Stress relaxation of wood treated with the formaldehyde in bending and in torsion during adsorption of water vapor (Forestry)

吸湿過程における木材の応力緩和挙動に及ぼす水分傾斜に基づく内部応力の影響を検討するために, 種々の程度にホルマール化処理を施したヒノキ材(Table 1)について曲げと捩りの応力緩和を測定した。得られた主な結果を要約すると次のとおりである。(1)曲げと捩りのいずれの場合にも, ホルマール化処理を施した材と未処理材の吸湿にともなう応力緩和挙動は非常によく類似しているが, 緩和弾性率や剛性率の値には差がある(Figs. 3と4)。(2)捩りの場合, 乾燥状態から飽湿状態まで吸湿させたときの全緩和量と全膨潤率との間には直線関係が認められた(Fig. 6)。(3)前報で示した式(1)と(2)を用いて求めた緩和剛性率の変化割合N(t)と含水率のそれR(t)との比較から, 両曲線の傾向は非常によく類似しているが, 値はつねにN(t)の方がR(t)よりも大なること, ならびに, 両曲線間の差は抗膨潤能(A. E.)が大なるほど少なくなることなどを見出した(Fig. 7)。(4)非晶領域にある隣接鎖状分子間の水素結合の切断速度が吸湿過程の応力緩和速度を支配するという仮定に基づいて得られた式(12)から推定した応力緩和曲線と実測した緩和曲線との比較から, 吸湿過程における応力の緩和は水分傾斜に基づく内部応力に影響されていることを明らかにした。Measurements of stress relaxation in bending and in torsion during adsorption of water vapor were carried out on Hinoki wood (Chamaecyparis obtusa ENDL.) treated with formaldehyde to varying extent. The results obtained are as follows : (1) It was found that the stress relaxation behaviors of the treated wood in bending and torsion during adsorption were the same as those of the untreated one, although the values were different (Figs. 3 and 4). (2) The linear relation between the total amount of stress relaxation induced by moisture in torsion and the total swelling from dryness to saturation of moisture was recognized (Fig. 6). (3) The tendency between the fractional change of relaxation rigidity N(t) and that of moisture content R(t), calculated by Eqs. (1) and (2) shown in the previous paper, was very similar, but the values of N(t) were always greater than those of R(t). However, the difference between them reduced as the antiswelling efficiency increased (Fig. 7). (4) The stress relaxation curves observed were compared with the theoretical ones calculated by making use of Eq.(11) obtained on the basis of the assumption that the breaking rate of hydrogen bonds between adjacent chain molecules in the amorphous regions controlled the rate of stress relaxation (Figs. 8 and 9). From these results, it was evident that the stress relaxation during adsorption of water vapor was affected by the internal stresses due to the moisture gradients

The stress relaxation of wet wood during the diffusion of hydrochloric acid (Forestry)

ヒノキ材に塩酸を作用させたときの応力緩和を捩りの方法を用いて検討した。得られた結果は次のとおりである。1)塩酸にあらかじめ浸漬してある場合(過程A)の応力緩和は温度に, また飽水状態のもとでほぼ平衡に達するまで緩和させたのち塩酸を作用させた場合(過程B)の応力緩和は濃度に, 影響される。2)過程Bの曲線(塩酸添加後)は過程Aの曲線よりもつねに低い値を示す。このような現象を示す理由としては応力下で塩酸が木材中に拡散する場合無応力状態でのそれよりも粘弾性挙動に関与している結合を多く切断し, 分子の再配列や流動がいっそう容易になるためと考えられる。3)水で飽和された木材の塩酸に対するアクセシビリティは作用させた温度と濃度の関数として表わされる。The action of hydrochloric acid on Hinoki wood (Chamaecyparis obtusa S. et Z.) was studied using the stress relaxation technique by means of torsional method. The results obtained are as follows : 1) The rate and extent of stress relaxation in hydrochloric acid are dependent on the concentration of the acid used and the temperature at which measurements are made. Especially, the relaxation behaviors in the process-A (the specimen immersed previously in hydrochloric acid of various concentrations is allowed to relax at different temperatures.) are affected mainly by temperature, and in the process-B (the specimen saturated with distilled water is allowed to relax previously in water, and then the relaxation behaviors after the addition of the acid are observed.), by the concentration of the acid. 2) The values of the relaxation curves after the addition of the acid in the process-B are lower than those in the process-A at each temperature. As a reason for this phenomenon, assumedly the more number of bonds contributing to the stress relaxation behaviors when the acid diffuses into the specimen saturated with water under loading is broken than when the dry specimen was immersed in the acid under the state of no load, and the scission makes the rearrangement and the flow of chain molecules more easy under the process-B. 3) Relative accessibilities of wood saturated with water to hydrochloric acid are obtained by extrapolating the linear portions of the stress relaxation curves (log stress vs. time) following the acid addition to the zero time ordinates. The accessible fractions to hydrochloric acid in wood saturated with water increase as either the acid concentration or temperature increases. Therefore, its determination is relative and should be reported in a manner to indicate the experimental conditions used in its determination in detail in the case of wood, as described by Lemiska et al

