• Title/Summary/Keyword: pH$_{24}$

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Changes of multi-purpose solutions for soft contact lens depending on using period or keeping temperature (사용기간 및 온도에 따른 소프트콘택트렌즈 다목적용액의 변화)

  • Park, Mi-Jung;Ha, Ju-Ryung;Lee, Young-Min;Han, Hyeun-Woo;Kim, Seung-Tae
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.381-389
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    • 2004
  • To investigate changes of multi-purpose solutions for soft contact lens(MPS) depending on using period or keeping temperature, we evaluate four brands of MPS. No significant difference was seen in protein deposit removing efficacy after samples had used for 24 weeks and kept at $4^{\circ}C$, $20^{\circ}C$ or $30^{\circ}C$. The pH values of the samples of 4 brands measured weekly over the 24 week testing period. The initial average pH value of samples were 7.0, 7.5, 7.6 or 8.2. One brand of MPS was in the range of the threshold for ocular awareness, which is outside the zone of 6.6 ~ 7.8. During the testing period, the pH value were decreased in using period-dependent manner. At the 24th week, the average pH values of samples turned to 6.6, 7.2, 7.2 or 7.7. However, the difference of keeping temperature was not associated with decreased levels of pH values. After 24 weeks, one of total 36 samples was contaminated by bacteria. Furthermore, the change of components was shown after 24 weeks in the analysis using thin layer chromatography and the analysis of UV absorption pattern. The results of our study provides that the keeping temperature of MPS is not the important factor of changes of MPS, but the using period of MPS can cause contact lens wearers discomfort.

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Classification of behavior at the signs of parturition of sows by image information analysis (영상정보에 의한 모돈의 분만징후 행동특성 분류)

  • Yang, Ka-Young;Jeon, Jung-Hwan;Kwon, Kyeong-Seok;Choi, Hee-Chul;Ha, Jae-Jung;Kim, Jong-Bok;Lee, Jun-Yeob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.607-613
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    • 2018
  • The aim of this study is to predict the exact time of parturition from analysis and classification of preliminary behavior based on parturition signals in sows. This study was conducted with 12 crossbred sows (with an average of 3.5 parities). Behavioral characteristics were analyzed for duration and the frequency of different behaviors on a checklist, which includes the duration of the basic behaviors (feeding, standing, lying down, and sitting). The frequency of specific behaviors (investigatory behavior, shame-chewing, scratching, and bar-biting) was also recorded. Image information was collected every two minutes for 24 hours before the first piglets were born. As a result, the basic behavior of a sows' standing time (22.6% of the time after 24 h, 24.9% after 12 h) and time lying down (55.9% after 24 h, 66.3% after 12 h) increased over the 12 h period before parturition, compared with the 24 h period before parturition (p<0.01). Feeding (13.42% after 24 h, 4.38% after 12 h) and sitting (8.2% after 24 h, 4.5% after 12 h) tended to decrease during the 12 h before parturition (p>0.05). The sows' investigatory behavior ($11.44{\pm}1.80$ after 24 h, $55.97{\pm}6.13$ after 12 h), scratching ($3.75{\pm}1.92$ after 24 h, $20.99{\pm}5.81$ after 12 h), and bar-biting ($0.69{\pm}0.15$ after 24 h, $3.71{\pm}1.53$ after 12 h) increased in the 12-hour period before parturition, compared with the 24-hour period before parturition (p<0.01). On the other hand, shame-chewing ($2.20{\pm}1.67$ after 24 h, $0.07{\pm}0.01$ after 12 h) decreased compared to the 12-hour period before parturition (p>0.05). Thus, standing, investigatory behavior, scratching, and bar-biting could be used as behaviors indicative of parturition in sows.

