• 한국식품과학회지
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• 제24권5호
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• pp.482-491
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• 1992

천연 다당류 고무질을 식품에 확대 이용하고자, sodium alginate, gum karaya 및 gum arabic을 가지고 pH 및 농도별로 SPI에 작용시켜 거품특성을 실험하였다. 표면장력은 3종의 고무질을 농도별로 첨가시 전체적으로 SPI의 등전점(pH 4.5) 부근인 pH 4.0 및 5.0에서 각각 $39.9{\sim}44.1$ 및 $41.7{\sim}44.8\;dyne/cm$이었고, pH 7.0 및 8.0에서는 각각 $43.9{\sim}46.4$ 및 $44.6{\sim}46.9\;dyne/cm$로써 전체적으로 대조구보다 다소 높았으며 pH 4.0 및 5.0에서가 pH 7.0 및 8.0에서 보다 다소 낮았다. 비점도는 pH 7.0 및 8.0에서 전체를 통하여 각각 $3.6{\sim}51.8$ 및 $4.0{\sim}51.2$이었으며, 특히 sodium alginate를 농도별로 첨가 시 pH 7.0 및 8.0에서 각각 $11.5{\sim}51.8$ 및 $10.1{\sim}51.2$로써 대조구에 비하여 크게 증가하였다. 거품형성능(overrun)은 15분 whipping시, 고무질의 종류 및 농도에 따라 pH 4.0 및 5.0에서 각각 $965.7{\sim}1689.0$ 및 $1182{\sim}1413%$이었고, pH 7.0 및 8.0에서 각각 $804.7{\sim}1018.0$ 및 $795.0{\sim}962.3%$로써 전체적으로 대조구보다 낮았으며 pH 4.0 및 5.0에서가 pH 7.0 및 8.0에서보다 높았다. 거품안정성(drainage)은 고무질 종류 및 농도에 따라 pH 4.0(대조구, 66.8분) 및 5.0(대조구, 53.4분)에서 각각 $22.7{\sim}41.41 및 $41.5{\sim}83.8$분이었고, pH 7.0(대조구, 20.4분) 및 8.0(대조구, 19.7분)에서 각각 $18.2{\sim}104.7$ 및 $21.0{\sim}84.6$분이었으며, 특히 sodium alginate 첨가시 효과가 현저하였으며 0.2% 첨가시 pH 5.0, 7.0 및 8.0에서 각각 대조구의 57, 413 및 315% 증진되었다. 거품의 열안정성은 15분 whipping시, pH 4.0(대조구, 30.2%) 및 5.0(대조구, 23.7%)에서 각각 $0{\sim}38.0$ 및 $0{\sim}57.0%$이었고 pH 7.0(대조구, 39.6%) 및 8.0(대조구, 43.6%)에서 각각 $0{\sim}59.4$ 및 $36.6{\sim}58.4%$이었으며 sodium alginate 첨가시가 가장 양호하였다. 전체적으로 보아 거품안정성이 높은 것은 열안정성도 높은 경향이며, 표면장력이 낮으면 거품형성능이 높아지고, 비점도가 높으면 거품안정성 및 열안정성이 높아지는 경향이 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3011-3015
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• 2013

Objective: This study aimed to investigate the expression of B7-H4 in human thyroid cancer and determine any association with patient clinicopathological parameters and survival. Methods: B7-H4 expression in 64 clinical thyroid cancer specimens was assessed with immunohistochemistry. Moreover, B7-H4 mRNA expression in 10 fresh resected specimens were evaluated by the reverse transcription-polymerase chain reaction (RT-PCR). Immunohistochemical staining of CD3 was performed to assess the number of tumor infiltrating T lymphocytes (TILs) in thyroid cancers. Results: Positive B7-H4 immunohistochemical staining was observed in 61 out of 64 (95.3%) specimens of thyroid cancer tissues. Significantly more B7-H4 mRNA copies were found in thyroid cancer tissue than that adjacent normal tissue. Moreover, B7-H4 expression in human thyroid cancer tissues was significantly correlated with patient TNM stages and extrathyroidal extension (P<0.05), being inversely correlated with the number of TILs (P<0.05). The overall survival rate of the patients with higher B7-H4 expression was significantly worse than that of the patients with lower B7-H4 expression. Conclusions: This present study suggests that high B7-H4 expression is associated with cancer progression, reduced tumor immunosurveillance and worse patient outcomes in human thyroid cancer.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.113-117
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• 1993

