Proton Magnetic Resonance Research Articles

Muscle fibre typology affects whole-body metabolic rate during isolated muscle contractions and human locomotion.

The wide variation in muscle fibre type distribution across individuals, along with the very different energy consumption rates in slow versus fast muscle fibres, suggests that muscle fibre typology contributes to inter-individual differences in metabolic rate during exercise. However, this has been hard to demonstrate due to the gap between a single muscle fibre and full-body exercises. We investigated the isolated effect of triceps surae muscle contraction velocity on whole-body metabolic rate during cyclic contractions in individuals a priori selected for their predominantly slow (n=11) or fast (n=10) muscle fibre typology by means of proton magnetic resonance spectroscopy (1H-MRS). Subsequently, we examined their whole-body metabolic rate during walking and running at 2m/s, exercises with comparable metabolic rates but distinct triceps surae muscle force and velocity demands (walking: low force, high velocity; running: high force, low velocity). Increasing triceps surae contraction velocity during cyclic contractions elevated net whole-body metabolic rate for both typology groups. However, the slow group consumed substantially less net metabolic energy at the slowest contraction velocity, but the metabolic difference between groups diminished at faster velocities. Consistent with the more economic force production during slow contractions, the slow group exhibited lower metabolic rates than the fast group while running, whereas metabolic rates were similar during walking. These findings provide important insights into the influence of muscle fibre typology on whole-body metabolic rate and emphasize the importance of considering muscle mechanical demands to understand muscle fibre typology related differences in whole-body metabolic rates. KEY POINTS: Muscle fibre typology is often suggested to affect whole-body metabolic rate, yet convincing in vivo evidence is lacking. Using isolated plantar flexor muscle contractions in individuals a priori selected for their predominantly slow or fast muscle fibre typology, we demonstrated that having predominantly slow muscle fibres provides a metabolic advantage during slow muscle contractions, but this benefit disappeared at faster contractions. We extended these results to full-body exercises, where we demonstrated that higher proportions of slow fibres associated with better economy during running but not when walking. These findings provide important insights into the influence of muscle fibre typology on whole-body metabolic rate and emphasize the importance of considering muscle mechanical demands to understand muscle fibre typology related differences in whole-body metabolic rate.

Noise suppression of proton magnetic resonance spectroscopy improves paediatric brain tumour classification.

Proton magnetic resonance spectroscopy (1H-MRS) is increasingly used for clinical brain tumour diagnosis, but suffers from limited spectral quality. This retrospective and comparative study aims at improving paediatric brain tumour classification by performing noise suppression on clinical 1H-MRS. Eighty-three/forty-two children with either an ependymoma (ages 4.6 5.3/9.3 5.4), a medulloblastoma (ages 6.9 3.5/6.5 4.4), or a pilocytic astrocytoma (8.0 3.6/6.3 5.0), recruited from four centres across England, were scanned with 1.5T/3T short-echo-time point-resolved spectroscopy. The acquired raw 1H-MRS was quantified by using Totally Automatic Robust Quantitation in NMR(TARQUIN), assessed by experienced spectroscopists, and processed with adaptive wavelet noise suppression (AWNS). Metabolite concentrations were extracted as features, selected based on multiclass receiver operating characteristics, and finally used for identifying brain tumour types with supervised machine learning. The minority class was oversampled through the synthetic minority oversampling technique for comparison purposes. Post-noise-suppression 1H-MRS showed significantly elevated signal-to-noise ratios (P < .05, Wilcoxon signed-rank test), stable full width at half-maximum (P > .05, Wilcoxon signed-rank test), and significantly higher classification accuracy (P < .05, Wilcoxon signed-rank test). Specifically, the cross-validated overall and balanced classification accuracies can be improved from 81% to 88% overall and 76% to 86% balanced for the 1.5T cohort, whilst for the 3T cohort they can be improved from 62% to 76% overall and 46% to 56%, by applying Naïve Bayes on the oversampled 1H-MRS. The study shows that fitting-based signal-to-noise ratios of clinical 1H-MRS can be significantly improved by using AWNS with insignificantly altered line width, and the post-noise-suppression 1H-MRS may have better diagnostic performance for paediatric brain tumours.

