Search

The environment can modify the physiology and body protective function of the skin. Propolis (PRP) and curcumin (CUR) possess important antioxidant and antimicrobial properties, and they can be administered in a combined way and using photodynamic therapy (PDT). Emulgels can control drug release due to the physicochemical properties of the gel and the emulsion. They constitute a good strategy for achieving an improved platform for the combined delivery of PRP and CUR. There are no other studies of emulgels composed of PRP and CUR and their performance as antimicrobial and skin healing using or not PDT. This study aimed to investigate the effect of Carbopol 934 P (C934P), 974 P (C974P) or polycarbophil (PC) on physicochemical stability, antioxidant activity, drug release profile, antimicrobial activity, and ex vivo skin permeation and retention of emulgels containing PRP and CUR. Formulations containing C974P or PC displayed improved stability and antioxidant activity. They displayed activity against Staphylococcus aureus and modified (extended) drug release, governed mainly by non-Fickian anomalous transport. C974P and PC resulted in improved emulgels for combined CUR and PRP delivery, allowing the drugs to cross the stratum corneum, and permeate the epidermis, reaching the dermis. The selected emulgels are candidates for further studies to prove their action and benefits to skin health.

This paper reports on the synthesis and characterization of original sodium calcium silicate glass, with CaF2 as a nucleating agent, along with the successful transformation of the as-made matrix into glass-ceramic. Characteristic temperatures of thermal events were investigated by Differential Thermal Analysis. Volumetric density, refractive index, molar volume, and electronic polarizability of the newly developed glasses were determined and discussed as a function of Ca(O/F2) and Na2O content, fixing glass former SiO2 at 50 mol%. Transmittance and optical band gap energy were evaluated. Network structure was studied through Raman spectroscopy and X-Ray diffraction. Moreover, Eu3+ was used as a local structural probe in equivalent Eu2O3-doped samples. Luminescence properties (emission spectra and transition lifetimes) allowed us to investigate the local environment of precursor glass and glass-ceramic. Calcium fluoride nanostructured glass-ceramic, with 20 nm-sized crystals, was obtained with significant transparency (60–70% in VIS region). The refractive index of synthesized glasses was too close to that of precepted crystals, which is the requisite for high transmittance. The decay time of Eu3+ ions embedded into the matrix has shown that the glass-ceramics environment's phonon energy is lower than in as-made glass, making this matrix an excellent candidate for photonics applications.

We report the recent progress on diode-pumped high-power continuous-wave Pr:LiYF4 (YLF) green laser and deep ultraviolet (DUV) laser generation via intracavity frequency doubling. Using two InGaN blue diode lasers as pump source to form a double-end pumping geometry, in this work, we have demonstrated a green laser at 522 nm with a maximum output power of 3.42 W, which is believed to be the highest power ever achieved in all-solid-state Pr3+ lasers in this specific spectral region. Moreover, by intracavity frequency doubling of the achieved green laser, we have further obtained a DUV laser at about 261 nm with a maximum output power of 1.42 W, which is far higher than previous results. The watt-level 261-nm laser paves the way towards the realization of simple and compact DUV source for a variety of applications.

Objective To evaluate the early stages of the setting process of chemically activated restorative glass-ionomer cements (GICs). Material and methods Five GICs were evaluated (n = 5): Equia Forte (GC), Equia Forte HT (GC), Ketac Universal (3M ESPE), Maxxion R (FGM) and Riva Self Cure (SDI) by Thermography, Fourier Transform Infrared Attenuated Total Reflectance Spectroscopy (FTIR-ATR) and Gillmore needle indentation mechanical testing. The FTIR-ATR spectra showed the formation of metal carboxylates within the cements and enabled the stabilization time (ST) to be determined and the thermographic camera measured the temperature field images in the sample. Data were statistically analyzed by ANOVA and Tukey–Kramer (α = 5%). Results The Gillmore needle test showed that the order of hardening was opposite to the order of ST values determined by FTIR. The results with the thermographic camera showed two stages of temperature variation, which coincided with the evolution of specific infrared bands. The exception was Maxxion R, which showed only a single step change in temperature. Conclusion The early stages of the GIC setting reaction show temperature changes, both endothermic and exothermic, at specific times, confirming the occurrence of individual chemical reactions. The early setting involves reactions other than carboxylate formation. Significance: This study gives further detail of the early stages of the setting of GICs, and past research regarding the setting reaction of GIC.

