Tuning the physiochemical properties of polycaprolactone-hydroxyapatite composite films by gamma irradiation for biomedical applications

Physiochemical properties of polycaprolactone-hydroxyapatite (PCL-HAp) composites were investigated in the pristine and after irradiation of γ rays (25, 50, 75, and 100 kGy). PCL-HAp composites were synthesized by solvent evaporation and characterized using spectroscopic methods as well as biological assays. The surface roughness (RMS) of the irradiated composite film (at 75 kGy) was 80 times higher than that of the pristine. Irradiation tailors the contact angle of the films from 77° to 90° (at 100 kGy). A decrease in particle size (at 100 kGy) of HAp nanorods in PCL-HAp composites film was observed. The XRD peak of PCL was slightly shifted from 21.2° to 21.7° (at 100 kGy) with the decrease in crystallite size. The peak intensity of the PCL and HAp altered on irradiation that was confirmed by FTIR and Raman analysis. Further, the bandgap of the irradiated film was lowered by 13 % (at 25 kGy). The luminescence intensity decreased due to the non-radiative process induced by the irradiation defects. All the samples possess hemocompatibility percentage of <10 % as per ASTM standards. At 75 kGy, fibroblast cell proliferation was higher than the pristine and other doses. The gamma-irradiated PCL-HAp composite films are potential candidates for tissue engineering applications.

Probing size-dependent defects in zinc oxide using synchrotron techniques: impact on photocatalytic efficiency

In the present study, synchrotron-based X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS) and X-ray excited optical luminescence (XEOL) have been used to investigate the induced defect states in metal oxide nanomaterials. Specifically, two synthesis approaches have been followed to develop unique nano-sized peanut-shaped (N-ZnO) nanostructures and micron-sized hexagonal rods (M-ZnO). XANES analysis at the Zn K-edge revealed the presence of defect states with a divalent oxidation state of zinc (Zn2+) in a tetrahedral structure. Furthermore, XAS measurements performed at the Zn L3,2-edge and O K-edge confirm higher oxygen-related defects in M-ZnO, while N-ZnO appeared to have a higher concentration of surface defects due to size confinement. Moreover, the in-line XEOL and time dependent-XEOL measurements exposed the radiative excitonic recombination phenomena occurring in the band-tailing region as a function of absorption length, X-ray energy excitation, and time. Based on the chronology developed in the defect state improvement, a possible energy band diagram is proposed to accurately locate the defect states in the two systems. Furthermore, the increased absorption intensity at the Zn L3,2-edge and the O K-edge under the UV lamp suggests delayed recombination of electrons and holes, highlighting their potential use as photo catalysts. The photocatalytic activity degrading the rhodamine B dye established M-ZnO as a superior catalyst with a rapid degradation rate and significant mineralization. Overall, this work provides valuable insights into ZnO defect states and provides a foundation for efficient advanced materials for environmental or other optoelectronic applications.

Comparison of topical purslane & topical 0.1% triamcinolone acetonide in the management of oral lichen planus - a double blinded clinical trial

AIM AND BACKGROUND

Oral lichen planus (OLP) is a chronic autoimmune mucocutaneous disorder of unknown etiology and treatment is targeted at alleviating symptoms. At present, corticosteroids are the mainstay treatment, and their side effects hamper their long-term use, demanding alternative therapy. This study intended to assess the efficacy of topical purslane (Portulaca oleracea) at two concentrations, 5% and 10%, in OLP and to compare the level of clinical improvement in comparison to topical 0.1% triamcinolone acetonide gel.

MATERIALS AND METHODS

After sample size determination, thirty-four subjects confirmed histopathologically with OLP were included in the study. They were divided into 3 groups, Group 1(Control) was treated with 0.1% triamcinolone acetonide, and Group 2(Case) and 3 (Case) were treated with topical purslane 5% and 10%, respectively. They were examined at baseline, 14 days, 30 days, 60 days, and 90 days. Clinical improvement was then analyzed at the end of 90 days using a visual analog scale (VAS) and Thongprasom's criteria.

RESULTS

The study was analyzed statistically and a P value of < 0.05 was considered statistically significant. Intragroup comparison revealed a statistically significant difference between the five time periods (baseline, 14 days, 30 days, 60 days, and 90 days) for the study variables (burning sensation, pain, lesion score, clinical response, symptomatic response) for all three groups (p = 0.001). Alleviation of all symptoms and remission of the lesion were noted for all three groups at the end of three months.

