In the present study the authors\' main goal is to avoid the corrosive attack of the chloride ions of 3.5% NaCl solution in saline medium on the mild steel (MS), by addition of small amount of a new derivative of the hydrazide called ligand (HL), as a corrosion inhibitor. This study had been achieved by employing different electrochemical measurements such as, open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentio-dynamic polarization (PDP) methods. The results of the electrochemical test (OCP), showed that, the open circuit potential of the mild steel in saline solution, was guided to more positive direction in presence of the ligand (HL), at its ideal concentration (1 × 10-3 M), compared to the (OCP), of the mild steel in absence of (HL). The results of the electrochemical methods, EIS and PDP presented that, the ligand (HL), was acted as a good corrosion inhibitor for hindering the corrosion process of the mild steel in 3.5% sodium chloride, as it was recorded a good percentage of the inhibition efficiency (77.45%, 53.41%, by EIS and PDP techniques respectively), at its optimum concentration (1 × 10-3 M). Also, the corrosion rate of the mild steel in the saline medium without (HL), was listed about (0.0017 mm/year), while in existence of (HL), was decreased to a value about (0.00061 mm/year). As well, some of electrical properties of (HL), and its derivative [Pd(II), Cr(III), and Ru(III)], complexes were investigated such as; the activation energy (Ea(ac)), which recorded values in the range of 0.02-0.44 (eV) range and electrical conductivity which listed values at room temperature in the range of 10-5-10-8 S.cm-1. The results of the AC and DC electrical conductivity measurements for (HL), and its derivative [Pd(II), Cr(III) and Ru(III)] complexes indicate semiconducting nature which suggests that these compounds could be used in electronic devices. Also, the complexes exhibited higher conductivity values than (HL). Photophysical studies showed good florescence properties of HL that indicated that it can be used to determine most of the drugs with no fluorescence properties by quenching and calculating quantum yield. Moreover, the hydrazide ligand (HL), has shown selectivity as an active anticancer candidate drug for both breast and colon cancer in humans. Density function theory demonstrated that, the frontier molecular orbital HOMOs of the complexes have exhibited similar behavior and the charge density has localized in the metallic region of all the studied complexes. Also, the values of the energy gap of the ligand (HL), and its complexes Pd(II), Cr(III) and Ru(III), had been arranged in this order HL > Cr(III) > Ru(III) > Pd(II). All characterization using different spectroscopic techniques were reported to elucidate the proposed structures such as; thermal analysis, elemental analysis of C, H, and N atoms, spectral analysis using IR, UV, 1H NMR techniques, scanning electron microscopy and energy dispersive X-ray analyses.

The future development of advanced molecular systems with controlled rotation requires the development of an effective methodology for assessing the rotational performance of artificial machine components. We identified two patterns of the dielectric behavior for polar rotators in a static non-polar framework of sizable crystal showing relations between the spectral and molecular-level features of solid-state rotary motion. Various functionalization of phenylene rotors with a fluorine atom(s) changed rotational performance from high to low with rotational barriers ranging from 6.06 to 11.84 kcal mol-1. The meta-F-substitution favored rotator-rotator contacts allowing for the implementation of fast rotary motion. Contrary, the presence of rotator-stator contacts inhibited independent rotator dynamics leading to opposite spectral behavior in terms of temperature evolution of loss peak amplitude. Our observations, supported by an analysis based on an asymmetric double well-potential model, show that easily noticeable spectral differences encoded some molecular-level information important for the implementation of rotary motion.

Cellulose nanofibers (CNFs) nanocomposites were prepared using poly(methylmethacrylate-co-methacrylic acid) (PMMA-co-MAA) to investigate the macromolecular mobility within the composite, with particular focus on the effect of H-bonding. Dynamic mechanical analysis (DMA) and broadband dielectric spectroscopy (BDS) were used to fully characterize the molecular mobility for which the effect of the introduction of H-bond forming moieties and the addition of CNFs (5 and 15 wt%) were assessed. Despite similar Tg values (determined by Differential Scanning Calorimetry), a deeper analysis of the relaxation times associated with the α-relaxation evidenced a significant effect induced by CNFs, which is in fact slowing down the macromolecular relaxation processes. The activation energy of the β-relaxation remained unchanged despite the introduction of MAA units in the main chain and the successive addition of CNFs. However, the latter led to the appearance at low frequencies of a new β\'-relaxation correlated with the interactions between the CNF surface -OH groups and the -COOH groups of the matrix. The γ-relaxation showed a 45 % increase in activation energy from PMMA to PMMA-co-MAA + CNF nanocomposites regardless of the CNF content, due to the possibility of CNFs to interact and hinder the motion of the main chain methyl groups in α position.

