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Unique Combination (unique + combination)
Selected AbstractsA Novel Case of L-transposition with a Right-dominant Double Aortic ArchCONGENITAL HEART DISEASE, Issue 4 2009David J. Goldberg MD ABSTRACT We describe a case of congenitally corrected transposition with a double aortic arch. This unique combination of lesions highlights the importance of a complete anatomic assessment prior to referral for surgery. [source] Anomalous Left Anterior Descending Coronary Artery from the Pulmonary Artery, Unroofed Coronary Sinus, Patent Foramen Ovale, and a Persistent Left-sided SVC in a Single Patient: A Harmonious Quartet of DefectsCONGENITAL HEART DISEASE, Issue 2 2009Andrew J. Klein MD ABSTRACT Unroofing of the coronary sinus without complex structural heart defects is a rare congenital defect often seen in conjunction with a persistent left-sided superior vena cava. Anomalous origin of the left anterior descending artery from the pulmonary artery with normal origin of the left circumflex coronary artery is an even rarer congenital cardiac defect. We report a case of a 54-year-old woman presenting with mild dyspnea on exertion who was found on invasive and noninvasive evaluations to have a unique combination of defects,unroofed coronary sinus, persistent left-sided superior vena cava, patent foramen ovale, and anomalous origin of the left anterior descending artery from the pulmonary artery without evidence of previous coronary ischemia. [source] High-altitude migration of the diamondback moth Plutella xylostella to the U.K.: a study using radar, aerial netting, and ground trappingECOLOGICAL ENTOMOLOGY, Issue 6 2002Jason W. Chapman Abstract 1. The high-altitude wind-borne migration of the diamondback moth Plutella xylostella in the U.K. in 2000 was investigated (a) by direct monitoring of insect flight by vertical-looking radar and by aerial netting, and (b) through evidence of temporal variation in P. xylostella abundance deduced from a network of light traps. 2. Migrating P. xylostella were identified by a unique combination of size and shape data derived from the continuously operating vertical-looking radar. 3. Radar-detected migratory overflights correlated significantly with associated peaks in abundance of P. xylostella estimated by catches in a U.K.-wide light trap network; however the correlation was stronger when light trap catches were lagged by 1 day. 4. The first notable catches of P. xylostella in the U.K. occurred in early May, and were accompanied by migrations over the radar from the east. 5. Radar data and back-tracking indicated that a major wind-borne migration of P. xylostella from The Netherlands to southern England took place in early May, and that this was responsible for the establishment of the U.K. population. 6. The origin of early-season P. xylostella occurring in Britain is discussed. [source] The structure and mode of action of different botulinum toxinsEUROPEAN JOURNAL OF NEUROLOGY, Issue 2006J. O. Dolly The seven serotypes (A,G) of botulinum neurotoxin (BoNT) are proteins produced by Clostridium botulinum and have multifunctional abilities: (i) they target cholinergic nerve endings via binding to ecto-acceptors (ii) they undergo endocytosis/translocation and (iii) their light chains act intraneuronally to block acetylcholine release. The fundamental process of quantal transmitter release occurs by Ca2+ -regulated exocytosis involving sensitive factor attachment protein-25 (SNAP-25), syntaxin and synaptobrevin. Proteolytic cleavage by BoNT-A of nine amino acids from the C-terminal of SNAP-25 disables its function, causing prolonged muscle weakness. This unique combination of activities underlies the effectiveness of BoNT-A haemagglutinin complex in treating human conditions resulting from hyperactivity at peripheral cholinergic nerve endings. In vivo imaging and immunomicroscopy of murine muscles injected with type A toxin revealed that the extended duration of action results from the longevity of its protease, persistence of the cleaved SNAP-25 and a protracted time course for the remodelling of treated nerve,muscle synapses. In addition, an application in pain management has been indicated by the ability of BoNT to inhibit neuropeptide release from nociceptors, thereby blocking central and peripheral pain sensitization processes. The widespread cellular distribution of SNAP-25 and the diversity of the toxin's neuronal acceptors are being exploited for other therapeutic applications. [source] Graphene Solution-Gated Field-Effect Transistor Array for Sensing ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 18 2010Markus Dankerl Abstract Graphene, with its unique combination of physical and electronic properties, holds great promise for biosensor and bioelectronic applications. In this respect, the development of graphene solution-gated field-effect transistor (SGFET) arrays capable of operation in aqueous environments will establish the real potential of graphene in this rapidly emerging field. Here, we report on a facile route for the scalable fabrication of such graphene transistor arrays and provide a comprehensive characterization of their operation in aqueous electrolytes. An on-chip structure for Hall-effect measurements allows the direct determination of charge carrier concentrations and mobilities under electrolyte gate control. The effect of the solution-gate potential on the electronic properties of graphene is explained using a model that considers