• Title/Summary/Keyword: Isolation Resistance

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Speckle Defect by Dark Leakage Current in Nitride Stringer at the Edge of Shallow Trench Isolation for CMOS Image Sensors

  • Jeong, Woo-Yang;Yi, Keun-Man
    • Transactions on Electrical and Electronic Materials
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    • v.10 no.6
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    • pp.189-192
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    • 2009
  • The leakage current in a CMOS image sensor (CIS) can have various origins. Leakage current investigations have focused on such things as cobalt-salicide, source and drain scheme, and shallow trench isolation (STI) profile. However, there have been few papers examining the effects on leakage current of nitride stringers that are formed by gate sidewall etching. So this study reports the results of a series of experiments on the effects of a nitride stringer on real display images. Different step heights were fabricated during a STI chemical mechanical polishing process to form different nitride stringer sizes, arsenic and boron were implanted in each fabricated photodiode, and the doping density profiles were analyzed. Electrons that moved onto the silicon surface caused the dark leakage current, which in turn brought up the speckle defect on the display image in the CIS.

MODELING AND PARAMETER IDENTIFICATION FOR A PASSIVE HYDRAULIC MOUNT

  • Zhang, Y.X.;Zhang, J.W.;Shangguan, W.B.;Feng, Q.Sh.
    • International Journal of Automotive Technology
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    • v.8 no.2
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    • pp.233-241
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    • 2007
  • A lumped parameter model is proposed for the analysis of dynamic behaviour of a Passive Hydraulic Engine Mount (PHEM), incorporating inertia track and throttle, which is characterized by effective and efficient vibration isolation behaviour in the range of both low and high frequencies. Most of the model parameters, including volume compliance of the throttle chamber, effective piston area, fluid inertia and resistance of inertia track and throttle are identified by an experimental approach. Numerical predictions are obtained through a finite element method for responses of dynamic stiffness of the rubber spring. The experiments are made for the purpose of PHEM validation. Comparison of numerical results with experimental observations has shown that the present PHEM achieves good performance for vibration isolation.

Isolation and characterization of induced disease resistance (ISR)-deficient mutants of a biocontrol bacterium Pseudomonas chlororaphis O6.

  • Han, Song-Hee;Cho, Baik-Ho;Kim, Young-Cheol
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.101.1-101
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    • 2003
  • Lipopolysaccharide, siderophore, and cyclic dipeptide have been shown to be necessary for ISR induction by pseudomnads. However, there is no report on cloning of genes or generating specific mutants involving in ISR activity. A biological control bacteium P. chlororaphis O6 induces resistance to Erwinia carotovora subsp. carotovara SCCI in tobacco and induces drought resistance in Arabidopsis. To isolate genes involved in ISR activity and induction of drough resistance of O6, we constructed Tn5 mutants and were used to screen for ISR activity and drought resistance activity using microtiter assay with tobacco and Arabidopsis. Thirty-three ISR-deficient mutants were selected, and the nine ISR-deficient mutants were also lost activity of drought resistance. The flanking sequence analysis of the ISR and drought resistance-deficient mutants showed that a gacS gene encoding a two-component sensor kinase, and a mce gene encoding a protein involved in mycobacterial cell entry were mutated. The flanking sequence of each Tn5 mutant altered ISR activity is currently under investigation. These results indicate that gacS and mce are important genes in induction of ISR activity and drought resistance of P. chlororaphis O6. Our works will open opportunities for identification of bacterial genes or traits that are involved in ISR activity and induced drought resistance of P. chlororaphis O6.

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Antimicrobial Resistance Profile of Acinetobacter spp. Isolates from Retail Meat Samples under Campylobacter-Selective Conditions

