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Different Generations (different + generation)
Selected AbstractsEvaluation of Gd(III)DTPA-terminated poly(propylene imine) dendrimers as contrast agents for MR imagingNMR IN BIOMEDICINE, Issue 1 2006Sander Langereis Abstract Different generations of Gd(III)DTPA-terminated poly(propylene imine) dendrimers {G1 [n,=,4 Gd(III) ions per molecule], G3 (n,=,16) and G5 (n,=,64)} and reference Gd(III)DTPA complex [G0 (n,=,1)] were characterized in terms of (i) longitudinal (r1) and transverse (r2) relaxivities in mouse blood plasma, (ii) concentration detection limits in vitro and (iii) in vivo contrast-enhanced MR imaging (CE-MRI) in mice at 1.5,,,T. Serial and dynamic CE-MRI were performed to monitor the distribution of MRI contrast agent in the heart, arteries, renal system, liver, spleen, bladder and tumor periphery. The relaxivities increased non-linearly with molecular weight (for G0 ionic r1,=,8.1,mM,1,s,1 and ionic r2,=,8.6,mM,1,s,1 to G5 19.3 and 25.0, respectively). The minimal detectable dendrimer concentration was more than two orders of magnitude lower for G5 (8.1,×,10,8,M) than for G0 (3.1,×,10,5,M). Sub-millimeter-sized blood vessels were well visualized with serial CE-MRI with each contrast agent. Dynamic CE-MRI showed timely renal clearance for all contrast agents, but a stronger and a prolonged blood signal enhancement for the higher generations of the dendritic contrast agent. Moreover, G0 and G1 showed a rapid tumor wash-in and wash-out, whereas G3 and G5 displayed a more gradual and prolonged tumor wash-in. In conclusion, both G0 and dendritic contrast agents G1, G3 and G5 are well suited for non-tissue-specific MRI of sub-millimeter-sized blood vessels and evaluating tumor microcirculatory characteristics in mice. Higher generations of dendritic contrast agents display lower concentration detection limits, which suggests their future use for molecular imaging. Copyright © 2006 John Wiley & Sons, Ltd. [source] Analysis of hopanes and steranes in single oil-bearing fluid inclusions using time-of-flight secondary ion mass spectrometry (ToF-SIMS)GEOBIOLOGY, Issue 1 2010S. SILJESTRÖM Steranes and hopanes are organic biomarkers used as indicators for the first appearance of eukaryotes and cyanobacteria on Earth. Oil-bearing fluid inclusions may provide a contamination-free source of Precambrian biomarkers, as the oil has been secluded from the environment since the formation of the inclusion. However, analysis of biomarkers in single oil-bearing fluid inclusions, which is often necessary due to the presence of different generations of inclusions, has not been possible due to the small size of most inclusions. Here, we have used time-of-flight secondary ion mass spectrometry (ToF-SIMS) to monitor in real time the opening of individual inclusions trapped in hydrothermal veins of fluorite and calcite and containing oil from Ordovician source rocks. Opening of the inclusions was performed by using a focused C60+ ion beam and the in situ content was precisely analysed for C27,C29 steranes and C29,C32 hopanes using Bi3+ as primary ions. The capacity to unambiguously detect these biomarkers in the picoliter amount of crude oil from a single, normal-sized (15,30 ,m in diameter) inclusion makes the approach promising in the search of organic biomarkers for life's early evolution on Earth. [source] Distributional Impacts of Pension Policy in Argentina: Winners and Losers within and Across GenerationsINTERNATIONAL SOCIAL SECURITY REVIEW, Issue 3 2006Camila Arza The paper deals with the life-cycle intra- and intergenerational income transfers operated by the pension system in Argentina by estimating the internal rates of return obtained by different generations and types of workers from their participation in the system. The empirical analysis confirms that earlier generations of workers benefited from higher social security returns than later generations, which retired under a matured system with large deficits. The worst-affected cohorts were those born after 1920, particularly suffering from a social security crisis and falling real wages. For future generations retiring fully under the new mixed pension system, returns will more closely depend on financial market performance and the evolution of administration costs. Intragenerational transfers were also observed for all cohorts under study, as a result of the original system design as well as adjustments adopted during the implementation process. The real distributional impact of progressive benefit formulas