Simple Microcontact Printing Technique to Obtain Cell Patterns by Lithography Using Grayscale, Photopolymer Flexographic Mold, and PDMS

Microcontact printing using PDMS embossing tools and its variations have aroused the interest of a wide spectrum of research fields, hence the feasibility of defining micro and nanoscale patterns. In this work, we have proposed and demonstrated a novel lithography method based on grayscale patterns printed in a flexographic photopolymer mold and transferred to epoxy resin and a single PDMS stamp to obtain different microprint pattern structures. The geometry of the patterns can be modified by adjusting the layout and grayscale of the stamp patterns. The functionality of this contact printing methodology was validated by generating human induced pluripotent stem cells (hiPSC) patterns. These specific micropatterns can be very useful for achieving complex differentiation in cell lines such as hiPSC. Microfabrication through the new technique provides a promising alternative to conventional lithography for constructing complex aligned surfaces; these structures could be used as components of biological patterns or microfluidic devices.Fil: Gimenez, Rocio. Universidad Tecnológica Nacional; ArgentinaFil: Pérez Sosa, Camilo José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Bourguignon, Natalia. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miriuka, Santiago Gabriel. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bhansali, Shekhar. University of Florida; Estados UnidosFil: Arroyo, Carlos R.. Universidad de Las Fuerzas Armadas; EcuadorFil: Debut, Alexis. Universidad de Las Fuerzas Armadas; EcuadorFil: Lerner, Betiana. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perez, Maximiliano Sebastian. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

GEMA—An Automatic Segmentation Method for Real-Time Analysis of Mammalian Cell Growth in Microfluidic Devices

Nowadays, image analysis has a relevant role in most scientific and research areas. This process is used to extract and understand information from images to obtain a model, knowledge, and rules in the decision process. In the case of biological areas, images are acquired to describe the behavior of a biological agent in time such as cells using a mathematical and computational approach to generate a system with automatic control. In this paper, MCF7 cells are used to model their growth and death when they have been injected with a drug. These mammalian cells allow understanding of behavior, gene expression, and drug resistance to breast cancer. For this, an automatic segmentation method called GEMA is presented to analyze the apoptosis and confluence stages of culture by measuring the increase or decrease of the image area occupied by cells in microfluidic devices. In vitro, the biological experiments can be analyzed through a sequence of images taken at specific intervals of time. To automate the image segmentation, the proposed algorithm is based on a Gabor filter, a coefficient of variation (CV), and linear regression. This allows the processing of images in real time during the evolution of biological experiments. Moreover, GEMA has been compared with another three representative methods such as gold standard (manual segmentation), morphological gradient, and a semi-automatic algorithm using FIJI. The experiments show promising results, due to the proposed algorithm achieving an accuracy above 90% and a lower computation time because it requires on average 1 s to process each image. This makes it suitable for image-based real-time automatization of biological lab-on-a-chip experiments.Fil: Isa Jara, Ramiro Fernando. Escuela Superior Politécnica de Chimborazo; Ecuador. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pérez Sosa, Camilo José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Macote Yparraguirre, Erick Leonel. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Revollo Sarmiento, Natalia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Lerner, Betiana. Florida International University; Estados Unidos. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miriuka, Santiago Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Delrieux, Claudio Augusto. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pérez, Maximiliano. Florida International University; Estados Unidos. Universidad de Buenos Aires; ArgentinaFil: Mertelsmann, Roland. Albert Ludwigs University of Freiburg; Alemani

Single cell transfection of human-induced pluripotent stem cells using a dropletbased microfluidic system

Microfluidic tools have recently made possible many advances in biological and biomedical research. Research in fields such as physics, engineering, chemistry and biology have combined to produce innovation in microfluidics which has positively impacted diverse areas such as nucleotide sequencing, functional genomics, single-cell studies, single molecules assays and biomedical diagnostics. Among these areas, regenerative medicine and stem cells have benefited from microfluidics since these tools have had a profound impact on their applications. In this study, we present a high-performance droplet-based system for transfecting individual human-induced pluripotent stem cells. We will demonstrate that this system has great efficiency in single cells and captured droplets, like other microfluidic methods but with lower cost. Moreover, this microfluidic approach can be associated with the PiggyBac transposase-based system to increase its transfection efficiency. Our results provide a starting point for subsequent applications in more complex transfection systems, single-cell differentiation interactions, cell subpopulations and cell therapy, among other potential applications.Fil: Pérez Sosa, Camilo José. Fundacion P/la Lucha C/enferm.neurologicas Infancia. Instituto de Neurociencias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Neurociencias.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sanluis Verdes, Anahi. Fundacion P/la Lucha C/enferm.neurologicas Infancia. Instituto de Neurociencias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Neurociencias.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Waisman, Ariel. Fundacion P/la Lucha C/enferm.neurologicas Infancia. Instituto de Neurociencias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Neurociencias.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lombardi, Antonella. Fundacion P/la Lucha C/enferm.neurologicas Infancia. Instituto de Neurociencias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Neurociencias.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rosero, Gustavo. Universidad Tecnológica Nacional; ArgentinaFil: la Greca, Alejandro Damián. Fundacion P/la Lucha C/enferm.neurologicas Infancia. Instituto de Neurociencias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Neurociencias.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bhansali, Shekhar. Florida International University; Estados UnidosFil: Bourguignon, Natalia. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Luzzani, Carlos Daniel. Fundacion P/la Lucha C/enferm.neurologicas Infancia. Instituto de Neurociencias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Neurociencias.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perez, Maximiliano Sebastian. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miriuka, Santiago Gabriel. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lerner, Betiana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; Argentin

Epoxy resin mold and PDMS microfluidic devices through photopolymer flexographic printing plate

Photopolymer flexographic printing plate is a new photopolymeric material used for microdevices fabrication. This work demonstrates that a photopolymer flexographic master mold can be used for the fabrication of PDMS (polydimethylsiloxane) microdevices by a multi-step manufacturing process. The methodology entails three main fabrication steps: (1) a photopolymer flexographic printing plate mold (FMold) is generated by UV exposure through a transparent film, (2) an epoxy resin mold (ERmold) is fabricated by transferring the features of the photopolymer mold and (3) a PDMS microdevice is manufactured from the epoxy resin mold. The characterization of the manufactured PDMS microdevices was performed using scanning electron microscopy (SEM) and profilometry. Results showed high accuracy in the replication of the profiles. To show the feasibility of the fabrication process a microdevice for microdroplet generation was designed, manufactured and tested. Hence, the manufacturing process described in this work provides an easy, robust, and low-cost strategy that facilitates the scaling-up of microfluidic devices without requiring any sophisticated equipment.Fil: Olmos Carreno, Carol Maritza. Universidad Tecnológica Nacional. Facultad Regional Haedo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vaca Mora, Andrea Vanessa. Universidad Tecnológica Nacional. Facultad Regional Haedo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rosero, Gustavo. Universidad Tecnológica Nacional. Facultad Regional Haedo; ArgentinaFil: Peñaherrera Pazmiño, Ana Belén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Haedo; ArgentinaFil: Pérez Sosa, Camilo José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Haedo; ArgentinaFil: de Sá Carneiro, Igor. Universidad Tecnológica Nacional. Facultad Regional Haedo; ArgentinaFil: Vizuete, Karla. Universidad de Las Fuerzas Armadas Espe; EcuadorFil: Arroyo, Carlos R.. Universidad de Las Fuerzas Armadas; EcuadorFil: Debut, Alexis. Universidad de Las Fuerzas Armadas; EcuadorFil: Perez, Maximiliano Sebastian. Universidad Tecnológica Nacional. Facultad Regional Haedo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Ingeniería Biomédica; ArgentinaFil: Cumbal, Luis. Universidad de Las Fuerzas Armadas; EcuadorFil: Lerner, Betiana. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Ingeniería Biomédica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Haedo; Argentin

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Observation of the Production of Three Massive Gauge Bosons at root s=13 TeV

The first observation is reported of the combined production of three massive gauge bosons (VVV with V = W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis is based on a data sample recorded by the CMS experiment at the CERN LHC corresponding to an integrated luminosity of 137 fb(-1). The searches for individualWWW, WWZ, WZZ, and ZZZ production are performed in final states with three, four, five, and six leptons (electrons or muons), or with two same-sign leptons plus one or two jets. The observed (expected) significance of the combinedVVV production signal is 5.7 (5.9) standard deviations and the corresponding measured cross section relative to the standard model prediction is 1.02(-0.23)(+0.26). The significances of the individual WWW and WWZ production are 3.3 and 3.4 standard deviations, respectively. Measured production cross sections for the individual triboson processes are also reported

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The second-order Fourier coefficients (v(2)) characterizing the azimuthal distributions of Y(1S) and Y(2S) mesons produced in PbPb collisions at root s(NN) = 5.02 TeV are studied. The Y mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb(-1). The scalar product method is used to extract the v2 coefficients of the azimuthal distributions. Results are reported for the rapidity range vertical bar y vertical bar < 2.4, in the transverse momentum interval 0 < pT < 50 GeV/c, and in three centrality ranges of 10-30%, 30-50% and 50-90%. In contrast to the J/psi mesons, the measured v(2) values for the Y mesons are found to be consistent with zero. (C) 2021 The Author(s). Published by Elsevier B.V.Peer reviewe