Sensitive Detection of SARS-CoV-2 Using a Novel Plasmonic Fiber Optic Biosensor Design

The coronavirus (COVID-19) pandemic has put the entire world at risk and caused an economic downturn in most countries. This work provided theoretical insight into a novel fiber optic based plasmonic biosensor that can be used for sensitive detection of SARS-CoV-2. The aim was always to achieve reliable, sensitive and reproducible detection. The proposed configuration is based on Ag–Au alloy nanoparticles films covered with a layer of graphene which promotes the molecular adsorption and a thiol-tethered DNA layer as a ligand. Here the combination of two recent approaches in a single configuration is very promising and can only lead to considerable improvement. We have theoretically analyzed the sensor performance in terms of sensitivity and resolution. To highlight the importance of the new configuration, a comparison was made with two other sensors. One is based on gold nanoparticles incorporated into a host medium, the other is composed of a bimetallic Ag-Au layer in the massive state. The numerical results obtained has been validated and show that the proposed configuration offers better sensitivity (7100 nm\RIU) and good resolution (figure of merit; FOM=38.88Tand signal-to-noise ratio; SNR=0.388). In addition, a parametric study was performed such as the graphene layers number and the size of the nanoparticles.

Multi and Single-Reference Methods for the Analysis of Multi-State Peroxidation of Enolates

In spite of being spin-forbidden, some enzymes are capable of catalyzing the incorporation of O₂ (³Σ⁻_g) to<br>organic substrates without needing any cofactor. It has been established that the process followed by these<br>enzymes starts with the deprotonation of the substrate forming an enolate. In a second stage, the peroxidation<br>of the enolate formation occurs, a process in which the system changes its spin multiplicity from a triplet state<br>to a singlet state. In this article, we study the addition of O₂ to enolates using state-of-the-art multi-reference<br>and single-reference methods. Our results confirm that intersystem crossing is promoted by stabilization of<br>the singlet state along the reaction path. When multi-reference methods are used, large active spaces are<br>required, and in this situation, Semistochastic Heat-Bath Configuration Interaction (SHCI) emerges as a<br>powerful method to study these multi-configurational systems and is in good agreement with LCCSD(T)<br>when the system is well-represented by a single-configuration.<br><br>

Multi and Single-Reference Methods for the Analysis of Multi-State Peroxidation of Enolates

In spite of being spin-forbidden, some enzymes are capable of catalyzing the incorporation of O₂ (³Σ⁻_g) to<br>organic substrates without needing any cofactor. It has been established that the process followed by these<br>enzymes starts with the deprotonation of the substrate forming an enolate. In a second stage, the peroxidation<br>of the enolate formation occurs, a process in which the system changes its spin multiplicity from a triplet state<br>to a singlet state. In this article, we study the addition of O₂ to enolates using state-of-the-art multi-reference<br>and single-reference methods. Our results confirm that intersystem crossing is promoted by stabilization of<br>the singlet state along the reaction path. When multi-reference methods are used, large active spaces are<br>required, and in this situation, Semistochastic Heat-Bath Configuration Interaction (SHCI) emerges as a<br>powerful method to study these multi-configurational systems and is in good agreement with LCCSD(T)<br>when the system is well-represented by a single-configuration.<br><br>

A Crevice Corrosion Model for Biomedical Trunnion Geometries and Surfaces Feature

Modular hip joint implants were introduced in arthroplasty medical procedures because they facilitate the tailoring of patients’ anatomy, the use of different materials in one single configuration, as well as medical revision. However, in certain cases, such prostheses may undergo deterioration at the head–neck junctions with negative clinical consequences. Crevice-corrosion is commonly invoked as one of the degradation mechanisms acting at those junctions despite biomedical alloys such as Ti6Al4V and CoCr being considered generally resistant to this form of corrosion. To verify the occurrence of crevice corrosion in modular hip joint junctions, laboratory crevice-corrosion tests were conducted in this work under hip joint-relevant conditions, i.e., using similar convergent crevice geometries, materials (Ti6Al4V and CoCr alloys vs. ceramic), surface finish, NaCl solution pHs (5.6 and 2.3), and electrochemical conditions. A theoretical model was also developed to describe crevice-corrosion considering relevant geometrical and electrochemical parameters. To verify the model, a FeCr alloy, known to be sensitive to this phenomenon, was subjected to the crevice-corrosion test in sulfuric acid. The experiments and the model predictions clearly showed that, in principle, crevice corrosion of Ti6Al4V or CoCr is not supposed to occur in typical crevices formed at the stem-neck junction of hip implants.

Giddy Ion Reloaded: Desktop Manager, Optimizer with Multi Utility Tool

The performance of our computer is vital in fulfilling the task of the user. The paper presents a solution for maintaining the performance of the computer specifically computers with Windows operating systems. In this article, the fundamental difference and problem of the Windows operating system are defined which roots in the architectural design of using single configuration storage. The security hole of windows authentication, the exploitation of Microsoft EFS, and the acquisition of password hashes from Microsoft SAM are also discussed. Various existing utility software is evaluated to investigate if they meet the user define criteria. This paper also proposes a user-level implementation of the AES 256 encryption algorithm for securing user files and a Network Blocking algorithm based on ARP Spoofing techniques that provide a user-level network monitoring capability. The proposed application is called “Giddy-ION Reloaded” which consists of four main modules; machine information acquisition and monitoring, machine optimization, machine cleaning, and tools module that is divided into submodule; encryption and decryption, network monitoring, desktop management, network optimization/ control, and task automation. The testing was conducted with the participants coming from a computer college, continuing education trainer/faculty, and various IT experts. The response from these groups was statistically treated and analyzed, where the Giddy ION rank top and shows promising results. The study is limited to windows machines with 64-bit support architecture. The developed application is ready for implementation and deployment as evidenced by its high overall performance rating as evaluated by the participants against the ISO 25010 standards.

