In this work, starch-based porous cryogels with controlled mechanical and electrical properties were prepared for tissue engineering applications. The starch cryogels were formulated using kappa-carrageenan, poly(vinyl alcohol) (PVA), and styrylpyridinium-substituted PVA (SbQ) into the composite. A conductive cryogel was polymerized by chemical oxidation of 3,4-ethylenedioxythiophene (EDOT) using iron(III) p-toluenesulfonate as a strategy to control the electrical properties. The physical, thermal, and mechanical properties were evaluated for the obtained composites. Macro- and nanoscale results confirmed the capability of tuning the mechanical properties of the material by the addition of biopolymers in different contents. The presence of kappa-carrageenan significantly increased the storage modulus and decreased the damping effect in the formulations. The presence of PVA showed a plasticizing effect in the formulations, confirmed by the buffering effect and an increase in storage modulus. PVA-SBQ improved the mechanical properties by cross-linking. The addition of PEDOT increased the mechanical and electrical properties of the obtained materials.

Extensive radiative transfer calculations to fit the more significant average spectral features displayed in measured reflectance spectra by cuticles of Chrysina resplendes scarabs have been carried out. A simulated annealing approach is the starting point to optimize the values of the spatial average uric acid volume fraction, the thickness of the retarder layer located between the two left-handed chiral structures in the cuticle, and the slope of the parameter describing the variation with depth of the uric acid volume fraction through the retarder layer. Both twisted arrangements are characterized in terms of their photonic behaviors to display the variation with depth of the photonic band gaps, effective refractive index and birefringence, wave numbers and relative densities of states.

Objective Evaluate the impact of a “fast” crystallization and simultaneous-glazing on the physicochemical properties of lithium-disilicate CAD/CAM-ceramic. Methods Lithium-disilicate bars and crowns (IPS e.max CAD, Ivoclar-Vivadent) were divided into four groups (n=30): WG/F (WG=with glaze/F=fast crystallization), NG/F (NG=no glaze), WG/C (C=conventional crystallization), and NG/C. A liquid/powder glaze system was used (IPS Ivocolor®, Ivoclar-Vivadent). Specimens were crystallized (Programat P310, Ivoclar-Vivadent) using the P161 program for C (approx. 20-25min), and P165 for F (approx. 14-16min). Bars (n=30) underwent three-point bending tests (flexural strength-FS in MPa and modulus of elasticity-E in GPa) using a universal testing machine. Crowns were analyzed via scanning electron microscopy (SEM) after selective etching, and to Raman, FTIR-ATR, and X-ray diffraction (XRD) spectroscopies to assess chemical composition. Results For FS, both factors/interaction were statistically significant. C (427.48±42.41MPa) showed significantly higher values than F (409.82±38.82MPa). WG (398.32±29.80MPa) exhibited significantly lower FS than NG (438.21±41.77MPa). For E data, both factors/interaction were significant. NG (90.28±14.71GPa) displayed higher E than WG (83.07±5.69GPa), while C (90.08±12.98GPa) exhibited higher E than F (83.46±9.40GPa). NG/C showed the best results for both variables. F groups showed (SEM) porous surfaces and crack-like marks on crystals. FTIR, Raman and XRD spectra confirmed the typical composition of a lithium-disilicate glass ceramic, and some attenuated signals and structural variations (XRD) in WG. Conclusions “Fast” crystallization and simultaneous-glazing produced weaker/less-rigid structures with irregular crystals and glassy phases. Simultaneous glazing may have hindered proper thermal distribution during crystallization. Significance “Fast” crystallization and simultaneous glazing with non-recommended systems, can adversely affect the final properties of lithium disilicate restorations.

AIM or PURPOSE To synthesize polylactic acid (PLA) nanofibrillar spun mats loaded with Ibuprofen (IBU) designed by electrospinning (ES) and airjet spinning (AJS), and to analyze its physicochemical properties, release profile and biocompatibility. MATERIALS and METHOD Solutions of 10% (w/v) of PLA with IBU (10%, 20% and 30%) were prepared using ES and AJS to obtain nanofibrillar spun membranes, which were evaluated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Fourier-transformed infrared spectroscopy (FT-IR). The drug release profile was analyzed by ultraviolet-visible spectrophotometry (UV-vis); and osteoblasts proliferation and adhesion was examined. T-student, likelihood ratio and one-way Anova tests were used to statistically compare fibers dimensions, release profile and cell proliferation respectively. RESULTS The combination between PLA and IBU didn´t affected the drug chemical nature. SEM analysis showed randomly arranged fibers, which formed a reticulated mesh. The fibers sizes were statistically different only for the 20% IBU group (p<0.05). Inflection point evaluated by TGA showed changes in function of IBU concentration; and DSC demonstrated thermodynamic stability of the scaffolds, with changes in enthalpy suggesting the presence of IBU. IBU presence was confirmed by FT-IR and by UV-vis. The release profiles (AJS vs ES) using the likelihood ratio test didn't showed statistical (LR = 0.13126 and P = 0.9365). Cell adhesion (4-24 hours) and cell viability (2, 4 and 6 days) showed similar behaviors. CONCLUSION(S) PLA-IBU nanofibrillar systems were obtained by AJS and ES. Both techniques allowed the obtention of membranes with stable and comparable physicochemical properties, release profiles and biocompatible behaviors.

