• 한국식품과학회지
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• 제12권2호
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• pp.133-139
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• 1980

미생물 균체로부터 유용 물질을 추출해 내는 기작(機作)을 조사하기 위하여 Rhodotorula rubra YUFE 1526의 냉동 건조 균체로 부터의 균체 유지 추출을 통하여 고찰하였으며, 다음과 같은 결과를 얻었다. 1. 균체 유지의 최적 추출 용매로는 메탈알코홀이 적합하였으며, extractable total lipid의 량은 균체량의 19.17 % 이었다. 2. 교반 속도의 영향은 없었으며, 최적 추출 온도는 $50^{\circ}C$이었고, 2시간 동안의 추출에서 90 %의 추출률을 보였다. 3. 균체 유지의 확산도는 $50^{\circ}C$에서 $9.4{\times}10^{-9}\;mm^2/min.$로서 최대를 보였으며 추출 온도에 따른 확산도는 다음과 같았다. $D=2.2e^{0002907T}{\times}10^{-9}\;mm^{2}/min\;20^{\circ}C{\leq}T{\leq}50^{\circ}C$ 4. 균체내의 유지 함유량이 변화되어도 확산도 값은 $9.4{\times}10^{-9}\;mm^2/min.$로서 거의 일정하였다. 5. 추출 모델의 설정을 통해 구해진 이론식이 실험치와 거의 일치하고 있었다.

• Bulletin of the Korean Chemical Society
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• 제11권5호
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• pp.391-395
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• 1990

The kinetics of thermnal cis-trans isomerization reaction of 1-bromopropene(1-BP) was studied at temperatures from 620.8 to 753.15 K over the pressure range 0.17-50.3 Torr. Both the inhibition effect by cyclohexene or propene and the catalytic effect by HBr showed a radical process as the main mechanism of the isomerization. In the suppression of the radical process by the inhibitors, the molecular process also contributed to overall reaction rate. The reactions demonstrated the first order kinetics under both uninhibited and inhibited conditions and could be represented by the expressions (R = 1.987 cal/mol/K) $k_{un}/s^{-1} = (3.45{\pm}1.50){\times}10^{11}$exp$[(- 48100{\pm}2000)/RT]\;k_{ink}/s^{-1} = (2.98{\pm}1.40){\times}10^{12}$exp$[(- 55800{\pm}1800)/RT]$> where $k_{un}$ is the observed rate constant of cis-1-bromopropene(1-B$P_c$) to trans-1-bromopropene(1-B$P_t$) under uninhibited condition at initial pressure of 50 Torr and $k_{ink}$ is the rate constant under maximal inhibition by cyclohexene. The ratio of rate constants for bromine atom elimination from the allylic hydrogen of reactant(1-BP) and from the inhibitors, propene and cyclohexene, were measured from the observed rates of the uninhibited and inhibited reactions. The inhibition efficiencies of cyclohexene and propene were compared kinetically from the rate constants and shown to give good agreement with the previous results reported from other alkyl bromide pyrolyses.

• 대기
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• 제31권4호
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• pp.361-376
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• 2021

"Gangwon Yeongdong Wind Experiments (G-WEX) Pilot Study: Downslope windstorms in the Taebaek Mountains, South Korea" is promoted based on joint organization by Gangwon Regional Office of Meteorology and National Institute of Meteorological Research and participation by 12 institutions to understand the mechanism in development of Yeongdong wind phenomena. The special observation (G-WEX) involved total of 5 intensive observations in March 2020 and April 2020. To collect the data necessary for the research on Yeongdong wind phenomena, (1) high-resolution surface observation network was used to examine surface wind and (2) atmospheric soundings were observed by using Rawinsonde, Wind profiler, Wind Lidar, and Drone. This study covers the detailed information on the special observational experiments for downslope windstorms in the leeward of the Taebaek Mountains, named as the Yeongdong wind, including the observational strategies, experimental designs, and pilot studies during the Intensified Observing Period (IOPs). According to 2020 G-WEX observation results, downslope windstorms were observed in 2~3 km of upper atmosphere when the strong winds happened around the top of the mountain near Daegwallyeong. Also, dry adiabatic expansion related to downslope windstorms caused temperature rise and led to formation of an inversion layer in altitude below 2.5 km. Bands of strong wind were located right under the altitude where downslope windstorms are observed with temporal rise of the temperature. As these are preliminary observation results, there needs to be continuous related researches and high-resolution weather observation.

