2,272 research outputs found

    Self-assembly in solution of a reversible comb-shaped supramolecular polymer

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    We report a single step synthesis of a polyisobutene with a bis-urea moiety in the middle of the chain. In low polarity solvents, this polymer self-assembles by hydrogen bonding to form a combshaped polymer with a central hydrogen bonded backbone and polyisobutene arms. The comb backbone can be reversibly broken, and consequently, its length can be tuned by changing the solvent, the concentration or the temperature. Moreover, we have proved that the bulkiness of the side-chains have a strong influence on both the self-assembly pattern and the length of the backbone. Finally, the density of arms can be reduced, by simply mixing with a low molar mass bis-urea

    A inovação aberta no processo de internacionalização de empresas: estudo de caso da Brasil Foods

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    TCC (graduação) - Universidade Federal de Santa Catarina. Centro SĂłcio-EconĂŽmico. RelaçÔes Internacionais.A presente monografia tem como objetivo o estudo do papel da inovação aberta no processo de internacionalização de empresas, a partir da revisĂŁo teĂłrica dos conceitos na literatura e de um estudo de caso real de uma empresa brasileira de grande porte: a Brasil Foods. A presente pesquisa possui carĂĄter de pesquisa exploratĂłria. Para desenvolver o objetivo principal, o trabalho apresenta trĂȘs objetivos especĂ­ficos, que sĂŁo: primeiro apresentar o conceito de inovação, seus graus de inserção e destacar a sua relevĂąncia no setor empresarial; segundo apresentar o conceito de inovação aberta e de inovação fechada e esclarecer a importĂąncia da difusĂŁo de informaçÔes; e, terceiro, apresentar os aspectos histĂłricos da internacionalização de empresas, introduzindo duas teorias do processo: Modelo de Uppsala e Perspectiva de Networks. Assim, pode-se exibir, portanto, um modelo conceitual Ă s relaçÔes entre as atividades de inovação aberta e a internacionalização de empresas em redes, levandose em consideração que a gestĂŁo de inovação nas empresas, atualmente, transcende a visĂŁo de inovação tecnolĂłgica, e, as redes internacionais ganham cada vez mais relevĂąncia como vantagem competitiva nas empresas ao atuar em mercados exteriores. Como resultado, concluiu-se que as estratĂ©gias de internacionalização de empresas em redes e as estratĂ©gias de inovação aberta, quando empregadas juntas, aumentam a velocidade de aprendizagem organizacional da Brasil Foods, acelerando os processos de internacionalização, confirmando que a inovação aberta estimula e intensifica a internacionalização de empresas que trabalham em redes

    Impact Factor: outdated artefact or stepping-stone to journal certification?

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    A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table

    How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers

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    Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program

    On The Rate and Extent of Drug Delivery to the Brain

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    To define and differentiate relevant aspects of blood–brain barrier transport and distribution in order to aid research methodology in brain drug delivery. Pharmacokinetic parameters relative to the rate and extent of brain drug delivery are described and illustrated with relevant data, with special emphasis on the unbound, pharmacologically active drug molecule. Drug delivery to the brain can be comprehensively described using three parameters: Kp,uu (concentration ratio of unbound drug in brain to blood), CLin (permeability clearance into the brain), and Vu,brain (intra-brain distribution). The permeability of the blood–brain barrier is less relevant to drug action within the CNS than the extent of drug delivery, as most drugs are administered on a continuous (repeated) basis. Kp,uu can differ between CNS-active drugs by a factor of up to 150-fold. This range is much smaller than that for log BB ratios (Kp), which can differ by up to at least 2,000-fold, or for BBB permeabilities, which span an even larger range (up to at least 20,000-fold difference). Methods that measure the three parameters Kp,uu, CLin, and Vu,brain can give clinically valuable estimates of brain drug delivery in early drug discovery programmes

    Differential branching fraction and angular analysis of Λb0→ΛΌ+Ό−\Lambda^{0}_{b} \rightarrow \Lambda \mu^+\mu^- decays

