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"Prasad, G"
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A novel and polarization insensitive triband absorber using a non-uniform design approach on a flexible material for X-band applications
To address the issue of satisfying absorption levels in the microwave X-band region, this study proposes a tri-band metasurface absorber that makes use of a new non-uniform technique. A unit cell is used to form the proposed absorber. This unit cell is printed on a jeans dielectric substrate, which has a dielectric constant of 2.2. copper material is chosen as a radiating patch for the proposed unit cell. The radiating patch contains different polygons with different sizes. The structure has been designed in four phases to have three absorption peaks. The structure that is being proposed is resonating at three different resonant frequencies, which are 9.98GHz, 10.43GHz, and 11.30GHz. Irrespective of polarization angles and mode of propagation, the structure produced absorptances as 95.1, 97.3, and 99.89, respectively for the corresponding resonant frequencies. The absorber that has been proposed possesses an electro-magnetic characteristic that is effective for microwave applications, particularly for satellite and radar telecommunications. Additionally, bending analysis confirms the robustness of the design under conformal conditions, making it suitable for practical X-band applications such as radar cross-section reduction, satellite communication systems and electromagnetic interference mitigation. This work contributes to SDG 9: United Nations Sustainable Development Goal 9 by advancing innovative, flexible electromagnetic absorber design for next-generation X-band applications.
Journal Article
CYP3A5 polymorphisms in renal transplant recipients: influence on tacrolimus treatment
Tacrolimus is a commonly used immunosuppressant after kidney transplantation. It has a narrow therapeutic range and demonstrates wide interindividual variability in pharmacokinetics, leading to potential underimmunosuppression or toxicity. Genetic polymorphism in CYP3A5 enzyme expression contributes to differences in tacrolimus bioavailability between individuals. Individuals carrying one or more copies of the wild-type allele *1 express CYP3A5, which increases tacrolimus clearance. CYP3A5 expressers require 1.5 to 2-fold higher tacrolimus doses compared to usual dosing to achieve therapeutic blood concentrations. Individuals with homozygous *3/*3 genotype are CYP3A5 nonexpressers. CYP3A5 nonexpression is the most frequent phenotype in most ethnic populations, except blacks. Differences between
genotypes in tacrolimus disposition have not translated into differences in clinical outcomes, such as acute rejection and graft survival. Therefore, although genotype-based dosing may improve achievement of therapeutic drug concentrations with empiric dosing, its role in clinical practice is unclear.
genotype may predict differences in absorption of extended-release and immediate-release oral formulations of tacrolimus. Two studies found that CYP3A5 expressers require higher doses of tacrolimus in the extended-release formulation compared to immediate release.
genotype plays a role in determining the impact of interacting drugs, such as fluconazole, on tacrolimus pharmacokinetics. Evidence conflicts regarding the impact of
genotype on risk of nephrotoxicity associated with tacrolimus. Further study is required.
Journal Article
Sustained freshening of Arabian Sea High Salinity Water induced by extreme precipitation events
In the northern Arabian Sea, high salinity levels are primarily sustained by year-round evaporation, driving the convective formation of Arabian Sea High Salinity Water (ASHSW) during the winter monsoon (November–February). Although precipitation has largely been discounted as a critical controlling mechanism for winter convection, recent years have seen a notable increase in extreme cyclones over the Arabian Sea, particularly in post-monsoon cyclones (September–December) since 2014. However, the extent to which these cyclone-induced freshwater inputs disrupt the region’s freshwater balance (evaporation – precipitation) and impact ASHSW formation remains unclear. Here, we present observational evidence supported by a suite of model simulation experiments, revealing a significant weakening in ASHSW formation triggered and sustained by extreme tropical cyclones. The addition of freshwater reduces the density of high-salinity water, augmenting stratification and disrupting the convective sinking process, ultimately limiting the depth of convective mixing. These findings underscore the profound implications of extreme cyclone-induced freshwater inputs.
In the northern Arabian Sea, excess evaporation sustains Arabian Sea High Salinity Water formation (ASHSW). This study shows that extreme precipitation events disrupt ASHSW by increasing freshwater input, enhancing stratification, and weakening winter convective mixing.
Journal Article
Diagnosis and Management of Barrett's Esophagus: An Updated ACG Guideline
Barrett's esophagus (BE) is a common condition associated with chronic gastroesophageal reflux disease. BE is the only known precursor to esophageal adenocarcinoma, a highly lethal cancer with an increasing incidence over the last 5 decades. These revised guidelines implement Grading of Recommendations, Assessment, Development, and Evaluation methodology to propose recommendations for the definition and diagnosis of BE, screening for BE and esophageal adenocarcinoma, surveillance of patients with known BE, and the medical and endoscopic treatment of BE and its associated early neoplasia. Important changes since the previous iteration of this guideline include a broadening of acceptable screening modalities for BE to include nonendoscopic methods, liberalized intervals for surveillance of short-segment BE, and volume criteria for endoscopic therapy centers for BE. We recommend endoscopic eradication therapy for patients with BE and high-grade dysplasia and those with BE and low-grade dysplasia. We propose structured surveillance intervals for patients with dysplastic BE after successful ablation based on the baseline degree of dysplasia. We could not make recommendations regarding chemoprevention or use of biomarkers in routine practice due to insufficient data.
