Why does such a successful theory like Quantum Mechanics have so many mysteries? The history of this theory is replete with dubious interpretations and controversies, and yet a knowledge of its predictions, however, contributed to the amazing technological revolution of the last hundred years. In its very beginning Einstein pointed out that there was something missing, due to contradictions with the relativity theory. So, even though Quantum Mechanics explains all the nanoscale physical phenomena, there were many attempts to find a way to “complete” it, e.g. hidden-variable theories. In this paper, we discuss some of those enigmas, with special attention to the concepts of physical reality imposed by quantum mechanics, the role of the observer, prediction limits, a definition of collapse, and how to deal with correlated states (the basic strategy for quantum computers and quantum teleportation). That discussion is carried out within the framework of accepting that there is in fact nothing important missing, rather we are just restricted by the limitations imposed by quantum mechanics. The mysteries are thus explained by a proper interpretation of those limitations, which is achieved by introducing two interpretation rules within the Copenhagen paradigm.

Pode-se escolher um tópico complexo em mecânica quântica e discuti-lo com um número mínimo de equações, e de forma simplificada para que um público com apenas conhecimento básico em física possa entender? Essa foi a pergunta apresentada aos alunos de pós-graduação das disciplinas de um ano de Mecânica Quântica I e II da Universidade Estadual de Campinas (UNICAMP), baseadas no livro “Quantum Mechanics” de J. J. Sakurai e Jim Napolitano. Os primeiros sete autores desse artigo são os alunos de pós-graduação (em ordem alfabética) que aceitaram o desafio. O tópico escolhido foi estados quânticos delocalizados, e será discutido utilizando termos coloquiais como fantasmas quânticos, ações fantasmagóricas, entidades divididas e capa de invisibilidade.

Can you pick a complex subject in quantum mechanics and discuss it with a minimum number of equations, in a simplified form that the general scientific public could understand? This was a question presented to graduate students of the one-year Quantum Mechanics course based on the text book Modern Quantum Mechanics by J. J. Sakurai and Jim Napolitano, at the State University of Campinas (UNICAMP), Brazil. The first seven authors of this paper are graduate students (alphabetical order) that accepted to try it. The chosen subject was “delocalized quantum states”, and it will be discussed using colloquial terms like quantum ghosts, spooky action, splitting beings and invisibility cloak.

A leucoencefalopatia multifocal progressiva (LMP) é uma doença desmielinizante do sistema nervoso central (SNC) causada pela reativação do vírus JC (JCV) em um ambiente de imunossupressão celular. Originalmente, LMP foi descrita em pacientes com infecção avançada pelo HIV, doenças linfoproliferativas e transplantados. No entanto, a utilização generalizada de anti-retrovirais para a infecção pelo HIV e novos imunomoduladores seletivos e imunossupressores, como Rituximab e Natalizumab, modificaram recentemente a epidemiologia, apresentação clínica e prognóstico da LMP. Neste artigo, vamos discutir os novos conceitos sobre LMP, enfatizando a recente modificação na epidemiologia, o impacto de novos tratamentos imunomoduladores na doença, síndrome inflamatória da reconstituição imune, novas estratégias de tratamento e outras doenças relacionadas ao JCV no SNC.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the CNS caused by reactivation of JC virus (JCV) in a setting of cellular immunosuppression. Originally, PML was observed in patients with advanced HIV infection, lymphoproliferative disorders and transplant recipients. However, the widespread use of HIV antiretroviral drugs and the new selective immunomodulatory and immunosuppressive medications, such as Rituximab and Natalizumab, has recently modified the epidemiology, clinical presentation and prognosis of PML. Herein, we discuss the new concepts on PML, emphasizing the recent modification in the epidemiology; the impact of new immunomodulatory treatments in the disease, PML-IRIS (Immune reconstitution inflammatory síndrome), new treatment strategies and other JCV related CNS diseases.

Visando determinar quais aspectos do exame neurológico (EN) seriam essenciais em uma situação específica (paciente com queixa neurológica, mas cuja história sugere ser improvável um problema neurológico), apresentou-se o mesmo questionário utilizado por Moore e Chalk no Canadá a 19 neurologistas do Rio de Janeiro, Brasil. Foram considerados os aspectos significativos do EN com pontuação igual ou superior a 3,5: campo visual, fundoscopia, movimentos de perseguição ocular, mímica facial, marcha, desvio pronador ou movimentos rápidos dos membros superiores, prova dedo-nariz, tônus nos membros superiores e inferiores, cinco reflexos tendinosos e reflexo plantar. Concluiu-se que, apesar de diferenças geográficas e econômicas entre Brasil e Canadá, neurologistas de ambos os países concordam sobre o exame neurológico essencial no cenário proposto.

