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排序方式: 共有3233条查询结果,搜索用时 15 毫秒
941.
Akiko Tamura Mio Sasaki Haruka Yamashita Isao Matsui-Yuasa Taro Saku Tadamasa Hikima Masaki Tabuchi Hiroshi Munakata Akiko Kojima-Yuasa 《Journal of Functional Foods》2013,5(4):1714-1723
Ethanol metabolism-associated oxidative stress contributes to the pathogenesis of alcoholic liver disease. We examined the effect of a Mate tea extract on ethanol-induced liver injury in vitro and in vivo models. Isolated hepatocytes were incubated with ethanol. An extract of Yerba-Mate tea (EMT) was added to the cultures simultaneously with ethanol. EMT treatment suppressed the ethanol-induced increase in cell death by inhibiting cytochrome p450 2E1 (CYP2E1) activity, which is related to the production of reactive oxygen species. Furthermore, we examined the effects of EMT on serum transaminase activity, and the progression of liver fibrosis in rats treated with ethanol and CCl4. Rats were fed a diet that included 0.005% or 0.02% EMT or no EMT. For a period of 3 weeks, the animals were provided drinking water containing 5% ethanol and were also treated with carbon tetrachloride (CCl4) (0.1 ml/kg of body weight). EMT treatment suppressed plasma ALT and AST activities in the ethanol- and CCl4-treated rats. EMT treatment also decreased CYP2E1 expression and increased ADH expression in the ethanol- and CCl4-treated rats. EMT treatment fully protected the rats against ethanol- and CCl4-induced liver injury. These results suggest that EMT may serve as a candidate for preventing ethanol-induced liver injury. 相似文献
942.
Legionella pneumophila is the principal etiologic agent of Legionnaires' disease. We found that the growth of L. pneumophila was markedly inhibited by its own cell lysate and the inhibitory effect was abolished by heat-treatment of the lysate. The genomic library of L. pneumophila was constructed in Escherichia coli and screened to determine the gene involved in the growth inhibition. A clone harboring the gene encoding anthranilate synthase (TrpE), which is involved in tryptophan biosynthesis, exhibited an inhibitory effect on the growth of L. pneumophila. Anthranilic acid exogenously added also exhibited antibacterial activity against L. pneumophila. A series of single-gene-knockout mutants of L. pneumophila lacking tryptophan synthesis genes were constructed and assessed for their susceptibility to anthranilic acid. Although the growth of mutants deficient in anthranilate phosphoribosyltransferase (TrpD) and N-(5'-phosphoribosyl)anthranilate isomerase (TrpF) was not affected by exogenous anthranilic acid, the indole-3-glycerophosphate synthase (TrpC) deficient mutant exhibited an increased susceptibility compared with the parent strain. These observations strongly indicate that 1-(2-carboxyphenylamino)-1'-deoxyribulose-5'-phosphate (CPADR-5'-P), which is an intermediate of tryptophan synthesis from anthranilic acid, is responsible for the growth inhibition of L. pneumophila. 相似文献
943.
Yuanqing Wang Fangming Jin Mitsuru Sasaki Wahyudiono Fengwen Wang Zhenzi Jing Motonobu Goto 《American Institute of Chemical Engineers》2013,59(6):2096-2104
Biomass as a source for chemicals production attracts growing attention due to the decreasing storage of fossil fuels and global warming caused by emission of CO2. In this study, conversion of glucose with copper oxide (CuO) was studied under alkaline hydrothermal conditions using a batch reactor and continuous flow reactor. CuO, as an oxidant, greatly improves the yields of lactic acid (LA) and acetic acid from glucose and was reduced into Cu2O and Cu. Selective production of LA with the highest yield of 59% and acetic acid with the highest yield of 32% can be achieved by controlling reaction time, temperature, and addition of CuO. A possible mechanism of conversion of glucose with CuO was proposed. © 2012 American Institute of Chemical Engineers AIChE J, 59: 2096–2104, 2013 相似文献
944.
