bluuebunny/crossref_metadata_2025 huggingface dataset:
Gamma Knife radiosurgery for brain metastasis: review of 103 patients
Authors: Dellaretti Filho Marcos Antônio , Cavalcanti Mendes George de Albuquerque , Reyns Nicolas , Touzet Gustavo , Dubois François , Lartigau Eric , Blond Serge
Published: January 2018

Objective: To assess clinical and imaging outcomes in patients treated with Gamma Knife stereotactic radiosurgery (SRS) for brain metastasis. Methods: One hundred and three patients with 158 intracranial metastasis consecutively underwent Gamma Knife SRS between January, 2004 and December, 2006. The results were based on last imaging and the date of the last visit. Average age of the patients was 56 years (range 32-84 years). Karnofsky performance status average was 87.6. Fifty-eight (56.3%) patients had single brain metastasis. The average tumor volume was 2.5cc (range 0.02-16.6 cc). The SRS marginal dose average was 23.4 Gy (range 15-25 Gy). Results: Treatment sequence was SRS alone (89 patients) or SRS plus whole-brain radiotherapy (WBRT) (14 patients). The 1-year local control was 80%, being better for tumors with volume <5cc than for ≥5 cc: 86% vs 53% (p<0.05). The 1-year distant brain metastasis-free survival incidence was 73%. The initial number of brain lesions (single vs multiple) was not a significant factor on distant brain metastasis: free survival at 1 year was 75% for single metastases and 70% for multiple lesions. Renal cancer was the only factor with a significant effect on distant brain metastasis. The median overall survival was 15 months. According to unifactorial and multifactorial analysis, three prognostic factors for overall survival were retrieved recursive partitioning analysis (RPA) class, Karnofsky index performance and tumor volume. Conclusion: In this series, SRS provided excellent local control with relatively low morbidity in patients with brain metastases.
Fratura evolutiva de crânio na infância – Relato de cinco casos e revisão de literatura
Authors: Dabdoub Carlos Benjamin , Henrique da Cunha Artur , Serra Suzana Maria , Silveira Elisabeth do Nascimento , Cirne de Azevedo Filho Hildo Rocha
Published: January 2018

A fratura evolutiva é uma rara complicação que se observa geralmente na infância. Caracteriza-se por afastamento progressivo das bordas das fraturas, às vezes associado à formação de um cisto leptomeníngeo, também conhecido como cisto leptomeníngeo pós-traumático. De acordo com a literatura internacional, sua prevalência varia entre 0,03% e 1,6%. Analisamos a casuística de pacientes internados com traumatismo cranioencefálico no Hospital da Restauração de Recife (Brasil), um centro de referência em neurocirurgia pediátrica, no período de 1° de dezembro de 2000 a 30 de abril de 2008. O grupo de estudo compreendeu crianças de 0 a 14 anos. Durante essa investigação foram realizadas 19.758 admissões na emergência pediátrica por traumatismo cranioencefálico, e 74% foram admitidos da área metropolitana e 26% do interior do estado de Pernambuco. Foi observada fratura craniana em 6,3% dos casos, dos quais cinco crianças (menores de 3 anos) desenvolveram fratura evolutiva, representando 0,4% das fraturas de crânio e 0,02% dos traumatismos cranioencefálicos admitidos. Foi achada em todos os casos uma massa pulsátil, que apareceu em média no quarto mês após o trauma. As cinco crianças foram submetidas a tratamento cirúrgico, que compreendeu a ressecção do cisto leptomeníngeo e do tecido cerebral herniado, reparo do defeito dural e cranioplastia. A nossa experiência e a revisão bibliográfica mostram que crianças menores de 3 anos com história de traumatismo cranioencefálico e fratura de crânio apresentam risco de desenvolver fratura evolutiva. No entanto, sendo uma condição rara crianças com fratura de crânio menores de 3 anos, é obrigatório o acompanhamento clínico. Quando diagnosticado, o tratamento cirúrgico imediato é indicado para prevenir déficit neurológico.
Hiponatremia na fase precoce do traumatismo raquimedular
Authors: Pereira Carlos Umberto , Machado Julianne Alves
Published: January 2018

Objetivo: Analisar pacientes com traumatismo raquimedular (TRM) e os níveis séricos de sódio nos 14 primeiros dias pós-trauma, tratamento e prognóstico. Método: Trata-se de um estudo prospectivo, longitudinal e descritivo realizado no Serviço de Neurocirurgia do Hospital de Urgência de Sergipe (HUSE). Resultados: Foi prevalente o sexo masculino (80%). A idade média foi de 38,4. Quanto mais alto o nível da lesão, maior relação com o surgimento de hiponatremia. Conclusão: Por causa da incidência precoce dessa patologia em pacientes pós-TRM, é importante conscientizar a comunidade médica para a importância do rastreamento dessa patologia, evitando o aumento da morbimortalidade.
Característica clínica e topográfica do glioma maligno em adolescente – Influência do tratamento intranasal com álcool perílico
Authors: Mafra de Carvalho Marques Caroline , Santos Davi da Silva , Ferreira Roberto Fabri , Silva Júlio Thomé , Landeiro Jose Alberto , Orlando da Fonseca Clóvis , Quirico-Santos Thereza
Published: January 2018

