Countries around the world are spending a lot of social costs due to various social problems such as traffic congestion, housing, and living environments caused by urbanization. It is judged that it is urban air mobility (UAM) that can solve these problems, so each country and local government are actively participating in the UAM industry to solve these problems. And it is promoting it to the public with a blueprint as the best alternative that can dramatically solve the congested traffic environment in the city center. However, I don’t think it explains in detail the many limited operating environments and risks to be overcome in order to commercialize UAM. Therefore, I would like to consider the low-altitude airspace operating environment and vertical take-off landing aerodynamic limitations required for stable commercialization of UAM aircraft.

BACKGROUND: Peripheral artery disease (PAD), which is caused by atherosclerosis of the peripheral vessels, is a progressive disease, especially in patients with many of the vascular risk factors. The aim of this study was to investigate the prevalence and risk factors of PAD in elderly chronic stage ischemic stroke patients in Korea. METHODS: Ninety-six elderly patients (> or =60 years) admitted to a local geriatric hospital with ischemic stroke in the chronic stage (mean duration of stroke, 590 days) were included in this study. Vascular risk profiles, routine blood tests, severity of stroke and ankle-brachial index (ABI) were measured. RESULTS: Of the 96 patients, 55 (57.3%) had PAD (ABI<0.9) of which 6 patients (6.3%) had severe PAD (ABI<0.5) and 22 patients (22.9%) had bilateral PAD. PAD was more frequently observed in patients with diabetes (65% vs. 15%, p=0.001), hypercholesterolemia (65% vs. 15%, p<0.001), previous history of coronary artery disease (CAD) (25% vs. 5%, p=0.01) and recurrent ischemic stroke (36% vs. 12%, p=0.01). The means of the total cholesterol and blood urea nitrogen were higher in patients with PAD. From the results of the binary logistic regression analysis, presence of diabetes (odds ratio [OR], 4.740; p=0.026), hypercholesterolemia (OR, 18.991; p<0.001), previous history of CAD (OR, 7.579; p=0.038) and lower Korean version of Modified Barthel Index (OR, 0.971; p=0.009) were independent risk factors for PAD. CONCLUSION: PAD is frequently observed in elderly patients with chronic ischemic stroke. Measuring ABI to diagnose PAD and controlling risk factors may be beneficial in these patients seen at geriatric hospitals and centers.
Aged ; Ankle Brachial Index ; Atherosclerosis ; Blood Urea Nitrogen ; Cerebral Infarction ; Cholesterol ; Coronary Artery Disease ; Hematologic Tests ; Humans ; Hypercholesterolemia ; Logistic Models ; Peripheral Arterial Disease ; Prevalence ; Risk Factors ; Stroke

BACKGROUND: Pulmonary complications including pneumonia and pulmonary edema frequently develop in critically ill surgical patients. Lung ultrasound (LUS) is increasingly used as a powerful diagnostic tool for pulmonary complications. The purpose of this study was to report how LUS is used in a surgical intensive care unit (ICU). METHODS: This study retrospectively reviewed the medical records of 67 patients who underwent LUS in surgical ICU between May 2016 and December 2016. RESULTS: The indication for LUS included hypoxemia (n = 44, 65.7%), abnormal chest radiographs without hypoxemia (n = 17, 25.4%), fever without both hypoxemia and abnormal chest radiographs (n = 4, 6.0%), and difficult weaning (n = 2, 3.0%). Among 67 patients, 55 patients were diagnosed with pulmonary edema (n = 27, 41.8%), pneumonia (n = 20, 29.9%), diffuse interstitial pattern with anterior consolidation (n = 6, 10.9%), pneumothorax with effusion (n = 1, 1.5%), and diaphragm dysfunction (n = 1, 1.5%), respectively, via LUS. LUS results did not indicate lung complications for 12 patients. Based on the location of space opacification on the chest radiographs, among 45 patients with bilateral abnormality and normal findings, three (6.7%) and two (4.4%) patients were finally diagnosed with pneumonia and atelectasis, respectively. Furthermore, among 34 patients with unilateral abnormality and normal findings, two patients (5.9%) were finally diagnosed with pulmonary edema. There were 27 patients who were initially diagnosed with pulmonary edema via LUS. This diagnosis was later confirmed by other tests. There were 20 patients who were initially diagnosed with pneumonia via LUS. Among them, 16 and 4 patients were finally diagnosed with pneumonia and atelectasis, respectively. CONCLUSIONS: LUS is useful to detect pulmonary complications including pulmonary edema and pneumonia in surgically ill patients.
Anoxia ; Critical Care* ; Critical Illness ; Diagnosis ; Diaphragm ; Fever ; Humans ; Lung* ; Medical Records ; Pneumonia ; Pneumothorax ; Pulmonary Atelectasis ; Pulmonary Edema ; Radiography, Thoracic ; Retrospective Studies ; Ultrasonography* ; Weaning

