889 resultados para anion gap
Resumo:
In induction machines the tooth frequency losses due to permeance variation constitute a signif'icant, portion of the total loss. In order to predict and estimate these losses it, is essential to obtain a clear understanding of the no-load distribution of the air gap magnetic field and the magnitude of flux pulsation in both stator and rotor teeth. The existing theories and methods by which the air gap permeance variation in a doubly slotted structure is calculated are either empirical or restricted. The main objective of this thesis is to obtain a detailed analysis of the no-load air gap magnetic field distribution and the effect of air gap geometry on the magnitude and waveform of the tooth flux pulsation. In this thesis a detaiiled theoretical and experimental analysis of flux distribution not only leads to a better understanding of the distribution of no-load losses but also provides theoretical analysis for calculating the losses with greater accuracy
Resumo:
Both reactive oxygen species (ROS) and ATP depletion may be significant in hypoxia-induced damage and death, either collectively or independently, with high energy requiring, metabolically active cells being the most susceptible to damage. We investigated the kinetics and effects of ROS production in cardiac myoblasts, H9C2 cells, under 2%, 10% and 21% O2 in the presence or absence of apocynin, rotenone and carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone. H9C2 cells showed significant loss of viability within 30 min of culture at 2% oxygen which was not due to apoptosis, but was associated with an increase in protein oxidation. However, after 4 h, apoptosis induction was observed at 2% oxygen and also to a lesser extent at 10% oxygen; this was dependent on the levels of mitochondrial superoxide anion radicals determined using dihydroethidine. Hypoxia-induced ROS production and cell death could be rescued by the mitochondrial complex I inhibitor, rotenone, despite further depletion of ATP. In conclusion, a change to superoxide anion radical steady state level was not detectable after 30 min but was evident after 4 h of mild or severe hypoxia. Superoxide anion radicals from the mitochondrion and not ATP depletion is the major cause of apoptotic cell death in cardiac myoblasts under chronic, severe hypoxia.
Resumo:
1- Oligoamines and EDTA inhibited the reduction of cytochrome-C and nitrobule tetrazolium (NBT) induced by the hypoxanthine/xanthine oxidase superoxide anion generating system in the following order of effectiveness: putrescine > diaminopropane > spermidine > EDTA > spermine > cadaverine. 2- Oligoamines and EDTA did not affect the rate of urate formation from the hypoxanthine/xanthine oxidase system. 3- Oligoamines and EDTA inhibited the reduction of cytochrome-C induced by stimulated PMNL's in the same order of effectiveness as mentioned before. 4- Oligoamines and EDTA inhibited luminol dependent stimulated PMNL's chemiluminescence. 5- Oligoamines and EDTA inhibited the aerobic photoreduction of NBT. 6- Oligoamines-copper sulphate complexes inhibited the reduction of cytochrome-C induced by the hypoxanthine/xanthine oxidase system more effectively than oligoamines or copper sulphate individually. 7- Superoxide anion, hydrogen peroxide and hydroxyl radical induced breakdown of isolated intact guinea pig liver lysosomes. 8- Oligoamines and EDTA protected isolated intact guinea pig liver lysosomes from the lytic effect of superoxide anion generated either by the hypoxanthine/xanthine oxidase system or by stimulated PMNL's. 9- Oligoamines and EDTA have no stabilizing effect on isolated intact guinea pig liver lysosomes. 10- The uptake of oligoamines by lysosomes was in the following order: putrescine > spermidine > spermine. 11- Oligoamines were metabolised into aldehyde compounds either by the hypoxanthine/xanthine oxidase system or stimulated PMNL's. 12- Oligoamines and EDTA have no effect on the activities of free lysosomal enzymes (acid phosphatase and -glucosaminidase). 13- Oligoamines and EDTA inhibited lipid peroxidation in guinea pig liver lysosomes induced either by the hypoxanthine/xanthine oxidase or ascorbic acid-ferrous sulphate. 14- Oligoamines and EDTA have no effect on the release of PGE_2 from stimulated peritoneal guinea pig PMNL's. 15- Oligoamines increased the uptake of (^3H)thymidine and (^3H)leucine by stimulated peritoneal guinea pig macrophages in the following order of effectiveness: spermine > spermidine > putrescine > cadaverine. 16- PGE_2, dibutyryl Cyclic AMP, and theophylline inhibited luminol dependent stimulated peritoneal guinea pig PMNL's chemiluminescence.
