Home About us Contact
|
Home About us Contact | ||
|
|
||
Additional Step (additional + step)
Selected AbstractsDefining the membrane proteome of NK cellsJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 1 2010Dhimankrishna Ghosh Abstract The present study was initiated to define the composition of the membrane proteome of the Natural Killer (NK) like cell line YTS. Isolated membranes were treated with reagents that have been reported to remove peripheral membrane proteins. Additional steps involving trifluoroethanol (TFE) were introduced in an effort to remove remaining nonintegral membrane proteins. This treatment resulted in the release of a subset of proteins without any apparent disruption of membrane integrity. The membranes were solubilized and digested with trypsin in 25% TFE. The resulting peptides were separated using an off-line two-dimensional reversed phase LC technique at alkaline and acidic pHs. Mass spectrometric analysis identified 1843 proteins with high confidence scores. On the basis of the presence of transmembrane regions or evidence of posttranslational modifications and prediction algorithms, approximately 40% of the identified proteins were predicted as plausible membrane proteins. The remaining species were largely involved in cellular processes and molecular functions that could be predicted to be transiently associated with membranes. The analytical approaches presented in this study offer robust generic methods for the identification and characterization of membrane proteins. These observations highlight the fact that the membrane is a dynamic entity that is composed of integral and stably associated proteins. Copyright © 2009 John Wiley & Sons, Ltd. [source] Submitochondrial localization of 6- N -trimethyllysine dioxygenase , implications for carnitine biosynthesisFEBS JOURNAL, Issue 22 2007Naomi Van Vlies The first enzyme of carnitine biosynthesis is the mitochondrial 6- N -trimethyllysine dioxygenase, which converts 6- N -trimethyllysine to 3-hydroxy-6- N -trimethyllysine. Using progressive membrane solubilization with digitonin and protease protection experiments, we show that this enzyme is localized in the mitochondrial matrix. Latency experiments with intact mitochondria showed that 3-hydroxy-6- N -trimethyllysine formation is limited by 6- N -trimethyllysine transport across the mitochondrial inner membrane. Because the subsequent carnitine biosynthesis enzymes are cytosolic, after production, 3-hydroxy-6- N -trimethyllysine must be transported out of the mitochondria by a putative mitochondrial 6- N -trimethyllysine/3-hydroxy-6- N -trimethyllysine transporter system. This transport system represents an additional step in carnitine biosynthesis that could have considerable implications for the regulation of carnitine biosynthesis. [source] Sequential integrated inversion of refraction and wide-angle reflection traveltimes and gravity data for two-dimensional velocity structuresGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2000Rosaria Tondi A new algorithm is presented for the integrated 2-D inversion of seismic traveltime and gravity data. The algorithm adopts the ,maximum likelihood' regularization scheme. We construct a ,probability density function' which includes three kinds of information: information derived from gravity measurements; information derived from the seismic traveltime inversion procedure applied to the model; and information on the physical correlation among the density and the velocity parameters. We assume a linear relation between density and velocity, which can be node-dependent; that is, we can choose different relationships for different parts of the velocity,density grid. In addition, our procedure allows us to consider a covariance matrix related to the error propagation in linking density to velocity. We use seismic data to estimate starting velocity values and the position of boundary nodes. Subsequently, the sequential integrated inversion (SII) optimizes the layer velocities and densities for our models. The procedure is applicable, as an additional step, to any type of seismic tomographic inversion. We illustrate the method by comparing the velocity models recovered from a standard seismic traveltime inversion with those retrieved using our algorithm. The inversion of synthetic data calculated for a 2-D isotropic, laterally inhomogeneous model shows the stability and accuracy of this procedure, demonstrates the improvements to the recovery of true velocity anomalies, and proves that this technique can efficiently overcome some of the limitations of both gravity and seismic traveltime inversions, when they are used independently. An interpretation of field data from the 1994 Vesuvius test experiment is also presented. At depths down to 4.5 km, the model retrieved after a SII shows a more detailed structure than the model obtained from an interpretation of seismic traveltime only, and yields additional information for a further study of the area. [source] Renal damage in rats induced by myocardial ischemia/reperfusion: Role of nitric oxideINTERNATIONAL JOURNAL OF UROLOGY, Issue 10 2006HAKAN PARLAKPINAR Background: It has been demonstrated that myocardial ischemia/reperfusion (MI/R) causes renal damage. However, the mechanism underlying this damage in kidneys during revascularization of myocardium is unclear. Direct renal ischemia/reperfusion has been implicated in the induction of inducible nitric oxide synthase (iNOS) that leads to increase production of nitric oxide (NO). Recently, excessive production of NO has been found to be involved in causing renal injury by formatting peroxinitrite (ONOO,). The aim of this study was to