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1.
Microbiol Resour Announc ; : e0045824, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39162470

RESUMEN

Priestia megaterium sp. strain IMGN3 was isolated from the soil in South Korea. Here, we report its draft genome sequence, comprising 12 contigs with a total sequence length of 5.64 Mbp. This genome will provide valuable resources for future genomic studies, particularly focusing on plant growth promotion and biocontrol.

2.
Microbiol Resour Announc ; : e0054024, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39083721

RESUMEN

Here, we report the complete genome sequence of Bacillus paramobilis sp. strain IMGN7, which was isolated from soil in South Korea. Its complete genome size is 5.28 Mbp. This genome will provide various insights for further studies about their function as biocontrol agents, such as bioremediation and antibiosis.

3.
Prev Nutr Food Sci ; 29(2): 220-227, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38974593

RESUMEN

Here, we aimed to isolate an acetic acid bacterium that is suitable for the production of unripe Citrus unshiu vinegar from traditional fermented vinegars. We compared the halo sizes of isolates to select a strain with superior acetic acid production capabilities and selected Komagataeibacter kakiaceti P6 (P6) as the final strain. Using Acetobacter pasteurianus CY (CY) and A. pasteurianus KACC 17058 (KACC 17058) as controls, we analyzed the total phenolic compounds, total flavonoid content, antioxidant activities, and organic acids of the selected strain to verify its suitability for acetic acid fermentation. On the 30th day of the fermentation period, P6 showed a total acidity of 4.86%, which was higher than that of control groups (CY, 4.16%; KACC 17058, 4.01%). The total phenolic compounds, total flavonoid content, 1,1-diphenyl-2-picrylhydrazyl scavenging activity, and ferric ion reducing antioxidant power values significantly increased during fermentation with P6 compared with the initial C. unshiu wine, and no significant differences were observed from the vinegars produced by CY and KACC 17058. Moreover, organic acid analysis revealed that the unripe C. unshiu vinegar produced with P6 had an acetic acid content of 26.15 mg/mL, which was significantly higher than those produced with CY and KACC 17058, indicating that the P6 strain effectively produces acetic acid without adversely affecting other quality aspects during fermentation. In conclusion, the novel P6 strain is expected to be used as a starter for fermenting unripe C. unshiu vinegar, and its excellent acetic acid production capabilities suggest potential applications for other vinegars.

4.
Microbiol Resour Announc ; 13(8): e0045924, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-38967471

RESUMEN

Here, we present the draft genome of Bacillus proteolyticus IMGN4, the gram-positive, soil-dwelling bacterium discovered in mountain Maemi, Republic of Korea in May 2019. The assembly resulted in 7 contigs, comprising a total of 6,063,502 base pairs and have 6,115 coding sequences.

5.
Microbiol Resour Announc ; : e0045724, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39083687

RESUMEN

Biocontrol using organisms like Pseudomonas alkylphenolica offers a viable alternative to chemical pesticides, enhancing plant growth and reducing environmental impact. This study details the genome of Pseudomonas alkylphenolica IMGN1, a strain known for promoting plant growth, advancing our understanding of biocontrol mechanisms.

6.
Microbes Infect ; 26(5-6): 105351, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38724000

RESUMEN

Mycobacterium abscessus (MAB), a non-tuberculous mycobacterium (NTM), causes chronic pulmonary inflammation in humans. The NLRP3 inflammasome is a multi-protein complex that triggers IL-1ß maturation and pyroptosis through the cleavage of caspase-1. In this study, we investigated the roles of NLRP3 and IL-1ß in the host's defense against MAB. The IL-1ß production by MAB was completely abolished in NLRP3, but not NLRC4, deficient macrophages. The NLRP3 inflammasome components, which are ASC and caspase-1 were also found to be essential for IL-1ß production in response to MAB. NLRP3 and IL-1ß deficiency did not affect the intracellular growth of MAB in macrophages, and the bacterial burden in lungs of NLRP3- and IL-1ß-deficient mice was also comparable to the burden observed in WT mice. In contrast, IL-1ß deficiency ameliorated lung pathology in MAB-infected mice. Notably, the lung homogenates of IL-1ß-deficient mice had reduced levels of IL-17, but not IFN-γ and IL-4 when compared with WT counterparts. Furthermore, in vitro co-culture analysis showed that IL-1ß signaling was essential for IL-17 production in response to MAB. Finally, we observed that the anti-IL-17 antibody administration moderately mitigated MAB-induced lung pathology. These findings indicated that IL-1ß production contribute to MAB-induced lung pathology via the elevation of IL-17 production.


