• Structural Engineering and Mechanics
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• v.91 no.1
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• pp.1-23
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• 2024

This paper formulates a new integral shear deformation shell theory to investigate the free vibration response of carbon nanotube (CNT) reinforced structures with only four independent variables, unlike existing shell theories, which invariably and implicitly induce a host of unknowns. This approach guarantees traction-free boundary conditions without shear correction factors, using a non-polynomial hyperbolic warping function for transverse shear deformation and stress. By introducing undetermined integral terms, it will be possible to derive the motion equations with a low order of differentiation, which can facilitate a closed-form solution in conjunction with Navier's procedure. The mechanical properties of the CNT reinforcements are modeled to vary smoothly and gradually through the thickness coordinate, exhibiting different distribution patterns. A comparison study is performed to prove the efficacy of the formulated shell theory via obtained results from existing literature. Further numerical investigations are current and comprehensive in detailing the effects of CNT distribution patterns, volume fractions, and geometrical configurations on the fundamental frequencies of CNT-reinforced nanocomposite shells present here. The current shell theory is assumed to serve as a potent conceptual framework for designing reinforced structures and assessing their mechanical behavior.

• Journal of Life Science
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• v.7 no.4
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• pp.392-401
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• 1997

The poliovirus is a small, and non-enveloped virus. The RNA genome of poliovirus is continuous, linear, and has a single open reading frame. This polyprotein precursor is cleaved proteolytically to yield mature products. Most of the cleavages occur by viral protease. The mature proteins derived from the P1 polyprotein precursor are the structural components of the viral capsid. The initial cleavage by 2A protease is indirectly involved in the cleavage of a cellular protein p220, a subunit of the eukaryotic translation initiation factor 4F. This cleavage leads to the shut-off of cap-dependent host cell translation, and allows poliovirus to utilize the host cell machinery exclusively for translation its own RNA, which is initiated by internal ribosome entry via a cap-independent mechanism. The functional role of the 2B, 2C and 2BC proteins are not much known. 2B, 2C, 2BC and 3CD proteins are involved in the replication complex of virus induced vesicles. All newly synthesized viral RNAs are linked with VPg. VPg is a 22 amino acid polypeptide which is derived from 3AB. The 3C and 3CD are protease and process most of the cleavage sites of the polyprotein precursor. The 3C protein is also involved in inhibition of RNA polymerase II and III mediated transcription by converting host transcription factor to an inactive form. The 3D is the RNA dependent RNA polymerase. It is known that poliovirus replication follows the general pattern of positive strand RNA virus. Plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA strands. Poliovirus RNA synthesis occurs in a membranous environment but how the template RNA and proteins required for RNA replication assemble in the membrane is not much known. The RNA requirements for the encapsidation of the poliovirus genome (packaging signal) are totally unknown. The poliovirus infection cycle lasts approximately 6 hours.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.111-119
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• 2010

Salmonella spp. are one of major pathogens for zoonosis in worldwide, and can replicate within host cells and generally cause enterocolitis and foodborne poisoning which represents a considerable public health burden. The present study was designated to investigate the safty for host cells, antibacterial effects of Saururus chinensis Baill water extract (SCWE) on pure culture and infection with Salmonella enterica serovar Typhimurium (S. typhimurium) in murine derived macrophage RAW 264.7 cells. The different treatment of SCWE concentration (1, 10 or $100{\mu}g/ml$) did not show any cytotoxic effect to RAW 264.7 cells for 24 h incubation. In determination of antibacterial activity of SCWE against S. typhimurium, bacterial viability was markedly decreased compared to SCWE-untreated control. In RAW 264.7 cells, SCWE significantly induced morphological change (p<0.05). In infection assay of S. typhimurium in RAW 264.7 cells pretreated with $100{\mu}g/ml$ of SCWE, which are non-cytotoxic concentration, bacterial uptake ability of macrophage was increased corresponding with morphological change, whereas bacterial survival rates within macrophage was markedly reduced comparing to that of SCWE-untreated control. Furthermore, nitric oxide (NO) production in SCWE-treated cells was slightly decreased until 24 h post infection. Taken together, these findings demonstrated that SCWE have the antibacterial activity for S. typhimurium and the protective effects against S. typhimurium infection through activating murine macrophage independent on NO, suggesting that SCWE were beneficial on the disease caused by intracellularly replicating pathogens as a safe alternatives of conventional chemotherapies.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.3
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• pp.177-191
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• 2021