CONCLUSION

Purslane is a magical herb with a plethora of rich nutrients, ease in accessibility and devoid of side effects. It was concluded that its preparation is beneficial and can be a safer alternative long-term drug for the management of OLP.

CLINICAL SIGNIFICANCE

With available literature evidence, our present study is the first of its kind to formulate a topical gel with purslane to treat symptomatic OLP. Our study had a longer follow-up of 3 months compared to other studies in the literature.

Intriguing physicochemical properties and impact of co-dopants on N-doped graphene oxide based ZnS nanowires for photocatalytic application

Superparamagnetic N-doped graphene oxide (GO)- with ZnS nanowires was synthesized by a one-step hydrothermal method by doping dilute amounts of Ga, Cr, In, and Al ions for water treatment and biomedical applications. In these experiments, to enhance their properties, 2% of Ga³⁺, In³⁺, and or Al³⁺ were codoped along with 2% Cr ions in these ZnS nanowires. The nanocomposite with the composition, In_0.02Cr_0.02Zn_0.96S, has better photocatalytic efficiency than other co-doped nanocomposites. The In (metalloids) and Cr (transition metal ion) are the best combinations to increase the magnetic properties which are beneficial for photocatalytic activity. Synthesized nanocomposite materials were characterized by several techniques such as X-ray diffraction, Field emission-scanning electron microscope (FESEM) with EDAX, vibrating sample magnetometer (VSM), UV-Vis, X-ray photoelectron spectroscopy (XPS), and fluorescence spectroscopy. The correlation of intriguing magnetic properties with their photocatalytic properties is also discussed. XPS was employed for the detection of surface defects, phase transformation, and the nature of chemical components present in the nanocomposites. The Frankel and substitutional defects have a direct impact on photocatalytic activity that was determined from the fluorescence (FL) spectroscopy. FL and XPS reveal that the Cr and In codoped composite has a higher percentage of defects hence its photocatalytic efficiency reaches 94.21%.

Evaluation of one-year effectiveness of clobazam as an add-on therapy to anticonvulsant monotherapy in participants with epilepsy having uncontrolled seizure episodes: An Indian experience

OBJECTIVES

To prospectively study the effectiveness and safety of clobazam as an add-on therapy in patients with epilepsy whose seizures are not adequately controlled with antiseizure medicine (ASM) monotherapy.

METHODS

We conducted a prospective, observational study at 28 neurology outpatient clinics in India from June 2017 to October 2019. Consecutive patients with epilepsy (older than 3 years) with inadequate seizure control with ASM monotherapy were initiated on clobazam. Patients were followed up at 1, 3, 6, 9, and 12 months. Seizure control and adverse events were assessed through personal interviews and seizure diaries.

RESULTS

Out of 475 eligible patients, data of 429 patients (men: 65.5%) were evaluated (46 excluded due to protocol deviations). The median age was 25 (range, 3-80 years) years and the median duration of epilepsy was 3 (0.1-30) years. The majority of patients had focal epilepsy (55.0%) and genetic generalized epilepsy (40.1%). The one-year follow-up was completed by 380 (88.5%) patients. At one-year follow-up, 317 (83.4%; N = 380) patients in the study remained seizure free. These 317 patients who were seizure free at 12 months comprised 73.9% of the evaluable population (N = 429). In 98.8% of patients, the primary reason for adding clobazam was inadequate control of seizures with treatment. During one-year follow-up, a total of 113 (22.6%) patients experienced at least one adverse event which included 103 (20.6%) patients who experienced 386 episodes of seizures.

CONCLUSION

The study provides preliminary evidence that clobazam is effective and well-tolerated as add-on therapy for a period of one year among patients with epilepsy inadequately stabilized with monotherapy.

TRIAL REGISTRATION NUMBER

CTRI/2017/12/010906.

Evaluation and correlation of condylar cortication by cone-beam computed tomography: A retrospective study

Background:

Temporomandibular joint (TMJ) is a ginglymo-diarthroidial joint with fibroelastic cartilage. The chondrogenesis initiates from the 12^th week of intrauterine life and the development of condyle is associated with growth. The condylar cortication shows distinct morphological variation for each individual in each stage of their life. The cortical bone around the condyle could be used as a factor for chronological age assessment and it can act as a tool in forensic medicine.

Aim and Objective:

The study was carried out to evaluate the cortical grading in mandibular condyle using two different applications and to correlate their grades with chronological age.

Setting and Design:

Hospital-based retrospective observational cross-sectional study.

