Artigos - Física e Química - FEIS

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Ensino remoto durante a pandemia da Covid-19 nas escolas estaduais do estado de São Paulo: em xeque a acessibilidade para estudantes cegos e com baixa visão
(2024-01-24) Lippe, Eliza Marcia Oliveira Lippe [UNESP]; Camargo, Eder Pires [UNESP]
O objetivo deste artigo é analisar os recursos de acessibilidade disponibilizados pelo Governo do Estado de São Paulo para a garantia de acesso e permanência dos estudantes cegos e com baixa visão na escola no período de 2020 a 2021 para as disciplinas da área do ensino de ciências. Desta forma, a reflexão central do texto foi: o direito ao acesso e a permanência à educação de estudantes cegos e com baixa visão do Estado de São Paulo foram garantidos com o projeto educacional implementado durante o período de isolamento social? Para tanto, utilizou-se como metodologias a pesquisa documental e análise de websites referentes a temática do estudo. Os resultados evidenciaram a exclusão que o ensino remoto proporcionou aos estudantes cegos e com baixa visão no processo de aprendizagem, tendo em vista a ausência de recursos de audiodescrição e materiais disponibilizados em braile nas escolas.
Desenho in silico de novos materiais híbridos multifuncionais à base de mordenita combinados com líquidos iónicos e clusters de prata: desvelando novos processos de captura separação e eliminação de CO2, NO, NO2, H2S e CH3SH.
(2023-11-29) Izquierdo Soto, Rodolfo Enrique
In silico design of novel multifunctional hybrid materials composites based on mordenite combined with ionic liquids and silver clusters. Unveiling new processes of capture, separation and elimination of CO2, NO, NO2, H2S, and CH3SH
(Universidade Estadual Paulista (Unesp), 2023-11-28) Izquierdo Soto, Rodolfo Enrique; Zadorosny, Rafael [UNESP]
The project focused on reducing CO2, H2S, CH3SH, SOx, and NOx emissions by developing new composites that capture and/or convert these pollutants. This project had an extensive and ambitious scope, we emphasize that combining the potentialities of Ionic liquids based on functionalized imidazolium cations (Im-ILs) and zeolites type mordenites, new composites with exceptional capacities can be obtained for gas capture. Im-ILs inside the zeolite cavities may introduce interesting modifications affecting the composite's physical and/or catalytic behavior
Superconducting Nanowires
(2023-01-01) Zadorosny, Rafael [UNESP]; Junior, Milton B.F. [UNESP]; Koblischka-Veneva, Anjela; Koblischka, Michael R.; Universidade Estadual Paulista (UNESP); Experimental Physics
Superconductivity is characterized by two critical lengths, the London penetration depth, Λ L (T), and the coherence length, Ξ(T), so nanowires may have at least one dimension below one of these characteristic lengths. Superconducting nanowires are mesoscopic one-dimensional (1D) objects if the diameter is smaller than Ξ. Consequently, nanostructuring superconducting materials may alter the superconducting properties, quantum fluctuations may dominate and show up effects that are not known from the respective bulk materials, e.g., size-dependent breakdowns of superconductivity or enhanced transition temperatures, T c. As Λ and Ξ increase towards T c, these effects may be prominent around T c. Besides the fundamental questions concerning the mechanisms of superconductivity, there are several possible applications of superconducting nanowires as interconnects, sensitive detectors of magnetic fields (SQUIDs), single photons (SNSPDs), microkelvin temperature variations (nanoSQUIDs), and quantum computer processors for hosting of qubits with improved stability. Superconducting nanowires can be made from metallic low-T c materials as well as from ceramic high-T c superconductors, and several different approaches to fabricating them are described in the literature, including patterning techniques, templating, and spinning processes. The latter techniques, solution blow-spinning, and electrospinning enabled a fully new class of superconducting materials, called fibrous non-woven fabrics with entirely new properties and possible applications.
