2,012 research outputs found

    How mineralogy and geochemistry can improve the significance of Pb isotopes in metal provenance studies

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    Lead isotopes combined with trace element data represent a powerful tool for non-ferrous metal provenance studies. Nevertheless, unconsidered geological factors and archaeological data, as well as ignored analytical procedures, may substantially modify the interpretation of the isotopic and trace element signature obtained as a potential ore candidate. Three archaeological examples, accompanied by high-resolution lead isotopic measurements (MC–ICP–MS), are presented here to discuss the above-mentioned criticisms and to propose some solutions. The first example deals with prehistoric/historical gold/silver-mining activity from Romania (the Baia Borşa and Roşia Montană ore deposits). The second one regards the lead/silver metallurgical activity from the Mont-Lozère massif (France) during medieval times. The third example focuses on the comparison between two batches of lead isotope data gathered on Roman lead ingots from Saintes-Maries-de-la-Mer, using different SRM 981 Pb values

    Effect of editors’ implementation of CONSORT guidelines on the reporting of abstracts in high impact medical journals: interrupted time series analysis

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    Objective To investigate the effect of the CONSORT for Abstracts guidelines, and different editorial policies used by five leading general medical journals to implement the guidelines, on the reporting quality of abstracts of randomised trials

    Lead isotope analyses of gold–silver ores from Roşia Montană (Romania): a first step of a metal provenance study of Roman mining activity in Alburnus Maior (Roman Dacia)

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    The Roşia Montană ore deposit (Apuseni Mountains, Romania) is Europe’s largest Au–Ag deposit. It also corresponds to the Roman Alburnus Maior mining site, known by historians and archaeologists due to the discovery of dozens of Roman wooden wax tablets during the underground works carried out during the 18th and 19th centuries.The present geochemical research is based on a detailed archaeological and geological study of the Roman mines at Roşia Montană, making use of archaeologically and geologically documented ore samples. The geochemical analyses allowed us to establish an accurate database for the ores exploited during Roman times at Roşia Montană (and probably before). This approach represents a contribution towards improving the accuracy of metal provenance studies of gold–silver ores during antiquity in Romania, and also at an European level, because the studied ore samples represent remnants of the original ores used by the Romans for the production of precious metals.Twenty-nine ore samples and one litharge roll have been selected, prepared and analysed by MC-ICP-MS (high-resolution measurements). A specific Roşia Montană Pb isotope signature of gold–silver ores extracted by the Roman miners was obtained. This signature is distinct when compared with other ore deposits from the Apuseni Mountains, as well as within a broader region (Maramureş ore district).A litharge roll discovered in a Roman inclined adit situated close to the surface, which attests the presence of metallurgical workshops, has also been analysed. The different lead isotope values of the litharge roll and the Roşia Montană gold–silver ores suggest that other ore sources from the South Apuseni Mountains or from elsewhere were also employed by the gold metallurgy developed at Roşia Montană during Roman times

    Peptídeos antimicrobianos de mamíferos: potencial e limitações para o tratamento de infecções por Staphylococcus aureus.

