Molecular Level Analysis Research Articles

Exploration of Methylmercury Adsorption on Montmorillonite Surfaces Through Density Functional Theory

To propel the development of a robust methylmercury immobilisation technology, CH3Hg+ adsorption on montmorillonite surfaces was simulated herein using density functional theory. This study involved a thorough molecular-level analysis, including factors such as electron potential energy, molecular orbital configurations, stable adsorption configurations, adsorption energies, charge distributions, and density of states. The principal findings are summarised as follows: (1) CH3Hg+ adsorption on the (001) surface was characterised by an adsorption energy ranging from −27 to −51.7 kJ/mol. In this case, Hg was attracted to the involved silicon–oxygen ring cavities. Meanwhile, on the (010) surface, CH3Hg+ exhibited an adsorption energy ranging between −119.4 and −154.3 kJ/mol. In this case, Hg was attracted to hydroxyl groups such as ≡Al(OH)(OH2) and ≡Si(OH), forming a covalent bond with the oxygen atom of these groups. (2) Comparative analysis revealed that the adsorption energy of CH3Hg+ on the (010) surface surpassed that on the (001) surface. On the (001) surface, electrostatic interactions were the predominant factor influencing adsorption, while on the (010) surface, electrostatic and covalent bonding interactions were important. Notably, the strength of electrostatic interactions was greater on the (001) surface than on the (010) surface. (3) The formation of covalent bonds between CH3Hg+ and the (010) surface was primarily attributed to the overlap of electron cloud between Hg and surface O atoms. In particular, the interaction between the s orbital of Hg and the p orbital of O facilitated the formation of a σ bond. Overall, these findings provide a theoretical framework for the advancement of efficient in situ immobilisation technologies for methylmercury.

The Utilization of Dissolved Organic Matter Spectral and Molecular Properties in Freshwater Eutrophication Studies: A Mini Review

Eutrophication is a major environmental issue affecting freshwater ecosystems worldwide. While its impact on the composition of dissolved organic matter (DOM) is well recognized, the relationships between DOM’s optical and molecular properties across eutrophication gradients remain underexplored. This review synthesizes recent research on DOM’s optical properties (derived from UV-Vis absorption and fluorescence spectroscopy) and molecular characteristics (analyzed using Fourier-transform ion cyclotron resonance mass spectrometry, FT-ICR MS) in freshwater systems of varying trophic states. Generalized additive model (GAM) analysis was used to assess correlations between DOM’s properties and the trophic state index (TSI). The dissolved organic carbon (DOC), a254, SUVA254, SR, HIX, BIX, and FI averaged 11.44 ± 11.97 mg/L, 23.23 ± 16.95 m−1. 2.98 ± 0.99 L·mg−1·m−1, 1.42 ± 0.38, 2.38 ± 1.31, 1.08 ± 0.16, and 2.11 ± 0.44, respectively, from mesotrophic to middle-eutrophic sites. The GAM results revealed a significant linear correlation between DOC and DOM’s optical properties, including a254, SUVA254, and FI, with the TSI, suggesting that DOM accumulation intensifies with eutrophication. DOM’s molecular properties, such as O/C and H/C ratios, double bond equivalents (DBEs), and CHOS% content, exhibited nonlinear correlations with the TSI. These trends imply a shift in DOM sources from terrestrial and macrophyte-derived inputs to those dominated by algal- and sediment-derived sources as eutrophication progresses. We concluded that DOM’s molecular indices alone may not serve as a reliable indicator of freshwater trophic states; future studies should focus on integrating both optical and molecular indices to offer a more comprehensive assessment of freshwater trophic states. Given the limited number of molecular variables examined in this study, this work only offers a preliminary investigation into the relationship between DOM molecular changes and freshwater eutrophication. More systematic studies focusing on the molecular-level analyses of DOM across varying trophic states on a broader geographic scale are needed.

Response and roles of algal organic matter under copper stress: Spectral and mass spectrometry analysis.

