384 research outputs found

    Characterization of rigor mortis of longissimus dorsi and triceps brachii muscles of male cattle carcasses

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    In this work, six bovine carcasses butchered in a slaughterhouse in Rio de Janeiro State, Brazil (SIE 504) were studied and temperature, pH, sarcomere length in different periods after slaughter (1, 5, 8, 12, 15 and24 h) of the longissimus dorsi (LD) and triceps brachii (TB) muscles as well as the shear force (meat tenderness) and colour were evaluated, aiming at characterizing the rigor mortis in the meat during industrial processing. Data statistic treatment demonstrated that carcass temperature and pH decreased gradually during the industrial chilling. The chilly room temperature varied from 10.2 to 4.0°C, the mean initial temperature of longissimus dorsi was 34.03°C and the final one was 7.12°C; the mean initial temperature of Triceps brachii was 39.00°C and the final one was 6.42°C. The mean initial pH of Longissimus dorsi was 6.47 and the final one was 5.46; the mean initial pH of Triceps brachii was 6.66 and the final one was 5.54. The smallest sarcomere size obtained in both muscles occurred at 12 h post mortem, and the sarcomere lengths were 1.44 and 1.41 μm, respectively. As for the colour parameters, the b* value presented higher correlation with the ultimate pH. The absence of cold shortening and the non-occurrence of dark firm and dry (DFD) meat indicate better quality of the meat analyzed.Keywords: Bovine carcass, muscles, rigor morti

    Multifaceted moir\'e superlattice physics in twisted WSe2_2 bilayers

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    Lattice reconstruction in twisted transition-metal dichalcogenide (TMD) bilayers gives rise to piezo- and ferroelectric moir\'e potentials for electrons and holes, as well as a modulation of the hybridisation across the bilayer. Here, we develop hybrid kp\mathbf{k}\cdot \mathbf{p} tight-binding models to describe electrons and holes in the relevant valleys of twisted TMD homobilayers with parallel (P) and anti-parallel (AP) orientations of the monolayer unit cells. We apply these models to describe moir\'e superlattice effects in twisted WSe2{}_2 bilayers, in conjunction with microscopic \emph{ab initio} calculations, and considering the influence of encapsulation, pressure and an electric displacement field. Our analysis takes into account mesoscale lattice relaxation, interlayer hybridisation, piezopotentials, and a weak ferroelectric charge transfer between the layers, and describes a multitude of possibilities offered by this system, depending on the choices of P or AP orientation, twist angle magnitude, and electron/hole valley.Comment: 44 pages, 27 figures, 6 appendices. For v2: Modelling and analysis for Q-point bands and minibands adde

    Placebo response in chronic peripheral neuropathic pain trials: systematic review and meta-analysis

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    Objective: To estimate the magnitude of the placebo and nocebo responses in chronic peripheral neuropathic pain (CNP) and explore possible associations with trial characteristics. // Methods: We searched CENTRAL, MEDLINE, and Embase for randomized controlled trials (RCTs) from inception to May 2020. We included placebo-controlled RCTs of ≥8 weeks investigating first-line pharmacological interventions for CNP. Primary endpoints were the placebo response, the proportion of patients receiving placebo with pain intensity reduction (PIR) ≥30% from baseline, and the nocebo response, the proportion of patients receiving placebo experiencing adverse events (AEs). Screening, data extraction, and bias assessment (with the Cochrane risk of bias tool) were conducted by independent reviewers. We pooled data using a random-effects model. // Results: We included 50 trials, with a combined 5,693 participants allocated to placebo, conducted between 1998 and 2020. Overall, 38% of patients receiving placebo reported PIR≥30% (95% CI 34 to 42, I2=86%); 23% reported PIR≥50% (95% CI 20 to 26; I2=81%). 50% of patients receiving placebo reported AEs (95% CI 0.43 to 0.58; I2=97%); 2% reported serious AEs (95% CI 2 to 3; I2=58%). In patients receiving active interventions, the placebo response accounts for 75% of the treatment effect on PIR≥30%, and the nocebo response accounts for 75% of the AEs. Interpreted inversely, only 25% of responses and 25% of adverse events can be attributed to the intervention. Publication year positively correlated with PIR≥30% and negatively correlated with AEs. Female sex negatively correlated with AEs. // Conclusions: The placebo and nocebo responses in parallel-designed RCTs in CNP are substantial and should be considered in trial interpretation and in the design of future trials

