Dietary diversity modification through school-based nutrition education among Bangladeshi adolescent girls: A cluster randomized controlled trial.

OBJECTIVE: To measure the efficacy of school-based nutrition education on dietary diversity of the adolescent girls in Bangladesh. METHODS: A matched, pair-cluster randomized controlled trial was conducted from July 2019 to September 2020. Randomization was done to select intervention and control schools. There were 300 participants (150 in the intervention and 150 in the control arm) at baseline. We randomly selected our study participants (adolescent girls) from grades six, seven, and eight of each school. Our intervention components included parents' meetings, eight nutrition education sessions, and the distribution of information, education, and communication materials. An hour-long nutrition education session was provided using audio-visual techniques in a class of intervention school once a week by trained staffs of icddr,b for two months. Data on dietary diversity, anthropometry, socio-economic and morbidity status, a complete menstrual history, and haemoglobin status of adolescent girls were collected at recruitment and after five months of intervention. We calculated the mean dietary diversity score of adolescent girls at baseline and at the endline. As the dietary diversity score was incomparable between the control and intervention arm at baseline, we performed the difference-in-difference analysis to assess the effect of the intervention. RESULTS: Mean age of the adolescent girls was 12.31 years and 12.49 years in the control and intervention arms respectively. Percentages of consumption of organ meat, vitamin A-rich fruits and vegetables, legumes, nuts, and seeds were higher in the intervention arm than in the control arm at the end-line. The mean dietary diversity score remained unchanged in the control arm at 5.55 (95% CI: 5.34-5.76) at baseline and 5.32 (95% CI: 5.11-5.54) at the endline. After the intervention, mean dietary diversity increased from 4.89 (95% CI: 4.67-5.10) at baseline to this mean was 5.66 (95% CI: 5.43-5.88) at the endline. Result from the difference-in-difference analysis revealed that the mean dietary diversity was likely to increase by 1 unit due to intervention. CONCLUSION: The shorter duration of the intervention in our study could not show whether it could change the behavior of adolescent girls in increasing dietary diversity through school-based nutrition education, but it showed a pathway for increasing dietary diversity at school. We recommend including more clusters and other food environment elements in retesting to increase precision and acceptability. TRIAL REGISTRATION: This study was registered with ClinicalTrials.gov, trial registration no: NCT04116593. https://clinicaltrials.gov/ct2/show/NCT04116593.

Recent advances in the tuning of the organic framework materials - The selections of ligands, reaction conditions, and post-synthesis approaches.

Organic framework materials, particularly metal-organic frameworks (MOFs), graphene-organic frameworks (GOFs), and covalent organic frameworks (COFs), have led to the revolution across fields including catalysts, sensors, gas capture, and biology mainly owing to their ultra-high surface area-to-volume ratio, on-demand tunable crystal structures, and unique surface properties. While the wet chemistry routes have been the predominant synthesis approach, the crystal phase, morphological parameters, and physicochemical properties of organic framework materials are largely affected by various synthesis parameters and precursors. In this work, we specifically review the influences of synthesis parameters towards crystal structures and chemical compositions of organic framework materials, including selected ligand types and lengths, reaction temperature/solvent/reactant compositions, as well as post-synthesis modification approaches. More importantly, the subsequent impacts on the general electronic, mechanical, surface chemical, and thermal properties as well as the consequent variation in performances towards catalytic, desalination, gas sensing, and gas storage applications are critically discussed. Finally, the current challenges and prospects of organic framework materials are provided.

Role of Oxygen Vacancy Ordering and Channel Formation in Tuning Intercalation Pseudocapacitance in Mo Single-Ion-Implanted CeO2-x Nanoflakes.

