Laryngeal Subsite Analysis of Granulomatosis With Polyangiitis (Wegener’s)

Wegener’s granulomatosis; Laryngeal manifestations; Subglottic stenosisGranulomatosi de Wegener; Manifestacions de la laringe; Estenosi subglòticaGranulomatosis de Wegener; Manifestaciones de la laringe; Estenosis subglóticaObjective To analyze specific intralaryngeal findings associated with granulomatosis with polyangiitis (GPA). Study Design Retrospective chart review. Setting Tertiary referral center. Methods A retrospective chart review was performed on all patients diagnosed with GPA who were evaluated at the laryngology division of Massachusetts Eye and Ear Infirmary between January 2006 and September 2019. Results Forty-four patients (14 male, 30 female) were evaluated for laryngeal pathology. The mean age at onset was 48 years. Nine patients (21%) were identified with only vocal fold disease, 11 (25%) with subglottic disease, and 8 (18%) with disease at the glottis and subglottis (transglottic). The remaining 16 patients (36%) had a normal airway upon examination although they presented with laryngeal symptoms. Patients with glottic disease had statistically significantly lower voice-related quality of life scores than patients with isolated subglottic stenosis. Conclusions Although laryngeal manifestations of GPA is often described as a subglottic disease presenting with respiratory symptoms, subsite analysis show that only 25% of patients had subglottic disease alone, with similar rates of glottic disease alone. Laryngeal subsites have different epithelial mucosa, function, and physiology, and understanding the specific sites of involvement will determine symptoms and enable better analysis of the underlying mechanisms of disease. Glottic disease is associated with a reduction in vocal fold motion and voice changes. Subglottic involvement presents more frequently with airway symptoms. Further research is necessary to better define the specific regions of laryngeal involvement in patients diagnosed with GPA

Mid-latency AEP Response in Blind 113 Mid-latency Auditory Evoked Potential Response Revealed as an Evidence of Neural Plasticity in Blind Individuals

Abstract There is a general impression that visually blind individuals show an exceptionally better perception of other sensory modalities such as hearing, touch and smell sensations. In this study, we intended to compare the mid-latency auditory evoked potential response (MLAEP) or Middle latency Response (MLR) to get an idea of the activity pattern of auditory thalamus and cortex between 30 visually handicapped subjects and 30 normal sighted subjects. The results showed a decrease in many of the MLR wave latencies, but highly significant for the wave Pa (P value <0.002). This fact can be reflected as an evidence of existence of crossmodal neuroplasticity. We also inferred that there are significant gender differences with latencies shorter in males than females (P value <0.02) in the blind subjects group which could be attributed to their rehabilitation training

Aspects of tautomerism 12-Some causes and consequences of participation in the solvolysis of acid chlorides

Solvolysis of nine representative half ester acid chlorides in aqueous acetone have been studied. Isomers solvolyse at distinctly different rates and furnish the original acids. Contrary to the well accepted views, no evidence for tautomerism or isomerism between the isomeric pairs of acid chlorides could be detected. In a number of cases alkoxy group participates in the solvolysis of neighbouring acid chlorides. This results in (a) rate enhancement and (b) partial or total shift of the reaction pattern from S<SUB>N</SUB>2 to S<SUB>N</SUB>1. Isomeric half ester acid chlorides, in the presence of a sufficiently strong Lewis acid, could give the same oxonium salt. Rearrangements observed in the reactions of unsymmetrical 1,2- and 1,3-dicarboxylic acid derivatives could be ascribed to the prior formation of common oxonium salt intermediates in the presence of Lewis acids

Challenges in engine health monitoring instrumentation during developmental testing of gas turbine engines

Developmental testing of gas turbine propulsion systems involves iterative experimental studies right from First Engine to Test (FETT) till production release. During initial design validation tests, engines require dedicated instrumentation for carrying out online monitoring with a capability to detect and isolate impending failures which may lead to structural damage. Instrumentation may be optimized further over the developmental lifecycle to determine the general engine health and life consumption of critical parts. Instrumentation generally focuses on monitoring of structural and aerodynamic behavior of engine subsystems. It is challenging to arrive at optimum instrumentation and methodologies of measurement with respect to engine performance and structural health monitoring. Structural health monitoring of rotating engine components poses challenges in acquiring high bandwidth data through either contact or non-contact sensing techniques and further data processing. Special instrumentation systems used for measuring various parameters from rotating parts as a part of health monitoring include slip rings, rotating telemetry, and non-intrusive strain measurement systems. Instrumentation of other engine parameters includes temperature, pressure, rotational speed, casing vibration, control actuator positions, flow rate, clearance between stationary and rotating parts and lubrication oil quality. Gas turbine engines are a complex assembly of rotating and stationary parts which operate at extreme temperatures which limits the operational capability of sensors. It is a challenging task to error budget complete measurement chains and arrive at uncertainties. Various aspects discussed in this paper are complex and inter disciplinary in nature. This paper provides a bird’s eye view of the challenges associated with measurement systems during developmental stage of a gas turbine engine

