874 research outputs found

    Effects of low-frequency noise on cardiac collagen and cardiomyocyte ultrastructure: an immunohistochemical and electron microscopy study

    Get PDF
    "Introduction: Low-frequency noise (LFN) leads to the development of tissue fibrosis. We previously reported the development of myocardial and perivascular fibrosis and a reduction of cardiac connexin43 in rats, but data is lacking concerning the affected type of collagen as well as the ultrastructural myocardial modifications. Objectives: The aim of this study was to quantify cardiac collagens I and III and to evaluate myocardial ultrastructural changes in Wistar rats exposed to LFN. Methods: Two groups of rats were considered: A LFN-exposed group with 8 rats continuously submitted to LFN during 3 months and a control group with 8 rats. The hearts were sectioned and the mid-ventricular fragment was selected. After immunohistochemical evaluation, quantification of the collagens and muscle were performed using the image J software in the left ventricle, interventricular septum and right ventricle and the collagen I/muscle and collagen III/muscle ratios were calculated. Transmission electron microscopy (TEM) was used to analyze mid-ventricular samples taken from each group. Results: The collagen I/muscle and collagen III/muscle ratios increased in totum respectively 80% (p<0.001) and 57.4% (p<0.05) in LFN-exposed rats. TEM showed interstitial collagen deposits and changes in mitochondria and intercalated discs of the cardiomyocytes in LFN-exposed animals. Conclusions: LFN increases collagen I and III in the extracellular matrix and induces ultrastructural alterations in the cardiomyocytes. These new morphological data open new and promising paths for further experimental and clinical research regarding the cardiac effects of low-frequency noise.

    Chemical composition, antioxidant and antimicrobial activity of phenolic compounds extracted from wine industry by-products

    Get PDF
    Winery by-products are a rich source of polyphenols, which have proven to have several beneficial biological properties, such as, antioxidant and antimicrobial activities. Therefore, this study aimed the extraction of polyphenols from winery by-products of two Portuguese red grape varieties, Touriga Nacional and Preto Martinho, and evaluate their phenolic profile, antioxidant properties and antimicrobial activity against antibiotic resistant bacteria. The polyphenols were extracted from the grapes' skins, seeds and stems. Extracts were analysed for total phenolic, anthocyanin and tannin contents, and the polyphenol profile was determined by High Performance Liquid Chromatography. The antioxidant activity of the extracts was determined by ABTS+ and DPPH methods. Antimicrobial susceptibility assay was performed using Kirby-Bauer disc diffusion method. Preto Martinho variety presented a higher polyphenolic content than Touriga Nacional. Malvidin 3-O-glucoside was the most abundant compound found in the skins extracts in both varieties. The main phenolic compound found in the seeds and stems extracts was catechin. From the several flavonols quantified, rutin was the most abundant. For both varieties, the seeds extracts showed the highest antioxidant and antimicrobial properties, followed by the stems extracts. The extracts showed antibacterial activity against all tested strains except on gram-negative bacteria Salmonella enteritidis, Escherichia coli and Pseudomonas aeruginosa. These results show that, natural products, such as polyphenols, may represent a source for the development of novel antimicrobials to combat gram-positive resistant bacteria and possibly be used as natural food preservatives. However, they were not effective against gram-negative resistant bacteria which shows that polyphenols, alone, might not substitute antibiotics.info:eu-repo/semantics/publishedVersio

    Photon trajectories in incoherent atomic radiation trapping as Levy flights

    Get PDF
    Photon trajectories in incoherent radiation trapping for Doppler, Lorentz, and Voigt line shapes under complete frequency redistribution are shown to be Levy flights. The jump length (r) distributions display characteristic long tails. For the Lorentz line shape, the asymptotic form is a strict power law r ^ (-3/2), while for Doppler the asymptotic is r ^ -2 (ln r)^ (-1/2). For the Voigt profile, the asymptotic form always has a Lorentz character, but the trajectory is a self-affine fractal with two characteristic Hausdorff scaling exponents

    The effectiveness of pilates training interventions on older adults’ balance: a systematic review and meta-analysis of randomized controlled trials