    Intensive monitoring studies for assessing medicines : a systematic review

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    Copyright © 2019 Torre, Cary, Borges, Ferreira, Alarcão, Leufkens, Costa and Martins. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Introduction: Intensive monitoring (IM) is one of the methods of post-marketing active surveillance based upon event monitoring, which has received interest in the current medicines regulatory landscape. For a specific period of time, IM involves primary data collection and is actively focused on gathering longitudinal information, mainly safety, since the first day of drug use. Objectives: To describe IM systems and studies' data published over 11-years period (2006-2016). Specifically, we reviewed study population/event surveillance, methodological approaches, limitations, and its applications in the real-world evidence generation data. Methods: We completed a systematic search of MEDLINE and EMBASE to identify studies published from 2006 to 2016, that used IM methodology. We extracted data using a standardized form and results were analyzed descriptively. The methodological quality of selected studies was assessed using the modified Downs and Black checklist. Results: From 1,400 screened citations, we identified 86 papers, corresponding to 69 different studies. Seventy percent of reviewed studies corresponded to established IM systems, of which, more than half were prescription event monitoring (PEM) and modified-PEM. Among non-established IM systems, vaccines were the most common studied drugs (n = 14). The median cohort size ranged from 488 (hospitals) to 10,479 (PEM) patients. Patients and caregivers were the event data source in 39.1% of studies. The mean overall quality score was similar between established and non-established IM. Conclusions: Over the study period, IM studies were implemented in 26 countries with different maturity levels of post-marketing surveillance systems. We identified two major limitations: only 20% of studies were conducted at hospital-level, which is a matter of concern, insofar as healthcare systems are facing a lack of access to new medicines at ambulatory care level. Additionally, IM access to data of drug exposure cohorts, either at identification or at follow-up stages, could somehow constitute a barrier, given the complexity of managerial, linkable, and privacy data issues.The publication fee was supported by the Center for Health Evaluation and Research (CEFAR), National Association of Pharmacies, Lisbon, Portugal.info:eu-repo/semantics/publishedVersio

    PEDOT:PSS-coated polybenzimidazole electroconductive nanofibers for biomedical applications

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    Bioelectricity drives several processes in the human body. The development of new materials that can deliver electrical stimuli is gaining increasing attention in the field of tissue engineering. In this work, novel, highly electrically conductive nanofibers made of poly [2,20 - m-(phenylene)-5,50 -bibenzimidazole] (PBI) have been manufactured by electrospinning and then coated with cross-linked poly (3,4-ethylenedioxythiophene) doped with poly (styrene sulfonic acid) (PEDOT:PSS) by spin coating or dip coating. These scaffolds have been characterized by scanning electron microscopy (SEM) imaging and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. The electrical conductivity was measured by the four-probe method at values of 28.3 S·m−1 for spin coated fibers and 147 S·m−1 for dip coated samples, which correspond, respectively, to an increase of about 105 and 106 times in relation to the electrical conductivity of PBI fibers. Human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) cultured on the produced scaffolds for one week showed high viability, typical morphology and proliferative capacity, as demonstrated by calcein fluorescence staining, 40 ,6-diamidino-2-phenylindole (DAPI)/Phalloidin staining and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide] assay. Therefore, all fiber samples demonstrated biocompatibility. Overall, our findings highlight the great potential of PEDOT:PSS-coated PBI electrospun scaffolds for a wide variety of biomedical applications, including their use as reliable in vitro models to study pathologies and the development of strategies for the regeneration of electroactive tissues or in the design of new electrodes for in vivo electrical stimulation protocols.info:eu-repo/semantics/publishedVersio

    Espectrometria de absorção atômica: o caminho para determinações multi-elementares

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    This paper present an overview of way covered for the spectrometry of atomic absorption (AAS), tracing a line of the historical events in its development and its establishment as a multielement technique. Additionally, the efforts carried by through several researchers in the search for the instrumental evolution, the advances, advantages, limitations, and trends of this approach are related. Several works focusing its analytical applications are cited employing simultaneous multielement determination by flame (FAAS) and/or graphite furnace (GF AAS), and fast sequential multielement determination using FAAS are reported in the present review

    Dung burial by roller dung beetles (Coleoptera: Scarabaeinae):An individual and specific-level study

