• 한국작물학회지
• /
• 제36권1호
• /
• pp.22-33
• /
• 1991

간장이 다른 수도 2품종에 대하여 NaCl, KCl, Mannitol을 처리하고 잎의 신장과 광합성능의 반응을 조사하였다. 그리고 염처리에 의하여 잎의 신장이 일시적으로 정지하고 신장률이 둔화되는 현상 및 높은 농도에서 광합성능이 저하되는 원인에 대하여 고찰하였다.

• The Korean Journal of Pain
• /
• 제22권3호
• /
• pp.199-205
• /
• 2009

Background: A major ingredient of green tea is epigallocatechin-3-gallate (EGCG), and this is known to have many beneficial effects for cancer prevention and also on the cardiovascular system and neurodegenerative diseases through its anti-oxidant, anti-angiogenic, anti-inflammatory, lipid-lowering and neuroprotective properties. Its actions on nociception and the spinal nervous system have been examined in only a few studies, and in these studies EGCG showed an antinociceptive effect on inflammatory and neuropathic pain, and a neuroprotective effect in motor neuron disease. This study was performed to investigate the effect of EGCG on acute thermal pain and the development of morphine tolerance at the spinal level. Methods: The experimental subjects were male Sprague-Dawley rats and the Hot-Box test was employed. A single or double-lumen intrathecal catheter was implanted at the lumbar enlargement for drug administration. An osmotic pump was used to infuse morphine for 7 days for induction of morphine tolerance. EGCG was injected repeatedly for 7 days at twice a day through the intrathecal catheter. Results: Intrathecal EGCG increased the paw withdrawal latency (PWL) after repeated administration for 7 days at twice a day, but this did not happen with administering on single bolus injection of EGCG. In addition, the antinociceptive effect of intrathecal morphine was not affected by co-administration with EGCG. A continuous 7-day infusion of morphine caused a significant decrease of the PWL in the control group (M + S, morphine plus saline). In contrast, intrathecal EGCG injection over 7 days blocked the decrease of the PWL in the experiment group (M + E, morphine plus EGCG). Conclusions: Intrathecal ECGC produced a weak antinociceptive effect for acute thermal pain, but it did not change the morphine's analgesic effect. However, the development of antinociceptive tolerance to morphine was attenuated by administering intrathecal EGCG.

• 한국태양에너지학회 논문집
• /
• 제32권5호
• /
• pp.118-123
• /
• 2012

Water balance has a significant impact on the overall fuel cell performance. Maintenance of proper water management should provide an adequate membrane hydration and avoidance of water flooding in the catalyst layer and gas diffusion layer. Considering the important of advanced water management in PEM fuel cell, this study proposes a simple one dimensional water transportation model of PEM fuel cell for use in a dynamic condition. The model has been created by assumption that the output is the water liquid saturation difference. The liquid saturation change is the total difference between the additional water and the removal water on the system. The water addition is obtained from fuel cell reaction and the electro osmotic drag. The water removal is obtained from capillary transport and evaporation process. The result shows that the capillary water transport of low temperature fuel cell is high because the evaporation rate is low.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권11호
• /
• pp.1501-1508
• /
• 2004

In this study the effect of extenders and temperatures on sperm viability and fertilizing capacity of boar sperm during long-term storage was investigated. Acrosomal integrity, membrane integrity, motility and hypo-osmotic resistance were evaluated by fluorescence and light microscopy. An in vitro fertilization test was performed to assess the fertilizing capacity of stored spermatozoa. The five diluents tested were ranked according to their ability to maintain sperm functional parameters and Zorlesco (ZO) extender with BSA or with PVA instead of BSA produced the best results. Zorlesco extender substituted with PVA (ZO+PVA) was found to maintain motility both at 15 and 20$^{\circ}C$. within 5 days of storage, but the quality of semen stored at 15$^{\circ}C$ decreased thereafter as compared to semen stored at 20$^{\circ}C$ Semen stored at 5$^{\circ}C$ demonstrated rapid loss of motility already within 24 h. Both fertilization and cleavage of semen stored at 20$^{\circ}C$ in ZO substituted with PVA instead of BSA did not change significantly until day 8 of storage. It is therefore concluded that PVA can be used to substitute for BSA and 20$^{\circ}C$ was more suitable than 15$^{\circ}C$ for boar semen storage, and in vitro fertilizing capacity of spermatozoa was maintained for at least 8 days in ZO+PVA at 20$^{\circ}C$.