Thermosensitive bioadhesive formulations can display increased retention time, skin permeation, and improve the topical therapy of many drugs. Acne is an inflammatory process triggered by several factors like the proliferation of the bacteria Propionibacterium acnes. Aiming for a new alternative treatment with a natural source, propolis displays great potential due to its antibiotic, anti-inflammatory, and healing properties. This study describes the development of bioadhesive thermoresponsive platform with cellulose derivatives and poloxamer 407 for propolis skin delivery. Propolis ethanolic extract (PES) was added to the formulations with sodium carboxymethylcellulose (CMC) or hydroxypropyl methylcellulose (HPMC) and poloxamer 407 (Polox). The formulations were characterized as rheology, bioadhesion, and mechanical analysis. The selected formulations were investigated as in vitro propolis release, cytotoxicity, ex vivo skin permeation by Fourier Transform Infrared Photoacoustic Spectroscopy, and the activity against P. acnes. Formulations showed suitable sol-gel transition temperature, shear-thinning behavior, and texture profile. CMC presence decreased the cohesiveness and adhesiveness of formulations. Polox/HPMC/PES system displayed less cytotoxicity, modified propolis release governed by anomalous transport, skin permeation, and activity against P. acnes. These results indicate important advantages in the topical treatment of acne and suggest a potential formulation for clinical evaluation.

The aim of this work was to evaluate the effects of sintering temperature over the structural, physical and mechanical properties in addition to the in vivo biological performance of nanostructured biocomposites obtained from the mixture between calcined fish bone (hydroxyapatite + β-tricalcium phosphate) and niobium pentoxide. The sintering temperatures varied from 650 to 1150°C, in steps of approximately 50°C. The results showed the formation of a stable triphasic nanostructured bioceramic with almost constant relative proportions between the CaNb2O6, PNb9O25 and Ca3(PO4)2 phases. Special attention was given to the sintering temperature at 1080°C because there was occurrence of a liquid phase, and the sample showed localised maximisations of linear shrinkage, density and Vickers hardness. This niobium-biphasic calcium phosphate 1080 (Nb-BCP-1080) nanostructured biocomposite presented measured values for compressive strength (242 ± 29 MPa), Young's modulus (19.63 ± 3.5 GPa), Poisson's ratio (0.248 ± 0.016) and flexural strength (24 ± 5.9 GPa) close to those of some human bones. Then, to further explore these characteristics, in vivo studies were performed by implanting 8.0-mm diameter discs of this material in calvaria of rats. Histological observation showed the occurrence of osseointegration between the neo-formed bone and the triphasic bioceramic just 45 days after implantation. In conclusion, the observations of this work unambiguously show that CaNb2O6–PNb9O25–Ca3(PO4)2 triphasic bioceramics are candidates for bone replacements where high and medium loads are demanded.

Background: Fusarium spp. has been considered as an onychomycosis agent, but little is known about the etiopathogenesis of fusarial onychomycosis; thus, the objective of this study was to characterize the fungal-nail interaction and the consequences of the nail infection process by Fusarium oxysporum using the human nail, in an exvivo model. Methods: The kinetic of biofilm production and infection by F. oxysporum using the nail as the only nutritional source were evaluated by scanning electron microscopy, number of culturable cells, metabolic activity, characterization of extracellular matrix, spectroscopy and histopathology analyses. Results: After evaluating the biofilm kinetic over 7 days using different parameters and techniques, it was possible to characterize the Fusarium-nail interaction. Conclusions: This study is a part of a big project aiming to clarify the fusarial pathogenesis and contributes to proving F. oxysporum is able to adapt, grow, develop, and form a biofilm on healthy human nails, which are crucial steps for the invasion process., This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - Brasil (CAPES) - Finance Code 001, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Fundacao de Amparo a Pesquisa do Estado do Parana (Fundacao Araucaria) and Financiadora de Estudos e Projetos (FINEP/COMCAP)., info:eu-repo/semantics/publishedVersion

In this report, Pr3+-doped calcium aluminosilicate (CAS) glasses were synthesized and their spectroscopic properties investigated. The present subject was motivated by the red emission of the Pr3+ ion that can be combined with the green-yellow emission of other luminescent ions like Ce3+ or Eu2+ for white light generation. This combination of materials has been required since commercial diode devices for white lighting exhibit low color rendering index (CRI) and high correlated color temperature (CCT) due to their low emission intensity in the red region. The results showed that when Pr3+-doped CAS glasses are excited at 445 nm, red and green broadband emissions (FWHM ∼ 1300 and 1800 cm−1, respectively) with a strong dependence on the ion concentration can be observed. The (x, y) coordinates in the CIE-1931 chromaticity diagram changed from (0.61, 0.36) to (0.47, 0.41) when the Pr3+ concentration varied from 0.2 to 2.0 wt.%, what was explained in terms of cross-relaxation mechanisms between Pr3+ ions. The luminescence quantum yield (QY), in the visible range from 450 to 800 nm, of the Pr3+-doped CAS glass was determined by an integrating sphere as 0.37, which is a relatively high value for Pr3+-doped glasses. At high Pr3+ concentrations, the studied system is appropriate to be combined with other green-yellow phosphor material for white light generation.

