Study of the Geometry and Electronic Structure of Self-Assembled Monolayers on the Au(111) Surface

123 p.[EN]A study of the geometries and electronic properties of organic molecular thin films adsorbed on Au(111) has been presented in this thesis. It contains DFT-based first principles calculations, that have been compared to experimental results, mainly STM/STS measurements. Three different systems have been analysed in detail: chemisorption of small thiolates, donor–acceptor charge-transfer complex adsorption, and co-adsorption of complementary polyarenes. These systems cover a wide range of the different strategies used to grow SAMs. Indeed, the relative strength of the interactions that steer the selfassembly of such films, ranging from strong to weak adsorbate–substrate interactions with distinct adsorbate–adsorbate interactions, results in a perfect playground to understand the underlaying physics in the formation of SAMs. With that aim we have used different theoretical tools throughout this work, that include, besides relaxed geometries and energetic analysis, induced electron densities, PDOS on atomic sites and molecular orbitals, band structure calculations, charge transfer analysis, etc.[ES]Esta tesis presenta un estudio teórico, mediante el formalismo de teoría funcional de densidad (dft), de las geometrías y propiedades electrónicas de films delgados de moléculas orgánicas adsorbidad en Au(111). En función de la intensidad relativa de las interacciones adsorvato-adsorbato y adsorbato-substrato, que gobiernan el autoensamblado de dichos films, tres sistemas diferentes son analizados en detalle: quimisorcion de pequeños thiolatos, adsorción de complejos donor-acceptor, y co-adsorción de poliarenos complemetarios. Con el objetivo de entender la física subyacente en la formacion de monocapas autoensambladas, resultados experimentales disponibles (principalmente medidas STM y STS) son contrastados gracias al uso de distintas herramientas teóricas, que incluyen, proyección de densidad de estados en orbitales atómicos y moleculares, cálculo de la estructura de bandas, transferencia de carga, etc

Linguistic Self-Esteem in Bilingual Adults

The present study investigated the psychology of linguistic self-esteem in bilingual speakers. Previous research suggested that students’ self-esteem strongly correlated with academic achievement, but current studies also suggest these trends may differ across ethnic minority groups and their majority group peers (Baumeister, Campbell, Krueger, & Vohs, 2003; Ferguson & Cramer, 2007). In addition, the growing bilingual student population in the United States highlights a need to assess how multiple languages interact with students’ self-esteem in academic settings (NCES, 2019). Recently, the Language Efficacy and Acceptance Dimension Scale was developed to assess linguistic self-esteem in bilingual adults (Neugebauer, 2011). Participants who are bilingual in English and Spanish were recruited and randomly assigned to read a simple or complex passage written in Spanish and complete various psychosocial measures. Because complex syntax could lead to lower levels of comprehension, it was predicted that those who read the complex passage will have lower linguistic self-esteem compared to those who read the simple passage. While the hypothesis was not supported, exploratory analyses gave insight into the relationship between linguistic self-esteem and constructs like cultural identity and affect

Estrategias de aprendizaje de estructuras morfológicas en alumnos de primer año de la Facultad de Ciencias Naturales y Museo, UNLP

Mediante el empleo del cuestionario CEPEA y del procesamiento estadístico del mismo con el análisis de grupos dentro de grupos se determinaron tres estrategias de estudio o aprendizaje, una superficial en la cual los alumnos aplican la memoria, otra profunda que combina la memoria y el razonamiento y por último una de logro o ambivalente que trata del razonamiento puro. Las dos primeras estrategias fueron las elegidas por el mayor porcentaje de alumnos, De todas maneras, los tres grupos mostraron un predominio de la estrategia superficial acompañada por la estrategia profunda.By using the questionnaire and the statistical processing CEPEA it for the analysis of groups within groups identified three strategies of study or learning, a surface where they apply memory, one that combines deep memory and reasoning, both strategies were chosen by the highest percentage of students, and finally one of achievement or ambivalent about pure reasoning. Still in all three groups showed a predominance of the surface strategy accompanied by the deep one

Proliferation tracing with single-cell mass cytometry optimizes generation of stem cell memory-like T cells.

