Discharge against medical advice in Special Care Newborn Unit in Chattogram, Bangladesh: Prevalence, causes and predictors.

INTRODUCTION: Discharge against medical advice (DAMA) is an unexpected event for patients and healthcare personnel. The study aimed to assess the prevalence of DAMA in neonates along with characteristics of neonates who got DAMA and, causes and predictors of DAMA. METHODS AND FINDINGS: This case-control study was carried out in Special Care Newborn Unit (SCANU) at Chittagong Medical College Hospital from July 2017 to December 2017. Clinical and demographic characteristics of neonates with DAMA were compared with that of discharged neonates. The causes of DAMA were identified by a semi-structured questionnaire. Predictors of DAMA were determined using a logistic regression model with a 95% confidence interval. A total of 6167 neonates were admitted and 1588 got DAMA. Most of the DAMA neonates were male (61.3%), term (74.7%), outborn (69.8%), delivered vaginally (65.7%), and had standard weight at admission (54.3%). A significant relationship (p < 0.001) was found between the variables of residence, place of delivery, mode of delivery, gestational age, weight at admission, and day and time of outcome with the type of discharge. False perceptions of wellbeing (28.7%), inadequate facilities for mothers (14.5%), and financial problems (14.1%) were the prevalent causes behind DAMA. Predictors of DAMA were preterm gestation (AOR 1.3, 95% CI 1.07-1.7, p = 0.013), vaginal delivery (AOR 1.56, 95% CI 1.31-1.86, p < 0.001), timing of outcome after office hours (AOR 477.15, 95% CI 236-964.6, p < 0.001), and weekends (AOR 2.55, 95% CI 2.06-3.17, p < 0.001). Neonates suffering from sepsis (AOR 1.4, 95% CI 1.1-1.7, p< 0.001), Respiratory Distress Syndrome (AOR 3.1, 95% CI 1.9-5.2, p< 0.001), prematurity without other complications (AOR 2.1, 95% CI 1.45-3.1, p < 0.001) or who were referred from north-western districts (AOR 1.48, 95% CI 1.13-1.95, p = 0.004) had higher odds for DAMA. CONCLUSIONS: Identification of predictors and reasons behind DAMA may provide opportunities to improve the hospital environment and service related issues so that such vulnerable neonates can complete their treatment. We should ensure better communication with parents, provide provision for mothers' corner, especially for outborn neonates, maintain a standard ratio of neonates and healthcare providers, and adopt specific DAMA policy by the hospital authority.

Avocado seed waste bioconversion into poly(3-hydroxybutyrate) by using Cobetia amphilecti and ethyl levulinate as a green extractant.

The avocado processing industry produces up to 1.3M tons of agro-waste annually. Chemical analysis of avocado seed waste (ASW) revealed that it is rich in carbohydrates (464.7 ± 21.4 g kg-1) and proteins (37.2 ± 1.5 g kg-1). Optimized microbial cultivation of Cobetia amphilecti using an acid hydrolysate of ASW, generated poly(3-hydroxybutyrate) (PHB) in a 2.1 ± 0.1 g L-1 concentration. The PHB productivity of C. amphilecti cultivated on ASW extract was 17.5 mg L-1 h-1. The process in which a novel ASW substrate was utilized has been further augmented by using ethyl levulinate as a sustainable extractant. This process achieved 97.4 ± 1.9 % recovery yield and 100 ± 1 % purity (measured by TGA, NMR, and FTIR) of the target PHB biopolymer, along with a high and relatively uniform PHB molecular weight (Mw = 1831 kDa, Mn = 1481 kDa, Mw/Mn = 1.24) (measured by gel permeation chromatography), compared to PHB polymer extracted by chloroform (Mw = 389 kDa, Mn = 297 kDa, Mw/Mn = 1.31). This is the first example of ASW utilization as a sustainable and inexpensive substrate for PHB biosynthesis and ethyl levulinate as an efficient and green extractant of PHB from a single bacterial biomass.

Carbon-Nitride Popcorn-A Novel Catalyst Prepared by Self-Propagating Combustion of Nitrogen-Rich Triazenes.

The interest in development of non-graphitic polymeric carbon nitrides (PCNs), with various C-to-N ratios, having tunable electronic, optical, and chemical properties is rapidly increasing. Here the first self-propagating combustion synthesis methodology for the facile preparation of novel porous PCN materials (PCN3-PCN7) using new nitrogen-rich triazene-based precursors is reported. This methodology is found to be highly precursor dependent, where variations in the terminal functional groups in the newly designed precursors (compounds 3-7) lead to different combustion behaviors, and morphologies of the resulted PCNs. The foam-type highly porous PCN5, generated from self-propagating combustion of 5 is comprehensively characterized and shows a C-to-N ratio of 0.67 (C3 N4.45 ). Thermal analyses of PCN5 formulations with ammonium perchlorate (AP) reveal that PCN5 has an excellent catalytic activity in the thermal decomposition of AP. This catalytic activity of PCN5 is further evaluated in a closer-to-application scenario, showing an increase of 18% in the burn rate of AP-Al-HTPB (with 2 wt% of PCN5) solid composite propellant. The newly developed template- and additive-free self-propagating combustion synthetic methodology using specially designed nitrogen-rich precursors should provide a novel platform for the preparation of non-graphitic PCNs with a variety of building block chemistries, morphologies, and properties suitable for a broad range of technologies.

