Electrophysiological Characterization of Subclinical and Overt Hypertrophic Cardiomyopathy by Magnetic Resonance Imaging-Guided Electrocardiography

BACKGROUND

Ventricular arrhythmia in hypertrophic cardiomyopathy (HCM) relates to adverse structural change and genetic status. Cardiovascular magnetic resonance (CMR)-guided electrocardiographic imaging (ECGI) noninvasively maps cardiac structural and electrophysiological (EP) properties.

OBJECTIVES

The purpose of this study was to establish whether in subclinical HCM (genotype [G]+ left ventricular hypertrophy [LVH]-), ECGI detects early EP abnormality, and in overt HCM, whether the EP substrate relates to genetic status (G+/G-LVH+) and structural phenotype.

METHODS

This was a prospective 211-participant CMR-ECGI multicenter study of 70 G+LVH-, 104 LVH+ (51 G+/53 G-), and 37 healthy volunteers (HVs). Local activation time (AT), corrected repolarization time, corrected activation-recovery interval, spatial gradients (GAT/GRTc), and signal fractionation were derived from 1,000 epicardial sites per participant. Maximal wall thickness and scar burden were derived from CMR. A support vector machine was built to discriminate G+LVH- from HV and low-risk HCM from those with intermediate/high-risk score or nonsustained ventricular tachycardia.

RESULTS

Compared with HV, subclinical HCM showed mean AT prolongation (P = 0.008) even with normal 12-lead electrocardiograms (ECGs) (P = 0.009), and repolarization was more spatially heterogenous (GRTc: P = 0.005) (23% had normal ECGs). Corrected activation-recovery interval was prolonged in overt vs subclinical HCM (P < 0.001). Mean AT was associated with maximal wall thickness; spatial conduction heterogeneity (GAT) and fractionation were associated with scar (all P < 0.05), and G+LVH+ had more fractionation than G-LVH+ (P = 0.002). The support vector machine discriminated subclinical HCM from HV (10-fold cross-validation accuracy 80% [95% CI: 73%-85%]) and identified patients at higher risk of sudden cardiac death (accuracy 82% [95% CI: 78%-86%]).

CONCLUSIONS

In the absence of LVH or 12-lead ECG abnormalities, HCM sarcomere gene mutation carriers express an aberrant EP phenotype detected by ECGI. In overt HCM, abnormalities occur more severely with adverse structural change and positive genetic status.

Technical development and feasibility of a reusable vest to integrate cardiovascular magnetic resonance with electrocardiographic imaging

BACKGROUND

Electrocardiographic imaging (ECGI) generates electrophysiological (EP) biomarkers while cardiovascular magnetic resonance (CMR) imaging provides data about myocardial structure, function and tissue substrate. Combining this information in one examination is desirable but requires an affordable, reusable, and high-throughput solution. We therefore developed the CMR-ECGI vest and carried out this technical development study to assess its feasibility and repeatability in vivo.

METHODS

CMR was prospectively performed at 3T on participants after collecting surface potentials using the locally designed and fabricated 256-lead ECGI vest. Epicardial maps were reconstructed to generate local EP parameters such as activation time (AT), repolarization time (RT) and activation recovery intervals (ARI). 20 intra- and inter-observer and 8 scan re-scan repeatability tests.

RESULTS

77 participants were recruited: 27 young healthy volunteers (HV, 38.9 ± 8.5 years, 35% male) and 50 older persons (77.0 ± 0.1 years, 52% male). CMR-ECGI was achieved in all participants using the same reusable, washable vest without complications. Intra- and inter-observer variability was low (correlation coefficients [rs] across unipolar electrograms = 0.99 and 0.98 respectively) and scan re-scan repeatability was high (rs between 0.81 and 0.93). Compared to young HV, older persons had significantly longer RT (296.8 vs 289.3 ms, p = 0.002), ARI (249.8 vs 235.1 ms, p = 0.002) and local gradients of AT, RT and ARI (0.40 vs 0.34 ms/mm, p = 0,01; 0.92 vs 0.77 ms/mm, p = 0.03; and 1.12 vs 0.92 ms/mm, p = 0.01 respectively).

CONCLUSION

Our high-throughput CMR-ECGI solution is feasible and shows good reproducibility in younger and older participants. This new technology is now scalable for high throughput research to provide novel insights into arrhythmogenesis and potentially pave the way for more personalised risk stratification.

CLINICAL TRIAL REGISTRATION

Title: Multimorbidity Life-Course Approach to Myocardial Health-A Cardiac Sub-Study of the MRC National Survey of Health and Development (NSHD) (MyoFit46). National Clinical Trials (NCT) number: NCT05455125. URL: https://clinicaltrials.gov/ct2/show/NCT05455125?term=MyoFit&draw=2&rank=1.

Delayed-enhancement cardiac magnetic resonance imaging detects disease progression in patients with mitral valve disease and atrial fibrillation

Objectives

The mechanism by which mitral valve (MV) disease leads to atrial fibrillation (AF) remains poorly understood. Delayed-enhancement cardiac magnetic resonance imaging (DE-MRI) has been used to assess left atrial (LA) fibrosis in patients with lone AF before catheter ablation; however, few studies have used DE-MRI to assess MV-induced LA fibrosis in patients with or without AF undergoing MV surgery.

Methods

Between March 2018 and September 2022, 38 subjects were enrolled; 15 age-matched controls, 14 patients with lone mitral regurgitation (MR), and 9 patients with MR and AF (MR + AF). Indexed LA volume, total LA wall, and regional LA posterior wall (LAPW) enhancement were defined by the DE-MRI. One-way analysis of variance was performed.

Results

LA volume and LA enhancement were associated (r = 0.451, P = .004). LA volume differed significantly between controls (37.1 ± 10.6 mL) and patients with lone MR (71.0 ± 35.9, P = .020 and controls and patients with MR + AF (99.3 ± 47.4, P < .001). The difference in LA enhancement was significant between MR + AF (16.7 ± 9.6%) versus controls (8.3 ± 3.9%, P = .006) and MR + AF versus lone MR (8.0 ± 4.8%, P = .004). Similarly, the was significantly more LAPW enhancement in the MR + AF (17.5 ± 8.7%) versus control (9.2 ± 5.1%, P = .011) and MR + AF versus lone MR (9.8 ± 6.0%, P = .020).

