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1.
It is shown that the purely growing electrostatic rippling mode can couple with the shear Alfven wave to give rise to an oscillatory electromagnetic instability in tokamak edge regions. This mechanism can be one of the causes of electromagnetic fluctuations observed near plasma edges. This instability can occur only in the very low temperature regions where resistivity fluctuations can become important due to large electron-ion collision frequency. 相似文献
2.
A Saleem N Ibrahim M Patel XG Li E Gupta J Mendoza P Pantazis EH Rubin 《Canadian Metallurgical Quarterly》1997,57(22):5100-5106
Camptothecins are a new class of anticancer drugs that target DNA topoisomerase I; current efforts are directed toward elucidating optimal combinations of these drugs with other antineoplastic agents. A rationale for the use of sequential therapy involving the combination of camptothecins with topoisomerase II-targeting drugs, such as etoposide, has arisen from observations of increased topoisomerase II protein levels in cell lines resistant to camptothecin. In an effort to understand potential mechanisms of resistance to this strategy, we developed a U-937 cell subline, denoted RERC, that is capable of surviving exposure to sequential topoisomerase poisoning. The RERC cells are 200-fold resistant to camptothecin, 8-fold resistant to etoposide, and 10-fold hypersensitive to cisplatin compared to the parental U-937 cells. Biochemical analyses indicate that the resistant phenotype involves alterations in both topoisomerase I and topoisomerase IIalpha. Topoisomerase I catalytic activity in the resistant cells is similar to that of the parental line but is resistant to camptothecin. Moreover, the resistant cells express a single mRNA species of topoisomerase I that codes for a mutation in codon 533. In addition, topoisomerase IIalpha protein levels are decreased 10-fold in the resistant line, coincident with a two-fold decrease in the expression of topoisomerase IIalpha mRNA. Collectively, these results indicate that resistance to sequential topoisomerase poisoning may involve a reduction in total cellular topoisomerase activity. 相似文献
3.
J.V. Lobato N. Sooraj Hussain C.M. Botelho A.C. Maurício A. Afonso J.D. Santos 《Thin solid films》2006,515(1):362-367
Synthetic bone grafts have been developed to provide an alternative to autografts and allografts. Bonelike® is a patented synthetic osteoconductive bone graft that mimics the mineral composition of natural bone. In the present preliminary animal studies a user-friendly version of synthetic bone graft Bonelike® have been developed by using a resorbable matrix, Floseal®, as a vehicle and raloxifene hydrochloride as a therapeutic molecule, that is known to decrease osteoclast activity and therefore enhanced bone formation. From histological and scanning electron microscopy evaluations, the use of Bonelike® associated with Floseal® and raloxifene hydrochloride showed that new bone was rapidly apposed on implanted granules and also that the presence of the matrix and therapeutic molecule does not alter the proven highly osteoconductivity properties of Bonelike®. Therefore, this association may be one step-forward for the clinical applications of Bonelike® scaffolds since it is much more easy-to-handle when compared to granular materials. 相似文献
4.
Marie L. Borum Kathleen L. Shehan Hans Fromm Saleem Jahangeer Marianne K. Floor Oliver Alabaster 《Lipids》1992,27(12):999-1004
The effect and possible interactive influence of different dietary amounts of wheat bran, fat and calcium on the fecal excretion,
concentration and composition of bile acids was studied in Fischer-344 rats. The fecal bile acids were analyzed using gas-liquid
chromatography. Dietary wheat bran increased both total bile acid excretion and fecal weight without changes in fecal bile
acid concentration. The proportion of fecal hyodeoxycholic acid decreased with increasing dietary fiber, whereas that of lithocholic
and deoxycholic acids increased significantly with fiber intake. The percent content of fecal chenodeoxycholic acid did not
change. Increasing dietary fat led to an increase in bile acid excretion without changes in either fecal weight or bile acid
concentration. In contrast, the level of dietary calcium did not affect the total excretion of bile acids. However, since
calcium increased the fecal weight, it consequently diluted bile acids and decreased their fecal concentration. Dietary fat
and calcium had no influence on fecal bile acid composition. There were no interactive effects of wheat bran, fat and calcium
on fecal bile acids. The finding in this study that dietary fiber, fat and calcium induce significant changes in fecal bile
acids may be of relevance to the potential of bile acids to promote carcinogenesis. 相似文献
5.
