Coulomb oscillations based on band-to-band tunneling in a degenerately doped silicon metal-oxide-semiconductor field-effect transistor

The Coulomb oscillations based on band-to-band tunneling through a valence band in silicon metal-oxide-semiconductor field-effect-transistors were discussed. It was found that the formation of tunnel barries and a quantum dot in a single-electron transistor structure originated from two p+ - p+ tunnel junctions and a p+ -doped channel with mesoscopic dimension, respectively. At liquid nitrogen temperature, the Coulomb-blockade oscillations with multiple peaks were also observed. Analysis shows that the single-electron charging effect based on band-to-band tunneling was confirmed using the electrical and thermal characterization of the quantum dots.open2

Fabrication of single-electron tunneling transistors with an electrically formed Coulomb island in a silicon-on-insulator nanowire

For the purpose of controllable characteristics, silicon single-electron tunneling transistors with an electrically formed Coulomb island are proposed and fabricated on the basis of the sidewall process technique. The fabricated devices are based on a silicon-on-insulator (SOI) metal-oxide-semiconductor (MOS) field effect transistor with them depletion gate. The key fabrication technique consists of two sidewall process techniques. One is the patterning of a uniform SOI nanowire, and the other is the formation of n-doped polysilicon sidewall depletion gates. While the width of a Coulomb island is determined by the width of a SOI nanowire, its length is defined by the separation between two sidewall depletion gates which are formed by a conventional lithographic process combined with the second-sidewall process. These sidewall techniques combine the conventional lithography and process technology, and guaran tee the compatibility with complementary MOS process technology. Moreover, critical dimension depends not on the lithographical limit but on the controllability of chemical vapor deposition and reactive-ion etching. Very uniform weakly p-doped SOI nanowire defined by the sidewall technique effectively suppresses unintentional tunnel junctions formed by the fluctuation of the geometry or dopant in SOI nanowire, and the Coulomb island size dependence of the device characteristics confirms the good controllability. A voltage gain larger than one and the controllability of Coulomb oscillation peak position are also successfully demonstrated, which are essential conditions for the integration of a single-electron tunneling transistor circuit. Further miniaturization and optimization of the proposed device will make room temperature designable single-electron tunneling transistors possible in the foreseeable future.open101

WATCHFUL OBSERVATION VERSUS EARLY AORTIC VALVE REPLACEMENT FOR SYMPTOMATIC PATIENTS WITH LOW-GRADIENT SEVERE AORTIC STENOSIS AND PRESERVED EJECTION FRACTION

Brief Communications Arising: arising from X. Dong, B. Milholland & J. Vijg Nature 538, 257–259 (2016); doi:10.1038/nature19793. Comments by: Beer, J.A.A. de, Bardoutsos, A. & Janssen, F. (2017)

Outer membrane protein a of Salmonella enterica serovar Typhimurium activates dendritic cells and enhances Th1 polarization

<p>Abstract</p> <p>Background</p> <p>Typhoid, which is caused by <it>Salmonella enterica </it>serovar Typhimurium, remains a major health concern worldwide. Multidrug-resistant strains of <it>Salmonella </it>have emerged which exhibit increased survivability and virulence, thus leading to increased morbidity. However, little is known about the protective immune response against this microorganism. The outer membrane protein (Omp)A of bacteria plays an important role in pathogenesis.</p> <p>Results</p> <p>We purified OmpA from <it>S. enterica </it>serovar Typhimurium (OmpA-sal) and characterized the role of OmpA-sal in promoting adaptive and innate immune responses. OmpA-sal functionally activated bone marrow-derived dendritic cells by augmenting expression of CD80, CD86, and major histocompatibility complex classes I and II. Interestingly, OmpA-sal induced production of interferon-γ from T cells in mixed lymphocyte reactions, thus indicating Th1-polarizing capacity. The expression of surface markers and cytokine production in dendritic cells was mediated by the TLR4 signaling pathway in a TLR4 Knock-out system.</p> <p>Conclusions</p> <p>Our findings suggest that OmpA-sal modulates the adaptive immune responses to <it>S. enterica </it>serovar Typhimurium by activating dendritic cells and driving Th1 polarization, which are important properties to consider in the development of effective <it>S. enterica </it>serovar Typhimurium vaccines and immunotherapy adjuvant.</p

On-chip Brillouin lasers based on 10 million-Q chalcogenide resonators without direct etch process

We present a new device platform which defines on-chip chalcogenide waveguide/resonators without directly etching chalcogenide. Using our platform, we have demonstrated chalcogenide ring resonators with record high Q-factor exceeding 1.1x107 which is 10 times larger than previous record on on-chip chalcogenide resonators. A ring cavity is designed and fabricated for Stimulated Brillouin lasing on our platform. Thanks to the high-Q factor, Brillouin lasing with threshold power of 1 mW is demonstrated. This value is more than an order of magnitude improvement than previous world record for on-chip chalcogenide Brillouin lasers. We also developed an efficient and flexible method for resonator waveguide coupling with our device platform. Coupling between a resonator and a waveguide can be varied from under coupled region to over-coupled regio

Familial Creutzfeldt-Jakob Disease with V180I Mutation

Creutzfeldt-Jakob disease (CJD) is an uncommon neurodegenerative disorder with an incidence of 1 per 1000,000 per year typically characterized by rapidly progressive dementia, ataxia, myoclonus and behavioral changes. Genetic prion diseases, which develop due to a mutations in the prion protein gene (PRNP), account for an estimated 10 to 15% of all CJD cases. We report a 75-yr-old woman with familial CJD carrying a V180I mutation which features late onset, slow progression, no periodic sharp wave complexes on electroencephalography, and extensive cortical ribboning with spared the cerebellum and the medial occipital lobes posterior to the parieto-occipital sulcus on MRI. To our knowledge, this is the first documented case of a point mutation at codon 180 in South Korea