Strategies to Enrich Electrochemical Sensing Data with Analytical Relevance for Machine Learning Applications: A Focused Review.

In this review, recent advances regarding the integration of machine learning into electrochemical analysis are overviewed, focusing on the strategies to increase the analytical context of electrochemical data for enhanced machine learning applications. While information-rich electrochemical data offer great potential for machine learning applications, limitations arise when sensors struggle to identify or quantitatively detect target substances in a complex matrix of non-target substances. Advanced machine learning techniques are crucial, but equally important is the development of methods to ensure that electrochemical systems can generate data with reasonable variations across different targets or the different concentrations of a single target.

Revealing Redox Behavior of Molybdenum Disulfide and Its Application as Rechargeable Antioxidant Reservoir.

Molybdenum disulfide (MoS) is a representative two-dimensional transition metal dichalcogenide and has a unique electronic structure and associated physicochemical properties. The redox property of MoS has recently attracted significant attention from various fields, such as biomedical applications. Intriguingly, MoS functions as an antioxidant in certain applications and as a pro-oxidant in others.

Recent Advances in Photoacoustic Agents for Theranostic Applications.

Photoacoustic agents are widely used in various theranostic applications. By evaluating the biodistribution obtained from photoacoustic images, the effectiveness of theranostic agents in terms of their delivery efficiency and treatment responses can be analyzed. Through this study, we evaluate and summarize the recent advances in photoacoustic-guided phototherapy, particularly in photothermal and photodynamic therapy.

Comparison of vaccination efficacy using live or ultraviolet-inactivated influenza viruses introduced by different routes in a mouse model.

Influenza is a major cause of highly contagious respiratory illness resulting in high mortality and morbidity worldwide. Annual vaccination is an effective way to prevent infection and complication from constantly mutating influenza strains. Vaccination utilizes preemptive inoculation with live virus, live attenuated virus, inactivated virus, or virus segments for optimal immune activation.

Enzyme Nanosheet-Based Electrochemical Aspartate Biosensor for Fish Point-of-Care Applications.

Bacterial infections in marine fishes are linked to mass mortality issues; hence, rapid detection of an infection can contribute to achieving a faster diagnosis using point-of-care testing. There has been substantial interest in identifying diagnostic biomarkers that can be detected in major organs to predict bacterial infections. Aspartate was identified as an important biomarker for bacterial infection diagnosis in olive flounder () fish.

Differential effect of SARS-CoV-2 infection on stress granule formation in Vero and Calu-3 cells.

Stress granule formation is induced by numerous environmental stressors, including sodium arsenite treatment and viral infection. Accordingly, stress granules can inhibit viral propagation and function as part of the antiviral host response to numerous viral infections. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antagonizes stress granule formation, in part, via interaction between SARS-CoV-2 nucleocapsid (N) protein and Ras-GTPase-activating SH3-domain-binding protein 1 (G3BP1).

Abiraterone Acetate Attenuates SARS-CoV-2 Replication by Interfering with the Structural Nucleocapsid Protein.

The drug repurposing strategy has been applied to the development of emergency COVID-19 therapeutic medicines. Current drug repurposing approaches have been directed against RNA polymerases and viral proteases. Recently, we found that the inhibition of the interaction between the SARS-CoV-2 structural nucleocapsid (N) and spike (S) proteins decreased viral replication.

Targeting the Interaction Between Spike Protein and Nucleocapsid Protein for Suppression and Detection of Human Coronavirus OC43.

Human coronavirus OC43 (HCoV-OC43) is the coronavirus most associated with "common colds", infections of the upper respiratory tract. Previously, we reported that direct interactions of nucleocapsid (N) protein and C-terminal domain of Spike protein (Spike CD) are essential for replication of SARS-CoV-2 and MERS-CoV. Thus, we developed a novel ELISA-based strategy targeting these specific interactions to detect SARS-CoV-2 and MERS-CoV.

Graphene for Nanobiosensors and Nanobiochips.

Graphene family nanomaterials have interesting electronic structures which determine their electrical, optical, and mechanical properties. Especially, their unique chemical properties enable interactions with biological substances and chemical reagents, and the interactions have further an influence on the observable properties of the graphene family nanomaterials. Such aspects render graphene family nanomaterials versatile for various types of biosensing as a target recognition unit and a recognition-to-signal transduction unit.

