A comparative study of ethanol production by Issatchenkia orientalis strains under stress conditions

The ability of 13 strains of multi-stress-tolerant Issatchenkia orientalis yeast to produce ethanol was examined under different stress conditions, including conditions of elevated H₂SO₄ and Na₂SO₄ concentrations and increased heat. The MF-121 strain produced a significant amount of ethanol after the incubation in acidic media containing high concentrations of salt, e.g., 50 g/l Na₂SO₄ at pH 2.0, or at high temperatures, e.g., 43°C, when compared with other strains.     

Evaluation of drug toxicity with hepatocytes cultured in a micro-space cell culture system

A micro-space cell culture system was recently developed in which cells such as hepatocytes can be cultured and formed into a multicellular three-dimensional (3D) architecture. In this study, we assessed the performance of HepG2 cells cultured in this micro-space cell culture system in a drug toxicity test, and evaluated the effects of micro-space culture on their hepatocyte-specific functions. The micro-space cell culture facilitated the formation of 3D HepG2 cell architecture. HepG2 cells cultured in a micro-space culture plate exhibited increased albumin secretion and enhanced mRNA expression levels of cytochrome P450 (CYP) enzyme compared to those cultured in a monolayer culture. When the cells were exposed to acetaminophen, a hepatotoxic drug, the damage to the HepG2 cells grown in micro-space culture was greater than the damage to the HepG2 cells grown in monolayer culture. In addition, human primary hepatocytes grown in micro-space culture also exhibited increased albumin secretion, enhanced CYP mRNA expression levels and increased sensitivity to acetaminophen compared to those grown in monolayer culture. These results suggest that this micro-space culture method enhances the hepatocyte-specific functions of hepatocytes, including drug-metabolizing enzyme activities, making hepatocytes grown in the micro-space culture system a useful tool for evaluating drug toxicity in vitro.     

Structured extended finite element methods for solids defined by implicit surfaces

A paradigm is developed for generating structured finite element models from solid models by means of implicit surface definitions. The implicit surfaces are defined by radial basis functions. Internal features, such as material interfaces, sliding interfaces and cracks are treated by enrichment techniques developed in the extended finite element method. Methods for integrating the weak form for such models are proposed. These methods simplify the generation of finite element models. Results presented for several examples show that the accuracy of this method is comparable to standard unstructured finite element methods. Copyright © 2002 John Wiley & Sons, Ltd.     

Life satisfaction and age concentration of the local area.

Data from a community sample of persons 60 years old and older were analyzed to determine if the concentration of older persons in the local area (operationally defined as census tracts) was related to the respondent's life satisfaction after controlling for the known effects of physical health, socioeconomic status, social participation, and other microlevel variables. Results showed that the effect of age concentration is negative, but that this effect differs according to the frequency with which a respondent visits a close friend who lives outside the neighborhood and the number of voluntary associations to which the respondent belongs. The more frequently respondents visited outside the neighborhood, the greater the negative effect of age concentration. On the other hand, the more voluntary association memberships respondents had, the smaller the negative effect of age concentration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased endogenous nitric oxide synthase inhibitor in patients with congestive heart failure

Nitric oxide (NO) plays a role in controlling vascular tone and regulates the contractile properties of cardiac myocytes. Patients with heart failure exhibit high plasma levels of nitrite/nitrate (NOx), a stable metabolite of NO, and of cytokines such as tumor necrosis factor-alpha, a potent inducer of NO synthase. An increase in inducible NO synthase activity has been found in cardiac tissue from patients with dilated cardiomyopathy. These findings raise the possibility that local or systemic overproduction of NO induced by cytokines exerts a chronic negative inotropic effect on the myocardium and may have detrimental effects on systemic hemodynamics in patients with heart failure. Plasma levels of NG,NG-dimethylarginine (asymmetric dimethylarginine; ADMA), a circulating endogenous NO synthase inhibitor, were measured in control subjects and patients with valvular, hypertensive, or ischemic heart diseases or idiopathic cardiomyopathy. The plasma levels of NOx and ADMA were assessed by high performance liquid chromatography. The plasma levels of NOx and ADMA were significantly elevated in patients with heart failure. Both NOx and ADMA were positively correlated with New York Heart Association functional class. There was a significant inverse correlation between plasma NOx and ejection fraction, as estimated by echocardiography. A significant relationship between plasma NOx and ADMA was found only in patients with moderate to severe heart failure (r=0.41, p=0.01). Findings suggest a compensatory role of a circulating endogenous NO synthase inhibitor against induced NO synthase activity in patients with heart failure.     