the microscopic structure of water at the graphene/electrolyte interface. The graphene SGFETs exhibit a high transconductance and correspondingly high sensitivity, together with an effective gate noise as low as tens of ,V. Our study demonstrates that graphene SGFETs, with their facile technology, high transconductance, and low noise promise to far outperform state-of-the-art Si-based devices for biosensor and bioelectronic applications. [source] Mechanisms of egg contamination by Salmonella EnteritidisFEMS MICROBIOLOGY REVIEWS, Issue 4 2009Inne Gantois Abstract Salmonella Enteritidis (SE) has been the major cause of the food-borne salmonellosis pandemic in humans over the last 20 years, during which contaminated hen's eggs were the most important vehicle of the infection. Eggs can be contaminated on the outer shell surface and internally. Internal contamination can be the result of penetration through the eggshell or by direct contamination of egg contents before oviposition, originating from infection of the reproductive organs. Once inside the egg, the bacteria need to cope with antimicrobial factors in the albumen and vitelline membrane before migration to the yolk can occur. It would seem that serotype Enteritidis has intrinsic characteristics that allow an epidemiological association with hen eggs that are still undefined. There are indications that SE survives the attacks with the help of antimicrobial molecules during the formation of the egg in the hen's oviduct and inside the egg. This appears to require a unique combination of genes encoding for improved cell wall protection and repairing cellular and molecular damage, among others. [source] Functionalized-Silk-Based Active Optofluidic DevicesADVANCED FUNCTIONAL MATERIALS, Issue 7 2010Konstantinos Tsioris Abstract Silk protein from the silkworm Bombyx mori has excellent chemical and mechanical stability, biocompatibility, and optical properties. Additionally, when the protein is purified and reformed into materials, the biochemical functions of dopants entrained in the protein matrix are stabilized and retained. This unique combination of properties make silk a useful multifunctional material platform for the development of sensor devices. An approach to increase the functions of silk-based devices through chemical modifications to demonstrate an active optofluidic device to sense pH is presented. Silk protein is chemically modified with 4-aminobenzoic acid to add spectral-color-responsive pH sensitivity. The functionalized silk is combined with the elastomer poly(dimethyl siloxane) in a single microfluidic device. The microfluidic device allows spatial and temporal control of the delivery of analytic solutions to the system to provide the optical response of the optofluidic device. The modified silk is stable and spectrally responsive over a wide pH range from alkaline to acidic. [source] A Computational Framework for Patient-Specific Analysis of Articular Cartilage Incorporating Structural Information from DT-MRIGAMM - MITTEILUNGEN, Issue 2 2009David M. Pierce Abstract Accurate techniques for simulating sof t biological tissue deformation are an increasingly valuable tool in many areas of biomechanical analysis and medical image computing. To model the morphology and the material response of human articular cartilage a phenomenological and patient-specific simulation approach incorporating the collagen fibre fabric is proposed. We then demonstrate a unique combination of ultra-high field Diffusion Tensor Magnetic Resonance Imaging (17.6T DT-MRI) and a novel numerical approach incorporating the empirical data to predict the collagen fibre fabric deformation for an indentation experiment (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Supported Lipid Bilayer on Nanocrystalline Diamond: Dual Optical and Field-Effect Sensor for Membrane DisruptionADVANCED FUNCTIONAL MATERIALS, Issue 1 2009Priscilla Kailian Ang Abstract It is demonstrated that a good biomimetic model lipid membrane with dynamic fluidity can be established on optically transparent nanocrystalline diamond (OTND) with surface roughness below 10,nm. Maigainin II, an antimicrobial peptide, is chosen to investigate the permeation of artificial bacterial membranes constructed on OTND. Due to the unique combination of optical transparency and highly sensitive surface conducting channel, intrinsic OTND affords the possibility of dual-mode sensing based on optical and field effect properties. This opens up new possibilities for making integrated biomolecule,semiconductor microdevices, or sensors where the binding of biomolecules can be tracked using confocal microscopy whilst the associated changes in charge density during membrane perforation can be tracked using the space charge effect in the semiconductor. Such a synergistic approach may provide a powerful methodology for the screening of specific bactericidal activity on biomimetic membrane systems. [source] The integration of thermal infrared imaging, discharge measurements and numerical simulation to quantify the relative contributions of freshwater inflows to small estuaries in Atlantic CanadaHYDROLOGICAL PROCESSES, Issue 20 2009Serban Danielescu Abstract Nutrient fluxes from developed catchments are often a significant factor in the declining water quality and ecological functioning in estuaries. Determining the relative contributions of surface water and groundwater discharge to nutrient-sensitive estuaries is required because these two pathways may be