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The beginning of the Portuguese Modern Mathematics movement coincides with the reopening of the pedagogical internships at the Pedro Nunes Secondary School (current name) in Lisbon, in 1956. The Mathematics methodologist at this School, Jaime Furtado Leote, is part of a ministerially appointed commission, in 1963, for the revision of the Mathematics programs of the upper secondary education. Knowing that school culture does not change by decree, the purpose of this article is to make known reports of the interns at this School, on the implementation of the pedagogical experience of Modern Mathematics lived by them, which show a reality that was not circulated in official channels and, therefore, less widespread. For this purpose, we searched and analyzed primary sources, namely, 30 written works produced by the interns, 18 unpublished, and interviews with 4 former interns. After a qualitative content analysis of the sources, we concluded that, despite the strong personal and institutional commitment, the implementation of the Modern Mathematics reform is involved in strong dilemmas and difficulties. The increase of formalism in mathematics appears as an almost vital need and trainee teachers warn against the inconvenience of its early use in teaching. When trying to embrace the new challenges, both in terms of content and methodologies, it is difficult to define a practicable program. Furthermore, we conclude that the School was, in theory and in practice, a center for pedagogical essays, who intended to form an elite to command Portugal. [ABSTRACT FROM AUTHOR]

Purpose: The pharmacology and clinical pharmacology and therapeutics (CPT) education during the undergraduate medical curriculum of NOVA Medical School, Lisbon, Portugal, was changed from a traditional programme (i.e. discipline-based, lectures) to a problem-based learning (PBL) programme (i.e. integrated, case-based discussions) without an increase in teaching hours. The aim of this study was to investigate whether this change improved the prescribing competencies of final-year medical students. Methods: Final-year students from both programmes (2015 and 2019) were invited to complete a validated prescribing assessment and questionnaire. The assessment comprised 24 multiple-choice questions in three subdomains (working mechanism, side-effects and interactions/contraindications), and five clinical case scenarios of common diseases. The questionnaire focused on self-reported prescribing confidence, preparedness for future prescribing task and education received. Results: In total, 36 (22%) final-year medical students from the traditional programme and 54 (23%) from the PBL programme participated. Overall, students in the PBL programme had significantly higher knowledge scores than students in the traditional programme (76% (SD 9) vs 67% (SD 15); p = 0.002). Additionally, students in the PBL programme made significantly fewer inappropriate therapy choices (p = 0.023) and fewer erroneous prescriptions than did students in the traditional programme (p = 0.27). Students in the PBL programme felt more confident in prescribing, felt better prepared for prescribing as junior doctor and completed more drug prescriptions during their medical training. Conclusion: Changing from a traditional programme to an integrated PBL programme in pharmacology and CPT during the undergraduate medical curriculum may improve the prescribing competencies of final-year students. [ABSTRACT FROM AUTHOR]

The carotid body (CB) is the main arterial chemoreceptor with a low threshold to hypoxia. CB activity is augmented by A-adenosine receptors stimulation and attenuated by D-dopamine receptors. The effect of aging on ventilatory responses mediated by the CB to hypoxia, ischemia, and to adenosine and dopamine administration is almost unknown. This study aims to investigate the ventilatory response to ischemia and to adenosine, dopamine, and their antagonists in old rats, as well as the effect of hypoxia on adenosine 3′,5′-cyclic monophosphate (cAMP) accumulation in the aged CB. In vivo experiments were performed on young and aged rats anesthetized with pentobarbitone and breathing spontaneously. CB ischemia was induced by bilateral common carotid occlusions. cAMP content was measured in CB incubated with different oxygen concentrations. Hyperoxia caused a decrease in cAMP in the CB at all ages, but no differences were found between normoxia and hypoxia or between young and old animals. The endogenous dopaminergic inhibitory tonus is slightly reduced. However, both the ventilation decrease caused by exogenous dopamine and the increase mediated by A-adenosine receptors are not impaired in aged animals. The bradycardia induced by adenosine is attenuated in old rats. The CB's peripheral control of ventilation is preserved during aging. Concerns have also arisen regarding the clinical usage of adenosine to revert supraventricular tachycardia and the use of dopamine in critical care situations involving elderly people. [ABSTRACT FROM AUTHOR]

