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  1. Article ; Online: Identification of the Segregation Kinetics of Ultrathin GaAsSb/GaAs Films Using AlAs Markers

    David Gonzalez / Sara Flores / Verónica Braza / Daniel F. Reyes / Alejandro Gallego Carro / Lazar Stanojević / Malte Schwarz / Jose María Ulloa / Teresa Ben

    Nanomaterials, Vol 13, Iss 798, p

    2023  Volume 798

    Abstract: For optoelectronic devices from the near to the far infrared, the advantages of using ultrathin III-Sb layers as quantum wells or in superlattices are well known. However, these alloys suffer from severe surface segregation problems, so that the actual ... ...

    Abstract For optoelectronic devices from the near to the far infrared, the advantages of using ultrathin III-Sb layers as quantum wells or in superlattices are well known. However, these alloys suffer from severe surface segregation problems, so that the actual profiles are very different from the nominal ones. Here, by inserting AlAs markers within the structure, state-of-the-art transmission electron microscopy techniques were used to precisely monitor the incorporation/segregation of Sb in ultrathin GaAsSb films (from 1 to 20 monolayers (MLs)). Our rigorous analysis allows us to apply the most successful model for describing the segregation of III-Sb alloys (three-layer kinetic model) in an unprecedented way, limiting the number of parameters to be fitted. The simulation results show that the segregation energy is not constant throughout the growth (which is not considered in any segregation model) but has an exponential decay from 0.18 eV to converge asymptotically towards 0.05 eV. This explains why the Sb profiles follow a sigmoidal growth model curve with an initial lag in Sb incorporation of 5 MLs and would be consistent with a progressive change in surface reconstruction as the floating layer is enriched.
    Keywords segregation ; III-Sb alloys ; STEM analyses ; Chemistry ; QD1-999
    Subject code 669
    Language English
    Publishing date 2023-02-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Estimación de mestizaje en dos poblaciones venezolanas usando marcadores informativos de ancestralidad y haplogrupos de ADN mitocondrial

    Álvaro Rodríguez / Sara Flores-Gutiérrez / Liana Fernández Gil / Irene Paradisi / Giulianna Antonelli / Dinorah Castro de Guerra

    Revista Argentina de Antropología Biológica, Vol 23, Iss

    2021  Volume 2

    Abstract: Los marcadores informativos de ancestralidad (AIM) autosómicos y los del ADN mitocondrial (ADNmt) son muy útiles para identificar el origen y los patrones de migración de las poblaciones. En este trabajo se estimó el mestizaje a partir de siete AIM en ... ...

    Abstract Los marcadores informativos de ancestralidad (AIM) autosómicos y los del ADN mitocondrial (ADNmt) son muy útiles para identificar el origen y los patrones de migración de las poblaciones. En este trabajo se estimó el mestizaje a partir de siete AIM en 188 individuos venezolanos, 84 del estado Guárico y 104 de la región centro occidental de Venezuela (RCO), se estimó la ancestralidad mitocondrial en el estado Guárico y se compararon ambas poblaciones según su origen y desarrollo histórico. Este estudio representa la primera aproximación a la composición genética de Guárico y es el primer reporte para Venezuela utilizando marcadores tipo AIM. Los resultados revelaron que los aportes amerindio y europeo predominan en estas poblaciones, pero el amerindio es mayor en Guárico (50,57 %) que en RCO (44,92 %), y el europeo lo es en RCO (38,46 % vs. 33,72 %). El origen del ADNmt en Guárico es de predominio amerindio (80 %), tendencia similar a lo reportado para RCO (75 %). El aporte amerindio en Guárico es el más alto reportado para Venezuela. Se concluye que las diferencias encontradas entre ambas muestras podrían deberse a la colonización más temprana de la RCO y a su desarrollo industrial moderado durante el siglo XIX. Así mismo, planteamos que los AIM aquí utilizados lograron una buena discriminación del aporte de los tres grupos ancestrales principales y que su uso simultáneo con polimorfismos de origen uniparental permite obtener, en forma económica, una mejor aproximación genética para explicar la dinámica del proceso de mestizaje que dio origen a la población venezolana actual.
    Keywords mestizaje ; poblaciones venezolanas ; marcadores de ancestralidad ; ADN mitocondrial ; Anthropology ; GN1-890 ; Physical anthropology. Somatology ; GN49-298
    Language Spanish
    Publishing date 2021-07-01T00:00:00Z
    Publisher Asociación de Antropología Biológica Argentina
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Social-Ecological Barriers to Access to Healthcare for Adolescents

    Whitney Garney / Kelly Wilson / Kobi V. Ajayi / Sonya Panjwani / Skylar M. Love / Sara Flores / Kristen Garcia / Christi Esquivel

    International Journal of Environmental Research and Public Health, Vol 18, Iss 4138, p

    A Scoping Review

    2021  Volume 4138

    Abstract: Access to healthcare for adolescents is often overlooked in the United States due to federal and state-sponsored insurance programs such as Medicaid and the Children’s Health Insurance Program. While these types of programs provide some relief, the issue ...