Eutrophication leads to various environmental issues, including pollution caused by the production of algal organic matter (AOM). Algae typically respond to environmental changes (e.g., light, temperature, copper [Cu(II)] concentration and pH) by regulating the production and release of different substances, thereby causing unpredictable effects on water quality. We explored the characteristics of AOM and the response mechanisms of algae under Cu(II) stress in the study, using fluorescence spectrum and high-resolution mass spectrometry (HRMS) analysis. The growth of Microcystis aeruginosa was inhibited under Cu(II) stress which was irreversible at Cu(II) concentration≥2μmol/L. Tryptophan- and humic-like fluorophores were important constituents of extracellular organic matter (EOM), and their contents increased with the addition of Cu(II), indicating that Cu(II) stimulates the production of tryptophan- and humic-like compounds. In addition, fulvic acid-like compounds in EOM were the main components binding to Cu(II) and were overproduced by algae under Cu(II) stress. It was found by HRMS at the molecular level that the formula numbers of EOM generally increased over inhibition time. Under 1μmol/L Cu(II) stress, nitrogenous compounds (CHON formulae) were the primary AOM, accounting for 37.3-52.0%. In addition, algae release a large amount of condensed aromatic structures to balance Cu(II) stress. This study provides a molecular-level analysis to explain the variation trends and response mechanisms of algae under various Cu(II) concentrations. The research methods are helpful for utilizing multiple advanced analysis methods to study algae growth and AOM release.

Molecular-Level Insights into Recalcitrant Ozonation Products from Effluent Organic Matter.

Wastewater ozonation is commonly employed to enhance the subsequent biodegradation of effluent organic matter (EfOM) and contaminants of concern. However, there is evidence suggesting the formation of recalcitrant ozonation products (OPs) from EfOM. To investigate the biodegradability of OPs we conducted batch biodegradation experiments using wastewater effluent ozonated with mass-labeled (18O) ozone. Molecular level analysis of EfOM was performed using reversed-phase liquid chromatography coupled with Fourier transform ion cyclotron resonance mass spectrometry (LC-FT-ICR MS) after 3 and 28 days in batch bioreactors. The use of mass labeling allowed for the unambiguous detection of OPs, with 2933 labeled OP features identified in the ozonated EfOM. Furthermore, employing polarity separation with LC facilitated the investigation of reactivity among different OP isomers. Overall, OPs exhibited a comparable proportion of recalcitrant and bioproduced molecular formulas when compared to the remaining EfOM, with 12% of OPs classified as recalcitrant and 17% bioproduced, indicating that OPs themselves are not inherently biodegradable. Additionally, recalcitrant OPs were found to be more polar based on the O/C ratios and retention time, in comparison to biodegradable OPs. Approximately one-third of the OP isomers displayed variations in their biodegradability, suggesting that studying the degradability of ozonated EfOM at the molecular formula level is heavily influenced by structural differences. Here, we offer unique insight into the biological transformation of EfOM after ozonation using labeled ozone and LC-FT-ICR MS analysis.

Comparative Analysis of Ca2+/Cation Antiporter Gene Family in Rosa roxburghii and Enhanced Calcium Stress Tolerance via Heterologous Expression of RrCAX1a in Tobacco.

Rosa roxburghii, a calciphilic species native to the mountainous regions of Southwest China, is renowned for its high vitamin C and bioactive components, making it valuable for culinary and medicinal uses. This species exhibits remarkable tolerance to the high-calcium conditions typical of karst terrains. However, the underlying mechanisms of this calcium resilience remain unclear. The Ca2+/cation antiporter (CaCA) superfamily plays a vital role in the transport of Ca2+ and other cations and is crucial for plant tolerance to metal stress. However, the roles and evolutionary significance of the CaCA superfamily members in R. roxburghii remain poorly understood. This study identified 22 CaCA superfamily genes in R. roxburghii, categorized into four subfamilies. The gene structures of these RrCaCAs show considerable conservation across related species. Selection pressure analysis revealed that all RrCaCAs are subject to purifying selection. The promoter regions of these genes contain numerous hormone-responsive and stress-related elements. qRT-PCR analyses demonstrated that H+/cation exchanger (CAX) RrCAX1a and RrCAX3a were highly responsive to Ca2+ stress, cation/Ca2+ exchanger (CCX) RrCCX4 to Mg2+ stress, and RrCCX11a to Na+ stress. Subcellular localization indicated that RrCAX1a is localized to the plant cell membrane, and its stable transformation in tobacco confirmed its ability to confer enhanced resistance to heavy Ca2+ stresses, highlighting its crucial role in the high-calcium tolerance mechanisms of R. roxburghii. This research establishes a foundation for further molecular-level functional analyses of the adaptation mechanisms of R. roxburghii to high-calcium environments.

