• The Plant Pathology Journal
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• 제26권4호
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• pp.417-420
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• 2010

The expression of HR-like lesion inducing gene of Oryza sativa (OsHRL) was slightly increased by Xanthomonas oryzae pv. oryzae (Xoo) infection. Transgenic rice plants over-expressing OsHRL gene were challenged with Xoo and the development of disease symptoms were examined to investigate the effect of OsHRL gene expression on plant defense responses. The over-expression of OsHRL increased disease resistance against Xoo compared with wild type plants.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1144-1149
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• 2001

In this paper, a sliding mode controller of a fluid engine mount using MR (Magneto-Rheological) fluid was discussed When the MR fluid is applied to a fluid mount, resistance of MR fluid can be controlled by electro-magnetic valve installed in the inertia track. Since the rheological property of the MR fluid shows a function of shear rate, the damping characteristics of the mount will be change according to the frequency. Changing an applied magnetic field to the valve changes the property of the mount, such as the resistance of the MR fluid, the notch and the resonant frequencies due to the fluid passing, quantity of the fluid passing, the effective piston area of the volumetric damping and stiffness. Therefore, the fluid mount using MR fluid can be regarded as a variable structure system The sliding mode control known well as a particular type of variable structure control was introduced in this study. The sliding mode control, which has inherent robustness, is also expected to improve the control performance in the engine mount The sliding mode controller for the mount formatted by taking into account the response property with a time constant to MR fluid and the variable mount property. The motion equations of the fluid mount are derived from Newton's law of motion and used in numerical simulation. Numerical simulations illustrate the effectiveness of the sliding mode controller.

• 한국축산식품학회지
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• 제41권5호
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• pp.883-893
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• 2021

Clostridium difficile present in feces of food animals may contaminate their meats and act as a potential source of C. difficile infection (CDI) to humans. C. difficile resistance to antibiotics, its production of toxins and spores play major roles in the pathogenesis of CDI. This is the first study to evaluate C. difficile prevalence in retail raw animal meats, its antibiotics susceptibilities and toxigenic activities in Al-Jouf, Saudi Arabia. Totally, 240 meat samples were tested. C. difficile was identified by standard microbiological and biochemical methods. Vitek-2 compact system confirmed C. difficile isolates were 15/240 (6.3%). Toxins A/B were not detected by Xpect C. difficile toxin A/B tests. Although all isolates were susceptible to vancomycin and metronidazole, variable degrees of reduced susceptibilities to moxifloxacin, clindamycin or tetracycline antibiotics were detected by Epsilon tests. C. difficile strains with reduced susceptibility to antibiotics should be investigated. Variability between the worldwide reported C. difficile contamination levels could be due to absence of a gold standard procedure for its isolation. Establishment of a unified testing algorithm for C. difficile detection in food products is definitely essential to evaluate the inter-regional variation in its prevalence on national and international levels. Proper use of antimicrobials during animal husbandry is crucial to control the selective drug pressure on C. difficile strains associated with food animals. Investigating the protective or pathogenic potential of non-toxigenic C. difficile strains and the possibility of gene transfer from certain toxigenic/ antibiotics-resistant to non-toxigenic/antibiotics-sensitive strains, respectively, should be worthy of attention.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.80.1-80
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• 2003

Several plant and microbial genes that could confer disease resistance in transgenic rice plants are being cloned and characterized. We are currently constructing transgenic rice lines that overexpress the gene products, such as a galactinol synthase, a defensin, and a bacterial ACC deaminase. Subtractive hybridization of a rice cDNA library constructed from the Xanthomonas oryzae-infected ice leaves resulted in isolation of many inducible cDNA clones including a elongation factor EF2, a oryzain alpha, a catalase, a aldehyde dehydrogenase, a S-adenosylmethionine synthetase, a caffeic acid O-methyltransferase, a glyceraldehyde-3-phosphate dehydrogenase, a light-regulated protein, nKY transcription factors, and a nucleotide diphosphate kinase. Some genes among those may be useful genetic sources for construction of disease resistant transgenic rice. Full lengths of the rice OsFIERG and a rice oryzain genomic clones were cloned, and serial deletion fragments of the promoter regions of these genes were fused with GUS reporter gene in pCAMBIA1201, respectively. Promoter activities of these constructs will be examined upon various stresses and Pathogen infections to obtain the pathogen specific inducible-promoter. This work was supported by a grant from BioGreen 21 Program, Rural Development Administration, Republic of Korea.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 International Symposium
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• pp.261-278
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• 2003