Conclusions

Patients with MR + AF had significantly more total and LAPW fibrosis compared with both controls and lone MR. Volume and delayed enhancement were associated, but there was no difference between MR and MR + AF.

An intelligent fuzzy-particle swarm optimization supervisory-based control of robot manipulator for industrial welding applications

The propensity of manufacturers to produce goods at affordable cost, with more accuracy, and at a faster rate force them to search for novel solutions, such as deploying robots in place of people in a sector that can accommodate their needs. Welding is one of the most crucial processes in the automotive industry. This process is time-consuming, subject to error, and demands skilled professionals. The robotic application can improve this area of production and quality. Other industries, such as painting and material handling, can also profit from the use of robots. This work describes the fuzzy DC linear servo controller, which functions as a robotic arm actuator. Robots have been widely employed in most productive sectors in recent years, including assembly plates, welding, tasks at higher temperatures, etc. Controlling a robot accurately is a difficult undertaking as a robot is very nonlinear with many joints that are often organized and unstructured. To carry out the effective task, an effective PID control based on fuzzy logic has been employed together with the method of Particle Swarm Optimization (PSO) approach for the estimate of the parameter. This offline technique determines the lowest number of optimal robotic arm control parameters. To verify the controller design with computer simulation, a comparative assessment of controllers is given by means of a fuzzy surveillance controller with PSO which improves the parameter gain to provide a rapid climb, a smaller overflow, no steady condition error signal, and effective torque control of the robot arm.

Finite element analysis of fractured femur bone with prosthetic bone plates using ANSYS software

Bones are living tissues made of calcium and phosphorus among other elements. In the early years, they replenish themselves and expand quickly. The bone is viewed as a homogenous, isotropic, linear-elastic material. The foundation of the human skeleton are the bones. It aids in supporting the body's softer areas. Trauma is a significant factor in both industrialised and developing nations in terms of mortality and disability. According to the World Health Organization (WHO), trauma will account for the majority of years of life lost in both developed and developing countries by the year 2020. One of the frequent traumas is a bone fracture. Using bone plates to connect the fractured bone is one way to treat the broken bone. This study compares bone plates constructed of several biomaterials (Stainless Steel, Titanium, Alumina, Nylon, and PMMA) to determine which one is the best. SOLIDWORKS is used to model the femur bone, while ANSYS is used for analysis. Also modelled, attached to a fractured bone, and examined are the fracture fixation plates.

Mechanisms of persistent atrial fibrillation and recurrences within 12 months post-ablation: Non-invasive mapping with electrocardiographic imaging

Introduction

Catheter ablation of persistent AF has not been consistently successful in terminating AF or preventing arrhythmia recurrences. Non-invasive Electrocardiographic Imaging (ECGI) can help to understand recurrences by mapping the mechanisms of pre-ablation AF and comparing them with the patterns of recurrent arrhythmias in the same patient.

Methods

Seventeen persistent AF patients underwent ECGI before their first catheter ablation. Time-domain activation maps and phase progression maps were obtained on the bi-atrial epicardium. Location of arrhythmogenic drivers were annotated on the bi-atrial anatomy. Activation and phase movies were examined to understand the wavefront dynamics during AF. Eight patients recurred within 12 months of ablation and underwent a follow-up ECGI. Driver locations and movies were compared for pre- and post-ablation AF.

Results

A total of 243 focal drivers were mapped during pre-ablation AF. 62% of the drivers were mapped in the left atrium (LA). The pulmonary vein region harbored most of the drivers (43%). 35% of the drivers were mapped in the right atrium (RA). 59% (10/17) and 53% (9/17) of patients had repetitive sources in the left pulmonary veins (LPV) and left atrial appendage (LAA), and the lower half of RA, respectively. All patients had focal drivers. 29% (5/17) of patients had macro-reentry waves. 24% (4/17) of patients had rotors. Activation patterns during persistent AF varied from single macro-reentry to complex activity with multiple simultaneous wavefronts in both atria, resulting in frequent wave collisions. A total of 76 focal driver activities were mapped in 7/8 patients during recurrence. 59% of the post-ablation AF drivers were mapped in the LA. The pulmonary vein region harbored 50% of total drivers. 39% of sources were mapped in the RA. AF complexity remained similar post-ablation. 58% (44/76) of pre-ablation sources persisted during recurrence. 38% (3/8) of patients had macro-reentry and one patient had rotors.

Conclusion

ECGI provides patient-specific information on mechanisms of persistent AF and recurrent arrhythmia. More than half pre-ablation sources repeated during post-ablation recurrence. This study provides direct evidence for drivers that persist days and months after the ablation procedure. Patient-tailored bi-atrial ablation is needed to successfully target persistent AF and prevent recurrence. ECGI can potentially predict recurrence and assist in choice of therapy.

ZnT2 Is Critical for TLR4-Mediated Cytokine Expression in Colonocytes and Modulates Mucosal Inflammation in Mice

A wide range of microbial pathogens can enter the gastrointestinal tract, causing mucosal inflammation and infectious colitis and accounting for most cases of acute diarrhea. Severe cases of infectious colitis can persist for weeks, and if untreated, may lead to major complications and death. While the molecular pathogenesis of microbial infections is often well-characterized, host-associated epithelial factors that affect risk and severity of infectious colitis are less well-understood. The current study characterized functions of the zinc (Zn) transporter ZnT2 (SLC30A2) in cultured HT29 colonocytes and determined consequences of ZnT2 deletion in mice on the colonic response to enteric infection with Citrobacter rodentium. ZnT2 in colonocytes transported Zn into vesicles buffering cytoplasmic Zn pools, which was important for Toll-like receptor 4 (TLR4) expression, activation of pathogen-stimulated NF-κβ translocation and cytokine expression. Additionally, ZnT2 was critical for lysosome biogenesis and bacterial-induced autophagy, both promoting robust host defense and resolution mechanisms in response to enteric pathogens. These findings reveal that ZnT2 is a novel regulator of mucosal inflammation in colonocytes and is critical to the response to infectious colitis, suggesting that manipulating the function of ZnT2 may offer new therapeutic strategies to treat specific intestinal infections.