Asunto(s)
Interleucina-17 , Interleucina-1beta , Pulmón , Macrófagos , Ratones Noqueados , Infecciones por Mycobacterium no Tuberculosas , Mycobacterium abscessus , Proteína con Dominio Pirina 3 de la Familia NLR , Animales , Ratones , Inflamasomas/metabolismo , Inflamasomas/inmunología , Interleucina-17/metabolismo , Interleucina-17/inmunología , Interleucina-1beta/metabolismo , Pulmón/patología , Pulmón/microbiología , Pulmón/inmunología , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Mycobacterium abscessus/inmunología , Infecciones por Mycobacterium no Tuberculosas/inmunología , Infecciones por Mycobacterium no Tuberculosas/microbiología , Infecciones por Mycobacterium no Tuberculosas/patología , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética
7.
Food Chem X ; 22: 101368, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38645938

RESUMEN

Distilled soju, a Korean traditional alcoholic beverage, is produced by fermenting rice with a variety of microorganisms including molds, yeasts, and lactic acid-producing bacteria, followed by distillation. Our study sought to improve the quality of distilled soju through co-fermentation with Saccharomyces cerevisiae and Wickerhamomyces anomalus, known for producing volatile aromatic compounds during the early stages of fermentation. Analysis of volatile aromatic compounds in co-fermented distilled soju revealed a substantial increase in compounds with boiling points below 200 °C. Among them, ethyl hexanoate, isobutanol, and isoamyl alcohol were identified as the major volatile aromatic compounds based on Log2 fold change analyses of the volatile aromatic compound pattern. In sensory evaluation, co-fermented distilled soju received higher scores in terms of odor and overall preference. Therefore, incorporating W. anomalus may improve the quality of distilled soju.

8.
Nutrients ; 15(23)2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-38068826

RESUMEN

Osteoporosis, which is often associated with increased osteoclast activity due to menopause or aging, was the main focus of this study. We investigated the inhibitory effects of water extract of desalted Salicornia europaea L. (WSE) on osteoclast differentiation and bone loss in ovariectomized mice. Our findings revealed that WSE effectively inhibited RANKL-induced osteoclast differentiation, as demonstrated by TRAP staining, and also suppressed bone resorption and F-actin ring formation in a dose-dependent manner. The expression levels of genes related to osteoclast differentiation, including NFATc1, ACP5, Ctsk, and DCSTAMP, were downregulated by WSE. Oral administration of WSE improved bone density and structural parameters in ovariectomized mice. Dicaffeoylquinic acids (DCQAs) and saponins were detected in WSE, with 3,4-DCQA, 3,5-DCQA, and 4,5-DCQA being isolated and identified. All tested DCQAs, including the aforementioned types, inhibited osteoclast differentiation, bone resorption, and the expression of osteoclast-related genes. Furthermore, WSE and DCQAs reduced ROS production mediated by RANKL. These results indicate the potential of WSE and its components, DCQAs, as preventive or therapeutic agents against osteoporosis and related conditions.


Asunto(s)
Enfermedades Óseas Metabólicas , Resorción Ósea , Osteoporosis , Femenino , Animales , Ratones , Osteoclastos , Resorción Ósea/tratamiento farmacológico , Enfermedades Óseas Metabólicas/metabolismo , Osteoporosis/tratamiento farmacológico , Ligando RANK/metabolismo , Factores de Transcripción NFATC/genética , Factores de Transcripción NFATC/metabolismo , Diferenciación Celular , Osteogénesis
9.
Adv Mater ; 35(44): e2303458, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37591512

