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        검색결과 4,953

        21.
        2024.03 구독 인증기관 무료, 개인회원 유료
        3,000원
        22.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study contrasted the response relationship and constraints of the Chinese phrase ‘S+給+NP1+V+NP2’ between ‘给’ and Korean ‘에 게’. Both ‘给’ and Korean ‘에게’ have something in common that they can lead to the objects of grant, communication, or benefit, but there were also certain constraints on the response relationship. In order to clarify this constraint, this study first classified semantic items according to the following nouns and trailing predicates of the phrase ‘S+給+NP1+V+NP2’ and their semantic relationships. Based on this, this paper compares Chinese ‘给’ with Korean ‘에게’ and analyzes the differences between the two. As a result of the analysis, the correspondence between the two was affected by the following constraints. First, the correspondence is established if the object ‘에 게1’ and ‘给1’ are living beings. Second, when ‘에게1’ contains [+benefit] or [+transmission] positive semantics, it is impossible to communicate with ‘给2’ to each other. Third, when both the subject of action and the posterior object are living things, there is a correspondence between ‘에게3’ and ‘给5’. However, there is a difference in the meaning of ‘给5’ and ‘에게3’ in Korean. ‘给5’ has a function that emphasizes the posterior predicate, but ‘에게3’ in Korean does not have such a function.
        6,300원
        24.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The waste secondary battery contains a significant amount of valuable metals, making its recycling highly desirable. However, conventional chemical methods for recycling are environmentally unfriendly and cost-ineffective. Rather than the chemical method, this paper deals with a mechanical method for recovering electrode materials from waste secondary batteries by blowing pressurized air onto the interface area between the electrode and the separator. Especially, in this study, the effective blowing angle were searched by simulating the separation of the electrode material from the separator through 1-way fluid structure interaction analysis based on the Cohesive Zone Modeling technique.
        4,000원
        25.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        역전기투석(reverse electrodialysis, RED)은 해수와 담수의 농도 차로부터 에너지를 얻는 이온교환막을 이용한 전 기막 공정이다. 해수와 담수에 포함된 다가 이온은 이온교환막의 고정 전하 그룹에 강하게 결합하여 높은 저항을 유발하며 uphill transport를 통해 개방회로 전압과 전력 밀도를 저하시킬 수 있다. 본 연구에서는 RED 응용을 위해 1가 이온 선택성 및 전기화학적 특성이 우수한 세공충진 음이온교환막(pore-filled anion-exchange membrane, PFAEM)을 제조하였다. 제조된 막의 1가 이온 선택성은 3.65였으며 동일 조건에서 1.27의 선택성을 갖는 상용막(ASE, Astom Corp.)보다 우수한 수준을 나 타내었다. 또한 제조된 막은 ASE 대비 낮은 전기적 저항 등 우수한 전기화학적 특성을 나타내었다. 0.459 M NaCl/0.0510 M Na2SO4의 해수와 0.0153 M NaCl/0.0017 M Na2SO4의 담수 조건에서 RED 성능을 평가한 결과 제조된 막을 적용하여 1.80 W/m2의 최대 전력 밀도를 얻었으며 이는 ASE 막 대비 40.6% 향상된 출력 성능이었다.
        4,300원
        26.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Composite-based piezoelectric devices are extensively studied to develop sustainable power supply and selfpowered devices owing to their excellent mechanical durability and output performance. In this study, we design a leadfree piezoelectric nanocomposite utilizing (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCTZ) nanomaterials for realizing highly flexible energy harvesters. To improve the output performance of the devices, we incorporate porous BCTZ nanowires (NWs) into the nanoparticle (NP)-based piezoelectric nanocomposite. BCTZ NPs and NWs are synthesized through the solidstate reaction and sol-gel-based electrospinning, respectively; subsequently, they are dispersed inside a polyimide matrix. The output performance of the energy harvesters is measured using an optimized measurement system during repetitive mechanical deformation by varying the composition of the NPs and NWs. A nanocomposite-based energy harvester with 4:1 weight ratio generates the maximum open-circuit voltage and short-circuit current of 0.83 V and 0.28 A, respectively. In this study, self-powered devices are constructed with enhanced output performance by using piezoelectric energy harvesting for application in flexible and wearable devices.
