Heavy Electron Superconductors in Terms of Block Spin Phenomenology

We investigate the relationship between superconductivity and spin glasses, which were observed to be coexistent in heavy fermion superconductors (HFSs). We begin by explaining the phase of spin glass using concepts of finite-sized block spin. We then introduce the phase of superconductivity in HFSs as collective Cooper pairing, that is, the pairing of block spins with net spin = 1/2, each of which is comprised of a large number of random spins that together produce a majority spin direction. The superconducting Bardeen-Cooper-Schrieffer (BCS)-type phonon-mediated electron-electron interaction is substituted for the BCS-type electron-electron interaction mediated by phonon-enhanced spin flips previously suggested by us. An effective charge of any value stemming from an electron attached to the flux of an electric field can be referred to as a composite charge. The distinguished difference between ours and the original BCS model is the following: (i) another BCS-type interaction, (ii) bare electrons that are substituted for block spins with net spin = 1/2 and net charge = e in the presence of electric fields, and (iii) Fermi-Dirac distributions that are replaced by a new distribution called as Brillouin distribution.     

Rational Design and Synthesis of Extremely Efficient Macroporous CoSe2–CNT Composite Microspheres for Hydrogen Evolution Reaction

Uniquely structured CoSe₂–carbon nanotube (CNT) composite microspheres with optimized morphology for the hydrogen‐evolution reaction (HER) are prepared by spray pyrolysis and subsequent selenization. The ultrafine CoSe₂ nanocrystals uniformly decorate the entire macroporous CNT backbone in CoSe₂–CNT composite microspheres. The macroporous CNT backbone strongly improves the electrocatalytic activity of CoSe₂ by improving the electrical conductivity and minimizing the growth of CoSe₂ nanocrystals during the synthesis process. In addition, the macroporous structure resulting from the CNT backbone improves the electrocatalytic activity of the CoSe₂–CNT microspheres by increasing the removal rate of generated H₂ and minimizing the polarization of the electrode during HER. The CoSe₂–CNT composite microspheres demonstrate excellent catalytic activity for HER in an acidic medium (10 mA cm^?2 at an overpotential of ≈174 mV). The bare CoSe₂ powders exhibit moderate HER activity, with an overpotential of 226 mV at 10 mA cm^?2. The Tafel slopes for the CoSe₂–CNT composite and bare CoSe₂ powders are 37.8 and 58.9 mV dec^?1, respectively. The CoSe₂–CNT composite microspheres have a slightly larger Tafel slope than that of commercial carbon‐supported platinum nanoparticles, which is 30.2 mV dec^–1.     

Metal microparticle – Polymer composites as printable,bio/ecoresorbable conductive inks

Biologically and environmentally resorbable electronic devices support application possibilities that cannot be addressed with conventional technologies. This paper presents highly conductive, water-soluble composites that can be printed to form contacts, interconnects, antennas, and other important features that are essential to nearly all systems of this type. An optimized material formulation involves in situ polymerization to yield a polyanhydride containing a dispersion of molybdenum microparticles at appropriate concentrations. Comparisons of essential physical and electrical properties of these materials to those of composites formed with other polymers and other metal microparticles reveal the relevant considerations. Various functional demonstrations of screen-printed test structures and devices illustrate the suitability of these conductive inks for use in water-soluble electronic devices. A key advantage of the material introduced here compared to alternatives is its ability to maintain conductance over significant periods of time while immersed in relevant aqueous solutions. Studies involving live animal models establish the biocompatibility.     

Amplification‐Free Multi‐RNA‐Type Profiling for Cancer Risk Stratification via Alternating Current Electrohydrodynamic Nanomixing

Simultaneous analysis of messenger RNA (mRNA), microRNA (miRNA), and long noncoding RNA (lncRNA)—multi‐RNA‐type profiling—is increasingly crucial in cancer diagnostics. Yet, rapid multi‐RNA‐type profiling is challenging due to enzymatic amplification reliance and RNA‐type‐dependent characteristics. Here, a nanodevice is reported to uniquely use alterable alternating current electrohydrodynamic (ac‐EHD) forces to enhance probe–target hybridization prior to direct native RNA target detection, without target amplification or surface functionalization. To exemplify clinical applicability, noninvasive screening of next‐generation prostate cancer (PCa) RNA biomarkers (of different types) in patient urine samples is performed. A strong correlation between multi‐RNA‐type expression and aggressive PCa is found, and the nanodevice performance is statistically evaluated. It is believed that this miniaturized system exhibits great potential for cancer risk stratification via multi‐RNA‐type profiling.     

Focus groups reveal perils and promises of managed care for nurse practitioners

Decades of practice and research suggest that nurse practitioners (NPs) provide cost-effective and high-quality care. Managed care's emphasis on prevention and cost savings led some policy makers to view NPs as a way to meet the need for primary care providers. However, access to and utilization of NPs has increasingly been controlled by managed care organizations (MCOs) through their selection of providers for primary care panels. This study employed qualitative methodology to examine NPs' experiences with MCOs. Three focus groups, comprising 27 NPs in New York and Connecticut, revealed NPs' mixed reactions to managed care and a range of sentiments regarding NPs' efforts to be listed as primary care providers. The results reflected NPs' concerns about their perceived "invisibility," as well as their sense of "invincibility" in the ways in which NPs are responding to the barriers posed by MCOs. They identified barriers to, as well as ways to facilitate, being listed by MCOs, and described the importance of NPs working individually and collectively in negotiating with MCOs.     

Episodic gonadotropin-releasing hormone gene expression revealed by dynamic monitoring of luciferase reporter activity in single, living neurons

The existence of an intrinsic oscillator for pulsatile gonadotropin-releasing hormone (GnRH) secretion in normal and transformed GnRH neurons raises the question of whether the corresponding gene also is expressed in an episodic manner. To resolve this question, we used a modification of conventional luciferase technology, which enabled continuous monitoring of GnRH gene activity in single, living neurons. With this method, the relative rate of endogenous gene expression is estimated by quantification of photons emitted by individual neurons microinjected with a GnRH promoter-driven luciferase reporter construct. Immortalized GT1-1 neurons, which secrete the decapeptide GnRH in a pulsatile manner conceptually identical to that of their nontransformed counterparts in vivo, were chosen as the model for these studies. First, we injected individual cells with purified luciferase protein and established that the reporter half-life was sufficiently short (50 min) to enable detection of transient changes in gene expression. Next, we subjected transfected GT1-1 cells to continuous monitoring of reporter activity for 16 h and found that the majority of them exhibited spontaneous fluctuations of photonic activity over time. Finally, we established that photonic activity accurately reflected endogenous GnRH gene expression by treating transfected GT1-1 cells with phorbol 12-myristate 13 acetate (a consensus inhibitor of GnRH gene expression) and observing a dramatic suppression of photonic emissions from continuously monitored cells. Taken together, these results demonstrate the validity of our "real-time" strategy for dynamically monitoring GnRH gene activity in living neurons. Moreover, our findings indicate that GnRH gene expression as well as neuropeptide release can occur in an intermittent manner.