High-strength concrete is undoubtedly one of the most innovative materials in construction. Its manufacture is simple and is carried out starting from essential components (water, cement, fine and ...aggregates) and a number of additives. Their proportions have a high influence on the final strength of the product. This relations do not seem to follow a mathematical formula and yet their knowledge is crucial to optimize the quantities of raw materials used in the manufacture of concrete. Of all mechanical properties, concrete compressive strength at 28 days is most often used for quality control. Therefore, it would be important to have a tool to numerically model such relationships, even before processing. In this aspect, artificial neural networks have proven to be a powerful modeling tool especially when obtaining a result with higher reliability than knowledge of the relationships between the variables involved in the process. This research has designed an artificial neural network to model the compressive strength of concrete based on their manufacturing parameters, obtaining correlations of the order of 0.94.
In this work, we report a heterojunction formed by a PbS/CdS bilayer using the chemical bath deposition (CBD) technique because it is a relatively simple, fast, and low-cost technique; is permitted ...to obtain high-quality thin films (TFs); and also covers large areas. Some characterizations have been carried out to confirm the identity of the involved bilayer. For the cadmium sulfide (CdS) film, optical properties such as absorption, transmission, reflection, extinction coefficient, and refractive index were measured. Moreover, the bandgap was calculated, and morphology was obtained by scanning electron microscopy (SEM). Also, X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM) were performed for the synthesis of CdS films. On the other hand, for the synthesis of lead sulfide (PbS) films, we performed TEM, energy-dispersive spectroscopy, and XRD. A surface morphological SEM image of the PbS film synthesized was also taken. The multiheterojunction PbS/CdS bilayer was characterized by the current–voltage (I–V) curve, and the behavior of the bilayer was evaluated under the conditions of darkness and controlled fixed lighting, detecting a very slight photosensitivity of the complete diodic device through those measurements. The calculated bandgap for the CdS TF was E g = 2.55 eV, while after a chosen thermal annealing, the bandgap decreased to 2.38 eV. On the other hand, the PbS film presented a cubic structure.
In this study we evaluate the chemical composition and neuroprotective effects of alkaloid fractions of the Amaryllidaceae species Rhodophiala pratensis, Rhodolirium speciosum, Phycella australis and ...Phaedranassa lehmannii. Gas chromatography-mass spectrometry (GC/MS) enable the identification of 41 known alkaloids. Rhodolirium speciosum and Rhodophiala pratensis were the most active extracts against acetylcholinesterase (AChE), with IC50 values of 35.22 and 38.13 μg/mL, respectively. The protective effect of these extracts on human neuroblastoma cells (SH-SY5Y) subjected to mitochondrial oxidative stress with rotenone/oligomycin A (R/O) and toxicity promoted by okadaic acid (OA) was evaluated. Only Phycella australis and Rhodophiala pratensis at 0.75 and 1.5 μg/mL, tend to reverse the cell death induced by R/O by around 12%. In OA assay, alkaloid fractions of Phycella Australis and Phaedranassa lehmannii displayed a concentration-dependent (0.375–3.0 μg/mL) effect with a maximum neuroprotective response of 78% and 84%, respectively. Afterwards, neuroprotective effects of Phycella australis (3 and 6 μg/mL) in mouse hippocampal slices stressed with oxygen glucose deprivation/reoxygenation (OGD/R), shown a protection greater than 14%. Finally, Phycella Australis (6 μg/mL) reverted the cell viability from 65% to 90% in slices treated with OA, representing a protection of 25% attributable to the alkaloids of this species.
•The inhibitory activity of AChE was evaluated in species Chilean Amarillidaceae species.•Amaryllidaceae alkaloids protected human neuroblastoma cells (SH-SY5Y) from neurotoxicity.•Phycella australis has neuroprotective activity in an OA-induced neurotoxicity model.•Phycella australis protect hippocampal slices in oxygen and glucose deprivation/reoxygenation (OGD/R) model.
Raspberry seed is a massive byproduct of raspberry juice and wine but usually discarded. The present study employed a microwave-assisted method for extraction of raspberry seed oil (RSO). The results ...revealed that omega-6 fatty acids (linoleic acid and γ-linolenic acid) were the major constituents in RSO. Cellular antioxidant enzyme activity such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were investigated in HepG2 cells treated with RSO. Induction of the synthesis of several antioxidants in H2O2-exposed HepG2 cells was found. RSO increased the enzyme activity of SOD, CAT, and GPx in H2O2-exposed HepG2. Furthermore, RSO inhibited the phosphorylation of upstream mitogen-activated protein kinases (MAPK) such as c-Jun N-terminal kinase (c-JNK) and extracellular signal-regulated kinase (ERK). Taken together, the possible mechanisms to increase antioxidant enzyme activities in HepG2 may through the suppression of ERK and JNK phosphorylation. Raspberry seed oil exhibited good effects on the activities of the intracellular antioxidant enzymes and seems to protect the liver from oxidative stress through the inhibition of MAPKs.
Context.
