bluuebunny/crossref_metadata_2025 huggingface dataset:
Cisto aracnóide intracraniano: Revisão de literatura
Authors: Araújo Filho Stélio da Conceição , Pinheiro Marques João Antônio , de Albuquerque Lucas Alverne Freitas , de Almeida João Paulo Cavalcante , Paiva Santos Flávia de
Published: January 2018

Objetivo: Revisão da literatura sobre os cistos aracnóides intracranianos – formação e evolução, dados epidemiológicos e clínicos, aspectos de neuroimagem e tratamento. Método: Realizamos pesquisa bibliográfica utilizando como base de dados o MEDLINE (National Library of Medicine), abrangendo o período de 1980 a 2006. As palavras-chave utilizadas foram arachnoid cysts e intracranial cysts. Também realizamos pesquisa manual em jornais e revistas médicas. Artigos com dados clínicos incompletos não foram incluídos no trabalho. Conclusões: Embora haja um consenso sobre a intervenção cirúrgica para os casos sintomáticos, a abordagem ideal ainda é controversa.
Lesão penetrante do crânio pela via transnasal: Relato de caso
Authors: Vieira de Faria José Weber , Alarcão Cariso Carlos Uderson de , Diniz Daniel Andrade , Xavier Erick Menezes , Fonseca Marra Júlio César da , Oliveira Lawal Natássia de
Published: January 2018

Lesões penetrantes no crânio são incomuns pela via transnasal e geralmente ocorrem como resultado de violência, acidentes de trabalho, de trânsito, ou por um evento casual. Este relato trata de introdução acidental de barra de metal, por uma das narinas, atravessando os planos da base do crânio e se alojando no cérebro de uma criança do sexo masculino de 4 anos de idade. Esta apresentava cefaléia, epistaxe e alteração visual. A radiografia e a tomografia computadorizada demonstraram o corpo estranho atingindo a região da sela túrcica à esquerda. Na arteriografia digital cerebral observou-se que a barra atingia a artéria carótida, em sua bifurcação e região de artéria cerebral média. Foi feita craniotomia pterional esquerda para retirada da barra com visualização direta. Encontrou-se lesão superficial da artéria carótida e da artéria oftálmica. Realizou-se contenção do sangramento. O paciente evoluiu no pós-operatório imediato com edema cerebral frontal unilateral, hipertensão intracraniana e fístula liquórica. Com um ano de evolução apresentava-se apenas com déficit visual. Esse caso chama a atenção por sua raridade e por demonstrar a importância da craniotomia e da microcirurgia no controle da hemorragia.
Hematoma intradural espontâneo do canal espinal: Relato de caso
Authors: de Holanda Luciano Ferreira , Holanda Rafael Rodrigues , Silva Filho Amauri Pereira da , Leão Segundo José da Costa , Holanda Vanessa Milanezi , Araújo Pereira Benedito Jamilson , Araújo Júnior Dorgival José de
Published: January 2018

Um caso de hematoma na intradural espinal espontâneo ao nível de T11-12, simulando um quadro de tumor, é relatado. O diagnóstico de processo expansivo intradural extramedular foi feito por meio de ressonância magnética. O exame histopatológico confirmou tratar-se de hematoma organizado. Hematomas espinais espontâneos são raros, e os casos descritos referem-se a hematomas extradurais. Não encontramos na literatura pesquisada hematoma intradural espinal espontâneo.
Hemangioma sacral com compressão radicular: Relato de caso
Authors: de Campos Marcelo Ferraz , Braga Luiz Carlos , Ribeiro André Tosta , Serpa Vidal Manoel Carioca , Silva Fernandes Silvio Marcelo , da Silva Marcelo Neri
Published: January 2018

Hemangiomas da coluna vertebral, considerados tumores benignos, são entidades comuns e raramente apresentam-se com sintomatologia neurológica. Neste relato apresentamos um caso de hemangioma sacral com compressão radicular de S1 (hipoestesia e dor).
Fisiopatologia cirúrgica do hematoma putaminal
Authors: Stávale Joaquim Marcos Augusto , Patriota Gustavo Cartaxo , Bianco André de Macedo
Published: January 2018

Os autores descrevem a fisiopatologia da hipertensão intracraniana relacionada aos hematomas putaminais espontâneos e a função da cirurgia no tratamento. O conhecimento da fisiopatologia desmistifica o resultado de muitas publicações prévias e torna óbvia a necessidade da operação nos casos em que se opta por tratar o paciente nos quais há hipertensão intracraniana.
Transoral needle procedures for upper cervical spine and clival lesions: technical note and indications
Authors: Marenco Horacio Armando , Joaquim Andrei Fernandes , Daniel Zullo João Flávio , Mudo Marcelo Luis
Published: January 2018

Transoral needle procedures are minimally invasive techniques derived from the transoral (or transoropharyngeal) approach to the upper cervical spine and clival region. They are indicated for diagnostic procedures and vertebroplasty. These techniques are appropriated to access midline pathologies from the lower clivus to the C2-C3 disk. This article describes in a step by step manner, the technique and indications for needle biopsy and vertebroplasty in this region, discussing technical nuances.
Tumor de células gigantes na coluna torácica: relato de caso
Authors: Kanitz Wilson Baldino , Rodighiero Maiara Piccoli , Pydd Alberto Arais , Pasa Marcelo
Published: January 2018