characterized by different nutrient concentrations and temporal variability, and may thus require different remedial actions. Quantifying the volumetric discharge of groundwater, which may occur via diffuse seepage or springs, remains a significant challenge. In this contribution, the total discharge of freshwater, including groundwater, to two small nutrient-sensitive estuaries in Prince Edward Island (Canada) is assessed using a unique combination of airborne thermal infrared imaging, direct discharge measurements in streams and shoreline springs, and numerical simulation of groundwater flow. The results of the thermal infrared surveys indicate that groundwater discharge occurs at discrete locations (springs) along the shoreline of both estuaries, which can be attributed to the fractured sandstone bedrock aquifer. The discharge measured at a sub-set of the springs correlates well with the area of the thermal signal attributed to each discharge location and this information was used to determine the total spring discharge to each estuary. Stream discharge is shown to be the largest volumetric contribution of freshwater to both estuaries (83% for Trout River estuary and 78% for McIntyre Creek estuary); however, groundwater discharge is significant at between 13% and 18% of the total discharge. Comparison of the results from catchment-scale groundwater flow models and the analysis of spring discharge suggest that diffuse seepage to both estuaries comprises only about 25% of the total groundwater discharge. The methods employed in this research provide a useful framework for determining the relative volumetric contributions of surface water and groundwater to small estuaries and the findings are expected to be relevant to other fractured sandstone coastal catchments in Atlantic Canada. Copyright © 2009 John Wiley & Sons, Ltd. [source] Extreme hydrochemical conditions in natural microcosms entombed within Antarctic iceHYDROLOGICAL PROCESSES, Issue 2 2004Martyn Tranter Abstract Cryoconite holes are near-vertical tubes that form in the surface of glaciers when solar-heated debris melts into the ice. Those that form in the McMurdo Dry Valleys of Antarctica are distinctive, in that they have ice lids and are closed to the atmosphere for periods of years to decades. Photoautotrophs and heterotrophs grow within this closed environment, perturbing the poorly buffered water chemistry, yet maintaining the potential for photosynthesis. Microbial excretion and decomposition of organic matter produces dissolved organic carbon (DOC): dissolved inorganic carbon ratios of ,1:2. Much of the dissolved nitrogen pool (80,100%) exists as dissolved organic nitrogen (DON). The DON:DOC ratio is ,1:11 (mol/mol), typical of organic particulate material at the Earth's surface. The combination of photoautotrophy, heterotrophy and weak chemical buffering within these microcosms promotes values of pH, pCO2, O2 saturation and percentage total dissolved nitrogen as DON that reach 10·99, 10,7·6 atm, 160% and 100% respectively, which are a unique combination among the surface waters on Earth. These ice-sealed cryoconite holes could be important analogues of refugia on Snowball Earth and other icy planets. Copyright © 2004 John Wiley & Sons, Ltd. [source] Primitive complement system of invertebratesIMMUNOLOGICAL REVIEWS, Issue 1 2004Masaru Nonaka Summary:, Most components of the human complement system have unmistakable domain architectures, making evolutionary tracing feasible. In contrast to the major genes of the adaptive immune system, which are present only in jawed vertebrates, complement component genes with unique domain structures are present not only in jawed vertebrates but also in jawless fish and non-vertebrate deuterostomes. Recent progress in genome analysis in several eukaryotes, occupying the phylogenetically critical positions, showed that most individual domains found in the complement components are metazoa specific, being found both in deuterostomes and in protostomes but not in yeast or plant. However, unique domain architecture of complement components is not present in protostomes, suggesting that the complement system has been established in the deuterostome lineage not by invention of new domains but by innovation of unique combination of the pre-existing domains. The recently assembled Ciona intestinalis draft genome contained the most modular complement genes, except for factor I. However, some possible C. intestinalis complement components show critical structural divergence from the mammalian counterparts, casting doubt on their mutual interaction. Thus, another integrative step seems to have been required to establish the modern complement system of higher vertebrates. [source] Thymic generation and regenerationIMMUNOLOGICAL REVIEWS, Issue 1 2003Jason Gill Summary:, The thymus is a complex epithelial organ in which thymocyte development is dependent upon the sequential contribution of morphologically and phenotypically distinct stromal cell compartments. It is these microenvironments that provide the unique combination of cellular interactions, cytokines, and chemokines to induce thymocyte precursors to undergo a differentiation program that leads to the generation of functional T cells. Despite the indispensable role of thymic epithelium in the generation of T cells, the mediators of this process and the differentiation pathway undertaken by the primordial thymic epithelial cells are not well defined. There is a lack of lineage-specific