Materials and Methods:

The study was carried out in 40 patients and 80 TMJs were assessed for cortication grades in Carestream 3D imaging and Image J applications. These grading from both the applications were correlated with the chronological age.

Statistical Analysis:

SPSS (Statistical Analysis for the Social Science) – Cohen's Kappa inter-examiner reliability and Spearman's correlation coefficient were used.

Results:

The radiological assessment of condylar cortication in individual application showed significant results and the relationship of cortication with chronological age showed a significant correlation.

Conclusion:

The condylar cortication grading is a simple technique and can be used as a factor for chronological age assessment. This is an initial study which used two different applications to view the cortication of the mandibular condyle and to correlate the cortication with chronological age. Hence, a large sample size-based study is required for further research.

Testing for nonlinearity in nonstationary time series: A network-based surrogate data test

The classical surrogate data tests, which are used to differentiate linear noise processes from nonlinear processes, are not suitable for nonstationary time series. In this paper, we propose a surrogate data test that can be applied on both stationary time series as well as nonstationary time series with short-term fluctuations. The method is based on the idea of constructing a network from the time series, employing a generalized symbolic dynamics method introduced in this work, and using any one of the several easily computable network parameters as discriminating statistics. The construction of the network is designed to remove the long-term trends in the data automatically. The network-based test statistics pick up only the short-term variations, unlike the discriminating statistics of the traditional methods, which are influenced by nonstationary trends in the data. The method is tested on several systems generated by linear or nonlinear processes and with deterministic or stochastic trends, and in all cases it is found to be able to differentiate between linear stochastic processes and nonlinear processes quite accurately, especially in cases where the common methods would lead to false rejections of the null hypothesis due to nonstationarity being interpreted as nonlinearity. The method is also found to be robust to the presence of experimental or dynamical noise of a moderate level in an otherwise nonlinear system.

Thermoelectric properties of GaN with carrier concentration modulation: an experimental and theoretical investigation

The present work investigates the less explored thermoelectric properties of the n-type GaN semiconductor by combining both experimental and computational tools. The Seebeck coefficients of GaN epitaxial thin films were experimentally measured in the wide temperature range from 77 K to 650 K in steps of ∼10 K covering both low and high-temperature regimes as a function of the carrier concentration (2 × 1016, 2 × 1017, 4 × 1017 and 8 × 1017 cm-3). The measured Seebeck coefficient at room temperature was found to be highest (-374 μV K-1) at the lowest concentration of 4 × 1016 cm-3, and decreases in magnitude monotonically (-327.6 μV K-1, -295 μV K-1, -246 μV K-1 for 2 × 1017, 4 × 1017, 8 × 1017 cm-3, respectively) as the sample carrier concentration increases. The Seebeck coefficient remains negative in the entire temperature range under study indicating that electrons are the dominant carriers. To understand the temperature-dependent behaviour, we also carried out the electronic structure and transport coefficient calculations using the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential and semiclassical Boltzmann transport theory implemented in WIEN2k and BoltzTraP code, respectively. The experimentally observed carrier concentrations were used in the calculations. The estimated results obtained under constant relaxation time approximations provide a very good agreement between the theoretical and experimental data of Seebeck coefficients in the temperature range from 260 to 625 K.

Local structure investigation of Co-Fe-Si-B ribbons by extended X-ray absorption fine-structure spectroscopy

In the present work, extended X-ray absorption fine-structure (EXAFS) investigations of Co₆₉Fe_xSi_21-xB₁₀ (x = 3, 5, 7) glassy ribbons were performed at the Co K-edge. The magnitude of the first peak of the Fourier transforms of the EXAFS signals is found to increase monotonically with increasing Si concentrations indicating the formation of the localized ordered structure at the atomic scale. The Co-Si coordination number (CN) increases at the expense of the CN of Co/Fe. Smaller interatomic distances are observed in the glassy phase compared with that in the crystalline phase which promotes the stability of the glassy phase. Calculations of the thermodynamic parameter (P_HSS), cohesive energy (E_C) and the atomic radius difference (δ) parameter show that the alloy composition Co₆₉Fe₃Si₁₈B₁₀ has a good glass-forming ability (GFA) with the highest CN of Si compared with other compositions. A linear correlation of CN with that of the GFA parameter (P_HSS) exists and the CN also plays a crucial role in the GFA of the glassy alloys. This parameter should be considered in developing different GFA criteria.

