Ion pairing in aqueous tetramethylammonium-acetate solutions by neutron scattering and molecular dynamics simulations.

Tetramethylammonium (TMA) is a ubiquitous cationic motif in biochemistry, found in the charged choline headgroup of membrane phospholipids and in tri-methylated lysine residues, which modulates histone-DNA interactions and impacts epigenetic mechanisms. TMA interactions with anionic species, particularly carboxylate groups of amino acid residues and extracellular sugars, are of substantial biological relevance, as these interactions mediate a wide range of cellular processes. This study investigates the molecular interactions between TMA and acetate, representing carboxylate-containing groups, using neutron scattering experiments complemented by force fields and molecular dynamics (MD) simulations.

Fluid flow and amyloid transport and aggregation in the brain interstitial space.

The driving mechanisms at the base of the clearance of biological wastes in the brain interstitial space (ISS) are still poorly understood and an actively debated subject. A complete comprehension of the processes that lead to the aggregation of amyloid proteins in such environment, hallmark of the onset and progression of Alzheimer's disease, is of crucial relevance. Here we employ combined computational fluid dynamics and molecular dynamics techniques to uncover the role of fluid flow and proteins transport in the brain ISS.

Binding mechanism of oligopeptides on solid surface: assessing the significance of single-molecule approach.

This paper addresses the complementarity and potential disparities between single-molecule and ensemble-average approaches to probe the binding mechanism of oligopeptides on inorganic solids. Specifically, we explore the peptide/gold interface owing to its significance in various topics and its suitability to perform experiments both in model and real conditions. Experimental results show that the studied peptide adopts a lying configuration upon adsorption on the gold surface and interacts through its peptidic links and deprotonated thiolate extremities, in agreement with theoretical predictions.

Mechanical induction in metazoan development and evolution: from earliest multi-cellular organisms to modern animal embryos.

The development and origin of animal body forms have long been intensely explored, from the analysis of morphological traits during antiquity to Newtonian mechanical conceptions of morphogenesis. Advent of molecular biology then focused most interests on the biochemical patterning and genetic regulation of embryonic development. Today, a view is arising of development of multicellular living forms as a phenomenon emerging from non-hierarchical, reciprocal mechanical and mechanotransductive interactions between biochemical patterning and biomechanical morphogenesis.

Impact of Fetal Umbilical Cord Blood CD34+ Cells on Breast Cancer Cell Lines: A Mechanism of Fetal Microchimerism.

Introduction: Fetal microchimerism could be involved in the regulation of breast cancer oncogenesis. CD34+ cells could be of a particular interest as up to 12% of the CD34+ population in maternal blood are of fetal origin. The aim of this research was to analyze the impact of umbilical cord blood (UCB) CD34+ on MCF-7 and MDA-MB-231 breast cancer cell lines, in order to uncover novel biological mechanisms and suggest novel treatment options for breast cancer.

Recent Advances in the Synthesis of Acyclic Nucleosides and Their Therapeutic Applications.

DNA is commonly known as the "molecule of life" because it holds the genetic instructions for all living organisms on Earth. The utilization of modified nucleosides holds the potential to transform the management of a wide range of human illnesses. Modified nucleosides and their role directly led to the 2023 Nobel prize.

Exploring the Corrosion Potential of Three Bio-Based Furan Derivatives on Mild Steel in Aqueous HCl Solution: An Experimental Inquiry Enhanced by Theoretical Analysis.

This research deals with the corrosion inhibition of mild steel in a highly corrosive aqueous HCl medium with a concentration of 0.5 M, using three different corrosion inhibitors: furan-2-carboxylic acid (), furan-2,5-dicarboxylic acid (), and furan-2,5-diyldimethanol (). Various electrochemical tests, such as potentiodynamic polarization (PP or Tafel curve) and electrochemical impedance spectroscopy, were systematically performed.

Effect of Sinetrol Xpur on metabolic health and adiposity by interactions with gut microbiota: a randomized, open label, dose-response clinical trial.

