Effects of psychosocial stimulation on improving home environment and child-rearing practices: results from a community-based trial among severely malnourished children in Bangladesh

ABSTRACT: BACKGROUND: Parenting programmes are effective in enhancing parenting practices and child development. This study evaluated the effects of a intervention with psychosocial stimulation (PS) on the quality of the home environment and mothers' child-rearing practices in a community-based trial with severely malnourished Bangladeshi children. METHOD: Severely underweight children (n = 507), 6-24 months of age, were randomly assigned to five groups: PS; food supplementation (FS); PS + FS; clinic-control (CC); and, hospital-control (CH). PS included fortnightly follow-up visits for six months at community clinics where a play leader demonstrated play activities and gave education on child development and child rearing practices. FS comprised cereal-based supplements (150-300 kcal/day) for three months. All groups received medical care, micronutrient supplements and growth monitoring. Mothers were given the Home Observation for Measurement of the Environment (HOME) inventory and a questionnaire on parenting at baseline and after six months to assess the outcome. RESULTS: 322 children completed the study. After six months of intervention the PS + FS and PS groups benefitted in the total HOME score (depending on the comparison group, effect sizes varied from 0.66 to 0.33 SD) The PS + FS and PS groups also benefitted in two HOME subscales: maternal involvement (effect sizes: 0.8 to 0.55 SD) and play materials, (effect sizes: 0.46 to 0.6 SD), and child-rearing practices scores (effect size: 1.5 to 1.1 SD). The PS + FS group benefitted 4.0 points in total HOME score compared with CH, 4.8 points compared with CC and 4.5 points compared with FS (p < 0.001 for all). The PS group benefitted 2.4 points compared with CH (p = 0.035), 3.3 points compared with CC (p = 0.004), and 2.9 points compared with FS (p = 0.006). Child-rearing practice scores of the PS + FS group improved 7.7, 6.4 and 6.6 points and the PS group improved 8.5, 7.2 and 7.4 points more than CH, CC and FS, respectively (p < 0.001 for all). CONCLUSIONS: Child-rearing practices of mothers of severely malnourished children and the quality of their home environment can be improved through community-based psychosocial stimulation with or without food supplementation. This may be of importance to promote child development.     

Quasi-reversible two-electron reduction of oxygen at iodine submonolayer-coated gold electrode in alkaline media

Oxygen reduction reaction (ORR) was investigated using polycrystalline gold (Au (poly)) electrode modified with chemisorbed iodine (I_(ads)) submonolayer (sub I_(ads)) in O₂-saturated 0.1 M KOH solution. The sub I_(ads) was tailored by potential-dependent partial reductive desorption of I_(ads) from its full monolayer. The Au (1 1 1) facet of the Au (poly) electrode was considered to remain bared at the sub I_(ads)/Au (poly) electrode. The interesting finding of the present study is that (unlike the bare Au (poly) electrode) the sub I_(ads)/Au (poly) electrode exhibited a quasi-reversible two-electron reduction of O₂ in alkaline media. The probable origin of the observed quasi-reversible behavior of the ORR is discussed. Experimental investigations were performed using cyclic and steady-state voltammetric, amperometric and coulometric techniques.     

Beverage-induced enhanced bioavailability of carbamazepine and its consequent effect on antiepileptic activity and toxicity

The present study was undertaken to investigate the food–drug interaction of carbamazepine (CBZ). Common fruit juices [grapefruit juice (GFJ), lime juice (LJ)], known to inhibit the enzyme cytochrome P450 3A4 (CYP3A4), and some widely consumed beverages [milk (M), black tea (BT)] were involved in this study in the presence of CBZ, as might happen during clinical therapy. The effects of the beverages on the pharmacokinetics and drug-induced toxicity of CBZ was observed after concomitant administration for a period of 28 days. Accordingly, the influence of altered bioavailability of CBZ on its antiepileptic activity was investigated. A significant shift in the C_max as well as T_max of CBZ was observed in the presence of LJ and GFJ. This increase in bioavailability significantly enhanced hepatotoxicity and delayed the onset of tremor and piloerection against pentylene tetrazole (PTZ)-induced seizure in experimental animals. However, increased toxicity of CBZ was found to be absent with BT. Thus, from our observation, LJ or GFJ in the presence of CBZ significantly increased the bioavailability of CBZ, which might lead to increased toxicity and antiepileptic activity of the drug.     

Recent advances in pre-clinical diagnosis of Alzheimer’s disease

Metabolic Brain Disease - Alzheimer’s disease (AD) is the most common dementia with currently no known cures or disease modifying treatments (DMTs), despite much time and effort from the...     

Enhanced ferromagnetism of ZnO@Co/Ni hybrid core@shell nanowires grown by electrochemical deposition method

The hybrid structure of ZnO NWs with the presence of different dopants recently has drawn many interests from researchers due to the possibility to integrate multiple functionalities into one single structure. In this article, we investigated the morphology, crystal structure and ferromagnetism of the ZnO@Co/Ni hybrid core@shell NWs prepared by a facile electrochemical deposition method. The results show that a thin layer of Ni and Co coated on the surface of ZnO NWs (confirmed by XRD, EDS, TEM and Raman scattering) can create a significant improvement of ferromagnetic property in such hybrid core@shell NWs. In which, for the coating time of 10, 15, 20 min, the value of M_s is around 0.67, 0.88 and 2.56 emu g⁻¹ for ZnO@Co NWs, and about 0.013, 0.022 and 0.031 emu g⁻¹ for ZnO@Ni NWs, respectively, in comparison with the number of 0.016 emu g⁻¹ for pure ZnO NWs. Interestingly, we also found the temperature dependence of ferromagnetism of such Co/Ni coated ZnO NWs. These results reveal the possibility to employ such hybrid core@shell NWs for many applications, e.g. spin field effect transistors.

