Clinical applications of spectroscopic techniques in conjunction with multivariate analysis in virus diagnosis

In view of the global pandemic that started in 2020, caused by COVID-19, the importance of the existence of fast, reliable, cheap diagnostic techniques capable of detecting the virus even in the first days of infection became evident. This review discusses studies involving the use of spectroscopic techniques in the detection of viruses in clinical samples. Techniques based on mid-infrared, near-infrared, Raman, and molecular fluorescence are explained and it was demonstrated how they can be used in conjunction with computational tools of multivariate analysis to build models capable of detecting viruses. Studies that used real clinical samples from 2011 to 2021 were analyzed. The results demonstrate the potential of the techniques in detecting viruses. Spectroscopic techniques, as well as chemometric techniques, were also explained. Viral diagnosis based on spectroscopy has interesting advantages compared to standard techniques such as: fast results, no need for reagents, non-destructiveness for the sample, no need for sample preparation, relatively low cost, among others. Several studies have corroborated the real possibility that, in the near future, we may have spectroscopic tools being successfully applied in viral diagnosis.

2,7-Carbazole Derived Organoboron Compounds: Synthesis and Molecular Fluorescence

Triarylboranes have drawn much attention in OLEDs owing to their remarkable solid-state luminescence properties. Here two new A-D-A type compounds, 2,7-bis(dimesitylboryl)-N-ethyl-carbazole (BCz) using triarylborane as electron acceptor and carbazole as electron donor while 2,7-bis((4-(dimesitylboryl)phenyl)ethynyl)-9-ethyl-carbazole (BPACz) using phenylacetylene as extra conjugated bridge, have been synthesized and their photoluminescence related properties in various states have been investigated both experimentally and theoretically. Both compounds show blue emission with high quantum yields, being potential candidates for blue OLED materials.

Design and validation of plasmid vectors for characterizing protein-protein interactions in Spodoptera frugiperda insect cells

There are limited molecular biology resources for interrogating protein-protein interactions (PPI) in insect cells. To address this deficiency, we developed plasmid vectors for localization, bi-molecular fluorescence complementation (BiFC), and co-immunoprecipitation (co-IP) assays in Sf9 insect cells. Plasmids were designed to express a protein of interest as a fusion with epitope tags and autofluorescent proteins using the Gateway cloning system. Two robust interactors were utilized to validate this system, the nucleoprotein (N) and the phosphoprotein (P) of maize mosaic virus. The viral N was fused with the carboxy-terminal portion of eYFP and a FLAG epitope tag, and P was fused with the amino-terminal portion of eYFP and a c-myc epitope tag. The two expression plasmids were co-transfected into Sf9 cells, and fluorescence microscopy was used to visualize BiFC and co-IP was performed to confirm that this system was sensitive enough to detect PPI between the two proteins. BiFC was seen in cells co-transfected with N and P and co-IP validated the interaction. This plasmid-based system can be used to investigate a variety of PPI that occur in insects. We validated viral protein interactions that occur in the insect vector which provides further insights into the biology of rhabdoviruses that are transmitted by insects. The ability to express viral and insect proteins in insect cells for studying PPI with this streamlined system represents an advancement for protein research in insects. Future work will focus on identifying interacting viral and host proteins and discovery of targets for control of viruses and insect vectors.

Proteasomal degradation of JAZ9 by SALT- AND DROUGHT-INDUCED RING FINGER1 during pathogen infection

E3 ubiquitin ligase SALT- AND DROUGHT-INDUCED RING FINGER1 (SDIR1) plays a novel role in modulating plant immunity against pathogens. The molecular interactors of SDIR1 during pathogen infection are not known. SDIR1 interacting Jasmonate ZIM-domain (JAZ) proteins were identified through a yeast two-hybrid (Y2H) screen. Full length JAZ9 interacts with SDIR1 only in the presence of coronatine, a bacteria secreted toxin, or jasmonic acid (JA) in Y2H assay. The bi-molecular fluorescence complementation and pull-down assays confirm the in planta interaction of these proteins. JAZ9 proteins, negative regulators of JA-mediated plant defense, were degraded during the pathogen infection by SDIR1 through a proteasomal pathway causing disease susceptibility against hemibiotrophic pathogens.

Comparison of Quantitative Detection Methods Based on Molecular Fluorescence Spectroscopy and Chromatographic Techniques Used for the Determination of Bisphenol Compounds

Analytical methods using the fluorescence properties of bisphenols (BPA, BPF and BPS) and their complexes with β-cyclodextrin and methyl-β-cyclodextrin were developed. The methods were applied for the analysis of thermal paper and canned food. Their performance was compared with a standard HPLC approach with a diode array and fluorescence detections. For comparison purposes, basic validation parameters (linear range, limit of detection, sensitivity, precision) were evaluated. It was concluded the developed methods facilitate fast and cost-effective determination of three bisphenol species in liquid samples, similar to the HPLC performance. They are also environmentally friendly. BPA, BPF and BPS can be routinely determined with the presented approach.

Correction to: Evaluation of Ac-Lys0(IRDye800CW)Tyr3-octreotate as a novel tracer for SSTR2-targeted molecular fluorescence guided surgery in meningioma

A correction to this paper has been published: https://doi.org/10.1007/s11060-021-03769-9

De Novo Creation of a Naked-Eye-Detectable Fluorescent Molecule Based on Quantum-Chemical Computation and Machine Learning

Correlations between molecular properties and structures, such as those between the absorption wavelength and conjugate length, are beneficial for designing materials and controlling their properties. However, determining the molecular structures that correlate with the target molecular properties (such as molecular fluorescence) is not an easy task. In this study, we have used a de novo molecule generator (DNMG) coupled with quantum-chemical computation (QC) to develop new fluorescent molecules, which are garnering significant attention in various disciplines. With massive parallel computation (1024 cores, 5 days), DNMG has produced 3,643 candidate molecules within the density functional theory (DFT; one of QC) framework. Among the generated molecules, we have selected an unreported molecule and synthesized it for photoluminescence spectrum measurement. Our experimental verification demonstrated that DNMG can successfully create a new molecule which emits fluorescence detectable by the naked eye, as predicted by the DFT.