Temporal correlation vortices and topological dispersion

Interference measurements of a polychromatic partially coherent light source verify the existence of a temporal correlation vortex. Topological dispersion is found to destabilize this singularity.     

Properly designed modular asymmetric synthesis for enantiopure sulfinamide auxiliaries from N-sulfonyl-1,2,3-oxathiazolidine-2-oxide agents

Simple and practical asymmetric synthesis of functionally differentiated aminoindanol based endo-N-sulfonyl 1,2,3-oxathiazolidine-2-oxide as sulfinyl transfer agents are developed. The importance of these new and unique sulfinyl transfer reagents are exemplified by the expedient production of several sulfinamide ligands, including either enantiomer of (R)-tert-butanesulfinamide in excellent yields and enantiopurities.     

Fabrication of Complex Hydrogel Structures Using Suspended Layer Additive Manufacturing (SLAM)

There have been a number of recently reported approaches for the manufacture of complex 3D printed cell‐containing hydrogels. Given the fragility of the parts during manufacturing, the most successful approaches use a supportive particulate gel bed and have enabled the production of complex gel structures previously unattainable using other 3D printing methods. The supporting gel bed provides protection to the fragile printed part during the printing process, preventing the structure from collapsing under its own weight prior to crosslinking. Despite the apparent similarity of the particulate beds, the way the particles are manufactured strongly influences how they interact with one another and the part during fabrication, with implications to the quality of the final product. Recently, the process of suspended layer additive manufacture (SLAM) is demonstrated to create a structure that recapitulated the osteochondral region by printing into an agarose particulate gel. The manufacturing process for this gel (the application of shear during gelation) produced a self‐healing gel with rapid recovery of its elastic properties following disruption. Here, the physical characteristics of the supporting fluid‐gel matrix used in SLAM are explored, and compared to other particulate gel supporting beds, highlighting its potential for producing complex hydrogel‐based parts.     

Norm inequalities related to the matrix geometric mean

Inequalities for norms of different versions of the geometric mean of two positive definite matrices are presented.     

Development and characterization of a bio-hybrid skin-like stretchable electrode

This work presents the design, fabrication and characterization of a polymer based stretchable electrode for cell monitoring. The final goal is the development of innovative bio-hybrid skin-like tactile sensors with mammalian cells as core biological elements; to achieve such aim the enabling technological approach is pursued in this investigation. Electrodes are needed to detect cells response, thus the first step of the bio-hybrid system fabrication is the development of a platform able to record such response and transmit it to the external world. The stretchable electrode is composed by a conductive layer (few ? of Ti plus 90 nm of Au) on a polymeric substrate (1 mm thick PDMS membrane). Cellular adhesion was verified and cellular response to an induced electrode strain of 1% was detected through fluorescence microscopy. Fluorescence intensities were 104.82 ± 9.64 a.u. and 129.66 ± 13.06 a.u. prior and during electrode strain, respectively. Electromechanical characterization of the stretchable electrode revealed excellent stability and reliability within the 1% strain, which is the operative range identified for the future tactile sensor application. Results showed that the electrode was conductive up to 14% of strain. Furthermore, frequency impedance measurements demonstrated the electrode capability of detecting presence of cells.     

Universal plesiochronous multiplexing (UPM) for arbitrary rateisochronous circuit emulation

The authors consider an alternative to ATM for the transport of arbitrary rate isochronous signals without cell loss, with minimal delay, and with the low jitter characteristic of PDH/SDH multiplexing. Configurable pulse-stuffing multiplex circuits implement a custom multiplexing format, as required for each application rate. The authors analyse the theoretical frequency coverage of the concept, and compare experimental against predicted jitter in test cases. The authors suggest a unified method and circuit architecture for the bulk mapping of any isochronous tributary into the corresponding SONET, DS3 or SDH carrier signal     

Simultaneous determination of centbutindole and its hydroxy metabolite in serum by high-performance liquid chromatography.

A high-performance liquid chromatographic assay has been developed and validated for the determination of centbutindole and its hydroxy metabolite in serum. The method involves extraction of serum samples with diethyl ether at pH greater than 8, back-extraction into 0.5 M hydrochloric acid and finally again with diethyl ether after addition of 2 M potassium hydroxide. Separation was accomplished by reversed-phase high-performance liquid chromatography on a cyano column with an acetonitrile-phosphate buffer system. The recovery of centbutindole and its metabolite was always greater than 80%. Calibration curves were linear over the concentration range 0.25-5 ng/ml for centbutindole and 0.05-1 ng/ml for the hydroxy metabolite. Although the lower limit of detection was 0.1 ng/ml for centbuntindole and 0.02 ng/ml for the hydroxy metabolite, the reliable limits of quantitation were 0.25 and 0.05 ng/ml, respectively, using 4 ml of serum.     

Effects of the hyperfine interactions on the decay of the collective nuclear excited states in α-hematite

In this paper the time dependence of the coherent decay of nuclear excited state in an α-⁵⁷Fe₂O₃ single crystal is presented. The experiment was carried out in diffraction geometry. A highly monochromatized and collimated beam of synchrotron radiation was used for the excitation of nuclear levels. Quantum beat spectra taken below and above the (7, 7, 7) pure nucleation reflection of hemative show a characteristic pattern corresponding to the magnetic an quadrupole hyperfine interactions. This work was performed under the auspices of the U.S. Department of Energy under Contract No. DE-AC02-76CH00016.     

A reappraisal of irreversible behaviour in the intermediate state of a type-I superconductor

The nonequilibrium behaviour of the intermediate state of non-ellipsoidal specimens of type-I superconductors is well documented. We present the identification of a signal due to an octupole moment of this intermediate state in the magnetization measurements on a disc shaped Pb specimen. We can also identify a quasi-irreversibility temperature, like the HTSC materials, in the magnetization data on a Pb disc. However, its precise value at a given H depends on the orientation of the plane of the disc with respect to the applied field and it cannot be treated as a material characteristics of Pb.     

The strategic use of information resources: an exploratory study

The authors present some extensive preliminary data on the strategic use of information resources. The objectives are to: (1) make a case for the need to distinguish between the two types of information resources, information and information technology (IT), in the context of competitive strategy; (2) provide preliminary empirical validation for the distinction based on a survey of senior information system (IS) executives representing 84 large US corporations; (3) analyze the organizational factors that facilitate or inhibit the use of information resources; and (4) report on the organizational decision-making processes currently being used by business firms for strategic IS applications