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Proceedings of SPIE--the International... Aug 2022Advances in nanotechnology enable the detection of trace molecules from the enhanced Raman signal generated at the surface of plasmonic nanoparticles. We have developed...
Advances in nanotechnology enable the detection of trace molecules from the enhanced Raman signal generated at the surface of plasmonic nanoparticles. We have developed technology to enable super-resolution imaging of plasmonic nanoparticles, where the fluctuations in the surface enhanced Raman scattering (SERS) signal can be analyzed with localization microscopy techniques to provide nanometer spatial resolution of the emitting molecule's location. Additional work now enables the super-resolved SERS image and the corresponding spectrum to be acquired simultaneously. Here we will discuss how this approach can be applied to provide new insights into biological cells.
PubMed: 37431396
DOI: 10.1117/12.2632824 -
IEEE Transactions on Biomedical... Feb 2020DNA measurement machines are undergoing an orders-of-magnitude size and power reduction. As a result, the analysis of genetic molecules is increasingly appropriate for...
DNA measurement machines are undergoing an orders-of-magnitude size and power reduction. As a result, the analysis of genetic molecules is increasingly appropriate for mobile platforms. However, sequencing these measurements (converting to the molecule's A-C-G-T text equivalent) requires intense computing resources, a problem for potential realizations as mobile devices. This paper proposes a step towards addressing this issue, the design and implementation of a low-power real-time FPGA hardware accelerator for the basecalling task of nanopore-based DNA measurements. Key basecalling computations are identified and ported to a custom FPGA which operates in tandem with a CPU across a high-speed serial link and a simple API. A measured speed-up over CPU-only basecalling in excess of 100X is realized with an energy efficiency improvement of three orders of magnitude.
Topics: Algorithms; Computational Biology; DNA; Nanopores; Sequence Analysis, DNA
PubMed: 31825872
DOI: 10.1109/TBCAS.2019.2958049 -
Interface Focus Jun 2019Electrostatic interactions play a pivotal role in many biomolecular processes. The molecular organization and function in biological systems are largely determined by...
Electrostatic interactions play a pivotal role in many biomolecular processes. The molecular organization and function in biological systems are largely determined by these interactions. Owing to the highly negative charge of RNA, the effect is expected to be more pronounced in this system. Moreover, RNA base pairing is dependent on the charge of the base, giving rise to alternative secondary and tertiary structures. The equilibrium between uncharged and charged bases is regulated by the solution pH, which is therefore a key environmental condition influencing the molecule's structure and behaviour. By means of constant-pH Monte Carlo simulations based on a fast proton titration scheme, coupled with the coarse-grained model HiRE-RNA, molecular dynamic simulations of RNA molecules at constant pH enable us to explore the RNA conformational plasticity at different pH values as well as to compute electrostatic properties as local p values for each nucleotide.
PubMed: 31065339
DOI: 10.1098/rsfs.2018.0066 -
Journal of Chromatography. A Oct 2023The value of the concept of retention indices (RI) to the practice of gas chromatography (GC) is highlighted, where the RI of a compound is one component of the strategy... (Review)
Review
The value of the concept of retention indices (RI) to the practice of gas chromatography (GC) is highlighted, where the RI of a compound is one component of the strategy to identify the compound. The widespread reliance on GC and then on mass spectrometry for 'identification', may result in inadequate confirmation of molecular identity. However, RI do provide a useful tentative indication of the possible molecule(s). Thus, the RI value is a useful first measure of the molecule identity, and shown here to be valuable provided limitations are recognised. An author has a responsibility to correctly calculate the index and then use the values for (tentative) identification. Tables of reference RI values are useful in this respect, but finding an 'exact match' RI value does not confirm the identity. Hence, it is necessary to understand how the RI value may be incorrectly used in this respect. The reviewer of written research is charged with ensuring the index values are applied in a rigorous manner. Selected case studies from our own work, support the care that must be exercised when reporting RI values. In terms of advanced GC operations, mention is made of multidimensional gas chromatography and comprehensive two-dimensional gas chromatography to acquire RI values on both the first and second columns in the two-column separation experiment.
Topics: Gas Chromatography-Mass Spectrometry; Mass Spectrometry; Reference Values
PubMed: 37717451
DOI: 10.1016/j.chroma.2023.464376 -
Biological Research Jul 2019In the growth condition(s) of plants, numerous secondary metabolites (SMs) are produced by them to serve variety of cellular functions essential for physiological... (Review)
Review
In the growth condition(s) of plants, numerous secondary metabolites (SMs) are produced by them to serve variety of cellular functions essential for physiological processes, and recent increasing evidences have implicated stress and defense response signaling in their production. The type and concentration(s) of secondary molecule(s) produced by a plant are determined by the species, genotype, physiology, developmental stage and environmental factors during growth. This suggests the physiological adaptive responses employed by various plant taxonomic groups in coping with the stress and defensive stimuli. The past recent decades had witnessed renewed interest to study abiotic factors that influence secondary metabolism during in vitro and in vivo growth of plants. Application of molecular biology tools and techniques are facilitating understanding the signaling processes and pathways involved in the SMs production at subcellular, cellular, organ and whole plant systems during in vivo and in vitro growth, with application in metabolic engineering of biosynthetic pathways intermediates.
Topics: Cell Culture Techniques; Gene Expression Regulation, Plant; Plant Growth Regulators; Plant Physiological Phenomena; Plant Roots; Plant Shoots; Plants; Secondary Metabolism; Signal Transduction; Stress, Physiological
PubMed: 31358053
DOI: 10.1186/s40659-019-0246-3 -
Toxicology in Vitro : An International... Feb 2024Phototoxicity, sometimes in the literature referred to as photo-irritation, is a chemically induced reaction requiring light. While it is generally accepted that...