Objetivo: Relatar e discutir o caso de um paciente com tumor de células gigantes da nona vértebra torácica com evolução peculiar. Relato do caso: Paciente com dor torácica radicular, detectada lesão na nona vértebra torácica, foi operado e recebeu diagnóstico anatomopatológico de tumor de células gigantes (TCG). Apresentou três recorrências locais, sendo a primeira manejada com reintervenção cirúrgica em dois tempos, na segunda também foi realizada reintervenção cirúrgica, porém com fenolização do sítio cirúrgico, preenchimento com metilmetacrilato e radioterapia pós-operatória. Apresentou semeadura de tumor retroesternal, o qual foi ressecado cirurgicamente, não tendo sido realizada terapia complementar. Uma terceira recorrência foi detectada durante procedimento de correção de falência da artrodese posterior, sendo realizada ressecção da lesão e quimioterapia pós-operatória. Durante o tratamento, desenvolveu imunossupressão e evoluiu para óbito em decorrência de suas complicações. Conclusão: O TCG acometendo a coluna torácica é pouco frequente. Trata-se de uma lesão benigna, agressiva localmente e com comportamento incerto. A ressecção cirúrgica com margens amplas é o tratamento padrão-ouro, porém nem sempre factível, em decorrência da localização da lesão.
Paraplegia espástica causada por cisticercose intramedular: apresentação de caso e breve revisão bibliográfica
Authors: de Holanda Luciano Ferreira , Araújo Pereira Benedito Jamilson , Holanda Rafael Rodrigues , Silva Filho Amauri Pereira da , Leão Segundo José da Costa , Oliveira Eugênio Pierre Vansant , Holanda Gabriela Nascimento
Published: January 2018

Relato de cisticercose intramedular em homem de 42 anos que há seis anos sentia parestesias em ambas as pernas, que evoluíram para ausência de sensação dolorosa, por fim paraparesia espástica dos membros inferiores. Ao exame físico, verificaram-se sinal de Babinski bilateral, espasticidade dos membros inferiores e déficit de sensibilidade abaixo de T7. Ressonância nuclear magnética mostrou uma lesão expansiva ao nível de T5. Durante a exérese do processo, constatou-se que se tratava de cisticercose, em sua forma tumoral intramedular. Após a retirada, o mesmo evoluiu de maneira satisfatória, porém sem regressões dos sintomas.
Estimulação encefálica profunda – Uma atualização
Authors: Krueger Eddy , Holguin Wilson Edwing Martin , Nohama Percy
Published: January 2018

A aplicação de estímulos elétricos nas regiões profundas do cérebro é definida como estimulação encefálica profunda (EEP). A EEP pode ser aplicada em patologias motoras e psicológicas, reduzindo ou tornando desnecessária a administração de medicação complementar. O objetivo deste artigo é mostrar uma atualização pertinente à EEP, baseando-se principalmente em artigos do último triênio. Foram selecionados artigos das bases de pesquisa Wiley Online Library (3), ScienceDirect (8), SciELO (1), BioMed Central (1), Google acadêmico (17) e livros (7), totalizando 37 referências selecionadas, das quais 15 artigos foram publicados no ano de 2010 e três, publicados em 2011. Dentre os parâmetros estimulatórios mais empregados durante o triênio 2009 a 2011, destacam-se: amplitude de 1 a 10 V; corrente entre 50 e 300 μA; frequência de 130 a 185 Hz e período ativo do pulso entre 60 e 220 μs. A EEP mostra-se como recurso viável para tratamento de patologias que apresentam distúrbios de movimento, como doença de Parkinson, distonias e mioclonias. Além disso, a EEP é eficiente para o tratamento de distúrbios psicológicos/neurológicos como depressão, epilepsia e cefaleia e possui forte incentivo a pesquisas que tenham aplicações diferenciadas, como o tratamento de viciados em drogas.
Diffuse pseudotumoral cerebral Schistosomiasis mansoni: a new form of presentation
Authors: Vale Thiago Cardoso , Oliveira Marcelo Magaldi , de Sousa-Pereira Sílvio Roberto , Lambertucci José Roberto , Silva Gusmão Sebastião Nataniel
Published: January 2018

We describe two cases of cerebral schistosomiasis mansoni with multiple pseudotumoral lesions diagnosed by stereotactic brain biopsy. Both patients presented with seizures and one with left visual impairment. Imaging techniques revealed multiple brain lesions involving cerebral parenchyma, pons, cerebellum and thalamus. Brain histopathologic specimens of the patients showed multiple schistosomal granulomas in distinct evolutive phases. All patients presented good clinical response to treatment and reversion of the brain lesions. This new form of neuroschistosomiasis must be considered by those who work in the endemic area for Schistosoma mansoni.
Biological markers and severe head trauma. Where are we?
Authors: Welling Leonardo Christiaan , Paula Guirado Vinicius Monteiro , Costa Glauce Damásio , Figueiredo Eberval Gadelha , de Andrade Almir Ferreira , Teixeira Manoel Jacobsen
Published: January 2018

Traumatic brain injury (TBI) constitutes a major health and socioeconomic problem throughout the world. Despite the significant advances in neuroradiology and cerebral monitoring it is still difficult to measure the degree of primary brain injury and continuing secondary damage with Glasgow Coma Scale score or the initial computed tomography. Predicting prognosis of TBI patients in early stages has a vital importance and is difficult in some instances. The present review shows that there has been an increasing interest in biochemical markers for traumatic brain injury during the last years. The potential correlation of markers with injury and outcome measures in severe head injury is promising.
Astrocitoma pilomixoide de fossa posterior em criança: relato de caso
Authors: Lima Sousa Eduardo Nogueira , Pinheiro Marques João Antonio , Spinola Almeida Túlio Cícero , Honcy Iuri Araujo , de Menezes Aguiar Gilnard Caminha , Pontes Rafael Figueirêdo , Mota de Melo Carlos Vinícius
Published: January 2018

