Acoustic noise reduction in the NexGen 7 T scanner.

PURPOSE: Driven by the Lorentz force, acoustic noise may arguably be the next physiological challenge associated with ultra-high field MRI scanners and powerful gradient coils. This work consisted of isolating and mitigating the main sound pathway in the NexGen 7 T scanner equipped with the investigational Impulse head gradient coil. METHODS: Sound pressure level (SPL) measurements were performed with and without the RF coil to assess its acoustic impact. Vibration measurements were carried out on the gradient coil, the RF coil, and on the patient table to distinguish the different vibration mechanisms and pathways. Vibrations of the RF coil were modified by either making contact with the patient bore liner with padding material or by changing directly the RF shield with phosphor bronze mesh material. RESULTS: SPL and vibration measurements demonstrated that eddy-currents induced in the RF shield were the primary cause of acoustic noise. Replacing the conventional solid copper shield with phosphor bronze mesh material altered the vibrations of the RF shield and decreased SPL by 6 to 8 dB at the highest frequencies in EPI, depending on the gradient axis, while boosting the transmit B1 + field by 15%. Padding led to slightly less sound reduction on the X and Z gradient axes, but with minimal impact for the Y axis. CONCLUSION: This study demonstrates the potential importance of eddy-current induced vibrations in the RF coil in terms of acoustic noise and opens new horizons for mitigation measures.

Does Using Corsi-Rosenthal Boxes to Mitigate COVID-19 Transmission Also Reduce Indoor Air Concentrations of PFAS and Phthalates?

The COVID-19 pandemic brought new emphasis on indoor air quality. However, few studies have investigated the impact of air filtration, a COVID-mitigation approach, on indoor air concentrations of semivolatile organic compounds (SVOCs). Using a quasi-experimental design, we quantified the impact of a relatively low-cost "do-it-yourself" air filter (Corsi-Rosenthal Box; CR Box) on indoor air concentrations of 42 PFAS and 24 other SVOCs. We sampled air before (October-November 2021) and during (February-March 2022) deployment of CR Boxes in 17 rooms located in an occupied Providence, Rhode Island office building. We measured sound levels in rooms with CR Boxes operating and not operating. While CR Boxes were deployed, concentrations of seven PFAS (N-EtFOSE, N-EtFOSA, FBSA, PFBS, PFHxS, PFOS, PFNA) were 28-61% lower and concentrations of five phthalates (DMP, DEP, DiBP, BBzP, DCHP) were 29-62% lower. Concentrations of five PFAS and one phthalate increased 23-44% during the intervention period, but the 95% CI of most of these estimates included the null. Daytime sound levels increased 5.0 dB when CR Boxes were operating. These results indicate that CR Boxes reduced exposure to several lower-volatility phthalates and sulfonated PFAS previously reported to be found in office building materials and products, with potentially distracting increases in sound levels.

Descriptive characterization of sound levels in an environmental justice city before and during a global pandemic.

Many environmental justice communities face elevated exposures to multiple stressors, given biases in urban and environmental policy and planning. This paper aims to evaluate sound level exposure in a densely populated environmental justice city in close proximity to major roadways, a nearby airport and high levels of industrial activity. In this study we collected various sound level metrics to evaluate the loudness and frequency composition of the acoustical environment in Chelsea, Massachusetts, USA. A total of 29 week-long sites were collected from October 2019 to June 2020, a time period that also included the influence of the COVID-19 pandemic, which drastically altered activity patterns and corresponding sound level exposures. We found that Chelsea is exposed to high levels of sound, both day and night (65 dB (A), and 80 dB and 90 dB for low frequency, and infrasound sound levels). A spectral analysis shows that 63 Hz was the dominant frequency. Distance to major roads and flight activity (both arrivals and departures) were most strongly correlated with all metrics, most notably with metrics describing contributing from lower frequencies. Overall, we found similar patterns during the COVID-19 pandemic but at levels up to 10 dB lower. Our results demonstrate the importance of noise exposure assessments in environmental justice communities and the importance of using additional metrics to describe communities inundated with significant air, road, and industrial sound levels. It also provides a snapshot of how much quieter communities can be with careful and intentional urban and environmental policy and planning.

