• Title/Summary/Keyword: resistance management

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Cap truss and steel strut to resist progressive collapse in RC frame structures

  • Zahrai, Seyed Mehdi;Ezoddin, Alireza
    • Steel and Composite Structures
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    • v.26 no.5
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    • pp.635-647
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    • 2018
  • In order to improve the efficiency of the Reinforced Concrete, RC, structures against progressive collapse, this paper proposes a procedure using alternate path and specific local resistance method to resist progressive collapse in intermediate RC frame structures. Cap truss consists of multiple trusses above a suddenly removed structural element to restrain excessive collapse and provide an alternate path. Steel strut is used as a brace to resist compressive axial forces. It is similar to knee braces in the geometry, responsible for enhancing ductility and preventing shear force localization around the column. In this paper, column removals in the critical position at the first story of two 5 and 10-story regular buildings strengthened using steel strut or cap truss are studied. Based on nonlinear dynamic analysis results, steel strut can only decrease vertical displacement due to sudden removal of the column at the first story about 23%. Cap truss can reduce the average vertical displacement and column axial force transferred to adjacent columns for the studied buildings about 56% and 61%, respectively due to sudden removal of the column. In other words, using cap truss, the axial force in the removed column transfers through an alternate path to adjacent columns to prevent local or general failure or to delay the progressive collapse occurrence.

Ferutinin, an Apoptosis Inducing Terpenoid from Ferula ovina

  • Matin, Maryam Moghaddam;Nakhaeizadeh, Hossein;Bahrami, Ahamd Reza;Iranshahi, Mehrdad;Arghiani, Nahid;Rassouli, Fatemeh Behnam
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2123-2128
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    • 2014
  • A current hurdle in cancer management is the intrinsic or acquired resistance of cancer cells to chemical agents that restricts the efficacy of therapeutic strategies. Accordingly, there is an increasing desire to discover new natural compounds with selective toxicity to combat malignancies. In present study, the cytotoxic and apoptosis-inducing activities of ferutinin, a terpenoid derivative from Ferula ovina, were investigated on human breast (MCF7) and bladder (TCC) cancer cells as well as normal fibroblasts (HFF3).The toxicity and DNA damage inducing effects of ferutinin were studied by MTT and comet assays, DAPI and PI staining and DNA laddering. The $IC_{50}$ values of ferutinin were identified and compared with routine prescribed drugs, doxorubicin and vincristine, by MTT test. Alkaline comet assay and DAPI staining revealed DNA damage due to ferutinin, which was significantly (p<0.001) higher in MCF7 and TCC than HFF3 cells. Apoptosis induction was evidenced by PI staining and DNA laddering. Our results suggest that ferutinin could be considered as an effective anticancer agent for future in vivo and clinical experiments.

The Probiotic and Adherence Properties of Lactobacillus reuteri Pg4 Expressing the Rumen Microbial β-Glucanase

  • Yu, B.;Liu, J.R.;Hsiao, F.S.;Lee, T.T.;Chiou, P.W.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.9
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    • pp.1324-1329
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    • 2008
  • This study was conducted to evaluate the potential of the transformed Lactobacillus reuteri Pg4 (T-Pg4) harboring the ${\beta}$-glucanase gene as a poultry probiotic. The probiotic properties of the T-Pg4 strain were evaluated in vitro by their adherence capability and acid and bile salt tolerance, and were evaluated in vivo by their survival and adhesion in the gastrointestinal tract (GIT) of specific-pathogen-free (SPF) chickens. The results showed that the T-Pg4 strain exhibited resistance to acidic conditions and contact with bile salt, and adhered efficiently to the crop and intestinal epithelial cells of chickens in vitro. The T-Pg4 strain also could survive and colonize the gastrointestinal epithelium of the experimental SPF chickens in vivo. In addition, radial enzyme diffusion was used to demonstrate that the Lactobacillus spp. randomly isolated from the GIT of the SPF chickens fed T-Pg4 possessed ${\beta}$-glucanase secretion capability. These findings have demonstrated that the transformed L. reuteri Pg4 survives transit through the stomach and intestine, and may secrete ${\beta}$-glucanase in the chicken GIT. Therefore, it is suggested that this organism could be used as a multifunctional poultry probiotic.