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    Antimicrobial peptides (AMPs) are small molecules produced by virtually all living organisms as a part of the innate immune system. They present a broad spectrum antimicrobial activity against a myriad of microorganisms, but also anti-inflammatory, immunomodulatory and antitumor effects, among others. Therefore, it was our objective to compile and analyze the current information about natural and synthetic AMPs, regarding their general mechanisms of action, potentials, and limitations for clinical use, especially for the treatment of Staphylococcus aureus infections. Furthermore, we intended to briefly discuss new routes of administration and the emergence of bacterial resistance to AMPs. To do so, two databases, PubMed and Scopus, and the keywords “Staphylococcus aureus”, “antimicrobial peptide” and “novel antibiotics” were used, and the articles were filtered by the English language for the period between 2011 and 2016. We found that AMPs possess different properties, with characteristic antimicrobial activities and secondary effects. Moreover, we also pointed some modifications that could be used to design new AMPs and different routes of administration that could be used to improve AMP capacity or to adapt it to a specific purpose, such as preventing biofilm formation in catheters or treating a specific disease. On the other hand, they also present limitations that include: development of bacterial resistance, cytotoxicity, and reduced stability, sometimes lower efficacy when compared to the actual treatment, high costs of production and also some inconsistent results between articles, which we believe that may be related to differences in methods and/or strains of S. aureus investigated.Peptídeos antimicrobianos (AMPs) são pequenas moléculas conservadas evolutivamente e encontradas virtualmente em todos os organismos vivos como parte de sua imunidade inata. Eles possuem um amplo espectro de atividade antimicrobiana contra diversos microrganismos, mas também ação anti-inflamatória, imunomodulatória, antitumoral, dentre outros efeitos. Desse modo, nosso objetivo foi compilar e analisar as informações mais atuais sobre AMPs naturais e sintéticos, considerando seus mecanismos gerais de ação, bem como seu potencial e limitações para uso clínico, especialmente no tratamento de infecções por Staphylococcus aureus. Além disso, discutimos brevemente o uso de novas vias de administração e a possibilidade do desenvolvimento de resistência bacteriana aos AMPs. Para tanto, foram usadas duas bases de dados, PubMed e Scopus e os descritores “Staphylococcus aureus”, “peptídeos antimicrobianos” e “novos antibióticos”. Os artigos foram filtrados para a língua inglesa e foram selecionadas publicações entre 2011 e 2016. Os resultados foram em sua maioria compatíveis com o que se obteve em revisões prévias, a saber, que existe uma grande variedade de AMPs, cada qual com características, atividades antimicrobianas e efeitos secundários específicos. Ademais, também foram apontadas modificações que podem ser usadas para o planejamento de novos AMPs e diferentes vias de administração que podem ser usadas para aprimorar os potenciais de um AMP, ou adaptá-lo para um propósito específico, como a prevenção de formação de biofilmes em cateteres ou no tratamento de uma doença específica. Por outro lado, eles também possuem limitações, que incluem: desenvolvimento de resistência bacteriana, citotoxicidade e reduzida estabilidade, eventualmente baixa eficácia quando comparados ao tratamento atual, elevados custos de produção, e mesmo inconsistências de resultados entre artigos, o que acreditamos estar relacionado a diferenças no método e/ou a cepa de S. aureus usados

    Development and evaluation of a pedagogical tool to improve understanding of a quality checklist: a randomised controlled trial.

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    OBJECTIVE: The aim of this study was to develop and evaluate a pedagogical tool to enhance the understanding of a checklist that evaluates reports of nonpharmacological trials (CLEAR NPT). DESIGN: Paired randomised controlled trial. PARTICIPANTS: Clinicians and systematic reviewers. INTERVENTIONS: We developed an Internet-based computer learning system (ICLS). This pedagogical tool used many examples from published randomised controlled trials to demonstrate the main coding difficulties encountered when using this checklist. Randomised participants received either a specific Web-based training with the ICLS (intervention group) or no specific training. OUTCOME MEASURES: The primary outcome was the rate of correct answers compared to a criterion standard for coding a report of randomised controlled trials with the CLEAR NPT. RESULTS: Between April and June 2006, 78 participants were randomly assigned to receive training with the ICLS (39) or no training (39). Participants trained by the ICLS did not differ from the control group in performance on the CLEAR NPT. The mean paired difference and corresponding 95% confidence interval was 0.5 (-5.1 to 6.1). The rate of correct answers did not differ between the two groups regardless of the CLEAR NPT item. Combining both groups, the rate of correct answers was high or items related to allocation sequence (79.5%), description of the intervention (82.0%), blinding of patients (79.5%), and follow-up schedule (83.3%). The rate of correct answers was low for items related to allocation concealment (46.1%), co-interventions (30.3%), blinding of outcome assessors (53.8%), specific measures to avoid ascertainment bias (28.6%), and intention-to-treat analysis (60.2%). CONCLUSIONS: Although we showed no difference in effect between the intervention and control groups, our results highlight the gap in knowledge and urgency for education on important aspects of trial conduct

    Minéralogie et signature isotopique du plomb des minerais auro-argentifères exploités durant l’époque romaine à Alburnus Maior (Rosia Montanà, Roumanie)

