비금속 재질인 PB, PE, PVC 수도관을 대상으로 염소 노출에 의한 물리⋅화학적 구조변화를 관찰하여 내구성에 미치는 영향을 평가하고자 하였다. 염소 노출은 NaOCl을 적용하여 0.4에서 2.1 g⋅hr/L의 노출 강도가 높아짐에 따라 PE, PB의 표면 형상 변화는 결정화와 crack이 일어남을 확인할 수 있었다. 또한 구성성분 비율과 작용기 변화는 aldehyde, ketone에 의한 carbonyl group 생성을 확인하였고 모든 재질에서 산화 과정이 연속적으로 일어나는 결과를 나타내었다. 이에 따른 내구성 변화는 인장강도와 신도를 측정하여 평가한 결과이며 최소 5에서 20 %의 초기상태 대비 변형률을 나타내었다. 최종적으로 염소 노출에 의한 취약성은 PB > PE > PVC 순서와 같으며 향후 갱생과 교체 주기 산정을 위한 진단 방법론으로 활용 용도가 높을 것으로 판단된다.

This study aimed to evaluate the effect of partially replacing pork backfat with string cheese on the quality of dry-cured goat meat sausages. Two formulations were prepared: A control (C0, 20% backfat) and a treatment (C10), in which 10% backfat was replaced with string cheese. Proximate composition, fatty acid profile, thiobarbituric acid reactive substances (TBARS), pH, water activity, color, and texture were analyzed. The addition of string cheese significantly reduced fat and increased protein and moisture (p<0.05). Fatty acid analysis revealed higher medium-chain saturated fatty acids (C4:0- C8:0) and total saturated fatty acids (SFA), with a lower unsaturated-to-saturated fatty acid (UFA/SFA) ratio. Both groups showed TBARS values below the sensory threshold, but the treatment had significantly lower lipid oxidation (p<0.05). The treatment also had a higher pH, while water activity showed no difference. In color, the treatment exhibited significantly higher a* (redness) and b* (yellowness) values. Textural analysis indicated increased hardness but reduced cohesiveness and gumminess. These findings suggest string cheese can act as a fat replacer and functional ingredient that improves the nutritional and physicochemical characteristics of dry-cured goat sausages.

In this study, carbon nanotube (CNT) purification results were compared between the conventional wet process using strong acids and the dry process using chlorine gas at high temperatures. To evaluate the effect of catalyst support in both methods, purification experiments were conducted using Tuball SWCNT from OCSiAl (without support) and CVD CNT synthesized with supported catalysts (Fe-Mo/MgO). Before and after treatment, the CNT samples were analyzed using scanning electron microscopy (SEM), Raman spectroscopy, and thermogravimetric analysis (TGA) to compare the morphology of CNT bundles, the distribution and content of impurities, and crystallinity. The results confirm that the dry process exhibited superior characteristics for both Tuball SWCNT and CVD CNT. In particular, changes in the IG/ID ratio observed in Raman spectroscopy and the reduction of residue in TGA clearly demonstrate high crystallinity and high-purity purification without damaging the CNTs. TGA reveals a reduction in ash content from 20.2 % to 3.2 % for Tuball SWCNT and from 63.1 % to 5.4 % for CVD CNT, while Raman spectroscopy confirms the preservation of the IG/ID ratio (~50) in Tuball SWCNT and its increase from 6.86 to 9.05 in CVD CNT. The purification method proposed in this study is expected to be effectively applied in fields requiring high-purity SWCNTs, such as electronics, sensors, and energy storage devices.