Cutaneous melanoma (CM) is associated with a higher mortality rate than most other skin cancers. The purpose of this expert consensus panel was to review the published literature on new technological advancements for the diagnosis and prognosis for CM and provide updated guidance on their usage.
A comprehensive literature search of PubMed, Scopus, and Google Scholar was completed for English-language original research articles on the topics of non-invasive diagnostic and prognostic testing for CM, including gene expression profiling (GEP) and electrical impedance spectroscopy (EIS). A panel of 10 dermatologists with significant expertise in the treatment of CM gathered to review the articles and create consensus statements. A modified Delphi process was used to approve each statement and a strength of recommendation was assigned using widely recognized Strength of Recommendation Taxonomy criteria.
The literature search produced 200 articles that met the criteria. A screening of the studies resulted in 19 articles. These were distributed to all panelists for review prior to a roundtable discussion. The panel unanimously voted to adopt 7 consensus statements and recommendations, 5 of which were given a strength of \"A\", 1 of which was given a strength of \"B,\" and 1 of which was given a strength of \"C\".
The 2-GEP test and EIS can aid in the precise diagnosis of clinically indeterminate lesions and the 23-GEP test can be used when histopathology is equivocal. The 31-GEP test can enhance prognostic assessment beyond AJCC8 staging and improve clinical decision-making. J Drugs Dermatol. 2024;23(9):774-781. doi:10.36849/JDD.8365R1.

Recent advancements in polymer science and manufacturing technologies triggered new developments of porous materials used for mitigating heat losses, such as thermal insulating polymeric foams. The major bottleneck in the optimization of these products, however, remains the absence of analytical methods able to scrutinize their large design space reasonably quickly and cost-effectively. This manuscript targets the paucity of data for polymeric foams by illustrating, at a proof-of-principle level, that several well-established analytical methods including optical microscopy, pycnometry, dielectric spectroscopy, thermogravimetric analysis, and nuclear magnetic resonance can be exploited for an extensive, yet logistically efficient, characterization of these materials. The purpose of this study is thus introducing an experimental platform for the characterization of market foam products and for the development of new polymeric foams with pore sizes that are particularly relevant for industrial and residential thermal insulation. Since this work introduces several new methodologies, it may be used as a guide for both laboratory users and specialists in the field, who may further improve the herein proposed experimental concepts.

Several medical techniques are based on the application of electromagnetic fields (EMFs) on the human body with therapeutic and/or diagnostic aims. The response of human tissues to the applied EMF is mediated by the tissues\' dielectric properties, which must therefore be characterized at the frequencies of the considered technique. Due to the heterogeneity and complexity of biological tissues, it is necessary to know their properties in vivo for the specific condition of interest. Traditional techniques for the dielectric characterization of biological tissues are invasive and, as such, not adoptable for this aim. Accordingly, alternative sensors and/or sensing methods are needed. Recently, a new wideband spectroscopy technique was proposed, based on quantities derived from the Magnetic Resonance (MRI) signal. Among these quantities, the water content was proposed to evaluate the dielectric properties at frequencies around a few GHz. This work verifies the possibility of deriving tissues\' dielectric properties in the frequency range of 1-20 GHz based on knowledge of the water content. The water content was retrieved through a dehydration procedure for five different ex vivo tissues. The achieved results were compared with references from the literature.

One of the most promising approaches to food quality assessments is the use of impedance spectroscopy combined with machine learning. Thereby, feature selection is decisive for a high classification accuracy. Physically based features have particularly significant advantages because they are able to consider prior knowledge and to concentrate the data into pertinent understandable information, building a solid basis for classification. In this study, we aim to identify physically based measurable features for muscle type and freshness classifications of bovine meat based on impedance spectroscopy measurements. We carry out a combined study where features are ranked based on their F1-score, cumulative feature selection, and t-distributed Stochastic Neighbor Embedding (t-SNE). In terms of features, we analyze the characteristic points (CPs) of the impedance spectrum and the model parameters (MPs) obtained by fitting a physical model to the measurements. The results show that either MPs or CPs alone are sufficient for detecting muscle type. Combining capacitance (C) and extracellular resistance (Rex) or the modulus of the characteristic point Z1 and the phase at the characteristic frequency of the beta dispersion (Phi2) leads to accurate separation. In contrast, the detection of freshness is more challenging. It requires more distinct features. We achieved a 90% freshness separation using the MPs describing intracellular resistance (Rin) and capacitance (C). A 95.5% freshness separation was achieved by considering the phase at the end of the beta dispersion (Phi3) and Rin. Including additional features related to muscle type improves the separability of samples; ultimately, a 99.6% separation can be achieved by selecting the appropriate features.

