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Made available in DSpace on 2022-05-01T08:44:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) In this research, the influence of synthesis process under Te4+ ion formation in lithium tellurite glass was investigated based in their optical and structural characteristics. The same 80TeO2 + 20Li2O nominal composition (in mol%) was used to prepare glasses with different synthesis temperatures (Ts = 600, 700, 750, 800 and 850 °C) and atmospheres (room, oxygen and argon). The study was based in the investigation of the UV–Vis absorption spectroscopy, Raman spectroscopy, photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies. The linear refractive index was measured in function of the wavelength ranging all the visible region. The results indicate that Te4+ concentration into the glass is strongly dependent on both synthesis temperature and atmosphere. A more intense emission is observed in glasses prepared in oxygen atmosphere and in the 750–800 °C temperature range. Programa de Pós-Graduação em Recursos Naturais - PGRN Universidade Estadual de Mato Grosso do Sul - UEMS Grupo Vidros e Cerâmicas Universidade Estadual Paulista - UNESP Instituto de Física de São Carlos - IFSC Universidade de São Paulo - USP Grupo Vidros e Cerâmicas Universidade Estadual Paulista - UNESP CAPES: 00.889.834/0001-08

Near-near infrared (N-NIR) Thermal Lens Spectroscopy (TLS) was used to monitor the transesterification reaction during biodiesel production. Fifteen aliquots were extracted from the reaction during 20 min and their thermo-optical properties were measured as a function of the reaction time. A spectroscopic investigation was performed between 855 and 990 nm to identify overtone absorptions bands (markers) to monitor the chemical reaction. The results show that the OH absorption overtone (∼970 nm) from alcohol, which is used in the reaction, is the most appropriated marker to monitor the biodiesel production. The time dependence of the thermo-optical parameter A(dn/dQ), which is the product between the absorption coefficient (A) and the refractive index dependence with the sample deposited heat (dn/dQ), exhibits a very good correlation with the ester production measured by chromatography. Besides, the measured thermal diffusivity values as function of reaction time indicates a strong dependence with the viscosity of the aliquots. It is possible to conclude that the used TLS in the N-NIR region contributes to the optimization of biodiesel production process by indicating the best time to stop the reaction.

Made available in DSpace on 2019-10-06T16:31:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-30 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul With the continued increase of technological uses of cerium oxide nanoparticles (CeO2 NPs or nanoceria)and their unregulated disposal, the accumulation of nanoceria in the environment is inevitable. Concomitantly, atmospheric carbon dioxide (CO2)levels continue to rise, increasing the concentrations of bicarbonate ions in aquatic ecosystems. This study investigates the influence of CeO2 NPs (from 0 to 100 μgL−1)in the presence and absence of an elevated bicarbonate (HCO3 −)ion concentration (1 mM), on vibrational biochemical parameters and photosystem II (PSII)activity in leaf discs of Salvinia auriculata. Fourier transform-infrared photoacoustic spectroscopy (FTIR-PAS)was capable of diagnostic use to understand biochemical and metabolic changes in leaves submitted to the CeO2 NPs and also detected interactive responses between CeO2 NPs and HCO3 − exposure at the tissue level. The results showed that the higher CeO2 NPs levels in the presence of HCO3 − increased the non-photochemical quenching (NPQ)and coefficient of photochemical quenching in dark (qPd)compared to the absence of HCO3. Moreover, the presence of HCO3 − significantly decreased the NPQ at all levels of CeO2 NPs demonstrating that HCO3 − exposure may change the non-radiative process involved in the operation of the photosynthetic apparatus. Overall, the results of this study are useful for providing baseline information on the interactive effects of CeO2 NPs and elevated HCO3 − ion concentration on photosynthetic systems. Grupo de Estudos em Recursos Vegetais Universidade Estadual de Mato Grosso do Sul, CP 350 Programa de Pós-Graduação em Recursos Naturais Centro de Estudos em Recursos Naturais Universidade Estadual de Mato Grosso do Sul, CP 350 Laboratório de Nanoquímica Ambiental Departamento de Física e Química Faculdade de Engenharia de Ilha Solteira Universidade Estadual Paulista (UNESP), Avenida Brasil, 56, Centro, Ilha Solteira Grupo de Óptica Aplicada Universidade Federal da Grande Dourados, CP 533 Grupo de Espectroscopia Óptica e Fototérmica Universidade Estadual de Mato Grosso do Sul, CP 350 Grupo de Óptica e Fotônica Instituto de Física Universidade Federal de Mato Grosso do Sul, CP 549 Laboratório de Nanoquímica Ambiental Departamento de Física e Química Faculdade de Engenharia de Ilha Solteira Universidade Estadual Paulista (UNESP), Avenida Brasil, 56, Centro, Ilha Solteira CNPq: 465360/2014-9