This study aimed to develop a model for accurately predicting the acute aquatic toxicity (48h- EC50) of chlorine disinfection by-products (DBPs). DBPs have caused environmental risks, but experimental toxicity data are difficult to obtain due to time, cost, and ethical constraints. Therefore, a deep learning model was developed using actual concentration-based data. Toxicity data for 139 aliphatic chlorinated compounds were from the OECD QSAR Toolbox and from aquatic toxicity test results provided by the japan ministry of the environment. Various concentration criteria, including nominal and measured concentrations, were encoded as additional inputs, and EC50 values were augmented via log transformation and structural string modifications to overcome small data limitations. The directed message passing neural network (D-MPNN) model, which considers bond directionality, was applied to reflect structural complexity accurately. Also, this model effectively reflected subtle structural differences and showed stable performance even with limited data. Comparisons between models with and without concentration criteria revealed that the model considering all concentration criteria had superior predictive accuracy. This result shows that concentration criteria are a critical factor in toxicity prediction. This study suggests a baseline model that works reliably even with small datasets reflecting realistic concentration criteria, showing its potential use for replacing some experiments and for screening toxic substances.

Sodium hypochlorite (NaOCl) is widely utilized as an endodontic irrigant due to its antimicrobial efficacy and tissue-dissolving capabilities. Its mechanisms of action involve hypochlorous acid, chloramines, and the solution’s high alkalinity, which contribute to tissue dissolution through protein degradation and saponification of lipids. While effective for disinfecting root canals, unintended extrusion beyond the apical foramen can cause severe chemical injury. Although cases of NaOCl accidents have been reported, detailed serial clinical documentation of tissue responses following such incidents remains limited in the literature. This case report presents a 66-year-old female who developed acute pain during root canal irrigation of the mandibular left lateral incisor (#32) due to NaOCl extrusion. Initial findings included a mucosal opening suggestive of subepithelial necrosis, followed by bilateral chin ecchymosis and intraoral tissue degradation. Over the following days, signs of liquefactive and fat necrosis emerged, eventually progressing to tissue remodeling with re-epithelialization and fibrotic healing. Cone-beam computed tomography revealed a periapical lesion with buccal bone fenestration, indicating a possible anatomical route for extrusion. The root canal was obturated once soft tissue healing was evident, and by 12 weeks, the affected area had fully recovered with scar-like integration into surrounding mucosa. This case report highlights the importance of identifying anatomical risk factors such as buccal bone fenestration to prevent extrusion and underscores the value of timely, conservative management. Close follow-up is important for monitoring soft tissue changes and guiding appropriate intervention.

재래흑염소는 다른 품종과의 유연관계, 기원 분석, 외래교잡염소와의 유전적 구조 및 평가 같은 유전학적 연구는 현재 부족한 실정이므로 본 연구는 재래흑염소와 외래교잡염소의 유전적 구조 및 혼합 양상 분석을 위해 실시하였다. 11개의 Microsatellite (MS) marker를 활용하여 재래흑염소 261두, 외래교잡염소 94두의 대립유전자형을 분석하였으며, 이를 통해 기초통계량 및 유전적 구조 및 혼합 양상 분석을 수행하였다. 그 결과 연구에 활용된 marker의 유전적 다양성 기초통계량 결과 재래흑염소의 observed heterozygosity, polymorphism information content (PIC) 수치가 각각 0.388 ~ 0.772, 0.362 ~ 0.754이며, 외래교잡염소 집단의 observed heterozygosity, PIC 수치는 각각 0.553 ~ 0.840, 0.664 ~ 0.915로 확인되어, 유전적 다양성 분석을 수행하기에 충분한 수치를 나타내었다. 또한, 재래흑염소 주요 대립유전자형 빈도와 외래교잡염소의 주요 대립유전자형 빈도를 비교하였을 때, marker별 대립유전자형의 빈도 분포에서 뚜렷한 차이를 보여, 두 집단 간, 재래흑염소 계통 간 대립유전자형 의 빈도 분포로 인한 유전적 구조의 차이를 확인하였다. 그리고 STRUCTURE 결과, K = 2가 최적의 K로 계산되었으며, 재래흑염소와 외래교잡염소 간의 유전적 혼합은 존재하지 않는 것으로 판단되었다. 따라서 본 연구 결과는 재래흑염소의 고유성을 제시할 수 있는 과학적 근거자료이며, 재래흑염 소 계통 간의 식별을 위한 기초 자료로 활용 가능할 것이다.