Chloroaluminum phthalocyanine (ClAlPc) is considered to be an important photosensitizer compound, and it has been extensively explored in photodynamic therapy (PDT) against several types of cancer cell lines. However, ClAlPc is known to be a highly hydrophobic compound. Thus, it requires physical association with a drug delivery system for clinical use. In this study, distinct formulations of PS70.5-b-PAA13 diblock copolymer nanostructures containing ClAlPc were studied. Results found in this study showed that the ClAlPc/PS70.5-b-PAA13 diblock composite presented micellar morphology and a size of 200 nm while dispersed in aqueous media. Additionally, zeta potential studies revealed that such formulations presented colloidal stability with low polydispersity index (PDI) values (0.121). The encapsulation efficiency of ClAlPc by such copolymer micelles, made through spectroscopic measures, was higher than 95% while at the phthalocyanine concentration range from 9.0 to 70 μmol L−1. Spectroscopic studies also showed that the existence of monomeric ClAlPc in such nanostructured micelles is closely dependent on the PS concentration. Low PS concentration resulted in monomeric ClAlPc, as observed from the correspondent absorption and emission spectra of freshly-prepared composite. However, even after 15 days of storage and at low PS concentration, the ClAlPc can self-aggregate within the polymer-micellar nanoenvironment (as observed through spectroscopic studies). Photophysical properties of ClAlPc incorporated in the PS-b-PAA copolymer system revealed promising values of oxygen singlet generation (ΦΔ1O2 = 0.3). Skin permeation studies performed by photoacoustic spectroscopy showed that the ClAlPc/PS-b-PAA nanosystem permeates and reaches the superficial dermis layer. In vitro tests, using Caco-2 cell-lines incubated with ClAlPc/PS-b-PAA formulations at different phthalocyanine concentrations, showed cellular damage after 30 min under light radiation (663 nm with LED, fluence of 1.62 μJ cm−2). The IC50 obtained for the system containing ClAlPc/PS-b-PAA was 1.74 · 10−7 mol L−1. Furthermore, no cytotoxicity effect was observed during cell growth tests performed using both ClAlPc/PS-b-PAA composite and pristine PS-b-PAA nanomicelles in the absence of light irradiation. These findings suggested that the PS-b-PAA diblock copolymer produced a promising nanostructured system suitable for the incorporation of the hydrophobic ClAlPc photosensitizer and for subsequent use in the PDT field.

Thermal lens and Z-scan have been the two most important and used techniques for determining third-order nonlinear optical properties and photothermal properties of optical materials. Both methods have response to thermal and electronic effects, depending on the magnitude of each effect and the experimental arrangement, one method becomes more suitable than the other in order to determine the desired property. In this paper the thermal lens effect is analyzed on time-resolved Z-scan measurements in the cw-single beam configuration. A ruby sample, which presents predominantly electronic effect, is compared to samples presenting predominant thermal effects. The theoretical and a complete experimental description are presented. The difference between both thermal and electronic effects on Z-scan method is assessed and quantified.

In this study, luminescence properties of Tb3+-doped low silica calcium aluminosilicate glasses are analyzed as a function of Tb3+ concentration (0.04–15.0 wt%). Decay curves for the 5D3 level are found to be non-exponential for all Tb3+ concentrations due to ion–ion energy transfer through cross-relaxation process. To identify the origin of the energy transfer mechanism, the decay curves were well fitted by Inokuti–Hirayama model (s = 6), which indicates that the energy transfer process is related to dipole–dipole interaction. Trivalent Tb-doped materials normally exhibit stronger green emission compared to blue emission, a feature that increases with Tb3+ concentration and is attributed to the cross-relaxation process. In this paper, we show a remarkable blue emission in comparison to other Tb3+-doped glasses. A theoretical model for the blue and green emissions, from 5D3 and 5D4 levels respectively, was proposed to establishing a link between the color emission and the 5D3 lifetime quenching due to a cross-relaxation process. This model was successfully applied to the experimental results of this paper as well as previous data in the literature.

