Magneto-strain effects in 2D ferromagnetic van der Waal material CrGeTe[Formula: see text].

The idea of strain based manipulation of spins in magnetic two-dimensional (2D) van der Waal (vdW) materials leads to the development of new generation spintronic devices. Magneto-strain arises in these materials due to the thermal fluctuations and magnetic interactions which influences both the lattice dynamics and the electronic bands. Here, we report the mechanism of magneto-strain effects in a vdW material CrGeTe[Formula: see text] across the ferromagnetic (FM) transition. We find an isostructural transition in CrGeTe[Formula: see text] across the FM ordering with first order type lattice modulation. Larger in-plane lattice contraction than out-of-plane give rise to magnetocrystalline anisotropy. The signature of magneto-strain effects in the electronic structure are shift of the bands away from the Fermi level, band broadening and the twinned bands in the FM phase. We find that the in-plane lattice contraction increases the on-site Coulomb correlation ([Formula: see text]) between Cr atoms resulting in the band shift. Out-of-plane lattice contraction enhances the [Formula: see text] hybridization between Cr-Ge and Cr-Te atoms which lead to band broadening and strong spin-orbit coupling (SOC) in FM phase. The interplay between [Formula: see text] and SOC out-of-plane gives rise to the twinned bands associated with the interlayer interactions while the in-plane interactions gives rise to the 2D spin polarized states in the FM phase.

A prospective randomized comparative study to evaluate the effect of palliative hypo-fractionated radiotherapy with concurrent chemotherapy versus hypo-fractionated radiotherapy alone in advanced and unresectable head and neck cancer with no metastasis.

Introduction: A short duration, palliative radiotherapy schedule for locally advanced and unresectable head and neck cancer (LAUHNC) was evaluated in terms of palliation of cancer-related symptoms and acute toxicities. Aims and objectives: The aim of the study was to compare the role and feasibility of hypo-fractionated radiotherapy with concurrent chemotherapy and hypo-fractionated radiotherapy in LAUHNC. Materials and methods: All the patients included in this study of LAUHNC were not fit for curative treatment. These patients are assessed on the basis of quality of life (QOL), tumour response, toxicities, and relief in symptoms. QOL was assessed on the basis of University of Washington QOL questionnaire version 4 before and after treatment. Patients are divided into two arms, Arm A patients received 40 Gy in ten fractions concurrent cisplatin 50 mg/m2 with weekly and Arm B patients received 40 Gy in ten fractions. To assess the tumour response response evaluation criteria in solid tumours criteria were used. Results: A total of 40 patients were enrolled in this study, with 20 patents in both arms. Three patients defaulted during treatment and one patient died during treatment. A total of 36 patients completed treatment. Before treatment common complaints was distressing pain in primary site, and difficulty in chewing and swallowing. After treatment there was reduction of pain and improvement in swallowing in both arms. Overall QOL improvement in Arm A (28.89 ± 18.44 to 46.67 ± 15.34) and in Arm B (31.11 ± 15.68 to 43.33 ± 15.72). Neither of the arms experienced grade IV mucositis and skin reaction. Conclusion: Toxicity in the form of mucositis and dermatitis was higher in the concurrent hypo-fractioned arm compared to the only hypo-fractionated radiotherapy arm during the treatment and in follow up period. The QOL in both individual arms showed statistically significant results, however when the QOL of both the arms was compared, the results were not statistically significant.

Band gap and defect engineering of bismuth vanadate using La, Ce, Zr dopants to obtain a photoelectrochemical system for ultra-sensitive detection of glucose in blood serum.

Bismuth vanadate (BiVO4) is a promising photoactive material for the design of photoelectrochemical (PEC) analytical devices for the non-enzymatic detection of glucose. In this work, un-doped and La/Ce/Zr doped BiVO4 photo anodes were developed by spray pyrolysis coating to generate unique 2D hierarchical architectures using the facile ultrasonic spray coating technique without any complex pre or post-treatment. The influence of different dopants on the morphology and photoelectrochemical activity of BiVO4 coatings was investigated. X-ray diffraction, scanning electron microscopy, UV-vis optical absorbance, and positron annihilation techniques were used to evaluate the structure, defects, and optical properties of BiVO4 films. DFT simulation confirmed the Zr doping induced band gap reduction in the BiVO4 lattice. The Zr doping on the Bi site in BiVO4 lattice provided significantly low Bi and V-based defect density and a higher bulk diffusion length of charge pairs (4 times that of pristine) as well as charge transfer efficiency and this led to the foremost photocurrent for water splitting. The Zr-doped BiVO4 photo anode showed remarkable sensitivity in glucose sensing. The sensitivity and limit of detection of the Zr-doped BiVO4 PEC device towards glucose were 0.14 mA cm-2 mM-1 and 1.22 µM, respectively, in the concentration range of 1-7 mM. The system showed sensitive detection of glucose in blood serum. This is the first time that a 2D morphology electrode design consisting of Zr-doped BiVO4, which leads to exceptionally high sensitivity for glucose sensing, has been reported.