No abstract available.
Compartment Syndromes*

OBJECTIVES: This study sought to evaluate trabecular changes in the mandible using fractal analysis and to explain the transient osteopenia related to rapid orthodontic tooth movement after orthognathic surgery. MATERIALS AND METHODS: Panoramic radiographs were taken of 26 patients who underwent bilateral sagittal split ramus osteotomy. Radiographs taken before the surgery and 1 month after surgery were overlapped, and 40x40 pixel square regions of interest were selected near the mandibular canines and 1st molars. After the image processing procedure, the fractal dimension was calculated using the box-counting method. RESULTS: Fractal dimension after orthognathic surgery decreased in a statistically significant manner (P<0.05). The change in fractal dimension on the canine side had greater statistical significance as compared to that seen on the 1st molar side. CONCLUSION: This study found that bone density decreases after orthognathic surgery due to transient osteopenia related to the regional acceleratory phenomenon. This result can provide a guide to evaluating orthodontic tooth movement after orthognathic surgery.
Bone Density ; Bone Diseases, Metabolic ; Fractals ; Humans ; Mandible ; Molar ; Orthognathic Surgery ; Osteotomy, Sagittal Split Ramus ; Tooth Movement

Two-point mutations (V419L and L925I) on the voltage-sensitive sodium channel of bed bugs (Cimex lectularius) are known to confer pyrethroid resistance. To determine the status of pyrethroid resistance in bed bugs in Korea, resistance allele frequencies of bed bug strains collected from several US military installations in Korea and Mokpo, Jeollanamdo, from 2009-2019 were monitored using a quantitative sequencing. Most bed bugs were determined to have both of the point mutations except a few specimens, collected in 2009, 2012 and 2014, having only a single point mutation (L925I). No susceptible allele was observed in any of the bed bugs examined, suggesting that pyrethroid resistance in bed bug populations in Korea has reached a serious level. Large scale monitoring is required to increase our knowledge on the distribution and prevalence of pyrethroid resistance in bed bug populations in Korea. Based on present study, it is urgent to restrict the use of pyrethroids and to introduce effective alternative insecticides. A nation-wide monitoring program to determine the pyrethroid resistance level in bed bugs and to select alternative insecticides should be implemented.

PURPOSE: To evaluate the CT and MR findings of bronchial anthracofibrosis. MATERIALS AND METHODS: Forty-one patients with ronchoscopically confirmed bronchial anthracofibrosis were included in this study. Thirty-six were female and five were male, and all were aged between 53 and 89 (mean, 70) years. The CT (n=41) and MR findings (n=5) were retrospectively analysed with regard to bron-chostenosis, atelectasis, air-space consolidation, lymph node enlargement, calcified lymph node, mass and bronchial wall thickening, as seen on CT, and signal intensity of the mass and lymph nodes, as seen on MR. RESULTS: CT scans revealed the presence of bronchostenosis (n=34, 83%), atelectasis (n=24, 59%), pneumonic consolidation (n=26, 63%), enlarged mediastinal lymph node (n=39, 95%), calcified lymph node (n=22, 54%), mass (n=4,10%), and thickening of bronchial wall (n=1, 2.4%). Multifocal involvement of bron-chostenosis, atelectasis, and air-space consolidation occurred in 61%, 50% and 30% of cases, retrospectively. MR imaging showed low signal intensity of mass (n=3) and lymph nodes (n=10) on T1WI and T2WI. but in one case, mass and lymph node showed central high signal intensity on T2WI. CONCLUSION: A multiplicity of bronchostenosis, atelectasis, air-space consolidation and enlarged mediastinal lymph nodes were characteristic CT findings of bronchial anthracofibrosis. Most MR findings included relatively low signal intensity of masses and lymph nodes on T2WI, possibly indicating the benign nature of the diseases
Female ; Humans ; Lung ; Lymph Nodes ; Magnetic Resonance Imaging ; Male ; Pneumoconiosis ; Pulmonary Atelectasis ; Retrospective Studies ; Tomography, X-Ray Computed