Objetivo: Analisar a influência da topografia da lesão tumoral na resposta ao tratamento intranasal com álcool perílico (POH) em jovens com glioma maligno recidivo. Método: Tendo como padrão a faixa etária de 0 a 19 anos, foram incluídos pacientes do sexo masculino (#153; #31) e feminino (#178) com glioma maligno em estágio terminal, recebendo terapia de suporte paliativa e administração intranasal diária de 440 mg de POH. Resultados: Cefaleia intensa, tontura, vômito, crise convulsiva, alteração de comportamento, fraqueza muscular, alteração visual e hemiplegia à direita foram os sintomas prevalentes antes da confirmação diagnóstica de glioma. Análise de imagem mostrou lesão tumoral nas regiões troncocerebral (#153), talamomesencefálica esquerda (#178) e frontotemporal e insular direita (#31). Paciente #178 não respondeu ao tratamento, evoluindo a óbito em três semanas, e paciente #31 permaneceu em tratamento com POH por aproximadamente 54 semanas. Apesar de nova recidiva, paciente #153 apresenta doença estável, sem qualquer evidência clínica de recorrência para mais de 200 semanas em tratamento exclusivo com álcool perílico por via intranasal. Conclusão: Pacientes adolescentes com glioma maligno recidivo apresentaram heterogeneidade de sintomas compatível com a região anatômica comprometida, indicando que a topografia da lesão tumoral foi um fator prognóstico de sobrevida, influenciando inclusive na resposta ao tratamento intranasal com o álcool perílico.
Epidemiologia de uma série de tumores primários do sistema nervoso central
Authors: Mendes Graziella Alebrant , Ongaratti Bárbara Roberta , Semmelmann Pereira-Lima Júlia Fernanda
Published: January 2018

Objetivo: Realizar um levantamento de dados descritivos em uma série de tumores primários do sistema nervoso central. Métodos: Foram avaliados 106 casos de tumores primários do sistema nervoso central, descrevendo a idade média, os sintomas apresentados, os tipos de tumores mais frequentes e sua localização. Resultados: A idade média foi de 47 anos e 71 casos (67%) foram do sexo feminino. Observaram-se 39 tipos de tumores primários do sistema nervoso central, sendo os mais frequentes os meningiomas (51 casos, 48%), seguidos por glioblastomas (19 casos, 18%). Quanto à localização, 51 casos (48%) apresentaram-se nas meninges. Cefaleia ocorreu em 52% dos casos. Conclusões: A faixa etária da amostra é similar a de outros estudos. Observou-se predominância de meningiomas em associação à predominância do sexo feminino, no qual este tumor prevalece. Os sintomas apresentados corroboram com os descritos na literatura.
Craniofaringioma cístico gigante de fossa posterior: Relato de caso
Authors: Clara Carlos Afonso , Walther de Almeida José Reynaldo , Marcondes Homero
Published: January 2018

O craniofaringioma localizado na fossa posterior é uma entidade rara, estimada em torno de 4%. Geralmente está associado a quadros clínicos graves que necessitam de tratamento cirúrgico. O seu prognóstico está relacionado com a possibilidade de remoção do tumor.

Apresentamos um caso de craniofaringioma cístico localizado na fossa posterior, de dimensões gigantes, tratado cirurgicamente e com bom resultado.
Redação de artigo científico
Authors: Gusmão Sebastião
Published: January 2018

Descrevem-se as orientações básicas para redação de artigo científico, tipo original, por meio da análise das diferentes partes ou seções desse tipo de trabalho. Abordam-se também as bases teóricas da redação científica e o estilo da linguagem científica.
Nutrição e neurocirurgia: uma revisão
Authors: Riboldi Bárbara Pelicioli , Contini Betânia , dos Santos Fernanda Trespach , da Silva Laís Souza , de Oliveira Vanessa Rossoni , da Cunha Fernanda Monte , Santis-Isolan Paola Maria Brolin , Isolan Gustavo Rassier
Published: January 2018

As alterações metabólicas e da composição corporal em decorrência da injúria cirúrgica resultam em necessidades nutricionais especiais para pacientes neurocirúrgicos. Essas alterações têm como característica a instalação de um estado hipermetabólico e hipercatabólico, observando-se uma redução nas reservas corporais de lipídeos e proteínas, resultando na dificuldade de cicatrização e risco aumentado de infecção. Além disso, com um aporte nutricional inadequado, os pacientes podem evoluir para um estado de desnutrição. Na ausência de diretrizes específicas de como o suporte nutricional deve suceder em traumas neurológicos, verificou-se a importância da realização de um artigo de revisão a respeito do suporte nutricional utilizado em pacientes neurocirúrgicos. A partir da pesquisa realizada no banco de dados Medline (1976-2010), observou-se que a estimativa energética é um fator decisivo no prognóstico do paciente, a suplementação de aminoácidos não se mostra necessária e que, além dos exames de rotina, devem-se realizar exames de eletrólitos e osmolalidade urinários e plasmáticos. O suporte nutricional ideal parece ser uma administração conjunta de nutrição enteral e parenteral e, quanto mais precocemente essa alimentação é iniciada, melhores são os desfechos clínicos. Considerando que é de competência do nutricionista a prescrição dietética da nutrição enteral, sua presença é essencial na equipe multiprofissional de suporte nutricional.
Reanimation eines Säuglings – ST-Hebungsinfarkt und Kammerflimmern, nicht nur ein Phänomen des Erwachsenen
Authors: Hübner Tobias , Kellner Patrick , Schroth Michael
Published: January 2018

