316 research outputs found

    Phase error statistics of a phase-locked loop synchronized direct detection optical PPM communication system

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    Receiver timing synchronization of an optical Pulse-Position Modulation (PPM) communication system can be achieved using a phased-locked loop (PLL), provided the photodetector output is suitably processed. The magnitude of the PLL phase error is a good indicator of the timing error at the receiver decoder. The statistics of the phase error are investigated while varying several key system parameters such as PPM order, signal and background strengths, and PPL bandwidth. A practical optical communication system utilizing a laser diode transmitter and an avalanche photodiode in the receiver is described, and the sampled phase error data are presented. A linear regression analysis is applied to the data to obtain estimates of the relational constants involving the phase error variance and incident signal power

    Effect of Poro and Thermo Elasticity on the Evolution of Fracture Permeability in A Coupled Fracture-Skin-Matrix System

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

    MASKING ANTI-PHAGOCYTIC SIGNAL OF TUMOR BY PRO-PHAGOCYTIC SIGNAL-A KEY TO IMMUREMENT OF CANCER CELL

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    Immune surveillance is a mechanism where cells and tissues are watched constantly by ever alerted immune system. Most incipient cancer cells are recognized and eliminated by the immune surveillance mechanism, but still tumors have the ability to evade immune surveillance and immunological killing. One greater arm that tumor use to evade immune surveillance, is by expressing anti-phagocytic signal (CD47). Here we present a provocative hypothesis where cancer cells are removed alive by phagocytic cell (DC). That in turn will elicit effective and higher immunogenic condition. All this could be possible by addition pro-phagocytic signal (PtdSer) over cancer cell surface (Breast Cancer), that mask the presence of anti-phagocytic signal (CD47). In other words, adding eat me signal (PtdSer) over the breast cancer cell surface that mask the presence of don't eat me signal or anti-phagocytic signal present in breast cancer cell surface. This could be possible by using bi-specific antibody, conjugated to PEG-modified liposomes, which carry (PtdSer) pro-phagocytic signal (or) eat me signal, which target both CD47 and EGFRVIII on breast carcinoma. The simultaneous masking of anti-phagocytic signal, and adding of pro–phagocytic signal over cancer cell, will enhance the phagocytic clearance of live tumor cell and elicit immunological killing

    ProNormz – An integrated approach for human proteins and protein kinases normalization

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    AbstractThe task of recognizing and normalizing protein name mentions in biomedical literature is a challenging task and important for text mining applications such as protein–protein interactions, pathway reconstruction and many more. In this paper, we present ProNormz, an integrated approach for human proteins (HPs) tagging and normalization. In Homo sapiens, a greater number of biological processes are regulated by a large human gene family called protein kinases by post translational phosphorylation. Recognition and normalization of human protein kinases (HPKs) is considered to be important for the extraction of the underlying information on its regulatory mechanism from biomedical literature. ProNormz distinguishes HPKs from other HPs besides tagging and normalization. To our knowledge, ProNormz is the first normalization system available to distinguish HPKs from other HPs in addition to gene normalization task. ProNormz incorporates a specialized synonyms dictionary for human proteins and protein kinases, a set of 15 string matching rules and a disambiguation module to achieve the normalization. Experimental results on benchmark BioCreative II training and test datasets show that our integrated approach achieve a fairly good performance and outperforms more sophisticated semantic similarity and disambiguation systems presented in BioCreative II GN task. As a freely available web tool, ProNormz is useful to developers as extensible gene normalization implementation, to researchers as a standard for comparing their innovative techniques, and to biologists for normalization and categorization of HPs and HPKs mentions in biomedical literature. URL: http://www.biominingbu.org/pronormz

    Controllability of nonlinear fractional Langevin delay systems

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    In this paper, we discuss the controllability of fractional Langevin delay dynamical systems represented by the fractional delay differential equations of order 0 < Î±,β â‰¤ 1. Necessary and sufficient conditions for the controllability of linear fractional Langevin delay dynamical system are obtained by using the Grammian matrix. Sufficient conditions for the controllability of the nonlinear delay dynamical systems are established by using the Schauders fixed-point theorem. The problem of controllability of linear and nonlinear fractional Langevin delay dynamical systems with multiple delays and distributed delays in control are studied by using the same technique. Examples are provided to illustrate the theory

    Control of the Cu morphology on Ru-passivated and Ru-doped TaN surfaces – promoting growth of 2D conducting copper for CMOS interconnects

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    Prolonging the lifetime of Cu as a level 1 and level 2 interconnect metal in future nanoelectronic devices is a significant challenge as device dimensions continue to shrink and device structures become more complex. At nanoscale dimensions Cu exhibits high resistivity which prevents its functioning as a conducting wire and prefers to form non-conducting 3D islands. Given that changing from Cu to an alternative metal is challenging, we are investigating new materials that combine properties of diffusion barriers and seed liners to reduce the thickness of this layer and to promote successful electroplating of Cu to facilitate the coating of high-aspect ratio interconnect vias and to allow for optimal electrical conductance. In this study we propose new combined barrier/liner materials based on modifying the surface layer of the TaN barrier through Ru incorporation. Simulating a model Cu(29) structure at 0 K and through finite temperature ab initio molecular dynamics on these surfaces allows us to demonstrate how the Ru content can control copper wetting, adhesion and thermal stability properties. Activation energies for atom migrations onto a nucleating copper island allow insight into the growth mechanism of a Cu thin-film. Using this understanding allows us to tailor the Ru content on TaN to control the final morphology of the Cu film. These Ru-modified TaN films can be deposited by atomic layer deposition, allowing for fine control over the film thickness and composition

