• Title/Summary/Keyword: Droplet control

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Guidelines for dental clinic infection prevention during COVID-19 pandemic (코로나 바이러스 대유행에 따른 치과 의료 관리 가이드라인)

  • Kim, Jin
    • Journal of Korean Academy of Dental Administration
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    • v.8 no.1
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    • pp.1-7
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    • 2020
  • Dental settings have unique characteristics that warrant specific infection control considerations, including (1) prioritizing the most critical dental services and provide care in a way that minimizes harm to patients due to delayed care, or harm to personnel from potential exposure to persons infected with the COVID-19 disease, and (2) proactively communicate to both personnel and patients the need for them to stay at home if sick. For health care, an interim infection prevention and control recommendation (COVID-19) is recommended for patients suspected of having coronavirus or those whose status has been confirmed. SARS-CoV-2, which is the virus that causes COVID-19, is thought to be spread primarily between people who are in close contact with one another (within 6 feet) through respiratory droplets that are produced when an infected person coughs, sneezes, or talks. Airborne transmission from person-to-person over long distances is unlikely. However, COVID-19 is a new disease, and there remain uncertainties about its mode of spreads and the severity of illness it causes. The virus has been shown to persist in aerosols for several hours, and on some surfaces for days under laboratory conditions. COVID-19 may also be spread by people who are asymptomatic. The practice of dentistry involves the use of rotary dental and surgical instruments, such as handpieces or ultrasonic scalers, and air-water syringes. These instruments create a visible spray that can contain particle droplets of water, saliva, blood, microorganisms, and other debris. While KF 94 masks protect the mucous membranes of the mouth and nose from droplet spatter, they do not provide complete protection against the inhalation of airborne infectious agents. If the patient is afebrile (temperature <100.4°F)* and otherwise without symptoms consistent with COVID-19, then dental care may be provided using appropriate engineering and administrative controls, work practices, and infection control considerations. It is necessary to provide supplies for respiratory hygiene and cough etiquette, including alcohol-based hand rub (ABHR) with 60%~95% alcohol, tissues, and no-touch receptacles for disposal, at healthcare facility entrances, waiting rooms, and patient check-ins. There is also the need to install physical barriers (e.g., glass or plastic windows) in reception areas to limit close contact between triage personnel and potentially infectious patients. Ideally, dental treatment should be provided in individual rooms whenever possible, with a spacing of at least 6 feet between the patient chairs. Further, the use of easy-to-clean floor-to-ceiling barriers will enhance the effectiveness of portable HEPA air filtration systems. Before and after all patient contact, contact with potentially infectious material, and before putting on and after removing personal protective equipment, including gloves, hand hygiene after removal is particularly important to remove any pathogens that may have been transferred to the bare hands during the removal process. ABHR with 60~95% alcohol is to be used, or hands should be washed with soap and water for at least 20 s.

Enhancement of Physical Properties and Efficacy of Pesticide Spray Solution by Addition of Adjuvants (Adjuvant에 의한 농약살포액의 물리성 개선 및 약효증진 효과)

  • Jin, Yong-Duk;Lee, Hee-Dong;You, Oh-Jong;Kim, Jin-Bae;Kwon, Oh-Kyung
    • The Korean Journal of Pesticide Science
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    • v.12 no.4
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    • pp.421-428
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    • 2008
  • This study was carried out to elucidate the effects of adjuvants on physicochemical properties and pest control efficacy of pesticide spray solution. Spray droplet sizes of pesticide solution decreased by addition of adjuvants even though its effect varied according to the pesticides. The adhesive effect of pesticides sprayed on target crops by addition of adjuvants varied according to the properties, the application methods, and the spray volume of pesticides. Wash-off of the deposited amount of active ingredients of the solution of tricyclazole WP and fenobucarb EC by simulated rainfall after spraying on rice plants dramatically reduced by adding adjuvants. The retained amount of active ingredients of the pesticides were $1.5{\sim}4.1$ times higher than those without adjuvants when subjected to simulated rainfall 6 hours after spraying. Addition of adjuvants to the propanil EC spray solution enhanced the control efficacy in barnyard grass, Echinocloa crus-galli Beauv. by $8{\sim}30%$, which showed a potential to reduce pesticide use.