Sensitivity Analysis of the Turning Motion of an Underwater Glider on the Viscous Hydrodynamic Coefficients

Autonomous underwater gliders (AUG) are a class of underwater vehicles that move using a buoyancy engine and forces from wings. Gliders execute turning motion with the help of a rudder or an internal roll control mechanism and the trajectory of the turn is a spiral. This paper analyses the sensitivity of the characteristics of spiral manoeuvre on the hydrodynamic coefficients of the glider. Based on the dynamics model of a gliding fish whose turn is enabled by a rudder, the effect of hydrodynamic coefficients of the hull and the rudder on the spiral motion are quantified. Local sensitivity analysis is undertaken using the indirect method. The order of importance of hydrodynamic coefficients is evaluated. It is observed that the spiral path parameters are most sensitive to the side force created by the rudder and the effect of the drag coefficient is predominant to that of the lift coefficients. This study will aid in quantifying the effect of change of geometry on the manoeuvrability of AUGs.

Isolation and Identification of Staphylococci and Pseudomonas from Diabetic Foot Ulcer in Perambalur District Hospitals in Tamil Nadu

Diabetic foot ulcers are still a problem for the health care system and are majorly influencing quality of life. Infected foot ulcer is one of the most feared complications of diabetes mellitus, leading to gangrene and it needs to be amputed. Diabetic foot lesions are major medical, social and economic problem and leading cause of hospitalization for patients with diabetes worldwide. The risk of a diabetic patient for developing a foot ulcer was estimated to be ~25%. Samples were collected from 65 infected patients of diabetic foot ulcer male and female. The mean age group was found to be 40-80 years with the clinical history such as age, sex, types of diabetes duration of diabetes, size of ulcer and duration of ulcer were observed and recorded. The Specific mediums were used for the isolation and identification using classical methods based on their morphology, Grams stain reaction, oxidase and catalase tests were performed to confirm the isolates were both gram-negative and gram-positive organisms Bergey’s manual of Determinative Bacteriology. Further, MALDI- TOF (Matrix-Assisted Laser Desorption/Ionization) was used to confirm the isolates identified in classical methods were Staphylococci (79%) and Pseudomonas (21%) In this study Among 68 isolates, identified in out of 41 isolates Pseudomonasaeruginosa (21%) Staphylococcus aureus (54%) Staphylococcus hominis (20%)and Staphylococcous hemolytic(5%). Although in gram positive organism Staphylococcus aureus (54%) was the most predominant isolate found in diabetic foot ulcer.

Percutaneous Nephrolithotomy in Supine versus Prone Position in Tertiary Hospital in Mysore: A Prospective Cohort Study

Introduction: Percutaneous Nephrolithotomy (PCNL) is a procedure of choice for large renal calculi. It is a common urological procedure. PCNL can be performed in various positions. Aim: To determine the surgical outcomes in patients undergoing PCNL in supine and prone positions. Materials and Methods: A cohort study was conducted on patients with renal and upper ureteral stones who underwent PCNL in either prone or supine position between August 2019 to August 2020 at Urology Department, JSS Hospital, Mysuru. Supine PCNL was done in the flank Free Oblique Supine Modified Lithotomy (FOSML) position. All the procedures were performed under fluoroscopy guidance. Surgical outcomes including operative time, length of hospital stay, Stone Free Rate (SFR), radiation dose, and postoperative complications were evaluated. The collected data was tabulated and frequency (n) and percentage (%) analysis was performed. The Chi-square test was used to find the level of significance. Results: A total of 70 patients were included in the study and out of which 35 patients were in the supine (46.37±14.73 years, 28 males and 7 females) and 35 patients (47.54±12.45 years, 23 males and 12 females) were in the prone PCNL groups. Statistically significant difference was observed in the mean operating time in the supine and prone PCNL groups (81.43 vs 127.71 minutes; p-value=0.001), with a higher stone-free rate (94.29% vs 91.43%; p-value=0.643) observed in the supine PCNL group. One patient in supine group had postoperative sepsis and one patient in prone group had bleeding requiring transfusion. The Visual Analog Scale (VAS) score in supine PCNL was (5.08±0.32) less than in prone group (8.03±0.40) (p-value <0.001). Conclusion: PCNL in the supine position compared with the prone position demonstrates significantly lower operative time with similar SFR and lower VAS score.

The Arrhythmic Substrate for Atrial Fibrillation in Patients with Mitral Regurgitation

Objective

Patients with severe mitral regurgitation commonly develop atrial fibrillation. The precise mechanisms of this relationship remain unknown. The objective of this study was to apply noninvasive electrocardiographic imaging of the atria during sinus rhythm to identify changes in atrial electrophysiology that may contribute to development of atrial fibrillation in patients with severe mitral regurgitation referred for mitral valve surgery.

Methods

Twenty subjects (9 atrial fibrillation and mitral regurgitation, 11 mitral regurgitation alone) underwent electrocardiographic imaging. Biatrial electrophysiology was imaged with activation maps in sinus rhythm. The reconstructed unipolar electrograms were analyzed for voltage amplitude, number of deflections and conduction heterogeneity. In subjects with mitral regurgitation, left atrial biopsies were obtained at the time of surgery. Results: Subjects with history of atrial fibrillation demonstrated prolonged left atrial conduction times (110±25 ms vs. mitral regurgitation alone (85±21), p=0.025); right atrial conduction times were unaffected. Variable patterns of conduction slowing were imaged in the left atria of most subjects, but those with prior history of atrial fibrillation had more complex patterns of conduction slowing or unidirectional block. The presence of atrial fibrillation was not associated with the extent of fibrosis in atrial biopsies.