Turning mannitol-rich agricultural waste to poly(3-hydroxybutyrate) with Cobetia amphilecti fermentation and recovery with methyl levulinate as a green solvent.

The present study explored the use of mannitol and mannitol-rich agro-industrial wastes as substrates for PHB production by Cobetia amphilecti isolated from the green Ulva sp. seaweed. Cultivation of C. amphilecti on mannitol, celery, and olive leaves (OLs) waste led to 4.20, 6.00, and 5.16 g L-1 of cell dry mass (CDM), 76.3, 25.5, and 12.0% of PHB content in CDM and 3.2, 1.53, and 0.62 g L-1 of PHB concentration, respectively; which suggested that they can be exploited as carbon substrates for the production of PHB. Extraction of PHB from C. amphilecti cultures by solubilization in the green solvent methyl levulinate (ML) (2% w/w, 140 °C, 1 h) indicated that the recovery yield and purity of PHB are above 97 and 90% w/w, respectively. The use of ML could be an attractive method for the recovery of PHB when safe and non-toxic solvents are required.

A Simple Iron-Catalyst for Alkenylation of Ketones Using Primary Alcohols.

Herein, we developed a simple iron-catalyzed system for the α-alkenylation of ketones using primary alcohols. Such acceptor-less dehydrogenative coupling (ADC) of alcohols resulted in the synthesis of a series of important α,ß-unsaturated functionalized ketones, having aryl, heteroaryl, alkyl, nitro, nitrile and trifluoro-methyl, as well as halogen moieties, with excellent yields and selectivity. Initial mechanistic studies, including deuterium labeling experiments, determination of rate and order of the reaction, and quantitative determination of H2 gas, were performed. The overall transformations produce water and dihydrogen as byproducts.

Iron-Catalyzed Coupling of Methyl N-Heteroarenes with Primary Alcohols: Direct Access to E-Selective Olefins.

An efficient Fe-catalyzed system is reported for direct α-olefination of methyl-substituted N-heteroarenes with primary alcohols. The catalytic dehydrogenative coupling enables a series of functionalized E-olefinated N-heteroaromatics with excellent selectivity (>99%). Initial mechanistic studies including deuterium-labeling experiments provide evidence for the participation of the benzylic C-H/D bond of alcohols.

Nickel-catalysed direct α-olefination of alkyl substituted N-heteroarenes with alcohols.

Catalytic α-olefination of alkylheteroarenes with primary alcohols via dehydrogenative coupling is presented. A simple nickel catalyst system stabilised by readily available nitrogen ligands enables a series of interesting E-configured vinylarenes (confirmed by X-ray crystal-structure analysis) to be synthesised in good to excellent yields with olefin/alkane selectivity of >20 : 1. Hydrogen and water are generated as byproducts and quantitative determination of H2 was performed.

Nickel-Catalyzed Alkylation of Ketone Enolates: Synthesis of Monoselective Linear Ketones.

Herein we have developed a Ni-catalyzed protocol for the synthesis of linear ketones. Aryl, alkyl, and heteroaryl ketones as well as alcohols yielded the monoselective ketones in up to 90% yield. The catalytic protocol was successfully applied in to a gram-scale synthesis. For a practical utility, applications of a steroid derivative, oleyl alcohol, and naproxen alcohol were employed. Preliminary catalytic investigations involving the isolation of a Ni intermediate and defined Ni-H species as well as a series of deuterium-labeling experiments were performed.

Mn(ii)-catalysed alkylation of methylene ketones with alcohols: direct access to functionalised branched products.

Herein an operationally simple alkylation of methylene ketones with primary alcohols is reported. Use of an inexpensive and earth abundant Mn/1,10-phenanthroline system enables direct access to a series of functionalised branched ketones including one-pot sequential double alkylation and Alzheimer's drug donepezil. Preliminary mechanistic investigation, determination of the rate and order of reactions and deuterium labeling experiments support the participation of the hydrogen-borrowing strategy for the ketone alkylation.

Nickel-catalysed alkylation of C(sp3)-H bonds with alcohols: direct access to functionalised N-heteroaromatics.

The first base-metal catalysed coupling of primary alcohols with methyl-N-heteroaromatics is reported. The use of an earth abundant and nonprecious NiBr2/L1 system enables access to a series of C(sp3)-alkylated N-heteroaromatics. Mechanistic studies have established the participation of a hydrogen-borrowing strategy for α-alkylation.

