162,737 research outputs found
Facile access to silyl-functionalized N-heterocyclic olefins with HSiCl3
No full textGhadwal R, Reichmann SO, Engelhardt F, Andrada DM, Frenking G. Facile access to silyl-functionalized N-heterocyclic olefins with HSiCl3. Chemical Communications. 2013;49(82): 9440.N-heterocyclic olefins (NHOs), IPrCH2 (1) and SIPrCH2 (2) (IPrCH2 = {N(2,6-iPr2C6H3)CH}2CCH2 and SIPrCH2 = {N(2,6-iPr2C6H3)CH2}2CCH2), react with HSiCl3 and afford IPrCH(SiHCl2) (3) and SIPrCH(SiHCl2) (4), respectively. Compounds 3 and 4 have been isolated in almost quantitative yield. Interestingly, treatment of the silylene IPr·SiCl2 with 1 also affords 3, where silylene insertion into a C–H bond is observed. Computational analysis shows a high energy barrier for silylene insertion, therefore a protonation–deprotonation mechanism is more likely
Bioética cristã segundo Engelhardt
No full textO surgimento da Bioética no cenário contemporâneo é uma resposta ao sofrimento que as diferentes correntes éticas impõem ao se digladiar, bem como uma tentativa de superá-lo. Esta dissertação aborda alguns aspectos da bioética cristã sob a ótica de Engelhardt e procura discutir seus problemas na realidade contemporânea. Partimos das visões éticas antigas percorrendo o caminho do medievo atingindo a modernidade e a superação dessa pela pós-modernidade. Buscamos entender os conflitos do homem contemporâneo e as suas diferentes visões morais. Entendemos que, como defende Engelhardt, as morais seculares não deram conta da demanda moderna pela superação do sofrimento. Por isso, consideramos que a bioética cristã é um modo de superar a realidade imanente do homem, harmonizando os diferentes modelos éticos e morais na arena do debateThe appearance of the Bioethics in the contemporary setting may be a answer to the suffer that the different ethics currents impose during they fight themselves, and may be a trying of superate him too. This dissertation take hand about some aspects of the Christian Bioethics under the optic of Engelhardt and try to discuss theirs questions in the contemporary reality. We begin from the ancient ethics visions going through the Middle Age till the Modernity that gave place to the pos-modernity. We try to understand the contemporary man s conflicts and his different moral visions. We perceive, so like Engelhardt, that the seculary Moral was not able to answer the modern question about the surpassing of the suffer. Therefore, consider that the Christian Bioethics is a manner of surpass the man s immanent reality, harmonizing the different ethics moral model in the arena of the debat
Unprecedented Borylene Insertion into a C–N Bond
No full textGhadwal R, Schürmann CJ, Engelhardt F, Steinmetzger C. Unprecedented Borylene Insertion into a C-N Bond. European Journal of Inorganic Chemistry. 2014;2014(29):4921-4926.Carbenes are well established reactive intermediates and play an important role in organic synthesis, whereas the scope of borylenes is rather limited. Selective borylene insertion into a C–N bond to yield boryl‐functionalized N‐heterocyclic olefins (NHOs), [{N(Dipp)N(DippBH)CHCH}CCH2]2 (6) and [{N(Dipp)N(DippBPh)CHCH}CCH2][{N(Dipp)N(2‐iPr‐6‐CHMeCH2BC6H3)CHCH}CCH2] (8) (Dipp = 2,6‐iPr2C6H3) is reported for the first time. KC8 reduction of (IPrCH2)BRX2 adducts (IPrCH2 = {N(Dipp)CH}2CCH2; R = X = I (2); R = Ph, X = Cl (4)) affords compounds 6 and 8. Surprisingly, treatment of (IPrCH2)BHCl2 (3) with KC8 yields completely unexpected diborane compound (IPr)BH2BH2(IPr) (7). Compound 2 is unstable in THF and induces ring opening reaction to form the borenium ion [(IPrCH2)B{O(CH2)4I}2]I (5
MINFLUX dissects the unimpeded walking of kinesin-1
No full textWe introduce an interferometric MINFLUX microscope that records protein movements with up to 1.7 nanometer per millisecond spatiotemporal precision. Such precision has previously required attaching disproportionately large beads to the protein, but MINFLUX requires the detection of only about 20 photons from an approximately 1-nanometer-sized fluorophore. Therefore, we were able to study the stepping of the motor protein kinesin-1 on microtubules at up to physiological adenosine-5′-triphosphate (ATP) concentrations. We uncovered rotations of the stalk and the heads of load-free kinesin during stepping and showed that ATP is taken up with a single head bound to the microtubule and that ATP hydrolysis occurs when both heads are bound. Our results show that MINFLUX quantifies (sub)millisecond conformational changes of proteins with minimal disturbance.Zeroing in on motor proteins The super-resolution microscopy technique MINFLUX enables localization of fluorophores using a minimal number of photons. Two studies now expand on the development and implementation of MINFLUX to track motor protein dynamics in vitro and in cells (see the Perspective by Fei and Zhou). Wolff et al . refined the precision of MINFLUX such that single-fluorophore tracking with nanometer precision was possible with only tens of photons. They tracked the movement of kinesin-1 on microtubules and were able to see individual 4-nanometer substeps and rotation of the protein during stepping in their analysis. Deguchi et al . applied MINFLUX with a labeling and tracking approach called motor-PAINT to monitor stepping of motor proteins on microtubules in living and fixed cells in both two and three dimensions. —MAFA high-resolution MINFLUX microscopy approach reveals kinesin steps, substeps, and rotations
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Are language production problems apparent in adults who no longer meet diagnostic criteria for attention-deficit/hyperactivity disorder?