Metal oxide pseudocapacitors are limited by low electrical and ionic conductivities. The present work integrates defect engineering and architectural design to exhibit, for the first time, intercalation pseudocapacitance in CeO2-x. An engineered chronoamperometric electrochemical deposition is used to synthesize 2D CeO2-x nanoflakes as thin as ∼12 nm. Through simultaneous regulation of intrinsic and extrinsic defect concentrations, charge transfer and charge-discharge kinetics with redox and intercalation capacitances together are optimized, where reduction increases the gravimetric capacitance by 77% to 583 F g-1, exceeding the theoretical capacitance (562 F g-1). Mo ion implantation and reduction processes increase the specific capacitance by 133%, while the capacitance retention increases from 89 to 95%. The role of ion-implanted Mo6+ is critical through its interstitial solid solubility, which is not to alter the energy band diagram but to facilitate the generation of electrons and to establish the midgap states for color centers, which facilitate electron transfer across the band gap, thus enhancing n-type semiconductivity. Critically, density functional theory simulations reveal, for the first time, that the reduction causes the formation of ordered oxygen vacancies that provide an atomic channel for ion intercalation. These channels enable intercalation pseudocapacitance but also increase electrical and ionic conductivities. In addition, the associated increased active site density enhances the redox such that the 10% of the Ce3+ available for redox (surface only) increases to 35% by oxygen vacancy channels. These findings are critical for any oxide system used for energy storage systems, as they offer both architectural design and structural engineering of materials to maximize the capacitance performance by achieving accumulative surface redox and intercalation-based redox reactions during the charge/discharge process.

Electronic structure transition of cubic CsSnCl3 under pressure: effect of rPBE and PBEsol functionals and GW method.

The antiperovskites based on metal halides have emerged as potential materials for advanced photovoltaic and electronic device applications. But the wide bandgap of non-toxic CsSnCl3 reduces its photovoltaic efficiency. Here, we report the change of electronic structure of CsSnCl3 at different pressure by using GGA-rPBE and GGA-PBEsol functionals and the GW method. We have shown that the prediction of electronic structure transition (semiconducting to metallic state) strongly depends on the exchange-correlation and the GW method gives the most reasonable values of the bandgap under pressure. The pressure increases the electronic density of states close to the Fermi level by pushing the valence electrons upward and thus, reduces the bandgap linearly. Afterward, we have also investigated the influence of pressure on absorption coefficient, and mechanical properties meticulously. Although the pressure shifts the absorption peak to lower photon energies, the absorption coefficient is slightly improved.

Low dimensional materials for glucose sensing.

Biosensors are essential components for effective healthcare management. Since biological processes occur on molecular scales, nanomaterials and nanosensors intrinsically provide the most appropriate landscapes for developing biosensors. Low-dimensional materials have the advantage of offering high surface areas, increased reactivity and unique physicochemical properties for efficient and selective biosensing. So far, nanomaterials and nanodevices have offered significant prospects for glucose sensing. Targeted glucose biosensing using such low-dimensional materials enables much more effective monitoring of blood glucose levels, thus providing significantly better predictive diabetes diagnostics and management. In this review, recent advances in using low dimensional materials for sensing glucose are summarized. Sensing fundamentals are discussed, as well as invasive, minimally-invasive and non-invasive sensing methods. The effects of morphological characteristics and size-dependent properties of low dimensional materials are explored for glucose sensing, and the key performance parameters such as selectivity, stability and sensitivity are also discussed. Finally, the challenges and future opportunities that low dimensional materials can offer for glucose sensing are outlined.

Improving the optical and thermoelectric properties of Cs2InAgCl6 with heavy substitutional doping: a DFT insight.

The next-generation indium-based lead-free halide material Cs2InAgCl6 is promising for photovoltaic applications due to its good air stability and non-toxic behavior. However, its wide bandgap (>3 eV) is not suitable for the solar spectrum and hence reduces its photoelectronic efficiency for device applications. Here we report a significant bandgap reduction from 2.85 eV to 0.65 eV via substitutional doping and its effects on the optoelectronic and opto-thermoelectric properties from a first-principles study. The results predict that Sn/Pb and Ga and Cu co-doping will enhance the density of states significantly near the valence band maximum (VBM) and thus reduce the bandgap via shifting the VBM upward, while alkali metals (K/Rb) slightly increase the bandgap. A strong absorption peak near the Shockley-Queisser limit is observed in the co-doped case, while in the Sn/Pb-doped case, we notice a peak in the middle of the visible region of the solar spectrum. The nature of the bandgap is indirect with Cu-Ga/Pb/Sn doping, and a significant reduction in the bandgap, from 2.85 eV to 0.65 eV, is observed in the case of Ga-Cu co-doping. We observe a significant increase in the power factor (PF) (2.03 mW m-1 K-2) for the n-type carrier after Pb-doping, which is ∼3.5 times higher than in the pristine case (0.6 mW m -1 K-2) at 500 K.

