study design: Two hundred consecutive pregnant women with singleton pregnancy admitted to the labor ward of a tertiary care center were recruited for the study. Maternal and cord blood samples were taken and analyzed for 25(OH) D level. Maternal and fetal outcomes were studied. RESULTS: High prevalence of hypovitaminosis D was found among pregnant women. Eighty-six percentage had vitamin D deficiency, 9.5% had insufficiency, and only 4.5% had sufficient vitamin D level. Women with preeclampsia had statistically significant vitamin D deficiency and insufficiency as compared to patients who had normal blood pressure levels (p = 0.04). Cesarean section rate was significantly higher in patients with vitamin D deficiency and insufficiency compared to sufficient group (p = 0.004). Cord blood 25(OH) D levels strongly correlated with maternal serum 25 (OH) D levels (p = 0.001, correlation coefficient r = 0.84). CONCLUSIONS: This study showed a very high prevalence of hypovitaminosis D among pregnant women and excellent correlation between maternal and fetal 25(OH) D levels. Hypovitaminosis D was associated with preeclampsia, increased Cesarean rate, and low birth weight babies.

Evaluation of Microleakage of Dental Composites Using Bonding Agents with Different Placement Techniques: An Invitro Study.

BACKGROUND: The rapid progress of adhesive dentistry over the past decade has been attributed to the significant advances in dentin bonding technology. Requirements of an ideal bonding agent are quite similar to those indicated by Buonocore despite of many improvements. As we enter the new millennium, it is important for us to examine the past. OBJECTIVE: To evaluate the microleakage of three bonding agents namely Single Bond, Prime & Bond NT and Excite using different composite materials namely Z100, Spectrum TPH, Tetric with three different placement techniques. MATERIALS AND METHODS: Fifty four extracted human premolars were taken & divided into 9 groups depending upon application of bonding agents followed by composite restorations. Specimens were subjected to thermal cycling at 6(0)C, 37(0)C, 54(0)C and again at 37(0)C & then placed in 10 ml each of freshly prepared 50% silver nitrate solution for 2 hour in darkness, washed & placed under sun light for 24 hours. The sectioned specimens were then observed under stereomicroscope to detect microleakage. RESULTS: On comparing the mean microleakage scores among the three groups, maximum microleakage scores have been obtained when no bonding agent was used, while least microleakage scores were obtained with double coat of bonding agent. CONCLUSION: The present study suggests that the placement of bonding agent technique before composite restoration can be effective to limit the microleakage at the tooth restoration interface.

Efficacy of Oral Brush Biopsy without Computer-Assisted Analysis in Oral Premalignant and Malignant Lesions: A Study.

BACKGROUND: In the present study, the reliability of oral brush biopsy in identifying dysplasia in clinically diagnosed oral potentially malignant and malignant lesions was evaluated while comparing the findings with scalpel biopsy in terms of sensitivity and specificity. MATERIALS AND METHODS: In our study, a total number of 50 patients that included both premalignant and malignant lesions were included. Oral brush cytology using a cytobrush was done for all patients, which was followed by incisional biopsy. Sensitivity, specificity, positive and negative predictive values were obtained. To see the agreement between two modalities Kappa test of agreement was applied. A P < 0.05 was considered to indicate statistical significance. Proportions were compared using Chi-square or Fisher's exact test. RESULTS: Brush cytology using a cytobrush is a reliable adjunct to histopathology in detecting oral premalignant and malignant oral lesions and can be easily performed with less cost and less discomfort. This technique showed a reasonable sensitivity and specificity thus substantiating its reliability in evaluation of oral premalignant and malignant lesions. CONCLUSION: The oral brush biopsy is a simple and rapid, non-invasive and relatively painless and well accepted by patient. It is suitable in population screening programs and for pre- and post-treatment observation of confirmed premalignant and malignant lesions and has proved applications in incapacitated areas.