  • Cha, Min-Hyeok;Kim, Sun Hee;Kim, Seokhwan;Lee, Woojung;Kwak, Hyo-Sun;Chi, Young-Min;Woo, Gun-Jo
    • Journal of Microbiology and Biotechnology
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    • v.31 no.5
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    • pp.733-739
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    • 2021
  • Acinetobacter strains are widely present in the environment. Some antimicrobial-resistant strains of this genus have been implicated in infections acquired in hospitals. Genetic similarities have been reported between Acinetobacter strains in nosocomial infections and those isolated from foods. However, the antimicrobial resistance of Acinetobacter strains in foods, such as meat, remains unclear. This study initially aimed to isolate Campylobacter strains; instead, strains of the genus Acinetobacter were isolated from meat products, and their antimicrobial resistance was investigated. In total, 58 Acinetobacter strains were isolated from 381 meat samples. Of these, 32 strains (38.6%) were from beef, 22 (26.5%) from pork, and 4 (4.8%) from duck meat. Antimicrobial susceptibility tests revealed that 12 strains were resistant to more than one antimicrobial agent, whereas two strains were multidrug-resistant; both strains were resistant to colistin. Cephalosporin antimicrobials showed high minimal inhibitory concentration against Acinetobacter strains. Resfinder analysis showed that one colistin-resistant strain carried mcr-4.3; this plasmid type was not confirmed, even when analyzed with PlasmidFinder. Analysis of the contig harboring mcr-4.3 using BLAST confirmed that this contig was related to mcr-4.3 of Acinetobacter baumannii. The increase in antimicrobial resistance in food production environments increases the resistance rate of Acinetobacter strains present in meat, inhibits the isolation of Campylobacter strains, and acts as a medium for the transmission of antimicrobial resistance in the environment. Therefore, further investigations are warranted to prevent the spread of antimicrobial resistance in food products.

Antimicrobial susceptibility of Staphylococcus aureus and S. intermedius isolated from dogs (개에서 분리한 Staphylococcus aureus와 S. intermedius의 항생제 감수성)

  • Byun, Jeong Hye;Kim, Tae Jung
    • Korean Journal of Veterinary Research
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    • v.47 no.1
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    • pp.43-50
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    • 2007
  • Staphylococci are Gram-positive, facultatively anaerobic cocci, normally found on the skin andmucosal surfaces of most warm-blooded animals and often involved in a wide variety of diseases in animals.Staphylococcal infections are treated with antibiotics and, consequently, antibiotic resistance and/or acquiredresistance have developed. Staphylococcus (S.) intermedius and Staphylococcus (S.) aureus are 2 comonveterinary isolates that are frequently associated with suppurative infections. This study was undertaken toexamine antimicrobial susceptibility of S. aureus (23 isolates) and S. intermedius (160 isolates) isolatedfrom dogs in Gwangju, Korea and investigate whether the antibiotic resistance of S. aureus and S.intermedius is efected by the site of isolation, age, and sex of dogs. More isolates were isolated fromadult dogs (71.3%) than juveniles (20.5%). Antimicrobial resistance was commonly found for Penicillin,Tetracycline, Trimethoprim-Sulphamethoxazole in both Staphylococcus species. All of the isolates weresusceptible to Amoxicillin/Clavulanic Acid, Cephalothin, Oxacilin, Neomycin, and Vancomycin. Appropriateprotocol for antibiotic use and strategies to reduce antimicrobial resistance rate will be needed. Periodicsubstitution of antimicrobial agents and limitation of antibiotic use should also be considered.

A Study on Method of Construction for Foamed Concrete adding EVA Chip that improves the Resistance of Cracking and Capability of Insulating (크랙저항성(抵抗性)과 단열성(斷熱性)을 향상(向上)시킨 EVA칩 첨가 기포콘크리트의 려공법(旅工法) 연구(硏究))

  • Lee, Jong-Shik;An, Jung-Chan;Lee, Jong-Hak
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.11a
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    • pp.5-9
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    • 2007
  • The construction method for Foamed-Concrete has not been important due to following process of construction work. However, according to the code about enhance of energy saving design policy and impact noise, noised isolation has been used in construction site so that the resistance for cracking and capability for insulating of Foamed-Concrete has been required. Therefore, new alternatives are demanded. Optimum mixing design, which can get the improvement of insulation and resistance of crack for Foamed-Concrete adding EVA chip, was derived and also the device, applying to construction site, was invented to equalize quality. This device can measure quantity of all input and placement, and show up the sum of placement and mixing design on a touch screen. This valuable construction method is friendly environment and recycling method because of using EVA chip, by-product of an EVA insole scrap burned or embedded, as a light-weight aggregate.