Chemical compounds present on the cuticle of social insects are important in communication, as they are used in recognition of nestmates and sexual partners as well as in caste distinction, varying according to several factors, such as genetic and environmental. In this context, some studies have explored the cuticular chemical profile as a tool for assessing intra- and interspecific differences in social insects, although few studies have investigated this in social wasps. This study aimed to assess the differences in cuticular chemical profiles among different geographic samples of the wasp Mischocyttarus consimilis Zikán. Our hypothesis was that environmental factors are decisive to compose the cuticular chemical profiles of colonies of these social wasps and that there are differences regarding the geographic distribution among colonies. We used Fourier Transform Infrared-Photoacoustic Spectroscopy (FTIR-PAS) to assess the chemical profiles of samples. Our results show that despite there are differences between the cuticular chemical composition of the wasps' samples from different populations, there is no significant correlation compared to the spatial distribution of the colonies nor with the environment. Thus, our hypothesis was refuted, and we can infer that in this species neither exogenous nor genetic factors stand out to differentiate the chemical signature of their colonies, but a combination of both.

Novel mononuclear silver(I) complexes based on thiocarbamoyl-pyrazoline ligands were synthesized and structurally characterized. Complexes 1 and 2 were prepared in good yields using a sonochemical method. X-ray diffraction studies revealed trigonal coordination geometry for the AgI atom in complex 1 and distorted trigonal pyramidal geometry in complex 2, according to τ4 parameter analysis. Investigation of photophysical properties revealed intense blue-greenish emissions both in solution and in the solid state when excited at 300 nm. This emission was tentatively attributed to mixed (M+X)LCT and IL electronic transitions taking place after ligand metalation, as shown by DFT calculations. Complete characterization of the prepared compounds was also performed, including 1H and 13C NMR experiments, elemental analysis, infrared spectroscopy, absorption/emission studies, and time-resolved luminescence experiments. The synthesized ligands and complexes 1 and 2 were also tested as antibacterial agents against two standard bacterial strains (Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922) and a panel of clinical S. aureus strains with distinct antibiotic-resistance profiles. Antitumor activity was investigated against melanoma cells (B16F10) and mammary carcinoma cells (4T1).

The thermoxidation of biodiesel was monitored using different spectroscopic techniques: UV–Vis and MIR absorption, Raman spectroscopy, and visible fluorescence. As the oxidation progressed, the UV–Vis absorption spectra showed an increase in the spectral range between 34,000 and 26,000 cm−1, while two main fluorescence bands (under ultraviolet excitation) were observed at around 21,000 and 15,000 cm−1. The UV–Vis absorption and fluorescence intensities presented opposite behavior during the processes, irrespective of the temperature used (90, 140, or 190 °C). These effects could be explained by the consumption of natural antioxidants, followed by the formation of primary oxidation compounds. The Raman and MIR absorption results indicated the existence of a cis-trans isomerization effect, followed by the formation of hydroperoxides during the oxidation, with the behavior being the same as that revealed by the UV–Vis absorption and fluorescence analyses. The comparison, under the same conditions, of different spectroscopy techniques that can be used to monitor the stages of thermoxidation of soybean biofuel provides important information for selection of an appropriate technique for evaluating biodiesel integrity.

Nano-catalysts based on ZnO-Ca x% (with x = 0, 0.1, 0.3, 0.5, 0.7, and 1.0 mol % Ca2+) were synthesized with a bio-friendly adaptation of the sol-gel method using gelatin as template. These materials were characterized by Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Micro-Raman, transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 physisorption, photoacoustic absorption spectroscopy (PAS), and photoluminescence spectroscopy (PL). The Raman results indicated that the signal, attributed to an E1(LO) mode at 580 cm−1, was characteristic of oxygen vacancies that decreased with the increased Ca2+ content in doped oxides. This agreed with the PL results, which showed that the green emission centered at 510 nm and attributable to structural defects in ZnO decreased for Ca-doped ZnO. Our oxides are constituted by nanoparticles with rod-like and spherical morphologies. All the nano-catalysts exhibited the band gap characteristics of semiconductor materials around 3.0 eV. ZnO-Ca 1.0% exhibited the best photocatalytic performance for degradation of Methyl Orange (MO) model dye, degrading about 82% after 240 min of UV–Vis irradiation at pH 7.0. The reaction mechanism was influenced by hydroxyl ( OH) and superoxide (O2 -) radicals and mainly by active holes (h+). This doped oxide also demonstrated efficiency in wastewater disinfection against heterotrophic bacteria and total coliforms, exhibiting a potential use as an antimicrobial agent for the treatment of hospital wastewater. Furthermore, our nanoparticles did not show significant cytotoxic effects on L929 fibroblast cells.