Der plötzliche Herztod ist mit etwa 80 000 bis 100 000 Fällen pro Jahr eine der häufigsten Todesursachen in Deutschland (Reanimationsregister). Dabei sind Reanimationsereignisse in der Erwachsenenmedizin deutlich häufiger als in der Kinderheilkunde. Wir berichten über einen 7 Monate alten männlichen Säugling, der leblos in der elterlichen Wohnung vorgefunden wurde. Der Primärrhythmus war Kammerflimmern und wurde durch 2-malige biphasische elektrische Schockabgabe erfolgreich terminiert. Nach ROSC (return of spontaneous circulation) wurde der Säugling auf eine pädiatrische Intensivstation verbracht. Im angefertigten 12-Kanal-EKG sah man das Bild eines akuten ST-Hebungsinfarkts (STEMI) der Vorderwand, sodass eine invasive Koronardiagnostik erfolgte. Dort zeigte sich ein Komplettverschluss des R. interventricularis anterior (RIVA) sowie ausgeprägte Koronaraneurysmata der anderen Herzkranzgefäße auf dem Boden eines Kawasaki-Syndroms.
Double-gated ultra-thin-body GaAs-on-insulator p-FETs on Si
Authors: Shim Jae-Phil , Kim Seong Kwang , Kim Hansung , Ju Gunwu , Lim Heejeong , Kim SangHyeon , Kim Hyung-jun
Published: January 2018

We demonstrated ultra-thin-body (UTB) junctionless (JL) p-type field-effect transistors (pFETs) on Si using GaAs channels. Wafer bonding and epitaxial lift-off techniques were employed to fabricate the UTB p-GaAs-on-insulator on a Si template. Subsequently, we evaluated the JL FETs having different p-GaAs channel thicknesses considering both maximum depletion width and doping concentration for high performance. Furthermore, by introducing a double-gate operation, we more effectively controlled threshold voltage and attained an even higher ION/IOFF of >106, as well as a low subthreshold swing value of 300 mV/dec.
Vacancy defects and optoelectrical properties for fluorine tin oxide thin films with various SnF2 contents
Authors: Zhou Yawei , Xu Wenwu , Li Jingjing , Yin Chongshan , Liu Yong , Zhao Bin , Chen Zhiquan , He Chunqing , Mao Wenfeng , Ito Kenji
Published: January 2018

Fluorine doped tin oxide (FTO) thin films were deposited on glass substrates by e-beam evaporation. Much higher carrier concentration, broader optical band gap, and average transmittance over 80% were obtained with SnF2 doped SnO2 thin films. Positron annihilation results showed that there are two kinds of vacancy clusters with different sizes existing in the annealed FTO thin films, and the concentration of the larger vacancy clusters of VSnO in the thin films increases with increasing SnF2 contents. Meanwhile, photoluminescence spectra results indicated that the better electrical and optical properties of the FTO thin films are attributed to FO substitutions and oxygen vacancies with higher concentration, which are supported by positron annihilation Doppler broadening results and confirmed by X-ray photoelectron spectroscopy. The results showed that widening of the optical band gap of the FTO thin films strongly depends on the carrier concentration, which is interpreted for the Burstein-Moss effect and is associated with the formation of FO and oxygen vacancies with increasing SnF2 content.
Preparation and microwave absorption properties of honeycomb core structures coated with composite absorber
Authors: Luo Hui , Chen Fu , Wang Fang , Wang Xian , Dai Weiyong , Hu Sheng , Gong Rongzhou
Published: January 2018

Honeycomb structure coated with paraffin filled with composite of graphene and flaky carbonyl iron powder (FCIP) as lossy filler have been studied. The composite of graphene/FCIP with different weight ratio were synthesized via mechanical milling, the electromagnetic properties of the samples were measured by transmission/reflection method in the frequency range of 8-12 GHz. The microwave absorbing properties of the microwave absorbing honeycomb structure (MAHS) and microwave absorbing honeycomb sandwich structure (MAHSS) were studied based on the Finite Element Method with periodical boundary conditions. The matching layer on the top of the honeycomb sandwich structure can enhanced the microwave absorption properties. It was shown that a light weight and broadband MAHSS could be implemented with the use of the magnetic material and dielectric material.
Decoupling control of a five-phase fault-tolerant permanent magnet motor by radial basis function neural network inverse
Authors: Chen Qian , Liu Guohai , Xu Dezhi , Xu Liang , Xu Gaohong , Aamir Nazir
Published: January 2018

This paper proposes a new decoupled control for a five-phase in-wheel fault-tolerant permanent magnet (IW-FTPM) motor drive, in which radial basis function neural network inverse (RBF-NNI) and internal model control (IMC) are combined. The RBF-NNI system is introduced into original system to construct a pseudo-linear system, and IMC is used as a robust controller. Hence, the newly proposed control system incorporates the merits of the IMC and RBF-NNI methods. In order to verify the proposed strategy, an IW-FTPM motor drive is designed based on dSPACE real-time control platform. Then, the experimental results are offered to verify that the d-axis current and the rotor speed are successfully decoupled. Besides, the proposed motor drive exhibits strong robustness even under load torque disturbance.
Heat transfer comparison of nanofluid filled transformer and traditional oil-immersed transformer
Authors: Zhang Yunpeng , Ho Siu-lau , Fu Weinong
Published: January 2018

