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The Science of the Total Environment Sep 2024Integrated health risk assessment strategies for emerging organic pollutants and heavy metals that coexist in water/soil media are lacking. Contents of perfluoroalkyl...
Integrated health risk assessment strategies for emerging organic pollutants and heavy metals that coexist in water/soil media are lacking. Contents of perfluoroalkyl compounds and potentially toxic elements in multiple media were determined by investigating a county where a landfill and a tungsten mine coexist. The spatial characteristics and sources of contaminants were predicted by Geostatistics-based and multivariate statistical analysis, and their comprehensive health risks were assessed. The average contents of perfluorooctane acid, perfluorooctanesulfonic acid, arsenic, and cadmium in groundwater were 3.21, 0.77, 1.69, and 0.14 μg L, respectively; the maximum content of cadmium in soils and rice highly reached 2.12 and 1.52 mg kg, respectively. In soils, the contribution of mine lag to cadmium was 99 %, and fertilizer and pesticide to arsenic was 59.4 %. While in groundwater, arsenic, cadmium and perfluoroalkyl compounds near the landfill mainly came from leachate leakage. Significant correlations were found between arsenic in groundwater and arsenic and cadmium in soils, as well as perfluoroalkyl compounds in groundwater and pH and sulfate. Based on these correlations, the geographically optimal similarity model predicted high-level arsenic in groundwater near the tungsten mine and cadmium/perfluoroalkyl compounds around the landfill. The combination of analytic network process, entropy weighting method and game theory-based trade-off method with risk assessment model can assess the comprehensive risks of multiple pollutants. Using this approach, a high health-risk zone located around the landfill, which was mainly attributed to the presence of arsenic, cadmium and perfluorooctanesulfonic acid, was found. Overall, perfluoroalkyl compounds in groundwater altered the spatial pattern of health risks in an arsenic‑cadmium contaminated area.
Topics: Groundwater; Water Pollutants, Chemical; Fluorocarbons; Arsenic; Environmental Monitoring; Cadmium; Risk Assessment; Soil Pollutants; Alkanesulfonic Acids; Mining; China
PubMed: 38876341
DOI: 10.1016/j.scitotenv.2024.173983 -
Journal of Agricultural and Food... Jul 2023The increased consumption of blue-green algae (BGA)-based dietary supplements has raised concern about their food safety, especially about cyanotoxin presence. The...
The increased consumption of blue-green algae (BGA)-based dietary supplements has raised concern about their food safety, especially about cyanotoxin presence. The hyphenation of liquid chromatography with ion mobility mass spectrometry represents a relevant tool to screen several compounds in a large variety of food matrices. In this work, ultrahigh-performance liquid chromatography coupled to traveling wave ion mobility spectrometry/quadrupole time-of-flight mass spectrometry (UHPLC-TWIMS-QTOF) was employed to establish the first comprehensive TWIMS-derived collision cross section database (CCS) for phycotoxins. The database included 20 cyanotoxins and 1 marine toxin. Accurate /, retention times, and CCS values were obtained for 81 adducts in positive and negative electrospray (ESI/ESI) modes. Reproducibility and robustness of the CCS measurements were determined to be independent of the matrix. A screening was carried out on 19 commercial BGA dietary supplements of different composition. Cyanotoxins were confidently identified in five samples based on retention time, /, and CCS.
Topics: Reproducibility of Results; Mass Spectrometry; Chromatography, Liquid; Marine Toxins; Cyanobacteria Toxins
PubMed: 37347990
DOI: 10.1021/acs.jafc.3c01060 -
Journal of Chemical Theory and... Mar 2024We present a simple and accurate GW implementation based on a combination of a Laplace transform (LT) and other acceleration techniques used in post-self-consistent...
We present a simple and accurate GW implementation based on a combination of a Laplace transform (LT) and other acceleration techniques used in post-self-consistent field quantum chemistry, namely, natural auxiliary functions and the frozen-core approximation. The LT-GW approach combines three major benefits: (a) a small prefactor for computational scaling, (b) easy integration into existing molecular GW implementations, and (c) significant performance improvements for a wide range of possible applications. Illustrating these advantages for systems consisting of up to 352 atoms and 7412 basis functions, we further demonstrate the benefits of this approach combined with an efficient implementation of the Bethe-Salpeter equation.
PubMed: 38469629
DOI: 10.1021/acs.jctc.3c01264 -
Journal of Chemical Theory and... Jan 2024We present a machine learning (ML) framework for predicting Green's functions of molecular systems, from which photoemission spectra and quasiparticle energies at...
