Thorium Complexation with Aliphatic and Aromatic Hydroxycarboxylates: A Combined Experimental and Theoretical Study.

Hydroxycarboxylic acids, viz., α-hydroxyisobutyric acid (HIBA) and mandelic acid (MA), have been widely employed as eluents for inner transition metal separation studies. Both extractants have identical functional groups (OH and COOH) with different side-chains. Despite their similarities in binding motifs, they show different retention behaviors for thorium and uranium in liquid chromatography. To understand the mechanism behind the trend, a detailed study on the aqueous phase interaction of thorium with both extractants is carried out by speciation, spectroscopy, and density functional theory-based calculations. Potentiometric titration experiments are carried out to reveal the stability and species formed. Electrospray ionization mass spectrometry is performed to identify the formation of different species by Th with both HIBA and MA. It is seen that for Th-HIBA and Th-MA, the dominating species are ML3 and ML4, respectively. A similar pattern observed in potentiometric speciation analysis supports the tendency of Th to form higher stoichiometric species with MA than with HIBA. The difference in the dominating species thus helps in explaining the reversal in the retention behavior of uranium and thorium in the reverse-phase liquid chromatographic separation. The results obtained are corroborated with extended X-ray absorption fine structure spectroscopic measurements and density functional theory (DFT) calculations.

Single-Atomic Co-N4 Sites with CrCo Nanoparticles for Metal-Air Battery-Driven Hydrogen Evolution.

Designing highly active and robust earth abundant trifunctional electrocatalysts for energy storage and conversion applications remain an enormous challenge. Herein, we report a trifunctional electrocatalyst (CrCo/CoN4@CNT-5), synthesized at low calcination temperature (550 °C), which consists of Co-N4 single atom and CrCo alloy nanoparticles and exhibits outstanding electrocatalytic performance for the hydrogen evolution reaction, oxygen evolution reaction, and oxygen reduction reaction. The catalyst is able to deliver a current density of 10 mA cm-2 in an alkaline electrolytic cell at a very low cell voltage of ∼1.60 V. When the catalyst is equipped in a liquid rechargeable Zn-air battery, it endowed a high open-circuit voltage with excellent cycling durability and outperformed the commercial Pt/C+IrO2 catalytic system. Furthermore, the Zn-air battery powered self-driven water splitting system is displayed using CrCo/CoN4@CNT-5 as sole trifunctional catalyst, delivering a high H2 evolution rate of 168 µmol h-1. Theoretical calculations reveal synergistic interaction between Co-N4 active sites and CrCo nanoparticles, favoring the Gibbs free energy for H2 evolution. The presence of Cr not only enhances the H2O adsorption and dissociation but also tunes the electronic property of CrCo nanoparticles to provide optimized hydrogen binding capacity to Co-N4 sites, thus giving rise to accelerated H2 evolution kinetics. This work highlights the importance of the presence of small quantity of Cr in enhancing the electrocatalytic activity as well as robustness of single-atom catalyst and suggests the design of the multifunctional robust electrocatalysts for long-term H2 evolution application.

Dual Single-Atomic Co-Mn Sites in Metal-Organic-Framework-Derived N-Doped Nanoporous Carbon for Electrochemical Oxygen Reduction.