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Isolation and Characterization of Halophilic Kocuria salsicia Strains from Cheese Brine

  • Youn, Hye-Young;Seo, Kun-Ho
    • Food Science of Animal Resources
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    • v.42 no.2
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    • pp.252-265
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    • 2022
  • Kocuria salsicia can survive in extreme environments and cause infections, including catheter-related bacteremia, in humans. Here, we investigated and evaluated the characteristics of nine K. salsicia strains (KS1-KS9) isolated from cheese brine from a farmstead cheese-manufacturing plant in Korea from June to December, 2020. Staphylococcus aureus American Type Culture Collection (ATCC) 29213 was used as a positive control in the growth curve analysis and biofilm-formation assays. All K. salsicia isolates showed growth at 15% salt concentration and temperatures of 15℃, 25℃, 30℃, 37℃, and 42℃. KS6 and KS8 showed growth at 5℃, suggesting that they are potential psychrotrophs. In the biofilm-formation analysis via crystal violet staining, KS6 exhibited the highest biofilm-forming ability at various temperatures and media [phosphate buffered saline, nutrient broth (NB), and NB containing 15% sodium chloride]. At 25℃ and 30℃, KS3, KS6, and KS8 showed higher biofilm-forming ability than S. aureus ATCC 29213. The antimicrobial resistance of the isolates was evaluated using the VITEK® 2 system; most isolates were resistant to marbofloxacin and nitrofurantoin (both 9/9, 100%), followed by enrofloxacin (7/9, 77.8%). Five of the nine isolates (5/9, 55.6%) showed multidrug resistance. Our study reports the abilities of K. salsicia to grow in the presence of high salt concentrations and at relatively low temperatures, along with its multidrug resistance and tendency to form biofilms.

Candida non albicans with a High Amphotericin B Resistance Pattern Causing Candidemia among Cancer Patients

  • Kalantar, Enayatollah;Assadi, Mojan;Pormazaheri, Helen;Hatami, Shiva;Barari, Maryam Agha;Asgari, Esfandiar;Mahmoudi, Elaheh;Kabir, Kourosh;Marashi, Seyed Mahmoud Amin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.24
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    • pp.10933-10935
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    • 2015
  • Background: Many scientists have reported Candida species to be of great concern because of the high frequency that they colonize and infect human hosts, particularly cancer patients. Moreover, in the last decades Candida species have developed resistance to many antifungal agents. Based on this, we aimed to identify and determine the prevalence of Candida spp from blood culture bottles among cancer patients and their antifungal resistance pattern. Materials and Methods: From the blood culture bottles isolation and identification of the Candida spp were performed by conventional microbiological techniques. The in vitro antibiotic resistance pattern of the isolates was determined by CLSI guidelines. Genomic DNA was isolated and amplified. Each gene was separated by agar gel electrophoresis. Results: Identification of Candida spp was based on the presence of yeast cells in direct examination, culture and DNA extraction. Of the 68 blood samples collected during the study period (April 2013 to October 2013), five (7.35%) were positive for the presence of Candida spp, 2 (40%) of which were identified as Candida albicans and 3 (60%) were Candida non-albicans. Conclusions: High resistance to amphotricin B was observed among all the Candida non-albicans isolates. Regular investigations into antifungal resistance will help us to get an updated knowledge about their antibiotic resistance pattern which may help the physician in selecting the antibiotics for empirical therapy.

Isolation of the Pathogenic Bacteria from Chicken and Antimicrobial Drug Sensitivity of the Strain Isolated (가금유래 주요병원성세균의 분리와 분리균주에 대한 약제감수성조사)