Development and application of a noise-hazard scheme for road maintainers.

BACKGROUND: Transportation road maintenance and repair workers, or "maintainers," are exposed to hazardous and variable noise levels and often rely on hearing protection devices (HPD) to reduce noise-exposure levels. We aimed to improve upon HPD use as part of the HearWell program that used a Total Worker Health, participatory approach to hearing conservation. METHODS: Full-shift, personal noise sampling was performed during the routine task of brush cutting. Work activities and equipment were recorded and combined with 1-min noise measures to summarize personal noise-exposure levels by equipment. Using noise-monitoring results, HPD noise reduction ratings, and input from worker-based design teams, a noise-hazard scheme was developed and applied to the task and equipment used during brush cutting. RESULTS: Average (standard deviation) and maximum Leq 1-minute, personal noise-exposure levels recorded during brush cutting included chainsaws at 92.1 (7.6) and max of 111 dBA, leaf blowers at 91.2 (7.5) and max 107 dBA, and wood chipper at 90.3 (7.3) and max of 104 dBA. The worker-designed noise-hazard scheme breaks down noise exposures into one of three color bands and exposure ranges: red (over 105 dBA), orange (90-105 dBA), or yellow (85-90 dBA). The scheme simplifies the identification of noise levels, assessment of noise-hazard, and choice of appropriate hearing protection for workers. CONCLUSION: Combining noise-exposure assessment with intervention development using participatory methods, we characterized noise exposure and developed an intervention to educate and assist in protecting workers as they perform noisy tasks.

Spatial and temporal determinants of A-weighted and frequency specific sound levels-An elastic net approach.

BACKGROUND: Urban sound levels are a ubiquitous environmental stressor and have been shown to be associated with a wide variety of health outcomes. While much is known about the predictors of A-weighted sound pressure levels in the urban environment, far less is known about other frequencies. OBJECTIVE: To develop a series of spatial-temporal sound models to predict A-weighted sound pressure levels, low, mid, and high frequency sound for Boston, Massachusetts. METHODS: Short-term sound levels were gathered at n = 400 sites from February 2015 - February 2016. Spatial and meteorological attributes at or near the sound monitoring site were obtained using publicly available data and a portable weather station. An elastic net variable selection technique was used to select predictors of A-weighted, low, mid, and high frequency sound. RESULTS: The final models for low, mid, high, and A-weighted sound levels explained 59 - 69% of the variability in each measure. Similar to other A-weighted models, our sound models included transportation related variables such as length of roads and bus lines in the surrounding area; distance to road and rail lines; traffic volume, vehicle mix, residential and commercial land use. However, frequency specific models highlighted additional predictors not included in the A-weighted model including temperature, vegetation, impervious surfaces, vehicle mix, and density of entertainment establishments and restaurants. CONCLUSIONS: Building spatial temporal models to characterize sound levels across the frequency spectrum using an elastic net approach can be a promising tool for noise exposure assessments within the urban soundscape. Models of sound's character may give us additional important sound exposure metrics to be utilized in epidemiological studies.

Cardiovascular and stress responses to short-term noise exposures-A panel study in healthy males.

BACKGROUND: While previous epidemiological studies report adverse effects of long-term noise exposure on cardiovascular health, the mechanisms responsible for these effects are unclear. We sought to elucidate the cardiovascular and stress response to short-term, low (31.5-125Hz) and high (500-2000Hz) frequency noise exposures. METHODS: Healthy male (n=10) participants were monitored on multiple visits during no noise, low- or high-frequency noise exposure scenarios lasting 40min. Participants were fitted with an ambulatory electrocardiogram (ECG) and blood pressure measures and saliva samples were taken before, during and after noise exposures. ECGs were processed for measures of heart rate variability (HRV): high-frequency power (HF), low-frequency power (LF), the root of the mean squared difference between adjacent normal heart beats (N-N) intervals (RMSSD), and the standard deviation of N-N intervals (SDNN). Systolic blood pressure (SBP), diastolic blood pressure (DPB), and pulse were reported and saliva was analyzed for salivary cortisol and amylase. Multivariate mixed-effects linear regression models adjusted for age were used to identify statistically significant difference in outcomes by no noise, during noise or after noise exposure periods and whether this differed by noise frequency. RESULTS: A total of 658, 205, and 122, HRV, saliva, and blood pressure measurements were performed over 41 person days. Reductions in HRV (LF and RMSSD) were observed during noise exposure (a reduction of 19% (-35,-3.5) and 9.1% (-17,-1.1), respectively). After adjusting for noise frequency, during low frequency noise exposure, HF, LF, and SDNN were reduced (a reduction of 32% (-57,-6.2), 34% (-52,-15), and 16% (-26,-6.1), respectively) and during high frequency noise exposure, a 21% (-39,-2.3) reduction in LF, as compared to during no noise exposure, was found. No significant (p<0.05) changes in blood pressure, salivary cortisol, or amylase were observed. CONCLUSIONS: These results suggest that exposure to noise, and in particular, to low-frequency noise, negatively impacts HRV. The frequencies of noise should be considered when evaluating the cardiovascular health impacts of exposure.