No full textIn this study, we examined sentence production in a sample of adults (N = 21) who had had attention-deficit/hyperactivity disorder (ADHD) as children, but as adults no longer met DSM-IV diagnostic criteria (APA, 2000). This “remitted” group was assessed on a sentence production task. On each trial, participants saw two objects and a verb. Their task was to construct a sentence using the objects as arguments of the verb. Results showed more ungrammatical and disfluent utterances with one particular type of verb (i.e., participle). In a second set of analyses, we compared the remitted group to both control participants and a “persistent” group, who had ADHD as children and as adults. Results showed that remitters were more likely to produce ungrammatical utterances and to make repair disfluencies compared to controls, and they patterned more similarly to ADHD participants. Conclusions focus on language output in remitted ADHD, and the role of executive functions in language production
Engelhardt e a Saúde Pública: Cobertura ou acesso universal?
No full textEngelhardt é um importante autor da bioética, principalmente em virtude de suas ideias sobre a autonomia/consentimento dos indivíduos, os amigos morais e o conceito de comunidades. Porém, foi no campo da saúde pública que este autor causou grande repercussão ao defender a cobertura universal de saúde. Segundo esta ideia, cada indivíduo teria acesso ao tipo de atendimento em saúde proporcional ao que pudesse ou quisesse comprar(1). Por outro lado, no âmbito de um sistema de saúde de acesso universal, como é o Sistema Único de Saúde (SUS), é importante conciliar a escassez de recursos públicos e a oferta de saúde gratuita, e esta dificuldade vem valorizando paulatinamente as ideias de Engelhardt. Desta maneira este trabalho tem como objetivo discorrer sobre o pensamento de Engelhardt sobre a saúde pública e tentar apontar como tais ideias tem motivado as propostas de mudança do sistema de saúde público brasileiro. Metodologia: Trata-se de pesquisa bibliográfica em bancos de dados e bibliotecas virtuais; de artigos publicados na íntegra e de livros da área da Bioética nos idiomas português e inglês
O Conceito de Pessoa Humana: Abordagens Bioética(s) em Engelhardt Jr e Lucien Sève
No full textResumo: Desde que Potter 1 lançou o metafórico neologismo bioética, ponte para o futuro do ser humano, em 1970, esse termo recebeu diversos matizes, fazendo-se possível, hoje, a abordagem da bioética no plural (bioéticas). Um dos temas mais flagrantes dessa pluralidade é o da pessoa humana. Em face disto me proponho, neste artigo, apresentar as posições acerca do conceito de pessoa humana em dois autores da área de bioética (s), a saber, Engelhardt e Sève, a fim de discutir em que medida o conceito de pessoa humana, nas concepções americana e francófona, se modificou (ou não) em face das intervenções tecnológicas na vida humana. No primeiro momento será apresentada a interpretação dada por cada autor ao conceito de pessoa. Em seguida se apresentará as confluências e as divergências destas bioéticas. Por fim se estabelecerá qual a contribuição que estas diferentes abordagens da pessoa humana, em bioéticas, traz às pessoas, de fato, no contexto das novas tecnologias.Palavras-chave: Pessoa; Embrião; Kant; Engelhardt Jr.; Lucien Sev
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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