Concepts.Wafer-Level Chip-Scale Concept with Handling Substrate.Low Accuracy Placement Layout with Isolation Trench.Possible Pitch of Interconnections down to $10{\mu}{\textrm}{m}$ (Sn-Grains).Wafer-to-Wafer Equipment Adjustment Accuracy meets this Request of Alignment Accuracy (+/-1.5 ${\mu}{\textrm}{m}$).Adjustment Accuracy of High-Speed Chip-to-Wafer Placement Equipment starts to meet this request.Face-to-Face Modular / SLID with Flipped Device Orientation.interchip Via / SLID with Non-Flipped Orientation SLID Technology Features.Demonstration with Copper / Tin-Alloy (SLID) and W-InterChip Vias (ICV).Combination of reliable processes for advanced concept - Filling of vias with W as standard wafer process sequence.No plug filling on stack level necessary.Simultanious formation of electrical and mechanical connection.No need for underfiller: large area contacts replace underfiller.Cu / Sn SLID layers $\leq$ $10{\mu}{\textrm}{m}$ in total are possible Electrical Results.Measurements of Three Layer Stacks on Daisy Chains with 240 Elements.2.5 Ohms per Chain Element.Contribution of Soldering Metal only in the Range of Milliohms.Soldering Contact Resistance ($0.43\Omega$) dominated by Contact Resistance of Barrier and Seed Layer.Tungsten Pin Contribution in the Range of 1 Ohm

• 대한치과보철학회지
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• 제37권6호
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• pp.741-755
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• 1999

As a material of metal-ceramic prosthesis, nickel as a form of Ni-Cr alloy has been used for many dental prostheses in many cases. However, several problems in use of the alloy have been revealed (ex : tissue stimulation, skin allergy, hypersensitivity, cytotoxicity and carcinogenecity). Little is known about nickel with respect to the relationship between Ni-prosthesis and gaining of Ni-resistance in oral microorganisms. The present study was undertaken to check wheather use of Ni-prosthesis leads to occurrence of Ni-resistant microorganisms. So this study may suggest the possible relationships between the oral microorganisms and nickel-resistance in oral environment. Bacteria were isolated from the gingival crevicular fluid on the pateints wearing Ni-Cr prosthesis. The isolated bacteria were tested for their Ni-resistance in nickel containing media at different concentration from 3mM to 110mM. E. coli HB101 was used as control. The Ni-resistant bacteria were isolated and biochemically identified. The Ni-resistant bacteria were tested several bio-chemical, molecular-biological tests. Performed tests were ; measuring the growth curve, antibiotic test, growth ability test in liquid media, isolation of the chromosome and plasmid, digestion of DNA by restriction enzyme, electrophoresis of chromosome and plasmid DNA, identification of Ni-resistant genes by the DNA hybridization. The results were as follows: 1) The bacteria isolated from gingival crevicular fluid on the patients wearing Ni-Cr alloy pros-thesis showed nickel-resistance. 2) The isolated microorganisms grew at nickel containing media of high concentrations (60mM-110mM). 3) Based on the biochemical tests, the isolated microorganisms were identified as Enterococcus faecalis(13 cases), Klebsiella pneumoniae(1 case) and Enterobacter gergeviae(1 case). 4) Enterococcus faecalis expressed not only nickel resistance but also the multi-drug resistance to several antibiotics ; chloramphenicol, kanamicin, streptomycin, lincomycin, clindamycin. However, all strain showed the sensitivity against the tetracycline. 5) DNA hybridization result suggest that there is no homology between the previousely known gene of nickel resistance in Klebsiella pneumoniae and chromosomal DNA of Enterococcus faecalis.

