Catalytic Deactivation and Regeneration of Nickel Microparticles in a Home-Built Microchannel-Coupled Millireactor: Substrate Specificity and Multiphase Flow Dependency.

Substrate-assisted product desorption often proposed in heterogeneous catalysis (nanozymes) denounces the catalytic deactivation of these catalysts. On the contrary, the catalytic deactivation of rigid heterogeneous catalyst becomes noticeable in a continuous flow reactor. Surprisingly, it has been addressed inadequately and in an isolated manner. In this study, we have developed a cost-effective non-lithographic method for the fabrication of a PDMS-based microchannel-coupled-millreactor. Immobilized nickel particles are resistant to leaching in the flow process. During continuous operation, millireactors show a strong catalytic activity for reduction of resazurin and p-nitrophenol with a conversion rate of almost 100 %. Catalytic poisoning is ubiquitous and gets gradually prominent whereas complete catalytic deactivation of magnetic Ni-microparticles is found to be an instantaneous process. Relatively large-sized resorufin binds predominantly to the surface and thereby blocks the access of the substrate to the Ni-particles. The dissociations of product molecules - resorufin and p-aminophenol are the rate-limiting steps that caused the abrupt deactivation of Ni-microparticle. The kinetic mechanism of heterogeneous derived from the Langmuir-Hinshelwood mechanism satisfactorily explains the catalytic poisoning and deactivation of nickel microparticles. This study sheds light on the intricacies of catalytic activity and poisoning of magnetic nickel microparticles.

A comprehensive diffusion-induced stress coupled multiscale modeling and analysis in hard-carbon electrodes of Li-ion batteries.

Particle fracture due to diffusion-induced stress (DIS) in electrodes is a key factor for lithium-ion battery (LIB) failure. Among many ways to minimize DIS, optimization of particle size and C-rates using state of charge (SOC) dependent varying properties can be a noble approach. Herein, a comprehensive multiscale modeling approach has been proposed to optimize the particle size by studying the DIS in hard carbon (HC) particles as the potential anode materials for high-energy LIBs. To accomplish this, density functional theory (DFT) was used to calculate the SOC dependent coefficient of volume expansion (CVE). Similarly, SOC dependent diffusivity and elastic modulus are calculated via molecular dynamics (MD) simulations. These results are transferred to a continuum model to examine the evolution of concentrations and DISs in hard carbon particles of radius 100-1000 nm lithiated at various C-rates (1C, 2C, 5C, and 10C). Our model successfully incorporates the variation of Li+ diffusivity and elastic modulus with SOC and tracks stress relaxation and volume expansion in the particles during lithiation. An optimized particle size has been recommended for hard carbon, considering both stresses for different C-rates. Our study provides a more realistic multiscale modeling framework for optimizing the DIS and can act as a guiding method towards achieving an optimum particle size so that capacity fading due to cracking can be avoided.

New Polymorphs of 2D Indium Selenide with Enhanced Electronic Properties.

The 2D semiconductor indium selenide (InSe) has attracted significant interest due its unique electronic band structure, high electron mobility, and wide tunability of its band gap energy achieved by varying the layer thickness. All these features make 2D InSe a potential candidate for advanced electronic and optoelectronic applications. Here, the discovery of new polymorphs of InSe with enhanced electronic properties is reported. Using a global structure search that combines artificial swarm intelligence with first-principles energetic calculations, polymorphs that consist of a centrosymmetric monolayer belonging to the point group D 3d are identified, distinct from well-known polymorphs based on the D 3h monolayers that lack inversion symmetry. The new polymorphs are thermodynamically and kinetically stable, and exhibit a wider optical spectral response and larger electron mobilities compared to the known polymorphs. Opportunities to synthesize these newly discovered polymorphs and viable routes to identify them by X-ray diffraction, Raman spectroscopy, and second harmonic generation experiments are discussed.

Shallow trapping vs. deep polarons in a hybrid lead halide perovskite, CH3NH3PbI3.

