We investigated the effects of three sizes of polystyrene (PS) microbeads (0.05, 0.5, and 6-μm diameter) on the survival, development, and fecundity of the copepod Tigriopus japonicus using acute and ...chronic toxicity tests. T. japonicus ingested and egested all three sizes of PS beads used and exhibited no selective feeding when phytoplankton were added. The copepods (nauplius and adult females) survived all sizes of PS beads and the various concentrations tested in the acute toxicity test for 96 h. In the two-generation chronic toxicity test, 0.05-μm PS beads at a concentration greater than 12.5 μg/mL caused the mortality of nauplii and copepodites in the F 0 generation and even triggered mortality at a concentration of 1.25 μg/mL in the next generation. In the 0.5-μm PS bead treatment, despite there being no significant effect on the F 0 generation, the highest concentration (25 μg/mL) induced a significant decrease in survival compared with the control population in the F 1 generation. The 6-μm PS beads did not affect the survival of T. japonicus over two generations. The 0.5- and 6-μm PS beads caused a significant decrease in fecundity at all concentrations. These results suggest that microplastics such as micro- or nanosized PS beads may have negative impacts on marine copepods.
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IJS, KILJ, NUK, PNG, UL, UM
3.
Online Diagnosis of Induction Motors Using MCSA Jung, Jee-Hoon; Lee, Jong-Jae; Kwon, Bong-Hwan
IEEE transactions on industrial electronics (1982),
12/2006, Volume:
53, Issue:
6
Journal Article
Peer reviewed
In this paper, an online induction motor diagnosis system using motor current signature analysis (MCSA) with advanced signal-and-data-processing algorithms is proposed. MCSA is a method for motor ...diagnosis with stator-current signals. The proposed system diagnoses induction motors having four types of faults such as breakage of rotor bars and end rings, short-circuit of stator windings, bearing cracks, and air-gap eccentricity. Although MCSA is one of the most powerful online methods for diagnosing motor faults, it has some shortcomings, which degrade performance and accuracy of a motor-diagnosis system. Therefore, advanced signal-and-data-processing algorithms are proposed. They are composed of an optimal-slip-estimation algorithm, a proper-sample-selection algorithm, and a frequency auto search algorithm for achieving MCSA efficiently. The proposed system is able to ascertain four kinds of motor faults and diagnose the fault status of an induction motor. Experimental results obtained on 3.7-kW and 30-kW three-phase squirrel-cage induction motors and voltage-source inverters with a vector-control technique are discussed
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•Pseudomonas putida is a promising strain for lignin valorisation.•A secretion system for recombinant lignin-depolymerising peroxidase was developed.•PpDyP was added to the flagellar ...type III secretion system.•Efficient oxidation activity was obtained against lignin model compounds.•The engineered strain showed efficient assimilation of various lignin substrates.
Pseudomonas putida is a promising strain for lignin valorisation. However, there is a dearth of stable and efficient systems for secreting enzymes to enhance the process. Therefore, a novel secretion system for recombinant lignin–depolymerising peroxidase was developed. By adopting a flagellar type III secretion system, P. putida KT-M2, a secretory host strain, was constructed and an optimal secretion signal fusion partner was identified. Application of the dye-decolourising peroxidase of P. putida to this system resulted in efficient oxidation activity of the cell-free supernatant against various chemicals, including lignin model compounds. This peroxidase-secreting strain was examined to confirm its lignin utilisation capability, resulting in the efficient assimilation of various lignin substrates with 2.6-fold higher growth than that of the wild-type strain after 72 h of cultivation. Finally, this novel system will lead efficient bacterial lignin breakdown and utilization through enzyme secretion, paving the way for sustainable lignin-consolidated bioprocessing.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Determining the exact abundance of microplastics on the sea surface can be susceptible to the sampling method used. The sea surface microlayer (SML) can accumulate light plastic particles, but this ...has not yet been sampled. The abundance of microplastics in the SML was evaluated off the southern coast of Korea. The SML sampling method was then compared to bulk surface water filtering, a hand net (50 μm mesh), and a Manta trawl net (330 μm mesh). The mean abundances were in the order of SML water > hand net > bulk water > Manta trawl net. Fourier transform infrared spectroscopy (FTIR) identified that alkyds and poly(acrylate/styrene) accounted for 81 and 11%, respectively, of the total polymer content of the SML samples. These polymers originated from paints and the fiber-reinforced plastic (FRP) matrix used on ships. Synthetic polymers from ship coatings should be considered to be a source of microplastics. Selecting a suitable sampling method is crucial for evaluating microplastic pollution.
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IJS, KILJ, NUK, PNG, UL, UM
Novel subtypes of Asian-origin (Goose/Guangdong lineage) H5 highly pathogenic avian influenza (HPAI) viruses belonging to clade 2.3.4, such as H5N2, H5N5, H5N6, and H5N8, have been identified in ...China since 2008 and have since evolved into four genetically distinct clade 2.3.4.4 groups (A-D). Since 2014, HPAI clade 2.3.4.4 viruses have spread rapidly via migratory wild aquatic birds and have evolved through reassortment with prevailing local low pathogenicity avian influenza viruses. Group A H5N8 viruses and its reassortant viruses caused outbreaks in wide geographic regions (Asia, Europe, and North America) during 2014-2015. Novel reassortant Group B H5N8 viruses caused outbreaks in Asia, Europe, and Africa during 2016-2017. Novel reassortant Group C H5N6 viruses caused outbreaks in Korea and Japan during the 2016-2017 winter season. Group D H5N6 viruses caused outbreaks in China and Vietnam. A wide range of avian species, including wild and domestic waterfowl, domestic poultry, and even zoo birds, seem to be permissive for infection by and/or transmission of clade 2.3.4.4 HPAI viruses. Further, compared to previous H5N1 HPAI viruses, these reassortant viruses show altered pathogenicity in birds. In this review, we discuss the evolution, global spread, and pathogenicity of H5 clade 2.3.4.4 HPAI viruses.
