Resonance Analysis Research Articles

Numerical analyses of acoustic vibrational resonance in a Helmholtz resonator

AbstractIn this study, the numerical analyses of a system, which describes the motion of air particles in the cavity of a Helmholtz resonator (HR), excited by a sound wave, was conducted. The low-frequency (LF) signal in the acoustic field is amplitude-modulated by an additive high-frequency (HF) perturbation, which can enhance the detection of the low-frequency, through Vibrational Resonance (VR) phenomena. The focus was on the combined effect, of amplitude and frequency of the acoustic excitation, on the motion of particles and induction of resonance. It was demonstrated that the system exhibits several nonlinear behaviours, VR ceasing to exist for a particular motion of the particles, which is dictated by the excitation frequency in relation to the resonator’s geometry. Furthermore, the regimes in which the performance of the system can be optimized, was identified, which facilitated the design of broadband acoustic resonators, suitable for most applications.

Non-Covalent Interactions of Lotus Root Polysaccharides and Polyphenols and their Regulatory Mechanism on Macrophage Functions

Despite the interaction between polyphenols and polysaccharides in food products, their specific non-covalent interactions and effects on macrophage functions are not well understood. Therefore, the interaction and mechanism of purified lotus root polysaccharide (PLRP) with polyphenols, and the regulatory mechanisms of the PLRP-polyphenol complex on the macrophage functionals were studied. By combining ferulic acid (FA) and chlorogenic acid (CHA) with PLRP, the complexes PLRP-FA, PLRP-CHA and the physical mixtures PLRP&FA and PLRP&CHA were prepared, where their mass ratios of polyphenols to PLRP were 143.97 and 601.67 mg g−1. Nuclear magnetic resonance (NMR), Fourier-transform infrared (FTIR), Ultraviolet (UV), and Transmission electron microscopy (TEM) analyses confirmed that PLRP and polyphenols may engage in non-covalent interactions via hydrogen bonds and hydrophobic interactions. We confirmed that non-covalent interactions led to high molecular weight, dense complexes. Both PLRP and its polyphenol complexes stimulated NO production by macrophages to varying degrees without exacerbating lipopolysaccharide-induced inflammatory responses. PLRP and PLRP-polyphenol complexes repaired cells with impaired antioxidant capacity, depending on doses. Those results indicated that after the combination of lotus root polysaccharide and polyphenol, the molecular weight and conformation changed significantly, which influenced the biological activity. RNA-seq analysis suggested that the regulatory mechanism of PLRP-polyphenol complex in macrophages may mainly involve oxidative phosphorylation, FoxO, TNF, IL-17, MAPK, NF-kappa B, and other signaling pathways. This study investigated the effects of polyphenol binding on the physicochemical characteristics and functional activities of polysaccharides, which provided references for the development of polysaccharide functional products and the control of nutritional quality.

1H NMR-Based Metabolomic Profiling and Comparison of Human Milk Across Different Lactation Stages in Secretors and Non-Secretors: A Study of Chinese Lactating Women

BackgroundHuman milk oligosaccharides (HMOs) and other milk-derived metabolites are crucial for infant health, influencing gut microbiota and overall development. ObjectiveThis study aims to uncover insights into the variations of HMOs and non-HMO metabolites based on secretor (Se) status, lactation time, mode of delivery, and infant sex. MethodsAn exploratory cross-sectional study was designed to compare the levels of HMOs and non-HMOs metabolites in milk samples from 129 lactating Chinese women within 1 year postpartum. Nuclear magnetic resonance analysis was employed for the identification and quantification of the metabolites. The metabolites measured were grouped into sugars, free amino acids, fatty acids, and metabolites related to energy metabolism. The influence of delivery mode and infant sex on milk metabolite composition were explored. ResultsUniform Manifold Approximation and Projection (UMAP) analysis of HMOs profiles revealed distinct clustering based on Se status, with significant differences in 2'-FL and 3-FL levels observed between Se+ and Se- groups. A decreasing trend for 2'-FL and 6-’SL levels, along with an increase in 3-FL levels, was observed with increasing lactating period within 12 months postpartum. Non-HMOs metabolite analysis indicated that Se status only affected glutamate levels. An increase in glutamine levels was observed 3–9 months postpartum. A continuous increase in o-phosphocholine levels was noted in 12 months postpartum, along with reductions in citrate and sn-glycero-phosphocholine levels. Delivery mode and infant sex did not affect both HMOs and non-HMOs levels. ConclusionsMetabolomic analysis of human milk reveals significant variation of HMOs, but not in non-HMOs, based on Se status. Changes in certain HMOs and non-HMOs levels were also observed over the one year of lactation. Understanding how these metabolites change over time may influence recommendations for maternal diet, supplementation, and the timing of breastfeeding to ensure optimal nutrient delivery to the infant.

