145 research outputs found
Flexible digital Scrambler/De-Scrambler system
The structural design of a flexible Scramble/De-Scrambler that uses aprogrammable length shift register and modulo-2 adder is presented. The key feature of the proposed design is its flexibility in varying the length of the delay elements pseudo-randomly and hence the encryption code. In addition, the encryption code can be re-programmed by the manufacturer through the EPROM involved in the design and by the user through the loadable pseudo-random sequence generator
Flexible digital Scrambler/De-Scrambler system
The structural design of a flexible Scramble/De-Scrambler that uses aprogrammable length shift register and modulo-2 adder is presented. The key feature of the proposed design is its flexibility in varying the length of the delay elements pseudo-randomly and hence the encryption code. In addition, the encryption code can be re-programmed by the manufacturer through the EPROM involved in the design and by the user through the loadable pseudo-random sequence generator
Hypoxia promotes breast cancer cell invasion through HIF-1a-mediated up-regulation of the invadopodial actin bundling protein CSRP2
Hypoxia is a common feature of solid tumours that promotes invasion and metastatic dissemination. Invadopodia are actin-rich membrane protrusions that direct extracellular matrix proteolysis and facilitate tumour cell invasion. Here, we show that CSRP2, an invadopodial actin bundling protein, is upregulated by hypoxia in various breast cancer cell lines, as well as in pre-clinical and clinical breast tumour specimens. We functionally characterized two hypoxia responsive elements within the proximal promoter of CSRP2 gene which are targeted by hypoxia-inducible factor-1 (HIF-1) and required for promoter transactivation in response to hypoxia. Remarkably, CSRP2 knockdown significantly inhibits hypoxia-stimulated invadopodium formation, ECM degradation and invasion in MDA-MB-231 cells, while CSRP2 forced expression was sufficient to enhance the invasive capacity of HIF-1a-depleted cells under hypoxia. In MCF-7 cells, CSRP2 upregulation was required for hypoxia-induced formation of invadopodium precursors that were unable to promote ECM degradation. Collectively, our data support that CSRP2 is a novel and direct cytoskeletal target of HIF-1 which facilitates hypoxia-induced breast cancer cell invasion by promoting invadopodia formation.The authors are grateful to Monika Dieterle, Arnaud Muller, Pter Nazarov and Muhammad Zaeem Noman (Oncology Department, LIH, Luxembourg) for technical assistance, support in statistical analyses and constructive discussions. The authors also warmly thank Sara A. Courtneidge for the gift of the Tks5-GFP construct (Oregon Health and Science University, Portland, USA). This work was mainly supported by a research grant from “Fondation Cancer” Luxembourg (FC/2016/02), and the National Research Fund (C16/ BM/11297905). Joshua Brown Clay is recipient of a Postdoctoral fellowship from “Fonds De La Recherche Scientifque” - FNRS “Télévie” (7.4512.16). Antoun Al Absi and Hannah Wurzer are recipients of PhD fellowships from the National Research Fund, Luxembourg (AFR7892325 and PRIDE15/10675146/CANBIO, respectively)
Novel composite materials of modified roasted date pits using ferrocyanides for the recovery of lithium ions from seawater reverse osmosis brine
In this paper, novel composite materials from modified roasted date pits using ferrocyanides were developed and investigated for the recovery of lithium ions (Li+) from seawater reverse osmosis (RO) brine. Two composite materials were prepared from roasted date pits (RDP) as supporting material, namely potassium copper hexacyanoferrate-date pits composite (RDP-FC-Cu), and potassium nickel hexacyanoferrate-date pits composite (RDP-FC-Ni). The physiochemical characterization of the RO brine revealed that it contained a variety of metals and salts such as strontium, zinc, lithium, and sodium chlorides. RDP-FC-Cu and RDP-FC-Ni exhibited enhanced chemical and physical characteristics than RDP. The optimum pH, which attained the highest adsorption removal (%) for all adsorbents, was at pH 6. In addition, the highest adsorption capacities for the adsorbents were observed at the initial lithium concentration of 100 mg/L. The BET surface area analysis confirmed the increase in the total surface area of the prepared composites from 2.518 m2/g for RDP to 4.758 m2/g for RDP-FC-Cu and 5.262 m2/g for RDP-FC-Ni. A strong sharp infrared peak appeared for the RDP-FC-Cu and RDP-FC-Ni at 2078 cm−1. This peak corresponds to the C≡N bond, which indicates the presence of potassium hexacyanoferrate, K4[Fe(CN)6]. The adsorption removal of lithium at a variety of pH ranges was the highest for RDP-FC-Cu followed by RDP-FC-Ni and RDP. The continuous increase in the adsorption capacity for lithium with increasing initial lithium concentrations was also observed. This could be mainly attributed to enhance and increased lithium mass transfer onto the available adsorption active sites on the adsorbents’ surface. The differences in the adsorption in terms of percent adsorption removal were clear and significant between the three adsorbents (P value < 0.05). All adsorbents in the study showed a high lithium desorption percentage as high as 99%. Both composites achieved full recoveries of lithium from the RO brine sample despite the presence of various other competing ions.This work was made possible by Qatar University collaborative internal grant # [QUCG-CAS-20/21-2]. The findings achieved herein are solely the responsibility of the author[s]
