Enrichment Ratio Research Articles

Bis(diphenyl)phosphinomethane Platinum(II) complex of 1-(benzo[d]thiazol-2-yl)-3-phenylthiourea: Crystal structure and DFT study

This study extensively describes synthesizing and characterizing a novel Pt(II) thiourea complex and its mixed ligand bisdiphenylphosphinomethane complex. The first complex [Pt(BtztH)2] is obtained by reacting K2PtCl4 and 1-(benzo[d]thiazol-2-yl)-3-phenylthiourea in 1:2 molar ratio. The second complex [Pt(Btzt)(dppm)] was synthesized by reacting dichlorobis(diphenyl)phosphinomethane platinum(II) complex with 1-(benzo[d]thiazol-2-yl)-3-phenylthioure in equimolar ratio with the presence of Et3N. Both complexes adopt square planar geometry, which were determined by FT-IR, 1H-nmr and X-ray crystallography. In comparison with the first complex, the second complex has doubly deprotonated, resulting in a dianion Pt(II) complex, which was determined by X-ray single crystal measurement. The asymmetric unit contained two unique molecules with distorted square planar geometry. A couple of non-covalent or intermolecular interactions stabilized the solid-state supramolecular assembly. Hirshfeld surface analysis was conducted in order to have a deeper understanding of the supramolecular assembly. Enrichment ratio calculations determined the pair of chemical species with the highest propensity for making interatomic contact. The [Pt(Btzt)(dppm)] compound was also investigated theoretically. The DFT study was performed by using B3LYP/Def2-TZVP method. Theoretical findings indicate that the HOMO-LUMO gaps range from 2.2 to 3.22 eV, indicating that the compounds possess favorable semiconductor properties. Within these complexes, the coordinated atoms exhibit strong electron donations to the Pt cation, while the Pt cation demonstrates significant back-donation to the ligand.

NMR characterization of uniformly 13C- and/or 15N-labeled, unsulfated chondroitins with high molecular weights.

Solution nuclear magnetic resonance (NMR) analysis of polysaccharides can provide valuable information not only on their primary structures but also on their conformation, dynamics, and interactions under physiological conditions. One of the main problems is that non-anomeric 1H signals typically overlap, and this often hinders detailed NMR analysis. Isotope enrichment, such as with 13C and 15N, will add a new dimension to the NMR spectra of polysaccharides, and spectral analysis can be performed with enhanced sensitivity using isolated peaks. For this purpose, here we have prepared uniformly 13C- and/or 15N-labeled chondroitin polysaccharides -4)-β-D-glucuronopyranosyl-(1-3)-2-acetamido-2-deoxy-β-D-galactopyranosyl-(1- with molecular weights in the range from 310 to 460 k by bacterial fermentation. The enrichment ratios for 13C and 15N were 98.9 and 99.8%, respectively, based on the mass spectrometric analysis of the constituent chondroitin disaccharides. 1H and 13C NMR signals were assigned mainly based on HSQC and 13C-detection experiments including INADEQUATE, HETCOR, and HETCOR-TOCSY. The carbonyl carbon signal of the N-acetyl-β-D-galactosamine residue was unambiguously distinguished from the C6 carbon of the β-D-glucuronic acid residue by the observation of 13C peak splitting due to 1JCN coupling in 13C- and 15N-labeled chondroitin. The T2* and T1 were measured and indicate that both rigid and mobile sites are present in the long sequence of chondroitin. The conformation, dynamics, and interactions of chondroitin and its derivatives will be further analyzed based on the results obtained in this study.

Zirconia Enrichment of Zircon from Arikya, Nasarawa State, Nigeria, by Magnetic and Gravity Separation Processes for Use as Reinforcing Agent in Composite Formulation

Acceptable zircon for composite formulation in the aerospace industry requires that the mineral contains a minimum of 65% zirconia (ZrO2). Despite having vast deposits of zircon, Nigeria’s aerospace industry has historically relied primarily on imported mild steel tubes for solid rocket motor cases (SRMCs) construction, resulting in three major challenges: low strength-to-weight ratio, pressure, and temperature containment. In this study, the Arikya zircon deposit located in northern Nigeria was investigated with the aim of upgrading low-grade zircon ore using magnetic and gravity separation processes for use in composite formulation for SRMCs. The dry high-intensity magnetic separator (DHIMS) produced a ZrO2 grade of 52.48%, recovery of 57.99%, and an enrichment ratio of 0.78 with a separation efficiency of 0.56, while the air-floating separator (AFS) generated the highest of 65.52% ZrO2 grade with 70.81% recovery and enrichment ratio of 1.25 with a separation efficiency of 0.25. The ZrO2 content increased from 40.77 to 65.52% after beneficiation. Iron oxide and titanium dioxide contaminants at 0.73 and 0.83% were reduced to 0.66 and 0.54%, respectively, while the specific gravity increased from 4.4 to 4.6 g/cm3. The ZrO2 content and specific gravity were improved to the minimum standard specified for zirconia-reinforced composite application and competed effectively with industrially/globally accepted zircon. These results demonstrated the efficacy of combining DHIMS and AFS to upgrade the low-grade zircon ore from Arikya, Nasarawa State.