There has been considerable speculation over the nature of charge carriers in organic-inorganic hybrid perovskites, i.e., whether they are free and band-like, or they are prone to self-trapping via short range deformation potentials. Unusually long minority-carrier diffusion lengths and moderate-to-low mobilities, together with relatively few deep defects add to their intrigue. Here we implement density functional methods to investigate the room-temperature, tetragonal phase of CH3NH3PbI3. We compare charge localization behavior at shallow levels and associated lattice relaxation versus those at deep polaronic states. The shallow level originates from screened Coulomb interaction between the perturbed host and an excited electron or hole. The host lattice has a tendency towards forming these shallow traps where the electron or hole is localized not too far from the band edge. In contrast, there is a considerable potential barrier that must be overcome in order to initiate polaronic hole trapping. The formation of a hole polaron (I2- center) involves strong lattice relaxation, including large off-center displacement of the organic cation, CH3NH3+. This type of deep polaron is energetically unfavorable, and active shallow traps are expected to shape the carrier dynamics in this material.

Development and characterization of a high temperature stress responsive subtractive cDNA library in Pearl Millet Pennisetum glaucum (L.) R.Br.

Pearl millet (Pennisetum glaucum L. R. Br.) is an important cereal crop grown mainly in the arid and semi-arid regions of India known to possess the natural ability to withstand thermal stress. To elucidate the molecular basis of high temperature response in pearl millet, 12 days old seedlings of P. glaucum cv. 841A were subjected to heat stress at 46 degrees C for different time durations ( 30 min, 2, 4, 8, 12 and 24 h) and a forward subtractive cDNA library was constructed from pooled RNA of heat stressed seedlings. A total of 331 high quality Expressed Sequence Tags (ESTs) were obtained from randomly selected 1050 clones. Sequences were assembled into 103 unique sequences consisting of 37 contigs and 66 singletons. Of these, 92 unique sequences were submitted to NCBI dbEST database. Gene Ontology through RGAP data base and BLASTx analysis revealed that about 18% of the ESTs showed homology to genes for "response to abiotic and biotic stimulus". About 2% of the ESTs showed no homology with genes in dbEST, indicating the presence of uncharacterized candidate genes involved in heat stress response in P. glaucum. Differential expression of selected genes (hsp101 and CRT) from the SSH library were validated by qRT-PCR analysis. The ESTs thus generated are a rich source of heat stress responsive genes, which can be utilized in improving thermotolerance of other food crops.

Intestinal Parasitic Infection in Children and Adolescents With Ocular Diseases: The Prevalence, Spectrum, and Effect of Lockdown During the COVID-19 Pandemic.

INTRODUCTION: People with visual impairments and blindness face challenges in performing regular tasks such as maintaining proper sanitation, which makes them vulnerable to intestinal parasitic infections. AIMS AND OBJECTIVES: This study aims to examine the prevalence and distribution of intestinal parasitic infections in children and adolescents with ocular diseases and to assess if the lockdown during the COVID-19 pandemic affected these rates. METHODS: This retrospective, hospital record-based study was conducted among children and adolescents attending the Regional Institute of Ophthalmology in Kolkata, India. It involved routine stool examinations as part of their treatment during 2019-2020. Early morning stool specimens were collected and brought to the institute laboratory in containers. Stools were examined under a microscope for cysts, ova, parasites, and adult worms. Findings were recorded in the laboratory record book. These data were then extracted into a spreadsheet and analyzed using IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York). RESULTS: The prevalence of intestinal parasitic infections was 8.59% (59 out of 687 patients). Among those 59 positive cases, Ascaris lumbricoides, Giardia lamblia, Entamoeba histolytica, Trichuris trichiura, Taenia spp., Enterobius vermicularis, and Isospora belli were detected in 27 (45.8%), 15 (25.4%), 8 (13.6%), 6 (10.2%), 3 (5.1%), 2 (3.4%), and 1 (1.7%) patients, respectively. The positivity rate of stool samples was higher from September and thereafter from January to March. The sample positivity rate was higher post-pandemic and lockdown, but not statistically significant (11.5% vs. 5.3%; χ²=4.044, df=1, p=0.44). CONCLUSION: Ascaris lumbricoides was the most commonly observed intestinal parasite in children and adolescents with ocular disease in our setting. Seasonal variation was noted with higher case positivity at the end of the rainy season and thereafter in winter. Therefore, we propose to strengthen the routine deworming program during this period in Eastern India. Higher sample positivity after the pandemic may be attributed to school closures during the lockdown period, which might have caused some children to miss their routine deworming medication.