Daptomycin-induced rhabdomyolysis and acute liver injury.

Daptomycin use is a known cause of rhabdomyolysis; its role in liver injury is less certain. We report a case of daptomycin-induced rhabdomyolysis with liver injury. This report indicates a role for liver function monitoring while receiving daptomycin, as well as the importance of promptly considering drug toxicities in acute and emergency care settings.

Use and Interchange of Incretin Mimetics in the Treatment of Metabolic Diseases: A Narrative Review.

PURPOSE: Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) and now tirzepatide, a dual GLP-1 RA/glucose-dependent insulinotropic polypeptide agonist, have numerous advantages in the treatment of type 2 diabetes and obesity, yet only 11% of patients with type 2 diabetes are prescribed a GLP-1 RA. This narrative review addresses the complexity and cost issues surrounding incretin mimetics to support clinicians. METHODS: This narrative review summarizes key trials on the differing effects of incretin mimetics on glycosylated hemoglobin and weight, provides a table with rationale for how to interchange among agents, and summarizes the key factors that guide drug selection beyond guidance from the American Diabetes Association. To support proposed dose interchanges, we preferentially selected high-quality, prospective randomized controlled trials with direct comparisons of agents and doses when available. FINDINGS: Tirzepatide produces the greatest reductions in glycosylated hemoglobin and weight, but its impact on cardiovascular events is still under investigation. Subcutaneous semaglutide and liraglutide are approved for weight loss specifically and are effective in the secondary prevention of cardiovascular disease. Although producing less weight loss, only dulaglutide has effectiveness in the primary and secondary prevention of cardiovascular disease. Semaglutide is the only orally available incretin mimetic; however, the oral formulation produces less weight loss versus its subcutaneous alternative and did not have cardioprotection in its outcomes trial. Although effective in controlling type 2 diabetes, exenatide extended release has the least impact on glycosylated hemoglobin and weight among commonly used agents, while not having cardioprotection. However, exenatide extended release may be preferred on some restrictive insurance formularies. IMPLICATIONS: Although trials have not explicitly studied how to interchange among agents, interchanges can be guided by comparisons between agents' impact on glycosylated hemoglobin and weight. Efficient changes among agents can help clinicians optimize patient-centered care, particularly in the face of changing patient needs and preferences, insurance formularies, and drug shortages.

Effects of Corsi-Rosenthal boxes on indoor air contaminants: non-targeted analysis using high resolution mass spectrometry.