Resumo:
Multidrug resistance protein MRP1 mediates the ATP-dependent efflux of many chemotherapeutic agents and organic anions. MRP1 has two nucleotide binding sites (NBSs) and three membrane spanning domains (MSDs) containing 17 transmembrane helices linked by extracellular and cytoplasmic loops (CL). Homology models suggest that CL7 (amino acids 1141-1195) is in a position where it could participate in signaling between the MSDs and NBSs during the transport process. We have individually replaced eight charged residues in CL7 with Ala, and in some cases, an amino acid with the same charge, and then investigated the effects on MRP1 expression, transport activity, and nucleotide and substrate interactions. A triple mutant in which Glu(1169), Glu(1170), and Glu(1172) were all replaced with Ala was also examined. The properties of R1173A and E1184A were comparable with those of wild-type MRP1, whereas the remaining mutants were either poorly expressed (R1166A, D1183A) or exhibited reduced transport of one or more organic anions (E1144A, D1179A, K1181A, (1169)AAQA). Same charge mutant D1183E was also not expressed, whereas expression and activity of R1166K were similar to wild-type MRP1. The moderate substrate-selective changes in transport activity displayed by mutants E1144A, D1179A, K1181A, and (1169)AAQA were accompanied by changes in orthovanadate-induced trapping of [alpha-(32)P]azidoADP by NBS2 indicating changes in ATP hydrolysis or release of ADP. In the case of E1144A, estradiol glucuronide no longer inhibited trapping of azidoADP. Together, our results demonstrate the extreme sensitivity of CL7 to mutation, consistent with its critical and complex dual role in both the proper folding and transport activity of MRP1.
Resumo:
In this presentation we will discuss the implications of the so called Nonlinear Shannon Limit. We will compare technologies including new fibres for long haul transmission and techniques to expand the capacity of existing standard single mode fibres.
Resumo:
We argue that in addition to host corruption per se, as accounted for by the existing literature, an explanation of inter-country variation in FDI needs to account for the distance between the host and home corruption, which we call relative corruption. We use a large matched home-host firm-level panel data-set for 1998-2006 from CEE transition countries. Year-specific selectivity corrected estimates suggest that, ceteris paribus, higher relative ‘grand’ corruption lowers foreign ownership as the returns to investment tends to be lower in more corrupt environment. However, after controlling for the selectivity bias, knowledge-intensive parent firms are found to hold controlling ownership, as the difficulty of successful joint venture looms large in more corrupt environment. Results are robust to alternative specifications.
Resumo:
We use Indian National Sample Survey employment–unemployment data for the urban sector for the years 1987 and 1999. Our results indicate that the gender wage gap had narrowed considerably between these two years, for all earnings deciles and for all education cohorts. The narrowing of the earnings gap can be attributed largely to a sharp increase in the returns to the labour market experience of women.
Resumo:
In the last decade, researchers in the social sciences have increasingly adopted neuroscientific techniques, with the consequent rise of research inspired by neuroscience in disciplines such as economics, marketing, decision sciences, and leadership. In 2007, we introduced the term organizational cognitive neuroscience (OCN), in an attempt to clearly demarcate research carried out in these many areas, and provide an overarching paradigm for research utilizing cognitive neuroscientific methods, theories, and concepts, within the organizational and business research fields. Here we will revisit and further refine the OCN paradigm, and define an approach where we feel the marriage of organizational theory and neuroscience will return even greater dividends in the future and that is within the field of clinical practice.
Resumo:
Purpose: The aim of this paper is to identify and gain insights into the significance of barriers contributing to the purported "gap" between academic management accounting research and practice. Design/methodology/approach: Drawing on diffusion of innovations theory, this study collects and analyses data from a questionnaire survey and follow-up interviews with 19 representatives of the four principal professional accounting bodies in Australia. Findings: Professional accounting bodies perceive the gap between academic research and practice in management accounting to be of limited concern to practitioners. The two most significant barriers to research utilisation by practitioners are identified as: difficulties in understanding academic research papers; and limited access to research findings. In acting as a conduit between the worlds of academia and practice, professional bodies have an important role to play by demonstrating the mutual value to both academics and practitioners resulting from a closer engagement between MA research and practice. Research limitations/implications: As one of the few empirically-based, theoretically informed investigations exploring the research-practice gap in management accounting, this study provides insights rather than "answers". Its findings therefore serve as a foundational basis for further empirical and theoretical enquiry. Originality/value: This study contributes to the conversation about the "research-practice gap" in management accounting by adopting a distinct theoretical vantage point to organize, analyse and interpret empirical evidence obtained from Australian professional accounting bodies about management accounting practice. © Emerald Group Publishing Limited.
Resumo:
Recent UK government initiatives aim to increase user involvement in the National Health Service (NHS) in two ways: by encouraging service users to take an active role in making decisions about their own care; and by establishing opportunities for wider public participation in service development. The purpose of this study was to examine how UK cancer service users understand and relate to the concept of user involvement. The data were collected through in-depth interviews, which were analysed for content according to the principles of grounded theory. The results highlight the role of information and communication in effective user involvement. Perhaps more importantly, this study suggests that the concept of user involvement is unclear to many cancer service users. This paper argues the need for increased awareness and understanding of what user involvement is and how it can work.