Plasma gradient modified scaffolds to generate a chemoattractant surface

A gradient of plasma polymerization of pyrrole was generated to model a chemoattractant surface; it was obtained by changing the polymerization time to manipulate the thickness and the deposited layer. The polymerization was generated with a power of 30W on a cylindrical vacuum reactor, the coverslip was polymerized covered by a cavity with a surface exposed of 0.7 cm every 35 min., the cells seeded were liver stellate cells (Ito); it was evaluated against a coverslip with continuous plasma polymerization of pyrrole (Ppy). The results show similar protein secretions, but cells proliferation was selective in the surface gradient regions

Therapeutic potential of topical administration of siRNAs against HIF-1α for corneal neovascularization.

Given the implications of the problem of neovascularization on ocular health, as well as the growth in the number of cases, the purpose of the present study has been testing the efficacy of siRNAs (small interfering RNA) designed to silence Hypoxia Inducible Factor -1α (HIF-1α) and to demonstrate that their use stops neovascularization in a model of corneal burn. Corneal wounds in the limbic zone were made in the eyes of New Zealand white rabbits. Topical applications of siRNAs were done the next day to the wound for four consecutive days and eyes were examined with a slit lamp. Evaluation of neovascularization progress was done by analyzing images by ImageJTM and to determine the neovascular area in Matlab ® was used. At the same time, a rabbit corneal cell line was used for in vitro study of hypoxia exposure and Western blot analysis of the cell's extracts were done. Under normal cell culture oxygenation, the expression of HIF-1α was lower than that observed under hypoxic conditions. After 2 h of hypoxia, there was a significant increase in the HIF-1α expression, effect that was maintained up to 6 h. The increased in HIF-1α was mimicked by a cell permeable prolyl-4-hydroxylase inhibitor. Cobalt chloride showed no capacity to increase HIF-1α in vitro. The effect of three different siRNA on HIF-1α was tested after 4 h of hypoxia. siRNA#1 was able to silence 80% of HIF-1α expression, siRNA#2 and siRNA#3 reduce the expression in 45% and 40% respectively. In addition, the three siRNA were tested in a corneal model of neovascularization. scrambledsiRNA#2 was the most effective inhibitor of blood vessel production, followed by siRNA#3 and siRNA#1. Compared to the scrambled siRNA (100% of blood vessel generation), siRNA#2 blocked the presence of blood vessels by 83 ± 2%, siRNA#3 inhibited 45 ± 7% and siRNA#1 only inhibited 18 ± 5%. The necessary time to observe the 50% of effect showed values of NV50 of 10.2 ± 2.4 days for the scrambled siRNA, 9.1 ± 1.4 for siRNA#1, 6.5 ± 1.85 for siRNA#2 and 4.8 ± 1.8 days for siRNA#3. In conclusion, the topical application of siRNA towards HIF-1α seems to be an effective and reliable method to stop neovascularization.This work was supported by a grant from Ministerio de Ciencia e Innovación (SAF2010-16024 and SAF2013-44416-R) and RETICS (RD12/0034/0003), and a grant from the Instituto de Salud Carlos III of Spain and Fondo Europeo de Desarrollo Regional (FEDER, “Una manera de hacer Europa”) (FIS-FEDER PI07-1168 to J. Mateo)S

Partition and propagate: an error derivation algorithm for the design of approximate circuits

Inexact hardware design techniques have become popular in error-tolerant systems, where energy efficiency is a primary concern. Several techniques aim to identify circuit portions that can be discarded under an error constraint, but research on systematic methods to determine such error is still at an early stage. We herein illustrate a generic, scalable algorithm that determines the influence of each circuit gate on the final output. The algorithm first partitions the graph representing the circuit, then determines the error propagation model of the resulting subgraphs. When applied to existing approximate design frameworks, our solution improves their efficiency and result quality

Transcriptome analyses throughout chili pepper fruit development reveal novel insights into the domestication process

Chili pepper (Capsicum spp.) is an important crop, as well as a model for fruit development studies and domestication. Here, we performed a time-course experiment to estimate standardized gene expression profiles with respect to fruit development for six domesticated and four wild chili pepper ancestors. We sampled the transcriptomes every 10 days from flowering to fruit maturity, and found that the mean standardized expression profiles for domesticated and wild accessions significantly differed. The mean standardized expression was higher and peaked earlier for domesticated vs. wild genotypes, particularly for genes involved in the cell cycle that ultimately control fruit size. We postulate that these gene expression changes are driven by selection pressures during domestication and show a robust network of cell cycle genes with a time shift in expression, which explains some of the differences between domesticated and wild phenotypes

Síntesis y caracterización de óxido de grafito dopado con carbonato de plata y su aplicación como fotocatalizador en la degradación del azul de metileno

Óxido grafito (OG) y OG dopado con Ag₂CO₃ (OG-Ag) fueron sintetizados por un método de Hummers modificado y evaluados en la fotodegradación de azul de metileno (AM). El OG y OG-Ag obtuvieron 50 y 80% de conversión en 30 min de reacción, respectivamente. Donde ambas reacciones se ajustaron a cinéticas de pseudo-primer orden respecto a 100 ppm de AM. Los materiales grafiticos fueron caracterizados por medio de espectroscopia FTIR, Raman, fotoelectrónica de rayos X (XPS) y Microscopia electrónica de barrido (SEM) con Espectroscopia de energía dispersiva de rayos X (EDS o EDX). Dichas micrografías mostraron comportamiento nemático debido a la formación de cúmulos superficiales de plata en la red de grafito asociados a una mala dispersión y un alto contenido de plata (c.a. 39.4% peso) obtenido por EDS.Graphite oxide (GO) and GO doped with Ag₂CO₃ (GO-Ag) were synthesized by a modified Hummers' method and evaluated in the methylene blue (MB) photodegradation. OG and OG-Ag obtained 50 and 80% conversion in 30 min of reaction, respectively. Where both reactions were adjusted to pseudo-first order kinetics with respect to 100 ppm of MB. The graphitic materials were characterized by FTIR, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with Energy-dispersive X-ray spectroscopy (EDS or EDX). These micrographs showed nematic behaviour due to the formation of superficial clusters of silver in the graphite network associated with a poor dispersion and a high silver content (c.a. 39.4% weight) obtained by EDS

Tissue culture of ornamental cacti

Cacti species are plants that are well adapted to growing in arid and semiarid regions where the main problem is water availability. Cacti have developed a series of adaptations to cope with water scarcity, such as reduced leaf surface via morphological modifications including spines, cereous cuticles, extended root systems and stem tissue modifications to increase water storage, and crassulacean acid metabolism to reduce transpiration and water loss. Furthermore, seeds of these plants very often exhibit dormancy, a phenomenon that helps to prevent germination when the availability of water is reduced. In general, cactus species exhibit a low growth rate that makes their rapid propagation difficult. Cacti are much appreciated as ornamental plants due to their great variety and diversity of forms and their beautiful short-life flowers; however, due to difficulties in propagating them rapidly to meet market demand, they are very often over-collected in their natural habitats, which leads to numerous species being threatened, endangered or becoming extinct. Therefore, plant tissue culture techniques may facilitate their propagation over a shorter time period than conventional techniques used for commercial purposes; or may help to recover populations of endangered or threatened species for their re-introduction in the wild; or may also be of value to the preservation and conservation of the genetic resources of this important family. Herein we present the state-of-the-art of tissue culture techniques used for ornamental cacti and selected suggestions for solving a number of the problems faced by members of the Cactaceae family