• Journal of Life Science
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• v.24 no.1
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• pp.54-60
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• 2014

Aromatic hydrocarbons are toxic environmental pollutants that are detrimental to the ecosystem and human health. Among them, chlorotoluene and nitrotoluene are toxic to hydrobios and irritate the skin, eyes, and respiratory organs of humans. We herein report the development of recombinant microbial biosensors for cheap and rapid monitoring of chlorotoluene and nitrotoluene compounds. Plasmids were constructed by inserting the xylR regulatory gene for BTEX (benzene, toluene, ethylbenzene, and xylene) degradation into upstream of Po' (the DmpR activator promoter Po with the deletion of its own upstream activating sequences) or Pu (the cognate promoter of XylR)::lacZ (the ${\beta}$-galactosidase gene) and transformed into Escherichia coli $DH5{\alpha}$. In the presence of inducers, the biosensor cells immobilized in agarose developed a red color in 1-2 h due to the hydrolysis of chlorophenol red ${\beta}$-D-galactopyranoside (CPRG), a substrate of ${\beta}$-galactosidase that was expressed by the inducers. Among BTEX, high responses were specifically observed with o-, m-, p-chlorotoluene ($0.1{\mu}M-100 mM$) and o-, m-, p-nitrotoluene (0.1 mM-100 mM). Po' demonstrated higher responses than those with Pu. The biosensors immobilized in agarose showed good stability after 21 days' storage at $4^{\circ}C$, and responses in untreated wastewater spiked with chlorotoluene and nitrotoluene, suggesting they can be used to detect compounds in wastewater.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.72-78
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• 2009

Exposure to HDI(hexamethylene di-isocyanate) commonly used in vehicle crash repair workshops remains a leading cause of occupational asthma. Although skin and eye contamination are considered as absorption routes, there are no occupational exposure standards for skin and ocular exposure. This is the reason why there are more empirical data should be provided. Therefore this study was to determine contamination levels of HDI on the skin, eyes, work surfaces, respirators and eye protectors. There was evidence of contamination on a variety of work surfaces, for example, door handles, bench top and spray gun, etc. A high proportion(47~80%) of skin wipe samples from neck, forehead, back hand, palm and wrist was positive for HDI contamination, even though spray time was relatively brief. The contamination levels from spraying inside spray booth were generally higher than outside booth due to poor work practices and inappropriate personal protective use like safety gloves. Apprentices had higher exposure levels than the qualified painters, likely due to lack of the recognition of safety and hygiene. The extent of contamination inside the PPE might provide an indication of the potential for respiratory & skin exposure and ocular exposure. Eye fluid samples from 4 out of 14 workers had the positive detection of HDI contamination, due to poor work practices like no or inappropriate eye protection. Considering the potential for dermal & ocular exposure to contribute to possible health symptoms including respiratory sensitization, the empirical data point to a need for improving work practices and appropriate PPE selection, use and maintenance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6B
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• pp.930-939
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• 2010

Recently, many researches for making more comfortable input device based on gaze detection have been vigorously performed in human computer interaction. However, these previous researches are difficult to be used in IPTV environment because these methods need additional wearing devices or do not work at a distance. To overcome these problems, we propose a new way of controlling IPTV interface by using a detected face and eye positions in single static camera. And although face or eyes are not detected successfully by using Adaboost algorithm, we can control IPTV interface by using motion vectors calculated by pyramidal KLT (Kanade-Lucas-Tomasi) feature tracker. These are two novelties of our research compared to previous works. This research has following advantages. Different from previous research, the proposed method can be used at a distance about 2m. Since the proposed method does not require a user to wear additional equipments, there is no limitation of face movement and it has high convenience. Experimental results showed that the proposed method could be operated at real-time speed of 15 frames per second. Wd confirmed that the previous input device could be sufficiently replaced by the proposed method.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.429-434
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• 2019