Due to the development of mobile devices and streaming technology, many changes in consumption patterns have appeared. In addition, social impact is becoming an era of non-face-to-face consumption due to the panthermic environment of COVID-19. Accordingly, in line with the non-face-to-face consumption trend, we focused on the importance of live commerce, which is emerging as a new distribution channel, and tried to investigate the causal relationship that the characteristics of live commerce and show hosts have on purchase intention. The respondents of this study were 235 general adults of live commerce users. Interaction, economics, entertainment as the characteristics of live commerce and attractiveness, professionality, and awareness as the characteristics of show hosts were set as independent variables. Purchase intention was set as the dependent variable, and content flow was set as the mediating variable. As a result of the study, it was found that the characteristics of live commerce such as Interaction, economics, entertainment, and the characteristics of show hosts such as attractiveness, professionality, and awareness all had a positive (+) significant effect on purchase intention. The impact was shown in the following order: entertainment of live commerce, awareness, attractiveness, professionality of show hosts, economics, interaction of live commerce. In addition, the results of the mediating effect of content flow on purchase intention are as follows. Content flow was found to play a mediating role between interaction, entertainment, attractiveness, professionality, awareness and purchase intention. On the other hand, economics was analyzed to have no mediating effect. The implications of this study are as follows. Companies and show hosts that sell products in live commerce should sell products that can inspire consumers rather than simply sell products. In addition, it is considered that content that provides entertainment and attractions gives pleasure to consumers. If not only a well-recognized show host, but also people with high recognition in various fields such as influencers and creators, become show hosts, consumers' content flow and purchase intentions will increase. And vendors must offer interesting content development and reasonable prices. Show hosts need to focus on active communication with consumers.

• Korean Journal of Environmental Biology
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• v.18 no.2
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• pp.205-213
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• 2000

Laboratory studies have revealed that naturally transformable bacteria develop competence under in situ conditions. Thus, the occurrence of competent bacteria in the environment can be considered as a certainty The persistence of free DNA in natural habitats is influenced by nucleolytic degradation and protection from degradation by adsorption to minerals. Although DNA seeded into natural environment was hydrolysed at substantial rates, but was still detectable at low levels after even several weeks. Compared to the number of laboratory based studies, only a few data have been published dealing with transformation of bacteria in the field. Recently, the potential transfer of recombinant DNA (rDNA) from deliberately or accidentally released bacteria to indigenous microbes has raised biosafety issues, since the persistence of rDNA becomes independent of the survival of its original host and leads to unpredictable, long-term ecological effects. The aim of the present review is to summarise recent literature on horizontal gene transfer (HGT) by transformation among bacteria in both soil and aquatic habitat and special emphasis is placed on recent reports which have addressed HGT among bacteria in the field. [Transformation, Horizontal gene transfer (HGT), recombinant DNA (rDNA), Genetically modified microorganisms (GMMs), Biosafety]

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.291-298
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• 2013