Encapsulation within a polymeric matrix facilitates targeted drug delivery and release under controlled conditions. This study employed a customized electrospraying system to fabricate zein and poly(vinyl alcohol) particles, optimizing operational parameters to achieve minimized particle size and optimal distribution. Characterization revealed that poly(vinyl alcohol) particles averaged 156 nm, with a peak count at 160 nm, while zein particles averaged approximately 148 nm, with a peak count at 205 nm. These particle sizes fall within the range of optimal potential uptake into the tissue, leading to a better absorption of bioactive agents. Fourier-transform infrared spectroscopy confirmed interactions between poly(vinyl alcohol), zein, and bovine serum albumin forming complex structures, suggesting that bovine serum albumin can be effectively encapsulated with these biopolymers. Our results confirmed that the system is suitable as a potential protein encapsulation method in the development of protein-based therapies.

In this work, the effect of iron(III) in the preparation of a conductive porous composite using a biomass waste-based starch template was evaluated. Biopolymers are obtained from natural sources, for instance, starch from potato waste, and its conversion into value-added products is highly significant in a circular economy. The biomass starch-based conductive cryogel was polymerized via chemical oxidation of 3,4-ethylenedioxythiophene (EDOT) using iron(III) p-toluenesulfonate as a strategy to functionalize porous biopolymers. Thermal, spectrophotometric, physical, and chemical properties of the starch template, starch/iron(III), and the conductive polymer composites were evaluated. The impedance data of the conductive polymer deposited onto the starch template confirmed that at a longer soaking time, the electrical performance of the composite was improved, slightly modifying its microstructure. The functionalization of porous cryogels and aerogels using polysaccharides as raw materials is of great interest for applications in electronic, environmental, and biological fields.

Spectrophotometry has been widely used to retrieve the dielectric function of a bulk iridium sample using an extended version of the Drude–Lorentz model. The parameters of the model are optimized using a spectral-projected-gradient-method-assisted acceptance-probability-controlled simulated annealing approach. Furthermore, optimized values of Drude parameters corresponding to the optical response of electrons and holes (scattering frequency of electrons, the ratio between scattering frequencies of holes and electrons, the ratio between effective masses of electrons and holes, the ratio between the number densities of holes and electrons, and electron volume plasma frequency) are used to evaluate charge transport and magnetic properties. These include static and dynamic conductivities, intrinsic mean free paths, the effective mass of charge carriers and their number densities, Fermi velocities and energies, densities of states at Fermi energies, mobilities, specific heats, Hall’s coefficient, thermal conductivities, charge carrier coupling constant, paramagnetic and diamagnetic susceptibilities, and the number of Bohr magnetons. In addition, optimized resonance energy values of the Lorentz contribution to the dielectric function were compared with the background information provided by density-functional-theory calculations for iridium. A decomposition of the energy loss function was used as the starting point to calculate the effective numbers of bound electrons involved in interband transitions, as well as the densities of states at the final energies of the sets of transitions considered. The Drude–Lorentz model involves charge carrier parameters for both electrons and holes, as well as the resonance energies correlating with the energies associated with quantum transitions. To a large extent, several physical quantities calculated from optimized parameters exhibit values close to those obtained from measurements or by applying other models, including quantum mechanics formulations.

Thermochromic smart windows have been extensively investigated due to two main benefits: first, the comfort for people in a room through avoiding high temperatures resulting from solar heating while taking advantage of the visible light, and second, the energy efficiency saving offered by using those systems. Vanadium dioxide (VO2) is one of the most used materials in the development of thermochromic devices. The countries located in the tropics show little use of these technologies, although studies indicate that due to their characteristics of solar illumination and temperature, they could benefit greatly. To optimize and achieve maximum benefit, it is necessary to design a window that adjusts to tropical conditions and at the same time remains affordable for extensive implementation. VO2 nanoparticles embedded in polymeric matrices are an option, but improvements are required by means of studying different particle sizes, dopants and polymeric matrices. The purpose of this review is to analyze what has been regarding toward the fabrication of smart windows based on VO2 embedded in polymeric matrices for tropical areas and provide a proposal for what this device must comply with to contribute to these specific climatic needs.