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.

Background absorption has been studied for an YLF:10%Yb3+ crystal at different intensities at room temperature. The cooling efficiency was measured by both the DLT (Differential Luminescence Thermometry) and TLS (Thermal Lens Spectroscopy) methods. Results show that background and coolant absorption saturate differently at room temperature. A cw Ti:sapphire pump beam was tuned from 920 nm to 1040 nm with an intensity range from 100 W/cm2 to 20,000 W/cm2. Changes of temperature and thermal strength were measured by DLT and TLS methods, respectively. The cooling efficiencies with these approaches at different wavelengths were then compared based on theoretical fits to the experimental results. The cooling efficiency at 1000 nm was found to be independent of pump intensity. There, the saturation of intensity of background absorption had the same value as that of Ytterbium. The cooling efficiency below 1000 nm dropped at elevated intensity. In this range, Ytterbium absorption saturated easily, reducing the cooling ion absorption, while the absorption of background impurities did not saturate as much as Ytterbium. Consequently the cooling efficiency was lowered. For wavelengths above 1000 nm, increases in the pump intensity led to improved cooling efficiency. In this range, background absorption saturated more easily than absorption of coolant ions and parasitic heating was reduced, leading to higher cooling efficiency. Thus we have devised a method of measuring differential absorption saturation and determined its effect on laser cooling at room temperature. Saturation effects of this kind have important consequences in the heat equation for radiation-balanced lasers.

This study used the visible fluorescence signal of scales from Astyanax lacustris fishes to differentiate ten populations of streams in Ivinhema River Basin, Upper Paraná Basin, Brazil. Scales were removed from the humeral region of each fish and the fluorescence spectroscopy was carried out with two excitation wavelengths: at 360 nm (UV-A) and 405 nm. The broad emission covers all visible regions and it is related to the organic fraction of scale, basically composed from type I collagen. By interpreting the experimental fluorescence spectra with multivariate statistical analysis, it was possible to discriminate the investigated populations. By exciting the inner face of scales at 405 nm, for instance, the obtained Wilk’s lambda was 0.143, and the ten sampled streams could be statistically differentiated with 85.2% of explanation. This fluorescence interpretation exhibits very good correlation with the diet composition, which was also investigated for the same fishes from which the scales were removed. The applied methodology was capable to analyze the scales of A. lacustris, and to provide meaningful and enlightening results for the differentiation of populations. This methodology is very important for aquatic environmental study, mainly because small fishes, non-migratory or with small migration rate, can exhibit differences among habitats, as response to genetic isolation and adjustment to local conditions.

Al2O3-Zn x% NPs, with x = 0, 1, 3, 5 or 10 mol% Zn2+ were synthesized by a modified sol–gel method. The influence of the insertion of Zn2+ dopant on the crystal lattice, morphology, optical and cytotoxic properties of Al2O3 was investigated. Rietveld refinement applied to DRX data revealed that the oxides are constituted by four crystalline phases: α-Al2O3, θ-Al2O3, δ-Al2O3 and α-Al2O3(*), and that the doping promoted changes in unit cell volume for all the crystalline phases. Raman signals indicated that the insertion of Zn2+ caused changes in the vibrations of bonds Al–O, mainly in tetrahedral sites of transition phases of Al2O3, which are preferentially occupied by Zn ions. The oxides exhibited photoluminescence emission in the visible and near-infrared region, but Al2O3-Zn 10% showed increased emission intensity in the visible region. The nanoparticles with spherical and elongated morphologies did not exhibit cytotoxic effects on L929 fibroblast cells. Zn-doped Al2O3 nanoparticles were synthesized by a modified sol-gel method. The influence of the insertion of Zn2+ dopant on the crystal lattice, morphology, optical and cytotoxic properties of Al2O3 was investigated.

Lutzomyia longipalpis and Lutzomyia cruzi are the main sandflies species involved in the transmission of Leishmania infantum protozoan in Brazil. The morphological characteristics can be used for species identification of males specimens, while females are indistinguishable. Although, sandflies identification is essential to understand vectorial capacity, and susceptibility to infectious agents or insecticides, there is a lack of new strategies for specimen identification. In this study, Fourier transform infrared photoacoustic spectroscopy combined with multivariate analysis identified intraspecific differences between Lutzomyia populations. Successfully group clustering was achieved by principal component analysis. The main differences observed can be related to the protein content of the specimens. A classification with 100% accuracy was obtained using machine learning approach, allowing the identification of sandflies specimens.

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.

