• 폴리머
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• 제38권4호
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• pp.530-534
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• 2014

다양한 기공도를 갖는 폴리에틸렌 분리막은 리튬이차전지의 격리막과 마이크로필터로 사용되고 있다. 폴리에틸렌 분리막을 대용량 리튬이차전지의 격리막에 응용하기 위해서는 고다공성 분리막의 제조가 요구된다. 본 연구에서는 열유도 상분리 공정으로 고다공성 폴리에틸렌 분리막을 제조하는데 있어, BET가 무독성 희석제로 사용 가능한지 여부를 실험하였다. 폴리에틸렌/BET 혼합물의 UCST-거동을 관찰하여 BET가 폴리에틸렌 다공막 제조용 희석제로 사용 가능함을 확인하였다. 폴리에틸렌/BET 혼합물로부터 제조된 분리막이 같은 조성에서 폴리에틸렌/파라핀 오일로부터 제조된 분리막에 비해 1.8배 높은 기공도를 나타내었다.

• 한국응용과학기술학회지
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• 제23권4호
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• pp.280-289
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• 2006

Multilayer adsorptions and BET adsorption are analyzed statistical-mechanically. Which ensemble is selected for the analysis is unimportant, because each ensemble yields the same results. However, the amount of mathematical manipulations and the matter of convenience vary from ensemble to ensemble. Hence, multilayer adsorptions and BET adsorption are examined using a canonical and a grand canonical ensembles, and an ensemble of subsystems. Also, the characteristics of multilayer and BET adsorptions are delineated.

• Genomics & Informatics
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• 제18권4호
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• pp.37.1-37.11
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• 2020

BET inhibitor, as an epigenetic regulator inhibitor, reduces the expression of oncogenes such as Myc and Bcl-2, which affects cancer growth and development. However, it has modest activity because of the narrow therapeutic index. Therefore, combination therapy is necessary to increase the anti-tumor effect. Paclitaxel, an anti-mitotic inhibitor, is used as second-line therapy for gastric cancer (GC) as a monotherapy or combination. In this study, we performed RNA sequencing of GC cells treated with iBET-151 and/or paclitaxel to identify the differentially expressed genes associated with possible mechanisms of synergistic effect. We also performed Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses to determine the most enriched terms and pathways of upregulated and downregulated genes. We found 460 genes in which iBET-151 and paclitaxel combination treatment changed more than single-treatment or no-treatment. Thus, additional functional studies are needed, but our results provide the first evidence of the synergistic effect between iBET-151 and paclitaxel in regulating the transcriptome of GC cells.

• Animal Bioscience
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• 제35권3호
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• pp.475-483
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• 2022

Objective: Methionine (Met) is involved in methyl group transfer besides protein synthesis. As the availability is limited and cost is high for synthetic Met, reductions in its inclusion in broiler diet may be possible by supplementing the low Met diets with methyl donors (MD) like betaine (Bet), folic acid (FA), vitamin B12 (B12), and biotin (Bio). An experiment was conducted to study the effects of supplementing the MD on performance (average daily gain [ADG], daily feed intake, feed efficiency [FE]), anti-oxidant variables, immune responses and serum protein concentration in broilers fed sub-optimal concentrations of dietary Met. Methods: Maize-soybean meal diet was used as control (CD). Different MD like Bet (0.2%), B12 (0.1 mg), FA (4 mg), or Bio (1.5 mg/kg) were supplemented to basal diet (BD) having no supplemental Met. The BD without MD was kept for comparison. Each diet was fed ad libitum to 10 replicates of 25 chicks in each from 1 to 42 d of age. Results: At the end of experiment, the ADG in MD group was higher than BD and lower than CD. The FE improved with FA or Bet compared to the BD. Breast meat weight was higher in Bet compared to the BD, while it was intermediate between BD and CD in other groups. The lipid peroxidation reduced with Bio, B12, or Bet, while the glutathione peroxidase activity improved with Bio or B12 compared to the BD. Lymphocyte proliferation improved with Bet compared to the BD. The serum protein concentrations increased with FA, Bio, or Bet compared to those fed BD. Conclusion: It can be concluded that the ADG can be improved partially with supplementation of MD while the FE improved with FA or Bet. Some MD also reduced the stress indices and improved immune responses compared to the BD fed broilers.

