Sriparna Basu

Modeling NPK release from spherically coated fertilizer granules

Abstract Controlled release of nutrients from fertilizers is desired for its optimal uptake by plants and crops. In our previous study [22] , we considered saturation of a non-electrolytic nutrient and its release from a spherically coated fertilizer granule, assuming only molecular diffusion. In the present study, release of three types of nutrients (NPK) from their commonly used commercial fertilizer sources, stuffed in a coated spherical fertilizer granule is investigated using both molecular and ionic diffusions. One of the nutrients is potassium chloride (KCl), a strong electrolyte, the other is diammonium phosphate ((NH 4 ) 2 HPO 4 ), a weak electrolyte, and the third is urea ((NH 2 ) 2 CO), a non-electrolyte. The release takes place from the granule’s surface area in contact with the soil. The contact area is varied from almost a point to the lower hemisphere with the help of a parameter. The latter case helps to evaluate the release time for basal form of fertilizer application. The effects of granule radius, nutrients release rate, contact area, association constant, pH, and temperature on the release time of nutrients are studied. Variations in release time are much more pronounced from a spherical granule of larger radius having almost point contact with alkaline soil at higher temperatures and for a weak electrolyte of lower association constant. The release time is computed using the techniques of deterministic mathematical modeling and computer simulation. Sensitivity analysis has also been done by giving small variations in the parameters of pH modulator, in the ionic diffusion coefficients of strong- and weak-electrolytes and evaluating root mean squared deviations (RMSD) in release time. Values of RMSDs are negligible, establishing the stability and accuracy of the technique used. Such studies are useful in manufacturing coated spherical granules according to the varying soil conditions, educating the farmers about optimal use of the granules, and also deciding the basal or dispersal form of application of nutrients according to the crop.

Postnatal changes in cerebral blood flow velocity in term intra-uterine growth-restricted neonates

Abstract Background: Intra-uterine growth-restricted (IUGR) fetuses are prone to hypoxic changes in the brain and neurodevelopmental sequelae in later life. Chronic hypoxaemia may also lead to polycythaemia in the fetal and neonatal period. Aim: To evaluate venous haematocrit and cerebral blood flow velocity (CBFV) in term IUGR neonates in the immediate postnatal period. Methods: This was a prospective observational study of 54 clinically healthy term IUGR neonates as cases and 50 term, appropriate-for-gestational-age (AGA), healthy neonates as controls. IUGR was defined as birthweight <10th per centile for gestational age. Neonates with perinatal asphyxia, sepsis and other systemic diseases were excluded. Resistance index (RI), pulsatility index (PI), peak systolic velocity (PSV) and vascular diameter were measured in the internal carotid, vertebral and middle cerebral arteries by transcranial colour Doppler ultrasound between 48 and 72 hours of life, along with the estimation of venous haematocrit. Neonates were observed for development of any complications until discharge and followed up clinically and radiologically for a minimum 6 months. Results: Significantly higher resistance (RI and PI) and lower PSV was recorded in all the cerebral arteries of the IUGR than the AGA group whereas no difference was observed in vascular diameters. Mean haematocrit was significantly higher in the IUGR than in the AGA group [55·7 (4·22) vs 45·1 (2·79) g/dl]. Haematocrit was positively correlated with RI and PI, and negatively correlated with PSV. After discharge, three infants in the IUGR group showed hypertonia and delayed developmental milestones along with hypoxic changes in MRI of the brain. Conclusions: Compared with their AGA counterparts, higher venous haematocrit and lower CBFV were observed in clinically healthy, term IUGR neonates during the early neonatal period. Delayed developmental milestones and hypoxic changes were detected by MRI in three infants. Since the study was limited by its sample size, larger studies are required to document the clinical significance of decreased CBFV and its usefulness as a marker of poor prognosis for future neurodevelopment.

Zinc Supplementation for Neonatal Hyperbilirubinemia: A Randomized Controlled Trial

