• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.310-317
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• 2020

A development of disposable strip-type galactose sensor for point-of-care testing (POCT) was studied, which was constructed using screen-printed carbon electrodes. Galactose levels were determined by the redox reaction of galactose oxidase in the presence of potassium ferricyanide as an electron transfer mediator in a small sample volume (i.e., less than 1 µL). The optimal performance of biosensor was systematically designated by varying applied potential, operating pH, mediator concentration, and amount of enzyme on the electrode. The sensor system was identified as a highly active for the galactose measurement in terms of the sensitivity (slope = 4.76 ± 0.05 nA/µM) with high sensor-to-sensor reproducibility, the linearity (R² = 0.9915 in galactose concentration range from 0 to 400 µM), and response time (t_95% = <17 s). A lower applied potential (i.e., 0.25 V vs. Ag/AgCl) allowed to minimize interference from readily oxidizable metabolites such as ascorbic acid, acetaminophen, uric acid, and acetoacetic acid. The proposed galactose sensor represents a promising system with advantage for use in POCT.

• Journal of Sensor Science and Technology
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• v.20 no.6
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• pp.400-405
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• 2011

This study introduced the development of a strip type disposable enzyme-linked immunosensor platform for the detection of IgG. Strips of the strip sensor were fabricated by using commercial nitrocellulose filter membranes and a housing holder for the strips was manufactured by using a standard injection molding process for a plastic material. An IgG-urease conjugate was prepared and used for the competitive immune-binding with sample IgG. From the enzymatic reaction between the conjugated urease and urea added, ammonia was generated and caused a localized alkaline pH change on the immobilized antibody band which was coated onto the sensor strips. This pH increase subsequently caused a color change of the antibody band in the presence of a pH indicator, phenol red. Used in conjunction with a competitive immunoassay format, the intensity of the color produced is directly linked with the concentration of target analyte, IgG, and specific measurement of IgG in a lateral flow immunoassay format was achieved over the range 100 ppb to 2000 ppb IgG.

• Journal of Sensor Science and Technology
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• v.20 no.1
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• pp.35-39
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• 2011

A disposable electrochemical immunosensor system has been developed for the detection of herbicide in aqueous samples. Disposable screen printed carbon electrodes(SPCE) were used as basic electrodes and an enzyme, horseradish peroxidase (HRP), and anti-herbicide antibodies was immobilised on to the working electrode of SPCE by using avidin-biotin coupling reactions. An herbicide-glucose oxidase conjugates have been used for the competitive immunoreaction with sample herbicides. The enzymatic reaction between the conjugated glucose oxidase and glucose added generates hydrogen peroxide, which was reduced by the peroxidase immobilised. The latter process caused an electrical current change, due to direct re-reduction of peroxidase by a direct electron transfer mechanism, which was measured to determine the herbicides in the sample. The optimal operational condition was found to be: $20\;{\mu}gl-1$ deglycosylated avidin loading to the working electrode and working potential +50 mV vs. Ag/AgCl. The total assay time was 15 min after sample addition. The detection limits for herbicides, atrazine and simazine, were found to be 3 ppb and 10 ppb, respectively.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.18-24
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• 1986

The mean perfusion pressure produced by 20 different design and size of disposable aortic perfusion cannulas [size range: 18F to 20F] at flow rates of 1 to 5 L/min was compared. A roller pump with perfusion tubing 10mm in inner diameter was used with a mixture of 0.9% normal saline and 100% glycerin [mixing ratio of 6.72:13.28] to make the viscosity as normal blood in 20oC as the test solution. Line pressure in these cannulas at a flow rate of 3L/min ranged from 13.2$\pm$4.47 to 157$\pm$1 34 mmHg in a case of absence of resistance, and from 11.4$\pm$1.14 to 227.2$\pm$4.47 mmHg in a case of presence of resistances 14 cannulas had gradients of less than 100Hg at a flow rate of 3L/min and 9 cannulas less than 100mmHg at 4L/min. The following results were obtained from this experimental study: .1] A wide range of line pressure was observed in disposable aortic perfusion cannulas currently in clinical use; 2] Some cannulas currently used for cardiopulmonary bypass in adults generated excessive line pressure; 3] Both the material and design affect function, with some designs safer than others. Cardiac surgeons should base the choice of aortic perfusion cannula on the best performance and safest design available to avoid cannula-related problems during operation.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.6 no.1
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• pp.41-46
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• 2000

The level of plasticizer such as diethyl phthalate (DEP), di-n-propyl phthalate (DprP), di-n-butyl phthalate (DBP), di-n-pentyl phthalate (DPP), butylbenzyl phthalate (BBP), di-(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP) and di-(2-ethylhexyl) adipate (DEHA) was determined in disposable sanitary gloves. Samples of disposable sanitary gloves were taken at retail shops, and their overall extractions in carbon tetrachloride were measured, after establishment of soxhlet appratus in 6 hours. All of 8 samples of disposable sanitary gloves at retail shops were polyethylene (PE). All of the manufactures was voluntarily labelled their boxes of gloves in line Korea Food Code. The level of phthalate esters and DEHA in all of 8 samples were not exceed the detection limit. The detection limits of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 1.8, 1.9, 1.3, 1.1, 0.9, 0.7, 2.1 and 0.8 mg/L, respectively.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.152-156
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• 2010