Effects of Jaeumkanghwa-tang on the Rat Hypothyroidism Induced by Propylthiouracil (PTU) (자음강화탕(滋陰降火湯)이 Propylthiouracil(PTU)로 유발된 Rat의 갑상선기능저하증에 미치는 영향)

  • Kim, Seok-Jung;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
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    • v.27 no.1
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    • pp.41-64
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    • 2014
  • Objectives: This study was to evaluate the effect of Jaeumkanghwa-tang (JEKHT) on the propylthiouracil (PTU)-induced rat hypothyroidism. Methods: Six groups, each of 8 rats per group were used in the present study - intact vehicle control, PTU control, Levothyroxine ($LT_4$), JEKHT 500, 250 and 125 mg/kg treated groups. JEKHT were administered once a day for 42 days as an oral dose of 500, 250 and 125 mg/kg, and hypothyroidism was induced by daily subcutaneous treatment of PTU 10 mg/kg for 28 days. The changes on the body and organ weight, serum hormone and lipid profiles, liver and testis antioxidant defense factors were observed with histopathology of organs. Results were compared with $LT_4$ 0.5 mg/kg intraperitoneally treated rats in this experiment. Results: PTU treatment, marked decrease of body weight, increases of thyroid weight, decreases of liver, testis, epididymis and prostate weights, decreases of serum Tri-iodothyronine ($T_3$), and Thyroxine ($T_4$) level with increase of serum Thyroid-stimulating hormone (TSH) level, decreases of serum testosterone and dihydrotestosterone (DHT) level with increases of serum Follicular stimulating hormone (FSH) level, increases of serum High density lipoprotein (HDL), decrease of triglyceride content, increase of serum Aspartate aminotransferase (AST) level, decreases of liver and testis antioxidant defense factors were observed. In addition, marked hyperplasia of follicular cells with decreases of follicular colloid contents and diameters was additionally demonstrated with the decrease of hepatocyte numbers per unit area due to hypertrophy of hepatocytes related to lipid droplet depositions, increase of a/oligospermatic epididymal tubules with epididymal atrophic changes, seminiferous tubular atrophy with decrease of stage I~II seminiferous tubules in testis, prostate tubular atrophic changes at histopathological inspections. However, these PTU induced hypothyroidism and related hepatic and male reproductive organ damages were favorably and dose-dependently inhibited by treatment of JEKHT 500, 250 and 125 mg/kg, and JEKHT also effectively regulated the PTU-induced abnormal antioxidant defense factor changes in the both liver and testis. Conclusions: JEKHT 500, 250 and 125 mg/kg dose-dependently inhibited PTU-induced hypothyroidism and related liver and male reproductive organ damages in rats.

Inhibitory Effects of Ethanol Extract of Red Sweet Pepper (Capsicum annuum L.) on Triglyceride Biosynthesis in Rhodosporidium toruloides (Rhodosporidium toruloides에서의 적색 파프리카 에탄올 추출물의 중성지방 억제 효과)

  • Kang, Ju-Won;Lee, Seung-Je;Ahn, Byung-Yong
    • Korean Journal of Plant Resources
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    • v.34 no.2
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    • pp.186-196
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    • 2021
  • In this study, we investigated inhibitory effect of red sweet pepper (Capsicum annuum L.) on triglyceride biosynthesis in Rhodosporidium toruloides. There was no significant difference in the total lipid content of all the experimental groups including 0.02, 0.1 and 0.5% (w/v) of red sweet pepper 70% ethanol extract treatment (RSPE). However, the triglyceride content was significantly decreased in RSPE group campared to the control group. When the formation of lipid droplet in the oleaginous yeast was examined, a small amount of fluorescence was observed compared to the control as the concentration of RSPE increased. The number of cells and free fatty acid increased in a concentration-dependent manner. These results suggest that RSPE has an anti-obesity effect.