The search for extrasolar planets around the nearest M dwarfs is a crucial step toward identifying the nearest Earth-like planets. One of the main challenges in this search is that M dwarfs ...can be magnetically active and stellar activity can produce radial velocity (RV) signals that could mimic those of a planet.
Aims.
We aim to investigate whether the 2.2-day period observed in optical RVs of the nearby active M dwarf star Gl 388 (AD Leo) is due to stellar activity or to a planet that corotates with the star as suggested in the past.
Methods.
We obtained quasi-simultaneous RVs of Gl 388 from 2019 to 2021 with SOPHIE, the optical échelle spectrograph (
R
~75k) at the Observatoire de Haute-Provence in France, and RV and Stokes V measurements with SPIRou, the near-infrared spectropolarimeter at the Canada France Hawaii Telescope (
R
~70k).
Results.
The SOPHIE RV time series (precision of 3–5 m s
−1
per visit) displays a periodic signal with a 2.23 ± 0.01 day period and 23.6 ± 0.5 m s
−1
amplitude, which is consistent with previous HARPS observations obtained in 2005–2006. The SPIRou RV time series (precision of 2 ms
−1
per visit) is flat at 5 ms
−1
rms and displays no periodic signals. RV signals of amplitude higher than 5.3 m s
−1
at a period of 2.23 days can be excluded with a confidence level higher than 99%. Using the modulation of the longitudinal magnetic field (B
ℓ
) measured with SPIRou as a proxy of stellar rotation, we measure a rotation period of 2.2305 ± 0.0016 days.
Conclusions.
SPIRou RV measurements provide solid evidence that the periodic variability of the optical RVs of Gl 388 is due to stellar activity rather than to a corotating planet. The magnetic activity nature of the optical RV signal is further confirmed by the modulation of B
ℓ
with the same period. The SPIRou campaign on Gl 388 demonstrates the power of near-infrared RV to confirm or infirm planet candidates discovered in the optical around active stars. Our SPIRou observations additionally reiterate how effective spectropolarimetry is at determining the stellar rotation period from the variations of B
ℓ
.
Giant condyloma acuminatum (GCA) or Buschke-Loewenstein tumor is a rare disease, with an estimated prevalence of 0.1%. It was initially described in 1896 by Buschke and later in 1925 by Buschke and ...Loewenstein. Classic condyloma acuminata (CCA) and squamous cell carcinoma (SCC) were initially described as different entities. These three entities are currently considered to correspond to the same spectrum of different but not exclusive malignant transformations, associated with multiple risk factors such infection by human papilloma virus (HPV), immunodeficiencies, poor hygiene, multiple sexual partners, and chronic genital infections. HPV subtypes 6 and 11 are associated with 90% of GCA. It presents as a cauliflower-like tumor in the genital region with bad odor, bleeding, and local infection, differential diagnosis with multiple conditions should be considered, and sexually transmitted diseases should always be investigated. GCA has a higher rate of malignant transformation than CCA and tends to infiltrate adjacent soft tissues. The therapeutic approach is controversial but is considered that the resection with free edges is the gold standard and can be combined with adjuncts. The recurrence rate is high. Overall mortality is 21% and is associated with morbidity caused by recurrences. Imiquimod cream 5% has recently shown good results as monotherapy and in combination with ablative and surgical treatments. The quality of life is diminished in patients with this condition. In this review, we address the different aspects of this rare entity including the therapeutic approach.
This work reports the synthesis of nanostructured Ce 1−x Ni x O 2−δ ( x = 0.05, 0.1, 0.15 and 0.2) oxides prepared by a cation complexation route and with the main objective of studying their redox ...properties using a combination of electron microscopy, synchrotron radiation X-ray diffraction (SR-XRD) and X-ray absorption near-edge spectroscopy (XANES). The Ce 1−x Ni x O 2−δ series of nanopowders maintain the cubic crystal structure ( Fm 3 m space group) of pure ceria, with an average crystallite size of 5–7 nm indicated by XRD patterns and confirmed by transmission electron microscopy. In situ SR-XRD and XANES carried out under reducing (5% H 2 /He; 5% CO/He) and oxidizing (21% O 2 /N 2 ) atmospheres at temperatures up to 500 °C show a Ni solubility limit close to 15 at% in air at room temperature, decreasing to about 10 at% after exposure to 5% H 2 /He atmosphere at 500 °C. At room temperature in air, the effect of Ni on the lattice parameter of Ce 1−x Ni x O 2−δ is negligible, whereas a marked expansion of the lattice is observed at 500 °C in reducing conditions. This is shown by XANES to be correlated with the reduction of up to 25% of Ce 4+ cations to the much larger Ce 3+ , possibly accompanied by the formation of oxygen vacancies. The redox ability of the Ce 4+ /Ce 3+ couple in nanocrystalline Ni-substituted ceria is greatly enhanced in comparison to pure ceria or achieved by using other dopants ( e.g. Gd, Tb or Pr), where it is limited to less than 5% of Ce cations.
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