Conclusions

Detailed changes in sinus rhythm atrial electrophysiology can be imaged noninvasively and can be used to assess the impact and evolution of atrial fibrillation on atrial conduction properties in patients with mitral regurgitation. If replicated in larger studies, electrocardiographic imaging may identify patients with mitral regurgitation at risk for atrial fibrillation and could be used to guide treatment strategies.

High-Efficiency Particulate Air Filters in the Era of COVID-19: Function and Efficacy

Aerosol-generating procedures in the office represent a major concern for health care–associated infection of patients and health care providers by SARS-CoV-2, the causative agent for coronavirus disease 2019 (COVID-19). Although the Centers for Disease Control and Prevention has not yet provided any recommendations for the use of portable air purifiers, air purifiers with high-efficiency particulate air (HEPA) filters have been discussed as an adjunctive means for decontamination of SARS-CoV-2 aerosols in health care settings. This commentary discusses HEPA filter mechanisms of action, decontamination time based on efficiency and flow rate, theoretical application to SARS-CoV-2, and limitations. HEPA filter functionality and prior guidance from the Centers for Disease Control and Prevention for SARS-CoV-1 suggest theoretical efficacy for HEPA filters to decontaminate airborne SARS-CoV-2, although direct studies for SARS-CoV-2 have not been performed. Any portable HEPA purifier utilization for SARS-CoV-2 should be considered an adjunctive infection control measure and undertaken with knowledge of HEPA filter functionality and limitations in mind.

Exploring the Potential Use of Hylocereus polyrhizus Peels as a Source of Cosmeceutical Sunscreen Agent for Its Antioxidant and Photoprotective Properties

Currently, consumers' demand for sunscreens derived from natural sources that provide photoprotection from ultraviolet (UV) radiation is pushing the cosmetic industry to develop breakthrough formulations of sun protection products by incorporating plant antioxidants as their active ingredients. In this context, the present study was initiated to evaluate the antioxidant and photoprotective properties of the underutilized Hylocereus polyrhizus peel extract (HPPE) using in vitro spectrophotometric techniques. The phytochemical screenings of HPPE conducted via high-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) revealed the presence of phenolic acids and flavonoids as the major secondary metabolites in HPPE. The antioxidant potentials evaluated based on 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical and total antioxidant capacity assays were in the range of 22.16 ± 0.24%-84.67 ± 0.03% with 50% inhibitory concentration (IC50) of 36.39 ± 0.04 μg/mL and 23.76 ± 0.14%-31.87 ± 0.26% (IC50 = 21.93 ± 0.07 μg/mL), respectively. For the photoprotective evaluation, the results showed that HPPE had significantly high absorbance values (3.1-3.6) at 290-320 nm with an exceptional sun protection factor (SPF) value of 35.02 ± 0.39 at 1.00 mg/mL. HPPE also possessed a broad-spectrum shielding power against both UVA and UVB radiations. Hence, in terms of practical implications, our findings would offer an exciting avenue to develop a photoprotective formulation incorporating the ethanolic extract of Hylocereus polyrhizus peels as a synergistic active ingredient for its excellent UV absorption properties and the strong antioxidant activities.

Endovascular Management of Radiation-Induced Hemorrhagic Cystitis

Radiation-induced hemorrhagic cystitis (HC) is an unpleasant and sometimes life-threatening complication confronted while treating pelvic malignancies. A wide array of treatment modalities such as bladder irrigation, fulguration, hyperbaric oxygen therapy, and surgical methods has been proposed to treat hematuria, but there is no consensus on the optimal therapeutic strategy for the same. Reported here is a successful superselective embolization of the bilateral vesical arteries in a patient with refractory radiation-induced HC. This technique proved to be effective in controlling intractable hemorrhage and can be considered an option for the treatment of HC not amenable to conventional techniques.

Silver (Ag) nanoparticles enhanced luminescence properties of Dy3+ ions in borotellurite glasses for white light applications

In the present work, the structural and optical properties of borotellurite glasses co-doped with Dy³⁺ ions and Ag nanoparticles were investigated. From HR-TEM analysis, the average Ag nanoparticle diameter was calculated as 13.7 ± 1 nm. The negative sign of the bonding parameter explored the ionic nature of metal-ligand (DyO) bonds. The emission spectra exhibited three emission bands in blue, yellow and red regions corresponding to ⁴F_9/2 → ⁶H_15/2, ⁴F_9/2 → ⁶H_13/2 and ⁴F_9/2 → ⁶H_11/2 transitions, respectively. The Yellow/Blue (Y/B) ratio of optimal BTD0.5A glass was found to be 1.881 and this low Y/B ratio indicated the fact that Dy³⁺ ions were located in higher symmetrical ligand environment. The CCT values are found to vary from 3717 to 3800 K and hence the present glasses may emit cool white light when excited with UV lamp. The radiative parameters were calculated for all the emission transitions by using JO theory. The decay curves are found to show non-exponential behavior for all the studied glasses. The obtained results were discussed in detail and compared with similar reported glasses.

Optimization of the Antioxidant Potentials of Red Pitaya Peels and Its In Vitro Skin Whitening Properties

In this study, response surface methodology (RSM) was employed for the optimization of the antioxidant potentials of red pitaya peels using independent variables: temperature (45–65 °C), ethanol concentration (70–90%, v/v) and time (80–120 min) through its responses, which were DPPH scavenging activity, ferric ion reducing antioxidant power (FRAP), and beta-carotene bleaching (BCB) inhibition, respectively. In Vitro anti-tyrosinase and vitamin C content assays were carried out spectrophotometrically to determine the skin whitening efficacy of the optimized red pitaya peel extract. A gas chromatography-mass spectrometry (GC-MS) analysis was employed to identify the chemical constituents present in the optimized extract. The optimized conditions were ethanol 82% (v/v) for 103 min at 56 °C with values of 75.98% for DPPH, 7.45 mM Fe2+/g dry weight for FRAP and 93.29% for BCB respectively. The in vitro anti-tyrosinase and vitamin C content evaluation of the optimized extract showed a good tyrosinase inhibition of 66.29% with IC50 of 24.06 µg/mL while the vitamin C content was 5.45 mg/g of the extract. The GC-MS analysis revealed the presence of thirty phytoconstituents with l-(+)-ascorbic acid 2,6-dihexadecanoate being the most abundant with a peak area of 14.66%. This study evidently suggests the potential of red pitaya peels to be exploited as a natural skin whitening agent in the cosmeceutical and pharmaceutical formulations.