Inhibitory Effect of Cell Differentiation against 3T3-L1 Pre-Adipocytes and Angiotensin Converting Enzyme (ACE) Activity of Ice Plant (Mesembryanthemum crystallinum) (아이스플랜트(Mesembryanthemum crystallinum)의 3T3-L1 전지방세포 분화 및 Angiotensin-Converting Enzyme(ACE) 활성 억제)

  • Kang, Seung Mi;Kim, Seon Jeong;Nam, Sanghae
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.8
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    • pp.1012-1017
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    • 2017
  • Mesembryanthemum crystallinum (Family: Aizoaceae) is an annual plant consisting of ice crystal-shaped bladder cells, which is responsible for its common name ice plant. This study investigated biological activities according to general components and extraction solvent in order to examine the functionality of ice plant. The total content of free amino acids was 32.57 mg/g, including 4.64 mg/g of L-alanine as the most abundant and 2.60 mg/g of ${\gamma}$-aminobutyric acid. Regarding angiotensin converting enzyme inhibitory activities of solvent fractions of ice plant, ethyl acetate fraction and chloroform fraction showed activities of $33.17{\pm}3.20{\sim}88.19{\pm}3.20%$ and $23.72{\pm}2.89{\sim}86.78{\pm}2.24%$, respectively, similar to $Captopril^{(R)}$ ($19.51{\pm}3.44{\sim}84.72{\pm}1.06%$) and $Enalapril^{(R)}$ ($24.93{\pm}1.12{\sim}91.32{\pm}3.62%$) as positive control groups. Regarding inhibition of lipid droplet production in 3T3-L1 preadipocytes by ice plant, anti-adipogenic activities were $53.00{\pm}0.45{\sim}65.75{\pm}0.31%$ and $44.16{\pm}0.29{\sim}63.32{\pm}0.36%$ in the ethyl acetate fraction and butanol fraction, respectively, showing the lowest lipid droplet production. The chloroform fraction and hexane fraction showed activities of $38.33{\pm}0.09{\sim}56.55{\pm}0.50%$ and $31.17{\pm}0.50{\sim}55.10{\pm}1.93%$, respectively, whereas the water fraction showed activity of $26.32{\pm}2.27{\sim}49.48{\pm}0.05%$. Therefore, all solvent fractions inhibited fat accumulation of 3T3-L1 preadipocytes according to treatment concentration. According to the results above, it would be possible to utilize ice plant as a new health functional material.

Inhibition of Pancreatic Lipase Activity and Adipocyte Differentiation in 3T3-L1 Cells Treated with Purple Corn Husk and Cob Extracts (자색옥수수 포엽과 속대 추출물의 리파아제 저해활성 및 3T3-L1 지방전구세포에서의 지방분화 억제효과)