PERFORMANCE OF CONCRETE PONTOON FLOATING BREAKWATER WITH DOUBLE CONFIGURATION

Development of floating breakwater are increasing along with the rising interest of floating infrastructure. One of the applications is floating breakwater using concrete pontoon. Large and rigid structure are possible to construct with the usage of concrete. However, it still limited with the available construction and transportation method to handle such a large structure. Double configurations of floating breakwater proposed to increase the structure’s performance with the size limitation. The breakwater performance tested with physical model in laboratory by comparing performance of single pontoon with double pontoon for various structure spacing. Pontoon size are 1.2 m in length, 0.3 m in width, and 0.15 m in height and tested with many combination of irregular waves and for double configurations model, the spacing of 30 cm, 60 cm, and 90 cm are used. The structure works optimal in low range harmonic period. Performance of single configuration are in the range of Kt 0.6 up to 0.97, transmission increased along with the waves period. The Kt value of double configuration are around 0.45 up to 0.8. Performance of double configuration determined by ratio of structure spacing with wavelength. Larger ratio resulted a better performance in condition where the spacing did not exceed 0.65 length of wavelength.

Ultrastructural Features of an Abundant and Ubiquitous Marine Ciliate, Uronychia binucleata (Protista, Ciliophora, Euplotida)

The ciliate genus Uronychia is a marine group with extremely differentiated cortical and ciliary structures. These structures define its unique evolutionary position in the whole subclass Euplotia. However, to date, few data about the ultrastructure of this genus and related taxa is available. In the present work, a dominant species, Uronychia binucleata, was investigated using scanning electron microscopy and transmission electron microscopy. The findings are as follows: (i) this species lacks the typical alveolar plate in its cortex, whereas the abundant electron-lucent vesicular structures occurred densely; (ii) the subpellicular microtubules form a triad configuration in the dorsal side, while appearing in a single configuration in the ventral side; (iii) the cortical granules are extrusomes, which represent a kind of mucocyst instead of ampules; (iv) two kinetosomes in different rows of one cirrus are linked by the single longitudinal connection; (v) the undulating membrane is highly developed and their insides and outsides are partially covered by the cortical flap; (vi) the single-membrane-bound pharyngeal disks interposed with microtubular sheets, and are distributed in three distinct zones. This first detailed report about the ultrastructural features of the genus Uronychia will be a key to improve the diagnosis and systematics of this widely distributed and ecologically important genus and its family Uronychiidae.

Intelligent Modularized Reconfigurable Mechanisms for Robots: Development and Experiment

With the development of intelligent flexible manufacturing, traditional industrial manipulators with a single configuration are difficult to meet a variety of tasks. Reconfigurable robots have developed rapidly which could change their configurations and end effectors for different tasks. The reconfigurable connecting mechanism (RCM) is a core component of reconfigurable robots. In this paper, two types of intelligent modularized RCMs with light weight, high payload, and large pose (position and attitude) error tolerance are developed. One is driven by shape memory alloy (SMA) and recovery spring. It is locked by steel balls and key. The other is driven by electromagnetic coil and locked by permanent magnet and key. The locking principle, mechanical system and control system of the two RCMs are detailed introduced. Both of them meet the requirements of high precision and high payload in the industrial field. Finally, the developed RCMs are respectively integrated to a practical robot and experimented. The experiment results verified the performance of the two RCMs.

Electron-impact single ionization of Si+

Electron-impact single ionization is studied in the Si+ ion by considering transitions among energy levels. The study includes excitation-autoionization (EA) and collisional ionization processes. The excitations are investigated up to shells with the principal quantum numbers n ≤ 10. It is shown that correlation effects included in the EA calculations play a crucial role in explaining measurements. The correlation effects diminish the EA cross sections by ∼30% compared to single-configuration calculations. However, the collisional ionization is not significantly affected by an extension of the basis of interacting configurations. Good agreement between the presented level-to-level distorted wave data and experimental measurements is found for the single ionization of the Si+ ion.

Intelligent Modularized Reconfigurable Mechanisms for Robots: Development and Experiment

With the development of intelligent flexible manufacturing, traditional industrial manipulators with a single configuration are difficult to meet a variety of tasks. Reconfigurable robots have developed rapidly which could change their configurations and end effectors for different tasks. The reconfigurable connecting mechanism (RCM) is a core component of reconfigurable robots. In this paper, two types of intelligent modularized RCMs with light weight, high payload, and large pose (position and attitude) error tolerance are developed. One is driven by shape memory alloy (SMA) and recovery spring. It is locked by steel balls and key. The other is driven by electromagnetic coil and locked by permanent magnet and key. The locking principle, mechanical system and control system of the two RCMs are detailed introduced. Both of them meet the requirements of high precision and high payload in the industrial field. Finally, the developed RCMs are respectively integrated to a practical robot and experimented. The experiment results verified the performance of the two RCMs.