Descrever um caso de astrocitoma pilomixoide, um tumor do sistema nervoso central raro, descrito e classificado recentemente diante de sintomatologia e achados pouco específicos. Análise e descrição de um caso de astrocitoma pilomixoide submetido a tratamento cirúrgico no Instituto José Frota, Fortaleza, Ceará. Paciente evolui com regressão importante dos sintomas, sem indícios de recidiva tumoral. O diagnóstico e a classificação correta dos tumores cerebrais são de extrema importância clínica, pois modificam de forma impactante o prognóstico, assim como a abordagem terapêutica.
Fratura do processo transverso da vértebra lombar: valor diagnóstico
Authors: Pereira Carlos Umberto , Silva Junior Eldon Bezerra , Andrade Santos Liani Patrícia
Published: January 2018

As fraturas isoladas do processo transverso são consideradas lesões menores. Em geral, são causadas por trauma direto ou avulsão resultante da contração muscular. Radiografias simples são pouco sensíveis para a detecção dessas fraturas, portanto a verdadeira frequência dessas fraturas pode ser subestimada. Com o advento da tomografia computadorizada (TC) helicoidal, tem aumentado à frequência dessa lesão. GS, 53 anos, masculino. Vítima de sequestro e colocado no porta-malas do carro. No setor de emergência, apresentou queixa de dores generalizadas, mais intensa na região lombar. Exame neurológico: normal. Rx simples de abdome: normal. Tomografia da coluna lombar: fratura do processo transverso esquerdo de L5. Tratamento conservador, com evolução satisfatória. Apesar de ser considerada um traumatismo leve, a fratura do processo transverso da vértebra lombar ocorre como resultado de forças intensas. Geralmente, está associado com lesão de vísceras abdominais ou geniturinárias. Seu diagnóstico tem sido feito por meio de exame de TC helicoidal. Seu tratamento inicial é conservador. Fraturas do processo transverso das vértebras lombares cada vez mais têm sido diagnosticadas. Existe associação com lesões de vísceras abdominais e geniturinárias. O tratamento inicial é conservador e cursa com bom prognóstico.
Lesões traumáticas de nervos cranianos
Authors: Cannoni Luiz Fernando , Haddad Luciano , Saade Nelson , Teixeira da Costa Márcio Alexandre , Esteves Veiga José Carlos
Published: January 2018

Objetivo: Documentar a incidência de lesões traumáticas de nervos cranianos, assim como a etiologia traumática, correlacionar as lesões dos nervos cranianos com achados radiológicos (lesões cranianas e intracranianas) e estudar lesões múltiplas de nervos cranianos. Métodos: Cinquenta e quatro pacientes admitidos no Serviço de Emergência da Santa Casa de Misericórdia de São Paulo com lesões traumáticas nos diferentes nervos cranianos foram incluídos. Todos os pacientes foram submetidos à radiografia simples de crânio, tomografia computadorizada e, quando indicada, ressonância magnética de encéfalo. Os pacientes foram divididos em três grupos de acordo com o escore da Escala de Coma de Glasgow (ECG) em: trauma leve (ECG de 13 a 15), moderado (ECG de 9 a 12) e grave (ECG de 3 a 8). Resultados: Os nervos cranianos mais afetados de forma isolada foram olfatório, facial e oculomotor. O atropelamento foi a causa mais comum de lesão de nervos cranianos de forma isolada, assim como nas lesões de múltiplos nervos. Contusões e hematomas extradurais foram as lesões intracranianas mais frequentes. Conclusão: Neuropatia craniana de etiologia traumática ocorre frequentemente e deve ser pesquisada à admissão do paciente, pois pode exigir descompressão de estruturas nervosas importantes como nervo óptico e facial.
A síndrome de Stevens-Johnson em pacientes neurocirúrgicos
Authors: D’Avila Rui , Figueiredo Eberval Gadelha , Teixeira Manoel Jacobsen
Published: January 2018

Objetivo: Realizar uma revisão sobre os riscos aos quais pacientes neurocirúrgicos estão submetidos em relação à síndrome de Stevens-Johnson (SSJ). Métodos: Utilizaram-se as bases de dados Cochrane, Medline, Bireme/Lilacs, buscando-se artigos dos últimos seis anos que abordassem situações clínicas relacionadas à SSJ em pacientes neurocirúrgicos. Os trabalhos foram avaliados quanto a resultados, relevância clínica, desenho do estudo e nível de evidência. Resultados: A carbamazepina é comumente implicada, sendo o HLA-B*1502 fator de risco para tal afecção na população chinesa Han e associado à mortalidade. Outras populações foram testadas para tal HLA, não se encontrando resultados homogêneos. Ácido valproico, lamotrigina, fenitoína, fenobarbital e oxcarbazepina também estão relacionados. O EMPACT (Erythema Multiforme associated with Phenytoin And Cranial radiation Therapy) é observado em pacientes portadores de malignidades intracranianas submetidos à radiação, que iniciam fenitoína para prevenção ou tratamento de crises convulsivas. Em até 73% dos casos, esse eritema pode evoluir para SSJ. Conclusão: Pacientes neurocirúrgicos são frequentemente expostos a fatores causais de SSJ. Seu manejo consiste em suporte e suspensão da terapia envolvida. Procedimentos terapêuticos devem ser utilizados com cautela, levando-se em consideração sua real necessidade, HLA suscetíveis, idade e comorbidades.
Análise morfométrica do acesso temporal lateral para amígdalo-hipocampectomia baseada em imagens de ressonância e tomografia
Authors: Olmo Tais Siqueira , Castro Flores Juan Antonio , Roelke Carlos Eduardo , Farias e Melo Homero José de
Published: January 2018