Chemodiversity and Molecular Mechanism Between Per-/Polyfluoroalkyl Substance Complexation Behavior of Humic Substances in Landfill Leachate

Landfill leachate contains a range of organic and inorganic pollutants, including per-/polyfluoroalkyl substances (PFASs), which can infiltrate into surrounding soil and groundwater through leaching processes, and can pose a threat to human health via food chains and drinking water processes. Thus, the transport of PFASs in landfill leachate is a research hotspot in environmental science. This study investigates the complexation and adsorption mechanisms between humic substances and PFASs in landfill leachate at the molecular level. Experimental results demonstrate that the binding constant logKsv of humic substances with PFASs correlates positively with specific ultraviolet absorbance (SUVA254), absorbance ratio (A250/A365), humification index (HIX), and fluorescence index (FI), while it exhibits a negative correlation with the biological index (BIX). These findings indicate that high aromaticity is a prerequisite for molecular interactions between humic substances and PFASs, with polar functional groups further facilitating the interaction. Molecular-level analysis revealed that humic substances undergo complexation and adsorption with PFASs through hydrophobic interactions, van der Waals forces, hydrogen bonding, ionic bonding, and covalent bonding, by functional groups such as hydroxyl, aliphatic C-H bonds, aromatic C=C double bonds, amides, quinones, and ketones. Future efforts should focus on enhanced co-regulation and mitigation strategies addressing the combined pollution of PFASs and humic substances in landfill leachate.

ORG-317 Repurposing as a Potential Agonist Targeting TMEM236 in Colorectal Cancer Treatment: Insights from Molecular Dynamics Simulation, Principal Component Analysis, and Free Energy Landscape Study.

<p> Background and objective: Colorectal Cancer (CRC) affects the colon and rectum part of the digestive system and is a significant global health concern, with approximately 1.1 million new cases annually. It ranks second in cancer-related deaths. Studies have shown future projections of CRC cases to enhance at a worrisome rate, estimating 3.2 million new cases and 1.6 million deaths worldwide by 2040. Studies have shown the downregulation of TMEM236 in CRC, and this study aimed to find the agonist to restore the function of TMEM236 via the drug repurposing method. </p><p> Methods: The different molecular and structural level analyses were performed to understand how the TMEM236 expression can be restored. To obtain the molecular level data, the following analyses were employed to understand the binding affinity and agonistic behaviour of the screened drugs: molecular docking, oral toxicity prediction, Molecular Dynamics (MD) simulation, Free Energy Landscape (FEL) analysis, and g_mmpbsa. </p><p> Results: The molecular docking, oral toxicity, and molecular interaction analyses have identified db06435, db05423, and db15197 drugs from the DrugBank database to either belong to an approved or investigational class of drugs as a potential agonist for TMEM236. The MD simulation and PCA analysis had shown db05423 (ORG-317) to exhibit stable interaction with TMEM236 protein. Similar results were obtained through FEL analysis. </p><p> Conclusion: The downregulation of TMEM236 expression and its constant binding affinity with db05423 during MD simulation suggest that this drug may restore the diminished function and expression of TMEM236. Additionally, it could function as an agonist and can be used for CRC treatment.</p>.

Accumulation of beneficial haplotypes in Huang-Huai-Hai wheat region and its application in molecular breeding

