Bioluminescent Magnetic Nanoparticles as Potential Imaging Agents for Mammalian Spermatozoa

Background: Nanoparticles have emerged as key materials for developing applications in nanomedicine, nanobiotechnology, bioimaging and theranostics. Existing bioimaging technologies include bioluminescent resonance energy transfer-conjugated quantum dots (BRET-QDs). Despite the current use of BRET-QDs for bioimaging, there are strong concerns about QD nanocomposites containing cadmium which exhibits potential cellular toxicity. Results: In this study, bioluminescent composites comprised of magnetic nanoparticles and firefly luciferase (Photinus pyralis) are examined as potential light-emitting agents for imaging, detection, and tracking mammalian spermatozoa. Characterization was carried out using infrared spectroscopy, TEM and cryo-TEM imaging, and ζ-potential measurements to demonstrate the successful preparation of these nanocomposites. Binding interactions between the synthesized nanoparticles and spermatozoon were characterized using confocal and atomic/magnetic force microscopy. Bioluminescence imaging and UV–visible-NIR microscopy results showed light emission from sperm samples incubated with the firefly luciferase-modified nanoparticles. Therefore, these newly synthesized luciferase-modified magnetic nanoparticles show promise as substitutes for QD labeling, and can potentially also be used for in vivo manipulation and tracking, as well as MRI techniques. Conclusions: These preliminary data indicate that luciferase-magnetic nanoparticle composites can potentially be used for spermatozoa detection and imaging. Their magnetic properties add additional functionality to allow for manipulation, sorting, or tracking of cells using magnetic techniques

Plan de patrocinio de la fundación Peace Makers

El curso de especialización para la gestión y dirección deportiva está dirigida a crear evaluaciones de calidad en el ámbito laboral dentro y fuera de las instalaciones deportivas y en el contacto para la búsqueda de nuevos patrocinadores que formen parte de la organización que brinda de sus servicios por igual; como para los beneficiarios que sobresalen. El objetivo es lograr mejorar la calidad de servicio que se brinda a las personas y eso se obtiene por medio de la realización de herramientas de trabajo que involucren las partes fundamentales de la organización que se desea evaluar. Las diferentes áreas administrativas son un pilar importante para desarrollar el trabajo tomando en cuenta mejorar sus Fortalezas, Oportunidades, Debilidades y Amenazas siendo estas una fuente prioritaria para el desarrollo de la investigación y obteniendo como resultado final la mejora, calidad y garantizar entes que aporten un apoyo al servicio que se brinda. Palabras clave: Gestión deportiva ; Dirección deportiva ; Administración deportiva ; Evaluación de calidad ; Marketing deportivo ; Gestión de patrocini

Community as an Institutional Learning Goal at the Unversity of Dayton

This working paper summarizes the work of the Habits of Inquiry and Reflection Community Fellows. It considers the meaning of community both in UD’s historic mission and in the ways it is practiced at UD now; identifies obstacles and failures; and offers recommendations for advancing community as a learning goal at UD

Reproducibility in the absence of selective reporting : An illustration from large-scale brain asymmetry research

Altres ajuts: Max Planck Society (Germany).The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes

2021: Erick S. Vasquez, Milestone Book Selection

Promotion to the rank of Associate Professor, Department of Chemical and Materials Engineeringhttps://ecommons.udayton.edu/svc_milestone/1089/thumbnail.jp

