Hydrogen peroxide (H2O2) is widely used in bleaching treatments in the pulp and paper industry, in wastewater treatment, and as a food additive. However, H2O2 solutions are unstable and decompose slowly when subjected to external factors such as light, high temperatures, or metal compounds. Therefore, a simple and reliable method to measure the concentration of H2O2 is required for its proper use in various applications. We determined the concentration of an H2O2 solution by measurement at a single wavelength (249 nm) without any reagents or complex analytical procedures. In the present work, the measurable concentration of H2O2 was as low as 0.015 wt% (4.41 mM) and as high as 0.300 wt% (88.2 mM), with high linearity (99.99% at 249 nm) between the concentration of H2O2 and the optical density (OD) values. In addition, the method could be used to measure the concentration of H2O2 in a peracetic acid solution without interference from acetic acid and peracetate ion.

This study evaluated a potential sterilization process that uses calcium hypochlorite (Ca(ClO)2) as a disinfectant and hydrogen peroxide (H2O2) as a neutralizing agent for monoculture processes of microalgae (Nannochloropsis oculata). The results showed that no contaminants (prokaryote) were present when the Ca(ClO)2 concentration was greater than 0.010%. The use of an equivalent amount of H2O2 completely neutralized Ca(ClO)2 and had an additional bactericidal effect because of the formation of singlet oxygen. No substantial difference was observed in the biomass accumulation and chlorophyll contents compared to those in cultures sterilized using conventional physical methods such as autoclaving. Therefore, chemical sterilization using Ca(ClO)2 and H2O2 has an excellent economic advantage, and we expect the proposed ecofriendly chemical sterilization method to become a critical culture technology for microalgae-related industrialization.

산화적 스트레스는 세포 및 조직 손상을 통해 피부의 탄력 및 보습 기능 저하, 피부 노화 촉진 을 비롯한 다양한 피부질환을 일으킨다. 본 연구의 목적은 인간 피부각질세포 (HaCaT keratinocyte)에서 산화적 스트레스에 대한 붉은 토끼풀 추출물의 효능을 검토하여, 피부에 효과적으로 사용할 수 있는 기능 성 소재로서의 활용 여부를 확인하고자 하였다. 본 연구에서는 붉은 토끼풀 추출물이 인간 피부각질세포에 서 산화적 스트레스에 따른 세포사를 억제시키는 것을 확인하여, 이를 조절하는 보호기전을 규명하였다. 이는 붉은 토끼풀 추출물이 Caspase-3 비활성, 세포사 촉진단백질 Bax 발현 억제, 세포생존 촉진단백질 Bcl-2 발현 증가 및 MAPK 신호전달계 단백질의 인산화 억제를 통해 H2O2에 의해 유도된 산화적 스트레 스를 보호할 수 있다는 것을 확인하였다. 따라서 붉은 토끼풀 추출물은 피부의 산화적 손상을 감소시키는 유용한 소재로 평가되며, 이는 피부보호 및 미용을 위한 다양한 제품 및 산업에 활용 가능성이 높은 것으로 판단된다.

Cerium oxide decorated on nickel hydroxide anchored on reduced graphene oxide (Ce-Ni(OH)2/rGO) composite with hexagonal structures were synthesized by facile hydrothermal method. Fourier transform infrared spectroscopy (FT-IR), highresolution transmission electron microscopy with selected area diffraction (HRTEM-SAED), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer– Emmett–Teller (BET) surface area analysis and electrochemical technology were used to characterize the composite. Due to its unique two-dimensional structures and synergistic effect among Ce2O3, Ni(OH)2 and rGO components indicated twodimensional hexagonal nano Ce-Ni(OH)2/rGO composite is promising electrode material for improved electrochemical H2O2 sensing application. From 50 to 800 μM, the H2O2 concentration was linearly proportional to the oxidation current, with a lower detection of limit of 10.5 μM (S/N = 3). The sensor has a higher sensitivity of 0.625 μA μM−1 cm− 2. In addition, the sensor demonstrated high selectivity, repeatability and stability. These findings proved the viability of the synthetic method and the potential of the composites as a H2O2 sensing option.