A systematic interpretation of the quantum cutting effect by a cooperative energy transfer mechanism in Te4+/Yb3+ co-doped tellurite glasses
(2023-06-01) Rufino Souza, Ana Kely; Silva, Junior Reis; Costa, Francine Bettio [UNESP]; Silos Moraes, Joao Carlos [UNESP]; Oliveira Nunes, Luiz Antonio de; Cunha Andrade, Luis Humberto da; Lima, Sandro Marcio; Universidade Estadual de Mato Grosso do Sul (UEMS); Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP)
The near-infrared downconversion (DC) mechanism in Te4+/Yb3+ co-doped 75TeO2–25Li2O tellurite glasses (amounts in mol%) was closely followed using optical and thermal spectroscopy techniques. The glasses were prepared by the conventional melt-quenching method, with a melting temperature of 800 °C, in an ambient atmosphere, which were the best synthesis conditions for observing Te4+ in the glass. The results indicated that excitation in the ultraviolet region led to an intense emission of two NIR photons (at around 978 nm) in the co-doped tellurite glasses. This effect revealed the occurrence of a cooperative energy transfer (CET) mechanism in the system, where a Te4+ ion was responsible for the excitation of two Yb3+ ions. The CET efficiency (ηCET) was calculated from the Te4+ lifetime, obtaining a maximum of 74% for the tellurite glass prepared with the highest Yb3+ concentration. The use of thermal lens spectroscopy confirmed the quantum cutting effect, by observing the dependence of the thermal properties of the glass on the Yb3+ concentration. A maximum DC efficiency of 137% was measured for the sample with 4 mol% of Yb3+.
A sustainable approach on the potential use of kale puree in edible wraps
(2023-06-01) Oliveira, Elaine Florinda Rodrigues de [UNESP]; Bonfim, Kely Silveira [UNESP]; Aouada, Fauze Ahmad [UNESP]; Azeredo, Henriette Monteiro Cordeiro de; Moura, Márcia Regina de [UNESP]; Universidade Estadual Paulista (UNESP); Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Edible films can be used to prevent food spoilage, and investigations in this regard are paramount. When prepared alongside biopolymers, these materials become totally biodegradable in a short period of time, decreasing the amount of solid residues discarded into the environment. The ingestion of fruits and vegetables has increased in the last decades due to significant health benefits, and their durability comprises an important parameter for their marketing and use. Vegetables come in a variety of colors, sizes and shapes, comprising relevant features for their commercialization and packaging and for final consumers. In this regard, kale leaves are highly consumed in Brazil and new alternatives to improve their physical and organoleptic characteristics for novel applications, such as food wraps and in the replacement of high perishability leaves, are of interest in this scenario. Thus, the aim of the present study was to develop kale puree and sodium alginate films and evaluate their solubility, mechanical and thermal properties and water vapor permeability, focusing on improving their physical and organoleptic properties. The films were prepared by casting sodium alginate solutions with the addition of kale puree employing a film generator. Puree incorporation reduced film water vapor permeability and solubility. Pure alginate films presented a contact angle of 50 ± 1°, increasing to 62 ± 2° with the addition of kale puree. The same was noted for the alginate film that, when cross-linked with kale puree displayed an angle increase of 72 ± 5° This behavior may be due to interactions between these components and the hydrophobic phases. Calcium chloride was added for film crosslinking, contributing to biopolymer chain separation and mobility. This study highlights important issues concerning the use of vegetables in the production of edible films, especially biodegradable films, and emphasizes the importance of their development, due to reduced environmental impacts, low costs and the fact that they comprise a renewable resource.
Influence of pinning centers of different natures on surrounding vortices
(2023-01-15) Carvalho dos Santos, Rodolfo [UNESP]; Duarte, Elwis Carlos Sartorelli [UNESP]; Okimoto, Danilo [UNESP]; Presotto, Alice [UNESP]; Sardella, Edson [UNESP]; Motta, Maycon; Zadorosny, Rafael [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Federal de São Carlos (UFSCar)
Studies involving vortex dynamics and their interaction with pinning centers are an important issue to reach higher critical currents in superconducting materials. The vortex distribution around arrays of engineered defects, such as blind and through holes, may help to improve the superconducting properties. Thus, in this work, we used the time-dependent Ginzburg-Landau theory to investigate the vortex dynamics in superconductors of mesoscopic dimensions with a large central square defect with three different configurations: (i) a hole which passes through the sample (interface with the vacuum); (ii) a superconducting region with lower critical temperature Tc; and (iii) a region with a more robust superconductivity, i.e., with a higher Tc. Such systems can be envisaged as elementary building blocks of a macroscopic decorated specimen. Therefore, we evaluated the influence of different interfaces on the vortex dynamics and their effects in the field-dependent magnetization and time-dependent induced electric potential variation. The results show that the superheating field is independent from the nature of the defect. However, the currents crowd at the vertices of the through hole producing a lower degradation of the local superconductivity, which may increase the upper critical field. On the other hand, the last type of defect can be used to control the vortex dynamics in the main superconducting region around the defect with more accuracy. While the first two defects are attractive for the vortices, the third type is repulsive, being needed several penetrated vortices in the superconducting matrix to allow penetration of vortices into the higher Tc domain.