• 대한환경공학회지
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• 제30권6호
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• pp.673-679
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• 2008

본 연구에서는 실리카 원으로 tetraethylorthosilcate(TEOS)를 이용하고, template로 cetyltrimethylammonium bromide(CTMABr)을 사용하여 메조포러스 실리카(mesoporous silica)를 수열합성 하였다. 최적의 합성 조건을 알기 위해 template와 실리카의 몰비를 조절하였다. 메조포러스 실리카의 표면 성질과 구조는 XRD, SEM 그리고 BET를 이용하여 살펴보았다. 비표면적($S_{BET}$), 전체 기공부피(V$_T$), 그리고 평균 기공지름(D$_{BJH}$)을 포함하는 N$_2$ 등온 흡착 특성은 BET식을 이용하여 확인하였다. 또한, 메조포러스 실리카의 Pb(II)와 Cd(II)의 흡착 특성은 Zeta potential과 ICP를 이용하여 측정하였다. 그 결과, N$_2$ 등온 흡착으로부터 S$_{BET}$는 100$\sim$1,500 m$^2$/g이었으며, 평균 기공 크기는 2$\sim$4 nm이었다. 메조포러스 실리카의 Pb이온과 Cd이온의 흡착 특성은 용액의 pH변화에 의존하였고, 기존의 흡착제인 실리카겔보다 더 좋은 흡착 거동을 보였다.

• 한국재료학회지
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• 제27권9호
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• pp.466-470
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• 2017

With the matters of climate change, energy security and resource depletion, a growing pressure exists to search for replacements for fossil fuels. Among various sustainable energy sources, hydrogen is thought of as a clean energy, and thus efficient hydrogen storage is a major issue. In order to realize efficient and safe hydrogen storage, various porous materials are being explored as solid-states materials for hydrogen storage. For those purposes, it is a prerequisite to characterize a material's textural properties to evaluate its hydrogen storage performance. In general, the textural properties of porous materials are analyzed by the Brunauer-Emmett-Teller (BET) measurement using nitrogen gas as a probe molecule. However, nitrogen BET analysis is sometimes not suitable for materials possessing small pores and surfaces with high curvatures like MOFs because the nitrogen molecule may sometimes be too large to reach the entire porous framework, resulting in an erroneous value. Hence, a smaller probe molecule for BET measurements (such as hydrogen) may be required. In this study, we describe a cost-effective novel cryostat for BET measurement that can reach temperatures below the liquefaction of hydrogen gas. Temperature and cold volume of the cryostat are corrected, and all measurements are validated using a commercial device. In this way, direct observation of the hydrogen adsorption properties is possible, which can translate directly into the determination of textural properties.

• 약학회지
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• 제49권3호
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• pp.198-204
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• 2005

Human foamy virus (HFV) integrase mediates integration of viral c-DNA into cellular DNA. In this process, HFV integrase recognizes its own viral DNA specifically and catalyzes insertion of viral c-DNA. In order to study catalytic domains and residues, three deletion mutants and two point mutants of HFV integrase were constructed and analyzed with respect to enzymatic activities. The C-terminal deletion mutant showed decreased enzymatic activities while the N-terminal deletion mutant lost the activities completely, indicating that the N-terminal domain is more important than the C-terminal domain in enzymatic reaction. The point mutants, in which an aspartic acid at the 164th position or a glutamic acid at the 200th position of the HFV integrase protein was changed to an alanine, lost the enzymatic activities completely. However, they were well complemented with other defective deletion mutants to recover enzymatic activities partially. Therefore, these results suggest that the aspartic acid and glutamic acid at the respective 164th and 200th positions are catalytic residues for enzymatic reaction.

