Inherent properties of binary tetrahedral semiconductors

A new approach utilising the concept of ionic charge theory has been used to explain the inherent properties such as lattice thermal conductivity and bulk modulus of 3,5 and 2,6 semiconductors. The lattice thermal conductivity of these semiconductors exhibit a linear relationship when plotted on a log scale against the nearest neighbour distance but fall on two straight lines according to the product of the ionic charge of the compounds. On the basis of this result a simple relationship of lattice thermal conductivity with bulk modulus is proposed and used to estimate the bulk modulus of these semiconductors. A fairly good agreement has been found between the experimantal and calculated values of these parameters for zinc blende structured solids.Comment: 6 pages, 19 reference

Development and validation of a new glaucoma screening test using temporally modulated flicker

Purpose Describing the psychometric characteristics and diagnostic accuracy of the Accelerator 4‐Alternative Forced‐Choice Flicker Test prototype (A4FTp) for detecting chronic open angle glaucoma (COAG). Methods A4FTp measures temporally‐modulated flicker thresholds in regions of the visual field with high susceptibility to glaucomatous loss. We initially evaluated its psychometric properties on 20 normals (aged 33.8 ± 8.5 years) who were tested multiple times over a period of 3 months. All subjects underwent four repetitions for shorter (T8) and longer (T12) staircase termination criteria, to determine the most suitable threshold criterion. Four randomly selected subjects underwent a total of 10 repetitions to study test‐retest repeatability and learning effects. To determine its diagnostic accuracy, one eye of 40 participants with COAG and 38 normal controls were tested with the A4FTp in comparison with the Frequency Doubling Technology (FDT; C20‐5 programme) and iVue Spectral Domain Optical Coherence Tomography (SD‐OCT). Tests were conducted in a random order with results masked to the clinician conducting the reference ophthalmic examination. The accuracy of each test was determined by analysis of the area under the receiver operator characteristic curve (AUROC). Results A4FTp flicker thresholds were stable, with standard deviations of only 0.52 decilog (dL) for T8, increasing to 1.32 dL for T12, and no significant flicker sensitivity threshold improvement over the 10 repeat runs. T8 was superior to T12 on several other measures, so it was used for the remaining comparisons. In terms of diagnostic accuracy, the mean AUROC for the three tests were A4FTp [T8 criterion; 0.82, 95% confidence interval (0.73–0.92)]; SD‐OCT [any RNFL parameter p < 1% level; 0.90 (0.83–0.97)]; and FDT [one or more locations missed at p < 5% level; 0.91 (0.82–0.96)]. There was no statistical difference in AUROC between A4FTp and SD‐OCT (p = 0.18) or FDT (p = 0.12). The A4FTp test duration averaged just over 2 min per eye, taking approximately one‐third of the time for completion of the HFA SITA 24‐2 algorithm (conducted as part of the reference examination) and twice the time for the suprathreshold FDT. Conclusion Test accuracy for the A4FTp was comparable to those of the FDT and SD‐OCT for the detection of COAG. Time taken to complete the A4FTp was relatively short and initial results are promising. With further refinement, the A4FTp could have a future role in glaucoma detection

Role of advanced technology in the detection of sight-threatening eye disease in a UK community setting.

Background/aims: To determine the performance of combinations of structural and functional screening tests in detecting sight-threatening eye disease in a cohort of elderly subjects recruited from primary care. Methods: 505 subjects aged ≥60 years underwent frequency doubling technology (FDT) perimetry, iVue optical coherence tomography (iWellness and peripapillary retinal nerve fibre layer (RNFL) scans) and intraocular pressure with the Ocular Response Analyzer, all performed by an ophthalmic technician. The reference standard was a full ophthalmic examination by an experienced clinician who was masked to the index test results. Subjects were classified as presence or absence of sight-threatening eye disease (clinically significant cataract, primary open-angle glaucoma, intermediate or advanced age-related macular degeneration and significant diabetic retinopathy). Univariate and multivariate logistic regression analyses were used to determine the association between abnormal screening test results and the presence of sight-threatening eye disease. Results: 171 subjects (33.8%) had one or more sight-threatening eye diseases. The multivariate analysis found significant associations with any of the target conditions for visual acuity of <6/12, an abnormal FDT and peripapillary RNFL thickness outside the 99% normal limit. The sensitivity of this optimised screening panel was 61.3% (95% CI 53.5 to 68.7), with a specificity of 78.8% (95% CI 74.0 to 83.1), a positive predictive value of 59.5% (95% CI 53.7 to 65.2) and an overall diagnostic accuracy of 72.9% (95% CI 68.8 to 76.8). Conclusions: A subset of screening tests may provide an accurate and efficient means of population screening for significant eye disease in the elderly. This study provides useful preliminary data to inform the development of further larger, multicentre screening studies to validate this screening panel

