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1.
Adv Mater ; : e2402777, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38781582

ABSTRACT

The ability to detect and image short-wave infrared light has important applications in surveillance, autonomous navigation, and biological imaging. However, the current infrared imaging technologies often pose challenges due to large footprint, large thermal noise and inability to augment infrared and visible imaging. Here, infrared imaging is demonstrated by nonlinear up-conversion to the visible in an ultra-compact, high-quality-factor lithium niobate resonant metasurface. Images with high conversion efficiency and resolution quality are obtained despite the strong nonlocality of the metasurface. The possibility of edge-detection image processing augmented with direct up-conversion imaging for advanced night vision applications is further shown.

2.
Int J Biol Macromol ; 263(Pt 2): 129787, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38296145

ABSTRACT

Two chia mucilages with different viscosities, obtained by extraction conditions optimized in a previous work, were homogenized by high pressure homogenization (HPH). Particle size, molecular weight, zeta potential, FTIR spectrum, rheological properties, water absorption capacity, water holding capacity and iron binding capacity were determined on both mucilages treated and without treatment. Homogenization led to a significant reduction in viscosity respect to chia mucilage controls, which can be related to the decrease in particle size and molecular weight. A high iron binding capacity was obtained for both mucilages. FTIR spectra of both mucilages with iron showed displacements in bands related with stretching of carboxylic uronic acids, suggesting the interaction site with this mineral. This interaction was also verified by particle size determination with a displacement to higher sizes in the presence of iron. Potential zeta showed a significant reduction in the presence of iron. A model to explain the binding between chia mucilage and iron is proposed. HPH appears as an alternative to expand chia mucilage functionality reducing the viscosity of chia mucilage solutions for the offer of a new ingredient also with optimal levels of hydration and iron binding capacity.


Subject(s)
Plant Mucilage , Salvia , Plant Mucilage/chemistry , Seeds/chemistry , Salvia/chemistry , Polysaccharides/chemistry , Iron/analysis , Water/analysis
3.
Rev. cir. (Impr.) ; 75(5)oct. 2023.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1530062

ABSTRACT

Introducción: Los quistes mesentéricos se pueden encontrar a lo largo de todo el mesenterio del intestino. Los pseudoquistes de mesenterio se caracterizan por carecer de revestimiento endotelial. Generalmente son asintomáticos y el diagnóstico se realiza mediante estudios de imagen. Material y Método: Reporte de un caso clínico Resultados: Presentamos el caso de una mujer de 50 años sana que consulta por tumoración indolora en flanco izquierdo. Se solicita TC y RNM donde se visualiza tumoración quistica de paredes finas, homogenea de 88mm de diámetro mayor con septos y tabiques. Se realiza abordaje laparoscópico identificando masa de 12cm que se protruye a nivel del mesenterio de la segunda asa yeyunal, se reseca in incidentes. La anatomía patológica informó pseudoquiste mesentérico, sin elementos de malignidad. Buena evolución posterior. Conclusiones: Los quistes mesentéricos son extremadamente infrecuentes. General-mente se localizan en el mesenterio del intestino delgado como en el caso presentado. Teniendo en cuenta las características histopatológicas, se clasifican en seis grupos. Si bien es excepcional su transformación maligna, el tratamiento consiste siempre en su resección quirúrgica. Se prefiere la laparoscopía por sus conocidos beneficios.


Introduction: Mesenteric cysts can be found throughout the entire intestine mesentery. Mesenteric pseudocysts are characterized by lack of endothelial lining. They are generally asymptomatic and the diagnosis can be made by imaging studies. Material and Method: Report of a clinical case Results: We present the case of a healthy 50-year-old woman consulted for a painless tumor on the left flank. She requested a CT and MRI where a thin-walled, homogeneous cystic tumor of 88mm in greatest diameter with septa and partitions was visualized. A laparoscopic approach was performed identifying a 12cm mass that protruded at the level of the mesentery of the second jejunal loop, it was resected without incident. The pathological anatomy reported a mesenteric pseudocyst, without elements of malignancy. Good subsequent evolution. Conclusions: Mesenteric cysts are extremely rare. They are generally located in the mesentery of the small intestine, as in the case presented. Taking into account the histopathological characteristics, they are classified into six groups. Although its malignant transformation is exceptional, the treatment always consists of its surgical resection. Laparoscopy is preferred for its well-known benefits.

