982 research outputs found
Energy-absorbing origami structure for crashworthiness design
This paper presents experimental and numerical investigations on the origami-patterned tube which is acknowledged as a
promising energy-absorption device. Its buckling mode leads to high performances in terms of specific energy absorption
(SEA) and crush force efficiency (CFE). The polygonal tube is prefolded by following an origami pattern, which is
designed to act as geometric imperfection and mode inducer. First, a series of quasi-static crushing tests are performed on
origami tubes with different materials and geometrical features. Specimens in SUS316L and AlSi10Mg are produced
through Additive Manufacturing (AM). It allows to conveniently produce few samples with a complex shape. Finite
Element Analysis (FEA) and Direct Image Correlation (DIC) are employed for a better insight into the complex crushing
behaviour. The Aluminum tube shows a brittle behaviour while SUS316L tubes have extremely promising performance
until local crack happens. Limits stemming from the employment of AM are explored and a new geometry is designed to
avoid cracking. Second, a numerical design exploration study is carried out to assess the sensitivity of origami pattern
features over the energy-absorption performance. ANSYS Autodyn is utilized as FE solver and DesignXplorer for
correlation and optimization. The benefits of new patterns are investigated through geometrical optimization, and an
improved geometry is proposed. The pattern stiffness is tuned to account for the external boundary conditions, resulting in
a more uniform crushing behaviour. A similar force trend is maintained with a SEA increment of 51.7% due to a drastic
weight reduction in areas with lower influence on post-buckling stiffnes
Simulation of wave-induced alongshore current during high waves at Haeundae beach, Korea
Strong wave-induced currents frequently develop at Haeundae Beach, Korea. Rip currents at the beach have threatened safety of swimmers in water. Near-shore currents at Haeundae Beach during a high wave time were measured on 4 June 2008 by using drogues equipped with GPS. The current field during measurement period showed westward flow along shoreline. Major driving force of the measured currents is thought to be the wave-induced force, and the tide-induced force was the second important driving force at the time. The wave-induced current field at the time is quantitatively described by using a numerical modelling system CST3D which adopts rearrangement of driving wave-induced forces, and the PESM for computation of advection terms. The computed wave-induced current field agrees reasonably well with the drogue measurements. The numerical model predicts development of rip current around the beach centre for S wave case, the result of which could be used for warning of possible rip current development at the site
Oleic acid from cancer-associated fibroblast promotes cancer cell stemness by stearoyl-CoA desaturase under glucose-deficient condition
Background
Cancer-associated fibroblasts (CAFs) coordinate the malignancy of cancer cells via secretory materials. Reprogrammed lipid metabolism and signaling play critical roles in cancer biology. Oleic acid (OA) serves as a source of energy under glucose-deficient conditions, but its function in cancer progression remains unclear. The present study investigated that CAFs in xenografted tumors had higher amounts of fatty acids, particularly OA, compared to normal fibroblasts, and promoted the cancer cell stemness in lung adenocarcinoma cells under glucose-deficient condition.
Methods
Xenografts were established in immunodeficient mice by injection of NCI-H460 (H460) cells. Lipids and fatty acids were evaluated using the BODIPY staining and fatty-acid methyl esters analysis. The expression levels of markers for lipid metabolism and cancer stemness were determined by western blot, flow cytometry, and real-time PCR. Cancer cell subclones against stearoyl-CoA desaturase (SCD) were produced by lentiviral vector and CRISPR/cas9 systems. The expression of SCD was examined immunochemically in human adenocarcinoma tissues, and its clinical relevance to survival rate in lung adenocarcinoma patients was assessed by Kaplan–Meier analysis.
Results
Transferred CAF-derived OA through lipid transporter upregulated SCD in cancer cells under glucose-deficient conditions, resulting in enhanced lipid metabolism and autophagosome maturation. By OA treatment under glucose deficient condition, cancer cell stemness was significantly enhanced through sequential activation of SCD, F-actin polymerization and nuclear translocation of yes-associated protein. These findings were confirmed by experiments using chemical inhibitors, SCD-overexpressing cells and SCD-knockout (KO) cells. When xenografted, SCD-overexpressing cells produced larger tumors compared with parental cells, while SCD-KO cells generated much smaller tumors. Analysis of tumor tissue microarray from lung adenocarcinoma patients revealed that SCD expression was the marker for poor prognosis involving tumor grade, clinical stage and survival rate.
