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For the special linear group $$\textrm{SL}_2(\mathbb {C})$$ SL 2 ( C ) and for the singular quadratic Danielewski surface $$x y = z^2$$ x y = z 2 we give explicitly a finite number of complete polynomial vector fields that generate the Lie algebra of all polynomial vector fields on them. Moreover, we give three unipotent one-parameter subgroups that generate a subgroup of algebraic automorphisms acting infinitely transitively on $$x y = z^2$$ x y = z 2 .

Given its central role in utilizing light energy, photoinduced electron transfer (PET) from an excited molecule has been widely studied

Generation units like photovoltaics systems require high efficiency using closed-loop control system. MPPT algorithm permits to track maximum power from photovoltaic module. This paper proposes the predictive control applied to a boost converter of solar plant to increase the controller performance. The controller consists in two control loops: the outer control loop calculates the inductor current oriented by voltage from MPPT algorithm to minimize input voltage error. And inner control loop employs the state-space boost converter model computed using its transfer function to predict the current. Duty cycle that guarantees the current tracks the reference current has computed by a minimized cost function using the future references and the predicted values. Additionally, the proposal employs constant switching frequency using a modulator. A lead-lag controller and sliding mode controller are implemented in order to compare the performance of the predictive controller in experimental setup and the results endorses the proposal.

Background So far there is no study comparing two distinct exercise interventions in people with visual impairment. This study aimed to evaluate the effects of two exercise programs on health-related fitness, quality of life, and exercise enjoyment in people with visual impairment. Methods Two exercise interventions were conducted: sports (i.e., Goalball, Football 5-a-side and Martial Arts) and functional training (i.e., Bodyweight exercises). Physical fitness was assessed by handgrip strength, flexibility, abdominal endurance, and cardiorespiratory fitness. The Physical Activity Enjoyment Scale (PACES) measured the pleasure in the practice of physical exercises, and the quality of life was measured by the WHOQOL-Bref. Results A significant time x group interaction terms were observed for flexibility (P P P = 0.018; Cohen d = 0.02). An improvement of 13.3% and 5.1% on the distance covered on the 6-min walk/run test after sports and functional training was also observed. Conclusion The functional training program was reported as more pleasant for participants. Sports-related exercises and functional training improved health-related fitness and quality of life for people with visual impairment.

Lactoferrin is part of the innate immune system, with antiviral activity against numerous DNA and RNA viruses. Rhinoviruses, the leading cause of the common cold, are associated with exacerbation of respiratory illnesses such as asthma. Here, we explored the effect of bovine lactoferrin (BLf) on RV-B14 infectivity. Using different assays, we show that the effect of BLf is strongest during adhesion of the virus to the cell and entry. Tracking the internalisation of BLf and virus revealed a degree of colocalisation, although their interaction was only confirmed in vitro using empty viral particles, indicating a possible additional influence of BLf on other infection steps. Supplementary Information The online version contains supplementary material available at 10.1007/s00705-021-04993-4.

The lipolytic yeast Yarrowia lipolytica produces cell-wall-associated lipases, namely Lip7p and Lip8p, that could have interesting properties as catalyst either in free (released lipase fraction—RLF) or cell-associated (cell-bound lipase fraction—CBLF) forms. Herein, a mixture of waste soybean frying oil, yeast extract and bactopeptone was found to favor the enzyme production. Best parameters for lipase activation and release from the cell wall by means of acoustic wave treatment were defined as: 26 W/cm2 for 1 min for CBLF and 52 W/cm2 for 2 min for RLF. Optimal pH and temperature values for lipase activity together with storage conditions were similar for both the free enzyme and cell-associated one: pH 7.0; T = 37 °C; and > 70% residual activity for 60 days at 4, − 4 °C and for 15 days at 30 °C.

Movie genre classification is a challenging task that has increasingly attracted the attention of researchers. The number of movie consumers interested in taking advantage of automatic movie genre classification is overgrowing, thanks to media streaming service providers’ popularization. In this paper, we addressed the multi-label classification of movie genres in a multimodal way. To this end, we created a dataset composed of trailer video clips, subtitles, synopses, and movie posters from 152,622 movie titles of the Movie Database (TMDb). Such a large dataset was carefully curated, organized, and made available as a contribution of this work. We labeled each movie of the dataset according to a set of eighteen genre labels. In the experimental evaluation performed in this paper, we computed different kinds of descriptors, such as Mel Frequency Cepstral Coefficients (MFCCs), Statistical Spectrum Descriptor (SSD), Local Binary Pattern (LBP) from spectrograms, Long-Short Term Memory (LSTM), and Convolutional Neural Networks (CNN). With these descriptors, we trained different monolithic classifiers using BinaryRelevance and ML-kNN techniques. Besides, we also explored the combination of classifiers/features using a late fusion strategy. The fusion of a LSTM trained on synopses and another LSTM trained on the movie subtitles provided our best results in F-Score (0.674) and AUC-PR (0.725) metrics. These results corroborate the existence of complementarity among classifiers trained on different sources of information in this field of application. As far as we know, this is the most comprehensive study developed in terms of diversity of multimedia sources of information to perform movie genre classification.