This study was conducted to evaluate the degradation and mineralization of PPCPs (Pharmaceuticals and Personal Care Products) using a CBD(Collimated Beam Device) of UV/H2O2 advanced oxidation process. The decomposition rate of each substance was regarded as the first reaction rate to the ultraviolet irradiation dose. The decomposition rate constants for PPCPs were determined by the concentration of hydrogen peroxide and ultraviolet irradiation intensity. If the decomposition rate constant is large, the PPCPs concentration decreases rapidly. According to the decomposition rate constant, chlortetracycline and sulfamethoxazole are expected to be sufficiently removed by UV irradiation only without the addition of hydrogen peroxide. In the case of carbamazepine, however, very high UV dose was required in the absence of hydrogen peroxide. Other PPCPs required an appropriate concentration of hydrogen peroxide and ultraviolet irradiation intensity. The UV dose required to remove 90% of each PPCPs using the degradation rate constant can be calculated according to the concentration of hydrogen peroxide in each sample. Using this reaction rate, the optimum UV dose and hydrogen peroxide concentration for achieving the target removal rate can be obtained by the target PPCPs and water properties. It can be a necessary data to establish design and operating conditions such as UV lamp type, quantity and hydrogen peroxide concentration depending on the residence time for the most economical operation.

본 연구는 유칼립투스(Eucalyptus pulverulenta) 잎에서 치료적 효과가 큰 α-pinene과 1,8-cineole 함량증가에 미치는 H2O2와 SA 처리의 영향에 대해 알아보기 위하여 수행하였다. 유칼립투스가지를 H2O2 수용액(0.3, 0.5, 1%)과 SA 수용액(0.1, 1mM)에 침지하거나 잎에 엽면살포(0.1mM SA, 1% H2O2)한 뒤 시간흐름(0, 0.5, 1, 2, 4시간)에 따른 α-pinene과 1,8-cineole의 함량변화를 분석한 결과, 침지처리에서 유칼립투스 잎의 α-pinene 함량(mg･L-1)은 0.1mM SA에 2시간 침지 후 1.62에서 5.48로 크게 증가하였으며(238.27%, p=0.012), 1,8-cineole 함량(mg･L-1)은 1mM SA에 4시간 침지 후 44.44에서 78.96으로 크게 증가하였다(77.66%, p=0.026). 살포처리에서는 0.1mM SA를 엽면살포 30분 후 α-pinene 함량(mg･L-1)은 1.62에서 3.91로(141.36%, p=0.007), 1,8-cineole 함량(mg･L-1)은 44.44에서 87.91로 증가하였다(97.82%, p=0.001). α-pinene과 1,8-cineole 모두 살포처리 30분 뒤 크게 증가하여, 엽면살포가 짧은 시간내에 방향화합물을 증가시키는데 침지처리보다 효과적이었으며, H2O2와 SA 처리는 α-pinene과 1,8-cineole의 함량증가에 유의한 영향이 있었다. 또한, SA의 처리가 H2O2보다 방향화합물 함량증가에 더 효과적이었으며, 유칼립투스 가지의 경우 원예치료 2시간 전에 0.1mM SA 용액에 담그거나 30분 전에 잎에 살포하면 monoterpene의 유칼립투스 함량이 크게 증가되었다.

최근 기능성과 친환경 화장품에 대한 관심이 증가하고 있으며, 이에 따라 안전하면서 효능이 우수한 식물 추출물을 활용한 소재 개발이 이루어지고 있는 실정이다. 따라서 본 연구에서도 주로 건강 기능성 소재로써 다양한 효능이 있는 것으로 알려진 그라비올라 추출물이 기능성 화장품 소재로써의 가 능성을 확인하고자 하였다. 그라비올라 추출물의 항산화 활성을 확인하고자 총 폴리페놀과 총 플라보노 이드 함량, DPPH radical 소거 활성을 측정하였고, HDF 세포에서의 세포 독성을 확인한 후 적정 농도 에서 HDF 세포에 과산화수소(H2O2)를 처리하여 산화적 스트레스에 대한 ROS 활성 억제 효과와 세포 보호 효과를 측정하였다. 본 실험 결과, 그라비올라 추출물은 항산화 지표가 되는 총 폴리페놀과 플라보 노이드의 100g당 26.6 mg(CA)/100g, 14.3 mg(CA)/100g의 높은 함량을 확인하였으며, 높은 radical 소 거 활성을 확인하였다. HDF 세포에 대한 세포 생존율을 측정한 결과, 모든 농도에서 유의한 세포 독성 이 나타나지 않았으며, 추후 100 μg/mL 농도에서 실험하였다. H2O2로 유도된 HDF 세포에 ROS 활성 억제를 측정한 결과, 농도 의존적인 ROS 활성 억제 효과를 확인하였고, H2O2를 4 시간, 24 시간, 48 시간 동안 처리 후 그라비올라 추출물의 세포 보호 효과를 측정한 결과, 25 μg/mL 농도에서 24시간까 지 89.92%의 높은 세포 보호 효과를 확인하였다. 이와 같은 결과를 통하여 그라비올라 추출물은 항산 화 활성이 우수하고, HDF 세포에 대한 독성이 거의 없으며, H2O2에 의해 발생하는 활성산소에 대한 효과적인 활성 억제 효과와 세포 보호 효과가 우수한 것으로 확인됨에 따라 항산화 및 세포 보호 효과 를 가진 다양한 기능성 소재로서의 가능성을 확인하였다.

