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9 pages, 1139 KiB

Open AccessArticle

Evaluation of the Abbott Panbio™ COVID-19 Ag Rapid Antigen Test for Asymptomatic Patients during the Omicron Wave

by Viet Tran, Giles Barrington, Zach Aandahl, Amelia Lawrence, Senudi Wijewardena, Brian Doyle and Louise Cooley

J 2023, 6(1), 198-206; https://doi.org/10.3390/j6010015 - 20 Mar 2023

Viewed by 1753

Abstract

Rapid antigen testing (RAT) is a cost-effective and time-efficient method of identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and therefore a critical part of infection control strategies. There is no published evidence evaluating the use of RAT during the Omicron wave of [...] Read more.

Rapid antigen testing (RAT) is a cost-effective and time-efficient method of identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and therefore a critical part of infection control strategies. There is no published evidence evaluating the use of RAT during the Omicron wave of the COVID-19 pandemic for asymptomatic patients or its performance between waves. All patients presenting to an Emergency Department over a two-week period without COVID-19 symptoms were screened for SARS-CoV-2 using both the Abbott Panbio RAT as well as the gold standard reverse transcriptase real-time polymerase chain reaction (PCR). The Abbott Panbio RAT sensitivity was 13% (95% CI 0.028, 0.336) for asymptomatic patients. The use of this test in asymptomatic patients during the Omicron wave had a statistically significant reduction in sensitivity compared with two reports of the same test in previous waves (13% vs. 86%, p < 0.0001; 13% vs. 83%, p < 0.0001). As SARS-CoV-2 continues to mutate, the sensitivity of RATs are altered and needs to be continually re-evaluated for each variant of concern if they are to be used as part of an infection control strategy. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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18 pages, 4198 KiB

Open AccessArticle

Design of Reliable Remobilisation Finger Implants with Geometry Elements of a Triple Periodic Minimal Surface Structure via Additive Manufacturing of Silicon Nitride

by Christof Koplin, Eric Schwarzer-Fischer, Eveline Zschippang, Yannick Marian Löw, Martin Czekalla, Arthur Seibel, Anna Rörich, Joachim Georgii, Felix Güttler, Sinef Yarar-Schlickewei and Andreas Kailer

J 2023, 6(1), 180-197; https://doi.org/10.3390/j6010014 - 18 Mar 2023

Viewed by 2206

Abstract

When finger joints become immobile due to an accident during sports or a widespread disease such as rheumatoid arthritis, customised finger joint implants are to be created. In an automated process chain, implants will be produced from ceramic or metallic materials. Artificial intelligence-supported [...] Read more.

When finger joints become immobile due to an accident during sports or a widespread disease such as rheumatoid arthritis, customised finger joint implants are to be created. In an automated process chain, implants will be produced from ceramic or metallic materials. Artificial intelligence-supported software is used to calculate three-dimensional models of the finger bones from two-dimensional X-ray images. Then, the individual implant design is derived from the finger model and 3D printed. The 3D printing process and the structures used are evaluated via model tests and the final implant design via a reliability calculation in a way to ensure that this is also possible via an AI process in the future. Using additive manufacturing with silicon nitride-based ceramics, model specimens and implants are produced via the lithography-based ceramic vat photopolymerisation process with full geometry or elements of triple periodic minimal surfaces structure. The model specimens are tested experimentally, and the loads are matched with a characteristic strength assuming a Weibull distribution of defects in the volume to generate and match failure probabilities. Calculated fracture forces of the silicon nitride-based ceramic structure was validated by comparison of simulation and tests, and the calculation can be used as a quality index for training of artificial intelligence in the future. The proposed method for individualized finger implant design and manufacturing may allow for correction of potential malpositions of the fingers in the future. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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12 pages, 2574 KiB

Open AccessArticle

Approximate Solutions for Undamped Nonlinear Oscillations Using He’s Formulation

by Stylianos Vasileios Kontomaris, Georgios Chliveros and Anna Malamou

J 2023, 6(1), 140-151; https://doi.org/10.3390/j6010010 - 28 Feb 2023

Cited by 2 | Viewed by 1551

Abstract

Solving nonlinear oscillations is a challenging task due to the mathematical complexity of the related differential equations. In many cases, determining the oscillation’s period requires the solution of complicated integrals using numerical methods. To avoid the complexity, there are many empirical equations in [...] Read more.