Journal Article
Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea
During winter, the dry, cool air brought by prevailing northeasterly trade winds leads to surface ocean heat loss and convective mixing in the northern Arabian Sea. The current paradigm is that the convective mixing process leads to the injection of nutrients up into the surface waters and exert a dominant control on winter productivity. By combining a variety of observations, atmospheric reanalysis and model simulations, we unraveled the processes responsible for the observed year-to-year chlorophyll-
a
variations in the northern Arabian Sea. Our findings suggest that the atmospheric high-pressure systems that traverse the northern Arabian Sea every winter and spring disrupt winter convective mixing and create an array of environmental conditions conducive to trigger phytoplankton blooms. The arrival of an atmospheric high with the anticyclonic flow in the northern Arabia Sea sets the stage for a sequence of events culminating in intermittent mixed-layer restratification due to buoyancy gain aided by increased specific humidity, supplemented with abundant sunlight due to clear skies, and suppressed turbulent mixing owing to weak winds. These combined with the mixed layer that is shallower than the euphotic zone and the influx of nutrients into the euphotic zone brought by convective mixing between the calm periods, caused unprecedented high concentrations of chlorophyll-
a
in the northern Arabian Sea.
Journal Article
Review of adjuvants to local anesthetics in peripheral nerve blocks: Current and future trends
In recent anesthetic practice, peripheral nerve blocks (PNBs) are used extensively for surgical anesthesia and nonsurgical analgesia. PNBs offer many benefits over other anesthetic techniques in a certain population of patients, and in some specific clinical setting, that may contribute to faster and safer pain relief, increased patient satisfaction, reduced hospital stay, and decreased overall healthcare cost. The technique involves the injection of the anesthetic in the vicinity of a specific nerve or bundle of nerves to block the sensation of pain transmitting to a specific portion of the body. However, the length of analgesia when a single anesthetic is used for PNB may not last long. Therefore, the practice of adding an additional agent called adjuvant has been evolved to prolong the analgesic effect. There are many such adjuvants available that are clinically being used for this purpose imparting great efficacy and safety to the anesthetic process. The adjuvants molecules are generally classified as opioids, alpha-2 agonist, steroids, etc. Most of them are safe to use and show little or no adverse event related to neurotoxicity and tissue damage. Although there is extensive use of such adjuvants in the clinical field, none of the molecules is approved by the FDA and is used as an off-label drug. The risk to benefit ratio must be assessed while using such an agent. This review will try to delineate the basic need of adjuvant in peripheral nerve block and will discuss the advantages and limitations of using different adjuvants and will discuss the future prospect of such application.
Journal Article
Post-operative analgesia techniques after total knee arthroplasty: A narrative review
Post-operative knee pain management has become a challenge to provide early relief and pain-free postoperative care to the patient. The major objectives of post-operative analgesic treatment are to reduce opioid requirements, post-operative pain, and adverse events related to opioid intake. This narrative review aimed to document post-operative analgesia techniques after total knee arthroplasty (TKA). The traditional approach involved high-dose opioid-based regimen, though opioid is considered strong analgesic, but are associated with a number of unwanted side effects to seek for alternative techniques. The role of sciatic nerve block in TKA pain is doubtful. Femoral Nerve Block (FNB) is still considered as the gold standard; however, FNB is associated with quadriceps weakness and risk of fall and sciatic block with foot drop. To overcome these drawback more distal nerve block techniques has evolved, namely saphenous nerve block in adductor canal, selective tibial which are claimed to provide comparable analgesia to that of femoral and sciatic nerve block. The combination of pre-emptive and multi-modal analgesia and technically well-delivered regional nerve blocks and postoperative physical therapy are an essential component which not only minimize the side effects of traditional opioid-based analgesia but also speed up functional recovery, increases patient satisfaction, and reduces the overall length of hospitalization and cost.
Journal Article
West Nile Virus in a changing climate: epidemiology, pathology, advances in diagnosis and treatment, vaccine designing and control strategies, emerging public health challenges – a comprehensive review
West Nile Virus (WNV), first identified in Uganda in 1937, remains a significant global health threat, adapting across diverse ecosystems and expanding geographically, particularly into temperate regions of Europe and North America. This review provides a comprehensive exploration of the latest insights and challenges in WNV management, focusing on epidemiological trends, molecular advancements, and public health implications. Recent data highlight WNV's expansion, driven by climate changes such as milder winters and longer warm seasons that increase mosquito activity and enable the virus to overwinter within mosquito populations. This facilitates year-round transmission and challenges current control strategies. Molecularly, advancements in genomic and proteomic technologies have deepened our understanding of WNV's replication and pathogenesis, identifying new therapeutic targets and improving diagnostic methods. However, the absence of an approved human vaccine leaves management dependent on supportive care, particularly for severe neurological cases. Effective vector control remains crucial, with innovative strategies including genetically modified mosquitoes and novel insecticides being pivotal. Furthermore, environmental factors like climate change and urbanization are altering vector behaviors and WNV transmission dynamics, necessitating adaptive public health strategies to manage these evolving threats. The review underscores the need for ongoing research, vaccine and therapeutic development, and enhanced public health infrastructures to better respond to WNV challenges. It stresses the critical role of integrating scientific research, public health policy, and community engagement to effectively address the persistent threat of WNV.
Journal Article