Good yield synthetic routes for the production of new B-alkyl-dithiaborane clusters are reported. The syntheses of the B-alkyl-dithiaboranes are based on the use of Fischer-type carbene reagents to activate the B-H bonds of dithiaborane for alkyl-addition reactions and are the first examples of transition-mediated reactions of dithiaborane to be reported. Thus, reactions employing arachno-$S_2B_7H_8$- and $(CO)_5M{C(R_1)R_2}$ (M = Cr, W; $R_1 = CH_3,\;C_6H_5;\; R_2 = OCH_3,\;SC_6H_5)$ were found to yield the intermidiate anions I, $[(CO)_5M{C(R_1)R_2S_2B_7H_8}]^-$, which upon protonation gave the corresponding neutral, air-sensitive cluster arachno-4-$RCH_2-6,8-S_2B_7H_8(R=CH_3,\;IIa;\;C_6H_5,\;IIb)$ range from 30 to 35% yield. Complexes IIa and IIb are isoelectronic with arachno-6,8-$S_2B_7H_9$ and, on the basis of the spectroscopic data, are proposed to adopt a similar arachno cage geometry in which an $RCH_2$ units are substituted to 4 position boron atom of the arachno-6,8-$S_2B_7H_9$.

• Asian-Australasian Journal of Animal Sciences
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• 제20권2호
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• pp.200-207
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• 2007

In vitro rumen incubation studies were conducted to determine effects of initial pH on bacterial attachment and fiber digestion. Ruminal fluid pH was adjusted to 5.7, 6.2 and 6.7, and three major fibrolytic bacteria attached to rice straw in the mixed culture were quantified with real-time PCR. The numbers of attached and unattached Fibrobacter succinogenes, Ruminococcus flavefaciens and Ruminocococcus albus were lower (p<0.05) at initial pH of 5.7 without significant difference between those at higher initial pH. Lowering incubation media pH to 5.7 also increased bacterial numbers detached from substrate regardless of bacterial species. Dry matter digestibility, gas accumulation and total VFA production were pH-dependent. Unlike bacterial attachment, maintaining an initial pH of 6.7 increased digestion over initial pH of 6.2. After 48 h in vitro rumen fermentation, average increases in DM digestion, gas accumulation, and total VFA production at initial pH of 6.2 and 6.7 were 2.8 and 4.4, 2.0 and 3.0, and 1.2 and 1.6 times those at initial pH of 5.7, respectively. The lag time to reach above 2% DM digestibility at low initial pH was taken more times (8 h) than at high and middle initial pH (4 h). Current data clearly indicate that ruminal pH is one of the important determinants of fiber digestion, which is modulated via the effect on bacterial attachment to fiber substrates.

• 문화기술의 융합
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• 제8권6호
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• pp.927-933
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• 2022

한 분자 내에 여러 가지 히드록시기가 존재 할 때, 특정 히드록시기만을 선택적으로 산화시키는 산화제는, 알코올을 포함한 유기화학 합성과정에서, 벤질알코올, 알릴알코올, 일차알코올, 이차알코올들이 있을 때, 특정 알코올만을 선택적으로 산화시키는 산화제로 사용할 수 있다. 우리는 (C₁₀H₈N₂H)₂Cr₂O₇을 합성하여, 적외선(FT-IR)과 원소분석 등으로 구조를 확인하였다. 유기용매들에서, (C₁₀H₈N₂H)₂Cr₂O₇을 이용하여 벤질알코올의 산화반응을 측정한 결과, 유기용매의 유전상수 값이 커짐에 따라 반응성이 증가했다. DMF, acetone 용매에서 (C₁₀H₈N₂H)₂Cr₂O₇을 이용하여알코올들의 산화반응을 측정한 결과, 벤질알코올, 알릴알코올, 일차알코올 및 이차알코올들을 알데히드나 케톤(65%~95%)으로 전환시키는 효율적인 산화제였다. DMF, acetone 용매에서 (C₁₀H₈N₂H)₂Cr₂O₇을 이용하여 알코올 혼합물들의 산화반응성을 측정한 결과, 이차알코올들이 있을 때, 벤질알코올, 알릴알코올, 일차알코올들을 선택적으로 산화(15%~95%) 시켰다. H₂SO₄ 촉매를 첨가 후, DMF 용매에서, (C₁₀H₈N₂H)₂Cr₂O₇은 벤질알코올과 그의 유도체들을 효과적으로 산화시켰다. Hammett 반응상수(ρ) 값은 -0.69(308K) 이었다. 본 실험에서 알코올의 산화반응 과정은 속도결정단계에서 수소화 전이가 일어났다.