Solving nonlinear oscillations is a challenging task due to the mathematical complexity of the related differential equations. In many cases, determining the oscillation’s period requires the solution of complicated integrals using numerical methods. To avoid the complexity, there are many empirical equations in the literature that can be used instead of rigorous mathematical analysis to provide an acceptable approximation. In this paper, a recently developed method, He’s formulation, is applied to find the period in many different cases of nonlinear oscillators. The cases are those of the Duffing equation, the Helmholtz nonlinear oscillator, the simple pendulum and the case of a vertical oscillation under the influence of a nonlinear elastic force. The results of the method are accurate; thus, He’s formulation is a strong tool for solving nonlinear oscillations. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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11 pages, 1106 KiB

Open AccessArticle

Negative Chronotropic Effects of Class I Antiarrhythmic Drugs on Guinea Pig Right Atria: Correlation with L-Type Ca²⁺ Channel Blockade

by Haruhito Hiiro, Kentaro Otsuka, Shogo Hamaguchi, Iyuki Namekata and Hikaru Tanaka

J 2023, 6(1), 104-114; https://doi.org/10.3390/j6010008 - 11 Feb 2023

Viewed by 2805

Abstract

The negative chronotropic effects of eight Vaughan Williams Class I antiarrhythmic drugs were examined in guinea pig right atrial tissue preparations. The drugs decreased the spontaneous beating rate at concentrations overlapping with their therapeutic blood levels. Cibenzoline, aprindine, flecainide, and propafenone showed stronger [...] Read more.

The negative chronotropic effects of eight Vaughan Williams Class I antiarrhythmic drugs were examined in guinea pig right atrial tissue preparations. The drugs decreased the spontaneous beating rate at concentrations overlapping with their therapeutic blood levels. Cibenzoline, aprindine, flecainide, and propafenone showed stronger effects; 10 µM of each drug decreased the beating rate to about 75% of initial values. Disopyramide, mexiletine, pilsicainide, and ranolazine showed weaker effects; 10 µM of each drug decreased the beating rate to about 90% of initial values. The potency of drugs correlated with the reported IC₅₀ values to block the L-type Ca²⁺ channel current rather than the Na⁺ and K⁺ channel currents. The reported IC₅₀ values for the blockade of the hyperpolarization-activated inward current (If) and the Na⁺-Ca²⁺ exchanger current were much higher than those for the blockade of the L-type Ca²⁺ channel current. These results indicate that the negative chronotropic effects of Class I antiarrhythmic drugs can be largely explained by their blockade of the L-type Ca²⁺ channel. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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17 pages, 3939 KiB

Open AccessArticle

Reducing the Immunogenicity of Pulchellin A-Chain, Ribosome-Inactivating Protein Type 2, by Computational Protein Engineering for Potential New Immunotoxins

by Reza Maleki, Libing Fu, Ricardo Sobhie Diaz, Francisco Eduardo Gontijo Guimarães, Otávio Cabral-Marques, Gustavo Cabral-Miranda and Mohammad Sadraeian

J 2023, 6(1), 85-101; https://doi.org/10.3390/j6010006 - 16 Jan 2023

Viewed by 2254

Abstract

Pulchellin is a plant biotoxin categorized as a type 2 ribosome-inactivating protein (RIPs) which potentially kills cells at very low concentrations. Biotoxins serve as targeting immunotoxins (IT), consisting of antibodies conjugated to toxins. ITs have two independent protein components, a human antibody and [...] Read more.