First-principles predictions of low lattice thermal conductivity and high thermoelectric performance of AZnSb (A = Rb, Cs).

Here, two compounds, AZnSb (A = Rb, Cs), have been predicted to be potential materials for thermoelectric device applications at high temperatures by using first-principles calculations based on density functional theory (DFT), density functional perturbation theory (DFPT), and Boltzmann transport theory. The layered structure, and presence of heavier elements Rb/Cs and Sb induce high anharmonicity (larger values of mode Grüneisen parameter), low Debye temperature, and intense phonon scattering. Thus, these compounds possess intrinsically low lattice thermal conductivity (κ l), ∼0.5 W m-1 K-1 on average at 900 K. Highly non-parabolic bands and relatively wide bandgap (∼1.37 and 1.1 eV for RbZnSb and CsZnSb, respectively, by mBJ potential including spin-orbit coupling effect) induce large Seebeck coefficient while highly dispersive and two-fold degenerate bands induce high electrical conductivity. Large power factor and low values of κ l lead to a high average thermoelectric figure of merit (ZT) of RbZnSb and CsZnSb, reaching 1.22 and 1.1 and 0.87 and 1.14 at 900 K for p-and n-type carriers, respectively.

First-principles prediction of structural stability and thermoelectric properties of SrGaSnH.

Thermoelectric (TE) materials based on earth-abundant and non-toxic elements are very useful in cost-effective and eco-friendly waste heat management systems. The constituents of SrGaSnH are earth-abundant and non-toxic, thus we have chosen SrGaSnH to study its structural stability and thermoelectric properties by using density functional theory (DFT), density functional perturbation theory (DFPT), and semi-classical Boltzmann transport theory. Our elastic and phonons calculations show that the compound has good structural stability. The electronic structure calculation discloses that it is an indirect bandgap (0.63 eV by mBJ potential including spin-orbit coupling (SOC) effect) semiconductor. Light band hole effective mass leads to higher electrical conductivity along the x-axis than that of along the z-axis. On the other side, the weak phonon scattering leads to high lattice thermal conductivity ∼ 6.7 W m-1 K-1 at 300 K. Although the power factor (PF) is very high along the x-axis (above 10 mW m-1 K-2 at 300 K), such large κ l dramatically reduces ZT. The maximum values of in-plane and cross-plane ZT are ∼1 (n-type), 0.8 (p-type) and 0.6 (n-type), (0.2 p-type) at 700 K, respectively. The present study has revealed that this compound has strong potential in eco-friendly TE applications.

NLGP Attenuates Murine Melanoma and Carcinoma Metastasis by Modulating Cytotoxic CD8+ T Cells.

Neem leaf glycoprotein (NLGP), a natural immunomodulator, attenuates murine carcinoma and melanoma metastasis, independent of primary tumor growth and alterations in basic cellular properties (cell proliferation, cytokine secretion, etc.). Colonization event of invasion-metastasis cascade was primarily inhibited by NLGP, with no effect on metastasis-related invasion, migration, and extravasation. High infiltration of interferon γ (IFN-γ)-secreting cytotoxic CD8+ T cells [CD44+, CD69+, GranB+, IFN-γ+, and interleukin 2+] was documented in the metastatic site of NLGP-treated mice. Systemic CD8+ T cell depletion abolished NLGP-mediated metastasis inhibition and reappeared upon adoptive transfer of NLGP-activated CD8+ T cells. Interferon γ-secreting from CD8+ T cells inhibit the expression of angiogenesis regulatory vascular endothelial growth factor and transforming growth factor ß and have an impact on the prevention of colonization. Neem leaf glycoprotein modulates dendritic cells (DCs) for proper antigen presentation by its DC surface binding and upregulation of MHC-I/II, CD86, and CCR7. Neem leaf glycoprotein-treated DCs specifically imprint CXCR3 and CCR4 homing receptors on activated CD8+ T cells, which helps to infiltrate into metastatic sites to restrain colonization. Such NLGP's effect on DCs is translation dependent and transcription independent. Studies using ovalbumin, OVA257-264, and crude B16F10 antigen indicate MHC-I upregulation depends on the quantity of proteasome degradable peptide and only stimulates CD8+ T cells in the presence of antigen. Overall data suggest NLGP inhibits metastasis, in conjunction with tumor growth restriction, and thus might appear as a promising next-generation cancer immunotherapeutic.

