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Anomalous Stretchable Conductivity Using an Engineered Tricot Weave
Lee, Yong-Hee,Kim, Yoonseob,Lee, Tae-Ik,Lee, Inhwa,Shin, Jaeho,Lee, Hyun Soo,Kim, Taek-Soo,Choi, Jang Wook American Chemical Society 2015 ACS NANO Vol.9 No.12
<P>Robust electric conduction under stretching motions is a key element in upcoming wearable electronic devices but is fundamentally very difficult to achieve because percolation pathways in conductive media are subject to collapse upon stretching. Here, we report that this fundamental challenge can be overcome by using a parameter uniquely available in textiles, namely a weaving structure. A textile structure alternately interwoven with inelastic and elastic yarns, achieved via a tricot weave, possesses excellent elasticity (strain up to 200%) in diagonal directions. When this textile is coated with conductive nanomaterials, proper textile engineering allows the textile to obtain an unprecedented 7-fold conductivity increase, with conductivity reaching 33,000 S cm<SUP>–1</SUP>, even at 130% strain, due to enhanced interyarn contacts. The observed stretching conductivity can be described well using a modified 3D percolation theory that reflects the weaving effect and is also utilized for stretchable electronic interconnects and supercapacitors with high performance.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-12/acsnano.5b05465/production/images/medium/nn-2015-05465x_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b05465'>ACS Electronic Supporting Info</A></P>
( Jaeho Lee ),( Yu Ri Choi ),( Miso Kim ),( Jung Mi Park ),( Moonjong Kang ),( Jaewon Oh ),( Chan Joo Lee ),( Sungha Park ),( Seok-min Kang ),( Ichiro Manabe ),( Soo-jin Ann ),( Sang-hak Lee ) 생화학분자생물학회(구 한국생화학분자생물학회) 2021 BMB Reports Vol.54 No.5
Our understanding of the differential effects between specific omega-3 fatty acids is incomplete. Here, we aimed to evaluate the effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on T-helper type 1 (Th1) cell responses and identify the pathways associated with these responses. Naïve CD4<sup>+</sup> T cells were co-cultured with bone marrow-derived dendritic cells (DCs) in the presence or absence of palmitate (PA), DHA, or EPA. DHA or EPA treatment lowered the number of differentiated IFN-γ-positive cells and inhibited the secretion of IFN-γ, whereas only DHA increased IL-2 and reduced TNF-α secretion. There was reduced expression of MHC II on DCs after DHA or EPA treatment. In the DC-independent model, DHA and EPA reduced Th1 cell differentiation and lowered the cell number. DHA and EPA markedly inhibited IFN-γ secretion, while only EPA reduced TNF-α secretion. Microarray analysis identified pathways involved in inflammation, immunity, metabolism, and cell proliferation. Moreover, DHA and EPA inhibited Th1 cells through the regulation of diverse pathways and genes, including Igf1 and Cpt1a. Our results showed that DHA and EPA had largely comparable inhibitory effects on Th1 cell differentiation. However, each of the fatty acids also had distinct effects on specific cytokine secretion, particularly according to the presence of DCs. [BMB Reports 2021; 54(5): 278-283]
Lee, Jaeho,Kim, Shanghyeon,Sim, Ji-Yeong,Lee, Daeun,Kim, Ha Hyung,Hwang, Jae Sam,Lee, Dong Gun,Park, Zee-Yong,Kim, Jae Il Elsevier 2019 Biochimica et biophysica acta, Biomembranes Vol.1861 No.1