Xiangrong Zhu Honglie Shen Koichi Tsukamoto Takeshi Yanagisawa Mamoru Okutomi Noboru Higuchi 《Ceramics International》2012
La0.67Sr0.33MnOz (LSMO) thin films were synthesized by means of metal-organic decomposition on the substrates including amorphous quartz, (1 0 0) Si chip, (1 0 0) MgO single crystal and polycrystalline Al2O3 ceramic plate. The structure and magnetotransport properties of the films were characterized. X-ray diffraction spectra show that all samples are polycrystalline with (2 0 2) preferred orientation. All films present metal–insulator transition and enhanced magnetoresistance (MR) effect below metal–insulator transition peak temperature (Tp). At room temperature (RT) low-field magnetoresistance effect (LFMR) and linear change of resistivity under applied field are exhibited by all the films. These magnetotransport properties were first ascribed to the porous structural characteristics in the films observed by atomic force microscope. Furthermore, the LSMO film synthesized on (1 0 0) MgO substrate presents a bit different magnetic properties and magnetotransport from the other samples, including broad ferromagnetic–paramagnetic transition zone, lower Tp and weaker LFMR at RT. However, for the samples synthesized on the other substrates, the LFMR effect is very similar to each other and their MR ratio reaches near 5% under 10 kOe field. Thus the substrate effect of LSMO film on (1 0 0) MgO is more intensive than that of the other samples. 相似文献
945.
Edson dos A. dos Santos Fernando Gon?alves Paulo César Prado Daniele Y. Sasaki Dênis P. de Lima Maria Lígia Rodrigues Macedo 《International journal of molecular sciences》2012,13(11):15241-15251
Insect pests have caused economic losses valued at billions of dollars in agricultural production. Anagasta kuehniella (Zeller), the Mediterranean flour moth, is of major economic importance as a flour and grain feeder and is often a severe pest in flourmills. This study provides a suitable route for the direct preparation of thiosulfonates 2 and 3 from thiols, under mild conditions, with good yields; these thiosulfonates were tested for their regulatory effect on insect growth. The chronic ingestion of thiosulfonates resulted in a significant reduction in larval survival and weight. In addition, the tryptic activity of larvae was sensitive to these thiosulfonates. Results suggest that thiosulfonates 2 and 3 have a potential antimetabolic effect when ingested by A. kuehniella. The use of AgNO3/BF3·OEt2 and Al(H2PO4)3/HNO3 provides a suitable route for the direct preparation of thiosulfonates from thiols under mild conditions with good yields. These thiosulfonates were toxic for A. kuehniella larvae, suggesting their potential as biotechnological tools. 相似文献
946.
The effect of the alkyl substituents on amidic N atoms in diglycolamide (DGA) compounds on solvent extraction has been investigated. The solubility in water and n-dodecane, lanthanide loading capacity, and distribution ratios (D) of lanthanides and actinides for various DGA compounds are reported. DGA derivatives with short alkyl chains, for example, methyl and ethyl groups, are very water soluble, while DGA derivatives with long alkyl chains, for example, octyl (TODGA), decyl (TDDGA), dodecyl (TDdDGA), and 2-ethylhexyl (TEHDGA) group are moderately soluble in n-dodecane. DGA derivatives with phenyl substituents have very low solubility in both aqueous and organic solvents, which suggests that these compounds will not be suitable for solvent extraction applications in the HNO3/n-dodecane systems. The lanthanide loading capacities of DGA extractants correlate with their alkyl chain lengths according to the following order: TDdDGA > TDDGA > TODGA > TEHDGA. The branched-alkyl-chain DGA derivative (TEHDGA) exhibits both lower D and loading capacity than TODGA. The results of masking-effect and solubility tests indicate that TEDGA is the best actinide masking agent among the water-soluble DGA derivatives tested. Actinide and lanthanide extractions using ten DGA compounds in six diluents (nitrobenzene, 1,2-dichloroethane, 1-octanol, chloroform, toluene, and n-dodecane) are also reported; it was observed that lipophilic DGA derivatives with shorter alkyl chains show higher D values. 相似文献
947.
948.