Measured reflectance spectra by cuticles of C. resplendens scarabs, in the spectral range 300 to 1000 nm, show high variability depending on the magnitude of the illuminated area, the position of the illuminated section, the elytron, a single specimen, and on the different specimens considered. This fact suggests variability in the depth dependence of the pitch and of the average uric acid concentration, and on the thickness of the retarder layer located between the two helicoidal structures characterizing the cuticle of these beetles.

Tissue engineering, also called regenerative medicine, is the application of the principles and methods of engineering and the biological sciences, to understand the relationship between the structure and function of tissues; and thus, to develop biological substitutes that restore, maintain, or improve the function of damaged or lost tissues. The tissue engineering triad is composed by the scaffolds, the cells and growth factors, or functionalization molecules (Gupte and Ma 2012; Ou and Hosseinkhani 2014).

Coloration in insects provides a fruitful opportunity for interdisciplinary research involving both physics and biology, and for a better understanding of the design principles of biological structures. In this research we used nanometric and micrometric analyses to investigate the morphological and mechanical properties of the black-orange-black (BOB) color pattern in scelionid wasps, which has never been studied. The primary objective of the present investigation was to explore the structural and mechanical differences in the mesoscutum of four species: Baryconus with an orange mesosoma (i.e. BOB pattern), all black Baryconus , Scelio with an orange mesosoma (i.e. BOB pattern), and all black Scelio . The most outstanding findings include the absence of multilayer structures that generate structural color, a pigment concentrated in the upper surface of the epicuticle, and surprising differences between the four species. Three of the four species showed an accordion-like structure in the furrow (notaulus), whereas the adjacent mesoscutum was different in each species. Moreover, the normalized color component spectra for blue, green and red colors of the black mesoscutum of each genus showed the same spectral dependence while the orange color manifested small changes in the dominant wavelength, resulting in slightly different orange tones.

Smart conductive materials are developed in regenerative medicine to promote a controlled release profile of charged bioactive agents in the vicinity of implants. The incorporation and the active electrochemical release of the charged compounds into the organic conductive coating is achieved due to its intrinsic electrical properties. The anti-inflammatory drug dexamethasone was added during the polymerization, and its subsequent release at therapeutic doses was reached by electrical stimulation. In this work, a Poly (3,4-ethylenedioxythiophene): κ-carrageenan: dexamethasone film was prepared, and κ-carrageenan was incorporated to keep the electrochemical and physical stability of the electroactive matrix. The presence of κ-carrageenan and dexamethasone in the conductive film was confirmed by µ-Raman spectroscopy and their effect in the topographic was studied using profilometry. The dexamethasone release process was evaluated by cyclic voltammetry and High-Resolution mass spectrometry. In conclusion, κ-carrageenan as a doping agent improves the electrical properties of the conductive layer allowing the release of dexamethasone at therapeutic levels by electrochemical stimulation, providing a stable system to be used in organic bioelectronics systems.

Small parasitoid wasps are abundant and extremely diverse, yet their colors have not been analyzed. One of the more common color patterns observed in these wasps is a black-orange-black pattern, which is especially common among neotropical species of Scelionidae ranging in size from 2 to 10 mm. Due to the methodological challenges involved in extracting and analyzing pigments from small-sized insects, other methods for examining colors need to be explored. In this work, we propose the use of microspectrophotometry in combination with statistical analysis methods in order to 8 study the spectral properties in such cases. We examined 8 scelionid genera and 1 genus from a distantly related family (Evaniidae), all showing the black-orange-black pattern. Functional Data Analysis and statistical analysis of Euclidean distances for color components were applied to study color differences both between and within genera. The Functional Data Analysis proved to be a better method for treating the reflectance data because it gave a better representation of the physical information. Also, the reflectance spectra were separated into spectral color component contributions and each component was labeled according to its own dominant wavelength at the maximum of the spectrum: Red, Green and Blue. When comparing spectral components curves, the spectral blue components of the orange and black colors, independent of the genera being compared, result almost identical, suggesting that there is a common compound for the pigments. The results also suggest that cuticle from different genera, but with the same color might have a similar chemical composition. This is the first time that the black and orange colors in small parasitoid wasps has been analyzed and our results provide a basis for future research on the color patterns of an abundant but neglected group of insects.