Insects can provide clues in a variety of ways to assist in criminal investigations. The FTIR-PAS technique has been successfully used to assess the cuticular chemical profiles of insect samples from different groups and for several goals. However, until now, it has never been used to evaluate samples of forensic interest, despite providing faster results, compared to the methods currently used. In this study, mid-infrared photoacoustic spectroscopy was employed to assess the cuticular chemical profiles of different stages of development of the blow fly Chrysomya megacephala sampled from two distinct populations. The results showed that this technique enabled detection of significant differences between the main vibrational modes of the chemical bonds present in the cuticles of the two populations and the different stages of development of the fly. The method enables identification of the age of individuals collected at the crime scene, as well as the distinction of different populations. Therefore, this methodology could assist in forensic investigations, in both estimating the Postmortem Interval and determining the location where the crime occurred, or whether the body had suffered some type of translocation. The technique provides high reproducibility and fast analysis, so its application for analysis of C. megacephala is a viable option in forensic crime investigations.

Made available in DSpace on 2018-12-11T16:51:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-06-01 Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul In this work, a lithium tellurite glass (80TeO2− 20Li2O, in mol%) was synthesized and its optical properties were analyzed. This glass matrix has been extensively studied, mainly due to its highly nonlinear optical properties, but there have been no reports concerning its luminescence properties. To the best of our knowledge, this is the first observation of visible emission related to Te4+ centers in a lithium tellurite glass. A broad and intense emission band was centered at 650 nm and there was a broad excitation band in the UV–Vis region. The emission lifetime at room temperature was approximately 7.0 ± 0.2 µs and the fluorescence quantum efficiency was 63 ± 6%. These characteristics indicated that the system consisting of Te4+ centers in lithium tellurite glass is a good candidate as a phosphor material for various applications. Grupo de Espectroscopia Óptica e Fototérmica Universidade Estadual de Mato Grosso do Sul, C. P. 351 Grupo de Pesquisa de Materiais Fotônicos e Energia Renovável Universidade Federal da Grande Dourados Grupo Vidros e Cerâmicas Faculdade de Engenharia de Ilha Solteira – UNESP Laboratório de Laser e Aplicações Universidade de São Paulo, C. P. 369 Grupo Vidros e Cerâmicas Faculdade de Engenharia de Ilha Solteira – UNESP Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul: 23/200.735/2014

Very few devices are capable to measure temperature with high precision and sensitive, mainly in the micro and nanoscale. It is known that for biological applications it is required high sensitivity devices in a short temperature range (288–323 K). Recent reports are proposing the use of ratiometric thermometers based in the luminescence of trivalent lanthanide ions. In this paper, the ratiometric thermometer characteristic was investigated in an alumino-phosphate glass doped with Eu2O3. The studied temperature range was 288 – 333 K, and the material presents high sensitivity values (1.25–1.68% per K). The luminescence of Eu3+-doped alumino-phosphate glass does no present losses by energy transfer mechanism in this temperature range, making a quick predicable thermometric parameter by use of ratio between the integrated intensities of 5D0 → 7F2 and 5D0 → 7F0 transitions, respectively. Both excitation and emission are in wavelengths not strongly absorbed by living tissues, becoming promising material to applications in the laboratories scale, as the temperature measurements of cell cultures, and monitoring of tissues that does not require high penetration of excitation wavelengths.

In this work, we report the use of the fluorescence spectroscopy to identify lubricant oils. Optical characterization was performed in four commercial lubricant oils that are used in the reciprocating compressors. Mid-infrared absorption of samples indicates the presence of aromatic rings showing bands at 1605 cm-1 (C=C stretching) and 815 cm-1 (C–H stretch out of plane). UV-VIS absorption spectra show bands of di and polyaromatic rings (around 230 nm and 260 nm respectively). Exciting the samples at 360 nm, a broad emission band centred at 440 nm is observed, indicating that this excitation is appropriate to be used for the diagnosis of the oil presence in the environment.

A dual-beam mode-mismatched configuration of the Thermal Lens (TL) technique was applied to characterize biodiesel, diesel and diesel/biodiesel blends. The excitation was performed using a tunable laser in the near-near infrared region in order to assess overtones and combination bands of the vibration modes. The thermo-optical properties of the fuels were also determined. The results showed that the biodiesel contents in diesel/biodiesel blends can be monitored with this technique, by excitation the third overtone of the C–H (4ν(C–H)) bond stretching vibration at 916 nm. Both the amplitude of the photothermal signal and thermal diffusivity are important parameters to quantify the biodiesel content in diesel/biodiesel blends.

Thermal lens spectroscopy (TLS) in the near-near-infrared region was used to explore the absorptions of overtones and combination bands of sulfentrazone (SFZ) herbicide diluted in methanol. This spectroscopic region was chosen in order to guarantee that only thermal lens effect is noted during the experimental procedure. The results showed that it was possible to detect very low concentrations (~2ng/μL) of SFZ in methanol by determining its thermal diffusivity or the absorption coefficient due to the 3ν(NH)+1δ(CH) combination band. This minimum SFZ concentration is the limit observed by chromatography method. The findings demonstrated that the TLS can be used for precise and accurate assessment of pesticides in ecosystems. Besides, the 3ν(NH)+1δ(CH) combination band at 960nm can be used as a marker for SFZ in methanol.