Campylobacter jejuni is a common foodborne pathogen found in poultry that can cause severe life-threatening illnesses in humans. It is important to detect this pathogen in food to manage foodborne outbreaks. This study reports a novel impedimetric phage protein-based biosensor to detect C. jejuni NCTC 11168 at 100 CFU/mL concentrations using a genetically engineered receptor-binding phage protein, FlaGrab, as a bioreceptor. The electrochemical impedance spectroscopy (EIS) technique was employed to measure changes in resistance upon interaction with C. jejuni. The sensitivity of the phage protein-immobilized electrode was assessed using the various concentrations of C. jejuni NCTC 11168 ranging from 102-109 colony forming units (CFU)/mL). The change transfer resistance of the biosensor increased with increasing numbers of C. jejuni NCTC 11168 cells. The detection limit was determined to be approximately 103 CFU/mL in the buffer and 102 CFU/mL in the ex vivo samples. Salmonella enterica subsp. enterica serotype Typhimurium-291RH and Listeria monocytogenes Scott A were used as nontarget bacterial cells to assess the specificity of the developed biosensor. Results showed that the developed biosensor was highly specific toward the target C. jejuni NCTC 11168, as no signal was observed for the nontarget bacterial cells.

Protein-surfactant interaction is a dynamic interplay of electrostatic and hydrophobic forces that ensues from the folding of a protein. We employ impedance spectroscopy (IS), a label-free method, to investigate the unfolding and refolding of human serum albumin (HSA), a globular plasma protein, in the presence of two surfactants: polysorbate-20 (Tween-20), a nonionic surfactant, and sodium dodecyl sulfate (SDS), an anionic surfactant. The equivalent electrical analog circuit was predicted from impedance spectra of HSA in an aqueous solution at physiological pH and room temperature, focusing on varying the concentration of codissolved surfactants. A change in the dielectric constant (ε\') and ionic conductivity (κ) is observed by comparing the surfactant-treated protein samples to the bare surfactant solutions to assess the conformational changes induced by surfactants in HSA. Far-UV circular dichroism analysis revealed a decrease in α-helices and an increase in β-sheets and random coils upon SDS addition, which were reversed by Tween-20. Dynamic light scattering supported the findings by measuring changes in the hydrodynamic diameter (dh) of HSA. Unfolding and refolding of HSA with surfactants were also observed through photoluminescence spectroscopy by examining the microenvironment surrounding the single tryptophan (W) within the protein, and the thermodynamic parameters were obtained using the modified Stern-Volmer equation. Our research explores the intriguing domain of protein-surfactant interactions, offering insights with promising applications across diverse biological processes and IS as a suitable alternative technique for investigating protein conformational changes by studying the electrical response of the samples.

The urgent need for real-time and noninvasive monitoring of health-associated biochemical parameters has motivated the development of wearable sweat sensors. Existing electrochemical sensors show promise in real-time analysis of various chemical biomarkers. These sensors often rely on labels and redox probes to generate and amplify the signals for the detection and quantification of analytes with limited sensitivity. In this study, we introduce a molecularly imprinted polymer (MIP)-based biochemical sensor to quantify a molecular biomarker in sweat using electrochemical impedance spectroscopy, which eliminates the need for labels or redox probes. The molecularly imprinted biosensor can achieve sensitive and specific detection of cortisol at concentrations as low as 1 pM, 1000-fold lower than previously reported MIP cortisol sensors. We integrated multimodal electrochemical sensors with an iontophoresis sweat extraction module and paper microfluidics for real-time sweat analysis. Several parameters can be simultaneously quantified, including sweat volume, secretion rate, sodium ion, and cortisol concentration. Paper microfluidic modules not only quantify sweat volume and secretion rate but also facilitate continuous sweat analysis without user intervention. While we focus on cortisol sensing as a proof-of-concept, the molecularly imprinted wearable sensors can be extended to real-time detection of other biochemicals, such as protein biomarkers and therapeutic drugs.