2,599 research outputs found
Human dopamine receptor nanovesicles for gate-potential modulators in high-performance field-effect transistor biosensors
The development of molecular detection that allows rapid responses with high sensitivity and selectivity remains challenging. Herein, we demonstrate the strategy of novel bio-nanotechnology to successfully fabricate high-performance dopamine (DA) biosensor using DA Receptor-containing uniform-particle-shaped Nanovesicles-immobilized Carboxylated poly(3,4-ethylenedioxythiophene) (CPEDOT) NTs (DRNCNs). DA molecules are commonly associated with serious diseases, such as Parkinson's and Alzheimer's diseases. For the first time, nanovesicles containing a human DA receptor D1 (hDRD1) were successfully constructed from HEK-293 cells, stably expressing hDRD1. The nanovesicles containing hDRD1 as gate-potential modulator on the conducting polymer (CP) nanomaterial transistors provided high-performance responses to DA molecule owing to their uniform, monodispersive morphologies and outstanding discrimination ability. Specifically, the DRNCNs were integrated into a liquid-ion gated field-effect transistor (FET) system via immobilization and attachment processes, leading to high sensitivity and excellent selectivity toward DA in liquid state. Unprecedentedly, the minimum detectable level (MDL) from the field-induced DA responses was as low as 10 pM in real- time, which is 10 times more sensitive than that of previously reported CP based-DA biosensors. Moreover, the FET-type DRNCN biosensor had a rapid response time (<1 s) and showed excellent selectivity in human serum
Flightless-I Controls Fat Storage in Drosophila
Triglyceride homeostasis is a key process of normal development and is essential for the maintenance of energy metabolism. Dysregulation of this process leads to metabolic disorders such as obesity and hyperlipidemia. Here, we report a novel function of the Drosophila flightless-I (fliI) gene in lipid metabolism. Drosophila fliI mutants were resistant to starvation and showed increased levels of triglycerides in the fat body and intestine, whereas fliI overexpression decreased triglyceride levels. These flies suffered from metabolic stress indicated by increased levels of trehalose in hemolymph and enhanced phosphorylation of eukaryotic initiation factor 2 alpha (eIF2??). Moreover, upregulation of triglycerides via a knockdown of fliI was reversed by a knockdown of desat1 in the fat body of flies. These results indicate that fliI suppresses the expression of desat1, thereby inhibiting the development of obesity; fliI may, thus, serve as a novel therapeutic target in obesity and metabolic diseases
Experimental investigations on the characteristics of snow accretion using the EMU-320 model train
This paper presents a snow accretion test conducted in a climate wind tunnel
to investigate the icing process on a model train. The model used within this
experiment was the cleaned-up and 2/3-scaled version of EMU-320, which is a
high-speed train in Korea. The model was designed without an electronic power
source or heat source so that the wheels did not rotate and snow accretion on
the model did not occur due to heat sources. To investigate snow accretion,
four cases with different ambient temperatures were considered in the climate
wind tunnel on Rail Tec Arsenal. Before analyzing the snow accretion on the
train, the snow flux and liquid water content of snow were measured so that
they could be used as the input conditions for the simulation and to ensure the
analysis of the icing process was based on the characteristics of the snow.
Both qualitative and quantitative data were obtained, whereby photographs was
used for qualitative analysis, and the density of the snow sample and the
thickness of snow accreted on the model were used for quantitative analysis.
Based on the visual observations, it was deduced that as the ambient
temperature increased, the range of the snow accreted was broader. The
thickness of snow accreted on the model nose was the largest on the upper and
lower part at -3 oC, and on the middle part at -5 oC. Additionally, the cross
section of snow accreted was observed to be trench-like. Similar icing
processes were observed to occur on the slope of nose. Snow accreted on all
components of the bogie, and for all cases, the thickness of snow at wheel was
the largest at an arc angle of 40 to 70 o. These detailed data of experimental
conditions can be applied as an input to simulations to improve simulations of
ice conditions. Thus, they can facilitate the development of appropriate
anti-icing designs for trainsComment: 31 pages, 23 Figures, 8 Table
Survivability assessment of Viton in safety-related equipment under simulated severe accident environments
To evaluate equipment survivability of the polymer Viton, used in sealing materials, the effects of its thermal degradation were investigated in severe accident (SA) environment in a nuclear power plant. Viton specimens were prepared and thermally degraded at different SA temperature profiles. Changes in mechanical properties at different temperature profiles in different SA states were investigated. The thermal lag analysis was performed at calculated convective heat transfer conditions to predict the exposure temperature of the polymer inside the safety-related equipment. The polymer that was thermally degraded at postaccident states exhibited the highest change in its mechanical properties, such as tensile strength and elongation
Prevalence of sarcopenia and sarcopenic obesity in Korean adults: The Korean Sarcopenic Obesity Study (KSOS)
*Context:* Sarcopenic obesity (SO), a combination of excess weight and reduced muscle mass and/or strength, is suggested to be associated with an increased risk of adverse health outcomes. 
*Objectives:* To examine the prevalence and characteristics of Sarcopenic and SO defined by using different indices such as Appendicular Skeletal muscle Mass (ASM)/height^2^ and Skeletal Muscle Index (SMI (%): skeletal muscle mass (kg)/weight (kg) × 100) for Korean adults. 
*Methods:* 591 participants were recruited from the Korean Sarcopenic Obesity Study (KSOS) which is an ongoing prospective observational cohort study. Analysis was conducted in 526 participants (328 women, 198 men) who had complete data on body composition using Dual X-ray absorptiometry and computed tomography. 
*Results:* The prevalence of sarcopenia and SO increases with aging. Using two or more standard deviations (SD) of ASM/height^2^ below reference values from young, healthy adults as a definition of sarcopenia, the prevalence of sarcopenia and SO was 6.3% and 1.3% in men and 4.1% and 1.7% in women over 60 years of age. However, using two or more SD of SMI, the prevalence of sarcopenia and SO was 5.1% and 5.1% respectively in men and 14.2% and 12.5% respectively in women. As defined by SMI, subjects with SO had 3 times the risk of metabolic syndrome (OR = 3.03, 95% confidence interval (CI) = 1.26-7.26) and subjects with non-sarcopenic obesity had approximately 2 times the risk of metabolic syndrome (OR = 1.89, 95% CI = 1.18-3.02) compared with normal subjects. 
*Conclusion:* Obese subjects with relative sarcopenia were associated with a greater likelihood for metabolic syndrome. As Koreans were more obese and aging, the prevalence of SO and its impact on health outcomes are estimated to be rapidly grow. Further research is requested to establish the definition, cause and consequences of SO.

Differential effect of NF-κB activity on β-catenin/Tcf pathway in various cancer cells
Abstractβ-Catenin/Tcf and NF-κB pathways play an important role in biological functions. We determined the underlying mechanisms of differential interaction between two pathways in various human cancer cell lines. NF-κB positively regulated β-catenin/Tcf pathways in human glioblastoma, whereas it has an opposite effect on β-catenin/Tcf pathways in colon, liver, and breast cancer cells. Expression of lucine zipper tumor suppressor 2 (lzts2) was positively regulated by NF-κB activity in colon, liver, and breast cancer cells, whereas negatively regulated in glioma cells. Downregulation of lzts2 increased the β-catenin/Tcf promoter activity and inhibited NF-κB-induced modulation of the nuclear translocation of β-catenin. These data indicate that the differential crosstalk between β-catenin/Tcf and NF-κB pathway in various cancer cells is resulted from the differences in the regulation of NF-κB-induced lzts2 expression
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