1,992 research outputs found
Superconductivity near the vibrational mode instability in MgCNi3
To understand the role of electron-phonon interaction in superconducting
MgCNi we have performed density functional based linear response
calculations of its lattice dynamical properties. A large coupling constant = 1.51 is predicted and contributing phonons are identified as
displacements of Ni atoms towards octahedral interstitials of the perovskite
lattice. Instabilities found for some vibrational modes emphasize the role of
anharmonic effects in resolving experimental controversies.Comment: 4 pages, 4 eps figures, replaces the older versio
Factors affecting In vitro methane production from cecum contents of White Roman geese
The goal of this research was to gain understanding of in vitro methane (CH4) production from the cecal contents of White Roman geese under various incubation conditions. Five experiments were conducted to ascertain the effects of i) incubation time, ii) pH, iii) the addition of formic acid to the culture media, iv) temperature, and v) the addition of salt to the nutritive liquid. Methane production increased significantly with the supplementation of formic acid in the culture fluid (Experiment III). Additionally, CH4 production Experiment V was higher than that without saline. In contrast, low CH4 production occurred under acidic conditions (pH âŠ5.4) and at temperatures higher or lower than typical bird body temperature (43 °C) without formic acid and saline solution in the culture media. Since bird body temperature cannot be controlled easily, approaches such as maintaining cecum fluid at low pH and preventing the formation of formic acid by adjusting the recipes of feeds could be considered for controlling in vivo CH4 production from the intestinal tract digesta of geese
Activation mechanisms of butyrylcholinesterase by 2,4,6-trinitrotoluene, 3,3-dimethylbutyl-N-n-butylcarbamate, and 2-trimethylsilyl-ethyl-N-n-butylcarbamate
The goal of this work was to propose a possible mechanism for the butyrylcholinesterase activation by 2,4,6-trinitrotoluene (TNT), 3,3-dimethylbutyl-N-n-butylcarbamate (1), and 2-trimethylsilyl-ethyl-N-n-butylcarbamate (2). Kinetically, TNT, and compounds 1 and 2 were characterized as the nonessential activators of butyrylcholinesterase. TNT, and compounds 1 and 2 were hydrophobic compounds and were proposed to bind to the hydrophobic activator binding site, which was located outside the active site gorge of the enzyme. The conformational change from a normal active site gorge to a more accessible active site gorge of the enzyme was proposed after binding of TNT, and compounds 1 and 2 to the activator binding site of the enzyme. Therefore, TNT, and compounds 1 and 2 may act as the excess of butyrylcholine in the substrate activator for the butyrylcholinesterase catalyzed reactions
What do they eat? A survey of eat-out habit of university students in Taiwan
[EN] Main purpose of this research is trying to understand food likeliness of
Taiwan college students, and probe whether these food are healthy. Three
survey steps are taken as: step 1, market survey for what kind of foods are
selling around the campuses; step 2, questionnaire investigation for students
food preference; step 3, analyzing whether these favorite foods are healthy or
not. The result shows: major consideration for students food selection are
âtasteâ and âpriceâ; 63% of students are taking food or snacks late at night
at least once a week. Top three most favorite foods are: Taiwanese fries (yan
su ji), carbon grilled chicken and fried fish steaks. Quantities of these foods
are small, prices are low, and easy access from roadside food stands.