The purpose of this study was to evaluate the effect of multiple application of all-in-one dentin adhesive system on microtensile bond strength to caries-affected dentin. Twenty one extracted human molars with occlusal caries extending into mid-dentin were prepared by grinding the occlusal surface flat. The carious lesions were excavated with the aid of caries detector dye. The following adhesives were applied to caries-affected dentin according to manufacturer's directions; Scotchbond(TM) Multi-Purpose in SM group, Adper Prompt L-Pop(TM) 1 coat in LP1 group, 2 coats in LP2 group, 3 coats in LP3 group, Xeno(R) III 1 coat in XN1 group, 2 coats in XN2 group, and 3 coats in XN3 group. After application of the adhesives, a cylinder of resin-based composite was built up on the occlusal surface. Each tooth was sectioned vertically to obtain the 1 x 1 mm2 sticks. The microtensile bond strength was determined. Each specimen was observed under SEM to examine the failure mode. Data were analyzed with one-way ANOVA. The results of this study were as follows; 1. The microtensile bond strength values were; SM (14.38 +/- 2.01 MPa), LP1 (9.15 +/- 1.81 MPa), LP2 (14.08 +/- 1.75 MPa), LP3 (14.06 +/- 1.45 MPa), XN1 (13.65 +/- 1.95 MPa), XN2 (13.98 +/- 1.60 MPa), XN3 (13.88 +/- 1.66 MPa). LP1 was significantly lower than the other groups in bond strength (p < 0.05). All groups except LP1 were not significantly different in bond strength (p > 0.05). 2. In LP1, there were a higher number of specimens showing adhesive failure. Most specimens of all groups except LP1 showed mixed failure.
Adhesives* ; Dentin* ; Humans ; Molar ; Tooth

BACKGROUND: It is well known that growth hormone (GH) stimulates animal growth, but studies on metabolic effects of growth hormone have recently been increasing. The purpose of this study was to clarify the effects of growth hormone treatment on body composition and glucose metabolism in hypophysectomized growth hormone-deficient rats. METHODS: The 20-week-old rnale Sprague-Dawley rats were hypophysectomized and replaced with cortisol and thyroxine for 8 weeks, then administered with recombinant human growth hormone for 2 weeks. Group 1 consisted of intact controls (n 15), while group 2 consisted of hypophysectomized controls (n 12), and group three consisted of those with GH treatment (n 13). The body weights, body composition, blood glucose levels, plasma insulin-like growth factor-I (IGF-I) levels, euglycemic hyperinsulinemic clamp test, and glycogen synthase activities in gastrocnemius muscle were measured before and after growth hormone treatment. RESULTS: Plasma IGF-I levels in GH-treated group increased to intact control group levels after 2 weeks of GH treatment. There were significant changes in body composition after the treatment (fat mass significantly decreased and lean body mass significantly increased). There were no changes in glucose metabolism in peripheral tissue after 2 weeks of GH treatment. CONCLUSION: Human GH treatment (4 IU/kg/day) in adult hypophysectomized GH-deficient rats changed the body composition, but did not alter the glucose metabolism in peripheral tissue.
Adult* ; Animals ; Blood Glucose ; Body Composition* ; Body Weight ; Glucose* ; Glycogen Synthase ; Growth Hormone* ; Human Growth Hormone ; Humans ; Hydrocortisone ; Insulin-Like Growth Factor I ; Metabolism* ; Muscle, Skeletal ; Plasma ; Rats* ; Rats, Sprague-Dawley ; Thyroxine

This study aimed to develop a UPLC-MS/MS method for determining plasma levels of L-aspartic acid and L-asparagine and the activity of L-asparaginase. L-aspartic acid, L-asparagine, and L-aspartic acid-2,3,3-d3 were extracted from human plasma by protein precipitation with sulfosalicylic acid (30%, v/v). The plasma samples were analyzed using an Imtakt Intrada amino acid analysis column with 25 mM ammonium formate and 0.5% formic acid in acetonitrile as the mobile phase with step gradient method at a flow rate of 0.5 mL/min. The injection volume was 5 µL, and the total run time was 15 min. Inter- and intra-batch accuracies (%) ranged from 96.62–106.0% for L-aspartic acid and 89.85–104.8%, for L-asparagine, and the coefficient of variation (CV%) did not exceed 7%. The validation results for L-aspartic acid and L-asparagine satisfied the specified criterion, however, the results for L-asparaginase activity assay showed a borderline validity. This study could be a foundation for further development of therapeutic drug monitoring systems using UPLC-MS/MS.
Ammonium Compounds ; Asparagine ; Aspartic Acid ; Drug Monitoring ; Humans ; Methods ; Plasma