Dispersing nanoparticles with high thermal conductivity into transformer oil is an innovative approach to improve the thermal performance of traditional oil-immersed transformers. This mixture, also known as nanofluid, has shown the potential in practical application through experimental measurements. This paper presents the comparisons of nanofluid filled transformer and traditional oil-immersed transformer in terms of their computational fluid dynamics (CFD) solutions from the perspective of optimal design. Thermal performance of transformers with the same parameters except coolants is compared. A further comparison on heat transfer then is made after minimizing the oil volume and maximum temperature-rise of these two transformers. Adaptive multi-objective optimization method is employed to tackle this optimization problem.
Accurate virial coefficients of gaseous krypton from state-of-the-art ab initio potential and polarizability of the krypton dimer
Authors: Song Bo , Waldrop Jonathan M. , Wang Xiaopo , Patkowski Konrad
Published: January 2018

We have developed a new krypton–krypton interaction-induced isotropic dipole polarizability curve based on high-level ab initio methods. The determination was carried out using the coupled-cluster singles and doubles plus perturbative triples method with very large basis sets up to augmented correlation-consistent sextuple zeta as well as the corrections for core-core and core-valence correlation and relativistic effects. The analytical function of polarizability and our recently constructed reference interatomic potential [J. M. Waldrop et al., J. Chem. Phys. 142, 204307 (2015)] were used to predict the thermophysical and electromagnetic properties of krypton gas. The second pressure, acoustic, and dielectric virial coefficients were computed for the temperature range of 116 K–5000 K using classical statistical mechanics supplemented with high-order quantum corrections. The virial coefficients calculated were compared with the generally less precise available experimental data as well as with values computed from other potentials in the literature {in particular, the recent highly accurate potential of Jäger et al. [J. Chem. Phys. 144, 114304 (2016)]}. The detailed examination in this work suggests that the present theoretical prediction can be applied as reference values in disciplines involving thermophysical and electromagnetic properties of krypton gas.
The effect of Pd ensemble structure on the O2 dissociation and CO oxidation mechanisms on Au—Pd(100) surface alloys
Authors: Oğuz Ismail-Can , Mineva Tzonka , Guesmi Hazar
Published: January 2018

The reactivity of various Pd ensembles on the Au—Pd(100) alloy catalyst toward CO oxidation was investigated by using density functional theory (DFT). This study was prompted by the search for efficient catalysts operating at low temperature for the CO oxidation reaction that is of primary environmental importance. To this aim, we considered Pd modified Au(100) surfaces including Pd monomers, Pd dimers, second neighboring Pd atoms, and Pd chains in a comparative study of the minimum energy reaction pathways. The effect of dispersion interactions was included in the calculations of the O2 dissociation reaction pathway by using the DFT-D3 scheme. The addition of the dispersion interaction strongly improves the adsorption ability of O2 on the Au—Pd surface but does not affect the activation energy barriers of the Transitions States (TSs). As for O2 to dissociate, it is imperative that the TS has lower activation energy than the O2 desorption energy. DFT-D3 is found to favor, in some cases, O2 dissociation on configurations being identified from uncorrected DFT calculations as inactive. This is the case of the second neighboring Pd configuration for which uncorrected DFT predicts positive Gibbs free energy (ΔG) of the O2 adsorption, therefore an endergonic reaction. With the addition of D3 correction, ΔG becomes negative that reveals a spontaneous O2 adsorption. Among the investigated Au—Pd (100) ensembles, the Pd chain dissociates most easily O2 and highly stabilizes the dissociated O atoms; however, it has an inferior reactivity toward CO oxidation and CO2 formation. Indeed, CO strongly adsorbs on the palladium bridge sites and therefore poisoning the surface Pd chain. By contrast, the second neighboring Pd configuration that shows somewhat lower ability to dissociate O2 turns out to be more reactive in the CO2 formation step. These results evidence the complex effect of Pd ensembles on the CO oxidation reaction. Associative CO oxidation proceeds with high energy barriers on all the considered Pd ensembles and should be excluded, in agreement with experimental observations.
Strain-dependent dynamic compressive properties of magnetorheological elastomeric foams
Authors: Wereley Norman M. , Perez Colette , Choi Young T.
Published: January 2018

This paper addresses the strain-dependent dynamic compressive properties (i.e., so-called Payne effect) of magnetorheological elastomeric foams (MREFs). Isotropic MREF samples (i.e., no oriented particle chain structures), fabricated in flat square shapes (nominal size of 26.5 mm x 26.5 mm x 9.5 mm) were synthesized by randomly dispersing micron-sized iron oxide particles (Fe3O4) into a liquid silicone foam in the absence of magnetic field. Five different Fe3O4 particle concentrations of 0, 2.5, 5.0, 7.5, and 10 percent by volume fraction (hereinafter denoted as vol%) were used to investigate the effect of particle concentration on the dynamic compressive properties of the MREFs. The MREFs were sandwiched between two multi-pole flexible plate magnets in order to activate the magnetorheological (MR) strengthening effect. Under two different pre-compression conditions (i.e., 35% and 50%), the dynamic compressive stresses of the MREFs with respect to dynamic strain amplitudes (i.e., 1%-10%) were measured by using a servo-hydraulic testing machine. The complex modulus (i.e., storage modulus and loss modulus) and loss factors of the MREFs with respect to dynamic strain amplitudes were presented as performance indices to evaluate their strain-dependent dynamic compressive behavior.
Evaluation of the magnetocaloric response of nano-sized La0.7Ca0.3Mn1-xNixO3 manganites synthesized by auto-combustion method
Authors: Gómez Adrián , Chavarriaga Edgar , Supelano Iván , Parra Carlos Arturo , Morán Oswaldo
Published: January 2018