Interoperator reproducibility of quantitative ultrasound analysis of hepatic steatosis in participants with suspected MASLD: A prospective study

ObjectivesTo evaluate the reproducibility of tissue attenuation imaging (TAI) and tissue scatter distribution imaging (TSI) measurements in adults with suspected metabolic dysfunction-associated steatotic liver disease (MASLD) between radiologists with varying experience. Materials and methodsParticipants with suspected MASLD were prospectively recruited. TAI and TSI were performed for each participant by two radiologists with different levels of experience. Interoperability reliability was assessed on the basis of Bland-Altman analysis and intraclass correlation coefficients (ICCs). The study determined and compared the diagnostic performance of TAI and TSI with clinical prediction models using proton magnetic resonance spectroscopy (1H-MRS) as a reference. ResultsA total of 180 participants (women, n = 56; men, n = 124, mean age, 46.98 ± 14.92 years; mean BMI, 25.81 ± 4.47) were enrolled from August 2022 to September 2022. Bland-Altman plots showed only slight deviation in the TAI and TSI results of the two radiologists; there was good interoperator reproducibility for TAI (ICC = 0.92) and TSI (ICC = 0.86). Senior and junior radiologists performed examinations labeled as TAI-1 and TSI-1, and TAI-2 and TSI-2, respectively. The areas under the curves (AUCs) of TAI-1, TAI-2, TSI-1, and TAI-2 for the detection of ≥5 % hepatic steatosis were 0.90, 0.96, 0.91 and 0.96, respectively. According to ROC analysis, the diagnostic performance of both radiologists for TAI and TSI was statistically similar and superior to that of the clinical prediction model. ConclusionsTAI and TSI have good reproducibility between radiologists with different levels of experience. Meanwhile, both TAI and TSI demonstrated good diagnostic performance for hepatic steatosis (≥5%), surpassing that of clinical prediction models.

The relationship between oxidative stress markers and 1H-Magnetic resonance spectroscopy findings in obsessive compulsive disorder

IntroductionThe purpose of this study was to examine N-acetyl aspartate (NAA)/creatine (Cr) and glutamate, glutamine, and gamma-aminobutyric acid complex (Glx)/Cr levels in patients with obsessive compulsive disorder (OCD) and healthy controls’ orbitofrontal cortex (OFC) and caudate nucleus (CN) by proton magnetic resonance spectroscopy (1H-MRS) method and to investigate their relationship with oxidative stress markers glutathione peroxidase (GPx) and superoxide dismutase (SOD). MethodsThis study included patients with OCD (n = 25) and healthy controls (n = 25) ranging in age from 18 to 65. We used the ELISA method to evaluate serum SOD and GPx levels. Levels of NAA/Cr and Glx/Cr in the orbitofrontal cortex and caudate nucleus were measured using the 1H-MRS method. ResultsOur study did not detect statistically significant differences in the orbitofrontal cortex Glx/Cr and NAA/Cr levels between the OCD patients and the control group. OCD patients exhibited a decrease in NAA/Cr levels, consistent with impaired neuronal integration, and an increase in Glx/Cr levels, consistent with hyperactivation, in the caudate nucleus compared to the control group. We observed a negative correlation between NAA/Cr levels in the caudate nucleus and the levels of SOD and GPx. ConclusionsOur study is the first to assess CN and OFC together in OCD patients using 3 T MR, investigating the relationship between neurometabolite concentrations and oxidative stress parameters. The negative correlation we observed between NAA/Cr levels and SOD and GPx in the caudate nucleus suggests that increased oxidative stress in this brain region in OCD patients may contribute to impaired neuronal integration and functionality.

Synthesis, characterization and luminescent properties of N-donor based samarium-tris-β-diketonate: Tuning optoelectronic characteristics for displays applications

Ternary Sm(III) complexes of general representation [Sm(TFDH)3L] were synthesized to understand influence of different auxiliary moieties on their optoelectronic properties. The synthesized complexes were thoroughly investigated using elemental, IR, NMR, UV and PL studies. In these complexes, the emitting metal ion is bonded with six O atoms from di-ketone 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione and two nitrogen atoms from neutral ligand i.e. 1,10-phenanthroline and its derivatives. Proton NMR spectral data showed that samarium ion induced chemical shift is dipolar in nature. The photoluminescence analysis showed that the complexes show intense orange-red emission due to 4G5/2 → 6H9/2 transition. Moreover, CIE color coordinates supported the results obtained from photoluminescence study, providing additional confirmation of the luminescent properties of prepared complexes within the orange-red region. Their utility in displays and OLED's was confirmed by studying their optical and electronic band gaps.