Structural, magnetic and dielectric properties in 3d-5dbased Sr2FeIrO6thin films

The structural, magnetic and dielectric properties have been investigated in 3d-5dbased double perovskite Sr₂FeIrO₆thin films deposited by pulse laser deposition technique. To understand the effect of strain, epitaxial films are grown with varying thickness as well as on different substrates i.e., SrTiO₃(100) and LaAlO₃(100). The films with highest thickness are found to be more relaxed. Atomic force microscope images indicate all films are of good quality where grain sizes increase with increase in film thickness. X-ray absorption (XAS) spectroscopy measurements indicate a Ir⁵⁺charge state in present films while providing a detailed picture of hybridization between Fe/Ir-dand O-porbitals. The bulk antiferromagnetic transition is retained in films though the transition temperature shifts to higher temperature. Both dielectric constant (ϵ_r) and loss (tan δ) show change around the magnetic ordering temperatures of bulk Sr₂FeIrO₆indicating a close relation between dielectric and magnetic behaviors. A Maxwell-Wagner type relaxation is found to follow over whole frequency range down to low temperature in present film. On changing the substrate i.e., LaAlO₃(100), theϵ_r(T) and (tan δ(T)) show almost similar behavior butϵ_rshows a higher value which is due to an increased strain coming from high mismatch of lattice parameters.

Expression of E- Cadherin and Levels of Dysplasia in Oral Leukoplakia - A Prospective Cohort Study

Aim:

Enormous attempts have been made to develop and establish markers that determines the susceptibility of potentially malignant tissues to transform to oral cancer. E - cadherin encoded by CDH1 gene is a protein which plays an important role in cellular adhesion. This study aimed to assess the relationship between the expression of E- cadherin and different grades of epithelial dysplasia in oral leukoplakia.

Materials and Methods:

Tumour biopsies from fifty leukoplakia patients was collected. Half of the tissue was sent for histopathological examination and other half was subjected to see E - cadherin expression by real time PCR.

Results:

On assessing, the expression of E - cadherin was found to be high in samples with mild dysplasia followed by samples with moderate dysplasia. Samples with severe dysplastic feature showed least expression of E - cadherin. All statistical analyses were performed using Statistical Package for Social science (SPSS) and was proven that there is significant decrease in the expression of E - cadherin as the degree of dysplasia increases with a p value 0.001 and confidence interval 95%.

Conclusion:

We conclude that loss of E - cadherin can be used as a tumour marker that could determine the susceptibility of normal and potentially malignant tissues to transform into oral cancers. To generalise our results, further prospective studies with a large sample size using quantitative real time PCR to read the gene expression should be carried out at multi centre levels.

The effect of orbital-lattice coupling on the electrical resistivity of YBaCuFeO5 investigated by X-ray absorption

Temperature-dependent X-ray absorption near-edge structures, X-ray linear dichroism (XLD) and extended X-ray absorption fine structure (EXAFS) spectroscopic techniques were used to investigate the valence state, preferred orbital and local atomic structure that significantly affect the electrical and magnetic properties of a single crystal of YBaCuFeO5 (YBCFO). An onset of increase of resistivity at ~180 K, followed by a rapid increase at/below 125 K, is observed. An antiferromagnetic (AFM)-like transition is close to the temperature at which the resistivity starts to increase in the ab-plane and is also observed with strong anisotropy between the ab-plane and the c-axis. The XLD spectra at the Fe L3,2-edge revealed a change in Fe 3d eg holes from the preferential [Formula: see text] orbital at high temperature (300-150 K) to the [Formula: see text] orbital at/below 125 K. The analysis of the Fe K-edge EXAFS data of YBCFO further revealed an unusual increase in the Debye-Waller factor of the nearest-neighbor Fe-O bond length at/below 125 K, suggesting phonon-softening behavior, resulting in the breaking of lattice symmetry, particularly in the ab-plane of Fe-related square pyramids. These findings demonstrate a close correlation between electrical resistivity and coupling of the preferred Fe 3d orbital with lattice distortion of a single crystal of YBCFO.