4.
Opt Lett ; 48(11): 2961-2964, 2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37262254

ABSTRACT

We investigate transient, photo-thermally induced metasurface effects in a planar thin-film multilayer based on a phase-transition material. Illumination of a properly designed multilayer with two obliquely incident and phase-coherent pulsed pumps induces a transient and reversible temperature pattern in the phase-transition layer. The deep periodic modulation of the refractive index, caused by the interfering pumps, produces a transient Fano-like spectral feature associated with a guided-mode resonance. A coupled opto-thermal model is employed to analyze the temporal dynamics of the transient metasurface and to evaluate its speed and modulation capabilities. Using near-infrared pump pulses with peak intensities of the order of 100 MW/cm2 and duration of a few picoseconds, we find that the characteristic time scale of the transient metasurface is of the order of nanoseconds. Our results indicate that inducing transient metasurface effects in films of phase-transition materials can lead to new opportunities for dynamic control of quality (Q)-factor in photonic resonances, and for light modulation and switching.

5.
Foods ; 12(8)2023 Apr 21.
Article in English | MEDLINE | ID: mdl-37107529

ABSTRACT

The canihua (Chenopodium pallidicaule) is a native Andean crop that stands out for its high content of protein, fiber, and minerals and that has a good fatty acid profile. We studied six canihuas cultivars, which were compared according to their proximate, mineral, and fatty acid composition. Based on the form of stems, termed growth habit, they belonged to two groups: decumbent (Lasta Rosada, Illimani, Kullaca, and Cañawiri) and ascending (Saigua L24 and Saigua L25). Dehulling is an important process applied to this grain. However, there is no information about how it affects the chemical composition of the canihua. Dehulling resulted in two levels, whole and dehulled canihua. The highest protein and ash contents were in whole Saigua L25 (19.6 and 5.12 g/100 g, respectively), and the highest fat content was found in dehulled Saigua L25, while the whole grains of Saigua L24 presented the highest fiber content (12.5 g/100 g). Dehulling mainly affected the macro-minerals content, while micro-minerals were only slightly linked to the dehulling. The growth habit influenced the C18:1 and C18:3 contents. In conclusion, the canihua had a nutritional composition influenced by each variety, strongly influenced by dehulling, and to a lesser extent by growth habit.

6.
J Sci Food Agric ; 103(8): 3860-3870, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36308762

ABSTRACT

BACKGROUND: The application of chia mucilage still remains restricted due to the difficulty in achieving high extraction yields. The effect of ultrasonic-assisted extraction (UAE) conditions (temperature, seed:water ratio and time) on the rheological properties of chia mucilage extracts and the relation to the proportion of translucent phase (TP) and opaque phase (OP) of the mucilage in the extract were evaluated. RESULTS: UAE allowed the efficient extraction of chia mucilage from chia seeds. The desired overall optimal combination to maximize both yield and apparent viscosity was achieved at a seed:water ratio 1:10, a temperature of 25.3 °C and 53.7 min extraction time; the optimal conditions to obtain the maximum yield and minimum apparent viscosity were a seed:water ratio close to 1:20, temperature of 48.8 °C and 208.4 min extraction time. CONCLUSION: The results obtained in the present work demonstrated that the differences in rheological properties of chia mucilage extracts are due to the extraction methods used. Therefore, it is possible to modulate the extraction conditions in order to obtain different characteristics of the mucilage, maintaining a high extraction yield. © 2022 Society of Chemical Industry.