could, however, be offset by state transfers to cover pension deficits and forward tax shifting in a context of unequal pension coverage. [source] Rhodium Complexed C2 -PAMAM Dendrimers Supported on Large Pore Davisil Silica as Catalysts for the Hydroformylation of OlefinsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2005Abstract Polyamidoamine (PAMAM) dendrimers up to the third generation were grown for the first time on the surface of a large-pore (18,nm) Davisil silica support. The supported dendrimers of generations 0, 1, 2 and 3 were phosphinomethylated and complexed with rhodium. All the generations were found to be very active for the hydroformylation of olefins. The hydroformylation of 1-octene was accomplished with a turnover frequency of 1700,h,1 at 70,°C. The G(1) material was found to be the most active when the different generations were compared at 50% conversion at 70,°C [source] Broadband dielectric spectroscopy on the molecular dynamics in different generations of hyperbranched polyesterJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2009Gamal Turky Abstract Dielectric spectroscopy (10,2 Hz to 106 Hz) was employed to investigate the molecular dynamics of hyperbranched polyesters where the number of the generation is systematically varied from 2 to 5. As a first result, the dielectric properties depends strongly on the generation of the hyperbranched polymers. For higher generations (3 to 5) at temperatures below Tg two relaxation processes are observed, a ,-process at lower temperatures and a ,-process at higher ones. The apparent activation energies are around 100 kJ/mol which seems to be too high for truly localized processes. For the Generation 2, only the ,-process is observed. For all investigated polymers the dielectric ,-relaxation could not be observed because of strong conductivity effects. Therefore, the conductivity is systematically analyzed which obeys the peculiarities found to be characteristic for semiconducting disordered materials. Especially, the Barton/Nakajima/Namikawa relationship is found to be valid. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Multigenerational analysis of spatial structure in the terrestrial, food-deceptive orchid Orchis masculaJOURNAL OF ECOLOGY, Issue 2 2009Hans Jacquemyn Summary 1In long-lived, terrestrial orchids, strong aggregation of adults and recruits within populations and pronounced spatial association between recruits and adults can be expected when seed dispersal is limited, probabilities of seed germination decrease with increasing distance from mother plants and/or not all mother plants contribute to future generations. When individuals are distributed evenly across life-history stages, these processes can also be expected to result in a significant fine-scale spatial genetic structure in recruits that will persist into the adult-stage class. 2We combined detailed spatial genetic and point pattern analyses across different generations with parentage analyses to elucidate the role of the diverse processes that might determine spatial structure in Orchis mascula. 3Analyses of spatial point patterns showed a significant association between adults and recruits and similar clustering patterns for both. Weak, but highly significant spatial genetic structure was observed in adults and recruits, but no significant differences were observed across life stages, indicating that the spatial genetic structure present in recruits persists into the adult stage. 4Parentage analyses highlighted relatively short seed dispersal distances (median offspring-recruitment distance: 1.55 and 1.70 m) and differential contribution of mother plants to future generations. 5Persistence of fine-scale spatial genetic structure from seedlings into the adult stage class is consistent with the life history of O. mascula, whereas relatively large dispersal distances of both pollen and seeds compared to the fine-scale clustering of adults and seedlings suggest overlapping seed shadows and mixing of genotypes within populations as the major factors explaining the observed weak spatial genetic structure. 6Nonetheless, comparison of the spatial association between recruits and adults with the genetic analysis of offspring-parent distances suggests that the tight clustering of recruits around adults was probably caused by decreasing probabilities of seed germination with increasing distance from mother plants. 