        4,000원
        27.
        2024.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this investigation, samples of the chemical (Hg1-xPbxBa2Ca1.8Mg0.2Cu3O8+δ) were prepared utilizing a solid-state reaction technique with a range of lead concentrations (x = 0.0, 0.05, 0.10, and 0.20). Specimens were pressed at 8 tons per square centimeter and then prepared at 1,138 K in the furnace. The crystalline structure and surface topography of all samples were examined using X-ray diffraction (XRD) and atomic force microscopy (AFM). X-ray diffraction results showed that all of the prepared samples had a tetragonal crystal structure. Also, the results showed that when lead was partially replaced with mercury, an increase in the lead value impacted the phase ratio, and lattice parameter values. The AFM results likewise showed excellent crystalline consistency and remarkable homogeneity during processing. The electrical resistivity was calculated as a function of temperature, and the results showed that all samples had a contagious behavior, as the resistivity decreased with decreasing temperature. The critical temperature was calculated and found to change, from 102, 96, 107, and 119 K, when increasing the lead values in the samples from 0.0 to 0.05, 0.10, and 0.20, respectively.
        4,000원
        28.
        2024.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        출혈성 담낭염은 담낭염의 형태 중 드문 것으로, 특히 그동안 출혈성 무결석 담낭염에 대한 보고는 제한적으로 이루어져 왔다. 본 증례보고에서는 척추추간판염으로 입원 중인 환자에게서 간기능 검사의 이상 소견이 발생하여 시행한 현장초음파상에서 보인 이상 소견을 기반으로 출혈성 담낭염을 의심하였다. 환자는 문헌상 초음파상에서 출혈성 담낭염의 특징으로 제시된 담낭벽의 불규칙한 비후, 후방 음영이나 층적을 동반하지 않는 내강 안 에코의 소견 등을 만족하였으며, 이어서 촬영한 CT에서도 조영제 누출의 소견이 보여 혈역학적으로 안정된 상태에서 조기에 경피적 배액술과 후속 담낭절제술을 시행하였다. 절제된 검체에서는 혈괴와 함께 화농성 담낭염 소견이 확인되었다. 기존에 항혈소판제, 항응고제 등의 약제 복용이나 알려진 출혈 경향이 없었던 화농성 척추추간판염 환자에게서 출혈성 무결석 담낭염을 현장초음파로 합병증 발생 전에 진단하여 치료한 증례로서 보고하는 바이다.
        4,000원
        29.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Highly safe lithium-ion batteries (LIBs) are required for large-scale applications such as electrical vehicles and energy storage systems. A highly stable cathode is essential for the development of safe LIBs. LiFePO4 is one of the most stable cathodes because of its stable structure and strong bonding between P and O. However, it has a lower energy density than lithium transition metal oxides. To investigate the high energy density of phosphate materials, vanadium phosphates were investigated. Vanadium enables multiple redox reactions as well as high redox potentials. LiVPO4O has two redox reactions (V5+/V4+/V3+) but low electrochemical activity. In this study, LiVPO4O is doped with fluorine to improve its electrochemical activity and increase its operational redox potential. With increasing fluorine content in LiVPO4O1-xFx, the local vanadium structure changed as the vanadium oxidation state changed. In addition, the operating potential increased with increasing fluorine content. Thus, it was confirmed that fluorine doping leads to a strong inductive effect and high operating voltage, which helps improve the energy density of the cathode materials.
