Encapsulating living cells within porous crystalline materials has emerged as a powerful strategy for improving cellular stability in chemically or physically harsh conditions. In this study, individual yeast cells were encapsulated with a zeolitic imidazolate framework-8 (ZIF-8) crystals via a biomimetic self-assembly process. Morphological analysis using electron microscopy confirmed the successful formation of a uniform and continuous protective shell around each cell. To evaluate the cytoprotective effect of the ZIF-8 coating, the encapsulated yeast cells were exposed to a range of pH conditions (pH 2~12). Fluorescence microscopy using fluorescein diacetate (FDA) staining revealed that over 50 % of the ZIF-8 encapsulated cells remained viable in alkaline environments (pH 8, 10, and 12), whereas non-encapsulated yeast cells showed 0 % viability across all tested conditions. The enhanced survival in alkaline media was attributed to the stability of the crystalline ZIF-8 shell, which remained partially intact and provided structural protection. In contrast, acidic conditions degraded the ZIF-8 shell, leading to cell membrane rupture and loss of viability. These findings demonstrate that ZIF-8 encapsulation can significantly improve the chemical resilience and survival of living yeast cells. This strategy holds great promise for applications in long-term cell preservation, transport, and pH-responsive biotechnological systems.

Using durian shell as a carbon source and triethanolamine as a nitrogen dopant, nitrogen-doped carbon dots (N-CDs) were prepared via the hydrothermal method. First, by exploring different reaction times, reaction temperatures, and carbon source/dopant ratios to synthesize nitrogen-doped carbon dots, it is concluded that the best process conditions are 200 ℃, reaction time being 15h, and the dopant addition amount being 2mL. Structure and characteristics of the synthesized CDs were analyzed using X-ray photoelectron spectroscopy, Fourier-transform infrared, fluorescence (FL), ultraviolet–visible absorption, and Raman spectra. The N-CDs showed blue FL with a quantum efficiency of 4.28%. The FL characteristics of the N-CDs were utilized for ion detection, which demonstrated that MnO− 4 and Cr 2 O2− 7 ions caused distinct FL quenching through static quenching, while other ions had no significant quenching effect. The detection limits for MnO− 4 and Cr 2 O2− 7 were 37.5 and 46.2 nM, respectively. The N-CDs were subsequently employed to detect these ions in actual water samples, producing satisfactory results. Therefore, the preparation of N-CDs using durian shell as raw material and its application in practical detection work have good application feedback, which not only provides a new way for the reuse of fruit and vegetable wastes but also provides a new detection means for environmental monitoring pollutants.

Korea is a major chestnut producer, and about half of its production is discarded as chestnut shells. This study aimed to manufacture an environmentally friendly adsorbent using these wastes. For this purpose, the optimum carbonization temperature of chestnut shells was derived through thermogravimetric analysis, with structural change confirmed through SEM analysis. The results showed that the sample that carbonized at 350oC for 60 min after phosphorylation had both the highest initial acetaldehyde removal rate and the longest duration compared to other samples. As a result, an eco-friendly adsorbent for acetaldehyde was produced from chestnut shell biomass. Through this research, it was confirmed that the adsorbent can be effectively used for acetaldehyde control while addressing the issue of recycling chestnut shell wastes.

Fiber supercapacitors have attracted significant interest as potential textile energy storage devices due to their remarkable flexibility and rapid charge/discharge capabilities. This study describes the fabrication of a composite fiber supercapacitor (FSC) electrode through a multi-shell architecture, featuring layers of carbon nanotube (CNT) conductive shells and MnO2 nanoparticle active shells. The number of layers was adjusted to assess their impact on FSC energy storage performance. Increasing the number of shells reduced electrode resistance and enhanced pseudocapacitive characteristics. Compared to the MnS@1 electrode, the MnS@5 electrode exhibited a high areal capacitance of 301.2 mF/cm2, a 411% increase, but showed a higher charge transfer resistance (RCT) of 701.6 Ω. This is attributed to reduced ion diffusion and charge transfer ability resulting from the thicker multi-shell configuration. These results indicate that fine-tuning the quantity of shells is crucial for achieving an optimal balance between energy storage efficiency and stability.