Nicotinamide adenine dinucleotide immobilized tungsten trioxide nanoparticles for simultaneous sensing of norepinephrine, melatonin and nicotine

Herein, we report the anionic surfactant, ethylene diamine tetraacetic acid (EDTA), mediated synthesis of WO₃ nanoparticles and its subsequent modification through gamma irradiation (GI) and electrochemical immobilization with nicotinamide adenine dinucleotide (NAD). Glassy carbon electrode (GCE) modified with GI-WO₃ NPs and the enzyme NAD exhibited strong electro-oxidation of three important biomolecules such as norepinephrine (NEP), melatonin (MEL) and nicotine (NIC) in 0.1 M phosphate buffer saline (PBS) at physiological pH of 7. Square wave voltammetry (SWV) studies exhibited three well-defined peaks at potentials of 120, 570 and 840 mV, corresponding to the oxidation of NEP, MEL and NIC respectively, indicating that simultaneous determination of these compounds is feasible at the NAD/GI EDTA-WO₃/GCE. The proposed sensor displayed a wide linear range of 0.010-1000 μM with the lowest detection limit of 1.4 nM for NEP, 2.6 nM for MEL and 1.7 nM for NIC respectively. Furthermore, the modified electrode was successfully applied to detect NEP, MEL and NIC in pharmaceutical and cigarette samples with excellent selectivity and reproducibility.

Effect of Fe ion implantation on the thermoelectric properties and electronic structures of CoSb3 thin films

In the present study, thin films of single-phase CoSb₃ were deposited onto Si(100) substrates via pulsed laser deposition (PLD) method using a polycrystalline target of CoSb₃. These films were implanted by 120 keV Fe-ions with three different fluences: 1 × 10¹⁵, 2.5 × 10¹⁵ and 5 × 10¹⁵ ions per cm². All films were characterised by X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM), Rutherford backscattering (RBS) spectrometry and X-ray absorption spectroscopy (XAS). XRD data revealed that the ion implantation decreased the crystalline nature of these films, which are recovered after the rapid thermal annealing process. The Seebeck coefficient S vary with the fluences in the temperature range of 300 K to 420 K, and is found to be highest (i.e., 254 μV K⁻¹) at 420 K for the film implanted with 1 × 10¹⁵ ions per cm². The high S and low resistivity lead to the highest power factor for the film implanted with 1 × 10¹⁵ ions per cm² (i.e., 700 μW m⁻¹ K⁻²) at 420 K. The changing of the sign of S from negative for the pristine film to positive for the Fe-implanted samples confirm that the Fe ions are electrically active and act as electron acceptors by replacing the Co atoms. XAS measurements confirm that the Fe ions occupied the Co site in the cubic frame of the skutterudite and exist in the 3+ oxidation state in this structure.

The power factor for the Fe ion-implanted samples is greater than that of the pristine sample with a value of 700 mW m⁻¹ K⁻² at 420 K for the I_1E15A sample.

Influence of defect structure on colour tunability and magneto optical behaviour of WO3 nanoforms

The present study reports the impact of thermal annealing on the structural, optical and magnetic properties of WO₃ nanostructures, synthesized using an acid precipitation method by, employing various spectroscopic and magnetic measurements. The X-ray diffraction and Raman measurements confirmed the orthorhombic structure of as dried WO₃·H₂O and monoclinic structure of WO₃ nanopowders annealed at or above 500 °C. The morphological characterization shows the formation of different microstructures like nanosheets, nanoplatelets and nanocuboids in the micro-scale with the variation of annealing temperatures. The optical band gap has been calculated using the Kubelka–Munk function. The room temperature photoluminescence (PL) spectra recorded at different excitation wavelengths show intense near ultraviolet (NUV) emission which might be due to the presence of localized states associated with oxygen vacancies, and the surface states in the conduction band. The emissions in visible region correspond to the structural defects such as oxygen vacancies present within the band gap and band to band transitions. The spectral chromaticity colour coordinates indicate that the light emitted from the prepared samples shows shift from violet to red region with the change of excitation wavelength. Magnetic measurements show decrease in room temperature ferromagnetism (FM) with annealing temperature. The X-ray absorption spectroscopy (XAS) measurements at O K-edge show the significant change in the W–O hybridizations. The decrease in PL intensity and ferromagnetic ordering with increase in annealing temperatures are directly correlated with the filling up of oxygen vacancies in the samples. The oxygen vacancies based F-Center exchange model is discussed to understand the origin of FM in WO₃ nanostructures.

Colour tunability in WO₃ nanoparticles with variation in excitation wavelength. Typical hysteresis loops of the annealed samples at 300 K.

Tuning of the Thermoelectric Properties of Bi2Te3 Nanorods Using Helium Ion Irradiation

The present study reports an enhancement of the power factor of Bi2Te3 nanorods NRs) by helium (He+) ion irradiation. High-resolution transmission electron microscopy studies revealed the formation of amorphous layers on the surface of the NRs at the high ion fluence. This amorphous nature is due to the accumulation of migrating point defect clusters at the surface of the NRs. Raman scattering experiments provide further insight to the observed structural modifications. At higher ion fluence, impurity-dominated scattering processes significantly enhance the value of the Seebeck coefficient of Bi2Te3 NRs. The He+ ion irradiation up to the ion fluence of 1 × 1016 ions/cm2 improves the thermoelectric transport properties with the highest power factor, 8.2 μW/m K2, at 390 K. Further investigations may result in the possibility of fabricating the Bi2Te3 NRs as thermoelectric generators with a high power factor for space applications.

