Molecular Volume Research Articles

Adsorption of Low-Molecular-Weight Carboxylic Acids to Anion Exchange Resins with Various Properties and the Mechanisms of Interaction

Anion exchange resin (AER) is often used to produce ultrapure water by removing low-molecular-weight (LMW) carboxylic acids (CAs). However, the adsorption performance of resins requires improvement, and the adsorption mechanisms are not fully clear. In this study, eight AERs with different polymer matrices, porosity types, and ammonium group properties were used to investigate the adsorption of common LMW CAs. The adsorption efficiency of strongly basic AERs (80–100%) was much higher than that of weekly basic AERs (2–56%). The adsorption kinetics were limited by intraparticle diffusion. In particular, for CAs with a molecular volume of > 83.5 Å, the gellular AERs showed an obvious size exclusion effect that was not as apparent for the macroporous AERs. The adsorption capacity and affinity were highly related to the polymer matrix. The polystyrene AERs showed 1.60–3.00 times higher maximum adsorption and 2.00–3.80 times greater adsorption affinity than their polyacrylic counterparts. Adsorption also depended on the CA structure. The carbon and carboxyl number of the CA affect the total negative atomic charge density, which in turn affects the CA–AER electrostatic interaction. Besides, hydrogen bonds between the carboxyl group and the AER matrix increased CA adsorption; this effect was especially prominent for diprotic CAs.

Quantitative multi-species toxicity modeling: Does a multi-species, machine learning model provide better performance than a single-species model for the evaluation of acute aquatic toxicity by organic pollutants?

The toxicological profile of any chemical is defined by multiple endpoints and testing procedures, including representative test species from different trophic levels. While computer-aided methods play an increasingly important role in supporting ecotoxicology research and chemical hazard assessment, most of the recently developed machine learning models are directed towards a single, specific endpoint. To overcome this limitation and accelerate the process of identifying potentially hazardous environmental pollutants, we are introducing an effective approach for quantitative, multi-species modeling. The proposed approach is based on canonical correlation analysis that finds a pair(s) of uncorrelated, linear combinations of the original variables that best defines the overall variability within and between multiple biological responses and predictor variables. Its effectiveness was confirmed by the machine learning model for estimating acute toxicity of diverse organic pollutants in aquatic species from three trophic levels: algae (Pseudokirchneriella subcapitata), daphnia (Daphnia magna), and fish (Oryzias latipes). The multi-species model achieved a favorable predictive performance that were in line with predictive models derived for the aquatic organisms individually. The chemical bioavailability and reactivity parameters (n-octanol/water partition coefficient, chemical potential, and molecular size and volume) were important to accurately predict acute ecotoxicity to the three aquatic organisms. To facilitate the use of this approach, an open-source, Python-based script, named qMTM (quantitative Multi-species Toxicity Modeling) has been provided.

Exploring the CSD Drug Subset: An Analysis of Lattice Energies and Constituent Intermolecular Interactions for the Crystal Structures of Pharmaceuticals

Intermolecular (synthonic) modelling is used for a statistical analysis of crystal lattice energies, together with their contributing intermolecular interactions for the crystallographic structures selected from the CCDC's Drug Subset (https://doi.org/10.1016/j.xphs.2018.12.011). Analysis of this selected subset reveal similarities in packing compared to other organic crystals in the CSD with linear relationships between molecular weight and unit cell volume, void space, and packing coefficient. Crystal lattice energy calculations converge within a 30 Å intermolecular radius characterised by a mean lattice energy of ca. -36 kcal mol−1 with ca. 85% and 15% due to dispersive and electrostatic interactions, respectively. The distribution of the strongest synthons within the individual structures reveals an average strength of −5.79 kcal mol−1. The diversity of chemical space within the drug molecules is in agreement with the analysis of atom types across the selected subset with phenyl groups being found to contribute the highest mean energy of −11.28 kcal mol−1, highlighting the importance of aromatic interactions within pharmaceutical compounds. Despite an initial focus on Z’ = 1 structures, this automated approach enables rapid and consistent quantitative analysis of lattice energy, synthon strength and functional group contributions, providing solid-form informatics for pharmaceutical R&D and a helpful basis for further investigations.

