bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal structure of an assembly intermediate of respiratory Complex II
Authors: Sharma Pankaj , Maklashina Elena , Cecchini Gary , Iverson T. M. 
Published: January 2018

AbstractFlavin is covalently attached to the protein scaffold in ~10% of flavoenzymes. However, the mechanism of covalent modification is unclear, due in part to challenges in stabilizing assembly intermediates. Here, we capture the structure of an assembly intermediate of the Escherichiacoli Complex II (quinol:fumarate reductase (FrdABCD)). The structure contains the E. coli FrdA subunit bound to covalent FAD and crosslinked with its assembly factor, SdhE. The structure contains two global conformational changes as compared to prior structures of the mature protein: the rotation of a domain within the FrdA subunit, and the destabilization of two large loops of the FrdA subunit, which may create a tunnel to the active site. We infer a mechanism for covalent flavinylation. As supported by spectroscopic and kinetic analyses, we suggest that SdhE shifts the conformational equilibrium of the FrdA active site to disfavor succinate/fumarate interconversion and enhance covalent flavinylation.
Myelination of Purkinje axons is critical for resilient synaptic transmission in the deep cerebellar nucleus
Authors: Barron Tara , Saifetiarova Julia , Bhat Manzoor A. , Kim Jun Hee 
Published: January 2018

AbstractThe roles of myelin in maintaining axonal integrity and action potential (AP) propagation are well established, but its role in synapse maintenance and neurotransmission remains largely understudied. Here, we investigated how Purkinje axon myelination regulates synaptic transmission in the Purkinje to deep cerebellar nuclei (DCN) synapses using the Long Evans Shaker (LES) rat, which lacks compact myelin and thus displays severe locomotion deficits. DCN neurons fired spontaneous action potentials (APs), whose frequencies were dependent on the extent of myelin. In the LES cerebellum with severe myelin deficiency, DCN neurons were hyper-excitable, exhibiting spontaneous AP firing at a much higher frequency compared to those from wild type (LE) and heterozygote (LEHet) rats. The hyper-excitability in LES DCN neurons resulted from reduced inhibitory GABAergic inputs from Purkinje cells to DCN neurons. Corresponding with functional alterations including failures of AP propagation, electron microscopic analysis revealed anatomically fewer active zones at the presynaptic terminals of Purkinje cells in both LEHet and LES rats. Taken together, these studies suggest that proper axonal myelination critically regulates presynaptic terminal structure and function and directly impacts synaptic transmission in the Purkinje cell-DCN cell synapse in the cerebellum.
Fast and effective mitochondrial delivery of ω-Rhodamine-B-polysulfobetaine-PEG copolymers
Authors: Morimoto Nobuyuki , Takei Riho , Wakamura Masaru , Oishi Yoshifumi , Nakayama Masafumi , Suzuki Makoto , Yamamoto Masaya , Winnik Françoise M. 
Published: January 2018

AbstractMitochondrial targeting and entry, two crucial steps in fighting severe diseases resulting from mitochondria dysfunction, pose important challenges in current nanomedicine. Cell-penetrating peptides or targeting groups, such as Rhodamine-B (Rho), are known to localize in mitochondria, but little is known on how to enhance their effectiveness through structural properties of polymeric carriers. To address this issue, we prepared 8 copolymers of 3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate and poly(ethyleneglycol) methacrylate, p(DMAPS-ran-PEGMA) (molecular weight, 18.0 < M
n
< 74.0 kg/mol) with two different endgroups. We labeled them with Rho groups attached along the chain or on one of the two endgroups (α or ω). From studies by flow cytometry and confocal fluorescence microscopy of the copolymers internalization in HeLa cells in the absence and presence of pharmacological inhibitors, we established that the polymers cross the cell membrane foremost by translocation and also by endocytosis, primarily clathrin-dependent endocytosis. The most effective mitochondrial entry was achieved by copolymers of M
n
< 30.0 kg/mol, lightly grafted with PEG chains (< 5 mol %) labeled with Rho in the ω-position. Our findings may be generalized to the uptake and mitochondrial targeting of prodrugs and imaging agents with a similar polymeric scaffold.
Nucleation and Ostwald Growth of Particles in Fe-O-Al-Ca Melt
Authors: Wang Linzhu , Li Junqi , Yang Shufeng , Chen Chaoyi , Jin Huixin , Li Xiang 
Published: January 2018