A 15-year-old female was admitted to the emergency room with a 5-month history of multiple vaginal and perianal lesions. Her past medical history was irrelevant except for microcytic and hypochromic anaemia diagnosed at 13 years of age. She had received all of the vaccines from our national immunisation programme including the vaccine against Human papillomavirus (types 6, 11, 16, 18). [Extracted from the article]

Zinc oxide (ZnO) is a widely versatile semiconductor with major importance from the technological point of view, presenting the advantage of being grown by a large number of techniques and having one of the richest varieties of morphologies. Due to the special interest in this semiconductor, several approaches have been employed to control the production of its nanostructures. Herein, we report the development of a vapour-based method, designated as laser-assisted flow deposition (LAFD), capable of producing ZnO micro and nanocrystals with different morphologies and with a high crystalline and optical quality. This new process allows a high yield of ZnO production, showing great prospects for scalable applications. In the present work, we review in detail the main growth parameters and their relationship with the produced morphologies, in addition to their influence on the structural and optical properties. Furthermore, an assessment of the possible growth mechanisms that may be involved in this new method is reported. Some potential applications of the ZnO structures produced by LAFD were also evaluated, with focus on the photocatalysis and photovoltaic fields. Additionally, the possibility of synthesizing ZnO composite nanostructures as well as the growth of other metal oxides using this technique was explored. [ABSTRACT FROM AUTHOR]

The present study is focused on the synthesis of zirconium dioxide (ZrO2) nanomaterials using the hydrothermal method assisted by microwave irradiation and solution combustion synthesis. Both synthesis techniques resulted in ZrO2 powders with a mixture of tetragonal and monoclinic phases. For microwave synthesis, a further calcination treatment at 800 °C for 15 min was carried out to produce nanopowders with a dominant monoclinic ZrO2 phase, as attested by X-ray diffraction (XRD) and Raman spectroscopy. The thermal behavior of the ZrO2 nanopowder was investigated by in situ XRD measurements. From the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images, the presence of near spherical nanoparticles was clear, and TEM confirmed the ZrO2 phases that comprised the calcinated nanopowders, which include a residual tetragonal phase. The optical properties of these ZrO2 nanopowders were assessed through photoluminescence (PL) and PL excitation (PLE) at room temperature (RT), revealing the presence of a broad emission band peaked in the visible spectral region, which suffers a redshift in its peak position, as well as intensity enhancement, after the calcination treatment. The powder resultant from the solution combustion synthesis was composed of plate-like structures with a micrometer size; however, ZrO2 nanoparticles with different shapes were also observed. Thin films were also produced by solution combustion synthesis and deposited on silicon substrates to produce energy storage devices, i.e., ZrO2 capacitors. The capacitors that were prepared from a 0.2 M zirconium nitrate-based precursor solution in 2-methoxyethanol and annealed at 350 °C exhibited an average dielectric constant (κ) of 11 ± 0.5 and low leakage current density of 3.9 ± 1.1 × 10−7 A/cm2 at 1 MV/cm. This study demonstrates the simple and cost-effective aspects of both synthesis routes to produce ZrO2 nanomaterials that can be applied to energy storage devices, such as capacitors. [ABSTRACT FROM AUTHOR]

An 8-month-old female infant is brought to the emergency department due to the appearance of a mass through the vaginal introitus and blood spotting in the diaper over the last 2 days, with apparently maintained urine output and without any other symptoms. GLO:81V/01aug21:jpc1-15319-fig-0001.jpg PHOTO (COLOR): 1 Mass in the vaginal introitus. gl The urinalysis showed haematuria, leukocyturia and nitrituria, and the blood analytical evaluation showed no significant alterations. The urine culture was negative. [Extracted from the article]