    Abstract Access to healthcare for adolescents is often overlooked in the United States due to federal and state-sponsored insurance programs such as Medicaid and the Children’s Health Insurance Program. While these types of programs provide some relief, the issue of healthcare access goes beyond insurance coverage and includes an array of ecological factors that hinder youths from receiving services. The purpose of this scoping review was to identify social-ecological barriers to adolescents’ healthcare access and utilization in the United States. We followed the PRISMA and scoping review methodological framework to conduct a comprehensive literature search in eight electronic databases for peer-reviewed articles published between 2010 and 2020. An inductive content analysis was performed to thematize the categories identified in the data extraction based on the Social-Ecological Model (SEM). Fifty studies were identified. Barriers across the five SEM levels emerged as primary themes within the literature, including intrapersonal-limited knowledge of and poor previous experiences with healthcare services, interpersonal-cultural and linguistic barriers, organizational-structural barriers in healthcare systems, community-social stigma, and policy-inadequate insurance coverage. Healthcare access for adolescents is a systems-level problem requiring a multifaceted approach that considers complex and adaptive behaviors.
    Keywords adolescents ; healthcare utilization ; healthcare access ; health services ; Medicine ; R
    Subject code 360
    Language English
    Publishing date 2021-04-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Suppressing the Effect of the Wetting Layer through AlAs Capping in InAs/GaAs QD Structures for Solar Cells Applications

    Nazaret Ruiz / Daniel Fernández / Lazar Stanojević / Teresa Ben / Sara Flores / Verónica Braza / Alejandro Gallego Carro / Esperanza Luna / José María Ulloa / David González

    Nanomaterials, Vol 12, Iss 1368, p

    2022  Volume 1368

    Abstract: Recently, thin AlAs capping layers (CLs) on InAs quantum dot solar cells (QDSCs) have been shown to yield better photovoltaic efficiency compared to traditional QDSCs. Although it has been proposed that this improvement is due to the suppression of the ... ...

    Abstract Recently, thin AlAs capping layers (CLs) on InAs quantum dot solar cells (QDSCs) have been shown to yield better photovoltaic efficiency compared to traditional QDSCs. Although it has been proposed that this improvement is due to the suppression of the capture of photogenerated carriers through the wetting layer (WL) states by a de-wetting process, the mechanisms that operate during this process are not clear. In this work, a structural analysis of the WL characteristics in the AlAs/InAs QD system with different CL-thickness has been made by scanning transmission electron microscopy techniques. First, an exponential decline of the amount of InAs in the WL with the CL thickness increase has been found, far from a complete elimination of the WL. Instead, this reduction is linked to a higher shield effect against QD decomposition. Second, there is no compositional separation between the WL and CL, but rather single layer with a variable content of InAlGaAs. Both effects, the high intermixing and WL reduction cause a drastic change in electronic levels, with the CL making up of 1–2 monolayers being the most effective configuration to reduce the radiative-recombination and minimize the potential barriers for carrier transport.
    Keywords InAs quantum dots solar cells ; AlAs capping ; (S)TEM ; Chemistry ; QD1-999
    Subject code 530
    Language English
    Publishing date 2022-04-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Filogeografía de mitogenomas indígenas de Uruguay

    Gonzalo Figueiro / Patricia Mut / Lucas Ale / Sara Flores-Gutiérrez / Gonzalo Greif / Pedro C. Hidalgo / Lorena Luna / Elizabeth Ackermann / Raúl Germán Negro / Lucía Spangenberg / Hugo Naya / Mónica Sans

    Revista Argentina de Antropología Biológica, Vol 24, Iss

    2022  Volume 1

    Abstract: Recientemente, diversos estudios sobre la población uruguaya han demostrado que está conformada por desiguales aportes de europeos, africanos y pueblos originarios, entre otros. El aporte indígena es mayor cuando se analiza la contribución por línea ... ...