PAAm/CMC/nanoclay nanocomposite hydrogel: understanding the influence of initiators on the chain-growth mechanisms
(2022-12-01) da Silva Fernandes, Renan [UNESP]; Tanaka, Fabrício Cerizza [UNESP]; Junior, Carlos Roberto Ferreira [UNESP]; Yonezawa, Uilian Gabaldi [UNESP]; de Moura, Márcia Regina [UNESP]; Aouada, Fauze Ahmad [UNESP]; Universidade Estadual Paulista (UNESP)
In this study, heat measurements were used to investigate the influence of three initiators on the chain-growth mechanisms of polyacrylamide/carboxymethylcellulose/nanoclay nanocomposite hydrogels. All the matrices had highly interconnected porous surfaces with intercalated configurations. Swelling degree measurements were conducted to investigate the effect of the various formed chains on the physicochemical properties of these matrices. According to the findings, hydrogels synthesized using a potassium persulfate initiator had the highest water absorbency (around 40.8 ± 0.8 g.g^−1), followed by those synthesized using sodium persulfate (38.1 ± 1.0 g.g^−1) and ammonium persulfate initiators (34.8 ± 0.7 g.g^−1). The nanoclay-containing nanocomposite had a similar water absorption tendency. Additionally, all the nanocomposites had a lower swelling degree than pure hydrogel because nanoclay acted as a physical crosslinker in the polymeric matrix, decreasing the chain elasticity and water sorption ability. Different physicochemical properties were then generated due to the difference in polymerization mechanisms. Chain combination was the preferred termination mechanism for the polymerization of the hydrogel with the highest water absorbency. It was also plausible to assume that chain transfer reactions favored the termination mechanisms of the polymerization of the nanocomposites synthesized using NaPS and APS initiators, generating polymeric chains with low molecular weight and reducing the water absorption capacity. The insertion of nanoclay inhibited the start of the polymerization initiation step by preventing the initiator from attacking the monomer. Thus, a better understanding of the interaction between the initiators and hydrogel components can aid in the synthesis of hybrid nanocomposites with desirable characteristics and properties.
Synthesis, Application and Effect of Hybrid Nanocomposites Based on Hydrogel and Nanoclay in Cement-Mortars
(2022-11-01) Watanuki Filho, Adhemar; Higuti, Ricardo Tokio [UNESP]; Moura, Marcia Regina de [UNESP]; Aouada, Fauze Ahmad [UNESP]; Science and Technology of Sao Paulo (IFSP); Universidade Estadual Paulista (UNESP)
Hybrid nanocomposite hydrogels, as admixtures for internal curing of cementitious materials, have been widely studied. This study analyzes the effect of applying 0.5% (wt/wt cement) of pre-soaked hydrogels based on polyacrylamide, carboxymethylcellulose, and three different concentrations of Cloisite-Na+ (0, 10, and 20% wt/wt) on the fresh and hardened properties of cementitious mortars. In general, all mortars with hydrogel decreased the consistency index, mainly M20, due to the high concentration of Cloisite-Na+ that modifies the release kinect of the hydrogel. The results showed a slight variation, with an overall average value of 99% water retention in all mortars. This behavior is due to the portion of hydrogel-mortars dosage water retained to reduce the availability of free water in the mixture because this amount of water is stored, a priori, within the polymer particles. At 28 d, the mortars produced with hydrogels containing 20% of nanoclay (M20) exhibit mechanical behavior similar to the reference mortar (M), which corroborates the percentage of voids found. Scanning electron microscope images confirm that the M and M20 mortars are uniform and possess few pores or microcracks. Thus, these hybrid hydrogels have the potential to be innovative materials for water control improvements in cementitious materials technology.