investigate whether NO has a role in this damage, using aminoguanidine (AMG), a known iNOS inhibitor and an antioxidant, in rats undergoing MI/R. Methods: Male Wistar rats were used for the experiments (n = 7 each group). In the MI/R group, the left coronary artery was occluded for 30 min and then reperfused for 120 min; the same procedure was used for the AMG group, with the additional step of AMG (200 mg/kg) administered 10 min prior to ischemia. A control group underwent sham operation. At the end of the reperfusion period, all rats were killed and their kidneys removed for biochemical determination and histopathological analysis. Results: Myocardial ischemia/reperfusion in the rat kidney was accompanied by a significant increase in malondialdehyde and NO production, and a decrease in glutathione content. Administration of AMG reduced malondialdehyde and NO production and prevented depletion of glutathione content. These beneficial changes in the biochemical parameters were also associated with parallel changes in histopathological appearance. Conclusion: These findings suggest that MI/R plays a causal role in kidney injury and AMG exerts renal-protective effects, probably by inhibiting NO production and antioxidant activities. [source] An innovative method to obtain porous PLLA scaffolds with highly spherical and interconnected poresJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008Cédryck Vaquette Abstract Scaffolding is an essential issue in tissue engineering and scaffolds should answer certain essential criteria: biocompatibility, high porosity, and important pore interconnectivity to facilitate cell migration and fluid diffusion. In this work, a modified solvent casting-particulate leaching out method is presented to produce scaffolds with spherical and interconnected pores. Sugar particles (200,300 ,m and 300,500 ,m) were poured through a horizontal Meker burner flame and collected below the flame. While crossing the high temperature zone, the particles melted and adopted a spherical shape. Spherical particles were compressed in plastic mold. Then, poly- L -lactic acid solution was cast in the sugar assembly. After solvent evaporation, the sugar was removed by immersing the structure into distilled water for 3 days. The obtained scaffolds presented highly spherical interconnected pores, with interconnection pathways from 10 to 100 ,m. Pore interconnection was obtained without any additional step. Compression tests were carried out to evaluate the scaffold mechanical performances. Moreover, rabbit bone marrow mesenchymal stem cells were found to adhere and to proliferate in vitro in the scaffold over 21 days. This technique produced scaffold with highly spherical and interconnected pores without the use of additional organic solvents to leach out the porogen. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Acute Ethanol Effects on Brain Activation in Low- and High-Level Responders to AlcoholALCOHOLISM, Issue 7 2010Ryan S. Trim Background:, A low level of response (LR) to alcohol is an important endophenotype associated with an increased risk of alcoholism. However, little is known about how neural functioning may differ between individuals with low and high LRs to alcohol. This study examined whether LR group effects on neural activity varied as a function of acute alcohol consumption. Methods:, A total of 30 matched high- and low-LR pairs (N = 60 healthy young adults) were recruited from the University of California, San Diego, and administered a structured diagnostic interview and laboratory alcohol challenge followed by two functional magnetic resonance imaging (fMRI) sessions under placebo and alcohol conditions, in randomized order. Task performance and blood oxygen level-dependent response contrast to high relative to low working memory load in an event-related visual working memory (VWM) task were examined across 120 fMRI sessions. Results:, Both LR groups performed similarly on the VWM task across conditions. A significant LR group by condition interaction effect was observed in inferior frontal and cingulate regions, such that alcohol attenuated the LR group differences found under placebo (p < 0.05). The LR group by condition effect remained even after controlling for cerebral blood flow, age, and typical drinking quantity. Conclusions:, Alcohol had differential effects on brain activation for low- and high-LR individuals within frontal and cingulate regions. These findings represent an additional step in the search for physiological correlates of a low LR and identify brain regions that may be associated with the low LR response. [source] Residual adenoid tissue post-curettage: role of nasopharyngoscopy in adenoidectomyANZ JOURNAL OF SURGERY, Issue 11 2009Alex J. Saxby Abstract Objective:, Curettage adenoidectomy is one of the most common methods of adenoidectomy. This study reports the incidence of residual adenoid tissue after curettage and grades the degree of post-nasal space obstruction using fibre-optic nasopharyngoscopy. Methods:, A retrospective study of 425 consecutive patients undergoing curette adenoidectomy in a 5-year period. Results:, Of the 425 patients, 288 (68%) had some residual adenoid tissue evident with nasopharyngoscopy, of which 104 (24%) had significant obstruction (grade 2 or 3). No age or sex difference was found in the likelihood or severity of residual adenoid tissue. Conclusions:, A significant proportion of patients will have residual adenoid tissue following curette adenoidectomy alone. Nasopharyngoscopy permits a more complete resection in a cost-effective, quick and easily performed additional step. [source] Separation of Pure and Immunoreactive Virus-Like