        4,000원
        30.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 실제 자연의 숲과 인위적으로 통제가 가능한 디지털 환경에서의 가상현실(VR)을 활용한 가상 숲에서 의 체험이 피험자의 심리적 또는 생리적으로 미치는 치유효과를 알아보기 위하여 수행되었다. 이를 밝혀내기 위해 C대학 건강한 학부생 81명을 실험참가자로 2022. 9. 5~12. 9에 걸쳐 디지털 환경 내에서의 시각을 통한 산림자극 효과를 실험하였다. 실험은 디지털환경(2D, 3D)에서 숲 환경을 통한 시각적 산림자극의 심리적, 생리적 회복 효과를 평가하였다. 심리적 효과분석인 SRI(스트레스 반응척도)의 실험결과는 집단 간 차이가 통계적으로 유의한 것으로 나타났다. 심리적 스트레스 측정을 위한 SRI 실험 결과는 세 집단 중 Control 집단을 제외한 디지털 환경에서의 2D 집단은 사전과 사후 간 차이가 미미한 것으로 나타났다. 3D 집단에서는 사전보다 사후가 낮게 나타났다. 이 결과 산림을 기반으로 한 디지털 환경(2D, 3D)에서 시각을 통한 산림자극이 심리적 스트레스를 유의하게 감소시켜주는 효과가 있음을 확인하였다. 디지털환경 내에서 시각을 통한 산림자극이 EEG(뇌파)에 미치는 변화 분석 결과, 이완이나 안정화 때 활성화 되는 것으로 나타나는 알파파(RA)가 긴장이나 각성 때 발현되는 베타파(RB) 보다 활성화 되는 것으로 확인 되었다. 본 연구는 신체적 거동 불편 등 이동 제약으로 인하여 자연 숲 환경에서 체험을 할 수 없는 이용자들에게 디지털환경 내에서 가상현실(VR) 속 숲 환경을 구현하여 시각적 산림자극 체험 기회를 제공함으로서 심리적, 생리적 회복 환경을 만들어 주는데 사용 할 수 있을 것으로 사료된다. 이러한 연구 결과가 디지털 환경에서 산림치유에 대한 활용의 기반이 되길 기대하고, 가상현실(VR)을 이용한 프로그램이 산림치유 활동에 도움이 되기를 기대한다.
        4,200원
        31.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to investigate the dietary changes among adults living alone during the COVID-19 pandemic in the Republic of Korea. An online survey was conducted to examine dietary changes before (in 2019) and during (in 2021) the pandemic. The data from 337 adults living alone who responded to the survey were used for analysis. The proportion of the respondents reporting frequent food consumption at convenience stores (≥3 times/week) increased during the pandemic (p=0.024), and the proportion of those frequently eating ready-to-eat and ready-to-cook food (≥3 times/week) was more than doubled (p<0.001). Additionally, the proportion of those frequently consuming delivered food (≥3 times/week) increased by 2.5 times (p<0.001). In conclusion, the dietary habits of adults living alone changed significantly during the COVID-19 pandemic, which may have a negative impact on their health. Therefore, the development of customized nutrition management programs to improve the dietary habits of adults living alone during emergencies like a pandemic is deemed necessary. This study can serve as a foundation for understanding the dietary changes of adults living alone in prolonged crisis.
        4,000원
        32.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although many attempts have been made to solve the atmospheric diffusion equation, there are many limits that prevent both solving it and its application. The causes of these impediments are primarily due to both the partial differentiation term and the turbulence diffusion coefficient. In consideration of this dilemma, this study aims to discuss the methodology and cases of utilizing a passive air sampler to increase the applicability of atmospheric dispersion modeling. Passive air samplers do not require pumps or electric power, allowing us to achieve a high resolution of spatial distribution data at a low cost and with minimal effort. They are also used to validate and calibrate the results of dispersion modeling. Currently, passive air samplers are able to measure air pollutants, including SO2, NO2, O3, dust, asbestos, heavy metals, indoor HCHO, and CO2. Additionally, they can measure odorous substances such as NH3, H2S, and VOCs. In this paper, many cases for application were introduced for several purposes, such as classifying the VOCs’ emission characteristics, surveying spatial distribution, identifying sources of airborne or odorous pollutants, and so on. In conclusion, the validation and calibration cases for modeling results were discussed, which will be very beneficial for increasing the accuracy and reliability of modeling results.