A novel Sm3+ singly doped LiCa3ZnV3O12 phosphor: a potential luminescent material for multifunctional applications

Sm³⁺ ion singly doped LiCa₃ZnV₃O₁₂ phosphors were developed for multifunctional applications in indoor illumination, optical thermometry, and safety signs.

Novel Eu3+-activated Ba2Y5B5O17 red-emitting phosphors for white LEDs: high color purity, high quantum efficiency and excellent thermal stability

Eu³⁺-activated Ba₂Y₅B₅O₁₇ (Ba₂Y_5−xEu_xB₅O₁₇; x = 0.1–1) red-emitting phosphors were synthesized by the conventional high temperature solid-state reaction method in an air atmosphere. Powder X-ray diffraction (XRD) analysis confirmed the pure phase formation of the as-synthesized phosphors. Morphological studies were performed using field emission-scanning electron microscopy (FE-SEM). The photoluminescence spectra, lifetimes, color coordinates and internal quantum efficiency (IQE) as well as the temperature-dependent emission spectra were investigated systematically. Upon 396 nm excitation, Ba₂Y_5−xEu_xB₅O₁₇ showed red emission peaking at 616 nm which was attributed to the ⁵D₀ → ⁷F₂ electric dipole transition of Eu³⁺ ions. Meanwhile, the influences of different concentrations of Eu³⁺ ions on the PL intensity were also discussed. The optimum concentration of Eu³⁺ ions in the Ba₂Y_5−xEu_xB₅O₁₇ phosphors was found to be x = 0.8. The concentration quenching mechanism was attributed to the dipole–dipole interaction and the critical distance (R_c) for energy transfer among Eu³⁺ ions was determined to be 5.64 Å. The asymmetry ratio [(⁵D₀ → ⁷F₂)/(⁵D₀ → ⁷F₁)] of Ba₂Y_4.2Eu_0.8B₅O₁₇ phosphors was calculated to be 3.82. The fluorescence decay lifetimes were also determined for Ba₂Y_5−xEu_xB₅O₁₇ phosphors. In addition, the CIE color coordinates of the Ba₂Y_4.2Eu_0.8B₅O₁₇ phosphors (x = 0.653, y = 0.345) were found to be very close to the National Television System Committee (NTSC) standard values (x = 0.670, y = 0.330) of red emission and also showed high color purity (∼94.3%). The corresponding internal quantum efficiency of the Ba₂Y_4.2Eu_0.8B₅O₁₇ sample was measured to be 47.2%. Furthermore, the as-synthesized phosphors exhibited good thermal stability with an activation energy of 0.282 eV. The above results revealed that the red emitting Ba₂Y_4.2Eu_0.8B₅O₁₇ phosphors could be potential candidates for application in near-UV excited white light emitting diodes.

A novel Ba₂Y₅B₅O₁₇:Eu³⁺ red-emitting phosphor with high color purity, high quantum efficiency and excellent thermal stability was developed.

Impact of Body Mass Index on Arterial Stiffness in Young Prehypertensives: A Cross Sectional Study

BACKGROUND

Obesity and hypertension pose a big threat to public health. Targeting the prehypertension stage to evaluate the vascular damage due to obesity can help us to plan early interventions.

STUDY DESIGN

A cross-sectional study.

METHODS

This study  as a part of the medical heath checkup program was conducted by the Medical College in Puducherry, India on all medical students of age group 18-25 years. Blood pressure (BP) recordings and body mass index (BMI) were classified into following four groups: Group1: Normotensives with normal BMI (n=109); Group 2: Normotensives with higher BMI (n=89); Group 3: Prehypertensive subjects with normal BMI (n=50); and Group 4: Prehypertensive subjects with higher BMI (n=99). Arterial stiffness, body fat composition, and lipid profile were evaluated. Correlation of arterial stiffness indices with BMI, BP, body fat, visceral fat, lipid profile were done using Pearson's correlation and the contribution of BMI to arterial stiffness was assessed using univariate regression analysis.

RESULTS

BMI, arterial stiffness, body fat, visceral fat, total cholesterol and total triglyceride showed a significant increase in prehypertensive group with higher BMI as compared to other groups. BMI showed significant correlation with arterial stiffness (P<0.0001) and found to be an independent contributing factor for arterial stiffness development in prehypertensives.

CONCLUSIONS

Vascular damage was seen in the prehypertensive stage itself and was more pronounced in individuals with higher BMI.

The Polyphyletic Origins of Primase-Helicase Bifunctional Proteins

We studied the evolutionary relationships of different primase-helicase bifunctional proteins, found mostly in viruses, virophages, plasmids, and organellar genomes, by phylogeny and correlation analysis. Our study suggests independent origins of primase-helicase bifunctional proteins resulting from multiple fusion events between genes encoding primase and helicase domains of different families. The correlation analysis further indicated strong functional dependencies of domains in the bifunctional proteins that are part of smaller genomes and plasmids. Bifunctional proteins found in some bacterial genomes exhibited weak coevolution probably suggesting that these are the non-functional remnants of the proteins acquired via horizontal transfer. We have put forward possible scenarios for the origin of primase-helicase bifunctional proteins in large eukaryotic DNA viruses and virophages.