Effect of PEG Molecular Weight and Volume Ratio of Chitosan/PEG and Silk Fibroin on Physicomechanical Properties of Chitosan/PEG-SF Scaffold as a Bio-mimetic Substrate in Skin-tissue Engineering Applications

Effect of PEG Molecular Weight and Volume Ratio of Chitosan/PEG and Silk Fibroin on Physicomechanical Properties of Chitosan/PEG-SF Scaffold as a Bio-mimetic Substrate in Skin-tissue Engineering Applications

Mechanistic insights of different release behaviors dominated by drug physicochemical properties in polyisobutylene pressure sensitive adhesive

The purpose of this study was to investigate the effect of the physicochemical parameters of drugs on their own release behaviors in polyisobutylene pressure sensitive adhesive (PIB PSA), which provided a theoretical guidance for the application of PIB in transdermal drug delivery system (TDDS). Seven drugs with different physicochemical parameters including clonidine (CLO), flurbiprofen (FLU), diclofenac (DIC), ibuprofen (IBU), zolmitriptan (ZOL), lidocaine (LID), tulobuterol (TUL) and the mixed adhesive (7:3, w/w) of Oppanol® B 15 N (M.W. = 108,000 Da) and Oppanol® N 50 (M.W. = 565,000 Da) were selected for in vitro drug release and skin permeation studies. Regression analysis was used to study the relationship between physicochemical parameters and release behaviors. The release behaviors of drugs were a negative correlation with polarizability and dipole moment per molecular volume (μ/V), which represented van der Waals and dipole–dipole interaction, respectively. Fourier transform infrared spectroscopy (FT-IR), modulated temperature differential scanning calorimetry (MDSC) and molecular dynamics simulation were used to provide molecular details of the interaction between the drug and PIB. The free volume and molecular mobility of PIB were characterized using mechanical property tests, rheology study, MDSC and molecular dynamics simulation. Based on the above results, drugs with high polarizability and μ/V had stronger van der Waals and dipole–dipole interaction with PIB, reducing the free volume and molecular mobility of PIB, so that the drug struggled to release from PIB. In addition, the diffusion activation energy of the drug was calculated by using the variable temperature release study to characterize the ease of drug release from the kinetic aspect. And the trends of in vitro drug release and skin penetration profiles were basically similar. Thus, it was thought that the physicochemical parameters of the drug played a vital role in the drug release behavior of PIB PSAs and would affect the skin penetration process, which provided a reference for the design and application of patches based on PIB PSAs in TDDS.

Catalyzed Hairpin Assembly-Assisted DNA Dendrimer Enhanced Fluorescence Anisotropy for MicroRNA Detection

Biomacromolecules have been employed successfully as fluorescence anisotropy (FA) amplifiers for biosensing in reported studies. However, the sensitivities of the traditional biomacromolecule amplified FA strategies need to be improved because of the relatively low molecular weight or volume of a single biomacromolecule and the 1:1 binding ratio between the fluorophore-linked probe and target. In this work, a DNA dendrimer with a high molecular weight and volume was employed as a new FA amplifier, which was coupled with target-catalyzed hairpin assembly (CHA) for the sensitive detection of miRNA-21. The fluorophore-modified probe DNA (pDNA) was fixed on the DNA dendrimer, resulting in a high FA value. The addition of miRNA-21 triggered the CHA process and produced plenty of H1-H2 hybrids. The complex of H1-H2 bound to the DNA dendrimer and released the pDNA through a toehold-mediated strand exchange reaction. Thus, a low FA value was obtained because of the low mass and volume of free pDNA. Based on the dramatically reduced FA, miRNA-21 was detected in the range of 1.0–19.0 nM and the limit of detection was 52.0 pM. In addition, our method has been successfully utilized for miRNA-21 detection in human serum. This strategy is sensitive and selective and is expected to be used to detect other biomolecules simply by changing the corresponding nucleic acid probe.

