Thermoplastic matrix composite processing model

The effects the processing parameters pressure, temperature, and time have on the quality of continuous graphite fiber reinforced thermoplastic matrix composites were quantitatively accessed by defining the extent to which intimate contact and bond formation has occurred at successive ply interfaces. Two models are presented predicting the extents to which the ply interfaces have achieved intimate contact and cohesive strength. The models are based on experimental observation of compression molded laminates and neat resin conditions, respectively. Identified as the mechanism explaining the phenomenon by which the plies bond to themselves is the theory of autohesion (or self diffusion). Theoretical predictions from the Reptation Theory between autohesive strength and contact time are used to explain the effects of the processing parameters on the observed experimental strengths. The application of a time-temperature relationship for autohesive strength predictions is evaluated. A viscoelastic compression molding model of a tow was developed to explain the phenomenon by which the prepreg ply interfaces develop intimate contact

Creating an integrated payment system: the evolution of Fedwire

Adapted from remarks given before the Seminar on Payment Systems in the European Union in Frankfurt, Germany, on February 27, 1997.Fedwire ; Electronic funds transfers ; Federal Reserve System

Characterization of the Transporter Protein Sodium-Potassium Adenosine Triphosphatase in the Myelin Membrane

Sodium-potassium adenosine triphosphatase (Na+/K+-ATPase) is an integral membrane protein with known involvement in the maintenance of resting membrane potentials, nutrient uptake, cellular signal transduction, and cell-cell adhesion. The functional enzyme contains a catalytic alpha subunit and a glycosylated beta subunit, of which three isoforms of each are known to exist in the central nervous system (CNS). Altered expression and/or activity of Na+/K+-ATPase subunit isoforms has been previously implicated in the pathophysiology of several neurological disorders. This study characterized Na+/K+-ATPase expression and distribution in the myelin membrane, identified its specific heterodimeric forms and binding partners, and explored its possible involvement in demyelinating disorders, such as multiple sclerosis. For the first time, Na+/K+-ATPase α1, α2, and α3, as well as the β1, β2, and β3 subunits, were shown to co-express within a tissue of the CNS. These six isoforms, in addition to six isozymes (α1β1, α2β1, α2β3, α3β1, α3β2, and α3β3), of Na+/K+-ATPase were identified in myelin isolated from mouse brain; this expression shared both similarities and differences with neurons, astrocytes and/or oligodendrocytes. The major isozymes of Na+/K+-ATPase identified in myelin were α1β1, α2β3, and α3β1. Co-immunoprecipitation (co-IP) assays demonstrated that the three alpha isoforms of Na+/K+-ATPase in the myelin sheath can interact with other Na+/K+-ATPase alpha and beta subunit isoforms, in addition to associating with certain myelin-specific proteins and other protein types. These protein binding partners of Na+/K+-ATPase have known cellular functions, including RNA splicing, involvement in cell-cell migration and adhesion, the mediation of cytoskeletal interactions, and the regulation of protein degradation and apoptosis; they also suggested localization of Na+/K+-ATPase to the adherens junctions, tight junctions, caveolin-1 enriched microdomains, lipid rafts and tetraspanin-enriched microdomains of myelin. Western blot analysis indicated that Na+/K+-ATPase expression varies over post-natal development. Distinct differences in protein expression were observed between healthy and diseased myelin. In particular, demyelinating ND4 mice exhibited severe impairment of Na+/K+-ATPase β1 subunit maturation. Overall, this study has provided a comprehensive look into Na+/K+-ATPase expression and interactions within the myelin sheath, emphasizing its importance to both myelin structure and function

The emerging securities market in Russia

Author's OriginalThis paper examines the Russian equity market from speculative infancy to its modern-day status as an asset in the global economy.Khambata, D. & Aybar, C. (1998). The Emerging Securities Market in Russia. Journal of East-West Business, 4(3), 5-17. doi: 10.1300/J097v04n03_0