Synthesis of OSL nanophosphor Li3B7O12:Mn and its dosimetric properties

The present paper reports the structural, morphological and optical properties of nanophosphor Li₃B₇O₁₂:Mn with an optimised dopant concentration of 0.25 mol% and its surface modification under the irradiation of 250 keV proton beams and gamma photons for ion fluence ranging from 1 × 10¹³ to 6.25 × 10¹⁵ ions cm^-2 and doses from 100 mGy-100 Gy, respectively. This nanophosphor has been synthesised by the high temperature solid state reaction method. Its optical properties are characterised by optically stimulated luminescence (OSL) and thermo luminescence (TL) techniques. This nanophosphor is polycrystalline in nature with a grain size of 40-80 nm confirmed by x-ray diffraction (XRD) and transmission electron microscopy (TEM). The OSL decay and TL glow curve response of the proton beam irradiated samples exhibit significant intensity at a fluence of 2.5 × 10¹⁴ ions cm^-2. Moreover, Li₃B₇O₁₂:Mn displays a linear response for gamma doses in the range of 100 mGy-50 Gy. We have also investigated the reusability and reproducibility of this material. The above study demonstrates that Li₃B₇O₁₂:Mn is a robust and promising candidate for medical proton dosimetry.

Morphological investigations on the growth of defect-rich Bi2Te3 nanorods and their thermoelectric properties

Bi₂Te₃ nanorods (NRs) have been successfully synthesized at different reaction temperatures via a surfactant-assisted hydrothermal method.

Mechanistic insights into the interaction between energetic oxygen ions and nanosized ZnFe2O4: XAS-XMCD investigations

Irradiation of nanosized zinc ferrite with swift heavy ions leads to cation redistribution and changes in magnetic interactions.

Current-voltage characteristics and electroresistance in LaMnO3-δ/La0.7Ca0.3MnO3/LaAlO3 thin film composites

In this communication, we report results of the electrical transport properties across the interface of composites consisting of n-type LaMnO_3-δ (LMO) and p-type La_0.7Ca_0.3MnO₃ (LCMO) manganites grown on LaAlO₃ (LAO) single crystalline substrates using low cost wet chemical solution deposition (CSD) and sophisticated, well-controlled dry chemical vapor deposition (CVD) chemical techniques. The XRD ϕ-scan studies reveal the single crystalline nature of both bilayered composites, with parallel epitaxial growth of LMO and LCMO layers onto the LAO substrate. The valence states of Mn ions in both layers of both composites were identified by performing X-ray photoelectron spectroscopy (XPS). The I-V characteristics of the LMO/LCMO interfaces show strong backward diode-like behavior at higher applied voltages well above the crossover voltage (V_NB). Below V_NB, the interfaces demonstrate normal diode-like characteristics throughout the studied temperature range. The electric field-induced modulation of the LMO/LCMO junction resistance of the interfaces has been observed. Electric field-dependent electroresistance (ER) modifications at different temperatures have also been studied. The electrical transport properties have been discussed in the context of various mechanisms, such as charge injection, tunneling, depletion region modification and thermal processes across the interface. The effects of structurally and chemically developed sharp interfaces between the LMO and LCMO layers on the transport properties of the presently studied bilayered thin film composites have been discussed on the basis of correlation between the physicochemical characterization and charge transport behavior. A comparison of different aspects of the transport properties has been presented in the context of the structural strain and crystallinity of the composites grown using both wet and dry chemical techniques.

