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排序方式: 共有1644条查询结果,搜索用时 15 毫秒
101.
Masao Sugawara Masamitsu Kataoka Kazunori Odashima Yoshio Umezawa 《Thin solid films》1989,180(1-2):129-133
Biomimetic “ion-channel sensors” based on host-guest molecular recognition were constructed by incorporating several kinds of receptor molecules in Langmuir-Blodgett (LB) molecular assemblies deposited directly on glassy carbon electrodes. The receptors used were valinomycin, bis(crown ether)s, macrocyclic polyamine and cyclodextrin polyamine. The binding of charged stimulants (metal ions, inorganic and organic anions) to these receptors induced a marked increase (or decrease) in the ion permeability of the membranes, as detected by cyclic voltammetry using [Fe(CN)6]4- or [Ru(bpy)3]2+ as marker ion. Such a mode of response, corresponding to model “channel opening (or closing)”, can be explained on the basis of the charge-charge interaction involving the stimulant, marker ion and lipid. 相似文献
102.
Claudia Penna Saveria Femmin Fabrizio Caldera Alberto Rubin Pedrazzo Claudio Cecone Edoardo Alfì Stefano Comit Takanobu Higashiyama Francesco Trotta Pasquale Pagliaro Roberta Cavalli 《International journal of molecular sciences》2021,22(8)
Heart failure (HF) prevalence is increasing among the aging population, and the mortality rate remains unacceptably high despite improvements in therapy. Myocardial ischemia (MI) and, consequently, ischemia/reperfusion injury (IRI), are frequently the basis of HF development. Therefore, cardioprotective strategies to limit IRI are mandatory. Nanocarriers have been proposed as alternative therapy for cardiovascular disease. Controlled reoxygenation may be a promising strategy. Novel nanocarriers, such as cyclic nigerosyl-nigerose (CNN), can be innovative tools for oxygen delivery in a controlled manner. In this study we analyzed new CNN-based formulations as oxygen nanocarriers (O2-CNN), and compared them with nitrogen CNN (N2-CNN). These different CNN-based formulations were tested using two cellular models, namely, cardiomyoblasts (H9c2), and endothelial (HMEC) cell lines, at different concentrations. The effects on the growth curve during normoxia (21% O2, 5% CO2 and 74% N2) and their protective effects during hypoxia (1% O2, 5% CO2 and 94% N2) and reoxygenation (21% O2, 5% CO2 and 74% N2) were studied. Neither O2-CNN nor N2-CNN has any effect on the growth curve during normoxia. However, O2-CNN applied before hypoxia induces a 15–30% reduction in cell mortality after hypoxia/re-oxygenation when compared to N2-CNN. O2-CNN showed a marked efficacy in controlled oxygenation, which suggests an interesting potential for the future medical application of soluble nanocarrier systems for MI treatment. 相似文献
103.
Calcium oxide/carbon dioxide reactivity in a packed bed reactor of a chemical heat pump for high-temperature gas reactors 总被引:2,自引:0,他引:2
Yukitaka Kato Mitsuteru Yamada Toshihiro Kanie Yoshio Yoshizawa 《Nuclear Engineering and Design》2001,210(1-3):1-8
The thermal performance of a chemical heat pump that uses a calcium oxide/carbon dioxide reaction system was discussed as a heat storage system for utilizing heat output from high temperature gas reactors (HTGR). Calcium oxide/carbon dioxide reactivity for the heat pump was measured using a packed bed reactor containing 1.0 kg of reactant. The reactor was capable of storing heat at 900 °C by decarbonation of calcium carbonate and generating up to 997 °C by carbonation of calcium oxide. The amount of stored heat in the reactor was 800–900 kJ kg−1. The output temperature of the reactor could be controlled by regulating the carbonation pressure. The thermal storage performance of the reactor was superior to that of conventional sensible heat storage systems. A heat pump using this CaO/CO2 reactor is expected to contribute to thermal load leveling and to realize highly efficient utilization of HTGR output due to the high heat storage density and high-quality temperature output of the heat pump. 相似文献
104.
Koji Takahashi Sota Watanabe Yoshio Urabe Masakazu Hisatsune 《Nuclear Engineering and Design》2009,239(12):2719-2727
Low cycle fatigue tests were conducted using 100A elbow specimens made of STPT410 carbon steel with local wall thinning. Local wall thinning by erosion/corrosion was simulated by machined pipe wall thinning. The local wall thinning areas were located at three different areas, called extrados, crown and intrados. The elbow specimens were subjected to cyclic in-plane bending under displacement control without internal pressure. The effects of eroded conditions, such as eroded ratio, eroded angle and position, on the low cycle fatigue behavior and fatigue life were discussed by using experimental results and finite element analyses. Also the location of crack initiation and the crack growth direction could be predicted by three dimensional elasto-plastic finite element analyses. In addition, the safety margin of eroded elbows against seismic loading was discussed by comparing the fictitious stress of elbows with the allowable stress limit demanded by the design code. 相似文献
105.
Giovanni Maizza Salvatore Grasso Yoshio Sakka Tetsuji Noda Osamu Ohashi 《Science and Technology of Advanced Materials》2007,8(7-8):644
A combined experimental/numerical methodology is developed to fully consolidate pure ultrafine WC powder under a current-control mode. Three applied currents, 1900, 2100 and 2700 A, and a constant pressure of 20 MPa were employed as process conditions. The developed spark plasma sintering (SPS) finite-element model includes a moving-mesh technique to account for the contact resistance change due to sintering shrinkage and punch sliding. The effects of the heating rate on the microstructure and hardness were investigated in detail along the sample radius from both experimental and modeling points of view. The maximum hardness (2700 HV10) was achieved for a current of 1900 A at the core sample, while the maximum densification was achieved for 2100 and 2700 A. A direct relationship between the compact microstructure and both the sintering temperature and the heating rate was established. 相似文献
106.
