Nonperturbative aspects of Euclidean Yang-Mills theories in linear covariant gauges : Nielsen identities and a BRST-invariant two-point correlation function

In order to construct a gauge-invariant two-point function in a Yang-Mills theory, we propose the use of the all-order gauge-invariant transverse configurations A(h). Such configurations can be obtained through the minimization of the functional A(min)(2) along the gauge orbit within the BRST-invariant formulation of the Gribov-Zwanziger framework recently put forward in [1,2] for the class of the linear covariant gauges. This correlator turns out to provide a characterization of nonperturbative aspects of the theory in a BRST-invariant and gauge-parameter-independent way. In particular, it turns out that the poles of are the same as those of the transverse part of the gluon propagator, which are also formally shown to be independent of the gauge parameter alpha entering the gauge condition through the Nielsen identities. The latter follow from the new exact BRST-invariant formulation introduced before. Moreover, the correlator enables us to attach a BRST-invariant meaning to the possible positivity violation of the corresponding temporal Schwinger correlator, giving thus for the first time a consistent, gauge parameter independent, setup to adopt the positivity violation of as a signature for gluon confinement. Finally, in the context of gauge theories supplemented with a fundamental Higgs field, we use to probe the pole structure of the massive gauge boson in a gauge-invariant fashion

Ophthalmic adverse drug reactions to systemic drugs: a systematic review

PURPOSE: To perform a comprehensive and systematic review regarding ophthalmic adverse drug reactions (ADRs) to systemic drugs to: (i) systematically summarize existing evidence, (ii) identify areas, ophthalmic ADRs or drugs that lacked systematization or assessment (namely drugs with original studies characterizing specific ophthalmic ADRs but without causality assessment nor without meta-analysis). METHODS: Systematic review of several electronic databases (last search 1/7/2012): Medline, SCOPUS, ISI web of knowledge, ISI Conference Proceedings, International Pharmaceutical Abstracts and Google scholar. Search query included: eye, ocular, ophthalmic, ophthalmology, adverse and reaction. Inclusion criteria were: (i) Primary purpose was to assess an ophthalmic ADR to a systemic medication; (ii) Patient evaluation performed by an ophthalmologist; (iii) Studies that specified diagnostic criteria for an ocular ADR. Different types of studies were included and analyzed separately. Two independent reviewers assessed eligibility criteria, extracted data and evaluated risk of bias. RESULTS: From 562 studies found, 32 were included (1 systematic review to sildenafil, 11 narrative reviews, 1 trial, 1 prospective study, 6 transversal studies, 6 spontaneous reports and 6 case series). Drugs frequently involved included amiodarone, sildenafil, hydroxychloroquine and biphosphonates. Frequent ophthalmic ADRs included: keratopathy, dry eye and retinopathy. CONCLUSIONS: To increase evidence about ophthalmic ADRs, there is a need for performing specific systematic reviews, applying strictly the World Health Organization's (WHO) definition of ADR and WHO causality assessment of ADRs. Some ophthalmic ADRs may be frequent, but require ophthalmological examination; therefore, ophthalmologists' education and protocols of collaboration between other specialties whenever they prescribe high-risk drugs are suggestions for the future

Efeitos antiangiogênicos in vivo convalidam a atividade antineoplásica potencial do metiljasmonato

Molecular plant components have long been aimed at the angiogenesis and anti-angiogenesis pathways, and have been tested as sources for antineoplasic drugs with promising success. The present work deals with the anti-angiogenic effects of Methyl Jasmonate. Jasmonate derivatives were demonstrated to selectively damage the mitochondria of cancer cells. In vitro, 1-10 mM Methyl Jasmonate induced the cell death of the human umbilical vein endothelial cells (HUVEC) and the Murine melanoma cells (B16F10), while micromolar concentrations were ineffective. In vivo, comparable concentrations were toxic and reduced the vessel density of the Chorioallantoic Membrane of the Chicken Embryo (CAM). However, 1-10 µM concentrations produced a complex effect. There was increased capillary budding, but the new vessels were leakier and less organised than corresponding controls. It is suggested that not only direct toxicity, but also the drug effects upon angiogenesis are relevant to the antineoplasic effects of Methyl Jasmonate.Moléculas de origem vegetal são, há muito, conhecidas como substâncias ativas sobre as vias de angiogênese e antiangiogênese e foram testadas como fonte de drogas antineoplásicas com sucesso promissor. Este trabalho trata dos efeitos antiangiogênicos do Metiljasmonato, um protótipo da família dos derivados do ácido jasmônico, que danificam seletivamente a mitocôndria de células neoplásicas. In vitro, metiljasmonato 1-10 mM promoveu a morte celular de células endoteliais humanas de cordão umbilical (HUVEC) e de melanoma murino (B16F10); concentrações micromolares foram inócuas. In vivo, concentrações equivalentes foram tóxicas e reduziram a densidade de vasos em membranas corioalantoicas de embrião de galinha (CAM). Entretanto, concentrações entre 1-10 µM produziram um efeito complexo. Ocorreu aumento no brotamento capilar, mas os novos vasos apresentaram-se frágeis e menos organizados que os controles correspondentes. Sugere-se que, além da toxicidade direta contra as células tumorais, a ação do metiljasmonato sobre a angiogênese seja relevante para seu efeito antineoplásico

