Uric acid levels in chronic kidney disease- a hospital based cross-sectional study in RIMS, Ranchi, Jharkhand

Background: Uric acid is the final end product of purine metabolism and is excreted mainly by proximal tubules of the kidney. Raised uric acid levels may lead to proximal tubular injury, endothelial dysfunction, oxidative stress and intra renal inflammation in patients with normal renal function. Uric acid has been deemed as an independent risk factor for progression of CKD. Aim was to study the uric acid levels in different stages of chronic kidney disease and its association with age, sex and other co-morbidities.Methods: 140 patients of chronic kidney disease admitted in RIMS, Ranchi were included in this study and their serum uric acid level were analyzed. Uric acid level more than 7 mg/dl was considered as hyperuricemia. The study was approved by the Institutional Ethics Committee, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India. Informed consent was taken from every patient included in the study.Results: Median age±SD was 55±13.47 years (IQR: 45,65; Range: 19-80). Mean±SD uric acid levels in stage 3 CKD was 4.4±1.9 mg/dl, stage 4 CKD was 6.5±4.1 mg/dl, stage 5 CKD was 8.8±3.1 mg/dl (p<0.05). Females were 31.4% and males were 69.6%. Male to female ratio was 2.2:1. The prevalence of hyperuricemia was 50% in females and 66.6% in males.Conclusions: Hyperuricemia is common among CKD patients and more common among males. Uric acid levels increase with progressive decline in eGFR. Monitoring and follow-up of such patients by may lead to delay in onset and progression of complications of CKD

Multivalency in lectins-a crystallographic,modelling and light-scattering study involving peanut lectin and a bivalent ligand

Multivalency is believed to be important in the activity of lectins, although definitive structural studies on it have been few and far between. We have now studied the complexation of tetravalent peanut lectin with a synthetic compound containing two terminal lactose moieties, using a combination of crystallography, dynamic light scattering and modelling. Light scattering indicates the formation of an apparent dimeric species and also larger aggregates of the tetrameric lectin in the presence of the bivalent ligand. Crystals of presumably crosslinked lectin molecules could be obtained. They diffract poorly, but X-ray data from them are good enough to define the positions of the lectin molecules. Extensive modelling on possible crosslinking modes of protein molecules by the ligand indicated that systematic crosslinking could lead to crystalline arrays. The studies also provided a rationale for crosslinking in the observed crystal structure. The results obtained provide further insights into the general problem of multivalency in lectins. They indicate that crosslinking involving multivalent lectins and multivalent carbohydrates could lead to an ensemble of a finite number of distinct periodic arrays rather than a unique array

A high-precision interpolation method for pulsed radio signals from cosmic-ray air showers

Analysis of radio signals from cosmic-ray induced air showers has been shown to be a reliable method to extract shower parameters such as primary energy and depth of shower maximum. The required detailed air shower simulations take 1 to 3 days of CPU time per shower for a few hundred antennas. With nearly 60,000 antennas envisioned to be used for air shower studies at the Square Kilometre Array (SKA), simulating all of these would come at unreasonable costs. We present an interpolation algorithm to reconstruct the full pulse time series at any position in the radio footprint, from a set of antennas simulated on a polar grid. Relying on Fourier series representations and cubic splines, it significantly improves on existing linear methods. We show that simulating about 200 antennas is sufficient for high-precision analysis in the SKA era, including e.g. interferometry which relies on accurate pulse shapes and timings. We therefore propose the interpolation algorithm and its implementation as a useful extension of radio simulation codes, to limit computational effort while retaining accuracy

Constraining the cosmic-ray mass composition by measuring the shower length with SKA

The current generation of air shower radio arrays has demonstrated that the atmospheric depth of the shower maximum Xmax can be reconstructed with high accuracy. These experiments are now contributing to mass composition studies in the energy range where a transition from galactic to extragalactic cosmic-ray sources is expected. However, we are still far away from an unambiguous interpretation of the data. Here we propose to use radio measurements to derive a new type of constraint on the mass composition, by reconstructing the shower length L. The low-frequency part of the Square Kilometer Array will have an extremely high antenna density of roughly 60.000 antennas within one square kilometer, and is the perfect site for high-resolution studies of air showers. In this contribution, we discuss the impact of being able to reconstruct L, and the unique contribution that SKA can make to cosmic-ray science.</p

A high-precision interpolation method for pulsed radio signals from cosmic-ray air showers

Analysis of radio signals from cosmic-ray induced air showers has been shown to be a reliable method to extract shower parameters such as primary energy and depth of shower maximum. The required detailed air shower simulations take 1 to 3 days of CPU time per shower for a few hundred antennas. With nearly $60,000$ antennas envisioned to be used for air shower studies at the Square Kilometre Array (SKA), simulating all of these would come at unreasonable costs. We present an interpolation algorithm to reconstruct the full pulse time series at any position in the radio footprint, from a set of antennas simulated on a polar grid. Relying on Fourier series representations and cubic splines, it significantly improves on existing linear methods. We show that simulating about 200 antennas is sufficient for high-precision analysis in the SKA era, including e.g. interferometry which relies on accurate pulse shapes and timings. We therefore propose the interpolation algorithm and its implementation as a useful extension of radio simulation codes, to limit computational effort while retaining accuracy.Comment: 19 pages, 12 figures. Submitted for publication in JINST (Journal of Instrumentation

Constraining the cosmic-ray mass composition by measuring the shower length with SKA

The current generation of air shower radio arrays has demonstrated that the atmospheric depth of the shower maximum Xmax can be reconstructed with high accuracy. These experiments are now contributing to mass composition studies in the energy range where a transition from galactic to extragalactic cosmic-ray sources is expected. However, we are still far away from an unambiguous interpretation of the data. Here we propose to use radio measurements to derive a new type of constraint on the mass composition, by reconstructing the shower length L. The low-frequency part of the Square Kilometer Array will have an extremely high antenna density of roughly 60.000 antennas within one square kilometer, and is the perfect site for high-resolution studies of air showers. In this contribution, we discuss the impact of being able to reconstruct L, and the unique contribution that SKA can make to cosmic-ray science.</p