  • Lee, Ki Yeon;Hong, Soo Young;Kim, Tae Hee;Kim, Jai Eun;Park, A-Reum;Noh, Hee Sun;Kim, Si Chang;Park, Jong Yeol;Ahn, Mun Seob;Jeong, Won Jin;Kim, Hee Yeon
    • Journal of Food Hygiene and Safety
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    • v.33 no.2
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    • pp.131-139
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    • 2018
  • Our review begins with the maize hybrid for grain, called 'Seakso 1,' which was developed in 2008 by the Gangwon Agricultural Research and Extension Services in Korea, and subsequently registered in 2011. In this study, we aimed to investigate the lipid metabolic enzyme activity and inhibitory effect on the adipocyte differentiation, in 3T3-L1 cells of the identified Seakso 1 corn husk and cob extracts (EHCS). We investigated the pancreatic lipase inhibitory effect and anti-adipogenic effect of EHCS.The lipid accumulation and adipocyte differentiation were measured by the procedure of Oil Red O staining, Real-time PCR and the Western blot analysis. The pancreatic lipase inhibitory activity of EHCS was measured at higher levels than those of the positive control (orlistat) at 100, 500, and $1,000{\mu}g/mL$. In particular, EHCS was noted as being significantly inhibited and including a measured adipocyte differentiation and lipid accumulation, when treated during the adipocyte differentiation process in 3T3-L1 cells. Based on the Oil Red O staining, EHCS inhibited lipid accumulation at 19.19%, 33.30% at $1000{\mu}g/mL$, $2000{\mu}g/mL$, respectively. The real-time PCR and Western blot analysis showed that EHCS significantly decreased in the mRNA expression and protein level of obesity-related factors, such as peroxisome-proliferatorsactivated-receptor-${\gamma}$ ($PPAR{\gamma}$) and CCAAT enhancer-binding-proteins ${\alpha}$ ($C/EBP{\alpha}$). This study potentially suggests that the Saekso 1 corn husk and cob extracts may improve lipid metabolism and reduce lipid accumulation.

Leaves of Cudrania tricuspidata on the Shoot Positional Sequence Show Different Inhibition of Adipogenesis Activity in 3T3-L1 Cells (꾸지뽕 신초 엽위별 잎 추출물의 항비만 효과)

  • Park, Ju Ha;Guo, Lu;Kang, He Mi;Son, Beung Gu;Kang, Jum Soon;Lee, Yong Jae;Park, Young Hoon;Je, Byoung Il;Choi, Young Whan
    • Journal of Life Science
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    • v.31 no.2
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    • pp.209-218
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    • 2021
  • This study aimed to evaluate the anti-obesity effects of Cudrania tricuspidata leaf extract in the order of leaf development on the shoot (L0, L1, L2, L3, L4, and L5). The leaves at the apex of a Cudrania tricuspidata shoot were classified as L0; the next leaves of the apex were classified as L1, L2, L3, and L4 from highest to lowest; and the lowest leaf was classified as L5. A series of 70% ethyl alcohol leaf extracts were screened for the inhibitory effects of adipogenesis in 3T3-L1 preadipocytes. We found that the apical leaf extract of Cudrania tricuspidata (CTL0) was the most effective. Next, a study was conducted on the inhibitory action mechanism of CTL0. Treatment with CTL0 significantly suppressed the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner, as confirmed by the decrease in lipid droplet content observed with Oil Red O staining. Treatment with 12.5 ㎍/ml, 25 ㎍/ml, and 50 ㎍/ml of CTL0 significantly reduced the lipid droplet content. Glucose and cellular triglyceride concentrations were reduced in the 3T3-L1 cells on the CTL0-treated medium compared to the differentiation medium (DM control, DMEM + insulin + dexamethasone + rosiglitazone). Compared with DM, CTL0 significantly inhibited the expression of key pro-adipogenic transcription factors, including peroxisome proliferator-activated receptor γ (PPARγ), LPL, A-FABP, and Glut4. These findings show that CTL0 extract has potent anti-obesity effects.

A Study on the Characteristics of Oil-water Separation in Non-point Source Control Facility by Coalescence Mechanism of Spiral Buoyant Media (나선형 부유 고분자 여재의 Coalescence 특성을 이용한 비점오염원 저감시설의 유수분리특성 연구)