Wearable Sensing Systems for Monitoring Mental Health.

Wearable systems for monitoring biological signals have opened the door to personalized healthcare and have advanced a great deal over the past decade with the development of flexible electronics, efficient energy storage, wireless data transmission, and information processing technologies. As there are cumulative understanding of mechanisms underlying the mental processes and increasing desire for lifetime mental wellbeing, various wearable sensors have been devised to monitor the mental status from physiological activities, physical movements, and biochemical profiles in body fluids. This review summarizes the recent progress in wearable healthcare monitoring systems that can be utilized in mental healthcare, especially focusing on the biochemical sensors (i.

Production of SARS-CoV-2 N Protein-Specific Monoclonal Antibody and Its Application in an ELISA-Based Detection System and Targeting the Interaction Between the Spike C-Terminal Domain and N Protein.

SARS-CoV-2 infections continue to spread quickly by human-to-human transmission around the world. Therefore, developing methods to rapidly detect SARS-CoV-2 with high sensitivity are still urgently needed. We produced a monoclonal antibody that specifically detects the N protein of SARS-CoV-2 and recognizes N protein in cell lysates of SARS-CoV-2-infected Vero cells but not in cell lysates of MERS-CoV- or HCoV-OC43-infected Vero cells.

Apoptosis Enhances the Replication of Human Coronavirus OC43.

Human coronavirus OC43 (HCoV-OC43) is one of the coronaviruses causing a mild common cold, but few studies have been made on this strain. Here, we identified the molecular mechanisms involved in HCoV-OC43-induced apoptosis and its implications for viral reproduction in Vero cells and MRC-5 cells. HCoV-OC43 infection induced apoptosis that was accompanied by cleavage of caspase-3 and PARP, degradation of cyclin D1, and cell cycle arrest at S and G2M phases.

ChemSkin Reference Chemical Database for the Development of an In Vitro Skin Irritation Test.

Since the animal test ban on cosmetics in the EU in 2013, alternative in vitro safety tests have been actively researched to replace in vivo animal tests. For the development and evaluation of a new test method, reference chemicals with quality in vivo data are essential to assess the predictive capacity and applicability domain. Here, we compiled a reference chemical database (ChemSkin DB) for the development and evaluation of new in vitro skin irritation tests.

Me-too validation study for in vitro skin irritation test with a reconstructed human epidermis model, KeraSkin™ for OECD test guideline 439.

We conducted a me-too validation study to confirm the reproducibility, reliability, and predictive capacity of KeraSkin™ skin irritation test (SIT) as a me-too method of OECD TG 439. With 20 reference chemicals, within-laboratory reproducibility (WLR) of KeraSkin™ SIT in the decision of irritant or non-irritant was 100%, 100%, and 95% while between-laboratory reproducibility (BLR) was 100%, which met the criteria of performance standard (PS, WLR≥90%, BLR≥80%). WLR and BLR were further confirmed with intra-class correlation (ICC, coefficients >0.

Redox Is a Global Biodevice Information Processing Modality.

Biology is well-known for its ability to communicate through (i) molecularly-specific signaling modalities and (ii) a globally-acting electrical modality associated with ion flow across biological membranes. Emerging research suggests that biology uses a third type of communication modality associated with a flow of electrons through reduction/oxidation (redox) reactions. This redox signaling modality appears to act globally and has features of both molecular and electrical modalities: since free electrons do not exist in aqueous solution, the electrons must flow through molecular intermediates that can be switched between two states - with electrons (reduced) or without electrons (oxidized).

Tethered molecular redox capacitors for nanoconfinement-assisted electrochemical signal amplification.

Nanostructured materials offer the potential to drive future developments and applications of electrochemical devices, but are underutilized because their nanoscale cavities can impose mass transfer limitations that constrain electrochemical signal generation. Here, we report a new signal-generating mechanism that employs a molecular redox capacitor to enable nanostructured electrodes to amplify electrochemical signals even without an enhanced reactant mass transfer. The surface-tethered molecular redox capacitor engages diffusible reactants and products in redox-cycling reactions with the electrode.

Prediction of the skin sensitization potential of didecyldimethylammonium chloride and 3,7-dimethyl-2,6-octadienal and mixtures of these compounds with the excipient ethylene glycol through the human Cell Line Activation Test and the Direct Peptide Reactivity Assay.