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    Alburnus Maior (Rosia Montanà, Roumanie), est un site minier important à l’époque romaine pour ses métaux précieux. Des études géologiques, gîtologiques et géochimiques ont été effectuées sur les corps de minerais exploités à l’époque romaine dans les chantiers miniers mis en évidence par l’archéologie minière. La démarche principale réside dans l’étude de minerais géo- et chrono- référencés par l’archéologie et la géologie pour identifier les sources des métaux précieux pendant l’antiquité romaine.Les études géologiques menées dans le massif de Cârnic, ont permis d’identifier quatre phases de minéralisation. Trois d’entre elles ont été exploitées par les Anciens. Chacune se traduit par un corpus d’associations minéralogiques en métaux précieux dont deux d’entre elles possèdent des minéraux rares à tellures et à germanium. Par ailleurs, les teneurs élémentaires des autres éléments chimiques étant très hétérogènes, l’isotopie du plomb (Pb) est l’outil idéal pour optimiser la caractérisation. Chaque phase de minéralisation possède sa propre signature en Pb. Malgré les différences isotopiques de Pb observées entre chacune d’elles, les signatures en Pb de Rosia Montanà (RM) constituent un champ isotopique très restreint. En comparaison avec d’autres districts miniers de Roumanie, le champ isotopique de RM est identifiable et affinera la filiation chimique à échelle régionale dans l’est de l’Europe.Alburnus Maior (Roşia Montană, Romania) was an important precious metals mining site during Roman times. Geological, ore deposit and geochemical studies have been carried out on the ore bodies exploited during the Roman period that have been discovered during archaeological excavations. The primary purpose of the present paper is to demonstrate the importance of the study of geologically and chronologically referenced ores by means of mining archaeology and geology for identifying the sources of precious metals from Roman Antiquity.The geological studies carried out in the Cârnic Massif allowed the identification of four mineralisation phases. Three of these four phases have been exploited by the ancient miners. Each mineralised phase is characterised by a specific precious metals mineral association, and two of them contain rare Te and Ge bearing minerals. As their elemental composition is heterogeneous, the use of lead isotopes represents a good methodology for refining their characterisation. Each mineralised phase has its own lead signature. In spite of some observed differences in terms of lead isotopes for each phase, the overall signature of Roşia Montană (RM) displays a well defined isotopic field. When compared to other mining districts in Romania, the isotopic field of RM is distinguishable, and this allows a better discrimination that can contribute to the provenance study of minerals from Eastern Europe

    Non epileptogenic Rasmussen`s encephalitis: a case report

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    Introduction: Rasmussen's encephalitis (RE) is a very rare chronic inflammatory unilateral encephalopathy with still unknown etiology. It predominantly affects children under the age of 10, but can also affect adolescents and adults. Current evidence on possible etiologies are divided in two main theories. The first one is based on brain inflammation caused by a reaction to a foreign antigen. The second one is based on an autoimmune disease that is limited to a single hemisphere of the brain. The common presentation is intractable and frequent focal motor seizures, often associated with progressive neurological decline, and progressive unilateral focal cortical atrophy. Progression of the inflammatory process in MRI is considered a good biomarker in RE. Objectives: Report a rare case of a female infant presenting atypical manifestations of uncommon symptoms without seizures caused by Rasmussen's encephalitis. Case Report: A ten-year-old right-handed female presented to the emergency department with sudden onset of abnormal involuntary movements of the right upper and lower limbs, face paresia of the same side and loss of attention without loss of consciousness. The involuntary contractions were brief, random, irregular, and worsened with activity, along with a positive milkmaid grip sign. She also displayed reduced movement speed and hyperactive biceps, triceps, patellar and ankle jerk reflexes. Associated with the motor abnormalities, the girl presented with a recent but progressive decrease in cognitive functions, which caused a decline in school performance and impaired reasoning, and affective blunting. She had no sign of previous neuropsychomotor development abnormality. She was taken to a quaternary hospital where a MRI and a CT of the brain were performed. MRI showed atrophy of the left cerebral hemisphere, predominantly in the operculum and head of the caudate nucleus, hypersignal in the insular cortex and adjacent white matter. CT presented with hypoattenuation of the left frontal lobe and parieto-occipital white matter associated with atrophy of the head of the caudate nucleus of the same side and enlargement of the adjacent fissures and sulcus. A subsequent PET-CT showed a left cerebral hemisphere hypometabolism, predominantly in the basal ganglia, temporal, frontal and insular lobes. Functional evaluation detected diffuse unilateral disorganization of brain electric activity, but no epileptic paroxysmal discharges were found on the electroencephalogram. After hospitalization, human immunoglobulin at the dose 2g/kg/day was used for five days. The girl remained stable, with no complications. After sixteen days, she was discharged with a rehabilitation program and follow-up care

    Efeito da curcumina na cicatrização de feridas: implicações para a educação em saúde no SUS