ZnO-Al x% nanoparticles (NPs), with x = 0, 1, 3, 5 or 10 mol% Al3+, were synthesized by a modified sol-gel method. The effects of Al3+ content on the structure, morphology and optical properties of Al-doped ZnO were investigated by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, photoacoustic absorption spectroscopy (PAS), photoluminescence spectroscopy (PL) and specific surface area determination. A single crystalline phase characteristic of ZnO with wurtzite structure was detected for all synthesized oxides. With increasing dopant content, the average crystallite size of the NPs decreased from 25 to 7 nm. ZnO-Al x% NPs exhibited enhanced optical properties with the absorption slightly shifted to the visible region and with the band gap energy (Eg) decreased from 3.12 (undoped ZnO) to 2.95 eV (ZnO-Al 3%). Undoped ZnO showed intense PL above 430 nm, which was considerably decreased with the insertion of Al3+. Despite the increase of the surface area with Al3+ doping of ZnO NPs, its catalytic activity in the decomposition reaction of Congo red showed a decrease with doping. Research has shown that ZnO NPs can selectively target and kill cancer cells and that its cytotoxicity is dependent of the concentration. The doping can be a method of shape the cytotoxicity of ZnO NPs and their optical and photocatalytic properties. In-vitro cytotoxicity studies showed that both undoped ZnO and Al-doped ZnO NPs synthesized were highly cytotoxic for fibroblast cells, suggesting that these nanomaterials could be promising anticancer agents.

Studies of venomous animals have shown that environmental and genetic factors contribute to determining the chemical composition of venom. It is well known that external effects cause differences in the toxicity, concentration, and prey specificity of venom. However, the influence of different factors on the chemical profile of Hymenoptera venom remains little explored. In view of this, the aim of this study was to evaluate intraspecific differences and the influence of diet on the chemical profile of Ectatomma brunneum venom using Fourier transform infrared photoacoustic spectroscopy. For the study of intraspecific variation of the venom, foragers were collected at locations with different environmental conditions, such as urban, intermediate, woodland and monoculture sites. To investigate the influence of diet on the venom, two colonies were sampled in the same area and were maintained in the laboratory under controlled diet conditions and at room temperature. The mid-infrared absorption spectra obtained were interpreted using discriminant function analysis. The results showed significant differences among the chemical profiles of the venoms of individuals from different environments and individuals exposed to a controlled diet in the laboratory, suggesting that venom composition was determined not only by genetic traits inherent to the species, but also by exogenous factors.

SUMMARY The purpose of this study was to evaluate the chemical bonds of a self-etch 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) adhesive to natural noncarious cervical lesions (NCCLs) and compare them with those occurring in sclerotic dentin in artificially prepared defects (APDs). Four human teeth with natural NCCLs on the buccal surface were selected. Artificial defects matching the natural lesions were prepared on the lingual surface of the same teeth serving as control. Micro-Raman (MR) spectroscopy was used to quantify mineral content in natural NCCLs and in APDs. Fourier transform infrared-photoacoustic spectroscopy (FTIR-PAS) readouts were taken before and after adhesive application to analyze the protein matrix/mineral (M:M) ratio and chemical interactions between 10-MDP adhesive and dentin. The MR and FTIR-PAS spectra collected from natural NCCLs demonstrated a larger area of the band (961 cm−1, PO4) and lower M:M ratio, respectively, characterizing a hypermineralized dentin, compared with APDs. FTIR-PAS demonstrated emergence of a peak (1179 cm−1, P=O) in spectra after adhesive treatment, demonstrating a more intense chemical interaction in natural NCCLs. The results demonstrated that chemical bonding of 10-MDP adhesive to natural NCCLs is more intense, due to the hypermineralized surface, and suggest that it is unnecessary to remove the hypermineralized layer with burs, as this may decrease the chemical bonding potential of 10-MDP.

In the present work, we explored multiple data from different biological levels such as cuticular hydrocarbons, chromosomal features, and mtDNA sequences in the Neotropical social wasp Mischocyttarus consimilis (J.F. Zikán). Particularly, we explored the genetic and chemical differentiation level within and between populations of this insect. Our dataset revealed shallow intraspecific differentiation in M. consimilis. The similarity among the analyzed samples can probably be due to the geographical proximity where the colonies were sampled, and we argue that Paraná River did not contribute effectively as a historical barrier to this wasp.