Delineating Differences in How US High Schools Are Racialized

Schools’ overt or explicit practices are a dominant lens through which education researchers and policymakers attempt to understand how schools are racially inequitable. Yet, Lewis and Diamond argue that contemporary racial inequalities are largely sustained through implicit factors, like institutional practices and structural inequalities. Ray’s framework on racialized organizations similarly outlines how our racialized sociopolitical structure becomes embedded in organizations, legitimating and perpetuating the racialized hierarchy. We apply illustrative cluster analysis techniques to rich data on schools, teachers, and students from the nationally representative High School Longitudinal Study of 2009 to find that structural inequities (e.g., student body, sector, average achievement) appear to be most salient in delineating the racialization of US high schools, whereas the characteristics of schools and teachers that are typically emphasized for closing racial inequities in educational outcomes (e.g., teacher qualifications, courses offered, stratification practices) are not salient differentiators across schools

Patterns of corporate ownership and privatization in Visegrad countries : 1989-1996

Author's OriginalThe article analyzes merger and acquisition activities in Visegrad Countries (the Czech Republic, Poland, Hungary and Slovakia). The analysis established linkages among the FDI, Privatization and M&A activities and reports the characteristics of transactions in the region in a comparative spirit. The findings indicate that majority of activities in the region involved foreign investors from Western Europe and USA. The M&A activities were concentrated in manufacturing segments such as automobiles, food processing, glass and clay, service segments such as telecom, utilities and financial services. The study also revealed some pre and post transaction ownership patterns in respective countries as well as methods of acquisition.Aybar, C., Khambata, D. & Milman, C. (2000). Patterns of Corporate Ownership and Privatization in Visegrad Countries: 1989-1996. Journal of East-West Business, 6(1), 57-80. doi:10.1300/J097v06n01_0

Laparoscopic Repair of Postoperative Perineal Hernia

Perineal hernias are infrequent complications following abdominoperineal operations. Various approaches have been described for repair of perineal hernias including open transabdominal, transperineal or combined abdominoperineal repairs. The use of laparoscopic transabdominal repair of perineal hernias is not well-described. We present a case report demonstrating the benefits of laparoscopic repair of perineal hernia following previous laparoscopic abdominoperineal resection (APR) using a nonabsorbable mesh to repair the defect. We have demonstrated that the use of laparoscopy with repair of the pelvic floor defect using a non absorbable synthetic mesh offers an excellent alternative with many potential advantages over open transabdominal and transperineal repairs

CELLULAR UPTAKE STUDY AND CYTOTOXICITY STUDY OF RESVERATROL-GOLD-PEG-FOLATE (RSV-AU-PEG-FA) NANOPARTICLES ON HELA HUMAN CERVICAL CANCER CELL LINE

Objective: This study aimed to evaluate the effectivity of resveratrol-gold-PEG-folate (RSV-Au-PEG-FA) nanoparticles formulation in resveratrol (RSV) targeted delivery and cytotoxicity effect on HeLa human cervical cancer cell line. Methods: Gold nanoparticles (AuNP) were used as carriers and folic acid (FA) was used as active targeting moiety, using polyethylene glycol-bis-amine (PEG-bis-amine) as linker. RSV-Au-PEG-FA nanoparticles were characterized by UV-Vis spectrophotometry, infrared spectroscopy, particle size analyzer (PSA), and transmission electron microscopy (TEM). Cellular uptake study was conducted by using fluorescence microscope. Cytotoxicity study was conducted by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: Cellular uptake study has shown that RSV-Au-PEG-FA nanoparticles are potential to be accumulated intracellularly in HeLa cells more than in Vero cells. Cytotoxicity study has shown RSV-Au-PEG-FA nanoparticles IC50 67.06±2.14 mM and RSV IC50 9.66±1.44 mM on HeLa cells Conclusion: RSV-Au-PEG-FA nanoparticles are potential to enhance RSV uptake by HeLa cells selectively