  • 박근식;김기석;남궁선
    • Korean Journal of Poultry Science
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    • v.7 no.1
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    • pp.53-64
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    • 1980
  • A total of 1503 specimens were submitted to the Poultry Disease Diagnostic Service Laboratory during the year 1966 and 1978. The most frequently diagnosed diseases in order of prevalence were avian mycoplasmosis, staphylococcosis, colibacillosis, salmonellosis and pullorum disease, the percentages of the conditions being 24.6%, 20.0%, 18.0%, 12.6% and 6.4%, respectively, The drug resistance of pathogenic mirnoorganisms isolated during the year 1978 from chicken with colicabacillosis, staphylococcosis or salmonellosis were investigated by the use of disc diffusion technique, the results being as follow. 1) Drug resistance of 63 strains of Escherichia coli More than 95% of the strains tested were sensitive to colistin and gentamicin. The percentages of strains sensitive to kanamycin, chloramphenicol, ampicillin and nitrofurantoin were 66.7%, 60.3%, 60.3% and 47.6%, respectively. Majority of the strains were highly resistant to streptomycin and tetracyline. All the strains were resisistant to bacitracin lincomycin, oleandomycin, penicillin and erythromycin. All the strains tested were resistant to more than two among 10 drugs in common use such as penicillin, erythromycin, streptomycin, tetracycline, neomycin, chloramphenicol, kanamycin, ampicillin and gentamicin, and 27 different resistance patterns were noted. The most frequent multiple resistance pattern was PC, EM, SM and TC (11.1%). 2) Drug resistance of 48 strains of Salmonella More than 95% of the strains tested were sensitive to colistin, gentamicin ana ampicillin. The percentages of st rains sensitive to kanamycin, tetracycline, neomycin and nitrofurantoin were 81,3%, 79%, 72.9%, and 68.0% respectively. None of them was sensitive to streptomycin, oleandomycin, erythromycin, lincomycin and bacitracin. All the strains were resistant to more than one among 7 drugs in common use such as streptomycin, erythromycin, neomycin, tetracycline, kanamycin, ampicillin and gentamicin. The most frequent resistance pattern was SM and EM(66.7%). 3) Drug resistance of 54 strains of Staphylococci All the strains tested were sensitive to gentmaicin, kanamycin and cephalothin. Majority of them were highly sensitive to bacitracin, methicillin, nitrofurantoin and chloramphenicol. The Percentages of strains sensitive to streptomycin, ampicillin, lincomycin and tetracycline were 66.7%, 55.6%, 44.4% and 27.8%, respectively. Among them, 51 strains were resistant to more than one among 11 drugs in common use such as tetracycline, lincomycin, ampicillin, penicillin, streptomycin, erythromycin, neomycin, oleandomycin, chloramphenicol, methicillin and bacitracin, and thirty one different resistance patterns were noted.

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Distribution and Drug Resistance of Salmonella Causing Enteric Fever in Taegu Area of Korea (대구지방에서의 장열성 Salmonella의 분포와 항균제내성)

  • Park, Jong-Wook;Suh, Seong-Il;Chun, Do-Ki
    • The Journal of the Korean Society for Microbiology
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    • v.22 no.3
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    • pp.295-300
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    • 1987
  • Salmonella strains isolated from blood in the Dong-san hospital, Taegu during the period from 1971 to 1986 were studied for species distribution, drug resistance, and R plasmids. The number of strains was 2,527 and all of them were classified into S. typhi and S. paratyphi A. Approximately 300 strains were isolated in the period from 1974 to 1976 and 1978, 268 in 1982, and 204 in 1983, but the numbers isolated in the 1980's have a tendency to decrease as compared with those of the 1970's. S. typhi occupied 85% or more of strains isolated until 1976, but the isolation frequency decreased yearly with some variation, and S. paratyphi A increased gradually from 1974. Only 4 strains of S. paratyphi A were resistant to some drugs, and the resistance was not transferred to E. coli by conjugation. S. typhi resistant to drugs were 15 in 1971 through 1973, 24 in 1974, and 13 in 1975, but afterwards only few resistant strains were isolated. These strains were resistant to two or more drugs; chloramphenicol(Cm), tetracycline(Tc), streptomycin(Sm), sulfisomidine(Su), ampicillin(Ap), and kanamycin(Km) and no strain resistant to other drugs tested was found. Strains resistant to 3 or less drugs didn't transfer the resistance to E. coli by conjugation. There were 15 strains resistant to four or more drugs, and were isolated in years from 1972 to 1976. These strains transferred the resistance to E. coli, and the resistance was considered to be mediated by R plasmids. Transfer frequency was higher at $25^{\circ}C$ than at $37^{\circ}C$ and patterns of transferred resistance were Cm, Tc, Sm, Su; Ap, Km; Cm. R plasmids having markers of Cm, Tc, Sm and Su were classified into Inc H1.

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