1H NMR and chemical analysis to characterize camellia oil obtained by different extraction methods: A comparative study using chemometrics

Camellia oil has become one of the most popular edible vegetable oils especially in China. It can be obtained by cold-pressing (CPE), soxhlet extraction (SE), aqueous enzymatic extraction (AEE), and supercritical carbon dioxide extraction (SC-CO2), while research on their efficient identification is limited. Thus, in this study, proton nuclear magnetic resonance (1H NMR) and conventional chemical analysis, respectively coupled to chemometrics, were employed to compare the camellia oils, produced by CPE, SE, AEE, and SC-CO2. The results showed an obviously overlapping among those four different extracted camellia oils, in both principal component analysis (PCA) and hierarchical clustering analysis (HCA), when using fatty acids as input variables. While two obtained PCA models showed good discrimination, according to the minor component compositions (α-tocopherol, squalene, stigmasterol, β-sitosterol, β-amyrin and lanosterol) and 1H NMR spectra, respectively. Additionally, by means of variable importance for the projection (VIP) scores, less 10 dominant 1H NMR spectra signals were screened out as detailed markers for different camellia oils classification. Therefore, 1H NMR combined with chemometrics may be applied as an efficient technique to classify different extracted camellia oils and potentially other vegetable oils.

Efficient activation of peroxyacetic acid by cobalt-iron alloy/oxide heterojunctions anchored in defect-rich biochar for pesticide degradation in water: Unravelling the radical-unradical mechanism

The activation processes of peracetic acid (PAA-AOPs) have garnered significant attention in wastewater treatment. In this study, an amorphous carbon-modified bimetallic CoFe alloy/oxide catalyst (CoFe@DBCx-y, where x represents biomass mass and y represents pyrolysis temperature) was developed to activate PAA for the degradation of organochlorine pesticides (OCPs). Due to the size effect, biochar dynamically regulates the particle size of metal species, which is influenced by the pyrolysis temperature. Among these systems, the CoFeDBC2.0–700/PAA oxidation system effectively removed 95.7 % of 2,4-dichlorophenoxyacetic acid (2,4-D), exhibiting a kinetic constant 1.7 times higher than that of the Nano/PAA system. Furthermore, quenching experiments and electron paramagnetic resonance (EPR) analysis revealed that high-valent metal oxides (MIV = O) and singlet oxygen (1O2) are the primary active species responsible for the removal of 2,4-D, whereas organic radicals (RO·) and hydroxyl radicals (·OH) play a secondary role. Electrochemical and Raman spectroscopy tests revealed the formation of a metastable surface complex (≡Co(III)–OO(O)CCH3) between PAA and the catalyst, which acted as an intermediate oxidant to generate reactive oxygen species (ROS) through a chain reaction. Carbon defects in the biochar functioned as an electron source, continuously replenishing the electrons consumed in the reaction and facilitating the valence cycling between Co and Fe. This study provides new insights into the remediation of pesticide-contaminated wastewater using PAA-AOPs with heterogeneous bimetallic carbon-based catalysts.