Conclusion
Our data indicate that CAFs-derived OA activated lipid metabolism in lung adenocarcinoma cells under glucose-deficient conditions, subsequently enhancing stemness and progression toward malignancy.This study was supported by Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and Technology (Grant Number: 2020R1A2C1010215) and the Brain Korea 21 future Veterinary Medicine Leading Education and Research Center, Research Institute of Veterinary Sciences, College of Veterinary Medicine, Seoul National University
Naftopidil for the treatment of lower urinary tract symptoms compatible with benign prostatic hyperplasia
Peer reviewedPublisher PD
Cost-effectiveness of chuna manual therapy and usual care, compared with usual care only for people with neck pain following traffic accidents: a multicenter randomized controlled trial
This is the first cost-effectiveness analysis of Chuna manual therapy (CMT) plus usual Korean traditional medicine for traffic accident victims using a randomized controlled trial. A total of 132 participants were equally allocated to the intervention group receiving 6–11 sessions of CMT plus usual Korean traditional medicine care for three weeks or usual care including acupuncture, cupping, herbal medicine, moxibustion, and traditional physiotherapy at three hospitals. At 12 weeks, from a healthcare perspective, the intervention group had significantly higher costs (mean (SD), 618 (318); difference, 15 to 1077 (1081) vs. −69; 95% CI, 377; p = 0.761). The intervention group dominated, with significantly higher QALYs gained at lower overall cost with a 72% chance of being cost-effective. From a societal perspective, the intervention was cost-saving for individuals who had neck pain after car accidents, although it was not cost-effective from the healthcare perspective ($40,038 per QALY gained). Findings support use of CMT as an integrated care treatment for whiplash from a societal perspective. Further studies with larger sample sizes are needed to determine cost-effectiveness in other cultural contexts
Transcription Factor Sp1 Is Involved in Expressional Regulation of Coxsackie and Adenovirus Receptor in Cancer Cells
Coxsackie and adenovirus receptor (CAR) was first known as a virus receptor. Recently, it is also known to have tumor suppressive activity such as inhibition of cell proliferation, migration, and invasion. It is important to understand how CAR expression can be regulated in cancers. Based on an existence of putative Sp1 binding site within CAR promoter, we investigated whether indeed Sp1 is involved in the regulation of CAR expression. We observed that deletion or mutation of Sp1 binding motif (−503/−498) prominently impaired the Sp1 binding affinity and activity of CAR promoter. Histone deacetylase inhibitor (TSA) treatment enhanced recruitment of Sp1 to the CAR promoter in ChIP assay. Meanwhile, Sp1 binding inhibitor suppressed the recruitment. Exogenous expression of wild-type Sp1 increased CAR expression in CAR-negative cells; meanwhile, dominant negative Sp1 decreased the CAR expression in CAR-positive cells. These results indicate that Sp1 is involved in regulation of CAR expression
Piezoelectric energy harvesting using solar radiation pressure enhanced by surface plasmons at visible to near-infrared wavelengths
A light-pressure electric generator (LPEG) device, which harvests piezoelectric energy using solar radiation enhanced by surface plasmons (SPs), is demonstrated. The design of the device is motivated by the need to drastically increase the power output of existing piezoelectric devices based on SP resonance. The solar radiation pressure can be used as an energy source by employing an indium tin oxide (ITO)/Ag double layer to excite the SPs in the near-infrared (NIR) and visible light regions. The LPEG with the ITO layer generates an open-circuit voltage of 295 mV, a short-circuit current of 3.78 μA, and a power of 532.3 μW cm−2 under a solar simulator. The power of the LPEG device incorporating the ITO layer increased by 38% compared to the device without the ITO layer. The effect of the ITO layer on the electrical output of the LPEG was analyzed in detail by measuring the electrical output when visible and NIR lights are incident on the device using optical bandpass filters. In addition, finite-difference time-domain simulation confirmed that the pressure of the incident light can be further amplified by the ITO/Ag double layer. Finally, the energy harvested from the LPEG was stored in capacitors to successfully illuminate red light-emitting diodes
Fibrinogen gamma-A chain precursor in CSF: a candidate biomarker for Alzheimer's disease
<p>Abstract</p> <p>Background</p> <p>Cerebrospinal fluid (CSF) may be valuable for exploring protein markers for the diagnosis of Alzheimer's disease (AD). The prospect of early detection and treatment, to slow progression, holds hope for aging populations with increased average lifespan. The aim of the present study was to investigate candidate CSF biological markers in patients with mild cognitive impairment (MCI) and AD and compare them with age-matched normal control subjects.</p> <p>Methods</p> <p>We applied proteomics approaches to analyze CSF samples derived from 27 patients with AD, 3 subjects with MCI and 30 controls. The AD group was subdivided into three groups by clinical severity according to clinical dementia rating (CDR), a well known clinical scale for dementia.</p> <p>Results</p> <p>We demonstrated an elevated level of fibrinogen gamma-A chain precursor protein in CSF from patients with mild cognitive impairment and AD compared to the age-matched normal subjects. Moreover, its expression was more prominent in the AD group than in the MCI and correlated with disease severity and progression. In contrast, fibrinogen gamma-A chain precursor protein was detected very low in the age-matched normal group.</p> <p>Conclusion</p> <p>These findings suggest that the CSF level of fibrinogen gamma-A chain precursor may be a candidate biomarker for AD.</p
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