Nano-Imaging of Chiro-Optical Force

Nanoscopic observation of chiro-optical phenomena is essential in wide scientific areas but has measurement difficulties; hence, its physics are still unknown. Currently, in most cases, chiro-optical phenomena have been investigated by polarized light handling far-field measurements or via predictions by theoretical simulations. To obtain a full understanding of the physics of chiro-optical systems and derive the full potentials, it is essential to perform in situ observation of the chiro-optical effect from the individual parts because the macroscopic chiro-optical effect cannot be translated directly into microscopic effects. In the present study, we observed the chiro-optical responses at the nanoscale level by detecting the chiro-optical forces, which were generated by illumination of the material/probe system with circularly polarized light. The induced optical force was dependent on the handedness of the incident circularly polarized light and well correlated to the electromagnetically simulated differential intensity of the longitudinal electric field. Our results facilitate the clarification of chiro-optical phenomena at the nanoscale level and could innovate chiro-optical nanotechnologies

Computer-Aided Designing and Manufacturing of Lingual Fixed Orthodontic Appliance Using 2D/3D Registration Software and Rapid Prototyping

The availability of 3D dental model scanning technology, combined with the ability to register CBCT data with digital models, has enabled the fabrication of orthognathic surgical CAD/CAM designed splints, customized brackets, and indirect bonding systems. In this study, custom lingual orthodontic appliances were virtually designed by merging 3D model images with lateral and posterior-anterior cephalograms. By exporting design information to 3D CAD software, we have produced a stereolithographic prototype and converted it into a cobalt-chrome alloy appliance as a way of combining traditional prosthetic investment and cast techniques. While the bonding procedure of the appliance could be reinforced, CAD technology simplified the fabrication process by eliminating the soldering phase. This report describes CAD/CAM fabrication of the complex anteroposterior lingual bonded retraction appliance for intrusive retraction of the maxillary anterior dentition. Furthermore, the CAD/CAM method eliminates the extra step of determining the lever arm on the lateral cephalograms and subsequent design modifications on the study model

Improvement of Strength and Oxidation Resistance at High Temperature in AISI 4140 Steel by Micro-Alloying Chromium and Tungsten for Automotive Engine Applications

Increasing the operating temperature and pressure of an automotive engine and reducing its weight can improve fuel efficiency and lower carbon dioxide emissions. These can be achieved by changing the engine piston material from conventional aluminum alloy to high-strength heat- resistant steel. American Iron and Steel Institute 4140 modified steels (AISI 4140 Mod.s), which have improved strength, oxidation resistance, and wear resistance at high temperature were developed by adjusting the AISI 4140 alloy compositions and optimizing the heat treatment process for automotive engine applications. In this study, the effects of modifying alloy compositions on the microstructure, mechanical properties (both at room and high temperatures), and oxidation of AISI 4140 Mod.s were investigated. Effective grain refinement occurred due to the influence of high-temperature stable carbide forming elements such as Mo, and V. The bainite structure changed to martensite structure under the influence Cr and Ni. As the Cr and W contents increased, the oxidation resistance was improved, and the oxide layer thickness decreased after 10 hours exposure at 500°C. The AISI 4140 Mod. exhibited a 35% improvement in room temperature strength, 70% improvement in high-temperature strength, and 40% improvement in high-temperature oxidation resistance compared to conventional AISI 4140

The Association Between Masticatory Function Assessment and Masseter Muscle Thickness in the Elderly

Purpose: Purpose: This study investigated the association between the objective indicator of masticatory function assessment and the masseter muscle thickness (MMT) using ultrasound imaging. Methods: Methods: A total of 99 subjects (males: 24, females: 75, mean age: 76) were analyzed. The maximum bite force (MBF) was measured with a pressure-sensitive sheet and an image scanner. The mixing ability index (MAI) was calculated by image analysis after asking the subjects to chew a wax specimen. The MMT during rest and clenching were obtained with a diagnostic ultrasound system, and the difference in MMT during rest and MMT during clenching was defined as the difference in masseter muscle thickness (DMMT). Multiple regression analysis was performed to determine the independent variables affecting MBF and MAI. Results: Results: The MBF showed correlation with the number of remaining teeth (β=0.346, p=0.002) and DMMT (β=0.251, p=0.011). The MAI correlated with only the number of remaining teeth (β=0.476, p<0.001). Conclusions: Conclusions: The DMMT reflects the state of masseter muscle contraction, and can be used as a predictor as well as the number of teeth when assessing masticatory function.22Nkc

Effects of Hot rolling Reduction on Microstructural Evolution and Mechanical Properties of 1.25Cr-1Mo-0.5V-0.3C Steel for High-Speed Rail Brake Discs

In this study, the effect of rolling of 1.25Cr-1Mo-0.5V-0.3C American Iron and Steel Institute 4340 modified steel for highspeed railway brake discs on the microstructure and mechanical properties was investigated. The materials were hot-rolled at 0%, 51%, and 66% reduction ratios, and then analyzed by optical microscopy, scanning electron microscopy, and electron backscattering diffraction (EBSD). needle-shaped ferrite block morphology in bainite varied with the rolling ratio. EBSD analysis reveals dynamic recovery and dynamic recrystallization, affected ferrite block boundaries and dislocation densities during rolling. Mechanical tests showed that hardness, toughness and elongation increase at higher rolling reduction ratio, while strength remained relatively constant. In particular, the impact toughness increased almost twice from the level of 70 J in S1 (0% reduction) to the level of 130 J in S3 (66% reduction). These results showed that the hot rolling can significantly improve the strength and toughness combination of cast brake discs material

Validation of a Novel Endoscopic Feature that Predicts Helicobacter pylori-negative Status: Does the Scratch Sign Reflect H. pylori Non-infection?