Mitochondrial Swelling and Uncoupling Activity of Long-Chain Fatty Acids

The effect of various fatty acids on the swelling-contraction and oxidative phosphorylation of mitochondria from rat liver and Ehrlich ascites tumor cell have been studied and the results are as follows: 1. The swelling of rat liver mitochondria is induced by fatty acid. The extent of this uncoupling action is in the descending order of myristate, laurate, parlmitate, stearate and behenate in saturated fatty acid and linoleate, linoleneate, richinoleate and oleate in the unsaturated fatty acid. This swelling action is stronger with unsaturated fatty acids than that of saturated ones and cis form is stronger than trans form. 2. The uncoupling oxidative phosphorylation of rat liver mitochondria is also observed with these fatty acids and the activities are proportional to the degree of the swelling action. 3. The degree of swelling of rat liver mitochondria is proportional to the concentration of oleate and is inhibited by anaerobiosis and respiratory inhibitor except amytal. 4. The mitochondria swollen by fatty acid can be recontracted reversibly by ATP, Mg++ and bovine serum albumin. 5. The swelling action of sodium oleate is the strongest on mitochondria from rat liver, followed by those from the liver of Ehrlich ascites tumor bearing mouse, Ehrlich ascites tumor cells and solid Ehrlich tumor cells. 6. Sodium oleate inhibits the incorporation of 32p into ATP, ADP, GTP and UDPG in mitochondria.</p

The effects of high fatty acid on the glucose metabolism of Ehrlich ascites tumor cells

The effects of high fatty acids such as oleic, richinoleic, linoleic, linolenic, palmitic and stearic acids, on the respiration, glycolysis, organic phosphate synthesis of Ehrlich ascites tumor cells, were studied. The unsaturated fatty acids added to the media enhanced the respiration of the tumor cells at the concentration lower than 0.2 mM, after a short incubation period and inhibited the respiration in a high concentration 0.4 mM. The saturated fatty acids did not show such effect. All the fatty acids, both of saturated and unsaturated, effected the increase in lactate formation in tumor cells, especially markedly at higher concentration being accompanied by the WQ increase and RQ around 1. The respiration lowered by the fatty acids was ameliorated by the addition of glucose. The lactate formation from glucose was greatly enhanced by the addition of fatty acids but hardly from pyruvate. The unsaturated high fatty acids proved to have a strong uncoupling action for oxidative phosphorylation. This effect could be recognized slightly in the saturated fatty acids. The addition of high fatty acid resulted in the striking decrease in ATP and ADP with the increase in AMP. With these results the discussion was conducted concerning the specificity of tumor cell related to the glucose and fatty acid metabolism.</p

Action of Pyrroloquinolinequinol As an Antioxidant Against Lipid Peroxidation in Solution

This is the publisher's version, also available electronically from: http://online.liebertpub.com/doi/pdfplus/10.1089/ars.1999.1.4-547.The activities of pyrroloquinoline quinone (PQQ), a coenzyme of methanol dehydrogenase and amine oxidase, and its reduced form pyrroloquinoline quinol (PQQH2 ) as an antioxidant have been measured in solution. PQQH2 was stable in the absence of oxygen but rapidly auto-oxidized to PQQ in the presence of oxygen in water. PQQH2 was stable in an aprotic solvent such as acetonitrile, even in air. PQQ did not exert appreciable antioxidant activity, whereas PQQH2 exerted higher reactivity than a-tocopherol toward galvinoxyl radical and peroxyl radical. PQQH2 acted as a potent antioxidant against the oxidation of methyl linoleate in acetonitrile induced by azo compound and produced a clear induction period, from which the apparent stoichiometric number was obtained as 1.1. PQQH2 reduced the a-tocopheroxyl radical and spared a-tocopherol in the oxidation of methyl linoleate. These results suggest that PQQH2 may act as a potent antioxidant, particularly in combination with a-tocopherol. Antiox. Redox Signal. 1, 547-554