Synthesizing dual single-atom catalysts (DSACs) with atomically isolated metal pairs is a challenging task but can be an effective way to enhance the performance for electrochemical oxygen reduction reaction (ORR). Herein, well-defined DSACs of Co-Mn, stabilized in N-doped porous carbon polyhedra (named CoMn/NC), are synthesized using high-temperature pyrolysis of a Co/Mn-doped zeolitic imidazolate framework. The atomically isolated Co-Mn site in CoMn/NC is recognized by combining microscopic as well as spectroscopic techniques. CoMn/NC exhibited excellent ORR activities in alkaline (E1/2 = 0.89 V) as well as in acidic (E1/2 = 0.82 V) electrolytes with long-term durability and enhanced methanol tolerance. Density functional theory (DFT) suggests that the Co-Mn site is efficiently activating the O-O bond via bridging adsorption, decisive for the 4e- oxygen reduction process. Though the Co-Mn sites favor O2 activation via the dissociative ORR mechanism, stronger adsorption of the intermediates in the dissociative path degrades the overall ORR activity. Our DFT studies conclude that the ORR on an Co-Mn site mainly occurs via bridging side-on O2 adsorption following thermodynamically and kinetically favorable associative mechanistic pathways with a lower overpotential and activation barrier. CoMn/NC performed excellently as a cathode in a proton exchange membrane (PEM) fuel cell and rechargeable Zn-air battery with high peak power densities of 970 and 176 mW cm-2, respectively. This work provides the guidelines for the rational design and synthesis of nonprecious DSACs for enhancing the ORR activity as well as the robustness of DSACs and suggests a design of multifunctional robust electrocatalysts for energy storage and conversion devices.

Comprehensive study on the origin of orthorhombic phase stabilization in Gd-doped HfO2 and DFT calculations.

In recent times, ultra-thin films of hafnium oxide (HfO2) have shown ferroelectricity (FE) attributed to the orthorhombic (o) phase of HfO2 with space group Pca21. This polar o-phase could be stabilized in the doped thin film of the oxide. In the present work, both polar and non-polar o-phases of HfO2 could be stabilized in Gd-doped bulk polycrystalline HfO2. Rietveld analysis of XRD data shows that the relative population of o-phases in the presence of the monoclinic (m) phase of HfO2 increases with increasing Gd-content. The local environment around the host atom has been investigated by time differential perturbed angular correlation (TDPAC) spectroscopy, synchrotron based X-ray near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) measurements showed a reduction in grain size with increasing Gd-dopant indicating a solute drag effect. It could be established that the segregation of the Gd-dopant in the grain boundary is a thermodynamically favorable process and the solute drag effect plays an important role in nucleation of the o-phase in bulk HfO2. Stabilization of Gd in both Pbca and Pca21 phases of HfO2 was supported by defect formation energy calculations using density functional theory (DFT). The present study has important implications in future applications of HfO2 in ferroelectric devices and in understanding the role of dopants in stabilizing the o-phase of HfO2 in the bulk.

Coupling Single-Ni-Atom with Ni-Co Alloy Nanoparticle for Synergistically Enhanced Oxygen Reduction Reaction.

Developing nonprecious metal-based oxygen reduction reaction (ORR) electrocatalysts with superior activity and durability is crucial for commercializing proton-exchange membrane (PEM) fuel cells. Herein, we report a metal-organic framework (MOF)-derived unique N-doped hollow carbon structure (NiCo/hNC), comprising of atomically dispersed single-Ni-atom (NiN4) and small NiCo alloy nanoparticles (NPs), for highly efficient and durable ORR catalysis in both alkaline and acidic electrolytes. Density functional theory (DFT) calculations reveal the strong coupling between NiN4 and NiCo NPs, favoring the direct 4e- transfer ORR process by lengthening the adsorbed O-O bond. Moreover, NiCo/hNC as a cathode electrode in PEM fuel cells delivered a stable performance. Our findings not only furnish the fundamental understanding of the structure-activity relationship but also shed light on designing advanced ORR catalysts.

Role of C and B4C barrier layers in controlling diffusion propagation across the interface of Cr/Sc multilayers.