AbstractTremendous focus has been put on the control of particle size distribution which effects the grain structure and mechanical properties of resulting metallic materials, and thus nucleation and growth of particles in solution should be clarified. This study uses classical nucleation theory and Ostwald ripening theory to probe the relationship between the compositions of Fe-O-Al-Ca melts and the behavior of particles under the condition of no external stirring. Our experimental data suggest that decreasing the initial Ca addition and Al addition is conductive to the increase of nucleation rate for calcium aluminate particles, which exhibits a same change trend with that predicted from classical nucleation theory. Based on the experimental evidence for particles size distribution in three-dimensional, we demonstrate that Ostwald ripening is the predominate mechanism on the coarsening of particles in Fe-O-Al-Ca melt at early stage of deoxidation under the condition of no external stirring but not at later stage.
DZ Chamaeleontis: a bona fide photoevaporating disc
Authors: Canovas H. , Montesinos B. , Schreiber M. R. , Cieza L. A. , Eiroa C. , Meeus G. , de Boer J. , Ménard F. , Wahhaj Z. , Riviere-Marichalar P. , Olofsson J. , Garufi A. , Rebollido I. , van Holstein R. G. , Caceres C. , Hardy A. , Villaver E. 
Published: January 2018

Context. DZ Cha is a weak-lined T Tauri star (WTTS) surrounded by a bright protoplanetary disc with evidence of inner disc clearing. Its narrow Hα line and infrared spectral energy distribution suggest that DZ Cha may be a photoevaporating disc.
Aims. We aim to analyse the DZ Cha star + disc system to identify the mechanism driving the evolution of this object.
Methods. We have analysed three epochs of high resolution optical spectroscopy, photometry from the UV up to the sub-mm regime, infrared spectroscopy, and J-band imaging polarimetry observations of DZ Cha.
Results. Combining our analysis with previous studies we find no signatures of accretion in the Hα line profile in nine epochs covering a time baseline of ~20 yr. The optical spectra are dominated by chromospheric emission lines, but they also show emission from the forbidden lines [SII] 4068 and [OI] 6300Å that indicate a disc outflow. The polarized images reveal a dust depleted cavity of ~7 au in radius and two spiral-like features, and we derive a disc dust mass limit of Mdust< 3 MEarth from the sub-mm photometry. No stellar (M⋆> 80 MJup) companions are detected down to 0.̋07 (~8 au, projected).
Conclusions. The negligible accretion rate, small cavity, and forbidden line emission strongly suggests that DZ Cha is currently at the initial stages of disc clearing by photoevaporation. At this point the inner disc has drained and the inner wall of the truncated outer disc is directly exposed to the stellar radiation. We argue that other mechanisms like planet formation or binarity cannot explain the observed properties of DZ Cha. The scarcity of objects like this one is in line with the dispersal timescale (≲105 yr) predicted by this theory. DZ Cha is therefore an ideal target to study the initial stages of photoevaporation.
The Caviar software package for the astrometric reduction of Cassini ISS images: description and examples
Authors: Cooper N. J. , Lainey V. , Meunier L.-E. , Murray C. D. , Zhang Q.-F. , Baillie K. , Evans M. W. , Thuillot W. , Vienne A. 
Published: January 2018

Aims. Caviar is a software package designed for the astrometric measurement of natural satellite positions in images taken using the Imaging Science Subsystem (ISS) of the Cassini spacecraft. Aspects of the structure, functionality, and use of the software are described, and examples are provided. The integrity of the software is demonstrated by generating new measurements of the positions of selected major satellites of Saturn, 2013–2016, along with their observed minus computed (O−C) residuals relative to published ephemerides.
Methods. Satellite positions were estimated by fitting a model to the imaged limbs of the target satellites. Corrections to the nominal spacecraft pointing were computed using background star positions based on the UCAC5 and Tycho2 star catalogues. UCAC5 is currently used in preference to Gaia-DR1 because of the availability of proper motion information in UCAC5.
Results. The Caviar package is available for free download. A total of 256 new astrometric observations of the Saturnian moons Mimas (44), Tethys (58), Dione (55), Rhea (33), Iapetus (63), and Hyperion (3) have been made, in addition to opportunistic detections of Pandora (20), Enceladus (4), Janus (2), and Helene (5), giving an overall total of 287 new detections. Mean observed-minus-computed residuals for the main moons relative to the JPL SAT375 ephemeris were − 0.66 ± 1.30 pixels in the line direction and 0.05 ± 1.47 pixels in the sample direction. Mean residuals relative to the IMCCE NOE-6-2015-MAIN-coorb2 ephemeris were −0.34 ± 0.91 pixels in the line direction and 0.15 ± 1.65 pixels in the sample direction. The reduced astrometric data are provided in the form of satellite positions for each image. The reference star positions are included in order to allow reprocessing at some later date using improved star catalogues, such as later releases of Gaia, without the need to re-estimate the imaged star positions.
The bipolar jet of the symbiotic star R Aquarii: A study of its morphology using the high-resolution HST WFC3/UVIS
camera
Authors: Melnikov Stanislav , Stute Matthias , Eislöffel Jochen 
Published: January 2018