RESUMEN

Stretchable conductive nanocomposites have been intensively studied for wearable bioelectronics. However, development of nanocomposites that simultaneously feature metal-like conductivity(> 100 000 S cm-1 ) and high stretchability (> 100%) for high-performance skin-mountable devices is still extremely challenging. Here a material strategy for such a nanocomposite is presented by using local bundling of silver nanowires stabilized with dual ligands (i.e., 1-propanethiols and 1-decanethiols). When the nanocomposite is solidified via solvent evaporation under a highly humid condition, the nanowires in the organic solution are bundled and stabilized. The resulting locally-bundled nanowires lower contact resistance while maintain their percolation network, leading to high conductivity. Dual ligands of 1-propanethiol and 1-decanethiol further boost up the conductivity. As a result, a nanocomposite with both high conductivity of ≈122,120 S cm-1 and high stretchability of ≈200% is obtained. Such superb electrical and mechanical properties are critical for various applications in skin-like electronics, and herein, a wearable thermo-stimulation device is demonstrated.

10.
Microorganisms ; 11(5)2023 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-37317332

RESUMEN

Inflammatory bowel disease (IBD) is an intestinal chronic inflammatory disease, and its incidence is steadily increasing. IBD is closely related to the intestinal microbiota, and probiotics are known to be a potential therapeutic agent for IBD. In our study, we evaluated the protective effect of Lactobacillus sakei CVL-001, isolated from Baechu kimchi, on dextran sulfated sodium (DSS)-induced colitis in mice. The oral administration of L. sakei CVL-001 according to the experimental schedule alleviated weight loss and disease activity in the mice with colitis. Furthermore, the length and histopathology of the colon improved. The expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß genes decreased in the colons of mice that were administered L. sakei CVL-001, whereas that of IL-10 increased. The expressions of genes coding for E-cadherin, claudin3, occludin, and mucin were also restored. In co-housed conditions, L. sakei CVL-001 administration did not improve disease activity, colon length, and histopathology. Microbiota analysis revealed that L. sakei CVL-001 administration increased the abundance of microbiota and altered Firmicutes/Bacteroidetes ratio, and decreased Proteobacteria. In conclusion, L. sakei CVL-001 administration protects mice from DSS-induced colitis by regulating immune response and intestinal integrity via gut microbiota modulation.

11.
Front Nutr ; 9: 895837, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35799581

RESUMEN

Atopic dermatitis (AD) is one of the most prevalent, chronic and persistent inflammatory skin diseases closely associated with intestinal microbiota. To evaluate the effect of D-galactose intake on AD, we orally administered D-galactose to BALB/c mice whose ears and skin were treated with 2,4-dinitrochlorobenzene (DNCB). D-galactose alleviated DNCB-induced AD-like phenotypes such as redness, scaling/dryness and excoriation. Ear thickness was also decreased by D-galactose administration. Histopathological analysis revealed decreased epidermal thickening, infiltration of immune cells, especially mast cells, in the dermis. Total levels of serum IgE representing the immunological response of AD were decreased by D-galactose administration. Microbiota analysis showed that D-galactose administration restored gut microbiota profiles, which were altered in AD mice, characterized by increased abundance of Bacteroidetes and decreased abundance of Firmicutes. The increased abundance of Bacteroides and the decreased abundance of Prevotella and Ruminococcus were reversed by D-galactose treatment, following improvement of AD. Our results suggest the possible use of D-galactose as a prebiotic to alleviate AD by altering gut microbiota.

12.
Adv Mater ; 34(23): e2200980, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35388541

RESUMEN

Highly conductive and stretchable nanocomposites are promising material candidates for skin electronics. However, the resistance of stretchable metallic nanocomposites highly depends on external strains, often deteriorating the performance of fabricated electronic devices. Here, a material strategy for the highly conductive and stretchable nanocomposites comprising metal nanomaterials of various dimensions and a viscoelastic block-copolymer matrix is presented. The resistance of the nanocomposites can be well retained under skin deformations (<50% strain). It is demonstrated that silver nanomaterials can self-organize inside the viscoelastic media in response to external strain when their surface is conjugated with 1-decanethiol. Distinct self-organization behaviors associated with nanomaterial dimensions and strain conditions are found. Adopting the optimum composition of 0D/1D/2D silver nanomaterials can render the resistance of the nanocomposites insensitive to uniaxial or biaxial strains. As a result, the resistance can be maintained with a variance of < 1% during 1000 stretching cycles under uniaxial and biaxial strains of <50% while a high conductivity of ≈31 000 S cm-1 is achieved.