The optical performance of low-bilayer-thickness metallic multilayers (ML) can be improved significantly by limiting the intermixing of consecutive layers at the interfaces. Barrier layers are supposed to exhibit a decisive role in controlling diffusion across the interfaces. The element-specific grazing incidence extended X-ray absorption fine structure technique using synchrotron radiation has been used in conjunction with grazing incidence X-ray reflectivity and diffuse X-ray scattering measurements to study the impact of the two most common barrier layers, viz., C and B4C, at the interfaces of Cr/Sc MLs. The diffusion propagation is reduced by both the barrier layers; however, it is found that the improvement is more significant with the B4C barrier layer. It is seen that C forms an intermixed layer with Sc and leads to carbide formation at the interface, which then acts as shielding and prevents further interdiffusion, while B4C hardly penetrates into Sc and stops the overlap between Sc and Cr directly by wetting the corresponding interface. Thus, the above measurements reveal crucial and precise information regarding the elemental diffusion kinetics at the interfaces of Cr/Sc MLs in a non-destructive way, which is very important for technological applications of these MLs as X-ray optical devices.

Comparative Study of Chemical Characteristic Analysis of Different Solvent-Extracted Solanum lycopersicum (Tomato Seed) Oil.

Tomato seeds are large waste byproducts from the processing of tomato into various food products like juice, sauce, and puree. One of the most potential uses of these tomato seeds is as a source of edible vegetable oil. The present study investigated the chemical characteristics including antioxidant activity, oxidative stability, and fatty acid composition of tomato seed extracted oil by aqueous and nonpolar (hexane) solvent. Fatty acid composition of tomato seed oils was determined by gas chromatography. Tomato seed oils were found to contain huge amount of linoleic acid, followed by oleic acid, palmitic acid, stearic acid, and linolenic acid. Polyunsaturated fatty acid and monounsaturated fatty acid content of the oil is near about 58% and 24%, respectively. Oxidative stability test of oil samples were evaluated by acid value, peroxide value, anisidine test, and TBA value. Antioxidant activity based on DPPH, FRAP, and ABTS assay of tomato seed oils was analyzed. The oil showed higher antioxidant activity-DPPH value (72-75%), FRAP value (9-11 µ mol/ml), and ABTS (37-39%). The results indicate hardly any difference in the fatty acid composition and antioxidant activity between aqueous and extracted and solvent-extracted tomato seed oil.

Quantification of physiological and mental workloads of faster and slower finishers of a long-distance military training activity.

BACKGROUND: Long-distance runs with equipment are practised in military training establishments to develop physical stamina and prepare for battles. A study was planned to quantify and compare the physiological and mental workloads of the early and late finishers of a military endurance run through the jungle terrain of north-eastern India in hot and humid conditions. METHODS: Twenty-five soldiers of the Indian Army completed a 15 km run through a rural and jungle track with 6.5 kg of equipment. Twelve participants who finished the race before 130 min were categorised as 'early finishers', and 13 were categorised as 'late finishers' who finished the race after 130 min. Physiological parameters, viz., heart rate (HR), breathing rate (BR), estimated core temperature (ECT), peak acceleration (PAC), and physiological intensity (PHYI) and mechanical intensity (MECHI) were recorded using BioHarness V.3 (Zephyr Technologies, USA) and NASA Task Load Index scores were obtained to assess mental workload. Mann-Whitney U test was applied to assess the level of significance at a p value of <0.05. RESULTS: HR, ECT and PAC were significantly higher (167.9 and 156.0 beats/min, 39.0℃ and 38.4℃, and 1.1 and 1.0 g, respectively) for the first group compared with the second group. The second group expressed higher BR and subjective responses ('total scores' were 76.5 and 82.5, respectively) than the first. The PHYI was significantly higher (from 7.2 to 6.3) for the first group, whereas the MECHI was similar in both groups. CONCLUSION: The successful completion by the first group can be attributed to their motivation to continue heavy work in an adverse environment, and their ability to negotiate with natural obstacles was reflected through controlled subjective responses. Adoption of a possible safe and stable approach to the same task might have led the second group to take a longer duration, exert higher mental effort and demand lower physiological cost.

Clinical perspectives, immunohematologic insights, and transfusion management in IgA-associated autoimmune hemolytic anemia.