Context. R Aqr is a symbiotic binary system consisting of a Mira variable with a pulsation period of 387 days and a hot companion which is presumably a white dwarf with an accretion disk. This binary system is the source of a prominent bipolar gaseous outflow.
Aims. We use high spatial resolution and sensitive images from the Hubble Space Telescope (HST) to identify and investigate the different structural components that form the complex morphology of the R Aqr jet.
Methods. We present new high-resolution HST WFC3/UVIS narrow-band images of the R Aqr jet obtained in 2013/14 using the [OIII]λ5007, [OI]λ6300, [NII]λ6583, and Hα emission lines. These images also allow us to produce detailed maps of the jet flow in several line ratios such as [OIII]λ5007/[OI]λ6300 and [NII]λ6583/[OI]λ6300 which are sensitive to the outflow temperature and its hydrogen ionisation fraction. The new emission maps together with archival HST data are used to derive and analyse the proper motion of prominent emitting features which can be traced over 20 years with the HST observations.
Results. The images reveal the fine gas structure of the jet out to distances of a few tens of arcseconds from the central region, as well as in the innermost region, within a few arcseconds around the stellar source. They reveal for the first time the straight, highly collimated jet component which can be traced to up to ~900 AU in the NE direction. Images in [OIII]λ5007, [OI]λ6300, and [NII]λ6583 clearly show a helical pattern in the jet beams which may derive from the small-scale precession of the jet. The highly collimated jet is accompanied by a wide opening angle outflow which is filled by low excitation gas. The position angles of the jet structures as well as their opening angles are calculated. Our measurements of the proper motions of some prominent emission knots confirm the scenario of gas acceleration during the propagation of the outflow. Finally, we produce several detailed line ratio maps which present a mosaic combined from the large field and the PSF-subtracted inner region.
Conclusions. The high signal-to-noise HST WFC3/UVIS images provide powerful tools for the study of the jet morphology and also bring detailed information about the physical jet gas conditions. The simultaneous observations of [OIII], [OI], [NII], and [SII] would allow us to measure basic parameters of the ionised gas in the R Aqr outflow such as electron density, electron temperature and hydrogen ionisation fraction, and compare them with other stellar jets.
Hematoma epidural pós-traumático na junção crânio-cervical: Relato de caso e revisão de literatura
Authors: Azevedo Oliveira Bruno de , Garcia Lopes Luiz Henrique , Oliveira Pinheiro Hector de , Lopes Pedro Garcia 
Published: January 2018

ResumoOs autores relatam um caso raro de hematoma epidural pós-traumático na região da junção crânio-cervical. Paciente de 63 anos, após grave acidente automobilístico, evoluiu com dor cervical intensa, refratária ao tratamento clínico. A ressonância magnética demonstrou um hematoma epidural desde a junção crânio-cervical até C1-C2, de localização póstero-lateral direita, sem alterações de partes ósseas. Optado pelo tratamento cirúrgico imediato, foi realizada laminectomia com retirada do hematoma. Houve desaparecimento da dor e resolução completa do hematoma, comprovado pela ressonância magnética. É feita revisão da literatura sobre o tema
A função multimodal do fator estimulador de colônias granulocitárias (G-CSF) na isquemia cerebral. Uma nova aplicação terapêutica?
Authors: Maset Angelo Luiz , Greco Oswaldo Tadeu , Ruiz Lilian Piron , Lago Mario Roberto , Ruiz Milton Artur 
Published: January 2018