Background: Sinetrol Xpur is a polyphenolic ingredient rich in citrus flavonoids that has shown weight loss effects in previous studies. The dose dependent nature, gut microbial actions of this product has not been explored previously, thus presented in this study.

Methods: In this open label study, we evaluated the effect of Sinetrol Xpur supplementation on healthy but overweight/obese adults (20-50 yrs) for 16 weeks.

Imino chemical shift assignments of tRNA, tRNA and tRNA from Escherichia coli.

Transfer RNAs (tRNAs) are an essential component of the protein synthesis machinery. In order to accomplish their cellular functions, tRNAs go through a highly controlled biogenesis process leading to the production of correctly folded tRNAs. tRNAs in solution adopt the characteristic L-shape form, a stable tertiary conformation imperative for the cellular stability of tRNAs, their thermotolerance, their interaction with protein and RNA complexes and their activity in the translation process.

Structural Insight into Melatonin's Influence on the Conformation of Dimer Studied by Molecular Dynamics Simulation.

The accumulation of amyloid-beta () oligomers is recognized as a potential culprit in Alzheimer's disease (AD). Experimental studies show that melatonin, a hormone that mainly regulates circadian rhythm and sleep, can interact with peptides and disrupt the formation of oligomers. However, how melatonin inhibits the oligomerization of soluble is unclear.

Environment-Stored Memory in Active Nematics and Extra-Cellular Matrix Remodeling.

Many active systems display nematic order, while interacting with their environment. In this Letter, we show theoretically how environment-stored memory acts an effective external field that aligns active nematics. The coupling to the environment leads to substantial modifications of the known phase diagram and dynamics of active nematics, including nematic order at arbitrarily low densities and arrested domain coarsening.

MolPlay: Democratizing Interactive Molecular Simulations and Analyses with a Portable, Turnkey Platform.

Computer-based tools for visualizing and manipulating molecular structures in real-time hold immense potential for accelerating research and improving education, but are only used to a limited extent. This paper explores the possibilities of these powerful techniques and presents a classification of common interactive modeling tasks, such as assembly, deformation, sampling of rare events, along with relevant use cases, especially for the study of membranes and membrane proteins. I introduce MolPlay─a platform that provides a ready-to-use software environment with a curated set of hands-on examples to democratize access to interactive molecular simulations and analyses (IMSA).

P-Collabs: Investigating Counterion-Mediated Bridges in the Multiply Phosphorylated Tau-R2 Repeat.

Tau is an intrinsically disordered (IDP) microtubule-associated protein (MAP) that plays a key part in microtubule assembly and organization. The function of tau can be regulated by multiple phosphorylation sites. These post-translational modifications are known to decrease the binding affinity of tau for microtubules, and abnormal tau phosphorylation patterns are involved in Alzheimer's disease.

Exploring High-Spin Color Centers in Wide Band Gap Semiconductors SiC: A Comprehensive Magnetic Resonance Investigation (EPR and ENDOR Analysis).

High-spin defects (color centers) in wide-gap semiconductors are considered as a basis for the implementation of quantum technologies due to the unique combination of their spin, optical, charge, and coherent properties. A silicon carbide (SiC) crystal can act as a matrix for a wide variety of optically active vacancy-type defects, which manifest themselves as single-photon sources or spin qubits. Among the defects, the nitrogen-vacancy centers () are of particular importance.

The stromal side of the cytochrome b6f complex regulates state transitions.

In oxygenic photosynthesis, state transitions distribute light energy between PSI and PSII. This regulation involves reduction of the plastoquinone pool, activation of the state transitions 7 (STT7) protein kinase by the cytochrome (cyt) b6f complex, and phosphorylation and migration of light harvesting complexes II (LHCII). In this study, we show that in Chlamydomonas reinhardtii, the C-terminus of the cyt b6 subunit PetB acts on phosphorylation of STT7 and state transitions.