T m 3 + / H o 3 + -codoped low silica calcium aluminosilicate (LSCAS) glasses were prepared and characterized using optical absorption, luminescence decay, and thermal lens techniques. The emission band at 2.0 µm exhibited an enhancement when the Ho concentration was increased. The luminescence quantum efficiency values were determined for both 3 F 4 and 5 I 7 levels of T m 3 + and H o 3 + ions, respectively. The high decrease of the quantum efficiency of the 3 F 4 ( T m 3 + ) level for high H o 3 + concentration evidenced efficient energy transfer processes from T m 3 + to H o 3 + . The heat generated in the energy transfer processes were estimated via a thermal lens experiment, and a rate equation model was proposed to explain the obtained result. The experimental and estimated parameters with the proposed theoretical model are in good agreement. Finally, the results of this work suggest the T m 3 + / H o 3 + -codoped LSCAS is a promising material for applications using the emission around 2.0 µm that is of great interest for biomedical applications.

One of the most significant materials in a solar panel is the glass, which provides transparency, UV protection as well as mechanical and chemical resistance. In this work, we describe the production of prototypes of four solar modules made using borosilicate, zinc-tellurite, Pr$^{3+}$ doped zinc-tellurite, and float glass as cover materials. The performance of these prototypes was evaluated under a solar simulator, and a device was developed to monitor all prototypes under real conditions. A comparison between indoor and outdoor measurements shows that outdoor results are fundamental to evaluate the performance of modified solar modules as the ones considered in this study. In addition, we demonstrate the fundamental role played by the refractive index of cover glasses in the performance of the prototypes, and discuss how this feature could be explored to achieve enhanced devices, as well as other benefits that may arise from this field of research., Comment: 6 pages, 3 figures

We evaluated a hydroalcoholic extract of Sapindus saponaria L. pericarps (ETHOSS), as a candidate to a topical antifungal medicine for onychomycosis. ETHOSS was produced by extracting the crushed fruits in ethanol. The saponin contents were identified and characterized by electrospray ionization mass spectrometry. We measured the in vitro antifungal activity against three dermatophyte fungi, isolated from onychomycosis: Trichophyton rubrum, T. mentagrophytes, and T. interdigitale, using broth microdilution tests. The minimum fungicide concentration of ETHOSS ranged from 195.31 to 781.25 μg/mL. The cytotoxicity of the crude extract was tested on the HeLa cell line, and its ability to permeate into healthy human nails by photoacoustic spectroscopy and Fourier transformation infrared spectrometer (FTIR) spectroscopy by attenuated total reflection. Besides its strong antifungal activity, ETHOSS showed low cytotoxicity in human cells. It was able to permeate and reach the full thickness of the nail in one hour, without the aid of facilitating vehicles, and remained there for at least 24 h. These results suggest that ETHOSS has great potential for treating onychomycosis.

Photoluminescence quantum yields denote a critical variable to characterise a fluorophore and its potential performance. Their determination, by means of methodologies employing reference standard materials, inevitably leads to large uncertainties. In response to this, herein we report for the first time an innovative and elegant methodology, whereby the use of neat solvent/reference material required by thermal lens approaches is eliminated by coupling it to photoluminescence spectroscopy, allowing for the discrimination between materials with similar photoluminescence quantum yields. To achieve this, both radiative and non-radiative transitions are simultaneously measured using a photoluminescence spectrometer coupled to a multiwavelength thermal lens spectroscopy setup in a mode-mismatched dual-beam configuration, respectively. The absorption factor independent ratio of the thermal lens and photoluminescence signals can then be used to determine the fluorescence quantum yield both accurately and precisely. We validated our reported method using rhodamine 6G and further applied it to three novel structurally related diketopyrrolopyrrole based materials, which, in contrast to results obtained by other methods, unveiled significant differences in their photoluminescence quantum yields.

