Properties of Graphene: A Theoretical Perspective

In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

Understanding Influenza

Influenza, a serious illness of humans and domesticated animals, has been studied intensively for many years. It therefore provides an example of how much we can learn from detailed studies of an infectious disease and of how even the most intensive scientific research leaves further questions to answer. This introduction is written for researchers who have become interested in one of these unanswered questions, but who may not have previously worked on influenza. To investigate these questions, researchers must not only have a firm grasp of relevant methods and protocols; they must also be familiar with the basic details of our current understanding of influenza. This article therefore briefly covers the burden of disease that has driven influenza research, summarizes how our thinking about influenza has evolved over time, and sets out key features of influenza viruses by discussing how we classify them and what we understand of their replication. It does not aim to be comprehensive, as any researcher will read deeply into the specific areas that have grasped their interest. Instead, it aims to provide a general summary of how we came to think about influenza in the way we do now, in the hope that the reader’s own research will help us to understand it better

Estudo da ototoxicidade em trabalhadores expostos a organofosforados Ototoxicity study in workers exposed to organophosphate

A exposição ocupacional e ambiental aos agrotóxicos evidencia-se como um grave problema de Saúde Pública em nosso país. Entre os sintomas apresentados, a tonteira se destaca, em decorrência de uma provável ação tóxica. OBJETIVO: O objetivo do estudo é caracterizar os resultados do exame vestibular de trabalhadores rurais expostos ocupacionalmente e ambientalmente aos agrotóxicos organofosforados. MATERIAL E MÉTODO: Foi realizado um estudo de coorte com corte transversal em 18 trabalhadores rurais de Teresópolis, RJ. A faixa etária variou de 16 a 59 anos com uma média de 39,6 anos, sendo 5 trabalhadores do sexo masculino e 13 do sexo feminino. Foram utilizados três questionários com perguntas relacionadas à saúde geral e auditiva e perguntas específicas à tonteira e suas relações com o trabalho. Todos os trabalhadores passaram por uma avaliação clínica e realizaram os exames vectoeletronistagmografia e audiometria. RESULTADOS: Os resultados mostraram que 16 trabalhadores apresentaram alterações do equilíbrio corporal de tipo periférico irritativo e 7 trabalhadores apresentaram perdas auditivas do tipo neurossensorial, sugerindo que os agrotóxicos induzem alterações do sistema vestibular através de uma intoxicação lenta e silenciosa. CONCLUSÕES: O olhar clínico sobre esta população exposta a substâncias neuro-ototóxicas requer uma abordagem interdisciplinar, assegurando uma intervenção terapêutica e preventiva eficaz.<br>Occupational and environmental exposure to agricultural pesticides represent an important health care problem in our country. Among the symptoms presented, dizziness stands out, because of a probable toxic action. AIM: The goal of our study was to characterize vestibular test results from rural workers occupationally and environmentally exposed to organophosphates used in agricultural pesticides. MATERIALS AND METHODS: We carried out a cohort cross-sectional study with 18 rural workers from Teresópolis, RJ. Age ranged between 16 and 59 years, with a mean value of 39.6 years, 5 were males and 13 females. We used three questionnaires with questions associated with general and auditory health, and more specific questions about dizziness and its association with work. All workers underwent clinical evaluation, audiometry and vectoelectronystagmography. RESULTS: results showed that 16 workers had irritative peripheral body balance disorder and 7 workers had sensorineural hearing loss, thus suggesting that agricultural pesticides cause vestibular alterations through a slow and silent intoxication. CONCLUSIONS: medical care for this population exposed to neurotoxic substances require an interdisciplinary approach, to guarantee efficient preventive and therapeutic measures

Investigating BRCA Mutations: A Breakthrough in Precision Medicine of Castration-Resistant Prostate Cancer

Despite the development of novel effective therapeutic strategies, metastatic castration-resistant prostate cancer (mCRPC) remains a disease with a lethal course and a high biological and molecular heterogeneity. To date, germline mutations in the BRCA gene represent one of the main risk factors for developing prostate cancer, with a strong association with aggressive phenotype and poor clinical outcomes. A better understanding of the genomic landscape of prostate cancer has strengthened the idea that "synthetic lethality" of this disease might be useful in cancer-drug discovery, focusing on agents such as platinum compounds and poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi). In this review, we summarize the main data available on BRCA mutations and discuss the clinical implications of these genomic aberrations in the management of prostate cancer, stressing the need to identify prognostic and predictive biomarkers and to deeply understand the mechanisms of treatment resistance, in order to maximize personalized medicine protocols and therefore clinical benefit