Objetivo: Análise morfométrica do acesso lateral para amígdalo-hipocampectomia, com ênfase na localização do “ponto hipocampal”. Métodos: Análise de 22 exames de ressonância magnética (RM) e tomografia computadorizada (TC) com o sistema AIMNAV (Micromar Inst), para determinação do ponto hipocampal, e o Advantage Workstation AW 4.3 (GE Medical Systems), para mensuração do corredor cirúrgico. Resultados: O “ponto hipocampal” se localiza a 31,9 mm do canal auditivo. Conclusão: Os dados morfométricos obtidos neste estudo têm utilidade prática na tática da abordagem lateral para amígdalo-hipocampectomia.
Parkinsonismo induzido por trazodona durante o tratamento de hérnia discal lombar: relato de caso
Authors: Almeida Vasques Marco de Agassiz
Published: January 2018

A utilização de medicações psicoativas vem crescendo ao longo dos anos, sendo essencial o conhecimento de seus efeitos colaterais e interações medicamentosas. O desenvolvimento de distúrbios de movimento associados ao uso dessas substâncias é uma situação bastante desconfortável para o paciente, sendo essencial o diagnóstico adequado mediante forte suspeição. Relata-se o caso de um paciente que desenvolveu sintomas de parkinsonismo durante tratamento de hérnia discal lombar na vigência do uso de trazodona. É dada ênfase aos mecanismos de produção desse fenômeno e à sua condução clínica.
Three years with a knife stuck in the brain
Authors: Dias Filho Luiz Coutinho , Caetano de Barros Alex , Félix da Mota Marina
Published: January 2018

Cranial stabbing injuries penetrating the brain are not commonly encountered. The cases in which the knife is retained constitute a challenge to the neurosurgeon. When a long-term permanence occurs, the reaction to the presence of the foreign body causes adherence to the nervous tissue and a higher risk is expected from the removal. The procedure should be performed with meticulous dissection and minimal oscillation of the blade thus avoiding damage to the adjacent structures. We report a case of a man who remained three years with a knife blade deeply lodged in the brain. After obtaining informed consent, the blade was removed; there were no postoperative complications. To our knowledge, this is the first case in which, after years of permanence, a knife blade was removed from the brain through a craniotomy.
Fraturas osteoporóticas da coluna vertebral
Authors: Matos Queiroz João Welberthon , Alves de Assis Pereira Paula Camila , Figueiredo Eberval Gadelha
Published: January 2018

As fraturas vertebrais são comuns em idosos e em mulheres no período pós-menopausa. Tais fraturas podem ter como etiologia principal a osteoporose ou ser decorrentes de trauma, infecções ou neoplasia. A osteoporose é caracterizada por diminuição da massa e modificação da microarquitetura óssea, sendo a manifestação mais comum a fratura patológica. Apresenta como manifestação clínica dor, diminuição da altura e desalinhamento da coluna vertebral, sintomas neurológicos, bem como alteração na autoestima e problemas sociais. O diagnóstico de osteoporose é dado por meio da realização de densitometria óssea, sendo esse o padrão-ouro, podendo-se lançar mão de outros métodos de imagem em situações específicas. O tratamento da osteoporose inclui métodos para a prevenção de fraturas, tais como reposição de cálcio e vitamina D, uso de bifosfonados, paratormônio e reposição hormonal. Quando em vigência de fratura, a conduta preferida ainda é a abordagem não cirúrgica, sendo feita por meio de imobilização, uso de analgésicos, fisioterapia e reabilitação motora. Quando em vigência de déficit neurológico, deformidade severa ou ausência de resposta ao tratamento conservador, está indicada a abordagem cirúrgica.
Coagulação endoscópica do plexo coroide no tratamento primário da hidranencefalia e da hidrocefalia extrema
Authors: do Amaral Leandro Custódio , Lemos Sérgio , Eduardo Thales , Rodrigues Pedrosa Hugo Abi-Saber , Lemos Sandro Pedroso , Souza Seabra Liz Custódio
Published: January 2018

Objetivos: Descrever a técnica de coagulação neuroendoscópica do plexo coroide e divulgá-la como opção de tratamento primário da hidranencefalia e da hidrocefalia extrema. Mostrar a casuística de coagulação endoscópica de plexo coroide do Serviço de Neurocirurgia do Hospital da Baleia em Belo Horizonte, MG, Brasil. Métodos: Imagens tomográficas foram avaliadas por um neurocirurgião, sendo selecionadas crianças portadoras de hidranencefalia e hidrocefalia extrema com cavidade ventricular única. Os pacientes foram acompanhados por até três anos no pós-operatório. Resultados: Foram tratadas seis crianças com hidranencefalia e seis com hidrocefalia extrema. Um paciente faleceu na primeira semana de pós-operatório em função de choque hipovolêmico e hipernatremia graves e outro cursou com aumento progressivo do perímetro cefálico e necessidade de derivação ventriculoperitoneal. Um terceiro paciente apresentou óbito tardio não relacionado à cirurgia endoscópica. Os demais apresentaram evolução adequada no pós-operatório. Conclusão: A coagulação endoscópica do plexo coroide mostrou-se alternativa eficaz no tratamento da hidranencefalia e da hidrocefalia extrema.
Current management of brain metastases
Authors: Hamamoto Filho Pedro Tadao , Machado Vitor César , Romero Flávio Ramalho , Ducati Luis Gustavo , Zanini Marco Antônio , Gabarra Roberto Colichio
Published: January 2018

Brain metastases are the most common tumors within the central nervous system. Recent advances on diagnosis and treatment modalities have allowed for longer survival. In this paper we review the indication of each modality of treatment: surgery, whole brain radiotherapy and stereotactic radiosurgery, as also recent advances on the knowledge of brain metastases biology that may improve the use of medical treatment and chemotherapy.
Carcinoma de plexo coroide: relato de caso e revisão de literatura
Authors: Lins Catarina Couras , da Cruz Adry Rodrigo Antonio Rocha , de Avellar Leonardo Miranda , Araújo Julia Ribeiro , Mello Brandão Marcio Cesar de
Published: January 2018