• KSBB Journal
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• 제13권2호
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• pp.168-173
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• 1998

Gamma irradiated and non-irradiated Agrimonia pilosa Ledebour were extracted by 70% ethanol. The combined effects of the Agrimonia pilosa Ledebour extract and NaCl on survival of Escherichia coli O157:H7 in tryptic soy broth were investigated. E. coli O157:H7 decreased ca 1 log cycle by the addition of 2% sample extract, and the anthbacterial activity was increased as the concentration of sample extract was increased. The irradiation effect of the sample on antibacterial activity was not observed. On the treatment of NaCl alone, E. coli O157:H7 was inactivated (ca 3~4 log cycle reduction within 48 hr) in more than 7% NaCl. The higher inactivation(ca 5 log cycle reduction within 48 hr) occurred in the presence of 2% sample extract and 5% NaCl than in the addition of each alone. The extracted antibacterial substance was stable in the pH range of 4.0 to 7.0, heat treatment at 121$^\circ C$ for 15 min, and freezing at -18$^\circ C$ and thawing at 37$^\circ C$. There fore, the sample extract, would substantially increase the food-safety in terms of E. coli O157:H7.

• 한국식품위생안전성학회지
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• 제12권4호
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• pp.304-309
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• 1997

A study was undertaken to determine the thermal inactivation of Escherichia coli O157:H7 as influenced by the effects of temperature, time, suspension medium and ascorbate. Tryptic soy broth was more heat resistant than pfosphate buffer (pH 7.1), with D values of 1.52~1.68 min at 6$0^{\circ}C$ and 1.51~1.63 min at 7$0^{\circ}C$ compared with 1.52~1.65 min at 6$0^{\circ}C$ and 1.26~1.61 min at 7$0^{\circ}C$ for phosphate buffer as suspension medium. E. coli O157:H7 was completely inhibited within 30 min when small inoculum (106 CFU/$m\ell$) was heated at 7$0^{\circ}C$. When E. coli O157:H7 was preheated at 48$^{\circ}C$ for 60 min in phosphate buffer before heating, D values were 1.28~1.60 min at 6$0^{\circ}C$, and 1.13~1.56 min at 7$0^{\circ}C$, showing that preheating increases the heat resistance of the strain. Phosphate buffer containing ascorbate (0.001 M) was enhanced the thermal inactivation of the strain when inoculated as large inoculum (109 CFU/$m\ell$), while ascorbic acid was no effect at low cell concentrations (109 CFU/$m\ell$).

• KSBB Journal
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• 제5권4호
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• pp.355-363
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• 1990

서울 인근의 생활하수에서 메탄올을 이용하는 박테리아를 분리하였다. 이의 최적 성장을 위한 온도 및 pH는 각각 $33^{\circ}C$ 및 7.1이었다. 최대비성장율은 $0.42hr^{-1}$을 나타내었다. 최소 배지조성은 기본배지의 양을 안정상테에서 연속발효법으로 구하였으며, 그 조성은 다음과 같다(g / l); Methanol 40, $(NH_4)_2\;SO_42,\;KH_2PO_4\;1.5,\;K_2HPO_4\;0.2,\;H_3PO_4\;0.79,\;Na_2HPO_4{\cdot}12H_2O\;0.15,\;MgSO_4{\cdot}7H_2O\;1.5,\;FeSO_4{\cdot}7H_2O\;0.034,\;MnSO_4{\cdot}4H_2O\;0.005,\;CuSO_4{\cdot}5H_2O\;0.0027,\;CaCl_2{\cdot}2H_2O\;0.25,\;ZnSO_4{\cdot}7H_2O\;0.007,\;(NH_4)_6\;Mo_7O_{24}{\cdot}4H_2O\;0.00048,\;H_3BO_3\;0.00068,\;CoCl_2\; 0.00024$ 최적 배지 조건에서 구한 최대 세포생산성은 3.8g / l / hr였으며, 이때의 회석율은 $0.23hr^{-1}$이었다. 최대 세포농도와 그대의 단백질의 함량은 각각 19.5g / l 및 70%였으며, 이때의 회석율은 $0.1hr^{-1}$이었다.