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

© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Development of novel bioimaging materials that exhibit organelle specific accumulation continues to be at the forefront of research interests and efforts. Among the various subcellular organelles, mitochondria, which are found in the cytoplasm of eukaryotic cells, are of particular interest in relation to their vital function. To date, most molecular probes that target mitochondria utilise delocalised lipophilic cations such as triphenylphosphonium and pyridinium. However, the use of such charged motifs is known to be detrimental to the working function of the mitochondrial transmembrane potential and there remains a strong case for development of neutral mitochondrial fluorescent probes. Herein, we demonstrate for the first time the exploitation of diketopyrrolopyrrole-based chemistries for the realisation of a neutral fluorescent probe that exhibits organelle specific accumulation within the mitochondria at the nanomolar level. The synthesised probe, which bears a neutral triphenylphosphine oxide moiety, exhibits a large Stokes shift and high fluorescence quantum yield in water, both highly sought-after properties in the development of bioimaging agents. In vitro studies reveal no interference with cell metabolism when tested for the human MCF7 breast cancer cell and nanomolar subcellular organelle colocalisation with commercially available mitochondrial staining agent Mitotracker Red. In light of its novelty, neutral structure and the preferential accumulation at nanomolar concentrations we anticipate this work to be of significant interest for the increasingly larger community devoted to the realisation of neutral mitochondrial selective systems and more widely to those engaged in the rational development of superior organic architectures in the biological field.

Wasps can synthesize chemical compounds called venom whose function is to overcome prey and assist in defense of the colonies. Geographic Parameters such as sex, age, the season of the year, and diet determined the composition of the venom location, genetics, environment. However, studies on the compositional variability of venom are still limited due to the difficulty in obtaining samples and the complexity of these substances. This work describes the use of the Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) to investigate inter- and intraspecific variability in the venom chemical composition (VCC) of the social wasp Polybia paulista (Von Ihering 1896) and the ant Ectatomma brunneum (Smith 1858). The results reveal significant differences in VCC among the ant and wasp, even for samples obtained from the same environment. The genetic component, therefore, seemed to be the predominant factor determining the compounds present. The findings also showed that exogenous factors, such as diet, could also be responsible for intraspecific differences, especially in wasps. The FTIR-PAS technique proved to be a reliable way of assessing intra- and interspecific differences in social Hymenoptera VCC.

International audience; In this work Thermal Lens Spectroscopy (TLS) is used for sensitive characterization of absorption in optical materials with particular application for solid-state laser cooling (optical refrigeration). TLS is used to characterize key parameters involved in 4f-4f transition in Yb3+:YLF and 4f-5d transition in Ce3+:YAG systems. The results confirm the excellent laser cooling results found in previous works on Yb3+:YLF crystal. In addition, although no cooling effect was observed in Ce3+:YAG sample, the TLS showed that this material exhibits promising characteristics towards laser cooling applications, such as high external quantum efficiency (>92%), and low parasitic background absorption of (1.2 ± 0.2) × 10−4 cm−1 at 885 nm. The key mechanisms that appear to inhibit net cooling in Ce3+:YAG are attributed to the intrinsic excited state absorption and/or 4f-4f transitions between the two lowest levels of Ce3+. This investigation was turned possible due to the high sensitivity of TLS for very low absorptions.

Made available in DSpace on 2019-10-06T16:57:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-04-15 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) Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul Te4+/Yb3+ co-doped 80%TeO2–20%Li2O glasses (amounts in mol%) were prepared by the conventional melt-quenching method in an ambient atmosphere, in order to investigate their optical characteristics for application in solar cells. An efficient near-infrared down-conversion mechanism was observed in these samples, involving the emission of two near infrared photons (at around 978 nm) after the absorption of one photon in the ultraviolet-blue region. This effect occurred by means of a process of cooperative energy transfer (CET) from Te4+ to Yb3+ ions. The CET efficiency (ηCET) was calculated from radiative transitions (lifetime) and also by a new method, developed in this work, based on rate equations quantifying the non-radiative transitions (thermal effect) involved in the system. The two methods showed very good agreement, with ηCET between 82 and 100% obtained for the sample prepared using a higher Yb3+ concentration (4 mol%). The results suggested that these tellurite materials could have potential applications in improving the efficiency of silicon-based solar cells. Grupo de Espectroscopia Óptica e Fototérmica Universidade Estadual de Mato Grosso do Sul, C.P. 351 Grupo Vidros e Cerâmicas Faculdade de Engenharia de Ilha Solteira – UNESP Laboratório de Laser e Aplicações Universidade de São Paulo Grupo Vidros e Cerâmicas Faculdade de Engenharia de Ilha Solteira – UNESP FAPESP: 2013/19747-9 Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul: 23/200.735/2014 Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul: 59/300.031/2015

