208 research outputs found
Effect of Co-Solvents on Transesterification of Refined Palm Oil in Supercritical Methanol
This study examined the non-catalytic transesterification of refined palm oil, using supercritical methanol as a solvent with and without the presence of co-solvent, i.e. toluene, benzene, or hexane. Without the presence of a co-solvent, methyl esters can be produced via the non-catalytic transesterification of palm oil at 300oC, using a methanol to oil molar ratio of 45:1, with 89.4% conversion achieved after 50 min. The reaction performance could be improved by adding either benzene or toluene (with 10% v/v solvent to oil) as co-solvent to 92.1 and 95.1%, respectively, while reducing the required amount of excess methanol from 45:1 to 25:1. Under most conditions, the conversion of palm oil decreased with the addition of hexane due to its antisolvent properties
Hot Compressed Water Extraction of Lignin by Using a Flow-Through Reactor
Japanese rice straw, an agricultural by-product, was utilized for the extraction of lignin by hot compressed water at temperatures of 443 - 503 K and a pressure of 4.0 MPa using a flow-through system, a simple and environmentally friendly extraction method requiring no chemicals other than water. Under these conditions, thermal softening of the Japanese rice straw occurred, allowing the removal of lignin via depolymerization reactions. Lignin as an extraction product was analyzed using utraviolet-visible (UV-vis) spectrophotometry. Lignin recovery approached 85% when the extraction was performed at 443 and 473 K with a flow rate of 4.67 ml min-1. At a constant residence time, recovery amounts increased with increasing flow rate at each temperature. The results suggested that this process may result in an advanced plant biomass components extraction technology
Redox-regulating sirtuins in aging, caloric restriction, and exercise.
The consequence of decreased nicotinamide adenine dinucleotide (NAD(+)) levels as a result of oxidative challenge is altered activity of sirtuins, which, in turn, brings about a wide range of modifications in mammalian cellular metabolism. Sirtuins, especially SIRT1, deacetylate important transcription factors such as p53, forkhead homeobox type O proteins, nuclear factor κB, or peroxisome proliferator-activated receptor γ coactivator 1α (which controls the transcription of pro- and antioxidant enzymes, by which the cellular redox state is affected). The role of SIRT1 in DNA repair is enigmatic, because it activates Ku70 to cope with double-strand breaks, but deacetylation of apurinic/apyrimidinic endonuclease 1 and probably of 8-oxoguanine-DNA glycosylase 1 decreases the activity of these DNA repair enzymes. The protein-stabilizing effects of the NAD+-dependent lysine deacetylases are readily related to housekeeping and redox regulation. The role of sirtuins in caloric restriction (CR)-related longevity in yeast is currently under debate. However, in mammals, it seems certain that sirtuins are involved in many cellular processes that mediate longevity and disease prevention via the effects of CR through the vascular, neuronal, and muscular systems. Regular physical exercise-mediated health promotion also involves sirtuin-regulated pathways including the antioxidant-, macromolecular damage repair-, energy-, mitochondrial function-, and neuronal plasticity-associated pathways. This review critically evaluates these findings and points out the age-associated role of sirtuins
Exploiting Symmetry in Relational Similarity for Ranking Relational Search Results
Abstract. Relational search is a novel paradigm of search which focuses on the similarity between semantic relations. Given three words (A, B, C) as the query, a relational search engine retrieves a ranked list of words D, where a word D ∈ D is assigned a high rank if the relation between A and B is highly similar to that between C and D. However,ifC and D has numerous co-occurrences, then D is retrieved by existing relational search engines irrespective of the relation between A and B. To overcome this problem, we exploit the symmetry in relational similarity to rank the result set D. To evaluate the proposed ranking method, we use a benchmark dataset of Scholastic Aptitude Test (SAT) word analogy questions. Our experiments show that the proposed ranking method improves the accuracy in answering SAT word analogy questions, thereby demonstrating its usefulness in practical applications
Subcritical Water Extraction and Direct Formation of Microparticulate Polysaccharide Powders from Ganoderma Lucidum
Ganoderma lucidum (hereafter G. lucidum) has been known as a food and raw material used in the development of medications because of its high content of polysaccharides, or ?-glucans, which support the immune function. In this work, subcritical water was applied to utilize G. lucidum for the extraction of polysaccharides at temperatures of 373–463K and a pressure level of 4.0 MPa using a semi-batch system. Furthermore, these extracts were atomized and contacted with hot air to produce microsphere particles. During extraction, thermal softening of G. lucidum occurred, allowing the removal of the polysaccharides and protecting other constituents in G. lucidum via hydrolysis. Scanning electron microscope (SEM) images showed that the microsphere particles formed were spherical and dimpled or shriveled particles with diameters varying from 1 to 6 ?m. Characteristics of the molecular mass revealed that main massed peaks of water soluble products were distributed at around 688–2636 m/z with a peak-to-peak mass difference of 162 m/z, consistent with the repeating unit of the glucans
Study of Field-Induced Magnetic Order in Singlet-Ground-State Magnet CsFeCl
The field-induced magnetic order in the singlet-ground-state system
CsFeCl has been studied by measuring magnetization and neutron diffraction.
The field dependence of intensity for the neutron magnetic reflection has
clearly demonstrated that the field-induced ordered phase is described by the
order parameter . A condensate growth of magnons is investigated through
the temperature dependence of and , and this ordering is
discussed in the context of a magnon Bose-Einstein condensation. Development of
the coherent state and the static correlation length has been observed in the
incommensurate phase in the field region of , a satellite peak was found in coexistence with the commensurate
peak at the phase boundary around 10 T, which indicates that the tilt of the
c-axis would be less than in the whole experiments.Comment: 5 pages, 5 figure
Hadronic EDMs in SUSY SU(5) GUTs with Right-handed Neutrinos
We discuss hadronic EDM constraints on the neutrino sector in the SUSY SU(5)
GUT with the right-handed neutrinos. The hadronic EDMs are sensitive to the
right-handed down-type squark mixings, especially between the second and third
generations and between the first and third ones, compared with the other
low-energy observables, and the flavor mixings are induced by the neutrino
Yukawa interaction. The current experimental bound of the neutron EDM may imply
that the right-handed tau neutrino mass is smaller than about 10^{14} GeV in
the minimal supergravity scenario, and it may be improved furthermore in future
experiments, such as the deuteron EDM measurement.Comment: 17 pages, 4 figures; comments and 2 figures adde
<Abstract of published report>Molecular analysis of extracellular-superoxide dismutase gene associated with high level in serum.
Large Supersymmetric Contribution to CP Asymmetry of B_d \to \phi K_S from Left-Handed Squark Mixing
Supersymmetric contribution to the CP asymmetry of B_d \to \phi K_S is
re-examined. It is emphasized that our analysis takes into account the recently
found constraint from the mercury electric dipole moment, in addition to the
well-known constraint from the branching ratio of b \to s \gamma. We show that,
despite these constraints, the CP asymmetry can considerably deviate from the
Standard Model prediction, if the CP-odd flavor mixing comes from left-handed
squarks. Alignment mechanism of sfermion masses and mixing may imprint the
required flavor mixing at high energy scale.Comment: 10 pages, 2 figure
Characteristics of Japanese Duchenne and Becker muscular dystrophy patients in a novel Japanese national registry of muscular dystrophy (Remudy)
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