We examined the spatial distribution and local characteristics of microplastics (0.33–5 mm) in surface water from six semi-enclosed bays and two coastal waters in Korea. Surveys were conducted in ...July from 2015 to 2017 using a Manta trawl. The mean abundance of total microplastics ranged from 1.12–4.74 particles/m3 among sites; the microplastics were mostly expanded polystyrene (EPS), paint particles, fragments and fibers. The mean microplastic abundance (2.85 particles/m3) in urban areas was about 1.5 times higher than in rural areas (1.86 particles/m3) (p < 0.05). EPS dominated at rural sites, while fragments, paint particles, and fibers were relatively more dominant in urban areas. The different types and quantities of microplastic particles indicated that the region-specific occurrence of microplastics is likely to be related to differences in human activities between urban and rural areas, even though fibers were distributed throughout the study area.
•Microplastic surveys at eight sites (total 83 stations) were conducted in coastal waters of Korea.•The mean microplastic abundance in urban areas was about 1.5 times higher than in rural areas (p < 0.05).•The predominant type of microplastics were fibers in the study areas.•The mean abundance of fibers in urban areas was significantly (p < 0.05) higher than in rural areas.•The highest mean abundance of microplastic in urban areas were observed in small size group.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK
The 26S proteasome, a self-compartmentalized protease complex, plays a crucial role in protein quality control. Multiple levels of regulatory systems modulate proteasomal activity for substrate ...hydrolysis. However, the destruction mechanism of mammalian proteasomes is poorly understood. We found that inhibited proteasomes are sequestered into the insoluble aggresome via HDAC6- and dynein-mediated transport. These proteasomes colocalized with the autophagic receptor SQSTM1 and cleared through selective macroautophagy, linking aggresomal segregation to autophagic degradation. This proteaphagic pathway was counter-balanced with the recovery of proteasomal activity and was critical for reducing cellular proteasomal stress. Changes in associated proteins and polyubiquitylation on inhibited 26S proteasomes participated in the targeting mechanism to the aggresome and autophagosome. The STUB1 E3 Ub ligase specifically ubiquitylated purified human proteasomes in vitro, mainly via Lys63-linked chains. Genetic and chemical inhibition of STUB1 activity significantly impaired proteasome processing and reduced resistance to proteasomal stress. These data demonstrate that aggresomal sequestration is the crucial upstream event for proteasome quality control and overall protein homeostasis in mammals.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
•We investigated floating microdebris with a Manta trawl and hand net.•Microplastics (<2mm) were present dominantly at all surveyed stations.•Dominant types were fibers, hard plastic, paint ...particles, and Styrofoam.•Fibers and hard plastic by a trawl were significantly high after the rainy season.•A hand-net (50μm) proved the missed microplastics (50–330μm) when trawl used.
We investigated floating debris around the mouth of the Nakdong River in the Southeastern Sea of Korea using a Manta trawl (330-μm mesh) and hand-net (50μm) before (May) and after (July) the rainy season in 2012. Microplastic (<2mm) was present at all of the stations, whereas Styrofoam (2–5mm) peaked only at a few stations far from the Nakdong River mouth in July. The dominant types were fibers (polyester), hard plastic (polyethylene), paint particles (alkyd), and Styrofoam (expanded polystyrene). The average abundances of fibers and hard plastic (<2mm) in the trawl were significantly higher in July than in May (p<0.005, p<0.05, respectively), while two orders of magnitude more microplastics (<2mm) were collected with the hand-net than with the trawl. Fibers and hard plastic by trawl were significantly compared temporally, and the hand-net proved the missed microplastics (50–330μm) when trawl used.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK
Local radiotherapy (RT) is important to manage metastatic triple-negative breast cancer (TNBC). Although RT primarily reduces cancer cells locally, this control can be enhanced by triggering the ...immune system via immunotherapy. RT and immunotherapy may lead to an improved systemic effect, known as the abscopal effect. Here, we analyzed the antitumor effect of combination therapy using RT with an anti-programmed cell death-1 (PD-1) antibody in primary tumors, using poorly immunogenic metastatic mouse mammary carcinoma 4T1 model. Mice were injected subcutaneously into both flanks with 4T1 cells, and treatment was initiated 12 days later. Mice were randomly assigned to three treatment groups: (1) control (no treatment with RT or immune checkpoint inhibitor (ICI)), (2) RT alone, and (3) RT+ICI. The same RT dose was prescribed in both RT-alone and RT+ICI groups as 10Gy/fx in two fractions and delivered to only one of the two tumor burdens injected at both sides of flanks. In the RT+ICI group, 200 µg fixed dose of PD-1 antibody was intraperitoneally administered concurrently with RT. The RT and ICI combination markedly reduced tumor cell growth not only in the irradiated site but also in non-irradiated sites, a typical characteristic of the abscopal effect. This was observed only in radiation-sensitive cancer cells. Lung metastasis development was lower in RT-irradiated groups (RT-only and RT+ICI groups) than in the non-irradiated group, regardless of the radiation sensitivity of tumor cells. However, there was no additive effect of ICI on RT to control lung metastasis, as was already known regarding the abscopal effect. The combination of local RT with anti-PD-1 blockade could be a promising treatment strategy against metastatic TNBC. Further research is required to integrate our results into a clinical setting.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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