Cross‐linking gold nanoparticles aggregation method based on localised surface plasmon resonance for quantitative detection of miR‐155

MiR‐155 plays a critical role in the formation of cancers and other diseases. In this study, the authors aimed to design and fabricate a biosensor based on cross‐linking gold nanoparticles (AuNPs) aggregation for the detection and quantification of miR‐155. Also, they intended to compare this method with SYBR Green real‐time polymerase chain reaction (PCR). Primers for real‐time PCR, and two thiolated capture probes for biosensor, complementary with miR‐155, were designed. Citrate capped AuNPs (18.7 ± 3.6 nm) were synthesised and thiolated capture probes immobilised to AuNPs. The various concentrations of synthetic miR‐155 were measured by this biosensor and real‐time PCR method. Colorimetric changes were studied, and the calibration curves were plotted. Results showed the detection limit of 10 nM for the fabricated biosensor and real‐time PCR. Also, eye detection using colour showed the weaker detection limit (1 µM), for this biosensor. MiR‐133b as the non‐complementary target could not cause a change in both colour and UV–visible spectrum. The increase in hydrodynamic diameter and negative zeta potential of AuNPs after the addition of probes verified the biosensor accurately fabricated. This fabricated biosensor could detect miR‐155 simpler and faster than previous methods.Inspec keywords: RNA, molecular biophysics, biochemistry, cancer, nanoparticles, gold, aggregation, surface plasmon resonance, molecular configurations, nanosensors, enzymes, calibration, ultraviolet spectra, visible spectra, eye, hydrodynamics, electrokinetic effects, biosensors, nanofabricationOther keywords: cross‐linking gold nanoparticles aggregation method, localised surface plasmon resonance, quantitative detection, cancers, diseases, biosensor, miR‐155 detection, miR‐155 quantification, SYBR green real‐time polymerase chain reaction, thiolated capture probes, citrate capped AuNPs, synthetic miR‐155, real‐time PCR method, colorimetric changes, calibration curves, eye detection, colour, detection limit, MiR‐133b, noncomplementary target, UV‐visible spectrum, hydrodynamic diameter, negative zeta potential, Au     

A novel zero dead zone PFD and efficient CP for PLL applications

This paper presents a high dynamic range programmable gain amplifier (PGA) with linear-in-dB and digital to analog converter (DAC) gain control using a BiCMOS process. The proposed PGA is composed of a folded Gilbert variable gain amplifier cell, a DC offset cancellation circuitry, two inductorless fixed gain amplifiers with bandwidth extension, a symmetrical exponential voltage generator, a novel buffer amplifier with active inductive peaking for testing purposes and a 10 bit R-2R DAC. The linear-in-dB and DAC gain control scheme facilitate the analog baseband gain tuning accuracy and stability, which also provides an efficient way for digital baseband automatic gain control. The PGA chip is fabricated using 0.13 μm SiGe BiCMOS technology. With a power consumption of 80 mA@1.2 V supply voltage, the fabricated circuit exhibits a tunable gain range of ? 30–27 dB (DAC linear gain step guaranteed), a 3 dB bandwidth of around 3.5 GHz and a gain resolution of better than 0.07 dB.     

Study of Creep–Fatigue Crack Growth Behavior in a Gas Turbine Casing

Journal of Failure Analysis and Prevention - A creep–fatigue crack growth on the outer surfaces of a turbine casing was assessed, and the turbine casing’s overall lifetime was...     

Plasmonic Metaparticles on a Blackbody Create Vivid Reflective Colors for Naked‐Eye Environmental and Clinical Biodetection

Plasmonic dipoles are famous for their strong absorptivity rather than their reflectivity. Here, the as‐yet unknown specular reflection and the Brewster effect of ultrafine plasmonic dipoles, metaparticles, are introduced and exploited as the basis of new design rules for advanced applications. A configuration of “Plasmonic metaparticles on a blackbody” is demonstrated and utilized for the design of a tailored perfect‐colored absorber and for visual detection of environmental dielectrics that is not readily done by extinction plasmonics. Moreover, the Plasmonic Brewster Wavelength (PBW) effect is introduced as a new platform for the naked‐eye and bulk biodetection of analytes. The technique operates based on slight changes of molecular polarizability which is not detectable via conventional plasmon resonance techniques. As a specific highlight, the clinical applicability of the PBW method is demonstrated while addressing the transduction plasmonic techniques' challenge in detection of bulk refractive index changes of the healthy and diseased human serum exosomes. Finally, the sputtering‐based fabrication method used here is simple, inexpensive, and scalable, and does not require the sophisticated patterning approach of lithography or precise alignment of light coupling for the biodetection.     