Electronic properties and low lattice thermal conductivity (κ l) of mono-layer (ML) MoS2: FP-LAPW incorporated with spin-orbit coupling (SOC).

This paper focuses on the electronic and thermoelectric properties of monolayer MoS2. Here, we have examined the structure of MoS2, in which the hole in the center of the hexagonal cage is considered as a void atom, termed 1H-MoS2. Density functional theory (DFT) employing the generalized gradient approximation (GGA) and spin-orbit coupling (SOC) has been used for all calculations. Incorporation of SOC resulted in a significant change in the profile of the band energy, specifically the splitting of the valence band maximum (VBM) into two sub-bands. The "split-off" energy is found to be ∼20.6 meV. The reduction of the band gap with SOC is a prominent feature at the K-K location in the Brillouin zone. The band gap calculated with the GGA is ∼1.75 eV. However, on implementation of SOC, the GGA band gap was reduced to ∼1.68 eV. The frequency-dependent phonon dispersion curve was obtained to analyse the thermodynamical stability. 1H-MoS2 is found to be thermodynamically stable with no imaginary frequency. We report a low value of lattice thermal conductivity (κ l) and low electron effective masses, which are desirable for potential applications in thermoelectric devices.

First-principles prediction of large thermoelectric efficiency in superionic Li2SnX3 (X = S, Se).

Thermoelectric materials create an electric potential when subjected to a temperature gradient and vice versa; hence they can be used to harvest waste heat into electricity and in thermal management applications. However, finding highly efficient thermoelectrics with high figures of merit, zT ≥ 1, is very challenging because the combination of a high power factor and low thermal conductivity is rare in materials. Here, we use first-principles methods to analyze the thermoelectric properties of Li2SnX3 (X = S, and Se), a recently synthesized class of lithium fast-ion conductors presenting high thermal stability. In p-type Li2SnX3, we estimate highly flat electronic valence bands that produce high Seebeck coefficients exceeding 400 µV K-1 at 700 K. In n-type Li2SnX3, the electronic conduction bands are slightly dispersive; however, the accompanying electron-acoustic phonon scattering is weak, which induces high electrical conductivity. The combination of a high Seebeck coefficient and electrical conductivity gives rise to high power factors, reaching a maximum of ∼4.5 mW m-1 K-2 at 300 K in both n-type Li2SnS3 and Li2SnSe3. Likewise, the thermal conductivity in Li2SnX3 is low as compared to conventional thermoelectric materials, 1.35-4.65 W m-1 K-1 at room temperature. As a result, we estimate a maximum zT of 1.1 in n-type Li2SnS3 at 700 K and of 2.1 (1.1) in n-type Li2SnSe3 at the same temperature (300 K). Our findings of large zT in Li2SnX3 suggest that lithium fast-ion conductors, typically employed as electrolytes in solid-state batteries, hold exceptional promise as thermoelectric materials.

Exciton-Driven Chemical Sensors Based on Excitation-Dependent Photoluminescent Two-Dimensional SnS.

Excitation wavelength-dependent photoluminescence (PL) in two-dimensional (2D) transition-metal chalcogenides enables a strong excitonic interaction for high-performance chemical and biological sensing applications. In this work, we explore the possible candidates in the domain of post-transition-metal chalcogenides. Few-layered 2D p-type tin monosulfide (SnS) nanoflakes with submicrometer lateral dimensions are synthesized from the liquid phase exfoliation of bulk crystals. Excitation wavelength-dependent PL is found, and the excitonic radiative lifetime is more than one order enhanced compared to that of the bulk counterpart because of the quantum confinement effect. Paramagnetic NO2 gas is selected as a representative to investigate the exciton-driven chemical-sensing properties of 2D SnS. Physisorption of NO2 results in the formation of dipoles on the surface of 2D SnS, causing the redistribution of photoexcited charges in the body and therefore modifying PL properties. For practical sensing applications, 2D SnS is integrated into a resistive transducing platform. Under light irradiation, the sensor exhibits excellent sensitivity and selectivity to NO2 at a relatively low operating temperature of 60 °C. The limit of detection is 17 parts per billion (ppb), which is significantly improved over other previously reported 2D p-type semiconductor-based NO2 sensors.