ObjectivesTo determine the efficacy of oral zinc for treatment of idiopathic neonatal hyperbilirubinemia in near-term and term (35–41 weeks) neonates.DesignRandomized placebo-controlled trial.SettingTertiary-care teaching hospitalParticipantsEighty newborns with idiopathic neonatal hyperbilirubinemia.InterventionNeonates were randomized to receive either oral zinc sulfate (10 mg/d) or placebo for 7 days.Main outcome measuresPrimary: total serum bilirubin levels at 48 (±12) h, 96 (±12) h and 144 (±12) h after intervention. Secondary: duration of phototherapy, and serum zinc and copper levels.ResultsBaseline mean (SD) total serum bilirubin levels were 14.8 (3.8) and 14.4 (3.5) mg/dL in zinc and placebo groups, respectively. No significant differences were observed in total bilirubin levels between the two groups after the intervention. Mean (SD) total serum bilirubin levels in zinc and placebo groups were 13.9 (2.5) vs. 13.4 (1.9) mg/dL (mean difference 0.566; 95% CI −0.535, 1.668, P=0.038) at 48 h, 13.1 (2.7) vs. 12.8 (2.3) mg/dL (mean difference 0.234; 95% CI −1.011, 1.479, P =0.708) at 96 h and 8.0 (2.0) vs. 8.6 (1.2) mg/dL (mean difference −0.569, 95% CI −1.382, 0.242, P=0.166) at 144 h. Although the mean duration of phototherapy in the zinc group was less by 21.3 h (95% CI 11.6, 30.9, P=0.052), the difference was not significant. Postintervention, serum zinc levels were significantly higher in the zinc-supplemented group while serum copper levels were comparable between the two groups.ConclusionsOral zinc sulfate, in a dose of 10 mg/day, is not effective in the management of idiopathic neonatal hyperbilirubinemia.

Mathematical model and computer simulation for release of nutrients from coated fertilizer granules

Controlled release of nutrients from coated fertilizer granules is desired for optimal uptake by plants and crops. We study the saturation and release of nutrients from a coated spherical fertilizer granule having varying contact areas with the soil using the techniques of mathematical modeling and computer simulation. The effects of granule radius, diffusion coefficient and contact area on saturation time as well as on the release time of nutrients are studied. The effect of evaporation loss on the saturation time is also investigated. Understanding these effects quantitatively is very useful in determining the radius and coating width while manufacturing such granules and also educating the farmers about selection of the granules.

Low-dose maternal warfarin intake resulting in fetal warfarin syndrome: In search for a safe anticoagulant regimen during pregnancy.

BACKGROUND Fetal exposure to maternal ingestion of warfarin is known to produce certain dysmorphic features in the neonate, known as fetal warfarin syndrome (FWS). There is a general consensus that maternal intake of warfarin at a daily dose of 5 mg or less is safe both for the infant and the mother. METHODS We report four cases of FWS born to mothers with rheumatic heart disease on warfarin prophylaxis during pregnancy at a dose less than 5 mg/day. RESULTS Along with typical facial features of FWS and multiple epiphyseal stippling in skeletal x-ray, Case 1 had Dandy-Walker malformation and Case 2 had laryngo-tracheomalacia and patent ductus arteriosus. CONCLUSION We emphasize the need for optimizing the choice and dosage schedule of anticoagulants during pregnancy, least harmful for the mother and her developing fetus.

Accidental aspiration of barium sulphate in an infant

Sir, A call was received from the Radiology Department to resuscitate a 7-month-old boy who had choked on barium sulphate. The parents revealed that the boy had been referred for a barium meal with follow-through examination following an ultrasonography examination that was suggestive of malrotation of the gut. While doing the procedure, the infant refused to swallow the barium sulphate and started crying. On being forced by the parents to swallow the barium sulphate, he aspirated. On examination, the infant was apnoeic and cyanosed. Direct laryngoscopy revealed the presence of particulate barium in the trachea; the barium was removed by direct suctioning and the infant was given oxygen inhalation. The cyanosis resolved, spontaneous respiration started and oxygen saturation improved. After 12 h, he developed fever, tachypnoea, subcostal retractions and bilateral coarse crepitations. The chest radiograph showed dense radioopacity in the mid and lower zones of the right lung with bilateral miliary shadows and hilar congestion (Fig. 1). His condition gradually improved. Though aspiration of barium sulphate has been reported [1], it is unusual in an infant. Aspirated barium in small amounts is generally well tolerated, but aspiration in a larger quantity could be fatal during the procedure itself, and even in the long run it can produce pneumonitis, peribronchial granulomatosis or fibrosis [2]. In modern imaging departments, this significant event should not happen because of meticulous care in administering the contrast media. References

