612 research outputs found
Synthesis and Characterization of Poly(butylene Oxide) Grafted Carbon Nanofibers
The grafting of polybutylene oxide onto purified and functionalized carbon nanofibers is reported. Grafting was possible after the insertion of 2-(formyloxy)ethyl 2-bromo-2-methylpropanoate onto the carbon nanofibers. The polymerization of tetrahydrofuran was mediated by copper(I) bromide and 1,1,4,7-pentamethyl diethylenetriamine. The polymer-grafted carbon nanofibers were characterized by Raman spectrsocopy, Transmission Electron Microscopy, and Thermogravimetric Analysis. TEM images of CNF-COOH (A), CNF-PBO (B), completely open tip of CNF-COOH, and coated tip of CNF-PBO (D) are shown in the left panel. The right panel depicts the distribution of bromine (blue), and carbon (red) atoms inside and in the vicinity of CNF-Br (as obtained by Electron Energy Loss Spectroscopy). The bottom shows the actual doped CNF. Preliminary data showed that these modified fibers have potential applications as smart (electrorheological) fluids
Prioritization of candidate cancer genes—an aid to oncogenomic studies
The development of techniques for oncogenomic analyses such as array comparative genomic hybridization, messenger RNA expression arrays and mutational screens have come to the fore in modern cancer research. Studies utilizing these techniques are able to highlight panels of genes that are altered in cancer. However, these candidate cancer genes must then be scrutinized to reveal whether they contribute to oncogenesis or are coincidental and non-causative. We present a computational method for the prioritization of candidate (i) proto-oncogenes and (ii) tumour suppressor genes from oncogenomic experiments. We constructed computational classifiers using different combinations of sequence and functional data including sequence conservation, protein domains and interactions, and regulatory data. We found that these classifiers are able to distinguish between known cancer genes and other human genes. Furthermore, the classifiers also discriminate candidate cancer genes from a recent mutational screen from other human genes. We provide a web-based facility through which cancer biologists may access our results and we propose computational cancer gene classification as a useful method of prioritizing candidate cancer genes identified in oncogenomic studies
Integration of a Canine Agent in a Wireless Sensor Network for Information Gathering in Search and Rescue Missions
Search and rescue operations in the context of emergency response to human or natural disasters have the major goal of finding potential victims in the shortest possible time. Multi-agent teams, which can include specialized human respondents, robots and canine units, complement the strengths and weaknesses of each agent, like all-terrain mobility or capability to locate human beings. However, efficient coordination of heterogeneous agents requires specific means to locate the agents, and to provide them with the information they require to complete their mission. The major contribution of this work is an application of Wireless Sensor Networks (WSN) to gather information from a multi-agent team and to make it available to the rest of the agents while keeping coverage. In particular, a canine agent has been equipped with a mobile node installed on a harness, providing information about the dog’s location as well as gas levels. The configuration of the mobile node allows for flexible arrangement of the system, being able to integrate static as well as mobile nodes. The gathered information is available at an external database, so that the rest of the agents and the control center can use it in real time. The proposed scheme has been tested in realistic scenarios during search and rescue exercises
Psoriasis and cardiovascular risk: Immune-mediated crosstalk between metabolic, vascular and autoimmune inflammation
Introduction and background
In the last few years, a substantial body of evidence indicates that cutaneous psoriasis and psoriatic arthritis patients are at higher risk of developing cardiovascular disease. However, underlying mechanism remains not completely understood. In this review we discuss the role of the immune system in the development of atherosclerosis, focusing on available data implicating the role of an enhanced immune-mediated proinflammatory status in psoriasis and psoriatic arthritis diseases.
Methods
A systematic search was performed on Pubmed until November 2014, with preference to the sources published within the past 8 years, including epidemiological studies (prospective and retrospective); cross-sectional case–control studies and reviews. Articles were selected according critical associations using the following keywords: arthritis, immune-mediated inflammatory diseases, and psoriasis. These were combined with closely related keywords reflecting cardiovascular diseases: atherogenesis, endothelial dysfunction, intima media thickness, subclinical atherosclerosis, plaque, thrombosis, thrombus, fibrinolysis, coagulation, and reactive oxygen species. Both types of disease selected terms were separately combined with non-traditional (innate and adaptive pro and anti-inflammatory immune molecules and cells) and traditional (metabolic related conditions and molecules) cardiovascular risk factors.