AIE-Active Fluorescent Porous Polymers for Recognizable Detection of Imidacloprid and Structure–Property Relationship

Aggregation-induced emission (AIE)-active aromatic tetraaldehydes are utilized as starting monomers to create two fluorescent polymers (PAN-TPEs) with hierarchical pores ranging from micropores (1.4–1.9 nm) to mesopores (3.8–26.2 nm). Their chemsensing properties for five pesticides, including imidacloprid, acetamiprid, triflumizole, lambda-cyhalothrin, and indoxacarb, are studied. It is found that the Stern–Volmer quenching coefficient and the limit of detection for imidacloprid in the water medium reach 53 745 M–1 and 28 ppb, respectively, which are much superior to those of the reported porous materials in the literature and exceed 3–10 times of the other four pesticides. Moreover, the polymers exhibit fast fluorescence response for imidacloprid (less than 4 s), and the detection sensitivity is nearly not affected by the common cations and anions. Additionally, the studies reveal that, for the polymer sample with narrower pore channels, the recognition ability for imidacloprid strongly depends on the molecular volumes of pesticides, whereas in the case of the polymer with larger pore sizes, the inner filter effect and the photoinduced electron transfer between the pesticides and the chromophore groups in the polymer skeleton become the major factors. The results are of significance for understanding the effects of porosity parameters and AIE groups in fluorescent porous polymers on the recognizable detection of imidacloprid from other pesticides.

Effect of Fe and Al on phosphorus distribution characteristics during solidification of Si-Fe-Al alloy melt

Phosphorus (P) in metallurgical grade silicon (MG-Si) affects the production of downstream silicon materials. By ignoring the influence of minor elements on P, MG-Si can be approximated to a Si-Fe-Al system, and the distribution characteristics of P directly affect its separation. This study investigated the effect of Fe and Al on the P distribution characteristics during solidification of the Si-Fe-Al alloy melt. In an experiment, MG-Si and the Si-Fe-Al alloy, with similar composition and solidification route, were subjected to the same in situ corrosion and acid leaching. Their comparison shows that the total concentration of Fe and Al increased from 0.59 to 6.35 wt%, while the removal efficiency of P only increased from 7.23% to 25.00%. The residual percentage of P in the Si matrix of MG-Si and the Si-Fe-Al alloy were 92.77% and 75.00%, respectively. Additionally, the dissolution of AlP at the grain boundary is the main reason for the separation of P by acid leaching. At 1685 K, the activity interaction coefficients εPFe and εPAl are − 3.1348 and − 15.5498, respectively, as calculated by the molecular volume interaction model. During the initial crystallization of Si in the Si-Fe-Al system, Fe and Al can reduce the segregation coefficient of P and transform it into AlP, thereby theoretically promoting the separation of P from Si. However, AlP and Si have similar crystal structure, and the low mismatch factor and strong binding force between them facilitate the capture of AlP by primary Si, which hinders the enhanced separation of P from Si. An accurate understanding of the formation mechanism of the distribution characteristics of P in MG-Si is of great significance to the optimal design of MG-Si purification scheme.

Controlling the microphase morphology and performance of cross-linked highly sulfonated polyimide membranes by varying the molecular structure and volume of the hydrophobic cross-linkable diamine monomers