7Synthesis. This study shows that the approach presented here, which combines spatial genetic and spatial pattern analyses with parentage analyses, may be broadly applied to other plant species to elucidate the processes that determine spatial structure within their populations. [source] Attaining organizational commitment across different generations of nursesJOURNAL OF NURSING MANAGEMENT, Issue 8 2008LARA CARVER PhD Aim, To inform nurse managers about the generational differences that exist among nurses, how it affects the work environment and how this information can be used to encourage organizational commitment. Background, Every person is born into a generational cohort of peers who experience similar life experiences that go on to shape distinct generational characteristics. Thanks to delayed retirements, mid-life career changes, job re-entry and a small but significant group of younger graduates, the nursing profession is now experiencing four generations in the workforce: Veterans, Baby Boomers, Generation X and the Millennial Generation. At the same time, the literature on organizational commitment is expanding and can provide a compelling context through which to view generational differences among nurses. Implications for nursing management, As part of an overall strategy to increase organizational commitment, consideration of generational differences in nurses can be helpful in leading to increased job satisfaction, increased productivity and decreased turnover among staff. In the face of the global nursing shortage, managers should increase their knowledge of generational diversity just as they have with ethnic and cultural diversity in the past. Understanding how to relate to the different generations and tap into their individual strengths can lead to improved nursing work environments. [source] Generational differences in soft knowledge situations: status, need for recognition, workplace commitment and idealismKNOWLEDGE AND PROCESS MANAGEMENT: THE JOURNAL OF CORPORATE TRANSFORMATION, Issue 1 2008Peter Busch Much knowledge management (KM) literature is focused on the improvements that can be made to organisations if they use their knowledge resource effectively. A great deal of knowledge rests in the heads of employees. Little to date has discussed the differences in soft knowledge utilisation amongst different generations of employees particularly in the IT sector. By generations we refer to the Baby Boomers, Generation X and Generation Y. Our study establishes that there were a number of differences between how the three Generations would deal with certain IT soft knowledge situations. These differences were along the following lines; issues of status in the workplace; need for recognition, typically by younger employees; issues of commitment to the workplace and finally idealism in the place of work. Copyright © 2008 John Wiley & Sons, Ltd. [source] Self-Assembly of Dendritic Macromolecules Based on the Ionic Interaction of Linear Chain Polyelectrolyte Cores with Oppositely Charged Focal Ionogenic Groups of DendronsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 12 2004Alexander Y. Bilibin Abstract Summary: A new principle for the design of dendritic macromolecules , the ionic binding of linear chain polyelectrolyte with oppositely charged focal ionogenic groups of dendrons , has been developed. The majority of the dendritic ionic complexes (DICs) are prepared with poly(styrenesulfonic acid) (PSS) as a polymeric core and L -aspartic acid dendrons of different generations. Two series of DICs were prepared using PSS and aspartic dendrons bearing terminal (located at the external periphery) methoxycarbonyl and hexyloxycarbonyl groups (C1- n and C6- n respectively where n is the generation number). Ionic binding of about 100% was found for dendrons of Generation 1,3. The solubility of the DICs was examined and the DICs prepared were studied by IR spectroscopy, 1H NMR and viscometry. Dendritic ionic complexes prepared using poly(styrenesulfonic acid) acid and aspartic dendrons bearing terminal methoxycarbonyl and hexyloxycarbonyl groups. [source] Immediate allergic reactions to cephalosporins and penicillins and their cross-reactivity in childrenPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 4 2005-Markovi, Marina Atanaskovi Penicillins and cephalosporins are the most important betalactams inducing IgE-mediated reactions. The safety of administering cephalosporins to penicillin-allergic children is a particular problem, because cephalosporin allergenic determinants have not been properly identified. A study was undertaken to evaluate the frequency of anaphylactic reactions to cephalosporins and penicillins and their cross-reactivity in a pediatric population. A