The 25-hydroxyvitamin D level in Kidney Transplant Recipients and Its Association With Renal Function and Other Cardio-Metabolic Risk Markers.

BACKGROUND: Vitamin D is the main hormone that plays a critical role in controlling mineral homeostasis. Transplant recipients frequently have altered levels of 25-hydroxyvitamin D (25[OH] D) and 1, 25-hydroxyvitamin (1, 25[OH] D). OBJECTIVES: To explore the status of vitamin D level in renal allograft recipients and its association with renal function and cardio-metabolic risk markers. METHODS: One hundred two adult kidney transplant recipients (KTRs) were included. Clinical history and information about transplantation and immunosuppression were recorded. Blood and urine samples were collected for relevant laboratory tests, including chronic kidney disease (CKD)-mineral and bone disorder markers (Ca, PO4, and 25[OH] D). RESULTS: The mean age was 35 ± 8 years, with a male/female ratio of 89/11%. The transplant duration was 34 ± 26 (4.5-112) months. All donors involved were living-related: fathers comprised 44%, wives 16%, sisters 13%, mothers 11%, and the others 16% (ie, brothers, sons, daughters, uncles, aunts). The immunosuppression regimen included prednisolone and tacrolimus in all, with mycophenolate mofetil in 96%. The estimated glomerular filtration rate showed CKD distribution from stage 1 to 5 in 6%, 29%, 44%, 15%, and 6%, respectively. Vitamin D level was lower in 22% (<20 ng/mL), insufficient (20-30 ng/mL) in 48%, and adequate (>30 ng/mL) in 30%. We compared different clinical and laboratory variables in 3 different vitamin D groups but found no difference in cardio-renal risk factors (P = Not Significant). Similarly, no correlation was seen between vitamin D levels and other clinical and metabolic factors. CONCLUSION: According to conventional cutoffs, the vitamin D (25[OH] D) level is inadequate in 70% of renal allograft recipients. The hormone level has no apparent association with renal function and major cardio-metabolic risk factors.

Performance Analysis of Linearly Arranged Concentric Circular Antenna Array with Low Sidelobe Level and Beamwidth Using Robust Tapering Technique.

In this research, a novel antenna array named Linearly arranged Concentric Circular Antenna Array (LCCAA) is proposed, concerning lower beamwidth, lower sidelobe level, sharp ability to detect false signals, and impressive SINR performance. The performance of the proposed LCCAA beamformer is compared with geometrically identical existing beamformers using the conventional technique where the LCCAA beamformer shows the lowest beamwidth and sidelobe level (SLL) of 12.50° and -15.17 dB with equal elements accordingly. However, the performance is degraded due to look direction error, for which robust techniques, fixed diagonal loading (FDL), optimal diagonal loading (ODL), and variable diagonal loading (VDL), are applied to all the potential arrays to minimize this problem. Furthermore, the LCCAA beamformer is further simulated to reduce the sidelobe applying tapering techniques where the Hamming window shows the best performance having 17.097 dB less sidelobe level compared to the uniform window. The proposed structure is also analyzed under a robust tapered (VDL-Hamming) method which reduces around 69.92 dB and 48.39 dB more sidelobe level compared to conventional and robust techniques. Analyzing all the performances, it is clear that the proposed LCCAA beamformer is superior and provides the best performance with the proposed robust tapered (VDL-Hamming) technique.