Influence of UV Irradiation Interval on Mineral Content in Metatarsus of Broiler Chicks (자외선 조사간격이 브로일러 병아리의 중족골 광물질 함량에 미치는 영향)

  • 장윤환;조인호;여영수;이은택;배은경;김중달
    • Korean Journal of Poultry Science
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    • v.20 no.3
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    • pp.133-140
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    • 1993
  • A study was conducted to investigate the concentrations of Ca, P and ash in metatarsal bone of broiler chicks exposed to UV light in different Interval. Day-old Hubbard broiler chicks (199=10 control+3 irradiation interval $\times$ 9 elapsed time $\times$ 7 replicate) were fed vitamin D3 deficient diet for 3 wk in a windowless subdued-light room and exposed to 297 nm UVB light by 0.068 mJ/$\textrm{cm}^2$ three times In 0, 12 or 24 h interval. The metatarsal bones were taken at 0, 6, 12, 18, 24, 48, 96, 144 or 240 h after last irradiation, separated from adhering tissue, ether extracted, dried and ashed. The Ca concentration was measured by atomic absorption spectrophotometry and P by ammonium metavanadate colorimetry. When the birds were continuously exposed to UVB light for 30 min without interval, the Ca content in metatarsus increased gradually according to the time after irradiation and reached the highest value 16.75% at 240 h after exposure. The P content also increased gradually until 144 h, where it was 9.75%. The ash content in metatarsus increased continuously until 240 h, the final time in this research, where 42.75% was shown. As 10 min three times irradiation in 12 h interval was applied to the chicks, the metatarsal Ca presented a small peak(13.31%) at 12 h after irradiation and a large peak(16.91%) at 144 h. P content showed a small peak(7.18%) at 12 h and a large level(8.34%) at 240 h. Ash content increased continuously until 240 h, where it was 46.53%. The small peaks in Ca and P concentration were thought to be derived from preirradiation at 12 and 24 h before final irradiation for 10 min. When 24 h interval system was treated, the peak value of Ca content(24.18%) occurred earlier(96 h) than those in 0 and 12 h interval systems. P content also showed the maximum value at 96 h(7.29%). Ash content presented an increasing trend until 240 h, where 45.75% was appeared. In respecting the method of UVB irradiation, the peak value of Ca content in metatarsus appeared earlier in 24 h interval system than in other systems. Meanwhile the ash contents in metatarsus of birds exposed to UVB light in 12 and 24 h interval procedures were higher than those in 0 h interval one. Therefore, it was concluded that a daily 10 min irradiation of UVB light would be desirable for increasing the Ca and ash content in metatarsus of brolier chicks.

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Factors Influencing Biohydrogenation and Conjugated Linoleic Acid Production by Mixed Rumen Fungi

  • Nam, In-Sik;Garnsworthy, Philip C.
    • Journal of Microbiology
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    • v.45 no.3
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    • pp.199-204
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    • 2007
  • The objective of this study was to evaluate the effect of soluble carbohydrates (glucose, cellobiose), pH (6.0, 6.5, 7.0), and rumen microbial growth factors (VFA, vitamins) on biohydrogenation of linoleic acid (LA) by mixed rumen fungi. Addition of glucose or cellobiose to culture media slowed the rate of biohydrogenation; only 35-40% of LA was converted to conjugated linoleic acid (CLA) or vaccenic acid (VA) within 24 h of incubation, whereas in the control treatment, 100% of LA was converted within 24 h. Addition of VFA or vitamins did not affect biohydrogenation activity or CLA production. Culturing rumen fungi at pH 6.0 slowed biohydrogenation compared with pH 6.5 or 7.0. CLA production was reduced by pH 6.0 compared with control (pH 6.5), but was higher with pH 7.0. Biohydrogenation of LA to VA was complete within 72 h at pH 6.0, 24 h at pH 6.5, and 48 h at pH 7.0. It is concluded that optimum conditions for biohydrogenation of LA and for CLA production by rumen fungi were provided without addition of soluble carbohydrates, VFA or vitamins to the culture medium; optimum pH was 6.5 for biohydrogenation and 7.0 for CLA production.