13.
Phytomedicine ; 99: 153934, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35172258

RESUMEN

BACKGROUND: Previously, we found that the water extract of Artermisia scoparia Waldst. & Kit suppressed the cytokine production of lipopolysaccharide (LPS)-stimulated macrophages and alleviated carrageenan-induced acute inflammation in mice. Artemisia contains various sesquiterpene lactones and most of them exert immunomodulatory activity. PURPOSE: In the present study, we investigated the immunomodulatory effect of estafiatin (EST), a sesquiterpene lactone derived from A. scoparia, on LPS-induced inflammation in macrophages and mouse sepsis model. STUDY DESIGN AND METHODS: Murine bone marrow-derived macrophages (BMDMs) and THP-1 cells, a human monocytic leukemia cell line, were pretreated with different doses of EST for 2 h, followed by LPS treatment. The gene and protein expression of pro-inflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and inducible nitric oxide synthase (iNOS) were measured by quantitative real-time polymerase chain reaction (qPCR) and Western blot analysis. The activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) was also evaluated at the level of phosphorylation. The effect of EST on inflammatory cytokine production, lung histopathology, and survival rate was assessed in an LPS-induced mice model of septic shock. The effect of EST on the production of cytokines in LPS-stimulated peritoneal macrophages was evaluated by in vitro and ex vivo experiments and protective effect of EST on cecal ligation and puncture (CLP) mice was also assessed. RESULTS: The LPS-induced expression of IL-6, TNF-α, and iNOS was suppressed at the mRNA and protein levels in BMDMs and THP-1 cells, respectively, by pretreatment with EST. The half-maximal inhibitory concentration (IC50) of EST on IL-6 and TNF-α production were determined as 3.2 µM and 3.1 µM in BMDMs, 3 µM and 3.4 µM in THP1 cells, respectively. In addition, pretreatment with EST significantly reduced the LPS-induced phosphorylation p65, p38, JNK, and ERK in both cell types. In the LPS-induced mice model of septic shock, serum levels of IL-6, TNF-α, IL-1ß, CXCL1, and CXCL2 were lower in EST-treated mice than in the control animals. Histopathology analysis revealed that EST treatment ameliorated LPS-induced lung damage. Moreover, while 1 of 7 control mice given lethal dose of LPS survived, 3 of 7 EST-treated (1.25 mg/kg) mice and 5 of 7 EST-treated (2.5 mg/kg) mice were survived. Pretreatment of EST dose-dependently suppressed the LPS-induced production of IL-6, TNF-α and CXCL1 in peritoneal macrophages. In CLP-induced mice sepsis model, while all 6 control mice was dead at 48 h, 1 of 6 EST-treated (1.25 mg/kg) mice and 3 of 6 EST-treated (2.5 mg/kg) mice survived for 96 h. CONCLUSION: These results demonstrated that EST exerts anti-inflammatory effects on LPS-stimulated macrophages and protects mice from sepsis. Our study suggests that EST could be developed as a new therapeutic agent for sepsis and various inflammatory diseases.

14.
Int J Mol Sci ; 23(1)2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35008917

RESUMEN

The ubiquitin proteasome system (UPS) is a protein degradation machinery that is crucial for cellular homeostasis in eukaryotes. Therefore, it is not surprising that the UPS coordinates almost all host cellular processes, including host-pathogen interactions. This protein degradation machinery acts predominantly by tagging substrate proteins designated for degradation with a ubiquitin molecule. These ubiquitin tags have been involved at various steps of the innate immune response. Hence, herpesviruses have evolved ways to antagonize the host defense mechanisms by targeting UPS components such as ubiquitin E3 ligases and deubiquitinases (DUBs) that establish a productive infection. This review delineates how herpesviruses usurp the critical roles of ubiquitin E3 ligases and DUBs in innate immune response to escape host-antiviral immune response, with particular focus on retinoic acid-inducible gene I (RIG-I)-like receptors (RLR), cyclic-GMP-AMP (cGAMP) synthase (cGAS), stimulator of interferon (IFN) genes (STING) pathways, and inflammasome signaling.