cell-surface-associated markers, which are needed to characterize putative thymic epithelial stem cell populations. This review explores the role of thymic stromal cells in T-cell development and thymic organogenesis, as well as the molecular signals that contribute to the growth and expansion of primordial thymic epithelial cells. It highlights recent advances in these areas, which have allowed for a lineage relationship amongst thymic epithelial cell subsets to be proposed. While many fundamental questions remain to be addressed, collectively these works have broadened our understanding of how the thymic epithelium becomes specialized in the ability to support thymocyte differentiation. They should also facilitate the development of novel, rationally based therapeutic strategies for the regeneration and manipulation of thymic function in the treatment of many clinical conditions in which defective T cells have an important etiological role. [source] A closed-loop proposal for hydrogen generation using steel waste and a prototype solar concentratorINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2009Abdul-Majeed Azad Abstract An economically viable and environmental-friendly method of generating PEM grade hydrogen has been proposed and is by the reaction of certain metals with steam, appropriately called ,metal,steam reforming',MSR. The drawbacks of conventional processes (hydrogen and carbothermic reduction schemes) are overcome by resorting to solution-based reduction schemes and are made economically feasible using iron oxides from steel industry's mill-scale waste. A novel aqueous-based room temperature technique using sodium borohydride (NaBH4) as the reducing agent has been developed that produces highly active nanoscale iron particles (,40,nm). By using hydrazine as an inexpensive and, compared with NaBH4, more stable reductant, body centered cubic iron particles with ,5,nm edges were obtained via solvothermal process under mild conditions from acid digested mill-scale waste. The nanoscale zerovalent iron (nZVI) powder showed improved kinetics and greater propensity for hydrogen generation than the coarser microscale iron. The rate constants for the MSR were obtained for all the reduction schemes employed in this work and are given by khydrogen=0.0158,min,1kcarbon=0.0248,min,1ksodiumborohydride=0.0521,min,1 and khydrazine=0.1454,min,1, assuming first order kinetics. Another innovative effort converted the magnetite waste directly into nZVI under solvothermal conditions, thus obviating the sluggish and time-consuming acid dissolution step. This particular aspect has significant ramification in terms of time and cost of making the iron precursor. To initiate and sustain the somewhat endothermic MSR process, a solar concentrator consisting of a convex polyacrylic bowl with reflective aluminum coating was fabricated and evaluated. This unique combination of mill-scale waste as iron source, hydrazine as reductant, mild process conditions and solar energy as the MSR actuator obviates several drawbacks plaguing the grand scheme of producing and delivering pure and humidified H2 to a PEMFC stack. Copyright © 2008 John Wiley & Sons, Ltd. [source] Good Deaths, Bad Deaths, and Preferences for the End of Life: A Qualitative Study of Geriatric OutpatientsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2002Elizabeth K. Vig MD OBJECTIVES: Patient involvement in decision-making has been advocated to improve the quality of life at the end of life. Although the size of the oldest segment of the population is growing, with greater numbers of older adults facing the end of life, little is known about their preferences for the end of life. This study aimed to explore the attitudes of older adults with medical illness about the end of life, and to investigate whether current values could be extended to end-of-life preferences. DESIGN: Descriptive study with interviews using open- and closed-ended questions. SETTING: Patients attending two university-affiliated geriatric clinics were interviewed in a private conference room near the clinic they attended or in their homes. PARTICIPANTS: Sixteen older men and women identified by their physicians as having nonterminal heart disease or cancer. MEASUREMENTS: The interview contained open-ended questions such as: "What are the most important things in your life right now?" and "What would you consider a good/bad death?" The interview also contained closed-ended questions about symptoms, quality of life, and health status. Additional questions elicited preferences for the end of life, such as location of death and the presence of others. The open-ended questions were tape-recorded, transcribed, and analyzed using qualitative methods. The closed-ended questions were analyzed using descriptive statistics. RESULTS: Patients with heart disease and cancer provided similar responses. Participants' views about good deaths, bad deaths, and end-of-life scenarios were heterogeneous. Each participant voiced a unique combination of themes in describing good and bad deaths. Because each participant described a multifaceted view of a good death, for instance, no theme was mentioned by even half of the participants. Participants provided differing explanations for why given themes contributed to good deaths. Currently valued aspects of life were not easily translated into end-of-life preferences. For example, although the majority of participants identified their family as being important, many gave reasons why they did