Milk Quality and Antimicrobial Resistance against Mastitis Pathogens after Changing from a Conventional to an Experimentally Organic Dairy Farm

  • Suriyasathaporn, Witaya
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.5
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    • pp.659-664
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    • 2010
  • The present study was to investigate the effect of the transition from conventional to organic dairy farming on the antimicrobial resistant pattern of pathogens in milk. A farm with tie-stall management, with an average herd size of 20 milking cows, was selected based on the owner' willingness to accept, for at least 6 months, the highly restricted protocol developed in this study. Comparisons of bacterial isolates and antimicrobial susceptibilities before changing to an organic farm system (BEFORE) and for 6 months after (AFTER) operating the experimental organic farm system were performed by Fisher's Exact Chi-square tests. Significant levels were defined at p<0.05. During the AFTER period, average frequency of antibiotic treatment was decreased from more than 3 cases/month to less than 1 case/month during which the antibiotic use was authorized only by the veterinarian. In total, 92 and 70 quarter milk samples from 24 and 18 cows during BEFORE and AFTER, respectively, were included in the study. Overall, isolates ranged from a non-resistant level for cephazolin to a very high resistant level to streptomycin (64.71% to 95.45%). Percentages of antimicrobial resistant isolates during BEFORE were significantly higher than during AFTER for ampicillin (43.48% and 5.88%, respectively) and streptomycin (95.45% and 64.71%, respectively). In conclusion, percentages of antimicrobial resistant isolates were decreased after 6 months of operating as an organic farm system.

A Electrical and Optical studies of WO3/Ag/WO3 Transparent Electrode by RF Magnetron Sputtering (RF 마그네트론 스퍼터링을 이용한 WO3/Ag/WO3 투명전극의 전기·광학적 특성 연구)

  • Kang, Dong-Soo;Lee, Boong-Joo;Kwon, Hong-Kyu;Shin, Paik-Kyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.11
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    • pp.1533-1537
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    • 2014
  • $WO_3/Ag/WO_3$ multilayer was researched by using RF magnetron sputtering with transparent electrode. Process gas flow ratio with $Ar/O_2$ were selected the optimum conditions at 70sccm/2sccm and $WO_3$ thin film at its conditions was appeared at transmittance about 80% in the visible light region to the average. $WO_3/Ag/WO_3$ multilayer thin films were fabricated from the same process condition which was the same gas flow ratio of Ar and $O_2$ $WO_3/Ag/WO_3$ thin films were appeared transmittance about 93% and sheet resistance about $6.41{\Omega}/{\square}$. From the SEM images, each thin films were appeared when $WO_3$ is 40nm and $O_2$ is 10nm.

Duplication-Aware Garbage Collection for Flash Memory-Based Virtual Memory Systems (플래시 메모리 기반의 가상 메모리 시스템을 위한 중복성을 고려한 GC 기법)

  • Ji, Seung-Gu;Shin, Dong-Kun
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.3
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    • pp.161-171
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    • 2010
  • As embedded systems adopt monolithic kernels, NAND flash memory is used for swap space of virtual memory systems. While flash memory has the advantages of low-power consumption, shock-resistance and non-volatility, it requires garbage collections due to its erase-before-write characteristic. The efficiency of garbage collection scheme largely affects the performance of flash memory. This paper proposes a novel garbage collection technique which exploits data redundancy between the main memory and flash memory in flash memory-based virtual memory systems. The proposed scheme takes the locality of data into consideration to minimize the garbage collection overhead. Experimental results demonstrate that the proposed garbage collection scheme improves performance by 37% on average compared to previous schemes.

A Study on Measurement of Mechanical Properties of Polyther Polyol Base Polyurethane Dispersion by 1,4-butanediol Chain Extension (Polyether Polyol을 이용한 수분산 폴리우레탄의 1,4-butanediol 사슬연장에 의한 물성변화)

  • Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.4
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    • pp.711-718
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    • 2014
  • In this paper, the mechanical property change was investigated by adding 1,4-butanediol as chain extender of polyurethane dispersion for leather coating. Reagents for the synthesis were polypropylene glycol(PPG), isoporon diisocyanate(IPDI), dimethylolpropionic acid(DMPA) and 1,4-BD. All samples showed good solvent resistance and flexibility by different content of the 1,4-BD. As results, samples which contains a lot of 1,4-BD showed good properties whth strength of $1.80kg_f/mm^2$ and abrasion test measurement of 49.54 mg.loss. According to elongation test, the sample which contains low amount of 1,4-BD was good property as 364 %.

