A Dictionary Approach to Electron Backscatter Diffraction Indexing.

We propose a framework for indexing of grain and subgrain structures in electron backscatter diffraction patterns of polycrystalline materials. We discretize the domain of a dynamical forward model onto a dense grid of orientations, producing a dictionary of patterns. For each measured pattern, we identify the most similar patterns in the dictionary, and identify boundaries, detect anomalies, and index crystal orientations. The statistical distribution of these closest matches is used in an unsupervised binary decision tree (DT) classifier to identify grain boundaries and anomalous regions. The DT classifies a pattern as an anomaly if it has an abnormally low similarity to any pattern in the dictionary. It classifies a pixel as being near a grain boundary if the highly ranked patterns in the dictionary differ significantly over the pixel's neighborhood. Indexing is accomplished by computing the mean orientation of the closest matches to each pattern. The mean orientation is estimated using a maximum likelihood approach that models the orientation distribution as a mixture of Von Mises-Fisher distributions over the quaternionic three sphere. The proposed dictionary matching approach permits segmentation, anomaly detection, and indexing to be performed in a unified manner with the additional benefit of uncertainty quantification.

Applications of Artificial Intelligence to Office Laryngoscopy: A Scoping Review.

OBJECTIVES/HYPOTHESIS: This scoping review aims to provide a broad overview of the applications of artificial intelligence (AI) to office laryngoscopy to identify gaps in knowledge and guide future research. STUDY DESIGN: Scoping Review. METHODS: Searches for studies on AI and office laryngoscopy were conducted in five databases. Title and abstract and then full-text screening were performed. Primary research studies published in English of any date were included. Studies were summarized by: AI applications, targeted conditions, imaging modalities, author affiliations, and dataset characteristics. RESULTS: Studies focused on vocal fold vibration analysis (43%), lesion recognition (24%), and vocal fold movement determination (19%). The most frequently automated tasks were recognition of vocal fold nodules (19%), polyp (14%), paralysis (11%), paresis (8%), and cyst (7%). Imaging modalities included high-speed laryngeal videos (45%), stroboscopy (29%), and narrow band imaging endoscopy (7%). The body of literature was primarily authored by science, technology, engineering, and math (STEM) specialists (76%) with only 30 studies (31%) involving co-authorship by STEM specialists and otolaryngologists. Datasets were mostly from single institution (84%) and most commonly originated from Germany (23%), USA (16%), Spain (9%), Italy (8%), and China (8%). Demographic information was only reported in 39 studies (40%), with age and sex being the most commonly reported, whereas race/ethnicity and gender were not reported in any studies. CONCLUSION: More interdisciplinary collaboration between STEM and otolaryngology research teams improved demographic reporting especially of race and ethnicity to ensure broad representation, and larger and more geographically diverse datasets will be crucial to future research on AI in office laryngoscopy. LEVEL OF EVIDENCE: NA Laryngoscope, 132:1993-2016, 2022.

Intracerebral GM-CSF contributes to transendothelial monocyte migration in APP/PS1 Alzheimer's disease mice.

Although tight junctions between human brain microvascular endothelial cells in the blood-brain barrier prevent molecules or cells in the bloodstream from entering the brain, in Alzheimer's disease, peripheral blood monocytes can "open" these tight junctions and trigger subsequent transendothelial migration. However, the mechanism underlying this migration is unclear. Here, we found that the CSF2RB, but not CSF2RA, subunit of the granulocyte-macrophage colony-stimulating factor receptor was overexpressed on monocytes from Alzheimer's disease patients. CSF2RB contributes to granulocyte-macrophage colony-stimulating factor-induced transendothelial monocyte migration. Granulocyte-macrophage colony-stimulating factor triggers human brain microvascular endothelial cells monolayer tight junction disassembly by downregulating ZO-1 expression via transcription modulation and claudin-5 expression via the ubiquitination pathway. Interestingly, intracerebral granulocyte-macrophage colony-stimulating factor blockade abolished the increased monocyte infiltration in the brains of APP/PS1 Alzheimer's disease model mice. Our results suggest that in Alzheimer's disease patients, high granulocyte-macrophage colony-stimulating factor levels in the brain parenchyma and cerebrospinal fluid induced blood-brain barrier opening, facilitating the infiltration of CSF2RB-expressing peripheral monocytes across blood-brain barrier and into the brain. CSF2RB might be useful as an Alzheimer's disease biomarker. Thus, our findings will help to understand the mechanism of monocyte infiltration in Alzheimer's disease pathogenesis.

Identification and characterisation of a novel antimicrobial polypeptide from the skin secretion of a Chinese frog (Rana chensinensis).

Amphibians secrete small antimicrobial polypeptides from their skin that have been explored as alternatives to conventional antibiotics. In this study, mass spectrometry was used to identify and characterise protein secretions from the skin of a Chinese frog, Rana chensinensis. The skin of this kind of frog has been used in traditional Chinese medicine for centuries as a remedy against inflammation. A novel antimicrobial peptide was identified and the characteristics of this peptide were analysed using far-ultraviolet circular dichroism. When dissolved in aqueous solution, the peptide displayed a high level of random coil structure, in contrast to a more ordered alpha-helical structure when dissolved in 50% trifluoroethanol. Functional studies showed that this peptide has potent antimicrobial activity both against Gram-positive and Gram-negative bacteria and has extremely low haemolytic activity to human red blood cells. Taken together, these studies suggest that this novel peptide can be further developed as an antimicrobial agent.