A multifrequency EPR study of poly(PADPA) synthesized with Trametes versicolor laccase from the aniline dimer p-aminodiphenylamine (PADPA) in the presence of anionic vesicles

Dejana Carić,Boris Rakvin,Marina Kveder,Katja Junker,Peter Walde,Edward Reijerse 한국물리학회 2015 Current Applied Physics Vol.15 No.11

Poly(PADPA) synthesized with the enzyme Trametes versicolor laccase (TvL) at pH = 3.5 in aqueous solution from the aniline dimer p-aminodiphenylamine (PADPA) was studied by EPR spectrometry at Xband and W-band frequencies. For the synthesis of poly(PADPA), vesicles formed from AOT (sodium bis- (2-ethylhexyl)sulfosuccinate) were used as structure-directing templates, and TvL/O2 as catalyst and oxidant. The isolated product is abbreviated as “poly(PADPA)-TvL-AOT” to distinguish it from poly(- PADPA) obtained by other means. The EPR spectrum of poly(PADPA)-TvL-AOT recorded at room temperature is complex. It can be decomposed into two separate Dysonetype spectral components. Furthermore, the spectra measured at high frequency exhibit a line broadening behavior in comparison to the spectra recorded at low frequency where there is no line broadening. This behavior was used to estimate the effective inter-chain spin exchange interaction for each monitored spectral component. The obtained effective distances between the polymer (or oligomer) chains in both identified components of poly(PADPA)-TvL-AOT can be explained by considering slightly different interactions between the chains and the AOT molecules present in the sample. Additionally, due to different average g tensor values, gav, of these components, it seems that each spectral component originates from one of two different molecular subunits (or local structural motifs) within the polymer (or oligomer) chains.

SiO2/MgCl2 이원 담체에 담지된 (n-BuCp)2ZrCl2 합성과 에틸렌-1-헥센 공중합

Ann Charise Cariño,박상준,고영수 한국공업화학회 2018 공업화학 Vol.29 No.4

본 연구에서는 (n-BuCp)2ZrCl2를 SiO2/MgCl2 이원 지지체에 담지시켰다. 촉매를 담지하기 전, SiO2/MgCl2 이원 지지체를 3종의 알킬알루미늄 화합물, 트리메틸알루미늄, 트리에틸알루미늄 또는 에틸알루미늄 세스퀴클로라이드로 표면처리 하였다. 합성된 표면 처리된 SiO2/MgCl2에 담지된 메탈로센 촉매로 에틸렌 및 1-헥센의 공중합을 하였다. 촉매특성 및 성능을 BET, XPS 분석, ICP-AES 분석 및 FE-SEM을 통해 비교 분석하였다. 생성된 공중합체를 DSC 분석, GPC 분석, 13C-NMR 분석 및 FE-SEM을 통해 비교 분석하였다. 합성된 SiO2/MgCl2 담지된 메탈로센 촉매의 분석은이들 촉매의 Zr 함량이 SiO2에 담지된 촉매에 비해 상대적으로 낮다는 것을 보여 주었다. 이것은 재결정된 MgCl2 및알킬알루미늄의 존재로 인한 SiO2의 표면적 감소에 기인할 수 있다. 또한, SiO2/MgCl2 담지된 메탈로센 촉매는 SiO2에담지된 메탈로센 촉매보다 활성이 높았으며 이 중 EASC-표면 처리 이원 지지체에 담지된 메탈로센촉매가 1.9 kg PE/(mmol-Zr*hr)의 가장 높은 활성을 보였다. 이것은 EASC가 강한 루이스 산으로 작용하기 때문이다. 또한, 사용된알킬알루미늄의 리간드가 클수록 생성된 중합체의 입자 표면이 더 거칠었다.

Effect of preparation condition in one-pot synthesis of MgCl2-supported Ziegler-Natta catalyst on ethylene-1-octene copolymerization

Ann Charise Cariño,고영수 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

MgCl2-supported Ziegler-Natta catalyst was prepared through one-pot synthesis. The effect of feedingconditions of 2-ethyl-1-hexanol (EHA) and Mg/Al molar ratio in feed were investigated in the one-potsynthesis. The longer EHA feeding time resulted in a higher concentration of Ti of the final catalyst,and consequently a higher activity in the ethylene polymerization. Moreover, a larger concentration ofEHA also resulted in higher activity for ethylene polymerization. A lower Mg/Al molar ratio in feed(M1) caused a smaller Ti content with a lower Ti binding energy in the final catalyst. However, M1catalyst showed very high activity in ethylene-1-octene copolymerizations. It also showed higher molecularweight capability as it produced a higher molecular weight copolymer.

The Combination of Naproxen and Citral Reduces Nociception and Gastric Damage in Rats

Mario I. Ortiz,Martha L. Ramírez-Montiel,Martha P. González-García,Héctor A. Ponce-Monter,Gilberto Castañeda-Hernández,Raquel Cariño-Cortés 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.10

It has been shown that the association of non-steroidal anti-inflammatory drugs with plant extracts can increase their antinociceptive activity, allowing the use of lower doses and, thus, limiting side effects. Therefore, the aim of this study was to examine the effects of the interaction between naproxen and citral on nociception and gastric injury in rats. Naproxen, citral, or combinations of naproxen and citral produced an antinociceptive effect. The administration of naproxen produced significant gastric damage, but this effect was not obtained with either citral or the naproxen-citral combination. The ED50 value was estimated for the individual drugs and an isobologram was constructed. The derived theoretical ED50 for the antinociceptive effect (423.8 mg/kg) was not significantly different from the observed experimental value (359.0 mg/kg); hence, the interaction between naproxen and citral mediating the antinociceptive effect is additive. These data suggest that the naproxen-citral combination interacts at the systemic level, produces minor gastric damage, and potentially has therapeutic advantages for the clinical treatment of inflammatory pain.