Results and conclusions
Psoriasis and psoriatic arthritis diseases illustrate that immune-mediated activated crossroads of inflammation beyond enhanced cardiovascular risk factors are the result of an interplay between different proatherogenic mediators derived from metabolic, vascular and autoimmune joint and skin inflamed target tissue. Consistent with this point of view, psoriasis and psoriatic arthritis diseases offer an invaluable opportunity to reinforce our knowledge about atherosclerotic cardiovascular disease.Fil: Kolliker Frers, Rodolfo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital Gral.de Agudos "ramos Mejia"; ArgentinaFil: Bisoendial, R. J.. University Of Amsterdam; Países BajosFil: Montoya, S. F.. Gobierno de la Ciudad de Buenos Aires. Hospital Gral.de Agudos "ramos Mejia"; ArgentinaFil: Kerzkerg, E.. Gobierno de la Ciudad de Buenos Aires. Hospital Gral.de Agudos "ramos Mejia"; ArgentinaFil: Castilla Lozano, Maria del Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); ArgentinaFil: Tak, P. P.. University Of Amsterdam; Países BajosFil: Milei, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); ArgentinaFil: Capani, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); Argentina. Universidad Arg."john F.kennedy"; Argentin
Desarrollo de la técnica de FICTION como nueva herramienta para el diagnóstico precoz de cáncer de pulmón
El cáncer de pulmón es una de las causas de muerte más frecuentes en el mundo occidental. La supervivencia global de los pacientes no supera el 15% a los 5 años, debido principalmente a que la mayor parte de los casos se diagnostican en estadios avanzados. Además de la prevención primaria, mediante la reducción del consumo de tabaco, son necesarias nuevas tecnologías para el diagnóstico precoz de la enfermedad.
Estudios recientes han demostrado que el TAC helicoidal del tórax es efectivo en la detección de nódulos pulmonares malignos en estadios precoces. En la actualidad se está valorando su eficacia en series amplias de pacientes de alto riesgo.
Recientemente se ha desarrollado una nueva técnica de citogenética molecular, el FICTION (Fluorescence Immunophenotyping and Interphase Cytogenetics as a Tool for the Investigation of Neoplasms). Esta técnica permite el análisis simultáneo de marcadores inmunofenotípicos y alteraciones genéticas presentes en las células tumorales. El objetivo de nuestro proyecto es su puesta a punto para el estudio de muestras de esputo y lavado broncoalveolar de pacientes con cáncer de pulmón. El fin último es estudiar la posibilidad de que esta técnica pueda ser utilizada, junto con el TAC helicoidal, en programas de detección precoz de cáncer de pulmón, para pacientes de alto riesgo.
En este trabajo presentamos una revisión de la contribución de las distintas técnicas de citogenética al estudio del cáncer de pulmón y la metodología de trabajo que vamos a llevar a cabo en nuestro proyecto
Lentiviral gene therapy reverts GPIX expression and phenotype in Bernard-Soulier syndrome type C
Bernard-Soulier syndrome (BSS) is a rare congenital disease characterized by macrothrombocytopenia and frequent bleeding. It is caused by pathogenic variants in three genes (GP1BA, GP1BB, or GP9) that encode for the GPIbα, GPIbβ, and GPIX subunits of the GPIb-V-IX complex, the main platelet surface receptor for von Willebrand factor, being essential for platelet adhesion and aggregation. According to the affected gene, we distinguish BSS type A1 (GP1BA), type B (GP1BB), or type C (GP9). Pathogenic variants in these genes cause absent, incomplete, or dysfunctional GPIb-V-IX receptor and, consequently, a hemorrhagic phenotype. Using gene-editing tools, we generated knockout (KO) human cellular models that helped us to better understand GPIb-V-IX complex assembly. Furthermore, we developed novel lentiviral vectors capable of correcting GPIX expression, localization, and functionality in human GP9-KO megakaryoblastic cell lines. Generated GP9-KO induced pluripotent stem cells produced platelets that recapitulated the BSS phenotype: absence of GPIX on the membrane surface and large size. Importantly, gene therapy tools reverted both characteristics. Finally, hematopoietic stem cells from two unrelated BSS type C patients were transduced with the gene therapy vectors and differentiated to produce GPIX-expressing megakaryocytes and platelets with a reduced size. These results demonstrate the potential of lentiviral-based gene therapy to rescue BSS type C
Comparative genomics among cyst nematodes reveals distinct evolutionary histories among effector families and an irregular distribution of effector-associated promoter motifs
JvS, MH and SvdE were supported by a grant from the Applied and Technical Science domain (TTW) of the Netherlands Organization for Scientific Research (NWO) under grant no. 14708. PT received support from the University of St Andrews Bioinformatics Unit (AMD3BIOINF), funded by Wellcome Trust ISSF award 105621/Z/14/Z. MS benefitted from funding by a VENI grant (17282) from the NWO domain Applied and Engineering Sciences.Potato cyst nematodes (PCNs), an umbrella term used for two species, Globodera pallida and G. rostochiensis, belong worldwide to the most harmful pathogens of potato. Pathotype-specific host plant resistances are an essential handle for PCN control. However, the poor delineation of G. pallida pathotypes hampers the efficient use of available host plant resistances. Long-read sequencing technology allowed us to generate a new reference genome of G. pallida population D383 and, as compared to the current reference, the new genome assembly is 42 times