Strong, Lightweight, Porous Materials

A new class of strong, lightweight, porous materials has been invented as an outgrowth of an effort to develop reinforced silica aerogels. The new material, called X-Aerogel is less hygroscopic, but no less porous and of similar density to the corresponding unmodified aerogels. However, the property that sets X-Aerogels apart is their mechanical strength, which can be as much as two and a half orders of magnitude stronger that the unmodified aerogels. X-Aerogels are envisioned to be useful for making extremely lightweight, thermally insulating, structural components, but they may also have applications as electrical insulators, components of laminates, catalyst supports, templates for electrode materials, fuel-cell components, and filter membranes

Highly porous and mechanically strong ceramic oxide aerogels

Structurally stable and mechanically strong ceramic oxide aerogels are provided. The aerogels are cross-linked via organic polymer chains that are attached to and extend from surface-bound functional groups provided or present over the internal surfaces of a mesoporous ceramic oxide particle network via appropriate chemical reactions. The functional groups can be hydroxyl groups, which are native to ceramic oxides, or they can be non-hydroxyl functional groups that can be decorated over the internal surfaces of the ceramic oxide network. Methods of preparing such mechanically strong ceramic oxide aerogels also are provided

Highly porous and mechanically strong ceramic oxide aerogels

Structurally stable and mechanically strong ceramic oxide aerogels are provided. The aerogels are cross-linked via organic polymer chains that are attached to and extend from surface-bound functional groups provided or present over the internal surfaces of a mesoporous ceramic oxide particle network via appropriate chemical reactions. The functional groups can be hydroxyl groups, which are native to ceramic oxides, or they can be non-hydroxyl functional groups that can be decorated over the internal surfaces of the ceramic oxide network. Methods of preparing such mechanically strong ceramic oxide aerogels also are provided

Diels-Alder Trapping of Photochemically Generated o-Quinodimethane Intermediates: An Alternative Route to Photocured Polymer Film Development

Photolysis of o-methylphenyl ketones generates bis-o-quinodimethane intermediates that can be trapped in situ by dienophiles through Diels-Alder cycloadditions. This well-known photochemical process is applied to a series of six new photoreactive monomers containing bis-(o-methylphenyl ketone) functionalities combined with diacrylate and triacrylate ester monomers for the development of acrylic ester copolymer blends. Irradiation of cyclohexanone solutions of the bis-(o-methylphenyl ketone)s and acrylate esters produce thin polymer films. Solid state 13C NMR data indicated 47- 100% reaction of the bis-(o-methylphenyl ketone)s, depending on experimental conditions, to yield the desired products. DSC and TGA analyses were performed to determine the glass transition temperature, T,, and onset of decomposition, Td, of the resulting polymer films. A statistical Design of Experiments approach was used to obtain a systematic understanding of the effects of experimental variables on the extent of polymerization and the final polymer properties

A drift-diffusion model for robotic obstacle avoidance

We develop a stochastic framework for modeling and analysis of robot navigation in the presence of obstacles. We show that, with appropriate assumptions, the probability of a robot avoiding a given obstacle can be reduced to a function of a single dimensionless parameter which captures all relevant quantities of the problem. This parameter is analogous to the Peclet number considered in the literature on mass transport in advection-diffusion fluid flows. Using the framework we also compute statistics of the time required to escape an obstacle in an informative case. The results of the computation show that adding noise to the navigation strategy can improve performance. Finally, we present experimental results that illustrate these performance improvements on a robotic platform. For more information: Kod*La

Dynamical Trajectory Replanning for Uncertain Environments

We propose a dynamical reference generator equipped with an augmented transient “replanning” subsystem that modulates a feedback controller’s efforts to force a mechanical plant to track the reference signal. The replanner alters the reference generator’s output in the face of unanticipated disturbances that drive up the tracking error. We demonstrate that the new reference generator cannot destabilize the tracker, that tracking errors converge in the absence of disturbance, and that the overall coupled reference-tracker system cannot be destabilized by disturbances of bounded energy. We report the results of simulation studies exploring the performance of this new design applied to a two dimensional point mass particle interacting with fixed but unknown terrain obstacles. For more information: Kod*La

Clinical heterogeneity can hamper the diagnosis of patients with ZAP70 deficiency