본 연구는 배수지에서 저수조를 포함한 대수용가의 수도꼭지에 이르는 구간에서 탁도와 잔류염소 농도의 시간적⋅공간적 변화를 분석하였다. 모니터링은 배수지, 중블록 유입 지점, 대수용가 유입 지점, 저수조 유출 지점, 수도꼭지 등 5개 지점에서 수행되었으며, 유량, 잔류염소, 탁도, pH, 전기전도도, 온도를 측정하였다. 연구 결과, 수돗물 이동 경로를 따라 잔류염소 농도는 점차 감소하고 탁도는 증가하는 경향을 보였다. 특히, 비업무시간대에는 수돗물 정체로 인한 수질 저하가 확인되었다. 또한, 저수조의 건전성을 평가하기 위해 반응계수를 산출한 결과, 시간에 따른 저수조 내부 건전성 저하와 수질 악화 가능성이 확인되었다. 본 연구는 수돗물의 이동 거리, 사용 시간대, 유량 변화 및 공급 방식에 따라 수질이 달라질 수 있음을 보여주며, 저수조에 의존하는 지역에서는 안전한 수돗물 공급을 위해 지속적인 모니터링과 관리가 필요함을 시사한다.

본 연구에서는 하수처리 과정에서 분리된 항생제 내성균(Antibiotic Resistant Bacteria, ARB)을 제거하기 위해 박테리오파지와 차아염소산 나트륨(NaClO)을 결합한 병용 처리 기술을 응용하였다. ARB를 감염시키는 용균성 박테리오파지는 폐수 샘플에서 성공적으로 분리되었다. 이러한 박테리오파지와 NaClO를 순차적으로 적용한 결과, 5시간 이내에 ARB를 상당히 감소시킬 수 있었다. 환경 안정성 평가에서는 분리된 박테리오파지가 온도, pH, 독성 물질에 대한 노출 등 다양한 조건에서도 효과를 유지하는 것으로 나타냈다. 또한, 실험실 규모의 반응기 실험을 통해 단독 염소 소독과 비교했을 때, 결합 처리가 ARB를 효과적으로 억제하는 것을 확인할 수 있었다. 박테리오파지와 차아염소산 병용 처리는 유기물, 질소(N), 인(P)과 같은 영양소 제거 효율에 영향을 미치지 않았다. 이러한 결과는 박테리오파지를 기반으로 한 생물학적 제어법과 기존의 소독 방식을 결합하여 폐수 처리 공정(Wastewater treatment plant, WWTP)에서 효과적인 항생제 내성 박테리아 제어 방안을 제시할 가능성을 시사한다.

In treatment processes of drinking water, the use of disinfectants is essential for eliminating microorganisms and pathogenic viruses. Chlorine dioxide (ClO2) is one of the most promising disinfectants. To ensure its effective application in drinking water treatment, it is crucial to investigate the stability and reactivity of ClO2 in drinking water treatment environments. Therefore, we examined the effects of various environmental factors such as temperature, light type, fluorescence intensity, and water quality on its stability. We also examined its reactivity with activated carbon and other inorganic compounds such as coagulants and hypochlorous acid. Findings revealed that ClO2 stability was influenced by several environmental factors. Typically, ClO2 is highly volatile. However, the rate of its volatility is independent of its concentration. As temperature and fluorescent light intensity increased, the concentration of ClO2 showed a rapid decline. Additionally, the presence of activated carbon significantly reduced ClO2 levels. In contrast, the reactivity of ClO2 with coagulants and hypochlorous acid was negligible. These findings provide essential insights for optimizing the use of ClO2 in drinking water treatment facilities.