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    Dung beetles (Coleoptera: Scarabaeinae) mediate many ecological functions that are important to maintain the ecosystem functioning of terrestrial environments. Although a large amount of literature explores the dung beetle-mediated ecological processes, little is known about the individual contribution from distinct species. Here, we aimed to examine the intra and interspecific variations in dung burial rates performed by two roller dung beetle species (Canthon smaragdulus Fabricius, 1781 and Canthon sulcatus Castelnau, 1840). Furthermore, we evaluated the relationship between dung beetle biomass and dung burial rates. We set up a laboratorial experiment with three treatments (two males, two females, and a couple) and 10 replicates per treatment for each dung beetle species, and dung burial rates were measured after exposing 100 g of mixed pig and human excrement for 48 hours. Our results demonstrate that dung burial rates of males, females, and couples within each species do not differ. However, C. smaragdulus individuals performed a larger dung burial than C. sulcatus individuals did. In addition, we found no effect of individual biomass on the amount of dung burial on intra and interspecific levels. These findings highlight the need for further research considering that distinct species, even from the same genus, may perform different rates of ecological processes, as well as about the importance for considering the beetle biomass when measuring their ecological functions. We call for studies to fill in the knowledge gap about the individual species’ contribution to the maintenance of different dung beetle-mediated ecological processes

    Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering

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    In this study entitled “Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering”, we describe the development of novel hydroxyapatite (HAp)-filled osteoinductive piezoelectric poly(vinylidene fluoride-cotetrafluoroethylene) (PVDF-TrFE) electrospun nanofibers as a potential strategy for supporting bone repair in delayed-union and non-union osteoporotic-related fractures, for which current clinical techniques have proven to be largely inadequate and scaffold-based tissue engineering approaches hold significant promise. While the piezoelectric properties of native bone tissue have been extensively discussed in the literature, including their key role in preserving tissue homeostasis and promoting tissue repair, they have been widely neglected in the design of scaffolds for bone tissue engineering (BTE) applications. Piezoelectric scaffolds can be used not only for mimicking the native piezoelectric features of bone but also to provide a platform for applying electrical or mechanical stimuli to damaged tissue, contributing to an accelerated regeneration process. The nanofibrous scaffolds generated in this study were capable of replicating the main electrical, structural and compositional properties of bone extracellular matrix (ECM). To the best of our knowledge, this was the first time that the combination of HAp with the piezoelectric polymer PVDF-TrFE was found to induce key shifts in the chemical structure of the polymer and promote ß phase nucleation, not only enhancing the piezoelectric features of the constructs but also improving their surface properties, including their ability to support mineralization in vitro. The HAp nanoparticles also provided meaningful bone-like biological cues (osteoinduction), enhancing the osteogenic differentiation of seeded human mesenchymal stem/stromal cells (hMSCs), which was confirmed by an increased ALP activity, cellderived calcium deposition and expression of important osteogenic gene markers. Overall, our findings highlight, for the first time, the potential of combining PVDFTrFE and HAp for developing electroactive and osteoinductive nanofibrous constructs with improved piezoelectric properties, surface features and osteogenic potential capable of improving bone tissue regeneration.Peer ReviewedPostprint (published version

    Surveillance of hemorrhagic fever and/or neuroinvasive disease: challenges of diagnosis

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      OBJECTIVE To evaluate the performance of post mortem laboratory analysis in identifying the causes of hemorrhagic fever and/or neuroinvasive disease in deaths by arbovirus infection. METHODS Retrospective cross-sectional study based on the differential analysis and final outcome obtained in patients whose samples underwent laboratory testing for arboviruses at the Pathology Center of the Adolfo Lutz Institute, in São Paulo, Brazil. RESULTS Of the 1355 adults clinically diagnosed with hemorrhagic fever and/or neuroinvasive disease, the most commonly attributed cause of death and the most common final outcome was dengue fever. Almost half of the samples tested negative on all laboratory tests conducted. CONCLUSION The failure to identify the causative agent in a great number of cases highlights a gap in the diagnosis of deaths of unknown etiology. Additional immunohistochemical and molecular assessments need to be added to the post-mortem protocol if all laboratory evaluations performed fail to identify a causative agent. While part of our findings may be due to technical issues related to sample fixation, better information availability when making the initial diagnosis is crucial. Including molecular approaches might lead to a significant advancement in diagnostic accuracy
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