본 연구는 꼬막 패각 잔골재와 PP 폐어망 섬유를 혼입한 자원순환 콘크리트의 역학적 성능과 계면 변화 영역에서의 미세구조 특성 을 분석하였다. 패각 잔골재와 폐어망 섬유를 적절한 방법으로 전처리하고 자원화를 고려하여 3D 프린팅 콘크리트 배합을 선정해 콘 크리트 시편을 제작하였다. 제작된 시편은 KS L ISO 679 규정에 따라 압축강도와 휨강도를 측정하였고, BSE 모드를 이용한 SEM 이 미지 촬영을 통해 미세구조를 분석하였다. SEM 이미지는 히스토그램 및 형상 기반 상 분리 방법, 그리고 계면 변화 영역의 픽셀값 차 이를 활용하여 이미지를 분리하고 미세구조를 분석하였다. 역학적 성능을 확인하기 위해 PP 섬유를 0.0%, 0.5%, 1.0vol.% 혼입한 시 편의 압축강도와 휨강도를 측정한 결과, PP 섬유 0.5vol.% 혼입 시 섬유 브릿징 효과로 인해 가장 높은 압축 및 휨강도가 나타났다. SEM 이미지 분석 결과, 일반 잔골재와 바인더 계면보다 패각 잔골재와 바인더 계면에서 더 큰 직경의 공극이 관찰되었으며, PP 섬유 와 바인더 계면에서는 상대적으로 작은 공극이 형성됨을 확인하였다. 이를 바탕으로 미세구조 분석 결과와 역학적 성능 간의 상관관 계를 규명하였다.

We report the synthesis of bimetallic Cu-Au nanotubes (NTs) and Cu@Au core-shell nanowires (NWs) for use as anti-oxidative electrodes. The fabrication involved two key approaches: galvanic replacement to produce Cu-Au NTs and the physical deposition of Au to form Cu@Au core-shell NWs. The galvanic replacement process generated hollow NTs through the Kirkendall effect, driven by the unequal diffusion rates of Cu and Au during the redox reaction. In contrast, the physical deposition of Au, facilitated by fast reduction kinetics using L-ascorbic acid, enabled the formation of a Au shell encapsulating the Cu NWs, preserving their structural integrity. Morphological and structural analyses confirmed the successful formation of both nanostructures. While the Cu-Au NTs exhibited hollow interiors and increased dimensions, the Cu@Au NWs displayed a solid core-shell morphology with minimal diameter increase. Electrical conductivity and thermal stability tests revealed the superior performance of the Cu@Au NWs. The sheet resistance of Cu@Au NWs remained as low as 4 Ω sq-1 and showed exceptional thermal stability, with minimal resistance variation (R/Ro ~1.36) even after 36 h at 120 °C under ambient conditions. In contrast, the Cu-Au NTs suffered rapid oxidation and structural instability. The physical deposition approach holds significant promise for the development of robust, low-resistance electrodes for long-term applications in harsh environments.

본 연구에서는 기존 율피 중에 존재하는 ellagic acid 정 량 할 수 있는 분석법을 확립하였다. 본 실험에서 사용된 밤과 율피, 율피 가루는 2023년 10월 서울 소재 전통 및 약령시장에서 구입하였다. 실험에서 사용된 밤 품종은 국 내에서 소비되는 품종으로 서산, 옥광, 이평, 석추, 중국산 을 구입하여 사용하였고, 가공된 율피와 율피가루의 원산 지는 공주, 아산지역의 제품을 구입하여 실험을 진행했다. 율피중에 존재하는 ellagic acid의 함량은 100% methanol 에서 0.077 mg/g으로 가장 높게 검출되었고, 50% methanol 과 ethanol에서 0.048 mg/g, 증류수에서는 0.011 mg/g로 확 인되었다. 유기용매에 비율이 낮을수록 ellagic acid의 함 량은 순차적으로 줄어듬을 확인하였다. Waters사의 HPLC 이용하였으며 분석용 컬럼은 Aegispak C18-L을 사용하였 고, 이동상은 A (1.2% phosphoric acid in DW)와 B (methanol)를 이용하여 gradient 를 사용하였다. 유속은 1.0 mL/min, 주입량은 10 μL, 컬럼 오븐은 35oC이였다. 검 량선 작성을 위해 1-50 g/mL 범위에서 상관계수(R2) 0.9999 이상의 직선성을 확인하였다. 검량선내 3개 농도를 이용 하여 정밀도와 정확성을 측정한 결과, 일내 정밀도는 0.09- 0.18%, 정확도는 99.9-105.8%, 일간 정밀도는 0.04-0.23%, 정확도는 99.8-105.9% 범위내로 확인되었다. 국내에 유통 되고 있는 시료 8가지 품종의 정보는 Table 10과 같이 정 리하였고, 확보된 시료를 분석한 결과 총 8개 시료에서 ellagic acid의 함량은 0.0002-0.0936 mg/g로 확인되었다. Ellagic acid의 검출 한계는 3개 시료에서 검출한계 0.016 μg/ mL, 정량한계 0.499 μg/mL로 확인되었다. Ellagic acid 측정 불확도 산출 결과 0.40±0.01 mg/kg (신뢰수준 95%, K=2)로 비교적 낮은 측정불확도 값을 산출하였다. 따라서 본 연 구에서는 율피 중 ellagic acid 정성 및 정량분석을 위해 유효성이 검증된 분석법 확립으로 인하여 율피 중 ellagic acid의 기준규격 설정 및 관리에 참고 자료가 될 수 있고, 향후 ellagic acid를 이용한 건강기능식품 개발에 있어 품종, 지역 및 추출용매에 따른 실험결과를 바탕으로 건강기능 식품 기준규격 관리와 활성 및 독성시험 연구의 근거 자 료가 될 수 있다고 판단된다.

