Field enhancement and spectral features of hexagonal necklaces of silver nanoparticles for enhanced nonlinear optical processes

Access to the online abstract in the journal: https://doi.org/10.1364/OE.26.022394 © 2018 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reservedThe nonlinear properties of hybrid metallic-dielectric systems are attracting great interest due to their potential for the enhancement of frequency conversion processes at nanoscale dimensions. In this work, we theoretically and experimentally address the correlation between the near field distribution of hexagonal plasmonic necklaces of silver nanoparticles formed on the surface of a LiNbO3 crystal and the second harmonic generation (SHG) produced by this nonlinear crystal in the vicinities of the necklaces. The spectral response of the hexagonal necklaces does not depend on the polarization direction and is characterized by two main modes, the absorptive high-energy mode located in the UV spectral region and the lower energy mode, which is strongly radiant and extends from the visible to the near infrared region. We show that the spatial distribution of the enhanced SHG is consistent with the local field related to the low energy plasmon mode, which spectrally overlaps the fundamental beam. The results are in agreement with the low absorption losses of this mode and the two-photon character of the nonlinear process and provide deeper insight in the connection between the linear and nonlinear optical properties of the hybrid plasmonic-ferroelectric system. The study also highlights the potential of hexagonal necklaces as useful plasmonic platforms for enhanced optical processes at the nanoscaleSpanish Ministry of Economy and Competitiveness (MINECO) under project MAT2016- 76106-R and the Comunidad de Madrid (grant S2013/MIT-2740). C.T. acknowledges funding from the VILLUM Foundation (Villum Investigator, grant no. 16498). L.E.B and M.O.R also acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through The “María de Maeztu” Programme for Units of Excellence in R&D (MDM-2014-0377

Enhancing nonlinear interactions by the superposition of plasmonic lattices on ꭕ(2)-nonlinear photonic crystals

Plasmonic structures have been revealed as efficient units to enhance localized nonlinear phenomena generated at dielectric-metal interfaces. However, their effect on the nonlinear interactions provided by quasi-phase matching processes in ꭕ(2) modulated dielectric crystals have been scarcely addressed, mainly due to the complexity in manufacturing appropriate periodic plasmonic structures overlying the ꭕ(2) dielectric structure. Here, by a simple method we have fabricated a periodic structure based on the combination of two commensurate lattices: a periodic lattice of chains of Ag nanoparticles and a periodic lattice of ꭕ(2)-modulation based on a ferroelectric domains structure. The hybrid system supports multiple surface plasmon lattice resonances (SLRs) at the technologically relevant NIR spectral region, which yield the enhancement of the nonlinear diffraction pattern generated by the ꭕ(2) structure. The superposition of the plasmonic and the ꭕ(2)-modulation lattice results in a 20-fold enhancement of the directional SHG due to the excitation of SLRs by the interacting waves involved in the nonlinear process. The results are obtained in lithium niobate, a widely used crystal in optoelectronics, and demonstrate the potential of the approach to design integrated solid-state platforms for on-chip optical steering, multiplexing or quantum technologiesThis work has been supported by the Spanish Government (Contracts MAT2016-76106-R and PID2019-108257GB-I00/ AEI/10.13039/501100011033 and María de Maeztu “Pro gramme for Units of Excellence in R&D CEX2018-000805-M) and Comunidad de Madrid (Grant SI1/PJI/2019-00105

Evaluación de la actividad antifúngica de extractos liquénicos e identificación de sus metabolitos

Los líquenes son los hongos que establecen una relación simbiótica con un alga o cianobacteria. En esta simbiosis se producen por parte del hongo, una serie de metabolitos secundarios conocidos como sustancias liquénicas; las cuales presentan una marcada actividad antibiótica. En Cuba no se tienen antecedentes sobre estudios de metabolitos liquénicos por lo que se propone; evaluar el efecto fungicida de extractos liquénicos producidos por especies cubanas así como identificar sus metabolitos. Se emplearon líquenes de diferentes zonas del país (Parmotrema dilatatum, P. tinctorum, P. praesorediosum P. cristiferum, Ramalina americana, Cladonia ceratophylla y Cladonia portentosa spp. pacífica), a los cuales se les extrajo con acetona, las sustancias liquénicas almacenadas en el talo. Los extractos fueron probados contra los hongos fitopatógenos Rhizoctonia solani y Phythophtora nicotianae; por el método de envenenamiento del medio de cultivo agar papa dextrosa a concentraciones de: 0,01%; 0,03% y 0,07%. Se utilizó un control negativo de dimetilsufóxido al 0,07% y se determinaron los porcentajes de inhibición, cuyos resultados fueron analizados estadísticamente. Los metabolitos secundarios presentes en los extractos se identificaron por cromatografía de capa fina (TLC). Exceptuando el extracto liquénico de P. cristiferum, todos los demás mostraron más de un 50% de inhibición del crecimiento de ambos hongos a la concentración de 0,07%, mientras que a las restantes concentraciones los valores fueron variados con diferencias significativas con respecto al control. Se lograron identificar tres metabolitos liquénicos: metil 2‘-O- metilmicrofilinato, 4-O-Demetilmicrofilinico y el ácido ramaniloico

