Current Flow Patterns Generated by Cochlear Implants

Cochlear implants are neural prosthetic devices that restore partial hearing in many, but not all, hearing impaired individuals. In a cochlear implant device, sound is processed by an external speech processor, encoded as a data stream, and transmitted via a radio-frequency link across the skin to a subcutaneously-implanted receiver/stimulator located near the external ear. The signals are decoded, converted to current pulses and delivered into the cochlea by means of a surgically-implanted, multiple-contact, electrode array to stimulate surviving auditory nerve fibers in a tonotopic manner. Stimuli are typically delivered in a monopolar-coupled manner relative to a remote return electrode. Specific knowledge of how currents flow within and out of the implanted cochlea are important for understanding how present devices recruit surviving auditory fibers, as well as improving the design and clinical application of future devices. Few studies have addressed this problem to date, so our specific knowledge is limited. Consequently, the goal of this dissertation was to better understand the routes taken by the stimulus current as it leaves the cochlea in individual cochlear implant subjects. This study assumes that a better understanding of the injected current flow patterns would lead to improved control over stimulus current, which may result in the reduction of extracochlear stimulation and better-targeted stimulation of the auditory nerve. Because current flow cannot be directly measured in cochlear implant users, this study uses surface artifact potentials to test predictions about how current may flow within and outside the cochlea. These surface potentials represent the far field of the stimulation delivered by the device, and are recorded non-invasively on the scalp, neck, and face of cochlear implant subjects during the active stimulation by the device. Results from the study indicate that differences exist in the primary current flow pathways for stimulation of apical and basal electrode contacts. This observation is counter to long held assumptions about current flow within the cochlea. Analytical head models and inverse dipole source localization methods have been developed to interpret these results further. Knowledge gained from this study may eventually lead to higher levels of performance for all cochlear implant users

Making the most of primary and community services : what works for BAME people with long-term conditions?

This report is the main empirical output from an exploratory research study into the uptake of primary and community diabetes and respiratory long-term conditions services in Black Asian and Minority Ethnic (BAME) communities in Nottingham City. The study was commissioned by NHS Nottingham City Clinical Commissioning Group ('the CCG') and undertaken by a team from two research centres at Sheffield Hallam University: the Centre for Regional Economic and Social Research (CRESR) led the research with support from the Centre for Health and Social Care Research (CHSCR)

Anxiety and its risk factors among non-Japanese residents living in Japan undergoing COVID-19 situation: A cross-sectional survey

Introduction In the context of collective efforts taken in Japan to control the spread of COVID-19, the state of emergency and social distancing have caused a negative impact on the mental health of all residents, including foreign communities in Japan. This study aimed to evaluate the level of anxiety and its associated factors among non-Japanese residents residing in Japan during the COVID-19 pandemic. Methods A web-based survey in 13 languages was conducted among non-Japanese residents living in Japan during the COVID-19 situation. The State-Trait Anxiety Inventory assessed the level of anxiety–State (STAI-S) scores prorated from its six-item version. The multivariable logistic regression using the Akaike Information Criterion (AIC) method was performed to identify the associated factors of anxiety among participants. Results From January to March 2021, we collected 392 responses. A total of 357 valid responses were analyzed. 54.6% of participants suffered from clinically significant anxiety (CSA). In multivariable logistic model analysis, the CSA status or the high level of anxiety was associated with three factors, including having troubles/difficulties in learning or working, decreased sleep duration, and decreased overall physical health (p<0.05). Conclusion Our study suggests several possible risk factors of anxiety among non-Japanese residents living in Japan undergoing the COVID-19 pandemic, including the troubles or difficulties in learning or working, the decrease in sleep duration, and the decrease in overall physical health.Revisión por pare

Metallacages with 2,6-dipicolinoylbis(N,N-dialkylthioureas) as novel platforms in nuclear medicine for 68Ga, 177Lu and 198Au