Autoimmune hemolytic anemia (AIHA) due to warm-reacting IgA autoantibodies is rare. Here, we explored the clinical and immunohematologic characteristics of patients suffering from IgA-associated warm AIHA (WAIHA) and their transfusion management. The 9-year study included 214 patients with WAIHA who were further classified into two groups: (1) IgA-associated WAIHA and (2) non-IgA-associated WAIHA. Clinical and laboratory details were obtained from patient files and the Hospital Information System. All immunohematologic investigations were performed following standard operating procedures and established protocols. Among the 214 patients with WAIHA, 17 (7.9%) belonged to the IgA-associated group; of these, two IgA-only WAIHA cases were found. The mean hemoglobin in this group was 5.58 g/dL, and 15 (88.2%) of these patients received a total of 32 units of packed red blood cell (RBC) transfusions. In vivo hemolytic markers were significantly abnormal in the IgA-associated WAIHA group when compared with the non-IgA group. Secondary WAIHA was found in 11 (64.7%) patients with IgA-associated WAIHA. Patients with IgA-associated WAIHA received more blood transfusions than individuals in the non-IgA group (p = 0.0004). A total of 17 (7.9%) patients with WAIHA experienced adverse events to blood transfusion. Detailed characterization of WAIHA with particular emphasis on IgA-associated and non-IgA-associated WAIHA is essential to evaluate the disease characteristics, access the degree of hemolysis, understand the immunohematologic behaviors of the antibodies, and manage blood transfusions.

Some Classes of Logarithmic-Type Imputation Techniques for Handling Missing Data.

In this manuscript, three new classes of log-type imputation techniques have been proposed to handle missing data when conducting surveys. The corresponding classes of point estimators have been derived for estimating the population mean. Their properties (Mean Square Errors and bias) have been studied. An extensive simulation study using data generated from normal, Poisson, and Gamma distributions, as well as real dataset, has been conducted to evaluate how the proposed estimator performs in comparison to several contemporary estimators. The results have been summarized, and discussion regarding real-life applications of the estimator follows.

An Exponential-Cum-Sine-Type Hybrid Imputation Technique for Missing Data.

In this study, a new exponential-cum-sine-type hybrid imputation technique has been proposed to handle missing data when conducting surveys. The properties of the corresponding point estimator for population mean have been examined in terms of bias and mean square errors. An extensive simulation study using data generated from normal, Poisson, and Gamma distributions has been conducted to evaluate how the proposed estimator performs in comparison to several contemporary estimators. The results have been summarized, and discussion regarding real-life applications of the estimator follows.

Nation-wide vector surveillance on Zika and Dengue did not indicate transmission of the American lineage-pandemic Zika virus in India.

OBJECTIVES: Following the Public Health Emergency of International Concern declared on Zika by the World Health Organization during 2016, the Indian Council of Medical Research carried out nationwide vector surveillance for Zika and Dengue viruses (ZIKV and DENV) in India as a preparedness measure in 2016-19. METHODS: High-risk zones distributed to 49 Districts in 14 states/union territories were included in the study. Seven ICMR institutions participated, following a standard operating protocol. Aedes specimens sampled weekly were processed by multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) for ZIKV/DENV and random samples crosschecked with real-time RT-PCR for ZIKV. RESULTS: Altogether, 79 492 Aedes specimens in 6492 pools were processed; 3 (0.05%) and 63 (0.97%) pools, respectively, were found positive for ZIKV and DENV. ZIKV infections were recorded in Aedes aegypti sampled during the 2018 sporadic Zika outbreak in Jaipur, Rajasthan. However, these belonged to the Asian lineage of the virus, already circulating in the country. Both Ae. aegypti and Aedes albopictus distributed to 8 states/union territories were found to be infected with DENV. Both sexes of Ae. albopictus were infected, indicating transovarial transmission. CONCLUSION: This investigation evinced no active transmission of the American lineage-pandemic Zika virus in India during the pandemic period.

Probing the solute-drag effect and its role in stabilizing the orthorhombic phase in bulk La-doped HfO2 by X-ray and gamma ray spectroscopy.