prospective survey was conducted in a group of 1170 children with suspected immediate allergic reactions to cephalosporins and/or penicillins, which were examined during a period of 8 yr. In vivo (skin tests and challenges) and in vitro tests (for specific IgE) were performed with standard concentration of penicillins and cephalosporins. When 1170 children with a clinical history of allergy to penicillins and/or cephalosporins were tested in vivo for immediate hypersensitivity to betalactams, 58.3% cases overall were found to be skin or challenge test positive. Among them, 94.4% patients were positive to penicillins and 35.3% to cephalosporins. The frequency of positive reactions in the in vivo testing was in the range from 36.4% to 88.1% for penicillins and from 0.3% to 29.2% for cephalosporins. However, 31.5% of the penicillin allergic children cross-reacted to some cephalosporin. If a child was allergic to a cephalosporin, the frequency of positive reactions to penicillin was 84.2%. The cross-reactivity between cephalosporins and penicillins varied between 0.3% and 23.9%. The cross-reactivity among different generations of cephalosporins varied between 0% and 68.8%, being the highest for first and second-generation cephalosporins and 0% for third generation cephalosporins. The frequency of immediate allergic reactions to cephalosporins is considerably lower compared to penicillins, and the degree of cross-reactivity between cephalosporins and penicillins depends on the generation of cephalosporins, being higher with earlier generation cephalosporins. The cross-reactivity among cephalosporins is lower compared to cross-reactivity between penicillins and cephalosporins. [source] Palaeoclimate reconstruction on Big Lyakhovsky Island, north Siberia,hydrogen and oxygen isotopes in ice wedgesPERMAFROST AND PERIGLACIAL PROCESSES, Issue 2 2002Hanno Meyer Abstract Late Quaternary permafrost deposits on Big Lyakhovsky Island (New Siberian Islands, Russian Arctic) were studied with the aim of reconstructing the palaeoclimatic and palaeoenvironmental conditions of northern Siberia. Hydrogen and oxygen stable isotope analyses are presented for six different generations of ice wedges as well as for recent ice wedges and precipitation. An age of about 200 ka BP was determined for an autochtonous peat layer in ice-rich deposits by U/Th method, containing the oldest ice wedges ever analysed for hydrogen and oxygen isotopes. The palaeoclimatic reconstruction revealed a period of severe winter temperatures at that time. After a gap in the sedimentation history of several tens of thousands of years, ice-wedge growth was re-initiated around 50 ka BP by a short period of extremely cold winters and rapid sedimentation leading to ice-wedge burial and characteristic ice-soil wedges (,polosatics'). This corresponds to the initial stage for the Late Weichselian Ice Complex, a peculiar cryolithogenic periglacial formation typical of the lowlands of northern Siberia. The Ice Complex ice wedges reflect cold winters and similar climatic conditions as around 200 ka BP. With a sharp rise in ,18O of 6, and ,D of 40,, the warming trend between Pleistocene and Holocene ice wedges is documented. Stable isotope data of recent ice wedges show that Big Lyakhovsky Island has never been as warm in winter as today. Copyright © 2002 John Wiley & Sons, Ltd. [source] Genetic linkage map construction and location of QTLs for fruit-related traits in cucumberPLANT BREEDING, Issue 2 2008X. J. Yuan Abstract A 173-point genetic linkage map of cucumber (Cucumis sativus L.), consisting of 116 SRAPs, 33 RAPDs, 11 SSRs, 9 SCARs, 3 ISSRs, and 1 STS, was constructed using 130 F2 progeny derived from a narrow cross between line S94 (Northern China open-field type) and line S06 (greenhouse European type). The seven linkage groups spanned 1016 cM with a mean marker interval of 5.9 cM. Using the F2 population and its F3 derived families, a total of 38 QTLs were detected on five linkage groups with an LOD threshold of 3.0 for nine fruit-related traits: fruit weight, length, and diameter, fruit flesh thickness, seed-cavity diameter, fruit-stalk length, fruit pedicel length, length/diameter and length/stalk ratio. Of the identified QTLs, fsl4.3 for fruit-stalk length explained the largest portion of phenotypic variation (r2 = ,30%). Several QTLs were detected in the same linkage region in different generations and different seasons. Additionally, several QTLs for various fruit traits were mapped to the same or neighbouring marker intervals, suggesting they are possible