Interlayer-engineered high remnant polarization (2Pr_r > 70μ\muC/cm2^2) in Hf0.5_{0.5}Zr0.5_{0.5}O2_2 thin films

In this letter, we report a high remnant polarization, 2P$_r$ > 70$\mu$C/cm$^2$ in thermally processed atomic layer deposited Hf$_{0.5}$Zr$_{0.5}$O$_2$ (HZO) film on Silicon with NH$_3$ plasma exposed thin TiN interlayer and Tungsten (W) as a top electrode. The effect of interlayer on the ferroelectric properties of HZO is compared with standard Metal-Ferroelectric-Metal and Metal-Ferroelectric-Semiconductor structures. The x-ray diffraction confirms that the thickness of the interlayer plays an important role to enhance the orthorhombic ferroelectric phase. The HRTEM images reveal that TiN acts as a seed layer for the local epitaxy in HZO and hence a 2X improvement in remnant polarization. Finally, the HZO devices are shown to be wake-up free, and exhibit endurance $>10^6$ cycles. This study opens a pathway to achieve epitaxial ferroelectric HZO films on Si with improved memory performance.Comment: 4 pages, 4 figure

Design Space and Variability Analysis of SOI MOSFET for Ultra-Low Power Band-to-Band Tunneling Neurons

Large spiking neural networks (SNNs) require ultra-low power and low variability hardware for neuromorphic computing applications. Recently, a band-to-band tunneling-based (BTBT) integrator, enabling sub-kHz operation of neurons with area and energy efficiency, was proposed. For an ultra-low power implementation of such neurons, a very low BTBT current is needed, so minimizing current without degrading neuronal properties is essential. Low variability is needed in the ultra-low current integrator to avoid network performance degradation in a large BTBT neuron-based SNN. To address this, we conducted design space and variability analysis in TCAD, utilizing a well-calibrated TCAD deck with experimental data from GlobalFoundries 32nm PD-SOI MOSFET. First, we discuss the physics-based explanation of the tunneling mechanism. Second, we explore the impact of device design parameters on SOI MOSFET performance, highlighting parameter sensitivities to tunneling current. With device parameters' optimization, we demonstrate a ~20x reduction in BTBT current compared to the experimental data. Finally, a variability analysis that includes the effects of random dopant fluctuations (RDF), oxide thickness variability (OTV), and channel-oxide interface traps DIT in the BTBT, SS, and ON regimes of operation is shown. The BTBT regime shows high sensitivity to the RDF and OTV as any variation in them directly modulates the tunnel length or the electric field at the drain-channel junction, whereas minimal sensitivity to DIT is observed

Smart-phone based spatio-temporal sensing for annotated transit map generation

City transit maps are one of the important resources for public navigation in today's digital world. However, the availability of transit maps for many developing countries is very limited, primarily due to the various socio-economic factors that drive the private operated and partially regulated transport services. Public transports at these cities are marred with many factors such as uncoordinated waiting time at bus stoppages, crowding in the bus, sporadic road conditions etc., which also need to be annotated so that commuters can take informed decision. Interestingly, many of these factors are spatio-temporal in nature. In this paper, we develop CityMap, a system to automatically extract transit routes along with their eccentricities from spatio-temporal crowdsensed data collected via commuters' smart-phones. We apply a learning based methodology coupled with a feature selection mechanism to filter out the necessary information from raw smart-phone sensor data with minimal user engagement and drain of batt

Mycobacterium tuberculosis 6-kDa Early Secreted Antigenic Target (ESAT-6) protein downregulates Lipopolysaccharide induced c-myc expression by modulating the Extracellular Signal Regulated Kinases 1/2

<p>Abstract</p> <p>Background</p> <p><it>Mycobacterium tuberculosis </it>(Mtb) causes death of 2–3 million people every year. The persistence of the pathogenic mycobacteria inside the macrophage occurs through modulation of host cell signaling which allows them, unlike the other non-pathogenic species, to survive inside the host. The secretory proteins of <it>M. tuberculosis </it>have gained attention in recent years both as vaccine candidates and diagnostic tools; they target the immune system and trigger a putatively protective response; however, they may also be involved in the clinical symptoms of the disease.</p> <p>Results</p> <p>Our studies showed that RD-1-encoded secretory protein ESAT-6 is involved in modulation of the mitogen-activated protein (MAP) kinase-signaling pathway inside the macrophage. ESAT-6 induced phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) in the cytoplasm but not in the nucleus, which normally is the case for MAP kinases. ESAT-6 also antagonized LPS-induced ERK1/2 phosphorylation in the nucleus. Stimulation of cells by ESAT-6 along with sodium orthovanadate (a tyrosine phosphatase inhibitor) restored phosphorylation of ERK1/2 in the nucleus, suggesting active dephosphorylation of ERK1/2 by some putative phosphatase(s) in the nucleus. Further, ESAT-6 was found to down regulate the expression of LPS-inducible gene <it>c-myc </it>in an ERK1/2-dependent manner.</p> <p>Conclusion</p> <p>This study showed the effect of secretory proteins of <it>M. tuberculosis </it>in the modulation of macrophage signaling pathways particularly ERK1/2 MAP kinase pathway. This modulation appears to be achieved by limiting the ERK1/2 activation in the nucleus which ultimately affects the macrophage gene expression. This could be a mechanism by which secretory proteins of Mtb might modulate gene expression inside the macrophages.</p

Schottky Barrier MOSFET Enabled Ultra-Low Power Real-Time Neuron for Neuromorphic Computing

Energy-efficient real-time synapses and neurons are essential to enable large-scale neuromorphic computing. In this paper, we propose and demonstrate the Schottky-Barrier MOSFET-based ultra-low power voltage-controlled current source to enable real-time neurons for neuromorphic computing. Schottky-Barrier MOSFET is fabricated on a Silicon-on-insulator platform with polycrystalline Silicon as the channel and Nickel/Platinum as the source/drain. The Poly-Si and Nickel make the back-to-back Schottky junction enabling ultra-low ON current required for energy-efficient neurons

Pancreatic neuroendocrine tumor in an individual with Von Hippel Lindau syndrome. A case report and review literature

Von Hippel Lindau (VHL) disease is a heritable cancer syndrome characterized by VHL gene mutation in 3p chromosome. Mutations occur at the exons. Rarely mutations at introns have been reported. It leads to accumulation of Hypoxic ischemic factor α (HIF α) which in turn leads to uncontrolled cellular proliferation. Few reports of pancreatic neuroendocrine tumors (PNETs) are there in the literature. Most of them are associated with a mutation in the exon of VHL gene. Association with intron mutation is not there. Here we are reporting a case of PNET in a patient who has a simultaneous mutation both at the exon and the intron