Degradation of carbamazepine in piezo-activation of persulfate systems: Comparison of PDS and PMS

The choice of persulfate (PS) is crucial to the degradation and energy efficiencies for piezo-activation of PS (PE-PS) systems. Herein, a comparison between piezoelectrically activated peroxydisulfate (PDS) and peroxomonosulfate (PMS) using BaTiO3 are comparatively investigated for carbamazepine (CBZ) degradation. By contrast, the PE-PMS system achieves better degradation and mineralization of CBZ, as well as higher reaction stoichiometric efficiencies (%RSE). Nevertheless, the energy consumption of the PE-PDS system is only 9.69% of the PE-PMS system. The quenching test, chemical probe determination, and electron spin resonance (EPR) analysis suggest that the concentration of •OH, SO4∙-, and 1O2 except ∙O2- of the PE-PMS system, is higher than that of the PE-PDS system. The piezoelectric current density and carrier separation efficiency of the PE-PMS system are higher than that of the PE-PDS system, demonstrating that the piezoelectrically activated PMS has higher reactivity than piezoelectrically activated PDS. The ∙O2- and •OH are the primary ROS in the PE-PDS system, while 1O2 and •OH are the major ROS in the PE-PMS system. Additionally, CBZ is effectively degraded by both PE-PMS and PE-PDS systems from actual water sources. This work compares the performance, energy cost, and mechanism of PE-PMS and PE-PDS systems systematically. Hopefully, all of that is designed to tender a helpful reference for the choice of PS in piezocatalytic research and application.

Bokeelamides: Lipopeptides from Bacteria Associated with Marine Egg Masses.

Moon snails (family: Naticidae) lay egg masses that are rich in bacterial species distinct from the surrounding environment. We hypothesized that this microbiome chemically defends the moon snail eggs from predation and pathogens. Herein, we report the discovery of bokeelamides, new lipopeptides from the egg mass-associated bacterium, Ectopseudomonas khazarica, which were discovered using mass spectrometry (MS)-based metabolomics. The structures of the bokeelamides were elucidated using two-dimensional (2D) nuclear magnetic resonance (NMR), tandem MS, Marfey's, and genomic analyses.

Electrochemical activation of periodate with graphite electrodes for degradation of high concentrations of thiocyanogen (SCN−) in mineral processing tail liquid

Cyanide has been widely used in gold extraction due to its cost-effectiveness, high selectivity and recovery. Regrettably, its wide application also leads to the presence of a large amount of thiocyanogen (SCN−) in the tail liquid of mineral processing plants, which affects the quality of the effluent water, and thus poses a threat to the ecological environment and human health. This paper investigates the degradation of high concentration of SCN− in water using electrochemical oxidation/periodate (E-GP/PI) system. A degradation rate of 90.25 % of SCN− was achieved by optimising various operating parameters. The effects of organic matter and typical heavy metal ion concentrations on the degradation of SCN− were investigated, and it was found that Cu2+ was able to promote the degradation of SCN− through the formation of stable complexes with SCN−, which enhanced the degradation rate to 96.48 %. However, the presence of Octadecyltrimethylammonium bromide (OTAB) and butylxanthin hindered the degradation process, where 500 mg/L of OTAB reduced the degradation rate of SCN− to 80.88 %, while 100 mg/L of butylxanthin reduced the degradation rate to 78.66 %. On this basis, experiments were carried out using real wastewater samples and SCN− degradation efficiencies of about 90 % were obtained. Afterwards, through electron paramagnetic resonance analysis, free radical burst, ion chromatograph and other research techniques, IO3 and O2– were obtained as the main drivers of SCN− degradation and SCN− degradation pathways were elucidated. Finally, the E-GP/PI system was shown to be effective in reducing the ecotoxicity of SCN− by increasing the 24-h LC50 from 12.5 % to 48.5 % in a toxicity test with daphnia. This study provides a new idea for the green and efficient treatment of SCN− rich beneficiation tail liquid.

Stereoselective synthesis of geminal bromofluoroalkenes by kinetically controlled selective conversion of oxaphosphetane intermediates.