Although anti-aging activities of melatonin, a hormone secreted by the pineal gland, have been reported in senescence-accelerated mouse models and several types of cells, its impact and mechanism on the senescence of human dental pulp cells (HDPCs) remains unknown. In this study, we examined the impact of melatonin on cellular premature senescence of HDPCs. Here, we found that melatonin markedly inhibited senescent characteristics of HDPCs after exposure to hydrogen peroxide (H2O2), including the increase in senescence-associated β-galactosidase (SA-β-gal)-positive HDPCs and the upregulation of p21 protein, an indicator for senescence. In addition, as melatonin attenuated H2O2-stimulated phosphorylation of c-Jun N-terminal kinase (JNK), while selective inhibition of JNK activity with SP600125 significantly attenuated H2O2-induced increase in SA-beta-gal activity. Results reveal that melatonin antagonizes premature senescence of HDPCs via JNK pathway. Thus, melatonin may have therapeutic potential to prevent stress-induced premature senescence, possibly correlated with development of dental pulp diseases, and to maintain oral health across the life span.

본 연구에서는 배가스 내 존재하는 오염물질인 NO의 처리효율을 증대시키기 위하여 NO 산화 공정을 연구하였으며, 강력한 산화력의 건식산화제를 제조하는 방법으로 H2O2 촉매분해가 도입되었다. H2O2 분해공정 상에서 적용 가능한 K-Mn/Fe2O3 불균일계 촉매가 제조되었으며, 이들이 가지는 물리화학 적 특성이 H2O2 분해반응에 미치는 영향이 조사되었다. 제조된 건식산화제는 NO가 포함된 모사 배가스를 처리하기 위한 NO 산화공정에 적용되었으며, 다양한 모사 배가스의 유량(5, 10, 20 L/min)에서 약 100% 가까운 NO 전환율을 확인 하였다.

본 연구에서는 촉매 상 H2O2 전환에 의해 건식산화제가 생성되었으며, 이를 이용한 NO 산 화 공정에 대한 연구를 진행하였다. 건식산화제를 생성하기 위한 H2O2 촉매 전환에 관한 실험을 수행 한 결과, Mn계 촉매의 성능이 가장 우수하였으며, 이를 통해 생성된 건식산화제를 NO 산화공정에 주 입하여 다양한 운전조건에서 NO 산화특성을 조사하였다. 그 결과, H2O2 주입량, 산화반응온도, 그리고 공간속도가 NO 산화율에 크게 영향을 미치는 것을 확인하였다. 그리고, 산화반응온도와 H2O2 주입량 이 증가할수록 NO 산화효율이 증가하였으며, 공간속도가 증가할수록 NO 산화효율이 감소하였다.

Traditionally, Centella asiatica leaf extracts are used to treat neurodegenerative diseases in India. Centella asiatica is reportedly used to enhance memory and treat dementia, but its promoting effect on neural stem cell differentiation has not been studied yet. In the present study, we investigated whether or not Centella asiatica leaf extracts act on neuronal precursor cells and neuronal cell lines to induce neuronal differentiation, neurite outgrowth, and neuroprotection. The neurogenesis-promoting potential of Centella asiatica leaf extracts was determined by differentiation assay on neural stem cells isolated from mouse embryos and PC12 cell lines. To understand the contribution of specific neural cell types towards increase after Centella asiatica treatment, neural stem cells were differentiated into various neural subtypes and checked by Western blotting using neural cell lineage-specific antibody markers. Neuroprotective activity of Centella asiatica was analyzed in PC12 cells exposed to 100 μM of H2O2. Cell growth was analyzed by MTT assay while cell death was analyzed by Western blotting detection of apoptosis-related proteins. Cells treated with Centella asiatica had significantly longer primary and secondary neurites as well as a higher number of neurites per cell compared to control cells. Expression levels of TUBBIII, TH, NF, and BDNF increased upon Centella asiatica treatment, suggesting that Centella asiatica has a neurogenesis-promoting effect. Centella asiatica also inhibited oxidative stress-induced neural cell damage through regulation of apoptosis- and cell cycle-related proteins. Thus, leaf extracts of Centella asiatica might promote neurogenesis, neuroregeneration, and neuroprotection in the context of neurodegenerative diseases.

