• Title/Summary/Keyword: 저 pH

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Studies on the Myofibrillar Proteins of Mollusca (연체류의 근원섬유단백질에 관한 연구)

  • 신완철;송재철;김영호
    • The Korean Journal of Food And Nutrition
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    • v.10 no.2
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    • pp.151-159
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    • 1997
  • In order to compare and examine the general characteristics of myofibrillar proteins which is an important protein source as a food resource and relates directly with muscle contraction, we have extracted the myofibrillar proteins from squid and clam. The ionic strength of myofibrillar proteins connected with Ca-ATPase activity, Mg-ATPase activity and EDTA-ATPase activity showed distinct differences between squid and clam. In the activity-pH curve, actomyosin of the clam had a weak biphasic response. In the low concentration of dioxane, myofibrillar proteins of the squid showed a sudden decrease in activity but myofibrillar proteins of the clam showed in increase in activity. Ethanol and metanol in low concentration caused myosin and HMM from the squid and clam to increase their activities. If we cause modification by NEM, under 10-6M concentration, the activity was increased but above 10-5M concentration, there was a sudden decrease in activity.

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Characterization of the Strong Proteolytic Bacteria Isolated from Low Salt Fermented Anchovy and of Protease Produced by that Strain (저식염멸치젓에서 분리한 단백질분해력이 강한 세균 및 생산된 단백분해효소의 특성)

  • CHA Yong-Jun;LEE Eung-Ho;LEE Kang-Hee;CHANG Dong-Suck
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.2
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    • pp.71-79
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    • 1988
  • For the purpose of producing low salt fermented anchovy by accelerated method with a strong proteolytic bacteria, in this study, a strong proteolytic bacterium was isolated from low salt fermented anchovy and its bacteriological characteristics and properties of protease were experimented. The results obtained were as fellows : three proteolytic bacteria, Aeromonas anaerogenes Barillus subtilis and Staphylococcus saprophyticus were isolated from low salt fermented anchovy($4\%\;of\;salt,\;4\%\;of\;KCl,\;0.5\%\;of\;lactic\;acid,\;6\%$of sorbitol and $4\%$ of alcohol extract of red pepper) after 40 days fermentation. Among these strains, which grow best at $30^{\circ}C$, pH 7.0, B. subtilis was found the best proteolytic strain and benefit for industrial use as shown $0.95\;hr^{-1}$ of specific growth rate, $89{\mu}g-Tyr/hr.ml$ of maximum activity after 12 hrs culture in TPY broth. The protease produced by by B. subtilis showed maximum activity at $35^{\circ}C$, pH 7.0, and molecular weight was estimated to be 23,000 by Sephadex G-100 filtration, and it was supposed to be a kind of metal chelator sensitive neutral protease from the results of strong sensitivity against EDTA, o-phenanthroline and metal ions such as $Cu^{2+},\;Ni^{2+},\;Fe^{2+}.Km$ value of that by method of Lineweaver-Burk was determinded to be $0.73\%$ for casein as a substrate.

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Preparation and Characterization of Double-Layered Coated Capsule Containing Low Molecular Marine Collagen and γ-Aminobutyric Acid Producing Lactobacillus brevis CFM20 (저분자 해양성 콜라겐과 γ-Aminobutyric Acid 생성 Lactobacillus brevis CFM20을 함유하는 이중코팅캡슐의 제조 및 특성)

  • Kim, Sun-Yeong;Oh, Do-Geon;Kim, Kwang-Yup
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.7
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    • pp.857-867
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    • 2017
  • This study was performed to encapsulate low molecular weight marine collagen and ${\gamma}$-aminobutyric acid (GABA)-producing lactic acid bacteria to inhibit degradation and improve survival rate during exposure to adverse conditions of the gastro-intestinal tract. Calcium-alginate method was used for the manufacture of a double-layered coated capsule. The inner core material was composed of collagen and lactic acid bacteria, and the coating materials were alginate and chitosan. The sizes and shapes of the double-coated capsule were affected mainly by centrifuge speed and pH. Manufactured capsules were observed with a scanning electron microscope and by confocal laser scanning microscopy to confirm the micromorphological changes of capsules and bacterial cells. As a result, double-layered coated capsules were not degraded at pH 1.2, whereas degradation occurred at pH 7.4. In addition, GABA and collagen were maintained in stable state at pH 1.2. Therefore, double-layered coated capsules developed in this study would not be degraded in the stomach and could be stably delivered to the small intestine to benefit intestinal and dermatic health.

