Cavity-enhanced Raman Microscopy of Individual Carbon Nanotubes

Raman spectroscopy reveals chemically specific information and provides label-free insight into the molecular world. However, the signals are intrinsically weak and call for enhancement techniques. Here, we demonstrate Purcell enhancement of Raman scattering in a tunable high-finesse microcavity, and utilize it for molecular diagnostics by combined Raman and absorption imaging. Studying individual single-wall carbon nanotubes, we identify crucial structural parameters such as nanotube radius, electronic structure and extinction cross-section. We observe a 320-times enhanced Raman scattering spectral density and an effective Purcell factor of 6.2, together with a collection efficiency of 60%. Potential for significantly higher enhancement, quantitative signals, inherent spectral filtering and absence of intrinsic background in cavity-vacuum stimulated Raman scattering render the technique a promising tool for molecular imaging. Furthermore, cavity-enhanced Raman transitions involving localized excitons could potentially be used for gaining quantum control over nanomechanical motion and open a route for molecular cavity optomechanics

Social media y proceso de decisión de compras en el Gimnasio Aventura Gym Universitaria, 2023

La investigación hecha tuvo como objetivo principal determinar la relación entre el social media en el proceso de decisión de compras. A su vez, la metodología que se utilizo es de tipo aplicada, con un enfoque cuantitativo de diseño no experimental de corte transversal. Asimismo, la muestra censal estuvo conformada por 153 clientes; a los cuales se les aplico el cuestionario en base a las variables de estudio, este cumplió con todos los requerimientos de validez mediante un juicio de expertos y la confiabilidad en el que los resultados fueron buenos. En función a la contrastación de hipótesis se usó la correlación Rho de Spearman, en donde los resultados alcanzados fueron de que el social media se relaciona con el proceso de decisión de compras con un nivel de correlación positiva baja (Rho de Spearman .364 y la Sig 0.00)

Highly coherent electron beam from a laser-triggered tungsten needle tip

We report on a quantitative measurement of the spatial coherence of electrons emitted from a sharp metal needle tip. We investigate the coherence in photoemission using near-ultraviolet laser triggering with a photon energy of 3.1 eV and compare it to DC-field emission. A carbon-nanotube is brought in close proximity to the emitter tip to act as an electrostatic biprism. From the resulting electron matter wave interference fringes we deduce an upper limit of the effective source radius both in laser-triggered and DC-field emission mode, which quantifies the spatial coherence of the emitted electron beam. We obtain $(0.80\pm 0.05)\,$nm in laser-triggered and $(0.55\pm 0.02)\,$nm in DC-field emission mode, revealing that the outstanding coherence properties of electron beams from needle tip field emitters are largely maintained in laser-induced emission. In addition, the relative coherence width of 0.36 of the photoemitted electron beam is the largest observed so far. The preservation of electronic coherence during emission as well as ramifications for time-resolved electron imaging techniques are discussed

Editorial

El numero 11 de la revista Perspectivas se caracteriza por un abordaje transdisciplinario en la sección de perspectivas desde las ciencias sociales y humanas en donde los autores y las autoras asumen una proximidad en sus escritos con los grupos estudiados. En la sección perspectivas desde las ciencias políticas el abordaje es interdisciplinario en la medida en que se ponen en dialogo distintas disciplinas sobre el eje de las ciencias políticas, tales como la economía, la sociología y las ciencias ambientales respectivamente. En la sección perspectivas desde el psicoanálisis el abordaje es disciplinario en dialogo con momentos epocales que permiten la reflexión en la contemporaneidad

Sexting y estilos de crianza en estudiantes de tercero a quinto de secundaria de instituciones educativas del distrito de Chancay