ResumoO fator estimulador de células granulocitárias (G-CSF) é uma glicoproteína descrita há mais de 20 anos, possui aprovação da FDA (Food and Drug Administration) e do Ministério da Saúde no Brasil para tratamento de estados neutropênicos e no transplante de medula óssea. O G-CSF estimula os precursores dos granulócitos e regula crucialmente a sobrevivência de neutrófilos maduros, pós-mitóticos, por meio da inibição da apoptose. Além do efeito sistêmico, mais recentemente, tem-se demonstrado uma surpreendente atividade do G-CSF no sistema nervoso central. A administração de G-CSF mobiliza células-tronco progenitoras da medula óssea para o sangue periférico, atravessa a barreira hematoencefálica (BHE) e se dirige à área acometida do cérebro. A atividade do G-CSF no sistema nervoso central tem sido caracterizada como multimodal, pois, além do efeito mobilizador de células da medula óssea, demonstrou-se uma ação direta neuroprotetora mediante diferentes mecanismos, tais como a atividade antiapoptótica em neurônios, regeneração da vascularização, efeito antiinflamatório e estimulação da neurogênese endógena. O objetivo deste relato é o de discutir essas nuances e uma possível aplicabilidade do G-CSF na isquemia cerebral.
Tratamento cirúrgico dos aneurismas do complexo da artéria comunicante anterior – detalhes técnicos
Authors: Tahara Adriana , Aguiar Paulo Henrique , Panagopoulos Alexandros Theodoros , Isolan Gustavo Rassier 
Published: January 2018

Resumo
Objetivo: Discutir as nuances técnicas das abordagens cirúrgicas dos aneurismas do complexo da artéria comunicante anterior conforme as características anatômicas e angiográficas das lesões. Métodos: Com base na experiência obtida com craniotomia pterional realizada em 30 casos de aneurismas do complexo da artéria comunicante anterior, complementada com retirada do processo clinoide anterior e teto orbitário. Resultados: A direção do segmento A1 se correlaciona com a do aneurisma. A patência dos segmentos A1 e A2 contralaterais deve ser observada. A aderência do aneurisma ao nervo óptico restringe a retração do lobo frontal. A aspiração do giro reto é útil quando o aneurisma tem localização alta. Conclusões: Os aneurismas da comunicante anterior estão entre os aneurismas intracranianos mais complexos. Os detalhes técnicos acima apontados são essenciais para o sucesso terapêutico.
Brainstem biopsies in adults: Review of 80 consecutive cases
Authors: Dellaretti Marcos , Reis Baltazar Leão , Touzet Gustavo , Reyns Nicolas , Dubois François , Gusmão Sebastião , Blond Serge 
Published: January 2018

Abstract
Objective: To retrospectively review the morbidity and mortality rates associated with stereotactic brainstem lesion biopsy, the success rate and the impact on treatment. Material and methods: Eighty consecutive stereotactic biopsies and literature review were performed to analyze clinical, radiographic and histopathological data. Results: Stereotactic biopsy of brainstem lesions conducted to the diagnosis in 96.3%. One death (1.3% of cases) occurred and 10% morbidity was associated with the procedure. Pathology showed that 65% of the adult brainstem intrinsic lesions were gliomas, 11.3% were metastasis, 8.7% were lymphomas and the remaining tumoral lesions were ganglioglioma, ependymoma and craniopharyngeoma. Non-tumoral lesions were the diagnosis in 11 cases. Conclusion: Empiric treatment of adult brainstem lesions is not prudent, because a wide spectrum of pathologies occur in this location. Stereotactic biopsy is a safe and effective method for determining the diagnostic of these lesions.
Céfalo-hematoma subperiosteal gigante ossificado na infância: Relato de caso e revisão de literatura
Authors: Bernardi Danilo Magnani , Biurrum Borba Luis Alencar , Maingué José Antônio , da Silva Paulo Eduardo Carneiro , Heinrich Cristina Belotserkovets , Araújo Júnior Francisco Alves de , da Cunha Marcelo Lemos Vieira , Amaral Verrísimo Denildo César 
Published: January 2018

ResumoHematoma subperiosteal ou céfalo-hematoma, apesar de condição conhecida em neonatos, é rara em adultos e mesmo em crianças maiores, o que levanta a suspeita de uma diferente patogênese entre as duas situações. A cronificação e a ossificação do céfalo-hematoma são condições extremamente infrequentes, com escasso material bibliográfico, e sua presença no adulto é fato inusitado na literatura. Reportamos o caso de um hematoma subperiosteal crônico de grandes proporções, ossificado, com um ano de evolução, tratado cirurgicamente, em um menino de 12 anos de idade com síndrome epiléptica e déficit cognitivo prévios. A revisão e a discussão de sua patogênese e seu tratamento foram realizadas para exposição da condição.
Aneurismas da artéria cerebelar posterior inferior: revisão crítica da técnica cirúrgica
Authors: Aguiar Paulo Henrique , Esteves Veiga José Carlos , Tahara Adriana , Isolan Gustavo Rassier 
Published: January 2018