Geminal bromofluoroalkenes are an important subclass of versatile organic interhalide, which can serve as useful synthetic precursors to monofluoroalkenes that are valuable amide group isosteres. Nonetheless, despite the vast advancement of olefination methodologies, the broadly applicable stereoselective synthesis remained elusive for geminal bromofluoroalkenes before our work. In particular, the seemingly straightforward Wittig-type approach with interhalogenated phosphorus ylide has been unsuccessful because of the difficulty in the diastereoselective oxaphosphetane formation. Here, we describe a conceptually distinctive strategy, by which the stereoselectivity is gained via the selective decomposition of the oxaphosphetane intermediates. The suitably identified phosphorus(III) reagent and reaction medium enabled efficient kinetic differentiation, which was supported by nuclear magnetic resonance analysis and density functional theory calculation. Through our method, the highly diastereoselective synthesis of geminal E-bromofluoroalkenes was accomplished in one step. Furthermore, the generality was demonstrated by accommodating a wide range of readily available carbonyl compounds, including ketones and pharmaceutical substrates.

Influence of pH on the Formation of Benzyl Ester Bonds Between Dehydrogenation Polymers and Konjac Glucomannan

A thorough understanding of the lignin–carbohydrate complex (LCC) structure has a significant meaning in the high-value utilization of lignocellulose. In this work, the complex (DHPKGC) was obtained by an addition reaction between konjac glucomannan (KGM) and quinone methides generated in the synthesis of dehydrogenation polymers (DHPs) to simulate the formation of LCCs. The effect of pH on the prepared DHPKGC was investigated. The structure of the DHPKGC was characterized by Fourier Transform Infrared (FTIR), 13C-Nuclear Magnetic Resonance (13C-NMR), and two-dimensional Heteronuclear Single Quantum Coherence Nuclear Magnetic Resonance (2D HSQC NMR) analyses. The results indicated the pH of 4.0 was conducive to the polymerization reaction between DHPs and oxidized KGM by the TEMPO/NaClO/NaBr system. In addition, the resultant DHPKGC was connected by benzyl ester linkages. Overall, this study aims to gain greater insight into the process of LCC formation in plants.

Sulfadimethylpyrimidine degradation by non-radical dominated peroxomonosulfate activated with geopolymer-loaded cobalt catalysts

Geopolymers are frequently employed as adsorbent materials to treat heavy metals in wastewater due to their special structure analogous to that of zeolites. Nevertheless, their utilization as catalyst supports has not been extensively employed. In this study, geopolymers were modified using carboxymethyl chitosan and subsequently converted into zeolite through the hydrothermal method. Following calcination with Co loading, Co@MGA was obtained. The results indicated that as-prepared Co@MGA exhibited an excellent performance in activating PMS to degrade SMT. Moreover, the mineralization rate of SMT reached 76 %. Quenching experiments and electron paramagnetic resonance analyses had demonstrated that the non-radical pathway predominated in the degradation process of SMT, and 1O2 was the primary reactive oxygen species. The formation of surface bond was further elucidated through in-situ Raman spectroscopy and electrochemical tests. The potential mechanism and pathways of SMT degradation within the Co@MGA/PMS system were proposed. The system exhibited adaptability to different pH levels and robust resistance to inorganic ions and humic acid. Co@MGA demonstrated excellent reusability and stability, suggesting that Co@MGA is a highly promising catalyst for the activation of PMS.

