Transmission power lines are essential to supply electrical energy to consumption centers. Keeping a reliable transmission system requires the early identification of faults. Image-based inspection ...of transmission lines makes fault identification faster and more accessible since it can be carried out using unmanned aerial vehicles (UAVs) in hard-to-reach places. In this paper, it is proposed to use a hybrid version of the You Only Look Once (YOLO) using ResNet-18 classifier, for power system inspection based on real images of failed components recorded by UAVs. This work assumed a dataset including 1,593 power grid inspection pictures for a supervised training. Based on YOLOv5x, with an mAP of 0.99262, the proposed method was superior to YOLOv5n, YOLOv5s, YOLOv5m, and YOLOv5l for object detection. For the multiclassification task, with an F1_score result of 0.96216, the proposed Hybrid-YOLO was superior to distinct architectures as the VGG-11, VGG-13, VGG-16, VGG-19, ResNet-34, ResNet-50, ResNet-152, DenseNet-121, DenseNet-161, DenseNet-169, DenseNet-201, YOLOv5, YOLOv6, and YOLOv7 versions.
•The UAVs are used for the inspection of transmission lines in hard-to-reach places.•Real photographs from field inspections are used to evaluate faulty insulators.•The proposed strategy was compared to well-established methods.•The Hybrid-YOLO outperforms the standard YOLOv5, YOLOv6, and YOLOv7.•Based on ResNet-18 a hybrid method has a better F1_score than other YOLO versions.
This paper describes the synthesis and characterization of PEI-coated gold nanoparticles (PEI-AuNP), which were applied as a new platform in the immobilization of laccase (LAC) originating from ...Aspergillus oryzae. This material (PEI-AuNP-LAC) was used in the construction of a biosensor based on a glassy carbon electrode coated with a bio-nanostructured film. The occurrence of direct electron transfer (DET) between the electroactive center of LAC and the electrode surface was observed by cyclic voltammetry (CV), suggesting that the presence of AuNP in the film acts as a bridge for electron transfer. In acetate buffer solution (pH 5.0), LAC shows a pair of well-defined redox waves with a formal potential (E⁰') of 0.226V vs. Ag/AgCl (3M KCl). The biosensor response indicated a surface-controlled process with an apparent electron transfer rate constant (k(s)) of 0.4 s⁻¹, charge transfer coefficient (α) of 0.5, and surface coverage concentration (Γ) of 3.45×10⁻¹⁰ mol cm⁻². The optimized biosensor showed the following limits of detection (LOD) for the phenolic compounds tested: 0.03 μM for catechol and guaiacol; 0.14 μM for pyrogallol and 0.21 μM for hydroquinone, using square-wave voltammetry (SWV). The proposed biosensor demonstrated high sensitivity, good repeatability and reproducibility, and long-term stability (only 20% decrease in response over 90 days and after 150 measurements by SWV for each film formed). This biosensor was successfully applied to catechol quantification in spiked water samples. Furthermore, this method showed great potential for application in the development of new devices for biosensing.
This paper studies the history of contractual choice in coffee plantations of São Paulo, Brazil. It focuses on the consolidation of non-captive labour markets in the early phases of the transition ...from slavery in the country, particularly in the 1840s–50s. Vis-à-vis the alternatives of fixed rents and fixed payments per time worked or piece rates, the paper examines the rationale for the adoption of sharecropping arrangements with European bonded labourers. New archival evidence suggests that sharecropping had no obvious productivity advantage over alternative labour–rental arrangements in this period, and that the adoption of sharecropping arrangements resulted from the positional advantage of its first proposers, who influenced later choices of contractual design. A credit-labour tie-up long outlived the original sharecropping arrangements, in turn allowing for the immigration of poor and credit-constrained Europeans, paving the way to insert Brazil into the circuits of mass migration without promoting institutional reforms to attract non-bonded immigrants.
MicroRNAs are small non-coding RNAs that regulate gene expression post-transcriptionally. They are involved in the regulation of physiological processes, such as adaptation to physical exercise, and ...also in disease settings, such as systemic arterial hypertension (SAH), type 2 diabetes mellitus (T2D), and obesity. In SAH, microRNAs play a significant role in the regulation of key signaling pathways that lead to the hyperactivation of the renin-angiotensin-aldosterone system, endothelial dysfunction, inflammation, proliferation, and phenotypic change in smooth muscle cells, and the hyperactivation of the sympathetic nervous system. MicroRNAs are also involved in the regulation of insulin signaling and blood glucose levels in T2D, and participate in lipid metabolism, adipogenesis, and adipocyte differentiation in obesity, with specific microRNA signatures involved in the pathogenesis of each disease. Many studies report the benefits promoted by exercise training in cardiovascular diseases by reducing blood pressure, glucose levels, and improving insulin signaling and lipid metabolism. The molecular mechanisms involved, however, remain poorly understood, especially regarding the participation of microRNAs in these processes. This review aimed to highlight microRNAs already known to be associated with SAH, T2D, and obesity, as well as their possible regulation by exercise training.