Prevalence, Clinico-Laboratory Features and Outcomes of Paediatric Scrub Typhus Cases in a Tertiary Care Centre in Eastern India: A prospective observational study.

Objectives: Scrub typhus is the most common rickettsial disease in India, caused by Orientia tsutsugamushi and transmitted by chigger mites. Previously prevalent in South India, a resurgence of scrub typhus cases has recently affected Eastern India. This study aimed to estimate the prevalence and describe the clinico-laboratory profile of scrub typhus in paediatric patients (1-12 years old) living in Eastern India. Methods: This prospective observational study was conducted from January to December 2019 at the Dr B C Roy Post Graduate Institute of Paediatric Sciences, Kolkata, India. All acute undifferentiated cases of febrile illness, in patients aged between 1-12 years, were tested using scrub typhus serology by ELISA. Demographic details, clinical features, laboratory findings, complications and treatment outcomes of these scrub typhus patients were extracted and analysed. Results: Out of 1,473 patients with acute febrile illness, 67 (4.5%) children were diagnosed with scrub typhus. The mean age of the selected patients was 5.22 ± 3.05 years, and the majority (64.2%) had been running a fever since the preceding 7-14 days. Gastrointestinal symptoms such as vomiting (43.3%) and abdominal pain (32.8%) were most frequently observed. Major clinical signs of scrub typhus were hepatomegaly (41.8%) and splenomegaly (31.3%). Complications were observed in 74.6% of patients, with thrombocytopenia (40.3%) and meningoencephalitis (29.9%) occurring more frequently. The case fatality rate of the study sample was 1.5%. Conclusion: Classical eschar was absent in three-fourth of the studied patients. Hence, this study advocates laboratory scrub typhus tests for all suspected cases in the endemic region (Eastern India). Prompt treatment with doxycycline and/or azithromycin could prevent complications such as thrombocytopenia/meningoencephalitis and reduce mortality.

An Investigation of Size Distribution and Calcium Signaling in Human Platelets.

Background Platelets are thin disc-shaped blood cells that play a major role in hemostasis, maintenance of vascular integrity, and blood coagulation. Large platelets are more reactive and seen in patients with cardiovascular disease. This study aims to analyze the changes in platelet size of ex vivo activated platelets which phenotypically simulates that of a patient at risk of cardiovascular disease and elucidate the calcium signaling pathway responsible for this change. Methodology Platelets were isolated from adult human blood by differential centrifugation. Calcium was mobilized into platelets by treatment with calcium ionophore A23187 in the presence of Ca2+. Platelet size distribution was analyzed using Coulter Counter Multisizer 4. The following signaling parameters were studied: intracellular Ca2+ measurement (using Fura-2/AM by fluorescence spectrophotometry), Ca2+-dependent thiol protease calpain assay (using fluorogenic substrate t-butoxycarbonyl-Leu-metchloromethylcoumarin in fluorescence microplate reader), platelet-derived microparticles (using FACS Calibur flow cytometry), and cytoskeletal protein talin expression (by western immunoblotting). Results When adult platelets were treated with A23187 and Ca2+, two subcellular populations (<2 µm and between 2-4 µm) were noted. The mean size of the second cell population was significantly higher than that of resting platelets (2.94 ± 0.13 µm vs. 2.82 ± 0.15 µm, t = 4.605, p = 0.00). A23187 treatment led to elevated intracellular Ca2+, release of platelet-derived microparticles, increase in calpain activity, and cytoskeletal talin degradation. These events were inhibited by calpeptin (a specific calpain inhibitor). Conclusions Elevated calcium caused talin degradation by calpain activity. Breakdown of this cytoskeletal protein leads to relative swelling of cells reflected by the increase in platelet size.

