•Easy obtention of Cu3(MoO4)2(OH)2 by sonochemistry route at room temperature.•Urchin-like morphology was obtained in aqueous solution using the sonochemistry method for copper molybdate.•High ...conversion rate in the esterification of oleic acid using the Cu3(MoO4)2(OH)2 as a solid catalyst.
Copper molybdate nanoplates were synthesized by a sonochemical process at room temperature, which we report as a simple and cost-effective route. Structural analysis of the material by the Rietveld method of X-ray diffraction (XRD) data revealed lindgrenite Cu3(MoO4)2(OH)2 in a single-phase structure. All the vibrational modes characteristic of the space group were identified by Raman vibrational and near-infrared (NIR) spectroscopies. The profile obtained for N2 adsorption/desorption was type III hysteresis, characteristic of mesoporous materials, with a surface area of 70.77(1) m2 g−1. The micrographs of the material obtained by scanning electron microscopy showed nanoplates with nanometric sizes and an anisotropic growth aspect. The catalytic activity of lindgrenite was evaluated by esterifying oleic acid with methanol, showing high conversion rate to methyl oleate and good catalyst stability after seven recycling cycles. Above all, the best catalytic performance was reached when we optimized parameters such as oleic acid:methanol molar ratio of 1:5, 5% of catalyst dosage, and reaction time of 5 h, resulting in 98.38% of conversion at 413 K. Therefore, sonochemically synthesized lindgrenite proved to be a high potential material for biofuel production by oleic acid esterification.
Nowadays the use of polymeric matrix composites to repair and strengthen the damaged pipe structures in the oil industry has become a common practice. Hence, it is essential to validate the ...performance of new developed composite laminate materials for the damaged pipe repair. In this study, the effectiveness of a new composite laminate for the pipes repair was investigated. First, the mechanical and thermal properties of the new developed composite laminate were determined. Next, two defect types, Type A (non-through wall) and Type B (through wall) were manufactured into the pristine pipe specimen and the evaluation of the performance of the repaired pipe was carried out by hydrostatic tests. The performance of the repaired pipe using the new developed composite laminate material was satisfactory in both defect types.
Yellow passion fruit peel and cupuaçu seeds are common wastes. Usually, they have few or no applications and are discarded, causing environmental pollution. To use them in a new way and reduce ...ecological pollution, we obtained the ash of yellow passion fruit peels by calcination. We characterized it using Fourier‐transform infrared spectroscopy with attenuated total reflectance (FTIR‐ATR), X‐ray fluorescence (XRF), X‐ray diffractometry (XRD), adsorption‐desorption of N2, scanning electron microscopy (SEM), basicity, and soluble alkalinity. It was observed that the ash was mainly composed of potassium (69%) in the form of carbonate, chloride, and sulfate, with a good surface area (11.23 m2 g−1). The cupuaçu butter was also extracted from the cupuaçu seeds and characterized, showing low acidity, peroxide, saponification, and iodine indexes, in addition to presenting a lipid profile with 57% saturated fatty acid and 43% unsaturated fatty acid. Oleic and stearic acids were present in higher proportions. These results demonstrate that this butter can be a sustainable input in biodiesel production. Thus, the ash was used as a heterogeneous catalyst in the butter transesterification. The biodiesel synthesis was optimized, resulting in 97.8% butter conversion into biodiesel under the following conditions: reaction time of 2 h, 5 wt% of catalyst, 80 °C, and a methanol‐to‐oil molar ratio of 30. This work, therefore, shows that it is possible to obtain and utilize bioinputs, such as cupuaçu butter and passion fruit peel ash, to produce biodiesel through transesterification, and the use of waste materials (precisely passion fruit peels and cupuaçu seeds) makes this method a cost‐effective and environmentally friendly approach to biofuel production.
