Conformal zinc sulfide coating of vertically aligned ZnO nanorods by two-step hydrothermal synthesis on wide bandgap seed layers for lead-free perovskite solar cells.

Vertically aligned ZnO nanorods (NRs) were grown hydrothermally on the wide bandgap (∼3.86 - 4.04 eV) seed layers (SLs) of grain size ∼162 ± 35 nm, prepared using ball-milled derived ZnO powder. The synthesized ZnO NRs were further decorated with ZnS nanocrystals to achieve a ZnO NR-ZnS core-shell (CS)-like nano-scaffolds by a subsequent hydrothermal synthesis at 70 °C for 1 h. UV-Vis-NIR spectroscopy, x-ray diffractometry (XRD), Raman spectroscopy and Field emission scanning electron microscopy (FESEM) coupled with Energy dispersive x-ray spectroscopy (EDX) analyses confirmed the formation of ZnS atop the vertically aligned ZnO NR arrays of ∼1.79 ± 0.17µm length and ∼165 ± 27 nm diameter. Transmission electron microscopy (TEM)/EDX analyses revealed that vertically aligned ZnO NRs (core dia. ∼181 ± 12 nm) arrays are conformally coated by an ultrathin ZnS (∼25 ± 7 nm) shell layer with a preferential ZnS{111}/ZnO{10-10}-like partial epitaxy. The ZnO NRs exhibited a sharp band edge near ∼384 nm having optical bandgap energy (Eg) of ∼3.23 eV. However, the ZnO NR-ZnS CS exhibited double absorption bands atEg∼ 3.20 eV (ZnO-core) andEg∼ 3.78 eV (ZnS-shell). The ZnS{111}/ZnO{10-10}-nano-scaffolds could be utilized to facilitate the enhanced absorption of UV photons as well as the radial junction formation between the Pb-free perovskite absorber and ZnS/ZnO NRs layers.

Influence of Sn doping on the optoelectronic properties of ZnO nanoparticles.

Zinc Oxide (ZnO) nanoparticles (NPs) obtained a lot of attention from researchers and industries because of their superior properties as an optoelectronic material. Doping, especially tin (Sn), can further fine-tune their optoelectronic properties. In this manuscript, we have reported the optoelectronic properties of Sn-doped ZnO NPs, which were synthesized by a simple chemical solution method. A wide range of dopant (Sn) concentrations were used in the ratios of 0, 1, 3, 5, 7, and 10 weight percent. The effects of dopant (Sn) concentration on the structural, morphological, elemental composition, and optical properties of ZnO NPs were investigated by using an X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM), X-ray photoelectron spectrometer (XPS) and UV-Vis-NIR respectively. XRD analysis revealed the shifting of diffraction patterns towards a higher angle along with decreasing intensity. The calculated crystallite size using the XRD varied from 40.12 nm to 28.15 nm with an increasing doping percentage. Sn doping notably influences the size of ZnO NPs, along with crystal quality, strain, and dislocation density. The X-ray photoelectron spectroscopy (XPS) study showed the presence of zinc (Zn), oxygen (O), and tin (Sn) with their preferred oxidation states in the synthesized NPs. UV-Visible spectroscopy (UV-Vis) showed that the bandgap changed from 3.55 to 3.85 eV with the increasing concentration of Sn. FE-SEM revealed that the structures and surfaces were irregular and not homogeneous. The above findings for ZnO nanostructures show their potential application in optoelectronic devices.

Facile extraction and characterization of calcium hydroxide from paper mill waste sludge of Bangladesh.

Herein, paper mill waste sludge (PMS) from two different sources has been investigated to extract calcium hydroxide, Ca(OH)2 by a facile and inexpensive extraction process. PMS samples, collected from local paper mill plants of Bangladesh, were the main precursors wherein HCl and NaOH were used for chemical treatment. The as-synthesized products were analysed by a variety of characterization tools including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) elemental analyses. Our studies confirm that the extracted product contains Ca(OH)2 as a major content, albeit it also includes CaCO3 phase owing to the inescapable carbonation process from the surrounding environment. The particle size of the synthesized products is in the range of 450-500 nm estimated from SEM micrographs. The crystallite domain size of the same estimated from XRD analyses and was found to be approximately 47 and 31 nm respectively for product-A and product-B considering major (101) Bragg peak of Ca(OH)2. The yield percentage of the isolated products is about 65% for samples collected from both sources.