Clinico-Laboratory Profile of Hypertriglyceridemia Thalassemia Syndrome: A Case Series in a Paediatric Tertiary Care Centre.

BACKGROUND: Increased hemolysis and repeated blood transfusion trigger oxidative stress resulting in numerous adverse effects in beta-thalassemia patients. Extreme elevation of triglyceride level is a rare clinical entity seen in these patients. It is presumed to be caused due to an increase in oxidative stress and is termed Hypertriglyceridemia Thalassemia Syndrome. OBJECTIVES: To assess the clinical and laboratory characteristics of beta-thalassemia patients presenting with hypertriglyceridemia and its correlation with the pre-transfusion hemoglobin level.  Methods: This hospital record-based retrospective study was conducted at the Dr B C Roy Post Graduate Institute of Paediatric Sciences, Kolkata, India. The study comprised 12 pediatric beta-thalassemia patients whose plasma appeared milky or chylous during a complete hemogram. Clinical examination and laboratory investigations were done to describe their clinico-laboratory features. A whole exome sequencing was carried out to assess their genetic background. Blood hemoglobin and serum triglyceride estimation was carried out initially and at follow-up to determine any correlation between the two.  Results: Out of 1482 patients, 12 (0.80 %) were diagnosed with Hypertriglyceridemia Thalassemia Syndrome. The median age of presentation was 12.5 months (Q1:10 months, Q3:14 months)., and the pretransfusion hemoglobin was 4.82 ± 1.16 g/dL. The lipid profile showed a triglyceride level of 858.3 ± 198.4 mg/dl and a total cholesterol level of 117.4 ± 16.15 mg/dl. Analysis revealed that the triglyceride levels were negatively correlated with the pretransfusion hemoglobin level (repeated measures correlation (rmcorr) = -0.65, 95% CI [-0.794, -0.425], p < 0.001). A genetic study highlighted c.92+5G>C as the commonest mutation. CONCLUSION: Hypertriglyceridemia was a rare presentation in transfusion-dependent beta-thalassemia patients. The serum triglyceride level significantly reduced when blood transfusion at regular intervals restored the patient's hemoglobin level.

Case of the Bromine Vacancy in Cs4PbBr6.

Typically defect tolerance is equated with a lack of deleterious defects or with abundant defects creating only shallow levels. Here, we address the idea that deep defects, when unavoidable, do not guarantee harmful consequences. Using halogen vacancy as a common defect among halides, we explore its behavior in Cs4PbBr6. It is a large gap material (band gap of ∼4 eV) known for its green emission at ∼520 nm. We show that its Br-vacancy is indeed a deep defect as obtained from hybrid density functional calculations. An analysis of the configuration coordinate diagram corresponding to the defect's charge transition levels enables us to conclude that the nonradiative recombination cycle will be hampered by an extremely slow hole capture process. Therefore, Br-vacancy will not suppress light emission in Cs4PbBr6. Although this finding does not signal that all deep defects will behave similarly, it indicates that defect tolerance may be achievable despite their occurrence.

Diagnostic Performance Between Chest CT Severity Score and Initial Reverse Transcription-Polymerase Chain Reaction (RT-PCR) Cycle Values in COVID-19 Patients and Their Relation With the Clinical Status of Patients.