Resistance exercise effects on hippocampus subfield volumes and biomarkers of neuroplasticity and neuroinflammation in older adults with low and high risk of mild cognitive impairment: a randomized controlled trial

Physical exercise is suggested to promote hippocampal neuroplasticity by increasing circulating neurotrophic and anti-inflammatory factors. Our aim was to explore the interplay between the effect of progressive resistance exercise on blood biomarker levels, hippocampal neurometabolite levels and hippocampal volume in older adults with a low compared to a high risk of mild cognitive impairment (MCI). Seventy apparently healthy male/female older adults (aged 60–85 years old) were randomly allocated to a 12 week lower limb progressive resistance or no intervention, stratified for low (< 26/30) or high (≥ 26/30) Montreal Cognitive Assessment (MoCA) score, indicating MCI risk. Outcome measures were blood levels of insulin-like growth factor-1 (IGF-1), interleukin-6 (IL-6) or kynurenine (KYN); hippocampal total and subfield volumes of the cornu ammonis 1 (CA1) and 4 (CA4), subiculum, presubiculum, and dentate gyrus measured with magnetic resonance imaging (MRI); and hippocampus neurometabolites including total N-acetylaspartate (NAA), myo-inositol (mIns), and total creatine (Cr) measured with proton magnetic resonance spectroscopy (1H-MRS). We evaluated the intervention effect, cognitive status effect, their interaction and the bivariate relationship between exercise-induced changes between the outcome measures. Higher kynurenine levels (p = 0.015) and lower subiculum volumes (p = 0.043) were found in older adults with high MCI risk compared to older adults with low MCI risk. Exercise-induced CA1 volume changes were negatively correlated with hippocampal tNAA/mIns level changes (r = -0.605, p = 0.006). This study provides valuable insight in the multifactorial processes related to resistance training in older adults with low or high MCI risk.

Boosted antibacterial efficacy: Di and triorganotin complexes via 2-[(2,3-dimethylphenyl)amino]benzoic acid

Using appropriate organotin chloride salts and a ligand called 2-[(2,3-dimethylphenyl) amino] benzoic acid (DMPAB), a condensation procedure produced novel complexes such as triphenyltin, dimethyl, diphenyl, and dibutyl-tin. For difficult identification, a variety of analytical methods were used, including elemental analysis, carbon and proton magnetic resonance, and infrared spectra. The agar ditch method was used to assess the antibacterial effectiveness against Staphylococcus aureus and Escherichia coli. When compared to the molecule generated from the ligand, the complexes showed more inhibitory action. Among the complexes tested, the dimethyltin carboxylate complex showed the strongest antibacterial action against Staphylococcus aureus and Escherichia coli.&#x0D; KEY WORDS: Complexes, Antibacterial properties, Condensation process, Agar Ditch, Staphylococcus aureus and Escherichia coli&#x0D; Bull. Chem. Soc. Ethiop. 2024, 38(3), 647-655. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v38i3.8

New diarylplatinum complexes containing 4,5-diazafluoren-9-one; synthesis, characterization, X-ray crystallography structure investigation and oxidative addition reaction studies

The synthesis of a new diarylplatinum(II) complex containing 4,5-diazafluoren-9-one (DAFO) was reported using the reaction of [Pt(p-tolyl)2(S(CH3)2)2] and DAFO with one to one equivalent. The platinum(IV), [PtIMe(p-tolyl)2DAFO], was then formed through the oxidative addition (OA) of iodomethane and [Pt(p-tolyl)2DAFO]. In the synthesized complexes, the DAFO was coordinated to the metal center as a chelating reagent through the nitrogen atoms. Identifications of the compounds were achieved using various techniques such as proton NMR, UV–Vis, FT-IR, CHN analyses. Furthermore, the organoplatinum(II) structure, involving DAFO, has been identified using single crystal X-ray crystallography. The band of MLCT in the visible region of Pt(II) was decayed in the oxidative addition and producing Pt(IV) complex. This variation in the visible region was applied to calculate the activation parameters of the reaction. The excess amounts of iodomethane were utilized to make pseudo-first-order status. At different temperatures kobs, k2, entropy and enthalpy changes of activation were determined.