Programmed cell death or apoptosis is associated with changes in K+ concentration in many cell types. Recent studies have demonstrated that two-pore domain K+ (K2P) channels are involved in mouse embryonic development and apoptotic volume decrease of mammalian cells. In cerebellar granule neurons that normally undergo apoptosis during the early developmental stage, TASK-1 and TASK-3, members of K2P channels, were found to be critical for cell death. This study was performed to identify the role of K+ channels in the H2O2-induced or cryo-induced cell death of mouse and bovine embryos. Mouse and bovine two-cell stage embryos (2-cells) exposed to H2O2 for 4 h suffered from apoptosis. The 2-cells showed positive TUNEL staining. Treatment with high concentration of KCl (25mM) inhibited H2O2-induced apoptosis of 2-cells by 19%. Cryo-induced death in bovine blastocysts showed positive TUNEL staining only in the cells near the plasma membrane. Cryoprotectant supplemented with 25 mM KCl reduced apoptosis slightly compared to cryoprotectant supplemented with 5 mM KCl. However, the combination of antioxidants (β-mercaptoethanol) with 25 mM KCl significantly decreased the rate of H2O2-induced and cryo-induced apoptosis compared to treatments with only antioxidants or 25 mM KCl. These results show that blockage of K+ channel efflux for a short-time reduces H2O2- and cryo-induced apoptosis in mouse and bovine embryos. Our findings suggest that apoptosis in mouse and bovine embryos might be controlled by modulation of K+ channels which are highly expressed in a given cell type.

The photocatalysts of Fe-ACF/TiO2 compositeswere prepared by the sol-gel method and characterizedby BET, XRD, SEM, and EDX. It showed that the BET surface area was related to adsorption capacity foreach composite. The SEM results showed that ferric compound and titanium dioxide were distributed on thesurfaces of ACF. The XRD results showed that Fe-ACF/TiO2 composite only contained an anatase structurewith a Fe mediated compound. EDX results showed the presence of C, O, and Ti with Fe peaks in Fe-ACF/TiO2 composites. From the photocataytic degradation effect, TiO2 on activated carbon fiber surface modifiedwith Fe (Fe-ACF/TiO2) could work in the photo-Fenton process. It was revealed that the photo-Fenton reactiongives considerable photocatalytic ability for the decomposition of methylene blue (MB) compared to non-treatedACF/TiO2, and the photo-Fenton reaction was improved by the addition of H2O2. It was proved that thedecomposition of MB under UV (365nm) irradiation in the presence of H2O2 predominantly accelerated theoxidation of Fe2+ to Fe3+ and produced a high concentration of OH. radicals.

콘택트렌즈 소독제로 쓰이는 H2Û2올 중화용 백긁 판올 이용하여 수회 반복 중화한 용액이 배양 각막상피세포의 Apoptosis룰 유도하는지 여부룹 조사하기 위해 본 연구 를 시행하였다 3% H202(AOSept)를 6시간 동안 9회에 걸쳐 통일 백금 판으로 풍화 한 용액을 배양 각막 상피세포에 배양액의 25% 농도로 1--2 띤 동안 처리하여 처음 중화한 용액과 9번째 중화한 용액음 중심으로 세포독성과 Apoptosis를 조사하였다. 세포똑성은 MTT assay를 이용하였으며 lnverted pþase-contrast microscope로 형 태 를 확얀하고 Toluiclin blue 염 색으로 Apoptotic Cell올 확언하였으며 Hoechst 33342 로 형광 염색하여 Apoptotic Index를 조사하였다. 또한 Annexin V - FITC깨ropiclium Iodide(PDstaíning, DePsipher TM assay. M30 CytoDEATH. TUNEL (TdT-dUTP terminal nick-end labelling) assay를 통해 형태적인 변화될 확인하였다. 생화학적 변 화인 DNA Fragmentation은 Agarose gel electrophoresis룹 사 행하였으며 Fas Antigen 의 발현을 조사하기 위하여‘ Irnmunocytochemistry와 Westem blotting올 시 행하 였다. H20z의 독성올 약화시키기 위해 사용되는 백금 판을 수회 재사용하여 중화한 용액닫 25% 농도로 1-2 일간 처리하였을 때 각막 상피세포의 Apoptosis가 유도되는 것 이 형 광 염 색， DNA ladder. Irnmunocytochemistry. Westem blotting등의 방법 으로 확인되었다. 따라서 중화된 H써2룹 25% 농도로 1-2 일 동안 처리한 결과， 세포 증식 저해와 Apoptosis 가 유도되므로 중화용 백금 판의 이용 횟수활 세한하거나 중화시간 을 증가시킬 필요가 있는 것으로 사료된다. 또한 완전하게 중화된 소독용 H202는 더 이상 소독효파가 없으므로 장시간 동안 렌즈의 소쪽보관 용액으로 사용해서는 안 된 다는 교육이 반드시 펼요할 것으로 판단된다.