Particles Using Gel Filtration Chromatography Following Immobilized Metal Ion Affinity ChromatographyBIOTECHNOLOGY PROGRESS, Issue 2 2001Yu-Shen Cheng A purification process was developed to obtain highly pure rVP2H particles, formed by a structural protein (VP2) of the infectious bursal disease virus (IBDV) with six additional histidine residues at its C-terminus. The ultimate goal was the development of an efficient subunit vaccine against IBDV infection. The particles within the infected High-Five (Hi-5) cell lysates were partially purified by employing immobilized metal ion (Ni2+) affinity chromatography (IMAC). The initial step could recover approximately 85% of immunoreactive rVP2H proteins but failed to separate the rVP2H particles from the free rVP2H proteins or its degraded products. To separate the particulate form from the free form of rVP2H, an additional step was added, which used either gel filtration chromatography or CsCl density gradient ultracentrifugation. Both were able to produce extremely pure rVP2H particles with a buoyant density close to 1.27 g/cm3. However, the former method can process a larger sample volume than does the latter. By integrating IMAC and gel filtration chromatography, 1 mg of extremely pure rVP2H particles was routinely obtained from a 500 mL Hi-5 cell culture broth. The separation of the particulate form from the free form of rVP2H proteins exposes their respective immunogenicity to induce the virus-neutralizing antibodies and the ability to protect chickens from IBDV infection. Additionally, the abundant quantities of pure rVP2H particles coupled with their uniform dimensions facilitates an understanding of higher order structure of the immunogenic particles and can therefore result in improved vaccines against the virus. [source] Effects of an Added Iodine Source (C2H5I) on Ru Metal,Organic Chemical Vapor Deposition,CHEMICAL VAPOR DEPOSITION, Issue 2 2003J.J. Kim Abstract The effects of an iodine source (C2H5I) on ruthenium (Ru) films grown on TiN/Ti/Si wafers by metal,organic (MO)CVD using Ru(EtCp)2 as a precursor were investigated. When an additional step of adsorbing iodine source was inserted during the Ru MOCVD process, the films became smoother and the root mean square (rms) surface roughness of the 30,nm thick Ru film became less than 10,% of the film thickness, as low as 1.71,nm. Moreover, the surface reaction-limited regime was extended to 400,°C, causing a wide process window. [source] Review and Restore for Case-Base MaintenanceCOMPUTATIONAL INTELLIGENCE, Issue 2 2001Thomas Reinartz Case-base maintenance is one of the most important issues for current research in case-based reasoning (CBR). In this article we propose an extended six-step CBR cycle and discuss its two additional steps as part of the maintenance phase of the CBR process. The review step covers assessment and monitoring of the knowledge containers, whereas the restore step actually modifies the contents of the containers according to recommendations resulting from the review step in order to keep the knowledge containers in a usable state. Here we focus our attention on the case base. For the review step, we define several quality measures based on different case and case-base properties that describe specific characteristics of the case base such as correctness, consistency, uniqueness, minimality, and incoherence. Then we use these measures to realize monitoring capabilities for the case-base container that indicate when the restore step is necessary. Finally, we also describe several methods for modifications of the case base in the restore step and their relation to the review step. An initial experimental evaluation shows the appropriateness of the proposed concepts and methods before we conclude the article with a discussion of related work and an outline of future directions to extend these aspects of maintenance in CBR. [source] Emission of trace toxic metals during pulverized fuel combustion of Czech coalsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 13 2003P. Danihelka Abstract A study of the trace elements emission (As, Se, Cd, Co, Cr, Cu, Zn, Hg, Tl, Pb, Ni, Sn, Sb, V, Mn and Fe) from pulverized coal combustion has been made at six heating and power stations situated in the Czech Republic. The amount of chlorine in coal has considerable influence on volatilization of some elements such as Zn, Cu, Pb, Hg and Tl, which is explained by the formation of thermodynamically stable compounds of these elements with chlorine. Generally, the affinities for Cl follows the order Tl > Cu > Zn > Pb > Co > Mn > Sn > Hg. The experimental data indicates enrichment of some of the trace toxic elements in the emissions (Cu, Zn, As, Se, Cd, Sn, Sb, Hg and Pb) and good agreement was obtained by thermodynamic equilibrium calculations with a few exceptions. In the case of Fe, Mn, Co, Cr and Sn calculated values are overestimated in the bottom ash and there are zero predicted amounts of these elements in the fly ash. In comparison, the results from experiments show up to 80% of these elements retained in fly ash. This implies that there exist additional steps leading to the enrichment by Fe, Mn, Co, Cr and Sn of small particles. Such mechanisms could include the ejection during devolatilization of small inorganic particles from the coal of bottom ash particles, or disintegration of the char containing these metals to small particles of fly ash. On the other hand, there are slightly overestimated or similar values of relative enrichment factors for As, V, Cu, Cd, Sb, Tl and Pb in the fly ashes and zero predicted values for bottom ashes. Our experimental results show about 5% or less of these elements