• 한국식품조리과학회지
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• 제17권2호
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• pp.117-122
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• 2001

마쇄한 마늘과 50% ethanol의 마늘 추출액을 분쇄돈육에 첨가하여 4$^{\circ}C$에 저장하면서 pH, POV가와 TBA가의 변화를 조사하였다. 분쇄돈육은 가열하지 않은 생육과 10$0^{\circ}C$에서 10분간 가열한 가열육으로 나누어 실험하였다. 마쇄한 마늘과 마늘 추출액을 분쇄돈육에 첨가하였을 때 저장 중 과산화물가와 TBA가는 마늘첨가량이 많을수록 현저한 감소로 지질의 산화 억제 효과를 나타내었으며, 특히 10% 마늘 추출액은 마쇄 마늘을 20% 첨가하였을 때와 거의 비슷한 효과를 보였다. 효과는 저장 중 4-6일째까지 가장 컸고 그 후에는 점차적으로 감소하였다. pH는 전반적으로 6일까지는 대체적으로 감소하였다가 그 이후 증가하였다. 마쇄한 마늘과 ethanol 50%의 마늘 추출액을 분쇄돈육에 첨가했을 때 약간의 pH 증가를 보였다. 생육과 가열육 모두 pH, 과산화 물가와 TBA가에서 비슷한 영향을 주었으나 생육보다 가열육에서 더 많은 변화를 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권12호
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• pp.1751-1755
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• 2017

Objective: An experiment was conducted to study the blood haematology, muscle pH, and serum cortisol changes in pigs with different levels of drip loss. Methods: Two groups (low and high) of 20 animals were selected from 100 pigs based on drip loss. All [$Duroc{\times}(Large\;White{\times}Landrace)$] pigs were slaughtered according to standard slaughtering procedures. At exsanguinations, blood samples were taken for the haematological parameters and serum cortisol analysis. The muscle samples were taken from longissimus dorsi muscle to evaluate the muscle pH and drip loss. Results: Haematological parameters of low drip loss group showed higher content of white blood cells and monocytes than high drip loss group (p<0.05). The low drip loss group had higher muscle pH at 45 min (p<0.05) and 24 h (p<0.001) post-mortem than the high drip loss group. However, there was no significant difference in serum cortisol levels (p>0.05). Conclusion: Drip loss is mainly affected by the muscle pH decline after slaughter and also might be affected by white blood cells and monocytes.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2663-2670
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• 2013

The purpose of stability testing is to provide evidence about how the quality of a drug varies with time under the influence of a variety of environmental factors. In this study, erythropoietin (EPO) was analyzed under different pH (pH 3 and pH 9) and temperature ($25^{\circ}C$ and $40^{\circ}C$) conditions according to current Good Manufacturing Practice (cGMP) and International Conference on Harmonisation (ICH) guidelines. The molecular weight difference between intact EPO and deglycosylated EPO was determined by SDS-PAGE, and aggregated forms of EPO under thermal stress and high-pH conditions were investigated by size exclusion chromatography. High pH and high temperature induced increases in dimer and high molecular weight aggregate forms of EPO. UPLC-ESI-TOF-MS was applied to analyze the changed modification sites on EPO. Further, normal-phase high-performance liquid chromatography was performed to identify proposed glycan structures and high pH anion exchange chromatography was carried out to investigate any change in carbohydrate composition. The results demonstrated that there were no changes in modification sites or the glycan structure under severe conditions; however, the number of dimers and aggregates increased at $40^{\circ}C$ and pH 9, respectively.

• 한국결정성장학회지
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• 제31권4호
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• pp.166-173
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• 2021

TiO₂의 rutile 상은 anatase 상에 비해서 고온에서 안정한 상을 형성하지만 anatase의 안정한 온도 영역은 합성조건에 따라 변화된다. 본 연구에서는 TiOSO₄와 에탄올과 증류수의 혼합용매를 사용하여 Sol-gel법으로 나노 사이즈의 TiO₂를 합성하여 pH 및 열처리 온도를 따른 anatase와 rutile의 상변화에 대하여 조사하였다. 제조한 TiO₂의 pH(3, 5, 7, 9)와 열처리 온도(500, 600, 700, 800, 900℃) 조건을 변화시켜 anatase와 rutile의 비율 변화를 관찰하였다. XRD, FE-SEM 분석을 통해 이와 같은 변화를 관찰한 결과, 500℃에서는 anatase TiO₂, 900℃에서는 rutile TiO₂가 관찰되었다. 이 중간 온도인 600, 700, 800℃에서는 pH에 따라 anatase와 rutile의 비율이 변화한다. 700℃를 기준으로 pH = 3, 5는 anatase TiO₂의 비율이 더 크고, pH = 7, 9는 rutile TiO₂의 비율이 더 크다는 결론을 얻었다.

• Molecules and Cells
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• 제19권2호
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• pp.232-238
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• 2005

Corneal endothelial cells play an important role in maintaining the transparency and ionic balance of the cornea. Inflammation causes many changes in the intracellular and extracellular environment of the cornea, including acidosis. We examined the relationship between changes in extracellular pH and expression of cyclooxygenase-2 in cultured bovine corneal endothelial cells. When extracellular pH ($[pH]_o$) was reduced to pH 6.4, COX-2 mRNA increased, with a peak at 2 h. This was blocked by pretreatment with actinomycin D and incubation with spermine NONOate (SPER/NO, a nitric oxide donor). Exposure to the $H^+$ ionophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP), also raised COX-2 mRNA levels. CCCP-induced COX-2 mRNA expression was also reduced by SPER/NO. These results were confirmed immuno-cytochemically. These data demonstrate that COX-2 expression is stimulated by the lowering of extracellular pH that could result from bacterial infection, and that this is countered by over-production of nitric oxide, which could also result from bacterial infection.