Research on the spoilage potential and metabolic patterns of specific spoilage bacteria in grouper (Epinephelus lanceolatus) during cold storage

Pseudomonas fragi and Serratia liquefaciens are key spoilage microorganisms in aerobically packed groupers during cold storage. Spoilage bacteria were inoculated into fillets to investigate their spoilage potential. The results showed that P. fragi had stronger degradation activity, and the P. fragi inoculated group had higher total volatile basic nitrogen (TVB-N) and K values, lower water holding capacity (WHC), and textural qualities. The P. fragi inoculated group had higher levels of carbonyl groups and lower levels of sulfhydryl groups, indicating higher levels of protein oxidation. The secondary and tertiary structure of myofibrillar protein (MP), scanning electron microscopy, and low-field nuclear magnetic resonance (LF-NMR) analyses showed that P. fragi degraded myofibrils more and induced water loss from the muscle. Metabolomics analyses indicated that purine metabolism and glycine, serine, and threonine metabolism were important pathways associated with P. fragi spoilage; linoleic acid metabolism and β-alanine metabolism were important pathways for S. liquefaciens spoilage.

Optimization, structural characterization, and biological applications of exopolysaccharide produced by Enterococcus faecium KT990028

The aim of this study was to select the best exopolysaccharide (EPS) producer among the Enterococcus strains to optimize, characterize, and evaluate its biological properties. Among the eleven strains, Enterococcus faecium KT990028 was selected, and the production conditions were optimized: 16.3 % (w/v) sucrose, 0.70 % (w/v) yeast extract, 8.3 % (w/v) reconstituted skimmed milk, at 38 °C in 15 h of incubation, producing 2.880 g/L of EPS. High performance anion exchange chromatography (HPAEC) analysis revealed that the molecular weight was 166.98 kDa. HPAEC, spectroscopy (FTIR), and nuclear magnetic resonance (1H NMR) analyses revealed that the EPS was a heteropolysaccharide composed of galactose (37.74 %), rhamnose (19.79 %), arabinose (17.71 %), glucose (9.50 %), fucose (7.93 %), and mannose (7.33 %). Scanning electron microscopy showed a three-dimensional microstructure in the form of decompressed plates, with wrinkles, and pores. By means of dynamic light scattering (DLS), the EPS showed an average size varying from 135.25 ± 10.56 nm and 410.60 ± 45.20 nm, as the concentration was increased from 0.5 mg/mL to 2.0 mg/mL, respectively. X-ray diffraction revealed that the EPS has an amorphous and crystalline nature, while thermogravimetric analysis indicated stability up to 400 °C. The antioxidant effect (5 mg/mL) against DPPH, ABTS, OH, and O2 was 64.50 ± 0.71 %, 47.50 ± 0.10 %, 68.36 ± 0.59 %, and 44.83 ± 0.86 %, respectively. It was also able to inhibit and biofilm disruption of Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 6057 and had an antimicrobial effect from 50 mg/mL for the strains of against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Listeria monocytogenes ATCC 19117, Staphylococcus aureus ATCC 6538, and Enterococcus faecalis ATCC 6057. Cell cytotoxicity carried out using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that the EPS was safe and promoted the proliferation of Vero cells. Thus, the results indicated that the EPS from E. faecium KT990028 is a promising functional biopolymer for possible applications in the food and pharmaceutical fields.

Chemoselective modification of chitosan with arginine and hydroxyproline: Development of antibacterial composite films for wound healing applications

This study explored the enhancement of chitosan for wound dressing applications through selective functionalization with arginine and hydroxyproline amino acids, combined with polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) in composite films. The research employed chemoselective amino acid grafting followed by solution casting to fabricate the composite materials. Fourier transform infrared (FTIR) analysis verified successful chitosan modification through the presence of a carbamate bond at 1719 cm−1 and an amide bond shift from 1660 to 1680 cm−1, with nuclear magnetic resonance (NMR) analysis providing additional confirmation. The composite films demonstrated exceptional properties, achieving maximum tensile strength of approximately 55 MPa and swelling ratio of about 400 %. Statistical analysis revealed significant variations in mechanical and swelling properties across formulations (p < 0.05), with analysis of variance (ANOVA) showing a between-group sum of squares of 122,980.519 for tensile strength and 352,306.333 for swelling. Duncan's multiple range test identified distinct groupings for tensile strength (5.67–119.67 MPa) and swelling ratios (320.33–565.33 %), demonstrating the impact of composition on material properties. Thermal stability analysis (25–600 °C) revealed a multi-step degradation process, confirming successful modification and composite formation. The amino acid-modified chitosan composites showed remarkable antibacterial enhancement, exhibiting 60 % greater activity against both Gram-positive and Gram-negative bacteria compared to unmodified chitosan. These findings demonstrate the potential of selectively functionalized chitosan composite films for advanced wound dressing applications, combining enhanced antibacterial efficacy with robust mechanical and thermal properties. Future research directions include formulation optimization and in vivo validation of clinical efficacy.

