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A divisória economia-sociologia : o custo de Parsons enquanto empresário social académico

Graça, João Carlos
Fonte: ISEG. SOCIUS Publicador: ISEG. SOCIUS
Tipo: Pré-impressão
Publicado em //2006 POR
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Em face das discussões recorrentes acerca da problemática das relações interdisciplinares, bem como dos debates suscitados mais recentemente pela emergência académica da chamada “nova sociologia económica”, torna-se importante começar por sublinhar que, bem ao contrário do sugerido em epígrafe, a definição de limites rigorosos identificando âmbitos de actuação distintos para a sociologia e para a economia académicas é um elemento fundamental daquilo a que podemos chamar projecto parsoniano. Presente desde estágios relativamente iniciais da sua elaboração teórica, este objectivo viria a manter-se ao longo de toda a trajectória intelectual de Talcott Parsons (1902-1979), reaparecendo já numa fase relativamente tardia sob a forma duma reflexão em torno do significado e do quadro de actuação da sociologia económica. Esta preocupação duradoura com a divisória economia-sociologia torna-se mais interessante ainda uma vez colocada em contexto, sendo desde logo digno de nota quanto a isso que: a) Parsons adquiriu o fundamental da sua formação académica avançada como economista; b) dois dos quatro autores aos quais ele reporta mais insistentemente as suas próprias ideias são economistas famosos e canónicos: Alfred Marshall e Vilfredo Pareto. Como veremos...

Uso de dexmedetomidina em anestesia geral para tratamento cirúrgico de aneurisma cerebral, em paciente gestante, portadora de doença hipertensiva específica da gestação: relato de caso

Souza,Kleber Machareth de; Anzoategui,Luiz César; Pedroso,Washington Cássio Justino; Gemperli,Werner Alfred
Fonte: Sociedade Brasileira de Anestesiologia Publicador: Sociedade Brasileira de Anestesiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2005 PT
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JUSTIFICATIVA E OBJETIVOS: A incidência de cirurgias não obstétricas em pacientes gestantes é de 0,36% a 2%. No entanto, cirurgias visando o tratamento cirúrgico de aneurisma cerebral em gestantes são extremamente raras. A doença hipertensiva específica da gestação, apresenta prevalência clínica de 10% na população gestante. Trata-se de uma doença de elevada complexidade clínica, acometendo múltiplos órgãos e sistemas. A dexmedetomidina, fármaco agonista alfa2, apresenta importante seletividade para estes receptores, quando utilizada em doses clínicas terapêuticas e promove adequada estabilidade hemodinâmica, se empregada no período peri-operatório. O objetivo deste relato foi apresentar uma técnica com a qual fosse possível a manutenção da homeostase materna, preservando ao máximo o fluxo sangüíneo útero-placentário e a vitalidade fetal, sem deixar de lado aspectos fundamentais relativos à otimização da relação oferta/demanda de oxigênio cerebral e adequação das condições do tecido cerebral propícias ao manuseio cirúrgico. RELATO DO CASO: Gestante com 19 anos encaminhada para tratamento cirúrgico de aneurisma cerebral, estando na vigésima sétima semana de gestação. No pré-operatório...