Phototoxicity, sometimes in the literature referred to as photo-irritation, is a chemically induced reaction requiring light. While it is generally accepted that phototoxicity testing can be performed in the majority of cases in vitro (i.e. without the use of experimental animals), these tests may sometimes provide contradictory predictions. Understanding the mechanisms of initiating events based on the molecule's structure and its ability to reach the excited state and consequently generate ROS enables the creation of predictive QSAR for this adverse outcome. The ability to predict the phototoxicity potential via a QSAR model is beneficial in reducing the number of mechanical in vitro/in chemico tests needed to demonstrate absence of phototoxicity and it is very helpful in the overall safety assessment process. The QSAR prediction model presented here focused on developing a robust platform freely available on the web via the link http://mltox.online to provide interpretable predictions of the phototoxicity of tested molecules. Great attention was devoted to interpretability and explainability of the prediction results. The web application allows the user to input a chemical by CAS number, SMILES code or trivial name. The user can choose between simple prediction or advanced tools options. These extended tools include the artificial intelligence explainability of model prediction using XSMILES (interactive visualization technique to support the interpretation of SMILES) and SHAP values (impact each element on the prediction). The comprehensive tools in question allow the user to explore the properties of phototoxic substances and to understand the prediction outcomes better.
Topics: Animals; Artificial Intelligence; Dermatitis, Phototoxic; Software
PubMed: 37820749
DOI: 10.1016/j.tiv.2023.105701 -
Angewandte Chemie (International Ed. in... Nov 2020A significant amount of attention has been given to the design and synthesis of co-crystals by both industry and academia because of its potential to change a molecule's...
A significant amount of attention has been given to the design and synthesis of co-crystals by both industry and academia because of its potential to change a molecule's physicochemical properties. Yet, difficulties arise when searching for adequate combinations of molecules (or coformers) to form co-crystals, hampering the efficient exploration of the target's solid-state landscape. This paper reports on the application of a data-driven co-crystal prediction method based on two types of artificial neural network models and co-crystal data present in the Cambridge Structural Database. The models accept pairs of coformers and predict whether a co-crystal is likely to form. By combining the output of multiple models of both types, our approach shows to have excellent performance on the proposed co-crystal training and validation sets, and has an estimated accuracy of 80 % for molecules for which previous co-crystallization data is unavailable.
PubMed: 32797658
DOI: 10.1002/anie.202009467 -
Functional & Integrative Genomics Jun 2023Introgression of disease resistance genes (R-genes) to fight against an array of phytopathogens takes several years using conventional breeding approaches. Pathogens... (Review)
Review
Introgression of disease resistance genes (R-genes) to fight against an array of phytopathogens takes several years using conventional breeding approaches. Pathogens develop mechanism(s) to escape plants immune system by evolving new strains/races, thus making them susceptible to disease. Conversely, disruption of host susceptibility factors (or S-genes) provides opportunities for resistance breeding in crops. S-genes are often exploited by phytopathogens to promote their growth and infection. Therefore, identification and targeting of disease susceptibility genes (S-genes) are gaining more attention for the acquisition of resistance in plants. Genome engineering of S-genes results in targeted, transgene-free gene modification through CRISPR-Cas-mediated technology and has been reported in several agriculturally important crops. In this review, we discuss the defense mechanism in plants against phytopathogens, tug of war between R-genes and S-genes, in silico techniques for identification of host-target (S-) genes and pathogen effector molecule(s), CRISPR-Cas-mediated S-gene engineering, its applications, challenges, and future prospects.
Topics: Plant Diseases; Genome, Plant; Crops, Agricultural; Plants, Genetically Modified; CRISPR-Cas Systems; Plant Breeding
PubMed: 37338599
DOI: 10.1007/s10142-023-01133-w -
Advances in Experimental Medicine and... 2016Salmonella enterica serovar Typhi (S. Typhi) is the cause of typhoid fever, a life-threatening bacterial infection that is very common in the developing world. Recent... (Review)
Review
Salmonella enterica serovar Typhi (S. Typhi) is the cause of typhoid fever, a life-threatening bacterial infection that is very common in the developing world. Recent spread of antimicrobial resistant isolates of S. Typhi makes typhoid fever, a global public health risk. Despite being a common disease, still very little is known about the molecular mechanisms underlying typhoid fever and S. Typhi pathogenesis. In contrast to other Salmonellae, S. Typhi can only infect humans. The molecular bases of this human restriction are mostly unknown. Recent studies identified a novel pathway that contributes to S. Typhi human restriction and is required for killing S. Typhi in macrophages of nonsusceptible species. The small Rab GTPase Rab32 and its guanine nucleotide exchange factor BLOC-3 are the critical components of this pathway. These proteins were already well known as important regulators of intracellular membrane transport. In particular, they are central for the transport of enzymes that synthetize melanin in pigment cells. The recent findings that Rab32 and BLOC-3 are required for S. Typhi host restriction point out to a novel mechanism restricting the growth of bacterial pathogen, dependent on the transport of still unknown molecule(s) to the S. Typhi vacuole. The identification of this novel antimicrobial pathway constitutes a critical starting point to study molecular mechanisms killing bacterial pathogens and possibly identify novel antimicrobial molecules.
Topics: Animals; Guanine Nucleotide Exchange Factors; Host-Pathogen Interactions; Humans; Macrophages; Salmonella typhi; Signal Transduction; Typhoid Fever; Vacuoles; Virulence; rab GTP-Binding Proteins
PubMed: 27193549
DOI: 10.1007/978-3-319-32189-9_17