With technological and social development, high-rise atypical buildings have emerged. In order to take into account the structural vulnerability due to their high-rise atypical shape, systems such as vibration control system and seismic isolation can be applied. In this study, dynamic behavior characteristics analysis was conducted based on the location of the seismic isolation system installation of the atypical facade shape Tapered and reverse shell structure models. With the installation of Lead Rubber Bearing(LRB), the maximum story drift ratio showed a decrease, but the maximum absolute acceleration showed a phenomenon in which the response was amplified in the middle and low story. LRB1(base isolation system) is the most effective for simultaneous control of the two dynamic responses, but the 46th floor of ‘Nor’ and’ RS’ and the 41st floor of ‘TA’ are considered the most effective installation location of the seismic isolation system in consideration of the burden of the seismic isolation system and the structure stability.

This study examines the effects of the TiO2 content and TiO2 position in the core or shell within tubular carbon nanofibers on the photocatalytic activity under visible light. Core–shell tubular carbon nanofiber composites whose cores are filled with TiO2 nanoparticles (PMTi(10)P) are fabricated through coaxial electrospinning and subsequent heat treatment. The PMTi(10)P composites with well-preserved TiO2 nanoparticles in the core part induce more oxygen vacancies, Ti3+ species, chemisorbed oxygen species, and anatase phases, significantly improving the photocatalytic performance. They act as photoelectron traps, allowing more photoelectrons and holes to participate in the photocatalytic reaction and extending the absorbance of TiO2 to the visible light region. The resulting PMTi(10)P photocatalyst exhibits excellent performance of 100% removal of methylene blue within 30 min and maintains nearly 100% removal of 15 ppm methylene blue over 10 regeneration cycles, indicating consistent and stable photocatalytic performance.

본 연구는 제주도 모슬포 해역에서 채집된 대형 포식성 복족류인 붉은입두꺼비고둥(Tutufa bufo) 두 개체를 대상 으로 테트로도톡신(TTX) 존재 여부를 조사하였다. 일본에 서 채집된 붉은입두꺼비고둥의 내장에서 TTX가 검출된 사례가 보고된 바 있으며, 최근 제주도 남부 해역에서 해 당 종이 혼획되고 있으나, 한국 해역에 분포하는 붉은입 두꺼비고둥의 TTX 축적에 대한 정보는 부족하다. 이에 본 연구에서는 경쟁적 효소면역분석법(cELISA) 을 사용하여 붉은입두꺼비고둥의 주요 연조직(전타액선, 구강부, 소화 선, 생식소, 아가미, 신장, 근육, 후타액선)을 분석하였다. 분석 결과, 모든 조직에서 TTX 농도는 검출 한계 미만으 로 나타났다. 그러나 TTX 축적에는 개체 간, 지역적, 계 절적 변동 가능성이 존재할 수 있으므로, 한국 해역에서 붉은입두꺼비고둥의 TTX 축적 위험을 정확하게 평가하기 위해서는 추가적인 시료 확보와 계절별 연구가 요구된다.

본 논문에서는 다중 연결 NURBS 패치 모델에 대한 등기하해석방법을 제시하고 이를 기하학적으로 엄밀한 쉘의 해석에 적용하였 다. 서로 다른 NURBS 패치를 연결할 떼 조정점 망(control point meshes)의 밀도와 패치간의 불연속성으로 인해 등기하해석이 부정확 해질 수 있다. 이러한 문제를 해결하기 위해 니셰(Nitsche) 방법을 등기하해석법에 적용하여 두 패치 사이의 변위와 견인력(traction) 의 정합성(compatibility)을 확보하였고, 최종 유도된 해석 방정식이 대칭성을 유지하도록 하였다. 추가되는 경계 조건은 패치간 경계 의 적분으로 표현되기 때문에 계산비용이 크게 증가되지 않는다. 시스템 방정식이 양정 행렬(positive definite matrix)이 되도록 안정 성 매개변수(stability parameters)를 도입하였으며 일반화된 고유치 해석을 통해 두 패치사이의 조정점 밀도에 따른 안정성 매개변수 의 값과 응력장의 해의 정확성을 분석하였다. 이 다중 패치 등기하해석법을 1차 전단변형을 고려한 기하학적으로 엄밀한 쉘요소의 해석에 적용하였으며, 니셰 방법을 사용함으로써 패치간의 변위 및 응력 연속성이 향상된 결과를 확인 할 수 있었다.