Properties, synthesis, characterization and application of hydrogel and magnetic hydrogels: A concise review
(2020-01-01) da Silva Fernandes, Renan [UNESP]; Tanaka, Fabrício Nunes [UNESP]; Angelotti, Arthur Maffei [UNESP]; Ferreira Júnior, Carlos Roberto [UNESP]; Yonezawa, Uilian Gabaldi [UNESP]; Watanuki Filho, Adhemar [UNESP]; de Moura, Márcia Regina [UNESP]; Aouada, Fauze Ahmad [UNESP]; Universidade Estadual Paulista (UNESP); (IFSP) - Campus Presidente Epitácio
Magnetic hydrogels are considered smart materials because they can respond to the magnetic field, and in some case, it can also present other sensibilities, like temperature, pH, etc. It can be obtained employing various techniques. Generally, their synthesis consists of a polymeric matrix and at least one magnetic component. The synthesis methods include the most common physical interactions (mixing method) and chemical crosslinking method (grafting method). Hydrogels and magnetic hydrogels can be used in different ways, since biomedical applications until agriculture and the environment. This diversity is based on their properties such as biodegradability, biocompatibility, atoxicity, absorption capacity, hydrophilicity. Beyond these properties, the incorporation of these magnetic particles is relatively easy, producing composites with good stability. It is believed that magnetic hydrogels will soon be able to replace existing materials with the full capacity both for application and for acceptance by the consumer likely.
Root development in Leucaena leucocephala (Lam.) de Wit enhances copper accumulation
(2023-01-01) Bomfim, Nayane Cristina Pires [UNESP]; Aguilar, Jailson Vieira [UNESP]; Ferreira, Tassia Caroline [UNESP]; dos Santos, Beatriz Silvério [UNESP]; de Paiva, Wesller da Silva [UNESP]; de Souza, Lucas Anjos; Camargos, Liliane Santos [UNESP]; Universidade Estadual Paulista (UNESP); Ciência e Tecnologia Goiano
Potentially toxic elements (PTE) in soil like copper (Cu) have been common in agricultural and mining areas worldwide. The sustainable remediation of these areas has been shown to have high socio-environmental relevance and phytoremediation is one of the green technologies to be considered. The challenge is to identify species that are tolerant to PTE, and to assess their phytoremediation potential. The objective of this study was to evaluate the physiological response of Leucaena leucocephala (Lam.) de Wit and to determine the species tolerance and phytoremediation potential to concentrations of Cu in the soil (100, 200, 300, 400 and 500 mg/dm3). The photosynthetic rate was not affected, while the content of chlorophylls decreased as Cu concentrations increased. There was an increased in stomatal conductance and water use efficiency from the treatment of 300. The root biomass and the length were bigger than the shoots, in the treatments above 300. Cu accumulation was greater in the roots than in the shoot of the plants, thus, the Cu translocation index to the shoot was lower. The ability to absorb and accumulate, mainly, Cu in the roots, allowed the development and growth of plants, since the parameters of photosynthesis and biomass accumulation were not affected by the Cu excess. This accumulation in the roots is characterized as a strategy for the phytostabilization of Cu. Therefore, L. leucocephala is tolerant to the Cu concentrations evaluated and has a potential phytoremediation of Cu in the soil.