Pulchellin is a plant biotoxin categorized as a type 2 ribosome-inactivating protein (RIPs) which potentially kills cells at very low concentrations. Biotoxins serve as targeting immunotoxins (IT), consisting of antibodies conjugated to toxins. ITs have two independent protein components, a human antibody and a toxin with a bacterial or plant source; therefore, they pose unique setbacks in immunogenicity. To overcome this issue, the engineering of epitopes is one of the beneficial methods to elicit an immunological response. Here, we predicted the tertiary structure of the pulchellin A-chain (PAC) using five common powerful servers and adopted the best model after refining. Then, predicted structure using four distinct computational approaches identified conformational B-cell epitopes. This approach identified some amino acids as a potential for lowering immunogenicity by point mutation. All mutations were then applied to generate a model of pulchellin containing all mutations (so-called PAM). Mutants’ immunogenicity was assessed and compared to the wild type as well as other mutant characteristics, including stability and compactness, were computationally examined in addition to immunogenicity. The findings revealed a reduction in immunogenicity in all mutants and significantly in N146V and R149A. Furthermore, all mutants demonstrated remarkable stability and validity in Molecular Dynamic (MD) simulations. During docking and simulations, the most homologous toxin to pulchellin, Abrin-A was applied as a control. In addition, the toxin candidate containing all mutations (PAM) disclosed a high level of stability, making it a potential model for experimental deployment. In conclusion, by eliminating B-cell epitopes, our computational approach provides a potential less immunogenic IT based on PAC. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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10 pages, 324 KiB

Open AccessArticle

Polynomial-Computable Representation of Neural Networks in Semantic Programming

by Sergey Goncharov and Andrey Nechesov

J 2023, 6(1), 48-57; https://doi.org/10.3390/j6010004 - 06 Jan 2023

Viewed by 1535

Abstract

A lot of libraries for neural networks are written for Turing-complete programming languages such as Python, C++, PHP, and Java. However, at the moment, there are no suitable libraries implemented for a p-complete logical programming language L. This paper investigates the issues of [...] Read more.

A lot of libraries for neural networks are written for Turing-complete programming languages such as Python, C++, PHP, and Java. However, at the moment, there are no suitable libraries implemented for a p-complete logical programming language L. This paper investigates the issues of polynomial-computable representation neural networks for this language, where the basic elements are hereditarily finite list elements, and programs are defined using special terms and formulas of mathematical logic. Such a representation has been shown to exist for multilayer feedforward fully connected neural networks with sigmoidal activation functions. To prove this fact, special p-iterative terms are constructed that simulate the operation of a neural network. This result plays an important role in the application of the p-complete logical programming language L to artificial intelligence algorithms. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

15 pages, 8329 KiB

Open AccessArticle

Evaluation of Interference Analysis from 5G NR Networks to Aeronautical and Maritime Mobile Systems in the Frequency Band 4800–4990 MHz

by Alexander Pastukh and Vladislav Sorokin

J 2023, 6(1), 17-31; https://doi.org/10.3390/j6010002 - 29 Dec 2022

Cited by 1 | Viewed by 1974

Abstract

The current deployment of 5G NR in the frequency band 4800–4990 MHz in multiple countries near the coastlines indicated that there might be a potential risk of harmful interference impacting aeronautical and maritime systems located in international airspace and international waters. This raised [...] Read more.

The current deployment of 5G NR in the frequency band 4800–4990 MHz in multiple countries near the coastlines indicated that there might be a potential risk of harmful interference impacting aeronautical and maritime systems located in international airspace and international waters. This raised numerous concerns about whether 5G NR system rollouts in that band need to be restricted by the power flux density limits created at the border of the territorial waters, which equals 12 nautical miles from the coastline. This work contains a case study based on the example of the Pacific region, where a simulation of aggregate interference from 5G NR base stations and user equipment deployed in the cities near the coastline using Monte Carlo analysis was conducted. The results of the study show that no harmful interference to the aeronautical and maritime services operating in international airspace and waters is expected even when the aircraft or vessels are located at the border of the territorial airspace and waters from the coastline. Therefore, no restriction to the 5G NR deployment in the coastline regions in the frequency band 4800–4990 MHz is required. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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22 pages, 1458 KiB

Open AccessArticle

The Impact of Nature Imagery and Mystery on Attention Restoration

by Trina Yap, Denise Dillon and Peter K. H. Chew

J 2022, 5(4), 478-499; https://doi.org/10.3390/j5040033 - 08 Nov 2022

Cited by 1 | Viewed by 3064

Abstract

The factors contributing to urbanization, such as population growth and the development of mega-cities, have increased environmental stressors on top of everyday stressors, resulting in information overload. This has led to the increasing incidence of direct attentional fatigue, which causes stress and mental [...] Read more.

