9,978 research outputs found
Using small molecules to facilitate exchange of bicarbonate and chloride anions across liposomal membranes
No full textBicarbonate is involved in a wide range of biological processes, which include respiration, regulation of intracellular pH and fertilization. In this study we use a combination of NMR spectroscopy and ion-selective electrode techniques to show that the natural product prodigiosin, a tripyrrolic molecule produced by microorganisms such as Streptomyces and Serratia, facilitates chloride/bicarbonate exchange (antiport) across liposomal membranes. Higher concentrations of simple synthetic molecules based on a 4,6-dihydroxyisophthalamide core are also shown to facilitate this antiport process. Although it is well known that proteins regulate Cl-/HCO3- exchange in cells, these results suggest that small molecules may also be able to regulate the concentration of these anions in biological systems
Moffatt vortices induced by the motion of a contact line
No full textA recent hydrodynamic theory of liquid slippage on a solid substrate (Kirkinis & Davis, Phys. Rev. Lett., vol. 110, 2013, 234503) gives rise to a sequence of eddies (Moffatt vortices) that co-move with a moving contact line (CL) in a liquid wedge. The presence of these vortices is established through secular equations that depend on the dynamic contact angle α and capillary number Ca. The limiting case \ud
α→O is associated with the appearance of such vortices in a \ud
channel. The vortices are generated by the relative motion of the interfaces, which in turn is due to the motion of the CL. This effect has yet to be observed in experiment
Nuisance parameters, composite likelihoods and a panel of GARCH models
No full textWe investigate the properties of the composite likelihood (CL) method for (T ×N_T ) GARCH panels. The defining feature of a GARCH panel with time series length T is that, while nuisance parameters are allowed to vary across N_T series, other parameters of interest are assumed to be common. CL pools information across the panel instead of using information available in a single series only. Simulations and empirical analysis illustrate that in reasonably large T CL performs well. However, due to the estimation error introduced through nuisance parameter estimation, CL is subject to the “incidental parameter” problem for small T.ARCH models; composite likelihood; nuisance parameters; panel data
A dysfunctional Cl inhibitor protein with a new reactive center mutation (Arg-444→Leu)
No full textAbstractA Pl mutation (Arg-444→Leu) was identified in a dysfunctional Cl inhibitor from a patient with type 2 hereditary angioneurotic edema. The mutation was defined at the level of the protein (by sequence analysis of the Pseudomonas aeruginosa elastase-derived reactive center peptide), and the mRNA (CGC→CTC) (by sequence analysis of PCR-amplified DNA)
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
Progress of international hydrogen production network for the thermochemical Cu–Cl cycle
No full textThis paper presents recent advances by an international team which is developing the thermochemical copper–chlorine (Cu–Cl) cycle for hydrogen production. Development of the Cu–Cl cycle has been pursued by several countries within the framework of the Generation IV International Forum (GIF) for hydrogen production with the next generation of nuclear reactors. Due to its lower temperature requirements in comparison with other thermochemical cycles, the Cu–Cl cycle is particularly well matched with Canada's Generation IV reactor, SCWR (Super-Critical Water Reactor), as well as other heat sources such as solar energy or industrial waste heat. In this paper, recent developments of the Cu–Cl cycle are presented, specifically involving unit operation experiments, corrosion resistant materials and system integration.Atomic Energy of Canada LimitedOntario Research Excellence FundNatural Sciences and Engineering Research Council of CanadaUniversity Network of Excellence in Nuclear Engineering (UNENE)Canada Research Chairs progra
ŻYCIE UKRYTE W SŁOWIE. "BEKSIŃSCY. PORTRET PODWÓJNY" MAGDALENY GRZEBIAŁKOWSKIEJ W ŚWIETLE POSTSTRUKTURALIZMU
No full textLife Hidden in Words. Magdalena Grzebiałkowska\u27s "Beksińscy. Portret podwójny" and Poststructuralism