INTRODUCTION: Reverse transcription-polymerase chain reaction (RT-PCR) is used as a standard test for the diagnosis of SARS-CoV-2 viral RNA from nasopharyngeal aspirates. However, this method lacks sensitivity and cannot assess disease severity. A CT scan of the thorax provides a CT severity score (CT-SS), which depicts lung involvement and disease severity. This study aims to investigate the diagnostic value of chest CT compared with RT-PCR cycle threshold (Ct) values in COVID-19 and relate it clinically with the disease severity of patients. METHODS: This retrospective observational study was conducted in a tertiary center from April 2021 to March 2022. We included 511 patients who had tested RT-PCR positive for COVID-19, were hospitalized, and had undergone high-resolution CT (HRCT) thorax. Data was collected from patient records regarding name, age, sex, admission data, baseline investigations including Ct value, management, and outcome. HRCT was reviewed to assess lung involvement and calculate CT-SS. Data was analyzed using SPSS Statistics version 25 (IBM Corp. Released 2017. IBM SPSS Statistics for Windows, Version 25.0. Armonk, NY: IBM Corp.). RESULT: The mean age of patients was 50.4 ± 13.7 years, and the majority (67.5%) were male. Gender-wise, there was no difference in RT-PCR cycle threshold (Ct) values; however, CT-SS was significantly higher in males (17.5 ± 4.8 vs.10.5 ± 6.6, t=-13.6, p<0.0001). ICU admission was needed for 34.8% of patients, and they had a significantly lower Ct value (21.7 ± 3.3 vs. 22.8 ± 3.7, t=21.10, p<0.0001) and higher CT-SS (16.3 ± 4.5 vs. 6.7 ± 5.1, t=-3.32, p=0.001). CONCLUSION: Ct values could not differentiate between moderate and severe patients. CT-SS was not related to the viral load at admission. Patients who succumbed had significantly lower Ct values and higher CT-SS.

Selenium Supplementation in Pregnancy-Maternal and Newborn Outcomes.

Background: Several studies have suggested that increased oxidative stress during pregnancy may be associated with adverse maternal and foetal outcomes. As selenium is an essential mineral with an antioxidant role, our aim was to perform a systematic review of the existing literature reporting the effects of selenium supplementation during pregnancy on maternal and neonatal outcomes. Materials and Methods: Six electronic databases (Medline, Embase, Cochrane Library, Web of Science, Scopus, and PubMed) were searched for studies reporting the effects of selenium supplementation during pregnancy and the postpartum period on maternal and neonatal outcomes. Only randomised controlled trials on human subjects reported in English and published up to October 2021 were included. Quality assessments were conducted using the modified Downs and Black quality assessment tool. Data were extracted using a narrative synthesis. Results: Twenty-two articles were included in our systematic review (seventeen reported on maternal outcomes, two on newborn outcomes, and three on both). Maternal studies reported the effects of selenium supplementation in the prevention of thyroid dysfunction, gestational diabetes, pregnancy-induced hypertension/preeclampsia, oxidative stress, postpartum depression, premature rupture of membranes, intrauterine growth retardation, breastmilk composition, and HIV-positive women. Newborn studies reported the effects of maternal selenium supplementation on foetal oxidation stress, foetal lipid profile, neonatal hyperbilirubinemia, and newborn outcomes in HIV-positive mothers. The majority of studies were inappropriately designed to establish clinical or scientific utility. Of interest, four studies reported that selenium supplementation reduced the incidence of thyroid dysfunction and permanent hypothyroidism during the postpartum period by reducing thyroid peroxidase and thyroglobulin antibody titres. Conclusion: The evidence supporting selenium supplementation during pregnancy is poor and there is a need for appropriately designed randomised controlled trials before routine use can be recommended.

Anionic and hidden hydrogen in ZnO.

First-principles calculations are performed to study energetics and kinetics of hydrogen in ZnO, in particular, the H(-) anion and the H(2) molecule on the interstitial site and in the oxygen vacancy. We show that the H(2) molecule kinetically trapped in the oxygen vacancy, rather than interstitial H(2), can explain a variety of experimental observations on "hidden" hydrogen in ZnO. The accumulation of shallow donors, especially the substitutional H, near the ZnO surface is important to the formation of hidden hydrogen in the ZnO bulk and can also lead to persistent photoconductivity.