Soluble expression and purification of a full-length asparaginyl tRNA synthetase from Fasciola gigantica

We report the molecular cloning, expression, and single-step homogeneous purification of a full-length asparaginyl tRNA synthetase (NRS) from Fasciola gigantica (FgNRS). Fasciola gigantica is a parasitic liver fluke of the class Trematoda. It causes fascioliasis that infects the liver of various mammals, including humans. Aminoacyl tRNA synthetases (AARS) catalyze the first step of protein synthesis. They attach an amino acid to its cognate tRNA, forming an amino acid-tRNA complex. The gene that codes for FgNRS was generated by amplification by polymerase chain reaction. It was then inserted in the expression vector pQE30 under the transcriptional control of the bacteriophage T5 promoter and lac operator. M15 Escherichia coli strain transformed with the FgNRS expression vector pQE30-NRS accumulates large amounts of a soluble protein of about 61 kDa. The protein was purified to homogeneity using immobilized metal affinity chromatography. The recombinant protein was further confirmed by immunoblotting with anti-His antibody. Following size exclusion chromatography, the FgNRS was stable and observed to be a dimeric protein. In this study, the expression and purification procedures have provided a simple and efficient method to obtain full-length FgNRS in large quantities. This will provide an opportunity to study the structure, dynamics and function of NRS.

Spectroscopic properties of Sm3+ ions doped Alkaliborate glasses for photonics applications

A new series of Sm³⁺ doped alkaliborate glasses have been prepared by melt quenching technique and their structural and spectroscopic properties were analysed employing XRD, FTIR, optical absorption, photoluminescence and decay spectral measurements in order to explore their suitability for photonic applications. The amorphous nature have been confirmed through XRD analysis and the FTIR spectra reveal the presence of fundamental stretching and bending vibrations of the borate networks in the prepared glasses. From the absorption peak positions, bonding parameter (δ) values were calculated to examine the nature of the metal-ligand bond. The optical band gap (E_opt) corresponds to the direct and indirect allowed transitions and the Urbach energies (ΔE) were calculated from the absorption spectra to understand the electronic band structure of the studied glasses. The Judd-Ofelt (JO) intensity parameters Ω_λ (λ=2, 4 and 6) were determined to explore the symmetry of the ligand environment around the Sm³⁺ ions in the studied glasses. The luminescence spectra exhibit four emission bands in the visible region due to the ⁴G_5/2→⁶H_5/2, ⁶H_7/2, ⁶H_9/2 and ⁶H_11/2 transitions. The radiative parameters such as transition probability (A), stimulated emission cross-section (σ_P^E), branching ratios (β_R) and radiative lifetime (τ_R) have been determined from the luminescence spectra using JO theory to ensure the suitability of the studied glasses for optoelectronic applications. The luminescence spectra were characterized through CIE 1931 chromaticity diagram to examine the dominant emission color of the studied glasses. The lifetime values of the Sm³⁺ doped studied glasses pertaining to the ⁴G_5/2 excited level have been determined through decay curve measurements and the non-exponential decay curves were fitted to the Inokuti-Hirayama model to analyze the energy transfer mechanism between the nearby Sm³⁺ ions. The obtained results were discussed and compared with the similar reported glasses.

Oral neoplasms in pickhandle barracuda Sphyraena jello from India

We report the spontaneous occurrence of oral neoplasms in pickhandle barracuda Sphyraena jello Cuvier, 1829 from Parangipettai, on the southeast coast of India. A total of 11736 fish were examined, of which 43 were affected with oral tumours, with an overall prevalence of 0.37%. Gross and clinical symptoms included reddish to grayish-white distended tumourous growths on the gingiva, intra-oral bones and tongue. The tumours exhibited delayed eruption and intra- or extra-oral swelling, varied in consistency from extremely firm to fleshy and released mucinous material. The majority of tumours consisted of numerous clumped toothlets, but some included hardened tissues. Local area invasion/transmission was observed in most cases; however, necropsy examination revealed no gross evidence of distant metastasis into visceral organs. Radiographic examination of compound odontomas revealed distinct unilocular radio-opaque mini-toothlets surrounded by defined radiolucency, whereas complex odontomas exhibited unilocular and indistinct radio-opaque masses within a much more extensive radiolucent zone. Histopathologically, the intra-oral tumour lesions were characterized by numerous imperfect (germ) toothlets consisting of a disorganized combination of dental tissues: pulp tissues with manifested and predominantly mixed hard dental tissues of immature dentine and enamel, numerous small to large and round to polyhedral ossicles embedded in hypocellular fibrous stromal tissues and sparsely spaced bland spindloid cells with cleft-like spaces of loose mucoid stroma. Histochemically, the neoplastic lesions stained positive for periodic acid-Schiff and Masson's trichrome. Based on the clinical and histological findings, the tumours were diagnosed as compound odontomas, complex odontomas, odontogenic myxomas, lingual myxomas and psammomatoid ossifying fibromas.

Methodology Considerations in Phase Mapping of Human Cardiac Arrhythmias

BACKGROUND

Phase analysis of cardiac arrhythmias, particularly atrial fibrillation, has gained interest because of the ability to detect organized stable drivers (rotors) and target them for therapy. However, the lack of methodology details in publications on the topic has resulted in ongoing debate over the phase mapping technique. By comparing phase maps and activation maps, we examined advantages and limitations of phase mapping.

METHODS AND RESULTS

Seven subjects were enrolled. We generated phase maps and activation maps from electrocardiographic imaging-reconstructed epicardial unipolar electrograms. For ventricular signals, phase was computed with (1) pseudoempirical mode decomposition detrending and (2) a novel Moving Average (MVG) detrending approach. For atrial fibrillation signals, MVG was modified to incorporate dynamic cycle length (DCL) changes (MVG-DCL). Phase maps were visually analyzed to study phase singularity points and rotors. Results show that phase is sensitive to cycle length choice, a limitation that was addressed by the MVG-DCL algorithm. MVG-DCL was optimal for atrial fibrillation analysis. Phase maps helped to highlight high-curvature wavefronts and rotors. However, for some activation patterns, phase generated nonrotational singularity points and false rotors.

CONCLUSIONS

Phase mapping computes singularity points and visually highlights rotors. As such, it can help to provide a clearer picture of the spatiotemporal activation characteristics during atrial fibrillation. However, it is advisable to incorporate electrogram characteristics and the time-domain activation sequence in the analysis, to prevent misinterpretation and false rotor detection. Therefore, for mapping complex arrhythmias, a combined time-domain activation and phase mapping with variable cycle length seems to be the most reliable method.