Alternative fuels hold considerable promise as substitutes for petroleum diesel fuel. As such, biodiesel is a promising renewable fuel that has been developed and tested by a number of research groups. Quality control of this transportation fuel is of great significance to its commercialization. Conventional chromatographic and spectroscopic analytical methods are most commonly used for biodiesel characterization, in some cases yielding information detail beyond that needed for the determination of biodiesel quality. By contrast, less common methods, such as photothermal techniques, are well suited to characterize a wide range of transportation fuels. The complexities of photothermal and chemical analytical techniques are roughly similar, as are the costs. Photothermal methods are based on spectroscopic and thermophysical properties of the sample, an advantage with respect to ordinary chromatography and spectroscopy techniques. Furthermore, some photothermal techniques can be adapted for remote signal detection, which can be used for in situ analysis in fuel production for inline biodiesel quality inspection and control. Therefore, an overview and outlook of the photothermal characterization is of considerable interest. In this paper, the applications of photothermal techniques in the characterization of biodiesel, petroleum diesel fuels, and their blends are reviewed. The review includes thermophysical properties and correlations for fuels, determination of blend levels, and biodiesel stability investigations. After the review, discussion and perspective are presented for future improvement of photothermal characterization and industrial applications.

Natural or synthetic biomaterials are increasingly being used to support bone tissue repair or substitution. The combination of natural calcium phosphates with biocompatible alloys is an important route towards the development of new biomaterials with bioperformance and mechanical responses to mimic those of human bones. This article evaluated the structural, physical, mechanical and biological properties of a new mechanical improved nanocomposite elaborated by association of fish biphasic calcium phosphate (BCP) and niobium pentoxide (Nb2O5). The nanocomposite (Nb-BCP) and the pure BCP, used as a positive control, were obtained by powder metallurgy. The density, porosity and microhardness were measured. The structural analysis was determined by X-ray diffraction (XRD) and the biological properties were studied in histological sections of critical size calvaria defects in rats, 7, 15, 30, 45 and 60 days after implantation of disks of both materials. Morphological description was made after scanning electron microscopy (SEM) and optical microscopy analysis. After sintering, the Nb-BCP nanocomposite presented four crystalline phases: 34.36% calcium niobate (CaNb2O6), 21.68% phosphorus niobium oxide (PNb9O25), 42.55% β-tricalcium phosphate (Ca3(PO4)2) and 1.31% of niobium pentoxide (Nb2O5) and exhibited increases of 17% in density, 66% in Vickers microhardness and 180% in compressive strength compared to pure BCP. In vivo study, showed biocompatibility, bioactivity and osteoconductivity similar to pure BCP. SEM showed the formation of globular accretions over the implanted nanocomposites, representing one of the stages of bone mineralization. In conclusion, the BCP and Nb2O5 formed a nanocomposite exhibiting characteristics that are desirable for a biomaterial, such as bioperformance, higher β-TCP percentage and improved physical and mechanical properties compared to pure BCP. These characteristics demonstrate the promise of this material for supporting bone regeneration.

Background It is known that bulk-fill have been widely studied and used by dentists in the clinic. However, the use of light-curing units that do not have the ability to adequately light-cure these materials at the appropriate depth can affect their clinical performance. The aim of this study was evaluating the influence of 5 different light curing units (LCUs) on the degree of conversion (DC) of a bulk-fill resin at depths of 0 to 4 mm and determined the effect of using 20s exposure and 40s. Material and methods Cylinders of composite were made in a stainless steel matrix (n=10). The specimens were exposed from the top surface using 5 LCUs: Valo® Cordless (VA); Radii Plus (RA); Emitter.D (EM), Biolux Plus (BI), Woodpecker® (WO). The emission wavelength and the power density was determined. After the photoactivation, the Raman vibrational modes were calculated taking as reference the peaks at 1,601 (aromatic bonds C=C) and 1,640 cm-1 (aliphatic bonds C=C). Results The largest difference in DC in 20s, comparing the values obtained in the first and last layer is for BI, with a variation from 61.24% to 53.86%. Comparing the LCUs, the last layer in 40s DC values are 57.40% (BI), 58.21% (WO), 58.97% (VA), 60.90% (RA) and 62.42% (EM). The higher the dose (J/cm²) and the close the λmax is to the maximum CQ absorption length (λmax ~ 470 nm) the better the DC value. Conclusions There was a significant difference in the DC values between the LCUs with increasing depth of the bulk-fill increments. Results indicate significant differences in DC among the different LCUs as well as enhanced DC when using 40s exposure compared to 20s. It is suggested that for DC improvement using lower power photoactivator increase the exposure time the exposure time should be 20s to 40s. Key words:Polymerization, Composite Resins, Raman spectroscopy.