Metal Halide Semiconductors beyond Lead-Based Perovskites for Promising Optoelectronic Applications.

In recent decades, metal halide semiconductors represented by lead-based halide perovskites have shown broad potential in optoelectronic applications. This family of semiconductors differs from traditional tetrahedral semiconductors in crystalline structure, chemical bonding, electronic-structure features, optoelectronic properties, as well as material fabrication method. At present, difficulties arising from both intrinsic material properties (including Pb toxicity and long-term stability) and technological aspects hinder their large-scale commercialization. In this Perspective, we focus on up-and-coming lead-free metal halide semiconductors toward high-performance optoelectronic applications. We start by outlining the advantages of metal halide semiconductors and their physical and chemical underpinnings. We then review composition and structure, electronic structure, optoelectronic properties, and device applications according to classification into three material categories, i.e., three-dimensional halide perovskites, low-dimensional perovskites and perovskite-like materials, and materials beyond perovskites. We conclude with an outlook on the challenges and opportunities of metal halide semiconductors and the future development of the field.

Framework contraction in Na-stuffed Si(cF136).

Systematic crystal structure refinements from powder X-ray diffraction data as well as density functional theory calculations demonstrate that the silicon clathrate II Si(cF136) exhibits a lattice contraction as Na is introduced solely into the Si(28) cages. When the Si(20) cages, in addition, begin to be filled with Na, a contrasting lattice expansion results. The nonmonotonic structural response to filling is an indication of markedly dissimilar guest-framework interactions for Na@Si(20) and Na@Si(28).

Reinforcement of ball shaped MoS2 nanoparticles in epoxy resin.

The present work involves the synthesis of molybdenum disulfide (MoS2) nanoparticles by annealing the precursor obtained from simple reflux method. XRD, FESEM and HRTEM confirmed the formation of 2H-MoS2 with ball shaped particles, where some of them possess coalesced dumbbell morphology. The reinforcement of polysulphide modified epoxy resin (PSER) by MoS2 with varying amounts from 0.150 to 0.200 wt% provides unique combination of the improved thermal stability, tribological and mechanical properties. XRD studies indicate interaction between the sulphur containing nanoparticles and the epoxy resin. Maximum improvements in tensile strength (440%) and toughness (534%) are observed with ball shaped MoS2 nanoparticles (0.150 wt%)/PSER composite. Also the coefficient of friction and wear resistance show improvements of 60 and 78% respectively for 0.175 wt% loading in PSER compared to the neat resin matrix. Thermal stability is found to be improved maximum by 23 degrees C, when 5% weight loss is taken as a point of comparison. Similar studies on synthetic microcrystalline MoS2 filled PSER show that improvements in all these properties are very inferior.

Molecular Analysis of Disease-Responsive Genes Revealing the Resistance Potential Against Fusarium Wilt (Fusarium udum Butler) Dependent on Genotype Variability in the Leguminous Crop Pigeonpea.

Fusarium wilt (FW), caused by Fusarium udum Butler (FU), is among the challenging factors in the production of pigeonpea. Therefore, exploring a superior pigeonpea genotype from landraces or local cultivars through the selection of innate resistance to FW using different biological and molecular approaches, and validating its resistance response, could be an alternative to sustainable crop improvement. Five distinct pigeonpea genotypes, with resistant (ICP2894) and susceptible (ICP2376) controls, were selected on the basis of the incidence percentage of FW, from three different states of India. Among them, the cultivar Richa, which displayed low incidence of FW (10.0%) during the genotype evaluation, was further examined for its innate resistance to FW. Molecular characterization of antioxidant (AO) enzyme [APX and SOD] and pathogenesis-related (PR) protein [CHS and ß-1, 3-glucanase] families were performed. The obtained results of reverse transcription-polymerase chain reaction-based expression study and in silico analysis showed a higher level of induction of PR and AO genes, and the strong interaction of their putative proteins with fungal cellobiohydrolase-c protein established their antifungal activity, conferring early plant defense responses to FU in Richa. Our study demonstrated a strong and combinatorial approach involving biological assay, molecular experiments, and in silico analysis to identify a superior pigeonpea genotype that was resistant to FW across a major biogeographic region.