A systematic study of the dependence of the magnetization on the magnetic field around the ferromagnetic–paramagnetic phase transition temperature is carried out on La0.7Ca0.3Mn1-xNixO3 (x=0, 0.02, 0.07, and 1) samples synthesized by auto-combustion method. The successful substitution of Mn3+ ions by Ni2+ ions in the La0.7Ca0.3MnO3 lattice is corroborated by X-ray diffraction technique. Banerjees criteria, Arrott plots, and the scaling hypothesis are used to analyze the experimental data. It is verified that the Ni-doping increases the operating temperature range for magnetocaloric effect through tuning of the magnetic transition temperature. Probably, the replacement of Mn3+ by Ni2+ ions in the La0.7Ca0.3MnO3 lattice weakens the Mn3+-O-Mn4+ double exchange interaction, which leads to a decrease in the transition temperature and magnetic moment in the samples. The Arrott plots suggest that the phase transition from ferromagnetic to paramagnetic in the nano-sized manganite is of second order. The analysis of the magnetization results show that the maximum magnetic entropy changes observed for x=0, 0.02, 0.07, and 0.1 compositions are 0.85, 0.77, 0.63, and 0.59 J/kg K, under a magnetic field of 1.5 T. These values indicate that the magnetic entropy change achieved for La0.7Ca0.3Mn1-xNixO3 manganites synthesized by auto-combustion method is higher than those reported for other manganites with comparable Ni-doping levels but synthesized by standard solid state reaction. It is also observed that the addition of Ni2+ increases the value of the relative cooling power as compared to that of the parent compound. The highest value of this parameter (∼60 J/kg) is found for a Ni-doping level of 2 % around 230 K in a field of 1.5 T.
Recycled Sm-Co bonded magnet filaments for 3D printing of magnets
Authors: Khazdozian Helena A. , Manzano J. Sebastián , Gandha Kinjal , Slowing Igor I. , Nlebedim Ikenna C.
Published: January 2018

Recycling of rare earth elements, such as Sm and Nd, is one technique towards mitigating long-term supply and cost concerns for materials and devices that depend on these elements. In this work recycled Sm-Co powder recovered from industrial grinding swarfs, or waste material from magnet processing, was investigated for use in preparation of filament for 3D printing of bonded magnets. Recycled Sm-Co powder recovered from swarfs was blended into polylactic acid (PLA). Up to 20 vol.% of the recycled Sm-Co in PLA was extruded at 160°C to produce a filament. It was demonstrated that no degradation of magnetic properties occurred due to the preparation or extrusion of the bonded magnet material. Good uniformity of the magnetic properties is exhibited throughout the filament, with the material first extruded being the exception. The material does exhibit some magnetic anisotropy, allowing for the possibility of the development of anisotropic filaments. This work provides a path forward for producing recycled magnetic filament for 3D printing of permanent magnets.
Magnetic field concentration using ferromagnetic material to propel a wireless power transfer based micro-robot
Authors: Kim Dongwook , Park Bumjin , Park Jaehyoung , Park Hyun Ho , Ahn Seungyoung
Published: January 2018

In this paper, we propose a novel coil structure, using a ferromagnetic material which concentrates the magnetic field, as the propulsion system of a wireless power transfer (WPT) based micro-robot. This structure uses an incident magnetic field to induce current during wireless power transfer, to generate a Lorentz force. To prevent net cancelation of the Lorentz force in the load coil, ferrite films were applied to one side of the coil segment. The demonstrated simplicity and effectiveness of the proposed micro-robot showed its suitability for applications. Simulation and experimental results confirmed a velocity of 1.02 mm/s with 6 mW power transfer capacity for the 3 mm sized micro-robot.
Molecular hydrodynamics: Vortex formation and sound wave propagation
Authors: Han Kyeong Hwan , Kim Changho , Talkner Peter , Karniadakis George Em , Lee Eok Kyun
Published: January 2018

In the present study, quantitative feasibility tests of the hydrodynamic description of a two-dimensional fluid at the molecular level are performed, both with respect to length and time scales. Using high-resolution fluid velocity data obtained from extensive molecular dynamics simulations, we computed the transverse and longitudinal components of the velocity field by the Helmholtz decomposition and compared them with those obtained from the linearized Navier–Stokes (LNS) equations with time-dependent transport coefficients. By investigating the vortex dynamics and the sound wave propagation in terms of these field components, we confirm the validity of the LNS description for times comparable to or larger than several mean collision times. The LNS description still reproduces the transverse velocity field accurately at smaller times, but it fails to predict characteristic patterns of molecular origin visible in the longitudinal velocity field. Based on these observations, we validate the main assumptions of the mode-coupling approach. The assumption that the velocity autocorrelation function can be expressed in terms of the fluid velocity field and the tagged particle distribution is found to be remarkably accurate even for times comparable to or smaller than the mean collision time. This suggests that the hydrodynamic-mode description remains valid down to the molecular scale.
Communication: Site-selective bond excision of adenine upon electron transfer
Authors: Cunha T. , Mendes M. , Ferreira da Silva F. , Eden S. , García G. , Limão-Vieira P.
Published: January 2018

