• Title/Summary/Keyword: Key Barrier

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A unique genetic lineage at the southern coast of China in the agar-producing Gracilaria vermiculophylla (Gracilariales, Florideophyceae)

  • Hu, Zi-Min;Liu, Ruo-Yu;Zhang, Jie;Duan, De-Lin;Wang, Gao-Ge;Li, Wen-Hong
    • ALGAE
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    • v.33 no.3
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    • pp.269-278
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    • 2018
  • Ocean warming can have significant negative impacts on population genetic diversity, local endemism and geographical distribution of a wide range of marine organisms. Thus, the identification of conservation units with high risk of extinction becomes an imperative task to assess, monitor, and manage marine biodiversity for policy-makers. Here, we surveyed population structure and genetic variation of the red seaweed Gracilaria vermiculophylla along the coast of China using genome-based amplified fragment length polymorphism (AFLP) scanning. Regardless of analysis methods used, AFLP consistently revealed a south to north genetic isolation. Populations at the southern coast of China showed unique genetic variation and much greater allelic richness, heterozygosity, and average genetic diversity than the northern. In particular, we identified a geographical barrier that may hinder genetic exchange between the two lineages. Consequently, the characterized genetic lineage at the southern coast of China likely resulted from the interplay of post-glacial persistence of ancestral diversity, geographical isolation and local adaptation. In particular, the southern populations are indispensable components to explore evolutionary genetics and historical biogeography of G. vermiculophylla in the northwestern Pacific, and the unique diversity also has important conservation value in terms of projected climate warming.

Amelioration of colitis progression by ginseng-derived exosome-like nanoparticles through suppression of inflammatory cytokines

  • Jisu Kim;Shuya Zhang ;Ying Zhu;Ruirui Wang;Jianxin Wang
    • Journal of Ginseng Research
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    • v.47 no.5
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    • pp.627-637
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    • 2023
  • Background: Damage to the healthy intestinal epithelial layer and regulation of the intestinal immune system, closely interrelated, are considered pivotal parts of the curative treatment for inflammatory bowel disease (IBD). Plant-based diets and phytochemicals can support the immune microenvironment in the intestinal epithelial barrier for a balanced immune system by improving the intestinal microecological balance and may have therapeutic potential in colitis. However, there have been only a few reports on the therapeutic potential of plant-derived exosome-like nanoparticles (PENs) and the underlying mechanism in colitis. This study aimed to assess the therapeutic effect of PENs from Panax ginseng, ginseng-derived exosome-like nanoparticles (GENs), in a mouse model of IBD, with a focus on the intestinal immune microenvironment. Method: To evaluate the anti-inflammatory effect of GENs on acute colitis, we treated GENs in Caco2 and lipopolysaccharide (LPS) -induced RAW 264.7 macrophages and analyzed the gene expression of proinflammatory cytokines and anti-inflammatory cytokines such as TNF-α, IL-6, and IL-10 by real-time PCR (RT-PCR). Furthermore, we further examined bacterial DNA from feces and determined the alteration of gut microbiota composition in DSS-induced colitis mice after administration of GENs through 16S rRNA gene sequencing analysis. Result: GENs with low toxicity showed a long-lasting intestinal retention effect for 48 h, which could lead to effective suppression of pro-inflammatory cytokines such as TNF-α and IL-6 production through inhibition of NF-κB in DSS-induced colitis. As a result, it showed longer colon length and suppressed thickening of the colon wall in the mice treated with GENs. Due to the amelioration of the progression of DSS-induced colitis with GENs treatment, the prolonged survival rate was observed for 17 days compared to 9 days in the PBS-treated group. In the gut microbiota analysis, the ratio of Firmicutes/Bacteroidota was decreased, which means GENs have therapeutic effectiveness against IBD. Ingesting GENs would be expected to slow colitis progression, strengthen the gut microbiota, and maintain gut homeostasis by preventing bacterial dysbiosis. Conclusion: GENs have a therapeutic effect on colitis through modulation of the intestinal microbiota and immune microenvironment. GENs not only ameliorate the inflammation in the damaged intestine by downregulating pro-inflammatory cytokines but also help balance the microbiota on the intestinal barrier and thereby improve the digestive system.