Comparison of compressive strength among three different intracanal post materials in primary anterior teeth: An in vitro study

Objective:

The objective of our study was to compare the fracture resistance and the mode of failure among three different post materials in primary anterior teeth.

Materials and Methods:

A total of sixty extracted primary anterior teeth were selected for the study. The samples were divided into three groups of twenty teeth each: Group I (Ribbond), Group II (Omega loop), and Group III (Glass fiber post). Pulp therapy was followed by intracanal post and crown buildup. The samples were mounted in self-cure acrylic and subjected to compressive strength test using universal testing machine (Instron). The maximum force at which the tooth fractured was recorded.

Results:

The values were subjected to one-way analysis of variance. The mean compressive strength values of Ribbond, omega loop, and glass fiber post were found to be 83.25 N, 61.60 N, and 75.55 N, respectively. The P value was found to be 0.220.

Conclusion:

Group I (Ribbond) showed the highest fracture resistance values followed by Group III (Glass fiber post) and Group II (Omega loop). Although there is difference in mean values, they were nonsignificant.

Electrophysiologic substrate in congenital Long QT syndrome: noninvasive mapping with electrocardiographic imaging (ECGI)

BACKGROUND

Congenital Long QT syndrome (LQTS) is an arrhythmogenic disorder that causes syncope and sudden death. Although its genetic basis has become well-understood, the mechanisms whereby mutations translate to arrhythmia susceptibility in the in situ human heart have not been fully defined. We used noninvasive ECG imaging to map the cardiac electrophysiological substrate and examine whether LQTS patients display regional heterogeneities in repolarization, a substrate that promotes arrhythmogenesis.

METHODS AND RESULTS

Twenty-five subjects (9 LQT1, 9 LQT2, 5 LQT3, and 2 LQT5) with genotype and phenotype positive LQTS underwent ECG imaging. Seven normal subjects provided control. Epicardial maps of activation, recovery times, activation-recovery intervals, and repolarization dispersion were constructed. Activation was normal in all patients. However, recovery times and activation-recovery intervals were prolonged relative to control, indicating delayed repolarization and abnormally long action potential duration (312±30 ms versus 235±21 ms in control). Activation-recovery interval prolongation was spatially heterogeneous, with repolarization gradients much steeper than control (119±19 ms/cm versus 2.0±2.0 ms/cm). There was variability in steepness and distribution of repolarization gradients between and within LQTS types. Repolarization gradients were steeper in symptomatic patients (130±27 ms/cm in 12 symptomatic patients versus 98±19 ms/cm in 13 asymptomatic patients; P<0.05).

CONCLUSIONS

LQTS patients display regions with steep repolarization dispersion caused by localized action potential duration prolongation. This defines a substrate for reentrant arrhythmias, not detectable by surface ECG. Steeper dispersion in symptomatic patients suggests a possible role for ECG imaging in risk stratification.

Infestation of Lernaeenicus seeri (Copepoda: Pennellidae) and Hirudinella ventricosa (Digenea: Hirudinellidae) on wahoo Acanthocybium solandri collected from Parangipettai, southeast coast of India

A commercially important fish, wahoo Acanthocybium solandri (Cuvier, 1832) (Scombridae), was collected to study the infestation of parasites from Parangipettai landing center, Tamil Nadu, southeast coast of India for a period of one year from January to December 2011. A total of 644 fish were captured and screened for parasites. Off 644 fish, 270 were infested by a parasitic copepod Lernaeenicus seeri Kirtisinghe, 1934 (Siphonostomatoida: Pennellidae) on the body surface. It is a mesoparasite, since the head and neck are inserted and attached to the muscle by making a wound/hole on the body and the rest of the parasite body with the egg sacs hanging outside. Prevalence was recorded as 42.29% with mean and maximum intensity at 3.22 and 33, respectively. Seasonal study showed that the prevalence was highest (62.82 %) during postmonsoon. Simultaneously, some of the fish (n = 144) were internally observed for the presence of parasites and we found that 101 fish were infested with an endoparasite digenean Hirudinella ventricosa (Pallas, 1774) (Hirudinellidae) in the stomach. Prevalence was recorded as 70.9%, and mean intensity of 1.62 and maximum intensity of 3 were also noted. The overall percentage of both copepod and digenean infestation were recorded as 60.42%. The infestation was high in postmonsoon season for both parasites. This is the first record of L. seeri from Indian waters and the second record of occurrence worldwide. Significant interactions were observed between season and infestation of both parasites (P<0.05).

Occurrence of heavy copepod infestation on Hemiramphus lutkei and double parasitisms on Hemiramphus far with copepod (Lernaeenicus hemiramphi) and isopod (Mothocya plagulophora)

In the present study about, 66 copepod parasites of Lernaeenicus hemiramphi of two Hemiramphus sp., H. far (17 copepod) and H. lutkei (49 copepod), and an isopod (Mothocya plagulophora) on the gill chamber were observed. H. lutkei was added as a new host for L. hemiramphi. The copepod infestation was almost on the ventral side of the hosts.

Occurrence of isopod Nerocila phaiopleura infestation on Whitefin wolf-herring (Chirocentrus nudus) from Southeast coast of India

The present study reported the first observation of isopod parasite, Nerocila phaiopleura infestation on Chirocentrus nudus an economically important fish from Cuddalore coast, Southeast coast of India. The maximum prevalence of 6.3 % and mean intensity of 3.2 were observed during pre-monsoon 2010 and monsoon 2010 respectively. The highest intensity 7 was observed in the single host during monsoon. The site of attachment leads to wound and offer the secondary infection. Two pathogenic bacteria Streptococcus aureus and E. coli were isolated from the wound.