Subject(s)
Plant Mucilage , Salvia , Plant Mucilage/chemistry , Viscosity , Ultrasonics , Salvia/chemistry , Polysaccharides/chemistry , Seeds/chemistry , Plant Extracts/chemistry , Water/analysis
7.
F1000Res ; 11: 345, 2022.
Article in English | MEDLINE | ID: mdl-36128553

ABSTRACT

Background: Risk perceptions of coronavirus disease 2019 (COVID-19) are considered important as they impact community health behaviors. The aim of this study was to determine the perceived risk of infection and death due to COVID-19 and to assess the factors associated with such risk perceptions among community members in low- and middle-income countries (LMICs) in Africa, Asia, and South America. Methods: An online cross-sectional study was conducted in 10 LMICs in Africa, Asia, and South America from February to May 2021. A questionnaire was utilized to assess the perceived risk of infection and death from COVID-19 and its plausible determinants. A logistic regression model was used to identify the factors associated with such risk perceptions. Results: A total of 1,646 responses were included in the analysis of the perceived risk of becoming infected and dying from COVID-19. Our data suggested that 36.4% of participants had a high perceived risk of COVID-19 infection, while only 22.4% had a perceived risk of dying from COVID-19. Being a woman, working in healthcare-related sectors, contracting pulmonary disease, knowing people in the immediate social environment who are or have been infected with COVID-19, as well as seeing or reading about individuals infected with COVID-19 on social media or TV were all associated with a higher perceived risk of becoming infected with COVID-19. In addition, being a woman, elderly, having heart disease and pulmonary disease, knowing people in the immediate social environment who are or have been infected with COVID-19, and seeing or reading about individuals infected with COVID-19 on social media or TV had a higher perceived risk of dying from COVID-19. Conclusions: The perceived risk of infection and death due to COVID-19 are relatively low among respondents; this suggests the need to conduct health campaigns to disseminate knowledge and information on the ongoing pandemic.


Subject(s)
COVID-19 , Aged , Cross-Sectional Studies , Developing Countries , Female , Humans , Pandemics , Poverty
8.
Nano Lett ; 22(15): 6141-6148, 2022 Aug 10.
Article in English | MEDLINE | ID: mdl-35867018

ABSTRACT

Resonant metasurfaces provide a unique platform for enhancing multiwave nonlinear interactions. However, the difficulties over mode matching and material transparency place significant challenges in the enhancement of these multiwave processes. Here we demonstrate efficient nonlinear sum-frequency generation (SFG) in multiresonant GaP metasurfaces based on guided-wave bound-state in the continuum resonances. The excitation of the metasurface by two near-infrared input beams generates strong SFG in the visible spectrum with a conversion efficiency of 2.5 × 10-4 W-1, 2 orders of magnitude higher than the one reported in Mie-type resonant metasurfaces. In addition, we demonstrate the nontrivial polarization dependence on the SFG process. In contrast to harmonic generation, the SFG process is enhanced when using nonparallel polarized input-beams. Importantly, by varying the input pump beam polarization it is possible to direct the SFG emission to different diffraction orders, thereby opening up new opportunities for nonlinear light sources and infrared to visible light conversion.

9.
Sci Adv ; 8(30): eabq4240, 2022 Jul 29.
Article in English | MEDLINE | ID: mdl-35905188

ABSTRACT

Metasurfaces consisting of nanoscale structures are underpinning new physical principles for the creation and shaping of quantum states of light. Multiphoton states that are entangled in spatial or angular domains are an essential resource for many quantum applications; however, their production traditionally relies on bulky nonlinear crystals. We predict and demonstrate experimentally the generation of spatially entangled photon pairs through spontaneous parametric down-conversion from a metasurface incorporating a nonlinear thin film of lithium niobate covered by a silica meta-grating. We measure the correlations of photon pairs and identify their spatial antibunching through violation of the classical Cauchy-Schwarz inequality, witnessing the presence of multimode entanglement. Simultaneously, the photon-pair rate is strongly enhanced by 450 times as compared to unpatterned films because of high-quality-factor resonances. These results pave the way to miniaturization of various quantum devices by incorporating ultrathin metasurfaces functioning as room temperature sources of quantum-entangled photons.

