7,480 research outputs found
Electromagnet Weight Reduction in a Magnetic Levitation System for Contactless Delivery Applications
This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper’s procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results
EFFECTS OF WALKING SPEED AND AGE ON THE DIRECTIONAL STRIDE REGULARJRY AND GAIT VARIABILITY IN TREADMILL WALKING
The purpose of this study was to assess the directional stride regularity (SR) and gait variability (GV) of data from shoe-type inertial measurement unit (IMU) sensors during levelled treadmill walking. The DynaStabtm (IMU based gait analysis system) including Smart Balance' (shoe-type data logger) was used to collect normal gait data from forty-four subjects in their 20s (n=20), 40s (n=13), and 60s (n=ll). Four different walking speeds (3, 4, 5, and 6 km/h, respectively) on a treadmill were applied for one-minute of continuous levelled walking. Only lateral kinematics (mediolateral acceleration and yawing and rolling angular velocities) revealed significant interactions from walking speed and age, demonstrating lower stride regularity and higher gait variability than the anteroposterior and vertical kinematics
Whole exome and targeted deep sequencing identify genome-wide allelic loss and frequent SETDB1 mutations in malignant pleural mesotheliomas.
Malignant pleural mesothelioma (MPM), a rare malignancy with a poor prognosis, is mainly caused by exposure to asbestos or other organic fibers, but the underlying genetic mechanism is not fully understood. Genetic alterations and causes for multiple primary cancer development including MPM are unknown. We used whole exome sequencing to identify somatic mutations in a patient with MPM and two additional primary cancers who had no evidence of venous, arterial, lymphovascular, or perineural invasion indicating dissemination of a primary lung cancer to the pleura. We found that the MPM had R282W, a key TP53 mutation, and genome-wide allelic loss or loss of heterozygosity, a distinct genomic alteration not previously described in MPM. We identified frequent inactivating SETDB1 mutations in this patient and in 68 additional MPM patients (mutation frequency: 10%, 7/69) by targeted deep sequencing. Our observations suggest the possibility of a new genetic mechanism in the development of either MPM or multiple primary cancers. The frequent SETDB1 inactivating mutations suggest there could be new diagnostic or therapeutic options for MPM
Sleeve Lobectomy as an Alternative Procedure to Pneumonectomy for Non-small Cell Lung Cancer
IntroductionThe aim of this study is to compare the outcomes of sleeve lobectomy (SL) and pneumonectomy (PN) and to determine which one is more acceptable standard procedure for patients with non-small cell lung cancer.MethodsFrom 1996 to 2005, 424 patients underwent SL (n = 157) and PN (n = 267) in our institution. Propensity score matching analysis was performed to compare these two groups for mortality, morbidity, survival, recurrence, and postoperative pulmonary function.ResultsIn each group, 105 patients were eligible for analysis. The operative mortality was lower in the SL group (1.0%) than the PN group (8.6%), (p < 0.0001). The morbidity was similar (33.4% versus 29.5%, p = 0.376). The 5-year survival was lower in the PN group (PN, 32.14% versus SL, 58.43%, p = 0.0002). The recurrence pattern (locoregional versus distant) did not differ between two groups (p = 0.180). The mean actual postoperative first second forced expiratory volume in the patients underwent SL was 2.05 ± 0.55 liter, which increased by 7.9% compared with the predicted-postoperative first second forced expiratory volume.ConclusionsOur results showed that the SL can be performed with low operative risk and may offer superior survival and better postoperative pulmonary function compared with the PN in selected patients. If anatomically feasible, a SL must be considered as a favorable alternative to PN in patients with non-small cell lung cancer
Change of voltage-gated potassium channel 1.7 expressions in monocrotaline-induced pulmonary arterial hypertension rat model
Purpose Abnormal potassium channels expression affects vessel function, including vascular tone and proliferation rate. Diverse potassium channels, including voltage-gated potassium (Kv) channels, are involved in pathological changes of pulmonary arterial hypertension (PAH). Since the role of the Kv1.7 channel in PAH has not been previously studied, we investigated whether Kv1.7 channel expression changes in the lung tissue of a monocrotaline (MCT)-induced PAH rat model and whether this change is influenced by the endothelin (ET)-1 and reactive oxygen species (ROS) pathways. Methods Rats were separated into 2 groups: the control (C) group and the MCT (M) group (60 mg/kg MCT). A hemodynamic study was performed by catheterization into the external jugular vein to estimate the right ventricular pressure (RVP), and pathological changes in the lung tissue were investigated. Changes in protein and mRNA levels were confirmed by western blot and polymerase chain reaction analysis, respectively. Results MCT caused increased RVP, medial wall thickening of the pulmonary arterioles, and increased expression level of ET-1, ET receptor A, and NADPH oxidase (NOX) 4 proteins. Decreased Kv1.7 channel expression was detected in the lung tissue. Inward-rectifier channel 6.1 expression in the lung tissue also increased. We confirmed that ET-1 increased NOX4 level and decreased glutathione peroxidase-1 level in pulmonary artery smooth muscle cells (PASMCs). ET-1 increased ROS level in PASMCs. Conclusion Decreased Kv1.7 channel expression might be caused by the ET-1 and ROS pathways and contributes to MCT-induced PAH