Identification of fibrinogen as a plasma protein binding partner for lecanemab biosimilar IgG.

Recombinant monoclonal therapeutic antibodies like lecanemab, which target amyloid beta in Alzheimer's disease, offer a promising approach for modifying the disease progression. Due to its relatively short half-life, lecanemab administered as a bi-monthly infusion (typically 10 mg/kg) has a relatively brief half-life. Interaction with abundant plasma proteins binder in the bloodstream can affect pharmacokinetics of drugs, including their half-life. In this study, we investigated potential plasma protein binding (PPB) interaction to lecanemab using lecanemab biosimilar. Lecanemab biosimilar used in this study was based on publicly available sequences. ELISA and western blotting were used to assess lecanemab biosimilar immunoreactivity in the fractions of human plasma obtained through size exclusion chromatography. The binding of lecanemab biosimilar to candidate plasma binders was confirmed by western blotting, ELISA, and surface plasmon resonance analysis. Using a combination of equilibrium dialysis, ELISA, and western blotting in human plasma, we first describe the presence of likely PPB partners to lecanemab biosimilar and then identify fibrinogen as one of them. Utilizing surface plasmon resonance, we confirmed that lecanemab biosimilar does bind to fibrinogen, although with lower affinity than to monomeric amyloid beta. In the context of lecanemab therapy, these results imply that fibrinogen levels could impact the levels of free antibodies in the bloodstream and that fibrinogen might serve as a reservoir for lecanemab. More broadly, these results indicate that PPB may be an important consideration when clinically utilizing therapeutic antibodies in neurodegenerative disease.

EVA1-Antibody Drug Conjugate is a new therapeutic strategy for eliminating glioblastoma-initiating cells.

The discovery of glioblastoma (GBM)-initiating cells (GICs) has impacted GBM research. These cells are not only tumorigenic, but also exhibit resistance to radiotherapy and chemotherapy. Therefore, it is crucial to characterize GICs thoroughly and identify new therapeutic targets. In a previous study, we successfully identified Epithelial V-like antigen 1 (EVA1) as a novel functional factor specific to GICs. Hybridoma cells were generated by immunizing BALB/c mice with EVA1-Fc fusion protein. The reactivity of the supernatant from these hybridoma cells was examined using EVA1-overexpressing cells and GICs. Candidate antibodies were further selected using Biacore surface plasmon resonance analysis and two cytotoxicity assays, antibody-dependent cell cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Among the antibodies, the cytotoxicity of the B2E5-antibody drug conjugate (B2E5-ADC) was evaluated by both adding it to cultured GICs and injecting it into GIC tumor-bearing brains. B2E5 demonstrated a high affinity for human EVA1 and effectively killed both EVA1-expressing cell lines and GICs in culture through ADCC and CDC. B2E5-ADC also exhibited strong cytotoxicity to GICs in culture and prevented their tumorigenesis in the brain when administered intracranially to the tumor-bearing brain. Our data indicate that B2E5-ADC is a new and promising therapeutic strategy for GBM.