In commercial products such as household deodorants or biocides, didecyldimethylammonium chloride (DDAC) often serves as an antimicrobial agent, citral serves as a fragrance agent, and the excipient ethylene glycol (EG) is used to dissolve the active ingredients. The skin sensitization (SS) potentials of each of these substances are still being debated. Moreover, mixtures of DDAC or citral with EG have not been evaluated for SS potency.

Pro- and Anti-oxidant Properties of Redox-Active Catechol-Chitosan Films.

Catechols are abundant in nature and are believed to perform diverse biological functions that include photoprotection (e.g., melanins), molecular signaling (e.

Validation of oxidative stress assay for schizophrenia.

Accumulating evidence implicates oxidative stress in a range of diseases, yet no objective measurement has emerged that characterizes the global nature of oxidative stress. Previously, we reported a measurement that employs the moderately strong oxidant iridium (Ir) to probe the oxidative damage in a serum sample and reported that in a small study (N = 15) the Ir-reducing capacity assay could distinguish schizophrenia from healthy control groups based on their levels of oxidative stress. Here, we used a larger sample size to evaluate the Ir-reducing capacity assay to assess its ability to discriminate the schizophrenia (N = 73) and healthy control groups (N = 45).

Me-too validation study for in vitro eye irritation test with 3D-reconstructed human cornea epithelium, MCTT HCE.

The need for in vitro eye irritation test replacing in vivo is steadily increasing. The MCTT HCE™ eye irritation test (EIT) using 3D reconstructed human cornea-like epithelium, was developed to identify ocular irritants from non-irritants those that are not requiring classification and labelling for eye irritation. Here, we report the results of me-too validation study, which was conducted to evaluate the reliability and relevance of the MCTT HCE EIT, according to performance standards (PS) of OECD TG 492.

Successful genetic modification of porcine spermatogonial stem cells via an electrically responsive Au nanowire injector.

Transgenic pigs are quite useful in many biomedical fields, such as xenotransplantation research and the production of biopharmaceutical materials. The genetic transformation of porcine spermatogonial stem cells (pSSCs) followed by differentiation into mature spermatozoa enables the effective production of transgenic pigs. Improving the transfection efficiency of pSSCs, however, has been much desired.

Optimizing the cutoff for the identification of skin sensitizers by the HaCaSens assay: Introducing an ROC-analysis-based cutoff approach.

The worldwide restricted use of animal testing makes it challenging to identify the skin sensitizing potentials of newly manufactured products. The HaCaSens assay has shown promise as an in vitro skin sensitizing assay comparable to existing assays, and is currently under pre-validation. However, there is little agreement on how to assess the results of the assay to discriminate sensitizers from non-sensitizers as the stimulation index (SI) cutoff value was arbitrarily chosen without appropriate statistical methods.

Radical Scavenging Activities of Biomimetic Catechol-Chitosan Films.

Recent studies showed that melanin-mimetic catechol-chitosan films are redox-active and their ability to exchange electrons confers pro-oxidant activities for the sustained, in situ generation of reactive oxygen species for antimicrobial bandages. Here we electrofabricated catechol-chitosan films, demonstrate these films are redox-active, and show their ability to exchange electrons confers sustained radical scavenging activities that could be useful for protective coatings. Electrofabrication was performed in two steps: cathodic electrodeposition of a chitosan film followed by anodic grafting of catechol to chitosan.

Signal processing approach to probe chemical space for discriminating redox signatures.

The discovery of discriminating molecular biomarkers often couples omics for data acquisition with advanced information processing methods for data analysis. Here, we move information processing upstream for data acquisition and report that a sample's "chemical space" can be actively probed using a tailored sequence of redox-based input signals. Specifically, we use a redox-active iridium salt (KIrCl) and an oxidative pulse-redox-relaxation input sequence to probe serum samples for chemical information.

The Role of Microsystems Integration Towards Point-of-Care Clozapine Treatment Monitoring in Schizophrenia.

We present a perspective on microsystems integration aspects for concurrent cellular and molecular sensing in a lab-on-a-chip device. While of interest for a range of applications, very few - narrowly focused - examples of such devices can be found in the literature. Here, we approach the challenge from a systems level, considering sensor integration both in parallel and in series.