are retained in bottom ashes, so they probably remain in the bottom ash inside unburned parts of coal. Copyright © 2003 John Wiley & Sons, Ltd. [source] Privacy and Commercial Use of Personal Data: Policy Developments in the United StatesJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 1 2003Priscilla Regan In the online and offline worlds, the value of personal information , especially information about commercial purchases and preferences , has long been recognised. Exchanges and uses of personal information have also long sparked concerns about privacy. Public opinion surveys consistently indicate that overwhelming majorities of the American public are concerned that they have lost all control over information about themselves and do not trust organisations to protect the privacy of their information. Somewhat smaller majorities favour federal legislation to protect privacy. Despite public support for stronger privacy protection, the prevailing policy stance for over thirty years has been one of reluctance to legislate and a preference for self-regulation by business to protect privacy. Although some privacy legislation has been adopted, policy debates about the commercial uses of personal information have been dominated largely by business concerns about intrusive government regulation, free speech and the flow of commercial information, costs, and effectiveness. Public concerns about privacy, reflected in public opinion surveys and voiced by a number of public interest groups, are often discredited because individuals seem to behave as though privacy is not important. Although people express concern about privacy, they routinely disclose personal information because of convenience, discounts and other incentives, or a lack of understanding of the consequences. This disconnect between public opinion and public behaviour has been interpreted to support a self-regulatory approach to privacy protections with emphasis on giving individuals notice and choice about information practices. In theory the self-regulatory approach also entails some enforcement mechanism to ensure that organisations are doing what they claim, and a redress mechanism by which individuals can seek compensation if they are wronged. This article analyses the course of policy formulation over the last twenty years with particular attention on how policymakers and stakeholders have used public opinion about the commercial use of personal information in formulating policy to protect privacy. The article considers policy activities in both Congress and the Federal Trade Commission that have resulted in an emphasis on "notice and consent." The article concludes that both individual behaviour and organisational behaviour are skewed in a privacy invasive direction. People are less likely to make choices to protect their privacy unless these choices are relatively easy, obvious, and low cost. If a privacy protection choice entails additional steps, most rational people will not take those steps. This appears logically to be true and to be supported by behaviour in the physical world. Organisations are unlikely to act unilaterally to make their practices less privacy invasive because such actions will impose costs on them that are not imposed on their competitors. Overall then, the privacy level available is less than what the norms of society and the stated preferences of people require. A consent scheme that is most protective of privacy imposes the largest burden on the individual, as well as costs to the individual, while a consent scheme that is least protective of privacy imposes the least burden on the individual, as well as fewer costs to the individual. Recent experience with privacy notices that resulted from the financial privacy provisions in Gramm-Leach-Bliley supports this conclusion. Finally, the article will consider whether the terrorist attacks of 11 September have changed public opinion about privacy and what the policy implications of any changes in public opinion are likely to be. [source] The effect of advice to walk 2000 extra steps daily on food intakeJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 4 2006A.-A. Koulouri Abstract Background, It is currently unclear how physical activity and diet interact within the ranges of activity seen in the general population. This study aimed to establish whether a small, acute, increase in physical activity would lead to compensatory change in energy intake and nutrient balance, and to provide power analysis data for future research in this field. Method, Twelve participants were studied over 7 days of habitual activity and 2 weeks after instruction to increase physical activity by 2000 steps per day. Physical activity was assessed using a diary, the ,activPAL' activity monitor and a pedometer. Dietary analyses from prospective food diaries were compared between the first and third weeks. Results, Participants increased step-counts (+2600 steps per day, P = 0.008) and estimated energy expenditure (+300,1000 kJ day,1, P = 0.002) but did not significantly change their energy intake, dietary composition or number of meals per day. From reverse power analysis 38 participants would be needed to exclude a change in energy intake of 400 kJ day,1 with 90% power at P < 0.05; 400 kJ day,1 would compensate for a 2000 steps per day increase in physical activity. Conclusion, These results did not demonstrate any compensatory increase in food consumption when physical activity was increased by walking an average of 2600 additional steps per day. Power analysis indicates that a larger study (n = 38) will be necessary to exclude such an effect with confidence. [source] | ||||||||||||||||