Application of biohybrid silsesquioxane based material modified with methylene blue for determination of sulphite
(2023-01-01) Freitas, Bianca Trama [UNESP]; Freitas, Rebeca Moreira Lima; Rodrigues, Aline Bento [UNESP]; Baroni, Abner Santos [UNESP]; dos Reis, Idalci Cruvinel; dos Santos Felipe, Alexsandro [UNESP]; Rodrigues, Beatriz Bento [UNESP]; Barbosa, Priscila Fernanda Pereira [UNESP]; Maraldi, Vitor Alexandre [UNESP]; dos Santos Franco, Fernanda [UNESP]; dos Santos Peixoto, Murilo [UNESP]; do Carmo, Devaney Ribeiro [UNESP]; Universidade Estadual Paulista (UNESP); Nanostructured Materials Laboratory
Detecting organic and inorganic contaminants is one of the most important environmental concerns today. Consequently, the search for low-cost materials and efficient technologies for solving such a problem has increased, becoming of the utmost importance.Within this context, the present study applied a new nanostructured bioinorganic hybrid material with great potential in the field of nanotechnology: yeast Saccharomyces cerevisiae chemically modified with cubic silsesquioxane. Based on voltammetric measurements with modified graphite paste electrodes with yeast/silsesquioxane and methylene blue (YSB), the value of anodic peak current decreased linearly as the concentration of sulphite increased. The limit of detection obtained was of 0.60 μmol L−1 and sensitivity amperometric (Sa) of 5.8 × 10−4 μA/mol L−1
Fractionalization of Majorana-Ising-type quasiparticle excitations
(2023-04-15) Sanches, J. E. [UNESP]; Lustosa, L. T. [UNESP]; Ricco, L. S.; Shelykh, I. A.; De Souza, M. [UNESP]; Figueira, M. S.; Seridonio, A. C. [UNESP]; Universidade Estadual Paulista (UNESP); University of Iceland; Mipt; Universidade Federal Fluminense (UFF)
We theoretically investigate the spectral properties of a quantum impurity (QI) hosting the here proposed Majorana-Ising-type quasiparticle excitation. It arises from the coupling between a finite topological superconductor (TSC) based on a chain of magnetic adatoms-superconducting hybrid system and an integer large spin S flanking the QI. It is noteworthy that the spin S couples to the QI via the Ising-type exchange interaction. As the Majorana zero modes (MZMs) at the edges of the TSC chain are overlapped, we counterintuitively find a regime wherein the Ising term modulates the localization of a fractionalized and resonant MZM at the QI site. Interestingly enough, the fermionic nature of this state is revealed as purely of the electron tunneling type and, most astonishingly, it has the Andreev conductance completely null in its birth. Therefore, we find that a resonant edge state appears as a zero mode and discuss it in terms of a poor man's Majorana [Dvir, Nature 614, 445 (2023)0028-083610.1038/s41586-022-05585-1].
Evaluation of tensile, thermal, and biological properties of natural rubber-based biocomposite with biosilicate and 45S5-K bioglass
(2023-06-10) Lima, Luiz R. M. [UNESP]; Caetano, Guilherme F.; Soares, Viviane O.; Santos, Renivaldo J. [UNESP]; Malmonge, José A. [UNESP]; Silva, Michael J. [UNESP]; Yarin, Alexander L.; Universidade Estadual Paulista (UNESP); FHO; Universidade de São Paulo (USP); Universidade Estadual de Maringá (UEM); University of Illinois at Chicago (UIC); Korea University
The objective of this work was to develop new NR-based biocomposite containing BioS and/or BL0 particles, which exhibit better tensile response, biocompatibility, and bioactivity for biomedical applications. Morphological, tensile, thermal, and biological tests were performed on the biocomposites to evaluate the influence of BioS and BL0 particles on the properties of the NR matrix. According to TG/DTG tests, the decomposition profiles of the NR/BioS and NR/BL0 biocomposites were similar to those of NR, whose main event could be seen in the 290–450°C temperature range, indicative of NR's structural degradation. Tensile analysis demonstrated that the addition of BioS or BL0 to the NR-based biocomposite improved the elastic modulus and the tensile strength at break (σat break) in comparison to NR. The σat break value of the NR matrix increased from 0.99 ± 0.06 MPa to 1.84 ± 0.09 and 2.29 ± 0.04 MPa for the NR/BioS and NR/BL0 specimens with 30 wt%. Indirect cytotoxicity testing revealed that NR, NR/BL0, and NR/BioS biocomposite specimens promote the attachment of MSCs cell, that is, greater than 70% viability as defined in ISO 10993-5:2009. The results indicate that BioS and BL0 particles have improved the tensile response and biological properties of the NR matrix, resulting in a range of potential biomedical applications.
Voltammetric and spectroscopic studies of water/formamide ratios in the production of the cerium (III) hexacyanoferrate (II) nanoparticles
(2023-01-01) do Carmo, Devaney Ribeiro [UNESP]; de Oliveira, Denys Ribeiro [UNESP]; Universidade Estadual Paulista (UNESP)
The present study describes the simple and fast preparation of Cerium (III) hexacyanoferrate (II) (CeHCF) solid nanoparticles at three different water/formamide (%) ratios used as solvent (v/v) (100:0, 80:20, 0:100). CeHCF nanoparticles (Nps) were characterized by fourier transform infrared pectroscopy (FTIR), x-ray diffraction (XRD), scanning electron microscopy (SEM), zeta potential and cyclic voltammetry (CV). Electrodes modified with CeHCF presented a well-defined redox pair with formal potential (Eo′) of approximately 0.29 V (vs. Ag/AgCl(sat) attributed to the Fe2 +/Fe3+ redox pair in the presence of cerium (III)). The Nps in the three systems investigates, presents a random size distribution to different surface, where most were distributed between 20 and 160 nm. Considering the three investigated systems, only CeHCF-1 (100:0) was sensitive to L-dopamine, presenting a linear signal region as a function of L-dopamine concentrations, with a limit of detection (LD) of 0.125 mmol L−1, limit of quantification (LQ) of 0.419 mmol L−1 and amperometric sensitivity (S) of 148.16 μA mmol L−1.
