Binding of -[Ru(phen)(3,4Apy)] to Model Lipid Membranes: Implications for New Tools in the Development of Antiamyloid Drugs.

This study explores the interactions of the -[Ru(phen)(Apy)] complex (RuApy, phen = 1,10-phenanthroline, Apy = 3,4-aminopyridine) with model lipid membranes to explain the role this complex plays in mitigating Aβ toxicity in PC12 neuronal cells. Fluorescence quenching, surface pressure isotherms in Langmuir monolayers, and infrared reflection-absorption analyses revealed that the positively charged RuApy interacts with the phosphate headgroups of monolayers, indirectly affecting ester carbonyl groups through hydrogen bonding with the amino group of the pyridine ligand of RuApy. These results offer a scenario for the protective effect of RuApy against Aβ toxicity in neuronal cells in which these interactions shield the electrostatic interactions of Aβ with lipid membranes, preserving membrane integrity and mitigating the deleterious influence of Aβ.

Nanoarchitectonics and Simulation on the Molecular-Level Interactions between Sulfonic Acid Calix[4]arene and Langmuir Monolayers Representing Healthy and Cancerous Cell Membranes.

The design of chemotherapeutic drug carriers requires precise information on their interaction with the plasma membrane since the carriers should be internalized by cells without disrupting or compromising the overall integrity of the membrane. In this study, we employ Langmuir monolayers mimicking the outer leaflet of plasma membranes of healthy and cancerous cells to determine the molecular-level interactions with a water-soluble calixarene derivative, -sulfonic acid calix[4]arene (SCX4), which is promising as drug carrier. The cancer membrane models comprised either 40% 1,2-dipalmitoyl--glycero-3-phosphocholine (DPPC) or 1,2-dioleoyl--glycero-3-phosphocholine (DOPC), 30% cholesterol (Chol), 20% 1,2-dipalmitoyl--glycero-3-phosphoethanolamine (DPPE), and 10% 1,2-dipalmitoyl--glycero-3-phospho-l-serine (DPPS).

Introducing all-inkjet-printed microneedles for in-vivo biosensing.

Microneedles are mainly used for pain-free drug administration and in biosensing for wearable systems. They are also promising for fields such as agronomy for precision farming, but their fabrication is not straightforward, often requiring expensive equipment and cleanroom protocols, being unsuitable for mass production. Here, we report a new and simple method for the scalable fabrication of all-inkjet-printed conductive microneedles based on silver nanoparticles (extensible to any other metallic nanoparticle ink) and a simple example of their application for monitoring the electrochemical properties of plants.

Organic Sulfur Markers as Proxies of Depositional Paleoeenvironments Related to Recôncavo and Amazon Basins, Brazil.

This study employed organic sulfur markers (S-markers) associated with geochemistry parameters to evaluate the paleoenvironment of different depositional settings in 24 samples collected in vertical sections of outcrops of the Candeias and Barreirinha Formations in Recôncavo and Amazon basins, respectively. A total of twenty-one S-markers from benzothiophene (BT), dibenzothiophene (DBT), and benzonaphtothiophenes (BNT) classes were optimized and quantified by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). S-markers efficiently evaluated and differentiated the depositional paleoenvironment in the source rocks based on the individual compound, in cross-validation with saturated biomarkers, and associated with parameters such as total organic carbon (TOC) and Rock-Eval pyrolysis.

Enhanced performance of impedimetric immunosensors to detect SARS-CoV-2 with bare gold nanoparticles and graphene acetic acid.

Immunosensors based on electrical impedance spectroscopy allow for label-free, real-time detection of biologically relevant molecules and pathogens, without requiring electro-active materials. Here, we investigate the influence of bare gold nanoparticles (AuNPs), synthesized via laser ablation in solution, on the performance of an impedimetric immunosensor for detecting severe acute respiratory syndrome coronavirus (SARS-CoV-2). Graphene acetic acid (GAA) was used in the active layer for immobilizing anti-SARS-CoV-2 antibodies, owing to its high density of carboxylic groups.

Ultrathin nanocapacitor assembled via atomic layer deposition.

We fabricated ultrathin metal - oxide - semiconductor (MOS) nanocapacitors using atomic layer deposition. The capacitors consist of a bilayer of Al2O3 and Y2O3 with a total thickness of ~10 nm, deposited on silicon substrate. The presence of the two materials, each slab being ~5 nm thick and uniform over a large area, was confirmed with Transmission Electron Microscopy and X-ray photoelectron spectroscopy (XPS).

Mechanochromic Displays Based on Photoswitchable Cholesteric Liquid Crystal Elastomers.

Stimuli responsive optical materials are attractive for many areas, from healthcare to art design. However, creating intricate color-changing patterns for visual information is still a challenge. This work describes the preparation of mechanochromic structural colored intricate pictures imprinted in cholesteric liquid crystal elastomers by using a chiral isosorbide molecular photoswitch.

Analysis of Macronutrients in Soil Using Impedimetric Multisensor Arrays.

The need to increase food production to address the world population growth can only be fulfilled with precision agriculture strategies to increase crop yield with minimal expansion of the cultivated area. One example is site-specific fertilization based on accurate monitoring of soil nutrient levels, which can be made more cost-effective using sensors. This study developed an impedimetric multisensor array using ion-selective membranes to analyze soil samples enriched with macronutrients (N, P, and K), which is compared with another array based on layer-by-layer films.

