Identification of K1/K10 and K5/K14 keratin pairs in human melanoma cell lines

Keratin expression in cultured malignant melanoma cells has been studied only rarely. Moreover, no studies have reported of universality of keratin expression in human malignant melanoma cells. In this study, therefore, we analyzed keratin expression in eight cell lines. Using a low-salt aqueous solution without high salt and Triton X-100, as a washing buffer for keratin extraction, followed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and immunological analysis, we demonstrated keratin expression in all eight human malignant melanoma cell lines. The keratin polypeptide expressions common to all melanoma cells were K1, K5, K10 and K14. In addition, K8, K13, K17 and K18, respectively, were detected in individual cells. A measure of keratin expression universality in malignant melanoma cells may have implications regarding their invasive and metastatic behaviors, co-expressed with vimentin.     

Thermodynamics of the system iron-aluminum-oxygen between 1073 K and 1573 K

Equilibrium oxygen pressures of the univariant ternary coexistences hematite + spinel + alumina, alloy + wustite + spinel, and alloy + spinel + alumina were determined at temperatures in the range 1123 to 1423 K using solid state electrochemical cells. The compositions of alloys and oxide phases of this Fe-Al-0 system that equilibrated with one another at 1273, 1423, and 1573 K were determined. These results and those from the literature are used to determine stabilities of the ternary oxide phases as a function of oxygen pressure and composition by constructing equilibrium oxygen pressure diagrams at 1073, 1173, and 1273 K. Formerly with McMaster University     

爱普生K100/K200渐成医疗行业打印“新宠”

爱普生黑白喷墨打印机K100/K200上市伊始,就凭借其速度快、成本低和健康环保的优良特性,受到医疗行业用户的广泛欢迎,成为各医疗用户的打印＂新宠＂。日前,K100/K200黑白喷墨打印机赢得陕西省某县人民医院采购大单,助力医疗信息化,为广大患者提供更快捷和更环保的贴心服务。     

Vitamin K requirement and the concentration of vitamin K in rat liver

The concentration of vitamin K was determined in the liver of different strains of rats, and in male and female warfarin-resistant rats by feeding 3H-vitamin K in a purified diet. In each case, the level of vitamin K in the liver correlated approximately with the amount of vitamin K fed. The results indicate that differences in the requirement for vitamin K between the sexes and between strains of rats are due principally to different required concentrations of vitamin K in liver and not to differences in absorption or turnover of the vitamin. The results of the determination of vitamin K epoxide levels in male and female warfarin-resistant rats, and other data, suggest that the amount of vitamin K required in liver may be in part due to differences in the activity of the enzyme, vitamin K epoxide reductase.     

Functional communication between cardiac ATP-sensitive K+ channel and Na/K ATPase

Insecticide resistance often is blamed for failures of insecticides to control cat fleas, Ctenocephalides felis (Bouché). Yet the genetics and adaptive advantage of resistance traits remain unexamined. Lethal doses of insecticides that kill 50% of the population fluctuate 7-fold within a cat flea strain. Many reports of flea resistance may be attributable to variable mortality from effects of solvents, substrates, humidities, temperatures, colonization, and ages of fleas. Resistance ratios (ratios of lethal doses of a resistant to a susceptible strain) are < 690-fold in fleas; lower than many other arthropods. This, plus strain variability, hinders resistance detection. Relationships between resistance levels, control failures, and health threats are unclear. Insensitive acetylcholinesterase, knockdown recovery, glutathione transferase conjugation, and mixed function oxidase/cytochrome P450 are demonstrated resistance mechanisms in cat fleas. Ecological genetics of resistance in cat fleas probably involves flea transfer among hosts, host movements, refugia, founder effects, and mortality from abiotic factors. Understanding cat flea resistance requires population monitoring before, during, and after insecticide treatments using conventional and rapid molecular bioassays. Sustained insecticide release devices such as flea collars and long-lived insecticide residues for premises possibly contribute to the development of resistance. New systemic and topical insecticides, especially when given prophylactically, may act similarly. Eliminating insecticides prevents insecticide resistance but necessitates application of biorational tactics incorporating mechanical, environmental, and cultural controls. Using high temperatures, low humidities, host grooming and such tactics as decreasing doses, increasing action thresholds, rotating insecticides, and leaving spatial and temporal refugia may suppress cat flea resistance.     