Resumo
Objetivo: Revisão crítica dos aspectos anatômicos da abordagem dos aneurismas da artéria cerebelar inferior posterior (ACIP); a abordagem extremo-lateral e os detalhes de suas variantes foram analisados. Métodos: Revisão da literatura e análise da experiência dos autores. Resultado: A abordagem extremo-lateral é a melhor abordagem cirúrgica para os aneurismas da ACIP. As indicações de by-pass e tratamento endovascular também devem ser consideradas. A principal complicação é a fístula de liquor, mas isquemia do tronco, hematoma de leito cirúrgico, contusão cerebelar, lesão dos nervos bulbares e instabilidade condilar também devem ser citadas. Conclusão: O conhecimento da anatomia microcirúrgica é fundamental na abordagem dos aneurismas da ACIP.
Cavernomas bulbares e ponto-bulbares: Discussão sobre dois casos
Authors: Stávale Joaquim Marcos Augusto , Patriota Gustavo Cartaxo , Macedo Bianco Andre de 
Published: January 2018

ResumoOs autores discutem a cirurgia de remoção de cavernomas bulbares e ponto-bulbares mostrando dois casos como exemplos. Estratégicas para essas operações e suas indicações são analisadas. Cavernomas bulbares e ponto-bulbares são possivelmente removíveis com baixo risco cirúrgico.
Síndrome da reperfusão encefálica. Hipóteses fisiopatológicas, bioquímicas e hemodinâmicas do fenômeno da hipoperfusão pós-hiperemia
Authors: Stávale Joaquim Marcos Augusto , Patriota Gustavo Cartaxo , Bianco André de Macedo 
Published: January 2018

ResumoO objetivo deste texto é o de estruturar e sistematizar novas hipóteses fisiopatológicas sobre as modificações hemodinâmicas do cérebro submetido à isquemia e à reperfusão. São propostas e analisadas hipóteses bioquímicas e hemodinâmicas do fenômeno da hipoperfusão pós-hiperemia.
Experiência no tratamento de aneurismas cerebrais após a implantação da embolização
Authors: de Oliveira Daniel Rodrigues , Neto Pedro Pianca , Sena Emerson , Viana de Souza José Carlos Mariano , Andrada Bernardo de , de Almeida Werther Garfield , Doutel Francisco , Glória Júnior Armando da , Weldes Francisco , Mariushi Wagner , Ludolf Paixão José Renato , Ribeiro Carlos Henrique 
Published: January 2018

Resumo
Objetivo: Demonstrar os resultados do Serviço comparando embolização e clipagem no tratamento dos aneurismas intracranianos durante o período de 1/9/2007 a 1/12/2008, quando a técnica de embolização foi implantada no Serviço. Pacientes e métodos: Foi realizado estudo retrospectivo no banco de dados do hospital com programa estatístico (Epi Info 2000®) e colhidas informações mediante análise do registro cirúrgico no Serviço naquele período. Os dados foram cruzados pelos dois métodos para cálculo de parâmetros estatísticos. Resultados: No período, foram tratados 61 pacientes: 43 mulheres e 18 homens; em 40 o tratamento foi a embolização e em 21, a clipagem. O tempo médio de permanência dos pacientes submetidos à clipagem foi de 37 dias e o dos submetidos à embolização, de 18,5 dias. Dos 21 pacientes do primeiro grupo, 47% apresentavam idade entre 51 e 60 anos e dos 40 do grupo da embolização, 55% tinham idade entre 41 e 60 anos. A mortalidade global foi de 11,47%; 9,5% nos casos de clipagem e 12,5% no grupo da embolização. Conclusão: Observou-se que a embolização reduziu o tempo médio de permanência e, indiretamente, custos hospitalares, não alterando a taxa de mortalidade. A maioria dos aneurismas diagnosticados era roto, justificando o grande período de internação e a taxa de óbitos. O emprego da embolização foi uma conquista importante do Serviço para a rede municipal do Rio de Janeiro na terapêutica dos aneurismas.