The Werner Syndrome Protein Is Involved in RNA Polymerase II Transcription

Balajee, Adayabalam S.; Machwe, Amrita; May, Alfred; Gray, Matthew D.; Oshima, Junko; Martin, George M.; Nehlin, Jan O.; Brosh, Robert; Orren, David K.; Bohr, Vilhelm A.
Fonte: The American Society for Cell Biology Publicador: The American Society for Cell Biology
Tipo: Artigo de Revista Científica
Publicado em /08/1999 EN
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Werner syndrome (WS) is a human progeroid syndrome characterized by the early onset of a large number of clinical features associated with the normal aging process. The complex molecular and cellular phenotypes of WS involve characteristic features of genomic instability and accelerated replicative senescence. The gene involved (WRN) was recently cloned, and its gene product (WRNp) was biochemically characterized as a helicase. Helicases play important roles in a variety of DNA transactions, including DNA replication, transcription, repair, and recombination. We have assessed the role of the WRN gene in transcription by analyzing the efficiency of basal transcription in WS lymphoblastoid cell lines that carry homozygous WRN mutations. Transcription was measured in permeabilized cells by [3H]UTP incorporation and in vitro by using a plasmid template containing the RNA polymerase II (RNA pol II)–dependent adenovirus major late promoter. With both of these approaches, we find that the transcription efficiency in different WS cell lines is reduced to 40–60% of the transcription in cells from normal individuals. This defect can be complemented by the addition of normal cell extracts to the chromatin of WS cells. Addition of purified wild-type WRNp but not mutated WRNp to the in vitro transcription assay markedly stimulates RNA pol II–dependent transcription carried out by nuclear extracts. A nonhelicase domain (a direct repeat of 27 amino acids) also appears to have a role in transcription enhancement...

Gene expression profiling in Werner syndrome closely resembles that of normal aging

Kyng, Kasper J.; May, Alfred; Kølvraa, Steen; Bohr, Vilhelm A.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
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Werner syndrome (WS) is a premature aging disorder, displaying defects in DNA replication, recombination, repair, and transcription. It has been hypothesized that several WS phenotypes are secondary consequences of aberrant gene expression and that a transcription defect may be crucial to the development of the syndrome. We used cDNA microarrays to characterize the expression of 6,912 genes and ESTs across a panel of 15 primary human fibroblast cell lines derived from young donors, old donors, and WS patients. Of the analyzed genes, 6.3% displayed significant differences in expression when either WS or old donor cells were compared with young donor cells. This result demonstrates that the WS transcription defect is specific to certain genes. Transcription alterations in WS were strikingly similar to those in normal aging: 91% of annotated genes displayed similar expression changes in WS and in normal aging, 3% were unique to WS, and 6% were unique to normal aging. We propose that a defect in the transcription of the genes as identified in this study could produce many of the complex clinical features of WS. The remarkable similarity between WS and normal aging suggests that WS causes the acceleration of a normal aging mechanism. This finding supports the use of WS as an aging model and implies that the transcription alterations common to WS and normal aging represent general events in the aging process.

Central Role for the Werner Syndrome Protein/Poly(ADP-Ribose) Polymerase 1 Complex in the Poly(ADP-Ribosyl)ation Pathway after DNA Damage

von Kobbe, Cayetano; Harrigan, Jeanine A.; May, Alfred; Opresko, Patricia L.; Dawut, Lale; Cheng, Wen-Hsing; Bohr, Vilhelm A.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /12/2003 EN
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A defect in the Werner syndrome protein (WRN) leads to the premature aging disease Werner syndrome (WS). Hallmark features of cells derived from WS patients include genomic instability and hypersensitivity to certain DNA-damaging agents. WRN contains a highly conserved region, the RecQ conserved domain, that plays a central role in protein interactions. We searched for proteins that bound to this region, and the most prominent direct interaction was with poly(ADP-ribose) polymerase 1 (PARP-1), a nuclear enzyme that protects the genome by responding to DNA damage and facilitating DNA repair. In pursuit of a functional interaction between WRN and PARP-1, we found that WS cells are deficient in the poly(ADP-ribosyl)ation pathway after they are treated with the DNA-damaging agents H2O2 and methyl methanesulfonate. After cellular stress, PARP-1 itself becomes activated, but the poly(ADP-ribosyl)ation of other cellular proteins is severely impaired in WS cells. Overexpression of the PARP-1 binding domain of WRN strongly inhibits the poly(ADP-ribosyl)ation activity in H2O2-treated control cell lines. These results indicate that the WRN/PARP-1 complex plays a key role in the cellular response to oxidative stress and alkylating agents, suggesting a role for these proteins in the base excision DNA repair pathway.