• Korean Journal of Acupuncture
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• 제36권2호
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• pp.93-103
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• 2019

Objectives : The aim of this study is to review the current trends in experimental studies on the acupuncture moxibustion treatment for visceral hypersensitivity. Methods : PubMed was searched for experimental studies about visceral hypersensitivity and acupuncture/moxibustion. Data were extracted and tabulated from the selected articles about experimental method, intervention, result and mechanism. Results : Total 23 articles were reviewed. Chronic visceral hypersensitivity animal model was applied in 17 studies (74%). Visceral hypersensitivity was measured by abdominal withdrawal reflex scoring or/and abdominal electromyogram. Acupoints like ST25, ST36, ST37, BL25, LI11, BL32 and PC6 were treated by electroacupuncture or moxibustion. All articles reported that electroacupuncture or moxibustion treatment is significantly effective in reducing visceral hypersensitivity. Treatment mechanisms were studied, related to mast cell, serotonin (5-HT) and receptor (5-HT3R and 5-HT4R), substance P (SP), vasoactive intestinal polypeptide (VIP), c-fos positive cell, corticotropin-releasing hormone (CRH), purinergic 2X (P2X)2, P2X3, P2X4, P2X7, N-methyl-D-aspartate (NMDA) receptor (NR1 and NR2B), prokinectin (PK) 1 and PK2. Conclusions : Evidences on acupuncture/moxibustion treatment for visceral hypersensitivity in animal studies warrant more research on effective acupoins, electro-acupuncture methods and treatment durations.

• Computers and Concrete
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• 제26권6호
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• pp.565-576
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• 2020

Experimental and discrete element methods were used to investigate the effects of angle of Y shape non-persistent joint on the tensile behaviour of joint's bridge area under brazilian test. concrete samples with diameter of 100 mm and thikness of 40 mm were prepared. Within the specimen, two Y shape non-persistent notches were provided. The large notch lengths were 6 cm, 4 cm and 2 cm. the small notch lengths were 3 cm, 2 cm and 1 cm. The angle of larger notch related to horizontal axis was 0°, 30°, 60°, 90°. Totally, 12 different configuration systems were prepared for Y shape non-persistent joints. Also, 18 models with different Y shape non-persistent notch angle and notch length were prepared in numerical model. The large notch lengths were 6 cm, 4 cm and 2 cm. the small notch lengths were 3 cm, 2 cm and 1 cm. The angle of larger notch related to horizontal axis was 0, 30, 60, 90, 120 and 150. Tensile strength of model materil was 1 MPa. The axial load was applied to the model by rate of 0.02 mm/sec. This testing showed that the failure process was mostly governed by the Y shape non-persistent joint angle and joint length. The tensile strengths of the specimens were related to the fracture pattern and failure mechanism of the discontinuities. It was shown that the tensile behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the joint length and joint angle. The minimum tensile strength occurs when the angle of larger joint related to horizontal axis was 60°. Also, the maximum compressive strength occurs when the angle of larger joint related to horizontal axis was 90°. The tensile strength was decreased by increasing the notch length. The failure pattern and failure strength are similar in both methods i.e. the experimental testing and the numerical simulation methods.