Computational Design of Mixed-Valence Tin Sulfides as Solar Absorbers.

Binary tin sulfides, such as SnS and SnS2, are appealing because of their simple stoichiometry and semiconducting properties and are, therefore, being pursued as potentially cost-effective materials for optoelectronic applications. The multivalency of Sn, that is, Sn(+2) and Sn(+4) allows yet more intermediate compositions, SnxSy, whose structures and properties are of interest. Sn2S3 is already under consideration as a mixed-valence semiconductor. Other intermediate compositions, for example, Sn3S4 and Sn4S5 have remained elusive, although their existences have been alluded to in literature. Here we report a comprehensive study of phase stability of the SnxSy series compounds, utilizing swarm-intelligence crystal structure search method combined with first-principles energetic calculations. We find that the stability of mixed-valence SnxSy compounds with respect to decomposition into pure-valence SnS and SnS2 is in general weaker than the SnxOy counterparts, likely due to differences in chemical bonding. Besides identifying the experimentally discovered stable phases of Sn2S3, our calculations indicate that the Sn3S4 phase is another mixed-valence composition which shows marginal stability with respect to decomposition into SnS and SnS2. Other studied compositions may be metastable under ambient conditions, with slightly positive formation enthalpies. We find two structures of Sn3S4 having comparably low energies, both of which feature one-dimensional chain-like fragments obtained by breaking up the edge-connected octahedral layers of SnS2. Both structures indicate lattice phonon stability and one shows quasi-direct band gap with a calculated value of 1.43 eV, ideal for solar absorbers. A further analysis of the composition-structure-property relationship supports the notion that low-dimensional Sn-S motifs and van der Waals interaction may lead to diverse structure types and chemical compositions, having functional properties that are yet to be identified in the SnxSy series with mixed valency.

A quick, easy and cost-effective in planta method to develop direct transformants in wheat.

Agrobacterium mediated in planta method was used to transform Indian elite wheat genotype HD2894 with herbicide-tolerant CP4-EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) gene. The apical meristems of germinated seeds were targeted for introgression of transgene. The obtained T1 plants were screened by spraying 1% glyphosate and only positive transformants survived. The presence of transgene was also confirmed by PCR and Southern hybridization. Using this method, 3.07% transformation rate was observed. To identify transgenic lines carrying stably integrated CP4-EPSPS gene, the transgenic populations were screened in T3 generation using 1% glyphosate and lines with 100% survival were considered as homozygous. No significant morpho-physiological variations were observed within the transgenic lines as compared to non-transgenic plants. The present study resulted in herbicide-tolerant transgenic wheat and provides a valuable tool for development of wheat genetic transformation.

Exploring Polaronic, Excitonic Structures and Luminescence in Cs4PbBr6/CsPbBr3.

Among the important family of halide perovskites, one particular case of all-inorganic, 0-D Cs4PbBr6 and 3-D CsPbBr3-based nanostructures and thin films is witnessing intense activity due to ultrafast luminescence with high quantum yield. To understand their emissive behavior, we use hybrid density functional calculations to first compare the ground-state electronic structure of the two prospective compounds. The dispersive band edges of CsPbBr3 do not support self-trapped carriers, which agrees with reports of weak exciton binding energy and high photocurrent. The larger gap 0-D material Cs4PbBr6, however, reveals polaronic and excitonic features. We show that those lattice-coupled carriers are likely responsible for observed ultraviolet emission around ∼375 nm, reported in bulk Cs4PbBr6 and Cs4PbBr6/CsPbBr3 composites. Ionization potential calculations and estimates of type-I band alignment support the notion of quantum confinement leading to fast, green emission from CsPbBr3 nanostructures embedded in Cs4PbBr6.