Water-Soluble Quaternary and Protonable Basic Chitotriazolans: Synthesis by Click Chemistry Conversion of Chitosan Azides and Investigation of Antibacterial Activity.

The azide transfer reaction and copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) can be used to convert the amino groups in chitosan to triazole 1,2,3-moieties. The resulting polymer has been named chitotriazolan. This synthesis was performed with six different quaternary ammonium alkynes and three amine alkynes to obtain a series of nine water-soluble chitotriazolan derivatives. The structure and complete conversion of the azide were confirmed by FT-IR and proton NMR spectroscopy. The derivatives were investigated for antibacterial activity against S. aureus, E. faecalis, E. coli, and P. aeruginosa. The activity of the quaternized chitotriazolan derivatives varied depending on the structure of the quaternary moiety and the species of bacteria. The basic protonable derivatives were less active or inactive against the bacteria.

Multi-modal neuroimaging reveals differences in alcohol-cue reactivity but not neurometabolite concentrations in adolescents who drink alcohol

BackgroundThe objective of this multi-modal neuroimaging study was to identify neuroscience-informed treatment targets for adolescent alcohol use disorder (AUD) by examining potential neural alterations associated with adolescent alcohol use. MethodsAdolescents (ages 17–19) who heavily used (n=49) or did not use alcohol (n=22) were recruited for a multi-modal neuroimaging protocol, including proton magnetic resonance spectroscopy within the dorsal anterior cingulate cortex (dACC) and an fMRI alcohol cue-reactivity task. The alcohol cue-reactivity task was analyzed across 11 a priori regions-of-interest (ROI), including the dACC, and in an exploratory whole-brain approach. Correlations were run between neurometabolite levels and alcohol cue-reactivity in the dACC. ResultsThere were no significant group differences in absolute neurometabolite concentrations. Compared to the control group, the alcohol-using group exhibited heightened alcohol cue reactivity in the left amygdala ROI (p=0.04). The whole-brain approach identified higher alcohol cue reactivity in the alcohol-using group compared to controls in the amygdala and occipital regions, and lower reactivity in the parietal lobe. Whole-brain sex effects were noted, with females displaying higher reactivity regardless of group. No significant correlations were found between neurometabolite levels and alcohol cue-reactivity in the dACC. ConclusionsThe null neurometabolic findings may be due to age, relatively low severity of alcohol use, and non-treatment-seeking status of the participants. Females showed overall higher reactivity to alcohol cues, indicating a sex effect regardless of alcohol use history. Higher amygdala reactivity in alcohol-using adolescents suggests that emotional processing related to alcohol cues may be a useful target for future adolescent AUD interventions.

New antibacterial, antifungal and antioxidant agents bearing sulfonamide

The successful nickel catalyzed synthesis of N-(aryl) substituted p-toluene sulphonamides is reported. The intermediate 4-methylbenzenesulphonamide was obtained by the reaction of p-toluenesulphonyl chloride and ammonium hydroxide. Substituted p-toluene sulphonamides were obtained by coupling 4-methylbenzenesulphonamide with readily available aryl halides via Buchwald-Hartwig cross-coupling reaction. The structures of the compounds were confirmed using Fourier Transform Infrared (FT-IR), proton NMR, carbon-13 NMR and mass spectroscopy. The new compounds were screened for antibacterial and antifungal activities against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus niger using agar diffusion technique. Some of the compounds showed improved antimicrobial activity when compared with ciprofloxacin and ketoconazole. The sulphonamides were further screened for antioxidant activity using 1,1-diphenyl-2-picrylhydrazide (DPPH), ferric reducing antioxidant potency (FRAP) and ferrous sulphate induced lipid peroxidation. The compounds showed improved antioxidant activity on comparison with ascorbic acid. Specifically, compound 20 was revealed by this study to be a lead antibacterial and antifungal agent whereas compound 17 showed a lead as antioxidant agent. The drug-likeness study indicated that none of the compounds violated Lipinski, Ghose, and Verber rules for drug-able molecules.