This work demonstrates that selective excision of hydrogen atoms at a particular site of the DNA base adenine can be achieved in collisions with electronegative atoms by controlling the impact energy. The result is based on analysing the time-of-flight mass spectra yields of potassium collisions with a series of labeled adenine derivatives. The production of dehydrogenated parent anions is consistent with neutral H loss either from selective breaking of C–H or N–H bonds. These unprecedented results open up a new methodology in charge transfer collisions that can initiate selective reactivity as a key process in chemical reactions that are dominant in different areas of science and technology.
Splice Expression Variation Analysis (SEVA) for inter-tumor heterogeneity of gene isoform usage in cancer
Authors: Afsari Bahman , Guo Theresa , Considine Michael , Florea Liliana , Kagohara Luciane T , Stein-O’Brien Genevieve L , Kelley Dylan , Flam Emily , Zambo Kristina D , Ha Patrick K , Geman Donald , Ochs Michael F , Califano Joseph A , Gaykalova Daria A , Favorov Alexander V , Fertig Elana J
Published: January 2018

Motivation

Current bioinformatics methods to detect changes in gene isoform usage in distinct phenotypes compare the relative expected isoform usage in phenotypes. These statistics model differences in isoform usage in normal tissues, which have stable regulation of gene splicing. Pathological conditions, such as cancer, can have broken regulation of splicing that increases the heterogeneity of the expression of splice variants. Inferring events with such differential heterogeneity in gene isoform usage requires new statistical approaches.

Results

We introduce Splice Expression Variability Analysis (SEVA) to model increased heterogeneity of splice variant usage between conditions (e.g. tumor and normal samples). SEVA uses a rank-based multivariate statistic that compares the variability of junction expression profiles within one condition to the variability within another. Simulated data show that SEVA is unique in modeling heterogeneity of gene isoform usage, and benchmark SEVA’s performance against EBSeq, DiffSplice and rMATS that model differential isoform usage instead of heterogeneity. We confirm the accuracy of SEVA in identifying known splice variants in head and neck cancer and perform cross-study validation of novel splice variants. A novel comparison of splice variant heterogeneity between subtypes of head and neck cancer demonstrated unanticipated similarity between the heterogeneity of gene isoform usage in HPV-positive and HPV-negative subtypes and anticipated increased heterogeneity among HPV-negative samples with mutations in genes that regulate the splice variant machinery. These results show that SEVA accurately models differential heterogeneity of gene isoform usage from RNA-seq data.

Availability and implementation

SEVA is implemented in the R/Bioconductor package GSReg.

Supplementary information

Supplementary data are available at Bioinformatics online.
Differential Age Effects of Transcranial Direct Current Stimulation on Associative Memory
Authors: Leach Ryan C , McCurdy Matthew P , Trumbo Michael C , Matzen Laura E , Leshikar Eric D
Published: January 2018

Objectives

Older adults experience associative memory deficits relative to younger adults (Old & Naveh-Benjamin, 2008). The aim of this study was to test the effect of transcranial direct current stimulation (tDCS) on face-name associative memory in older and younger adults.

Method

Experimenters applied active (1.5 mA) or sham (0.1 mA) stimulation with the anode placed over the left dorsolateral prefrontal cortex (dlPFC) during a face-name encoding task, and measured both cued recall and recognition performance. Participants completed memory tests immediately after stimulation and after a 24-h delay to examine both immediate and delayed stimulation effects on memory.

Results

Results showed improved face-name associative memory performance for both recall and recognition measures, but only for younger adults, whereas there was no difference between active and sham stimulation for older adults. For younger adults, stimulation-induced memory improvements persisted after a 24-h delay, suggesting delayed effects of tDCS after a consolidation period.

Discussion

Although effective in younger adults, these results suggest that older adults may be resistant to this intervention, at least under the stimulation parameters used in the current study. This finding is inconsistent with a commonly seen trend, where tDCS effects on cognition are larger in older than younger adults.
Communication failure: analysis of prescribers’ use of an internal free-text field on electronic prescriptions
Authors: Ai Angela , Wong Adrian , Amato Mary , Wright Adam
Published: January 2018

Importance

Electronic prescribing promises to improve the safety and clarity of prescriptions. However, it also can introduce miscommunication between prescribers and pharmacists. There are situations where information that is meant to be sent to pharmacists is not sent to them, which has the potential for dangerous errors.

Objective

To examine how frequently prescribers or administrative personnel put information intended for pharmacists in a field not sent to pharmacists, classify the type of information included, and assess the potential harm associated with these missed messages.

Design, Setting, Participants

Medication record data from our legacy electronic health record were requested for ambulatory care patients seen at an academic medical center from January 1, 2000, to May 31, 2015 (20 123 881 records). From this database, 6 060 272 medication orders met our inclusion criteria. We analyzed a random sample of 10 000 medication orders with internal comments.

Main Outcomes and Measures

Reviewers classified internal comments for intent. Comments intended for pharmacists were also sorted into descriptive categories and analyzed for the potential for patient harm.

Results

We found that 11.7% of the prescriptions in our sample contained comments that were intended to be sent to pharmacists. Many comments contained information about the dose, route, or duration of the prescription (38.0%). Approximately a third of the comments intended for pharmacists contained information that had the potential for significant or severe harm if not communicated.