• 멤브레인
• /
• 제30권5호
• /
• pp.293-306
• /
• 2020

물 부족을 포함한 기후 변화의 해로운 결과는 효과적인 정수에 대한 관심을 가져왔다. 또한, 수질 오염 수준이 높아지고 환경 파괴 수준이 심해지면서 오염 물질을 제거하려는 방안들이 요구되고 있다. 물을 정화하기 위해 반투막을 통한 삼투압 절차들을 사용할 수 있으며, 최근 연구에 따르면 탄소 양자점(CQD), 그래핀 양자점(GQD) 및 산화 그래핀 양자점(GOQD)을 포함한 나노입자를 복합 박막(TFC)에 합체하면 유사한 수준의 염 거부율을 유지하면서 물흐름을 증가시킬 수 있다. 이러한 효과 외의 여러 가지 효과가 있지만 그 중에서도 친수성을 높이고, 살균 성질을 보이고, 방오 특성으로 인해 박테리아 및 기타 미생물의 축적을 방지하면서 막의 효과가 감소하는 것을 막는 것을 보여준다. 이 보고서는 양자점이 합체된 정수용 복합 막에서 양자점의 제조 과정, 응용, 기능성, 성질 및 역할을 논의한다.

• 한국식품영양학회지
• /
• 제29권5호
• /
• pp.808-817
• /
• 2016

In this study, we investigated the effects of pre-soaking in salt and sugar solution prior to air drying at $50^{\circ}C$ on the characteristics of dried apples. Pre-soaking solutions included single solutions of salt 2% and sugar 2%; and combined solutions of salt 2%+sugar 2% and salt 2%+sugar 5%, respectively. The effects of pre-soaking condition and drying were evaluated in terms of moisture content (MC), water activity, color, antioxidant activity determined by DPPH radical scavenging activity, shear force, microbial contents, and sensory evaluation of apple slices. The control sample without pre-soaking showed the most rapid drying rate; in addition, the single solutions showed higher MC and water activity after drying time of 120 min, as compared to combined solutions. In all samples, MC and water activity showed high correlation coefficients of 0.91 to 0.97; whereas, shear force was negatively correlated with MC and water activity. The single solution of salt 2% showed decrease in change of color, including L, a, and b values, and the number of aerobic bacteria during drying. In addition, highest antioxidant activity and values of sensory preferences were observed in the dried apple pre-soaked in single solution of salt 2%.

• 폴리머
• /
• 제26권4호
• /
• pp.468-476
• /
• 2002

순수한 PAN 섬유의 예비산화와 가수분해의 과정을 통하여 제조된 oxy-PAN은 염기와 산용액에 담그었을 때 신장과 수축 거동을 보임이 알려져 있다. 본 연구에서는, 염기 (NaOH) 용매에서 약 30%의 신장과 산 (HCl) 용매에서 30∼50%의 수축 거동을 관찰하였다. 기계적 특성에 대한 실험에서, oxy-PAN 섬유가 수축되었을 때 향상된 기계적 특성을 나타내었다. 이러한 거동과 기계적 특성은 인체의 근육과 선형 구동체의 그것들과 유사하였다. NaOH와 HCl 용액에서 oxy-PAN 섬유의 길이가 변화하는 중요한 요인으로는 친수화 또는 소수화 구조의 전환에 의한 영향이다. 다른 요인으로는 oxy-PAN 섬유와 용액간의 이온과 물의 교환, 이온의 농도차에 의한 삼투압 등이 영향을 준다. Oxy-PAN 섬유의 신장 및 수축과 기계적 특성에 영향을 미치는 여러 가지 요인들을 규명하기 위한 보다 많은 연구가 필요하지만, 본 연구실에서 제조된 oxy-PAN 섬유가 인공 근육 및 선형 구동체로 적용될 수 있는 충분한 가능성이 있음을 제시한다.