<P><B>Abstract</B></P> <P>The emergence of drug-resistant pathogenic bacteria threatens human health. Resistance to existing antibiotics is increasing, while the emergence of new antibiotics is slowing. Cationic antimicrobial peptides (CAMPs) are fascinating alternative antibiotics because they possess a broad spectrum of activity, being active against both Gram-positive and Gram-negative bacteria including those resistant to traditional antibiotics. However, low bioavailability resulting from enzymatic degradation and attenuation by divalent cations like Mg<SUP>2+</SUP> and Ca<SUP>2+</SUP> limits their use as antibiotic agents. Here, we report the design of new CAMPs showing both high antibacterial activity and serum stability under physiological ion concentrations. The peptides were designed by applying two approaches, the use of <SMALL>D</SMALL>-enantiomer and lipidation. Based on the sequence of the CopW (LLWIALRKK-NH<SUB>2</SUB>), a nonapeptide derived from coprisin, a series of novel <SMALL>D</SMALL>-form CopW lipopeptides with different acyl chain lengths (C6, C8, C10, C12, C14, and C16) were synthesized and evaluated with respect to their activity and salt sensitivity. Among the analogs, the <SMALL>D</SMALL>-form lipopeptide dCopW3 exhibited MIC values ranging from 1.25 to 5 μM against multidrug-resistant bacteria. Significantly, this compound did not induce bacterial resistance and was highly stable in human serum proteases. The results emphasize the potential of cationic <SMALL>D</SMALL>-form lipopeptide as therapeutically valuable antibiotics for treating drug-resistant bacterial infections.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CopW analogs were designed by introduction of <SMALL>D</SMALL>-amino acid and fatty acid to improve salt sensitivity and serum stability </LI> <LI> In physiological salt condition, dCopW3 most efficiently inhibited MDR-pathogen growth with a low hemolytic activity </LI> <LI> dCopW3 rapidly killed bacteria <I>via</I> bacterial membrane disruption </LI> <LI> dCopW3 reduced the possibility of the potential emergence of bacterial resistance </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
이재호 ( Jaeho Lee ),조광훈 ( Gwang-hun Cho ),이금연 ( Geumyeon Lee ),임창용 ( Changyong Yim ),이영세 ( Young-sei Lee ),김태욱 ( Taewook Kim ) 한국공업화학회 2023 공업화학 Vol.34 No.4
선택적 촉매 환원(SCR)은 질소산화물 배출을 줄이는 가장 효과적인 방법이지만, V<sub>2</sub>O<sub>5</sub>-WO<sub>3</sub>/TiO<sub>2</sub> 촉매가 좁은 작동온도(300~400 ℃) 범위를 가지기 때문에, V<sub>2</sub>O<sub>5</sub>-WO<sub>3</sub>/TiO<sub>2</sub> 촉매의 작동 온도범위가 200~450 °C인 새로운 촉매를 개발하였다. SCR 과정에서 생성되는 촉매 독인 황산암모늄은 350 °C 이상으로 가열함으로써 제거할 수 있다. 촉매 활성 부위의수를 증가시키고 활성 물질의 분산을 촉진하기 위해 TiO<sub>2</sub> 지지체에 티타늄 이소프로폭사이드(TTIP) 처리를 여러 TTIP/TiO<sub>2</sub> 질량비로 진행하였다. 그 중 5 wt% TTIP 부하에서 높은 W 분산성으로 인해 열 안정성이 증가하였고 V<sup>5+</sup>가 형성되어 최적의 성능을 보였다. 5 wt% TTIP 부하로 처리된 촉매를 One-step co-precipitation으로 제조하였을 때 기존의 방법보다 더 나은 V-OH와 W-OH 분산 및 상호작용 향상이 나타나 더 낮은 온도에서 높은 촉매 활성으로 인해 향상된 성능을 보였다. 이를 향후 TTIP를 이용하여 TiO<sub>2</sub>촉매의 표면을 개선하려는 연구자에게 이해하기 쉽게 설명하고자 하였다. Selective catalytic reduction (SCR) is the most effective method for reducing nitrogen oxide emissions, but the operating temperature range of V<sub>2</sub>O<sub>5</sub>-WO<sub>3</sub>/TiO<sub>2</sub> catalysts is narrow (300~400 °C). In this study, a new catalyst with an operating temperature range of 200~450 °C was developed. The catalyst poison, ammonium bisulfate, generated during the SCR process can be removed by heating above 350 °C. To increase the number of active sites and promote the dispersion of active materials, titanium isopropoxide (TTIP) treatment was performed on the TiO<sub>2</sub> support with various TTIP/TiO<sub>2</sub> mass ratios. Among them, the 5 wt% TTIP loaded catalyst showed improved performance due to higher thermal stability caused by high W dispersion and the formation of V5+. In addition, the 5 wt% TTIP-loaded catalyst prepared by a one-step co-precipitation method showed greater V-OH and W-OH dispersion and enhanced interactions in contrast to conventional methods, resulting in higher catalytic activity at lower temperatures. This review article aims to provide an accessible explanation for researchers investigating how to improve the surface properties of TiO2 catalysts using TTIP.