Background/Aims Identification of Helicobacter pylori infection status is necessary as H. pylori is associated with gastric malignancy. Recently, a red linear scrape-like appearance on the gastric mucosa, called the “scratch sign,” was reported to be associated with H. pylori-negative gastric mucosal status. Herein, we aimed to validate the association between the scratch sign and H. pylori infection status. Methods The data of patients who underwent screening endoscopy at Bundang Jesaeng General Hospital between March 2023 and April 2023 were reviewed. Patients were classified as having an H. pylori current infection or non-infection status based on the results of rapid urease tests. Patients who had undergone H. pylori eradication therapy were excluded. Endoscopic features of the gastric mucosa were assessed using the Kyoto classification of gastritis. Results The scratch sign appeared more frequently in patients with non-infection than in those with current infection status (32.7% vs. 10.6%, respectively; P<0.001). Multivariate analysis showed that only the presence of sticky mucus was significantly associated with the presence of the scratch sign. Patient without the scratch sign had a higher prevalence of open-type atrophy, intestinal metaplasia, enlarged folds, and diffuse redness, which reflected a higher Kyoto score. Conclusions Presence of the gastric mucosal scratch sign, a novel endoscopic marker, is indicative of H. pylori-negative status and appears to be inversely correlated with the presence of sticky mucus. In addition to the Kyoto classification of gastritis, detection of the scratch sign may facilitate identification of the H. pylori infection status

A two-photon fluorescent probe for lysosomal zinc ions

The selective detection of zinc ions in lysosomes over that in cytosol is achieved with a fluorescent probe, which enabled the fluorescence imaging of endogenous zinc ions in lysosomes of NIH 3T3 cells as well as mouse hippocampal tissues by two-photon microscopy under excitation at 900 nm.open

Chirality control of inorganic materials and metals by peptides or amino acids

Chirality exists everywhere in nature and may be one of the most important features in biological systems. The chirality of amino acid molecules is transferred to the peptide sequences, determining the secondary and further three-dimensional structures. As a result, even the macroscopic chirality observed in many living features can be controlled by the peptide sequence. Interestingly, recent studies have shown that achiral inorganic materials and metals, according to the crystallographic point group, can develop chiral morphologies that are precisely controlled by the amino acids and peptides. As a result, strong chiral optical responses can be generated even at visible wavelengths. In this review, we have highlighted recent pioneering examples to show the enantioselective interactions between inorganic materials/metals and amino acids/peptides and discussed the underlying mechanisms.Y

Serum uric acid is associated with coronary artery calcification in early chronic kidney disease: a cross-sectional study

Background Although uric acid (UA) is regarded as a risk factor for cardiovascular disease, whether UA is an independent risk factor contributing to coronary artery calcification in chronic kidney disease (CKD) is not well known. We evaluated whether UA level is associated with coronary artery calcium (CAC) score in a predialysis CKD cohort. Methods A total of 1,350 subjects who underwent coronary computed tomography as part of the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease were analysed. We conducted a logistic regression analysis to evaluate the association between UA and the presence of CAC. Results CAC was detected in 705 (52.2 %) patients, and the level of UA was significantly higher in CAC > 0 patients. UA showed a positive relationship with CAC > 0 in age- and sex-adjusted logistic regression analysis (Odds ratio (OR) 1.11, 95 % confidence interval (CI) 1.04–1.19, P = 0.003). However, UA showed no association with CAC > 0 in multivariate analysis. Further analysis showed that UA showed a positive association with CAC > 0 only in estimated glomerual filtration rate (eGFR) > 60 ml/min/1.73 m2 (OR 1.23, 95 % CI 1.02–1.49, P = 0.036) but not in eGFR 30–59 ml/min/1.73 m2 (OR 0.92, 95 % CI 0.78–1.08, P = 0.309) or < 30 ml/min/1.73 m2 (OR 0.92, 95 % CI 0.79–1.08, P = 0.426). Conclusions UA level was significantly associated with CAC in early CKD, but not in advanced CKD.This study was supported by the Research Program funded by the Korea Center for Disease Control and Prevention (2011E3300300, 2012E3301100, 2013E3301600, 2013E3301601, 2013E3301602, 2016E3300200, 2016E3300201, 2016E3300202, 2019E320100, 2019E320101, and 2019E320102)

Associations between Sympathetic Activity, Plasma Concentrations of Renin, Aldosterone, and Parathyroid Hormone, and the Degree of Intractability of Blood Pressure Control in Hemodialysis Patients

This study was designed to examine how such factors as hemodialysis parameters, body mass index, renin and aldosterone concentrations, sympathetic nervous activity, and parathyroid hormone concentrations are associated with the control of hypertension in hemodialysis patients. Hemodialysis patients (n=114) were grouped into four categories. Group 1 had normal BP without antihypertensive medication. Group 2 needed one antihypertensive drug, Group 3 needed combination of two or three categories of antihypertensive drugs without minoxidil. Group 4 needed more than three categories of antihypertensive drugs including minoxidil. Parathyroid hormone, β2-microglobulin, renin and aldosterone, epinephrine, norepinephrine, and hemodialysis parameters were measured. The fractional clearance of urea as Kt/V urea was significantly lower in Group 3 and Group 4 than in Group 2 (p<0.01). Concentrations of parathyroid hormone were significantly higher in Group 4 than the other groups (p<0.01). Pre-hemodialysis norepinephrine concentrations were significantly higher in Group 4 than the other groups (p<0.05). Traditional factors associated with hypertension did not seem to be relevant to the degree of hypertension in hemodialysis patients in the present study. In conclusion, poor Kt/V urea, elevated parathyroid hormone concentrations, and elevated concentrations of plasma norepinephrine seemed to be the factors that might be associated with control of hypertension in hemodialysis patients