Randomness assisted in-line holography with deep learning.

We propose and demonstrate a holographic imaging scheme exploiting random illuminations for recording hologram and then applying numerical reconstruction and twin image removal. We use an in-line holographic geometry to record the hologram in terms of the second-order correlation and apply the numerical approach to reconstruct the recorded hologram. This strategy helps to reconstruct high-quality quantitative images in comparison to the conventional holography where the hologram is recorded in the intensity rather than the second-order intensity correlation. The twin image issue of the in-line holographic scheme is resolved by an unsupervised deep learning based method using an auto-encoder scheme. Proposed learning technique leverages the main characteristic of autoencoders to perform blind single-shot hologram reconstruction, and this does not require a dataset of samples with available ground truth for training and can reconstruct the hologram solely from the captured sample. Experimental results are presented for two objects, and a comparison of the reconstruction quality is given between the conventional inline holography and the one obtained with the proposed technique.

Structured transmittance illumination coherence holography.

The coherence holography offers an unconventional way to reconstruct the hologram where an incoherent light illumination is used for reconstruction purposes, and object encoded into the hologram is reconstructed as the distribution of the complex coherence function. Measurement of the coherence function usually requires an interferometric setup and array detectors. This paper presents an entirely new idea of reconstruction of the complex coherence function in the coherence holography without an interferometric setup. This is realized by structured pattern projections on the incoherent source structure and implementing measurement of the cross-covariance of the intensities by a single-pixel detector. This technique, named structured transmittance illumination coherence holography (STICH), helps to reconstruct the complex coherence from the intensity measurement in a single-pixel detector without an interferometric setup and also keeps advantages of the intensity correlations. A simple experimental setup is presented as a first step to realize the technique, and results based on the computer modeling of the experimental setup are presented to show validation of the idea.

Design and development of high power RF amplifier for 88 in. room temperature cyclotron at Variable Energy Cyclotron Centre (VECC), Kolkata.

A tetrode based high power radio frequency (RF) amplifier has been designed, developed, and commissioned at Variable Energy Cyclotron Centre, Kolkata, India, for the 88-in. room temperature K130 cyclotron. The amplifier feeds power to a RF cavity based on the quarter-wave cantilever-type resonating structure to develop a high accelerating voltage for particle acceleration. The initial design of this amplifier was based on tetrode tube, which has already become obsolete. A new design of the RF amplifier has been made with a different tetrode of much lower power to satisfy the requirement of the cyclotron. This paper gives detailed insight into the various issues of the tetrode amplifier design and operational experience for the K130 cyclotron RF system.

An unexpected rash with gastroenteritis: erythema multiforme associated with campylobacter infection.

We present the first documented case of erythema multiforme following campylobacter gastroenteritis.

The short-term effects of Eudragit-L-coated prednisolone metasulphobenzoate (Predocol) on bone formation and bone mineral density in acute ulcerative colitis.

BACKGROUND: The aetiology of bone loss in ulcerative colitis is multifactorial, but corticosteroid treatment is an important risk factor. A novel formulation of Eudragit-L-coated prednisolone metasulphobenzoate (Predocol) has been developed, in order to deliver high mucosal levels of prednisolone within the colon but with little systemic absorption. The aim of this study was to investigate its efficacy, and short-term effects on bone formation and bone mineral density. METHODS: In a 12-week longitudinal study 13 patients with active colitis were treated with a reducing dose of Predocol. Disease activity scores were recorded and the bone formation marker osteocalcin was measured before, during and after treatment, with hip and spine bone mineral density assessed at baseline and after treatment. RESULTS: Eleven of the 13 patients completed the study. Compared with baseline, disease activity scores improved significantly after 4 weeks [difference in means, 6.9; 95% confidence interval (CI), 5.2, 8.7; P < 0.0001] and 12 weeks (difference in means, 5.7; 95% CI, 3.3, 8.2; P < 0.0001) of treatment. Osteocalcin did not fall compared with baseline [16.91 mg/l (95% CI, 12.70, 21.12)], after 4 weeks [13.67 mg/l (95% CI, 8.72, 18.60)] (difference in means, 3.25; 95% CI, 2.37, 8.87; P = 0.23) or 12 weeks [23.91 mg/l (95% CI, 16.10, 31.74)] (difference in means, 13.23; 95% CI, 2.45, 16.48; P = 0.13) of treatment. Similarly, bone mineral density at the hip [0.99 g/cm (95% CI, 0.90, 1.09)] did not change after 12 weeks of treatment [1.00 g/cm (95% CI, 0.89, 1.11)] (difference in means, 0.01; 95% CI, 0.25, 0.34; P = 0.74). Spine bone mineral density did not fall from pre-treatment levels [1.20 g/cm (95% CI, 1.11, 1.30)] after 12 weeks [1.19 g/cm (95% CI, 1.10, 1.29)] (difference in means, 0.01; 95% CI, 0.004, 0.01; P = 0.26). CONCLUSIONS: These results confirm that Predocol is effective treatment for acute ulcerative colitis and short courses of the steroid have no adverse effects on bone formation and bone mineral density. The encouraging results from this study suggest that Predocol may be a significant advance in preventing corticosteroid induced bone loss in ulcerative colitis.

Radio frequency cavity analysis, measurement, and calibration of absolute Dee voltage for K-500 superconducting cyclotron at VECC, Kolkata.

Variable Energy Cyclotron Centre has commissioned a K-500 superconducting cyclotron for various types of nuclear physics experiments. The 3-phase radio-frequency system of superconducting cyclotron has been developed in the frequency range 9-27 MHz with amplitude and phase stability of 100 ppm and ±0.2(0), respectively. The analysis of the RF cavity has been carried out using 3D Computer Simulation Technology (CST) Microwave Studio code and various RF parameters and accelerating voltages ("Dee" voltage) are calculated from simulation. During the RF system commissioning, measurement of different RF parameters has been done and absolute Dee voltage has been calibrated using a CdTe X-ray detector along with its accessories and known X-ray source. The present paper discusses about the measured data and the simulation result.

Precision phase control for the radio frequency system of K500 superconducting cyclotron at Variable Energy Cyclotron Centre, Kolkata.

Variable Energy Cyclotron Centre (VECC) has commissioned K500 Superconducting cyclotron (SCC) based on MSU and Texas A&M university cyclotrons. The radio frequency (RF) system of SCC has been commissioned with the stringent requirement of various RF parameters. The three-phase RF system of Superconducting cyclotron has been developed in the frequency range 9-27 MHz with amplitude and phase stability of 100 ppm and ±0.1°, respectively. The phase control system has the option to change the relative phase difference between any two RF cavities and maintain the phase stability within ±0.1° during round-the-clock cyclotron operation. The said precision phase loop consists of both analogue In-phase∕Quadrature modulator to achieve faster response and also Direct Digital Synthesis based phase shifter to achieve wide dynamic range as well. This paper discusses detail insights into the various issues of phase control for the K500 SCC at VECC, Kolkata.