Could nitrogen compounds be indicators of tolerance to high doses of Cu and Fe in the cultivation of Leucaena leucocephala?
(2023-01-01) Bomfim, Nayane Cristina Pires [UNESP]; Aguilar, Jailson Vieira [UNESP]; Ferreira, Tassia Caroline [UNESP]; de Souza, Lucas Anjos; Camargos, Liliane Santos [UNESP]; Universidade Estadual Paulista (UNESP); Instituto Federal Goiano
Nitrogen metabolism and the production of primary and secondary metabolites vary according to biotic and abiotic factors such as trace elements (TE) stress, and can, therefore, be considered biomarkers. The present study evaluated the effect of copper (Cu) and iron (Fe) TE, separately, on the metabolism of nitrogen compounds and biomass production, partitioned into shoot and roots of Leucaena leucocephala (Lam.) de Wit., and identified possible defense mechanisms linked to nitrogen metabolism. At 120 days of cultivation, the biomass production of L. leucocephala was higher when exposed to excess Fe than Cu. Nonetheless, the biomass gain (%) of plants exposed to Cu was higher, especially the biomass gains in roots. The tolerance and biomass production of L. leucocephala is related to the regulation of nitrogen metabolism and production of secondary metabolites. The biochemistry of plant metabolism against the excess of Cu and Fe TE manifested similarly, but with some specifics regarding the chemical nature of each metal. There was a reduction in the content of ureides and proteins and an increase in amino acids in the roots in relation to the increase in Cu and Fe concentrations. There was low accumulation of proline in the roots in treatments 400 and 500 mg/dm3 compared to the control for both TE. On the other hand, the total phenolic compounds in the roots increased. Our results indicate that the increased synthesis of amino acids and the accumulation of phenolic compounds is involved in the tolerance of L. leucocephala to Cu and Fe.
Synthesis of β-Arylbutenolides Mediated by BF 3·oMe 2
(2022-08-26) Finêncio, Beatriz M. [UNESP]; Santos, Fernanda A. [UNESP]; Laurentiz, Rosangela S. [UNESP]; Universidade Estadual Paulista (UNESP)
The reaction of phenols or aryl ethers with tetronic acid mediated by BF3·OMe2 was investigated. This strategy allowed for the preparation of β-(hydroxyaryl)butenolides and β-arylbutenolides in a single step in a simpler way than previously reported synthetic methods.
Effect of Curing Modes on the Mechanical Properties of Commercial Dental Resin-Based Composites: Comparison between Different LEDs and Microwave Units
(2022-10-01) Vermudt, Alef; Kuga, Milton Carlos [UNESP]; Besegato, João Felipe [UNESP]; Oliveira, Eliane Cristina Gulin de [UNESP]; Leandrin, Thaís Piragine [UNESP]; Só, Marcus Vinicius Reis; Moraes, João Carlos Silos [UNESP]; Pereira, Jefferson Ricardo; University of Southern Santa Catarina–Unisul; Universidade Estadual Paulista (UNESP); University Federal of Rio Grande do Sul (UFRGS)
Resin-based composites (RBCs) have transformed restorative dentistry and its procedures. However, the characteristics of RBCs have been modified over the years to enhance the physical and chemical properties of the materials. This context raises the need for studies that evaluate whether the properties of the RBCs that are commercially available are clinically adequate with different curing modes. This study aimed to evaluate the mechanical behavior of commercial RBCs after undergoing different curing modes. Twenty-three RBCs of different classes were evaluated. For curing the specimens, a microwave (BMS45, Brastemp) (for 3 min at 450 W) and three LED units were used: an Emitter A Fit (Schuster (second generation)) (light-curing for 15 s with an irradiance of 1250 mW/cm2), VALO (Ultradent (third generation)) (light-curing for 15 s with an irradiance of 1100 mW/cm2), and Emitter Now Duo (Schuster (second generation)) (light-curing for 15 s with an irradiance of 1100 mW/cm2). A total of 670 RBC specimens of 8 mm in diameter and 1 mm in depth were obtained. Afterward, a biaxial flexure strength test was performed until the failure of the specimens, using a universal testing machine set at a speed of 0.5 mm/min. The same specimens were subjected to infrared spectroscopy for evaluating the degree of conversion. Tukey’s test was used for multiple comparisons at a significance level of 5%. The light-curing mode did not affect the flexure strength of the RBCs (p > 0.05), but the type and shade of RBCs did so (p < 0.05). In conclusion, the type of RBC directly interferes with the mechanical behavior of the material. However, the curing modes within the same RBC did not change the mechanical properties.