    Get PDF
    Pilates training intervention programs have gained attention as a potential approach to enhancing balance in older adults, thereby reducing the risk of falls. In light of these considerations, this systematic review and meta-analysis aimed to critically evaluate the existing evidence and determine the effect of Pilates training intervention programs on older adults’ balance. Materials and Methods: The literature was searched through the PubMed, Web of Science, and Scopus databases from inception until July 2023. The primary keywords used for the literature search included “elderly” or “older adults” and “pilates training” and “balance”. Results: The systematic review through qualitative analysis showed robust evidence about the efficacy of Pilates intervention programs in improving older adults’ balance. The pooled meta-analysis of static and dynamic balance showed that eight (53%) out of a total fifteen analyzed interventions presented a significant effect of Pilates in improving the participants’ balance, without between-study heterogeneity. In addition, the meta-analysis regarding dynamic balance showed that six (67%) out of nine analyzed interventions presented a significant effect of Pilates in improving the participants’ balance, without heterogeneity between studies. Similarly, the meta-analysis regarding static balance showed that four (50%) out of eight analyzed studies presented significant effects on the older adults’ balance, where moderate between-study heterogeneity was found. Sensitivity analysis showed that three studies reduced the between-study heterogeneity (19, 17.6, and 17%), regressing from moderate to low heterogeneity, p < 0.05. Conclusions: This systematic review and meta-analysis underscores the potential of Pilates training as a valuable intervention to enhance balance in the elderly populationThis work is supported by national funding through the Portuguese Foundation for Science and Technology, I.P., under the project UIDB/04045/2020.info:eu-repo/semantics/publishedVersio

    Rainfall Prediction in the State of ParaĂ­ba, Northeastern Brazil Using Generalized Additive Models

    Get PDF
    The state of ParaĂ­ba is part of the semi-arid region of Brazil, where severe droughts have occurred in recent years, resulting in significant socio-economic losses associated with climate variability. Thus, understanding to what extent precipitation can be influenced by sea surface temperature (SST) patterns in the tropical region can help, along with a monitoring system, to set up an early warning system, the first pillar in drought management. In this study, Generalized Additive Models for Location, Scale and Shape (GAMLSS) were used to filter climatic indices with higher predictive efficiency and, as a result, to perform rainfall predictions. The results show the persistent influence of tropical SST patterns in ParaĂ­ba rainfall, the tropical Atlantic Ocean impacting the rainfall distribution more effectively than the tropical Pacific Ocean. The GAMLSS model showed predictive capability during summer and southern autumn in ParaĂ­ba, highlighting the JFM (January, February and March), FMA (February, March and April), MAM (March, April and May), and AMJ (April, May and June) trimesters as those with the highest predictive potential. The methodology demonstrates the ability to be integrated with regional forecasting models (ensemble). Such information has the potential to inform decisions in multiple sectors, such as agriculture and water resources, aiming at the sustainable management of water resources and resilience to climate risk

    Intensity modulated radiotherapy for localized prostate cancer: rigid compliance to dose-volume constraints as a warranty of acceptable toxicity?

    Get PDF
    BACKGROUND: To report the toxicity after intensity modulated radiotherapy (IMRT) for patients with localized prostate cancer, as a sole treatment or after radical prostatectomy. METHODS: Between August 2001 and December 2003, 132 patients with prostate cancer were treated with IMRT and 125 were evaluable to acute and late toxicity analysis, after a minimum follow-up time of one year. Clinical and treatment data, including normal tissue dose-volume histogram (DVH) constraints, were reviewed. Gastro-intestinal (GI) and genito-urinary (GU) signs and symptoms were evaluated according to the Radiation Therapy Oncology Group (RTOG) toxicity scales. Median prescribed dose was 76 Gy. Median follow-up time was of 26.1 months. RESULTS: From the 125 patients, 73 (58.4%) presented acute Grade 1 or Grade 2 GI and 97 (77.2%) presented acute Grade 1 or Grade 2 GU toxicity. Grade 3 GI acute toxicity occurred in only 2 patients (1.6%) and Grade 3 GU acute toxicity in only 3 patients (2.4%). Regarding Grade 1 and 2 late toxicity, 26 patients (20.8%) and 21 patients (16.8%) presented GI and GU toxicity, respectively. Grade 2 GI late toxicity occurred in 6 patients (4.8%) and Grade 2 GU late toxicity in 4 patients (3.2%). None patient presented any Grade 3 or higher late toxicity. Non-conformity to DVH constraints occurred in only 11.2% of treatment plans. On univariate analysis, no significant risk factor was identified for Grade 2 GI late toxicity, but mean dose delivered to the PTV was associated to higher Grade 2 GU late toxicity (p = 0.042). CONCLUSION: IMRT is a well tolerable technique for routine treatment of localized prostate cancer, with short and medium-term acceptable toxicity profiles. According to the data presented here, rigid compliance to DHV constraints might prevent higher incidences of normal tissue complication
    • 

    corecore