Disposable contact lenses, which are one type of soft contact lenses, provide convenience in use, but also cause various ocular infectious diseases. Microorganisms that cause eye diseases include Acanthamoeba, bacteria, Fungi, and so on. It is impossible to prevent microorganism contamination completely due to the use of hands as wearing contact lenses. The contamination by various microorganisms leads to infectious keratitis, but it is not well known for the exact microorganisms that affect the disease. For this reason, to identify the microorganisms, two groups that are commonly used for disinfection of lenses were divided: normal saline solution and multiple purpose solution. Using these solutions the degree of microorganism contamination was observed according to the days of 1, 3, 5, 10, and 15. Twenty students by two groups from Ophthalmic Optics department at D college in Daegu Metropolitan city participated in the experiment after their ocular health conditions were checked. During they wore one-day disposable lenses for 1, 3, 5, 10, and 15 days, bacteria were cultured in media. The results, which were Gram stained by selecting the cultured colonies, show as followings: Gram positive cocci 33%, Gram-negative cocci 2%, Gram positive bacilli 34%, and the Gram negative bacilli 31%, respectively. As for the identification of potential pathogens, VITEK system and API kit methods were used. Keratitis caused by bacteria known as Staphylococcus aureus, Pseudomonas aeruginosa were detected as a result of wearing contact lenses. This study examined the distribution of bacteria as wearing one-day disposable contact lenses and pathogenic bacteria according to the duration of wearing them. In conclusion, the importance of hygiene when using contact lenses is suggested.

• Food Science and Preservation
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• v.12 no.4
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• pp.317-322
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• 2005

The purposes of this study were to assess the microbiological contamination level of various disposable kitchen utensils and evaluate the effectiveness of gamma irradiation as a sterilization process for the utensils. The 51 kinds in 17 groups of disposable kitchen utensils were tested for the enumeration of total aerobic plate count, coliforms, fungi and Salmonella. Generally, cell density of microorganisms in disposable kitchen utensils were lower than that of cooking utensils currently using in kitchen. The survivals of total aerobic plate counts, putrefactive bacteria, on the surface of the disposable utensils were ranged up to $10^3\;CFU/100\;cm^2$. Filamentous fungi were detected in 13 samples. Coliform bacteria were detected in two kinds of samples but Salmonella spp. was detected below detection limits in all the samples. The microorganisms survived on the surface of utensils were effectively eliminated by gamma irradiation process at 3 kGy.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.23-27
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• 2022

Disposable wet wipes provided by general restaurants in the Jeju Special Self-Governing Province were evaluated for compliance with the labeling requirements and the degree of bacterial contamination set by the Ministry of Food and Drug Safety. Of the 32 types of disposable wipes, five types of disposable wipes did not indicate the name and location of the business office of the manufacturer. Only 12 types of wet wipes were marked with the date of manufacture and expiration date. Bacterial contamination was seen in 9 types of wet wipes through bacterial culture but these were absent in the remaining 23 types (71.9%). The results of the antimicrobial susceptibility test for the 9 identified strains showed no methicillin-resistant coagulase-negative staphylococci (MRCNS) or multidrug-resistant bacteria. Through this study, it is recommended that the date of manufacture and expiration date must be indicated on the surface of disposable wet wipes designated as hygiene products, and clean uncontaminated wet wipes must comply with storage standards. In addition, the results are expected to contribute to the enhancement and improvement of hygiene management supervision, personal hygiene management, and an improvement in national health.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.51-58
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• 2008

Purpose: This study was assessed to investigate adverse effect induced by overuse of disposable soft contact lenses (CL). Methods: Three disposable lenses (etafilcon A, hilabilcon A, and nelfilcon A) were applied to 19 normal subjects free from any eye diseases for either a single day or variable periods by when subjects complained any discomforts. On the first and last days, localizations of lens' center on corneal surface and blink rates were recorded at every case. Results: Among CL wearers, 10.5% and 47.4% of total subjects quit wearing on the second day and third day, respectively. The case of stopping disposable lens wear was continuously increased with extended hour of lens application. On fourth day, 70.2% of CL wearers reported severe discomforts such as redness, dryness, irritation, pain and blurred vision. When subjects stopped CL wear, decentration of lens from the center of cornea was observed when it compared to the case of single usage of disposable CL. Also about 80% of total subjects showed increased blink rate when CL were worn for more than 2 days. These changes in lens centration and blink rate were consistantly shown regardless of lens types. Conclusions: Blurred vision and acute/chronic discomforts could occur to CL wearers by decentration of lens and increased blink rate when CL were overused more than 2 days even the numbers of two parameters measured in this study were variable by each subject or lens types. Therefore, consideration of individual characteristics and lens types is critical to prevent adverse effects may induced by overusage of disposable lens.

• 한국가시화정보학회:학술대회논문집
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• 2002.04a
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• pp.85-99
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• 2002