Facile synthesis of Cu2O nanorods in the presence of NaCl by successive ionic layer adsorption and reaction method and its characterizations.

Cuprous oxide (Cu2O) nanorods have been deposited on soda-lime glass substrates by the modified successive ionic layer adsorption and reaction technique by varying the concentration of NaCl electrolyte into the precursor complex solution. The structural, electrical and optical properties of synthesized Cu2O nanorod films have been studied by a variety of characterization tools. Structural analyses by X-ray diffraction confirmed the polycrystalline Cu2O phase with (111) preferential growth. Raman scattering spectroscopic measurements conducted at room temperature also showed characteristic peaks of the pure Cu2O phase. The surface resistivity of the Cu2O nanorod films decreased from 15 142 to 685 Ω.cm with the addition of NaCl from 0 to 4 mmol and then exhibited an opposite trend with further addition of NaCl. The optical bandgap of the synthesized Cu2O nanorod films was observed as 1.88-2.36 eV, while the temperature-dependent activation energies of the Cu2O films were measured as about 0.14-0.21 eV. Scanning electron microscope morphologies demonstrated Cu2O nanorods as well as closely packed spherical grains with the alteration of NaCl concentration. The Cu2O phase of nanorods was found stable up to 230°C corroborating the optical bandgap results of the same. The film fabricated in presence of 4 mmol of NaCl showed the lowest resistivity and activation energy as well as comparatively uniform nanorod morphology. Our studies demonstrate that the nominal presence of NaCl electrolytes in the precursor solutions has a significant impact on the physical properties of Cu2O nanorod films which could be beneficial in optoelectronic research.

Influence of the Substrate, Process Conditions, and Postannealing Temperature on the Properties of ZnO Thin Films Grown by the Successive Ionic Layer Adsorption and Reaction Method.

Here, we report the effect of the substrate, sonication process, and postannealing on the structural, morphological, and optical properties of ZnO thin films grown in the presence of isopropyl alcohol (IPA) at temperature 30-65 °C by the successive ionic layer adsorption and reaction (SILAR) method on both soda lime glass (SLG) and Cu foil. The X-ray diffraction (XRD) patterns confirmed the preferential growth thin films along (002) and (101) planes of the wurtzite ZnO structure when deposited on SLG and Cu foil substrates, respectively. Both XRD and Raman spectra confirmed the ZnO and Cu-oxide phases of the deposited films. The scanning electron microscopy image of the deposited films shows compact and uniformly distributed grains for samples grown without sonication while using IPA at temperatures 50 and 65 °C. The postannealing treatment improves the crystallinity of the films, further evident by XRD and transmission and reflection results. The estimated optical band gaps are in the range of 3.37-3.48 eV for the as-grown samples. Our experimental results revealed that high-quality ZnO thin films could be grown without sonication using an IPA dispersant at 50 °C, which is much lower than the reported results using the SILAR method. This study suggests that in the presence of IPA, the SLG substrate results in better c-axis-oriented ZnO thin films than that of deionized water, ethylene glycol, and propylene glycol at the optimum temperature of 50 °C. Air annealing of the samples grown on Cu foils induced the formation of Cu x O/ZnO junctions, which is evident from the characteristic I-V curve including the structural and optical data.

The effect of substrate temperature and oxygen partial pressure on the properties of nanocrystalline copper oxide thin films grown by pulsed laser deposition.

The data presented in this paper are related to the research article entitled "Pulsed laser deposition of single phase n- and p-type Cu2O thin films with low resistivity" (S.F.U. Farhad et al., 2020) [1]. The detailed processing conditions of copper oxide thin films and a variety of characterization techniques used are described in the same ref. [1]https://doi.org/10.1016/j.matdes.2020.108848. Thin films need to grow on different substrates to elucidate various properties of the individual layer for attaining optimum processing conditions required for devising efficient optoelectronic junctions as well as thin film stacks for different sensing applications. This article describes the effect of substrate temperature and oxygen partial pressure on the structural, morphological, optical, and electrical properties of pulsed laser deposited (PLD) nanocrystalline copper oxide thin films on quartz glass, ITO, NaCl(100), Si(100), ZnO coated FTO substrates. The low temperature grown copper oxide and zinc oxide thin films by PLD were used for devising solid n-ZnO/p-Cu2O junction and investigated their photovoltaic and interface properties using dynamic photo-transient current measurement at zero bias voltage and TEM/EDX respectively. These datasets are made publicly available for enabling extended analyses and as a guide for further research.