Real Effect of pH on CIE L*, a*, and b*, of Loins during 24 h Chilling of Beef Carcasses

  • Min, J.S.;Kim, I.S.;Yoon, Y.T.;Lee, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.2
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    • pp.279-282
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    • 2002
  • Twenty six male Hanwoo (Korean cattle) carcasses were measured for pH, temperature and instrumental color changes of loins during 24 h post-mortem carcass chilling at $4^{\circ}C$ in the cooler. The average internal temperature of loins was about $5^{\circ}C$ after 24 h of chilling, and with the exclusion of those with an ultimate pH>6.0 (dark-cutters), the average pH value was 5.5. When all carcasses were considered for the partial correlation coefficient between color and pH, with the temperature effect excluded, CIE $L^*$, $a^*$ and $b^*$ seemed to be affected significantly by pH during chilling process (p<0.001). However, when carcasses with dark-cutting condition were excluded, the correlation coefficients were much lower. In contrast, when the partial correlation coefficients between color and temperature, excluding the effect of pH on them, were analyzed, the relationship between color and temperature did not change much after values of DFD (dark, firm, dry) beef were excluded. The results suggested that the known interrelationship of color and pH in chilled beef loins be mainly due to the influence of temperature on pH and color.

Antibacterial Activity of Aqueous Garlic Extract Against Escherichia coli O157:H7, Salmonella typhimurium and Staphylococcus aureus (마늘 물추출물의 Escherichia coli O157:H7, Salmonella typhimurium, Staphylococcus aureus에 대한 항균활성)

  • Lee, Seung-Yoon;Nam, Sang-Hyun;Lee, Hyun-Jung;Son, Song-Ee;Lee, Hu-Jang
    • Journal of Food Hygiene and Safety
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    • v.30 no.2
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    • pp.210-216
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    • 2015
  • This study was investigated about the antibacterial effects of aqueous garlic extract (AGE) against Escherichia coli O157:H7 (E. coli O157:H7), Salmonella typhimurium (S. typhimurium) and Staphylococcus aureus (S. aureus). The minimum inhibitory concentration (MIC) of AGE against E. coli O157:H7, S. typhimurium, and S. aureus was 24, 48 and 24 mg/mL, respectively. In addition, the minimum bactericidal concentration (MBC) of AGE against E. coli O157:H7, S. typhimurium, and S. aureus was all of 96 mg/mL. The growth of E. coli O157:H7 was significantly inhibited at the concentration of AGE 24 mg/mL at 24 hr post-incubation (p < 0.01), but that of S. aureus was not significantly inhibited at the same concentration. However, the growth of S. aureus at the concentration of AGE 96 mg/mL was significantly inhibited at 24 hr post-incubation compared to that of untreated bacteria (p < 0.01). At the concentration of AGE 48 (p < 0.05) and 96 mg/mL (p < 0.001), the growth of S. typhimurim was significantly inhibited at 24 hr after incubation compared to that of untreated bacteria. With the results of this study, AGE can be used as alternative to antibiotics and chemical food preservatives.

Study on Online Monitoring of Dissolved Oxygen, pH and Cell Concentration in E. coli Cultivation Processes Using MABOOMSTM (마이크로플레이트 기반 생물반응기 시스템 (MABOOMSTM)을 이용한 대장균 배양공정에서 용존산소, pH 및 세포농도의 온라인 모니터링 연구)

  • Sohn, Ok-Jae;Rhee, Jong Il
    • KSBB Journal
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    • v.28 no.1
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    • pp.24-30
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    • 2013
  • Dissolved oxygen, pH and cell concentration have been online monitored in cultivation processes with Escherichia coli by using a $MABOOMS^{TM}$ (microplate-based bioreactor with optical online monitoring systems). Fluorescent sensing membranes containing Ru ${(dpp)_3}^{2+}$ or HPTS were prepared with GA sol-gel matrix and coated into a well of a 24-well microplate. Fluorescence intensity was measured and correlated to the dissolved oxygen or pH. Cell concentrations were also online monitored by measuring optical reflectance at 650 nm. A well of a 24-well microplate could also be divided into 4 parts, each of which was coated with fluorescent sensing membranes for the detection of dissolved oxygen or pH. The 24-well microplate coated with fluorescent sensing membranes or a 4-divided sensing membrane. was used to online monitor the dissolved oxygen, pH and cell concentration during E. coli cultivations. The online monitoring results showed the characteristics of cell growth in cultivation processes very well.