Current oral squamous cell carcinoma chemotherapies demonstrate off-target toxicity, which could be reduced by local delivery. Curcumin acts via many cellular targets to give anti-cancer properties; however the bioavailability is hindered by its physicochemical characteristics. The incorporation of curcumin into emulgel systems could be a promising approach for its solubilization and delivery. The aim of this work was to develop emulgel systems containing curcumin for the treatment of oral cancer. The emulgels containing curcumin were prepared with poloxamer 407, acrylic acid derivatives, oil phase (sesame oil or isopropyl myristate). The more stable system was evaluated for mechanical and rheological properties, as well as, the in vitro drug release profile, permeation and cytotoxic potential to oral mucosa models. The flow-throw system evidenced that the formulations could keep 5 min over porcine oral mucosa. Emulgel showed pseudoplastic behavior and a gelation temperature of 33 °C, which ensure their higher consistency. In addition, 70% of the incorporated curcumin was released within 24 h in an in vitro drug release study and could permeate porcine oral mucosa. Monolayers cultures and tissue-engineered models showed the selectivity of the drug and systems for tumor cells. The physicochemical properties, subsequent release and permeation of curcumin to selectivity kill cancer cells could be improved by the incorporation into emulgel systems.

Fish oil (FO) is a natural source of omega-3 fatty acids, with well-established beneficial effects in inflammatory diseases when FO is orally administered. This study investigated the effects of a topically applied FO preparation (FOP) on phenol-induced ear edema and evaluated the percutaneous penetration of FOP in ear tissue. After applying phenol, groups of mice received FOP on the ear. After 1 h, ear tissue was collected to determine the percent inhibition of edema, myeloperoxidase activity, and to perform photoacoustic spectroscopy (PAS). Treatment with FOP did not reduce edema, but reduced myeloperoxidase activity. The FOP decreased the area of bands that characterize inflamed tissue and penetrated into the tissue. These results indicated an inhibitory effect of FOP on leukocyte recruitment in phenol-induced ear edema. These data support the applicability of PAS as a non-destructive method for evaluating the inflammatory response, percutaneous penetration and antiinflammatory activity of compounds.

Natural or synthetic biomaterials are increasingly being used to support bone tissue repair or substitution. The combination of natural calcium phosphates with biocompatible alloys is an important route towards the development of new biomaterials with bioperformance and mechanical responses to mimic those of human bones. This article evaluated the structural, physical, mechanical and biological properties of a new mechanical improved nanocomposite elaborated by association of fish biphasic calcium phosphate (BCP) and niobium pentoxide (Nb

The challenge of modifying the solar spectrum intensifies efforts in the pursuit of enhanced materials and optical systems. In this work, we present novel and efficient near infrared-emitting Eu2+ and Nd3+ co-doped sodium calcium silicate glasses. Optical absorption, excitation spectra, emission decay time, were measured and discussed as a function of Nd2O3 content. Laser power-dependent emission intensity was used to evaluate the transfer mechanism, and an energy level diagram was proposed. For the sample doped with optimized neodymium content, energy transfer efficiency reached 70%. For co-doped samples, the excitation spectrum was broadly intense and perfectly overlapped with the solar spectrum in the NUV region. Therefore, NUV/Visible can be efficiently converted into NIR, precisely where the C-Si response is maximal, through the Eu2+→Nd3+ pathway. This work’s outcomes made the focused materials worthy for solar cell applications, optimizing energy conversion lost by thermalization, into useful energy.

Four alternative fuels (AF) were blended with ultralow sulfur diesel (ULSD) at five different proportions (10, 20, 30, 50, and 100 vol % AF) to create 20 binary mixtures in this work. Two renewable jet AFs and two renewable diesel AFs were investigated. Interactions between the components in the mixtures were analyzed by means of spectroscopy (Raman, near-infrared), thermophysical (thermal diffusivity, thermo-optic coefficient), and physical (density) techniques. Correlations among the data were investigated using principal component analysis and partial least-squares regression. Trends in Raman intensities and band positions as well as thermophysical properties showed that the AF/ULSD blends resembled two-component mixtures despite the known complexities of the constituents. Specifically, spectra combined according to the percentages of the components in each mixture; thermophysical and physical properties exhibited similar behavior. The spectra showed strong correlations with all three physical properties, creating the possibility for predicting the properties of similar AF/ULSD mixtures. These properties are governed by the chemical compositions of the fuels.