The Huang-Huai-Hai wheat region (HHHR) is characterized by the largest cultivation area and yield among all the major wheat-producing regions in China. Over the past 70 years, significant advances in wheat breeding have been achieved in this region, resulting in high and stable yields as well as improved disease resistance. However, there is a notable deficiency in the systematic molecular-level analyses of wheat breeding advantages in HHHR. To bridge this gap, we used a Wheat 55K SNP array to evaluate 384 accessions from a core collection of wheat germplasms across China to systematically analyze the distribution patterns of beneficial haplotypes associated with traits related to yield and powdery mildew resistance specific to HHHR. Our findings indicate that varieties from HHHR demonstrate significantly superior performance in terms of yield-related traits and powdery mildew resistance compared to those from other wheat regions. Using genome-wide association studies (GWAS) analysis, we identified the QTNs associated with both grain yield and powdery mildew resistance. Importantly, beneficial haplotypes were found at significantly higher frequencies in the HHHR than in other wheat-growing regions. Based on these haplotypes, the MFP-a gene was identified as potentially regulating jasmonic acid synthesis while also playing a role in grain development and conferring powdery mildew resistance. Furthermore, identity by descent (IBD) analysis revealed specific conserved genomic segments that have become fixed through selective breeding practices in HHHR, which may serve as invaluable resources for the targeted enhancement of yield and disease resistance traits in other wheat-growing areas. Finally, using the Aimengniu breeding lineage as a case study, we elucidated the genetic basis underlying the key founder parental formations utilized in breeding programs. This study not only provides essential references and guidance for future molecular breeding initiatives in China but also has implications for enhancing wheat production worldwide.

Molecular-level analysis of alkyl chain dependent voltage-induced microfluidic alcohol droplet actuation on Teflon/Pt/glass substrate: Revealing the unconventional directional movement

Current study investigates the voltage-induced actuation of alcohol droplets on a Teflon/Pt/Glass substrate, emphasizing the influence of alkyl chain length on microfluidic droplet behavior. The wetting and electrowetting properties of different alcohols with increasing carbon chain length, namely, methanol, ethanol, 1-propanol, and 1-butanol, are examined by using both experimental techniques and the simulations of classical molecular dynamics (MD). An increase in the wetting nature of these alcohol droplets is observed with the increase in carbon chain length. A greater penetration into the Teflon surface is observed for alcohols with longer alkyl chain lengths from MD simulations. The evaporative nature of alcohol droplets and the consequent effect of evaporation on wetting are also examined. Voltage-modified change in contact angle, droplet displacement or spreading, and voltage-induced work of spreading, are investigated to study the actuation of such alcohol droplets. A unique, voltage-triggered directional displacement/spreading of the droplets towards ground electrode is observed, in contrast to the conventional electrowetting behavior. These insights underscore the influence of molecular interactions in voltage-actuated droplet dynamics, having significant implications as a design parameter in the development of digital microfluidics-based lab-on-a-chip devices.

Molecular level analysis of the influence of natural biomaterials on aviation flame retardant performance

The use of natural biomaterials in flame retardant formulations as sustainable alternatives has gained significant interest in recent years. Given the high-risk environment in which airplanes operate, aviation safety remains a top priority. Flame retardants (FRs) are crucial for preventing or reducing the spread of flames in flammable materials used in aircraft construction and interior furnishings, thus mitigating fire risks. This study aims to analyze the molecular-level influence of natural biomaterials on aviation flame retardant performance, with a focus on lignin. Lignin, a natural polymer derived from plant cell walls, offers an environmentally friendly alternative to conventional synthetic flame retardants. Lignin-based composites can be applied to various aircraft components, such as wings and fuselage. The study employs Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Nuclear Magnetic Resonance (NMR) to investigate the molecular interactions of these biomaterials. Additionally, to assess thermal stability and degradation, Thermo-gravimetric Analysis (TGA) is utilized. The results indicate that lignin enhances flame retardancy by promoting the formation of a protective char layer and improving thermal stability. This research also provides insights into the molecular mechanisms underlying lignin’s effectiveness as a flame retardant and explores its potential in developing high-performance aircraft flame retardants.

Fast thermo-osmotic flow through covalent organic framework multilayers for desalination

Thermo-osmosis, a liquid flow driven by temperature difference (∆T) in a solid-liquid interface, is promising to utilize low-grade heat energies for water desalination. However, the water flux of thermo-osmosis is hard to be enhanced. Herein, the potential of COF multilayers for thermo-osmotic desalination is investigated via non-equilibrium molecular dynamics (NEMD) simulations. To this end, TpMA multilayers with fine water stability and sub-nanometer pores are selected. The TpMA multilayers show excellent water flux and nearly 100 % NaCl rejections. By the analysis of interfacial and interior resistances, it is extrapolated that the TpMA nanosheet with a thickness of 200 nm has a water flux of 3096 L/(m2·h) at the ∆T of 60 K. By the molecular-level analysis, it is revealed that the coexistence of single-file and two-chains of water structure in the flow direction brings in high thermo-osmotic flows. The high NaCl rejection is due to the strong sieving effect of pores on the hydration of Cl−. Finally, the thermo-osmosis is compared with reverse osmosis. Based on the resistance analysis, it is found that the ∆T of 60 K is equivalent to the ∆P of 180 bar at most to reach the same water flux. These findings will inspire researchers with an alternative technology for high-efficiency desalination using low-grade heat energies.