        4,000원
        33.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 에너지 소모가 큰 기존 진공 증류 공정의 대안으로 친환경이면서 에너지 효율적인 투과증발 분리 공정을 이용하여 1,2 hexane diol/water (1,2 HDO/water) 혼합물에서 물을 분리하는 데 적용되었다. 사용한 분리막은 glutaraldehyde (GA)로 가교된 PVA를 알루미나 중공사 막(Al-HF) 내부에 코팅하여 사용하였다. 1,2 HDO/water 투과증발 분리공 정에서는 PVA/GA 비율, 경화 온도 및 투과증발 분리공정 운전 조건에 대한 막의 최적화를 연구하였다. 장기 안정성 시험에 서 PVA/GA (몰 비율 = 0.08, 경화 온도 = 80°C) 로 코팅된 Al-HF 막이 공정온도 40°C에서 1.90~2.16 kg/m2h 범위의 투과 도를 보였으며, 투과용액의 수분 함량은 99.5% (separation factor = 68) 이상이었다.
        4,000원
        34.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구 논문은 기후 변화에 대한 전 세계적인 우려와 온실 가스 배출 감소를 위한 필수적인 요구에 대응하여 마 이크로기공 고분자(PIM-1)의 이용을 탐구한 것이다. 연구는 PIM-1 막을 이산화탄소(CO2) 가스 분리 막으로 사용하는 현대적 인 소재로서의 응용에 집중하고 있다. 연구는 PIM-1 막의 합성, 분자량 제어, 그리고 제각각의 특성 분석 기술을 통해 포괄적 인 통찰을 제공하며, 이러한 특성 분석 기술을 통해 PIM-1의 고유한 교차결합 및 강성 구조에서 비롯된 내재적 다공성이 특 히 이산화탄소의 선택적 투과에 활용되고 있다. 논문은 PIM-1의 가교된 구조로부터 비롯된 내재적 다공성이 특히 이산화탄 소의 선택적 투과에 활용되고 있다. 논문은 PIM-1의 튜닝 가능한 화학적 특성을 강조하며, 가스 분리 막의 맞춤 및 최적화를 가능케 하는 특성에 대한 이해를 제시하고 있다. 분자량을 통제함으로써 고분자량(H-PIM-1) 막은 낮은 분자량 대비 더 뛰어 난 CO2 투과성과 선택성을 나타내며, 이를 통해 PIM-1 막의 특성을 조절하는 데 분자량의 중요성을 강조하고 있다. 연구 결 과는 PIM-1 막 특성을 조절하는 데 분자량이 중요한 역할을 하는 것을 강조하며, 이는 기후 변화의 긴급한 글로벌 도전에 대 응하기 위한 효율적이고 선택적인 CO2 포집을 위한 차세대 막 기술의 발전에 기여하고 있다.
        4,000원
        35.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Leydig cells, crucial for testosterone production, express ion channels like ANO1 that influence hormone secretion. This study investigates the expression and role of the Tandem of P domains in a weak inward rectifying K+ channel-related Acid-Sensitive K+-1 (TASK-1) channel in these cells, exploring its impact on testicular function and steroidogenesis. Methods: TASK-1 expression in Leydig cells was confirmed using immunostaining, while RT-PCR and Western Blot (WB) validated its expression in the TM3 Leydig cell line. The effect of a TASK-1 channel blocker on cell viability was assessed through live/dead staining and MTT assays. Additionally, the blocker’s effect on testosterone secretion was evaluated by measuring testosterone levels. Results: Immunohistochemical analysis revealed a predominant presence of TASK- 1, along with c-Kit and ANO-1, in Leydig cells adjacent to seminiferous tubules and also in Sertoli and spermatogenic cells. Expression levels of TASK-1 mRNA and protein were significantly higher in TM3 Leydig cells compared to TM4 Sertoli cells. In addition, blocking TASK-1 in TM3 cells with ML365 induced cell death but did not affect LHinduced testosterone secretion. Conclusions: These findings suggest that TASK-1 in Leydig cells is crucial for their viability and proliferation, highlighting its potential importance in testicular physiology.