Modular Multiplication Algorithm Design for Application of Cryptosystem based on Public Key Structure (공개키 기반의 암호 시스템에 적합한 모듈러 연산기 알고리즘의 효율적인 설계)

  • Kim, Jungl-Tae;Hur, Chang-Woo;Ryu, Kwang-Ryul
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.469-472
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    • 2003
  • The computational cost of encryption is a barrier to wider application of a variety of data security protocols. Virtually all research on Elliptic Curve Cryptography(ECC) provides evidence to suggest that ECC can provide a family of encryption algorithms that implementation than do current widely used methods. This efficiency is obtained since ECC allows much shorter key lengths for equivalent levels of security. This paper suggests how improvements in execution of ECC algorithms can be obtained by changing the representation of the elements of the finite field of the ECC algorithm. Specifically, this research compares the time complexity of ECC computation eve. a variety of finite fields with elements expressed in the polynomial basis(PB) and normal basis(NB).

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Sustained release of alginate hydrogel containing antimicrobial peptide Chol-37(F34-R) in vitro and its effect on wound healing in murine model of Pseudomonas aeruginosa infection

  • Shuaibing Shi;Hefan Dong;Xiaoyou Chen;Siqi Xu;Yue Song;Meiting Li;Zhiling Yan ;Xiaoli Wang ;Mingfu Niu ;Min Zhang;Chengshui Liao
    • Journal of Veterinary Science
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    • v.24 no.3
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    • pp.44.1-44.17
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    • 2023
  • Background: Antibiotic resistance is a significant public health concern around the globe. Antimicrobial peptides exhibit broad-spectrum and efficient antibacterial activity with an added advantage of low drug resistance. The higher water content and 3D network structure of the hydrogels are beneficial for maintaining antimicrobial peptide activity and help to prevent degradation. The antimicrobial peptide released from hydrogels also hasten the local wound healing by promoting epithelial tissue regeneration and granulation tissue formation. Objective: This study aimed at developing sodium alginate based hydrogel loaded with a novel antimicrobial peptide Chol-37(F34-R) and to investigate the characteristics in vitro and in vivo as an alternative antibacterial wound dressing to treat infectious wounds. Methods: Hydrogels were developed and optimized by varying the concentrations of crosslinkers and subjected to various characterization tests like cross-sectional morphology, swelling index, percent water contents, water retention ratio, drug release and antibacterial activity in vitro, and Pseudomonas aeruginosa infected wound mice model in vivo. Results: The results indicated that the hydrogel C proved superior in terms of cross-sectional morphology having uniformly sized interconnected pores, a good swelling index, with the capacity to retain a higher quantity of water. Furthermore, the optimized hydrogel has been found to exert a significant antimicrobial activity against bacteria and was also found to prevent bacterial infiltration into the wound site due to forming an impermeable barrier between the wound bed and external environment. The optimized hydrogel was found to significantly hasten skin regeneration in animal models when compared to other treatments in addition to strong inhibitory effect on the release of pro-inflammatory cytokines (interleukin-1β and tumor necrosis factor-α). Conclusions: Our results suggest that sodium alginate -based hydrogels loaded with Chol-37(F34-R) hold the potential to be used as an alternative to conventional antibiotics in treating infectious skin wounds.

In Vitro Evaluation of Swine-Derived Lactobacillus reuteri: Probiotic Properties and Effects on Intestinal Porcine Epithelial Cells Challenged with Enterotoxigenic Escherichia coli K88

  • Wan, Zhilin;Wang, Li;Chen, Zhuang;Ma, Xianyong;Yang, Xuefen;Zhang, Jian;Jiang, Zongyong
    • Journal of Microbiology and Biotechnology
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    • v.26 no.6
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    • pp.1018-1025
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    • 2016
  • Probiotics are considered as the best effective alternatives to antibiotics. The aim of this study was to characterize the probiotic potential of lactobacilli for use in swine farming by using in vitro evaluation methods. A total of 106 lactic acid bacterial isolates, originating from porcine feces, were first screened for the capacity to survive stresses considered important for putative probiotic strains. Sixteen isolates showed notable acid and bile resistance, antibacterial activity, and adherence to intestinal porcine epithelial cells (IPEC-1). One isolate, LR1, identified as Lactobacillus reuteri, was selected for extensive study of its probiotic and functional properties in IPEC-1 cell models. L. reuteri LR1 exhibited good adhesion to IPEC-1 cells and could inhibit the adhesion of enterotoxigenic Escherichia coli (ETEC) to IPEC-1 cells. L. reuteri LR1 could also modulate transcript and protein expression of cytokines involved in inflammation in IPEC-1 cells; the Lactobacillus strain inhibited the ETEC-induced expression of proinflammatory transcripts (IL-6 and TNF-α) and protein (IL-6), and increased the level of anti-inflammatory cytokine (IL-10). Measurement of the permeation of FD-4 showed that L. reuteri LR1 could maintain barrier integrity in monolayer IPEC-1 cells exposed to ETEC. Immunolocalization experiments showed L. reuteri LR1 could also prevent ETEC-induced tight junction ZO-1 disruption. Together, these results indicate that L. reuteri LR1 exhibits desirable probiotic properties and could be a potential probiotic for use in swine production.