not want their family members present when they died. CONCLUSIONS: Because of the heterogeneity of views and the difficulty in inferring end-of-life preferences from current values, older adults should be asked not only questions about general values, but also specific questions about their end-of-life choices and the reasons for these choices. A thorough understanding of an individual's end-of-life preferences may help health professionals working with older adults develop patient-centered care plans for the end of life. [source] Masticatory muscle architecture in the Laotian rock rat Laonastes aenigmamus (Mammalia, Rodentia): new insights into the evolution of hystricognathyJOURNAL OF ANATOMY, Issue 4 2009Lionel Hautier Abstract We present the first descriptive comparison of the skull, mandible and jaw muscles of the recently recovered Laotian rock rat Laonastes aenigmamus. The gross anatomy of five specimens captured in Laos and internal architecture of the jaw musculature were studied using dissections. The following muscles are described: temporal, masseter, pterygoids, digastric, mylohyoid, geniohyoid and transverse mandibular. The description of the masticatory apparatus of L. aenigmamus offers a rare opportunity to assess the order of establishment of the morphological characters during the evolution of Ctenohystrica. Striking convergences have occurred during the evolution of Diatomyidae and L. aenigmamus presents a unique combination of myological features that corresponds to a mixture of sciurognathous and hystricognathous characters. If L. aenigmamus is a sciurognathous rodent, we have to assume that it independently acquired a pars reflexa of the superficial masseter. We show for the first time that the development of this pars reflexa has occurred several times during the evolution of Ctenohystrica and can no longer be considered a synapomorphic feature of ,Hystricognathi'. These results bring new insights into the evolution of hystricognathy and have profound implications for the interpretation of the fossil record of early hystricognath rodents. [source] Syndiotactic polystyrene: Process and applicationsADVANCES IN POLYMER TECHNOLOGY, Issue 3 2006Jürgen Schellenberg Abstract In this review, a summary is provided of the manufacturing process for syndiotactic polystyrene together with an overview of applications of syndiotactic polystyrenes, including selected examples of typical applications. The manufacturing process of syndiotactic polystyrene, consists of several basic sections: catalyst premix preparation, monomer treatment, polymerization reaction using a powder bed reactor together with an evaporative cooling system, devolatilization and extrusion, and finally finishing, including cooling and crystallization of the strands. This process is suitable for providing a wide range of syndiotactic polystyrenes comprising homopolymers, with a broad range of melt flow rates as well as copolymers of various comonomer contents, leading to products with various melting temperatures. Essential relationships and correlations of the separate process stages are demonstrated, in addition to useful analytical methods to control the process. These polymers' unique combination of heat resistance, chemical resistance, and electrical properties has led to their successful application in automotive, electrical and electronics, consumer and industrial uses. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25:141,151, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20069 [source] Target transform fitting: a new method for the non-linear fitting of multivariate data with separable parametersJOURNAL OF CHEMOMETRICS, Issue 6 2001Porn Jandanklang Abstract Data fitting is an important technique in chemistry. The number of parameters to be fitted is a most significant aspect: the larger the number, the more difficult the task. A unique combination of target factor analysis with non-linear data fitting can result in complete or partial separation of the parameters, which can then be fitted independently. Thus, instead of one multiparameter fit, several fits are performed with only one or a few parameters. The procedure can also support model development. Applications in kinetics and chromatography are presented. Copyright © 2001 John Wiley & Sons, Ltd. [source] Changes in practice at the nurse,doctor interface.JOURNAL OF CLINICAL NURSING, Issue 1 2003Using focus groups to explore the perceptions of first level nurses working in an acute care setting Summary ,,A unique combination of factors has recently triggered a rapid change in the clinical practice of nurses in the UK. ,,This study was carried out to explore the consequences of changing practice at the nurse,doctor interface, as perceived by first level nurses working in an acute care setting in the UK. ,,Qualitative data were collected using focus group interviews and analysed thematically. ,,Findings suggest that role change to these nurses is represented by a ,shift' in the practice of technical activities from junior doctors and a corresponding delegation of nursing activity to care assistants. ,,It is suggested that the wholesale incorporation of technical interventions into the role of the nurse without an increase in the number of qualified nurses is turning nursing back to a task system of care delivery. ,,This has the potential to depersonalize patients and reduce work satisfaction for nurses. [source] Effects of genetic impoverishment on plant community diversityJOURNAL OF ECOLOGY, Issue 5 2003Rosemary E. Booth Summary 1Established individuals removed at random from populations of 11 long-lived herbaceous species coexisting in a local area of ancient limestone pasture at Cressbrookdale in North Derbyshire were subjected to clonal propagation to produce stocks of genetically identical individuals sufficient to create 36 model communities identical in species composition but widely contrasted in genetic diversity. 