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Potential Development (potential + development)
Selected AbstractsFlow Injection Analysis of Sulfide Using a Cinder/Tetracyano Nikelate Modified Screen-Printed ElectrodeELECTROANALYSIS, Issue 9 2005Jyh-Myng Zen Abstract Flow injection analysis (FIA) of sulfide is presented using a screen-printed carbon electrode modified with a cinder/tetracyano nickelate hybrid (designated as cinder/NiTcSPE). Hybridization of NiTc was achieved in iron-enriched industrial waste cinder material through the bimetallic formation of FeIII[NiII(CN)4]. The electrocatalytic oxidation of sulfide is mediated by the higher oxidation state of Ni in this hybrid-bimetallic complex. The system shows a detection limit (S/N=3) of 0.06,,M and a linear working range up to 1,mM in pH,10, 0.1,M KCl solution. Taking into account the relatively low volatility of the analyte in alkaline conditions, the system is ideally suited for the accurate detection of sulfide. The response of the electrode to sulfide is highly reproducible, thereby offering the potential development of a disposable amperometric sensor for sulfide. Selective detection of sulfide in cigarette smoke is presented in this study as an example of a real sample application. [source] Modulation of amyloid-, aggregation and toxicity by inosose stereoisomersFEBS JOURNAL, Issue 8 2008Mark Nitz Amyloid-, (A,) aggregation and amyloid formation are key pathological features of Alzheimer's disease, and are considered to be two of the major contributing factors to neurodegeneration and dementia. Identification of small molecule inhibitors that are orally available, have low toxicity and high central nervous system bioavailability is one approach to the potential development of a disease-modifying treatment for Alzheimer's disease. We have previously identified inositol stereoisomers as exhibiting stereospecific inhibition of A, aggregation and toxicity in vitro and in vivo. We report here the effects of inosose versus inositol stereoisomers on A, fibrillogenesis as determined using CD and fluorescence spectroscopy and negative-stain electron microscopy. The inososes differ from inositols by the oxidation of one of the hydroxyl groups to a ketone. These molecules help in the further elucidation of the structure,activity relationships of inositol,A, interactions and identify both allo -inositol and epi -2-inosose as in vitro inhibitors of A, aggregation. [source] Tumour immunology, vaccination and escape strategiesINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 3 2003A. García-Lora Summary Our increasing knowledge of the mechanisms by which tumour cells escape immune effector cells is helping to establish new approaches to therapeutic vaccination against tumour development. One of the escape mechanisms used by tumour cells is the generation of multiple variants with different HLA phenotypes. These MHC class I phenotypic alterations play a key role in the tumour,host scenario, as they are crucial molecules for antigen presentation to T cells and modulation of natural killer (NK) cell activity. This review presents evidence indicating that tumours develop sophisticated MHC phenotypes that allow them to escape immune surveillance. We evaluate the importance of these alterations in terms of the potential development of therapeutic approaches to immune vaccination. [source] Explanatory Variables for per Capita Stocks and Flows of Copper and ZincJOURNAL OF INDUSTRIAL ECOLOGY, Issue 1-2 2006Claudia R. Binder A number of potential explanatory variables for the stocks and flows of copper and zinc in contemporary technological societies are co-analyzed with the tools of exploratory data analysis. A one-year analysis (circa 1994) is performed for 50 countries that comprise essentially all anthropogenic stocks and flows of the two metals. The results show that (1) The key explanatory variable for metal use is gross domestic product (GDP) per capita (purchasing power parity, PPP). By itself, GDP explains between one-third and one-half of the variance of per capita copper and zinc use. Other variables that were significantly correlated with copper and zinc use included stock of passenger cars and television sets (per 1, 000 people); two infrastructure variables, wired telephone connections, urban population, and value added inmanufacturing. The results do not provide evidence supporting the Kuznets curve hypothesis for these metals. (2) Metal use per capita can be estimated using multiple regression equations. For copper, the natural logarithm of use is related to the explanatory variables GDP (PPP), value added in manufacturing, and urban population. This model explains 80% of the variance among the different countries (r2= 0.79). The natural logarithm of zinc use is related to GDP (PPP) and value added in manufacturing with an r2 of 0.75; (3) For both metals, rates of metal fabrication, use, net addition to stock, and discard in low-and high-income countries differ significantly from each other. Our statistical analyses thus provide a basis for estimating the potential development of metal use, net addition to stock, and discard, using data on explanatory variables that are available at the international level. [source] Investigation of redox initiators for free radical frontal polymerizationPOLYMER INTERNATIONAL, Issue 8 2009Huan Yu Abstract BACKGROUND: The reaction temperature for frontal polymerization (FP) initiated by redox initiators can be greatly decreased compared with FP initiated by peroxide initiator and disulfide initiator. We report the synthesis of poly(hydroxyethyl acrylate)s via free radical FP using benzoyl peroxide (BPO)/N,N -dimethylaniline (DMA) and ammonium persulfate (APS)/N,N,N,,N,-tetramethylethylenediamine (TMEDA) couples as redox initiators at ambient pressure. RESULTS: The results show that unlike the phenomenon of bubbles and ,fingers' when using BPO alone, a self-sustaining and stable front can be obtained when the [DMA]/[BPO] ratio is higher than 1 (mol/mol). A slight increase of the DMA (or TMEDA) reductant concentration causes a marked decrease of front temperature to 53 °C (or 61 °C). CONCLUSION: We investigated the effects of the ratio of the oxidant to the reductant and the initiator and monomer concentrations on certain parameters of FP: formation of bubbles, front velocity and front temperature. This opens the way to the