Morphological control is essential for tuning the performance of polymer electrolyte membranes (PEMs). Block copolymerization is an effective but complicated way to control the morphology of PEMs. It is urgent to explore a simple alternative method to achieve this target. Herein, the molecular engineering strategy that changes the molecular structure and volume of hydrophobic cross-linkable diamine and introduces a hydrophobic network structure was used to optimize the microphase morphology of sulfonated polyimides (SPIs). Three diamine monomers containing tetrafluorostyrol pendant groups have been synthesized (4-(2,3,5,6-tetrafluoro-4-vinylphenoxy)benzene-1,3-diamine (TFVPDM), 1,3-bis(2-trifluoromethyl-4-amino-phenoxy)-5-(2,3,5,6-tetrafluoro-4-vinylphenoxy)benzene (6FTFPB), 2,2-bis(3-amino-4-(2,3,5,6-tetrafluoro-4-vinylphenoxy)phenyl)hexafluoropropane (6FATFVP)). Based on these monomers, 4,4′-diaminostilbene-2,2′-disulfonic acid (DASDSA) and 1,4,5,8-naphthalenetetracarboxylicdianhydride (NTDA), three cross-linked SPIs (CSPIs: CSPI-T-10, CSPI-TP-10, CSPI-AP-10) with similar ion-exchange capacity (IEC) value of 2.29–2.46 meq. g−1 but different main-chain structures were prepared through polycondensation and thermal cross-linking process. The introduced hydrophobic cross-linked structure improves the oxidative stability and methanol resistance of CSPI membranes. The CSPI membranes prepared from cross-linkable hydrophobic diamine with larger molecular volume and containing hydrophobic structural units in the main chain exhibit more pronounced phase separation morphology and higher proton conductivity. Moreover, the methanol resistance of CSPI membranes is dependent on the combined effect of IEC, degree of crosslinking (DC), and main-chain structure. The higher DC and main-chain containing hydrophobic structure are beneficial for enhancing the methanol resistance. The CSPI-AP-10, which was prepared from the 6FATFVP with the largest molecular volume, more hydrophobic cross-linkable pendant groups and hydrophobic linkages, exhibits the best performance. The CSPI-AP-10 membranes showed high proton conductivity and excellent methanol resistance. The direct methanol fuel cells (DMFCs) assembled from CSPI-AP-10 have a high max power density (PDmax) of 106.2 mW cm−2 in 2 M methanol and 75.1 mW cm−2 in 10 M methanol. The results indicated that the CSPI-AP-10 was a promising candidate as a PEM in DMFC application.

HLA-B evolutionary divergence is associated with poor outcomes after SARS-CoV-2 infection

Abstract Objectives Human leukocyte antigens (HLA) are highly diverse transmembrane proteins that present viral peptides to T cells and launch pathogen-specific immune responses. We aim to investigate the correlation between HLA evolutionary divergence (HED), a surrogate for the capacity to present different peptides, and the outcomes of SARS-CoV-2 infection in a cohort from the St. Louis Metropolitan area. Methods We enrolled adult patients with SARS-CoV-2 infection confirmed by RT-PCR who were hospitalized at two tertiary hospitals in St. Louis between March and July 2020. Genomic DNA was extracted from peripheral blood and genotyped by next-generation sequencing (NGS). HLA alleles were assigned based on key-exon sequences (G group) and limited to the 2-field resolution. HED was calculated by Grantham distance, which considers the difference in composition, polarity, and molecular volume between each pair of amino acids from maternal and paternal HLA. The HED score was obtained for HLA class I (HLA-A, -B, and -C) genotypes using the HLAdivR package in R. Clinical data were collected retrospectively from electronic medical records. A poor outcome was defined as an admission to the intensive care unit (ICU), a need for mechanical ventilation, or death. A favorable outcome was defined as the absence of the above poor outcomes. Results A total of 234 patients were enrolled in this study, 96 being females (41%). The median age and BMI were 66 years old and 28.30 kg/m2, respectively. African Americans comprised 71.4% of the cohort. Only 19 patients (8.1%) presented with no comorbidity; the rest had one or more comorbidities, with cardiovascular diseases being the most common. A total of 137 (58.5%) patients had poor outcomes from SARS-CoV-2 infection, while 97 (41.5%) patients had a favorable outcome. We detected a significant association between higher HLA-B HED and favorable outcomes, with each 1-point increase in HLA-B HED associated with 8% increased probability for the composite endpoint (OR 1.08, 95% CI=1.01-1.16, P = 0.04). The HED scores calculated for HLA-A or HLA-C were not significantly different between patients with favorable or poor outcomes. In a multivariate logistic regression analysis, increased HLA-B HED score, younger age, and no comorbidity were independently associated with favorable outcomes (P = 0.02, P = 0.01, and P = 0.05, respectively). Conclusion Our study shows a significant correlation between lower HLA-B HED scores and poor outcomes after SARS-CoV-2 infection. This finding suggests that maximizing the presentation of diverse SARS-CoV-2 peptides by HLA-B alleles may improve the clearance of SARS-CoV-2. Further studies are warranted to understand the functional and mechanistic implications of this finding.