Zika virus (ZIKV) is an arthropod-borne flavivirus that reemerged in 2007 and, since then, has caused several outbreaks and spread to over 80 countries worldwide. Along with this, ZIKV infections ...have been associated with severe clinical outcomes, including neurological manifestations, especially in newborns, posing a major threat to human health. However, there are no licensed vaccines or specific antiviral agents available yet; thereby, there is an urgent need for the discovery of novel therapeutic strategies to fight this infection. In this context, seaweeds are proven sources of biologically relevant products, including antiviral ones, that remain poorly explored. Herein, we evaluated the antiviral potential of the dichloromethane extract of the red seaweed Bryotamnion triquetrum against ZIKV. MTT assay was carried out to evaluate the extract's toxicity in Vero cells, while standard plaque assays were performed for viral titer quantification in the antiviral assays. The B. triquetrum extract possessed great inhibitory activity on the ZIKV replication in Vero cells, with an EC50 of 1.38 µg/ml and a higher selectivity index than ribavirin (289.85 and 75.20, respectively), a licensed antiviral drug. The investigation of its mechanism of action revealed a moderate virucidal effect while it strongly impaired virus replication at both early and late steps of the virus replication cycle with moderate inhibition at the attachment stage. Finally, the B. triquetrum extract presented a remarkable synergistic effect with ribavirin at suboptimal concentrations, which also highlights the promising antiviral potential of this product as a drug candidate to combat ZIKV infection. Keywords: Rhodophyta; Algae; arbovirus; antiviral; Zika.
Syphilis is a sexually transmitted disease (STD) caused by Treponema pallidum subspecies pallidum. In 2016, it was declared an epidemic in Brazil due to its high morbidity and mortality rates, mainly ...in cases of maternal syphilis (MS) and congenital syphilis (CS) with unfavorable outcomes. This paper aimed to mathematically describe the relationship between MS and CS cases reported in Brazil over the interval from 2010 to 2020, considering the likelihood of diagnosis and effective and timely maternal treatment during prenatal care, thus supporting the decision-making and coordination of syphilis response efforts.
The model used in this paper was based on stochastic Petri net (SPN) theory. Three different regressions, including linear, polynomial, and logistic regression, were used to obtain the weights of an SPN model. To validate the model, we ran 100 independent simulations for each probability of an untreated MS case leading to CS case (PUMLC) and performed a statistical t-test to reinforce the results reported herein.
According to our analysis, the model for predicting congenital syphilis cases consistently achieved an average accuracy of 93% or more for all tested probabilities of an untreated MS case leading to CS case.
The SPN approach proved to be suitable for explaining the Notifiable Diseases Information System (SINAN) dataset using the range of 75-95% for the probability of an untreated MS case leading to a CS case (PUMLC). In addition, the model's predictive power can help plan actions to fight against the disease.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
RCC usually develops and progresses asymptomatically and, when detected, it is frequently at advanced stages and metastatic, entailing a dismal prognosis. Therefore, there is an obvious demand for ...new strategies enabling an earlier diagnosis. The importance of metabolic rearrangements for carcinogenesis unlocked a new approach for cancer research, catalyzing the increased use of metabolomics. The present study aimed the NMR metabolic profiling of RCC in urine samples from a cohort of RCC patients (n = 42) and controls (n = 49). The methodology entailed variable selection of the spectra in tandem with multivariate analysis and validation procedures. The retrieval of a disease signature was preceded by a systematic evaluation of the impacts of subject age, gender, BMI, and smoking habits. The impact of confounders on the urine metabolomics profile of this population is residual compared to that of RCC. A 32-metabolite/resonance signature descriptive of RCC was unveiled, successfully distinguishing RCC patients from controls in principal component analysis. This work demonstrates the value of a systematic metabolomics workflow for the identification of robust urinary metabolic biomarkers of RCC. Future studies should entail the validation of the 32-metabolite/resonance signature found for RCC in independent cohorts, as well as biological validation of the putative hypotheses advanced.