A novel approach to the structural distortions of U/Th snub-disphenoids and their control on zircon → reidite type phase transitions of U1-x Th x SiO4.

Coffinite (USiO4) and thorite (ThSiO4) are conspicuous radiogenic silicates in the geonomy. They form U1-x Th x SiO4 (uranothorite) solid solutions in zircon-type phase. Investigating the phase-evolution of these minerals is of utmost significance in realizing their applicability in the front-as well as at the back-end of nuclear industries. We carried out a systematic study of zircon- to reidite-type (tetragonal I41/amd to I41/a) structural transitions of U1-x Th x SiO4 solid solution, and investigated their mechanical behaviour. We found a unique behaviour of transition pressure with the change in U-Th concentration in the solid solution. The phase transition pressure (p t) is found to be minimum for x = 0.5. We develop the necessary formalism and present an efficient method to estimate the longitudinal and angular distortions of U/ThO8-triangular dodecahedra (snub-disphenoids). We have parameterized two new factors: δ (longitudinal distortions) and σ 2 (angular distortions) to quantify the polyhedral distortions. A detailed analysis of U/ThO8 snub-disphenoidal distortions is presented to address such variation of p t with U and Th concentration. We argue that our approach is independent of polyhedral volume and can be used for any AB8 (A: cation, B: anion) type snub-disphenoidal system.

Role of hypofractionated palliative radiotherapy in patients with stage four head-and-neck squamous cell carcinoma.

BACKGROUND: Large number of patients with head-and-neck cancer presents with factors such as advanced disease, poor general condition, and associated comorbidities due to which radical treatment is not recommended in these patients. In this scenario, the aim of the present study is to assess the role and feasibility of hypofractionated palliative radiotherapy in these patients. SUBJECTS AND METHODS: This study was conducted on patients with histopathologically proven cases of squamous cell carcinoma of the head-and-neck region who were surgically unresectable. The quality of life (QOL) was assessed before and after 1 month of radiotherapy using University of Washington Quality of Life questionnaire version 4. All patients received 40 Gy in 10 fractions, twice weekly by two lateral fields covering primary and secondary disease. Response evaluation criteria in solid tumor criteria were used to assess the tumor response. Toxicity was assessed weekly using radiation therapy oncology group criteria. RESULTS: A total of 50 patients were enrolled in this study, out of which 46 completed the planned treatment of 40 Gy in 10 fractions. Common complaints were distressing pain at the primary site (42%), neck swelling (30%), difficult in swallowing (18%), and change in voice (10%). Statistically significant improvements were observed in overall QOL (26.9 ± 9.63 to 55.65 ± 19.28) and none of them experienced Grade IV mucositis or skin toxicity. Good objective response was seen in 82.6% and 84.7% of patients at primary and nodal sites, respectively. CONCLUSIONS: This hypofractionated palliative radiotherapy regimen is a good treatment option in patients with Stage IV head-and-neck cancer, who are not fit for treatment with curative intent.

Luminescence Properties of SrZrO3/Tb(3+) Perovskite: Host-Dopant Energy-Transfer Dynamics and Local Structure of Tb(3+).

SrZrO3 perovskite (SZP) was synthesized using gel-combustion route and characterized systematically using X-ray diffraction and time-resolved photoluminescence techniques. A detailed analysis of the optical properties of Tb(3+) ions in SrZrO3 was performed to correlate them with the local environment of the lanthanide ions in this perovskite. Photoluminescence (PL) spectroscopy showed that emission spectrum consists of host as well as Tb(3+) emission indicating the absence of complete host-dopant energy transfer. On the basis of emission spectrum and PL decay study it was also observed that Tb(3+) is not homogeneously distributed in SrZrO3 perovskite; rather, it is occupying two different sites. It is corroborated using extended X-ray absorption fine structure studies that Tb(3+) is stabilized on both six-coordinated Zr(4+) and eight-coordinated Sr(2) site. The energies calculated using density functional theory (DFT) indicates that Tb occupation in Sr site is energetically more favorable than Zr site. The analysis of valence charge distribution also substantiated our structural stability analysis of site-selective Tb doping in SrZrO3. Time-resolved emission spectroscopy is employed to elucidate the difference in the spectral feature of Tb(3+) ion at Sr(2+) and Zr(4+) site. DFT-calculated density of states analysis showed that energy mismatch of Tb-d states with Zr-d and O-p states of SZP makes the energy transfer from host SZP to Tb(3+) ion difficult.