Tumores do plexo coroide são tumores raros de origem neuroectodérmica, Correspondem a 0,4% a 0,6% de todos os tumores cerebrais, com incidência anual de 0,3 caso por milhão. Em sua maioria, são tumores benignos, raramente se apresentando na forma maligna. Os locais mais comumente relatados são os ventrículos. Relato de caso: Trata-se de carcinoma de plexo coroide em criança de 6 anos de idade que iniciou quadro com cefaleia, paresia do oculomotor, evoluindo com distúrbio de marcha. Foi submetida à biopsia, com confirmação histopatológica do carcinoma de plexo coroide. Esse paciente foi submetido à cirurgia, evolui bem com recuperação quase total no pós-cirúrgico imediato.
Effektivität und Sicherheit von getunnelten pleuralen Dauerkathetern
Authors: Lücke Eva , Steffen Uwe , Riedel Sandra , Schreiber Jens
Published: January 2018

Bei symptomatischen malignen Pleuraergüssen sollte ein therapeutisches Verfahren gewählt werden, welches die Dyspnoe und die konsekutive Einschränkung der Lebensqualität in der meist palliativen Situation verbessert. Ein dauerhaft implantierter Pleurakatheter (indwelling pleural catheter – IPC) ist eine der aktuell zur Verfügung stehenden Methoden, deren Bedeutung in den letzten Jahren zugenommen hat. Effektivität und Sicherheit dieser Methode sind unter realen klinischen Bedingungen außerhalb von Studien noch unzureichend geklärt. Es wurden die Daten von 94 Patienten, die aus klinischer Indikation mit einem IPC versorgt wurden, retrospektiv analysiert. Ausgewertet wurden neben Sicherheit und Effektivität die Patientencharakteristika, peri- und postinterventionelle Komplikationen, wie Infektionen oder das Auftreten eines Pneumothorax, und der längerfristige Verlauf mit dem Schwerpunkt der Frage, ob eine Pleurodese eingetreten ist. Insgesamt 89,5% (n = 85) der Patienten erhielten den IPC aufgrund eines rezidivierenden Pleuraergusses bei maligner Grunderkrankung. Die mittlere Krankenhausverweildauer nach Implantation lag für diejenigen Patienten, die nicht noch im Krankenhaus an ihrer infausten Erkrankung verstorben sind, bei 3,29 Tagen. Bei 21,2% (n = 20) der Patienten kam es zu einer Pleurodese. Methodenbedingte Komplikationen traten bei 33,7% (n = 32) der Patienten auf, lediglich bei 8 Patienten gab es jedoch weiteren Handlungsbedarf. Spätkomplikationen sind bei 9 Patienten aufgetreten. Die mittlere Überlebenszeit nach Implantation lag bei durchschnittlich 88,72 Tagen. Zusammenfassend zeigen die Daten, dass der IPC eine technisch einfach durchführbare, minimalinvasive Alternative zu rezidivierenden Punktionen oder anderen Pleurodeseverfahren ist. Ein wesentlicher Vorteil ist die ambulante Versorgungsmöglichkeit.
Internal photoemission for photovoltaic using p-type Schottky barrier: Band structure dependence and theoretical efficiency limits
Authors: Shih Ko-Han , Chang Yin-Jung
Published: January 2018

Solar energy conversion via internal photoemission (IPE) across a planar p-type Schottky junction is quantified for aluminum (Al) and copper (Cu) in the framework of direct transitions with non-constant matrix elements. Transition probabilities and k-resolved group velocities are obtained based on pseudo-wavefunction expansions and realistic band structures using the pseudopotential method. The k-resolved number of direct transitions, hole photocurrent density, quantum yield (QY), and the power conversion efficiency (PCE) under AM1.5G solar irradiance are subsequently calculated and analyzed. For Al, the parabolic and “parallel-band” effect along the U-W-K path significantly enhances the transition rate with final energies of holes mainly within 1.41 eV below the Fermi energy. For Cu, d-state hot holes mostly generated near the upper edge of 3d bands dominate the hole photocurrent and are weekly (strongly) dependent on the barrier height (metal film thickness). Hot holes produced in the 4s band behave just oppositely to their d-state counterparts. Non-constant matrix elements are shown to be necessary for calculations of transitions due to time-harmonic perturbation in Cu. Compared with Cu, Al-based IPE in p-type Schottky shows the highest PCE (QY) up to about 0.2673% (5.2410%) at ΦB = 0.95 eV (0.5 eV) and a film thickness of 11 nm (20 nm). It is predicted that metals with relatively dispersionless d bands (such as Cu) in most cases do not outperform metals with photon-accessible parallel bands (such as Al) in photon energy conversion using a planar p-type Schottky junction.
Numerical simulation of turbulence and terahertz magnetosonic waves generation in collisionless plasmas
Authors: Kumar Narender , Singh Ram Kishor , Sharma Swati , Uma R. , Sharma R. P.
Published: January 2018