Size-regulated group separation of CoFe2O4 nanoparticles using centrifuge and their magnetic resonance contrast properties
Magnetic nanoparticle (MNP)-based magnetic resonance imaging (MRI) contrast agents (CAs) have been the subject of extensive research over recent decades. The particle size of MNPs varies widely and is known to influence their physicochemical and pharmacokinetic properties. There are two commonly used methods for synthesizing MNPs, organometallic and aqueous solution coprecipitation. The former has the advantage of being able to control the particle size more effectively; however, the resulting particles require a hydrophilic coating in order to be rendered water soluble. The MNPs produced using the latter method are intrinsically water soluble, but they have a relatively wide particle size distribution. Size-controlled water-soluble MNPs have great potential as MRI CAs and in cell sorting and labeling applications. In the present study, we synthesized CoFe(2)O(4) MNPs using an aqueous solution coprecipitation method. The MNPs were subsequently separated into four groups depending on size, by the use of centrifugation at different speeds. The crystal shapes and size distributions of the particles in the four groups were measured and confirmed by transmission electron microscopy and dynamic light scattering. Using X-ray diffraction analysis, the MNPs were found to have an inverse spinel structure. Four MNP groups with well-selected semi-Gaussian-like diameter distributions were obtained, with measured T(2) relaxivities (r(2)) at 4.7 T and room temperature in the range of 60 to 300 mM(−1)s(−1), depending on the particle size. This size regulation method has great promise for applications that require homogeneous-sized MNPs made by an aqueous solution coprecipitation method. Any group of the CoFe(2)O(4) MNPs could be used as initial base cores of MRI T(2) CAs, with almost unique T(2) relaxivity owing to size regulation. The methodology reported here opens up many possibilities for biosensing applications and disease diagnosis. PACS: 75.75.Fk, 78.67.Bf, 61.46.D
Comparison of air pollution and the prevalence of allergy-related diseases in Incheon and Jeju City
PurposeA high level of air pollutants can increase the number of patients with allergy-related diseases such as asthma and allergic rhinitis (AR). To analyze the association between air pollution and allergic disease, we investigated 2 areas in Korea: Incheon, an industrial area, and Jeju, a non-industrialized area.MethodsSecond grade students at elementary schools (11 schools in Incheon and 45 schools in Jeju) were examined in a cross-sectional study. A questionnaire was used and a skin prick test was performed. The levels of NO2, CO2, O3, particulate matter (PM) PM10/2.5, formaldehyde, tVOCs, and dust mites in the classrooms and grounds were determined.ResultsThe levels of outdoor CO, PM10, and PM2.5 were significantly higher in Incheon (P<0.01). The levels of indoor CO, CO2, PM10, PM2.5 were significantly higher in Incheon (P<0.01). The prevalence rates of AR symptoms at any time, AR symptoms during the last 12 months, diagnosis of rhinitis at any time, and AR treatment during the last 12 months were significantly higher in Incheon (P<0.01). The prevalence rate of wheezing or whistling at any time, and wheezing during the last 12 months were significantly higher in Incheon (P<0.01).ConclusionWe found that the children living in Incheon, which was more polluted than Jeju, had a higher rate of AR and asthma symptoms compared to children in Jeju. To determine the effect of air pollution on the development of the AR and asthma, further studies are needed
Sensitization rates of airborne pollen and mold in children
PurposeAeroallergens are important causative factors of allergic diseases. Previous studies on aeroallergen sensitization rates investigated patients groups that had visited pediatric allergy clinics. In contrast, we investigated sensitization rates in a general population group of elementary school to teenage students in Incheon, Jeju, and Ulsan.MethodsAfter obtaining parental consent, skin-prick tests were performed on 5,094 students between March and June 2010. Elementary school students were tested for 18 common aeroallergens, whereas middle and high school students were tested for 25 allergens. The 25 allergens included Dermatophagoides pteronyssinus, Dermatophagoides farinae, pollen (birch, alder, oak, Japanese cedar, pine, willow, elm, maple, Bermuda grass, timothy grass, rye grass, orchard grass, meadow grass, vernal grass, mugwort, Japanese hop, fat hen, ragweed, and plantain), and mold (Penicillatum, Aspergillus, Cladosporium, and Alternaria).ResultsThe sensitization rates in descending order were 25.79% (D. pteronyssinus), 18.66% (D. farinae), 6.20% (mugwort), and 4.07% (willow) in Incheon; 33.35% (D. pteronyssinus), 24.78% (D. farinae), 15.36% (Japanese cedar), and 7.33% (Alternaria) in Jeju; and 32.79% (D. pteronyssinus), 30.27% (D. farinae), 10.13% (alder), and 8.68% (birch) in Ulsan. The dust mite allergen showed the highest sensitization rate among the 3 regions. The sensitization rate of tree pollen was the highest in Ulsan, whereas that of Alternaria was the highest in Jeju. The ragweed sensitization rates were 0.99% in Incheon, 1.07% in Jeju, and 0.81% in Ulsan.ConclusionThe differences in sensitization rates were because of different regional environmental conditions and distinct surrounding biological species. Hence, subsequent nationwide studies are required
- …