Zika virus (ZIKV) infection has been associated with severe complications both in the developing and adult nervous system. To investigate the deleterious effects of ZIKV infection, we used human ...neural progenitor cells (NPC), derived from induced pluripotent stem cells (iPSC). We found that NPC are highly susceptible to ZIKV and the infection results in cell death. ZIKV infection led to a marked reduction in cell proliferation, ultrastructural alterations and induction of autophagy. Induction of apoptosis of Sox2
cells was demonstrated by activation of caspases 3/7, 8 and 9, and by ultrastructural and flow cytometry analyses. ZIKV-induced death of Sox2
cells was prevented by incubation with the pan-caspase inhibitor, Z-VAD-FMK. By confocal microscopy analysis we found an increased number of cells with supernumerary centrosomes. Live imaging showed a significant increase in mitosis abnormalities, including multipolar spindle, chromosome laggards, micronuclei and death of progeny after cell division. FISH analysis for chromosomes 12 and 17 showed increased frequency of aneuploidy, such as monosomy, trisomy and polyploidy. Our study reinforces the link between ZIKV and abnormalities in the developing human brain, including microcephaly.
Purpose The purpose of this study was to investigate outcomes after hip arthroscopy in a consecutive series of patients aged 50 years or older and determine how long patients avoided total hip ...replacement. Methods Between 2006 and 2008, prospectively collected data were retrieved from our database on 153 patients aged 50 years or older undergoing hip arthroscopy for femoroacetabular impingement. Data collected included range of motion, Modified Harris Hip Score (MHHS), Hip Outcome Score (HOS) for activities of daily living, HOS for sports, and Short Form 12 score. Survivors were defined as patients not requiring total hip replacement (THR). Survivorship was analyzed by use of the Kaplan-Meier method. Results THR was required after the arthroscopic treatment in 20% of patients (31 of 153). At 3 years (with data available in 64 patients), patients with greater than 2 mm of joint space had survivorship of 90% whereas those with 2 mm or less had survivorship of 57% ( P = .001). In the patients who did not require THR, the MHHS improved from 58 to 84. The HOS for activities of daily living improved from 66 to 87 ( P = .001), and the HOS for sports improved from 42 to 72 ( P = .001). The physical component of the Short Form 12 improved from 38 to 49 ( P = .001), whereas the mental component did not change (54 preoperatively v 53 postoperatively, P = .53). Median patient satisfaction was 9. Conclusions On the basis of early results, patients with greater than 2 mm of joint space can expect improvement over preoperative status in pain and function after hip arthroscopy for femoroacetabular impingement. In patients aged 50 years or older with 2 mm of joint space or less and low preoperative MHHSs, early conversion to THR was seen. Level of Evidence Level IV, therapeutic case series.
Uncertainty remains about how long the protective immune responses against severe acute respiratory syndrome coronavirus 2 persists, and suspected reinfection in recovered patients has been reported. ...We describe a case of reinfection from distinct virus lineages in Brazil harboring the E484K mutation, a variant associated with escape from neutralizing antibodies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Characterization of honey by the stingless bees produced in the semi-arid region of the Brazilian northeast.•Concentration of carboxylic acids and physic-chemistry parameters were used in the ...evaluation.•Analysis of principal components and hierarchical cluster analysis was performed.
The physicochemical characteristics of honey vary according to bee species, climate, region, period of collection, processing and storage. In this context, this work aimed to perform a comparative study of the physicochemical characteristics of Melipona subnitida and M. fasciculata honey collected at different periods and regions of the State of Piauí, Brazil. Twenty-nine honey samples were collected and evaluated by principal component analysis from physicochemical analysis data. Twenty-two percent of the parameters analyzed differed between species. Evaluating the collection period, the honey of M. subnitida and M. fasciculata presented differences among themselves. The study revealed a similarity between the physicochemical parameters of the honey of the two species of bees, in addition, the time was one of the determining factors in the formation of clusters.
Chronic Chagas disease cardiomyopathy, caused by Trypanosoma cruzi infection, is a major cause of heart failure in Latin America. Galectin-3 (Gal-3) has been linked to cardiac remodeling and poor ...prognosis in heart failure of different etiologies. Herein, we investigated the involvement of Gal-3 in the disease pathogenesis and its role as a target for disease intervention. Gal-3 expression in mouse hearts was evaluated during T. cruzi infection by confocal microscopy and flow cytometry analysis, showing a high expression in macrophages, T cells, and fibroblasts. In vitro studies using Gal-3 knockdown in cardiac fibroblasts demonstrated that Gal-3 regulates cell survival, proliferation, and type I collagen synthesis. In vivo blockade of Gal-3 with N-acetyl- d -lactosamine in T. cruzi –infected mice led to a significant reduction of cardiac fibrosis and inflammation in the heart. Moreover, a modulation in the expression of proinflammatory genes in the heart was observed. Finally, histological analysis in human heart samples obtained from subjects with Chagas disease who underwent heart transplantation showed the expression of Gal-3 in areas of inflammation, similar to the mouse model. Our results indicate that Gal-3 plays a role in the pathogenesis of experimental chronic Chagas disease, favoring inflammation and fibrogenesis. Moreover, by demonstrating Gal-3 expression in human hearts, our finding reinforces that this protein could be a novel target for drug development for Chagas cardiomyopathy.
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Human kallikreins 5 and 7 (KLK5 and KLK7) exhibit trypsin- and chymotrypsin-like activities and are involved in pathologies related to skin desquamation process. A series of new ...3-acyltetramic acids were developed as a novel class of inhibitors of KLK5, KLK7 and trypsin enzymes. The nature and length of the acyl chain is crucial to the KLK5, KLK7 and trypsin inhibition activities, and the most potent compounds (but not the most selective) 2b, 2c and 2g showed low micromolar IC50 values. While very few of the compounds were selective for KLK5, the selective inhibition of trypsin against chymotrypsin was achieved. Our molecular modelling studies revealed that the double bond in 2g provided the best fit in the binding site of KLK5, while the hydrogen bonding interactions modulated the best fit of 2c in the binding site of KLK7 due to the hydrophobicity of the cavity.
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