First-principles prediction of phonon-mediated superconductivity in XBC (X = Mg, Ca, Sr, Ba).

From first-principles calculations, we predict four new intercalated hexagonal XBC (X = Mg, Ca, Sr, Ba) compounds to be dynamically stable and phonon-mediated superconductors. These compounds form a LiBC like structure but are metallic. The calculated superconducting critical temperature, Tc, of MgBC is 51 K. The strong attractive interaction between σ-bonding electrons and the B1g phonon mode gives rise to a larger electron-phonon coupling constant (1.135) and hence high Tc; notably, higher than that of MgB2. The other compounds have a low superconducting critical temperature (4-17 K) due to the interaction between σ-bonding electrons and low energy phonons (E2u modes). Due to their energetic and dynamic stability, we envisage that these compounds can be synthesized experimentally.

Nanoarchitectured Graphene-Organic Frameworks (GOFs): Synthetic Strategies, Properties, and Applications.

Graphene-organic frameworks (GOFs) is a new class of graphene-based materials in which structure and properties can be designed by controlling the length and concentration of organic ligands, comparable to their tunable metal-organic frameworks (MOFs) counterpart. The structural properties (e.g., surface area, pore volume) and physico-chemical properties (e.g., electronic, thermal, and mechanical) of GOFs can be tuned based on the synthetic conditions. Such GOFs are promising as the next generation of novel materials for a wide range of potential applications such as H2 storage, electronic devices, sensors, drug carriers, etc. Here we report a review summarizing synthetic strategies, properties, and applications of GOFs.

Zebrafish as a Model to Evaluate Nanoparticle Toxicity.

Nanoparticles are increasingly being developed for in vivo use, from targeted drug delivery to diagnostics, where they have enormous potential, while they are also being used for a variety of applications that can result in environmental exposure for humans. Understanding how specific nanoparticles interact with cells and cell systems is essential to gauge their safety with respect to either clinical or environmental exposure. Zebrafish is being increasingly employed as a model to evaluate nanoparticle biocompatibility. This review describes this model and how it can be used to assess nanoparticle toxicity at multiple levels, including mortality, teratogenicity, immunotoxicity, genotoxicity, as well as alterations in reproduction, behavior and a range of other physiological readouts. This review also provides an overview of studies using this model to assess the toxicity of metal, metal oxide and carbon-based nanoparticles. It is anticipated that this information will inform research aimed at developing biocompatible nanoparticles for a range of uses.

Doped graphene/Cu nanocomposite: A high sensitivity non-enzymatic glucose sensor for food.

An amperometric non-enzymatic glucose sensor was developed based on nitrogen-doped graphene with dispersed copper nanoparticles (Cu-NGr). The sensing element was tested in conjunction with a modified glassy carbon electrode for glucose detection. The Cu-NGr composite was prepared by one pot synthesis from a mixture of graphene oxide, copper nitrate and uric acid, followed by thermal annealing at 900°C for 1h. Detailed characterizations showed homogeneous copper nanoparticle dispersion and the presence of significant proportion of graphitic nitrogen. The developed electrode presented high electrocatalytic activity towards glucose through synergetic effect of copper nanoparticles and nitrogen-doped graphene. Amperometric analysis confirmed high glucose sensitivity and ultra-low detection of 10nM glucose over a linear range. The sensor was tested for direct application to detect glucose in food samples for which the sensor displayed high selectivity with excellent reproducibility and recovery in complex food materials.

Boron-Functionalized Graphene Oxide-Organic Frameworks for Highly Efficient CO2 Capture.