Iron nanoparticles as food additives and food supplements, regulatory and legislative perspectives

Sara Madai Chavarría-Fernández,Rubén Jiménez-Alvarado,Eva María Santos-López,Aldahir Alberto Hernández-Hernandez,Raquel Cariño-Cortés 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.6

Recently, the use of nanotechnology in food has gained great interest. Iron nanoparticles with unique chemical, physical and structural properties allow their potential use mainly as iron fortifiers, colorants and antimicrobial agents. However, in the market we can find only supplements and food colorants based on iron nanoparticles. Their use in food fortification has so far been focused only on in vitro and in vivo experimental studies, since the toxicological evaluation of these studies has so far been the basis for the proposals of laws and regulations, which are still in an early stage of development. Therefore, the aim of this work was to summarize the use of the different forms of iron nanoparticles (oxides, oxyhydroxides, phosphates, pyrophosphates and sulfates) as food additives and supplements and to resume the perspectives of legislation regarding the use of these types of nanoparticles in the food industry.

Artificial Closed Ecosystems for Human Habitation of Space

Cary A. Mitchell 한국원예학회 2004 한국원예학회 학술발표요지 Vol.2004 No.10

The effects of drag reducing polymers on flow stability : Insights from the Taylor-Couette problem

Cari S. Dutcher,Susan J. Muller 한국유변학회 2009 Korea-Australia rheology journal Vol.21 No.4

Taylor-Couette flow (i.e., flow between concentric, rotating cylinders) has long served as a paradigm for studies of hydrodynamic stability. For Newtonian fluids, the rich cascade of transitions from laminar, Couette flow to turbulent flow occurs through a set of well-characterized flow states (Taylor Vortex Flow, wavy Taylor vortices, modulated wavy vortices, etc.) that depend on the Reynolds numbers of both the inner and outer cylinders (Rei and Reo). While extensive work has been done on (a) the effects of weak viscoelasticity on the first few transitions for Reo=0 and (b) the effects of strong viscoelasticity in the limit of vanishing inertia (Rei and Reo both vanishing), the viscoelastic Taylor-Couette problem presents an enormous parameter space, much of which remains completely unexplored. Here we describe our recent experimental efforts to examine the effects of drag reducing polymers on the complete range of flow states observed in the Taylor- Couette problem. Of particular importance in the present work is 1) the rheological characterization of the test solutions via both shear and extensional (CaBER) rheometry, 2) the wide range of parameters examined, including Rei, Reo, and Elasticity number El, and 3) the use of a consistent, conservative protocol for accessing flow states. We hope that by examining the stability changes for each flow state, we may gain insights into the importance of particular coherent structures in drag reduction, identify simple ways of screening new drag reducing additives, and improve our understanding of the mechanism of drag reduction.

[프로젝트 리포트] 미국 서북부 건설 현장의 포스트 텐션 적용 장경간 무량판 최근 사례

Cary Kopczynski,박재욱(Park Jae Wook) 대한건축학회 2010 建築 Vol.54 No.3

The effects of drag reducing polymers on flow stability : Insights from the Taylor-Couette problem

Dutcher, Cari S.,Muller, Susan J. The Korean Society of Rheology 2009 Korea-Australia rheology journal Vol.21 No.4

Taylor-Couette flow (i.e., flow between concentric, rotating cylinders) has long served as a paradigm for studies of hydrodynamic stability. For Newtonian fluids, the rich cascade of transitions from laminar, Couette flow to turbulent flow occurs through a set of well-characterized flow states (Taylor Vortex Flow, wavy Taylor vortices, modulated wavy vortices, etc.) that depend on the Reynolds numbers of both the inner and outer cylinders ($Re_i$ and $Re_o$). While extensive work has been done on (a) the effects of weak viscoelasticity on the first few transitions for $Re_o=0$ and (b) the effects of strong viscoelasticity in the limit of vanishing inertia ($Re_i$ and $Re_o$ both vanishing), the viscoelastic Taylor-Couette problem presents an enormous parameter space, much of which remains completely unexplored. Here we describe our recent experimental efforts to examine the effects of drag reducing polymers on the complete range of flow states observed in the Taylor-Couette problem. Of particular importance in the present work is 1) the rheological characterization of the test solutions via both shear and extensional (CaBER) rheometry, 2) the wide range of parameters examined, including $Re_i$, $Re_o$ and Elasticity number E1, and 3) the use of a consistent, conservative protocol for accessing flow states. We hope that by examining the stability changes for each flow state, we may gain insights into the importance of particular coherent structures in drag reduction, identify simple ways of screening new drag reducing additives, and improve our understanding of the mechanism of drag reduction.

帝王切開가母子에게주는 得失

Tylar, Cari W. 藥業新聞社 1984 (月刊) 醫藥情報 Vol.1984 No.12