Sonochemical synthesis of doped CeF3 nanoparticles exhibiting room temperature ferromagnetism and white light emission.

In this study we demonstrate the remarkable bi-functionalities of doped CeF3 nanoparticles. The sonochemically synthesized triple doped CeF3:Mn2+:Dy3+:Tb3+ nanoparticles exhibited room temperature ferromagnetism and also serves as a good white light emitting phosphor material. The particles were found to be mostly spherical in shape and the average size was in the range of approximately 75 nm. Room temperature ferromagnetism was observed for this triple doped sample and the saturation magnetization was found to be 4.56 x 10(-3) microB/Mn atom. First-principles spin-polarized plane wave based supercell calculations, using the projector augmented wave potentials, on Mn-doped CeF3 confirmed its ferromagnetic properties. The simultaneous observation of both room temperature ferromagnetism and white light emission from doped fluoride nanoparticles reveals the complexity and uniqueness of these results.

Interconversion of perovskite and fluorite structures in Ce-Sc-O system.

CeScO(3) was synthesized by a two-step synthesis route involving a combustion method followed by vacuum heating at 1100 degrees C in the presence of Zr sponge which acts as an oxygen getter. The compound was characterized by various techniques such as X-ray diffraction (XRD), high temperature XRD, thermogravimetry, diffuse reflectance (DR)-UV visible spectrophotometry, and Raman spectroscopy. Fluorite-type (F-type) solid solution with composition Ce(0.5)Sc(0.5)O(1.75) was observed as an intermediate during the synthesis of CeScO(3). Only by mere redox reaction was a reversible transformation between fluorite-type structure and perovskites structure observed. CeScO(3) was found as semiconducting oxide with band gap of 3.2 eV arising mainly between O p states in the valence band and Sc d and Ce d states in the conduction band with small contributions coming from Ce f and Sc p states. First-principles potential plane-wave-based calculations were performed for the band gap and its origin in CeScO(3). Photoluminescence measurement showed that CeScO(3) is a potential host material giving broad blue emission. This was further confirmed by demonstrating CeScO(3) doped with 2 mol % Tb(3+) compound as an efficient green light emitter.

Weekly cisplatin or gemcitabine concomitant with radiation in the management of locally advanced carcinoma cervix: results from an observational study.

OBJECTIVE: The use of non-platinum drugs in concurrent chemoradiation in carcinoma cervix has not been well explored and hence a two arm study was planned to compare the outcome of concomitant cisplatin or gemcitabine in locally advanced carcinoma cervix. METHODS: Thirty six patients were evaluated in this study for response rates and complications. These patients were divided into two arms, sixteen patients in the cisplatin arm and twenty patients in the gemcitabine arm. Cisplatin and gemcitabine were given as i.v. infusion at doses of 40 mg/m(2) and 150 mg/m(2) respectively for five weeks concomitant with radiotherapy. All patients had received pelvic radiotherapy to a dose of 50 Gy/25 fraction/5 weeks by four field box technique followed by high-dose-rate brachytherapy (3 sessions, each of 7.5 Gy to point A). RESULTS: Median follow up was of 10.4 months (range, 3 to 36 months) and 10.9 months (range, 2 to 49 months) in the cisplatin and gemcitabine arms, respectively. At first follow up, 68.8% in the cisplatin arm and 70% in the gemcitabine arm had achieved complete response (p=0.93). Similar response rates were noted in different stages in both arms. None of the patients except one developed grade 4 toxicity. Similar toxicity profiles were observed in both arms. Local disease control, distant disease free survival and overall survival was 68.8% vs. 70%, 93.8% vs. 85%, 68.8% vs. 60% in the cisplatin and gemcitabine arms, respectively. CONCLUSION: Weekly gemcitabine had similar disease control and tolerable toxicity profile with cisplatin. Gemcitabine may be used as an alternative to cisplatin in patients with compromised renal function.