The objective of this study was to evaluate the efficiency of Laser-Induced Breakdown Spectroscopy (LIBS) to detect the presence of bioaccumulated Fe and Pb in scales of Salminus brasiliensis and Prochilodus lineatus, and to compare the results from this technique with those obtained using the conventional atomic absorption spectrometry technique. The study used fish collected in the Amambai River, Upper Parana River, Brazil. The LIBS technique detected the presence of Fe in S. brasiliensis scales and Fe and Pb in P. lineatus scales on different regions. Using atomic absorption spectrometry, we verified a significant difference in Fe concentration in scales between the species analyzed, with a higher concentration in S. brasiliensis than in P. lineatus (p = 0.0004). Pb was not detected using atomic absorption spectrometry in either species because the concentration of this element was below the limit of detection of this technique. The LIBS technique was efficient in detecting Fe and Pb in scales of the two species analyzed, proving to be a promising tool for environmental monitoring.

The increased use of fertilisers is a well-known problem; linked to this, there is an always higher demand for phosphorus (P). Because of this, it is crucial to use P from all possible sources and, if necessary, turn it into a soluble form, available for plants/crops. In this paper we report the use of aerobic phosphate solubilising bacteria (PSB) on the scales of the tilapia (Coptodon rendalli) fish, a waste from the food industry; this is the first time that PSB were employed on fish scales to mediate the available P. The scales were calcined to 700 °C to obtain a nanoscale powdery material (more easily solubilised), made of hydroxyapatite, Ca10(PO4)6(OH)2, a calcium phosphate with very low solubility. Seventeen different PSB strains were tested for their ability to solubilise phosphate (commercial tricalcium phosphate - TCP) and hydroxyapatite from fish scale (FSHA). The best performing bacterial strain (Acidovorax oryzae ZS 1–7) led to a P solubilisation more than 60 times higher than the negative control – at 325 mg/L, almost 40% of the available P was solubilised – one of the highest increased efficiencies reported for PBS. Such solubilisation was linked to a decrease of the pH to more acidic values of about 4. The strain ZS 1–7 showed higher P solubilisation efficiency with fish-derived FSHA than with commercial TCP. This approach showed a promising strategy for the valorisation of residues of the fish industry, turning them into a source of P, to be used for sustainable agriculture.

The dual-beam mode-mismatched thermal lens (TL) technique in the near infrared (NIR) and visible spectral regions, as well as mid-infrared (MIR) absorption conventional spectroscopy, were applied to carry out a full spectroscopic characterization of chloroform, dichloromethane, methanol, and ethanol. Absorption spectra due to overtones and combination bands of C−H and O−H bond stretching were acquired in a wide spectral region (870–1040 nm) using a tunable Ti3+:sapphire laser, enabling determination of the anharmonicity constants (χ) and dissociation energies. Moreover, the solvents thermal diffusivities were obtained and absorption coefficients ~10−4 cm−1 or lower were found in some spectral transparence windows in chloroform and dichloromethane. The TL technique proved to be a very sensitive methodology able to determine of overtones with low absorption coefficients.

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.

The aim of this study was to evaluate the fluorescence of Astyanax lacustris fish scales when excited in the UV-A and blue regions for use as a bioindicator of aquatic ecosystems. This species was firstly defined as Astyanax altiparanae, popularly known as "lambari-do-rabo-amarelo". Currently, abiotic/biotic environmental integrity is generally assessed using limnological and physicochemical parameters related to biological indicators in streams or rivers, which are not sufficient to evaluate the real environmental conditions: in some cases, these parameters can be strongly dependent on local weather conditions. In this study, after the fish scales were excited with UV-A (360nm) and blue (405nm) photons, a strong and broad visible fluorescence band (from blue to red) could be observed that was mainly related to collagen and hydroxyapatite, independent of whether the excitation was applied to the inside or outside of the scale. Selected emission wavelengths were used as variables and the fluorescence intensities were interpreted using multivariate discriminant statistical analysis to compare streams with known different levels of integrity. The fluorescence data showed strong correlation with the electrical conductivity of the water, indicating that the scales of A. lacustris could be employed as bioindicators of environmental integrity on water chemistry monitoring programs.

An uncommon emissive pseudotetranuclear compound, {[Au2(C3H6NS2)2][Au(C3H6NS2)2]2(PF6)2}, was synthesized and characterized in terms of its structure and optical properties. The synthesis produced a crystalline compound composed of four gold atoms with two different oxidation states (Au+ and Au3+) in the same crystalline structure. The title complex belonged to a triclinic crystalline system involving the centrosymmetric P1 space group. X-ray diffractometry and vibrational spectroscopy (infrared, Raman, and SERS) were used for structural characterization of the new crystal. The vibrational spectroscopy techniques supported the X-ray diffraction results and confirmed the presence of bonds including Au–Au and Au–S. Optical characterization performed using UV–vis spectroscopy showed that under ultraviolet excitation, the emissive crystalline complex presented characteristic broad luminescent bands centered at 420 and 670 nm.