Analysis of ARID2 Gene Mutation in Oral Squamous Cell Carcinoma

Background: The ARID2 gene, encoding a sub unit of the chromatin remodelling complex, has a possible tumour suppressor function and has been found to be frequently mutated in various tumours, including gingivo buccal oral squamous cell carcinomas. The present study was designed to analyse the presence of ARID2 gene mutations in the distinct genetic South Indian (Dravidian) population. Materials and Methods: Genomic DNA from thirty biopsy tissue samples of histopathologically confirmed cases of oral squamous cell carcinoma (OSCC) were subjected to PCR amplification with intronic primers encompassing exons 19 and 20 of ARID2. Subsequently, the PCR amplicons were purified and subjected to Sanger sequencing using forward primers for analysis of mutational status. Results: Our study yielded a 6% occurrence of mutations in the ARID2 gene among the thirty OSCC samples. Two samples showed a C(5174)A nonsense mutation whereby the “C” nucleotide was substituted with an “A” nucleotide at position 5174, resulting in the conversion of serine amino acid at codon 1725 to a premature STOP codon. Conclusion: Identification of ARID2 gene mutations in OSCCs in this distinct ethnic population reaffirms that aberrations in the chromatin remodelling complex could indeed also contribute to tumorigenesis, thus providing new insights for future research.

Correction: Charge transport mechanisms in sol-gel grown La0.7Pb0.3MnO3/LaAlO3 manganite films

Correction for 'Charge transport mechanisms in sol-gel grown La_0.7Pb_0.3MnO₃/LaAlO₃ manganite films' by Eesh Vaghela et al., Phys. Chem. Chem. Phys., 2017, DOI: 10.1039/c6cp07730g.

Charge transport mechanisms in sol-gel grown La0.7Pb0.3MnO3/LaAlO3 manganite films

In this communication, structural, microstructural, transport and magnetotransport properties are reported for La_0.7Pb_0.3MnO₃/LaAlO₃ (LPMO/LAO) manganite films having different thicknesses. All the films were irradiated with 200 MeV Ag⁺¹⁵ swift heavy ions (SHI). Films were grown using the sol-gel method by employing the acetate precursor route. Structural measurements were carried out using the X-ray diffraction (XRD) method at room temperature, while atomic force microscopy (AFM) was performed for the surface morphology. Temperature dependent resistivity under different applied magnetic fields for all the films shows metal to insulator transition at temperature T_P. In addition to the metal to insulator transition at T_P, the films also exhibit low temperature resistivity upturn behavior. Resistivity, T_P and upturn behavior are highly influenced by the film thickness, applied magnetic field and irradiation. To understand the nature of charge transport for the low temperature resistivity behavior and metallic and insulating (semiconducting) regions, various models and mechanisms have been verified and the most suitable mechanism has been found for each region in the resistivity curves. Magnetoresistance (MR) is affected by temperature, film thickness and irradiation. MR behavior has been understood in terms of combined and separate contributions from grains and grain boundaries in the films.

Enhancement of thermoelectrical performance in Au-ion implanted V2O5 thin films

The present study reports an enhancement of thermoelectric performance in Au ion implanted V₂O₅ thin films.

Structural, optical and magnetic properties of N ion implanted CeO2 thin films

The present study reports the structural, morphological, optical and magnetic properties of N ion implanted CeO₂ thin films deposited by a RF magnetron sputtering technique.

Facile synthesis of KCl:Sm3+ nanophosphor as a new OSL dosimetric material achieved through charge transfer between the defect states

Since precise control of nanoscale features is in high demand, it is being exploited to develop and improve OSL dosimetric materials, where striking improvement might also be expected in lanthanide-doped metal halides.

Annealing Temperature Dependent Structural and Optical Properties of RF Sputtered ZnO Thin Films

This work investigates the effect of annealing temperature on structural and optical properties of ZnO thin films grown over Si 100 and glass substrates using RF sputtering technique. Annealing temperature has been varied from 300 °C to 600 °C in steps of 100, and different microstructural parameters such as grain size, dislocation density, lattice constant, stress and strain have been evaluated. The structural and surface morphological characterization has been done using X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). XRD analysis reveals that the peak intensity of 002 crystallographic orientation increases with increased annealing temperature. Optical characterization of deposited films have been done using UV-Vis-NIR spectroscopy and photoluminescence spectrometer. An increase in optical bandgap of deposited ZnO thin films with increasing annealing temperature has been observed. The average optical transmittance was found to be more than 85% for all deposited films. Photoluminiscense spectra (PL) suggest that the crystalline quality of deposited film has increased at higher annealing temperature.