Preparation of degradable bio-based silicone/epoxy hybrid resins towards low dielectric composites

Epoxy resins are well-known adhesive materials, however, the high dielectric constant (Dk) limited their application in microelectronic devices. Additionally, non-degradability is a bottleneck for all thermosetting resins, and the discarded resins posed the great threat to environment. Herein, a bio-based eugenol epoxy was grafted onto the polymethylhydrosiloxane (PMHS-x) main chain via a hydrosilylation reaction to simultaneously lower the Dk and enable degradability. The curing kinetics of bio-based silicone/epoxy hybrid resins with methyl hexahydrophthalic anhydride (MHHPA) or 4,4′-diaminodiphenylmethane (DDM) were studied. The cured resins exhibited low Dk and hydrophobicity by taking advantage of the low polarity, large molecular volume and high dissociation energy of the siloxane segments. The polysiloxane degradation process took place under alkaline conditions, allowing the retrieval of reinforced fibers from the composites. To better illustrate the superiority of the bio-based silicone/epoxy hybrid resins, quartz fiber reinforced composites were prepared. Compared to the commercial epoxy based composite, the impact strength of the PMHS-x with a silicon hydrogen content of 0.8 × 10-2 mol·g−1 was increased by 26.5 %, meanwhile, the Dk was decreased by 16.7 %. The bio-based silicone/epoxy hybrid resins not only alleviated the environmental pollution but also provided a reliable approach for fiber recycling from epoxy composites. The low polarity and degradability were integrated into bio-based silicone/epoxy hybrid resins, which provided a novel way to prepare environment-friendly materials suitable for microelectronic devices.

Theoretical investigation of entropic barocaloric effect in spin-crossover systems

We report a theoretical investigation of the entropic barocaloric effect in a spin crossover system. From our model Hamiltonian, the total entropy, which includes the contributions from the lattice (vibrational), magnetic and configurational entropies, was obtained and worked out for a systematic study of the barocaloric effect. The barocaloric effect was parametrically investigated in three scenarios: second order, threshold of second-first order and first order phase transition. Besides, a procedure for obtaining the molecular volume change during the low spin to high spin phase transition conversion was proposed, through the entropic barocaloric measurements.

Volumetric determination of reverse micelle structural properties and the validity of commonplace approximations

Molecular volumes within reverse micelles are important in determining many aggregate properties. Molecular volumes also depend upon differences in molecular environment and thereby might also be capable of detecting changes in molecular structure and interactions within an aggregate. However, approximations are typically used in their place along with approximations of aggregate radius, aggregation number, surfactant tail length, and reverse micelle shape particularly for Aerosol OT systems. Consequently, volumetric measurements have not been thoroughly tested as a measure of aggregate properties. Volumetric methods do not require the commonly used approximations. Therefore, comparison with previous approaches will demonstrate volumetric measurements’ utility in measuring aggregate structural properties and provide a useful assessment of the applicability of these commonplace approximations. Partial molar volumes of water and surfactant, evaporation rate, and reverse micelle radius are measured over the w0 = 0–40 range for water/Aerosol OT/isooctane solutions. These results are used to calculate how aggregation number, surfactant layer thickness, head group area, and water droplet structure change with aggregate radius. Volumetric measurements reveal a surfactant layer structural transition at w0 = 5, an aggregate shape change at w0 = 25, and reproduced the general trends in structural properties. Important variations from approximated methods are noted. Molecular volume and aggregate radius approximations were found valid in many but not all situations. However, approximations of aggregation number and tail length created important miscalculations of some properties when treating reverse micelles as spherical. It was found that consideration of an ellipsoidal reverse micelle shape for w0 < 10 could account for previously identified changes in surfactant layer thickness and head group area that were based on a spherical geometry.