Films and fibers of PMMA/ZnO nanocomposites (100/0, 99/01, 97/03, 95/05, 90/10, and 85/15 wt.%) were produced by casting and electrospinning, respectively. Their structural, thermal, and optical properties were investigated by XRD, SEM, TGA, PAS, and PL. The incorporation of ZnO NPs reduced the diameter of PMMA fibers and the presence of beads. The surfaces of the fibers exhibited greater hydrophobicity, compared to the films, with contact angles of around 120° and 94°, respectively. PMMA films containing ZnO exhibited higher thermal stability than the pure polymer, while the corresponding fibers did not show any changes in thermal stability. The dispersion of the ZnO NPs at the surface and in the bulk of the nanocomposites appeared to be relatively homogeneous. ZnO improved the optical properties of the PMMA, with an intense absorption band near 370 nm observed for all the nanocomposites, which also exhibited luminescence with emission in the near-UV region, both attributed to ZnO. Biological tests demonstrated that fibers and films with up to 1% of ZnO exhibited good performance in the proliferation of fibroblast cells, indicating their potential for applications in tissue engineering. The fibers provided higher cell viability than the films, presumably due to their greater surface area and/or more suitable surface morphology. Nanocomposites with 15% ZnO inhibited cell proliferation, due to the cytotoxicity of the ZnO NPs. Although several applications of PMMA have been suggested by biomedical researchers, until now there have been no reports on the specific uses of fibers and films of PMMA/ZnO nanocomposites as scaffolds for fibroblast cell proliferation.

Astyanax altiparanae fish species is considered very generalist and opportunist, occupying different types and sizes of environments. This characteristic turns it very appropriate as bioindicator or biomarked. Therefore, in this work, A. altiparanae fish species was used to identify populations by using the Fourier transform infrared spectroscopy directly in its scales. The discriminant analysis applied in the infrared spectra demonstrated a significant differentiation among the analyzed populations, with the first and second canonical roots explain together 100% of the data variation. The obtained results were correlated with environmental descriptors and diet of fishes, and a better agreement was obtained when spectroscopic data were compared with the composition of food present in the fish stomachs. However, this study indicates that the combination of infrared absorption spectroscopy with discriminant analysis is a very appropriate methodology to be used in fish scales as bioindicator for intraspecific study.

Via this article, the optical features and ionizing radiation shielding competences of xTeO2 − (100 − x)Li2O, where x = 70 to 95 in steps of 5 mol% glasses to be used in nuclear shielding areas were evaluated. These glasses were coded as TL05-TL30 according to x value. Refractive index (noptical), molar (refractivity (Rmolar) and polarizability (αmolar)), reflection loss (Rloss), Optical transmission factor (Toptical), dielectric constants (estatic and eoptical), and metallization criterion (Mcriterion) of TL-glasses have been investigated. The mass (MAC) and linear (LAC) attenuation coefficients were examined via Geant4 toolkit simulation code and verified via Phy-X/PSD. Results revealed that the (noptical) was increased from 2.24 to 2.30. The Rmolar varied from 17.432 to 19.122 (cm3/mol), the αmolar increased from 6.917 to 7.588 (×10−24 cm3), and the (estatic) varied from 5.022 to 5.308. The TL30 glasses possess the lowest values, while TL05 found to possess the maximum MAC values. The MAC values were in the order of (MAC)TL05 > (MAC)TL10 > (MAC)TL15 > (MAC)TL20 > (MAC)TL25 > (MAC)TL30 which highlights the role of Te addition to the glass matrix to enhance the shielding capacity of theses glasses. The HVL of these TL-glasses can be arranged in reverse order with MAC, where (HVL)TL30 > (HVL)TL25 > (HVL)TL20 > (HVL)TL15 > (HVL)TL10 > (HVL)TL05. The highest Zeff values are found at the low photon energy and ranged from 48.91 to 49.47 at 0.015 MeV for TL30 and TL05, respectively. While at 15 MeV, Zeff values are found 28.42 and 32.97 for TL30 and TL05, respectively. The TL05 glass with the highest TeO2 ratio has the largest Zeq values. The TL05 glass owns very low values of energy absorption buildup factor (EABF) and exposure buildup factor (EBF). This indicates that the TL05 sample was more effective than other samples in absorbing gamma radiation. One can conclude that the investigated TL-glasses have high ability to attenuate gamma-ray, especially TL05 glass sample. Therefore, these glasses can be applied in the field of nuclear protection.