Intraprostatic hormone dosage: Validation of a novel prostate biopsy technique.

Background: Advances in chromatography and mass spectrometry have allowed us to develop a novel technique for measuring intraprostatic hormone concentrations directly on prostate needle biopsies, rather than using traditional punch excision. This has significant clinical implications as intraprostatic dihydrotestosterone and testosterone levels could help monitor prostate growth, neoplasia and castration resistance.

Methods: Patients undergoing radical cystoprostatectomy for bladder cancer were prospectively included.

Molecular Origin of Distinct Hydration Dynamics in Double Helical DNA and RNA Sequences.

Water molecules are essential to determine the structure of nucleic acids and mediate their interactions with other biomolecules. Here, we characterize the hydration dynamics of analogous DNA and RNA double helices with unprecedented resolution and elucidate the molecular origin of their differences: first, the localization of the slowest hydration water molecules─in the minor groove in DNA, next to phosphates in RNA─and second, the markedly distinct hydration dynamics of the two phosphate oxygen atoms O and O in RNA. Using our Extended Jump Model for water reorientation, we assess the relative importance of previously proposed factors, including the local topography, water bridges, and the presence of ions.

Yeast cell responses and survival during periodic osmotic stress are controlled by glucose availability.

Natural environments of living organisms are often dynamic and multifactorial, with multiple parameters fluctuating over time. To better understand how cells respond to dynamically interacting factors, we quantified the effects of dual fluctuations of osmotic stress and glucose deprivation on yeast cells using microfluidics and time-lapse microscopy. Strikingly, we observed that cell proliferation, survival, and signaling depend on the phasing of the two periodic stresses.

[Pediatric aphereses (workshop SFGM-TC)].

Practice of pediatric aphereses - in particular when caring for low-weight children - differs from the practice of adult aphereses, since pediatric aphereses represent low numbers of procedures, which has practical implications in terms of practical training and retraining for involved healthcare personnel, as needed for habilitation and validation of ongoing competencies. A specific training is mandatory in order to ensure both the child and the staff safety during and after collection, as well as ensure high quality of the collected cell product and that its meets predefined specifications that depend on its intended use. Low and very low-weight children deserve a particular attention for a number of procedural and clinical aspects: the nature and quality of venous accesses to ensure proper operation of the cell separator, management of hemodynamic fluctuations in relation with the relative importance of the extracorporeal blood volume as compared to the total blood volume of the child, risks and clinical manifestations of citrate toxicity, minimization of stress during the procedure that may include but is not limited to pharmacological sedation.

Characterization of tryptophan oxidation affecting D1 degradation by FtsH in the photosystem II quality control of chloroplasts.

Photosynthesis is one of the most important reactions for sustaining our environment. Photosystem II (PSII) is the initial site of photosynthetic electron transfer by water oxidation. Light in excess, however, causes the simultaneous production of reactive oxygen species (ROS), leading to photo-oxidative damage in PSII.

Development of Photonic Multi-Sensing Systems Based on Molecular Gates Biorecognition and Plasmonic Sensors: The PHOTONGATE Project.

This paper presents the concept of a novel adaptable sensing solution currently being developed under the EU Commission-founded PHOTONGATE project. This concept will allow for the quantification of multiple analytes of the same or different nature (chemicals, metals, bacteria, etc.) in a single test with levels of sensitivity and selectivity at/or over those offered by current solutions.

Recent Computational Advances Regarding Amyloid-β and Tau Membrane Interactions in Alzheimer's Disease.

The interactions of amyloid proteins with membranes have been subject to many experimental and computational studies, as these interactions contribute in part to neurodegenerative diseases. In this review, we report on recent simulations that have focused on the adsorption and insertion modes of amyloid-β and tau proteins in membranes. The atomistic-resolution characterization of the conformational changes of these amyloid proteins upon lipid cell membrane and free lipid interactions is of interest to rationally design drugs targeting transient oligomers in Alzheimer's disease.