Study of graphene device electronic properties with horizontal and vertical double vacancy defects

Abstract

Graphene device electronic properties with double vacancy (DV) defects for two cases, along the direction and perpendicular to the current pathways graphene device, were investigated by using the first principles calculations in combination with density functional theory. The bond lengths, density of states, transmission probability, and current-voltage curves are computed. For relaxed pristine graphene the bond length is around 1.43?Å. However, the bond lengths near the defects for relaxed graphene for DV case are modified to 1.40-1.49?Å. It is also observed that I???V graph is nonlinear based on the current-voltage curve of graphene device which contain DV defects. Furthermore, it has been shown that having the DV defects lead to reduce the current relative to the case of perfect graphene device. Moreover, we noted that when the voltage is increased from zero to one volt new peaks are created near Fermi level in the transmission spectrum graphs. In addition, we noted that the current for the vertical DV defect is smaller than the pristine and horizontal DV device because the number of blocked electrons current pathways in vertical DV defect is larger than the two other cases, namely the pristine and horizontal DV defect cases The obtained results can be useful for the construction of new nanoelectronic devices and may have practical applications.     

Adaptive Markov-based approach for dynamic virtual machine consolidation in cloud data centers with quality-of-service constraints

Dynamic virtual machine (VM) consolidation is one of the emerging technologies that has been considered for low-cost computing in cloud data centers. Quality-of-service (QoS) assurance is one of the challenging issues in the VM consolidation problem since it is directly affected by the increase of resource utilization due to the consolidations. In this paper, we take advantage of Markov chain models to propose a novel approach for VM consolidation that can be used to explicitly set a desired level of QoS constraint in a data center to ensure the QoS goals while improving system utilization. For this purpose, an energy-efficient and QoS-aware best fit decreasing algorithm for VM placement is proposed, which considers QoS objective when determining the location of a migrating VM. This algorithm employs an online transition matrix estimator method to deal with the nonstationary nature of real workload data. We also propose new policies for detecting overloaded and underloaded hosts. The performance of our proposed algorithms is evaluated through simulations. The results show that the proposed VM consolidation algorithms in this paper outperforms the benchmark algorithms in terms of energy consumption, service-level agreement violations, and other cost factors.     

Investigation of drill pipe rotation effect on cutting transport with aerated mud using CFD approach

In drilling with aerated mud, appropriate hole cleaning has a great impact on decreasing the drilling time and cost. Thus, investigating the impact of diverse drilling parameters such as pipe rotation on the hole cleaning looks as a key. In this study, the combination of $k-\epsilon$ turbulent model and Eulerian-Eulerian multiphase model was used to investigate the three phase flow in the concentric annulus. Furthermore, the collision of cutting – cutting, cutting-drill pipe and cutting-well was considered in the simulations. In the first step, for validating the computational setup, the simulation outcomes were compared with the previous experimental works. The impact of pipe rotation on hole cleaning at various water and air flow rates, inclination and cutting sizes was scrutinized. The simulation results demonstrated that the impact of pipe rotation on the hole cleaning can be different depending on the different hole conditions. In the low inclination and air rates, rising the pipe rotation from 0 to 75 RPM brings about dropping the cutting concentration, but increasing the pipe rotation from 75 to 125 RPM comes about raising the cutting concentration. On the other hand, in low inclination and high flow rates of air, rising the pipe rotation causes a high accumulation of cutting. Lastly, at high inclination, the cutting concentration in annulus decreases with increasing the pipe rotation and this is independent of air and water flow rates. The simulation outcomes also showed that the impact of pipe rotation on hole cleaning at large cutting size is not as much as small cutting size.     

An Evolutionary Game-Theoretic Approach for Base Station Allocation in Wireless Femtocell Networks

Wireless Personal Communications - A set of moving nodes communicating with each other without any infrastructure is considered a mobile ad hoc network (MANET). Stability is a big problem with this...     

A stochastic process-based server consolidation approach for dynamic workloads in cloud data centers

The Journal of Supercomputing - With the development of information technology, there is a need for computational works everywhere and every time. Thus, people should be able to carry out their...