2Three levels of genetic diversity were imposed. In one treatment, all individuals of each species were genetically unique. The second contained four randomly selected genotypes of each species. In the third, there was no genetic diversity in any of the species but each community contained a unique combination of genotypes. 3Over a period of 5 years the communities were allowed to develop in microcosms containing natural rendzina soil and exposed to a standardized regime of simulated grazing and trampling. The treatments were maintained by the removal of flowers, immature seed-heads and seedlings originating from the seed-bank and seed rain. Point quadrat surveys were used to monitor changes in species composition and diversity in the three experimental treatments. 4During the experiment a distinction rapidly developed between five canopy dominants and five subordinates, a process that caused the vegetation structure to closely resemble that occurring at Cressbrookdale. 5A gradual loss of species diversity occurred in all three treatments but by the end of the fifth growing season species diversity was higher in the most genetically diverse communities. 6Ordination of the 36 communities at intervals over a 5-year period revealed a gradual convergence in the species composition of the 4-genotype and 16-genotype communities and this effect was more strongly developed in the latter. A comparable process was not observed in the 1-genotype communities, suggesting that interaction between particular genotypes of different species in local neighbourhoods may be an essential part of the mechanism that determines the predictable composition of a mature pasture community. 7It is concluded that, under the conditions of this experiment, genetic diversity within component species reduced the rate at which species diversity declined. The relative importance in this effect of factors such as greater disease resistance and moderated competitive interactions remains uncertain. [source] Novel microfibrous-structured silver catalyst for high efficiency gas-phase oxidation of alcoholsAICHE JOURNAL, Issue 6 2010Jiping Mao Abstract Novel microfibrous-structured silver catalysts were developed for gas-phase selective oxidation of mono-/aromatic-/di-alcohols. Sinter-locked three-dimensional microfibrous networks consisting of 5 vol % 8-,m-Ni (or 12-,m-SS-316L) fibers and 95 vol % void volume were built up by the papermaking/sintering processes. Silver was then deposited onto the surface of the sinter-locked fibers by incipient wetness impregnation method. At relatively low temperatures (e.g., 380°C), the microfibrous-structured silver catalysts provided quite higher activity/selectivity compared to the electrolytic silver. The microfibrous Ag/Ni-fiber offered much better low-temperature activity than the Ag/SS-fiber. The interaction at Ag particles and Ni-fiber interface not only visibly increased the active/selective sites of Ag+ ions and Agn,+ clusters but also significantly promoted their low-temperature reducibility and ability for O2 activation. In addition, the microfibrous structure provided a unique combination of large void volume, entirely open structure, high thermal conductivity and high permeability. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Optimization of multicomponent photopolymer formulations using high-throughput analysis and kinetic modelingAICHE JOURNAL, Issue 5 2010Peter M. Johnson Abstract While high throughput and combinatorial techniques have played an instrumental role in materials development and implementation, numerous problems in materials science and engineering are too complex and necessitate a prohibitive number of experiments, even when considering high throughput and combinatorial approaches, for a comprehensive approach to materials design. Here, we propose a unique combination of high throughput experiments focused on binary formulations that, in combination with advanced modeling, has the potential to facilitate true materials design and optimization in ternary and more complex systems for which experiments are never required. Extensive research on the development of photopolymerizable monomer formulations has produced a vast array of potential monomer/comonomer, initiator and additive combinations. This array dramatically expands the range of material properties that are achievable; however, the vast number of potential formulations has eliminated any possibility of comprehensive materials design or optimization. This limitation is addressed by maximizing the benefits and unique capabilities of high throughput experimentation coupled with predictive models for material behavior and properties. The high throughput experimentation-model combination is useful to collect a limited amount of data from as few as 11 experiments on binary combinations of 10 analyzed monomers, and then use this limited data set to predict and optimize formulation properties in ternary resins that would have necessitated at least 1000 high throughput experiments and several orders of magnitude greater numbers of traditional experiments. A data analysis approach is demonstrated, and the model development and implementation for one model application in which a range of material properties are prescribed, and an optimal formulation that meets those properties is predicted and evaluated. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Towards a Socio-Cognitive Approach to Knowledge TransferJOURNAL OF MANAGEMENT STUDIES, Issue 5 2008Torsten Ringberg abstract Dominant research streams in the knowledge transfer field, such as the positivist and social constructionist approaches, largely assume that knowledge transfer is accomplished through instructions and/or socially constructed practices. Underlying these views is the belief that texts and practices carry with them the codes necessary for their own decoding and therefore enable an unproblematic knowledge transfer. In contrast, we argue that the decoding of information into meaningful knowledge is always mediated by people's private and cultural models, which are created from the unique combination of their cognitive dispositions (i.e. acumen, memory, creativity, volitions, emotions) and socio-cultural interaction. The degree to which people apply these models reflectively and/or categorically (i.e. automatically) depends on the need for cognition as well as environmental demands and feedback. Therefore, knowledge transfer is always tentative, because it depends on the application of private and cultural models along the continuum that goes from reflective to categorical processing. We present first a critique of the positivist and social constructionist positions; then we introduce a socio-cognitive model that captures and explicates socio-cognitive processes involved in sense making during knowledge transfer. Finally, we explore future research streams and managerial implications. [source] Beamline 10.3.2 at ALS: a hard X-ray microprobe for environmental and materials sciencesJOURNAL OF SYNCHROTRON RADIATION, Issue 3 2004Matthew A. Marcus Beamline 10.3.2 at the ALS is a bend-magnet line designed mostly for work on environmental problems involving heavy-metal speciation and location. It offers a unique combination of X-ray fluorescence mapping, X-ray microspectroscopy and micro-X-ray diffraction. The optics allow the user to trade spot size for flux in a size range of 5,17,µm in an energy range of 3,17,keV. The focusing uses a Kirkpatrick,Baez mirror pair to image a variable-size virtual source onto the sample. Thus, the user can reduce the effective size of the source, thereby reducing the spot size on the sample, at the cost of flux. This decoupling from the actual source also allows for some independence from source motion. The X-ray fluorescence mapping is performed with a continuously scanning stage which avoids the time overhead incurred by step-and-repeat mapping schemes. The special features of this beamline are described, and some scientific results shown. [source] The XMaS beamline at ESRF: instrumental developments and high-resolution diffraction studiesJOURNAL OF SYNCHROTRON RADIATION, Issue 6 2001S. D. Brown The beamline, which is situated on a bending magnet at ESRF, comprises a unique combination of instrumentation for high-resolution and magnetic single-crystal diffraction. White-beam operation is possible, as well as focused and unfocused monochromatic modes. In addition to an eleven-axis Huber diffractometer, which facilitates simple operation in both vertical and horizontal scattering geometries, there is an in-vacuum polarization analyser and slit system, mirrors for harmonic rejection, sub 4.2,K and 1,Tesla magnetic field sample environment, plus a diamond phase plate for polarization conditioning. The instrumentation developed specifically for this beamline is described, and its use illustrated by recent scientific results. [source] Recollections of Irving H. Sher 1924,1996: Polymath/information scientist extraordinaireJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 14 2001Eugene Garfield Over a 35-year period, Irving H. Sher played a critical role in the development and implementation of the Science Citation Index® and other ISI® products. Trained as a biochemist, statistician, and linguist, Sher brought a unique combination of talents to ISI as Director of Quality Control and Director of Research and Development. His talents as a teacher and mentor evoked loyalty. He was a particularly inventive but self-taught programmer. In addition to the SCI,® Social Sciences Citation Index,® and Arts and Humanities Citation Index,® Sher was involved with the development of the first commercial SDI system, the Automatic Subject Citation Alert, now called Research Alert,® and Request-A-Print Cards. Together we developed the journal impact factor and the Journal Citation Reports.