• Korean Journal of Veterinary Research
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• v.15 no.1
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• pp.109-114
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• 1975

A total of 2,065 quarter milk samples of 534 dair cows from 35 herds were examined for mastis and the results obtained were as follows: 1. 654 quarters (31.6%) of 301 dairy cows (56.3%) from 34 herds (97.1%) were infected with mastitis. It was found that 8 cows (1.5%) showed clinical mastitis and other cows were subclinical. 2. Low infection rate of mastis was shown in first delivery cattle and higher infection rate in more deliverable of cattle. 3. The main causative organisms of the matitis were Staphylococcus aureus (19.4%), Streptococcus agalactiae (11.3%) and Streptococcus dysgalatiae (5%). 4. The majority of causative organisms were very resistant to colistin and highly sensitive to tetracycline. Especially Streptococcus strains were highly sensitive to leukomycin, and Staphylococcus aureus were highly sensitive to tetracycline and the other bacteria were highly sensitive to tetracycline and kanamycin.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.560-565
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• 1999

The present work was conducted to investigate the drug susceptibility of microorganisms isolated from canine external ear canals. Antifungal susceptibility test of M pachydermatis (17 strains) was perfomed by agar dilution method, using 11 antifungal drugs including amphotericin B(A), nystatin(N), pimaricin(P), griseofulvin(G), bifonazole(B), clotrimazole(C), miconazole(M), econazole(E), ketoconazole(K), tolnaftate(T), 5-fluorocytosine(F). All isolates were highly sensitive to K, M, T(geometric mean MIC ; GM $MIC{\leq}0.16{\mu}g/ml$) but they weren't sensitive to P, F and G(GM $MIC{\geq}92.37{\mu}g/ml{\sim}{\geq}128{\mu}g/ml$). Antibacterial susceptibility test against 119 isolates of bacteria was performed by agar dilution method, using 9 antibacterial drugs including erythromycin(ET), chloramphenicol(CP), gentamycin(G), vancomycin(V), ampicillin(AP), amoxacillin(AX), chlortetracycline(CT), ciprofloxacin(CF), enrofloxacin(EF). All isolates of Staphylococcus spp(101 strains) were highly sensitive to EF, CF, G(GM MIC $0.33{\sim}1.47{\mu}g/ml$). In other gram positive cocci(4 strains), they were highly sensitive to EF, CF, V(GM MIC $1{\sim}4.76{\mu}g/ml$) and CT(GM MIC 1 UFL unit/ml). In gram positive rods(13 strains), they were highly sensitive to EF, CF, G(GM $MIC{\leq}0.19{\sim}1{\mu}g/ml$). In Pseudomonas aeruginosa(1 strain), it was highly sensitive to AX, EF, ET, CF(GM MIC $0.06{\sim}1{\mu}g/ml$) and CT(GM MIC 1 UFL unit/ml). All isolates weren't sensitive to AP(GM MIC 16~>$32{\mu}g/ml$).

• Journal of the Optical Society of Korea
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• v.10 no.3
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• pp.130-142
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• 2006

Lab-on-a-chip technology is attracting great interest because the miniaturization of reaction systems offers practical advantages over classical bench-top chemical systems. Rapid mixing of the fluids flowing through a microchannel is very important for various applications of microfluidic systems. In addition, highly sensitive on-chip detection techniques are essential for the in situ monitoring of chemical reactions because the detection volume in a channel is extremely small. Recently, a confocal surface enhanced Raman spectroscopic (SERS) technique, for the highly sensitive biological analysis in a microfluidic sensor, has been developed in our research group. Here, a highly precise quantitative measurement can be obtained if continuous flow and homogeneous mixing condition between analytes and silver nano-colloids are maintained. Recently, we also reported a new analytical method of DNA hybridization involving a PDMS microfluidic sensor using fluorescence energy transfer (FRET). This method overcomes many of the drawbacks of microarray chips, such as long hybridization times and inconvenient immobilization procedures. In this paper, our recent applications of the confocal Raman/fluorescence microscopic technology to a highly sensitive lab-on-a-chip detection will be reviewed.

• Toxicological Research
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• v.17
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• pp.197-199
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• 2001

Enhancement of antigen-specific IgE is a hallmark of allergic hyperresponsiveness, therefore it is necessary to adopt or develop a highly sensitive and specific assay for determination of allergen-specific IgE levels in vivo. In this presentation, we introduce an ELISA (enzyme linked immunosorbent assay) system developed to measure the levels of chicken egg ovalbumin (OVA)-specific IgE in serum. The ELISA method uses a commercially available purified rat anti-mouse IgE as a capture Ab and biotinylated OVA as a detection reagent. Avidin-peroxidase with its substrate is used for color development resulting in optical density measurement at 405 nm. The ELISA system produces a highly sensitive dose-response relation-ship between optical density levels and the dilution titer of the OVA-IgE standard serum but no cross-reaction with unrelated IgE or IgG. It is believed that the system is an Efficient tool to delineate an adjuvant effect of environmental pollutants on development of asthmatic and atopic responses.