We present a machine learning (ML) framework for predicting Green's functions of molecular systems, from which photoemission spectra and quasiparticle energies at quantum many-body level can be obtained. Kernel ridge regression is adopted to predict self-energy matrix elements on compact imaginary frequency grids from static and dynamical mean-field electronic features, which gives direct access to real-frequency many-body Green's functions through analytic continuation and Dyson's equation. Feature and self-energy matrices are represented in a symmetry-adapted intrinsic atomic orbital plus projected atomic orbital basis to enforce rotational invariance. We demonstrate good transferability and high data efficiency of the proposed ML method across molecular sizes and chemical species by showing accurate predictions of density of states (DOS) and quasiparticle energies at the level of many-body perturbation theory () or full configuration interaction. For the ML model trained on 48 out of 1995 molecules randomly sampled from the QM7 and QM9 data sets, we report the mean absolute errors of ML-predicted highest occupied and lowest unoccupied molecular orbital energies to be 0.13 and 0.10 eV, respectively, compared to @PBE0. We further showcase the capability of this method by applying the same ML model to predict DOS for significantly larger organic molecules with up to 44 heavy atoms.
PubMed: 38150268
DOI: 10.1021/acs.jctc.3c01146 -
International Journal of Psychiatry in... Mar 2024Resilience measures are typically based on subjective self-assessment, which is prone to bias. Objective biological/physiological measures of resilience are therefore... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Resilience measures are typically based on subjective self-assessment, which is prone to bias. Objective biological/physiological measures of resilience are therefore needed. Hair cortisol concentration is a particularly promising candidate as a biomarker for resilience.
METHODS
We conducted a meta-analytic review from inception to April 2023 in PubMed, EMBASE, Cochrane Library, and Psych Info databases. All data were analyzed using a random-effects model.
RESULTS
Eight studies were identified that included a total of 1,064 adults. The random effects model demonstrated that resilience and hair cortisol concentration were inversely correlated (r = -0.18, 95% confidence interval [CI] = -0.27 to -0.09) with substantial heterogeneity ( = 54.2%, = 0.03). The inverse association was stronger in those who were age 40 years or younger compared to those who were over 40 years. The correlation coefficients between psychological resilience and hair cortisol concentration among adults assessed by different resilience measures were r = -0.29 (95% CI = -0.49 to -0.08) for the CD-RISC-10; r = -0.21 (95% CI = -0.31 to -0.11) for the CDRISC- 25, and r = -0.08 (95% CI = -0.22 to 0.06) for the BRS. Six of eight studies examined the connection between resilience and perceived stress, where the weighted mean correlation coefficient was r = -0.45 (95% CI = -0.56 to -0.33), with considerable heterogeneity ( = 76.2%, = 0.001).
CONCLUSIONS
There is a negative association between psychological resilience and hair cortisol concentration based on these eight studies. Additional research, particularly prospective studies, is needed to determine whether hair cortisol concentration can be used as a biomarker for psychological resilience.
Topics: Adult; Humans; Resilience, Psychological; Hydrocortisone; Prospective Studies; Hair; Stress, Psychological; Biomarkers; Psychological Tests
PubMed: 37222570
DOI: 10.1177/00912174231178108 -
Journal of Biomolecular Structure &... Sep 2023Determining the structure-odor relationship has always been a very challenging task. The main challenge in investigating the correlation between the molecular structure...
Determining the structure-odor relationship has always been a very challenging task. The main challenge in investigating the correlation between the molecular structure and its associated odor is the ambiguous and obscure nature of verbally defined odor descriptors, particularly when the odorant molecules are from different sources. With the recent developments in machine learning (ML) technology, ML and data analytic techniques are significantly being used for quantitative structure-activity relationship (QSAR) in the chemistry domain toward knowledge discovery where the traditional Edisonian methods have not been useful. The smell perception of odorant molecules is one of the aforementioned tasks, as olfaction is one of the least understood senses as compared to other senses. In this study, the XGBoost odor prediction model was generated to classify smells of odorant molecules from their SMILES strings. We first collected the dataset of 1278 odorant molecules with seven basic odor descriptors, and then 1875 physicochemical properties of odorant molecules were calculated. To obtain relevant physicochemical features, a feature reduction algorithm called PCA was also employed. The ML model developed in this study was able to predict all seven basic smells with high precision (>99%) and high sensitivity (>99%) when tested on an independent test dataset. The results of the proposed study were also compared with three recently conducted studies. The results indicate that the XGBoost-PCA model performed better than the other models for predicting common odor descriptors. The methodology and ML model developed in this study may be helpful in understanding the structure-odor relationship.Communicated by Ramaswamy H. Sarma.
PubMed: 37723894
DOI: 10.1080/07391102.2023.2258415 -
The Journal of Organic Chemistry Nov 2023A facile tandem oxa-Nazarov cyclization and dibromination has been developed. The combination of Cu(OTf) and diphenyl phosphate (DPP-H) was found to synergistically...