Optical properties of Yb3+ doped ZnO/MgO nanocomposites

[EN] Yb3þ doped ZnO/MgO nanocomposite were prepared by combustion synthesis method. The samples were further heated to 1000 °C to improve their crystallinity and photoluminescent efficiency. The concentrations of Yb3þ and Mg2þ were varied between 1–2% and 5–70% respectively in prepared samples. The nano-powders were characterized by Scanning Electron Microscopy and X-ray Diffraction for morphology and structural determination. XRD studies have revealed the wurtzite structure for MgxZn1"xO for Mg concentrations below 30%. Higher concentrations of Mg results in Yb3þ doped ZnO/ MgO nanocomposite containing three phases; the wurzite hexagonal phase typical of ZnO, the cubic phase of MgO and a small amount of cubic Yb2O3 phase. As expected, the amount of cubic phase in nanopowders increased with the increase of Mg concentration in ZnO. The crystallite size of ZnO/MgO composites decreased from 55 nm to 30 nm with increase of Mg content. SEM images of Yb3þ doped ZnO/MgO nanocomposite with higher Mg content (450%) showed clearly distinct hexagonal and cubical shaped nano-particles. Photoluminescent emission showed a broad band in the range (435 nm to 700 nm). Pure ZnO nano-phosphor showed an emission peak around 545 nm, which is blue shifted with Mg content. The photoluminescence intensity increased with increase of Mg content in ZnO and it became maximum with 30% Mg concentration. Time resolved decay curves of photoluminescence indicated decay time in microsecond time scaleThis work was supported by Ministerio de Economia y Competitividad (ENE2013-46624-C4-4-R), Generalitat Valenciana (PROMETEUS-II/2014/044) and the European Commission through NanoCIS project (FP7-PEOPLE-2010-IRSES ref. 269279).Marí, B.; Singh, KC.; Verma, N.; Jindal, J. (2016). Optical properties of Yb3+ doped ZnO/MgO nanocomposites. Ceramics International. 42(11):13018-13023. https://doi.org/10.1016/j.ceramint.2016.05.079S1301813023421

TableHop: an actuated fabric display using transparent electrodes

We present TableHop, a tabletop display that provides controlled self-actuated deformation and vibro-tactile feedback to an elastic fabric surface while retaining the ability for high-resolution visual projection. The TableHop surface is made of a highly stretchable pure spandex fabric that is electrostatically actuated using electrodes mounted on its underside. We use transparent indium tin oxide electrodes and high-voltage modulation to create controlled surface deformations. This setup actuates pixels and creates deformations in the fabric up to $\pm$ 5mm. Since the electrodes are transparent, the fabric surface can function as a diffuser for rear-projected visual images, and avoid occlusion by users. Users can touch and interact with the fabric to create expressive interactions as with any fabric based shape-changing interface. By using frequency modulation in the high-voltage circuit, we can also create localised tactile sensations on the user's finger-tip when touching the surface. We provide detailed simulation results of the shape of the surface deformation and the frequency of the haptic vibrations. These results can be used to build prototypes of different sizes and form-factors. We finally create a working prototype of TableHop that has 30$\times$40 cm surface area and uses a grid of 3$\times$3 transparent electrodes. Our prototype uses a maximum of 2.2 mW and can create tactile vibrations of up to 20 $Hz$. TableHop can be scaled to large interactive surfaces and integrated with other objects and devices. TableHop will improve user interaction experience on 2.5D deformable displays

Luminescence properties of the Eu2+ /Eu3 + activated Barium aluminate phosphors with varies Gd3+ concentration