New Approaches for Overcoming Current Issues of Plasma Sputtering Process During Organic-electronics Device Fabrication: Plasma Damage Free and Room Temperature Process for High Quality Metal Oxide Thin Film

  • Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.100-101
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    • 2012
  • The plasma damage free and room temperature processedthin film deposition technology is essential for realization of various next generation organic microelectronic devices such as flexible AMOLED display, flexible OLED lighting, and organic photovoltaic cells because characteristics of fragile organic materials in the plasma process and low glass transition temperatures (Tg) of polymer substrate. In case of directly deposition of metal oxide thin films (including transparent conductive oxide (TCO) and amorphous oxide semiconductor (AOS)) on the organic layers, plasma damages against to the organic materials is fatal. This damage is believed to be originated mainly from high energy energetic particles during the sputtering process such as negative oxygen ions, reflected neutrals by reflection of plasma background gas at the target surface, sputtered atoms, bulk plasma ions, and secondary electrons. To solve this problem, we developed the NBAS (Neutral Beam Assisted Sputtering) process as a plasma damage free and room temperature processed sputtering technology. As a result, electro-optical properties of NBAS processed ITO thin film showed resistivity of $4.0{\times}10^{-4}{\Omega}{\cdot}m$ and high transmittance (>90% at 550 nm) with nano- crystalline structure at room temperature process. Furthermore, in the experiment result of directly deposition of TCO top anode on the inverted structure OLED cell, it is verified that NBAS TCO deposition process does not damages to the underlying organic layers. In case of deposition of transparent conductive oxide (TCO) thin film on the plastic polymer substrate, the room temperature processed sputtering coating of high quality TCO thin film is required. During the sputtering process with higher density plasma, the energetic particles contribute self supplying of activation & crystallization energy without any additional heating and post-annealing and forminga high quality TCO thin film. However, negative oxygen ions which generated from sputteringtarget surface by electron attachment are accelerated to high energy by induced cathode self-bias. Thus the high energy negative oxygen ions can lead to critical physical bombardment damages to forming oxide thin film and this effect does not recover in room temperature process without post thermal annealing. To salve the inherent limitation of plasma sputtering, we have been developed the Magnetic Field Shielded Sputtering (MFSS) process as the high quality oxide thin film deposition process at room temperature. The MFSS process is effectively eliminate or suppress the negative oxygen ions bombardment damage by the plasma limiter which composed permanent magnet array. As a result, electro-optical properties of MFSS processed ITO thin film (resistivity $3.9{\times}10^{-4}{\Omega}{\cdot}cm$, transmittance 95% at 550 nm) have approachedthose of a high temperature DC magnetron sputtering (DMS) ITO thin film were. Also, AOS (a-IGZO) TFTs fabricated by MFSS process without higher temperature post annealing showed very comparable electrical performance with those by DMS process with $400^{\circ}C$ post annealing. They are important to note that the bombardment of a negative oxygen ion which is accelerated by dc self-bias during rf sputtering could degrade the electrical performance of ITO electrodes and a-IGZO TFTs. Finally, we found that reduction of damage from the high energy negative oxygen ions bombardment drives improvement of crystalline structure in the ITO thin film and suppression of the sub-gab states in a-IGZO semiconductor thin film. For realization of organic flexible electronic devices based on plastic substrates, gas barrier coatings are required to prevent the permeation of water and oxygen because organic materials are highly susceptible to water and oxygen. In particular, high efficiency flexible AMOLEDs needs an extremely low water vapor transition rate (WVTR) of $1{\times}10^{-6}gm^{-2}day^{-1}$. The key factor in high quality inorganic gas barrier formation for achieving the very low WVTR required (under ${\sim}10^{-6}gm^{-2}day^{-1}$) is the suppression of nano-sized defect sites and gas diffusion pathways among the grain boundaries. For formation of high quality single inorganic gas barrier layer, we developed high density nano-structured Al2O3 single gas barrier layer usinga NBAS process. The NBAS process can continuously change crystalline structures from an amorphous phase to a nano- crystalline phase with various grain sizes in a single inorganic thin film. As a result, the water vapor transmission rates (WVTR) of the NBAS processed $Al_2O_3$ gas barrier film have improved order of magnitude compared with that of conventional $Al_2O_3$ layers made by the RF magnetron sputteringprocess under the same sputtering conditions; the WVTR of the NBAS processed $Al_2O_3$ gas barrier film was about $5{\times}10^{-6}g/m^2/day$ by just single layer.