Characterization of Free and Glycosidically Bound Volatile and Non-Volatile Components of Shiikuwasha (Citrus depressa Hayata) Fruit

Shiikuwasha, a citrus fruit native to Okinawa, Japan, has various cultivation lines with distinct free volatile and non-volatile components. However, the glycosylated volatiles, which are sources of hidden aromas, remain unknown. This study aimed to characterize the chemical profiles of free and glycosidically bound volatile as well as non-volatile components in the mature fruits of six Shiikuwasha cultivation lines: Ishikunibu, Izumi kugani-like, Kaachi, Kohama, Nakamoto seedless, and Ogimi kugani. Free volatiles were analyzed using solid-phase microextraction–gas chromatography–mass spectrometry. Glycosides were collected via solid-phase extraction and hydrolyzed with β-glucosidase, and the released volatiles were measured. Additionally, the non-volatile components were determined using non-targeted proton nuclear magnetic resonance analysis. Total free and bound volatiles ranged from 457 to 8401 µg/L and from 104 to 548 µg/L, respectively, and the predominant free volatiles found were limonene, γ-terpinene, and p-cymene. Twenty volatiles were released from glycosides, including predominant 1-hexanol and benzyl alcohol, with Kaachi and Ogimi kugani showing higher concentrations. Principal component analysis (PCA) revealed that taste-related compounds like sucrose, citrate, and malate influenced line differentiation. The PCA of the combined data of free and bound volatile and non-volatile components showed flavor component variances across all lines. These findings provide valuable insights into the chemical profiles of Shiikuwasha fruits for fresh consumption and food and beverage processing.

Electrocardiographic criteria for the diagnosis of left ventricular hypertrophy in patients with severe aortic stenosis

Abstract Introduction There is a lack of data regarding the performance of current electrocardiographic (EKG) criteria for left ventricular hypertrophy (LVH) in patients with severe aortic stenosis (AS). Purpose To test the performance of the current EKG scores to diagnosis LVH in AS patients, and also to compare the performance of a new proposed score. Methods The present study evaluated 80 patients with severe AS that underwent cardiac magnetic resonance to diagnose LVH, defined as left ventricular indexed mass of 95 g/m² for female and 115 g/m² for male patients. The EKG criteria used for left ventricular hypertrophy were Sokolow-Lyon criteria, Romhilt-Estes point score system, Cornell voltage criteria and Peguero-Lo Presti criteria. Results Among the 80 patients included in analysis, 58.7% were male and the mean age was 64±8 years. There was a high prevalence of comorbidities, highlighting diabetes (32.5%), hypertension (67.5%), atrial fibrillation (5.0%) and coronary artery disease (11.3%). Regarding echocardiogram, the median left ventricle ejection fraction was 64 (56-68)% and the median indexed aortic valve area was 0.43 (0.35-0.49) cm²/m². Cardiac magnetic resonance analysis demonstrated a mean left ventricle mass of 168±55g, and the LVH incidence was 26.3%. Regarding EKG, Strain pattern was found in 49.1% of the patients, Cornell voltage criteria was positive in 51.3%, Sokolow-Lyon criteria in 51.3%, Romhilt-Estes point score system in 42.5% and Peguero-Lo Presti criteria in 61.3%. Discriminative capacity of electrocardiographic criteria for LVH is shown in Figure 1. Peguero-Lo Presti score had the best diagnostic accuracy in the overall population and in male sex (AUC 0.776), while Cornell voltage criteria had the best diagnostic accuracy in female patients (AUC 0.776). Based on linear regression model, the proposed score was created to predict LVH at cardiac magnetic resonance: 48 + (1.3 x Deepest S wave) + (0.5 x S wave in V1 or V2 plus R wave in V5). The proposed score cutoff value of 90.5 mm had a sensitivity of 0.765 and specificity of 0.707 (for male sex: 0.769 and 0.655, respectively; for female sex: 0.750 and 0.759, respectively). Compared to the scores described in the literature, the proposed score had the best area AUC for the overall population (Figure 1), for female and male patients (AUC 0.796, 0.819 and 0.780, respectively). Conclusion In patients with severe AS, the proposed score had the best diagnostic accuracy compared to the scores described in the literature for LVH identification, followed by Peguero-Lo Presti score, even when analyzed based on gender. Besides, the proposed score had also acceptable sensitivity and specificity for LVH detection.AUC of electrocardiographic scores.