Screening the growth inhibition mechanism of sulfate reducing bacteria by chitosan/lignosulfonate nanocomposite (CS@LS) in seawater media
Sulfate-reducing bacteria (SRBs) induced biofilm formation is a global industrial concern due to its role in the development of microbial-induced corrosion (MIC). Herein, we have developed a biodegradable chitosan/lignosulfonate nanocomposite (CS@LS) as an efficient green biocide for the inhibition of SRBs biofilms. We investigated in detail the inhibition mechanism of SRBs by CS@LS in seawater media. Stable CS@LS-1:1 with 150–200 nm average size, and zeta potential of + 34.25 mV was synthesized. The biocidal performance of CS@LS was evaluated by sulfate reduction profiles coupled with analysis of extracted extracellular polymeric substances (EPS) and lactate dehydrogenase (LDH) release assays. As the nanocomposite concentration was increased from 50 to 500 µg/mL, the specific sulfate reduction rate (SSRR) decreased from 0.278 to 0.036 g-sulfate/g-VSS*day showing a relative sulfate reduction inhibition of 86.64% as compared to that of control. Similarly, the specific organic uptake rate (SOUR) decreased from 0.082 to 0.039 0.036 g-TOC/g-VSS*day giving a relative co-substrate oxidation inhibition of 52.19% as compared to that of control. The SRBs spiked with 500 µg/mL CS@LS showed a reduction in cell viability to 1.5 × 106 MPN/mL. To assess the biosafety of the nanocomposite on the marine biota, the 72-hours acute toxicity assays using zebrafish embryo model revealed that the LC50 for the CS@LS was 103.3 µg/mL. Thus, CS@LS can be classified as environment friendly. The nanocomposite showed long-term stability and excellent antibacterial properties against SRBs growth and is thus potentially useful for combating the problems of biofilm growth in harsh marine and aquatic environments.The authors are grateful for the financial support from NPRP grant (NPRP8-286-02-118) from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors. The authors are thankful to J. Ponraj, M Helal, and M. Pasha at the Core lab of QEERI/HBKU, Doha, Qatar for TEM and SEM analysis, respectively. Open Access funding provided by the Qatar National Library
A New CMOS Controllable Impedance Multiplier with Large Multiplication Factor
This paper presents a new compact controllable impedance multiplier using CMOS technology. The design is based on the use of the translinear principle using MOSFETs in subthreshold region. The value of the impedance will be controlled using the bias currents only. The impedance can be scaled up and down as required. The functionality of the proposed design was confirmed by simulation using BSIM3V3 MOS model in Tanner Tspice 0.18 μm TSMC CMOS process technology. Simulation results indicate that the proposed design is functioning properly with a tunable multiplication factor from 0.1- to 100-fold. Applications of the proposed multiplier in the design of low pass and high pass filters are also included
An Improved Current Mirror Cell
A new configuration for the design of a current mirror is presented. The proposed configuration eliminates the DC matching error caused by the difference between drain-to-source voltages of both input and output transistors. The circuit can be used to enhance the accuracy of analog circuits for current levels from 0 to few hundreds microamperes The proposed configuration was verified by HSPICE simulator level 49 in 0.8m CMOS process technology. Simulation results show that DC matching error is substantially reduced compared to the cascade configuratio
An Improved Current Mirror Cell
A new configuration for the design of a current mirror is presented. The proposed configuration eliminates the DC matching error caused by the difference between drain-to-source voltages of both input and output transistors. The circuit can be used to enhance the accuracy of analog circuits for current levels from 0 to few hundreds microamperes The proposed configuration was verified by HSPICE simulator level 49 in 0.8m CMOS process technology. Simulation results show that DC matching error is substantially reduced compared to the cascade configuratio
An Improved Current Mirror Cell
A new configuration for the design of a current mirror is presented. The proposed configuration eliminates the DC matching error caused by the difference between drain-to-source voltages of both input and output transistors. The circuit can be used to enhance the accuracy of analog circuits for current levels from 0 to few hundreds microamperes The proposed configuration was verified by HSPICE simulator level 49 in 0.8m CMOS process technology. Simulation results show that DC matching error is substantially reduced compared to the cascade configuratio
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