Blue SHG enhancement by silver nanocubes photochemically prepared on a RbTiOPO4 ferroelectric crystal

This is the peer reviewed version of the following article: Blue SHG enhancement by silver nanocubes photochemically prepared on a RbTiOPO4 ferroelectric crystal, which has been published in final form at http://doi.org/10.1002/adma.201401603. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsSilver nanocubes with low size dispersion have been selectively photo-deposited on the positive surface of a periodically poled RbTiOPO 4 ferroelectric crystal. The obtained nanocubes show preferential orientations with respect to the substrate suggesting ep itaxial growth. The plasmonic resonances supported by the nanocubes are exploited to enhance blue SHG at the domain wallsThis work has been supported by the Spanish Government under projects MAT2010–17443, MAT2011–29255-C02–02 and MAT2013– 43301-R, Comunidad de Madrid under grant S2009/1756 and Generalitat de Catalunya under project 2009SGR23

Limberg flap: a review

Alexander Alexandrovich Limberg, Surgeon and Dentist, greatly contributed to the modern practice of plastic surgery. He defined the rhomboid flap (Limberg flap). The simplicity and effectiveness of the Limberg flap make it versatile, allowing adequate aesthetics with few complications. The split is made up of two equilateral triangles with angles of 60° and 120°, respectively. An adequate knowledge of the mechanisms of rotation and sliding of skin tissues is essential to indicate the use of this type of flap and to perform it. The skin can be moved from adjacent sites and must be mobile enough to close the defect with minimal tension. The Limberg flap is a flap that takes advantage of the laxity of the skin adjacent to the defect to allow the transposition of tissue with similar characteristics to the excised tissue

Más allá de las dimensiones del cuidado. Sistematización de la experiencia de enseñanza aprendizaje sobre el cuidado

The systematization of the teaching experience in human care is part of the project called Human Care in Nursing Education, Research, Care, and Administration. Its objective is to encourage the sharing of experiences in teaching and learning about Human Care, in order to make known the reach of the interaction and to recognize the knowledge that has been promoted or where a synergy has been generated from practice, collective and personal experience. The design of the study is qualitative; using the Participative Action Research and Learning by Experience methods. In this study, we describe what we do, feel and live, documenting the participants' opinion regarding, what is care? From the interpretation of opinion emerges a conceptual synergy unique, its own, and novel regarding the definition of care given by the respondents in a collective teaching session. Caring is to give love and support to a person in order to minimize the anguish and enter into a stage of tranquility, providing a feeling of security and confidence at the moment. (Affection 1): Caring is direct or indirect attention that is given to the human being founded on holism, observation, communication and feelings in order to strengthen the weaknesses and team work and, in this way, achieves what has been planned. (Affection 5) and among others, human care is the key to caring with human quality founded in affection, confidence and personal presence with the objective that the person achieves the greatest satisfaction in the moment and occasion of his/her health status. (Affection 24).Esta sistematización de experiencia sobre la enseñanza del Cuidado Humano se inscribe en el proyecto titulado Cuidado Humano en Educación, Investigación, Administración y Cuidado en Enfermería, cuya finalidad es favorecer el intercambio de experiencias en la enseñanza y el aprendizaje sobre el Cuidado Humano; concienciar los alcances de la interacción y reconocer el conocimiento que se ha potenciado o dónde se ha generado una sinergia desde la práctica, la experiencia colectiva y la experiencia personal. Materiales y Métodos: El diseño del estudio es cualitativo; utilizando el método Investigación Acción Participativa y el Aprendizaje por Experiencia. En el mismo se describe lo que hacemos, sentimos y vivimos, documentando la opinión de los participantes sobre ¿Qué es el cuidado? De la interpretación de las opiniones, emerge una sinergia conceptual, única, propia y novedosa sobre la definición de cuidado dada por los informantes, en una sesión colectiva de enseñanza. Los resultados son los conceptos de cuidado que emergen de forma empírica y significativa: entre otros, Cuidado es brindar amor y apoyo a la persona para que minimice la angustia y entre en un estadio de tranquilidad, proporcionándole en el momento, un sentimiento de seguridad y confianza. (Afecto 1); y entre otros, el cuidado humano es la clave de la atención, con calidad humana, fundamentada en el afecto, la confianza y con la presencia del personal, con el fin de que la persona alcance la mayor satisfacción, en el momento y en la ocasión, de su estado de salud. (Afecto 24). En conclusión, la sistematización de la práctica pedagógica sobre el cuidado humano proporciona una de las vías para hacer más significativo entre las enfermeras la contribución del cuidado en la vida de los cuidados y de los cuidadores como principio universal, conjuntamente, con el amor, en la vida de los humanos y de la humanidad