Studies on the Removal of Phytate from Korean Rapeseed(Brassica napus, L) Proteins -Ⅰ. Effects of pH and Salts on Protein and Phytate Solubility of Defatted Rapeseed Flour- (한국산 평지 종실 단백질의 Phytate 제거에 관한 연구 -제1보. 평지 종실 단백질과 Phytate 의 용해도에 대한 pH와 염류의 영향-)

  • Huh, Chai-Ok;Yang, Cha-Bum
    • Applied Biological Chemistry
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    • v.29 no.2
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    • pp.212-218
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    • 1986
  • Proteins in Korean rapeseeds, as in many other plantseeds, are usually bound to phytate molecules. These phytate-bound proteins are of little value as foodstuffs because of their poor solubility in digestive systems. Therefore it is necessary to remove phytates from proteins in order to convert these proteins io a useful foodstuff. In the work, an efficient procedure for removal of phytates from defatted Korean rapeseed was found. The influence of pH on the solubility of protein and phytate of rapeseed flour showed that the former was the lowest at pH 5.0 and began to increase as pH further raised. Meanwhile, the latter was the highest at pH 6.0, however, it was decreased abruptly at alkaline pH, especially to content of 1.3% at pH 11.5. The solubility cf protein was relatively high in NaCl aqueous solution at $pH\;6.0{\sim}8.0$, and did not male any noticeable difference depending on NaCl concentration. On the other hand, the solubility of phytate was high at pH of below 6.0 showing an abrupt decrease at pH of above 6.0. The solubility of protein in $CaCl_2$ aqueous solution was highest at $pH\;6.0{\sim}8.0$, however, there was no significant change at the whole range of tested pH of the solution. A maximum solubility of phytate was shown at $pH\;3.0{\sim}4.0$. And it was decreased abruptly at a higher pH of the above range and also decreased at a lower pH with higher $CaCl_2$ concentration. The solubility of phytate in $Na_2SO_3$ aqueous solution was highest at $pH\;5.0{\sim}8.0$. As the concentration goes up the maximum value of solubility was found to move to higher pHs. Depending on the concentration of $Na_2SO_3$, the decreasing pattern was changed in an alkaline solution. The solubility of phytate in the solution containing low concentration of $Ca^{2+}$ ion was low in all treatments at pH of above 7.0 and showed the maximum value at low pH as $Ca^{2+}$ ion concentration increases. The solubility of protein at pH 11.5 showed the highest value in $1mM\;Ca^{2+}$ ion solution.

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ART Outcomes in WHO Class I Anovulation: A Case-control Study (저성선자극호르몬 성선저하증 여성에서 보조생식술의 임신율)

  • Han, Ae-Ra;Park, Chan-Woo;Cha, Sun-Wha;Kim, Hye-Ok;Yang, Kwang-Moon;Kim, Jin-Young;Koong, Mi-Kyoung;Kang, Inn-Soo;Song, In-Ok
    • Clinical and Experimental Reproductive Medicine
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    • v.37 no.1
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    • pp.49-56
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    • 2010
  • Objective: To investigate assisted reproductive technology (ART) outcomes in women with WHO class I anovulation compared with control group. Design: Retrospective case-control study. Methods: Twenty-three infertile women with hypogonadotropic hypogonadism (H-H) who undertook ART procedure from August 2003 to January 2009 were enrolled in this study. A total of 59 cycles (H-H group) were included; Intra-uterine insemination with super-ovulation (SO-IUI, 32 cycles), in vitro fertilization with fresh embryo transfer (IVF-ET, 18 cycles) and subsequent frozenthawed embryo transfer (FET, 9 cycles). Age and BMI matched 146 cycles of infertile women were collected as control group; 64 cycles of unexplained infertile women for SO-IUI and 54 cycles of IVF-ET and 28 cycles of FET with tubal factor. We compared ART and pregnancy outcomes such as clinical pregnancy rate (CPR), clinical abortion rate (CAR), and live birth rate (LBR) between the two groups. Results: There was no difference in the mean age ($32.7{\pm}3.3$ vs. $32.6{\pm}2.7$ yrs) and BMI ($21.0{\pm}3.1$ vs. $20.8{\pm}3.1kg/m^2$) between two groups. Mean levels of basal LH, FSH, and $E_2$ in H-H group were $0.62{\pm}0.35$ mIU/ml, $2.60{\pm}2.30$ mIU/ml and $10.1{\pm}8.2$ pg/ml, respectively. For ovarian stimulation, H-H group needed higher total amount of gonadotropin injected and longer duration for ovarian stimulation (p<0.001). In SO-IUI cycles, there was no significant difference of CPR, CAR, and LBR between the two groups. In IVF-ET treatment, H-H group presented higher mean $E_2$ level on hCG day ($3104.8{\pm}1020.2$ pg/ml vs. $1878.3{\pm}1197.7$ pg/ml, p<0.001) with lower CPR (16.7 vs. 37.0%, p=0.11) and LBR (5.6 vs. 33.3%, p=0.02) and higher CAR (66.7 vs. 10.0%, p=0.02) compared with the control group. However, subsequent FET cycles showed no significant difference of CPR, CAR, and LBR between the two groups. Conclusion: H-H patients need higher dosage of gonadotropin and longer duration for ovarian stimulation compared with the control groups. Significantly poor pregnancy outcomes in IVF-ET cycles of H-H group may be due to detrimental endometrial factors caused by higher $E_2$ level and the absence of previous hormonal exposure on endometrium.