The purpose of this study was to analyze perceptions to hindering factors and development factors for water leisure activation. In order to accomplish the study purpose, this study employed a survey method with water leisure participants and employees from 6 regions(participants=205, employees=117). The data were analyzed using independent t-tests at a=.05 and following findings were derived from current study. First, among 20 hindering factors, water leisure participants had higher levels of perceptions than employees in licence system, limited activation regulation, departure report regulation, absence of exclusive organization, lack of providing information, lack of participative events and support systems. Second, relatively highly perceived hindering factors included departure report regulation, limited activation regulation, licence system, lack of government support, lack of mooring facility and lack of exclusive charged organization, in order. Third, the important development factors perceived by participants included support for licence and education and diversified water leisure programs but those perceived by employees included placement of educated experts and related event host and publicity. Finally, relatively highly perceived development factors included activation of free experience, promotion of marina development, support for licence and education, diversified programs and support for water leisure business. Accordingly, the findings provided fundamental information that both central and regional government can utilize for further activating water leisure. In addition, several development strategies were discussed on financial support, facility support, human resource support, education support and event support perspectives.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4525-4530
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• 2015

Background: The MTHFR C677T polymorphism is a genetic alteration affecting an enzyme involved in folate metabolism, but its relationship to host susceptibility to prostate cancer remains uncertain. The aim of this study was to investigate the association between MTHFR C677T polymorphism and prostate cancer by performing a meta-analysis. Materials and Methods: Pubmed and Web of Science databases were searched for case-control studies investigating the association between MTHFR C677T polymorphism and prostate cancer. Odds ratios (OR) and 95% confidence intervals (95%CI) were used to assess any link. Results: A total of 22 independent studies were identified, including 10,832 cases and 11,993 controls. Meta-analysis showed that there was no obvious association between MTHFR C677T polymorphism and risk of prostate cancer under all five genetic models. There was also no obvious association between MTHFR C677T polymorphism and risk of prostate cancer in the subgroup analyses of Caucasians. In contrast, MTHFR C677T polymorphism was associated with increased risk for prostate cancer in Asians with the allele model (C vs G: OR=1.299, 95 %CI =1.121-1.506, P=0.001, $P_{heterogeneity}=0.120$, $I^2=45%$), additive genetic model (CC vs TT: OR =1.925, 95 % CI= 1.340-2.265, P=0.00, $P_{heterogeneity}=0.587$, $I^2=0.00%$), recessive model (CC vs TT+TC: OR= 1.708, 95 % CI=1.233-2.367, P=0.001, $P_{heterogeneity}=0.716$, $I^2=0.00%$), and heterozygote genetic model (CT vs TT: OR=2.193, 95 % CI =1.510-3.186, P=0.000, $P_{heterogeneity}=0.462$, $I^2=0.00%$). Conclusions: These results suggest that the MTHFR C677T polymorphism does not contribute to the risk of prostate cancer from currently available evidence in populations overall and Caucasians. However, the meta analysis indicates that it may play a role in prostate cancer development in Asians.

• Journal of Ginseng Research
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• v.40 no.2
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• pp.127-134
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• 2016

Background: Rhizospheric fungi play an essential role in the plantesoil ecosystem, affecting plant growth and health. In this study, we evaluated the fungal diversity in the rhizosphere soil of 2-yr-old healthy Panax notoginseng cultivated in Wenshan, China. Methods: Culture-independent Illumina MiSeq and culture-dependent techniques, combining molecular and morphological characteristics, were used to analyze the rhizospheric fungal diversity. A diffusion test was used to challenge the phytopathogens of P. notoginseng. Results: A total of 16,130 paired-end reads of the nuclear ribosomal internal transcribed spacer 2 were generated and clustered into 860 operational taxonomic units at 97% sequence similarity. All the operational taxonomic units were assigned to five phyla and 79 genera. Zygomycota (46.2%) and Ascomycota (37.8%) were the dominant taxa; Mortierella and unclassified Mortierellales accounted for a large proportion (44.9%) at genus level. The relative abundance of Fusarium and Phoma sequenceswas high, accounting for 12.9% and 5.5%, respectively. In total,113 fungal isolates were isolated from rhizosphere soil. They were assigned to five classes, eight orders (except for an Incertae sedis), 26 genera, and 43 species based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer. Fusarium was the most isolated genus with six species (24 isolates, 21.2%). The abundance of Phoma was also relatively high (8.0%). Thirteen isolates displayed antimicrobial activity against at least one test fungus. Conclusion: Our results suggest that diverse fungi including potential pathogenic ones exist in the rhizosphere soil of 2-yr-old P. notoginseng and that antagonistic isolates may be useful for biological control of pathogens.