        4,000원
        36.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pigs are considered a “mixing vessel” that can produce new influenza strains through genetic reassortments, which threaten public health and cause economic losses worldwide. We performed surveillance of swine influenza virus (SIV) using 114,140 nasal swabs from 11,414 Korean farms from 2009 to 2022, and characterized their genetic evolution at each farm level. A total of 169 farms out of the 11,414 (1.48%) were SIV-positive. The positivity rate for the H1N2 subtype, which is most dominant in the pig population, was 37.87% (64/169). Through hemagglutinin (HA) gene analysis, 64 H1N2-positive farms were classified into Eurasian avian-like (46/64, 71.88%), triple-reassortant (14/64, 21.88%), pdm09 (3/64, 4.69%), and classical swine (1/64, 1.56%) groups. The estimated evolutionary rate of HA in H1N2 from 2009 to 2022 in Korea is 1.5309 × 10-3/site/year (95% HPD intervals from 1.0003 × 10-3 to 2.1735 × 10-3) with an estimated mean growth rate of 0.0114. Estimates of the relative genetic diversity of clades over time suggested that the HA of H1N2 exhibited an increase in population size. The results of this study showed that the Eurasian avian-like-HA of the H1N2 subtype was dominant in the pig population. The continued evolution of the HA of H1N2, which is critical for cell entry, might lead to genetic diversity and the loss of vaccine cross-protection. These results indicate that continus surveillance is imperative for monitoring the evolution of the swine influenza virus.
        4,000원
        37.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Uncoupling protein 1 (UCP1) is a unique mitochondrial membranous protein expressed in brown adipose tissue (BAT) in mammals. While its expression in response to cold temperatures and adipogenic inducers is well-characterized in mammals and human infants, the molecular characterization and expression of UCP1 in fish remain unexplored. To address this gap, we analyzed UCP1 expression in response to adipogenic inducers in a fish cell line, rainbow trout gonadal cells (RTG-2), and compared it with UCP1 expression in three mammalian preadipocytes, 3T3-L1, T37i, and WT1 exposed to the Peroxisome proliferator-activated receptor gamma (PPARγ) agonists, rosiglitazone (Rosi). In mammalian preadipocytes, UCP1 protein was highly expressed by Rosi, with an induction of adipogenesis observed in a time-dependent manner. This suggests that UCP1 plays a significant role in adipogenesis in mammals. However, RTG-2 cells showed no response to adipogenic inducers and exhibited only marginal expressions of UCP1. These results imply that RTG-2 cells may lack crucial responsive mechanisms to adipogenic signals or that the adipogenic response is regulated by other mechanisms. Further studies are needed to confirm these phenomena in fish preadipocytes when an appropriate cell line is established in future research.