    Abstract Recientemente, diversos estudios sobre la población uruguaya han demostrado que está conformada por desiguales aportes de europeos, africanos y pueblos originarios, entre otros. El aporte indígena es mayor cuando se analiza la contribución por línea materna, aunque su origen étnico/geográfico no es claro, ni tampoco cuándo ni cómo llegaron los distintos grupos. Para aportar al conocimiento del poblamiento prehistórico e histórico del territorio y sus relaciones con otras poblaciones se analizan, por secuenciación masiva, 32 genomas mitocondriales completos (mitogenomas) de habitantes actuales del país, identificados previamente por sus regiones hipervariables como correspondientes a los cuatro haplogrupos principales de origen americano. Se determinaron siete nuevos subhaplogrupos (A2be, A2bf, B2an, C1d1h, C1b30, C1b31 y D1x), otro se redenominó (C1d1d - actual C1d1g) y se plantea la revisión de los criterios de asignación de B2b6 y D1g5. Se estimó la antigüedad de los subhaplogrupos nuevos, que varía entre 4554 y 11985 años, con la excepción de C1d1g, cuya edad fue estimada en 20736 años. Algunas secuencias pudieron ser vinculadas a distintos grupos étnicos o a diversas regiones geográficas, como Amazonia, Chaco, Pampa, o Andes. Se discuten las nuevas asignaciones desubhaplogrupos y las de algunos previamente definidos, así como su distribución geográfica y antigüedad, con relación al panorama general de América del Sur.
    Keywords ADN mitocondrial ; migraciones ; Sudamérica ; Anthropology ; GN1-890 ; Physical anthropology. Somatology ; GN49-298
    Language Spanish
    Publishing date 2022-01-01T00:00:00Z
    Publisher Asociación de Antropología Biológica Argentina
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Tailoring of AlAs/InAs/GaAs QDs Nanostructures via Capping Growth Rate

    Nazaret Ruiz / Daniel Fernandez / Esperanza Luna / Lazar Stanojević / Teresa Ben / Sara Flores / Verónica Braza / Alejandro Gallego-Carro / Guillermo Bárcena-González / Andres Yañez / José María Ulloa / David González

    Nanomaterials, Vol 12, Iss 14, p

    2022  Volume 2504

    Abstract: The use of thin AlA capping layers (CLs) on InAs quantum dots (QDs) has recently received considerable attention due to improved photovoltaic performance in QD solar cells. However, there is little data on the structural changes that occur during capping ...

    Abstract The use of thin AlA capping layers (CLs) on InAs quantum dots (QDs) has recently received considerable attention due to improved photovoltaic performance in QD solar cells. However, there is little data on the structural changes that occur during capping and their relation to different growth conditions. In this work, we studied the effect of AlA capping growth rate (CGR) on the structural features of InAs QDs in terms of shape, size, density, and average content. As will be shown, there are notable differences in the characteristics of the QDs upon changing CGR. The Al distribution analysis in the CL around the QDs was revealed to be the key. On the one hand, for the lowest CGR, Al has a homogeneous distribution over the entire surface, but there is a large thickening of the CL on the sides of the QD. As a result, the QDs are lower, lenticular in shape, but richer in In. On the other hand, for the higher CGRs, Al accumulates preferentially around the QD but with a more uniform thickness, resulting in taller QDs, which progressively adopt a truncated pyramidal shape. Surprisingly, intermediate CGRs do not improve either of these behaviors, resulting in less enriched QDs.
    Keywords InAs QDs ; AlAs capping ; STEM ; growth rate control ; Chemistry ; QD1-999
    Subject code 530
    Language English
    Publishing date 2022-07-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Effectiveness of the association between carbamazepine and peripheral analgesic block with ropivacaine for the treatment of trigeminal neuralgia

    Laurinda Lemos / Ramalho Fontes / Sara Flores

    Journal of Pain Research, Vol 2010, Iss default, Pp 201-

    2010  Volume 212

    Abstract: Laurinda Lemos1,2, Ramalho Fontes3, Sara Flores2, Pedro Oliveira4, Armando Almeida11Life and Health Sciences Research Institute (ICVS), School of Health Sciences, Campus de Gualtar, University of Minho, Braga, Portugal; 2Hospital Center of Alto Ave, Unit ...