Molecular-Level Analysis of Oxygen and Asphalt Behavior on Aggregate Surfaces

Molecular-Level Analysis of Oxygen and Asphalt Behavior on Aggregate Surfaces

Characterisation of dissolved organic matter in two contrasting arsenic-prone sites in Kandal Province, Cambodia

Aquifers throughout Asia are impacted by the release of geogenic arsenic (As) into groundwater by microbial reduction of As-bearing Fe(III) (oxy)hydroxide minerals, severely impacting water quality. Groundwater dissolved organic matter (DOM) is likely key to As release, mainly as electron donor or electron shuttles. This study used optical analyses and ultra-high resolution mass spectrometry to examine the sources and composition of groundwater DOM in the As-prone aquifers of Kandal Province, Cambodia, at boreholes with differing host lithology (clay- and sand-dominated). Groundwater and surface water DOM composition were related to As concentrations, to infer the potential role of DOM in promoting As release. Optical and molecular-level analyses indicated an overall dominance of terrestrial-derived DOM in the groundwater samples, with higher freshness index and relative abundance (RA) of aliphatic compounds in clay compared to sand-dominated lithology. Compared to surface water, groundwater DOM had relatively lower O/C ratios and nominal oxidation state of carbon (−0.19 to −0.13 compared to 0.04 for ground and surface water, respectively), with a lower %RA of aliphatic compounds and higher %RA of carboxyl-rich alicyclic molecules, suggesting microbial processing of DOM since percolation into the aquifer. Concentrations of As across both sites were negatively correlated with DOM tryptophan:fulvic-like fluorescence and the %RA of aliphatics, potentially indicating microbial degradation of biolabile DOM in connection with As release, which is consistent with its role as an electron donor source. Together these data support DOM composition as an important control on microbial mediated As release.

Molecular Insights of 5-Hydroxymethylfurfural in a Mixture of Ionic Liquids and Alkylated Phenolic Solvents.

This paper presents all-atom molecular dynamics to understand the separation behavior of 5-hydroxymethylfurfural (5-HMF) from 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]+[BF4]- using alkylated phenols as extractants. We have utilized four solvents such as 4-methyl phenol (4-MP), 4-ethyl phenol (4-EP), 4-propyl phenol (4-PP), and 4-butyl phenol (4-BP). We perform structural, dynamic, and rigorous thermodynamic analyses of 5-HMF in the mixture of ILs and solvents. The [BMIM]+[BF4]- show a strong interaction with phenols. The self-diffusion coefficient of 5-HMF shows a 3-fold increase with a decrease in the methyl group on the phenol. The solvation-free energy (ΔGsolvation) of 5-HMF shows favorably in phenols. On the other hand, the transfer free energy (ΔGtransfer) of 5-HMF presents favorable from ILs to phenols. The partition coefficient (log P) values show favorability for separation of 5-HMF using phenols. Overall, the molecular level analysis provides the role of the alkyl group effect on the phenols for extracting 5-HMF from the ILs.

Regulatory Role of IL6 in Immune-Related Adverse Events during Checkpoint Inhibitor Treatment in Melanoma