BACKGROUND: In response to COVID-19, attention was drawn to indoor air quality and interventions to mitigate airborne COVID-19 transmission. Of developed interventions, Corsi-Rosenthal (CR) boxes, a do-it-yourself indoor air filter, may have potential co-benefits of reducing indoor air contaminant levels. OBJECTIVE: We employed non-targeted and suspect screening analysis (NTA and SSA) to detect and identify volatile and semi-volatile organic contaminants (VOCs and SVOCs) that decreased in indoor air following installation of CR boxes. METHODS: Using a natural experiment, we sampled indoor air before and during installation of CR boxes in 17 rooms inside an occupied office building. We measured VOCs and SVOCs using gas chromatography (GC) high resolution mass spectrometry (HRMS) with electron ionization (EI) and liquid chromatography (LC) HRMS in negative and positive electrospray ionization (ESI). We examined area count changes during vs. before operation of the CR boxes using linear mixed models. RESULTS: Transformed (log2) area counts of 71 features significantly decreased by 50-100% after CR boxes were installed (False Discovery Rate (FDR) p-value < 0.2). Of the significantly decreased features, four chemicals were identified with Level 1 confidence, 45 were putatively identified with Level 2-4 confidence, and 22 could not be identified (Level 5). Identified and putatively identified features (Level ≥4) that declined included disinfectants (n = 1), fragrance and/or food chemicals (n = 9), nitrogen-containing heterocyclic compounds (n = 4), organophosphate esters (n = 1), polycyclic aromatic hydrocarbons (n = 8), polychlorinated biphenyls (n = 1), pesticides/herbicides/insecticides (n = 18), per- and polyfluorinated alkyl substances (n = 2), phthalates (n = 3), and plasticizers (n = 2). IMPACT STATEMENT: We used SSA and NTA to demonstrate that do-it-yourself Corsi-Rosenthal boxes are an effective means for improving indoor air quality by reducing a wide range of volatile and semi-volatile organic contaminants.

The Impact of Exercise and Virtual Reality Executive Function Training on Cognition Among Heavy Drinking Veterans With Traumatic Brain Injury: A Pilot Feasibility Study.

Executive function (EF) underlies self-control deficits in alcohol use disorder (AUD) and traumatic brain injury (TBI). Cognitive training is a promising adjunctive treatment targeting TBI- and AUD- related cognitive dysfunction. However, major limitations related to compliance and generalizability in the field of cognitive training exist. Physical activity is associated with enhanced cognitive performance across several executive functions and may enhance the benefits of cognitive training. Virtual reality provides multisensory embodied experiences which are likely to engage brain networks more efficiently than standard cognitive training systems, ultimately resulting in greater near- and far-transfer effects. This pilot study aimed to obtain feasibility data and a preliminary assessment of an enriched virtual reality (VR) EF training (EFT) intervention combined with exercise (NCT03786276). Using an 8-week randomized adaptive design study, 30 AUD treatment seeking U.S. Veterans completed nine sessions of exercise-only (n = 15) or gameplay control (n = 15) over 3 weeks, followed by a week-4 repeat assessment in Phase 1. Twenty-three participants completed and moved onto Phase II, where they completed up to nine sessions of VR-EFT plus exercise and completed a week-8 end-of-study assessment. Primary outcomes included feasibility to retain participants, usability, and satisfaction of using VR-EFT. Secondary and exploratory outcomes included within group assessment of change in cognitive function, alcohol use, alcohol craving, and post-concussive symptoms among the three treatment conditions.VR-EFT was feasible with moderate usability and high acceptability ratings.The most common VR-related adverse effect was motion sickness (n = 2/16, 12.5%). The VR-EFT condition was associated with significant improvement in inhibition-switching and visual scanning (both p < 0.05) during Phase II. Exercise-only was associated with significant improvements in cognitive inhibition, cognitive flexibility, reductions in alcohol craving, and number of standard alcohol drinks per week (all p ≤ 0.05). The gaming-control condition was associated with improvement in cognitive flexibility and visuospatial immediate recall (both p < 0.05) during Phase 1. Recruitment and retention of U.S. veterans with AUD and TBI into an exercise plus VR-EFT intervention is feasible, but technological barriers may impact usability. VR-EFT was associated with improvement in executive function domains that were targeted in as little as 3-week and nine sessions of VR-EFT exposure. Results are promising and indicate the need for a larger controlled investigation to assess the efficacy of VR-EFT to enhance treatment outcomes among AUD treatment-seeking U.S. veterans with co-occurring AUD and TBI. Clinical Trial Registration: www.ClinicalTrials.gov, Identifier: NCT03786276.

Acupuncture for acute musculoskeletal pain management in the emergency department and continuity clinic: a protocol for an adaptive pragmatic randomised controlled trial.