The Werner syndrome protein operates in base excision repair and cooperates with DNA polymerase β

Harrigan, Jeanine A.; Wilson, David M.; Prasad, Rajendra; Opresko, Patricia L.; Beck, Gad; May, Alfred; Wilson, Samuel H.; Bohr, Vilhelm A.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
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Genome instability is a characteristic of cancer and aging, and is a hallmark of the premature aging disorder Werner syndrome (WS). Evidence suggests that the Werner syndrome protein (WRN) contributes to the maintenance of genome integrity through its involvement in DNA repair. In particular, biochemical evidence indicates a role for WRN in base excision repair (BER). We have previously reported that WRN helicase activity stimulates DNA polymerase beta (pol β) strand displacement synthesis in vitro. In this report we demonstrate that WRN exonuclease activity can act cooperatively with pol β, a polymerase lacking 3′–5′ proofreading activity. Furthermore, using small interference RNA technology, we demonstrate that WRN knockdown cells are hypersensitive to the alkylating agent methyl methanesulfonate, which creates DNA damage that is primarily repaired by the BER pathway. In addition, repair assays using whole cell extracts from WRN knockdown cells indicate a defect in long patch (LP) BER. These findings demonstrate that WRN plays a direct role in the repair of methylation-induced DNA damage, and suggest a role for both WRN helicase and exonuclease activities together with pol β during LP BER.

A cluster of Escherichia coli O157: nonmotile infections associated with recreational exposure to lake water.

Feldman, Katherine A.; Mohle-Boetani, Janet C.; Ward, Judy; Furst, Karen; Abbott, Sharon L.; Ferrero, Dennis V.; Olsen, Alfred; Werner, S. Benson
Fonte: Association of Schools of Public Health Publicador: Association of Schools of Public Health
Tipo: Artigo de Revista Científica
Publicado em //2002 EN
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OBJECTIVES: To identify cases and determine risk factors for an outbreak of Escherichia coli (E. coli) O157: nonmotile (NM) infections in children attending a summer day care program in California. METHODS: The authors conducted a retrospective cohort study; the cohort comprised first and second graders who attended the day care program during the last week in August 1999. Shiga toxin testing and molecular subtyping using pulsed-field gel electrophoresis were performed on isolates. Lake water, lake bottom sediment samples, and waterfowl feces from the lake environs were cultured for E. coli O157. RESULTS: Three cases of Shiga toxin-producing E. coli O157: NM infections with matching pulsed-field gel electrophoresis patterns and four probable cases were found. Children who swallowed more than a mouthful of water had a higher attack rate than those who swallowed less than a mouthful or none at all (43% vs. 10%, relative risk = 4.43, 95% confidence interval 1.12, 17.50). CONCLUSIONS: E. coli O157: NM infections were associated with swallowing water from a freshwater lake. Potential sources of contamination include feces from humans, cattle, or deer. This outbreak illustrates the value in screening patients with diarrhea for E. coli O157...

Loss of serum response factor in keratinocytes results in hyperproliferative skin disease in mice

Koegel, Heidi; von Tobel, Lukas; Schäfer, Matthias; Alberti, Siegfried; Kremmer, Elisabeth; Mauch, Cornelia; Hohl, Daniel; Wang, Xiao-Jing; Beer, Hans-Dietmar; Bloch, Wilhelm; Nordheim, Alfred; Werner, Sabine
Fonte: American Society for Clinical Investigation Publicador: American Society for Clinical Investigation
Tipo: Artigo de Revista Científica
EN
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The transcription factor serum response factor (SRF) plays a crucial role in the development of several organs. However, its role in the skin has not been explored. Here, we show that keratinocytes in normal human and mouse skin expressed high levels of SRF but that SRF expression was strongly downregulated in the hyperproliferative epidermis of wounded and psoriatic skin. Keratinocyte-specific deletion within the mouse SRF locus during embryonic development caused edema and skin blistering, and all animals died in utero. Postnatal loss of mouse SRF in keratinocytes resulted in the development of psoriasis-like skin lesions. These lesions were characterized by inflammation, hyperproliferation, and abnormal differentiation of keratinocytes as well as by disruption of the actin cytoskeleton. Ultrastructural analysis revealed markedly reduced cell-cell and cell-matrix contacts and loss of cell compaction in all epidermal layers. siRNA-mediated knockdown of SRF in primary human keratinocytes revealed that the cytoskeletal abnormalities and adhesion defects were a direct consequence of the loss of SRF. In contrast, the hyperproliferation observed in vivo was an indirect effect that was most likely a consequence of the inflammation. These results reveal that loss of SRF disrupts epidermal homeostasis and strongly suggest its involvement in the pathogenesis of hyperproliferative skin diseases...