Conclusion

We found undelivered comments that were clearly intended for pharmacists and contained important information for either pharmacists or patients. This poses a legitimate safety concern, as a portion of comments contained information that could have prevented severe or significant harm.
Greco-Roman Historiography
Authors: Orlin Eric M.
Published: January 2018

The practice of writing history in the ancient world differed markedly from the practices employed by historians today, in large measure because ancient historians conceived of their task differently. The term “history” derives from the Greek word historiê, which means “inquiry,” used by Herodotus to describe his work. This inquiry could take many forms, and the boundaries between history as we understand it and such genres as ethnography, geography, and biography were never clearly defined. To the extent that ancient historians did practice their craft in a way familiar to us, the choice of genre impacted the work that each has left to us. In addition, deep connections with other forms of writing, including prose genres such as oratory as well as poetic genres of epic and tragedy, contributed to the development of historical writing in ways not always recognizable to the modern practice of history. Most ancient histories were explicitly didactic in nature. They aimed to be useful to the reader, either imparting practical knowledge on how to address certain situations or lessons for moral improvement through the provision of historical examples; sometimes they aimed at both at the same time. Even making sense of the past meant something different in a world where the gods might be considered to play active roles in human affairs. Modern scholars have therefore expended energy in exploring the ways that ancient historians approached issues that are central to our own notions of historical writing, including most prominently the truth value of a text, a historian’s use of sources, and his objectivity. These studies have made it abundantly clear that ancient writers aimed both to make sense of the past and to produce works of literary merit and that the boundaries between history and other genres always remained fluid. Modern scholars disagree considerably over how far individual historians pushed the boundaries in balancing their aims with their understanding of their task, and modern readers must constantly work to be aware of the differences between ancient and modern historiography to make use of these texts in an appropriate fashion.
Daoism and Philosophy
Authors: Lee Jung
Published: January 2018

Along with Confucianism, Daoism represents one of the major indigenous philosophical and religious traditions of China. Although we can trace the origins of Daoism to the 4th century bce, the term “Daoism” (daojia道家, lit. “family of the Way”) only gained currency during the Western Han (206 bce–6 ce) when the neologism was coined by the historian Sima Tan 司馬談 (d. 110 bce) in his “Essentials of the Six Schools” (liujia zhi yaozhi六家之要指), long after the introduction of such foundational texts as the Laozi老子and Zhuangzi莊子. Having said that, we can note certain family resemblances among textual sources and master-disciple lineages during the pre-Han period that point to shared views on the cosmology of the Way (dao道, lit. “road” or “path”), the ultimate metaphysical force in the cosmos, and self-cultivation practices or “techniques of the Way” (dao shu道術) that would enable the adept to attune or merge with the Way and lead a more realized life. It is the presence of these “techniques of the Way” that led Sima Tan to label certain individual “experts” and practitioners “Daoists.” Toward the end of the Eastern Han in 142 ce, we witness the beginnings of Daoism as an organized, institutional religion with the founding of the Way of the Celestial Masters (tian shi dao天師道) and then later with the emergence of subsequent religious communities like the Shangqing 上清 or Highest Clarity and Quanzhen 全真 or Complete Perfection. Although there has been an historical proclivity, now less pronounced, on the part of some Chinese scholars and Western sinologists to bifurcate Daoism into “philosophical Daoism” and “religious Daoism,” the distinction needlessly essentializes aspects of Daoism and ignores the complex process of poetic influence and conceptual appropriation within the tradition. With this in mind, this entry will focus on selections that highlight the philosophical dimensions of the Daoist tradition, beginning with a section on Daoism in the context of early Chinese philosophy along with dedicated sections on the Laozi and Zhuangzi. The rest of the entry will be organized into topics that address particular aspects of Daoist philosophy, including epistemology, ethics, metaphysics, social and political philosophy, and comparative studies.
Nicholas Bozon
Authors: Postlewate Laurie
Published: January 2018

Nicholas Bozon is the author of religious texts composed in England from the late 13th to the early 14th century in a wide range of forms, including sermon exempla, allegories, verse proverbs, saints’ lives, and devotional lyrics. Bozon’s works are composed primarily in the dialect of French used in England in the later period of Anglo-Norman literary activity, with occasional use of Latin and Middle English. For eight of the works in which his name is given, Bozon is associated in at least one manuscript with the Order of Saint Francis, del ordre de freres menours, and indeed his entire literary production, in both prose and verse, transmits a penetrating spiritual message by means of striking imagery and entertaining stories. Bozon’s oeuvre is marked, both in form and technique, by a penchant for collecting and assembling images, stories, and examples that might well be used in preaching; however, the manuscript transmission of the works, as well as the pastoral and devotional content, lead us to consider the possibility of both lay and religious audiences. A compilation structure in which elements of various kinds are listed and developed is found in the following works: a collection of moralized facts of nature, a sequence of sermonizing poems, a collection of verse adaptations on aphoristic sayings, two allegorical poems itemizing and visualizing lists of sins, and a legendary of female saints’ lives. Other works of a more devotional nature include a verse description of the Incarnation and Passion as a courtly tale of love, and poems to the Virgin. Bozon’s texts are of interest for multiple reasons: they demonstrate the focus on identifying and understanding vice and virtue that marks so much of vernacular literature in the post-Lateran IV period; they offer evidence of the vitality and evolution of the French language in late medieval Britain; and they show the importance of translation and adaptation in the development of vernacular literature. Also, the textual trace of Bozon as a preacher and poet provides a window onto the wider activities and methods of the Franciscan order, whose pastoral mission was to indoctrinate and inspire the lay public. Bozon’s literary production is an excellent example of how sermon literature had a cultural impact extending well beyond the context of the pulpit. Bozon’s works have almost all been edited, albeit in somewhat piecemeal fashion and in editions that are sometimes dated. Studies of Bozon are surprisingly scarce, however, given the breadth and variety of his output. This neglect may in part be explained by the tendency of earlier (predominantly Continental) scholarship to disparage Insular French and the deviations from the norm of Continental versification that characterize its poetry.
Interracial Marriage in the Atlantic World
Authors: Newman Brooke
Published: January 2018