A facile tandem oxa-Nazarov cyclization and dibromination has been developed. The combination of Cu(OTf) and diphenyl phosphate (DPP-H) was found to synergistically promote the coupling of conjugated 1,2-diketones and bromosuccinimide to form 2,4-dibromo-3(2-furanones in good yields.
PubMed: 37910640
DOI: 10.1021/acs.joc.3c01941 -
Journal of the American Chemical Society Jun 2024Couplings between vibrational motions are driven by electronic interactions, and these couplings carry special significance in vibrational energy transfer,...
Couplings between vibrational motions are driven by electronic interactions, and these couplings carry special significance in vibrational energy transfer, multidimensional spectroscopy experiments, and simulations of vibrational spectra. In this investigation, the many-body contributions to these couplings are analyzed computationally in the context of clathrate-like alkali metal cation hydrates, including Cs(HO), Rb(HO), and K(HO), using both analytic and quantum-chemistry potential energy surfaces. Although the harmonic spectra and one-dimensional anharmonic spectra depend strongly on these many-body interactions, the mode-pair couplings were, perhaps surprisingly, found to be dominated by one-body effects, even in cases of couplings to low-frequency modes that involved the motion of multiple water molecules. The origin of this effect was traced mainly to geometric distortion within water monomers and cancellation of many-body effects in differential couplings, and the effect was also shown to be agnostic to the identity of the ion. These outcomes provide new understanding of vibrational couplings and suggest the possibility of improved computational methods for the simulation of infrared and Raman spectra.
PubMed: 38771156
DOI: 10.1021/jacs.4c03198 -
Molecules (Basel, Switzerland) Sep 2023The affinity of specific phenolic compounds (PCs) and capsaicinoids (CAPs) present in three varieties (Friariello, Cayenne and Dzuljunska Sipka) to the transient...
The affinity of specific phenolic compounds (PCs) and capsaicinoids (CAPs) present in three varieties (Friariello, Cayenne and Dzuljunska Sipka) to the transient receptor potential vanilloid member 1 (TRPV1) was investigated by integrating an analytic approach for the simultaneous extraction and analysis through high-performance liquid chromatography coupled with ion trap mass spectrometry (HPLC/ITMS) and UV detection (HPLC-UV) of PCs and CAPs and structural bioinformatics based on the protein modelling and molecular simulations of protein-ligand docking. Overall, a total of 35 compounds were identified in the different samples and CAPs were quantified. The highest content of total polyphenols was recorded in the pungent Dzuljunska Sipka variety (8.91 ± 0.05 gGAE/Kg DW) while the lowest was found in the non-pungent variety Friariello (3.58 ± 0.02 gGAE/Kg DW). Protein modelling generated for the first time a complete model of the homotetrameric human TRPV1, and it was used for docking simulations with the compounds detected via the analytic approach, as well as with other compounds, as an inhibitor reference. The simulations indicate that different capsaicinoids can interact with the receptor, providing details on the molecular interaction, with similar predicted binding energy values. These results offer new insights into the interaction of capsaicinoids with TRPV1 and their possible actions.
Topics: Humans; Capsicum; Capsaicin; Chromatography, High Pressure Liquid; Plant Extracts; Mass Spectrometry; Phenols; Fruit
PubMed: 37836615
DOI: 10.3390/molecules28196772 -
Physics of Fluids (Woodbury, N.Y. :... Aug 2023The search for efficient capillary pumping has led to two main directions for investigation: first, assembly of capillary channels to provide high capillary pressures,...
The search for efficient capillary pumping has led to two main directions for investigation: first, assembly of capillary channels to provide high capillary pressures, and second, imbibition in absorbing fibers or paper pads. In the case of open microfluidics (i.e., channels where the top boundary of the fluid is in contact with air instead of a solid wall), the coupling between capillary channels and paper pads unites the two approaches and provides enhanced capillary pumping. In this work, we investigate the coupling of capillary trees-networks of channels mimicking the branches of a tree-with paper pads placed at the extremities of the channels, mimicking the small capillary networks of leaves. It is shown that high velocities and flow rates (7 mm/s or 13.1 l/s) for more than 30 s using 50% (v/v) isopropyl alcohol, which has a 3-fold increase in viscosity in comparison to water; 6.5 mm/s or 12.1 l/s for more than 55 s with pentanol, which has a 3.75-fold increase in viscosity in comparison to water; and >3.5 mm/s or 6.5 l/s for more than 150 s with nonanol, which has a 11-fold increase in viscosity in comparison to water, can be reached in the root channel, enabling higher sustained flow rates than that of capillary trees alone.
PubMed: 37675268
DOI: 10.1063/5.0157801