The Role of the Secondary Coordination Sphere in Metal-Mediated Dioxygen Activation

Shook, Ryan L.; Borovik, A.S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 19/04/2010 EN
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Alfred Werner proposed nearly 100 years ago that the secondary coordination sphere has a role in determining physical properties of transition metal complexes. We now know that the secondary coordination sphere impacts nearly all aspects of transition metal chemistry, including the reactivity and selectivity in metal-mediated processes. These features are highlighted in the binding and activation of dioxygen by transition metal complexes. There are clear connections between the control of the secondary coordination sphere and the ability of metal complexes to 1) reversibly bind dioxygen or 2) bind and activate dioxygen to form highly reactive M–oxo complexes. In this forum article, several biological and synthetic examples are presented and discussed in terms of structure-function relationships. Particular emphasis is given to systems with defined non-covalent interactions, such as intramolecular hydrogen bonds involving dioxygen-derived ligands. To further illustrate these effects, the homolytic cleavage of C–H bonds by M–oxo complexes with basic oxo ligands is described.

Conformational Isomerism of trans-[Pt(NH2C6H11)2I2] and the Classical Wernerian Chemistry of [Pt(NH2C6H11)4]X2 (X = Cl, Br, I)1

Johnstone, Timothy C.; Lippard, Stephen J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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X-ray crystallographic analysis of the compound trans-[Pt(NH2C6H11)2I2] revealed the presence of two distinct conformers within one crystal lattice. This compound was studied by variable temperature NMR spectroscopy to investigate the dynamic interconversion between these isomers. The results of this investigation were interpreted using physical (CPK) and computational (molecular mechanics and density functional theory) models. The conversion of the salts [Pt(NH2C6H11)4]X2 into trans-[Pt(NH2C6H11)2X2] (X = Cl, Br, I) was also studied and is discussed here with an emphasis on parallels to the work of Alfred Werner.

Serines 440 and 467 in the Werner syndrome protein are phosphorylated by DNA-PK and affects its dynamics in response to DNA double strand breaks

Kusumoto-Matsuo, Rika; Ghosh, Deblina; Karmakar, Parimal; May, Alfred; Ramsden, Dale; Bohr, Vilhelm A.
Fonte: Impact Journals LLC Publicador: Impact Journals LLC
Tipo: Artigo de Revista Científica
Publicado em 14/01/2014 EN
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WRN protein, defective in Werner syndrome (WS), a human segmental progeria, is a target of serine/threonine kinases involved in sensing DNA damage. DNA-PK phosphorylates WRN in response to DNA double strand breaks (DSBs). However, the main phosphorylation sites and functional importance of the phosphorylation of WRN has remained unclear. Here, we identify Ser-440 and −467 in WRN as major phosphorylation sites mediated by DNA-PK. In vitro, DNA-PK fails to phosphorylate a GST-WRN fragment with S440A and/or S467A substitution. In addition, full length WRN with the mutation expressed in 293T cells was not phosphorylated in response to DSBs produced by bleomycin. Accumulation of the mutant WRN at the site of laser-induced DSBs occurred with the same kinetics as wild type WRN in live HeLa cells. While the wild type WRN relocalized to the nucleoli after 24 hours recovery from etoposide-induced DSBs, the mutant WRN remained mostly in the nucleoplasm. Consistent with this, WS cells expressing the mutants exhibited less DNA repair efficiency and more sensitivity to etoposide, compared to those expressing wild type. Our findings indicate that phosphorylation of Ser-440 and −467 in WRN are important for relocalization of WRN to nucleoli, and that it is required for efficient DSB repair.