Thermodynamics of the Fe-Ni-O and Fe-Ni systems at 1065 K to 1380 K

Abstract

Equilibrium oxygen potentials and compositions were measured in the temperature range of 1065 to 1380 K by equilibrating the Fe-Ni-O mixtures in flowing CO/CO₂ gas atmospheres, identifying the phases by X-ray diffraction and metallography, and analyzing the phases by electron microprobe analysis. The data at 1280 K agree with well-estabished data for the Fe-O and Ni-O binaries and with previous published measurements in the wustite-alloy region of the Fe-Ni-O ternary. The data for the spinel-alloy region at 1280 K are in excellent agreement with recent measurements by a similar technique, but disagree with previous data. This is attributed to deficiencies in the experimental techniques used in previous measurements. New data are presented at 1065 K, 1180 K and 1380 K.

The derived activities of iron and nickel in iron-nickel alloys agree with recent mass spectrometric data.

Résumé

Les potentiels d'oxygime des melanges Fe-Ni-O, en équilibre avec des atmosphères de CO-CO₂, ont été mesurés entre 1065 °K et 1380°K. Les phases solides ont été identifiées par diffraction rayons-X, et par étude métallographique: leur composition a été determinée ,à l'aide d'une microsonde électronique. Les valeurs calculées à 1280°K sont en accord avec celles normalement acceptées sur les systèmes binaires FeO et NiO aussi bien qu'avec les résultats préalablement publies dans la region “wustite-alliage” du système ternaire Fe-Ni-O. Les résultats pour les compositions spinel-alli age à 1280°K sont en bon accord avec des mesures récentes, obtenues en utilisant une technique éxperimentale sembl able, mais ils sont en désaccord avec des résultats antérieurs que nous jugeons moins précis à cause de la technique éxperimentale utilisée. De plus, de nouvelles valeurs à 1065 °K, 1180 °K et à1380 °K sont présentées.

Les activités deduites pour Ie Fe et le Ni, dans les alliages Fe-Ni, correspondent bien avec les valeurs récentes obtenues, par spectrométrie de masse.     

Fatigue crack growth behavior in inconel 706 at 297 K and 4.2 K

The near-threshold fatigue crack growth rate (FCGR) behavior of Inconel 706 was investigated at ambient (297K) and liquid helium (4.2 K) temperatures, respectively. Specimen orientation did not affect the FCGR properties of Inconel 706. At 297 K, a significant influence of R-ratio on the rates of crack propagation was observed while at 4.2 K, the R -ratio effect was minimal. The extent of oxide-induced crack closure was shown to be insignificant in influencing near-threshold crack growth kinetics of Inconel 706 at both temperatures of 297 and 4.2 K. Roughness-induced crack closure was believed to be the dominant mechanism responsible for the influence of R -ratio on the FCGR properties of Inconel 706; this was proved quantitatively by direct crack closure measurements conducted at 297 and 4.2 K. A greater degree of roughness-induced crack closure was observed at 297 K than at 4.2 K; this correlated with the more pronounced R-ratio effect at 297 K. Decreasing the temperature from 297 to 4.2 K decreased the growth rates of fatigue cracks in Inconel 706. The effect of temperature on crack propagation behavior increased with increasing R-ratio. Crack closure could not rationalize this temperature effect. Moreover, the increase in material strength or Young's modulus on cooling from 297 to 4.2 K could not totally account for the influence of temperature on the near-threshold FCGR properties. Dislocation dynamics appears to offer a qualitative explanation for this temperature effect.