• 한국동물학회지
• /
• 제38권4호
• /
• pp.570-579
• /
• 1995

담수산과 해수에 적응된 guppy 아가미 상피내 점액세포의 미세구조를 주사 및 투과 전자현미경으로 관찰하고, 점액질 조성의 변화를 조직화학적으로 분석하여 다음의 결과를 얻었다. 점액세포는 아가미궁에서 돌출되어 형성된 일차층판상피에 주로 위치하였다. 미성숙점액 세포에는 과립형질내세망과 Golgi 복합체가 잘 발달되어 있었으며, 성숙 점액세포는 거의 점액과립들로 가득 채워져 있었다. 담수산 guppy 아가미 상피내 점액세포의 점액질은 중성점액질과, 산성점액질인 sialomucin 및 sulfomucin을 다량 포함하고 있었으며, 바닷물에 적응시킨 경우에서는 sialomucin과 sulfomucin이 약간 감소하였다. 바닷물에 적응된 guppy의 아가미 상피내 점액세포의 수는 담수산과 비교하여 3배이상 감소하였다. 이는 서식환경을 해수로 옮긴 결과, 변화된 삼투적 스트레스에 대응한 결과일 뿐 아니라 담수보다는 높은 염분농도인 해수환경의 감소된 감염기회와도 연관된 결과라고 생각된다.

• 병원약사회지
• /
• 제35권4호
• /
• pp.430-440
• /
• 2018

Background : Hyponatremia is the most common electrolyte disturbance in hospitalized patients and has been associated with increased morbidity and mortality. Tolvaptan, a vasopressin receptor antagonist, is increasingly used for the treatment of euvolemic and hypervolemic hyponatremia. The aim of this study was to evaluate the effectiveness and safety of tolvaptan for the management of hyponatremia. Methods : This study was a retrospective evaluation of 106 patients who received at least one dose of tolvaptan for hyponatremia at a single tertiary academic hospital between January 2014 and June 2015. The primary endpoint was the change in serum sodium concentration after tolvaptan administration within 24 hours, with secondary endpoints of overcorrection and adverse effects. Results : The mean initial dose of tolvaptan was $20.2{\pm}7.2mg$ and the median duration of treatment was 15 days (range, 1-261 days). The maximal changes in sodium levels at 24 and 48 hours were $8.2{\pm}4.7mmol/L$ and $10.5{\pm}15.3mmol/L$, respectively. Of 99 patients in whom sodium concentrations were followed up, sodium overcorrection was observed in 26 (26.3%) patients, which was associated with concomitant use of an enzyme inhibitor (odds ratio [OR] = 4.80, 95% Cl: 1.27-18.15). However, sex, body mass index (BMI), serum albumin, a daily dose of tolvaptan, and concomitant use of hypertonic saline did not show any significant difference in overcorrection. The most commonly reported adverse effects were mild and related to aquaresis, such as polyuria, thirst, and constipation. However, severe adverse effects such as hyperkalemia, hypotension, and one death related to osmotic demyelination were also reported. Conclusions : Tolvaptan is effective for treating hyponatremia. Nevertheless, the drug should be used cautiously due to serious adverse effects related to sodium overcorrection.

• 한국식품영양학회지
• /
• 제19권4호
• /
• pp.358-365
• /
• 2006

두께 1 mm의 감자 절편을 분자량 200에서 6000까지의 PEG용액에 침지했을 때 PEG의 분자량이 작을 수록 초기 탈수 속도가 빨랐으나 최종 탈수량은 PEG 분자량이 클수록 증가하여 PEG 6000인 경우 초기수분의 약 80%까지 탈수되었다. 감자절편을 저분자 용액인 NaCl, PEG400 용액에 침지한 경우, 조직의 뒤틀림 현상은 나타나지 않고 plasmolysis가 일어나면서 탈수와 부피가 감소되는 반면, PEG 600 용액에 침지시부터 조직의 뒤틀림 현상이 동반된 탈수 현상이 나타났으며, 고분자 용액인 PEG 4000 용액에 침지한 경우 cytonhysis 현상을 동반한 탈수와 부피 감소가 더욱 분명하게 관찰되었다. 초기 탈수 속도는 저분자 용액에 침지 시 더 빨랐으나 최종 탈수량은 고분자용액에 침지 시 더 컸으며 탈수량이 역전되는 시기는 cytorrhysis가 일어나는 시기와 일치하였다. 따라서 고분자 용질의 고농도 용액에 시료를 침지하면 용질의 함침량은 적게 하면서 탈수량을 증가시킬 수 있음을 알 수 있었다.