8 research outputs found
Effect of Fabric Anisotoropy on Quasi-Elastic Modulus of Sand and Clay
Get PDF砂質土および粘性土の擬似弾性係数に及ぼす堆積構造の異方性の影響を調べるために，堆積構造の異なる供試体を作製し，ベンダーエレメントを用いて直交する３方向のせん断波速度を求め比較した.さらに、繰り返し載荷試験および単調載荷試験からヤング率を求め，弾性係数の異方性を調べた.その結果，ベンダーエレメント試験では，堆積面に平行に伝播・振動するせん断波から得られたせん断弾性係数は,他の２方向で得られたそれよりも高く，今回行った試験では豊浦砂に比べNSF粘土のせん断弾性係数の異方性が高いことがわかった.同様に，載荷試験から求めたヤング率も，小ひずみ域では堆積面に垂直な方向に比べ平行な方向のヤング率が高く，ベンダーエレメント試験の結果と同様の傾向を示した.application/pdfjournal articl
Adsorption-Induced Changes in Ribonuclease A Structure and Enzymatic Activity on Solid Surfaces
No full textRibonuclease
A (RNase A) is a small globular enzyme that lyses
RNA. The remarkable solution stability of its structure and enzymatic
activity has led to its investigation to develop a new class of drugs
for cancer chemotherapeutics. However, the successful clinical application
of RNase A has been reported to be limited by insufficient stability
and loss of enzymatic activity when it was coupled with a biomaterial
carrier for drug delivery. The objective of this study was to characterize
the structural stability and enzymatic activity of RNase A when it
was adsorbed on different surface chemistries (represented by fused
silica glass, high-density polyethylene, and poly(methyl-methacrylate)).
Changes in protein structure were measured by circular dichroism,
amino acid labeling with mass spectrometry, and in vitro assays of
its enzymatic activity. Our results indicated that the process of
adsorption caused RNase A to undergo a substantial degree of unfolding
with significant differences in its adsorbed structure on each material
surface. Adsorption caused RNase A to lose about 60% of its native-state
enzymatic activity independent of the material on which it was adsorbed.
These results indicate that the native-state structure of RNase A
is greatly altered when it is adsorbed on a wide range of surface
chemistries, especially at the catalytic site. Therefore, drug delivery
systems must focus on retaining the native structure of RNase A in
order to maintain a high level of enzymatic activity for applications
such as antitumor chemotherapy
Mechanism of Photolytic Decomposition of N-Halamine Antimicrobial Siloxane Coatings
No full textGenerally, antimicrobial N-halamine siloxane coatings can be rehalogenated repetitively upon loss of their biocidal efficacies, a marked advantage over coatings containing other antimicrobial materials. However, the N-halamine materials tend to slowly decompose upon exposure to ultraviolet irradiation as in direct sunlight. In this work the mechanism of photolytic decomposition for the N-halamine siloxanes has been studied using spectroscopic and theoretical methods. It was found that the N-chlorinated coatings slowly decomposed upon UVA irradiation, whereas the unhalogenated coatings did not. Model compound evidence in this work suggests that upon UVA irradiation, the N−Cl bond dissociates homolytically, followed by a Cl radical migration to the alkyl side chain connected to the siloxane tethering group. An alpha and/or beta scission then occurs causing partial loss of the biocidal moiety from the surface of the coated material, thus precluding complete rechlorination. NMR, FTIR, GCMS, and computations at the DFT (U)B3LYP/6-311++G(2d,p) level of theory have been employed in reaching this conclusion
Straw blood cell count, growth, inhibition and comparison to apoptotic bodies-4
No full text2 cells that were transformed into straw cells. . Regeneration of regular cells from straw cells, three proteins at 63, 57, and 52 KD were abundantly expressed in the early stage of the process.<p><b>Copyright information:</b></p><p>Taken from "Straw blood cell count, growth, inhibition and comparison to apoptotic bodies"</p><p>http://www.biomedcentral.com/1471-2121/9/26</p><p>BMC Cell Biology 2008;9():26-26.</p><p>Published online 20 May 2008</p><p>PMCID:PMC2397387.</p><p></p
Inhibitory Activity of Carbonyl Compounds on Alcoholic Fermentation by Saccharomyces cerevisiae
No full textAldehydes and acids play important
roles in the fermentation inhibition
of biomass hydrolysates. A series of carbonyl compounds (vanillin,
syringaldehyde, 4-hydroxybenzaldehyde, pyrogallol aldehyde, and <i>o</i>-phthalaldehyde) were used to examine the quantitative
structure–inhibitory activity relationship of carbonyl compounds
on alcoholic fermentation, based on the glucose consumption rate and
the final ethanol yield. It was observed that pyrogallol aldehyde
and <i>o</i>-phthalaldehyde (5.0 mM) reduced the initial
glucose consumption rate by 60 and 89%, respectively, and also decreased
the final ethanol yield by 60 and 99%, respectively. Correlating the
molecular descriptors to inhibition efficiency in yeast fermentation
revealed a strong relationship between the energy of the lowest unoccupied
molecular orbital (<i>E</i><sub>LUMO</sub>) of aldehydes
and their inhibitory efficiency in fermentation. On the other hand,
vanillin, syringaldehyde, and 4-hydroxybenzaldehyde (5.0 mM) increased
the final ethanol yields by 11, 4, and 1%, respectively. Addition
of vanillin appeared to favor ethanol formation over glycerol formation
and decreased the glycerol yield in yeast fermentation. Furthermore,
alcohol dehydrogenase (ADH) activity dropped significantly from 3.85
to 2.72, 1.83, 0.46, and 0.11 U/mg at 6 h of fermentation at vanillin
concentrations of 0, 2.5, 5.0, 10.0, and 25.0 mM correspondingly.
In addition, fermentation inhibition by acetic acid and benzoic acid
was pH-dependent. Addition of acetate, benzoate, and potassium chloride
increased the glucose consumption rate, likely because the salts enhanced
membrane permeability, thus increasing glucose consumption
Straw blood cell count, growth, inhibition and comparison to apoptotic bodies-2
No full textBular transformation induced by dehydration. DNA ladder did appear (right panel) in CACO2 cells during a failed tubular transformation . Measurement of caspase-3/7 activity during dehydration induced tubular transformation in CACO2 cells. . Inhibition of tubular transformation by small molecules in vivo. Blood samples are counted from a single dose sc at 24 hr.<p><b>Copyright information:</b></p><p>Taken from "Straw blood cell count, growth, inhibition and comparison to apoptotic bodies"</p><p>http://www.biomedcentral.com/1471-2121/9/26</p><p>BMC Cell Biology 2008;9():26-26.</p><p>Published online 20 May 2008</p><p>PMCID:PMC2397387.</p><p></p