A lateral flow immunoassay platform utilizing antibody functionalized water soluble CdSe/ZnS semiconductor quantum dots (QDs) was developed for the analysis of human serum amyloid A-1 (hSAA1) in a buffer solution. hSAA1 was chosen as a target protein because it is regarded as a potential biomarker associated with early diagnosis and prognosis in patients of lung cancer. The immunoassay strip on a nitrocellulose membrane was fabricated by spraying two lines composed of a test line with a monoclonal antibody against hSAA1 (10G1) (anti hSAA1) and a control line of anti-chicken IgY. While the CdSe/ZnS QDs synthesized in an organic phase were transferred to a water phase by ligand exchange using carboxylic acid modified alkane thiol. The QDs was then conjugated to monoclonal antibody against hSAA1 (14F8) [anti hSAA1 (14F8)] and used as a fluorescent detection probe. The sequential lateral flow of hSAA1 in different concentration and QDs-anti hSAA1 (14F8) complex allowed to form the surface sandwich complex of anti hSAA1 (10G1)/hSAA1/QD-anti hSAA1 (14F8), which was then analyzed using fluorescence microscope. A 100 nM concentration of hSAA1 protein can be detected by naked eyes under an optimized lateral flow buffer condition with a sensing time of 5 mins.

• Journal of the Korean Vacuum Society
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• v.6 no.4
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• pp.348-353
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• 1997

Hydrogenated amorphous carbon(a-C:H) films were deposited on p-type Si(100) by DC saddle-field plasma enhanced CVD to investigate the effect of substrate bias on optical properties and structural changes. They were deposited using pure methane gas at a wide range of substrate bias at room temperature and 90 mtorr. The substrate bias voltage ($V_s$) was employed from $V_s=0 V$ to $V_s=400 V$. The information of optical properties was investigated by photoluminescence and transmitance. Chemical bondings of a-C:H have been explored from FT-IR and Raman spectroscopy. The thickness and relative hydrogen content of the films were measured by Rutherford backscattering spectroscopy (RBS) and elastic recoil detection (ERD) technigue. The growth rate of a-C:H film was decreased with the increase of $V_s$, but the hydrogen content of the film was increased with the increase of $V_s$. The a-C:H films deposited at the lowest $V_s$ contain the smallest amount of hydrogen with most of C-H bonds in the of $CH_2$ configuration, whereas the films produced at higher $V_s$ reveal dominant the $CH_3$ bonding structure. The emission of white photoluminescence from the films were observed even with naked eyes at room temperature and the PL intensity of the film has the maximum value at $V_s$=200 V. With $V_s$ lower than 200 V, the PL intensity of the film increased with V, but for V, higher than 200 V, the PL intensity decreased with the increase of $V_s$. The peak energy of the PL spectra slightly shifted to the higher energy with the increase of $V_s$. The optical bandgap of the film, determined by optical transmittance, was increased from 1.5 eV at $V_s$=0V to 2.3 eV at $V_s$=400 V. But there were no obvious relations between the PL peak and the optical gap which were measured by Tauc process.

• Journal of The Korean Ophthalmological Society
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• v.58 no.3
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• pp.321-326
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• 2017

Purpose To identify the correspondence between the central sensitivity of several visual field (VF) tests and ganglion cell inner plexiform layer (GC-IPL) thickness in early glaucoma patients with parafoveal scotoma. Methods Fifty-seven eyes from 57 patients with glaucomatous optic neuropathy and parafoveal scotoma were analyzed using the standard automated perimetry (SAP) C10-2 test, the SAP C24-2 test, and the frequency doubling technology perimetry (FDT) C24-2 test. The correlation between the VF central sensitivity and the GC-IPL thickness from macular scans via optical coherence tomography was analyzed. Results The central sensitivity was $27.51{\pm}5.43dB$, $27.39{\pm}5.05dB$, and $22.09{\pm}5.08dB$ for SAP C24-2, SAP C10-2, and FDT C24-2, respectively. Mean GC-IPL thickness was $70.2{\pm}8.5{\mu}m$. Using regression analysis, the value of log $R^2$ between the logarithmic central sensitivity and GC-IPL thickness was 0.498, and the linear $R^2$ between the antilogarithmic central sensitivity and GC-IPL thickness in SAP C10-2 was 0.486, and both were statistically significant (p < 0.05). This relationship was stronger in early glaucoma patients compared to late glaucoma patients using SAP C10-2. Conclusions The structure-function relationship between GC-IPL thickness and central sensitivity was better with SAP C10-2, especially in early glaucoma patients, compared to other VF modalities.