Larvicidal potential of extracts and isolated compounds from Piper cubeba fruits against Aedes aegypti (Diptera: Culicidae) larvae
(2022-01-01) Gomes, Ana Carolina [UNESP]; Borges, Alexandre; Zoca, Daniela Garcia; Silva, Marcio Luís Andrade e; Machado, Aline Rafaela da Silva Rodrigues; Machado, Alex Martins; Santos, Mario F. C.; de Laurentiz, Rosangela da Silva [UNESP]; Universidade Estadual Paulista (UNESP); Centro Universitário–UNIFUNEC; Universidade de Franca; Universidade Federal de Mato Grosso do Sul (UFMS); Universidade Federal do Espírito Santo (UFES)
Aedes aegypti is the primary vector of virus transmission that causes dengue, yellow fever, chikungunya and zika. The primary prevention method has been vector control and synthetic insecticides that can cause environmental side effects. Thus, the work aimed to evaluate the larvicidal potential of extracts and isolated compounds from Piper cubeba against A. aegypti larvae. The larvicidal activity method was executed according to the World Health Organization protocol. The larvae were analyzed by scanning electron microscopy (SEM). Through molecular docking, the action mechanism was investigated. The hydroalcoholic and hexane extracts showed similar larvicidal activity with LC50 of 191.1 μg/mL and 185.84 μg/mL, respectively. Between isolated compounds, hinokinin presented LC50= 97.74 μg/mL. The SEM analysis showed structural damage to the larva’s tegument caused by extracts and isolated compounds. Therefore, the results demonstrate the larvicidal action of hinokinin and extracts, which can lead to the development of new natural larvicides.
In vivo schistosomicidal activity of (±)-licarin A-loaded poly(ε-caprolactone) nanoparticles
(2022-10-01) Lima, Thais C.; Magalhães, Lizandra G.; de L. Paula, Lucas A.; Cunha, Wilson R.; Januário, Ana H.; Pauletti, Patricia M.; Bastos, Jairo K.; Mnuquian, Hallana Alves; Forim, Moacir R.; Morais-Urano, Raquel P.; Laurentiz, Rosangela S. [UNESP]; Tondato, Wellington N. [UNESP]; Molina, Eduardo F.; Santos, Mario F.C.; e Silva, Márcio L.A.; Universidade de Franca; Universidade de São Paulo (USP); Universidade Federal de São Carlos (UFSCar); Universidade Estadual Paulista (UNESP); Universidade Federal do Espírito Santo (UFES)
Schistosomiasis mansoni is an infectious parasitic disease caused by worms of the genus Schistosoma, and praziquantel (PZQ) is the medication available for the treatment of schistosomiasis. However, the existence of resistant strains reinforces the need to develop new schistosomicidal drugs safely and effectively. Thus, the (±)-licarin A neolignan incorporated into poly-Ɛ-caprolactone (PCL) nanoparticles and not incorporated were evaluated for their in vivo schistosomicidal activity. The (±)-licarin A -loaded poly(ε-caprolactone) nanoparticles and the pure (±)-licarin A showed a reduction in the number of worm eggs present in spleens of mice infected with Schistosoma mansoni. In addition, the (±)-licarin A incorporated in the concentration of 20 mg/kg and 200 mg/kg reduced the number of worms, presenting percentages of 56.3% and 41.7%, respectively.

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