523 research outputs found
Digital holographic microscopy based on a modified lateral shearing interferometer for three-dimensional visual inspection of nanoscale defects on transparent objects
Long-term risks of complicated grief and insomnia in student survivors of the Sewol ferry disaster in South Korea: A four-year observational follow-up study
Background: The Sewol ferry disaster in April 2014 resulted in the drowning of 304 people. Of the 325 students on board, 250 died and 75 were rescued.
The measure of stress caused by bereavement and sleep problems is common and can be a chronic health concern for disaster survivors. The aim of this study was to determine longitudinal predictive factors of complicated grief and insomnia among student survivors of the disaster.
Methods: This study centered on 67 student survivors who were enrolled in the disaster registry after graduating from high school. The self-report data as presented by the participants were collected at baseline (27 months after the disaster, T1) and again at two years later (51 months after the disaster, T2). Thirty-one participants completed both T1 and T2 surveys. The noted predictive variables, in this case, were event-related rumination, coping strategy, social support, attachment, meaning in life, and adverse childhood experiences. The outcome variables were complicated grief and insomnia.
Results: Dysfunctional coping (T1) was positively associated with complicated grief (T2) (coefficient = 0.070; p<0.001). Intrusive rumination (T1) (coefficient = -0.114; p<0.001), social support (T1) (coefficient = -0.031; p<0.001), and meaning in life – search (T1) (coefficient = -0.082; p<0.001) were negatively associated with insomnia (T2). In contrast, dysfunctional coping (T1) (coefficient = 0.041; p = 0.012), adverse childhood experiences (T1) (coefficient = 0.280; p = 0.007), and insomnia (T1) (coefficient = 0.166; p<0.001) were positively associated with insomnia (T2).
Conclusions: Dysfunctional coping influenced how student survivors of the Sewol ferry disaster suffered from complicated grief and insomnia over time. In this case, the findings from the current study indicate that interventions that target coping strategies should be provided to improve the resolution of grief and sleep among survivors. [Ethiop.J. Health Dev. 2020;34(Special issue-3):97-106]
Keywords: Sewol ferry disaster, student survivors, coping strategy, complicated grief, insomni
Effect of Different Resistance Training Structures on Basic Physical Fitness and Isokinetic Muscular Contraction
PURPOSE This study aimed to investigate the effects of different resistance training structures on basic physical fitness, 1-repetition maximum (1RM), and isokinetic shoulder and knee muscle functions in male college students. METHODS Forty college students were divided into four groups: control group (CG, n=10), compound set training group (CSG, n=10), pyramid set training group (PSG, n=10), and superset training group (SSG, n=10). Excluding CG, each group performed a different resistance exercise method at an intensity of 60~80% 1RM for 60~90 min, three times a week for eight weeks. To compare the effects of resistance training structures, we confirmed body composition, basic physical fitness, 1RM, as well as isokinetic shoulder and knee functions. RESULTS Results indicated that the PSG exhibited the most significant improvement in relative peak torque in isokinetic shoulder and knee testing compared to the other groups. Additionally, all exercise groups positively affected back strength, 40m sprint, and 1RM compared to the CG, although no significant differences were observed among exercise groups. CONCLUSIONS The findings suggest scientific evidence supporting the effectiveness of pyramidal resistance training in improving isokinetic shoulder and knee muscle functions in male college students
Validation of a CT-guided intervention robot for biopsy and radiofrequency ablation: experimental study with an abdominal phantom
PURPOSE:We aimed to evaluate the accuracy of a needle-placement robot for biopsy and radiofrequency ablation on an abdominal phantom.METHODS:A master-slave robotic system has been developed that includes a needle-path planning system and a needle-inserting robot arm with computed tomography (CT) and CT fluoroscopy guidance. For evaluation of its accuracy in needle placement, a commercially available abdominal phantom (Model 057A; CIRS Inc.) was used. The liver part of the phantom contains multiple spherical simulated tumors of three different size spheres. Various needle insertion trials were performed in the transverse plane and caudocranial plane two nodule sizes (10 mm and 20 mm in diameter) to test the reliability of this robot. To assess accuracy, a CT scan was performed after each trial with the needle in situ.RESULTS:The overall error was 2 mm (0–2.6 mm), which was calculated as the distance from the planned trajectory before insertion to the actual needle trajectory after insertion. The standard deviations of the insertions on two nodules (10 mm and 20 mm in diameter) were 0.5 mm and 0.2 mm, respectively.CONCLUSION:The CT-compatible needle placement robot for biopsy and radiofrequency ablation shows relatively acceptable accuracy and could be used for radiofrequency ablation of nodules ≥10 mm under CT fluoroscopy guidance
Experimental observation of hidden Berry curvature in inversion-symmetric bulk 2H-WSe2
We investigate the hidden Berry curvature in bulk 2H-WSe2 by utilizing the
surface sensitivity of angle resolved photoemission (ARPES). The symmetry in
the electronic structure of transition metal dichalcogenides is used to
uniquely determine the local orbital angular momentum (OAM) contribution to the
circular dichroism (CD) in ARPES. The extracted CD signals for the K and K'
valleys are almost identical but their signs, which should be determined by the
valley index, are opposite. In addition, the sign is found to be the same for
the two spin-split bands, indicating that it is independent of spin state.