• Parasites, Hosts and Diseases
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• v.60 no.4
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• pp.295-299
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• 2022

Malaria elimination and control require prompt and accurate diagnosis for treatment plan. Since microscopy and rapid diagnostic test (RDT) are not sensitive particularly for diagnosing low parasitemia, highly sensitive diagnostic tools are required for accurate treatment. Molecular diagnosis of malaria is commonly carried out by nested polymerase chain reaction (PCR) targeting 18S rRNA gene, while this technique involves long turnaround time and multiple steps leading to false positive results. To overcome these drawbacks, we compared highly sensitive cytochrome oxidase gene-based single-step multiplex reaction with 18S rRNA nested PCR. Cytochrome oxidase (cox) genes of P. falciparum (cox-III) and P. vivax (cox-I) were compared with 18S rRNA gene nested PCR and microscopy. Cox gene multiplex PCR was found to be highly specific and sensitive, enhancing the detection limit of mixed infections. Cox gene multiplex PCR showed a sensitivity of 100% and a specificity of 97%. This approach can be used as an alternative diagnostic method as it offers higher diagnostic performance and is amenable to high throughput scaling up for a larger sample size at low cost.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.70.1-70
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• 2003

It was investigated whether culture filtrates produced by X. fastiduosa could be used to determine varietal susceptibility in grape cultivars to anthracnose as a substitute for pathogen inoculation or field screening. Bioassay of grape leaves with culture filtrates showed that their phytotoxicities were active and host-selective. Ethyl acetate extracts from those also showed the toxicities and host selectivity among grape cultivars. The sensitive range of plants to culture filtrates and their ethyl acetate extracts was consistent with the host range to the pathogen. Susceptible cultivars were sensitive to even highly diluted culture filtrates but resistant cultivars were not affected even at original culture filtrates. Susceptible cultivars were sensitive to the undiluted culture filtrates than highly diluted culture filtrates and the younger leaves were the more sensitive to the culture filtrates and their ethyl acetate extracts in grapes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.90-95
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• 1995

This paper describes the highly-sensitive Si magnetic sensor using the amplitude modulation in order to real ice the integrated magnetic sensor which to sensor a weak magnetic field. Generally, the most important two parameters in Hall IC which degrade the ability of magnetic detection are the variation of offset according to the variation of temperature and the noise of amplifiers. In this paper, we use a Hall element and compensator to reduce the offset and the nouse of amplifiers by Using amplititude modulation method.

• Current Optics and Photonics
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• v.2 no.3
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• pp.221-225
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• 2018

We suggested the use of miniature hollow glass tubes having high ultraviolet (UV) transmission characteristics for the protection of optical-fiber-type UV sensors. We have recently proposed a highly sensitive optical sensor in the UV spectral range, using a fiber Bragg grating (FBG) coated with an azobenzene polymer as the photoresponsive material. In this study, we used UV-transparent miniature glass tubes to protect the etched FBG with the azobenzene polymer coating. This technique will be very useful for protecting various fiber-based UV sensors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2197-2202
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• 2014

In this paper, we report on an investigation of highly sensitive sensing performance of a hydrogen sensor composed of palladium (Pd) nanowires. The Pd nanowires have been grown by electrodeposition into nanochannels and liberated from the anodic aluminum oxide (AAO) template by dissolving in an aqueous solution of NaOH. A combination of photo-lithography, electron beam lithography and a lift-off process has been utilized to fabricate the sensor using the Pd nanowire. The hydrogen concentrations for 2% and 0.1% were obtained from the sensitivities (${\Delta}R/R$) for 1.92% and 0.18%, respectively. The resistance of the Pd nanowires depends on absorption and desorption of hydrogen. Therefore, we expect that the Pd nanowires can be applicable for detecting highly sensitive hydrogen gas at room temperature.

• Mycobiology
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• v.34 no.2
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• pp.99-103
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• 2006

Toxicity of the fungicide Flutolanil was in vitro tested against 20 isolates of Macrophomina phaseolina and cotton seedlings of ten commercial cotton cultivars. The isolates were recovered from roots of cotton plants obtained from different cotton-growing areas in Egypt. Most of the tested isolates were sensitive to Flutolanil; however, they varied in sensitivity. Twenty-five percent of the isolates were highly sensitive where $IC_{50}$ ranged from < 1 to $5.1{\mu}g/ml$, 20% of the isolates were sensitive where $IC_{50}$ ranged from 15 to $30{\mu}g/ml$, 45% of the isolates were moderately sensitive where $IC_{50}$ ranged from 46 to $58.5{\mu}g/ml$, and 10% of the isolates were not much sensitive (tolerant) where $IC_{50}$ was > $100{\mu}g/ml$. Flutolanil was very safe on both shoots and roots of the tested cultivars ($IC_{50}\;>\;100{\mu}g/ml$). Treating cotton seeds with Flutolanil resulted in highly significant (P < 0.01) reductions in pathogenicity of 18 isolates and a significant reduction (P < 0.05) in pathogenicity of isolate $M_{29}.\;M_{1}$ was the only isolate, which was insensitive to the application of Flutolanil. In vivo toxicity to Flutolanil was not correlated with its in vitro toxicity. However, a highly significant correlation (r = 0.60, P < 0.01) was observed between pathogenicity of isolates and the in vivo toxicity of the fungicide.