    Raw Meat and Antibiotic Resistance: A Comprehensive Study on Prevalence of Pathogens in Food Animals

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    This review examines the use of antimicrobial agents in food animals and their impact on human health, particularly the emergence and spread of Antimicrobial Resistance (AMR). While antimicrobial agents are commonly used in food animal production to prevent and treat bacterial infections, overuse has been linked to AMR. Various strategies to reduce antimicrobial use in food animals, including vaccines, improved animal husbandry practices, and alternative therapies, are discussed. However, the review acknowledges the limitations of these strategies, such as cost-effectiveness and potential unintended consequences. Information on the percentage of antimicrobial use and resistance in food animals is provided for different classes of antibiotics. The percentages of use and resistance vary among these classes, with tetracyclines having the highest percentage of use and erythromycin and tylosin having the highest percentage of resistance. The review cites studies on the prevalence of antimicrobial resistance in food animals, including Escherichia coli isolates from broiler chickens in the UK and Egypt. The review highlights the need for a comprehensive approach to reducing antimicrobial use in food animals and controlling the spread of AMR, including implementing more effective regulatory policies, promoting responsible use of antimicrobial agents, and developing alternative therapies and management practices. Overall, the review emphasizes the importance of addressing the issue of AMR in food animals to preserve the effectiveness of antimicrobial agents for both animal and human health

    5-Fluoro-6′H,7′H,8′H-spiro­[indoline-3,7′-pyrano[3,2-c:5,6-c′]di-1-benzopyran]-2,6′,8′-trione

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    In the title compound, C26H12FNO6, the central pyran ring and both benzopyran systems are nonplanar, having total puckering amplitudes of 0.139 (2), 0.050 (1) and 0.112 (2) Å, respectively. The central pyran ring adopts a boat conformation. The crystal structure is stabilized by C—H⋯O, N—H⋯O, N—H⋯F and C—H⋯π inter­actions

    Self-Limiting Temperature Window for Thermal Atomic Layer Etching of HfO2 and ZrO2 Based on the Atomic-Scale Mechanism

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    HfO2 and ZrO2 are two high-k materials that are important in the downscaling of semiconductor devices. Atomic-level control of material processing is required for the fabrication of thin films of these materials at nanoscale device sizes. Thermal atomic layer etching (ALE) of metal oxides, in which up to one monolayer of the material can be removed, can be achieved by sequential self-limiting (SL) fluorination and ligand-exchange reactions at elevated temperatures. However, to date, a detailed atomistic understanding of the mechanism of thermal ALE of these technologically important oxides is lacking. In this paper, we investigate the hydrogen fluoride (HF) pulse in the first step in the thermal ALE process of HfO2 and ZrO2 using first-principles simulations. We introduce Natarajan–Elliott analysis, a thermodynamic methodology, to compare reaction models representing the self-limiting (SL) and continuous spontaneous etching (SE) processes taking place during an ALE pulse. Applying this method to the first HF pulse on HfO2 and ZrO2, we found that thermodynamic barriers impeding continuous etching are present at ALE-relevant temperatures. We performed explicit HF adsorption calculations on the oxide surfaces to understand the mechanistic details of the HF pulse. A HF molecule adsorbs dissociatively on both oxides by forming metal–F and O–H bonds. HF coverages ranging from 1.0 ± 0.3 to 17.0 ± 0.3 HF/nm2 are investigated, and a mixture of molecularly and dissociatively adsorbed HF molecules is present at higher coverages. Theoretical etch rates of −0.61 ± 0.02 Å/cycle for HfO2 and −0.57 ± 0.02 Å/cycle for ZrO2 were calculated using maximum coverages of 7.0 ± 0.3 and 6.5 ± 0.3 M–F bonds/nm2, respectively (M = Hf, Zr

    5-Chloro­spiro­[indoline-3,7′-6H,7H,8H-pyrano[3,2-c:5,6-c′]di[1]benzopyran]-2,6′,8′-trione

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    The asymmetric unit of the title compound, C26H12ClNO6, consists of two independent mol­ecules. The central pyran rings and both the 1-benzopyran ring systems are nearly planar in both mol­ecules [r.m.s. deviations of pyan rings = 0.0264 (1) and 0.0326 (1) Å for molecules A and B, respectively; r.m.s. deviations of benzopyran rings = 0.0439 (1) and 0.0105 (1) for molecule A, 0.0146 (1) and 0.0262 (1) Å for molecule B]. In the crystal, the molecules are linked by C—H⋯O, N—H⋯O and C—H⋯π inter­actions
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