Facile electrochemical synthesis of ZnO@Co and ZnO@Ni hybrid core@shell nanowires with enhanced ferromagnetism.     

Highly sensitive p-type 4H-SiC van der Pauw sensor

This paper presents for the first time a p-type 4H silicon carbide (4H-SiC) van der Pauw strain sensor by utilizing the strain induced effect in four-terminal devices. The sensor was fabricated from a 4H-SiC (0001) wafer, using a 1 μm thick p-type epilayer with a concentration of 10¹⁸ cm⁻³. Taking advantage of the four-terminal configuration, the sensor can eliminate the need for resistance-to-voltage conversion which is typically required for two-terminal devices. The van der Pauw sensor also exhibits an excellent repeatability and linearity with a significantly large output voltage in induced strain ranging from 0 to 334 ppm. Various sensors aligned in different orientations were measured and a high sensitivity of 26.3 ppm⁻¹ was obtained. Combining these performances with the excellent mechanical strength, electrical conductivity, thermal stability, and chemical inertness of 4H-SiC, the proposed sensor is promising for strain monitoring in harsh environments.

This paper presents for the first time a p-type 4H silicon carbide (4H-SiC) van der Pauw strain sensor by utilizing the strain induced effect in four-terminal devices.     

Polypyrrole/tannin biobased nanocomposite with enhanced electrochemical and physical properties

In this research, tannin (TA) extracted from Acacia mangium and a cationic surfactant, cetyltrimethylammonium bromide (CTAB), were used to modify and enhance the physical and electrochemical properties of a polypyrrole (PPy) composite. Brunauer–Emmett–Teller (BET) analysis presented a higher degree of surface area and porosity for the PPy/TA/CTAB nanocomposite. A highly porous and rod like structure with a lumpy surface was observed for PPy/TA prepared in the presence of CTAB by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). Cyclic voltammograms of the modified SPE electrode using PPy/TA/CTAB displayed an enhanced current response compared to the electrode modified with only PPy or PPy/TA. Electrochemical Impedance Spectroscopy (EIS) exhibited a lower value of charge transfer resistance (R_ct) and higher electron transfer for the modified electrode, making the nanocomposite a promising candidate for biosensor application.

Tannin (TA) extracted from Acacia mangium and a cationic surfactant, cetyltrimethylammonium bromide (CTAB), were used to modify and enhance the physical and electrochemical properties of polypyrrole (PPy) composite.     

Interaction between functionalized graphene and sulfur compounds in a lithium–sulfur battery – a density functional theory investigation

Lithium–sulfur (Li–S) batteries are emerging as one of the promising candidates for next generation rechargeable batteries. However, dissolution of lithium polysulfides in the liquid electrolyte, low electrical conductivity of sulfur and large volume change during electrochemical cycling are the main technical challenges for practical applications. In this study, a systematic first-principles density functional theory calculation is adopted to understand the interactions between graphene and graphene with oxygen containing functional groups (hydroxyl, epoxy and carboxyl groups) and sulphur (S₈) and long chain lithium polysulfides (Li₂S₈ and Li₂S₄). We find the adsorption is dominated by different mechanisms in sulphur and lithium polysulfides, i.e. van der Waals attraction and formation of coordinate covalent Li–O bonds. The adsorption strength is dependent on the inter-layer distance and electron rich functional groups. Through these mechanisms, sulphur and lithium polysulfides can be successfully retained in porous graphene, leading to improved conductivity and charge transfer in the cathode of Li–S batteries.

Functionalized graphene can successfully anchor sulfur compounds via moderate interactions, leading to improved conductivity and charge transfer in the cathode of Li–S batteries.     

Electrochemical oxidation of As(iii) on Pd immobilized Pt surface: kinetics and sensing performance

Pd nanoparticles were electrochemically immobilized on a Pt surface in the presence of sodium dodecyl sulfate (SDS) molecules to study the electrokinetics of arsenite oxidation reactions and the corresponding sensing activities. The X-ray photoelectron spectroscopy (XPS) analysis showed that on the Pt surface, Pd atoms exist as adatoms and the contents of Pd(0) and Pd(ii) were 75.72 and 24.28 at%, respectively, and the particle sizes were in the range of 61–145 nm. The experimental results revealed that the catalytic efficiency as well as the charge transfer resistance (at the redox potential of the Fe(ii)/Fe(iii) couple) increased in the order of Pt < Pt–Pd < Pt–Pd_sds. A Pt–Pd_sds electrode exhibited an open circuit potential (OCP) of 0.65 V in acidic conditions; however, when 50.0 mM NaAsO₂ was present, the OCP value shifted to 0.42 V. It has been projected that the As(iii) oxidation proceeds using a sequential pathway: As(iii) → As(iv) → As(v). After optimization of the square wave voltammetric data, the limits of detection of As(iii) were obtained as 1.3 μg L⁻¹ and 0.2 μg L⁻¹ when the surface modification of the Pt surface was executed with Pd particles in the absence and presence of the SDS surfactant, respectively. Finally, real samples were analyzed with excellent recovery performance.

Amplification of true surface area can be improved when Pd particles are deposited on a substrate in the presence of sodium dodecyl sulfate (SDS) surfactant. In acidic medium, As(iii) undergoes a two-step oxidation process.