The recent observation of ferroelectricity in ultra thin films of hafnium oxide (HfO2) has been attributed to the orthorhombic (o) phase of HfO2 with space group Pca21. Although this oxide is polymorphic in nature, this polar o-phase is known to be stabilized in the doped thin film oxide. The objective of the present experiment is to stabilize the o-phases in La doped bulk polycrystalline HfO2 and investigate their evolution with the doping concentration through Time Differential Perturbed Angular Correlation (TDPAC), X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) measurements. The present work reports the presence of both the polar Pca21 phase and the antipolar Pbca phase at different La-concentrations. Two o-phases of HfO2 with space groups Pca21 and Pbca, difficult to distinguish by other complimentary methods, could be unambiguously identified by utilizing the atomic scale sensitivity of the electric field gradient (EFG) embedded in TDPAC spectroscopy. The determination of the oxidation state and the local environment of La-atoms by XANES and EXAFS measurements illuminates the microscopic role of the dopant in stabilizing the o-phase. The "solute drag model" proposes a critical crystallite size for the nucleation of the o-phase in bulk HfO2 and explains the role of the La-dopant in stabilizing the o-phase. Thus the present study shows the possibility of stabilizing the polar o-phase and hence attaining ferroelectricity in bulk HfO2 to augment the scope of future application for this ferroelectric device.

Evaluation of nutraceutical application of xylooligosaccharide enzymatically produced from cauliflower stalk for its value addition through a sustainable approach.

There is increasing attention on the exploration of waste feedstocks as economically viable substrates for the production of prebiotic oligosaccharides, especially xylooligosaccharides, as excellent candidates for the maintenance and promotion of gut microbiota. XOS, an emerging prebiotic that has several functional attributes and beneficial health effects, is mainly produced by different processes, especially enzymatic hydrolysis through the valorisation of xylan enriched lignocellulosic materials. The present study deals with the enzymatic production of xylooligosaccharide (XOS) from xylan rich cauliflower stalk, a novel source. Delignification with alkali (NaOH) was found to be more efficient than acid and autohydrolysis, resulting in a higher extraction yield of xylan (18.42%). Alkaline extraction for 120 minutes at 1.25 M alkali concentration produced maximum xylan yield. FTIR analysis of xylan extracted from cauliflower stalk by an alkaline (NaOH) pretreatment method showed typical absorption bands at 1729 cm-1 that correspond to acetyl groups exhibiting the typical xylan specific band. Enzymatic hydrolysis was carried out with indigenously produced crude endoxylanase obtained from Aspergillus niger MTCC 9687 and the effects of substrate concentration, enzyme concentration, pH, time and temperature were investigated. High resolution MS analysis showed the presence of xylobiose as the major XOS. The major 1H spectral signals of XOS liberated from enzymatically hydrolysed alkali extracted cauliflower stalk xylan showed the presence of ß-anomeric protons in the spectral region of 4.0-4.7 ppm. Prebiotic efficacy of cauliflower stalk derived XOS alone and synbiotic combinations with known probiotic strains (Lactiplantibacillus plantarum, Bifidobacterium bifidum, Lactobacillus delbrueckii ssp. Helveticus) were evaluated. Butyrate was found to be the major short chain fatty acid produced by XOS supplemented fermentation media. All the synbiotic combinations showed significantly higher antioxidant and antimicrobial activities and reduced the viability of human bone cancer MG-63 cells. The individual profiles of antimicrobial components of XOS were identified as dihydroxy benzoic acid and aspartic acid by HPLC coupled to a photodiode array detector.

Insight into the charging-discharging of magnetite electrodes: in situ XAS and DFT study.