In order to determine which aspects would be essential to the neurological examination (NE) in a given specific situation (a patient referred with a potential neurological complaint, but the history suggests that a neurological problem is unlikely), we presented the same questionnaire used by Moore and Chalk in Canada to 19 neurologists in Rio de Janeiro, Brazil. We considered significant aspects of NE, whose average responses were greater than or equal to 3.5: visual fields, fundoscopy, pursuit eye movements, facial muscle power testing, gait, pronator drift or rapid arm movement in upper limbs, finger-nose, tone in arms and legs, five tendon reflexes, and plantar responses. We concluded that, despite geographical and economical differences between Brazil and Canada, neurologists from both countries agree about the essential NE in the proposed scenario.

Tuberculomas cerebrais são responsáveis por 10-20% das lesões parenquimatosas em países em desenvolvimento. A maioria destas lesões é observada ao diagnóstico de tuberculose ou logo após o início do tratamento. Descrevemos um caso de uma paciente de 32 anos com história de 14 meses de evolução de perda visual progressiva e cefaleia. A história patológica revelou tuberculose pulmonar 8 anos antes. A ressonância magnética do crânio mostrou uma lesão isointensa nas sequências T1 e T2 captantes de contraste no quiasma óptico. Fizemos o diagnóstico presuntivo de tuberculoma ótico-quiasmático e inciamos isoniazida, rifampicina, pirazinamida e etambutol. Apesar do tratamento, a paciente evoluiu para amaurose bilateral. O rápido diagnóstico desta condição é extremamente importante já que a presença de captação de contraste está associada à amaurose em pacientes com tuberculose.

Brain tuberculomas account for 10-20% of space occupying brain lesions in developing countries. Most lesions are observed at time of tuberculosis diagnosis or soon after starting treatment. We herein describe a 32 year-old patient with a 14-month history of headache and progressive visual loss. Her past medical history revealed pulmonary tuberculosis treated eight years before. A brain MRI showed a T1- and T2-weighted isointense contrast-enhancing lesion in the optic chiasm. A presumptive diagnosis of optochiasmatic tuberculoma was made and isoniazid, rifampin, pyrazinamide, and ethambutol were started. Despite treatment, the patient evolved to blindness. The prompt recognition of this condition is extremely important since the presence of optochiasmal enhancement is associated with blindness in patients with tuberculosis.

Enquanto a mieloradiculite pelo CMV é complicação conhecida em pacientes com SIDA e imunossupressão grave, a mieloradiculite necrosante por HSV-2 é rara e muitas vezes associada a sequelas ou desfecho fatal. Descrevemos um paciente de 46 anos de idade, infectado pelo HIV com imunossupressão profunda e sustentada que apresentou paraparesia aguda ascendente e retenção urinária. A RM de coluna lombar mostrou o realce de contraste no cone medular e cauda equina e ambos PCR para CMV e HSV-2 no LCR foram positivos. Apesar do tratamento, o paciente morreu 20 dias depois. Revisamos os principais aspectos diagnósticos e terapêuticos da mieloradiculite associada aos herpesvírus e discutimos a abordagem em casos semelhantes.

While CMV myeloradiculitis is a known complication in AIDS patients with severe immunosuppression, HSV-2 necrotizing myeloradiculitis is rare and often associated with disabling a fatal outcome. We hereby describe a 46 year-old HIV infected patient with profound and sustained immunosuppression who presented with an acute ascending paraparesis and urinary retention. Lumbar spine MRI showed contrast enhancement at the conus medullaris and cauda equine, and both CMV and HSV-2 CSF PCR were positive. Despite treatment, the patient died 20 days later. We review the main diagnostic and therapeutic aspects of herpes virus associated myeloradiculitis and discuss the approach in similar cases.

O objetivo deste artigo é ressaltar uma rara condição caracterizada por paralisia supranuclear do olhar conjugado para baixo associada a ptose palpebral bilateral em um homem de 53 anos, causada por tumor mesencefálico radio-induzido, e discutir os aspectos relacionados ao controle supranuclear dos movimentos oculares verticais.

The purpose of this article is to highlight an uncommon combination of supranuclear downward gaze paralysis with bilateral eyelid ptosis in a 53-years-old man with a radiation induced midbrain tumor and to discuss the aspects regarding the centers and pathways that mediate supranuclear vertical gaze movements.