Water-Mediated Synthesis, Antibacterial and Antioxidant Evaluation of New Fused Pyrimido-pyrimidine and Pyrimido-purines Derived From Nucleobases

Introduction: A simple and eco-friendly synthesis of novel substituted pyrimido[1,6- a]pyrimidine, pyrimido[1,2-g]purine, and pyrimido[2,1-e]purine was accomplished by refluxing of nucleobases (cytosine, adenine or guanine) and dibenzalacetone (DBA) in water using NaOH as a catalyst. Methods: The molecular structures of the resulting products were characterized by infrared spectroscopy (FT-IR), mass spectrometry, and proton (1H) and carbon (13C) nuclear magnetic resonance (NMR). Results: The antibacterial activity of the newly fused heterocycles was assayed against the Gram-positive bacterium Staphylococcus aureus (ATCC 6538) and Gram-negative Escherichia coli (ATCC 8737) using gentamicin as a standard commercially available antibiotic Conclusion: as a standard commercially available antibiotic. Conclusion: In addition, the antioxidant capacity was screened using the 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH•) and the 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS+•) radicals scavenging assay.

In vitro analysis of quercetin-like compounds from mistletoe Dendrophthoe pentandra (L.) Miq as a potential antiviral agent for Newcastle disease

Background Recent evidence suggests that some flavonoid compounds obtained from crude methanol extract of mistletoe leaves (Dendrophthoe pentandra L. Miq), also known as Benalu Duku (BD), have antimicrobial effects. Thus, the plant has the potential to eliminate viruses that may cause outbreaks in chicken farms. This study aimed to prove the in vitro ability of flavonoid compounds, namely quercetin-like compounds (QLCs), to eliminate field viruses, specifically the Newcastle disease virus (NDV). Methods This research was performed in two stages. An in vitro test was used with a post-test of the control groups designed at a significance of 0.05. BD leaves (5 kg) were extracted using a maceration method with methanol and then separated into hexane, chloroform, ethyl acetate, and methanol fractions. The final extracted products were separated using semi-preparative high-performance liquid chromatography (HPLC) to obtain QLCs. The QLCs were identified and compared with quercetin using HPLC, proton and carbon nuclear magnetic resonance spectrometry, Fourier transform infrared spectrophotometry, and ultra-performance liquid chromatography–mass spectrometry. The activity of QLCs was tested in vitro against the NDV at a virulence titer of 10−5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. Results Solutions of 0.05% (w/v) QLCs were discovered to have antiviral activity against NDVs, with an average cytopathogenic effect antigenicity at a 10−5 dilution (p&lt;0.05). Conclusions QLCs from flavonoids from the leaves of BD have in vitro antiviral bioactivity against NDV at a virulence titer of 10-5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. QLCs may have the potential to be developed as medicinal compounds for the treatment of other human or animal viral infections.

Synthesis and Spectral Analysis of Chromium, Copper Complexes of 2-Hydroxy-1, 2-diphenylethan-1

Various chemical process have been utilized to analyze chromium (II) and copper (II) complexes with Benzoin. The fore mentioned complexes were analyzed for elemental analyses, and characterized by infrared, electronic spectra, NMR spectroscopy. The data analysis showed the metal ion formation of 1:1 ligand to metal ratio representing the [Cr (B)] H2O and [Cu (B)] 2H2O ionic complex in which B represents the Benzoin. According to the data analyzed by Infrared spectroscopy, it is through the carbonyl and hydroxyl oxygen’s of the Benzoin that chelation chemistry takes place. The complex structural analysis was elucidated by electronic spectral data analysis and by proton NMR spectroscopy. The complex systems with the metals also showed antimicrobial property against many bacterial strains.&#x0D;

Photophysical analysis and Judd–Ofelt calculation of Eu (III) complexes: Influence of various neutral ligands on luminescent properties