Selective differentiation of naive T cells into multipotent T cells is of great interest clinically for the generation of cell-based cancer immunotherapies. Cellular differentiation depends crucially on division state and time. Here we adapt a dye dilution assay for tracking cell proliferative history through mass cytometry and uncouple division, time and regulatory protein expression in single naive human T cells during their activation and expansion in a complex ex vivo milieu. Using 23 markers, we defined groups of proteins controlled predominantly by division state or time and found that undivided cells account for the majority of phenotypic diversity. We next built a map of cell state changes during naive T-cell expansion. By examining cell signaling on this map, we rationally selected ibrutinib, a BTK and ITK inhibitor, and administered it before T cell activation to direct differentiation toward a T stem cell memory (TSCM)-like phenotype. This method for tracing cell fate across division states and time can be broadly applied for directing cellular differentiation

Patterns of Text Readability in Human and Predicted Eye Movements

It has been shown that multilingual transformer models are able to predict human reading behavior when fine-tuned on small amounts of eye tracking data. As the cumulated prediction results do not provide insights into the linguistic cues that the model acquires to predict reading behavior, we conduct a deeper analysis of the predictions from the perspective of readability. We try to disentangle the three-fold relationship between human eye movements, the capability of language models to predict these eye movement patterns, and sentence-level readability measures for English. We compare a range of model configurations to multiple baselines. We show that the models exhibit difficulties with function words and that pre-training only provides limited advantages for linguistic generalization

Enseñanza de las ciencias morfológicas en ingresantes a la Facultad de Ciencias Naturales y Museo de la UNLP

The public University in La Plata from the beginning, tried to analyze and elucidate the theme of failure and dropout in the first years of university life, where such factors ranging psychological, sociological, economic, organizational or due to student interaction and the institution.\nSince 1968 is assigned a value to the social composition of entrants as another factor involved. While it is a subject that was always present, not many studies. The course General Zoology statistically treated the situation of four cohorts of students in first year of the Bachelor in Biology, with the following results: 47.22% (2008), 51.76% (2009), 50. 66% (2010) and 51.61% (2011) of students who drop out of race. Extrapolating a series of variables that play for the college dropout: Variables indicative of prior education and counseling received by the student demographic variables and personal students, variables indicating the student’s employment status and variables related to characteristics of their parents.\nThese variables influence independently or in an interrelated manner. From this theme, since 2009 is implemented in the FCNyM the tutorial system. It is expected that over time, this kind of support is accepted and profited massively by the students, making the increase in retention due to the neutralization of any of the above variables.La Universidad pública en La Plata desde los inicios, trató de analizar y dilucidar el tema del fracaso y la deserción en los primeros años de la vida universitaria, donde fluctúan factores de índole psicológicos, sociológicos, económicos, organizativos o relacionados con la interacción del estudiante y la Institución. Desde 1968 se le asigna un valor a la composición social de los ingresantes como otro factor involucrado. Si bien es un tema que siempre estuvo presente, no son muchos los estudios realizados. En la Cátedra de Zoología General se trató estadísticamente la situación de cuatro cohortes de alumnos de primer año de la carrera de Licenciatura en Biología, obteniéndose los siguientes porcentajes de alumnos que abandonan la carrera: 47,22% (2008), 51,76% (2009), 50,66% (2010) y 51,61% (2011). Se extrapolan una serie de variables que juegan a favor de la deserción universitaria: Variables indicativas de la educación y orientación previa recibida por el alumno, variables demográficas y personales del estudiante, variables indicativas de la situación laboral del alumno y variables relacionadas con características de sus padres.\nEstas variables influyen de forma independiente o de manera interrelacionada. A partir de esta temática, desde 2009 se implementa en la FCNyM el sistema de tutorías. Es esperable que con el transcurso del tiempo, este tipo de apoyo sea aceptado y aprovechado masivamente por los alumnos, logrando el aumento de la permanencia gracias a la neutralización de alguna de las variables antes mencionadas

Effect of 2’-nitroflavone on the expression of receptors associated with EGFR activity in breast cancer cells

Flavonoids were proposed as chemopreventive and chemotherapeutic agents per se or in combination with traditional antitumoral drugs. Epidermal growth factor receptor (EGFR) is associated with tumorigenesis of several tissues and it can be involved in the molecular mechanism of action of several flavonoids. With the aim of investigating if a combinatory therapy involving 2'-nitroflavone (2'NF), a synthetic flavonoid with antitumor properties, and EGFRinhibitors would be a possible effective treatment for breast cancer, we studied if this flavone modulates the expression of EGFR or other receptors that interact or modulate EGFR activity. MDA-MB-231 and MCF-7 breast cancer cells were treated with 2´NF at different concentrations for48 h. Afterwards, the protein content of EGFR, ErbB2, ER alpha, Met and IGF-IR were assessed by immunoblotting. Besides, PARP cleavage and phosphorylation of p38 were determined in the same experimental conditions. Results showed that 2´NF produced a reduction on the content ofErbB2 and IGF-IR in MDA-MB-231 cells, while in MCF-7 cells a decrease on the expression of EGFR, ErbB2 and ER alpha was observed. Both cell lines presented an increment in p38 phosphorylation and PARP cleavage upon 2'NF treatment. In conclusion, 2'NF demonstrated to have effects on the expression of receptors associated with EGFR activity which could justify a possible combinatorytherapy involving 2'NF and EGFR inhibitors.Fil: Cebrón, Julieta Rocío. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; ArgentinaFil: Bojorge, Mariana Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; ArgentinaFil: Marder, Nora Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; ArgentinaFil: Miquet, Johanna Gabriela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Gonzalez, Lorena. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaBuenos Aires Breast Cancer SymposiumArgentinaUniversidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y NeurocienciasInstituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina ExperimentalCentro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno"Universidad Austral. Facultad de Ciencias Biomédicas. Instituto de Investigaciones en Medicina Traslaciona

Unmet Needs in Patients With Heart Failure: The Importance of Palliative Care in a Heart Failure Clinic.