Purpose: The aim of the present in vitro study was to microscopically evaluate and describe the deformation of Lindeman surgical burs and the bone surface roughness after repeated osteotomies and sterilization cycles. Materials and Methods: Twenty-one Lindeman surgical burs were analyzed under scanning electron microscopy (SEM) to evaluate the damage of the bur's integrity after 0, 1, 3, 5, 7, or 9 osteotomies on bovine ribs. Eighteen bone specimens were obtained after osteotomy for roughness analysis using profilometry. One-way analysis of variance was used to compare the mean roughness values across the experimental groups, and P <= .05 was considered to indicate statistical significance. Results: Representative SEM images illustrated that all analyzed burs presented with some type of deformation at both the tip and the body, even after their first use. The mean roughness values were independent of the number of uses (P > .05); however, the standard deviation increased with the number of uses of the burs. Conclusions: These results suggest that even after their first use, rotatory surgical burs will have some type of deformation and that their cutting efficiency on the bone will vary and will be difficult to predict. (C) 2019 American Association of Oral and Maxillofacial Surgeons

A unified description involving structural morphology and composition, dispersion of optical constants, modeled and measured reflection spectra and photonic crystal characterization is devised. Light reflection spectra by the cuticles of scarab beetles (Chrysina chrysargyrea and Chrysina optima), measured in the wavelength range 300–1000 nm, show spectrally structured broad bands. Scanning electron microscopy analysis shows that the pitches of the twisted structures responsible for the left-handed circularly polarized reflected light change monotonically with depth through the cuticles, making it possible to obtain the explicit depth-dependence for each cuticle arrangement considered. This variation is a key aspect, and it will be introduced in the context of Berreman’s formalism, which allows us to evaluate reflection spectra whose main features coincide in those displayed in measurements. Through the dispersion relation obtained from the Helmholtz’s equation satisfied by the circular components of the propagating fields, the presence of a photonic band gap is established for each case considered. These band gaps depend on depth through the cuticle, and their spectral positions change with depth. This explains the presence of broad bands in the reflection spectra, and their spectral features correlate with details in the variation of the pitch with depth. The twisted structures consist of chitin nanofibrils whose optical anisotropy is not large enough so as to be approached from modeling the measured reflection spectra. The presence of a high birefringence substance embedded in the chitin matrix is required. In this sense, the presence of uric acid crystallites through the cuticle is strongly suggested by frustrated attenuated total reflection and Raman spectroscopy analysis. The complete optical modeling is performed incorporating the wavelength-dependent optical constants of chitin and uric acid.

The purpose of this project is to describe the application of an ionized gas to different lines of breast cancer cells, added to application of a clinical photon beam, by measuring variations in cell death rate. This procedure may lead to implementation of a new in vitro technique for studying new radiobiological approaches for adjuvant methods to radiotherapy techniques.

We report measurements of the optical transmission, between 240 and 1040 nm, and electrical resistivity of polycrystalline zirconium thin films as they absorb hydrogen. Both are measured as H-2 pressure is increased up to 880 mbar, at room temperature. Films, 20-22 nm thick, are deposited on fused quartz substrates by e-beam evaporation at 5.3 x 10(-7) mbar base pressure and covered with a 8.0 nm Pd over-coat. The morphology of the films is studied by means of AFM images. The complex refractive indices of Zr and Pd are extracted numerically from the transmission spectra by using a spectral projected gradient method for different hydrogen pressures. The corresponding dielectric functions for various Zr hydrogen concentrations are described with the parametric Drude-Lorentz and Brendel-Bormann (DL & BB) models. The Acceptance-Probability-Controlled Simulated Annealing approach is applied to calculate the parameters of the DL & BB model. This allows us to describe the effect of increasing hydrogen absorption on these parameters and in derived quantities, like the relaxation time and the effective mass of conduction electrons, the electrical resistance, the Fermi energy, and the electronic density of states at the Fermi level. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Nosotros presentamos un metodo que utiliza simultaneamente dos modelos matematicos, con el objetivo de optimizar el diseno de un desacelerador Zeeman, con miras a la implementacion de atomos ultrafrios a la fisica del estado solido. Proponemos la implementacion novedosa de una simulacion por medio de elementos finitos con la cual es posible predecir con mucha precision el perfil de intensidad del campo magnetico generado por el diseno realizado. Al poder predecir el comportamiento del desacelerador Zeeman se adquiere un mayor control, a partir del cual es posible optimizar las diferentes variables experimentales. El metodo propuesto es aplicado para el diseno y construccion de un desacelerador Zeeman solenoidal de tipo "Spin Flip" para atomos de estroncio. El perfil de intensidades de campo magnetico generado por el desacelerador Zeeman construido concuerda con el perfil de intensidades de campo magnetico necesario para el enfriamiento de atomos de estroncio y tiene ademas la ventaja que la intensidad de campo magnetico tiende a cero en los extremos. Ambas condiciones permiten incrementar la cantidad de atomos enfriados y atrapados

We investigate the variation of the oscillation frequency of the Mg2+ and O2− ions in the magnesium oxide lattice due to the interactions of the surface with water monolayers by means of Low Energy Electron Diffraction. Our key result is a new technique to determine the adsorbate vibrations produced by the water monolayers on the surface lattice as a consequence of their change in the surface Debye temperature and its chemical shift. The latter was systematically investigated for different annealing times and for a constant external thermal perturbation in the range of 110–300 K in order to accomplish adsorption or desorption of water monolayers in the surface lattice.