Severe occlusive carotid artery disease: hemodynamic assessment by MR perfusion imaging in symptomatic patients

BACKGROUND: The purpose of this study was to assess the capability of magnetic resonance imaging (MRI) and cytology and flow cytometric (FCM) deoxyribonucleic acid (DNA) analysis in fine-needle aspiration biopsy (FNAB)-derived materials for diagnosing malignancy of the parotid lesions and the efficacy of FCM analysis in FNAB. METHODS: Magnetic resonance imaging findings and FCM results (ploidy and S + G2 + M phases [S + G2M] fraction) and cytology in FNAB-derived materials in 26 patients with 26 parotid lesions (12 benign lesions, 14 malignancies) were assessed for predicting malignancy. Flow cytometric results in aspirates were compared with those in surgically resected tissues. RESULTS: When a single predictor was used, cytology (92% accuracy) was most accurate for malignancy, followed by ill-defined margin (88% accuracy) and aneuploidy (88% accuracy). The combination of FCM and cytology raised the rate of sufficient materials from 92% to 100% and accuracy from 92% to 96% compared with cytology alone. The same highest accuracy (96%) was obtained with the combination of the ill-defined margin or other findings such as cytology, aneuploidy, or a high (S + G2M) fraction (6% <). Deoxyribonucleic acid ploidy in the FNAB showed full agreement with that in the surgical specimens. Receiver operating characteristic curves showed that the diagnosis of malignancy with (S + G2M) fraction in FNAB was superior to that in surgical specimens, but no significant difference was noted. CONCLUSIONS: A combination of MRI findings, cytology, and FCM results is optimal for diagnosing malignancies of the parotid lesions, and FNAB may replace the surgical specimens in FCM analysis.     

The performance of several oxygen scavengers in varying oxygen environments at refrigerated temperatures: implications for low-oxygen modified atmosphere packaging of meat

The oxygen scavenging capacity of four commercially available iron-based oxygen scavengers was studied. Individual oxygen scavenger sachets were placed in pouches and filled with 1%, 2%, 6%, 12% or 22% oxygen, 40% carbon dioxide and balance nitrogen, and stored at 3 °C or 10 °C, with or without a drip pad infused with water and monitored over 24 h. The four scavengers all reduced oxygen from the packs at the oxygen concentrations and temperatures tested. However, for all of the conditions measured, the scavengers did not absorb their nominal capacity in the 24-h period. In anoxic modified atmosphere packaging of beef steaks, it is essential to reduce residual oxygen levels to below 0.05% as quickly as possible to minimise the formation of metmyoglobin. While the scavengers tested were effective in removing oxygen, the rate of removal would appear not to be fast enough to create the anoxic conditions required to prevent metmyoglobin formation in beef steaks, particularly in those cuts, which are highly susceptible to metmyoglobin formation. Reproducibility was also a critical issue for the scavengers, particularly at low oxygen concentrations. None of the scavengers had a coefficient of variation of less than 20% at the low oxygen concentrations. Therefore, to obtain consistent results, it is recommended that multiple scavengers be used.     

In-flight particulate matter concentrations in commercial flights are likely lower than other indoor environments

Air quality in indoor environments can have significant impacts on people's health, comfort, and productivity. Particulate matter (PM; also referred to as aerosols) is an important type of air pollutant, and exposure to outdoor PM has been associated with a variety of diseases. In addition, there is increasing recognition and concern of airborne transmission of viruses, including severe acute respiratory syndrome corona-virus 2 (SARS-CoV-2), especially in indoor environments. Despite its importance, indoor PM data during the COVID-19 pandemic are scarce. In this work, we measured and compared particle number and mass concentrations in aircraft cabins during commercial flights with various indoor environments in Atlanta, GA, during July 2020, including retail stores, grocery stores, restaurants, offices, transportation, and homes. Restaurants had the highest particle number and mass concentrations, dominated by cooking emissions, while in-flight aircraft cabins had the lowest observed concentrations out of all surveyed spaces.     

Ethanol and co-product generation from pressurized batch hot water pretreated T85 bermudagrass and Merkeron napiergrass using recombinant Escherichia coli as biocatalyst

Pretreatment of grasses is required to maximize ethanol yield during fermentation. T85 bermudagrass and Merkeron napiergrass (Pennisetum purpureum Schumach.) were either left untreated or were pressurized batch hot water (PBHW) pretreated for 2 min at 230 °C at 5% w/v whole grass solids loading. Following a 24 h enzymatic digestion, untreated and PBHW pretreated grasses were evaluated for ethanol production and co-product generation including potential fermentation inhibitors. Fermentations of PBHW pretreated grasses with E. coli LY01 produced twice the ethanol of their untreated counterparts. PBHW pretreated Merkeron napiergrass produced 224.5 mg/g grass ethanol (73% maximum theoretical yield) and PBHW pretreated T85 bermudagrass reached 213.0 mg/g grass (70% maximum theoretical ethanol yield). Pretreatment by PBHW resulted in increased solubilization of hemicelluloses. PBHW pretreatment also produced potential fermentation inhibitors such as acetic, formic, cinnamic acids, and aldehydes. Despite some of these inhibitors remaining with the solids after PBHW pretreatment, there was more efficient hydrolysis of the cellulose and remaining hemicellulose during the enzymatic digestion of the grasses prior to fermentation when compared to the untreated grasses. This increase in digestibility observed with enzymes prior to fermentation resulted in increased ethanol yields during bioconversion using E. coli LY01 as the biocatalyst.     

Neuroprotective Strategies after Neonatal Hypoxic Ischemic Encephalopathy

Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating disease that primarily causes neuronal and white matter injury and is among the leading cause of death among infants. Currently there are no well-established treatments; thus, it is important to understand the pathophysiology of the disease and elucidate complications that are creating a gap between basic science and clinical translation. In the development of neuroprotective strategies and translation of experimental results in HIE, there are many limitations and challenges to master based on an appropriate study design, drug delivery properties, dosage, and use in neonates. We will identify understudied targets after HIE, as well as neuroprotective molecules that bring hope to future treatments such as melatonin, topiramate, xenon, interferon-beta, stem cell transplantation. This review will also discuss some of the most recent trials being conducted in the clinical setting and evaluate what directions are needed in the future.     

Concept of Operations for Personal Remote Sensing Unmanned Aerial Systems

Unmanned Aerial Systems (UASs) have rapidly grown into a significant part of the world-wide aviation budget. However, regulations and official standards have lagged significantly. Within the U.S., there has been significant pressure to develop the regulations to allow commercial and governmental agencies to utilize UASs within the National Airspace System (NAS). The authors propose a concept of operation document that incorporates existing regulations and ensures an acceptable level of performance based on experience with a Personal Remote Sensing (PRS) Unmanned Aerial System (UAS).     

Application of thermal imaging to validate a heat transfer model for polymer electrolyte fuel cells

Heat management in polymer electrolyte membrane fuel cells (PEMFCs) plays a vital role in stack performance and durability, and overall system efficiency. A computational model assembled by the authors has been used to study the heat generated and distributed in single-cell and two-cell PEMFC stacks, with a focus on temperature variation on the external surfaces of the stack under different heat loads.