Evaluation of Viral Inactivation on Dry Surface by High Peak Power Microwave (HPPM) Exposure.

Previous research has shown that virus infectivity can be dramatically reduced by radio frequency exposure in the gigahertz (GHz) frequency range. Given the worldwide SARS-CoV-2 pandemic, which has caused over 1 million deaths and has had a profound global economic impact, there is a need for a noninvasive technology that can reduce the transmission of virus among humans. RF is a potential wide area-of-effect viral decontamination technology that could be used in hospital rooms where patients are expelling virus, in grocery and convenience stores where local populations mix, and in first responder settings where rapid medical response spans many potentially infected locations within hours. In this study, we used bovine coronavirus (BCoV) as a surrogate of SARS-CoV-2 and exposed it to high peak power microwave (HPPM) pulses at four narrowband frequencies: 2.8, 5.6, 8.5, and 9.3 GHz. Exposures consisted of 2 µs pulses delivered at 500 Hz, with pulse counts varied by decades between 1 and 10,000. The peak field intensities (i.e. the instantaneous power density of each pulse) ranged between 0.6 and 6.5 MW/m2 , depending on the microwave frequency. The HPPM exposures were delivered to plastic coverslips containing BCoV dried on the surface. Hemagglutination (HA) and cytopathic effect analyses were performed 6 days after inoculation of host cells to assess viral infectivity. No change in viral infectivity was seen with increasing dose (pulse number) across the tested frequencies. Under all conditions tested, exposure did not reduce infectivity more than 1.0 log10. For the conditions studied, high peak power pulsed RF exposures in the 2-10 GHz range appear ineffective as a virucidal approach for hard surface decontamination. © 2023 Bioelectromagnetics Society.

Temperature Dynamics in Rat Brains Exposed to Near-Field Waveguide Outputs at 2.8 GHz.

Biological effects in the microwave band of the radiofrequency (RF) spectrum are thermally mediated. For acute high-power microwave exposures, these effects will depend on transient time-temperature histories within the tissue. In this article, we summarize the transient temperature response of rats exposed to RF energy emanating from an open-ended rectangular waveguide. These exposures produced specific absorption rates of approximately 36 and 203 W/kg in the whole body and brain, respectively. We then use the experimentally measured thermal data to infer the baseline perfusion rate in the brain and modify a custom thermal modeling tool based upon these findings. Finally, we compare multi-physics simulations of rat brain temperature against empirical measurements in both live and euthanized subjects and find close agreement between model and experimentation. This research revealed that baseline brain perfusion rates in rat subjects could be larger than previously assumed in the RF thermal modeling literature, and plays a significant role in the transient thermal response to high-power microwave exposures. © 2021 Bioelectromagnetics Society.

Evaluation of inactivation of bovine coronavirus by low-level radiofrequency irradiation.

Inactivation of influenza A virus by radiofrequency (RF) energy exposure at levels near Institute of Electrical and Electronics Engineers (IEEE) safety thresholds has been reported. The authors hypothesized that this inactivation was through a structure-resonant energy transfer mechanism. If this hypothesis is confirmed, such a technology could be used to prevent transmission of virus in occupied public spaces where RF irradiation of surfaces could be performed at scale. The present study aims to both replicate and expand the previous work by investigating the neutralization of bovine coronavirus (BCoV), a surrogate of SARS-CoV-2, by RF radiation in 6-12 GHz range. Results showed an appreciable reduction in BCoV infectivity (up to 77%) due to RF exposure to certain frequencies, but failed to generate enough reduction to be considered clinically significant.

Revisiting 35 and 94 GHZ Millimeter Wave Exposure to the Non-Human Primate Eye.

A previous study reported thermal effects resulting from millimeter wave exposures at 35 and 94 GHz on non-human primates, specifically rhesus monkeys' (Macaca mulatta) corneas, but the data exhibited large variations in the observed temperatures and uncertainties in the millimeter wave dosimetry. By incorporating improvements in models and dosimetry, a non-human primate experiment was conducted involving corneal exposures that agreed well with a three-layer, one-dimensional, thermodynamic model to predict the expected surface temperature rise. The new data indicated that the originally reported safety margins for eye exposures were underestimated by 41 ± 20% over the power densities explored. As a result, the expected minimal visible lesion thresholds should be raised to 10.6 ± 1.5 and 7.1 ± 1.0 J cm at 35 and 94 GHz, respectively, provided that the power density is less than 6 W cm for subjects that are unable to blink. If the blink reflex was active, a power density threshold of 20 W cm could be used to protect the eye, although the eyelid could be burned if the exposure was long enough.

The effects of nasal closure on quality of life in patients with hereditary hemorrhagic telangiectasia.