Background There are increasing calls to establish heart failure (HF) clinics due to their effectiveness in the interdisciplinary management of people living with HF. However, although a recommendation exists for palliative care (PC) providers to be part of the interdisciplinary team, few of the established HF clinics include them in their teams. Therefore, in this qualitative study, we aimed to understand the unmet PC needs of patients with HF attending an already established HF clinic. Methods Secondary qualitative analysis of structured interviews undertaken within a larger study to validate the German version of the Needs Assessment Tool: Progressive Disease-Heart Failure (NAT: PD-HF). The NAT: PD-HF is a tool that aims to assess unmet needs in patients with HF. The interviews took place between January and March 2020 with patients from the ambulatory HF Clinic of a University Hospital in Switzerland. For this analysis, we transcribed and thematically analyzed the longest and most content-rich interviews until we reached data saturation at 31 participants. The interviews lasted 31 min on average (24-48 min). Results Participants (n = 31) had a median age of 64 years (IQR 56-77), the majority had reduced ejection fraction, were men, and were classified as having a New York Heart Association functional class II. Participants were in general satisfied with the treatment and information received at the HF clinic. However, they reported several unmet needs. We therefore identified three ambivalences as main themes: (I) "feeling well-informed but missing essential discussions", (II) "although feeling mostly satisfied with the care, remaining with unmet care needs", and (III) "fearing a referral to palliative care but acknowledging its importance". Conclusion Although patients who are receiving multidisciplinary management in ambulatory HF clinics are generally satisfied with the care received, they remain with unmet needs. These unmet needs, such as the need for advance care planning or the need for timely and tactful end-of-life discussions, can be fulfilled by PC providers. Including personnel trained in PC as part of the multidisciplinary team could help to address patients' needs, thus improving the quality of care and the quality of life of people living with HF

High clustering rates of multidrug-resistant Mycobacterium tuberculosisgenotypes in Panama

Background: Tuberculosis continues to be one of the leading causes of death worldwide and in the American region. Although multidrug-resistant tuberculosis (MDR-TB) remains a threat to TB control in Panama, few studies have focused in typing MDR-TB strains. The aim of our study was to characterize MDR Mycobacterium tuberculosis clinical isolates using PCR-based genetic markers. Methods: From 2002 to 2004, a total of 231 Mycobacterium tuberculosis isolates from TB cases country-wide were screened for antibiotic resistance, and MDR-TB isolates were further genotyped by double repetitive element PCR (DRE-PCR), (GTG)5-PCR and spoligotyping. Results: A total of 37 isolates (0.85%) were resistant to both isoniazid (INH) and rifampicin (RIF). Among these 37 isolates, only two (5.4%) were resistant to all five drugs tested. Dual genotyping using DRE-PCR and (GTG)5-PCR of MDR Mycobacterium tuberculosis isolates revealed eight clusters comprising 82.9% of the MDR-TB strain collection, and six isolates (17.1%) showed unique fingerprints. The spoligotyping of MDR-TB clinical isolates identified 68% as members of the 42 (LAM9) family genotype.Background: Tuberculosis continues to be one of the leading causes of death worldwide and in the American region. Although multidrug-resistant tuberculosis (MDR-TB) remains a threat to TB control in Panama, few studies have focused in typing MDR-TB strains. The aim of our study was to characterize MDR Mycobacterium tuberculosis clinical isolates using PCR-based genetic markers. Methods: From 2002 to 2004, a total of 231 Mycobacterium tuberculosis isolates from TB cases country-wide were screened for antibiotic resistance, and MDR-TB isolates were further genotyped by double repetitive element PCR (DRE-PCR), (GTG)5-PCR and spoligotyping. Results: A total of 37 isolates (0.85%) were resistant to both isoniazid (INH) and rifampicin (RIF). Among these 37 isolates, only two (5.4%) were resistant to all five drugs tested. Dual genotyping using DRE-PCR and (GTG)5-PCR of MDR Mycobacterium tuberculosis isolates revealed eight clusters comprising 82.9% of the MDR-TB strain collection, and six isolates (17.1%) showed unique fingerprints. The spoligotyping of MDR-TB clinical isolates identified 68% as members of the 42 (LAM9) family genotype