본 논문에서는 다중 연결 NURBS 패치 모델에 대한 등기하해석방법을 제시하고 이를 기하학적으로 엄밀한 쉘의 해석에 적용하였 다. 서로 다른 NURBS 패치를 연결할 떼 조정점 망(control point meshes)의 밀도와 패치간의 불연속성으로 인해 등기하해석이 부정확 해질 수 있다. 이러한 문제를 해결하기 위해 니셰(Nitsche) 방법을 등기하해석법에 적용하여 두 패치 사이의 변위와 견인력(traction) 의 정합성(compatibility)을 확보하였고, 최종 유도된 해석 방정식이 대칭성을 유지하도록 하였다. 추가되는 경계 조건은 패치간 경계 의 적분으로 표현되기 때문에 계산비용이 크게 증가되지 않는다. 시스템 방정식이 양정 행렬(positive definite matrix)이 되도록 안정 성 매개변수(stability parameters)를 도입하였으며 일반화된 고유치 해석을 통해 두 패치사이의 조정점 밀도에 따른 안정성 매개변수 의 값과 응력장의 해의 정확성을 분석하였다. 이 다중 패치 등기하해석법을 1차 전단변형을 고려한 기하학적으로 엄밀한 쉘요소의 해석에 적용하였으며, 니셰 방법을 사용함으로써 패치간의 변위 및 응력 연속성이 향상된 결과를 확인 할 수 있었다.

Fluorescent Carbon Quantum Dots (FCQDs), a new generation of carbon nanomaterials, have attracted a lot of attention throughout the years. This paper applied a straightforward and environmentally beneficial way to create water-soluble FCQDs hydrothermally from coconut shells. The as-prepared FCQDs have desirable functional groups and exhibit strong blue-emitting fluorescence with a relative quantum yield of 0.6 and 0.7%. The optical bandgap of FCQDs is calculated using UV–Vis spectra to be between 3.9 and 4.4 eV. Optical studies show that FCQDs have good fluorescence properties when excited at 360 nm. Whereas the fluorescence decay lifetime using TCSPC are 1.6–0.99 ns. The synthesized FCQDs were found by HRTEM to have a spherical shape and a particle-size distribution of 2.8–5.4 nm. As-prepared FCQDs has a very low hemotoxicity of 0.5 to 1.3%, which indicates that they have acceptable biocompatibility and are not hazardous. According to the DPPH antioxidant data, FCQDs had a stronger antioxidant activity compared to earlier reports. These important characteristics enable its applications in biomedical, food packaging, fluorescence imaging, photocatalysis, and sensing. The enhanced antioxidant characteristics of the produced FCQDs make them appropriate for use in biomedical, bioimaging, chemical, and industrial applications. The as-synthesized FCQDs were used for the detection of ferric ions with good selectivity.

Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum causes fowl typhoid in poultry. In this study, we isolated Salmonella from a Korean retail chicken shell egg and performed whole-genome sequencing, from which we identified one chromosome (4,659,977-bp) and two plasmids (plasmid_1: 87,506 bp and plasmid_2: 2,331 bp). The isolate serotype was confirmed to be Gallinarum, with a biovar type of Gallinarum, which was finally identified as Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum. Multilocus sequence typing confirmed that the isolate was that of sequence type 78. The antimicrobial resistance gene, aac(6')- laa, was identified on the chromosome, and 166 virulence genes were detected on the chromosome and plasmid_1.

In this study, we report significant improvements in lithium-ion battery anodes cost and performance, by fabricating nano porous silicon (Si) particles from Si wafer sludge using the metal-assisted chemical etching (MACE) process. To solve the problem of volume expansion of Si during alloying/de-alloying with lithium ions, a layer was formed through nitric acid treatment, and Ag particles were removed at the same time. This layer acts as a core-shell structure that suppresses Si volume expansion. Additionally, the specific surface area of Si increased by controlling the etching time, which corresponds to the volume expansion of Si, showing a synergistic effect with the core-shell. This development not only contributes to the development of high-capacity anode materials, but also highlights the possibility of reducing manufacturing costs by utilizing waste Si wafer sludge. In addition, this method enhances the capacity retention rate of lithium-ion batteries by up to 38 %, marking a significant step forward in performance improvements.