• Asian-Australasian Journal of Animal Sciences
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• 제24권5호
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• pp.662-669
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• 2011

An experiment was conducted with broiler (Cobb 400) male chicks (n = 480) to determine the effect of betaine (Bet) supplementation (0 and 800 mg/kg) to diets containing five concentrations (15, 18, 20, 22 and 24 g/kg crude protein, CP) of methionine (Met) in a $2{\times}5$ factorial study for performance, carcass traits, immune responses, and serum parameters. Each diet was fed ad libitum from 1 to 42 d of age to 8 replicates of 6 chicks. Birds were housed in battery brooders placed in an open-sided poultry shed. Body weight gain, feed intake, feed conversion efficiency and slaughter variables were recorded at 21 and 42 d of age. Serum biochemical profile, antibody production against Newcastle disease (ND) and lymphocyte proliferation ratio (LPR) were analysed at 42 d of age. Supplementing Bet to diets containing sub-optimal concentrations of Met (15 g/kg) improved weight gain and breast yield at 21 d of age (p<0.01), and feed conversion efficiency at 42 d of age (p<0.05). Feed efficiency at 21 d of age, body weight gain at 42 d of age, slaughter variables except breast yield at 21 d of age and ND antibody titres were not affected (p>0.05) by the interaction. LPR increased (p<0.05) with Bet supplementation at 20 g Met/kg CP equal to those broilers fed 24 g Met without Bet. Bet supplementation enhanced the concentrations of protein, globulin and cholesterol in serum of broilers fed sub-optimal concentrations of Met. Results suggested that Bet supplementation (800 mg/kg diet) enhanced growth (21 d), feed conversion efficiency (42 d), breast yield and lymphocyte proliferation in broilers fed a diet containing 15 g Met/kg CP.

• 대한화학회지
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• 제42권6호
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• pp.696-702
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• 1998

황피독에 저항성을 가지는 수성가스 전환반응용 CoMo 계열 촉매에 알칼리금속염 첨가가 반응활성에 미치는 영향에 대하여 연구하였다. 알칼리금속염의 음이온과 양이온의 각각에 대한 영향을 알아보기 위하여 크게 두 경우로 나누어 촉매를 제조하였다. 그 하나는, 양이온을 K로 고정시키고 음이온을 변형시킨 경우로서, 반응활성의 변화는 BET 표면적의 변화로 설명되었다. 다른 한 경우는, 음이온을 $NO_3^-$로 고정시키고 알칼리금속 이온을 변형시킨 경우로서, Li가 첨가된 촉매의 활성이 가장 뛰어났으며 다른 양이온의 경우에는 서로 비슷한 낮은 활성을 보였다. 알칼리금속의 첨가량의 변화에 따른 BET 표면적의 변화와 반응활성의 변화가 같은 경향을 보였다. 알칼리금속염의 양이온을 변화시킨 경우에는 BET 표면적과 정8면체 배위구조 속의 $Mo^{6+}$에 대한 정4면체 배위구조 속의 $Mo^{6+}$의 비, 즉 $Mo^6+[T]/Mo^{6+}[O]$ 값의 복합적인 관계를 통해 반응활성의 변화를 설명할 수 있었다.

• 폴리머
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• 제29권4호
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• pp.399-402
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• 2005

본 연구에서는 친환경 가소제(BET, EBN, ESO)를 첨가한 에틸 셀룰로오스 필름과 몬모릴로나이트(MMT) 나노입자를 이용한 생분해성 나노복합재료를 Hakke mixer를 이용하여 용융가공 공정으로 제조하였다. 제조한 에틸 셀룰로오스 필름의 유리전이온도는 BET의 함량을 30 $wt\%$까지 증가시켰을 때 $122^{circ}C$에서 $71^{circ}C$로 감소하는 결과를 보였다. 여기에 2차 가소제로 에폭시화된 콩기름을 10$wt\%$ 함량으로 첨가할 경우에 유리전이온도가 $81^{circ}C$에서 $61^{circ}C$로 감소하였다. 가소효과는 EBN보다 BET가 더 효과적이었다. 에틸 셀룰로오스 필름에 가소제를 첨가할수록 기계적인 물성은 감소하였으나, 몬모릴로나이트의 첨가와 ESO가소제의 에폭시 개환중합을 통하여 기계적 물성을 증가시킬 수 있었다.