• 동아시아식생활학회지
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• 제10권4호
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• pp.298-304
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• 2000

This experiment was carried out to investigate the changes in pH, proximate composition, pH, VBN, TBA, minerals, and fatty acid of venison extracts, from three slaughtered deers with 180~210 kg live weight (♀, Elk deer, 28~30 months of age) at 4$^{\circ}C$. Proximate composition was not affected by storage periods. The pH, VBN, and TBA ranged from 4.60~4.62, 13.52~15.75 mg%, and 0.20~0/81mg/kg. respectively. The pH, VBN, and TBA gradually increased during storage period (p<0.050. Among minerals, K, P, Na, Mg, and Ca were major mineral contents and the Ca, mg, Na contents significantly decreased (p<0.05) according to the storage period. The major fatty acid found in venison extracts were oleic acid, palmitic acid, stearic acid, linoleic acid. Oleic acid, linolenic acid, and arachidonic acid decreased during storage, but palmitic acid, heptadeanonic acid, and stearic acid increased during the storage. U/S (unsalturated fatty acid/saturated fatty acid) ratio tended to decrease during the storage.

• Mycobiology
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• 제39권4호
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• pp.249-256
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• 2011

Microorganisms are significantly affected when the ambient pH of their environment changes. They must therefore be able to sense and respond to these changes in order to survive. Previous investigators have studied various fungal species to define conserved pH-responsive signaling pathways. One of these pathways, known as the Pal/Rim pathway, is activated in response to alkaline pH signals, ultimately targeting the PacC/Rim101 transcription factor. Although the central signaling components are conserved among divergent filamentous and yeast-like fungi, there is some degree of signaling specificity between fungal species. This specificity exists primarily in the downstream transcriptional targets of this pathway, likely allowing differential adaptation to species-specific environmental niches. In this review, the role of the Pal/Rim pathway in fungal pH response is discussed. Also highlighted are functional differences present in this pathway among human fungal pathogens, differences that allow these specialized microorganisms to survive in the various micro-environments of the infected human host.

• Membrane and Water Treatment
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• 제6권2호
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• pp.141-160
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• 2015

This study aims to investigate the impacts of chemical cleaning on the performance of a reverse osmosis membrane. Chemicals used for simulating membrane cleaning include a surfactant (sodium dodecyl sulfate, SDS), a chelating agent (ethylenediaminetetraacetic acid, EDTA), and two proprietary cleaning formulations namely MC3 and MC11. The impact of sequential exposure to multiple membrane cleaning solutions was also examined. Water permeability and the rejection of boron and sodium were investigated under various water fluxes, temperatures and feedwater pH. Changes in the membrane performance were systematically explained based on the changes in the charge density, hydrophobicity and chemical structure of the membrane surface. The experimental results show that membrane cleaning can significantly alter the hydrophobicity and water permeability of the membrane; however, its impacts on the rejections of boron and sodium are marginal. Although the presence of surfactant or chelating agent may cause decreases in the rejection, solution pH is the key factor responsible for the loss of membrane separation and changes in the surface properties. The impact of solution pH on the water permeability can be reversed by applying a subsequent cleaning with the opposite pH condition. Nevertheless, the impacts of solution pH on boron and sodium rejections are irreversible in most cases.

• Journal of Oral Medicine and Pain
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• 제18권1호
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• pp.83-96
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• 1993

Even though the increasing interest in fermented milk, the information on the influence of fermented milk on oral health in literature is sparce. We have investigated the effect of fermented milk on saliva. Thirty-three healthy unmedicated subjects at the age of their twenties were included in this study and divided into control, fermented milk, and milk groups. And, the experiment period was 70 days. The authors examined the number of salivary S.mutans, Lactobacilli, pH, and viscosity at the beginning of the experiment. And, we investigated the changes of the these factors at 10,40, and 70 days after. The authors came to the following conclusions The obtined results were as follows : 1. There were no significant changes in the numbers of saliary S. mutans in the control, fermented milk, andmilk groups through the experimental period. 2. There was no significant change in the number of salivary lactobacilli in the fermented milk group throiugh the experimental period. 3. There was a decrease in salivary pH after 40 and 70 days in fermented milk group. 4. There were no significant changes in the values of salivary viscosity at a low shear rate in all groups, but there were increases in these values at a high shear rate in the fermented milk and milk groups through the experimental period.

• Applied Biological Chemistry
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• 제21권2호
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• pp.109-111
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• 1978

본실험(本實驗)에서는 저장중(貯藏中)에 면양근육내(績羊筋肉內)의 보수성(保水性), 단백질(蛋白質) 추출성(抽出性) 및 pH에 대(對)한 변화(變化)의 차이(差異)를 관찰(觀察)하였다. 보수성(保水性)은 pH치(値)와 같이 도살후(屠殺後) 서서히 저하(低下)되어 약(約) 2-4시간후(時間後) 최소치(最少値)에 도달(到達)하였다가 그 후(後) 저장(貯藏)의 진행(進行)과 더불어 회복(回復)되였다. 단백질추출성(蛋白質抽出性)도 같은 경향(傾向)을 보였으나 도살후(屠殺後) 6시간(時間)까지 pH치(値)의 변화(變化)는 보수성(保水性) 및 단백질(蛋白質) 추출성(抽出性)의 변화(變化)보다 더 빨랐다. 10일간저장중(日間貯藏中) 보수성(保水性), 단백질추출성(蛋白質抽出性) 및 pH치(値)의 회복(回復)의 속도(速度)도 같은 양상(樣相)을 보였다.