Nickel-Catalyzed Hydrogen-Borrowing Strategy for α-Alkylation of Ketones with Alcohols: A New Route to Branched gem-Bis(alkyl) Ketones.

The α-alkylation of ketones using an earth-abundant and nonprecious NiBr2/L1 system is reported. This nickel-catalyzed reaction could be performed in gram scale and successfully applied in the synthesis of donepezil (Alzheimer's drug) and functionalization of steroid hormones and fatty acid derivatives. Synthesis of N-heterocycles, methylation of ketones, and one-pot double alkylation to bis-hetero aryl ketones using two different alcohols with a single catalyst broadens the scope of the catalytic protocol. Preliminary mechanistic studies using defined Ni-H species and deuterium-labeling experiments established the participation of the borrowing-hydrogen strategy.

Nickel-Catalyzed Phosphine Free Direct N-Alkylation of Amides with Alcohols.

Herein, we developed an operational simple, practical, and selective Ni-catalyzed synthesis of secondary amides. Application of renewable alcohols, earth-abundant and nonprecious nickel catalyst facilitates the transformations, releasing water as byproduct. The catalytic system is tolerant to a variety of functional groups including nitrile, allylic ether, and alkene and could be extended to the synthesis of bis-amide, antiemetic drug Tigan, and dopamine D2 receptor antagonist Itopride. Preliminary mechanistic studies revealed the participation of a benzylic C-H bond in the rate-determining step.

Stereoselective synthesis of O-tosyl azabicyclic derivatives via aza Prins reaction of endocyclic N-acyliminium ions: application to the total synthesis of (±)-epi-indolizidine 167B and 209D.

A diastereoselective protocol has been established for the synthesis of 4-O-tosyl piperidine containing hexahydroindolizin-3(2H)-one, hexahydro-1H-quinolizin-4(6H)-one and 1,3,4,10b-tetrahydropyrido[2,1-a]isoindol-6(2H)-one derivatives via the aza-Prins cyclization reaction of cyclic N-acyliminium ions mediated by p-toluene sulphonic acid (p-TSA) under mild conditions. The reaction is highly diastereoselective and gives excellent yields. This method has been applied to an efficient total synthesis of indolizidine alkaloids, (±)-epi-indolizidine 167B and 209D.

Epidemiology and pathophysiology of Helicobacter pylori infection in children.

Helicobacter pylori is one of the commonest bacterial pathogens in human. The organism is associated with development of peptic ulcer diseases, lymphoproliferative disorders and gastric cancer. Residence in a developing country, poor socio-economic conditions and genetic predisposition are regarded as risk factors. Prevalence of infection is higher in developing countries and re-infection is higher among under five children. It is transmitted mainly through feco-oral route in developing countries and gastro-oral route in developed nations. Transmission of 'close-contact infection' depends on the degree of mixing and age-distribution between susceptible and infected individuals. Host and bacterial factors with interaction of environment contribute pathogenicity. H. pylori cytotoxin-associated geneA (cagA), vacuolating toxinA (vacA) and adherence factors to gastric epithelium have been linked to enhanced pathogenicity of the bacterium. Host genetic polymorphism of cytokines, related legends, receptors and enzymes influence H. pylori infection.

Mid-arm circumference: an alternative measure for screening low birth weight babies.

Birth weight is a reliable and sensitive indicator for predicting the immediate or later outcome of a newborn child. In a developing country like Bangladesh, where more than 75% of deliveries occur in rural community and are mostly attended by Traditional Birth Attendants (TBA) or relatives, birth weight cannot be recorded mainly due to paucity of suitable weighing scale. To overcome the problem associated with weighing the newborn, it was considered justified to find out other simpler measurements that could be used as substitute of weighing, in order to identify low birth weight babies. A cross sectional, analytical, hospital based study was conducted at Dhaka city on 560 newborn babies born during a period of 18 months in 2000-2001 to examine relative validity of mid-arm circumference as a screening measure of low birth weight babies. Mid-arm circumference, length, head circumference, chest circumference, abdominal girth, and calf circumference were considered. The study showed a strong correlation (p < 0.001) between mid-arm circumference (r = 0.956) and birth weight, followed by calf circumference (r = 0.946) and birth weight. Other parameters were also strongly correlated (p < 0.001). The study showed that in identifying newborns of <2500 gm a mid-arm circumference of <9 cm had the best sensitivity (96.2%) and specificity (97.3%). A value of <8 cm and <6.8 cm for mid-arm circumference showed highest validity for picking up newborns weighing <2000 gm and <1500 gm respectively. Measurement of arm circumference is easier, convenient and statistically superior to other anthropometrical parameters in this work. The researchers recommend designing of simple 'Tri-colored tape' for early detection of 'At Risk' newborns in rural community for their timely management.