This article presents the preparation and characterization of a series of four tris-β-diketonate Eu(III) complexes with formulation of [Eu(tfaa)3(L)n], tfaa denotes the 1,1,1-trifluoroacetylacetone, L to monodentate or bidentate neutral ligand with nitrogen and oxygen as donor atom and n can be 1 and 2. The characterization of synthesized complexes was done using infrared spectroscopy, thermo-gravimetric analysis and proton NMR spectroscopy. UV–vis absorption, photoluminescence as well as time-resolved luminescence spectroscopies were also employed to examine the spectroscopic features of ternary complexes. The proton NMR and IR spectral information has suggested the bonding of organic moieties to the Eu(III) ion. The chemical shift obtained for the protons of primary and secondary moieties are shifted in an opposite direction. The band gap values (optical and electronic) suggest the semiconducting nature of prepared europium complexes. The trivalent ion centered emission is shown by all the prepared complexes on excitation under UV-light. The hypersensitive peak situated at about 612 nm responsible for red emission is corresponding to 5D0→7F2 transition and found to be sensitive to the chelating environment present at around emissive ion. Red emanating europium materials have acquired significant utilization in OLEDs, flat panel displays and solid state electronics.

Neurometabolic and Brain Functional Alterations Associated with Cognitive Impairment in Patients with Myasthenia Gravis: A Combined 1H-MRS and fMRI Study

Whether patients with myasthenia gravis (MG) exhibit cognitive impairment is controversial. Also the underlying mechanisms are unknown. We aimed to investigate alterations in cognitive function, neurometabolite levels, and brain function in patients with MG and to explore the associations between abnormal regional brain functional activity, neurometabolite concentrations in the MPFC and left thalamus, and cognitive activity in patients with MG. Neuropsychological tests, proton magnetic resonance spectroscopy, and resting-state functional magnetic resonance imaging were performed on 41 patients with MG and 45 race-, sex-, age-, and education-matched healthy controls (HCs). The results suggest that MG is accompanied by cognitive decline, as indicated by global cognitive function, visual-spatial function, language, memory, abnormalities in regional brain functional activity, and neurometabolite alterations (including GABA, NAA, and Cho) in the medial prefrontal cortex (MPFC) and left thalamus. Cognitive impairment in patients with MG may be related to abnormal regional brain functional activity and changes in neurometabolites, and regional brain functional activity may be modulated by specific neurometabolites.

Proteomic Analysis of the Mycobacterium tuberculosis Outer Membrane for Potential Implications in Uptake of Small Molecules.

Increased resistance to current antimycobacterial agents and a potential bias toward relatively hydrophobic chemical entities highlight an urgent need to understand how current anti-TB drugs enter the tubercle bacilli. While inner membrane proteins are well-studied, how small molecules cross the impenetrable outer membrane remains unknown. Here, we employed mass spectrometry-based proteomics to show that octyl-β-d-glucopyranoside selectively extracts the outer membrane proteins of Mycobacterium tuberculosis. Differentially expressed proteins between nutrient-replete and nutrient-depleted conditions were enriched to identify proteins involved in nutrient uptake. We demonstrate cell surface localization of seven new proteins using immunofluorescence and show that overexpression of the proteins LpqY and ProX leads to hypersensitivity toward streptomycin, while overexpression of SubI, SpmT, and Rv2041 exhibited higher membrane permeability, assessed through an EtBr accumulation assay. Further, proton NMR metabolomics suggests the role of six outer membrane proteins in glycerol uptake. This study identifies several outer membrane proteins that are involved in the permeation of small hydrophilic molecules and are potential targets for enhancing the uptake and efficacy of anti-TB drugs.

Honey produced by apini and meliponini in Brazil: multivariate analysis of physicochemical parameters, sugar and metabolite profiles

The objective of this study was to investigate honey samples from two bee tribes grouped in Meliponini (stingless bee) and Apini (Apis mellifera) honeys from Brazil, in order to compare their chemical composition. Thirty-four honey samples were collected and evaluated by proton NMR spectroscopy, HPLC and physicochemical parameters, using chemometric methods. Principal component analysis (PCA) was able to discriminate Apini and Meliponini goups. Additionally, the partial least squares discriminant analysis (PLS-DA) models were able to predict the Apini and Meliponini honey samples with sensitivity, specificity and accuracy values close to 100%. Frequency values between 4.00 − 3.00 ppm, corresponding to the sugar region, were important for the classification by the PLS-DA model using NMR data. For the PLS-DA model using physicochemical data, the main parameters for classification were water activity, reducing sugar, moisture, refractive index, total soluble solids, maltose and glucose. Since stingless honeys have no regulation, the data presented in this study can compose a database to assist in the establishment of regulatory criteria. Moreover, the chemometric models proposed can be used as a tool for the quality control of honey, especially for authentication purposes.