This study aimed to investigate the effect of Liriope platyphylla and organic acids on enteric methane mitigation in goats using an open-circuit simplified respiration chamber system. Methane recovery was evaluated by injecting 3% standard methane gas for 30 min at 3 L/min. The percentage of methane recovery from the four chambers was 99±5.4%. Following the recovery test, an animal experiment was conducted using eight castrated Boer goats (body weight 46.6±7.77 kg) using a 2×2 crossover design. Experimental diets were as follows: 1) Control (CON), commercial concentrate and tall fescue, and 2) Treatment (MIX), concentrate supplemented with L. platyphylla and organic acids and tall fescue. Goats were offered feed at 2% of body weight (dry matter basis) in equal portions twice daily at 8:00 and 15:30. The goats were adapted to the feed and methane chamber for 10 and 3 days, respectively. Methane emission was measured one day per goat using tunable diode laser absorption spectroscopy, and temperature and airflow measurements were used to estimate methane emissions. Dry matter intake (DMI), body weight, and methane emission were measured during each period. Methane production with CON and MIX was 24.48 and 22.68 g/d, respectively, and 26.81 and 24.83 g/kg DMI, respectively. Although the differences were not significant, the use of supplements resulted in a numerical reduction in methane in MIX compared with CON. Collaboration with experts in other areas, including various engineering departments, is imperative to measure methane emissions using a chamber system accurately.

This study was conducted to evaluate in vitro antioxidant activity of goat meat hot water extracts and the changes in apoptosis-related protein expression levels in the cancer cells treated with these extracts. Goat meat hot water extracts were prepared using different cuts of goat meat, including foreleg, hindleg, loin, and rib. Among these extracts, the foreleg and hindleg extracts displayed higher (P<0.05) ABTS radical scavenging activity than the other two extracts. Protein expression levels of BAX, p53, and p21 were not different in the cells treated with the extracts from different cuts, regardless of the cell type. Only p53 expression in HT-29 cells was elevated (P<0.05) after loin extract treatment. These results suggest that antioxidant activity and apoptosis-related effects of goat meat hot water extract varied with cut of meat under in vitro conditions. Because all data was obtained from the in vitro experiment, the ability to generalize conclusions is limited. Additional in vivo studies are necessary.

This study aimed to investigate the effects of Centella asiatica powder on the quality characteristics and storage stability of goat meat Tteokgalbi. The goat meat Tteokgalbi samples were prepared with four different quantities (0, 0.5, 1, and 1.5%) of Centella asiatica powder. The moisture content of the samples containing Centella asiatica powder was significantly lower than that of the control (p<0.05). The protein content of the samples containing Centella asiatica powder was significantly higher than that of the control (p<0.05). As the proportion of Centella asiatica powder increased, the pH, L*, and a* values of the uncooked and cooked samples decreased (p<0.05). The water holding capacity and the cooking yield of the uncooked and cooked samples were higher in the samples containing Centella asiatica powder than in the control (p<0.05). Also, with the increasing amounts of the Centella asiatica powder, the thiobarbituric acid reactive substance (TBARS) levels decreased. The 1-1.5% Centella asiatica powder group showed lower levels of volatile basic nitrogen (VBN) than the other groups as per the assay (p<0.05). The results indicate that Centella asiatica powder could enhance the quality characteristics and storage stability of goat meat Tteokgabi.

본 연구는 집단급식소에서 제공되는 빈도수가 높은 비 가열 및 가열조리 엽경채류에 사용되는 차아염소산나트륨 수에 대하여 미생물적 안전성을 평가하고자 수행되었다. 비병원성 대장균과 장출혈성 대장균의 칵테일(E. coli O157:H7)을 엽경채류(초기 균수 7-8 log CFU/g)에 인위적 으로 오염시킨 후 차아염소산나트륨을 5분간 침지 후 흐 르는 물에 3번 씻어서 생균수를 측정하였다. 실험 결과 초 기 오염물질에 비해 살균효과가 1-2 log CFU/g 저감화하 여 대조군에 대해 유의적인 차이가 있었다(P<0.05). 잎채 소의 특성에 따라 약간의 차이가 있었는데 표면적이 클수 록, 덜 거칠고 잎이 부드러울수록 살균효과가 높았다. 200 mg/kg으로 처리하였을 때 100 mg/kg에 비해 0.1-0.3 log CFU/g만큼 효과가 더 감소하였으나 농도 증가에 따 른 유의적 차이는 없었다(P>0.05). 그러므로 학교급식위생 관리지침에서 제시한 기준 이상으로 차아염소산나트륨 농 도를 높이는 것은 불필요하다고 판단된다. 그러나 잎채소 는 일반적으로 미생물의 초기 오염도가 높기 때문에 차아 염소산나트륨 처리만으로는 안전한 수준의 저감을 달성하 기 어려워 생물학적 위험이 잔존한다. 따라서 여름철에 가 열하지 않은 잎채소의 대체 조리방법을 개발하는 것이 안 전성에 보다 효과적인 것으로 판단된다.