This paper presents numerical simulations of laser beam (x-mode) coupling with a magnetosonic wave (MSW) in a collisionless plasma. The coupling arises through ponderomotive non-linearity. The pump beam has been perturbed by a periodic perturbation that leads to the nonlinear evolution of the laser beam. It is observed that the frequency spectra of the MSW have peaks at terahertz frequencies. The simulation results show quite complex localized structures that grow with time. The ensemble averaged power spectrum has also been studied which indicates that the spectral index follows an approximate scaling of the order of ∼k−2.1 at large scales and scaling of the order of ∼k−3.6 at smaller scales. The results indicate considerable randomness in the spatial structure of the magnetic field profile which gives sufficient indication of turbulence.
Toroidal Alfvén eigenmode driven by energetic electrons during high-power auxiliary heating on HL-2A
Authors: Yu L. M. , Chen W. , Ding X. T. , Ji X. Q. , Shi Z. B. , Yuan B. S. , Ma R. R. , Chen S. Y. , Li Y. G. , Li J. X. , Song S. D. , Yang Z. C. , Shi P. W. , Jiang M. , Zhang Y. P. , Huang M. , Li W. , Feng B. B. , Zhou Y. , Ma Rui , Song X. M. , Yu D. L. , Cao J. Y. , Lu B. , Dong J. Q. , Liu Yi. , Zhong W. L. , Yan L. W. , Yang Q. W. , Xu M. , Duan X. R. , Liu Y.
Published: January 2018

Toroidal Alfvén eigenmodes (TAEs) driven by energetic electrons have been observed first during high-power electron cyclotron resonant heating and neutral beam injection on HL-2A. The mode frequencies are in a wide range of 170–370  kHz and are proportional to the Alfvén velocity. The toroidal mode number is confirmed as n = 4. According to the calculated results from the Alfvén mode code, there exists a core localized TAE mode with poloidal mode numbers m = 4 and m = 5 at ρ∼0.35, and the calculated frequency is close to the experimental observation. Besides, the radial mode structures are obtained. Therefore, the modes are identified as TAEs. The TAEs propagate in the electron diamagnetic drift direction poloidally. The energy distribution of energetic electrons is obtained by the relativistic shift-down of the 3-rd harmonic frequency effect of the rough non-thermal spectrum from electron cyclotron emission. Therefore, TAEs should be driven by the energetic electrons with energy in the range of 150–230 keV.
Approximating Matsubara dynamics using the planetary model: Tests on liquid water and ice
Authors: Willatt Michael J. , Ceriotti Michele , Althorpe Stuart C.
Published: January 2018

Matsubara dynamics is the quantum-Boltzmann-conserving classical dynamics which remains when real-time coherences are taken out of the exact quantum Liouvillian [T. J. H. Hele et al., J. Chem. Phys. 142, 134103 (2015)]; because of a phase-term, it cannot be used as a practical method without further approximation. Recently, Smith et al. [J. Chem. Phys. 142, 244112 (2015)] developed a “planetary” model dynamics which conserves the Feynman-Kleinert (FK) approximation to the quantum-Boltzmann distribution. Here, we show that for moderately anharmonic potentials, the planetary dynamics gives a good approximation to Matsubara trajectories on the FK potential surface by decoupling the centroid trajectory from the locally harmonic Matsubara fluctuations, which reduce to a single phase-less fluctuation particle (the “planet”). We also show that the FK effective frequency can be approximated by a direct integral over these fluctuations, obviating the need to solve iterative equations. This modification, together with use of thermostatted ring-polymer molecular dynamics, allows us to test the planetary model on water (gas-phase, liquid, and ice) using the q-TIP4P/F potential surface. The “planetary” fluctuations give a poor approximation to the rotational/librational bands in the infrared spectrum, but a good approximation to the bend and stretch bands, where the fluctuation lineshape is found to be motionally narrowed by the vibrations of the centroid.
A numerical study of bubble and spike velocities in shock-driven liquid metals
Authors: Karkhanis V. , Ramaprabhu P. , Cherne F. J. , Hammerberg J. E. , Andrews M. J.
Published: January 2018

We use detailed continuum hydrodynamics and molecular dynamics simulations to investigate the dynamics of ejecta that are initialized with large amplitude perturbations and non-sinusoidal shapes. Insights from the simulations are used to suggest a modified expression for the velocity associated with ejected spike structures, whereas a recently suggested model explains the observed bubble velocities. Specifically, we find the asymptotic bubble velocity prediction given by Mikaelian is in excellent agreement with the simulations, when a nonlinear correction for finite amplitudes is used in that model. In contrast, existing models can overpredict observed spike velocities if they do not include the modification of the initial spike growth rates due to nonlinearities. Instead, we find that when potential flow models are corrected with a suitable nonlinear prefactor, this leads to predictions in close agreement with our simulation data. We also propose a simple empirical expression for the nonlinear correction for spike velocities which is able to reproduce results from our simulations and published experimental and simulation data over a wide range of initial conditions and Mach numbers. We discuss extensions of these models to initial interfaces with arbitrary shapes. In particular, for non-sinusoidal shapes, the bubble and spike velocities are still predicted by these models provided we use an effective wavelength λeff which is the wavelength of an equivalent sinusoid that has the same missing area. The issues of nonlinearity, non-standard shapes and shock Mach number addressed in this work are relevant to recent experimental campaigns involving twice-shocked targets.
Fokker-Planck coefficients for a magnetized ion-electron plasma
Authors: Cohen S. , Sarid E. , Gedalin M.
Published: January 2018

The Fokker-Planck coefficients are developed for an ion-electron plasma in an ambient uniform magnetic field. The calculation is based on the binary collision model where a single encounter between an ion and an electron is first considered. The collision is taken as a perturbation to the free helical motion of the two particles involved, and the terms are kept up to the second order. The collision process is reformulated in terms of the changes of the perpendicular and parallel speeds and gyrophase shift. This new approach allows us to properly take into account the persisting helical motion in the magnetic field when the collisional interaction ceases.
Reentry blackout prediction for atmospheric reentry demonstrator mission considering uncertainty in chemical reaction rate model
Authors: Jung Minseok , Kihara Hisashi , Abe Ken-ichi , Takahashi Yusuke
Published: January 2018