10.
Cir. Urug ; 6(1): e402, jul. 2022. ilus
Article in Spanish | LILACS, UY-BNMED, BNUY | ID: biblio-1384412

ABSTRACT

La diverticulosis puede presentarse en cualquier sector del tubo digestivo. La topografía de intestino delgado es infrecuente, se presenta sobre todo a nivel del yeyuno y en un 35% de los casos se asocia con diverticulosis colónica. Es más frecuente en mayores de 40 años. Los divertículos van disminuyendo de tamaño y número hacia el sector distal. Habitualmente el diagnóstico es incidental, sin embargo, pueden presentar complicaciones de las cuales se destacan por frecuencia el sangrado gastrointestinal y la diverticulitis. Se plantea que la deficiencia de fibra dietética generaría anomalías en el peristaltismo intestinal, lo que junto con fenómenos pseudo-obstructivos y alta presión intraluminal, actuaría en áreas de debilidad focal provocando la lesión. Presentamos el caso de una paciente de 88 años con una oclusión de colon a la cual se le realizó una cirugía de Hartmann, en el intraoperatorio se identificó divertículos de yeyuno sin elementos complicaciones.


Subject(s)
Humans , Female , Aged, 80 and over , Diverticulum/diagnosis , Colon/surgery , Intestinal Obstruction/surgery , Jejunum , Octogenarians , Intraoperative Complications
11.
Pathog Glob Health ; 116(4): 236-243, 2022 06.
Article in English | MEDLINE | ID: mdl-34928187

ABSTRACT

Vaccine hesitancy is considered one of the greatest threats to the ongoing coronavirus disease 2019 (COVID-19) vaccination programs. Lack of trust in vaccine benefits, along with concerns about side effects of the newly developed COVID-19 vaccine, might significantly contribute to COVID-19 vaccine hesitancy. The objective of this study was to determine the level of vaccine hesitancy among communities in particular their belief in vaccination benefits and perceived risks of new vaccines. An online cross-sectional study was conducted in 10 countries in Asia, Africa, and South America from February to May 2021. Seven items from the WHO SAGE Vaccine Hesitancy Scale were used to measure a construct of belief in vaccination benefit, and one item measured perceived riskiness of new vaccines. A logistic regression was used to determine which sociodemographic factors were associated with both vaccine hesitancy constructs. A total of 1,832 respondents were included in the final analysis of which 36.2% (range 5.6-52.2%) and 77.6% (range 38.3-91.2%) of them were classified as vaccine hesitant in terms of beliefs in vaccination benefits and concerns about new vaccines, respectively. Respondents from Pakistan had the highest vaccine hesitancy while those from Chile had the lowest. Being females, Muslim, having a non-healthcare-related job and not receiving a flu vaccination during the past 12 months were associated with poor beliefs of vaccination benefits. Those who were living in rural areas, Muslim, and those who did not received a flu vaccination during the past 12 months had relatively higher beliefs that new vaccines are riskier. High prevalence of vaccine hesitancy in some countries during the COVID-19 pandemic might hamper COVID-19 vaccination programs worldwide. Programs should be developed to promote vaccination in those sociodemographic groups with relatively high vaccine hesitancy.