Khan Muhammad Hussain Saleem Zainab Ahmad Muhammad Sohaib Ahmed Ayaz Hamail Mazzara Manuel Raza Rana Aamir 《Neural computing & applications》2021,33(21):14507-14521
Neural Computing and Applications - Preserving red-chili quality is of utmost importance in which the authorities demand quality techniques to detect, classify, and prevent it from impurities. For... 相似文献
6.
M. A. Javed M. Saleem N. Shakir S. A. Khan 《European Journal of Lipid Science and Technology》1984,86(4):160-161
Physico-chemical properties of the seed oils of three species of Rosaceae family, namely Prunus armeniaca (apricot), Prunus cerasifera (prune), and Prunus persica (peach) have been determined. Fatty acid composition of the oils and amino acids composition of seed cake proteins have also been determined and their utility in every day life has been discussed. 相似文献
7.
The diffusion coefficients at zero penetrant concentration, D0, of n-heptane, n-heptane, n-octane, n-decane, and 2,2,4-trimethylpentane (TMP) in LDPE were obtained in the range of 25–50°C, using the desorption method. The dependence of D0 on the size and shape of the penetrant is reported. It was found that D0 decreases with increasing penetrant molecule size. The activation energies of diffusion in the temperature range of 25–50°C increase with increasing penetrant molecule size and are independent of temperature. The results are interpreted in terms of the free volume theory and semiquantitative estimates of the free volume parameters are reported. 相似文献
8.
Raina Aman Qazi Mohammad Saleem Khan Luqman Ali Shah Rizwan Ullah Ayesha Kausar Rozina Khattak 《Polymer-Plastics Technology and Engineering》2020,59(9):928-951
ABSTRACTFabrication of electronic materials from nanocomposite of biopolyesters reinforced with carbon nanotubes can be regarded as the effective alternative for conventional nanocomposites consisting of non-biodegradable polymers. Commercial availability of biopolyester-based nanocomposites is limited because of their high cost compared to other polymers, but the factor of their compostable nature is worthless for environmental protection. Such nanocomposites have potential applications in biodegradable sensors, EMI materials, etc. In this review, the current progress of biopolyester/CNTs nanocomposites in the field of biodegradable electronics is reviewed and also the impact of CNTs dispersion on electrical, thermal and mechanical properties of eco composites is stipulated. 相似文献
9.
Thin layer chromatography and infrared spectophotometry of the fat of Eriobotrya japonica shows the presence of hydrocarbons (3.1%), was esters (5.3%), triglycerides (786%) and the last polar fraction containing fatty acids, colouring matter etc. (13.0%). After the saponification of the fat, the fatty acids C12-C24 and fatty alcohols C12-C26 determined first time as methyl esters and acetates respectively were identified by the application of gas liquid chromatography. 相似文献
10.
The diffusion coefficient at zero penetrant concentration D0 of dichloromethane, chloroform, carbon tetrachloride, cyclohexane, benzene, o-xylene, m-xylene, and p-xylene, and n-hexane in LDPE were measured at 25°C, using the desorption method. The D0 values obtained in this way are correlated with the size, shape, and chemical nature of the penetrant molecules. The temperature dependence of the diffusion coefficients of toluene and n-hexane in LDPE are also reported in the limited temperature range of 25–45°C. It indicates that, in spite of a size larger than that of toluene, n-hexane has a lower activation energy of diffusion. 相似文献