A numerical simulation model of plasma flows and electromagnetic waves around a vehicle was developed to predict a radio frequency blackout. Plasma flows in the shock layer and the wake region were calculated using a computational fluid dynamics technique with a three-dimensional model. A finite-catalytic wall condition known to affect plasma properties, such as the number density of electrons, was considered for accurate prediction. A parametric study was performed to investigate the effect of uncertainty in the chemical reaction rate model on evaluating a radio frequency blackout. The behavior of electromagnetic waves in plasma was investigated using a frequency-dependent finite-difference time-domain method. Numerical simulations of reentry blackout were performed for the Atmospheric Reentry Demonstrator mission at various altitudes. The plasma flows and the complex movement of electromagnetic waves around the Atmospheric Reentry Demonstrator vehicle were clarified. The predicted signal loss profile was then directly compared with the experimental flight data to validate the present models. The numerical results generally reproduced the trends over altitudes of the measured data. It is suggested that the present simulation model can be used to investigate the radio frequency blackout and signal loss of electromagnetic waves in the communication of a reentry vehicle. It was confirmed that high associative ionization reaction rates contribute to reducing the electron density in the wake region and radio frequency blackout. It is suggested that the accuracy of predicting the signal loss improved when considering the uncertainty in the chemical reaction model for associative ionizations.
A theoretical study on tunneling based biosensor having a redox-active monolayer using physics based simulation
Authors: Kim Kyoung Yeon , Lee Won Cheol , Yun Jun Yeon , Lee Youngeun , Choi Seoungwook , Jin Seonghoon , Park Young June
Published: January 2018

We developed a numerical simulator to model the operation of a tunneling based biosensor which has a redox-active monolayer. The simulator takes a realistic device structure as a simulation domain, and it employs the drift-diffusion equation for ion transport, the non-equilibrium Green's function formalism for electron tunneling, and the Ramo-Shockley theorem for accurate calculation of non-faradaic current. We also accounted for the buffer reaction and the immobilized peptide layer. For efficient transient simulation, the implicit time integration scheme is employed where the solution at each time step is obtained from the coupled Newton-Raphson method. As an application, we studied the operation of a recently fabricated reference-electrode free biosensor in various bias conditions and confirmed the effect of buffer reaction and the current flowing mechanism. Using the simulator, we also found a strategy to maximize the sensitivity of the tunneling based sensor.
Prototype of the novel CAMEA concept—A backend for neutron spectrometers
Authors: Markó Márton , Groitl Felix , Birk Jonas Okkels , Freeman Paul Gregory , Lefmann Kim , Christensen Niels Bech , Niedermayer Christof , Jurányi Fanni , Lass Jakob , Hansen Allan , Rønnow Henrik M.
Published: January 2018

The continuous angle multiple energy analysis concept is a backend for both time-of-flight and analyzer-based neutron spectrometers optimized for neutron spectroscopy with highly efficient mapping in the horizontal scattering plane. The design employs a series of several upward scattering analyzer arcs placed behind each other, which are set to different final energies allowing a wide angular coverage with multiple energies recorded simultaneously. For validation of the concept and the model calculations, a prototype was installed at the Swiss neutron source SINQ, Paul Scherrer Institut. The design of the prototype, alignment and calibration procedures, experimental results of background measurements, and proof-of-concept inelastic measurements on LiHoF4 and h-YMnO3 are presented here.
Diets of native and introduced apex predators in Hawai'i
Authors: Mostello Carolyn S. , Conant Sheila
Published: January 2018

We report here on the diets of four apex predators in Hawai‘i: the native pueo or Hawaiian short-eared owl (Asio flammeus sandwichensis) and three introduced species, the barn owl (Tyto alba pratincola), the feral cat (Felis catus) and the small Indian mongoose (Herpestes javanicus). To better understand dietary relationships between these predators, we studied diet, focusing on areas where they occur together. We collected disgorged owl pellets, and cat and mongoose faecal scats from eight areas located on five of the main Hawaiian Islands and identified prey items to the lowest possible taxonomic level. All species consumed rodents, birds, and arthropods, and the mammal species also included plants in their diets. The two owl species and the cat preyed primarily on rodents, whereas small cockroaches predominated in the diet of the mongoose. Diets of the owl species and the cat, but not the mongoose, varied significantly between areas. Dietary overlap was highest between the pueo and the barn owl and lowest between the owl species and the mongoose. Although barn owls took more rats than pueo, there was no evidence that the two owl species partitioned house mouse prey by size. On islands where there are no mongoose, both owls took a greater proportion of large arthropods in their diet, suggesting that mongoose reduced the abundance of the arthropod species that owls commonly took. There was no significant difference in pueo diets before and after introduction of the barn owl.
Migrant rap in the periphery
Authors: Leppänen Sirpa , Westinen Elina
Published: January 2018

Focusing on a YouTube performance by an emergent Finnish Somali rapper and the audience responses it has generated, this paper looks at ways in which rap music engages with the issue of belonging. Drawing on recent theorizations of belonging as a multi-dimensional, contingent and fluid process, along with sociolinguistic work on globalization and superdiversity, Finnish hip hop culture and popular cultural practices in social media, the paper investigates how belonging is performatively and multi-semiotically interrogated in its online context. It shows how rap can serve as a significant site and channel for new voices in turbulent social settings characterized by rapid social change and complex diversity, as well as provide affordances for critical responses to and interventions into xenophobic and nationalist debates and discourses of belonging.
Negotiating sustainability across scales
Authors: Singh Jaspal Naveel , Bartlett Tom
Published: January 2018