Abstract Background Heterometallic gold metallacages are of great interest for the incorporation of several cations. Especially in nuclear medicine, those metallacages can serve as a platform for radionuclides relevant for imaging or therapy (e.g. 68Ga or 177Lu). Moreover, the radionuclide 198Au is an attractive beta emitter, for potential application in nuclear medicine. Here, we aim to synthesize a new set of gold metallacages and to study their ability to coordinate to 68Ga, 177Lu and 198Au. Results New heterometallic gold metallacages of composition [M{Au(Lmorph-κS)}3] (M = La3+, Tb3+, Lu3+ or Y3+) and [Ga{Au(Lmorph-κS)}2]NO3 have been synthesized from 2,6-dipicolinoylbis(N,N-morpholinylthiourea) (H2Lmorph) with [AuCl(THT)] and the target M3+ metal ions in yields ranging from 33 (Lu) to 62% (Tb). The characterization of the compounds bases on ESI–MS, 1H NMR, IR, EA and single-crystal X-ray diffraction techniques (all except the Ga derivative). Selected gold cages derived from H2Lmorph were compared to previously reported gold cages that were derived from 2,6-dipicolinoylbis(N,N-diethylthiourea) (H2Ldiethyl). The tested metallacages show similar IC50 values close to that of auranofin in four different cancer cell lines (MCF-7, PC-3, U383, U343), e.g. 4.5 ± 0.7 µM for [Ga{Au(Ldiethyl)}2]NO3 on PC-3. The radiolabeling experiments thereof show high radiochemical purities with 68Ga and 198Au and low radiochemical purity with 177Lu. Conclusions The results indicate that these gold metallacages could serve as a novel platform for inclusion of different (radio)nuclides with potential theranostic applications in nuclear medicine

Performance of real-world functional vision tasks by blind subjects improves after implantation with the Argus® II retinal prosthesis system.

BackgroundThe main objective of this study was to test Argus II subjects on three real-world functional vision tasks.DesignThe study was designed to be randomized and prospective. Testing was conducted in a hospital/research laboratory setting at the various participating centres.ParticipantsTwenty eight Argus II subjects, all profoundly blind, participated in this study.MethodsSubjects were tested on the three real-world functional vision tasks: Sock Sorting, Sidewalk Tracking and Walking Direction Discrimination task MAIN OUTCOME MEASURES: For the Sock Sorting task, percentage correct was computed based on how accurately subjects sorted the piles on a cloth-covered table and on a bare table. In the Sidewalk Tracking task, an 'out of bounds' count was recorded, signifying how often the subject veered away from the test course. During the Walking Direction Discrimination task, subjects were tested on the number of times they correctly identified the direction of testers walking across their field of view.ResultsThe mean percentage correct OFF versus ON for the Sock Sorting task was found to be significantly different for both testing conditions (t-test, P &lt; 0.01). On the Sidewalk Tracking task, subjects performed significantly better with the system ON than they did with the system OFF (t-test, P &lt; 0.05). Eighteen (18) of 27 subjects (67%) performed above chance with the system ON, and 6 (22%) did so with system OFF on the Walking Direction Discrimination task.ConclusionsArgus II subjects performed better on all three tasks with their systems ON than they did with their systems OFF

Performance of real-world functional vision tasks by blind subjects improves after implantation with the Argus® II retinal prosthesis system

The main objective of this study was to test Argus II subjects on three real-world functional vision tasks

Reduced Exercise Capacity, Chronotropic Incompetence, and Early Systemic Inflammation in Cardiopulmonary Phenotype Long Coronavirus Disease 2019

BackgroundMechanisms underlying persistent cardiopulmonary symptoms after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (postacute sequelae of coronavirus disease 2019 [COVID-19; PASC] or "long COVID") remain unclear. This study sought to elucidate mechanisms of cardiopulmonary symptoms and reduced exercise capacity.MethodsWe conducted cardiopulmonary exercise testing (CPET), cardiac magnetic resonance imaging (CMR) and ambulatory rhythm monitoring among adults &gt;1 year after SARS-CoV-2 infection, compared those with and those without symptoms, and correlated findings with previously measured biomarkers.ResultsSixty participants (median age, 53 years; 42% female; 87% nonhospitalized; median 17.6 months after infection) were studied. At CPET, 18/37 (49%) with symptoms had reduced exercise capacity (&lt;85% predicted), compared with 3/19 (16%) without symptoms (P = .02). The adjusted peak oxygen consumption (VO2) was 5.2 mL/kg/min lower (95% confidence interval, 2.1-8.3; P = .001) or 16.9% lower percent predicted (4.3%-29.6%; P = .02) among those with symptoms. Chronotropic incompetence was common. Inflammatory markers and antibody levels early in PASC were negatively correlated with peak VO2. Late-gadolinium enhancement on CMR and arrhythmias were absent.ConclusionsCardiopulmonary symptoms &gt;1 year after COVID-19 were associated with reduced exercise capacity, which was associated with earlier inflammatory markers. Chronotropic incompetence may explain exercise intolerance among some with "long COVID.