Burden of rotavirus diarrhea in under-five Indian children

Need and purposeRotavirus is the most common cause of severe diarrhea in infants and young children worldwide. The burden of rotavirus diarrhea in Indian children is not well established. The present study reviewed the epidemiology of rotavirus diarrhea in hospitalized children and in the community, molecular serotyping and under-five mortality caused by rotavirus diarrhea.MethodsPublications, reporting rotavirus diarrhea in Indian children, were retrieved through a systematic search of databases including Medline, PubMed, IndMed, websites of WHO, UNICEF, National Family Health Survey, Ministry of Health and Family Welfare, and Government of India. ‘Human’ studies in ‘English’ language were included. Age group selected was 0 month to 5 years. No restrictions were applied in terms of study design and time frame.ConclusionsStool sample positivity varied from 4.6% in Kolkata to 89.8% in Manipur, among hospitalized children, and from 4% in Delhi to 33.7% in Manipur in community. Most cases of rotavirus diarrhea in India are caused by G1, G2, and G untypeable strains with distinct regional variations. Rotavirus was identified as an etiological agent in 5.2 to 80.5% cases of nosocomial diarrhea. Data are lacking for rotavirus mortality.

Universal newborn screening — Is it going to be a reality in India?

Universal newborn screening is quite well established in most of the developed countries. In India, the exact prevalence of various metabolic disorders is not known due to lack of any large scale multicentric study to screen metabolic disorders and absence of any organized system of universal newborn screening. Like other developing countries, India is facing an increasing challenge of noncommunicable diseases, of which many are preventable. Endocrinopathies and other genetic/metabolic diseases constitute an important proportion of such problems. The unique clinical dilemma with these disorders is that either they are asymptomatic or have only non-specific signs and symptoms in the early stages, thereby rendering their early diagnosis almost impossible without a screening program. Some of these disorders like congenital hypothyroidism have a debilitating impact on the developing neonatal brain, if not diagnosed early.

Candida Blood Stream Infection in Neonates: Experience from A Tertiary Care Teaching Hospital of Central India.

ObjectivesTo assess the epidemiology of neonatal Candida blood stream infection.MethodsMedical records of neonates with Candida blood stream infection over 5 years (September 2010 to August 2015) were reviewed. Clinical details, species distribution and antifungal susceptibility were noted.Results114 neonates developed Candida blood stream infection. Commonly isolated Candida species were C. tropicalis, C. albicans and C. parapsilosis. Susceptibility for fluconazole and amphotericin B was 86.6% and 68.3%, respectively. Central line >7 days and hospital stay >28 days were independent risk factors associated with non-albicans Candida infection.ConclusionsEarly removal of central line, timely fungal culture and antifungal susceptibility are necessary for early and appropriate treatment and better outcome.

Omphalocele, Inguino-scrotal Hernia and Primary Pulmonary Hypertension: A Rare Combination in a Neonate

To the Editor: Omphalocele, characterized by an extraperitoneal herniation of abdominal viscera through a central midline defect, has a prevalence of 0.8–3.9/10,000 births [1]. Though the incidence of associated anomalies is high (50– 88 %) [2], its association with inguino-scrotal hernia is rare. We report a full term, low-birth-weight neonate with omphalocele, inguino-scrotal hernia and primary pulmonary hypertension (PPHN). A 26-y-old, non-alcoholic, non-smoker, primigravida mother, presented with polyhydramnios and fetal distress at 40 wk’ gestation. A baby-boy weighing 2.2 kg was delivered by emergency cesarean section. One and 5-min Apgar scores were 3 and 6, respectively. On clinical examination, a large omphalocele (umbilical defect 5.5 cm) containing visible coils of intestines and another swelling in the left groin extending to the scrotum was visible (Fig. 1). On auscultation, peristaltic sounds were heard over the scrotum. Rest of the clinical examination was normal. Radiograph abdomen showed omphalocele and bowel loops inside the scrotum indicating inguino-scrotal hernia (Fig. 2). The baby developed respiratory distress at 1 h with >10 % difference in preductal and postductal oxygen saturation in both pulse oximetry and arterial blood gas analysis. Bedside echocardiography showed tricuspid regurgitation with high pulmonary arterial pressure. Chest radiograph and karyotyping were normal. He was managed with mechanical ventilation, intravenous sildenafil and magnesium sulphate but succumbed to death on day 4. Common gastro-intestinal anomalies associated with omphalocele include diaphragmatic hernia, malrotation, intestinal atresias/duplication, hepatobiliary abnormalities, transesophageal fistula and imperforate anus [3]. A single case report has described an association of inguinal hernia with omphalocele [4]. Congenital heart diseases including atrial septal defect, ventricular septal defect, tetralogy of Fallot, pulmonary artery stenosis, and PPHN are seen in 30–50 % of omphaloceles [2]. It is difficult to comment