Investigations on the effect of gamma-ray irradiation on the gas sensing properties of SnO2 nanoparticles

In recent years, SnO2 nanoparticles (NPs) have been subjected to various modifications in order to improve their performance in sensing and other applications. Here, we report the synthesis of SnO2 NPs by microwave irradiation, and subsequent exposure to gamma (γ) radiation at different doses (0-150 kGy) to induce desirable physico-chemical properties. The irradiated samples were characterized by x-ray powder diffraction (XRD), transmission electron microscopy (TEM and HR-TEM), and photoluminescence (PL) to evaluate the effect of γ-ray irradiation on their morphology and microstructure. The results revealed that the bulk crystal structure remained unchanged after irradiation, while the existence of defects and a damaged over-layer have been confirmed by PL and HR-TEM respectively. The influence of γ-irradiation on the electrical and CO sensing characteristics was also investigated in the temperature range between 150 and 400 °C. γ-irradiated SnO2 NP based resistive sensors showed better CO sensing characteristics (i.e. higher response and lower working temperature) compared to non-irradiated SnO2. Upon optimizing the γ-ray dose irradiation level and working temperature, a ten-fold enhancement in the response to CO has been achieved (R/R 0 = 12 to 50 ppm of CO in air) in 50 kGy irradiated SnO2 NP based sensors operating at 150 °C. A possible mechanism for the enhanced sensing performance of γ-irradiated SnO2 NPs has been proposed.

Understanding the origin of ferromagnetism in Er-doped ZnO system

The present study reports the structural, optical and magnetic properties of ZnO with doping of Er ions at dilute concentrations (0 ≤ x ≤ 0.05).

Optical and surface enhanced Raman scattering properties of Au nanoparticles embedded in and located on a carbonaceous matrix

Au nanoparticles (NPs) on the surface and embedded in a matrix have been the subject of studies dealing with a variety of spectroscopic and sensing applications.

Direct growth of few layer graphene on SiO2 substrate by low energy carbon ion implantation

A simple method that enables the direct fabrication of few layer graphene on SiO₂/Si substrates with precise control of layer thickness by implantation of C ions is explored.

Effect of hydrogen ion implantation on cholesterol sensing using enzyme-free LAPONITE®-montmorillonite electrodes

Electrochemical profiling of LAPONITE®-montmorillonite/indium tin oxide (L-MMT/ITO) electrodes irradiated with 20 keV H₂⁺ ion beam with variable fluence ranging from 10¹² to 10¹⁶ ions per cm².

Structural, magnetic and electronic properties of iron doped barium strontium titanate

Very less known magnetic and the electronic properties of iron doped barium strontium titanate are reported.

Laser irradiation induced photo-crystallization in nano-structured amorphous Se90−xHgxS10(x = 0, 5, 10, 15) thin films

The present study focuses on the influence of laser irradiation induced photo crystallization on the modification of the optical and electrical properties of thermally evaporated amorphous Se_90−xHg_xS₁₀(x= 0, 5, 10, 15) thin films.

Probing the highly transparent and conducting SnOx/Au/SnOx structure for futuristic TCO applications

A SnO_x/Au/SnO_x transparent conductive oxide (TCO) multilayered film was fabricated with a total thickness of 75 nm using both e-beam and thermal evaporation techniques.

Modified structural, surface morphological and optical studies of Li3+ swift heavy ion irradiation on zinc oxide nanoparticles

Synthesized ZnO NPs were irradiated with 50 MeV Li³⁺ SHI two fluences: 5 × 10¹¹ and 1 × 10¹³ ions per cm². The electronic and nuclear energy losses are found to be 15.61 keV μm⁻¹ and 0.087 keV μm⁻¹ in the range 206.1 μm for the range of the projectile ions of Li³⁺ at 50 MeV.

Gamma irradiation studies of composite thin films of poly vinyl alcohol and coumarin

Composite films of imperatorin (a coumarin molecule) and poly vinyl alcohol (PVA) are prepared by a solution casting method.

Comparative evaluation of enzyme-free nanoclay-ionic liquid based electrodes for detection of bioanalytes

Enzyme-free electrodes were fabricated using mixed nanoclays and ionic liquids.

Structural, optical and magnetic properties of Sm doped ZnO at dilute concentrations

The work is important for the development of semiconductor devices which may create new dimensionality to control and achieve high temperature ferromagnetism.

Pycnodysostosis: A bone dysplasia with unusual oral manifestation

Pycnodysostosis, a sclerosing bone dysplasia, is a rare autosomal recessive disorder with an estimated prevalence rate of one in one million. Patients with pycnodyostosis usually have normal intelligence, sexual development and life span. This condition is characterized by increased bone density and fragility along with oral manifestations like malposition teeth, hypoplastic maxilla, receded chin and delayed eruption of permanent teeth with discharging sinuses in the jaws because of poor blood supply. This is one such rare case report of a 47-year-old patient presenting with a complaint of fractured jaw and reviewing the clinical and radiographic characteristics of pycnodysostosis.