• 대한의생명과학회지
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• 제3권1호
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• pp.55-67
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• 1997

최근 항생제의 남용과 오용으로 인한 약제 내성균의 증가로 사회적으로 많은 문제를 야기하고 있다. 이러한 약제 내성균의 종류와 결과는 임상에서 환자의 치료에 많은 도움이 되리라 판단된다. 1996년 1월 1일부터 12월 31일까지 전북지역 종합병원 임상병리과에서 분리된 6,135균주에 관한 세균의 종류와 항생제 감수성 결과는 아래와 같다. 분리동정 된 균종은 Escherichia coli 1,134 균주 (18.4%) P. aeruginosa 856 균주 (13.9%) coagulase negative Staphylococcus 793 균주 (12.89%) Staphylococcus aureus 555 균주 (9.02%) Pseudomonas cepacia 421 균주 (6.84%) Enterobacter cloacae 366 균주 (5.95%), Enterococcus faecalis (4.86%) Klebsiella pneumoniae 220 균주 (3.85%) 순으로 나타났으며 검체별로는 소변에서는 E. coli가 40.6% (800 균주)로, 농에서는 B. cepacia가 18% (199 균주), 객담에서는 P. aeruginosa가 43.7% (306 균주) 혈액에서는 Enterobacter cloacae가 25.8% (166 균주), coagulase negative Staphylococcus (19.6%) P. aeruginosa 56 균주 (8.1%) 순으로 분리되었으며 그람음성 간균 중에서 항생제 감수성결과 P. aeruginosa는 ceftazidime imipenem을 제 외 하고는 나머지 항생제에서는 거의 내성을 나타냈으나, 같은 포도당 비 발효그람음성 간균인 B. cepacia는 aztreonam, ceftazidime, ciprofloxacin, piperacillin, trimethoprim/sulfa에서 약 90％이상의 감수성을 보여 대조를 이루었다. 그람양성균들은 vancomycin, teicoplanin에서 90% 이상의 감수성을 보였으며, 그외는 거의 내성이었다. Enterococcus faecalis는 penicillin-G, ampicillin, ciprofloxacin에서 85%이상이 감수성을 보였다. 검체별 항생제 감수성을 보면 Enterobacter cloacae는 다른 검체에서 보다 blood에서 분리된 검체가 항생제 감수성이 낮았고, P. aeruginosa는 urine에서 분리된 검체가 감수성이 낮게 나타나 검체별 균의 감수성의 차이가 있음을 보여주었다. 이 연구에서 나타난 결과 많이 사용되고 있는 항생제는 내성이 많이 발생하고 있음을 보여주고 있으며 내성이 그리 나타나지 않던 균들이 내성이 점차 보이기 시작하여 이들 균들에 대한 대책이 요구되며 세균감염의 진단, 치료시 항생제의 선택시 항생제 검사 후에 사용하는 것이 바람직하리라 생각된다.

• 대한토목학회논문집
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• 제35권5호
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• pp.1025-1037
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• 2015

