2,636 research outputs found

    Brain–Machine Interfaces: The Role of the Neurosurgeon

    Get PDF
    The neurotechnology field is set to expand rapidly in the coming years as technological innovations in hardware and software are translated to the clinical setting. Given our unique access to patients with neurological disorders, expertise with which to guide appropriate treatments and technical skills to implant brain-machine interfaces (BMIs), neurosurgeons have a key role to play in the progress of this field. We outline the current state and key challenges in this rapidly advancing field including implant technology, implant recipients, implantation methodology, implant function, ethical, regulatory and economic considerations. Our key message is to encourage the neurosurgical community to proactively engage in collaborating with other healthcare professionals, engineers, scientists, ethicists and regulators in tackling these issues. By doing so, we will equip ourselves with the skills and expertise to drive the field forward and avoid being mere technicians in an industry driven by those around us

    Pubertal timing in girls and depression: A systematic review

    Get PDF
    Background: Because the incidence of depression increases after puberty, it is possible that pubertal timing in girls influences the onset of depression. Our objective was to assess the effect of early and late puberty in girls on the incidence of depression. Methods: We systematically searched relevant databases for controlled studies that assessed the impact of pubertal timing in girls on the incidence of depression or depressive symptoms. The last search was completed in August 2013. Two authors selected the studies, extracted the data, and assessed the quality of the evidence. Meta-analyses of the adjusted and unadjusted results were calculated using random effects. Results: Four cohort studies were included (n=8055 participants). Early puberty significantly increased the risk of new cases of depression in the unadjusted meta-analysis (RR=1.33; CI 95%: 1.02, 1.73) but not in the adjusted estimate of two of the included studies (RR=1.48; CI 95%: 0.69, 2.28). For late puberty, no significant associations were found (unadjusted RR=1.28; CI 95%: 0.87, 1.88). Two studies assessed the effect of early puberty on depressive symptoms and found positive associations. The quality of the available evidence was rated as very low. Limitations: The polled results had wide confidence intervals, and the available evidence was of very low quality. Conclusions: The available evidence supports little confidence regarding the impact of pubertal timing on the onset of depression in girls but suggests that early puberty in girls may increase the risk of depression. Further higher quality studies are needed to clarify the association between pubertal timing and the incidence of depression in girls and women

    A systematic review of the energy and climate impacts of teleworking

    Get PDF
    Information and communication technologies (ICTs) increasingly enable employees to work from home and other locations (‘teleworking’). This study explores the extent to which teleworking reduces the need to travel to work and the consequent impacts on economy-wide energy consumption. Methods/Design: The paper provides a systematic review of the current state of knowledge of the energy impacts of teleworking. This includes the energy savings from reduced commuter travel and the indirect impacts on energy consumption associated with changes in non-work travel and home energy consumption. The aim is to identify the conditions under which teleworking leads to a net reduction in economy-wide energy consumption, and the circumstances where benefits may be outweighed by unintended impacts. The paper synthesises the results of 39 empirical studies, identified through a comprehensive search of 9,000 published articles. Review results/Synthesis: Twenty six of the 39 studies suggest that teleworking reduces energy use, and only eight studies suggest that teleworking increases, or has a neutral impact on energy use. However, differences in the methodology, scope and assumptions of the different studies make it difficult to estimate ‘average’ energy savings. The main source of savings is the reduced distance travelled for commuting, potentially with an additional contribution from lower office energy consumption. However, the more rigorous studies that include a wider range of impacts (e.g. non-work travel or home energy use) generally find smaller savings. Discussion: Despite the generally positive verdict on teleworking as an energy-saving practice, there are numerous uncertainties and ambiguities about its actual or potential benefits. These relate to the extent to which teleworking may lead to unpredictable increases in non-work travel and home energy use that may outweigh the gains from reduced work travel. The available evidence suggests that economy-wide energy savings are typically modest, and in many circumstances could be negative or non-existent

    Liquid phase alkylation of anisole and phenol catalyzed by niobium phosphate

    Full text link
    The catalytic activity of niobium phosphate was evaluated in the liquid phase alkylation reaction of anisole with 1-dodecene, 1- octene, 2-octanol and 1-octen-3-ol and in the reaction of phenol with 1-octen-3-ol. Best results were achieved in the alkylation of anisole and phenol with 1-octen-3-ol that produced mainly monoalkylate products. In the reaction with phenol the major products formed were octenylphenols (C-alkylation) and phenyl-octenyl ether (O-alkylates). The reaction favors the formation of C-alkylates over O-alkylates

    Análise comparativa de mapas de eletroforese bidimensional (2-DE) de Helicobacter pylori de pacientes brasileiros com úlcera duodenal e gastrite crônica: relato preliminar