Subject(s)
COVID-19 , Influenza Vaccines , Africa , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Cross-Sectional Studies , Female , Humans , Male , Pakistan , Pandemics , SARS-CoV-2 , South America/epidemiology , Vaccination , Vaccination Hesitancy
12.
Narra J ; 2(1): e74, 2022 Apr.
Article in English | MEDLINE | ID: mdl-38450393

ABSTRACT

Vaccine hesitancy is considered as one of the greatest challenges to control the ongoing coronavirus disease 2019 (COVID-19) pandemic. A related challenge is the unwillingness of the general public to pay for vaccination. The objective of this study was to determine willingness-to-pay (WTP) for COVID-19 vaccine among individuals from ten low- middle-income countries (LMICs) in Asia, Africa, and South America. Data were collected using an online questionnaire distributed during February - May 2021 in ten LMICs (Bangladesh, Brazil, Chile, Egypt, India, Iran, Nigeria, Pakistan, Sudan, and Tunisia). The major response variable of in this study was WTP for a COVID-19 vaccine. The assessment of COVID-19 vaccine hesitancy was based on items adopted from the World Health Organization (WHO) Strategic Advisory Group of Experts (SAGE) vaccine hesitancy scale constructs. In this study, 1337 respondents included in the final analysis where the highest number of respondents was from India, while the lowest number was from Egypt. A total of 88.9% (1188/1337) respondents were willing to pay for the COVID-19 vaccination, and 11.1% (149/1337) were not. The average WTP for COVID-19 vaccination was 87.9 US dollars ($), (range: $5-$200). The multivariate model analysis showed that the country, monthly household income, having a history of respiratory disease, the agreement that routine vaccines recommended by health workers are beneficial and having received the flu vaccination within the previous 12 months were strongly associated with the WTP. Based on the country of origin, the highest mean WTP for COVID-19 vaccine was reported in Chile, while the lowest mean WTP for the vaccine was seen among the respondents from Sudan. The availability of free COVID-19 vaccination services appears as a top priority in the LMICs for successful control of the ongoing pandemic. This is particularly important for individuals of a lower socio- economic status. The effects of complacency regarding COVID-19 extends beyond vaccine hesitancy to involve less willingness to pay for COVID-19 vaccine and a lower value of WTP for the vaccine.

13.
Food Res Int ; 138(Pt A): 109772, 2020 12.
Article in English | MEDLINE | ID: mdl-33292951

ABSTRACT

Complexing iron with organic compounds has been considered an alternative strategy to mitigate the problems associated with the level of bioavailable iron and the acceptability of products supplemented with this mineral. CMP contains specific amino acids associated with iron binding. The present study aims to optimize the conditions of Fe/CMP complex formation and understand the molecular basis of interactions between CMP and iron ions. Results showed that CMP can bind ferrous iron in a 1:1.5 M ratio, forming a stable peptide-iron complex, where CMP assembles in a tetrameric form. FTIR spectra indicated that iron binding altered the secondary structures of CMP. The iron-binding sites of CMP corresponded primarily to acid residues of Glu, Asp and sialic acid. Moreover, Fe/CMP complex remained stable in a wide pH range (2.0-6.5), suggesting the adequacy to be efficiently added in food or beverages and to keeping complexed in the digestion environment. Finally, Fe/CMP complex was added to a commercial beverage (2 mg of Fe per serving of beverage) and no changes were observed in their colour during storage. A model to explain the binding between CMP and iron is proposed. These results suggest a potential application of this peptide for iron fortification.


Subject(s)
Beverages , Iron , Amino Acids , Dietary Supplements , Peptides
14.
ACS Nano ; 14(2): 1379-1389, 2020 Feb 25.
Article in English | MEDLINE | ID: mdl-31877017