Asunto(s)
Herpesviridae/inmunología , Inmunidad Innata , Transducción de Señal , Ubiquitina/metabolismo , Animales , Humanos , Factores Inmunológicos/metabolismo , Inflamación/patología
15.
Front Immunol ; 12: 738070, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34777348

RESUMEN

Mycobacterium abscessus (MAB) is one of the rapidly growing, multidrug-resistant non-tuberculous mycobacteria (NTM) causing various diseases including pulmonary disorder. Although it has been known that type I interferons (IFNs) contribute to host defense against bacterial infections, the role of type I IFNs against MAB infection is still unclear. In the present study, we show that rIFN-ß treatment reduced the intracellular growth of MAB in macrophages. Deficiency of IFN-α/ß receptor (IFNAR) led to the reduction of nitric oxide (NO) production in MAB-infected macrophages. Consistently, rIFN-ß treatment enhanced the expression of iNOS gene and protein, and NO production in response to MAB. We also found that NO is essential for the intracellular growth control of MAB within macrophages in an inhibitor assay using iNOS-deficient cells. In addition, pretreatment of rIFN-ß before MAB infection in mice increased production of NO in the lungs at day 1 after infection and promoted the bacterial clearance at day 5. However, when alveolar macrophages were depleted by treatment of clodronate liposome, rIFN-ß did not promote the bacterial clearance in the lungs. Moreover, we found that a cytosolic receptor nucleotide-binding oligomerization domain 2 (NOD2) is required for MAB-induced TANK binding kinase 1 (TBK1) phosphorylation and IFN-ß gene expression in macrophages. Finally, increase in the bacterial loads caused by reduction of NO levels was reversed by rIFN-ß treatment in the lungs of NOD2-deficient mice. Collectively, our findings suggest that type I IFNs act as an intermediator of NOD2-induced NO production in macrophages and thus contribute to host defense against MAB infection.


Asunto(s)
Interferón Tipo I/metabolismo , Pulmón/microbiología , Macrófagos Alveolares/microbiología , Infecciones por Mycobacterium no Tuberculosas/microbiología , Mycobacterium abscessus/crecimiento & desarrollo , Óxido Nítrico/metabolismo , Proteína Adaptadora de Señalización NOD2/metabolismo , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Interacciones Huésped-Patógeno , Pulmón/inmunología , Pulmón/metabolismo , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Infecciones por Mycobacterium no Tuberculosas/inmunología , Infecciones por Mycobacterium no Tuberculosas/metabolismo , Mycobacterium abscessus/inmunología , Mycobacterium abscessus/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Proteína Adaptadora de Señalización NOD2/genética , Receptor de Interferón alfa y beta/genética , Receptor de Interferón alfa y beta/metabolismo , Transducción de Señal
16.
Science ; 373(6558): 1022-1026, 2021 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-34446604

RESUMEN

Skin electronics require stretchable conductors that satisfy metallike conductivity, high stretchability, ultrathin thickness, and facile patternability, but achieving these characteristics simultaneously is challenging. We present a float assembly method to fabricate a nanomembrane that meets all these requirements. The method enables a compact assembly of nanomaterials at the water-oil interface and their partial embedment in an ultrathin elastomer membrane, which can distribute the applied strain in the elastomer membrane and thus lead to a high elasticity even with the high loading of the nanomaterials. Furthermore, the structure allows cold welding and bilayer stacking, resulting in high conductivity. These properties are preserved even after high-resolution patterning by using photolithography. A multifunctional epidermal sensor array can be fabricated with the patterned nanomembranes.

17.
J Microbiol ; 59(9): 807-818, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34449057

RESUMEN

The causative factor of COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously mutating. Interestingly, identified mutations mainly occur in the spike (S) protein which interacts with the ACE2 receptor and is cleaved via serine protease TMPRSS2. Some mutated strains are becoming dominant in various parts of the globe because of increased transmissibility as well as cell entry efficacy. Remarkably, the neutralizing activity of monoclonal antibodies, convalescent sera, and vaccines against the variants has been reported to be significantly reduced. Therefore, the efficacy of various monoclonal antibodies therapy and vaccines against these variants is becoming a great global concern. We herein summarize the current status of SARS-CoV-2 with gears shifted towards the recent and most common genetic variants in relation to transmission, neutralizing activity, and vaccine efficacy.