        3,000원
        38.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Foot-and-mouth disease (FMD), which affects cloven-hoofed animals, is economically important because of its highly contagious nature. FMD virus (FMDV), the causative agent of FMD, involves seven serotypes (O, A, Asia1, C, and SAT 1-3). Serotype Asia1 is unique to the Asian territory and is subdivided into nine genetic groups (G-I-IX) based on nucleotide variations in the VP1 sequence. Asia1 Shamir, the most representative Asia1 vaccine, is not highly protective against the Asia1/MOG/05 (G-V) lineage found in North Korea in 2007. Therefore, we investigated whether a chimeric virus strain (Asia1/MOG/Shamir), in which the VP4, VP2, and VP3 sequences of Asia1/MOG/05 were combined with the VP1 sequence of Asia1 Shamir, can simultaneously protect against both viruses. We determined the optimal viral growth conditions for the commercial utilization of this chimeric virus strain. Of the three types of cell culture media, the Cellvento medium resulted in the highest amount of antigen in the samples. The chimeric strain was proliferated in a small bioreactor to produce a test vaccine, and its immunogenicity was evaluated in pigs. The virus neutralization (VN) titer against the Asia1 Shamir virus was > 1/100 after the second immunization with the chimeric vaccine in pigs. In addition, a single dose of the test vaccine resulted in a VN titer of > 1/100 against the Asia1/MOG/05 strain. Taken together, our chimeric vaccine strain provided sufficient protection against the Asia1/MOG/05 and Asia1 Shamir viruses, suggesting its potential as a novel vaccine for both these strains.
        4,000원
        39.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Salivary gland dysfunction is a common complication of diabetes. Decreased saliva production and changes in saliva composition may cause oral diseases. Reactive oxygen species (ROS) generation in the salivary glands results in the loss of acinar cells and decreased saliva secretion. Glucagon-like peptide 1 (GLP-1) is the incretin hormone that regulates blood glucose level and can suppress ROS production and inflammation through its antioxidant effects. Dipeptidyl peptidase-4 (DPP-4) is an enzyme that breaks down GLP-1. In this study, we evaluated the pathological role of DPP-4 and GLP-1 on salivary gland dysfunction in type 2 diabetic db/db mice. We observed reduced salivary secretion and histopathological alteration of salivary glands in the db/db mice. The increased DPP-4 and decreased GLP-1 levels in the salivary glands were also detected in the db/db mice. Furthermore, the db/db mice had increased apoptosis and oxidative injury in salivary glands. There was an accumulation of advanced glycation end products and mucus in the salivary glands of the db/db mice. In conclusion, these results showed the possible involvement of DPP-4 and GLP-1, leading to increased ROS-induced apoptosis in diabetes-related salivary gland dysfunction. DPP-4 and GLP-1 may be a pharmacological target for patients with diabetes-related salivary gland dysfunction.
        4,300원
        40.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Iron is an essential nutrient for mammalian cells. Most iron absorption occurs in the duodenal epithelial cells and is regulated by hepcidin, which is produced and secreted in the liver. High hepcidin levels can cause iron deficiency anemia due to iron absorption failure. Inside the cell, iron conjugates with a porphyrin ring and is placed with an iron coordinated to heme. One of the heme-binding proteins, known as progesterone receptor membrane component 1 (Pgrmc1), is a non-canonical progesterone receptor associated with diverse molecular gene regulation. Previous studies showed that Pgrmc1 is related to iron homeostasis via hepcidin; however, these mechanisms remain to be elucidated. In the present study, to investigate the role of Pgrmc1 in mammalian iron metabolism, we introduced Pgrmc1 knockout (KO) mice and performed molecular biological analyses using qPCR and western blotting. Pgrmc1 deficiency decreased Hamp mRNA expression and hepcidin protein levels. However, Pgrmc1 deficiency failed to decrease Hamp transcript expression and hepcidin protein levels in siPGRMC1-transfected HepG2 cells and primary Pgrmc1 KO hepatocytes, respectively. PGRMC1 knockdown cells revealed low HAMP mRNA levels upon cyclic AMP (cAMP) activation, suggesting that PGRMC1 promotes HAMP mRNA transcription via cAMP activation. It has been implicated that hepatic Pgrmc1 cannot control hepcidin directly; however, the internal environment caused by the lack of Pgrmc1 may potentially cause low hepcidin levels.
        4,000원
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