The factors contributing to urbanization, such as population growth and the development of mega-cities, have increased environmental stressors on top of everyday stressors, resulting in information overload. This has led to the increasing incidence of direct attentional fatigue, which causes stress and mental fatigue. The attention restoration theory centres on the environment’s capacity to restore attentional deficits and suggests that there are certain qualities in the environment that restore attention, which leads to improvements in our physical, mental, and social well-being. An environment can be restorative through the activation of involuntary attention, which limits the need for directed attention. This study explored for effects of natural, built, and mixed environment types and levels of mystery on attention restoration in university undergraduates. Perceived and actual levels of attention restoration were measured using a perceived restoration scale (PRS) and the digit symbol substitution task (DSST), respectively. A total of 101 participants viewed a restorative image followed by the completion of the DSST and the PRS for each of the 18 images depicting different environments. Actual attention restoration was measured by latency values in the DSST instead of through both speed and error rates due to some operational issues with the DSST which interfered with the full achievement of the study’s aims. There was an effect of different environments and mystery on perceived attention restoration. However, there appeared to be no effect on actual attention restoration, indicating a disconnect between perceived and actual restoration. Further research is required to confirm the specific effects of natural and built environments and mystery on attention restoration. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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8 pages, 1382 KiB

Open AccessArticle

Biosorption of Eriochrome Black T Using Exserohilum rostratum NMS1.5 Mycelia Biomass

by Endar Hidayat, Saranya Khaekhum, Seiichiro Yonemura, Yoshiharu Mitoma and Hiroyuki Harada

J 2022, 5(4), 427-434; https://doi.org/10.3390/j5040029 - 18 Oct 2022

Viewed by 1307

Abstract

The presence of eriochrome black T (EBT) dye in waste water causes a significant hazard to human health and ecology. In the current study, biosorption was employed to eliminate EBT from water. Thus, we utilized endophytic fungi strain Exserohilum rostratum NMS1.5 mycelia biomass [...] Read more.

The presence of eriochrome black T (EBT) dye in waste water causes a significant hazard to human health and ecology. In the current study, biosorption was employed to eliminate EBT from water. Thus, we utilized endophytic fungi strain Exserohilum rostratum NMS1.5 mycelia biomass as biosorbent agent. The process was carried out at room temperature by magnetic stirring. The results indicated that an increase in pH would decrease adsorption capacity and removal percentage. In addition, an increased EBT concentration would decrease the removal percentage and increase biosorption capacity. The equilibrium time indicated that after 300 min of mixing, the percentage removal and biosorption capacity were 80.5% and 100.61 mg/g, respectively. The biosorption isotherms and kinetics were compatible with the Freundlich model and the pseudo-second-order. This research indicates that E. rostratum NMS1.5 may be utilized as an environmentally friendly and affordable alternative biosorbent material for EBT removal. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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24 pages, 4271 KiB

Open AccessArticle

Virtual Reality Greenspaces: Does Level of Immersion Affect Directed Attention Restoration in VR Environments?

by Denise Dillon and Jiaying Cai

J 2022, 5(3), 334-357; https://doi.org/10.3390/j5030023 - 05 Aug 2022

Viewed by 3643

Abstract

Research on attention restoration theory has provided consistent results over the years, and exposure to nature has been found to significantly improve and restore directed attention fatigue. However, rapid urbanisation has made it increasingly difficult for human beings to interact with unpolluted nature. [...] Read more.