A Leaky RLS Algorithm: Its Optimality and Implementation

金沢大学理工研究域電子情報学系A leaky recursive least squares (LRLS) algorithm obtained by a criterion of the ridge regression with the exponential weighting factor was recently proposed by one of the authors. On the other hand, an optimization criterion for improving the method of total least squares (TLS) has been proposed by Chandrasekaran et al. In this work, it is expressed that there is a case where the equation obtained by the criterion of the LRLS algorithm is identical to one obtained by the extended criterion of Chandrasekaran et al. In addition, some implementations of the LRLS filter by using the method for updating the eigendecomposition of rank-one matrix updates, or by using the leaky least mean square (LLMS) algorithm, are introduced to decrease the computational complexity of the LRLS algorithm. Moreover, by means of computer experiments, it is shown that the LRLS and the LLMS algorithms yield more precise estimation parameters than the RLS algorithm when the method of Chandrasekaran et al. is more useful than that of LS and TLS. Besides, it is demonstrated that the LLMS algorithm can be effectively introduced into a noise reduction system for noisy speech signals to support the theoretical results in this work

Continuous Measurement of Tissue Oxygen and Carbon Dioxide Gas Tensions in Dog Liver in Ischemia/Reperfusion

An experiment was conducted to determine whether the oxygen and carbon dioxide gas tensions in liver tissue (PtO2 and PtCO2, respectively) reflect the state of microcirculation and/or metabolism in the ischemic liver. Subjects were divided into three groups: group 1, 30 min ischemia; group 2, 60 min ischemia; group 3, four times of intermittent 15 min ischemia after every 10 min of reperfusion. PtO2, PtCO2 and tissue blood flow (TBF) were measured by mass spectrometry, comparatively studied with the serum GOT level as an indicator of liver tissue damage. Furthermore, the time point at which the PtCO2 increase for 1 min initially became less than 1/2 of the maximum value was located on the transit curve of PtCO2, referred to as the critically anaerobic (CA) point, with which new indices of critically anaerobic score (CAS) and time (CAT) (see details in text) were developed. The profiles of PtO2 and PtCO2 during ischemia and reperfusion were clearly demonstrated, and the CA point was observed 12.7 +/- 2.9 min after induction of ischemia. PtO2 was positively correlated with TBF and negatively with the serum GOT level. Furthermore, not only CAS but also CAT were significantly correlated with PtO2, TBF, and the serum GOT level. It was concluded that PtCO2 reflects the state of anaerobic tissue metabolism during ischemia and PtO2 reflects the magnitude of microcirculatory disturbance and tissue injury caused by ischemia/reperfusion. Therefore, continuous monitoring of not only PtO2 but also PtCO2 is beneficial for patients undergoing hepatic surgery with ischemia

Genome-wide DNA methylation profiles in both precancerous conditions and clear cell renal cell carcinomas are correlated with malignant potential and patient outcome

To clarify genome-wide DNA methylation profiles during multistage renal carcinogenesis, bacterial artificial chromosome array-based methylated CpG island amplification (BAMCA) was performed. Non-cancerous renal cortex tissue obtained from patients with clear cell renal cell carcinomas (RCCs) (N) was at the precancerous stage where DNA hypomethylation and DNA hypermethylation on multiple bacterial artificial chromosome (BAC) clones were observed. By unsupervised hierarchical clustering analysis based on BAMCA data for their N, 51 patients with clear cell RCCs were clustered into two subclasses, Clusters AN (n = 46) and BN (n = 5). Clinicopathologically aggressive clear cell RCCs were accumulated in Cluster BN, and the overall survival rate of patients in Cluster BN was significantly lower than that of patients in Cluster AN. By unsupervised hierarchical clustering analysis based on BAMCA data for their RCCs, 51 patients were clustered into two subclasses, Clusters AT (n = 43) and BT (n = 8). Clinicopathologically aggressive clear cell RCCs were accumulated in Cluster BT, and the overall survival rate of patients in Cluster BT was significantly lower than that of patients in Cluster AT. Multivariate analysis revealed that belonging to Cluster BT was an independent predictor of recurrence. Cluster BN was completely included in Cluster BT, and the majority of the BAC clones that significantly discriminated Cluster BN from Cluster AN also discriminated Cluster BT from Cluster AT. In individual patients, DNA methylation status in N was basically inherited by the corresponding clear cell RCC. DNA methylation alterations in the precancerous stage may generate more malignant clear cell RCCs and determine patient outcome