less fragmented. For comparison of diversification patterns of six effector families between G. pallida and G. rostochiensis, an additional reference genome was generated for an outgroup, the beet cyst nematode Heterodera schachtii (IRS population). Large evolutionary contrasts in effector family topologies were observed. While VAPs diversified before the split between the three cyst nematode species, the families GLAND5 and GLAND13 only expanded in PCN after their separation from the genus Heterodera. Although DNA motifs in the promoter regions thought to be involved in the orchestration of effector expression ('DOG boxes') were present in all three cyst nematode species, their presence is not a necessity for dorsal gland-produced effectors. Notably, DOG box dosage was only loosely correlated with expression level of individual effector variants. Comparison of the G. pallida genome with those of two other cyst nematodes underlined the fundamental differences in evolutionary history between effector families. Re-sequencing of PCN populations with deviant virulence characteristics will allow for the linking of these characteristics with the composition of the effector repertoire as well as for the mapping of PCN diversification patterns resulting from extreme anthropogenic range expansion.Publisher PDFPeer reviewe
Fragility Curves for Thin-Walled Cold-Formed Steel Wall Frames Affected by Ground Settlements Due to Land Subsidence
Land subsidence phenomenon due to ground water withdrawal is a current problem in many places around the world, particularly in the shallows of Mexico. This causes ground differential settlements that affect structures, mainly dwellings and buildings based on reinforced concrete and masonry. Eventually, these structural materials do not exhibit an adequate performance beyond a certain level of angular distortion. This work presents the results about a study regarding the performance of thin-walled cold-formed steel wall frames with different sheathing systems affected by angular distortions simulating ground differential settlements due to land subsidence. The wall frames are composed by vertical (studs) and horizontal elements (tracks), with different sheathing systems: polystyrene, OSB, gypsum and calcium silicate. By means of experimental testing of wall frames subjected to monotonic lateral loads, the rotational stiffness was obtained for the wall frames with polystyrene. Likewise the rotational stiffness of the other wall frame systems was calculated based on the data provided by other author’s publications. On the other hand, by means of numerical simulation, all the wall frame systems were modeled in structural analysis software, calibrating them based on the rotational stiffness. Also, the moment-rotation curves were calculated for the studs and tracks based on the direct strength method. A non-linear static pull down analysis was performed producing several degrees of angular distortion simulating ground settlements for all the wall frames sheathing systems. With the data acquired fragility curves were calculated according three levels of damage for the wall frames with different sheathing system
Preparation and characterization of micro-nano engineered targets for high-power laser experiments
[EN] The continuous development of ultra-fast high-power lasers (HPL) technology with the ability of working at unprecedented repetition rates, between 1 and 10 Hz, is raising the target needs for experiments in the different areas of interest to the HPL community. Many target designs can be conceived according to specific scientific issues, however to guarantee manufacturing abilities that enable large number production and still allow for versatility in the design is the main barrier in the exploitation of these high repetition rate facilities. Here, we have applied MEMS based manufacturing processes for this purpose. In particular, we have focused on the fabrication and characterization of submicrometric conductive membranes embedded in a silicon frame. These kinds of solid targets are used for laser-driven particle acceleration through the so-called Target Normal Sheath Acceleration mechanism (TNSA). They were obtained by top-down fabrication alternating pattern transfer, atomic layer deposition, and selective material etching. The adaptability of the approach is then analyzed and discussed by evaluating different properties of targets for use in laser-driven particle acceleration experiments. These characteristics include the surface properties of membranes after fabrication and the high density of the target array. Finally, we were able to show their efficiency for laser-driven proton acceleration in a series of experiments with a 3 TW table-top laser facility, achieving stable proton acceleration up to 2 MeV.The authors highly appreciate the collaboration of Radosys (Budapest) which provided CR-39 detector material, etching bath, and readout equipment. This project has been financed by the Spanish Ministry for Economy and Competitiveness within the Retos-Colaboracion 2015 initiative, ref. RTC-2015-3278-1. P. Mur has received a grant of the Garantia Juvenil 2015 program. This work has made use of the Spanish ICTS Network MICRONANOFABS partially supported by MEINCOM.Zaffino, R.; Seimetz, M.; Quirión, D.; Ruiz-De La Cruz, A.; Sánchez, I.; Mur, P.; Benlliure, J.... (2018). Preparation and characterization of micro-nano engineered targets for high-power laser experiments. Microelectronic Engineering. 194:67-70. https://doi.org/10.1016/j.mee.2018.03.011S677019
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