Research on attention restoration theory has provided consistent results over the years, and exposure to nature has been found to significantly improve and restore directed attention fatigue. However, rapid urbanisation has made it increasingly difficult for human beings to interact with unpolluted nature. Countries such as Singapore began to integrate nature into city planning and into the designs of buildings to help resident satisfaction and well-being. Local studies have had contradictory outcomes; residents report significantly higher restoration and affect towards vertical integrated greeneries, but many would still prefer traditional on-the-ground foliage. Interest in outdoor greenspaces is variable because Singapore’s high heat and humid climate make it uncomfortable to interact with outside nature for prolonged periods. The current study tested alternative modalities that can provide residents with on-the-ground foliage interactions, without the discomfort of being outdoors. Virtual exposures with different levels of immersion (high and low) and types of scenes (nature and urban) were tested for effects on perceived presence, perceived restoration and objective restoration. A total of 120 adult participants completed the study, which revealed that a virtual reality-nature condition provided significantly superior directed attention restoration and higher presence ratings. Immersive tendency did not affect perceived presence; neither did it moderate the relationship between perceived presence and its corresponding perceived restoration. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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8 pages, 528 KiB

Open AccessCase Report

Central Apnea in Patients with COVID-19 Infection

by Vikram Venkata Puram, Anish Sethi, Olga Epstein, Malik Ghannam, Kevin Brown, James Ashe and Brent Berry

J 2023, 6(1), 164-171; https://doi.org/10.3390/j6010012 - 03 Mar 2023

Cited by 1 | Viewed by 3326

Abstract

Background: The Coronavirus Disease 2019 (COVID-19) is a global pandemic that has killed over 1.5 million people worldwide. A constellation of multisystem involvement with SARS-CoV-2 has been reported. COVID-19 has been shown to affect the human nervous system, however, both the extent and [...] Read more.

Background: The Coronavirus Disease 2019 (COVID-19) is a global pandemic that has killed over 1.5 million people worldwide. A constellation of multisystem involvement with SARS-CoV-2 has been reported. COVID-19 has been shown to affect the human nervous system, however, both the extent and severity of involvement have yet to be fully elucidated. In this manuscript, we aimed to better understand the effect of COVID-19 on neuro-respiratory status by studying COVID-19 patients who presented with central apnea. Methodology: We analyzed patient characteristics, clinical outcomes, laboratory results, and imaging results of three patients with symptomatic, PCR-proven COVID-19 and episodes of central apnea. Results: Of the three patients included in this study, two patients developed new central apnea, and one patient developed an exacerbation of underlying central apnea despite COVID-19 treatments with systemic steroids and remdesivir. All occurred, on average, 15 days after the onset of COVID-19 symptoms. At 1-year follow-up, all patients experienced complete resolution of apneic breathing. Conclusions: Physicians should be vigilant for the presentation of COVID-19 with central apnea. Central apnea may be a complication in patients with severe COVID-19 infection. More research is warranted to further understand this association. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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6 pages, 384 KiB

Open AccessViewpoint

Kupffer Cells as a Target for Immunotherapy

by Takashi Sakai and Wen-Ling Lin

J 2022, 5(4), 532-537; https://doi.org/10.3390/j5040036 - 07 Dec 2022

Viewed by 1855

Abstract

Kupffer cells (KCs) are resident macrophages in the liver. Recent studies have revealed that KCs are closely related to inflammatory liver diseases, including nonalcoholic liver diseases (NAFLD). From this point of view, KC transplantation can be a candidate for immunotherapy against inflammatory diseases. [...] Read more.

Kupffer cells (KCs) are resident macrophages in the liver. Recent studies have revealed that KCs are closely related to inflammatory liver diseases, including nonalcoholic liver diseases (NAFLD). From this point of view, KC transplantation can be a candidate for immunotherapy against inflammatory diseases. Similar to general macrophages, KCs show several different phenotypes according to their environment. Activated KCs are involved in either proinflammatory responses or anti-inflammatory responses. Thus, to manipulate KCs for immunotherapy, it is crucial to control the direction of KC activation. Here, we summarize the outlook and the issues hindering immunotherapy using KC transplantation. Full article

(This article belongs to the Special Issue Feature Paper of J in 2022)

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