  • Kang, Sung-Won;Kim, Seog-Ku;Kim, Young-Im;Yun, Sang-Leen;Kim, Soo-Hae;Kim, Mee-Kyung
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.8
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    • pp.950-955
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    • 2007
  • Non-point source control system which had been designed only for oil-water separation in the fields of oil refinery and garage was upgraded in this research for the removal of runoff pollutants in impervious urban area. Pollutants including oil from driveway and bridge were eliminated by two types of pathway in the system. One is the coalescence mechanism that the oil droplets in the runoff come into contact with each other in the spiral buoyant media surface and form larger coalesced droplets of oil that are carried upstream to the oil layer. The other is the precipitation that solids in runoff were settled by gravity in the system. In this research, coalescing characteristics of oil and water separation were investigated through image analyses, and efficiencies of the non-point source control system were evaluated using dust in driveway and waste engine oil. Media made of high density and high molecular weight polyethylene was indeterminate helical shape and had sleek surface by analysing SEM photographs and BET. Surface area and specific gravity of media which were measured directly were 1,428 $mm^2$ and 45.3 $kg/m^3$ respectively. From the image analyses of the oil droplets photographs which were taken by using microscope, it was proved clearly that the coalescence was the main pathway in the removal of oil from the runoff. Finally, the performances of the non-point source control system filled up with the media were suspended solid $86.6\sim95.2%$, $COD_{Cr}$, $87.3\sim95.4%$, n-Hexane extractable materials $71.8\sim94.8%$ respectively.

Rheological behavior and IPL sintering properties of conductive nano copper ink using ink-jet printing (전도성 나노 구리잉크의 잉크젯 프린팅 유변학적 거동 및 광소결 특성 평가)

  • Lee, Jae-Young;Lee, Do Kyeong;Nahm, Sahn;Choi, Jung-Hoon;Hwang, Kwang-Taek;Kim, Jin-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.5
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    • pp.174-182
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    • 2020
  • The printed electronics field using ink-jet printing technology is in the spotlight as a next-generation technology, especially ink-jet 3D printing, which can simultaneously discharge and precisely control various ink materials, has been actively researched in recent years. In this study, complex structure of an insulating layer and a conductive layer was fabricated with photo-curable silica ink and PVP-added Cu nano ink using ink-jet 3D printing technology. A precise photocured silica insulating layer was designed by optimizing the printing conditions and the rheological properties of the ink, and the resistance of the insulating layer was 2.43 × 1013 Ω·cm. On the photo-cured silica insulating layer, a Cu conductive layer was printed by controlling droplet distance. The sintering of the PVP-added nano Cu ink was performed using an IPL flash sintering process, and electrical and mechanical properties were confirmed according to the annealing temperature and applied voltage. Finally, it was confirmed that the resistance of the PVP-added Cu conductive layer was very low as 29 μΩ·cm under 100℃ annealing temperature and 700 V of IPL applied voltage, and the adhesion to the photo-cured silica insulating layer was very good.

Effect of Surfactant Micelle on Lipid Oxidation in Corn Oil-in-Water Emulsion with Phenol Compounds (Phenol성 물질이 첨가된 Corn Oil-in-Water Emulsion의 산화에 미치는 Surfactant Micelle의 영향)

  • Kim, Byung-Gyu;Chun, Sung-Sook;Cho, Young-Je
    • Applied Biological Chemistry
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    • v.47 no.1
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    • pp.72-77
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    • 2004
  • The purpose of this research was to determine the effect of phenol compounds from green tea leaves and surfactant micelles on lipid oxidation in com oil-in-water emulsion (O/W). The concentration of phenol and surfactant in continuous phase of the O/W with exceed Brij 700 and phenol compounds was measured. The particle size of O/W with phenol (100 ppm) increased with increasing added exceed surfactant $(0{\sim}2.0%)$ and the concentration of surfactant and phenols in the continuous phase higher than these of control. Lipid oxidation rates, as determined by the formation of lipid hydroperoxides and headspace hexanal, in the O/W emulsions containing phenol compounds (100 ppm) and exceed surfactant $(0{\sim}2.0%)$ decreased with increasing concentration of exceed surfactant. The ability of the phenol compounds and exceed surfactant to inhibit hydroperoxide and headspace hexanal producing as lipid oxidation in O/W was BHT>procyanidin B3-3-O-gallate> (+)-gallocatechin > (+)-catechin and 2% > 1 % > 0% of exceed surfactant. These results indicate that phenol compounds and exceed surfactant could alter the physical location of hydroperoxide in O/W.