This paper represents voices of community organizers on Barra, a small island in the Outer Hebrides, Scotland. Although, arguably Barra is geographically and socio-politically located in the peripheries of Scotland, Britain and Europe, the island has been a center of North Atlantic maritime trade networks for centuries. In the current phase of Europeanization and devolution of powers within the United Kingdom, the community finds itself in the position of having to attend to multiple scales: the European Union, the United Kingdom, Scotland and the island itself with its various interest groups. We draw on ethnographic interviews with community organizers that were elicited for the research project Sustainability on the Edge to illustrate some political challenges and possibilities of such scalar realities. We show that community organizers construct a voice that emphasises a historical quality of what it means to live on Barra while inflecting this quality with worldly knowledge that enables access to resources from outside the island. Our findings remind us that centers and peripheries are neither fixed categories that could simply be mapped on geographical visualisations nor notions independent of discursive practice.
Multilingualism as utopia
Authors: Stroud Christopher , Williams Quentin
Published: January 2018

The challenge of contemporary South Africa is that of building a (post)nation of postracial equity in a fragmented world of a globalized ethical, economic and ecological meltdown. In this paper, we seek to explore the idea of multilingualism as a technology in the conceptualization of alternative, competing futures. We suggest that multilingualism is understood in terms of how encounters across difference are mediated and structured linguistically offer a space for interrupting colonial relationships. Furthermore, we argue that multilingualism should be approached as a site where colonial power dynamics of languages and speakers are troubled, and where the potential for new empowering linguistic mediations of the mutualities of our common humanity with different others are worked out.
Upstream analysis of alternative splicing: a review of computational approaches to predict context-dependent splicing factors
Authors: Carazo Fernando , Romero Juan P , Rubio Angel
Published: January 2018

Alternative splicing (AS) has shown to play a pivotal role in the development of diseases, including cancer. Specifically, all the hallmarks of cancer (angiogenesis, cell immortality, avoiding immune system response, etc.) are found to have a counterpart in aberrant splicing of key genes. Identifying the context-specific regulators of splicing provides valuable information to find new biomarkers, as well as to define alternative therapeutic strategies. The computational models to identify these regulators are not trivial and require three conceptual steps: the detection of AS events, the identification of splicing factors that potentially regulate these events and the contextualization of these pieces of information for a specific experiment. In this work, we review the different algorithmic methodologies developed for each of these tasks. Main weaknesses and strengths of the different steps of the pipeline are discussed. Finally, a case study is detailed to help the reader be aware of the potential and limitations of this computational approach.
Designing risk prediction models for ambulatory no-shows across different specialties and clinics
Authors: Ding Xiruo , Gellad Ziad F , Mather Chad , Barth Pamela , Poon Eric G , Newman Mark , Goldstein Benjamin A
Published: January 2018

Objective

As available data increases, so does the opportunity to develop risk scores on more refined patient populations. In this paper we assessed the ability to derive a risk score for a patient no-showing to a clinic visit.

Methods

Using data from 2 264 235 outpatient appointments we assessed the performance of models built across 14 different specialties and 55 clinics. We used regularized logistic regression models to fit and assess models built on the health system, specialty, and clinic levels. We evaluated fits based on their discrimination and calibration.

Results

Overall, the results suggest that a relatively robust risk score for patient no-shows could be derived with an average C-statistic of 0.83 across clinic level models and strong calibration. Moreover, the clinic specific models, even with lower training set sizes, often performed better than the more general models. Examination of the individual models showed that risk factors had different degrees of predictability across the different specialties. Implementation of optimal modeling strategies would lead to capturing an additional 4819 no-shows per-year.

Conclusion

Overall, this work highlights both the opportunity for and the importance of leveraging the available electronic health record data to develop more refined risk models.
Protoplanetary disc response to distant tidal encounters in stellar clusters
Authors: Winter A J , Clarke C J , Rosotti G , Booth R A
Published: January 2018

The majority of stars form in a clustered environment. This has an impact on the evolution of surrounding protoplanetary discs (PPDs) due to either photoevaporation or tidal truncation. Consequently, the development of planets depends on formation environment. Here, we present the first thorough investigation of tidally induced angular momentum loss in PPDs in the distant regime, partly motivated by claims in the literature for the importance of distant encounters in disc evolution. We employ both theoretical predictions and dynamical/hydrodynamical simulations in 2D and 3D. Our theoretical analysis is based on that of Ostriker (1994) and leads us to conclude that in the limit that the closest approach distance xmin ≫ r, the radius of a particle ring, the fractional change in angular momentum scales as (xmin/r)−5. This asymptotic limit ensures that the cumulative effect of distant encounters is minor in terms of its influence on disc evolution. The angular momentum transfer is dominated by the m = 2 Lindblad resonance for closer encounters and by the m = 1, ω = 0 Lindblad resonance at large xmin/r. We contextualize these results by comparing expected angular momentum loss for the outer edge of a PPD due to distant and close encounters. Contrary to the suggestions of previous works, we do not find that distant encounters contribute significantly to angular momentum loss in PPDs. We define an upper limit for closest approach distance where interactions are significant as a function of arbitrary host to perturber mass ratio M2/M1.
Military Force Planning and National Security
Authors: Owens Mackubin T.
Published: January 2018

One component of military policy in particular lies at the very crossroads of strategic planning and structural arenas of policy. This is force planning, the interactive, intertemporal art intended to ensure that deficiencies in today’s force structure are being corrected while preparing for a future that may resemble the present or differ from it in unexpected ways. While force planners must think about what the future security environment might look like, what technologies might be available, and how future forces might leverage these emerging technologies to meet the challenges of a future security environment, they must always be cognizant of domestic structural factors. This chapter argues that a force planner must always be guided by a coherent strategic logic. Structural factors can never be eliminated, but a strong strategic rationale can minimize them.