The structural changes of Fe3O4 nanoparticle electrodes in Li ion batteries during charging-discharging cycles have been investigated using in situ X-ray absorption spectroscopy (XAS). Chemometric methods viz., Principal Component Analysis (PCA) and Multivariate Curve Resolution-Alternate Least Square (MCR-ALS) have been used for analysis of the in situ XANES data during the charge-discharge cycle, which help to identify the various species formed during the lithiation-delithiation of Fe3O4. The concentration variation of the different species has also been determined and the detailed intercalation-conversion mechanism of the Fe3O4 electrodes during the first discharge has been established. Subsequently, the first charge and second discharge cycles were also studied to apprehend the difference in redox reaction between the first discharge and subsequent cycles. The above studies clearly identify the four species involved in the whole intercalation-conversion process of Fe3O4 electrode of a Li ion battery and also indicate the irreversibility of the conversion reaction in subsequent cycles which may be one of the reasons for capacity fading of these electrodes. The above results have also been corroborated with density functional theory (DFT)based ab inito calculations.

Interface modification of Cr/Ti multilayers with C barrier layer for enhanced reflectivity in the water window regime.

The influence of a carbon barrier layer to improve the reflectivity of Cr/Ti multilayers, intended to be used in the water window wavelength regime, is investigated. Specular grazing-incidence X-ray reflectivity results of Cr/Ti multilayers with 10 bilayers show that interface widths are reduced to ∼0.24 nm upon introduction of a ∼0.3 nm C barrier layer at each Cr-on-Ti interface. As the number of bilayers increases to 75, a multilayer with C barrier layers maintains almost the same interface widths with no cumulative increase in interface imperfections. Using such interface-engineered Cr/C/Ti multilayers, a remarkably high soft X-ray reflectivity of ∼31.6% is achieved at a wavelength of 2.77 nm and at a grazing angle of incidence of 16.2°, which is the highest reflectivity reported so far in the literature in this wavelength regime. Further investigation of the multilayers by diffused grazing-incidence X-ray reflectivity and grazing-incidence extended X-ray absorption fine-structure measurements using synchrotron radiation suggests that the improvement in interface microstructure can be attributed to significant suppression of inter-diffusion at Cr/Ti interfaces by the introduction of C barrier layers and also due to the smoothing effect of the C layer promoting two-dimensional growth of the multilayer.

Management of primary pulmonary alveolar proteinosis: A multicentric experience.

BACKGROUND: Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by alveolar accumulation of surfactant material with reduced lung function and resulting hypoxemia. It is characterized by a variable clinical course, and whole lung lavage (WLL) is the standard treatment. Herein, we report our multicentric experience of management of primary PAP. MATERIALS AND METHODS: This retrospective study included patients with PAP managed at various armed forces respiratory centers from 2009 to 2019. The diagnosis of primary PAP was based on histopathologic confirmation on transbronchial lung biopsy or open lung biopsy and absence of causes of secondary PAP. We analyzed the response to WLL in these patients as well as the safety of the procedure. RESULTS: During the above-specified period, ten patients with a diagnosis of PAP were admitted to various armed forces respiratory centers. The median age of the patients was 34.5 years (range 23-59); there were nine males (90%). The mean duration (± standard deviation) of symptoms was 10.8 (±2.70) months. For management, WLL was done for eight patients with a median volume of 23.5 L (range 18-45) per patient. All the patients showed significant symptomatic response as well as improvement in physiological parameters with no major complications. The median follow-up of all patients was 18 (range 5-44) months. CONCLUSIONS: WLL is a safe, effective therapy in an experienced setting in patients with PAP and provides long-lasting benefits.

Exhaled nitric oxide as a guiding tool for bronchial asthma: A randomised controlled trial.