Asunto(s)
COVID-19 , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , COVID-19/inmunología , COVID-19/transmisión , COVID-19/virología , Humanos , Mutación , Internalización del Virus
18.
ACS Appl Mater Interfaces ; 13(31): 36967-36975, 2021 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-34339166

RESUMEN

An electrospun nanofiber membrane significantly improves the electrical performances of triboelectric nanogenerators (TENGs) due to its high surface area. In recent years, composite nanofibers were applied to a TENG using various electrospinning system types to further enhance the performance of TENGs; however, the effects of the systems on the energy harvesting capability of TENGs have not been investigated thoroughly. This study aims to fabricate polyimide/poly(vinylidene fluoride-co-trifluoroethylene) composite nanofiber-based TENGs with three different nozzle systems: single nozzle, conjugated nozzle, and multinozzles, and two different collectors: plate collector and drum collector. A TENG with multinozzle-drum system-based nanofibers produced an output voltage of 364 V, a short-circuit current of 17.2 µA, a transferred charge of 29.72 nC, and a power density of 2.56 W/m2 at a load resistance of 100 MΩ, which were ∼7 times higher than those of other system-based nanofibers. Under the 10,000 cycles of loading, the TENG stably harvested electric energy. The TENG could also harvest energy from the human body motions, and it is sufficient to illuminate 117 light-emitting diodes and drive several electronic devices. The proposed TENG exhibits excellent electric performances as a wearable energy harvester.

19.
Sensors (Basel) ; 21(14)2021 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-34300675

RESUMEN

The concept of an intelligent reflecting surface (IRS) has recently emerged as a promising solution for improving the coverage and energy/spectral efficiency of future wireless communication systems. However, as the number of reflecting elements in an IRS increase, the beam training protocol in IRS-assisted millimeter-wave (mmWave) cellular systems requires a large beam training time because it needs to find the best beam pairs for the link between the base station (BS) and the IRS, as well as the link between the IRS and the mobile station (MS). In this paper, a fast beam training technique for IRS-assisted mmWave cellular systems with a uniform rectangular array is proposed for detecting the best beam pairs of BS-IRS and IRS-MS links simultaneously. Two different types of beam training signals (BTSs) are proposed to distinguish simultaneously transmitted beams from the BSs in multi-cell multi-beam environments: the Zadoff-Chu sequence based BTS (ZC-BTS) and m-sequence based BTS (m-BTS). The correlation properties of ZC-BTSs and m-BTSs are analyzed in multi-cell multi-beam environments. In addition, the effect of symbol time offset on the ZC-BTS and m-BTS is analyzed. Finally, simulation results reveal that the proposed technique can significantly reduce the beam training time for IRS-assisted mmWave cellular systems.


Asunto(s)
Simulación por Computador
20.
Artículo en Inglés | MEDLINE | ID: mdl-33673463

RESUMEN

Due to safety issues in the construction industry, interest in research on occupational safety and health (OSH) regulations remains high. Previous studies indicated that OSH regulations not only affect performance in and of themselves, but also indirectly by increasing awareness of such regulations. Studies also demonstrated that OSH regulation can affect innovation and corporate safety. However, the effect of OSH regulation on innovation remains unclear, as the relationship between the perception of OSH regulation and innovation is not fully understood. This study measures the innovation efficiency of companies in the Korean construction industry using data envelopment analysis (DEA), and investigates the relationship between innovation efficiency and companies' perceptions of OSH regulations. Results indicate that companies that positively recognize OSH regulations tend to be more innovative than those that do not. This study also validates differences in innovation efficiency depending on the perception of OSH regulations by bootstrap DEA. The results of this study suggest appropriate strategies to promote innovation in the construction industry from the perspectives of both government and practitioners in firms.


Asunto(s)
Industria de la Construcción , Salud Laboral , Eficiencia , Percepción , República de Corea
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