    Get PDF
    O Helicobacter pylori é uma bactéria reconhecida como a principal causa de úlcera péptica e gastrite crônica. Recentemente, o proteoma do H. pylori tem sido desenvolvido visando identificar fatores patogênicos relacionados ao microorganismo. Neste estudo preliminar, cepas de H. pylori foram isoladas de fragmento de mucosa gástrica de pacientes com úlcera duodenal e gastrite crônica. Posteriormente, realizou-se uma análise proteômica parcial dessas cepas, através da lise bacteriana e da separação de proteínas através da eletroforese de duas dimensões (2-DE). Por análise comparativa, foi possível verificar a expressão protéica diferencial entre os dois mapas 2-DE obtidos. Os dados poderão ser úteis para esclarecer a importância de diferentes proteínas relacionadas à patogênese da bactéria. Este estudo será complementado utilizando um maior número de amostras e a identificação protéica do H. pylori através da espectrometria de massa do tipo MALDI-TOF.Helicobacter pylori is a bacterium recognized as the major cause of peptic ulcer and chronic gastritis. Recently, a proteome-based approach was developed to investigate pathogenic factors related to H. pylori. In this preliminary study, H. pylori strains were isolated from gastric biopsies of patients with chronic gastritis and duodenal ulcers. A partial proteomic analysis of H. pylori strains was performed by bacterial lyses and proteins were separated by two-dimensional gel electrophoresis (2-DE). A comparative analysis was performed to verify a differential protein expression between these two 2-DE maps. These data should be useful to clarify the role of different proteins related to bacterial pathogenesis. This study will be completed using a larger number of samples and protein identification of H. pylori by MALDI-TOF mass spectrometry

    Liquid-liquid equilibria of UCON + (sodium or potassium) phosphate salt aqueous two-phase systems at 23 °C

    Get PDF
    Six phase diagrams for UCON−phosphate salt aqueous two-phase systems (ATPSs), at 23 °C, are presented. The ATPSs were obtained combining UCON (a random copolymer of 50 % ethylene oxide and 50 % propylene oxide) and a phosphate salt (KH2PO4, K2HPO4, potassium phosphate buffer pH = 7, NaH2PO4, Na2HPO4, and sodium phosphate buffer pH = 7). Among the salts used, Na2HPO4 proved to be the most effective in ATPS formation, providing the greatest heterogeneous region in the phase diagram. The previous established relation between the anion valence and the concentration needed to form a biphasic system was confirmed: higher valence requires lower concentration. Na+ salts require, in all cases, lower concentration to form ATPSs than the corresponding K+ salts. The size of the heterogeneous region in the phase diagrams increases with an increase of the pH value of the salt used in ATPS preparation.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/43439/2008Fundo Europeu de Desenvolvimento Regional (FEDER) - FEDER/POCI/201

    Polymorphism analysis of the CTLA-4 gene in paracoccidioidomycosis patients

    Get PDF
    The CTLA-4 protein is expressed in activated T cells and plays an essential role in the immune response through its regulatory effect on T cell activation. Polymorphisms of the CTLA-4 gene have been correlated with autoimmune, neoplastic and infectious illnesses. This work aimed to verify possible associations between single nucleotide polymorphisms (SNPs) in CTLA-4, -318C/T in the promoter and +49A/G in exon 1 and paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. For this purpose, 66 chronic form PCM patients and 76 healthy controls had their allele, genotype and haplotype frequencies determined. The genetic admixture structure of the patients and controls was evaluated to eliminate ancestral bias. The comparison of frequencies indicated no significant differences between patients and controls that could link the SNPs to PCM. Groups were admixture matched with no difference observed in population ancestry inference, indicating that the absence of association between CTLA-4 polymorphisms and PCM could not be attributed to ancestral bias. This study showed that there was no association between the CTLA-4 SNPs -318 and +49 and the resistance or susceptibility to PCM.22022

    Interference with Hemozoin Formation Represents an Important Mechanism of Schistosomicidal Action of Antimalarial Quinoline Methanols

    Get PDF
    Heme is an essential molecule to most living organisms, but once in a free state it exerts toxic effects. Blood-feeding organisms evolved efficient ways to detoxify free heme derived from hemoglobin digestion. A key mechanism present in some hematophagous organisms consists of the crystallization of heme into a pigment named hemozoin. Schistosoma mansoni is one of the etiologic agents of human schistosomiasis, a parasitic disease that affects over 200 million people in tropical and subtropical areas. Hemozoin formation represents the main heme detoxification pathway in S. mansoni. Here, we report that the antimalarial quinoline methanols quinine and quinidine exert schistosomicidal effects notably due to their capacity to interfere with hemozoin formation. When quinine or quinidine were administered intraperitoneally during seven days to S. mansoni-infected mice (75 mg/kg/day), both worm and eggs burden were significantly reduced. Interestingly, hemozoin content in female worms was drastically affected after treatment with either compound. We also found that quinine caused important changes in the cellular organization of worm gastrodermis and increased expression of genes related to musculature, protein synthesis and repair mechanisms. Together, our results indicate that interference with hemozoin formation is a valid chemotherapeutic target for development of new schistosomicidal agents
    • …
    corecore