POINCARE PLOT OF HEART RATE VARIABILITY : AN APPROACH TOWARDS EXPLAINING THE CARDIOVASCULAR AUTONOMIC FUNCTION IN OBESITY

Abstract : Obesity has been shown to affect cardiovascular function. Heart rate variability (HRV) has been an accepted method of measuring cardiovascular autonomic function. The aim of the study is to evaluate the impact of obesity on HRV using Poincaré plot (POP) analysis. A finding of sympathovagal imbalance in pre-obese adults in respiratory sinus arrhythmia (RSA) could provide important diagnostic information about early subclinical autonomic dysfunction in obesity. Thirty one obese (BMI 26.84±2.47) adult males (25.42±7.86 years) were compared with 31 normal subjects (25.38±4.61 years). In all participants, anthropometric and blood pressure (BP) measurements were performed. After rest at supine position for 5 minutes, they were asked to do control deep breathing for 1 minute. HRV was measured in terms of POP analysis. Differences in Resting heart rate (RHR) (P≤0.025), Pulse pressure (PP) (P≤0.048), SD1 (P≤0.042) and SD2 (P≤0.039) of the POP between the two groups were significant. Correlation between Body mass index (BMI) and (PP) (p=0.19); SD1 (p=0.47) and SD2 (p=0.39) of the POP were significant in obese groups. Obesity is r e l a t e d t o s y m p a t h o v a g a l i m b a l a n c e c h a r a c t e r i z e d b y d e p r e s s e d parasympathetic tone and increased sympathetic activity. Nonlinear methods like POP permit simple assessment of autonomic function, despite measuring different aspects of HRV

Producing amyloid fibrils in vitro: A tool for studying AL amyloidosis

Amyloid light-chain (AL) amyloidosis is the second most common form of systemic amyloidosis which is characterized by a high level of mortality and no effective treatment to remove fibril deposition. This disorder is caused by malfunctioning of B-cells resulting in production of abnormal protein fibrils composed of immunoglobulin light chain fragments that tend to deposit on various organs and tissues. AL amyloidosis is set apart from other forms of amyloidosis in that no specific sequences have been identified in the immunoglobulin light chains that are amyloid fibril formation causative and patient specific. This unusual feature hinders the therapeutic progress and requires either direct access to patient samples (which is not always possible) or a source of in vitro produced fibrils. While isolated reports of successful AL amyloid fibril formation from various patient-specific protein sequences can be found in literature, no systematic research on this topic was performed since 1999.In the present study we have developed a generalized approach to in vitro fibril production from various types of previously reported [1-3] amyloidogenic immunoglobulin light chains and their fragments. We describe the procedure from selection and generation of starting material, through finding of optimal assay conditions, to applying a panel of methods to confirm successful fibril formation. Procedure details are discussed in the light of the most recent findings and theories on amyloid fibril formation. The reported protocol produces high quality AL amyloid fibrils that can subsequently be used in the development of the much-needed amyloid-targeting diagnostic and therapeutic approaches

Impact of heat treatment on the mechanical performance of hot extruded Al6061-BN reinforced metal matrix composites

Boron nitride (BN) reinforced Al6061 aluminum-based composites are synthesized by conventional stir casting method followed by exposure to hot extrusion. The optical images confirmed the distribution of BN nanoparticles in the aluminum alloy matrix. The concentration of BN is varied from (0.5, 1.5, 3, 4.5, 6, 7.5, and 9 wt%) in the composites and its effect on the tensile strength was investigated. The results revealed that both extruded and heat-treated composites specimens showed enhanced toughness and tensile strength by increasing BN nanoparticle concentration. The heat-treated composite samples showed lower flexibility of up to 40%, and further, it exhibited 37% greater hardness and 32% enhancement in tensile strength over the extruded sample. The tensile properties of Al6061-BN composites were evaluated by temperature-dependent internal friction (TDIF) analysis and the results showed that the as-prepared composite's strength increased with temperature