A theoretical and electrochemical impedance spectroscopy study of the adsorption and sensing of selected metal ions by 4-morpholino-7-nitrobenzofuran

The selectivity of a novel chemosensor, based on a modified nitrobenzofurazan referred to as NBD-Morph, has been investigated for the detection of heavy metal cations (Co2+, Pb2+, Mg2+, Ag+, Cu2+, Hg2+, Ni2+, and Zn2+). The ligand, 4-morpholino-7-nitrobenzofurazan (NBD-Morph), was characterized using spectroscopic techniques including FT-IR and 1H NMR. Vibrational frequencies obtained from FT-IR and proton NMR (1H) chemical shifts were accurately predicted employing the density functional theory (DFT) at the B3LYP level of theory. Furthermore, an examination of the structural, electronic, and quantum chemical properties was conducted and discussed. DFT calculations were employed to explore the complex formation ability of the NBD-Morph ligand with Co2+, Pb2+, Mg2+, Ag+, Cu2+, Hg2+, Ni2+, and Zn2+ metal cations. The comparison of adsorption energies for all possible conformations reveals that NBD-Morph exhibits sensitivity and selectivity towards metal ions, including Pb2+, Cu2+, Ag+, and Ni2+. However, an assessment of their reactivity using QTAIM topological parameters demonstrated the ligand's greater complexation ability toward Cu2+ or Ni2+ than those formed by Pb2+ or Ag+. Additionally, molecular electrostatic potential (MEP), Hirshfeld surfaces, and their associated 2D-fingerprint plots were applied to a detailed study of the inter-molecular interactions in NBD-Morph-X (X = Pb2+, Cu2+, Ag+, Ni2+) complexes. The electron localization function (ELF) and the localized-orbital locator (LOL) were generated to investigate the charge transfer and donor-acceptor interactions within the complexes. Electrochemical analysis further corroborates the theoretical findings, supporting the prediction of NBD-Morph's sensory ability towards Ni2+ metal cations. In conclusion, NBD-Morph stands out as a promising sensor for Ni2+.

Endocannabinoid levels in plasma and neurotransmitters in the brain: a preliminary report on patients with a psychotic disorder and healthy individuals.

Interactions between the endocannabinoid system (ECS) and neurotransmitter systems might mediate the risk of developing a schizophrenia spectrum disorder (SSD). Consequently, we investigated in patients with SSD and healthy controls (HC) the relations between (1) plasma concentrations of two prototypical endocannabinoids (N-arachidonoylethanolamine [anandamide] and 2-arachidonoylglycerol [2-AG]) and (2) striatal dopamine synthesis capacity (DSC), and glutamate and y-aminobutyric acid (GABA) levels in the anterior cingulate cortex (ACC). As anandamide and 2-AG might reduce the activity of these neurotransmitters, we hypothesized negative correlations between their plasma levels and the abovementioned neurotransmitters in both groups. Blood samples were obtained from 18 patients and 16 HC to measure anandamide and 2-AG plasma concentrations. For all subjects, we acquired proton magnetic resonance spectroscopy scans to assess Glx (i.e. glutamate plus glutamine) and GABA + (i.e. GABA plus macromolecules) concentrations in the ACC. Ten patients and 14 HC also underwent [18F]F-DOPA positron emission tomography for assessment of striatal DSC. Multiple linear regression analyses were used to investigate the relations between the outcome measures. A negative association between 2-AG plasma concentration and ACC Glx concentration was found in patients (p = 0.008). We found no evidence of other significant relationships between 2-AG or anandamide plasma concentrations and dopaminergic, glutamatergic, or GABAergic measures in either group. Our preliminary results suggest an association between peripheral 2-AG and ACC Glx levels in patients.