® Sher was also the inventor of the SYSTABAR System of coding references and Sherhand. He was involved in key reports on citation-based historiography, forecasting Nobel prizes, and served as a referee for JASIS over a 20-year period. [source] Strategic processes @ Nike,making and doing knowledge managementKNOWLEDGE AND PROCESS MANAGEMENT: THE JOURNAL OF CORPORATE TRANSFORMATION, Issue 1 2008George Stonehouse This paper contrasts theory with practice through a case study of strategic processes of knowledge management (KM) at Nike Incorporated. From its origins as a small specialist enterprise in 1972 to a multi-billion dollar global brand, the corporation has been continuously at the forefront of developments in management practice and business innovation. This case study has been compiled from interviews with senior managers and numerous secondary sources. The paper begins with a discussion of an insider perspective on the trajectory of the organization in terms of its strategic goals and decisions on markets, customers, products, services and business processes. It then goes on to explore and critique the dynamic interplay of the processes of strategizing, learning, creativity and innovation at Nike as the basis for its knowledge-based competitive advantage (CA). The case thus represents KM as a unique combination of processes in which learning; strategy and creativity are organized and strategically embedded within a large global organization. This has implications for future theorizing in KM, which, as we illustrate in this paper, demands a more integrative approach to research and practice. One of the key lessons for practice is that span of activity, as well as strategy, will influence the relationship between strategizing, organizing and learning and this interplay determines the success (or failure) of KM. Copyright © 2008 John Wiley & Sons, Ltd. [source] Towards advanced circuit board materials: adhesion of copper foil to ultra-high molecular weight polyethylene compositePOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2002Dmitry Abstract Polyethylene based composites are attractive materials for advanced circuit board applications because of their unique combination of properties: low dielectric constant and loss factor, light weight, high flexural modulus and low thermal expansion coefficient controlled in all spatial directions. This investigation describes a process to consolidate chopped fibers of ultra-high molecular weight polyethylene concurrently with its bonding to a copper foil. Bonding is affected by a thin sheet of low-density polyethylene, incorporating a crosslinking agent with a concentration gradient across the sheets thickness. In this single step process, the composite material is formed and bonded to the metal foil, achieving good adhesion without the use of extraneous glue. Copyright © 2002 John Wiley & Sons, Ltd. [source] Cyclopia (synophthalmia) in Smith,Lemli,Opitz syndrome: First reported case and consideration of mechanism,AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 1 2010David D. Weaver Abstract Here we present a 24-week fetus with Smith,Lemli,Opitz syndrome (SLOS), alobar holoprosencephaly (HPE) and cyclopia (synophthalmia). Following birth, we suspected SLOS in this fetus due to the additional findings of ambiguous genitalia and bilateral 2,3 toe syndactyly. The diagnosis of SLOS was confirmed by finding an elevated amniotic fluid 7-dehydrocholesterol level (9,890,ng/ml; normal range,=,3,9,ng/ml), and molecularly by detecting two different mutations in the DHCR7 gene, the gene causing SLOS. The first mutation was an IVS8-1G>T change and the second was a deletion of exons 3 and 4; this latter mutation has not been reported previously. The mother carries the deletion, while the father carries the splice-site mutation. Also of note, the father has an abnormally low total plasma cholesterol level (104,109,mg/dl). This is the most severe case of HPE described in any patient with SLOS. We postulate that the HPE in this case resulted from severe impairment of Sonic Hedgehog signaling secondary to abnormal cholesterol metabolism; however, the unique combination of mutations in the fetus functionally appears to be no different from other homozygous null mutations reported in DHCR7. Therefore, there must be other yet to be identified factors that contributed to the severity of HPE in SLOS. © 2010 Wiley-Liss, Inc. [source] A mass spectrometry-based strategy for detecting and characterizing endogenous proteinase activities in complex biological samplesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 3 2008Sarah Robinson Abstract Endogenous proteinases in biological fluids such as human saliva produce a rich peptide repertoire that reflects a unique combination of enzymes, substrates, and inhibitors/activators. Accordingly, this subproteome is an interesting source of biomarkers for disease processes that either directly or indirectly involve proteolysis. However, the relevant proteinases, typically very low abundance molecules, are difficult to classify and identify. We hypothesized that a sensitive technique for monitoring accumulated peptide products in an unbiased, global manner would be very useful for detecting and profiling proteolytic activities in complex biological samples. Building on the longstanding use of 18O isotope-based approaches for the classification of proteolytic and other enzymatic processes we devised a new method for evaluating endogenous proteinases. Specifically, we showed that upon ex vivo incubation endogenous proteinases in human parotid saliva introduced 18O from isotopically enriched water into the C-terminal carboxylic groups of their peptide products. Subsequent peptide sequence determination and inhibitor profiling enabled the detection of discrete subsets of proteolytic products that were generated by different enzymes. As a proof-of-principle we used one of these fingerprints to identify the relevant activity as tissue kallikrein. We termed this technique PALeO. Our results suggest that PALeO is a rapid and highly sensitive method for globally assessing proteinase activities in complex biological samples. [source] | |||||||||||||||||||||||||||||||