The transformations wrought in the Atlantic world during the colonial era brought Native Americans, Europeans, and Africans into sustained contact in the Americas for the first time, fostering interethnic mixing, sexual violence and intimacy, and intermarriage. In a wide variety of colonial sites across the Atlantic, interracial marriages expanded kinship and trading networks, cemented military and political alliances, and facilitated the adaptation and survival of Native communities. Interracial marriages not only provided economic and social benefits to European and Euro-American explorers, traders, and settlers and the indigenous populations whom they encountered, they also served as a powerful political tool in contested borderlands far from imperial centers. In Latin America, North America, the Caribbean, and along the West African coast, European males mingled socially and sexually with women of Indian, African, and mixed heritage, though the vast majority of these interracial relationships took place outside the sanctity of marriage, and many involved some level of coercion. While historians have traditionally held that racially mixed marriages occurred with greater regularity in Spain’s New World colonies, in contrast to the French and English empires, more recent scholarship has demonstrated the ubiquity of interracial concubinage, informal marriage, and intermarriage throughout the early modern Atlantic world. Responses to the frequency and visibility of illicit interracial relations were nonetheless uneven and changed over time, as the emergence of legal, social, and cultural prohibitions against interracial marriage prevented the widespread acceptance of racially exogamous mixed unions and intermarriage. Focusing on official attitudes toward and legal restrictions on racial interaction and interracial marriage as well as everyday practices, these newer studies track the extent to which colonial policies varied in response to local conditions and broader imperial developments. Attention to intermarriage as a tool of colonization and strategy for assimilation has underscored the critical role of Native women as cultural intermediaries. Scholars argue that the toleration or ban of interracial marital unions by officials depended upon a range of interrelated factors: demographic conditions, the ancestry of the female partners (European, Indian, African, or mixed heritage), public attitudes toward interracial mixture, colonizing and trading goals, and transatlantic religious and intellectual currents. Intermarriage, and the inclusion of mixed-raced offspring in kinship networks, fundamentally transformed family structures, shaped developing notions of racial difference, and posed challenges to group cohesion and individual and national identity.
Animal Population Ecology
Authors: Egerton Frank N. , Mayer Gregory C.
Published: January 2018

Animal population ecology comprises the study of the growth, regulation, and interactions of animal populations. As a level of organization, the population comes between individuals on the one hand and communities on the other, but there is not a sharp distinction between those phenomena that affect the levels above and below from those of the population: a population’s growth may be much effected by the behavior of its constituent individuals, while the presence of predators, prey, and competitors in the community will likewise have important effects on the population. Nonetheless, the population is a worthy area of emphasis (for greater consideration of multispecies interactions and other aspects of community structure and function, see the separate Oxford Bibliographies article “Community Ecology”). Animals share a number of relevant ecological features that make a separation from plants useful: animals are all heterotrophs, mostly exist as biologically separate and genetically distinct individuals, and most are sexual. There are greater or lesser exceptions to all of these features, but they unify the phenomena of animal populations, and make counting individuals an intuitive and practical way of accounting for their populations’ growth and numbers. That part of ecology that deals with populations of animals is thus an interesting partition, and as a distinct area of study is well-justified by historical development and current practice.
Preterm Delivery and Low Birth Weight Among Neonates Conceived With Intracytoplasmic Sperm Injection Compared With Conventional In Vitro Fertilization
Authors: Keyhan Sanaz , Truong Tracy , Li Yi-Ju , Jackson-Bey Tia , Eaton Jennifer L.
Published: January 2018

OBJECTIVE:

To examine the prevalence of prematurity and low birth weight (LBW) among singletons conceived with intracytoplasmic sperm injection (ICSI) compared with those conceived with conventional in vitro fertilization (IVF).

METHODS:

Using the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System, we conducted a retrospective cohort study of women undergoing a first, fresh autologous ICSI or conventional IVF cycle from 2004 to 2013. Singleton live births were included in the analysis. Primary outcomes were preterm delivery and LBW. Secondary outcomes were very preterm delivery, preterm LBW, term LBW, and very LBW. Logistic regression models and propensity score matching were used to compare perinatal outcomes between ICSI and IVF cycles. Subset analyses were performed after stratification by sperm source, male factor infertility, and female prognosis.

RESULTS:

Of the 90,401 cycles included in the analysis, ICSI was used in 60,719 (67.2%) and conventional IVF was used in 29,682 (32.8%). After propensity score matching and covariate adjustment, the two groups had similar odds of preterm delivery (adjusted odds ratio [OR] 1.02, 95% CI 0.89–1.18) and LBW (adjusted OR 0.92, 95% CI 0.78–1.10). Using the matched data set, subset analyses demonstrated no significant association between the method of fertilization and the examined perinatal outcomes.

CONCLUSION:

Rates of preterm delivery and LBW were similar between pregnancies conceived with ICSI and conventional IVF after propensity score matching and stratifying by baseline patient characteristics. Previously reported differences in these outcomes were likely secondary to patients' inherent risk factors rather than the fertilization procedure itself.