The Schistosoma mansoni genome encodes thousands of long non-coding RNAs predicted to be functional at different parasite life-cycle stages

Next Generation Sequencing (NGS) strategies, like RNA-Seq, have revealed the transcription of a wide variety of long non-coding RNAs (lncRNAs) in the genomes of several organisms. In the present work we assessed the lncRNAs complement of Schistosoma mansoni, the blood fluke that causes schistosomiasis, ranked among the most prevalent parasitic diseases worldwide. We focused on the long intergenic/intervening ncRNAs (lincRNAs), hidden within the large amount of information obtained through RNA-Seq in S. mansoni (88 libraries). Our computational pipeline identified 7029 canonically-spliced putative lincRNA genes on 2596 genomic loci (at an average 2.7 isoforms per lincRNA locus), as well as 402 spliced lncRNAs that are antisense to protein-coding (PC) genes. Hundreds of lincRNAs showed traits for being functional, such as the presence of epigenetic marks at their transcription start sites, evolutionary conservation among other schistosome species and differential expression across five different life-cycle stages of the parasite. Real-time qPCR has confirmed the differential life-cycle stage expression of a set of selected lincRNAs. We have built PC gene and lincRNA co-expression networks, unraveling key biological processes where lincRNAs might be involved during parasite development. This is the first report of a large-scale identification and structural annotation of lncRNAs in the S. mansoni genome

Knowledge of Brazilian dentists and students in treating dentine hypersensitivity

Objective: To evaluate knowledge of undergraduates and qualified dentists from a Brazilian Dental School in treating Dentine Hypersensitivity (DH). Methodology: Data obtained from a 22-item questionnaire were analysed and arranged in distribution figures. Results: Of 100 respondents, 66.3% indicated that up to 25% of their patients had DH; 41.7%, that the duration of discomfort was up to eight weeks; 78.4%, that they examined a patient with DH within the last two-four weeks; and 70.4%, that this was done after the patient initiated the conversation on DH. Most of participants responded DH affects patients’ quality of life, and its aetiology was attrition, exposed dentine, occlusal interference, gingival recession or abrasion. The most common ways to diagnose DH were sensitivity history analysis, clinical examination, clinical testing and probing; and conflicting conditions were fractured restoration, bleaching sensitivity, marginal leakage, chipped tooth and periodontal disease. Furthermore, 82.5% and 78.7% of respondents indicated they were confident in diagnosing DH and providing advice to patients, but only 38.8% identified hydrodynamic theory as its underlying mechanism. To evaluate pain from DH they considered self-assessment, dental examination, dietary analysis and thermal assessment; and as recommendations, the use of desensitizing dentifrices, education on toothbrushing, in-office application of desensitizing products, and restorations. Conclusion: There is still confusion concerning the aetiology, the diagnosis and the subsequent management of DH, and both students and qualified dentists need better education

Vascular trauma: a five year review

O presente trabalho pretende avaliar a casuística dos traumatismos vasculares agudos admitidos no Serviço de Cirurgia Vascular dos Hospitais da Universidade de Coimbra (HUC) durante o período de 5 anos, compreendido entre Julho de 2004 e Junho de 2009. Foram avaliados 97 doentes, sendo a principal causa de traumatismo as lesões iatrogénicas, seguida dos acidentes de viação. No grupo de doentes não relacionados com procedimentos coronários percutâneos verificou-se que no membro superior as artérias umeral e radial foram as mais afectadas, enquanto no membro inferior foram as artérias femoral superficial e poplítea. A isquémia aguda foi a principal forma de apresentação. Relativamente ao tratamento deste grupo de doentes, a RATT (ressecção e anastomose topo-topo) e o enxerto foram os mais utlizados no membro superior, enquanto a trombectomia e o bypass foram as técnicas mais aplicadas a nível do membro inferior. Não houve mortalidade mas a morbilidade foi elevada, predominando as lesões neurológicas nos traumatismos do membro superior, e a amputação nos do membro inferior. Os resultados deste trabalho foram concordantes com o que está publicado na literatura em que se demonstra um aumento progressivo dos traumatismos de origem iatrogénica

Dynamics of the first-order metamagnetic transition in magnetocaloric La(Fe,Si)(13): Reducing hysteresis

The influence of dynamics and sample shape on the magnetic hysteresis in first‐order magnetocaloric metamagnetic LaFe13–xSix with x = 1.4 is studied. In solid‐state magnetic cooling, reducing magnetic and thermal hysteresis is critical for refrigeration cycle efficiency. From magnetization measurements, it is found that the fast field‐rate dependence of the hysteresis can be attributed to extrinsic heating directly related to the thickness of the sample and the thermal contact with the bath. If the field is paused partway through the transition, the subsequent relaxation is strongly dependent on shape due to both demagnetizing fields and thermal equilibration; magnetic coupling between adjacent sample fragments can also be significant. Judicious shaping of the sample can both increase the onset field of the ferromagnetic–paramagnetic (FM–PM) transition but have little effect on the PM–FM onset, suggesting a route to engineer the hysteresis width by appropriate design. In the field‐paused state, the relaxation from one phase to the other slows with increasing temperature, implying that the process is neither thermally activated or athermal; comparison with the temperature dependence of the latent heat strongly suggests that the dynamics reflect the intrinsic free energy difference between the two phases