Schinus terebinthifolia Raddi, Anacardiaceae, is a Brazilian plant species, with anti-inflammatory and healing properties. This plant is popularly used for the treatment of several disorders, including thyroid dysfunctions. However, its influence on thyroid physiology is not fully understood. This study investigated the effects of a S. terebinthifolia leaf methanolic extract on the proliferation, viability, and reactive oxygen species (ROS) level of rat thyroid follicular cells. For this, PCCL3 cells were treated with different concentrations of the extract (1–100 μg/ml) and times of exposure (24, 48, and 72 h). The 30 μg/ml concentration significantly reduced cell viability. Thyrocytes treated with the extract presented altered cell morphologies and evidence of oxidative stress. The 50 μg/ml concentration of the extract elicited a pronounced increase in ROS level. The results demonstrated that S. terebinthifolia leaf is harmful to thyroid cells after exposure to high concentrations for prolonged periods. These potentially harmful effects should be considered when this medicinal plant is used in humans. This observation is particularly relevant to individuals with an increased risk of thyroid dysfunctions.

Injections of insulin are the main treatment for diabetes, but in the long run this therapy can induce serious drawbacks. This has inspired new drugs able to decrease insulin requirements. For instance, human amylin (hIAPP) is a small hormone cosecreted by pancreatic β-cells with insulin to which is a synergistic partner. However, the high amyloidogenicity of hIAPP precluded it as a therapeutics and led to the design of pramlintide (sIAPP), a chimeric analogue with substitutions (A25P, S28P, and S29P) inherited from the aggregation-resistant rat isoform (rIAPP). Despite sIAPP advantages, it still shares with hIAPP a poorly soluble profile at physiological pH that hampers its mixture with insulin. Recent improvements, as charge-enhanced mutants, have been proposed. For instance, sIAPP+ was screened in silico by purely microcanonical thermostatistical methods and adds to sIAPP an S20R mutation to uplift its solubility. This suggests that such physically inspired computational approach may also be auspicious on devising effective coformulations of insulin with amylin analogues. In this seminal attempt, we make comparative multicanonical simulations of regular acting human insulin coformulated with hIAPP, sIAPP, or sIAPP+. To assess the respective physicochemical stabilities against aggregation, we characterize the structural-phase transitions through the microcanonical thermodynamic formalism and evaluate their time lags using the classical nucleation theory. These results are then correlated with estimates of solvation free energies, modeled by the Poisson-Boltzmann equation, and structural propensities. Experimental essays are compared to our simulations and support our methodology.

Quantum dots (QDs) have attracted considerable attention as fluorescent probes for life sciences. The advantages of using QDs in fluorescence-based studies include high brilliance, a narrow emission band allowing multicolor labeling, a chemically active surface for conjugation, and especially, high photostability. Despite these advantageous features, the size of the QDs prevents their free transport across the plasma membrane, limiting their use for specific labeling of intracellular structures. Over the years, various methods have been evaluated to overcome this issue to explore the full potential of the QDs. Thus, in this review, we focused our attention on physical and biochemical QD delivery methods—electroporation, microinjection, cell-penetrating peptides, molecular coatings, and liposomes—discussing the benefits and drawbacks of each strategy, as well as presenting recent studies in the field. We hope that this review can be a useful reference source for researches that already work or intend to work in this area. Graphic Abstract: Strategies for the intracellular delivery of quantum dots discussed in this review (electroporation, microinjection, cell-penetrating peptides, molecular coatings, and liposomes).[Figure not available: see fulltext.]

Incorporation of quantum dots (QDs) into porous matrices has triggered the development of novel optical devices. In this work, TiO2 sensitized by CdTe incorporated into bacterial nanocellulose (BNC) membranes were tested as photoelectrodes in a photoelectrochemical cell directed to the water splitting for hydrogen generation. The flexible membranes were produced by immersing BNC membranes in an aqueous solution of CdTe capped with glutathione (CdTe–GSH) and further deposited over a thin layer of TiO2. Incorporation of CdTe–GSH into BNC membranes was confirmed by infrared spectroscopy. Fluorescence spectroscopy revealed that the luminescence intensity increased with the immersion time in the CdTe–GSH solution. Field-emission gun scanning electron microscopy (FEG-SEM) images revealed that the CdTe/QDs (5 nm) were homogeneously dispersed on the cellulose nanofibers. BNC/CdTe–GSH membranes was tested as photoelectrodes. Photoelectrochemical cells exhibited a significant photocurrent in wavelengths ranging from 400 to 800 nm, which indicates their potential for applications as flexible electrodes, sensors and photovoltaic systems.

Bismuth triiodide (BiI3) has been studied aiming the development of lead-free photovoltaic materials. It can also be used as X-ray detectors due to the high density of its elements (bismuth and iodine). We investigate the mechanical stress, hardness, and elastic properties of BiI3 thin films deposited by thermal evaporation. The stress was determined by the bending beam technique using the Stoney equation. The films are tensile with stress of approximately 27 MPa. The hardness and the elastic modulus were determined by nanoindentation technique using a Berkovich diamond tip. The hardness of the films is approximately 0.8 GPa and the reduced Young´s modulus is ∼28 GPa for maximum penetration depth of 10% of the film thickness.

Bismuth triiodide (BiI3) is a potential candidate for application in solar cell due to its good optoelectronic properties and because it is free of toxic elements. It can be used as the absorber material in solar cells or converted into the perovskite-like material MA3Bi2I9, suitable also for photovoltaic applications. Bismuth triiodide has been prepared by physical vapour transport (PVT) and by solution process through spin coating. In this work we present optical and structural/topological properties of BiI3 deposited by thermal evaporation under high vacuum. The films are slightly tensile, polycrystalline, homogenously distributed and with good adherence on several substrates, with an indirect bandgap of 1.81 eV, index of refraction of 3.3 (630 nm), photoluminescence centered at 1.74 eV and a Raman peak at 118cm-1 associated with the Ag mode.