• 한국식품조리과학회지
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• 제5권2호
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• pp.9-17
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• 1989

This study was carried out in order to study the emulsifying properties of kidney bean protein isolate. Kidney bean protein isolate was tested for the purpose of finding out the effect of pH, addition of NaCl, and heat treatment on the solbulity and emulsion capacity, emulsion stability, surface hydropobicity and emulsion viscosity. The results were summarized as follows. 1 The solubility of kidney bean protein isolate was affected by pH and showed the lowest value at pll 4.5 which is isoelectric point of kidney bean isolate. When the kidney bean protein isolate was heated, the highest value observed at pH 2 and pH 7 was 96.11%, 97.41% respectively. 2. The emulsion capacity of kidney bean protein isolate was not significantly different with each pH. With addition of NaCl, emulsion capacity decreased steadily. When heated thr highest value observed at pH 2 and pH 7 was 82.91 ml oil/100 mg protein ($60^{\circ}C$), 82.08 m1 oil/100 mg protein ($80^{\circ}C$) respectively. 3. The emulsion stability was significantly higher at pH 4.5 than that of pH 2 and pH 7 (p 0.05) When NaCl was added, emulsion stability was generally increased after 2hrs. When heated, the highest value observed at pH 2 and pH 7 was 21.25% ($80^{\circ}C$),23.7%($100^{\circ}C$) respectively after 2hrs. 4. Surface hydrophobicity increased sharply as 0.2 M NaCl was added to pH 4.5. When heated, the surface hydrophobicity increased as the temperature increased. 5. The highest value of emulsion viscosity was observed at pH 4.5 and pH 7 when 0.2 M NaCl was added. Under heat treatment, the highest value was 48,000 cps at pH 4.5 ($40^{\circ}C$). In the case of pH 7, the highest value was 105,000 cpa at $100^{\circ}C$.

• 대한환경공학회지
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• 제35권1호
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• pp.17-22
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• 2013

본 연구는 조류 개체 수 증가로 pH가 급격하게 상승한 원수가 정수장으로 유입될 때 pH 조정을 위해 사용하는 이산화탄소($CO_2$) 주입이 응집효율 및 용존 알루미늄 농도변화에 미치는 영향을 고찰하였다. 응집제 1 mg/L에 주입에 따른 pH 감소는 LAS -0.0384, PAC -0.0254, A-PAC -0.0201, PACS2 -0.0135로 나타났다. 용존 알루미늄 농도는 pH 7.44에서 0.02 mg/L, pH 7.96에서 0.07 mg/L, pH 8.16에서 0.12 mg/L, pH 8.38에서 0.39 mg/L로 응집공정의 pH 증가에 따라 용존 알루미늄 농도가 증가하는 것으로 나타났다. 여기서 주목할 점은 급속 교반 후 pH 8.0을 초과할 때부터 용존 알루미늄 농도는 급격하게 증가하는 것이다. 그러므로 높은 pH의 원수가 유입되는 정수장에서 알루미늄 농도가 먹는 물 수질 기준 만족하기 위해서는 응집공정의 pH가 7.8 이하로 유지되도록 공정관리가 필요하며, 원수 pH가 8.0 이상 유입되는 경우 이산화탄소($CO_2$) 주입으로 pH를 7.3 내외로 일정하게 유지할 수 있었다. 또한 이산화탄소($CO_2$) 주입으로 응집공정에서 pH를 조정함으로써 탁도 및 응집제 절감, 용존 알루미늄 농도 감소 효과를 확인할 수 있었다.