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Return to Work in Multi-ethnic Breast Cancer Survivors - A Qualitative Inquiry

  • Tan, Foo Lan;Loh, Siew Yim;Su, TinTin;Veloo, V.W.;Ng, Lee Luan
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5791-5797
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    • 2012
  • Introduction: Return-to-work (RTW) can be a problematic occupational issue with detrimental impact on the quality of life of previously-employed breast cancer survivors. This study explored barriers and facilitators encountered during the RTW process in the area of cancer survivorship. Materials and Methods: Six focus groups were conducted using a semi-structured interview guide on 40 informants (employed multiethnic survivors). Survivors were stratified into three groups for successfully RTW, and another three groups of survivors who were unable to return to work. Each of the three groups was ethnically homogeneous. Thematic analysis using a constant comparative approach was aided by in vivo software. Results: Participants shared numerous barriers and facilitators which directly or interactively affect RTW. Key barriers were physical-psychological after-effects of treatment, fear of potential environment hazards, high physical job demand, intrusive negative thoughts and overprotective family. Key facilitators were social support, employer support, and regard for financial independence. Across ethnic groups, the main facilitators were financial-independence (for Chinese), and socialisation opportunity (for Malay). A key barrier was after-effects of treatment, expressed across all ethnic groups. Conclusions: Numerous barriers were identified in the non-RTW survivors. Health professionals and especially occupational therapists should be consulted to assist the increasing survivors by providing occupational rehabilitation to enhance RTW amongst employed survivors. Future research to identify prognostic factors can guide clinical efforts to restore cancer survivors to their desired level/type of occupational functioning for productivity and wellbeing.

Research on Personalization for Social Network Service in IPTV (IPTV 소셜네트워크서비스를 위한 개인화에 관한 연구)

  • Kim, Hyun-Suk;Kim, So-Hyun
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.884-887
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    • 2009
  • Social Network Service has been extremely popular these days and providing diverse features and functions to users. Social networking and interest sharing in between users are key factors of SNS and this circles back to draw more users to the service. Web is the first media to provide SNS and mobile is the next. The service based on mobile environmental uniqueness such as Location-based-service(LBS) is the key success factors to convert users to web SNS to mobile SNS. TV has also been a possible SSN market to draw users to share interests and participation. However TV has been always community electronics in family members and personalization to provide SNS has been barrier to overcome. In this study, we explorer ideas of key factors of personalization in TV environment and conducted a field study to define characteristics of TV personalization in terms of depth, method, style and structure. Research finds out that there are significant differences in these categories.

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Generation and Distribution of Symmetric/Asymmetric Secret Keys for Secure Communications in Koinonia High-rate WPAN (Koinonia 고속 WPAN에서 보안을 위한 대칭/비대칭 비밀 키 교환 방법)

  • Yim Soon-Bin;Jung Ssang-Bong;Lee Tae-Jin;June Sun-Do;Lee Hyeon-Seok;Kwon Tai-Gil;Cho Jin-Woong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.6B
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    • pp.551-560
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    • 2006
  • Security in WPAN is one of the most fundamental issues to overcome the barrier of wireless environment. Although piconet security mechanisms have been defined in the WPAN standards, many remains open and are left for implementation. Koinonia is a high-rate Wireless Personal Area Network (WPAN) technology, and is developed for multimedia traffic transmission in personal area. In Koinonia WPAN, a piconet consists of one master and more than one slave, and piconet security mechanisms is not defined at all. Therefore, we propose a robust piconet security mechanism for secure communications between slaves in a piconet. Based on security requirements analysis, our proposed protocols are shown to meet the security needs for Koinonia high-rate WPAN.

Research on Possibilies of Social Network Services through IPTV (IPTV를 통한 SNS 가능성에 관한 연구)

  • Kim, Hyun-Suk;Kim, So-Hyun
    • Journal of the HCI Society of Korea
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    • v.4 no.1
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    • pp.11-15
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    • 2009
  • Social Network Service has been extremely popular these days and providing diverse features and functions to users. Social networking and interest sharing in between users are key factors of SNS and this circles back to draw more users to the service. Web is the first media to provide SNS and mobile is the next. The service based on mobile environmental uniqueness such as Location-based-service(LBS) is the key success factors to convert users to web SNS to mobile SNS. TV has also been a possible SSN market to draw users to share interests and participation. However TV has been always community electronics in family members and personalization to provide SNS has been barrier to overcome. In this study, we explorer ideas of key factors of personalization in TV environment and conducted a field study to define characteristics of TV personalization in terms of depth, method, style and structure. Research finds out that there are significant differences in these categories.

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