Prediction of speed of sound and specific heat capacity of ionic liquids using predictive SAFT-based equation of state

In this work, the predictive PC-SAFT EoS has been developed to predict the speed of sound, the isochoric and isobaric heat capacity of ionic liquids (ILs) over a wide range of pressures and temperatures. In this new methodology, the segment number and diameter of ILs have been estimated using the surface area and molecular volume of the UNIFAC model. The segment energy and association energy parameters have been obtained using an inverse relationship between dispersion/association energy and segment diameter. The results show that the predictive PC-SAFT model can predict the specific isochoric and isobaric heat capacity of ILs up to high pressure, accurately. In the case of the speed of sound, the model performance is acceptable by considering using no adjustable model parameters. To check the model capability, the new model results have been compared to the electrolyte PC-SAFT EoS.

Low dielectric and thermal properties of polyimides based on PMDA, BPADA, TPE-Q and TPE-R

The polyimides were prepared by pyromellitic dianhydride (PMDA) or 4,4'-(4,4'-Isopropylidenediphenoxy)diphthalic anhydride (BPADA) as dianhydride monomer and 1,4-bis(4-aminophenoxy)benzene(TPE-Q) or 1,3-bis(4-aminophenoxy)benzene(TPE-R) as diamine monomer. The polyimides were well characterized by FT-IR, thermogravimetric analysis, dynamic thermomechanical analysis, dielectric measurement and tensile test. The flexibility of polyimide molecular chain was judged by the comparison of molecular volumes, molecular length and conformation transition energy through molecular simulations.

The study on QSAR and relations between molecular descriptors of 5, 8-quinoline quinones derivatives

The electronic, hydrophobic and global reactivity parameters of modeled 28 different 5,8-quinolinequinone derivatives have been calculated using DFT (B3LYP)/6-31G(d,p) method and basis set. The molecular descriptors are chosen molecular polarizability, dipole moment, frontier molecular orbital energy, molecular volume, ionization potential, electron affinity, electronegativity, molecular hardness, molecular softness, electrophilic index, molar refractivity, octanol–water partition coefficient, entropy and capacity of heat. The relations between molecular descriptors have been investigated dependent on their correlations. QSAR/QSPR models have been derived for anti-proliferative and anti-inflammatory activity of these 5, 8-quinolinequinone (s) derivatives. The dependence of the electronegativity parameter on both electronic and thermochemical parameters is found to be the best correlated parameter.

Connecting Non-Gaussian Water Density Fluctuations to the Lengthscale Dependent Crossover in Hydrophobic Hydration.

We connect density fluctuations in liquid water to lengthscale dependent crossover in hydrophobic hydration. Specifically, we employ indirect umbrella sampling (INDUS) simulations to characterize density fluctuations in observation volumes of various sizes and shapes in water and as a function of temperature and salt concentration. Consistent with previous observations, density fluctuations are Gaussian in small molecular scale volumes, but they display non-Gaussian "low-density fat tails" in larger volumes. These non-Gaussian tails are indicative of the proximity of water to its liquid to vapor phase transition and have implications on biomolecular interactions and function. We show that the onset of non-Gaussian fluctuations in large volumes is accompanied by the formation of a cavity in the observation volume. We develop a model that uses the physics of cavity-water interface formation as a key ingredient and show that it captures the nature of non-Gaussian density fluctuations over a broad region in water and in salt solutions. We discuss the limitations of this model in the very low density region of the distribution. Our calculations provide new insights into the origins of non-Gaussian density fluctuations in water and their connections to lengthscale dependent crossover in hydrophobic hydration.