Quantitative perfusion by cardiac magnetic resonance analysis reveals compromised myocardial perfusion in patients with angina with non-obstructive coronary artery disease

Abstract Introduction Stress perfusion cardiac magnetic resonance (CMR) visually detects myocardial ischemia through first-pass contrast-enhanced imaging by identifying perfusion defects. However, in generalized myocardial diseases like angina with non-obstructed coronary arteries (ANOCA), visual assessment becomes challenging due to diffuse sub-endocardial perfusion defects, or the findings may even falsely appear normal. Fully automated quantitative perfusion (QP), allowing absolute quantification of myocardial blood flow (MBF) and deriving myocardial perfusion reserve (MPR), might increase diagnostic accuracy in ANOCA patients. Therefore, the purpose of this study is to test the use of QP in detecting ANOCA diagnosed by the invasive golden standard. Methods This study is a cross-sectional cohort study assessing the use of fully automated QP CMR in patients with ANOCA compared with age- and sex-matched healthy controls. All participants underwent adenosine stress perfusion CMR, including visual assessment and quantification of MBF and MPR. Furthermore, all ANOCA patients underwent intracoronary function testing (ICFT) to idenity vasospasm and/or coronary microvascular dysfunction. Results This study included 24 ANOCA patients (83% women, 56.8±8.9 years) and 25 healthy controls (80% women, 56.2±7.2 years). Visual perfusion assessment showed no group differences in terms of perfusion defects (p=0.536). However, in QP, ANOCA patients had higher relative MBF than healthy controls (0.83±0.15 vs 0.74±0.17, p=0.046), while global perfusion was significantly lower during stress (2.43±0.72 vs 2.99±0.65 ml/g/min, p=0.006). Moreover, ANOCA patients had significantly lower MPR than healthy controls (2.24 ±0.79 vs 2.68 ±0.64, respectively p=0.036), with a higher prevalence of an impared MPR (50% vs. 20%, p=0.027). MPR was not significantly different between the various ANOCA entities as stratified during ICFT (p=0.766). Conclusions ANOCA patients displayed significantly reduced MPR, indicating impaired perfusion. The prevalence of diminished MPR was higher in the ANOCA group compared to the healthy controls, constrasting with no differences in visual assessment. These results are promising and underscores the possibilities of the use of QP in detecting vasomotor dysfunction non-invasively in ANOCA patients.Quantitative Perfusion by CMR results

Solving the Puzzle of the Carbonic Acid Vibrational Spectrum - an Anharmonic Story.

Against the general belief that carbonic acid is too unstable for synthesis, it was possible to synthesize the solid[1,2] as well as gas-phase carbonic acid.[3] It was suggested that solid carbonic acid might exist in Earth's upper troposphere and in the harsh environments of other solar bodies,[4] where it undergoes a cycle of synthesis, decomposition, and dimerization.[5] To provide spectroscopic data for probing the existence of extraterrestrial carbonic acid,[2,6] matrix-isolation infrared (MI-IR) spectroscopy has shown to be essential.[3,4,6-8] However, early assignments within the harmonic approximation using scaling factors impeded a full interpretation of the rather complex MI-IR spectrum of H2CO3. Recently, carbonic acid was detected in the Galactic center molecular cloud,[9] triggering new interest in the anharmonic spectrum.[10] In this regard, we substantially reassign our argon MI-IR spectra based on accurate anharmonic calculations. We calculate a four-mode potential energy surface (PES) at the explicitly correlated coupled-cluster theory using up to triple-zeta basis sets, i. e., CCSD(T)-F12/cc-pVTZ-F12. On this PES, we perform vibrational self-consistent field and configuration interaction (VSCF/VCI) calculations to obtain accurate vibrational transition frequencies and resonance analysis of the fundamentals, first overtones, and combination bands. In total, 12 new bands can be assigned, extending the spectral data for carbonic acid and thus simplifying detection in more complex environments. Furthermore, we clarify disputed assignments between the cc- and ct-conformer.