Surface Modification and Transport Modeling of Micron- and Nano-Sized Materials

Nanoparticle-based technologies are an emerging field with the promise to impact a wide range of application areas. However, that potential is somewhat married to a host of research questions that remain to be answered. This work explores the surface modification of magnetic nanoparticles in a controlled fashion to produce hybrid nanoparticle (metal/polymer) systems with different morphologies, understand in-situ behavior of stimuli-responsive polymers grafted to a substrate, and obtain better computational methods for particle-tracking and -deposition. Nanoparticle surface modification was performed using ATRP, obtaining homo-, block-co-, and ‘twoaced/biphasic’ polymer structures on the nanoparticle surfaces. Biphasic Janus nanoparticles (JPs) were formed using a magnetic nanoparticle core and an innovative technique combining non-covalent solid protection with sequential controlled radical polymerization to form the two surface-grafted polymer phases. Surface-confined polymerizations were conducted using pH- and thermo-responsive materials. Poly(methacrylic acid) (PMAA) and a series of (aminoalkyl) methacrylate polymers were used as pH responsive polymers. Additionally, poly(N-isopropylacrylamide) (PNIPAM) was selected as the thermo-responsive material for this study. In-situ characterization techniques, including atomic force microscopy (AFM), dynamic light scattering (DLS), and ellipsometry, were used to evaluate the thermo- and pH-responsiveness of these stimuli responsive materials. A new general-oscillator (GENOSC) model was used to determine swelling ratio, thickness, and optical constant changes in the polymer brush as pH was changed in-situ. AFM was used to study morphological changes due to changes in pH and temperature. Nanoparticle temperature responsiveness was investigated using DLS. A related effort involved the use of computational fluid dynamic (CFD) methods to track (micron-sized) particles in certain geometries, including a human lung morphology. Predicted particle transport and deposition was compared to Lagrangian computational approaches and available experimental data. The Eulerian particle phase modeling method developed resulted in the accurate prediction of both near-wall particle tracking and wall deposition. This Eulerian-Eulerian model is a new tool that has potential for particle tracking in physiological morphologies. This combination of experimental and computational research has led to new nano- and micro-particle surface modification methods and particle transport modeling

Fabricated Nanogap-rich Plasmonic Nanostructures Through an Optothermal Surface Bubble in a Droplet

A rapid and cost-effective method for the fabrication of nanogap-rich structures is demonstrated in this Letter. The method utilizes the Marangoni convection around an optothermal surface bubble inside a liquid droplet with a nanoliter volume. The liquid droplet containing metallic nanoparticles reduces the sample consumption and confines the liquid flow. The optothermal surface bubble creates a strong convective flow that allows for the rapid deposition of the metallic nanoparticles to form nanogap-rich structures on any substrate under ambient conditions. This method will enable a broad range of applications such as biosensing, environmental analysis, and nonlinear optics

Functional Holey Graphene Oxide: A New Electrochemically Transformed Substrate Material for Dopamine Sensing

Increasing active sites through generating holes within the basal plane of graphene sheets is an effective strategy to enhance catalytic performance in various applications such as sensors, electrocatalysis, and electronics. In this study, we report a simple two-step electrochemical approach to convert graphene oxide (GO) into holey graphene oxide (HGO)—graphene sheets with holes ranging from several to tens of nanometers in diameter. The resultant HGO graphene has an order of magnitude more effective surface area than GO, and behaves almost as a reversible electrode system in terms of peak-to-peak seperation value (ΔE) and heterogeneous electron transfer rate constant (k0) towards the Fe(CN)63−/4− redox probe. Characterization of the HGO surface using atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and cyclic voltammetry confirmed generation of holes on the graphene sheets. β-Cyclodextrin (β-CD) was immobilized on ‘as prepared’ HGO demonstrating an additional advantage from the presence of oxygen-containing functional groups on the resultant HGO surface. The β-CD-HGO nanocomposite was investigated as a potential dopamine (DA) sensor material using amperometric techniques. The linear range for DA detection was 0.1–800 μM (N = 3), sensitivity was 4.4 nA μM−1 cm−2, and the detection limit was 7.6 nM (S/N = 3). In addition to enhanced catalytic performance, HGO can be easily modified with materials such as β-cyclodextrin, as well as nanoparticles, bioactive molecules, and stimuli responsive polymers, providing a promising sensor platform

Reproducibility in the absence of selective reporting: An illustration from large‐scale brain asymmetry research

The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes