Continuous Electroformation of Gold Nanoparticles in Nanoliter Droplet Reactors

Gold nanoparticles (AuNPs) are employed in numerous applications, including optics, biosensing and catalysis. Here, we demonstrate the stabilizer-free electrochemical synthesis of AuNPs inside nanoliter-sized reactors. Droplets encapsulating a gold precursor are formed on a microfluidic device and exposed to an electrical current by guiding them through a pair of electrodes. We exploit the naturally occurring recirculation flows inside confined droplets (moving in rectangular microchannels) to prevent the aggregation of nanoparticles after nucleation. Therefore, AuNPs with sizes in the range of 30 to 100 nm were produced without the need of additional capping agents. The average particle size is defined by the precursor concentration and droplet velocity, while the charge dose given by the electric field strength has a minor effect. This method opens the way to fine-tune the electrochemical production of gold nanoparticles, and we believe it is a versatile method for the formation of other metal nanoparticles.ISSN:1433-7851ISSN:1521-3773ISSN:0570-083

Microfluidic Platform for Profiling of Extracellular Vesicles from Single Breast Cancer Cells

Extracellular vesicles (EVs) are considered as valuable biomarkers to discriminate healthy from diseased cells such as cancer. Passing cytosolic and plasma membranes before their release, EVs inherit the biochemical properties of the cell. Here, we determine protein profiles of single EVs to understand how much they represent their cell of origin. We use a microfluidic platform which allows to immobilize EVs from completely isolated single cells, reducing heterogeneity of EVs as strongly seen in cell populations. After immunostaining, we employ four-color total internal reflection fluorescence microscopy to enumerate EVs and determine their biochemical fingerprint encoded in membranous or cytosolic proteins. Analyzing single cells derived from pleural effusions of two different human adenocarcinoma as well as from human embryonic kidney (SkBr3, MCF-7 and HEK293, respectively), we observed that a single cell secretes enough EVs to extract the respective tissue fingerprint. We show that overexpressed integral plasma membrane proteins are also found in EV membranes, which together with populations of colocalized proteins, provide a cell-specific, characteristic pattern. Our method highlights the potential of EVs as a diagnostic marker and can be directly employed for fundamental studies of EV biogenesis.ISSN:1520-6882ISSN:0003-270

Detección automática de fallas de baleros en un proceso de manufactura: Un estudio comparativo

Se presenta un estudio comparativo de diferentes técnicas de aprendizaje computacional para la detección automática de fallas de baleros durante un proceso de manufactura. El objetivo es reducir costos por el pago de garantías e incrementar el prestigio de la marca. Mediciones recolectadas por sensores acústicos en línea de producción generan señales asociadas con el componente bajo estudio. A partir de las señales generadas se desea determinar si los baleros son defectuosos o no antes de que el producto salga a la venta. Se propone una solución basada en aprendizaje computacional y se evalúan diversas técnicas de clasificación. La mayoría de los métodos obtienen resultados aceptables, dando evidencia de la viabilidad del enfoque propuesto. Los métodos basados en similitud obtienen los mejores resultados en cuando a efectividad de detección, además de que son fáciles de implementar y altamente eficiente

Enrichment and Analysis of Breast Cancer Cell-Derived Extracellular Vesicles by Laser-Assisted Protein Adsorption in Thermoplastic Microchannels

Extracellular vesicles (EVs) and their cargo proteins, DNAs and RNAs are very promising biomarkers. Accessible through liquid biopsies, EVs can reveal valuable diagnostic information on the health or disease state of a patient. Here, we propose a method for the enrichment of cancer cell-derived EVs and subsequent on-chip cargo protein analysis in thermoplastic microchannels. For this purpose, we characterized and optimized a technique for localized multiplexed surface functionalization, referred to as laser-assisted protein adsorption after photobleaching (LAPAP). Using LAPAP, we successfully immobilized antibodies in defined areas of the device to capture and analyze EVs by immunoassays. We employ the method for the identification and quantification of MCF-7 cell-derived EVs and cancer-associated proteins

Repayment policy for multiple loans.

The Repayment Policy for Multiple Loans is about a given set of loans and a monthly incoming cash flow: what is the best way to allocate the monthly income to repay such loans? In this article, we close the almost 20-year-old open question about how to model the repayment policy for multiple loans problem together with its computational complexity. Thus, we propose a mixed integer linear programming model that establishes an optimal repayment schedule by minimizing the total amount of cash required to repay the loans. We prove that the most employed repayment strategies, such as the highest interest debt and the debt snowball methods, are not optimal. Experimental results on simulated cases based on real data show that our methodology obtains on average more than 4% of savings, that is, the debtor pays approximately 4% less to the bank or loaner, which is a considerable amount in finances. In certain cases, the debtor can save up to 40%

Repayment policy for multiple loans, Yasmín A. Ríos-Solís, Mario A. Saucedo-Espinosa, Gabriel A. Caballero-Robledo, detailed data

The zip contains the instances. Archive How to red the instances explains how to read the instances of the zip file The excel corresponds to the solutions of our model and the other models of the literature

Histogram with the number of instances which have a particular relative saving, in percentage, when solved with the RPML formulation instead of being planned with the highest interest rule.

<p>Histogram with the number of instances which have a particular relative saving, in percentage, when solved with the RPML formulation instead of being planned with the highest interest rule.</p

Intervals from which the parameters of the instances were uniformly chosen.

<p>Intervals from which the parameters of the instances were uniformly chosen.</p

Schematic representation of conditions (6) for a single loan <i>j</i>.

<p>The principal amount <i>m</i>_<i>j</i> and each installment are multiplied by their accumulation factor after <i>t</i> periods. If the installment amounts (yellow, red, and green, respectively) are equal to the principal with its accumulation factor (blue) as it happens at time <i>t</i> = 3, then loan <i>j</i> has been completely repaid.</p