Studies on the processing of rapid fermented anchovy prepared with low salt contents by adapted microorganism. -3. Processing of low salt fermented anchovy with proteolytic bacteria and quality stability during storage- (미생물을 이용한 저식염 멸치젓의 속성발효에 관한 연구 -3. 단백질분해세균을 이용한 저식염 멸치젓의 제조 및 저장중의 품질 안정성-)

  • Cha, Yong-Jun;Lee, Kang-Hee;Lee, Eung-Ho;Kim, Jin-Soo;Joo, Dong-Sik
    • Applied Biological Chemistry
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    • v.33 no.4
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    • pp.330-336
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    • 1990
  • In order to Process rapid fermented anchovy with low salt contents, processing condition of rapid fermented anchovy by proteolytic bacteria, and its chemical composition and quality stability during storage were examined. Culture was performed(pH 7.0, $40^{\circ}C$, 45strokes/min) for 15hrs after the addition of 1% of NaCl, 1% of sodium erythorbate and 20m1 of B. licheniformis p-5 cultures($3.2{\times}10^4cells/ml$) to 100g of raw anchovy, and then low salt fermented anchovy as final product was made by adding of several(3% of NaCl, 4% of KCI, 4% of ethyl alcohol(w/v), 0.5% of ginger, 0.5% of garlic powder) for stability and flavor enhancement. During 60days of storage, histamine contents was adequate in a food sanitation aspect, and microflora decreased sharply while volatile basic nitrogen increased slowly. Free amino acids are the major part in unique fermented anchovy taste. The volatile fatty acids is the most important component in the anchovy's flavor. From the results of experiments, it was supposed that rapid fermented anchovy processed with proteolytic bacteria was suitable.

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The Agricultural Utilization of Daecheong Lake Sediments and Algae (대청호(大淸湖) 저니(底泥) 및 조류(藻類)의 농업적(農業的) 활용(活用) 연구(硏究))

  • Chang, Ki-Woon;Lim, Jae-Shin;Lee, In-Bog
    • Korean Journal of Soil Science and Fertilizer
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    • v.27 no.2
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    • pp.111-116
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    • 1994
  • These studies were carried out to investigate the possibility on the agricultural utilization of lake sediment collected in the Daecheong Lake. Several parameters to estimate the degree of maturity of compost by windrow system were tested during a 50 day periods, and the results were as follows : During the composting of Daecheong Lake sediment, C/N ratio decreased gradually from 18.9 at the beginning to 13.1 at the final, while CEC increased from 33.5me/100g to 62.5me/100g. The temperature of lake sediment pile was the highest as $52^{\circ}C$ at 15th day and then decreased slowly until $30^{\circ}C{\sim}40^{\circ}C$ after 50 days. The results may be suggested that Daecheong Lake sediment compost reaches an acceptable level of stability after about 50 days. In order to know the effect of the Lake sediment and its compost on the growth of tomato(Lycopersicum esculentum M.), pot experiments were performed. The appiication of lake sediment(AS) itself, sediment organic fertilizer(SOF), and NPK mixed with sediment organic fertilizer(NSF) was more effective for tomato plant height, fresh and dry weight, and chlorphyll content than those of control treatment. Also, the lake sediment compost improved the physico-chemical properties of soil such as pH, total carbon, total nitrogen, available phosphorous and CEC.

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Fast Mode Decision for MPEG-2 to H.264 Transcoding (MPEG-2에서 H.264로 변환하기 위한 고속 모드 결정 기법)

  • Kim, Won-Kyun;Park, Kyung-Jun;You, Jong-Min;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3C
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    • pp.269-277
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    • 2007
  • In this paper, we present a efficient transcoding method from MPEG-2 to H.264. The proposed transcoder is the transcoding method for spatial domain which consists of MPEG-2 decoder part and H.264 encoding part. In transcoder, we can get useful information to estimate less probable modes from MPEG-2 decoder. Using this information, H.264 encoder chooses the macroblock mode of I-frame and P-frame adaptively to reduce the whole complexity of the transcoder. Our experimental result shows that the proposed algorithm can archive about $30\sim60%$ computational saving without significant degradation of visual quality and increasing of bit rate.

Elemental analysis of the fluoride varnish effects on root caries initiation (불소 바니쉬 도포 후 초기 치근 우식 발현에 대한 정량원소분석)

  • Park, Se-Eun;Yi, Kee-Wook;Kim, Hae-Young;Son, Ho-Hyun;Chang, Ju-Hea
    • Restorative Dentistry and Endodontics
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    • v.36 no.4
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    • pp.290-299
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    • 2011
  • Objectives: The usage of fluoride varnish for a moderate to low caries-risk group has not been well validated. This study aimed to evaluate the preventive and therapeutic efficacies of fluoride varnish on the initiated root caries. Materials and Methods: Ten premolars were sectioned into quarters, further divided into two windows, one of which was painted with Fluor Protector (1,000 ppm fluoride, Ivoclar Vivadent). An initial lesion with a well-preserved surface layer was produced by pH cycling. Scanned line analysis using energy dispersive spectrometry determined the weight percentages of Ca and P in the demineralized layer. Scanning Electron microscopy and confocal laser scanning microscopy (CLSM) evaluated the varnish-applied root surfaces. Results: The mean lesion depth (SD) was 12.3 (2.6) ${\mu}m$ (single cycling) and 19.6 (3.8) ${\mu}m$ (double cycling). Double cycling extended the lesion depth, but induced no more mineral loss than single cycling (p < 0.05). The mean weight percentages of Ca and P between groups with and without varnish were not significantly different (p < 0.05). A CLSM showed varnish remained within 15 ${\mu}m$ of the surface layer. Conclusions: When a mild acid challenge initiated root tissue demineralization, the application of low-concentration fluoride varnish did not influence the lesion depth or the mineral composition of the subsurface lesion.

Effects of growth interruption on the photoluminescence characteristics of InGaAs/InP quantum wells (성장정지효과에 의한 InGaAs/InP 양자우물구조의 Photoluminescence 특성 변화)

  • 문영부;이태완;김대연;윤의준;유지범
    • Journal of the Korean Vacuum Society
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    • v.7 no.2
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    • pp.104-111
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    • 1998
  • The InGaAs/InP quantum wells(QWs) were grown by low pressure metalorganic chemical vapor deposition and the effects of growth interruption steps on their interfacial structures were investigated by measuring photoluminescence spectra. When InP or InGaAs surface was treated under the same group V ambient, the full width at half maximum (FWHM) of the QW peak increased possibly due to the incorporation of impurities during the growth interruption time. When InP surface was treated under $AsH_3$, howerer, the PL peak showed red-shift due to the As-P exchange reaction and the change of FWHM was not remarkable. The effective thickness of InAs interfacial layer formed during $AsH_3$, treatment on the InP surface was calculated to be 1~2 monolayers. In the case of InGaAs treatment under $PH_3$, the PL peak energy and the FWHM increasied. This results suggest that $PH_3$ treatment on the InGaAs surface suppresses the incorporation of As into the subsequent InP layer and the local replacement of As by P occurs simultaneously.

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