Methanol synthesis from carbon dioxide at atmospheric pressure over Cu/ZnO catalyst. Role of methoxide species formed on ZnO support

Methanol synthesis from CO₂ and H₂ was carried out over a Cu/ZnO catalyst (Cu/Zn = 3/7) at atmospheric pressure, and the surface species formed were analyzed by diffuse reflectance FT-IR spectroscopy and temperature programmed desorption method. Two types of formate species and zinc methoxide were formed in the course of the reaction. Zinc methoxide was readily hydrolyzed to methanol. H₂O formed through the reverse water gas shift reaction was suggested to be involved in the hydrolysis of zinc methoxide.     

Hyaluronidase activity in human pus from which Streptococcus intermedius was isolated

Hyaluronidase (HAase) activity was detected in both a human pus sample and the culture supernatant of the only bacterial isolate from the pus, Streptococcus intermedius, using a zymographic technique. The optimum pH range for HAase activity was similar for both samples. Although the bands showing the strongest HAase activity of these samples differed from each other with respect to molecular size, both samples were equally inhibited by an antiserum raised against HAase of S. intermedius. These results suggest that S. intermedius may produce HAase in vivo as well as in vitro, and that this enzyme and/or its fragments may play an important role in host tissue degradation.     

Morphological differences in nuclear materials released from hamster sperm heads at an early stage of incorporation into immature oocytes, mature oocytes, or fertilized eggs

To elucidate the effects of ooplasmic factors on the early morphological changes in hamster sperm heads within the ooplasm, immature ovarian oocytes at the germinal vesicle stage (GV oocytes), ovulated fully mature oocytes, and fertilized eggs at anaphase II or the pronuclear stage (PN eggs) were examined in detail 15-30 min after insemination or reinsemination. Thin-sectioning studies demonstrated distinct materials released from the sperm nucleus over the entire postacrosomal nuclear surface immediately after disappearance of the sperm nuclear envelope. The release occurred in all of the oocytes and eggs prior to or even in the absence of subsequent chromatin decondensation. Depending upon the stage of the penetrated oocyte or egg, however, the materials varied in morphology: several hemispherical projections of amorphous material within mature oocytes; a number of electron-dense globules within GV oocytes and PN eggs; and both forms within eggs at anaphase II-telophase II. These observations and the fact that only the release of the amorphous material was accompanied by sperm chromatin decondensation indicate that this release was the initial process of chromatin decondensation, whereas the release of the globules resulted from a deficiency or lack of ooplasmic factors affecting the sperm nucleus. Restriction of the release in both forms of material to the late meiotic phase suggests changes in the factors associated with progression of meiosis. To approach an understanding of the mechanism of successful decondensation of sperm chromatin, the ooplasmic factors considered responsible for the stage-dependent release of nuclear materials are discussed.     

Development of a ghost cancel reference signal for TV broadcasting

A method for reducing ghost interference of TV signals is described. As part of a ghost canceler that is designed to eliminate ghost signals inside a signal receiver, the authors developed a ghost cancel reference (GCR) signal as part of the EDTV (extended definition television) system. In this system, a bar signal with a rise waveform of sin x/x is inserted as a reference signal into the vertical blanking period using a special send sequence on the transmitter's side. With this GCR, the ghost canceler built into a TV receiver is able to detect ghost signals with a delay time of about 45 μs or less (i.e. from the limit of subjective observation to that of objective observation). This GCR method has been adopted as Japan's standard for broadcasting and was introduced in the fall of 1989