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    Chronic wounds represent a burden for the Unified Health System, and curcumin emerges as a cost-effective option in their treatment. The objective of the study is to analyze the evidence for the use of curcumin, alone or in combination with other medicinal active ingredients or biophysical agents in the healing of chronic wounds in adults. This is a narrative review from April to September 2023, employing structured search strategies based on PICO and MeSH Terms related to "curcumin," "chronic wounds," and "wound healing." Studies without restrictions on the year of publication were included, with participants over 18 years of age and with chronic wounds. Studies in Portuguese, Spanish or English were included. Of the 525 articles identified, six met the inclusion criteria. The study highlights promising results of curcumin in the healing of chronic wounds, especially in diabetic patients. However, the need for more clinical studies on the subject is highlighted.Introducción: Las heridas crónicas representan una carga para el Sistema Único de Salud, y la curcumina surge como una opción costo-efectiva en su tratamiento. Objetivo: Analizar la evidencia sobre el uso de la curcumina, sola o en combinación con otros principios activos medicinales o agentes biofísicos, en la curación de heridas crónicas en adultos. Metodología: Esta es una revisión narrativa de abril a septiembre de 2023, que emplea estrategias de búsqueda estructuradas basadas en términos PICO y MeSH relacionados con "curcumina", "heridas crónicas" y "cicatrización de heridas". Se incluyeron estudios sin restricción de año de publicación, con participantes mayores de 18 años y con heridas crónicas. Se incluyeron estudios en portugués, español o inglés. Resultados: De los 523 artículos identificados, seis cumplieron los criterios de inclusión. Consideraciones finales: El estudio destaca resultados prometedores de la curcumina en la curación de heridas crónicas, especialmente en diabéticos. Sin embargo, se destaca la necesidad de realizar más estudios clínicos sobre el tema.Feridas crônicas representam um ônus para o Sistema Único de Saúde, e a curcumina emerge como uma opção custo-efetiva no seu tratamento. O objetivo do estudo é analisar as evidências do uso da curcumina, isoladamente ou em combinação com outros ativos medicinais ou agentes biofísicos na cicatrização de feridas crônicas em adultos. Trata-se de uma revisão narrativa de abril a setembro de 2023, empregando estratégias de busca estruturada baseadas em PICO e MeSH Terms relacionados à "curcumin," "chronic wounds," e "wound healing". Foram incluídos estudos sem restrição de ano de publicação, com participantes com idade superior a 18 anos e que apresentassem feridas crônicas. Foram incluídos estudos em português, espanhol ou inglês. Dos 525 artigos identificados, seis atenderam aos critérios de inclusão. O estudo destaca resultados promissores da curcumina na cicatrização de feridas crônicas, principalmente em pacientes diabéticos. Contudo, ressalta-se a necessidade de mais estudos clínicos sobre a temática

    The influence of annealings on structure and microhardness of Fe-Mo-V-Nb-C steel processed by high-pressure torsion

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    The influence of high-pressure torsion on microstructure, microhardness and thermal stability of lowcarbon steel Fe-0,1Mo-0,6Mn-0,8Cr-0,2Ni-0,3Si-0,2Cu-0,1V-0,06Nb-0,09C, (wt.%) was investigated. It was shown that ultrafine-grained structure formed by high-pressure torsion possesses a high microhardness (H[mu]=7,0 GPa) and high thermal stability up to the temperature of 400°С

    Computed tomography segmental calcium score (SCS) to predict stenosis severity of calcified coronary lesions

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    To estimate the probability of a parts per thousand yen50 % coronary stenoses based on computed tomography (CT) segmental calcium score (SCS) and clinical factors. The Institutional Review Board approved the study. A training sample of 201 patients underwent CT calcium scoring and conventional coronary angiography (CCA). All patients consented to undergo CT before CCA after being informed of the additional radiation dose. SCS and calcification morphology were assessed in individual coronary segments. We explored the predictive value of patient's symptoms, clinical history, SCS and calcification morphology. We developed a prediction model in the training sample based on these variables then tested it in an independent test sample. The odds ratio (OR) for a parts per thousand yen50 % coronary stenosis was 1.8-fold greater (p = 0.006) in patients with typical chest pain, twofold (p = 0.014) greater in patients with acute coronary syndromes, twofold greater (p < 0.001) in patients with prior myocardial infarction. Spotty calcifications had an OR for a parts per thousand yen50 % stenosis 2.3-fold (p < 0.001) greater than the absence of calcifications, wide calcifications 2.7-fold (p < 0.001) greater, diffuse calcifications 4.6-fold (p < 0.001) greater. In middle segments, each unit of SCS had an OR 1.2-fold (p < 0.001) greater than in distal segments; in proximal segments the OR was 1.1-fold greater (p = 0.021). The ROC curve area of the prediction model was 0.795 (0.95 confidence interval 0.602-0.843). Validation in a test sample of 201 independent patients showed consistent diagnostic performance. In conjunction with calcification morphology, anatomical location, patient's symptoms and clinical history, SCS can be helpful to estimate the probability of a parts per thousand yen50 % coronary stenosis
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