This is an Accepted Manuscript of an article published by Taylor & Francis in Transactions of the Indian Ceramic Society on 2015, available online: http://www.tandfonline.com/10.1080/0371750X.2015.1082932[EN] BaAl2O4:Eu2(+)/Eu3(+) (1mol %) co-doped with varying concentrations of Gd3(+) (1, 2, 5 and 10mol%) were prepared by combustion synthesis method at 600 degrees C. All the compositions were investigated for their structural and photoluminescence properties. Samples prepared in open atmosphere showed the presence of both Eu3(+) and Eu2(+) states which indicates the reduction of Eu3(+) to Eu2(+) during the preparation of these compounds. The prepared materials at 600 degrees C showed high intense broad peaks around 498nm corresponding to Eu2(+) and small peaks in the red region which are attributed to the presence of Eu3(+). In the 1000 degrees C annealed compounds, the intensity of the peak at 498nm got increased. The intensity of this broad band for BaAl2O4:Eu2(+)/Eu3(+)(1mol%):Gd3(+)(1mol%) was three times than that of BaAl2O4:Eu2(+)/Eu3(+)(1mol%). Thus second rare earth ion (Gd3(+)) acted as a good sensitizer and enhanced the photoluminescence intensity. The XRD spectra revealed the presence of hexagonal phase of BaAl2O4 as main phase and a small amount of a mixed phase Ba O! 6.6 Al2O3. Doping of Eu3(+), Gd3(+) did not change the crystalline structure of barium aluminate (BaAl2O4).This work was supported by the Generalitat Valenciana through grant PROMETEUS 2009/2013 and the European Commission through Nano CIS project (FP7-PEOPLE2010-IRSES ref. 269279).Marí, B.; Singh, K.; Verma, N.; Mollar García, MA.; Jindal, J. (2015). Luminescence properties of the Eu2+ /Eu3 + activated Barium aluminate phosphors with varies Gd3+ concentration. Transactions of the Indian Ceramic Society. 74(3):157-161. https://doi.org/10.1080/0371750X.2015.1082932S15716174

Luminescence Properties of CaAl2O4:Eu3+, Gd3+ Phosphors Synthesized by Combustion Synthesis Method

[EN] CaAl2O4:Eu3+ (1 mol.%) co-doped with varying concentration of Gd3+ (1, 2, 5, and 10 mol.%) were prepared by combustion synthesis method at 600 C and further annealed at 1000 ºC. All the compositions were investigated for their structural and photoluminescence properties. It was observed that both states of europium i.e. Eu3+ and Eu2+ were present and ratio of these states changes on heating at 1000 ºC. The materials synthesized at 600 ºC showed high intense peak around 440 nm due to presence of Eu2+ and less intense peaks in the red region which were due to presence of Eu3+. On annealing the compounds at 1000 ºC, intensity of peak around 440 nm decreases and intensity of peaks in the red region increases significantly. The 5D0 !7 F3 transition due to Eu3+ at 657 nm appears as the highest intensity peak. All co-doped samples annealed at 1000 ºC showed the higher intensity than the mono doped sample which is due to energy transfer from the Gd3+ to Eu3+. The second rare-earth ion (Gd3+) acts as sensitizer and enhances the photoluminescence intensity. The X-ray diffraction spectra reveal the monoclinic phase of CaAl2O4 in all the samples which showed that Eu3+ and Gd3+ do not change the crystalline structure of calcium aluminate.This work was supported by the Generalitat Valenciana through grant PROMETEUS 2009/2013 and the European Commission through Nano CIS project (FP7-PEOPLE-2010-IRSES ref. 269279).This work was supported by the Generalitat Valenciana through grant PROMETEUS 2009/2013 and the European Commission through Nano CIS project (FP7- PEOPLE-2010-IRSES ref. 269279).Verma, N.; Singh, K.; Marí, B.; Mollar García, MA.; Jindal, J. (2017). Luminescence Properties of CaAl2O4:Eu3+, Gd3+ Phosphors Synthesized by Combustion Synthesis Method. Acta Physica Polonica A. 132(4):1261-1264. https://doi.org/10.12693/APhysPolA.132.1261S12611264132

Pattern of adverse drug reactions with chemotherapeutic drugs in a tertiary care hospital of North India: a retrospective study

Background: Adverse drug reactions are important causes of mortality and morbidity in the patients. Early detection, evaluation and monitoring of ADRs is essential to improve public health. Methods: This was an observational, non-interventional and retrospective study conducted at the ADR monitoring centre of a tertiary care hospital of North India. Suspected ADR forms reported over a period of 4 years involving at least one chemotherapeutic drug with at least one dose were analyzed. Results: A total of 261 chemotherapeutic drugs associated ADRs were analyzed. Out of these, maximum numbers of ADRs were reported by males (54%). Maximum reporting was done by Skin and VD department (37.93%). Causality assessment was probable in maximum number of cases (54%). Most common ADRs were skin rashes (21.46%), followed by jaundice, urticaria and fixed drug eruptions. Maximum ADRs were suspected to be caused by Anti tubercular drugs (31.42%) followed by anticancer drugs (14.56%). Conclusions: ADRs due to antibiotics and anticancer drugs is a significant health problem