The landscape of clinical management for metastatic melanoma (MM) and other solid tumors has been modernized by the advent of immune checkpoint inhibitors (ICI), including programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors. While these agents demonstrate efficacy in suppressing tumor growth, they also lead to immune-related adverse events (irAEs), resulting in the exacerbation of autoimmune diseases such as rheumatoid arthritis (RA), ulcerative colitis (UC), and Crohn’s disease (CD). The immune checkpoint inhibitors offer promising advancements in the treatment of melanoma and other cancers, but they also present significant challenges related to irAEs and autoimmune diseases. Ongoing research is crucial to better understand these challenges and develop strategies for mitigating adverse effects while maximizing therapeutic benefits. In this manuscript, we addressed this challenge using network-based approaches by constructing and analyzing the molecular and signaling networks associated with tumor-immune crosstalk. Our analysis revealed that IL6 is the key regulator responsible for irAEs during ICI therapies. Furthermore, we conducted an integrative network and molecular-level analysis, including virtual screening, of drug libraries, such as the Collection of Open Natural Products (COCONUT) and the Zinc15 FDA-approved library, to identify potential IL6 inhibitors. Subsequently, the compound amprenavir was identified as the best molecule that may disrupt essential interactions between IL6 and IL6R, which are responsible for initiating the signaling cascades underlying irAEs in ICI therapies.

The NAC activator, MdNAC77L, regulates anthocyanin accumulation in red flesh apple

Anthocyanin is widely acknowledged as a crucial component contributing to apple fruit quality. However, research on the influence of NAC transcription factors on anthocyanin accumulation in red flesh apple is limited. In this study, a NAC transcription factor MdNAC77L was identified as highly related to the change of anthocyanin content, based on a combined anthocyanin metabolome and transcriptome analysis. Overexpression of MdNAC77L significantly increased the accumulation of anthocyanin in both apple and strawberry fruits, along with the expression of several anthocyanin-related enzymes. Molecular-level analyses demonstrated that MdNAC77L was directly combined with the promoters of three pivotal enzymes (dihydroflavonol 4-reductase, anthocyanin synthase, and UDP-flavonoid glucosyltransferase) of anthocyanin biosynthetic pathway. We found that ABA strongly induced the expression of MdNAC77L, which activated the expression of three downstream target genes. In addition, MdNAC77L showed higher transcript accumulation in flesh with lower anthocyanin content than that in red peel. We revealed the new core factor, MdNAC77L, involved in anthocyanin accumulation in apple red flesh. This research provides a fresh perspective on the intricate regulatory mechanisms governing anthocyanin biosynthesis in red-fleshed apples.

Probing the inner structure and dynamics of pH-sensitive block copolymer nanoparticles with nitroxide radicals using scattering and EPR techniques

This research emphasizes the crucial role of electron paramagnetic resonance (EPR) spectroscopy in nanoparticle analysis, showcasing its distinctive ability to probe molecular-level details. We demonstrate the synthesis and self-assembly of a new class of pH-responsive amphiphilic diblock copolymers, specifically poly[N-(2-hydroxypropyl)-methacrylamide]-block-poly[2-(diisopropylamino)ethyl methacrylate] (PHPMA-b-PDPA), incorporating 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radicals covalently bound to the hydrophilic PHPMA segment. The copolymer synthesis involved a three-step process, combining reversible addition − fragmentation chain transfer (RAFT) polymerization with carbodiimide (DCC) chemistry. TEMPO radical-containing nanoparticles (RNPs) were created using microfluidic (MF) nanoprecipitation, a technique essential for generating uniform nanoparticles with predictable biodistribution and cellular uptake. Adjusting MF protocol parameters allowed fine-tuning of RNP sizes. EPR spectroscopy confirmed the formation of core–shell RNPs, with features aligning closely with those obtained from scattering techniques like dynamic light scattering (DLS), static light scattering (SLS), small-angle X-ray scattering (SAXS), and cryo-transmission electron microscopy (cryo-TEM). EPR spectroscopy emerges as a potent tool for molecular-level analysis of colloidal polymer systems. This study highlights the EPR-spin label method’s efficacy in probing the internal structural features and dynamics of core–shell nanoparticles, especially their response to pH-triggered disassembly. The findings open new avenues for the use of pH-responsive TEMPO-labeled diblock copolymers in controlled drug delivery applications.