INTRODUCTION: Epistaxis is the most common symptom of hereditary hemorrhagic telangiectasia (HHT). Complete nasal closure is one of the treatment options for patients with severe, intractable epistaxis. In our experience, this surgery can be life changing in a positive sense; but many patients as well as their physicians understandably fear that such a procedure will diminish certain aspects of quality of life (QOL). METHODS: Case-control study of HHT patients treated at the University of Utah HHT Center of Excellence with and without nasal closure from January 2005 to January 2016. Patients were matched according to epistaxis severity. Each included patient was issued three surveys: Epistaxis Severity Score (ESS), the Pittsburg Sleep Quality Index (PSQI), and the Nasal Obstruction Symptom Evaluation (NOSE). RESULTS: After treatment, the mean PSQI and NOSE scores were not significantly different between the two groups. However, the mean ESS score in the nasal closure group was significantly lower at 1.10 compared to the severe epistaxis group with a mean score of 3.99 (P = .027). CONCLUSION: The results of this study demonstrate that nasal closure significantly improves epistaxis severity without having a significant effect on sleep or nasal obstruction as they relate to QOL. These findings suggest that nasal closure should be considered for HHT patients with chronic severe epistaxis. LEVEL OF EVIDENCE: 4.

The Discovery of N-(1-Methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)-5-((6- ((methylamino)methyl)pyrimidin-4-yl)oxy)-1H-indole-1-carboxamide (Acrizanib), a VEGFR-2 Inhibitor Specifically Designed for Topical Ocular Delivery, as a Therapy for Neovascular Age-Related Macular Degeneration.

A noninvasive topical ocular therapy for the treatment of neovascular or "wet" age-related macular degeneration would provide a patient administered alternative to the current standard of care, which requires physician administered intravitreal injections. This manuscript describes a novel strategy for the use of in vivo models of choroidal neovascularization (CNV) as the primary means of developing SAR related to efficacy from topical administration. Ultimately, this effort led to the discovery of acrizanib (LHA510), a small-molecule VEGFR-2 inhibitor with potency and efficacy in rodent CNV models, limited systemic exposure after topical ocular administration, multiple formulation options, and an acceptable rabbit ocular PK profile.

Discovery of Oral VEGFR-2 Inhibitors with Prolonged Ocular Retention That Are Efficacious in Models of Wet Age-Related Macular Degeneration.

The benefit of intravitreal anti-VEGF therapy in treating wet age-related macular degeneration (AMD) is well established. Identification of VEGFR-2 inhibitors with optimal ADME properties for an ocular indication provides opportunities for dosing routes beyond intravitreal injection. We employed a high-throughput in vivo screening strategy with rodent models of choroidal neovascularization and iterative compound design to identify VEGFR-2 inhibitors with potential to benefit wet AMD patients. These compounds demonstrate preferential ocular tissue distribution and efficacy after oral administration while minimizing systemic exposure.

Penetrating trauma to the head and neck from a nail gun: a unique mechanism of injury.

Published reports of nail gun injuries to the head and neck are rare. We describe the cases of three patients who sustained nail gun injuries to the head and who were managed at our institution. All patients were treated successfully and all recovered with minimal morbidity. Any physician who is called on to manage a nail gun injury to the head or neck should understand that most likely the patient will have sustained a surprisingly limited amount of tissue injury, owing to the relatively low velocity of the projectile compared with that delivered by firearms. Computed tomography and selective angiography can play a vital role in assessing the integrity of relevant vascular structures. Moreover, catheter angiography with embolization can be a most useful nonsurgical adjunct to control the extent of vascular injury.

The Young's procedure for severe epistaxis from hereditary hemorrhagic telangiectasia.

BACKGROUND: Surgical treatment of epistaxis in hereditary hemorrhagic telangiectasia (HHT) has historically been managed with the laser procedure or the septodermoplasty procedure. For transfusion-dependent patients with severe epistaxis we have been performing the Young's procedure or surgical closure of the nostrils. The objective of this study was to report treatment of severe epistaxis related to HHT with the Young's procedure and assess patient outcome. METHODS: Patients with severe iron or blood transfusion-dependent epistaxis who underwent a Young's procedure in three otolaryngology HHT centers were reviewed. Patients were evaluated for postoperative epistaxis and subjective outcome. RESULTS: Forty-three patients underwent a Young's procedure for severe epistaxis and were observed for a mean of 34 months. The procedure was well tolerated by all patients and 30 of 36 patients (83%) experienced complete cessation of bleeding after the Young's procedure. Patients had a mean increase in hemoglobin of 4.68 g/dL after the procedure. The average Glasgow Benefit Inventory score after surgery was 43.56. No patients requested a reversal of the procedure. CONCLUSION: The Young's procedure is a safe and efficacious procedure with complete cessation of epistaxis in most patients with severe epistaxis and HHT.

Specific sensing between inositol epimers by a bis(boronate).

Bis(boronates) that utilize internal photoinduced electron transfer (PET) quenching mechanisms can specifically signal the binding of chiro-inositol without responding to its epimer, myo-inositol.