Takamatsu K Takano A Yakushiji N Morohashi K Morishita K Matsuura N Makishima M Tai A Sasaki K Kakuta H 《ChemMedChem》2008,3(5):780-787
Retinoid X receptor (RXR) agonists (rexinoids) are attracting much attention for their use in treatment of cancers, including tamoxifen-resistant breast cancer and taxol-resistant lung cancer, and metabolic disease. However, known RXR agonists have a highly lipophilic character. In addition, no subtype-selective RXR agonists have been found. We previously reported an RXRalpha-preferential agonist 4-[N-methanesulfonyl-N-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-2-naphthyl)amino]benzoic acid (6 a). The RXR agonistic activity is much less than that of well-known RXR agonists. To develop potent, less-lipophilic, and subtype-selective RXR agonists, we created new RXR agonists possessing alkoxy and isopropyl groups as a lipophilic domain of the common structure of well-known RXR agonists. As a result, compounds possessing branched alkoxy groups, 6-[N-ethyl-N-(3-isopropoxy-4-isopropylphenyl)amino]nicotinic acid (NEt-3IP: 7 a) and 6-[N-ethyl-N-(3-isobutoxy-4-isopropylphenyl)amino]nicotinic acid (NEt-3IB: 7 c), showed RXR agonistic activity as potent as, or more potent than, the activities of representative RXR agonists. Moreover, NEt-3IP (7 a) was found to be the first RXRalpha/beta-selective (or RXRalpha/beta-dual) agonist. Being potent, less lipophilic, and having RXR subtype-selective activity, NEt-3IP (7 a) is expected to become a new drug candidate and to be a useful biological tool for clarifying each RXR subtype function. 相似文献
949.
Hisami Sasaki Kenji Yokoi Osamu Okumura 《Journal of the American Oil Chemists' Society》1990,67(1):64-72
From the practical standpoint of fabric softener formulation, a comparative study was made on adsorption behavior toward fabrics
of binary systems consisting of di(hydrogenated tallow) dimethyl ammonium chloride (purified Arquad 2HT) and typical polyoxyethylenated
nonionic surfactants which are commonly used as auxiliary agents for softeners.
Soxhlet extraction of treated fabrics and quantitative analysis by high-performance liquid chromatography (HPLC) gave significant
results indicating many of these nonionic surfactants, assumed to be inherently unadsorbable in rinse-cycle treatment, were
highly adsorbable even at a high bath ratio by being applied with the water-insoluble cationic surfactant. Moreover, it was
also disclosed that the hydrophobic structure of nonionic surfactants is another factor, other than hydrophobicity, determining
adsorption.
Furthermore, the mechanism of this nonionic adsorption was elucidated on the basis of results of structural analyses of binary
dispersions by differential scanning calorimetry (DSC), X-ray diffraction, electron spin resonance spectroscopy (ESR) and
transmission electromicroscopy (TEM) in addition to partition measurements of the surfactants into the dispersed and the continuous
aqueous phases.
It was concluded that the primary driving force for this nonionic adsorption is an association with the lamellar of Arquad
2HT and that the cationic vesicles act as “anchors” in adsorption. 相似文献
950.
The suppression of plasma very low density lipoprotein (VLDL) triglyceride levels by dietary fish oils rich in polyunsaturated
n−3 fatty acids has been attributed to decreased hepatic VLDL secretion. To investigate the effect of n−3 fatty acids on lipid
metabolism and VLDL secretion in a tissue culture system, we incubated rabbit hepatocytes with oleic acid and eicosapentaenoic
acid (EPA) and examined [3H]glycerol and [14C]fatty acid incorporation into hepatocyte triglyceride and phospholipid and into media VLDL. Glycerol incorporation studies
showed that EPA failed to stimulate VLDL triglyceride secretion from hepatocytes as occurred with oleic acid (P<0.05). Oleic
acid preferentially enhanced hepatocyte triglyceride synthesis while EPA stimulated significantly phospholipid synthesis (P<0.01).
Varying the relative concentrations of oleic acid and EPA at a constant total fatty acid concentration corroborated preferential
triglyceride synthesis from oleic acid. Synthesis shifted predominantly to phospholipids with increasing concentrations of
EPA and lower levels of oleic acid. Incorporation of the [14C]fatty acids (800 μM) followed similar patterns: 87% of [14C]oleic acid was incorporated into hepatocyte triglyceride and 44% of [14C]EPA was assimilated in hepatocyte phospholipid (p<0.001). Fatty acids at trace concentrations (53 nM) showed a more divergent
pattern of lipid incorporation: 60% of [14C]oleic acid was incorporated into triglyceride while 91% of [14CEPA was incorporated into phospholipid (p<0.001). We conclude that in primary rabbit hepatocyte culture, which appears to
be a useful model to study lipid metabolism and VLDL secretion, EPA is avidly incorporated into phospholipid while oleic acid
predominantly becomes esterified in triglyceride. In addition, EPA, unlike oleic acid, fails to stimulate hepatocyte VLDL
secretion. These divergent effects on hepatocyte lipid metabolism are, at least in part, likely to be responsible for fish
oil induced suppression of plasma triglycerides. 相似文献