Dermatological formulations can enable a more efficient therapy by directly delivering the active ingredient to the action site. Photodynamic therapy is a promising technique to eliminate the microorganism in wounds. The present work aims to obtention a dermatological bioadhesive and stimuli-responsive platform that efficiently solubilizes aluminum phthalocyanine hydroxide (AlPcOH) photosensitizer. A better formulation for dermatological application was obtained after evaluation of the formulation polymeric composition and mechanical characterization. Ex-vivo permeation and complete rheological assays were carried out. The photodynamic potential of AlPcOH was evaluated quantitatively and qualitatively. AlPcOH was shown to be incorporated mostly in monomeric form when subjected to the solid dispersion method. Satisfactory results were achieved for the formulation composed of 0.05, 20, and 0.20 % w/w of AlPcOH, F127 and Carbopol. This formulation was easily administered and presented adequate retention at the application site. Furthermore, the system showed a gelation temperature of 29.1 °C, ensuring the preparation, filling, and administration in the bodýs temperature. The nanostructured thermo-responsive platform promoted AlPcOH skin permeation effects and demonstrated a high capacity to generate reactive oxygen species (ФΔ1O2 for AlPcOH of 0.68 in ethanol). All the information provided in this study supports the potential of the AlPcOH-containing platform designed to treat wounds aggravated by microbial infections. It suggests future in vitro and in vivo applications of the platform developed.

Bioactive ferroelectric composites based on polyvinylidene fluoride, hydroxyapatite and β-tricalcium phosphate have been synthesized and their structural, microstructural, bioactive, and ferroelectric properties are characterized. Structural and FTIR investigations showed the presence of the polar polyvinylidene fluoride (β2) phase, while ferroelectric characterizations revealed remnant polarizations and coercive field, around 0.04 μC/cm2 and 28 kV/cm, respectively, for these biocompatible samples. Structural and microstructural analysis of samples previously immersed in simulated body fluid for 7 days revealed a large apatite phase growth (1.45 μm) on the composites' surfaces as a strong indication of their elevated bioactivity and potentialities for bone tissue engineering.

Made available in DSpace on 2018-11-26T17:16:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT) In this work, the combination of three different thermal lens spectroscopic methodologies was used to better determine the fluorescence quantum yield and to observe the concentration quenching in Yb3+-doped binary tellurite glasses (in mol%, 80TeO(2) 20Li(2)O and 80TeO(2) - 20WO(3)). The samples were synthesized by the conventional melt-quenching method and then studied using optical spectroscopy and thermal lens spectroscopy (Us). These characterizations enabled investigation of the radiative and nonradiative processes involved in the ytterbium doped systems. High fluorescence quantum yield was obtained for low Yb3+ doping (>90%), and in both glasses the Yb3+ presented concentration quenching mainly caused by impurities, host-ion interaction and OH- vibrations. The observations suggested that there is a possibility of doping the glasses with higher Yb concentration (>1.6 x 1021 ions/cm(3)) with low reduction of the quantum yield. (C) 2016 Elsevier B.V. All rights reserved. Univ Estadual Mato Grosso do Sul, Grp Espectroscopia Opt & Fototerm, Programa Posgrad Recursos Nat, CP 351, Dourados, MS, Brazil Univ Estadual Paulista, Dept Fis & Quim, Av Brasil 56, BR-15385000 Ilha Solteira, SP, Brazil Fundacao Univ Fed Grande Dourados, Fac Ciencias Exatas & Tecnol, Dourados, MS, Brazil Univ Estadual Maringa, Dept Fis, Av Colombo 5790, BR-87020900 Maringa, PR, Brazil Univ Sao Paulo, Inst Fis Sao Carlos, CP 369, BR-13560970 Sao Carlos, SP, Brazil Univ Estadual Paulista, Dept Fis & Quim, Av Brasil 56, BR-15385000 Ilha Solteira, SP, Brazil FAPESP: 2013/19747-9 Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT): 59/300.031/2015 Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT): 23/200.735/2014

Mucoadhesive nanostructured systems comprising poloxamer 407 and Carbopol 974P® have already demonstrated good mucoadhesion, as well as improved mechanical and rheological properties. Curcumin displays excellent biological activity, mainly in oral squamous cancer; however, its physicochemical characteristics hinder its application. Therefore, the aim of this study was to develop nanostructured formulations containing curcumin for oral cancer therapy. The photophysical interactions between curcumin and the formulations were elucidated by incorporation kinetics and location studies. They revealed that the drug was quickly incorporated and located in the hydrophobic portion of nanometer-sized polymeric micelles. Moreover, the systems displayed plastic behavior with rheopexy characteristics at 37 °C, viscoelastic properties and a gelation temperature of 36 °C, which ensures increased retention after application in the oral cavity. The mucoadhesion results confirmed the previous findings with the nanostructured systems showing a residence time of 20 min in porcine oral mucosa under flow system conditions. Curcumin was released after 8 h and could permeate through the porcine oral mucosa. Cytotoxicity testing revealed that the formulations were selective to cancer cells over healthy cells. Therefore, these systems could improve the physicochemical characteristics of curcumin by providing improved release and permeation, while selectivity targeting cancer cells.