INTRODUCTION: Chronic musculoskeletal pain causes a significant burden on health and quality of life and may result from inadequate treatment of acute musculoskeletal pain. The emergency department (ED) represents a novel setting in which to test non-pharmacological interventions early in the pain trajectory to prevent the transition from acute to chronic pain. Acupuncture is increasingly recognised as a safe, affordable and effective treatment for pain and anxiety in the clinic setting, but it has yet to be established as a primary treatment option in the ED. METHODS AND ANALYSIS: This pragmatic clinical trial uses a two-stage adaptive randomised design to determine the feasibility, acceptability and effectiveness of acupuncture initiated in the ED and continued in outpatient clinic for treating acute musculoskeletal pain. The objective of the first (treatment selection) stage is to determine the more effective style of ED-based acupuncture, auricular acupuncture or peripheral acupuncture, as compared with no acupuncture. All arms will receive usual care at the discretion of the ED provider blinded to treatment arm. The objective of the second (effectiveness confirmation) stage is to confirm the impact of the selected acupuncture arm on pain reduction. An interim analysis is planned at the end of stage 1 based on probability of being the best treatment, after which adaptations will be considered including dropping the less effective arm, sample size re-estimation and unequal treatment allocation ratio (eg, 1:2) for stage 2. Acupuncture treatments will be delivered by licensed acupuncturists in the ED and twice weekly for 1 month afterward in an outpatient clinic. ETHICS AND DISSEMINATION: This study has been reviewed and approved by the Duke University Health System Institutional Review Board. Informed consent will be obtained from all participants. Results will be disseminated through peer-review publications and public and conference presentations. TRIAL REGISTRATION NUMBER: NCT04290741.

Involuntary attentional shifts as a function of set and processing fluency.

In laboratory tasks, involuntary cognitions of various kinds (e.g., mental imagery) have been elicited by external stimuli. These effects reveal, among other things, the capacities of involuntary processes. In most cases, these cognitions do not require, for their generation, executive functions such as a shift in selective attention. In Experiment 1, subjects were presented with a clock of 12 words in the stead of numbers and were instructed to focus on the center of the screen and to not count the number of letters of a word at a certain location. Involuntary counting of the critical word occurred on 39% of the trials. This effect requires an involuntary shift of attention. Experiment 2, involving Chinese ideographs, concerned the effect of stimulus fidelity and processing fluency. Native English speakers and a separate group of subjects who could read Chinese ideographs were presented with an array similar to that of Experiment 1 and instructed to not read any of the words. Some words were easy to read (e.g., regular Chinese words and English words), and some words were more difficult to read (e.g., Chinese "loan" words and English pseudowords). For the subjects who could read Chinese ideographs, more involuntary reading occurred for regular ideographs than for loan words. For the Native English speakers, comparable effects were found with the English stimuli. Together, these studies reveal that attentional phenomena of this kind can be influenced involuntarily and systematically through external control.

Characteristics of Lawn and Garden Equipment Sound: A Community Pilot Study.

More than 11 million gas powered leaf blowers (GLB) operate in the US. Most are powered by inefficient 2-stroke engines. The noise is intolerable to some and many communities have enacted ordinances restricting their use. This pilot study aimed to characterize the low, medium, and high frequency sound components from commercial grade GLBs over distance, evaluate the adequacy of the A-weighted decibel (dB [A]) to describe this sound, and discuss the impact of GLB sound in a community setting. In a field experiment with 2 leaf blowers and a hose vacuum, the time averaged A-weighted dB(A) (LAEQ) and un-weighted dB (LEQ) metrics, and low, mid, and high frequency GLB sound components were evaluated at intervals out to 800 feet from point of operation (centroid). Sound levels at 50 feet for each GLB were consistent with manufacturer ratings. The sound from the 2 GLBs and hose vacuum exceeded 100 decibels for both LEQ and LAEQ at the centroid. At all distance intervals, LEQ was 11.2-12.5 decibels higher compared with LAEQ. With the exception of the high frequency dB, all sound metrics emitted from this equipment were found to exceed WHO outdoor daytime standards (55 dB) up to 800 feet away from the centroid. The dominance of the low frequency component over distance indicates that a dB-based metric is a more appropriate descriptor of this sound compared with a dB(A)-based metric. The loudness of GLB sound at point of operation is especially concerning for the auditory and non-auditory health of workers and others regularly exposed in close proximity. The ability of this sound - in particular its lower frequency components - to travel over long distances suggests that GLB sound has a wide ranging impact on surrounding communities and raises concerns over its adverse health impacts.