ABSTRACT

High-index III-V semiconductor nanoantennas have gained great attention for enhanced nonlinear light-matter interactions, in the past few years. However, the complexity of nonlinear emission profiles imposes severe constraints on practical applications, such as in optical communications and integrated optoelectronic devices. These complexities include the lack of unidirectional nonlinear emission and the severe challenges in switching between forward and backward emissions, due to the structure of the susceptibility tensor of the III-V nanoantennas. Here, we propose a solution to both issues via engineering the nonlinear tensor of the nanoantennas. The special nonlinear tensorial properties of zinc-blende material can be used to engineer the nonlinear characteristics via growing the nanoantennas along different crystalline orientations. Based on the nonlinear multipolar effect, we have designed and fabricated (110)-grown GaAs nanoantennas, with engineered tensorial properties, embedded in a transparent low-index material. Our technique provides an approach not only for unidirectional second-harmonic generation (SHG) forward or backward emission but also for switching from one to another. Importantly, switching the SHG emission directionality is obtained only by rotating the polarization of the incident light, without the need for physical variation of the antennas or the environment. This characteristic is an advantage, as compared to other nonlinear nanoantennas, including (100)- and (111)-grown III-V counterparts or silicon and germanium nanoantennas. Indeed, (110)-GaAs nanoantennas allow for engineering the nonlinear nanophotonic systems including nonlinear "Huygens metasurfaces" and offer exciting opportunities for various nonlinear nanophotonics technologies, such as nanoscale light routing and light sources, as well as multifunctional flat optical elements.

15.
Adv Sci (Weinh) ; 6(15): 1802119, 2019 Aug 07.
Article in English | MEDLINE | ID: mdl-31406659

ABSTRACT

Dynamical tuning of the nonlinear optical wavefront allows for a specific spectral response of predefined profiles, enabling various applications of nonlinear nanophotonics. This study experimentally demonstrates the dynamical switching of images generated by an ultrathin silicon nonlinear metasurface supporting a high-quality leaky mode, which is formed by partially breaking a bound-state-in-the-continuum (BIC) generated by the collective magnetic dipole (MD) resonance excited in the subdiffractive periodic systems. Such a quasi-BIC MD state can be excited directly under normal plane wave incidence and leads to a strong near-field enhancement to further boost the nonlinear process, resulting in a 500-fold enhancement of the third-harmonic emission experimentally. Due to sharp spectral features and asymmetry of the unit cell, it allows for effective tailoring of the nonlinear emissions over spectral or polarization responses. Dynamical nonlinear image tuning is experimentally demonstarted via polarization and wavelength control. The results pave the way for nanophotonics applications such as tunable displays, nonlinear holograms, tunable nanolaser, and ultrathin nonlinear nanodevices with various functionalities.

16.
Nano Lett ; 19(6): 3905-3911, 2019 06 12.
Article in English | MEDLINE | ID: mdl-31136193

ABSTRACT

Second-harmonic generation (SHG) in resonant dielectric Mie-scattering nanoparticles has been hailed as a powerful platform for nonlinear light sources. While bulk-SHG is suppressed in elemental semiconductors, for example, silicon and germanium due to their centrosymmetry, the group of zincblende III-V compound semiconductors, especially (100)-grown AlGaAs and GaAs, have recently been presented as promising alternatives. However, major obstacles to push the technology toward practical applications are the limited control over directionality of the SH emission and especially zero forward/backward radiation, resulting from the peculiar nature of the second-order nonlinear susceptibility of this otherwise highly promising group of semiconductors. Furthermore, the generated SH signal for (100)-GaAs nanoparticles depends strongly on the polarization of the pump. In this work, we provide both theoretically and experimentally a solution to these problems by presenting the first SHG nanoantennas made from (111)-GaAs embedded in a low index material. These nanoantennas show superior forward directionality compared to their (100)-counterparts. Most importantly, based on the special symmetry of the crystalline structure, it is possible to manipulate the SHG radiation pattern of the nanoantennas by changing the pump polarization without affecting the linear properties and the total nonlinear conversion efficiency, hence paving the way for efficient and flexible nonlinear beam-shaping devices.