The photophysical properties of iridium(III) porphyrins complexes with two different axial ligands (Cl(CO) and bipyridine (bpy)) in solution and in cellulose acetate polymer matrix were investigated. The axial ligands substitution was made aiming to evaluate the photophysical properties and the solubility in different solvents. Therefore, dissimilar from the free porphyrin, non-polar solvents (as toluene) favours the quantum yield of iridium(III)porphyrins and ligands with a more extended π-conjugated compound as bpy results in higher yields. Moreover, despite all the porphyrins reveals a negative solvatochromism, the substitution of Cl(CO) ligand by bpy ligand exhibits similar solubility either on non-polar or polar solvents. The observed photoluminescence (PL) at room temperature appears at NIR region in contrast to the previously reported iridium(III) porphyrins. Comparing with free porphyrin H 2 TTP, the red/NIR PL spectra of the iridium(III)porphyrins (either in solution and in the polymer matrix) reveals remarkable changes. Particularly, a more significative decrease of the red/NIR intensity ratio was detected for [Ir(ttp)(bpy) 2 2 where the maxima of the NIR emission can be adjusted under suitable excitation wavelength. Unlabelled Image • Study of photophysical properties of Ir(III) porphyrins complexes in solution and in cellulose acetate matrix. • Porphyrin with extended conjugated ligand, as 4,4-bipyridine, decrease red/NIR emission intensity ratio. • Ir(III) porphyrins immobilized in cellulose acetate revealed two main emitting broad bands at red/NIR wavelengths. • PL spectra of Ir(III)porphyrins can be tunable by suitable choice of solvent, ligand framework and excitation wavelength. [ABSTRACT FROM AUTHOR]

Hybrid metal oxide nano- and microstructures exhibit novel properties, which make them promising candidates for a wide range of applications, including gas sensing. In this work, the characteristics of the hybrid ZnO-Bi2O3 and ZnO-Zn2SnO4 tetrapod (T) networks are investigated in detail. The gas sensing studies reveal improved performance of the hybrid networks compared to pure ZnO-T networks. For the ZnO-T-Bi2O3 networks, an enhancement in H2 gas response is obtained, although the observed p-type sensing behavior is attributed to the formed junctions between the arms of ZnO-T covered with Bi2O3 and the modulation of the regions where holes accumulate under exposure to H2 gas. In ZnO-T-Zn2SnO4 networks, a change in selectivity to CO gas with high response is noted. The devices based on individual ZnO-T-Bi2O3 and ZnO-T-Zn2SnO4 structures showed an enhanced H2 gas response, which is explained on the basis of interactions (electronic sensitization) between the ZnO-T arm and Bi2O3 shell layer and single Schottky contact structure, respectively. Density functional theory-based calculations provide mechanistic insights into the interaction of H2 and CO gas molecules with Bi- and Sn-doped ZnO(0001) surfaces, revealing changes in the Fermi energies, as well as charge transfer between the molecules and surface species, which facilitate gas sensing. [ABSTRACT FROM AUTHOR]

Zinc oxide nanorod (ZnO NR) films for photocatalytic and energy conversion applications were synthesized by pulsed electrodeposition. The films were prepared on modified fluorine-doped tin oxide (FTO) glass coated with thin layers of ZnO seeds and porous anatase titanium dioxide (TiO 2 ). The ZnO seed layers were prepared electrochemically, whilst the TiO 2 layers by spin-coating. Morphological and structural analysis of the films reveal the effect of the TiO 2 intermediate layers on ZnO NRs was to improve vertical alignment, increase spatial density and decrease diameter. Room temperature photoluminescence (PL) results show that the ZnO NRs exhibit near band edge recombination and deep level emission in the green and red spectral regions. The green emission was almost suppressed for ZnO NRs grown using the TiO 2 intermediate layer followed by two step electrodeposition of ZnO. The prepared films demonstrated photoelectrochemical behaviour in aqueous electrolytes. Additionally, the ZnO NRs prepared with a TiO 2 intermediate layer demonstrated increased stability to photo-dissolution. [ABSTRACT FROM AUTHOR]