One of the severe combined immunodeficiencies (SCIDs), which is caused by a genetic defect in the signal transduction pathways involved in T-cell activation, is the ZAP70 deficiency. Mutations in ZAP70 lead to both abnormal thymic development and defective T-cell receptor (TCR) signaling of peripheral T-cells. In contrast to the lymphopenia in most SCID patients, ZAP70-deficient patients have lymphocytosis, despite the selective absence of CD8+ T-cells. The clinical presentation is usually before 2 years of age with typical findings of SCID. Here, we present three new ZAP70-deficient patients who vary in their clinical presentation. One of the ZAP70-deficient patients presented as a classical SCID, the second patient presented as a healthy looking wheezy infant, whereas the third patient came to clinical attention for the eczematous skin lesions simulating atopic dermatitis with eosinophilia and elevated immunoglobulin E (IgE), similar to the Omenn syndrome. This study illustrates that awareness of the clinical heterogeneity of ZAP70 deficiency is of utmost importance for making a fast and accurate diagnosis, which will contribute to the improvement of the adequate treatment of this severe immunodeficiency

Aqueous Hg²⁺ associates with TiO₂ nanoparticles according to particle size, changes particle agglomeration, and becomes less bioavailable to zebrafish

Altinok, Ilhan/0000-0003-3475-521X; Boyle, David/0000-0001-6919-7137; Patsiou, Danae/0000-0002-4863-3486; Henry, Theodore/0000-0002-9675-9454WOS: 000374604100024PubMed: 26970871Engineered nanoparticles (NPs) have unique physicochemistry and potential to interact with other substances in the aqueous phase. Here, gene [metallothionein 2 (mt2)] expression changes in larval zebrafish were used to evaluate the association between aqueous Hg2+ and TiO2 (NPs and bulk particle size control) to investigate the relationship between changes in Hg2+ behavior and TiO2 size. During 24 h exposures, TiO2 agglomerates increased in size and in the presence of 25 mu g Hg-2+/L, greater increases in size were observed. the concentration of Hg2+ in suspension also decreased in the presence of TiO2-NPs. Mercury increased expression of mt2 in larval zebrafish, but this response was lessened when zebrafish were exposed to Hg2+ in the presence of TiO2-NPs, and which suggests that TiO2-NPs alter the bioavailability of Hg2+ to zebrafish larvae. This ameliorative effect of TiO2 was also likely due to surface binding of Hg2+ because a greater decrease in mt2 expression was observed in the presence of 1 mg/L TiO2-NPs than 1 mg/L TiO2-bulk. in conclusion, the results show that Hg2+ will associate with TiO2-NPs, TiO2-NPs that have associated Hg2+ will settle out of the aqueous phase more rapidly, and agglomerates will deliver associated Hg2+ to sediment surfaces. (C) 2016 Elsevier B.V. All rights reserved

Detección de ADN de Brucella melitensis mediante la prueba de PCR en muestras de leche de ovejas postaborto

Laboratory diagnosis of brucellosis is generally performed by microbiological and serological methods. PCR assay is a specific and sensitive choice for the detection of different bacterial agents. An evaluation of this test was carried out for the detection of Brucella melitensis DNA in sheep milk. 102 milk samples from sheep after abortion were taken and studied using bacteriological culture, PCR and milk ring test (MRT). PCR found B. melitensis DNA in 24 (23.5%) out of 102 milk samples, while only 8 (7.8%) of the samples were positive to B. melitensis through direct culture. MRT found 28 (27.4%) positive milk samples. The detection limit for PCR in sheep milk inoculated with B. melitensis strain 16 M was 1.7x103-1.7x104 cfu/ml. PCR and MRT coincidence was 96%. The diagnostic sensitivity and specificity were determined as 100% and 81.3% respectively for PCR assay and 75% and 75% for MRT. PCR is a useful tool for a fast diagnosis of B. melitensis in sheep milk.  El diagnóstico de laboratorio de brucelosis es generalmente realizado por métodos microbiológicos y serológicos. La prueba PCR es reconocida como una alternativa específica y sensible para la detección de diferentes agentes bacterianos. Se realizó una evaluación de la prueba PCR para la detección de ADN de Brucella melitensis en leche de oveja. Ciento dos muestras tomadas de ovejas postaborto fueron analizadas por métodos de cultivo bacteriológico, prueba PCR y prueba del anillo en leche (MRT). El PCR detectó ADN de B. melitensis en 24 (23,5%) de 102 muestras de leche, mientras que solamente 8 (7,8%) muestras de leche fueron positivas a B. melitensis por cultivo directo. El MRT detectó 28 (27,4%) muestras positivas de leche. El límite de detección de B. melitensis 16 M por PCR fue de 1,7x103-1,7x104 ufc/ml en leche inoculada. La concordancia entre PCR y MRT fue 96%. La sensibilidad diagnóstica y la precisión fueron determinadas como el 100% y el 81,3% respectivamente para la prueba de PCR y el 75% y el 75% para MRT. En conclusión, PCR es una herramienta muy útil para el diagnóstico rápido de B. melitensis en leche de oveja. &nbsp