A study on knowledge, attitude and practice regarding voluntary blood donation among medical students in Puducherry, India

Knowledge, attitude and practice studies have been used to understand the various factors that influence blood donation which is the basis for donor mobilization and retention strategies. Role of youngsters in voluntary blood donation is crucial to meet the demand of safe blood. The present study was aimed to assess the level of knowledge, attitude and practice regarding voluntary blood donation among the health care students. A validated and pre-tested questionnaire on knowledge, attitude and practice on blood donation were assessed among 371 medical students from Sri Lakshmi Narayana Institute of Medical Sciences and Research Institute, Puducherry, India. Result showed that knowledge on blood donation among respondents was 44.8% (1st year 36.7%, 2nd year 42.8% and 3rd year 54.9%). About 62.6% of non-donors (1st year 51%, 2nd year 61% and 3rd year 77%) showed positive attitude by expressing their willingness to donate blood while 22.8%.of the non-donors had negative attitude (1st year 33%, 2nd year 23% and 3rd year 13%). In practice 13.2% of students had donated blood (1st year 10%, 2nd year 13% and 3rd year 24%), in which 2.7% of male students alone donating blood on regular basis. Over all 3rd year student showed significantly higher knowledge compared with 1st years, in attitude and practice section 3rd year student's showed significantly higher positive attitude and practice than that of 1st and 2nd years. The present study reveals that there is a positive association among knowledge, attitude and practice on blood donation, which suggest that positive attitude and practice can be improved by inculcating knowledge on blood donation among college students to recruit and donate blood regularly, which will help to achieve 100% of blood donation on voluntary basis.

Occurrence of tumour (odontoma) in marine fish Sphyraena jello from the southeast coast of India

We examined the occurrence of odontoma in the marine fish Sphyraena jello sourced from 3 different landing centers (Cuddalore, Parangipettai and Nagapattinam) in Tamil Nadu (southeast India). A total of 19783 fishes were examined for odontoma presence, of which 2393 were affected with odontoma. The overall prevalence was 12.1% among the 3 stations. Fish landed at Parangipettai showed the highest peak prevalence of odontoma (16.8%) during the pre-monsoon, followed by Nagapatinam (9.1%) during summer 2011. The tumour lengths in premaxilla, supermaxilla and dentary bone were 1.1-3.6, 1.4-5.9 and 1.2-4.1 cm, respectively, and tumour widths were 0.3-1.9, 0.7-3.1 and 0.5-1.9 cm. Higher prevalence (0.206%) of tongue tumour along with odontoma was observed at Nagapattinam whereas it was lower (0.162%) at Cuddalore. Odontoma histopathology showed dense fibrous tissue with fine teeth roots. TEM analysis showed virus-like particles associated with odontoma. Radiography of the odontoma showed that the tumour masses were bony in nature and tissues were merged with upper and lower jaw.

Morphometry examination of placenta in birth weight of full-term newborns in Puducherry, India

irth weight is an important determinant of child survival, healthy growth and development. Low birth weight is a well-established risk factor for adverse long term health, particularly cardiovascular disease and metabolic syndrome. The ability of the fetus to grow and thrive in utero is presumed to be a function of the placenta. The present study was aimed to assess the morphometry examination of placenta in normal and low birth weight babies in the Union territory of Puducherry. Morphometry examination includes Placenta weight, number of cotyledons, maternal and fetal surface area and site of umbilical cord insertion were measured in normal and low birth weigh babies. Result showed among 200 subjects, mean birth weight of normal and low birth babies were 2806 and 2058 g, respectively. The prevalence rate of low birth babies (less than 2500 g) was 22%. The placental morphometry study namely placental weight, number of cotyledons, maternal and fetal surface area and insertion of umbilical cord at centre were significantly (p<0.001) reduced in the low birth weight babies when compared with normal birth weight babies. Study revealed that morphometry analysis of placenta significantly influences the birth weight of new born. In conclusion, study recommends the early measurements of placenta by non-invasive techniques like ultrasonography will be helpful in early prediction of low birth weight fetus in utero itself and for better management to avoid such low birth weight.

Fungal keratitis caused by Macrophomina phaseolina - A case report

A 70 year old female patient presented with complaints of pain, watering and swelling in the right eye. She gave a history of fall, as she was walking in the paddy field of her farm. Ophthalmological and Microbiological investigation revealed a fungal keratitis with an unusual fungus Macrophomina phaseolina which is primarily a plant pathogen, with a potential to cause human infections especially in immuno-compromised patients. The patient responded well to the antifungal treatment with Oral Voriconazole with absence of recurrence and dissemination.

Efficient synthesis of silver nanoparticles from Prosopis juliflora leaf extract and its antimicrobial activity using sewage

In this paper, aqueous extract of fresh leaves of Prosopis juliflora was used for the synthesis of silver (Ag) nanoparticles. UV-Vis spectroscopy studies were carried out to asses silver nanoparticles formation within 5 min, scanning electron microscopic was used to characterize shape of the Ag nanoparticles, X-ray diffraction analysis confirms the nanoparticles as crystalline silver and facecentered cubic type and Fourier transform infra-red assed that shows biomolecule compounds which are responsible for reduction and capping material of silver nanoparticles. The anti microbial activity of silver nanoparticle was performed using sewage. The approach of plant-mediated synthesis appears to be cost efficient, eco-friendly and easy methods.

Noninvasive electroanatomic mapping of human ventricular arrhythmias with electrocardiographic imaging

The rapid heartbeat of ventricular tachycardia (VT) can lead to sudden cardiac death and is a major health issue worldwide. Efforts to identify patients at risk, determine mechanisms of VT, and effectively prevent and treat VT through a mechanism-based approach would all be facilitated by continuous, noninvasive imaging of the arrhythmia over the entire heart. Here, we present noninvasive real-time images of human ventricular arrhythmias using electrocardiographic imaging (ECGI). Our results reveal diverse activation patterns, mechanisms, and sites of initiation of human VT. The spatial resolution of ECGI is superior to that of the routinely used 12-lead electrocardiogram, which provides only global information, and ECGI has distinct advantages over the currently used method of mapping with invasive catheter-applied electrodes. The spatial resolution of this method and its ability to image electrical activation sequences over the entire ventricular surfaces in a single heartbeat allowed us to determine VT initiation sites and continuation pathways, as well as VT relationships to ventricular substrates, including anatomical scars and abnormal electrophysiological substrate. Thus, ECGI can map the VT activation sequence and identify the location and depth of VT origin in individual patients, allowing personalized treatment of patients with ventricular arrhythmias.