The thermal-wave resonant cavity (TWRC) technique has been used for thermal diffusivity measurements by many researchers. This study aims to reduce the uncertainty associated with TWRC signal processing (curve fitting) by means of numerical simulation and experimental verification. Simulations show that the plot of signal amplitude versus cavity length can be fitted to a simplified model reported previously when the initial fitting position is at least twice the thermal-wave diffusion length (2 μg), and that the uncertainty caused by different end positions is negligible in the range of 6–10 μg. Upon consideration of the simulation results, signal-to-noise ratio, and clearly defined amplitude curve shape, fitting ranges of about 2.2–8.0 μg and 2.2–8.7 μg were chosen for the experimental data. Thermal diffusivity values (1.438 ± 0.001) × 10−7 and (1.436 ± 0.001) × 10−7 m2 s−1, respectively, were obtained for distilled water, in excellent agreement with the accepted literature value. The ratio of standard deviation to the mean value is smaller than 0.07%, one order of magnitude lower than typical results reported in the literature. Similar simulation results were obtained for air and methanol as intra-cavity samples.

The small energy difference between the fundamental level and the first opposite parity configuration of Pr3+-doped hosts is particularly challenging for the characterization of radiative transitions using the Judd-Ofelt theory, although modified versions of the theory have been proposed in the past for the investigation of praseodymium doped materials. Here, we present a detailed spectroscopic investigation on two sets of calcium aluminosilicate glasses, with 34 wt% of SiO2 (CAS) and with 7 wt% of SiO2 (LSCAS), doped with different concentrations of Pr3+ (0.5, 1.0 and 2.0 wt%). We use the standard Judd-Ofelt theory to characterize the glasses and the results and derived spectroscopic quantities — such as transition probabilities, radiative lifetimes and branching ratios — are compared to results obtained by the modified Judd-Ofelt theories. The analysis showed that the modified theories could lead to smaller values of root mean square deviations. However, a better agreement between experimental data and the standard theory was achieved when the derived spectroscopic quantities are taken into account. Moreover, the branching ratios of the P 0 3 → H 4 3 and D 2 1 → H 4 3 transitions were over 60% for both glass hosts, suggesting its potential use as solid-state laser devices.

Aim: To evaluate and characterize the etiopathogenesis of the fusarial onychomycosis in an ex vivo study through fragments of sterile human nail, without the addition of any nutritional source. Materials & methods: The infection and invasion of Fusarium oxysporum in the nail were evaluated by scanning electron microscopy (SEM), CFU, matrix, histopathology and Fourier Transform Infrared Spectrometer coupled to an equipment with diamond accessory (FTIR-ATR). Results: F. oxysporum infected and invaded across the nail, regardless of application face. However, the dorsal nail surface was the strongest barrier, while the ventral was more vulnerable to infection and invasion process. The fungal–nail interaction resulted in the formation of a dense biofilm. Conclusion: F. oxysporum infect and invade the healthy human nail, resulting in biofilm formation. Therefore, F. oxysporum is likely a primary onychomycosis agent.

International audience; In this report, Ti3+, 4+/Eu2+, 3+ co-doped OH− free low silica calcium aluminosilicate glasses (LSCAS) were synthesized and their optical properties investigated aiming applications as phosphors for white light generation. This research explores the possibility of combining the broad emission bands in the visible of these glasses co-doped with Ti3+,4+/Eu2+ ions with those in the red emitted by Eu3+, in addition to the high luminescence quantum yield they present. The excitation and emission results show that exciting the samples at 300 nm, a broad emission band is generated, embracing very well the visible region. The emission spectra were analyzed by (x-y) CIE-1931 chromaticity diagram and the color rendering index (CRI) presented Ra values up to 80, with the correlate color temperature (CCT) varying from 4995 to 6609 K. The luminescence quantum yield determined by Thermal Lens Spectroscopy showed values of 38 and 42% for the samples with (in wt%) 0.1Eu2O3-2.0TiO2 and 0.5Eu2O3-2.0TiO2, respectively. Finally, the energy transfer processes between these luminescent ions were discussed, highlighting the potential of the Eu–Ti LSCAS glasses as candidates for the development of devices for white light generation.