These observed CD behaviors are what are expected from Berry curvature of a
monolayer of WSe2. In order to see if CD-ARPES is indeed representative of
hidden Berry curvature within a layer, we use tight binding analysis as well as
density functional calculation to calculate the Berry curvature and local OAM
of a monolayer WSe2. We find that measured CD-ARPES is approximately
proportional to the calculated Berry curvature as well as local OAM, further
supporting our interpretation.Comment: 6 pages, 3 figure
Evaluation of combinatorial cis-regulatory elements for stable gene expression in chicken cells
This is an Open Access article distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Recent successes in biotechnological application of birds are based on their unique physiological traits such as unlimited manipulability onto developing embryos and simple protein constituents of the eggs. However it is not likely that target protein is produced as kinetically expected because various factors affect target gene expression. Although there have been various attempts to minimize the silencing of transgenes, a generalized study that uses multiple cis-acting elements in chicken has not been made. The aim of the present study was to analyze whether various cis-acting elements can help to sustain transgene expression in chicken fibroblasts.
Results: We investigated the optimal transcriptional regulatory elements for enhancing stable transgene expression in chicken cells. We generated eight constructs that encode enhanced green fluorescent protein (eGFP) driven by either CMV or CAG promoters (including the control), containing three types of key regulatory elements: a chicken lysozyme matrix attachment region (cMAR), 5′-DNase I-hypersensitive sites 4 (cHS4), and the woodchuck hepatitis virus posttranscriptional regulatory element (WPRE). Then we transformed immortalized chicken embryonic fibroblasts with these constructs by electroporation, and after cells were expanded under G418 selection, analyzed mRNA levels and mean fluorescence intensity (MFI) by quantitative real-time PCR and flow cytometry, respectively. We found that the copy number of each construct significantly decreased as the size of the construct increased (R2 = 0.701). A significant model effect was found in the expression level among various constructs in both mRNA and protein (P < 0.0001). Transcription with the CAG promoter was 1.6-fold higher than the CMV promoter (P = 0.027) and the level of eGFP expression activity in cMAR- or cHS4-flanked constructs increased by two- to three-fold compared to the control CMV or CAG promoter constructs. In addition, flow cytometry analysis showed that constructs having cis-acting elements decreased the level of gene silencing as well as the coefficient of variance of eGFP-expressing cells (P < 0.0001).
Conclusions: Our current data show that an optimal combination of cis-acting elements and promoters/enhancers for sustaining gene expression in chicken cells is suggested. These results provide important information for avian transgenesis and gene function studies in poultry
Semi-Automatic Measurement of the Airway Dimension by Computed Tomography Using the Full-With-Half-Maximum Method: a Study of the Measurement Accuracy according to the Orientation of an Artificial Airway
parameters on the correct measurement of the airway dimension.
Materials and Methods: An airway phantom with 11 poly-acryl tubes of various
lumen diameters and wall thicknesses was scanned using a 16-MDCT (multidetector
CT) at various tilt angles (0, 30, 45, and 60 ). The CT images were reconstructed
at various reconstruction kernels and thicknesses. The axis of each airway
was determined using the 3D thinning algorithm, with images perpendicular to
the axis being reconstructed. The luminal radius and wall thickness was measured
by the full-width-half-maximum method. The influence of the CT parameters (the
size of the airways, obliquity on the radius and wall thickness) was assessed by
comparing the actual dimension of each tube with the estimated values.
Results: The 3D thinning algorithm correctly determined the axis of the oblique
airway in all tubes (mean error: 0.91+-0.82 ). A sharper reconstruction kernel,
thicker image thickness and larger tilt angle of the airway axis resulted in a significant
decrease of the measured wall thickness and an increase of the measured
luminal radius. Use of a standard kernel and a 0.75-mm slice thickness resulted
in the most accurate measurement of airway dimension, which was independent
of obliquity.
Conclusion: The airway obliquity and imaging parameters have a strong influence
on the accuracy of the airway wall measurement. For the accurate measurement
of airway thickness, the CT images should be reconstructed with a
standard kernel and a 0.75 mm slice thickness.This work was supported by the Korea Science and
Engineering Foundation (KOSEF) grant funded by the
Korea government (MOST) (No. R01-2006-000-11244-0)
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