    Abstract Laurinda Lemos1,2, Ramalho Fontes3, Sara Flores2, Pedro Oliveira4, Armando Almeida11Life and Health Sciences Research Institute (ICVS), School of Health Sciences, Campus de Gualtar, University of Minho, Braga, Portugal; 2Hospital Center of Alto Ave, Unit of Fafe, Fafe, Portugal; 3Department of Neurology, Hospital São Marcos, Braga, Portugal; 4Products and Systems Engineering, Campus de Azurém, University of Minho, Guimarães, PortugalAbstract: Treatment of trigeminal neuralgia (TN) is achieved by using adjuvant analgesics like antiepileptics, with carbamazepine (CBZ) being the first-line approach for TN patients, although side effects may be present. Other approaches using gabapentin, namely when associated with peripheral analgesic block of TN trigger points with the local anesthetic ropivacaine (ROP), resulted in decreased pain and daily drug intake (reduced side effects). This study evaluates if the association between CBZ and the peripheral block with ROP reinforces the clinical value of CBZ. In this parallel, double-blinded study, idiopathic TN patients were randomized to receive during 4 weeks either CBZ (CBZ; n = 21) or CBZ associated with the peripheral analgesic block using ROP (CBZ + ROP; n = 24). The primary outcome measures were the following: i) pain intensity, evaluated by the numerical rating scale; ii) number of pain crises; and iii) number needed to treat. Evaluation points were at the beginning (day 1) and end (day 29) of treatment and after a follow-up of 5 months (month 6). Both protocols resulted in a decrease of pain intensity and number of pain crises, but only the association CBZ + ROP showed i) a significant stronger reduction in pain intensity at month 6 and ii) a significant decrease in the daily dose of CBZ given to patients (both at day 29 and month 6). In contrast, the daily dose in CBZ-only patients remained constant or even increased. The number needed to treat for the association CBZ + ROP over the CBZ protocol reduced from 5 at the end of the 4-week treatment to 3 after the ...
    Keywords Medicine (General) ; R5-920
    Subject code 616
    Language English
    Publishing date 2010-10-01T00:00:00Z
    Publisher Dove Medical Press
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Dendritic Cell‐Mediated Cross‐Priming by a Bispecific Neutralizing Antibody Boosts Cytotoxic T Cell Responses and Protects Mice against SARS‐CoV‐2

    Rodrigo Lázaro‐Gorines / Patricia Pérez / Ignacio Heras‐Murillo / Irene Adán‐Barrientos / Guillermo Albericio / David Astorgano / Sara Flores / Joanna Luczkowiak / Nuria Labiod / Seandean L. Harwood / Alejandro Segura‐Tudela / Laura Rubio‐Pérez / Yudhi Nugraha / Xiaoran Shang / Yuxing Li / Carlos Alfonso / Kaylin A. Adipietro / Dinendra L. Abeyawardhane / Rocío Navarro /
    Marta Compte / Wenbo Yu / Alexander D. MacKerell Jr / Laura Sanz / David J. Weber / Francisco J. Blanco / Mariano Esteban / Edwin Pozharski / Raquel Godoy‐Ruiz / Inés G. Muñoz / Rafael Delgado / David Sancho / Juan García‐Arriaza / Luis Álvarez‐Vallina

    Advanced Science, Vol 10, Iss 34, Pp n/a-n/a (2023)

    2023  

    Abstract: Abstract Administration of neutralizing antibodies (nAbs) has proved to be effective by providing immediate protection against SARS‐CoV‐2. However, dual strategies combining virus neutralization and immune response stimulation to enhance specific ... ...

    Abstract Abstract Administration of neutralizing antibodies (nAbs) has proved to be effective by providing immediate protection against SARS‐CoV‐2. However, dual strategies combining virus neutralization and immune response stimulation to enhance specific cytotoxic T cell responses, such as dendritic cell (DC) cross‐priming, represent a promising field but have not yet been explored. Here, a broadly nAb, TNT, are first generated by grafting an anti‐RBD biparatopic tandem nanobody onto a trimerbody scaffold. Cryo‐EM data show that the TNT structure allows simultaneous binding to all six RBD epitopes, demonstrating a high‐avidity neutralizing interaction. Then, by C‐terminal fusion of an anti‐DNGR‐1 scFv to TNT, the bispecific trimerbody TNTDNGR‐1 is generated to target neutralized virions to type 1 conventional DCs (cDC1s) and promote T cell cross‐priming. Therapeutic administration of TNTDNGR‐1, but not TNT, protects K18‐hACE2 mice from a lethal SARS‐CoV‐2 infection, boosting virus‐specific humoral responses and CD8+ T cell responses. These results further strengthen the central role of interactions with immune cells in the virus‐neutralizing antibody activity and demonstrate the therapeutic potential of the Fc‐free strategy that can be used advantageously to provide both immediate and long‐term protection against SARS‐CoV‐2 and other viral infections.
    Keywords bispecific trimerbody ; cross‐priming ; CTL responses ; dendritic cells ; neutralizing antibody ; SARS‐CoV‐2 ; Science ; Q
    Subject code 570 ; 616
    Language English
    Publishing date 2023-12-01T00:00:00Z
    Publisher Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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