The article analyzes Magdalena Grzebiałkowska\u27s biographical "Beksińscy. Portret podwójny" which focuses on the lives of Zdzisław Beksiński and Tomasz Beksiński. The author looks at the construction of the biography and its relationship to poststructuralism, which allows for an appreciation of the literary features of the book. He points to how the specificity of the content, language, a mode of narration in Grzebiałkowska\u27s book make it a full-fledged literary work itself. As such the book departs from a typical biographical scheme. Juxtaposing the book with poststructural ideas leads to the reconsideration of the role of the author in the process of shaping of a biographical narrative
Intracellular Cl- activity and cellular Cl- pathways in cultured human airway epithelium
No full text Cl- transport was studied in human nasal epithelium, a predominantly Na+-absorbing proximal airway epithelium. Intracellular Cl- activity (aClc) and the electrical potentials across the apical (Va) and basolateral (Vb) membranes were measured with double-barreled, Cl- -selective microelectrodes to characterize the driving forces for Cl- flow across each membrane. Under control conditions (bilateral Krebs-bicarbonate Ringer), Va was -26.1 +/- 1.2 mV, Vb was -36.2 +/- 1.2 mV, and aCL(c) was 42.7 +/- 2.0 mM (n = 34), indicating that Cl- is near electrochemical equilibrium across the apical membrane but significantly above equilibrium across the basolateral membrane. Reduction of luminal [Cl-] from 120 to 3 mM reduced aClc from 42.7 +/- 4.0 to 27.0 +/- 3.5 mM, depolarized Va, and increased fractional apical membrane resistance (fRa) and transepithelial resistance (Rt). Serosal bumetanide reduced aClc by 10 mM without affecting electrical parameters. Reduction of serosal [Cl-] from 120 to 3 mM resulted in a rapid decrease in Vb, a decrease in fRa and an increase in Rt. Also, serosal [Cl-] reduction led to a slow decrease in aClc rom 45.5 +/- 2.5 to 31.1 +/- 4.2 mM) that could be inhibited by bumetanide. The data are consistent with the following conclusions: 1) Cl- is transported across the apical membrane through a conductive pathway; and 2) Cl- is translocated across the basolateral membrane by an electrically silent bumetanide-sensitive cotransport system and by a minor conductive path. </jats:p
Systems, methods and devices for the capture and hydrogenation of carbon dioxide with thermochemical Cu—Cl and Mg—Cl—Na/K—CO2 cycles
No full textSystems, methods, and devices for producing hydrogen and capturing CO2 from emissions combine both H2 production and CO2 capture processes in forms of thermochemical cycles to produce useful products from captured CO2. The thermochemical cycles are copper-chlorine (Cu—Cl) and magnesium-chlorine-sodium/potassium cycles (Mg—Cl—Na/K—CO2). One system comprises a Cu—Cl cycle, a CO2 capture loop, and a hydrogenation cycle. Another system comprises an Mg—Cl—Na/K—CO2 cycle and a hydrogenation cycle. Devices for hydrogen production, CO2 capture, hydrogenation, and process and equipment integration include a two-stage fluidized/packed bed, hybrid two-stage spray-fluidized/packed bed reactor, a two-stage wet-mode absorber, a hybrid two-stage absorber, and a catalyst packed/fluidized bed reactor
Clean hydrogen production with the Cu–Cl cycle – Progress of international consortium, I: Experimental unit operations
No full textAdvancement of the thermochemical copper–chlorine (Cu–Cl) cycle for hydrogen production is reviewed and discussed in this paper. Individual unit operations and their linkage into an integrated cycle are being developed by a Canadian consortium, as part of the Generation IV International Forum (GIF) for hydrogen production with the next generation of nuclear reactors. This paper focuses on the consortium’s latest advances on the Cu–Cl cycle, particularly with respect to hydrogen production with Canada’s Generation IV reactor, called SCWR (Super-Critical Water Reactor). Other heat sources may also be utilized for the Cu–Cl cycle, such as solar energy or industrial waste heat. In this first of two companion papers, recent developments in Canada’s nuclear hydrogen program are reported, specifically unit operation experiments of the Cu–Cl cycle and system integration. The following second companion paper will present system modeling with Aspen Plus, corrosion resistant materials, thermochemistry, safety, and reliability aspects of the Cu–Cl cycle.Atomic Energy of Canada LimitedOntario Research Excellence FundNatural Sciences and Engineering Research Council of CanadaUniversity Network of Excellence in Nuclear Engineering (UNENE)Canada Research Chairs progra
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