• 셀메드
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• 제11권3호
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• pp.16.1-16.7
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• 2021

Cancer is an abnormal growth of cells in body which leads to death. These cells are born due to imbalance in cell proliferation mechanism. In 2018, WHO released new statistics on cancer incidence, mortality, and prevalence worldwide i.e., GLOBOCAN 2018 estimates for 28 types of cancer in which more prevalence of cervix and breast cancer. According to survey, in India about 7.8 million cancer deaths and 11.5 million new cases arise in 2018, which will increase to 19.3 million new cases per year by 2025. Though breast cancer as such is not explained anywhere in Ayurvedic compendia, correlations can be done with the Stana Arbuda. Ayurveda, the ancient system of medicine came into existence 1000's of years ago with an objective of maintaining the health of people and treating diseases. Many herbs used in Ayurveda have been screened for activity against cancer and in-vitro and in-vivo studies have given promising leads. The plant, called as "Mother of Medicine", Haritaki has been extensively studied for its various ailments because of its extraordinary healing potency. Haritaki (Terminalia chebula Retz.), Family: Combretaceae have a great therapeutic value and is widely distributed in India. Dried fruit of Terminalia chebula contains high quantities phenolic compounds consist of ellagic acid, gallic acid and chebulic acid. The fruit extract of T. chebula is having different biological properties like anticancer, antioxidant, hepatic and renal protective activities etc. In this study, we focus on the use of CO₂ extract of Terminalia chebula, on the breast cancer cell line MDA-MB-231. All tests proved that CO₂ extract of Terminalia chebula containing active chemical component, therefore our experiment showed the positive results for CO₂ extract of Terminalia chebula against breast cancer cell line cancer MDA-MB-231. The MTT assay results were used to evaluate the anti-cancer activity of the extract. The percentage of cell growth and cell viability were calculated from tabulated result values of MTT assay. Cell viability MTT assay also showed significant growth inhibition, at the same time statistical analysis of MTT assay also proved significant results.

• Advances in nano research
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• 제13권3호
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• pp.207-216
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• 2022

In this paper, a novel model is developed for frequency behavior of single walled carbon nanotubes. The governing equation of motion is constructed method based on the Sander theory using Rayleigh-Ritz's method The frequencies enhances on increasing the power law index using simply supported, clamped and clamped free end conditions. The frequency curve for C-F is less than other conditions. It is due to the physical constraints which are applied on the edge of the CNT. It is observed that the C-F boundary condition have less frequencies from the other two conditions. The frequency phenomena for zigzag are insignificant throughout the aspect ratio. Moreover when index of power law is increased then frequencies increases for all boundary conditions. The natural frequency mechanism for the armchair (10, 10) for various values of power law index with different boundary conditions is investigated. Here frequencies decrease on increases the aspect ratio for all boundary conditions. The frequency curves of SS-SS edge condition is composed between the C-C and C-F conditions. The curves of frequency are less significant from small aspect ratio (L/d = 4.86 ~ 8.47) and decreases fast for greater ratios. It is found that the frequencies via aspect ratios, armchair (10, 10) have higher values from zigzag (10, 0). It is due to the material structure which is made by the carbon nanotubes. The power law index have momentous effect on the vibration of single walled carbon nanotubes. The present frequency result is also compared numerically experimentally with Raman Spectroscopy.

• Biomolecules & Therapeutics
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• 제30권6호
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• pp.520-528
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• 2022

