38 research outputs found
Catalytic oxidation of trichloroethylene over 5% [alpha]-Fe2O3/[gamma]-Alumina on a honeycomb monolith
This study addresses the ability of iron oxide to catalytically oxidize low concentrations of trichloroethylene (TCE) with air. The catalytic oxidation of trichloroethylene in a tubular reactor system was evaluated experimentally as a function of temperature and space velocity. A gas chromatograph with electron capture and flame ionization detectors was used for quantitative analysis of feed and product streams. X-ray diffraction measurement were used to qualitatively analyze the catalyst. The result indicate that over 99% conversion of 109 ppmv trichloroethylene in air is achieved at 1,490 v/v/hr and 450 °C, and at 21,768 v/v/hr, 550 °C. The major products from the oxidation of trichloroethylene over iron oxide are CO2, Cl2, and HCl, with trace amount of CC14, CHCI3 and CO at lower temperatures
Endocytic BDNF secretion regulated by Vamp3 in astrocytes
Brain-derived neurotrophic factor (BDNF) regulates diverse brain functions via TrkB receptor signaling. Due to the expression of TrkB receptors, astrocytes can internalize extracellular BDNF proteins via receptor-mediated endocytosis. Endocytosed BDNF can be re-secreted upon stimulation, but the molecular mechanism underlying this phenomenon remains unrecognized. Our study reveals that vesicle-associated membrane protein 3 (Vamp3) selectively regulates the release of endocytic BDNF from astrocytes. By using quantum dot (QD)-conjugated mature BDNF (QD-BDNF) as a proxy for the extracellular BDNF protein, we monitored the uptake, transport, and secretion of BDNF from cultured cortical astrocytes. Our data showed that endocytic QD-BDNF particles were enriched in Vamp3-containing vesicles in astrocytes and that ATP treatment sufficiently triggered either the antero- or retrograde transport and exocytosis of QD-BDNF-containing vesicles. Downregulation of Vamp3 expression disrupted endocytic BDNF secretion from astrocytes but did not affect uptake or transport. Collectively, these results provide evidence of the selective ability of astrocytic Vamp3 to control endocytic BDNF secretion during BDNF recycling. © 2021, The Author(s).1
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Evaluation of Sediment Trapping Efficiency of Vegetative Filter Strips Using Machine Learning Models
The South Korean government has recently focused on environmental protection efforts to improve water quality which has been degraded by nonpoint sources of water pollution from runoff. In order to take care of environmental issues, many physically-based models have been used. However, the physically-based models take a large amount of work to carry out site simulations, and there is a need to find faster and more efficient approaches. For an alternative approach for sediment management using the physically-based models, the machine learning-based models were used for estimating sediment trapping efficiency of vegetative filter strips. The seven nonlinear regression algorithms of machine learning models (e.g., decision tree, multilayer perceptron, k-nearest neighbors, support vector machine, random forest, AdaBoost and gradient boosting) were applied to select the model which best estimates the sediment trapping efficiency of vegetative filter strips. The sediment trapping efficiencies calculated by the machine learning models showed similar results as those of vegetative filter strip modeling system (VFSMOD-W) model. As a result of the accuracy evaluation among the seven machine learning models, the multilayer perceptron model-derived the best fit with VFSMOD-W model. It is expected that the sediment trapping efficiency of the vegetative filter strips in various cases in agricultural fields in South Korea can be predicted easier, faster and accurately by the machine learning models developed in this study. Machine learning models can be used to evaluate sediment trapping efficiency without complicated physically-based model design and high computational cost. Therefore, decision makers can maximize the quality of their outputs by minimizing their efforts in the decision-making process.</p
Induced neural stem cells from distinct genetic backgrounds exhibit different reprogramming status
Somatic cells could be directly converted into induced neural stem cells (iNSCs) by ectopic expression of defined transcription factors. However, the underlying mechanism of direct lineage transition into iNSCs is largely unknown. In this study, we examined the effect of genetic background on the direct conversion process into an iNSC state. The iNSCs from two different mouse strains exhibited the distinct efficiency of lineage conversion as well as clonal expansion. Furthermore, the expression levels of endogenous NSC markers, silencing of transgenes, and in vitro differentiation potential were also different between iNSC lines from different strains. Therefore, our data suggest that the genetic background of starting cells influences the conversion efficiency as well as reprogramming status of directly converted iNSCs.ope
Ectopic expression of Arabidopsis H+-pyrophosphatase AVP1 enhances drought resistance in bottle gourd (Lagenaria siceraria Standl.)
Leuconostoc kimchii sp nov., a new species from kimchi
A Gram-positive, catalase-negative, facultatively anaerobic, coccus-shaped bacterium, designated IH25(T), was isolated from kimchi, a traditional Korean vegetable product. Phylogenetic analysis based on almost complete 16S rDNA sequences placed the isolate in a monophyletic clade corresponding to the genus Leuconostoc. All validly described species in the genus Leuconostoc, with the exception of Leuconostoc fallax, showed high sequence identity of over 97 %, The 16S rDNA sequence of strain IH25(T) showed the highest homology to those of Leuconostoc gelidum DSM 5578(T) (98.9 %) and Leuconostoc citreum KCTC 3526(T) (98.3 %). However, DNA-DNA hybridization experiments indicated that the organism represents a novel genomic species in the genus, since the previously known leuconostocs share DNA homology with strain IH25(T) of less than 70%. In this work, it is proposed that isolate IH25(T) be classified in the genus Leuconostoc as Leuconostoc kimchii sp. nov. The type strain of Leuconostoc kimchii is IH25(T) (= KCTC 2386(T) = IMSNU 11154(T)).
An Energy Efficient Method for Tracking Mobile Ubiquitous Robots Using Wireless Sensor Network
Abstract. In general, it requires lots of complicated and expensive processing functions to find the exact location of a mobile target. For example, Ubiquitous Robotic Companion (URC) system should be equipped with powerful resources or be given an aid from the external servers to find its location for itself. Sensor network that consists of inexpensive low-power sensors can provide an efficient solution to find the exact location of such a mobile target at a low price. In such applications, if all sensor nodes have to always wake up to find location of the mobile robot, we have to pay a lot of waste of resources such as battery power and channel utilization. In this paper, we propose a cheap and energy efficient location tracking method of a mobile robot by minimizing the number of sensor nodes participating in the task of target tracking
Coagulation, deformability, and aggregation of RBCs and platelets following exposure to dielectric barrier discharge plasma with the use of different feeding gases
There are several applications for non-thermal plasma at atmospheric pressure, such as the sterilization of infected tissues, wound healing, and delicate surgery. Non-thermal plasma generates reactive oxygen/nitrogen species (RONS). In this study, we examined human red blood cells (RBCs), platelet function, and blood coagulation, following treatments with different feeding gases (air, nitrogen (N2), and argon (Ar)) of the dielectric barrier discharge plasma (DBDP) at different exposure times. This is the first study to evaluate the effects of DBDP on hemolysis, deformability, aggregation, and morphology of RBCs, as well as platelet function and blood coagulation at three doses (5, 10 and 15 min exposure). In comparison to N2 and Ar DBDP, air DBDP at more than 10 min exposure to RBC in culture plate with 2 ml liquid solution caused hemolysis and alterations in RBC deformability and aggregation owing to the higher levels of hydrogen peroxide, hydroxyl oxidants and other RONS. Moreover, air DBDP affected platelet function at high doses (more than 10 min exposure). Consequently, the air DBDP at, or more, than 10 min exposure affects blood coagulation and blood cells. The proposed method is useful for assessing the performances and dose optimization of various non-thermal plasma types used with different type of gases in biological applications