Antimicrobial susceptibility and detection of enterotoxin by multiplex PCR of Staphylococcus aureus isolated from dogs and cats in Seoul (서울지역의 개와 고양이에서 분리한 Staphylococcus aureus의 항생제 감수성 및 multiplex PCR을 이용한 장독소의 검출)

  • Kim, Neung-Hee;Chae, Hee-Sun;Son, Hong-Rak;Kim, Chang-Ki;Kim, Sun-Heung;Lee, Jung-Hark;Kim, Chul-Hun
    • Korean Journal of Veterinary Service
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    • v.33 no.3
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    • pp.263-269
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    • 2010
  • The antimicrobial susceptibility of 73 strains of Staphylococcus aureus isolated from dogs and cats was determined against 16 antimicrobial agents. All isolates were susceptible to cephalothin (CF), vancomycin (VA), rifampin (RA), quinupristin-dalfopristin (SYN) and linezolid (LZD), whereas more than 86.3% of the isolates were resistant to penicillin (P). In the case of enterotoxin production, 8.2% of 73 strains produced enterotoxin A and 1 strain produced enterotoxin C. Appropriate protocols for antimicrobial agents and strategies to reduce antimicrobial resistance will need to be investigated in the future.

Effectiveness of Different Classes of Fungicides on Botrytis cinerea Causing Gray Mold on Fruit and Vegetables

  • Kim, Joon-Oh;Shin, Jong-Hwan;Gumilang, Adiyantara;Chung, Keun;Choi, Ki Young;Kim, Kyoung Su
    • The Plant Pathology Journal
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    • v.32 no.6
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    • pp.570-574
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    • 2016
  • Botrytis cinerea is a necrotrophic pathogen causing a major problem in the export and post-harvest of strawberries. Inappropriate use of fungicides leads to resistance among fungal pathogens. Therefore, it is necessary to evaluate the sensitivity of B. cinerea to various classes of fungicide and to determine the effectiveness of different concentrations of commonly used fungicides. We thus evaluated the effectiveness of six classes of fungicide in inhibiting the growth and development of this pathogen, namely, fludioxonil, iprodione, pyrimethanil, tebuconazole, fenpyrazamine, and boscalid. Fludioxonil was the most effective ($EC_{50}$ < $0.1{\mu}g/ml$), and pyrimethanil was the least effective ($EC_{50}=50{\mu}g/ml$), at inhibiting the mycelial growth of B. cinerea. Fenpyrazamine and pyrimethanil showed relatively low effectiveness in inhibiting the germination and conidial production of B. cinerea. Our results are useful for the management of B. cinerea and as a basis for monitoring the sensitivity of B. cinerea strains to fungicides.

Performance Evaluation of Long-Life Asphalt Concrete Overlays Based on Field Survey Monitoring in National Highways (일반국도 현장조사 모니터링을 통한 장수명 아스팔트 덧씌우기 포장의 공용성 분석)

  • Baek, Jongeun;Lim, Jae Kyu;Kwon, Soo Ahn;Kwon, Byung Yoon
    • International Journal of Highway Engineering
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    • v.17 no.3
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    • pp.69-76
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    • 2015
  • PURPOSES : Performance evaluation of four types of asphalt concrete overlays for deteriorated national highways. METHODS : Pavement distress surveys for crack rate and rut depth have been conducted annually using an automated pavement survey vehicle since 2007. Linear and non-linear performance prediction models of the asphalt concrete overlays were developed for 43 sections. The service life of the asphalt overlays was defined as the number of years after which a crack rate of 30% or rut depth of 15mm is observed. RESULTS : The service life of the asphalt overlays was estimated as 17.4 years on an average. In 90.7% of the sections, the service life of the overlays was 15 years or more which is 1.5 times the life of conventional asphalt concrete overlays used in national highways. The performance of the overlays was dependent on the type of asphalt mixture, traffic volume levels, and environmental conditions. CONCLUSIONS : The usage of stone mastic asphalt (SMA) and polymer-modified asphalt (PMA) for the overlays provided good resistance to cracking and rutting development. It is recommended that appropriate asphalt concrete overlays must be applied depending on the type of existing pavement distress.