La presente investigación intenta aportar en alguna medida al conocimiento real acerca de las variables materias de estudio. Así mismo, su objetivo general es determinar la relación que existe entre el sexting y los estilos de crianza en estudiantes de tercero a quinto de secundaria de instituciones educativas del distrito de Chancay. Respecto a la metodología empleada, se realizó el estudio bajo un enfoque cuantitativo de nivel descriptivo correlacional, de diseño no experimental y de corte transversal. Para la recolección de información de las variables de estudio se empleó los siguientes instrumentos: la Escala de Conductas de Sexting (ECS) de Chacón et al. (2016) y la Escala de Estilos de Crianza de Steinberg, adaptada por Merino y Arndt (2004). La muestra estuvo conformada por 344 estudiantes de ambos sexos. Finalmente, los resultados obtenidos mostraron una significancia asintótica bilateral de 0,260 > 0,05, indicando que no existe relación entre las variables sexting y estilos de crianza en la población de estudio. Sin embargo, dos de las dimensiones de los estilos de crianza (compromiso y autonomía psicológica) si guardan relación con la práctica del sexting, aunque, en un grado bajo y muy bajo respectivamente

Morphology and ecology of the Mexican cave anole Anolis alvarezdeltoroi

We redescribe the ecologically unusual lizard Anolis alvarezdeltoroi, previously known from a single specimen, based on newly collected and previously unidentified preserved specimens from the type-locality region in Chiapas, as well as new localities in Veracruz and Oaxaca. We include information on color, morphological variation, and natural history. Anolis alvarezdeltoroi occupies limestone caves, an unusual habitat for anoles. We found individuals active on limestone surfaces during the day at heights from 0.42 to 5 m, and sleeping mainly in cave interiors, with some individuals observed on ceilings deep within caves.NSF grant DEB 0844624 to Steven Poe as well as DGAPA, UNAM (PAPIIT no. 224009) and CONACYT (no. 154093), both to Adrián Nieto Montes de Oca.Geological Science

pre-clinical assessment of pharmacological and molecular properties

SARS-CoV-2, the cause of the COVID-19 pandemic, exploits host cell proteins for viral entry into human lung cells. One of them, the protease TMPRSS2, is required to activate the viral spike protein (S). Even though two inhibitors, camostat and nafamostat, are known to inhibit TMPRSS2 and block cell entry of SARS-CoV-2, finding further potent therapeutic options is still an important task. In this study, we report that a late-stage drug candidate, otamixaban, inhibits SARS-CoV-2 cell entry. We show that otamixaban suppresses TMPRSS2 activity and SARS-CoV-2 infection of a human lung cell line, although with lower potency than camostat or nafamostat. In contrast, otamixaban inhibits SARS-CoV-2 infection of precision cut lung slices with the same potency as camostat. Furthermore, we report that otamixaban's potency can be significantly enhanced by (sub-) nanomolar nafamostat or camostat supplementation. Dominant molecular TMPRSS2-otamixaban interactions are assessed by extensive 109 μs of atomistic molecular dynamics simulations. Our findings suggest that combinations of otamixaban with supplemental camostat or nafamostat are a promising option for the treatment of COVID-19

Convocation

Program listing performers and works performe

Plasminogen Alleles Influence Susceptibility to Invasive Aspergillosis

Invasive aspergillosis (IA) is a common and life-threatening infection in immunocompromised individuals. A number of environmental and epidemiologic risk factors for developing IA have been identified. However, genetic factors that affect risk for developing IA have not been clearly identified. We report that host genetic differences influence outcome following establishment of pulmonary aspergillosis in an exogenously immune suppressed mouse model. Computational haplotype-based genetic analysis indicated that genetic variation within the biologically plausible positional candidate gene plasminogen (Plg; Gene ID 18855) correlated with murine outcome. There was a single nonsynonymous coding change (Gly110Ser) where the minor allele was found in all of the susceptible strains, but not in the resistant strains. A nonsynonymous single nucleotide polymorphism (Asp472Asn) was also identified in the human homolog (PLG; Gene ID 5340). An association study within a cohort of 236 allogeneic hematopoietic stem cell transplant (HSCT) recipients revealed that alleles at this SNP significantly affected the risk of developing IA after HSCT. Furthermore, we demonstrated that plasminogen directly binds to Aspergillus fumigatus. We propose that genetic variation within the plasminogen pathway influences the pathogenesis of this invasive fungal infection