Introdução: A auto-rotação cefálica ativa é um teste rápido, de simples realização, não invasivo, que não causa desconforto ao paciente, pode ser realizado com facilidade em crianças e avalia o reflexo vestíbulo-ocular nas freqüências fisiológicas de movimentação da cabeça, utilizadas na vida cotidiana (de 1 a 4 Hz). Forma de estudo: clínico retrospectivo não randomizado. Objetivo: Avaliar pacientes com queixas de tontura/vertigem através da auto-rotação cefálica ativa comparando os sintomas com as alterações encontradas. Material e método: Um grupo de 1281 pacientes com queixa de tontura/vertigem foi submetido ao teste de auto-rotação cefálica ativa horizontal com alvo fixo, como uma etapa da avaliação otoneurológica. Resultados: As idades variaram de três a 93 anos com média de 49,6 anos, sendo 946 (73,8%) do sexo feminino e 335 (26,2%) do sexo masculino. A queixa de vertigem foi relatada por 896 (69,9%) dos pacientes e a tontura por 385 (30,1%). A faixa de freqüência de resposta à prova de auto-rotação cefálica variou de 1,5 a 7,5Hz com média de 3,5Hz. A prova de auto-rotação cefálica ativa foi normal em 937 (73,1%) e alterada em 344 (26,9%) dos pacientes. As alterações mais freqüentes foram as relacionadas ao ganho (aumento, redução) isoladas ou associadas a alterações de fase e simetria, em 241 (19%) pacientes. O aumento do ganho isolado foi verificado em 92 pacientes (7,2%). Conclusão: Não houve relação entre as alterações na prova de auto-rotação cefálica ativa horizontal e as queixas de tontura e vertigem.

Introduction: Active cephalic auto-rotation is a rapid, easy, painless and comfort test, that can be done in children and evaluate the vestibulo-ocular reflex in the physiologic frequencies of head, used in the every day life (from one to four hertz). Study design: clinical retrospective not randomized. Aim: Evaluate patients with complaints of dizziness/vertigo through the active cephalic auto-rotation comparing symptoms with alterations found. Material and method: A group of 1281 patients with dizziness underwent the horizontal active cephalic auto-rotation test with fixed target, as a part of otoneurological evaluation to verify the alterations that showed up. Results: Ages rate from three to 93 years with average of 49,6 years, being 946 (73,8%) females and 335 (26,2%) males. The vertigo complaint was reported by 896 (69,9%) patients and dizziness by 385 (30,1%). The frequency answering rate to cephalic auto-rotation test ranged from 1,5 to 7,5Hz with average of 3,5Hz.The active cephalic auto-rotation test was normal in 937 (73,1%) and abnormal in 344 (26,9%) patients. The most frequent alterations were those having to do with the gain (increase - reduction) isolated or associated to alterations of phase and symmetry in 241 (19%) patients. The increase of gain isolated was verified in 92 (7,2%) patients. Conclusion: There was no relation between alterations in the active cephalic auto-rotation test and the complaints of dizziness and vertigo.

This paper is a data basis which includes tables of integral, differential, and momentum transfer cross sections for elastic electron scattering from CF4, CCl4, SiCl4, SiBr4, SiI4, CH3F CH2F2, CHF3, CH3Cl, CH2Cl2, CHCl3, CF3Cl, CF2Cl2, CFCl3, CH3Br, CH3I, SiH3Cl, SiH3Br, SiH3I, GeH3Cl, GeH3Br, SnH3Br, C2H6, Si2H6, Ge2H6, B2H6, Ga2H6, H2O, H2S, H2Se, H2Te, trimethylarsine (TMAs), N2O, and O3. These tables show our new results, along with some of our previously published cross sections, and can easily be compared to future experimental data and other new theoretical results. Our scattering amplitudes were calculated using the Schwinger multichannel method with norm-conserving pseudopotentials. Our results are in good agreement with other theoretical data and experimental results when available.

This paper reports results for rotational excitation of H2O and H2S molecules by electron impact. It is also a databasis including tables of previously published rotationally resolved cross sections for CH4, SiH4, GeH4, SnH4, PbH4, NH3, PH3, AsH3, SbH3, CF4, CCl4, SiCl4 SiBr4, and SiI4. Our scattering amplitudes were calculated using the Schwinger multichannel method with norm-conserving pseudopotentials and the rotational resolved cross sections were obtained with the help of the adiabatic nuclei rotation approximation. Our results are in good agreement with other theoretical data and experimental results when available.

We report elastic differential cross sections (DCS) for the scattering of electron by H2, CH4, C2H4, SiH4, and H2O in the 5 to 20 eV energy range. These cross sections were obtained using the Schwinger variational principle. In our procedures the scattering wave function is expanded as a combination of plane waves. In the present implementation the exchange potential and polarization effects are not considered and all results are obtained at the static level of approximation. For all molecules, except H2, our calculated DCS agree reasonably well with avaliable experimental data and with other theoretical results (obtained at the static-exchange level of approximation). Our study suggests that the Schwinger variational principle with plane wave expansion may become an efficient method for studying electron-molecule scattering.