Hepatitis B vaccine in patients with human immunodeficiency virus infection

La infección por virus de hepatitis B (VHB) representa un problema de salud pública a nivel mundial, especialmente entre las personas infectadas con el VIH, en quienes la coinfección modifica el curso y la historia natural de la enfermedad, así como la morbimortalidad, lo cual hace imperativo diseñar estrategias encaminadas a la prevención de la infección por VHB en pacientes infectados con VIH. La vacunación constituye la forma más importante de prevención, aunque su efectividad se ve alterada, de acuerdo al estado inmunológico y virológico del paciente.26-33Hepatitis B is a public health problem in the entire world, mainly among HIV infected people in whom the coinfection change the course, natural history and morbi-mortality of the disease. Because of this, it is imperative to design strategies to prevent hepatitis B infection in HIV patients. Vaccination is the most important tool for prevention, although its efficacy varies according to immunologic and virologic status of the patient

Close companions around young stars

Multiplicity is a fundamental property that is set early during stellar lifetimes, and it is a stringent probe of the physics of star formation. The distribution of close companions around young stars is still poorly constrained by observations. We present an analysis of stellar multiplicity derived from APOGEE-2 spectra obtained in targeted observations of nearby star-forming regions. This is the largest homogeneously observed sample of high-resolution spectra of young stars. We developed an autonomous method to identify double lined spectroscopic binaries (SB2s). Out of 5007 sources spanning the mass range of $\sim$0.05--1.5 \msun, we find 399 binaries, including both RV variables and SB2s. The mass ratio distribution of SB2s is consistent with a uniform for $q0.95$. The period distribution is consistent with what has been observed in close binaries ($<10$ AU) in the evolved populations. Three systems are found to have $q\sim$0.1, with a companion located within the brown dwarf desert. There are not any strong trends in the multiplicity fraction (MF) as a function of cluster age from 1 to 100 Myr. There is a weak dependence on stellar density, with companions being most numerous at $\Sigma_*\sim30$ stars/pc$^{-2}$, and decreasing in more diffuse regions. Finally, disk-bearing sources are deficient in SB2s (but not RV variables) by a factor of $\sim$2; this deficit is recovered by the systems without disks. This may indicate a quick dispersal of disk material in short-period equal mass systems that is less effective in binaries with lower $q$.Comment: 25 pages, 20 figures. Accepted to A

The Neurovascular Unit Dysfunction in Alzheimer's Disease

Funding: This work was supported by Fondo Nacional de Ciencia y Tecnologia (FONDOCyT) from the Ministry of Higher Education, Science and Technology, Dominican Republic (2015-3A2-127 to M.P.-H.) and (2018-2019-2A3-208 to J.L.-M. and M.P.-H.). Acknowledgments: The authors want to express their gratitude to the Mexican families who have donated the brain of their loved ones affected by Alzheimer’s disease and made our research possible. We also want to express our gratitude to the Union Medical University Clinic, Dominican Republic, for their support and collaboration in developing of this research project. This work is dedicated to the memory of José Raúl Mena López †.Peer reviewedPublisher PD

Randomized clinical trial of the safety and immunogenicity of the Tdap vaccine in pregnant Mexican women

ABSTRACT Immunization with the tetanus, diphtheria, and pertussis (Tdap) vaccine raises controversies on immunogenicity and possible antibody interference. We performed an experimental, double-blind, parallel group controlled clinical trial to evaluate the safety and immunogenicity of the Tdap vaccine in 204 pregnant women and their children and to determine its interference in antibody production. Pregnant women 18 to 38 y of age with 12 to 24 weeks gestation, a low obstetric risk, and without serious disease were randomly selected. The experimental group received 0.5 mL IM of Tdap and the control group normal saline. Six blood samples were drawn before and after solution application, and from the umbilical cord of the infants and at 2, 4, and 6 months of age. Pertactin and Pertussis toxin antibodies and possible interference of maternal antibodies with the vaccine were determined. In the experimental group, antibodies against Bordetella pertussis pertactin (anti-PRN) (112 E/mL 95% CI 89.9–139.9) and antibodies against pertussis toxin (anti-PT) (24.0 E/mL, 95% CI 18.3–31.4) were elevated in the mother before vaccination. These were higher in the umbilical cord and descended in the infant at 2 months (71.4 (95% CI 56.8–89.7 and 10.9; 95% CI 8.7–13.7, respectively). Anti-PT showed a delay in production. Tdap safety was confirmed with only mild local pain at 24 and 48 hours. Anti-PRN and anti-PT antibodies in the infant descend at 2 months of age. There is a delay in anti-PT in children of immunized mothers. Further studies are needed to elucidate its clinical significance