On-line monitoring of microorganism cultivation processes using optical sensing membranes for simultaneous detection of dissolved oxygen and pH (용존산소와 pH의 동시 검출용 광학 센서 막을 이용한 미생물 발효공정의 온라인 모니터링)

  • Kim, Chun-Kwang;Rhee, Jong-II
    • KSBB Journal
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    • v.24 no.1
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    • pp.106-112
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    • 2009
  • An optical sensing membrane has been fabricated to measure the concentration of dissolved oxygen(DO) and pH value simultaneously. It has employed HPTS as a pH sensitive dye and a ruthenium(II) complex as a DO sensitive dye. The sensing membrane has been applied to wells in a 24-well microtiter plate. Using the 24-well microtiter plate the concentrations of dissolved oxygen and pH values have been on-line monitored during the cultivations of E.coli DH5${\alpha}$, B.cereus 318 and P.pastoris X-33. On-line monitoring of DO and pH in microorganism cultivation processes showed good performance of the sensing membrane containing 5 mM HPTS and 2 or 5 mg/mL Rudpp.

Effects of Freeze-Drying Time on Quality of Freeze-Dried Kimchi (동결건조 시간이 동결건조김치의 품질에 미치는 영향)

  • Ko, Young-Tae;Kang, Jung-Hwa
    • Korean Journal of Food Science and Technology
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    • v.34 no.1
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    • pp.91-95
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    • 2002
  • Effects of freeze-drying time on the microbiological, sensory, and other characteristics of freeze-dried kimchi were investigated to optimize freeze-drying time for kimchi. Quality attributes of freeze-dried kimchi, including number of lactic acid bacteria (LAB), pH, sensory properties, brittleness, rehydration property, moisture content, and microstructure of Chinese cabbage were observed for 24, 48 and 72 h, respectively. Number of LAB and pH of the kimchi freeze-dried for 24 h were significantly changed in comparison with those of the kimchi not freeze-dried. However, further freeze-drying did not change markedly number of LAB and pH. Overall acceptability of the sample freeze-dried for 48 of 72 h was better than that of the sample freeze-dried for 24 h. As freeze-drying time increased, brittleness of the dried sample increased, and rehydration property was improved while dried weight and moisture content of the sample decreased. In conclusion, the sample freeze-dried for 48 h was better than the sample freeze-dried for 24 or 72 h, based on sensory properties and other characteristics.

The effects of PPARβ/δ overexpression on PGC-1α mRNA and protein stability after accute endurance exercise in mice skeletal muscle (생쥐의 골격근에 PPARβ/δ 과발현이 1회 지구성 운동 후 안정시 PGC-1α mRNA와 단백질 안정성에 미치는 영향)

  • Koh, Jin-Ho;Jung, Su Ryun;Kim, Ki-Jin
    • 한국체육학회지인문사회과학편
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    • v.55 no.4
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    • pp.507-516
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    • 2016
  • The purpose of this study is to identify the effects of PPARβ/δ over-expression on PGC-1α mRNA and protein stability after single bout of swimming exercise in mice skeletal muscle. Empty vector (EV) or PPARβ/δ was over-expressed in tibialis anterior(TA) using electroporation(EPO) technique to compare with non-treatment muscle(control; Con). TA muscles were dissected at 0h, 24h or 54h after termination of exercise. PGC-1α mRNA in Con, EV and PPARβ/δ over-expressed muscles were increased 6.8 fold (p<.001), 6.2 fold(p<.001) and 7.1 fold(p<.001), respectively, than sedentary(Sed) group at 0h after exercise and then reverted to Sed group levels at 24h and 54h after termination of exercise. PGC-1α and PGC-1α ubiquitination in EV treated muscles were increased 2.2 fold and 1.74 fold, respectively, than Sed group at 24h after termination of exercise, and then reverted to Sed group levels at 54h after termination of exercise. PGC-1α in PPARβ/δ over-expressed muscles at 24h and 54h after termination of exercise were increased 2.5 fold and 2.2 fold, respectively, than Sed group, but PGC-1α ubiquitination was not increased at 24h and 54h after termination of exercise. Our results indicate that PPARβ/δ over-expression does not increase PGC-1α mRNA stability, but increase PGC-1α protein stability through post-translation mechanism after termination of exercise.