character associations for controlling cucumber fruit development. [source] The effect of hyperbranched polymers on processing and thermal stability of biodegradable polyestersPOLYMER ENGINEERING & SCIENCE, Issue 3 2009Yanir Shaked Nanomodification of poly-hydroxy-butyrate (PHB), with hyperbranched polymers (HBP), was studied. Solid-hyperbranched polyesters of different generations were incorporated into a biobased and biodegradable, thermoplastic, polyester. Thermal, rheological, and molecular weight measurements had indicated that due to the interactions between the hydroxyl groups and the polar esters in PHB, the rate of recrystallization was significantly increased. Furthermore, the degree of crystallinity and nonisothermal crystallization temperature were also increased. Molecular weight measurements did not indicate a reduction or retention when HBPs were incorporated. These results are of great significance for the processing of biodegradable polymers and specifically for PHB, where improved processability and enhanced crystallization are of importance. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source] Adenoviral vectors for gene transfer and therapyTHE JOURNAL OF GENE MEDICINE, Issue S1 2004Christoph Volpers Abstract Due to the very efficient nuclear entry mechanism of adenovirus and its low pathogenicity for humans, adenovirus-based vectors have become gene delivery vehicles that are widely used for transduction of different cell types, especially for quiescent, differentiated cells, in basic research, in gene therapy applications, and in vaccine development. As an important basis for their use as gene medicine, adenoviral vectors can be produced in high titers, they can transduce cells in vivo with transgenes of more than 30 kb, and they do not integrate into the host cell genome. Recent advances in the development of adenoviral vectors have brought considerable progress on issues like target cell specificity and tropism modification, long-term expression of the transgene, as well as immunogenicity and toxicity in vivo, and have suggested that the different generations of non-replicative and replicative vectors available today will each suit best for certain applications. Copyright © 2004 John Wiley & Sons, Ltd. [source] Generational attitudes of rural mental health nursesAUSTRALIAN JOURNAL OF RURAL HEALTH, Issue 2 2009Andrew Crowther Abstract Objective:,To determine how attitudes of rural mental health nurses differ across generations. Design:,Survey. Setting:,Mental health services in rural New South Wales. Participants:,Practising mental health nurses. Main outcome measures:,Survey responses. Results:,Survey response rate 44%. A total of 89 mental health nurses, clustered in inpatient units and community health centres, responded. Of these nurses, 4 were veterans, 52 baby boomers, 17 Generation X and 5 Generation Y. Conclusions:,There are significant differences in how mental health nurses from different generations view their work, and in what is expected from managers. Managers need to modify traditional working styles, allowing greater flexibility of employment. They must also accept lower staff retention rates, and facilitate the development of younger staff. [source] A Convergent Approach to Biocompatible Polyglycerol "Click" Dendrons for the Synthesis of Modular Core,Shell Architectures and Their Transport BehaviorCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2008Monika Wyszogrodzka Dipl.-Ing. Abstract Dendrimers are an important class of polymeric materials for a broad range of applications in which monodispersity and multivalency are of interest. Here we report on a highly efficient synthetic route towards bifunctional polyglycerol dendrons on a multigram scale. Commercially available triglycerol (1), which is highly biocompatible, was used as starting material. By applying Williamson ether synthesis followed by an ozonolysis/reduction procedure, glycerol-based dendrons up to the fourth generation were prepared. The obtained products have a reactive core, which was further functionalized to the corresponding monoazido derivatives. By applying copper(I)-catalyzed 1,3-dipolar cycloaddition, so-called "click" coupling, a library of core,shell architectures was prepared. After removal of the 1,2-diol protecting groups, water-soluble core,shell architectures 24,27 of different generations were obtained in high yields. In the structure,transport relationship with Nile red we observe a clear dependence on core size and generation of the polyglycerol dendrons. [source] | ||||||||||||||||||||||