Mast cells are an effector cell that plays a pivotal role in type I hypersensitive immune responses. Mast cells exist in connective tissues, such as skin and mucosal tissue, and contain granules which contain bioactive substances such as histamine and heparin in cells. The granules of mast cells are secreted by antigen stimulation to cause the type I allergic hypersensitivity. In addition, stimulated by antigen, mast cells synthesize and secrete various eicosanoids and cytokines. While AT9283 is known to have anticancer effects, the therapeutic effect of AT9283 on allergic disorders is completely unknown. In this study, it was found that AT9283 reversibly inhibited antigen-IgE binding-induced degranulation in mast cells (IC₅₀, approx. 0.58 μM) and suppressed the secretion of the inflammatory cytokines IL-4 (IC₅₀, approx. 0.09 μM) and TNF-α (IC₅₀, approx. 0.19 μM). For a mechanism of mast cell inhibition, while not inhibiting Syk phosphorylation, AT9283 suppressed the activation of LAT, a downstream substrate protein of Syk, in a dose-dependent manner. As expected, AT9283 also inhibited the activation of PLCγ1 and Akt, downstream signaling molecules of Syk/LAT, and MAP kinases such as JNK, Erk1/2, and P38. In an in vitro protein tyrosine kinase assay, AT9283 directly inhibited Syk activity. Next, AT9283 dose-dependently inhibited passive cutaneous anaphylaxis (PCA), an IgE-mediated allergic acute response, in mice (ED50, approx. 34 mg/kg, p.o.). These findings suggest that AT9283 has potential to use as a new drug for alleviating the symptoms of IgE-mediated allergic disorders.

• Journal of Audiology & Otology
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• 제23권2호
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• pp.63-68
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• 2019

Background and Objectives: To investigate the relationship between hearing impairment and alcohol drinking patterns in South Korean adults. Subjects and Methods: Data collection was performed by Korean National Health and Nutrition Survey from January 1 to December 31, 2012. Data analyses were performed from February 20 to March 3, 2018. Data from 3,860 adults 20 years of age or older without a history of malignancy or chronic otitis media in the Korean National Health and Nutrition Survey 2012 database who participated in the health questionnaires, and who had available results from otologic examinations that included pure tone audiogram, were included. Pure-tone average hearing thresholds were calculated at 500, 1,000, 2,000, and 4,000 Hz. Hearing loss was defined as a pure-tone average >40 dB in one or both ears. The Alcohol Use Disorder Identification Test was used to evaluate drinking statuses of subjects. Data were analyzed using the complex-sample χ²-test of independence and a complex-sample logistic regression analysis. Results: Of the 29,954,319 individuals in the weighted cross-sectional study population, 15,106,040 (50.4%) were men and 14,848,098 (49.6%) were women. A total of 8.1% of men and 7% of women had hearing impairment. The degrees of drinking with appropriate, risky, and hazardous drinking habits were 58.2, 32.1, and 9.7% among men; and 76.4, 12.5, and 11.1% among women, respectively. Among men, the odds ratio of hearing loss increased by 2.506 times when comparing hazardous and appropriate drinking (confidence interval, 1.083 to 5.800, p=0.002). Moderate alcohol consumption (≤2 drinks per day) was not protective for hearing in either group. Conclusions: As hazardous drinking tends to coexist with hearing impairment in men, appropriate prevention and intervention strategies should be emphasized. A longitudinal study to investigate harmful drinking and the mechanism of hearing loss should be performed.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1476-1484
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• 2023

Laboratory experiments and point monitoring of reservoir sediments have proven that stable sulfate reduction (SSR) can lower the concentrations of toxic metals and sulfate in acidic groundwater for a long time. Here, we hypothesize that SSR occurred during in situ leaching after uranium mining, which can impact the fate of acid groundwater in an entire region. To test this, we applied a sulfur isotope fractionation method to analyze the mechanism for natural attenuation of contaminated groundwater produced by acid in situ leaching of uranium (Xinjiang, China). The results showed that δ³⁴S increased over time after the cessation of uranium mining, and natural attenuation caused considerable, area-scale immobilization of sulfur corresponding to retention levels of 5.3%-48.3% while simultaneously decreasing the concentration of uranium. Isotopic evidence for SSR in the area, together with evidence for changes of pollutant concentrations, suggest that area-scale SSR is most likely also important at other acid mining sites for uranium, where retention of acid groundwater may be strengthened through natural attenuation. To recapitulate, the sulfur isotope fractionation method constitutes a relatively accurate tool for quantification of spatiotemporal trends for groundwater during migration and transformation resulting from acid in situ leaching of uranium in northern China.