Particles of titanium dioxide were prepared in the presence of europium ions (TiO 2 :Eu) by a solvothermal method and thermal annealed in air at 500 °C. The spectroscopic properties of TiO 2 :Eu particles were analyzed indicating that the Eu 3+ ions are likely distributed at the surface or near the surface of the titanium dioxide particles. The photoluminescence analysis showed that the intraionic emission was strongly sensitive to reduced pressure conditions, as seen by its absence under vacuum conditions. The ion emission was re-established as soon as the atmosphere was restored. Additionally, the ion integrated emission intensity follows a linearly dependence with pressure in the range of 150–800 mbar revealing a high sensitivity to small variations in pressure, which is an unprecedented result. This innovation will allow the study of new technologies in the area of low vacuum sensors where TiO 2 :Eu may act as the active element of an optical sensor for a pressure device. [ABSTRACT FROM AUTHOR]

The existence of extended defects (i.e., dislocations) in inorganic semiconductors, such as GaN or ZnO, responsible for broad emission peaks in photoluminescence analysis remains unresolved. The possible assignments of these luminescence bands are still matter of discussion. In this study, two different zinc oxide samples, grown under different oxygen partial pressures and substrate temperatures, are presented. Epitaxial and structural properties were analysed by means of X-ray diffraction and transmission electron microscopy techniques. They confirm that the layers are single-phase with a good crystalline quality. Nevertheless, a different density of threading dislocations, with a higher contribution of edge dislocations, was found. Photoluminescence spectroscopy has been used to investigate the optical properties. The steady state luminescence spectra performed at 14 K evidenced the donor bound exciton recombination and deep green and red emission bands. The red band with a maximum at 1.78 eV was found to be stronger in the sample grown at lower oxygen pressure which also shows higher density of threading dislocations. From the temperature and excitation density dependence of the red band, a donor acceptor pair recombination model was proposed, where hydrogen and zinc vacancies are strong candidates for the donor and acceptor species, respectively. [ABSTRACT FROM AUTHOR]

Niobium oxides have been reported as an alternative to tantalum, and its oxide, for the production of capacitors, but these materials still require a further and exhaustive study. Understanding the dynamics of the oxidation process from NbO to Nb2O5 is essential to explain and control the properties of a niobium oxide based capacitors. In situ XRD analysis of NbO powders was performed from 100 to 1100°C, which showed a temperature range where only amorphous phase is present. The capacitor anodes, formed from the same type of NbO powders, were then heat-treated in air from room-temperature (RT) to 550°C and recorded with a video camera to see the colour shift. The presence of core–shell structures and the increase of the shell thickness/amount with temperature are visible in SEM. Finally, in situ spectroscopy studies were performed, in order to observe the interference spectra which are responsible for the observed colours. [ABSTRACT FROM AUTHOR]

Cadmium selenide nanocrystals were grown over silica surfaces using a one-step synthetic method involving the thermal degradation of the single-molecule precursor [Cd(Se2CNEt2)2], Et＝C2H5. The X-ray powder diffraction patterns for the SiO2/CdSe nanocomposites show diffraction peaks consistent with the presence of hexagonal-CdSe. Scanning and transmission electron microscopy show inorganic composite particles formed by islands of CdSe nanocrystals at the SiO2 surfaces. A series of SiO2/CdSe particles were obtained in which the samples show quantum size effects in their optical spectra. [Copyright &y& Elsevier]