Inside Cover: Molecular Design of an Environmentally Sensitive Fluorescent Nucleoside, 3‐Deaza‐2′‐Deoxyadenosine Derivative: Distinguishing Thymine by Probing the DNA Minor Groove (ChemBioChem 11/2014) 下载免费PDF全文
107.
Formaldehyde (HCHO) emitted from the furniture and the walls in the rooms injures the eyes, nose, and respiratory organs and causes allergies, which is called sick house syndrome. We designed and synthesized novel colorimetric HCHO-sensing molecules (KD-XA01 and KD-XA02) which possess an enaminone structure and developed a hand-held instrument to monitor indoor HCHO gas with the use of KD-XA01. These sensing molecules produced speedy color changes from colorless to yellow under mild conditions, which was caused by the fact that the enaminone structure in the reagent reacts with HCHO to give a lutidine derivative. This reaction took place not only in the solution phase but also in the solid phase (surface of the cellulose paper). To take advantage of this phenomena, a handy and rapid monitoring system has been developed for detecting indoor HCHO gas using a highly sensitive and selective detection tablet constructed from the porous cellulose paper that contains silica gel as an adsorbent, KD-XA01, and phosphoric acid under optimum conditions. This instrument detected the surface color change of the tablet from white to yellow, which was monitored as a function of the intensity of the reflected light illuminated by an LED (475 nm). The response was proportional to the HCHO concentration at a constant sampling time and flow rate; 0.05 ppm HCHO, which is under the standard value set by the World Health Organization, was able to be detected in 5 min. The detection limit was 0.005 ppm. This monitoring system was not interfered by carbonyl compounds such as acetaldehyde and acetone, alcohols, hydrocarbons, and typical gases such as carbon monoxide, carbon dioxide, nitrogen dioxide, etc., which contributes to the measurement of correct HCHO concentrations. It was possible to monitor the HCHO gas in the room of a new apartment and school using this instrument; the response values were in good agreement with those obtained by the standard DNPH method. This highly sensitive, selective, and handy HCHO gas monitor is widely applicable and convenient for users who are not specialists in this field. 相似文献
108.
Ana Luísa Falcomer Letícia Santos Araújo Priscila Farage Jordanna Santos Monteiro Eduardo Yoshio Nakano Renata Puppin Zandonadi 《Critical reviews in food science and nutrition》2020,60(3):479-493
AbstractGluten-related disorders (GRD) affects approximately 10% of the general population. The only treatment for GRD is still so far is the lifelong complete exclusion of gluten from the daily diet. The correct information about the presence/absence of gluten in food is very important to this group. The present study aimed to evaluate the prevalence of gluten contamination in gluten-free industrial and non-industrial products. In this systematic review, 24 cross-sectional studies were analyzed. The authors developed specific search strategies for Science Direct, Scopus, Web of Science, Google Scholar and ProQuest Dissertations & Theses Global. The authors evaluated the methodological quality of the included studies using criteria from Meta-analysis of Statistics Assessment and Review Instrument (MASTARI). We performed the statistical meta-analysis by metafor package of R program. 95.83% (n?=?23) of the studies presented positive results for contamination (over 20?ppm). In industrial food products, studies showed a contamination prevalence of 13.2% (95% CI: 10.8%–15.7%). In non-industrial food products, studies showed a contamination prevalence of 41.5% (95% CI: 16.6%–66.4%). Despite the non-industrial products presented higher contamination prevalence than the industrial products, the difference was not significant (p?=?0.072). The findings indicate cross-contamination in industrialized and non-industrialized products. As expected, industrial products labeled as gluten-free showed a lower percentage of gluten-contamination than non-industrialized. Despite that, any contaminated sample found in this group present greater relevance than non-labeled foods. It indicates that foods labeled as “gluten-free” should not be considered safe for patients with GRD since information on the label regarding the presence/absence of gluten is unreliable. Therefore, any gluten-contamination in products labeled as gluten-free is a serious problem to whom present GRD. Further studies are needed to estimate gluten cross-contamination in food service meals and industry better. 相似文献
109.
High-Temperature Active Oxidation of Chemically Vapor-Deposited Silicon Carbide in CO─CO2 Atmosphere
Takayuki Narushima Takashi Goto Yoshio Yokoyama Yasutaka Iguchi Toshio Hirai 《Journal of the American Ceramic Society》1993,76(10):2521-2524
Active oxidation behavior of CVD-SiC in CO─CO2 atmospheres was investigated using a thermogravimetric technique in the temperature range between 1823 and 1923 K. The gas pressure ratio, P CO2 / P CO , was controlled between 10−4 and 10−1 at 0.1 MPa. Active oxidation rates (mass loss rates) showed maxima at a certain value of P CO2 / P CO , ( P CO2 / P CO )* , In a P CO2 / P CO region lower than the ( P CO2 / P CO )* a carbon layer was formed on the SiC surface. In a P CO2 / P CO region higher than the ( P CO2 / P CO )* , silica particles or a porous silica layer was observed on the SiC surface. 相似文献
110.
用光致荧光谱、傅里叶变换红外光谱(FTIR)和扫描电子显微镜(SEM)对用阳极氧化法制成的多孔硅层在1%NH3/H2O2溶液中的腐蚀现象进行了研究。红外分析表明,Si-O键和H-O键的强度随NH3/H2O2溶液的腐蚀时间的增加而增加,Si-H键强主匠随腐蚀时间增加而减少。光致荧光谱的峰值在腐蚀开始时先下降后上升,半高宽变窄,谱峰的以边明显蓝移。分析研究表明,1%NH3/H2O2溶液对多孔硅层有腐蚀 相似文献