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    The differential branching fraction of the rare decay Λb0→ΛΌ+Ό−\Lambda^{0}_{b} \rightarrow \Lambda \mu^+\mu^- is measured as a function of q2q^{2}, the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 \mbox{ fb}^{-1}, collected by the LHCb experiment. Evidence of signal is observed in the q2q^2 region below the square of the J/ψJ/\psi mass. Integrating over 15 < q^{2} < 20 \mbox{ GeV}^2/c^4 the branching fraction is measured as d\mathcal{B}(\Lambda^{0}_{b} \rightarrow \Lambda \mu^+\mu^-)/dq^2 = (1.18 ^{+ 0.09} _{-0.08} \pm 0.03 \pm 0.27) \times 10^{-7} ( \mbox{GeV}^{2}/c^{4})^{-1}, where the uncertainties are statistical, systematic and due to the normalisation mode, Λb0→J/ψΛ\Lambda^{0}_{b} \rightarrow J/\psi \Lambda, respectively. In the q2q^2 intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon (AFBlA^{l}_{\rm FB}) and hadron (AFBhA^{h}_{\rm FB}) systems are measured for the first time. In the range 15 < q^2 < 20 \mbox{ GeV}^2/c^4 they are found to be A^{l}_{\rm FB} = -0.05 \pm 0.09 \mbox{ (stat)} \pm 0.03 \mbox{ (syst)} and A^{h}_{\rm FB} = -0.29 \pm 0.07 \mbox{ (stat)} \pm 0.03 \mbox{ (syst)}.Comment: 27 pages, 10 figures, Erratum adde

    Mapping adipose and muscle tissue expression quantitative trait loci in African Americans to identify genes for type 2 diabetes and obesity

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    Relative to European Americans, type 2 diabetes (T2D) is more prevalent in African Americans (AAs). Genetic variation may modulate transcript abundance in insulin-responsive tissues and contribute to risk; yet published studies identifying expression quantitative trait loci (eQTLs) in African ancestry populations are restricted to blood cells. This study aims to develop a map of genetically regulated transcripts expressed in tissues important for glucose homeostasis in AAs, critical for identifying the genetic etiology of T2D and related traits. Quantitative measures of adipose and muscle gene expression, and genotypic data were integrated in 260 non-diabetic AAs to identify expression regulatory variants. Their roles in genetic susceptibility to T2D, and related metabolic phenotypes were evaluated by mining GWAS datasets. eQTL analysis identified 1,971 and 2,078 cis-eGenes in adipose and muscle, respectively. Cis-eQTLs for 885 transcripts including top cis-eGenes CHURC1, USMG5, and ERAP2, were identified in both tissues. 62.1% of top cis-eSNPs were within ±50kb of transcription start sites and cis-eGenes were enriched for mitochondrial transcripts. Mining GWAS databases revealed association of cis-eSNPs for more than 50 genes with T2D (e.g. PIK3C2A, RBMS1, UFSP1), gluco-metabolic phenotypes, (e.g. INPP5E, SNX17, ERAP2, FN3KRP), and obesity (e.g. POMC, CPEB4). Integration of GWAS meta-analysis data from AA cohorts revealed the most significant association for cis-eSNPs of ATP5SL and MCCC1 genes, with T2D and BMI, respectively. This study developed the first comprehensive map of adipose and muscle tissue eQTLs in AAs (publically accessible at https://mdsetaa.phs.wakehealth.edu) and identified genetically-regulated transcripts for delineating genetic causes of T2D, and related metabolic phenotypes

    Job Resources and Matching Active Coping Styles as Moderators of the Longitudinal Relation Between Job Demands and Job Strain

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    Background: Only in a few longitudinal studies it has been examined whether job resources should be matched to job demands to show stress-buffering effects of job resources (matching hypothesis), while there are no empirical studies in which the moderating effect of matching personal characteristics on the stress-buffering effect of job resources has been examined. Purpose: In this study, both the matching hypothesis and the moderating effect of matching active coping styles were examined with respect to the longitudinal relation between job demands, job resources, and job strain.Method: The study group consisted of 317 beginning teachers from Belgium. The two-wave survey data with a 1-year time lag were analyzed by means of structural equation modeling and multiple group analyses. Results: Data did not support the matching hypothesis. In addition, no support was found for the moderating effect of specific active coping styles, irrespective of the level of match. Conclusion: To show stress-buffering effects of job resources, it seems to make no difference whether or not specific types of job demands and job resources are matched, and whether or not individual differences in specific active coping styles are taken into account
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