Transparent undoped ZnO and additionally doped with Ga and Bi thin films were produced by magnetron sputtering. The thin films were comprehensively characterized by X-ray absorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission and scanning transmission electron (TEM, STEM) microscopy and Raman spectroscopy. All undoped and doped films crystallise in a ZnO phase with the hexagonal wurtzite crystal structure. The local structure of the thin films was investigated by temperature-dependent X-ray absorption spectroscopy at the Zn and Ga K-edges, as well as at the Bi L 3 -edge. It was found that the doping of Ga3+ and Bi3+ ions in the ZnO wurtzite structure produces distinct effects on the thin film microstructure. The substitution of Zn2+ ions by smaller Ga3+ ions introduces a static disorder to the thin film structure, which is evidenced by an increase in the mean-square relative displacements σ2(Zn‒O) and σ2(Zn‒Zn). At the same time, large Bi3+ ions do not substitute zinc ions, but are likely located in the disordered environment at the ZnO grain boundaries. This conclusion was directly supported by energy-dispersive X-ray spectroscopy combined with TEM and STEM observations as well as by resonant and non-resonant μ-Raman experiments at room temperature, where the ZnO and ZnO:Bi spectra are similar, suggesting a lack of structural disorder in the wurtzite cell. On the other hand, the Raman disorder-activated phonon is pronounced for Ga-doping of the ZnO lattice, confirming the compositional disorder. Both XRD and XPS ruled out Ga 2 O 3 phase in Ga-doped ZnO; conversely, Bi 2 O 3 and a small amount of Bi‒metal phases are clearly discerned by XPS experiments, further suggesting that Bi is not incorporated in the ZnO wurtzite cell, but segregated to grain boundaries. • Small Ga3+ ions substitute zinc ions and introduce static disorder to the film structure. • μ-Raman showed that the activation of the density of phonon states potentiated by structural/composition disorder. • Detailed information on local structure from radial distribution at Zn-K, Ga-K and Bi-L 3 absorption edges. • Bi atoms segregate to grain boundaries. [ABSTRACT FROM AUTHOR]

Tetragonal Er0.5Nb0.5O2 and monoclinic ErNbO4 micro- and nanoparticles were prepared by the citrate sol–gel method and heat-treated at temperatures between 700 and 1600 °C. ErNbO4 revealed a spherical-shaped crystallite, whose size increased with heat treatment temperatures. To assess their optical properties at room temperature (RT), a thorough spectroscopic study was conducted. RT photoluminescence (PL) spectroscopy revealed that Er3+ optical activation was achieved in all samples. The photoluminescence spectra show the green/yellow 2H11/2, 4S3/2→4I15/2 and red 4F9/2→4I15/2 intraionic transitions as the main visible recombination, with the number of the crystal field splitting Er3+ multiplets reflecting the ion site symmetry in the crystalline phases. PL excitation allows the identification of Er3+ high-energy excited multiplets as the preferential population paths of the emitting levels. Independently of the crystalline structure, the intensity ratio between the green/yellow and red intraionic transitions was found to be strongly sensitive to the excitation energy. After pumping the samples with a resonant excitation into the 4G11/2 excited multiplet, a green/yellow transition stronger than the red one was observed, whereas the reverse occurred for higher excitation photon energies. Thus, a controllable selective excited tunable green to red color was achieved, which endows new opportunities for photonic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