Tracking suspended particulate organic matter biochemistry from glacial meltwater runoff to coastal waters of an Antarctic fjord

Increased glacier melting runoff in Antarctica involves intensification of freshwater, nutrients, sediments and organic matter inputs from land to the sea, which is impacting coastal ecosystems. Basic environmental characteristics of water and biochemical composition of suspended particulate organic matter (POM) both in the proglacial melting runoff system (PROGLARS) of Collins Glacier and marine surface waters of Collins Bay was studied based on organic biopolymers and molecular level analysis of amino acids (AAs), to discern among sources and degradation state in the two environments. Hierarchical Clustering Analysis revealed that PROGLARS stations and marine stations form two distinct groups in terms of water physicochemical characteristics and suspended POM biochemical composition. These differences are the consequence of low restricted contribution of freshwater from Collins Glacier runoff into the coastal-marine environment. Our results evidenced low concentrations of terrestrial suspended POM in marine waters of Collins Bay mainly attributed to low meltwater inputs between the 1st and 7th of February 2018. In terms of macromolecular composition, the predominance of proteins, denote the labile nature of suspended POM in the two environments. Suspended POM in Collins Bay is labile, poorly degraded, representing a protein supplemented food resource, with high energetic value and easily assimilated by heterotrophic marine organism. AAs composition supported less degraded suspended POM derived from marine phytoplankton in surface waters of Collins Bay, whereas, great degradation of suspended POM in the proglacial runoff system of Collins Glacier. Changes in the biochemistry of suspended POM caused by glacial melting and retreat, may affect food features and availability, the productivity of ecosystems, and ultimately, the capacity of Antarctic fjords to act as carbon sinks and climate regulators. Considering low influence of Collins Glacier meltwater in coastal marine waters of Collins Bay, due to the relatively slow retreat of Collins Glacier and low development of its meltwater runoff system, the results of our work are relevant as baseline information for comparison with other Antarctic fjords. Further knowledge about meltwater runoff and suspended POM input dynamics in Antarctic coastal ecosystems, is critical, particularly in areas prone to undergo increased glacier melting in the following decades.

Identification of novel anti-leishmanials targeting glutathione synthetase of the parasite: a drug repurposing approach.

Drug repurposing has emerged as an effective strategy against infectious diseases such as visceral leishmaniasis. Here, we evaluated four FDA-approved drugs-valrubicin, ciclesonide, deflazacort, and telithromycin-for their anti-leishmanial activity on Leishmania donovani parasites, especially their ability to target the enzyme glutathione synthetase (LdGS), which enables parasite survival under oxidative stress in host macrophages. Valrubicin and ciclesonide exhibited superior inhibitory effects compared to deflazacort and telithromycin, inhibiting the promastigotes at very low concentrations, with IC50 values of 1.09 ± 0.09 μm and 2.09 ± 0.09 μm, respectively. Subsequent testing on amastigotes revealed the IC50 values of 1.74 ± 0.05 μm and 3.32 ± 0.21 μm for valrubicin and ciclesonide, respectively. Molecular and cellular level analysis further elucidated the mechanisms underlying the anti-leishmanial activity of valrubicin and ciclesonide.

Molecular and cellular level analysis of the mechanism of nutritional intervention in preventing epidemic virus infection

Molecular nutrition encompasses a wider range of investigations than nutritional genomics, which can be considered a scientific investigation of how different nutrients and dietary components influence the cellular and molecular mechanisms of the body and health. In effect, increasing antioxidant elements in daily diets can assist with combating the inflammatory response caused by cytokines in the human body. Antioxidants can impede the oxidation process and hence avoid the creation of free radicals in the cytoplasm that can damage the cells via chain reactions. Contamination sequences, batch effects, uneven sampling, unreported taxa, technological biases, and heteroscedasticity are all significant issues in molecular microbial biology. Artificial Intelligence (AI) methodologies to uncover hidden patterns, connections, and interactions within metabolomics data, allowing them to provide personalized food recommendations based on individual health profiles. A multi-scale convolutional neural network (MCNN) classifies cellular images into phenotypes in a single coherent step utilizing the image’s pixel intensity values. Hence, the proposed AI-MCNN has been an essential nutrient that assists the immune system in various ways, including acting as an antioxidant to protect healthy cells, promoting immune cell development and function, and creating antibodies. According to epidemiological research, people who are undernourished are more likely to get bacterial, viral, and other diseases. Nutritional epidemiology investigates dietary or nutritional parameters concerning illness prevalence in communities. Nutritional epidemiology results often add to the evidence that provides dietary recommendations for preventing disease and related disorders.