Broadband Enhancement of Magneto-Optical Effects in Hybrid Waveguide-Plasmonic Surfaces for Sensing.

Conventional magnetophotonic nanostructures typically function within narrow wavelength and incident angle ranges, where resonance is observed and magneto-optical (MO) effects are amplified. Expanding these operational ranges may allow for improved applications, including in (bio)sensing devices. In this study, we describe a hybrid magnetoplasmonic waveguide grating (HMPWG) in which the coupling of plasmonic resonances and waveguide modes leads to enhanced MO effects and sensitivity, according to full-wave electromagnetic simulations.

Toward Machine-Learning-Accelerated Design of All-Dielectric Magnetophotonic Nanostructures.

All-dielectric magnetophotonic nanostructures are promising for integrated nanophotonic devices with high resolution and sensitivity, but their design requires computationally demanding electromagnetic simulations evaluated through trial and error. In this paper, we propose a machine-learning approach to accelerate the design of these nanostructures. Using a data set of 12 170 samples containing four geometric parameters of the nanostructure and the incidence wavelength, trained neural network and polynomial regression algorithms were capable of predicting the amplitude of the transverse magneto-optical Kerr effect (TMOKE) within a time frame of 10 s and mean square error below 4.

Solid-State NMR Characterization of Mefloquine Resinate Complexes Designed for Taste-Masking Pediatric Formulations.

Mefloquine (MQ) is an antimalarial medication prescribed to treat or malaria prevention.. When taken by children, vomiting usually occurs, and new doses of medication frequently need to be taken.

Advancing sustainability in the steel industry: the key role of the triple helix sectors.

The steel industry, crucial to the global economy, grapples with critical sustainable challenges, including high energy consumption, greenhouse gas emissions, and non-renewable resource utilization, making sustainability imperative for upholding its economic role without compromising the planet or societal well-being. This study proposes a framework aimed at advancing sustainability in the steel industry through the articulation of the triple helix sectors (university, industry, and government). Based on the integrative review scientific method, systematic selection, interpretation, and synthesis of information from various sources were carried out to map a technical-scientific scenario of sustainability in the steel industry.

Prevalence and Risk Factors Associated with Chronic Occupational Low Back Pain among Healthcare Professionals Working at Hospitals: Exploratory Survey Study.

 This study aimed to describe the methodological process for developing a questionnaire to identify the prevalence and risk factors for chronic occupational low back pain in healthcare professionals working at hospitals.  An exploratory crossectional survey study was carried out in Belo Horizonte, MG, Brazil, and its metropolitan region, in two stages. Initially, the authors prepared a questionnaire based on the Roland Morris disability questionnaire and sent it to a committee of low back pain specialists for validation using the Delphi technique.

Multidimensional calibration spaces in Staphylococcus Aureus detection using chitosan-based genosensors and electronic tongue.

Mastitis diagnosis can be made by detecting Staphylococcus aureus (S. aureus), which requires high sensitivity and selectivity. Here, we report on microfluidic genosensors and electronic tongues to detect S.

Effects induced by η-p-cymene ruthenium(II) complexes on Langmuir monolayers mimicking cancer and healthy cell membranes do not correlate with their toxicity.

The mechanism of chemotherapeutic action of Ru-based drugs involves plasma membrane disruption and valuable insights into this process may be gained using cell membrane models. The interactions of a series of cytotoxic η-p-cymene ruthenium(II) complexes, [Ru(η-p-cymene)P(3,5-C(CH)-CH)Cl] (1), [Ru(η-p-cymene)P(3,5-CH-CH)Cl] (2), [Ru(η-p-cymene)P(4-CHO-3,5-CH-CH)Cl] (3), and [Ru(η-p-cymene)P(4-CHO-CH)Cl] (4), were examined using Langmuir monolayers as simplified healthy and cancerous outer leaflet plasma membrane models. The cancerous membrane (CM1 and CM2) models contained either 40 % 1,2- dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 30 % cholesterol (Chol), 20 % 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), and 10 % 1,2-dipalmitoyl-sn-glycero-3-phospho-l-serine (DPPS).

Brownian Motion Governs the Plasmonic Enhancement of Colloidal Upconverting Nanoparticles.

Upconverting nanoparticles are essential in modern photonics due to their ability to convert infrared light to visible light. Despite their significance, they exhibit limited brightness, a key drawback that can be addressed by combining them with plasmonic nanoparticles. Plasmon-enhanced upconversion has been widely demonstrated in dry environments, where upconverting nanoparticles are immobilized, but constitutes a challenge in liquid media where Brownian motion competes against immobilization.

Sticky Multicolor Mechanochromic Labels.

Sticky-colored labels are an efficient way to communicate visual information. However, most labels are static. Here, we propose a new category of dynamic sticky labels that change structural colors when stretched.

Magnetochiroptical nanocavities in hyperbolic metamaterials enable sensing down to the few-molecule level.

In this work, we combine the concepts of magnetic circular dichroism, nanocavities, and magneto-optical hyperbolic metamaterials (MO-HMMs) to demonstrate an approach for sensing down to a few molecules. Our proposal comprises a multilayer MO-HMM with a square, two-dimensional arrangement of nanocavities. The magnetization of the system is considered in polar configuration, i.