지반과 상부 구조물 사이의 경계에서 유연성이 확보된 지진동 격리 받침 시스템을 설치한 후에 전체 구조물의 고유 주기를 연장하고 구조물에 전달되는 지진 가속도를 저감하여 구조물을 보호하는 면진 설계 방식이 최근 건설 현장에서 널리 활용되고 있다. 하지만 도심지의 현대 구조물이 점차 대형화 및 고층화 되면서 기존의 면진 받침을 그대로 사용하기에는 지진 발생시 저항 능력의 부족으로 인한 전단파괴 혹은 잔류변형이 발생하여 구조물의 사용성 향상을 위한 보수 및 붕괴 위험에 따른 철거의 문제점을 발생시킨다. 따라서 본 연구에서는 기존에 주로 사용되는 면진 받침의 저항 강도와 복원성을 향상시키기 위하여 부가적인 개장 시스템을 설치하고 지진 하중에 대한 성능을 평가하고자 한다. 초탄성 형상기억합금 소재의 보강 봉을 납 적층 고무 받침에 설치한 면진 시스템을 설계하고 단자유도 스프링 모델로 모형화하여 지진 데이터를 활용하고 비선형 동적 해석을 실시하였다. 본 연구에서 제안된 면진 시스템이 성능적인 우수성을 입증하기 위하여 기존에 사용된 면진 받침과 여기에 추가로 강재 봉으로 보강된 면진 시스템과의 극한 전단 저항력, 복원성 및 잔류변형 발생 등을 해석을 통하여 비교 평가하였다. 그 결과 초탄성 형상기억합금 소재의 제어 봉으로 보강된 면진 받침이 다른 면진 받침과 비교하여 지진저항 성능에 있어서 우수함을 확인하였다.

• 대한수의학회지
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• 제29권3호
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• pp.303-313
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• 1989

To investigate the epidemiological trait of intestinal diseases of animals caused by thermophilic Campyllobacter spp., isolation of etiological agent was carried out and the profiles of plasmids and the transfer of resistance plasmid in the isolated Campylobacter spp. were examined. The results were as follows. 1. A total of 110 isolates of C jejuni and C coli were subjected to the test for the presence of plasmid DNA. Of the isolates examined, 60% of the isolates were noted to harbor plasmid DNA. Plasmid occurrencer ate from pigs, chickens and cattle were 76.2%, 61.7% and 37.7%, respectively. The plasmids of a large molecular weight, ranging from 36 Md to 86Md, were identified with the strains of tetracycline resistant. 2. Transfer frequency of tetracycline resistant plasmids was higher in the case of the filter mating method than in the broth mating method by the factor of 10~1,000. 3. Tetracycline resistant plasmids of C jejuni were transferrable to C jejuni and C coli by conjugation. In a low frequency, the transfer of tetracycline plasmid was also possible to Vibrio parahemolyticus. However, it was impossible to transfer to Streptococcus fecalis, E coli and Vibrio cholerae. 4. Tetracycline resistant plasmids of C jejuni were impossible to transfer to Campylobacter spp. and related bacteria by transformation.

• 한국동물위생학회지
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• 제29권3호
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• pp.277-285
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• 2006

Plasmids are covalently closed circular molecules of DNA that are stably inherited and replicate somewhat independently of the bacterial chromosome. Genes carried on plasmids can mediate a wide variety of important functions, including antibiotics (R plasmids) and heavy metals resistance, toxins production, cell penetration, iron chelation, complement resistance, and metabolic characteristics such as sucrose and lactose fermentation. Fifty strains of lactobacilli were isolated from 26 staters and 29 fermented milk products. They were classified 27 strains as Lactobacillus paracasei subsp paracasei, 11 stains as Lactococcus lactis subsp cremoris, 6 strains as L delbrueckii subsp lactis, 4 strains as L acidophius, and 2 strains as L delbrueckii subsp bulgaricus. All of these strains were examined for drug resistance and transferability of R plasmids. All of the isolates were sensitive to Am, C, CF, E, NB, P, T, and Te. But resistant to SXT 94% (47 strains), K 66% (33 strains), S 56% (28 strains), ENR 50% (25 strains), NOR 38% (19 strains) CIP 38% (19 strains), GM 16% (8 strains), and N 14% (7 strains), in order. And 32 different resistant patterns were found. The most frequently encountered patterns were CIP-ENR-K-NOR-S-SXT (5 strains). In vitro R plasmids transfer experiment, 57 antibiotic resistant strains which were not transfer to the recipient 2 Escherichia coli strains by conjugation, These results indicate that Lactobacillus in internal trade market' stater recognize R factor but transmissible R plasmid is not existed.