Nanoscale Sensor Technologies for Disease Detection via Volatolomics

The detection of many diseases is missed because of delayed diagnoses or the low efficacy of some treatments. This emphasizes the urgent need for inexpensive and minimally invasive technologies that would allow efficient early detection, stratifying the population for personalized therapy, and improving the efficacy of rapid bed‐side assessment of treatment. An emerging approach that has a high potential to fulfill these needs is based on so‐called “volatolomics”, namely, chemical processes involving profiles of highly volatile organic compounds (VOCs) emitted from body fluids, including breath, skin, urine and blood. This article presents a didactic review of some of the main advances related to the use of nanomaterial‐based solid‐state and flexible sensors, and related artificially intelligent sensing arrays for the detection and monitoring of disease with volatolomics. The article attempts to review the technological gaps and confounding factors related to VOC testing. Different ways to choose nanomaterial‐based sensors are discussed, while considering the profiles of targeted volatile markers and possible limitations of applying the sensing approach. Perspectives for taking volatolomics to a new level in the field of diagnostics are highlighted.     

Relative timing [asynchronous design]

Relative timing (RT) is introduced as a method for asynchronous design. Timing requirements of a circuit are made explicit using relative timing. Timing can be directly added, removed, and optimized using this style. RT synthesis and verification are demonstrated on three example circuits, facilitating transformations from speed-independent circuits to burst-mode and pulse-mode circuits. Relative timing enables improved performance, area, power, and functional testability of up to a factor of 3/spl times/ in all three cases. This method is the foundation of optimized timed circuit designs used in an industrial test chip, and may be formalized and automated.     

Correction to diamond et al. (2010).

Reports an error in "Ongoing traumatic stress response (OTSR) in Sderot, Israel" by Gary M. Diamond, Joshua D. Lipsitz, Zvi Fajerman and Omit Rozenblat (Professional Psychology: Research and Practice, 2010[Feb], Vol 41[1], 19-25). In the article “Ongoing Traumatic Stress Response (OTSR) in Sderot, Israel,” by Diamond, Lipsitz, Fajerman and Rozenblat (Professional Psychology: Research and Practice, 2010, Vol. 41, No. 1., pp. 19–25), due to a production error, the last author’s name was misspelled in the byline and the author note. The correct spelling is Ornit Rozenblat. (The following abstract of the original article appeared in record 2010-02467-003.) In Sderot, a small city in southern Israel, seven years of continuous missile attacks have led to dramatic increases in treatment seeking for anxiety symptoms. For some clients, the clinical picture is consistent with a diagnosis of post traumatic stress disorder (PTSD). For other clients, however, the onset and constellation of symptoms are less typical of PTSD. In these cases, anxiety symptoms seem to evolve gradually and be associated with ongoing, daily stress about imminent attacks, rather than with a discrete, past traumatic event. Much of their avoidance behavior is reality based. They report hyperarousal, severe distress, and loss of control during and immediately following actual missile attacks. However, they are less likely to exhibit reexperiencing symptoms. Furthermore, in contrast to the typical presentation of PTSD, their symptoms tend to diminish dramatically or completely resolve when they are no longer within harm’s way. We suggest that this clinical presentation may be best understood as an ongoing traumatic stress response (OTSR), rather than PTSD or PTSD symptoms. We consider diagnostic features which discriminate between these two phenomena as well as implications for treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correlation among microstructure,strength, and electrical conductivity of Cu-Ni-Be alloy

The UNS C17510 commercial Cu-Ni-Be alloy was heat treated in three different ways: AT, simple aging; HT, aging in the hardened condition; and TMT, a special thermo-mechanical treatment. It was found that in the electrical conductivity range of 50 to 60 pct IACS the TMT treatment results in a much higher yield strength than either the AT or the HT treatments. Three types of particles have been identified: relatively large primary beryllides, very small -γ precipitates, and small non-coherent nickel-rich beryllides (NRB). Based on measurements of the size distribution of NRB pre-cipitates and by means of an existing theoretical model, it was shown that these precipitates together with a dense dislocation network are responsible for the increased strength of the alloy follow-ing TMT.     

Free convection boundary-layer flow over horizontal plates and discs

Free convection flows near horizontal surfaces are discussed for those cases in which a similarity solution can be obtained. Particular cases considered are those of asymptotically large and vanishingly small Prandtl numbers. The solution for the relevant velocity, temperature and pressure functions has to be carried-out numerically. For the particular cases when the Prandtl number is either sufficiently large, or sufficiently small, this integration would yield general functions, no longer dependent on the Prandtl number. Numerical data are included.     

Metal Oxide Heterostructure Array via Spatially Controlled–Growth within Block Copolymer Templates

Nanofabrication is continuously searching for new methodologies to fabricate 3D nanostructures with 3D control over their chemical composition. A new approach for heterostructure nanorod array fabrication through spatially controlled–growth of multiple metal oxides within block copolymer (BCP) templates is presented. Selective growth of metal oxides within the cylindrical polymer domains of polystyrene‐block‐poly methyl methacrylate is performed using sequential infiltration synthesis (SIS). Tuning the diffusion of trimethyl aluminum and diethyl zinc organometallic precursors in the BCP film directs the growth of AlO_x and ZnO to different locations within the cylindrical BCP domains, in a single SIS process. BCP removal yields an AlO_x‐ZnO heterostructure nanorods array, as corroborated by 3D characterization with scanning transmission electron microscopy (STEM) tomography and a combination of STEM and energy‐dispersive X‐ray spectroscopy tomography. The strategy presented here will open up new routes for complex 3D nanostructure fabrication.     

Single Domain 10 nm Ferromagnetism Imprinted on Superparamagnetic Nanoparticles Using Chiral Molecules

The rapid growth in demand for data and the emerging applications of Big Data require the increase of memory capacity. Magnetic memory devices are among the leading technologies for meeting this demand; however, they rely on the use of ferromagnets that creates size reduction limitations and poses complex materials requirements. Usually magnetic memory sizes are limited to 30–50 nm. Reducing the size even further, to the ≈10–20 nm scale, destabilizes the magnetization and its magnetic orientation becomes susceptible to thermal fluctuations and stray magnetic fields. In the present work, it is shown that 10 nm single domain ferromagnetism can be achieved. Using asymmetric adsorption of chiral molecules, superparamagnetic iron oxide nanoparticles become ferromagnetic with an average coercive field of ≈80 Oe. The asymmetric adsorption of molecules stabilizes the magnetization direction at room temperature and the orientation is found to depend on the handedness of the chiral molecules. These studies point to a novel method for the miniaturization of ferromagnets (down to ≈10 nm) using established synthetic protocols.