One-step System으로 6시간 동안 중화된 H202의 배양 각막상피 세포에 대한 세 포독성과 Apoptosis를 조사하기 위해 세포에 15분간 직접 처리하여 세포의 형태적 변화， 생화화적 변화 그리고 면역화학적 발현 여부 등올 확인하였다. 세포독성은 형 태적 변화와 MTT Assay률 시행하였고 Apoptosis는 Hoechst 잃342의 형광염색으로 산 정 한 Apoptotic index, DePsipher™ assay를 이 용한 mitochondria 활성 과 변화를 확인하였으며 immunocytochemistry로 각막 상피세포 막의 수용체인 FAS 의 발현 여 부도 조사하였다. 중화된 H202를 15분간 처리 후 세포독성을 조사한 결과， 같은 디스크로 중화를 반 복한 경우 독성이 높게 나타났으며 세포증식도 느리게 나타났다.24시간 동안 세포를 정상 배양액으로 환원시켜 조사한 결과， 세포 독성에서 회복효과가 거의 없고 Apoptotic index도 높게 나타났다. 또한 미토콘드리아 활성과 초기 Apoptosis 에 대 한 검증도 모두 양성으로 나타났다. 그리고 Apoptosis 유도의 가장 중요한 경로인 FAS-FAS ligand system에 대 한 조사에 서 중화된 H20z를 처 리 한 세 포의 FAS 가 정 싱세포에서 보다 강하게 발현되는 것을 immunocytochemistry로 확인할 수 있었다. 이상의 결과로 강력한 apoptosis 유도 물질인 H202를 콘태트렌즈 소독을 위해 One-step system으로 중화한 경우에도 불완전하게 중화된 Hz02에 의해 각막상피세 포의 Apoptosis가 유도되 므로 중화용 백금 디 스크의 반복된 사용올 금지 하거 나 반복 사용 시에는 시간을 더 늘려야 할 것으로 사료된다.

Pt/C catalysts were prepared using black carbon (CB), and evaluated for their potential application as a catalyst of liquid-phase catalystic exchange for tritium treatment. CB was treated with 10% H2O2 solution for 0 and 2 hours at 105°C, Ethylene glycol and 40wt% Pt were added to the dried treated sample to prepare a Pt/C catalyst. The physical and chemical properties of the prepared catalysts were evaluated by BET, XRD, elemental analysis (EA), and TEM analyses. As a result of BET analysis, the surface area of CB without 10% H2O2 was 237.2 m2·g-1, and after treatment with 10% H2O2, it decreased to 181.2 m2·g-1 for 2 hours. However, the internal surface area increased, indicating the possibility that more Pt could be distributed inside the CB treated with 10% H2O2. In the XRD analysis results, the presence of Pt was confirmed by observing the Pt peak in the prepared Pt/C catalyst, and it was also observed through TEM analysis that Pt was evenly distributed within the CB. The elemental analysis (EA) results showed that the ratio of S and N decreased and the ratio of O increased with increasing 10% H2O2 treatment time. The H2O2 treated carbon supported Pt catalysts and polytetrafluoroethylene were then loaded together on a foamed nickel carrier to obtain hydrophobic catalysts. Our hydrophobic Pt catalyst using H2O2 treated black carbon are expected to be usefully used in the tritium treatment system.

As a part of an infrastructure project on medicinal herb-based remedies, we conducted a phytohemical investigation of the 100% MeOH extract from the aerial part of Boehmeria quelpaertense; our findings resulted in the isolation of flavonoids (1-2), isoquercitrin (1) and hyperoside (2). The identification and structural elucidation of these compounds were based on 1H-,13C-NMR, and LC ESI IT-TOF MS data. All the compounds isolated from this plant were reported for the first time. In this study, we examined the antioxidant activity of the 1 and 2 on the hydrogen peroxide (H2O2)-induced oxidative stress in a Rat Cardiomyoblast cell line (H9c2). The pretreatment of the flavonoids showed that it protects against H2O2-mediated cell death in the H9c2 cell line. Also, it decreases the intracellular reactive oxygen species (ROS) levels by the flavonoids in the H2O2-treated H9c2 cell line. These results showed that the 1 and 2 are a source of antioxidants. As a result, they might be helpful in preventing the progress of various oxidative stress mediated diseases, including myocardial infarction.