Metal complexes with varying intramolecular hydrogen bonding networks

Lacy, David C.; Mukherjee, Jhumpa; Lucas, Robie L.; Day, Victor W.; Borovik, A.S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Alfred Werner described the attributes of the primary and secondary coordination spheres in his development of coordination chemistry. To examine the effects of the secondary coordination sphere on coordination chemistry, a series of tripodal ligands containing differing numbers of hydrogen bond (H-bond) donors were used to examine the effects of H-bonds on Fe(II), Mn(II)–acetato, and Mn(III)–OH complexes. The ligands containing varying numbers of urea and amidate donors allowed for systematic changes in the secondary coordination spheres of the complexes. Two of the Fe(II) complexes that were isolated as their Bu4N+ salts formed dimers in the solid-state as determined by X-ray diffraction methods, which correlates with the number of H-bonds present in the complexes (i.e., dimerization is favored as the number of H-bond donors increases). Electron paramagnetic resonance (EPR) studies suggested that the dimeric structures persist in acetonitrile. The Mn(II) complexes were all isolated as their acetato adducts. Furthermore, the synthesis of a rare Mn(III)–OH complex via dioxygen activation was achieved that contains a single intramolecular H-bond; its physical properties are discussed within the context of other Mn(III)–OH complexes.

Major employment dislocation

Fonte: Alfred P. Sloan School of Management, Massachusetts Institute of Technology Publicador: Alfred P. Sloan School of Management, Massachusetts Institute of Technology
Formato: iii, 150 p.; 10083820 bytes; application/pdf
ENG
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Robert B. McKersie, Werner Sengenberger.; Includes bibliographical references.

Estratificação qualitativa extrínseca de peles e couros bovinos provenientes de dois Estados brasileiros.

OLIVEIRA, A. R. de; JACINTO, M. A. C.; COSTA, A. J.; PEREIRA, M. de A.; GONÇALVES, A. N. D.; LOOSLI, A. W.
Fonte: In: CONGRESSO DA SOCIEDADE BRASILEIRA DE ZOTECNIA, 46., 2009, Maringá. Anais... Maringá: SBZ: UEM, 2009. Publicador: In: CONGRESSO DA SOCIEDADE BRASILEIRA DE ZOTECNIA, 46., 2009, Maringá. Anais... Maringá: SBZ: UEM, 2009.
Tipo: Artigo em anais de congresso (ALICE)
PT_BR
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Com o objetivo dee estratificar aa qualidade extrínseca de ppeles e couros provenientes de dois estados brasileiiros, foram avaliados 10000 couros procedentes de propriedades paulistas e 10000 couros procedentes de propriedades sulmatogrossenses. As peles (couros crus) foram classificadas em ?A?, ?B? ou ?D? e, logo após o curtimento até o wet blue, a classsificação comercial foi acompanhada no curtume, segundo escores que variavam de ?A? a ?E?, além do refugo (?R?)). A maioria ddas peles ? 8 9,5% das peles paulistas e 96,3% das peles sulmatogrossenses ? foram prontamente desclassificadas porque continham marcas a fogo na região do grupo, o que não é permittido. Na classificação comercial do curtume, em ambos estados, a maioria dos couros obteve classificações ?C? e ?D? , apresentando defeitos que podem ser corrigidos nos processos industriais de acabamento.; 2009

Alfred Werner e Heinrich Rheinboldt: genealogia e legado científico

Toma,Henrique E.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 PT
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The centenary of Alfred Werner's Nobel Prize in Chemistry has prompted this retrospect on his important contributions for the development of stereochemistry and for the understanding of the nature of the coordination compounds. His genealogy has been described, including a discussion on the famous Jørgensen-Werner controversy. As an extension, it has also been reported the German biography of Heinrich Rheinboldt, the founder of the Chemistry School at the University of São Paulo, and his relation with Werner's scientific heritage.