17.
Cir Cir ; 86(1): 38-43, 2019.
Article in English | MEDLINE | ID: mdl-30951037

ABSTRACT

INTRODUCTION: The inability to identify, express feelings, and not distinguish between emotions and bodily sensations, is known as alexithymia. In 1988, it developed The Toronto Alexithymia Scale (TAS-20), consists of 20 items and three factors: a) difficulty of identifying feelings and differences between feelings and bodily sensations; b) difficulty of describing feelings; and c) externally oriented thinking. It's considered that people with eating disorders have specific deficits in identify and communicate their feelings. OBJECTIVE: The present study has as purpose to the instrument validation. METHODS: It was a cross-sectional study and psychometric character design of a single sample, formed of 435 persons suffering eating disorder (ED), with an age range of 12-68 years, of which 91% were women and 9% were men. To obtain the reliability of the instrument, applies internal consistency test, which resulted in an alpha of 0.89, then applied a factor analysis of principals components with oblimin rotation. RESULTS: According to statistical analysis, were eliminated six items, so the scale finished with 14 items, and to analyze it observed that these items correspond with the two main factors of the original scale. The ED patients present alexithymia. DISCUSSION: The scale satisfies the criteria of validity necessary for use in this population.


INTRODUCCIÓN: La incapacidad para identificar y expresar sentimientos, y no distinguir entre las emociones y las sensaciones corporales, se conoce como alexitimia. En 1988 se desarrolló la Escala de Alexitimia de Toronto (TAS-20), que está conformada por 20 reactivos y tres factores: a) dificultad para identificar los sentimientos y las diferencias entre sentimientos y sensaciones corporales; b) dificultad para describir sentimientos; y c) pensamiento orientado externamente. Se considera que las personas con trastornos de la conducta alimentaria (TCA) tienen déficits específicos en la identificación y la comunicación de sus sentimientos. OBJETIVO: Realizar la validación de dicho instrumento. MÉTODO: Estudio de tipo transversal y de carácter psicométrico con diseño de una sola muestra, conformada por 435 personas con diagnóstico de TCA, con un rango de edad de 12 a 68 años, de las cuales el 91% eran mujeres y el 9% eran hombres. Para obtener la confiabilidad del instrumento se aplicó una prueba de consistencia interna, que dio como resultado un alfa de 0.89; posteriormente se hizo un análisis factorial de componentes principales con rotación oblimin. RESULTADOS: De acuerdo con el análisis estadístico, se eliminaron seis reactivos, de tal forma que la escala finalizó con 14 reactivos, y al analizarlos se observó que concordaban con los dos factores principales de la escala original. Las pacientes con TCA presentan alexitimia. DISCUSIÓN: La escala satisface los criterios de validez necesarios para ser utilizada en dicha población.


Subject(s)
Affective Symptoms/complications , Affective Symptoms/epidemiology , Diagnostic Self Evaluation , Feeding and Eating Disorders/complications , Adolescent , Adult , Affective Symptoms/diagnosis , Aged , Child , Cross-Sectional Studies , Female , Humans , Male , Mexico/epidemiology , Middle Aged , Prevalence , Young Adult
18.
Nanoscale ; 11(4): 1745-1753, 2019 Jan 23.
Article in English | MEDLINE | ID: mdl-30623948

ABSTRACT

We investigate second- and third-harmonic generation from individual AlGaAs nanoantennas using far-field mapping with radially- and azimuthally-polarized cylindrical vector beams. Due to the unique polarization structure of these beams, we are able to determine the crystal orientation of the nanoantenna in a single scanning map. Our method thus provides a novel and versatile optical tool to study the crystal properties of semiconductor nanoantennas. We also demonstrate the influence of cylindrical vector beam excitation on the resonant enhancement of second- and third-harmonic generation driven by electric and magnetic anapole-like modes, despite falling in the strong absorption regime of AlGaAs. In particular, we observe a greater nonlinear conversion efficiency from a single nanoantenna excited with a radially-polarized beam as compared to an azimuthally polarized cylindrical vector beam. The fundamental field of the radially-polarized beam strongly couples to the multipoles increasing the near-field enhancement of the nanoantenna. Our work introduces new ways to study individual nanostructures and to tailor the efficiencies of nonlinear phenomena at the nanoscale using non-conventional optical techniques.