The capture and storage of CO2 have been suggested as an effective strategy to reduce the global emissions of greenhouse gases. Hence, in recent years, many studies have been carried out to develop highly efficient materials for capturing CO2 . Until today, different types of porous materials, such as zeolites, porous carbons, N/B-doped porous carbons or metal-organic frameworks (MOFs), have been studied for CO2 capture. Herein, the CO2 capture performance of new hybrid materials, graphene-organic frameworks (GOFs) is described. The GOFs were synthesized under mild conditions through a solvothermal process using graphene oxide (GO) as a starting material and benzene 1,4-diboronic acid as an organic linker. Interestingly, the obtained GOF shows a high surface area (506 m2 g-1 ) which is around 11 times higher than that of GO (46 m2 g-1 ), indicating that the organic modification on the GO surface is an effective way of preparing a porous structure using GO. Our synthetic approach is quite simple, facile, and fast, compared with many other approaches reported previously. The synthesized GOF exhibits a very large CO2 capacity of 4.95 mmol g-1 at 298 K (1 bar), which is higher those of other porous materials or carbon-based materials, along with an excellent CO2 /N2 selectivity of 48.8.

Self-Assembled N/S Codoped Flexible Graphene Paper for High Performance Energy Storage and Oxygen Reduction Reaction.

A novel flexible three-dimensional (3D) architecture of nitrogen and sulfur codoped graphene has been successfully synthesized via thermal treatment of a liquid crystalline graphene oxide-doping agent composition, followed by a soft self-assembly approach. The high temperature process turns the layer-by-layer assembly into a high surface area macro- and nanoporous free-standing material with different atomic configurations of graphene. The interconnected 3D network exhibits excellent charge capacitive performance of 305 F g(-1) (at 100 mV s(-1)), an unprecedented volumetric capacitance of 188 F cm(-3) (at 1 A g(-1)), and outstanding energy density of 28.44 Wh kg(-1) as well as cycle life of 10 000 cycles as a free-standing electrode for an aqueous electrolyte, symmetric supercapacitor device. Moreover, the resulting nitrogen/sulfur doped graphene architecture shows good electrocatalytic performance, long durability, and high selectivity when they are used as metal-free catalyst for the oxygen reduction reaction. This study demonstrates an efficient approach for the development of multifunctional as well as flexible 3D architectures for a series of heteroatom-doped graphene frameworks for modern energy storage as well as energy source applications.

Co-Doping of Activated Graphene for Synergistically Enhanced Electrocatalytic Oxygen Reduction Reaction.

Doping of graphene has emerged as a key strategy to improve the electrocatalytic performance of the oxygen reduction reaction (ORR). Activated graphene co-doped with iodine and nitrogen atoms (NIG) was developed in this work using a facile scalable approach. The onset potential, current density, and four-electron reduction pathway of the newly developed catalyst were significantly improved. The charge-transfer resistance of co-doped NIG was found to be much lower than nitrogen-doped graphene (NG); furthermore, the stability of NIG and its resistance to methanol crossover were also improved. The synergistically enhanced ORR performance of NIG was found to be a result of a high strain and size advantage of the larger iodine atom clusters (compared to nitrogen), which facilitate the simultaneous enrichment of anode electrons and O2 and H2 O molecule transport at catalytic sites, inducing four-electron transfer in a single step. These results are promising for application in alkaline fuel cells.

Reconstruction using a pedicled upper arm fillet flap after excision of a malignant peripheral nerve sheath tumor: A case report.

Non-salvageable extremities have been utilized for harvesting fillet flaps as part of the "spare parts" concept in traumatic and oncologic settings. Here we report on the use of a pedicled fillet flap of the upper arm for chest wall reconstruction after excision of a malignant peripheral nerve sheath tumor in a patient with neurofibromatosis. Pedicled flaps as part of the "spare parts" concept provide the advantage of reduced donor-site morbidity, immediate closure, intact vasculature, and adequate soft tissue coverage of large defects. Malignant peripheral nerve sheath tumor is a rare aggressive tumor with a poor prognosis that may result in large defects post resection. Limited data describes the use of pedicled fillet flaps of the upper extremity. We report the use of a pedicled fillet flap of the upper arm as a viable option that can be successfully used for coverage of soft tissue defects of the shoulder and chest wall post complex resections in an oncologic setting.