Referenced Publication Years Spectroscopy applied to iMetrics: Scientometrics, Journal of Informetrics, and a relevant subset of JASIST

Leydesdorff, Loet; Bornmann, Lutz; Marx, Werner; Milojević, Staša
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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We have developed a (freeware) routine for "referenced publication years spectroscopy" (RPYS) and apply this method to the historiography of "iMetrics," that is, the junction of the journals Scientometrics, Informetrics, and the relevant subset of JASIST (approx. 20%) that shapes the intellectual space for the development of information metrics (bibliometrics, scientometrics, informetrics, and webometrics). The application to information metrics (our own field of research) provides us with the opportunity to validate this methodology, and to add a reflection about using citations for the historical reconstruction. The results show that the field is rooted in individual contributions of the 1920s-1950s (e.g., Alfred J. Lotka), and was then shaped intellectually in the early 1960s by a confluence of the history of science (Derek de Solla Price), documentation (e.g., Michael M. Kessler's "bibliographic coupling"), and "citation indexing" (Eugene Garfield). Institutional development at the interfaces between science studies and information science has been reinforced by the new journal Informetrics since 2007. In a concluding reflection, we return to the question of how the historiography of science using algorithmic means--in terms of citation practices--can be different from an intellectual history of the field based...

Convergence Properties of Kronecker Graphical Lasso Algorithms

Tsiligkaridis, Theodoros; Hero III, Alfred O.; Zhou, Shuheng
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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This paper studies iteration convergence of Kronecker graphical lasso (KGLasso) algorithms for estimating the covariance of an i.i.d. Gaussian random sample under a sparse Kronecker-product covariance model and MSE convergence rates. The KGlasso model, originally called the transposable regularized covariance model by Allen ["Transposable regularized covariance models with an application to missing data imputation," Ann. Appl. Statist., vol. 4, no. 2, pp. 764-790, 2010], implements a pair of $\ell_1$ penalties on each Kronecker factor to enforce sparsity in the covariance estimator. The KGlasso algorithm generalizes Glasso, introduced by Yuan and Lin ["Model selection and estimation in the Gaussian graphical model," Biometrika, vol. 94, pp. 19-35, 2007] and Banerjee ["Model selection through sparse maximum likelihood estimation for multivariate Gaussian or binary data," J. Mach. Learn. Res., vol. 9, pp. 485-516, Mar. 2008], to estimate covariances having Kronecker product form. It also generalizes the unpenalized ML flip-flop (FF) algorithm of Dutilleul ["The MLE algorithm for the matrix normal distribution," J. Statist. Comput. Simul., vol. 64, pp. 105-123, 1999] and Werner ["On estimation of covariance matrices with Kronecker product structure...

Coordination Chemistry: An Audacious Dream of Alfred Werner; Química de Coordenação: Um Sonho Audacioso de Alfred Werner

Leandro Marcos Santos; Universidade Federal de Alfenas; Luís Eduardo Sarto; Universidade Federal de Alfenas; Gabriela Francini Bozza; Universidade Federal de Alfenas; Eduardo T. de Almeida; Universidade Federal de Alfenas
Fonte: Revista Virtual de Química Publicador: Revista Virtual de Química
Tipo: ; Formato: binary/octet-stream
Publicado em 01/11/2014 PT
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2013 was the centennial celebration of the Nobel Prize awarded to Alfred Werner in recognition of his important scientific contributions to Inorganic Chemistry. Through his ideological audacity, acumen in chemical experimentation and wide theoretical knowledge, Werner was able to found the conceptual basis for understanding and explaining one of the most fascinating areas of Inorganic Chemistry: Coordination Chemistry. This paper presents the scientific findings and also the available tools at the time Werner developed his theory for which he was awarded the Nobel Prize in Chemistry in 1913. DOI: 10.5935/1984-6835.20140083; Em 2013 comemoraram-se cem anos que Alfred Werner foi laureado com o Prêmio Nobel, em reconhecimento por suas importantes contribuições científicas à Química Inorgânica. Somando sua audácia ideológica, sua perspicácia na experimentação química e seu vasto conhecimento teórico, Werner foi capaz de fundar as bases conceituais para a compreensão e explicação de uma das mais fascinantes áreas da Química Inorgânica: a Química de Coordenação. Este artigo apresenta as constatações científicas e também as ferramentas disponíveis na época em que Werner desenvolveu sua teoria que lhe rendeu o Prêmio Nobel de Química em 1913. DOI: 10.5935/1984-6835.20140083

