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The intimate relationships of the older population have seldom been analyzed from a sociological perspective. This study provides novel information on what is desired in a partner after the age of 50 in Spain. The academic debate on this topic has been limited. Therefore, the contribution of this article is mainly an exploration of the empirical data. The database used is the Spanish General Social Survey prepared by the Sociological Research Center. The results indicate that personality is the most valued factor, followed by values and physical appearance. The variables with the greatest explanatory power in the estimated multinomial logit model are age, sex, level of education and cohabitation status. Educational homogamy appears among those with higher levels of education, with men more interested in physical appearance and women more interested in values and education. These last two characteristics are also more highly valued among those who are older. [ABSTRACT FROM AUTHOR]

Multifunctional triple color photoluminescent (PL) nitrogen–boron doped carbon quantum dots (CQDs) with high quantum yield (QY) of 58% are fabricated by one step femtosecond pulsed laser irradiation of a single precursor (2‐aminopyrimidine‐5‐boronic acid) in solution. In situ generated non‐linear and linear emissions are used to monitor CQDs formation which results in enhanced second harmonic generation, two photon absorption (2PA), and linear fluorescence; implying triple mode emission. These CQDs present blue, green, and possible red color rendering which are mostly independent to the respective excitation wavelengths (λ) with large stokes shift of 100 nm. Solid‐state photoluminescence with QY of 46% is achieved by incorporating CQDs into thin transparent nanoporous silica (pSiO2) films (thickness 50 µm) to form a CQDs‐pSiO2 composite which exhibits reverse saturable absorption at λ = 800 nm with 2PA coefficient and excited state absorption cross‐section of 4.94 × 10−10 m W−1 and 6.23 × 10−17 cm2, respectively. CQDs‐pSiO2 is also sensitive to glucose concentration down to 1.0 mg dL−1 in a wide linear range up to 100 mg dL−1. This work therefore demonstrates facile, controllable, and up‐scalable bottom‐up fabrication of CQDs forming multifunctional solid‐state CQDs‐pSiO2 with proven application in optical limiting and glucose sensing. [ABSTRACT FROM AUTHOR]

This research investigates individual expectations of economic support from different sources: partner, family, friends and formal help. Using data from the International Social Survey Programme (ISSP) the study compares Norway, as representative of the Scandinavian model, and Spain, as representative of the Mediterranean model. The findings confirm that family plays a more important role as a source of economic support in Spain while formal help is far more important in Norway. Moreover, gender and life course have a significant impact on expectations of economic support in both countries, although the differences do not go in the same direction. Women expect more financial support from their partners than men do in Norway, while Spanish women tend to rely more on support from their families. Regarding life course, although expectations of economic support from the family are higher for young and older people in both countries, the life-cycle effect is stronger in Spain. [ABSTRACT FROM AUTHOR]

A computer generated hologram (CGH) reconstructed with a sub-100-fs laser pulse at the focal plane of a conventional refractive lens experiences a large amount of spatial chirp. We report the shaping of a 12 fs laser pulsed beam by means of a Fourier CGH implemented onto a spatial light modulator, using a hybrid diffractive-refractive lens triplet that provides spatial-chirp compensation. Experimental results demonstrate that parallel, arbitrary, and high-resolution patterning is possible with the proposed device. [ABSTRACT FROM AUTHOR]

Background and O bjectives: Nanotechnology has become a significant area of research focused mainly on increasing the antibacterial and mechanical properties of dental materials. The aim of the present systematic review and meta-analysis was to examine and quantitatively analyze the current evidence for the addition of different nanoparticles into dental restorative materials, to determine whether their incorporation increases the antibacterial/antimicrobial properties of the materials. Materials and M ethods: A literature search was performed in the Pubmed, Scopus, and Embase databases, up to December 2018, following PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines for systematic reviews and meta-analyses. Results: A total of 624 papers were identified in the initial search. After screening the texts and applying inclusion criteria, only 11 of these were selected for quantitative analysis. The incorporation of nanoparticles led to a significant increase (p-value <0.01) in the antibacterial capacity of all the dental materials synthesized in comparison with control materials. Conclusions: The incorporation of nanoparticles into dental restorative materials was a favorable option; the antibacterial activity of nanoparticle-modified dental materials was significantly higher compared with the original unmodified materials, TiO 2 nanoparticles providing the greatest benefits. However, the high heterogeneity among the articles reviewed points to the need for further research and the application of standardized research protocols., Competing Interests: The authors declare no conflict of interest.

Fluorescent carbon quantum dots (CQDs) are synthesized by laser irradiation of carbon glassy particles suspended in polyethylene glycol 200 by two methods, a batch and a flow jet configuration. The flow jet configuration is carried out by the simple combination of common laboratory objects to construct a home-made passage reactor of continuous flow. Despite the simplicity of the system, the laser energy is better harvested by the carbon microparticles, improving the fabrication efficiency a 15% and enhancing the fluorescence of CQDs by an order of magnitude in comparison with the conventional batch. The flow jet-synthesized CQDs have a mean size of 3 nm and are used for fluorescent imaging of transparent healthy and cancer epithelial human cells. Complete internalization is observed with a short incubation time of 10 min without using any extra additive or processing of the cell culture. The CQDs are well fixed in the organelles of the cell even after its death; hence, this is a simple manner to keep the cell information for prolonged periods of time. Moreover, the integrated photostability of the CQDs internalized in in vitro cells is measured and it remains almost constant during at least 2 h, revealing their outstanding performance as fluorescent labels., Competing Interests: The authors declare no competing financial interest.

The analytical solution of the Rayleigh-Sommerfeld on-axis diffraction integral for an ultrashort light pulse diffracted by circularly symmetric hard apertures is derived. The particular case of a circular aperture is treated in detail. The time changes of the instantaneous intensity along the axial direction are predicted. An analysis of the standard deviation width shows a pulse broadening about the axial positions where the instantaneous intensity reaches a zero value. We show that the temporal shape of the instantaneous intensity depends on the number of oscillation cycles at the central frequency of the real electric field.

Recently, using parageometrical optics concepts, a hybrid, diffractive-refractive, lens triplet has been suggested to significantly improve the spatiotemporal resolution of light spots in multifocal processing with femtosecond laser pulses. Here, we carry out a rigorous wave-optics analysis, including the spatiotemporal nature of the wave equation, to elucidate both the spatial extent of the diffractive spots and the temporal duration of the pulse at the output plane. Specifically, we show nearly transform-limited behavior of diffraction maxima. Moreover, the temporal broadening of the pulse is related to the group velocity dispersion, which can be pre-compensated for in practical applications. Finally, some numerical simulations of the spatiotemporal wave field at the output plane in a realistic case are provided.

We propose, analyze and numerically illustrate a photonic-based technique for waveform generation of electrical signals approaching the 50 GHz bandwidth with time apertures as large as a few nanoseconds, by low-frequency, up to 2 GHz, electro-optic phase modulation of time-stretched optical pulses. Synthesis of the electrical waveform relies on phase-to-amplitude conversion of the modulated signal by a group delay dispersion circuit designed to behave as a transversal filter with N taps. Although arbitrary waveform generation capabilities are limited, a wide variety of user-defined signals are numerically demonstrated by appropriately designing the low-frequency signal driving the electro-optical modulator. Frequency upshifting is controlled by the chirp of the stretched pulse which provides an additional degree of freedom. Finally, optical-to-electrical conversion allows for the user-defined electrical waveform. Simulations are given for square waveform generation demonstrating the high resolution and wide-band capabilities of the technique.