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EVALUATION OF KINETIC PARAMETERS IN ENZYMIC NON-LINEAR PROGRESS REACTIONS

  • Lee Hyun-Jae;Kim Soo Ja
    • Journal of the Korean Chemical Society
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    • v.15 no.1
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    • pp.11-14
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    • 1971
  • A modified form of the integrated Michaelis-Menten equation would provide a useful means of evaluating enzyme kinetic parameters in nonlinear progress reaction with time. A slight modification of the Lineweaver-Burk form (and other variants) using for the velocity, the change in substrate concentration divided by time ($\={v}$), and for the velocity, the change in substrate for the time interval ($\={S}$), allows this linear reciprocal form to be used with negligible error even when as much as half of the substrate is utilized during the time interval.

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A Pilot Study Exploring Temporal Development of Gut Microbiome/Metabolome in Breastfed Neonates during the First Week of Life

  • Imad Awan;Emily Schultz;John D. Sterrett;Lamya'a M. Dawud;Lyanna R. Kessler;Deborah Schoch;Christopher A. Lowry;Lori Feldman-Winter;Sangita Phadtare
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.26 no.2
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    • pp.99-115
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    • 2023
  • Purpose: Exclusive breastfeeding promotes gut microbial compositions associated with lower rates of metabolic and autoimmune diseases. Its cessation is implicated in increased microbiome-metabolome discordance, suggesting a vulnerability to dietary changes. Formula supplementation is common within our low-income, ethnic-minority community. We studied exclusively breastfed (EBF) neonates' early microbiome-metabolome coupling in efforts to build foundational knowledge needed to target this inequality. Methods: Maternal surveys and stool samples from seven EBF neonates at first transitional stool (0-24 hours), discharge (30-48 hours), and at first appointment (days 3-5) were collected. Survey included demographics, feeding method, medications, medical history and tobacco and alcohol use. Stool samples were processed for 16S rRNA gene sequencing and lipid analysis by gas chromatography-mass spectrometry. Alpha and beta diversity analyses and Procrustes randomization for associations were carried out. Results: Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria were the most abundant taxa. Variation in microbiome composition was greater between individuals than within (p=0.001). Palmitic, oleic, stearic, and linoleic acids were the most abundant lipids. Variation in lipid composition was greater between individuals than within (p=0.040). Multivariate composition of the metabolome, but not microbiome, correlated with time (p=0.030). Total lipids, saturated lipids, and unsaturated lipids concentrations increased over time (p=0.012, p=0.008, p=0.023). Alpha diversity did not correlate with time (p=0.403). Microbiome composition was not associated with each samples' metabolome (p=0.450). Conclusion: Neonate gut microbiomes were unique to each neonate; respective metabolome profiles demonstrated generalizable temporal developments. The overall variability suggests potential interplay between influences including maternal breastmilk composition, amount consumed and living environment.

Enhanced Stability of LiCoO2 Cathodes in Lithium-ion Batteries Using Surface Modification by Atomic Layer Deposition

  • Jung, Yoon-S.;Cavanagh, Andrew S.;Dillon, Anne C.;Groner, Markus D.;George, Steven M.;Lee, Se-Hee
    • Journal of the Korean Ceramic Society
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    • v.47 no.1
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    • pp.61-65
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    • 2010
  • Ultrathin atomic layer deposition (ALD) coatings were found to enhance the performance of lithium-ion batteries (LIBs). Previous studies have demonstrated that $LiCoO_2$ cathode powders coated with metal oxides with thicknesses of $\sim100-1000{\AA}$ grown using wet chemical techniques improved LIB performance. In this study, $LiCoO_2$ powders were coated with conformal $Al_2O_3$ ALD films with thicknesses of only $\sim3-4{\AA}$ established using 2 ALD cycles. The coated $LiCoO_2$ powders exhibited a capacity retention of 89% after 120 charge-discharge cycles in the 3.3~4.5 V (vs. $Li/Li^+$) range. In contrast, the bare $LiCoO_2$ powders displayed only a 45% capacity retention. This dramatic improvement may result from the ultrathin $Al_2O_3$ ALD film acting to minimize Co dissolution or to reduce surface electrolyte reactions.

A Study of Public-Academia Cooperative Research in the USA for Improvement of Atmospheric Research in Korea: Based on the CIRES Case (한국의 관학 대기과학 연구 발전을 위한 미국 협동연구 사례 분석 - 콜로라도대학 환경과학협동연구소를 중심으로)