Electrically Induced Hydrodynamic Effect in Nematics Caused by Volume Reduction

A pressure gradient caused by the local field-induced reduction of the effective molecular volume results in a flow of the nematic liquid crystal (NLC). Here, the hydrodynamics of homeotropically aligned NLC molecules under the influence of this pressure gradient was studied theoretically. The equations describing the system were written and solved in the steady-state case using analytical methods, and the stationary velocity of the observed flow was found. We discussed the obtained results and compared them with existing experimental results.

Feasibility of 68Ga-Labeled Fibroblast Activation Protein Inhibitor PET/CT in Light-Chain Cardiac Amyloidosis

BackgroundSystemic amyloid light chain (AL) amyloidosis is the most common type of amyloidosis, leading to cardiomyocyte necrosis and interstitial fibrosis. Gallium-68-labeled fibroblast activation protein inhibitor 04 (68Ga-FAPI-04) has recently been introduced for imaging fibroblast activation in cardiac diseases. To date, cardiac fibroblast and cardiac amyloidosis (CA) phenotype activities have not been mapped. ObjectivesThe aim of this study was to evaluate the feasibility of 68Ga-FAPI-04 positron emission tomography (PET)/computed tomography (CT) in assessing AL CA. MethodsThirty consecutive patients (mean age: 59.1 ± 7.7 years; 20 men, 10 women) with biopsy-proven AL amyloidosis were enrolled prospectively (including 27 with AL CA and 3 without AL CA). All patients underwent 68Ga-FAPI-04 PET/CT (107.4 ± 26.5 MBq). Global standardized uptake values and left ventricular (LV) molecular volume were calculated in correlation to echocardiography (n = 30), cardiac magnetic resonance (n = 18), and clinical biomarkers. Subsequently, the patients were categorized as having patchy (PET-patchy), extensive (PET-extensive), and negative (PET-negative) patterns. ResultsOf all patients, 80% (24 of 30) showed increased LV uptake (PET-patchy [n = 4] vs PET-extensive [n = 20]), whereas 6 patients did not show visible myocardial uptake. Standardized uptake value ratio and LV molecular volume were significantly higher in the PET-extensive than the PET-patchy group (2.79 mL ± 1.22 mL vs 1.53 mL ± 0.66 mL [P = 0.045] and 198.3 mL ± 59.97 mL vs 127.8 mL ± 25.82 [P = 0.005], respectively). Additionally, 68Ga-FAPI-04 uptake was significantly correlated with clinical biomarkers (Mayo stage and N-terminal pro–brain natriuretic peptide), interventricular septal thickness, left ventricular ejection fraction (LVEF), LV end-systolic volume, extracellular volume, and LV global strain (P < 0.05). Conclusions68Ga-FAPI-04 PET/CT is feasible in detecting myocardial fibroblast activation in patients with AL CA in correlation with myocardial remodeling. It might provide complementary information on cardiac molecular characterization and staging of disease.

Clamping of spin-crossover solid inducing crystal bending and spatial spin organization

The present work investigates the effect of mechanical clamping on thermally induced spin transition in a deformable spin-crossover single crystal. We performed the analysis, which combined Monte Carlo and molecular dynamics simulations, on a 2D rectangular lattice using an electro-elastic model, taking into account for the change of spin states and volume along the transition process. The molecules (the sites) of the crystal can be either in the low-spin (LS) or in the high-spin (HS) states which are respectively characterized with small and bigger molecular volumes. We found that straining the system edge along the thermal spin transition not only influences the nature of the phase transition which changes from first-order to continuous but also causes the appearance of significant macroscopic bending effects. Furthermore, the spatiotemporal investigations of the strained spin transition networks revealed the formation of spatially modulated HS/LS patterns resulting from the system's bending which promotes spatially organized tensile and compressive regions. These results demonstrate the interplay/competition between the stretching effects favored by temperature and the macroscopic bending triggered by the external constraints imposed to the lattice, lead to the emergence of complex self-organized spin structures and shape deformation in the strained SCO solids.