Insulin secretory defect may be the major determinant of GDM in lean mothers.

AIMS: To compare the insulin sensitivity and secretion indices of pregnant Bangladeshi women with GDM and normal glucose tolerance (NGT). METHODS: This cross sectional study was performed with 40 GDM and equal number of NGT pregnant women diagnosed on basis of WHO criterion-2013 during 24-40 weeks of gestation. Glucose was measured by glucose oxidase method and fasting insulin by chemiluminescent immunoassay. Equations of homeostatic model assessment (HOMA) were used to calculate indices of insulin resistance (HOMA-IR), ß-cell function (HOMA-B) and insulin sensitivity (HOMA-%S). RESULTS: The GDM group had significantly higher insulin resistance as indicated by higher fasting insulin value [GDM vs. NGT; 10.23 (7.94-14.50) vs. 7.07 (5.28-11.07) µIU/ml] and HOMA-IR [GDM vs. NGT; 2.47 (1.75-3.43) vs. 1.50 (0.99-2.22)] and poor ß-cell secretion [GDM vs. NGT; HOMA-B: 113.37 (90.30-191.35) vs. 150.98 (109.85-271.72), median (IQR); p < 0.001 for all]. HOMA-B was significantly lower in GDM than NGT with BMI < 23 kg/m2 [GDM vs. NGT; 63.37 (49.19-83.83) vs. 134.89 (93.50-193.17) ng/ml; p = 0.010] despite having statistically comparable difference in IR. BMI was found to be a significant predictor of HOMA-IR in GDM. CONCLUSIONS: Though impairments of both insulin secretion and sensitivity are hallmarks in the pathogenesis of GDM, ß-cell dysfunction contributes more to development of GDM in those with relatively lower BMI in our population.

Author Correction: Childhood ecology influences salivary testosterone, pubertal age and stature of Bangladeshi UK migrant men.

In the version of this Article originally published, the units for the 'Weight' column in Table 1 were incorrect; they should have been kg. This has now been corrected.

Childhood ecology influences salivary testosterone, pubertal age and stature of Bangladeshi UK migrant men.

Male reproductive investment is energetically costly, and measures of human reproductive steroid hormones (testosterone), developmental tempo (pubertal timing) and growth (stature) correlate with local ecologies at the population level. It is unclear whether male reproductive investment in later life is 'set' during childhood development, mediated through adulthood, or varies by ethnicity. Applying a life-course model to Bangladeshi migrants to the United Kingdom, here we investigate plasticity in human male reproductive function resulting from childhood developmental conditions. We hypothesized that childhood ecology shapes adult trade-offs between reproductive investment and/or other fitness-related traits. We predicted correspondence between these traits and developmental timing of exposure to ecological constraints (Bangladesh) or conditions of surplus (United Kingdom). We compared: Bangladesh sedentees (n = 107); Bangladeshi men who migrated in childhood to the United Kingdom (n = 59); migrants who arrived in adulthood (n = 75); second-generation UK-born and raised children of Bangladeshi migrants (n = 56); and UK-born ethnic Europeans (n = 62). Migration before puberty predicted higher testosterone and an earlier recalled pubertal age compared with Bangladeshi sedentees or adult migrants, with more pronounced differences in men who arrived before the age of eight. Second-generation Bangladeshis were taller, with higher testosterone than sedentees and adult migrants, and higher waking testosterone than Europeans. Age-related testosterone profiles varied by group, declining in UK migrants, increasing in sedentees, and having no significant relationship within UK-born groups. We conclude that male reproductive function apparently remains plastic late into childhood, is independent of Bengali or European ethnicity, and shapes physiological trade-offs later in life.