BACKGROUND: Evidence regarding the role of non-invasive marker of airway inflammation, fractional exhaled nitric oxide (FeNO) to guide asthma treatment is equivocal. We aimed to evaluate if the use of FeNO to adjust inhaled corticosteroid treatment resulted in reduced daily corticosteroid use and lesser exacerbations. METHODS: 100 patients of bronchial asthma in the age group of 12-70 years were randomised to receive inhaled corticosteroids based on either FeNO measurements (n = 50) or as per Global Initiative for Asthma (GINA) guidelines. Follow up was done every 2 months for period of 12 months. Results were compared in terms of mean daily inhaled corticosteroid use and number of exacerbations. RESULTS: After the follow up period of 12 months, mean daily dose of ICS (SD) required in FeNO group was 267.5 µg (126.29), as opposed to control group in which mean daily dose of steroid was 320.00 µg (138.69). However this observed difference in steroid dose was statistically insignificant (p value = 0.061). The estimated mean (SD) rate of asthma exacerbation experienced in follow up period of 12 months in FeNO group was 0.3 episodes (0.54) per patient per year (95% confidence interval, 0.145-455) and 0.4 episodes (0.61) per patient per year in control group (95% confidence interval, 0.228-572). However this difference in rate of exacerbations between the two study groups was not statistically significant (p = 0.387). CONCLUSION: FeNO guided management strategy for asthma did not result in statistically significant reduction in dose of inhaled corticosteroids or number of asthma exacerbations.

Oxygen vacancy mediated cubic phase stabilization at room temperature in pure nano-crystalline zirconia films: a combined experimental and first-principles based investigation.

We report here the stabilization of the cubic phase under ambient conditions in the thin films of zirconia synthesized by electron beam evaporation. The cubic phase stabilization was achieved without the use of chemical stabilizers and/or concurrent ion beam bombardment. Films of two different thicknesses (660 nm and 140 nm) were deposited. While the 660 nm as-deposited films were in the cubic phase, as indicated by X-ray diffraction and Raman spectroscopy, the 140 nm as-deposited films were amorphous and the transformation to the cubic phase was obtained after thermal annealing. Extended X-ray absorption fine structure measurements revealed the existence of oxygen vacancies in the local structure surrounding zirconium for all films. However, the amount of these oxygen vacancies was found to be significantly higher for the amorphous films as compared to that for the films in the cubic phase (660 nm as-deposited and 140 nm annealed films). The stabilization of the cubic phase is attributed to the breaking of the oxygen-zirconium bonds due to the presence of the oxygen vacancies, which results in the suppression of the soft X2- mode of vibration of the oxygen sub-lattice. Our first-principles modeling under the framework of density functional theory shows that the cubic structure with oxygen vacancies is indeed more stable under ambient conditions than its pristine (without vacancies) counterpart due to breaking of the oxygen bonds. The requirement of a critical amount of these vacancies for cubic phase stabilization is discussed.

Characterization of drug resistance and genetic diversity of Plasmodium falciparum parasites from Tripura, Northeast India.

Monitoring of anti-malarial drug resistance is vital in Northeast India as this region shares its international border with Southeast Asia. Genetic diversity of Plasmodium parasites regulates transmission dynamics, disease severity and vaccine efficacy. P. falciparum chloroquine resistance transporter (Pfcrt), multidrug resistance-1 (Pfmdr-1) and kelch 13 propeller (PfK-13) genes which govern antimalarial drug resistance and three genetic diversity markers, merozoite surface protein 1 and 2 (Pfmsp-1, Pfmsp-2) and glutamate rich protein (Pfglurp) were evaluated from Tripura, Northeast India using molecular tools. In the Pfcrt gene, 87% isolates showed triple mutations at codons M74I, N75E and K76T. 12.5% isolates in Pfmdr-1 gene showed mutation at N86Y. No polymorphism in PfK-13 propeller was found. Polyclonal infections were observed in 53.85% isolates and more commonly in adults (p = 0.0494). In the Pfmsp-1 locus, the K1 allelic family was predominant (71.2%) followed by the 3D7/IC family (69.2%) in the Pfmsp-2 locus. RII region of Pfglurp exhibited nine alleles with expected heterozygosity of 0.85. The multiplicity of infection for Pfmsp-1, Pfmsp-2 and Pfglurp were 1.56, 1.31 and 1.06 respectively. Overall, the study demonstrated a high level of chloroquine resistance and extensive parasite diversity in the region, necessitating regular surveillance in this population group.