The electric city newspaper: urban age electric city conference (Shoreditch Electric Light Station, London 6-7 December 2012)

Fonte: The London School of Economics and Political Science, Alfred Herrhausen Society Publicador: The London School of Economics and Political Science, Alfred Herrhausen Society
Tipo: Book; NonPeerReviewed Formato: application/pdf
Publicado em /12/2012 EN; EN
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In 1879 Thomas Edison invented the light bulb and built the first power station in Pearl Street in Manhattan in 1882, while the German inventor Werner von Siemens installed the first electric elevator in Mannheim in 1880. Since then, electricity has powered – directly or indirectly – the shape and dynamics of urban life. In cities of the developed world, we take for granted that electricity feeds the complex systems which sustain and sometimes spectacularly fail us. In emerging cities of the developing world, a light bulb is still embraced as a symbol of civilisation by some, while others celebrate their urbanity in a visual cacophony of neon. The Electric City is, in many ways, the crucible of patterns of production, consumption and pollution of the 21st century ‘urban age’ as cities struggle with their impact on the social and environmental well-being of the planet. After having tackled the urban economy, health and well-being, violence, security, social inclusion and design at conferences held in – amongst others – Hong Kong, Chicago, New York, São Paulo and Johannesburg, the Urban Age returns to London for its eleventh conference since 2005. We turn our attention to the challenges and responsibilities faced by cities in the digital age as Climate Change and economic pressures continue to define our everyday urban realities. Since its inception...

Spontaneously resolving chiral cis-[dinitrobis(ethylenediamine)cobalt]X complexes (X = Cl, Br) from the Alfred Werner collection of original samples at the University of Zurich - Alfred Werner's missed opportunity to become the 'Louis Pasteur' of coordination compounds

Blacque,Olivier; Berke,Heinz
Fonte: Universidad Nacional Autónoma de México, Facultad de Química Publicador: Universidad Nacional Autónoma de México, Facultad de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
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17 original crystals of [Λ-dinitrobis(ethylenediamine)cobalt]X complexes from the Alfred Werner collection of original samples of the University of Zurich were studied by single crystal X-ray diffraction revealing that the complexes with X = Cl, Br can undergo spontaneous chiral resolution upon crystallization. The main focus of this article was the chiral [Λ- and Δ-dinitrobis(ethylenediamine)cobalt]Cl complexes, which crystallize from racemic solution in the space group P 21 mainly as synthetical twins enriched in one enantiomer, but to a small extent also as pure enantiomorphs. The twinning effect was recognized and correctly described by PhD student Richard Hessen of the Alfred Werner group (PhD thesis 1914). Richard Hessen eventually resolved the [Δ- and Λ-dinitrobis(ethylenediamine)cobalt]Cl complex by the conglomerate salt resolution method. Based on the availability of the pure [Δ- or Λ-dinitrobis(ethylenediamine)cobalt]Cl complex, he carried out seeding experiments, which proved that the [Δ- and Λ-dinitrobis(ethylenediamine)cobalt]Cl complexes can be enriched to a great extent in one enantiomer by spontaneous chiral resolution. Already in the period of time from 1900 to 1904, various PhD students of Alfred Werner's group (Adolf Grün...