With a bandgap energy of ≈3.3 eV at room temperature, zinc oxide (ZnO) exhibits physical properties that make it a potential candidate for several technological applications. Sustainable development requires, among other actions, removal of organic pollutants by employing non‐toxic structures, which can be achieved considering the photocatalytic properties of ZnO. In this work, high optical and structural quality ZnO crystals with distinct morphologies (nanotetrapods and microrods) are produced by laser‐processing. By adding silver to the growth precursors it is possible to produce ZnO/Ag composites in a single and short step, boosting a synergetic conjugation of the properties of both materials. The ZnO structures produced with and without silver are fully characterized by electronic microscopy and optical spectroscopy. Moreover, their photocatalytic activity is analyzed using methylene blue as a model‐test contaminant, revealing that the nanotetrapods exhibit a better performance than the microrods. This effect is further enhanced by the presence of silver on the ZnO surface, hindering the photoinduced carriers' recombination, as corroborated by the photoluminescence results. ZnO micro and nanocrystals with different morphologies (nanotetrapods and microrods) are produced by laser‐assisted flow deposition method and their photocatalytic activity is tested, reveling a better performance for the nanotetrapods. By adding silver to the precursor rods, ZnO/Ag composites are formed in a single and short step. Nanotetrapods grown in the presence of silver evidence the best performance in the degradation of the dye when compared to the remained crystals. [ABSTRACT FROM AUTHOR]

In the present work, we report on development of three-dimensional flexible architectures consisting of an extremely porous three-dimensional Aerographite (AG) backbone decorated by InP micro/nanocrystallites grown by a single step hydride vapor phase epitaxy process. The systematic investigation of the hybrid materials by scanning electron microscopy demonstrates a rather uniform spatial distribution of InP crystallites without agglomeration on the surface of Aerographite microtubular structures. X-ray diffraction, transmission electron microscopy and Raman scattering analysis demonstrate that InP crystallites grown on bare Aerographite are of zincblende structure, while a preliminary functionalization of the Aerographite backbone with Au nanodots promotes the formation of crystalline In2O3 nanowires as well as gold-indium oxide core-shell nanostructures. The electromechanical properties of the hybrid AG-InP composite material are shown to be better than those of previously reported bare AG and AG-GaN networks. Robustness, elastic behavior and excellent translation of the mechanical deformation to variations in electrical conductivity highlight the prospects of AG-InP applications in tactile/strain sensors and other device structures related to flexible electronics. [ABSTRACT FROM AUTHOR]

Hybrid nanostructures from metal oxides are promising for sensing applications. The synthesis of hybrid networks and single structures based on ZnO tetrapods (ZnO‐T) with MexOy and ZnxMe1−xOy (Me = Bi and Sn) is described by Rainer Adelung, Oleg Lupan, Abhishek Kumar Mishra, Yogendra Kumar Mishra, and co‐workers in article number 1604676. ZnO‐T with Zn2SnO4 networks allows change in selectivity from H2 gas to CO gas with high response. [ABSTRACT FROM AUTHOR]

ZnO microrods were grown by laser assisted flow deposition technique in order to study their luminescence behaviour in the near band edge spectral region. Transmission electron microscopy analysis put in evidence the high crystallinity degree and microrod's compositional homogeneity. Photoluminescence revealed a dominant 3.31 eV emission. The correlation between this emission and the presence of surface states was investigated by performing plasma treatments with hydrogen and nitrogen. The significant modifications in photoluminescence spectra after the plasma treatments suggest a connexion between the 3.31 eV luminescence and the surface related electronic levels. [ABSTRACT FROM AUTHOR]

We studied the optical properties of metalorganic chemical vapour deposited (MOCVD) InGaN/GaN multiple quantum wells (MQW) subjected to nitrogen (N) implantation and post-growth annealing treatments. The optical characterization was carried out by means of temperature and excitation density-dependent steady state photoluminescence (PL) spectroscopy, supplemented by room temperature PL excitation (PLE) and PL lifetime (PLL) measurements. The as-grown and as-implanted samples were found to exhibit a single green emission band attributed to localized excitons in the QW, although the N implantation leads to a strong reduction of the PL intensity. The green band was found to be surprisingly stable on annealing up to 1400°C. A broad blue band dominates the low temperature PL after thermal annealing in both samples. This band is more intense for the implanted sample, suggesting that defects generated by N implantation, likely related to the diffusion/segregation of indium (In), have been optically activated by the thermal treatment. [ABSTRACT FROM AUTHOR]