potential development of FP using more appropriate monomers with low boiling points. Copyright © 2009 Society of Chemical Industry [source] The Value of Enhanced Magnetic Resonance Imaging in the Evaluation of Endocochlear Disease,THE LARYNGOSCOPE, Issue 1 2002Joseph L. Hegarty MD Abstract Background Gadolinium-enhanced magnetic resonance imaging (GdMRI) is routinely used in the evaluation and management of suspected retrocochlear pathology such as vestibular schwannoma. However, its value in the evaluation and diagnosis of cochlear pathology associated with sensorineural hearing loss (SNHL) has been less clear. Study Design Retrospective review of case histories and imaging studies of patients with SNHL and cochlear enhancement on GdMRI diagnosed between 1998 and 2000. Results Five patients with SNHL who required gadolinium administration to establish the diagnosis of endocochlear disease were identified. Diagnosed lesions included an intralabyrinthine schwannoma, intracochlear hemorrhage, radiation-induced ischemic change, autoimmune labyrinthitis, and meningogenic labyrinthitis. In these illustrative cases, the GdMRI demonstrated intrinsic high signal or contrast enhancement within the cochlea and labyrinth in the absence of a retrocochlear mass. In one patient with meningogenic labyrinthitis, cochlear enhancement on MRI led to prompt cochlear implantation before the potential development of cochlear ossification. Conclusion Our experience suggests that GdMRI plays a crucial role in the diagnosis of cochlear pathology associated with sensorineural hearing loss and may directly impact patient management. [source] Closed-loop feedback computer-controlled infusion of phenylephrine for maintaining blood pressure during spinal anaesthesia for caesarean section: a preliminary descriptive study,ANAESTHESIA, Issue 12 2007W. D. Ngan Kee Summary We describe the novel use of a closed-loop feedback computer-controlled infusion of phenylephrine for maintaining blood pressure in 53 patients having spinal anaesthesia for elective caesarean section. A simple on,off algorithm was used that activated an intravenous phenylephrine infusion at 100 ,g.min,1 when systolic blood pressure was less than or equal to baseline and stopped the infusion when systolic blood pressure exceeded baseline. Up to uterine incision, 94.6% of all systolic blood pressure measurements were within the range (baseline ± 20%). Seven patients (13.2%) had one or more episodes of hypotension (systolic blood pressure < 80% of baseline) and 23 patients (37.7%) had one or more episodes of hypertension (systolic blood pressure >,120% of baseline). No patient had nausea or vomiting and in no case was umbilical arterial blood pH < 7.2. Calculated system performance parameters were comparable with those of previously published closed-loop systems and provide a reference for the potential development and comparison of more advanced algorithms. [source] Susceptibility of the pine processionary caterpillar Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) toward ,-endotoxins of Bacillus thuringiensis under laboratory conditionsANNALS OF APPLIED BIOLOGY, Issue 3 2001A B SHEVELEV Summary A series of natural crystal proteins from B. thuringiensis subsp. Alesti 12,25, caucasicus, galleriae 11,67, galleriae 6,96, kenyae, and shondungensis and spore-crystal preparations from finitimus 11,66 and from a recombinant strain of B. thuringiensis subsp. kurstaki expressing Cry 1 Ga1 only, were assessed as a toxic agent for the pine processionary caterpillar, Thaumetopoea pityocampa. Some preparations had a thoroughly investigated composition and contained Cry1Aa, Cry1Ab2, Cry1Ab7, Cry1D, Cry1F, Cry 1 Ga1, Cry9Aa, Cry26 crystal proteins, whereas crystals of B. thuringiensis subsp. caucasicus, kenyae, and shondungensis harboured predominantly unidentified toxins distant from commonly used prototypes. Bioassays were based on the simultaneous assignment of each treatment to groups of 20 full sibling first-instar larvae, obtained from broods of a population from North-western Italy. The toxin was applied to pine needles by the leaf dipping method and the effect was registered in both feeding inhibition and mortality. B. thuringiensis subsp. caucasicus, kenyae, galleriae 6,96, alesti, and galleriae 11,67 gave the best results in terms of both feeding inhibition and larval mortality. Broods tested in B. thuringiensis bioassays showed a substantial variation in susceptibility to the toxins, suggesting the potential development of resistance in the population. [source] Disulfide Bond Substitution by Directed Evolution in an Engineered Binding ProteinCHEMBIOCHEM, Issue 8 2009Antoine Drevelle Dr. Abstract Breaking ties: The antitumour protein, neocarzinostatin (NCS), is one of the few drug-carrying proteins used in human therapeutics. However, the presence of disulfide bonds limits this protein's potential development for many applications. This study describes a generic directed-evolution approach starting from NCS-3.24 (shown in the figure complexed with two testosterone molecules) to engineer stable disulfide-free NCS variants suitable for a variety of purposes, including intracellular applications. The chromoprotein neocarzinostatin (NCS) has been intensively studied for its antitumour properties. It has recently been redesigned as a potential drug-carrying scaffold. A potential limit of this protein scaffold, especially for intracellular applications, is the presence of disulfide bonds. The objective of this work was to create a disulfide-free NCS-derived scaffold. A generic targeted approach was developed by using directed evolution methods. As a starting point we used a previously engineered NCS variant in which a hapten binding site had been created. A library was then generated in which cysteine Cys88 and Cys93 and neighbouring residues were randomly substituted. Variants that preserved the hapten binding function were selected by phage display and further screened by colony filtration methods. Several sequences with common features emerged from this process. The corresponding proteins were expressed, purified and their biophysical properties characterised. How these selected sequences rescued folding ability and stability of the disulfide-free protein was carefully examined by using calorimetry and the results were interpreted with molecular simulation techniques. [source] | |||||||||||||