An experimental study has been carried out to assess the adhesion quality of composite-to-metal bonded joints under salt spray ageing conditions. The tests were performed according to the ASTM ...standard of floating roller peel tests with a new specimen layup. The layup and geometry of the specimen was defined in order to have the Carbon Fiber Reinforced Polymer (CFRP) and carbon steel as the rigid and flexible substrate, respectively. Specimens were exposed to salt spray (or salt fog) for 30 and 90days. The results show that the adhesion performance (i.e. average peel load) of the joints progressively decreases with increasing the ageing time. The fracture surfaces of dry specimens (non-aged) exhibit a cohesive failure within the adhesive layer, which indicates a good adhesion between the CFRP-steel interfaces. Interface degradation is indicated by a drop in peel load and adhesive failure. The percentage of adhesive failure increases with ageing times. Fracture surfaces of the adhesive failure exhibit deposition of NaCl crystal at the interface. Peel test successfully assessed the interface adhesion in aged and non-aged conditions, and can be used as a fast, easy and reliable test to study the long term durability in case of composite-metal bonded joints.
The design and qualification of composite repairs for pipelines usually requires hydrostatic tests for the determination of the failure pressure. In this work, the use of a shaft blister test to ...assess the failure pressure of composite repairs is proposed. Blister tests were conducted to investigate the interfacial debonding of a composite plate bonded to steel substrate. The blister test specimen represents a composite repair applied to a pipeline with a defect. The onset debonding load is used to predict the failure pressure. A 3D digital image correlation (DIC) has been used to follow up the debonding propagation and evaluate the blister shape. 3D finite element model with a cohesive zone model has been used to simulate loaded shaft blister test. A good correlation between blister tests results and finite element simulation results was obtained. The validated finite element model was used to predict failure pressure in bonded composite repaired pipes with different values of defect diameter and repair thickness. The results show that the blister test could replace hydrostatic tests for the analysis of the composite repairs performance.
We use data taken as part of Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3) observations of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) to identify massive ...and evolved galaxies at 3 < z < 4.5. This is performed using the strength of the Balmer break feature at rest-frame 3648 A, which is a diagnostic of the age of the stellar population in galaxies. Using the WFC3 H-band-selected catalog for the CANDELS GOODS-S field and deep multi-waveband photometry from optical (HST) to mid-infrared (Spitzer) wavelengths, we identify a population of old and evolved post-starburst galaxies based on the strength of their Balmer breaks (Balmer break galaxies, BBGs). The galaxies are also selected to be bright in rest-frame near-IR wavelengths and hence massive. We identify a total of 16 BBGs. Fitting the spectral energy distribution of the BBGs shows that the candidate galaxies have average estimated ages of ~800 Myr and average stellar masses of ~5 x 10 super(10) M sub(middot in circle), consistent with being old and massive systems. Two of our BBG candidates are also identified by the criteria that are sensitive to star-forming galaxies (Lyman break galaxy selection). We find a number density of ~3.2 x 10 super(-5) Mpc super(-3) for the BBGs, corresponding to a mass density of ~2.0 x 10 super(6) M sub(middot in circle) Mpc super(-3) in the redshift range covering the survey. Given the old age and the passive evolution, it is argued that some of these objects formed the bulk of their mass only a few hundred million years after the big bang.
Production of glycerol oligomers by heterogeneous catalysis is being studied as an option for valorization of this biodiesel by-product. In this study, the catalytic activity of dolomite and the ...effects of parameters such as catalyst loading, reaction temperature, and reaction time were evaluated. Reusability and stability test were also performed. The material was tested as-received and after a thermal treatment, being characterized by XRD, FTIR, N
2
adsorption–desorption, SEM, CO
2
-TPD and TG/DTG. Reaction products were analyzed by GC-FID for oligomers composition and ICP to verify metallic species leaching. The thermal treatment led to a decrease of the particle size, increase of the specific surface area and improved basicity. Calcined dolomite showed better catalytic performance than natural dolomite, leading to almost 80% glycerol conversion and selectivities for diglycerol and triglycerol of 51% and 3%, respectively. Kinetic test revealed that the reaction is slow along the first hours and later the reaction rate increases. Ca and Mg are leached to the reaction medium but the catalyst could be reused up to 2 cycles, with similar diglycerol yield. The reaction conditions for this material are less severe than those reported previously, which added to the low cost and reusability capacity turns suitable for glycerol oligomerization process.
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