A consensus of key opinion leaders on the management of pre-diabetes in the Asia-Pacific region / Journal of the ASEAN Federation of Endocrine Societies

@#<p>The Asia-Pacific region carries a high disease burden, with over half of the global diabetic population residing in this region. Increasing evidence shows that without targeted intervention, the progression from impaired glucose tolerance (IGT) to type 2 diabetes occurs more frequently in Asians compared with Caucasians. Furthermore, IGT is independently associated with an increased risk of cardiovascular disease, and should be managed as early as possible. Because diabetes is now a major public health issue, strategies aimed at prevention and treatment are urgently required. Lifestyle modification, including weight loss, dietary changes and increased physical activity, play a major role in controlling the disease. Significant evidence also supports the effectiveness of a combination of lifestyle modification and pharmacologic therapy, such as metformin, in delaying the onset of diabetes. Although the importance of lifestyle interventions is well recognized throughout Asia, many countries do not have formal recommendations to guide the diagnosis and management of individuals at risk of progression to diabetes. At a recent regional meeting, experts from the Asian region convened to develop consensus recommendations to guide clinicians in the management of Asian patients with pre-diabetes. These consensus recommendations provide a clear and concise approach to the management of individuals with IGT based on the available evidence and current best clinical practice.</p>

A consensus of key opinion leaders on the management of pre-diabetes in the Asia-Pacific Region / Journal of the ASEAN Federation of Endocrine Societies

@#The Asia-Pacific region carries a high disease burden, with over half of the global diabetic population residing in thisregion. Increasing evidence shows that without targeted intervention, the progression from impaired glucose tolerance(IGT) to type 2 diabetes occurs more frequently in Asians compared with Caucasians. Furthermore, IGT is independently associated with an increased risk of cardiovascular disease, and should be managed as early as possible. Because diabetes is now a major public health issue, strategies aimed at prevention and treatment areurgently required. Lifestyle modification, including weight loss, dietary changes and increased physical activity, play a major role in controlling the disease. Significant evidence also supports the effectiveness of a combination of lifestylemodification and pharmacologic therapy, such as metformin, in delaying the onset of diabetes. Although the importanceof lifestyle interventions is well recognized throughout Asia, many countries do not have formal recommendations to guide the diagnosis and management of individuals at risk of progression to diabetes. At a recent regional meeting,experts from the Asian region convened to develop consensus recommendations to guide clinicians in themanagement of Asian patientswith pre-diabetes. These consensus recommendations provide a clear and conciseapproach to the management of individuals with IGT based on the available evidence and current best clinical practice.

Increasing access to safe menstrual regulation services in Bangladesh by offering medical menstrual regulation.

In spite of wide availability of menstrual regulation services, women often resort to a variety of medicines for inducing abortion. The Bangladeshi Government is now supporting attempts to investigate the introduction of medical menstrual regulation in the public sector. This study examined the acceptability of medical menstrual regulation in public sector urban-based clinics, public sector rural-based clinics and urban-based clinics run by Marie Stopes, a non-governmental organization. Of the 2,976 women who attended for menstrual regulation services during the eight-month study period, 68% attended urban Maternal and Child Welfare Centres and the Marie Stopes clinics, while 32% went to the rural public facilities of the Union Health and Family Welfare Centre. Women were offered both medical and manual vacuum aspiration methods of menstrual regulation; 1,875 (63%) chose the medical method and 1,101 (37%) chose manual vacuum aspiration. Around 7.1% of women at Maternal and Child Welfare centres and 11.9% at the Marie Stopes clinics knew about medical menstrual regulation before taking the service, compared to a much higher proportion (43%) at the rural facilities. Overall 61.4% of women who used medical menstrual regulation found the method satisfactory, and 34.2% were very satisfied. Of the 3.9% of women who were not satisfied, most received services from rural facilities.

Factors associated with the outcome of open tibial fractures.