  • Song, Byunghyun
    • Atmosphere
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    • v.23 no.3
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    • pp.357-365
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    • 2013
  • A public-academia cooperative research system is suggested to improve the level of national research on atmospheric science and to enable the National Institute of Meteorological Research (NIMR) to meet its overloaded demand for research and results. As a practical example of cooperative research the CIRES case was reviewed. CIRES, the Cooperative Institute for Research in Environmental Sciences, located at the University of Colorado Boulder, is one of NOAA's 18 cooperative research centers located at universities across the U.S. NOAA, the National Oceanic and Atmospheric Administration, as a part of government, gives clear guideline for research topics and supplies research funds to research centers and audits their research processes and accomplishments. NOAA Boulder Laboratories, as a large, well-established government research center managed by government scientists, supplies depth of experiences and major research infra-structure to CIRES. CIRES pursues innovative and challenging research with their younger and brand-new researchers who are university employees. This cooperative work between government research organizations and the university produces high level research efficiently. Not only does Boulder have a beautiful natural setting where researchers live and work but also the city is a home to many scientific agencies and research facilities. This robust scientific network provides rich opportunities for CIRES researchers to collaborate with others in their scientific fields.

The coupling effect of drying shrinkage and moisture diffusion in concrete

  • Suwito, A.;Ababneh, Ayman;Xi, Yunping;Willam, Kaspar
    • Computers and Concrete
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    • v.3 no.2_3
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    • pp.103-122
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    • 2006
  • Drying shrinkage of concrete occurs due to the loss of moisture and thus, it is controlled by moisture diffusion process. On the other hand, the shrinkage causes cracking of concrete and affects its moisture diffusion properties. Therefore, moisture diffusion and drying shrinkage are two coupled processes and their interactive effect is important for the durability of concrete structures. In this paper, the two material parameters in the moisture diffusion equation, i.e., the moisture capacity and humidity diffusivity, are modified by two different methods to include the effect of drying shrinkage on the moisture diffusion. The effect of drying shrinkage on the humidity diffusivity is introduced by the scalar damage parameter. The effect of drying shrinkage on the moisture capacity is evaluated by an analytical model based on non-equilibrium thermodynamics and minimum potential energy principle for a two-phase composite. The mechanical part of drying shrinkage is modeled as an elastoplastic damage problem. The coupled problem of moisture diffusion and drying shrinkage is solved using a finite element method. The present model can predict that the drying shrinkage accelerates the moisture diffusion in concrete, and in turn, the accelerated drying process increases the shrinkage strain. The coupling effects are demonstrated by a numerical example.

Intelligent Robust Base-Station Research in Harsh Outdoor Wilderness Environments for Wildsense

  • Ahn, Junho;Mysore, Akshay;Zybko, Kati;Krumm, Caroline;Lee, Dohyeon;Kim, Dahyeon;Han, Richard;Mishra, Shivakant;Hobbs, Thompson
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.3
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    • pp.814-836
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    • 2021
  • Wildlife ecologists and biologists recapture deer to collect tracking data from deer collars or wait for a drop-off of a deer collar construction that is automatically detached and disconnected. The research teams need to manage a base camp with medical trailers, helicopters, and airplanes to capture deer or wait for several months until the deer collar drops off of the deer's neck. We propose an intelligent robust base-station research with a low-cost and time saving method to obtain recording sensor data from their collars to a listener node, and readings are obtained without opening the weatherproof deer collar. We successfully designed the and implemented a robust base station system for automatically collecting data of the collars and listener motes in harsh wilderness environments. Intelligent solutions were also analyzed for improved data collections and pattern predictions with drone-based detection and tracking algorithms.

Characteristics of Spawning Sites in the Natural Environment of the Korean Endemic Species, Liobagrus somjinensis (Siluriformes: Amblycipitidae) in the Yocheon (stream), Seomjingang (river), Korea (섬진강 수계 요천에 서식하는 한국고유종 섬진자가사리 Liobagrus somjinensis (Siluriformes: Amblycipitidae)의 자연산란장 특징)

  • Kim, Hyeong Su;Kim, Su Hwan;Park, Jong Young
    • Korean Journal of Ichthyology
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    • v.27 no.4
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    • pp.300-305
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    • 2015
  • The characteristics of 11 spawning sites in the natural environment of the Korean endemic species, Liobagrus somjinensis were investigated in the Yocheon (stream) of Seomjingang (river), located in Sikjeong-dong, Namwon-si, Jeollabuk-do, Korea from May to June 2015. The spawning sites had largely two parts, the upper region close to the surface of the waters and under region at bottom: the upper part was covered with a large and flat boulder over about 256 mm in size, whereas the under part consisted mainly of pebbles and sand. The large boulder put on the upper region may be seen as a bulwark for guarding eggs laid at the under (bottom) region. All the sites under the boulder showed a similar structure having a small hollow filled with an egg mass and an individual (male). The spawning bottoms left clean having no any benthic invertebrates and detritus. The egg shape was spherical, yellow and covered with a transparent membrane and the egg size was $3.31{\pm}0.15mm$ (n=30) in diameter. The development stage of each egg mass under the boulder was almost same from morula stage to formation stage of eye lens. The average number of eggs in 11 spawning sites was $121{\pm}35.5$ (84~176) and the average number of female fecundity in ovary was $143{\pm}31.3$ (110~232).