19.
Cir Cir ; 86(1): 43-49, 2018.
Article in Spanish | MEDLINE | ID: mdl-29681643

ABSTRACT

Introduction: The inability to identify, express feelings, and not distinguish between emotions and bodily sensations, is known as alexithymia. In 1988, it developed The Toronto Alexithymia Scale (TAS-20), consists of 20 items and three factors: a) difficulty of identifying feelings and differences between feelings and bodily sensations; b) difficulty of describing feelings; and c) externally oriented thinking. It's considered that people with eating disorders have specific deficits in identify and communicate their feelings. Objective: The present study has as purpose to the instrument validation. Methods: It was a cross-sectional study and psychometric character design of a single sample, formed of 435 persons suffering eating disorder (ED), with an age range of 12-68 years, of which 91% were women and 9% were men. To obtain the reliability of the instrument, applies internal consistency test, which resulted in an alpha of 0.89, then applied a factor analysis of principals components with oblimin rotation. Results: According to statistical analysis, were eliminated six items, so the scale finished with 14 items, and to analyze it observed that these items correspond with the two main factors of the original scale. The ED patients present alexithymia. Discussion: The scale satisfies the criteria of validity necessary for use in this population.


Introducción: La incapacidad para identificar y expresar sentimientos, y no distinguir entre las emociones y las sensaciones corporales, se conoce como alexitimia. En 1988 se desarrolló la Escala de Alexitimia de Toronto (TAS-20), que está conformada por 20 reactivos y tres factores: a) dificultad para identificar los sentimientos y las diferencias entre sentimientos y sensaciones corporales; b) dificultad para describir sentimientos; y c) pensamiento orientado externamente. Se considera que las personas con trastornos de la conducta alimentaria (TCA) tienen déficits específicos en la identificación y la comunicación de sus sentimientos. Objetivo: Realizar la validación de dicho instrumento. Método: Estudio de tipo transversal y de carácter psicométrico con diseño de una sola muestra, conformada por 435 personas con diagnóstico de TCA, con un rango de edad de 12 a 68 años, de las cuales el 91% eran mujeres y el 9% eran hombres. Para obtener la confiabilidad del instrumento se aplicó una prueba de consistencia interna, que dio como resultado un alfa de 0.89; posteriormente se hizo un análisis factorial de componentes principales con rotación oblimin. Resultados: De acuerdo con el análisis estadístico, se eliminaron seis reactivos, de tal forma que la escala finalizó con 14 reactivos, y al analizarlos se observó que concordaban con los dos factores principales de la escala original. Las pacientes con TCA presentan alexitimia. Discusión: La escala satisface los criterios de validez necesarios para ser utilizada en dicha población.


Subject(s)
Affective Symptoms/epidemiology , Feeding and Eating Disorders/epidemiology , Adolescent , Adult , Aged , Child , Communication Barriers , Comorbidity , Cross-Sectional Studies , Emotions , Female , Humans , Male , Mexico/epidemiology , Middle Aged , Prevalence , Principal Component Analysis , Psychometrics , Reproducibility of Results , Sensation , Severity of Illness Index , Young Adult
20.
Light Sci Appl ; 7: 44, 2018.
Article in English | MEDLINE | ID: mdl-30839609

ABSTRACT

We demonstrate that a dielectric anapole resonator on a metallic mirror can enhance the third harmonic emission by two orders of magnitude compared to a typical anapole resonator on an insulator substrate. By employing a gold mirror under a silicon nanodisk, we introduce a novel characteristic of the anapole mode through the spatial overlap of resonantly excited Cartesian electric and toroidal dipole modes. This is a remarkable improvement on the early demonstrations of the anapole mode in which the electric and toroidal modes interfere off-resonantly. Therefore, our system produces a significant near-field enhancement, facilitating the nonlinear process. Moreover, the mirror surface boosts the nonlinear emission via the free-charge oscillations within the interface, equivalent to producing a mirror image of the nonlinear source and the pump beneath the interface. We found that these improvements result in an extremely high experimentally obtained efficiency of 0.01%.

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