BACKGROUND: Although open tibial fractures are common in Malaysia, the outcomes for these patients have not been evaluated in the literature. This retrospective study was conducted to examine the factors associated with infection and non-union in open tibial fractures managed at Hospital Tengku Ampuan Afzan (HTAA), Kuantan, in 2009. METHODS: From 1 January until 31 December 2009, the Department of Orthopaedics of HTAA managed 58 patients with open tibial fracture who had a minimum of a one year follow-up period. The median age was 24.5 years (range: 4 to 72 years). The open tibial fractures were graded using the Gustilo open fracture classification as follows: 4 grade I, 21 grade II, 24 grade IIIA and 9 grade IIIB. All open fractures were subjected to a standard treatment protocol at HTAA, which includes the use of prophylactic antibiotics, emergency debridement, fracture stabilisation, wound coverage, and bone reconstruction when required. The mean time from injury to the initial debridement was 29.7 hours (range: 13 to 216 hours). RESULTS: Seventeen (29%) cases were complicated by infection, and 10 patients (17%) developed non-union. The grade of the open fracture was significantly associated with infection, and age and the time interval between the injury and the initial wound debridement were significantly associated with non-union. CONCLUSION: The high rates of infection and non-union, particularly in severe open fractures, indicate that there is a need to improve the management of open tibial fractures treated at HTAA. The time to initial debridement is an important factor that can be readily amended to improve the outcome. Further studies with larger sample sizes are likely needed to replicate and confirm our findings.

Beneficial effect of the leaves of Murraya koenigii (Linn.) Spreng (Rutaceae) on diabetes-induced renal damage in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Murraya koenigii (Linn.) Spreng (curry leaf) is widely used as a nephroprotective agent in kidney's infirmities among diabetics by the traditional practitioners in Malaysia. However, the latter role of curry leaf has been grossly under reported and is yet to receive proper scientific evaluation. AIM OF THE STUDY: The present study was designed to investigate the beneficial effect of the leaves of Murraya koenigii (Linn.) on diabetes-induced renal damage in vivo with regard to prove its efficacy by local traditional practitioners in the treatment of kidney frailties in diabetics. MATERIALS AND METHODS: Aqueous (AQ) extract of the leaves of Murraya koenigii (Linn.) was administered to both normal and streptozotocin (STZ) induced diabetic male rats (Sprague-Dawley strain). Animals were divided into six groups (n=6) and treated with variable dose levels of AQ extract (200 and 400mg/kg body weight/day) for 30 days. At the end of 30 days, animals were sacrificed, blood was collected, processed and stored at -70°C for the zestimation of serum urea and creatinine, changes in plasma antioxidant capacity by FRAP assay, and glutathione peroxidase levels, in the normal and STZ-induced diabetic rats. Histological changes of the kidneys of these animals were also evaluated by light microscopy to determine the beneficial effect of the leaves. RESULTS: Daily oral administration of variable dose levels of the AQ extract for 30 days, produced significant dose dependant decrease in serum urea and creatinine levels (p<0.001), and marked increase in the levels of plasma antioxidant capacity (p<0.01) in diabetic treated rats, compared to the control (non-diabetic) subjects. However, the normal treated rats showed minimal variation in these parameters in comparison to normal controls. Histological studies of the kidneys of these animals showed comparable tissue regeneration by the AQ extract. CONCLUSION: The results of our study scientifically support the traditional belief for using the leaves of Murraya koenigii (Linn.) as adjuvant, in the treatment of pain disorders related to renal impairments among diabetics.

Children at risk of developing dehydration from diarrhoea: a case-control study.

To identify the factors related to dehydration from diarrhoea, a hospital-based case-control study was carried out among under-2-year-old Bangladeshi children. The study compared 80 cases who had 'some' or severe dehydration with 160 age-matched controls who had 'no signs' of dehydration. All the cases and controls were examined and the mothers were interviewed in the hospital and followed at home on the 14th day of illness. Thirty-eight factors were studied for their probable influence on the development of dehydration. In bivariate analysis, 17 factors were found to be associated significantly with the development of dehydration and were treated with stepwise logistic regression analysis. A combination of vomiting, oral rehydration therapy at home, mother's dirty finger nails, and residing more than 3 km away from the hospital provided the maximum sensitivity (77.5 per cent) and specificity (91.2 per cent) for predicting development of dehydration. These prognostic factors would be helpful for community health workers to identify children at risk of developing diarrhoea-associated dehydration, and preventive strategies could be designed to alter the prognostic factors.