The Characterization of Polycyclic Aromatic Hydrocarbons in Northeastern US Trucking Terminals.

In recent years, significant attention has been given to polycyclic aromatic hydrocarbons (PAHs) exposures given their mutagenic and carcinogenic properties. However, levels of exposure and the key determinants of exposure are not well defined for the trucking industry. We measured ultrafine particle characteristics at 10 trucking terminals of varying operating size and location in the Northeast region of the United States using particle concentration counter and a surface area analyzer. Multivariate mixed-effects linear regression models were used to assess determinants of the concentration of total bound PAHs (tPAH), the total aerosol active surface area (AS), and the ratio tPAH/AS overall and individually within docks, trucking cabs, and administrative offices. Associations between PAH measures with integrated measures of elemental carbon (EC), organic carbon (OC), and particulate matter (PM)2.5 were assessed by Spearman rank correlation. In adjusted models, tPAH, AS, and tPAH/AS average concentrations (95% confidence interval) were significantly higher in truck cabs compared to office locations (1.26 (ng m-3) (1.18, 1.35); 0.99 (mm2 mm-3) (0.91, 1.08); 0.26 (ng mm-2) (0.18, 0.33), respectively). In the loading dock, AS concentrations were significantly higher than in the office (0.67 (0.61, 0.71), while the tPAH/AS was not (-0.63 (-0.67, -0.58). In each location, average tPAH concentrations were moderately but significantly correlated with EC (r = 0.47-0.63) and with tPAH/AS (r = 0.34-0.40) in the truck cabs and loading docks. In conclusion, key predictors of tPAH, AS, and tPAH/AS within the trucking industry are work location (in particular truck cabs and terminal docks) and terminal characteristics (size). The association of tPAH and tPAH/AS with EC concentrations in dockworkers and pick-up and delivery drivers is consistent with occupational exposure attributable to vehicle exhaust. Therefore, measurement of tPAH, AS, and tPAH/AS to characterize ultrafine particles and bound PAH concentrations provide additional information regarding exposures in the trucking industry not captured by integrated measures by EC, OC, and PM2.5.

Multiclonal methicillin-resistant Staphylococcus aureus (MRSA) outbreak and its control after use of the Veterans Affairs (VA) MRSA bundle in a VA long-term care facility, 2004-2014.

A multiclonal methicillin-resistant Staphylococcus aureus (MRSA) outbreak with 91 infections occurred in our Veterans Affairs (VA) community living center over 46 months. Both similar and unique strains were shown by repetitive polymerase chain reaction to contribute to the outbreak, including 1 strain causing infections over a 33-month period. Most infections were soft tissue infections (67%). For 21 months after the initiation of the VA MRSA bundle, no infections were identified, and low rates of infection have been sustained an additional 4 years. The average annual rate of MRSA infection decreased by 62% (P < .001) from 0.6 per 1,000 resident days for 4 years prior to the bundle implementation to 0.09 per 1,000 resident days for 4 years after the bundle implementation.

Retinal arterial macroaneurysm causing multilevel retinal hemorrhage.

BACKGROUND: Retinal arterial macroaneurysms are focal dilatations of the retinal arteries that present with varying degrees of retinal hemorrhage or exudation. They are most often associated with hypertension and may masquerade as many other retinal conditions. CASE REPORT: A hypertensive 59-year-old man presented to the clinic with a sudden onset of painless vision loss in the left eye. Best-corrected visual acuities were 20/20 in the right eye and counting fingers at 3 feet with eccentric viewing in the left. Dilated fundus examination found a multilevel retinal hemorrhage involving most of the superior arcade and extending into the macular area. A diagnosis of retinal arterial macroaneurysm was given after fluorescein angiography and evaluation by a retina specialist. Hemorrhage resolved without treatment, and visual acuity returned to 20/25 by the 6-month follow-up visit. CONCLUSIONS: Optometrists should be aware of presenting signs and symptoms associated with retinal macroaneurysms as well as the many differentials and possible treatments. Given the high incidence of associated systemic disease, proper knowledge of necessary systemic workup is also critical.