• The Journal of the Petrological Society of Korea
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• v.19 no.4
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• pp.255-267
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• 2010

The primary utilization of recently improved (U-Th)/He thermochronometry is to reveal the low-T thermal histories of shallow crustal sections or transient episodes (such as wildfires or meteorite impacts) because of the high sensitivity of He diffusion to temperature in host minerals. In this contribution, we present reviews and perspectives regarding how this method can be used to characterize the ejection-related shock metamorphism of Martian meteorites. The temperature conditions of shock metamorphism can be constrained through shock recovery experiments, paleomagnetism, and $^{40}Ar/^{39}Ar$ and (U-Th)/He dating. The most reliable constraints can be deduced when these independent approaches are combined. However, the thermal history of the ALH84001 Martian meteorite has been under serious debate because the different methods have yielded contrasting results. Recent work has shown how single-grain (U-Th)/He and $^{40}Ar/^{39}Ar$ dating, two noble-gas based thermochronometries with different T sensitivities, can be used to resolve this issue, providing a good example for future research on other meteorites.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.95-110
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• 1992

Much progress has been made in understanding the subcellular events of the human lung injuries after acute exposure to environmental air pollutants. Host of those events represent oxidative damages mediated by reactive oxygen species such as superoxide, hydrogen peroxide, and the hydroxy, free radical. Recently, nitric oxide (NO) was found to be endogenously produced by endothelial cells and cells of the reticulo-endothelial system as endothelialderived relaxation factor (EDRF) which is a vasoactive and neurotransmitter substance. Together with superoxide, NO can form another strong oxidant, peroxonitrite. The relative importance of exogenous sources of $N0/N0_2$ and endogenous production of NO by the EDRF producing enzymes in the oxidative stresses to the heman lung has to be elucidated. The exact events leading to chronic irreversible damage are still yet to be known. From chronic exposure to oxidant gases, progressive epithelial and interstitial damages develop. Type I epithelial cells become thicker and cover a smaller average alveolar surface area while thee II cells proliferate instead. Under acute damages, the extent of loss of the alveolar epithelial cell lining, especially type II cells appears to be a good predictor of the ensuing irreversible damage to alveolar compartment. Interstitial matrix undergo remodeling during chronic exposure with increased collagen fibers and interstitial fibroblasts. However, Inany of these changes can be reversed after cessation of exposure. Among chronic lung injuries, genetic damages and repair responses received particular attention in view of the known increased lung cancer risks from exposure to several air pollutants. Heavy metals from foundry emission, automobile traffics, and total suspended particulate, especially polycystic aromatic hydrocarbons have been positively linked with the development of lung cancer. Asbestos in another air pollutant with known risk of lung cancer and mesothelioma, but asbestos fibers are nonauthentic in most bioassays. Studies using the electron spin resonance spin trapping method show that the presence of iron in asbestos accelerates the production of the hydroxy, radical in vitro. Interactions of these reactive oxygen species with particular cellular components and disruption of cell defense mechanisms still await further studies to elucidate the carcinogenic potential of asbestos fibers of different size and chemical composition. The distribution of inhaled pollutants and the magnitude of their eventual effects on the respiratory tract are determined by pollutant-independent physical factors such as anatomy of the respiratory tract and level and pattern of breathing, as well as by pollutant-specific phyco-chemical factors such as the reactivity, solubility, and diffusivity of the foreign gas in mucus, blood and tissue. Many of these individual factors determining dose can be quantified in vitro. However, mathematical models based on these factors should be validated for its integrity by using data from intact human lungs.