Problems of them are high calories, easy to accumulate free radical in
human body, plus insanitary food processing environment. They are harmful
to student health. We suggest Taiwan government take it seriouslyShih, K.; Wang, M.; Shih, H.; Lee, S.; Lin, T. (2020). What do they eat? A survey of eat-out habit of university students in Taiwan. Editorial Universitat PolitĂšcnica de ValĂšncia. 421-430. https://doi.org/10.4995/INN2019.2019.10562OCS42143
Differences in the Fine Motor Performance of Children in Hong Kong and the United States on the Bruininks-Oseretsky Test of Motor Proficiency
ObjectiveCross-cultural differences in motor development is an important issue for occupational therapists to address in the assessment process. The cultural variability of performance in scores interpretation can mislead therapists in their decisions regarding the need for intervention. This study aimed to investigate the differences in fine motor performance on the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) between school-aged children of Hong Kong and the United States.MethodsThe four fine motor subtests of the BOTMP were administered to a random sample of 264 Hong Kong children aged 6â10 years. The performance scores of participants were compared with those of the American normative samples.ResultsNo significant difference was found in the scores between the two groups in Upper Limb Coordination and Response Speed subtests. However, the Hong Kong children performed significantly better in the subtests of Visual-Motor Control and Upper Limb Speed and Dexterity. In addition, significant gender difference was also present in all subtest scores except for the subtest of Upper Limb Speed and Dexterity.ConclusionThe results suggest that occupational therapists should be cautious of cross-cultural differences when interpreting fine motor performance scores using the BOTMP for Hong Kong school- aged children
Benzene-di-N-substituted carbamates as conformationally constrained substrate analogs of cholesterol esterase
Benzene-1,2-, 1,3-, and 1,4-di-N-substituted carbamates (1-15) are synthesized as the constrained analogs of gauche, eclipsed, and anti conformations, respectively, for the glycerol backbones of triacylglycerol. Carbamates 1-15 are characterized as the pseudo substrate inhibitors of cholesterol esterase. Long chain carbamates are more potent inhibitors than short chain ones. Comparison of different geometries for benzene-di-substituted carbamates, such as benzene-1,2-di-N-octylcarbamate (3) (ortho-3), benzene-1,3-di-N-octylcarbamate (8) (meta-8), and benzene-1,4-di-N-octylcarbamates (13) (para-13), indicates that inhibitory potencies are as followed: meta-8 > para-13 > ortho-3. Therefore, we suggest that the preferable conformation for the C(sn-1)-O/C(sn-2)-O glycerol backbone in the enzyme-triacylgycerol complex is the eclipsed conformation. Meanwhile, kinetic data indicate that among ortho, meta, and para carbamates, meta carbamates most resemble the substrate cholesterol ester
Responses of Helicoverpa armigera to tomato plants previously infected by ToMV or damaged by H-Armigera
We report the comparative inducing effects of a phytopathogen and a herbivorous arthropod on the performance of an herbivore. Tomato, Lycopersicon esculentum Mill., was used as the test plant, and tomato mosaic virus (ToMV) and corn earworm, Helicoverpa armigera Hubner, were used as the phytopathogen and herbivore, respectively. There were decreases in the efficiency of conversion of ingested food and efficiency of conversion of digested food when H. armigera was reared on tomato plants that had been previously inoculated with ToMV. However, virus inoculation did not affect feeding or oviposition preferences by H. armigera. In contrast, approximate digestibility, total consumption, relative growth rate, and relative consumption rate were lower for fourth-instar H. armigera that fed on plants previously damaged by the same herbivore. Feeding and oviposition were both deterred for H. armigera that fed on previously damaged plants. The duration of development of H. armigera was also prolonged under this treatment. Infection by ToMV and feeding damage by H. armigera increased the host plant's peroxidase and polyphenol oxidase activity, respectively, suggesting that the performance of H. armigera may be affected by the induced phytochemistry of the host plant. Overall, this study indicated that, in general, insect damage has a stronger effect than ToMV infection on plant chemistry and, subsequently, on the performance of H. armigera
Probing structure-function relationships of serine hydrolases and proteases with carbamate and thiocarbamate inhibitors
Benzene-1,3-di-N-n-octylcarbamate (1), benzene-1-hydroxyl-3-N-n-octylcarbamate (2), benzene-1,3-di-N-n-ocztylthiocarbamate (3), and benzene-1-hydroxyl-3-N-n-octylthiocarbamate (4) are synthesized from 1,3-benzene-diol and are characterized as the pseudo-substrate inhibitors of acetylcholinesterase, butyrylcholinesterase, cholesterol esterase, lipase, trypsin, and chymotrypsin. For these six enzyme inhibitions by 1-4, the pK(i) values are linearly correlated with their log k(i) values - Bronsted plots. Therefore, 1-4 inhibit these enzymes through a common mechanism. Moreover, both pK(i) and log k(i) values for the inhibitions by 1,3, and 4 are linearly correlated with both pK(i) and log k(i) values for the inhibitions by 2, respectively. Thus, the pK(i) values for the inhibitions by 2 are defined as the nucleophilicity constants of these enzymes (n(enzyme)). The log k(2) values for the inhibitions by 1-4 are also linearly correlated with the n(enzyme) values. Therefore, the nucleophilicity for serine hydrolases and proteases toward 1-4 also applies the Swain-Scott correlations
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