본 연구는 장미 ‘Bubble Gum’의 절화수명을 연장시키기 위하여 미산성 차아염소산수(Slightly acidic hypochlorous water, HOCl, pH 6.26)의 처리효과와 절화수명 연장제로써 의 가능성을 구명하고자 수행되었다. 침지처리는 30μL･L-1의 미산성 차아염소산수를 0분, 0.5분, 1분, 3분, 5분간 침지처 리 후 수돗물(Tap water, control)에 꽂아 두었다. 대조구의 절화수명은 8.7일인데 비해 5분 침치처리 시 10.8일로 대조 구보다 2.1일 수명을 연장시켰다. 상대생체중은 모든 처리구 에서 2일까지 증가하였고, 수분흡수율은 모든 처리구에서 6일 까지 증가하다가 감소하는 추세를 보였다. 화색 변화율인 ΔE 값은 3분(5.25), 5분(6.48), 30초(6.65), 1분(6.79) 침지처리 에서 대조구보다 낮았으며, 상대 화폭 증가율은 5분 침지 처 리구가 145%로 화폭의 증가율이 가장 컸고, 엽록소함량은 처 리 간 차이가 없었다. 결론적으로 절화장미 ‘Bubble Gum’의 절화수명은 미산성 차아염소산수의 5분 침지 처리가 효과적 으로 연장시켰다.

The effect of permanganate oxidation was investigated as water treatment strategy with a focus on comparing the reaction characteristics of NaOCl and sodium permanganate (NaMnO4) in algae (Monoraphidium sp., Micractinium inermum, Microcystis aeruginosa)-contained water. Flow cytometry explained that chlorine exposure easily damaged algae cells. Damaged algae cells release intracellular organic matter, which increases the concentration of organic matter in the water, which is higher than by NaMnO4. The oxidation reaction resulted in the release of toxin (microcystin-LR, MC-LR) in water, and the reaction of algal organic matter with NaOCl resulted in trihalomethanes (THMs) concentration increase. The oxidation results by NaMnO4 significantly improved the concentration reduction of THMs and MC-LR. Therefore, this study suggests that NaMnO4 is effective as a pre-oxidant for reducing algae damage and byproducts in water treatment process.

To improve the shelf-life of Centella asiatica, Centella asiatica was treated with gel packs containing slow-released chlorine dioxide (ClO2) gas at 3-5 ppm for 20 days at 4℃. The weight loss rate, as well as the changes in pH, color, and texture of the treated samples, were investigated. The weight of the control and ClO2 gas-treated samples was decreased during the storage period. The change in weight of the control was slightly faster than that of the samples treated with 3 and 4 ppm ClO2 gas. The pH of the control and the ClO2 gas treated samples were decreased during the storage period and there was no significant difference between the control and ClO2 gas treated samples. Concerning color (lightness, redness, and yellowness) changes of Centella asiatica during the storage period, there was no significant difference between the control and ClO2 gas treated samples. The change in shear force in the leaf and stem of Centella asiatica during the storage period was slightly lower in the 4 ppm ClO2 gas treated samples (in the leaf) compared to the control and 3 and 4 ppm ClO2 gas treated samples (in the stem) compared to the control and 5 ppm ClO2 gas treated sample.