Modelling of adsorption of anionic azo dye using Strychnos potatorum Linn seeds (SPS) from aqueous solution with artificial neural network (ANN)

Synthetic dyes used in the textile and paper industries pose a major threat to the environment. In the present research work, the adsorption efficiency of the natural adsorbent Strychnos potatorum Linn (Fam: Loganiaceae) seeds were examined against the reactive orange-M2R dye from aqueous solution by varying the process conditions such as contact time, pH, adsorbent dosage, and initial dye concentration on adsorption of anionic azo dye. This study compares different types of artificial neural networks which are feedforward artificial neural network (FANN) and nonlinear autoregressive exogenous (NARX) model to predict the efficiency of a cost-effective natural adsorbent Strychnos potatorum Linn seeds on removing reactive orange-M2R dye from aqueous solution. Twelve training algorithms of neural network were compared, and the prediction on the adsorption performance of anionic azo dye from aqueous solution using Strychnos potatonum Linn seeds was evaluated by using the root mean squared error (RMSE), mean absolute error (MAE), coefficient of determination (R²), and accuracy. For FANN model, Levenberg-Marquardt (LM) backpropagation with 19 hidden neurons was selected as the optimum FANN model, with R² of 0.994 and accuracy of 87.20%, 98.21%, and 66.60% for training, testing, and validation datasets, respectively. For NARX model, LM with 8 hidden neurons was selected as the most suitable training algorithm, with R² value of more than 0.99 and accuracy of 88.00%, 90.91%, and 75.00% for training, testing, and validation datasets, respectively. NARX model accurately predicted the adsorption of anionic azo dye from aqueous solution using Strychnos potatonum Linn seeds with better performance than FANN model.

Foetal sacrococcygeal teratoma: extremes in clinical presentation

Sacrococcygeal teratoma (SCT) is a congenital tumour that can be diagnosed by ultrasonography (USG). We present our experience with the management of two cases of SCT in our institution between 2008 and 2009. In the first case, SCT was diagnosed at 17 weeks' gestation. The patient was followed up with fortnightly USG to monitor the tumour size, foetal growth and signs of foetal hydrops. The patient delivered a baby girl by Caesarean section at 37 weeks, with good Apgar scores. The neonate underwent an uneventful resection of SCT on Day 1 of life. In the second case, SCT was diagnosed at 20 weeks during screening. In view of foetal hydrops and anaemia, the patient underwent three in utero foetal blood transfusions. A baby boy was delivered by Caesarean section at 28 weeks. There was a large friable SCT with massive haemorrhage. Despite maximal resuscitative efforts, the neonate died 30 minutes after birth.

The use of anti-D immunoglobulins for rhesus prophylaxis: audit on knowledge and practices among obstetricians

INTRODUCTION

The development of anti-D antibodies results from foetomaternal sensitisation occurring in rhesus (Rh) negative blood group women who carry an Rh-positive foetus. Despite guidelines on Rh immunoprophylaxis, isoimmunisation continues to occur, suggesting that the guidelines are not being fully applied by obstetricians. This study aims to establish the adequacy of knowledge on Rh immunoprophylaxis among obstetricians and trainees in obstetrics and gynaecology in Singapore, and their usual practice in the care of an Rh-negative mother; and hence to audit their practice in accordance with evidence-based guidelines.

METHODS

An anonymous questionnaire survey auditing obstetricians' knowledge of guidelines on anti-D prophylaxis and their usual practice in the clinical setting.

RESULTS

The mean score achieved on the questionnaire was 75.9 percent. Many obstetricians did not know that anti-D immunoglobulins (Ig) should be given within 72 hours of a sensitising event for successful immunoprophylaxis. In clinical practice, all the obstetricians who participated in the questionnaire would offer anti-D Ig prophylaxis to Rh-negative women both antenatally and postnatally. However, only 12.7 percent of them would routinely perform a Kleihauer test in Rh-negative women following delivery.

CONCLUSION

The knowledge on anti-D prophylaxis among obstetricians can be improved. A continual system of education to raise awareness of evidence-based practices as well as clinical audit has been implemented to address this.