Multicomponent synthesis, structural and molecular dynamics simulation studies of a novel spirooxindole derivative

The 4′-(4-chlorobenzoyl)-3,-(2,6-dichlorophenyl)-1′-methylspiro(indole-3,2′-pyrrolidin)-2(1H)-one (SOD1) compound has been synthesized and the single crystals are grown by the slow evaporation method using ethanol. Initially, FT-IR and NMR (1H and 13C NMR) spectroscopic studies were used to confirm the structure of the compound. Single crystal X-ray diffraction data were used to determine the solid state structure of the grown single crystals. The title compound SOD1 crystallizes in the orthorhombic space group Pbca. The crystal packing analysis of the compound shows that distinct hydrogen bonding intermolecular interactions construct the R22(12), R22(8), and R12(8), supramolecular synthons to stabilize the packing modes. The propensity of intermolecular interactions is quantified by the Hirshfeld surface analysis, 2-D fingerprint plots and enrichment ratio analysis. Further, the 3-D packing topology of the molecular fragments is visualized through energy frameworks, which reveal the predominance of dispersion energy over other interaction energies. The optimized structure's geometric parameters were computed using DFT calculations using B3LYP/6–311+G(d,p) basis set and compared with the crystal structure parameters obtained by the X-ray diffraction studies. To explore the anticancer activity of the spiro compound, molecular docking with the 6FS1 protein was performed and the binding score of -7.7 kcal/mol was observed. Further, the binding interaction was explored by the dynamics simulation studies.

Selective uneven enrichment of soil organic carbon among different-sized sediments under a rain-induced overland flow: 13C stable isotope evidence

Soil organic carbon (SOC) enrichment varies among sediments of different sizes during rain-induced overland flow erosion. This selective transport of SOC is complex in conjunction with the exposure of labile and stable organic carbon (OC), accompanied by heterogeneous aggregate disintegration under raindrop effects. Utilizing the variations in δ13C values of SOC fractions, we traced this selective transport, linking it to aggregate-wrapped SOC changes during erosion. A modified soil pan facilitated the simultaneous monitoring of splash and sheet erosion via artificially simulated rainfall, with control over the intensity and slope. Aggregate composition, SOC distribution, and δ13C values in the erosion samples were analyzed. The results indicated that distinct sorting existed within the aggregate fragments. Along with SOC variation among different sediment sizes, the proportions of clay and fine silt within sediment aggregates increased as a function of slope and rainfall intensity, whereas particulate OC within aggregates decreased. The SOC enrichment ratios (ERocs) and δ13C values in splash-eroded sediments were positively correlated with those in sheet-eroded sediments. The ERocs in splash-eroded sediments were lower than those in sheet-eroded sediments, but δ13C values were the opposite. Moreover, δ13C values of SOC enriched in sediment particles of all sizes from aggregate stripping were lower than those of the original soil. This indicates that raindrop hits promote heavy C loss during sheet erosion, which is different for mineral-associated and particulate OC. As the slope and rainfall intensity increased, δ13C values for all sediment sizes decreased over the course of erosion. Interestingly, the highest δ13C values were observed under a rainfall intensity of 60 mm h−1, whereas the highest SOC concentrations were noted on a 5° slope. These observations suggest divergent mechanisms affect δ13C values and SOC concentrations in eroded sediments. All these results verified that selective sorting existed for the light SOC fraction. Finally, the internal selective transport of one SOC fraction may explain the enhanced mineralization and reaggregation capacity of the deposited sediments.

Investigation of the molecular basis of halogenated Schiff base derivative by combined crystallographic and computational studies

Halogenated Schiff base derivatives are gaining more popularity in supramolecular chemistry due to the synergistic effect of hydrogen and halogen-based noncovalent interactions, which helps to design novel therapeutic materials. In this work, we have examined the nature of molecular interactions to investigate the structure-functional relationship of a halogen-based derivative. The FTIR, HRMS and NMR spectroscopic techniques confirmed the formation of the desired novel Schiff base compound. Further, crystal structure studies showed an infinite 1D supramolecular chain formed by type-I halogen…halogen interaction. The Hirshfeld surface and enrichment ratio analyses were performed to visualize and assess the role of diverse interactions involved in crystal packing. The QTAIM, NCI, LOL and ELF studies were conducted extensively to comprehend the strength of interaction constructed based on electron density distribution. The global and local reactive indices were determined using DFT studies to analyze the molecular properties of the compound. Antibacterial activity against MRSA bacteria was performed and showed a good zone of inhibition. The docking analysis was performed for 1mwt protein and validated. The in silico molecular docking studies of the halogenated Schiff base structure with the penicillin-binding protein showed a good docking affinity of −7.5 kcal/mol and supported by in vitro studies. The ligand binding stability within the protein’s active site was further demonstrated by molecular dynamics (MD) simulation studies for the Schiff base molecule. Communicated by Ramaswamy H. Sarma

Live cell pool and rare cell isolation using Enrich TROVO system

Although several technologies have been developed to isolate cells of interest from a heterogenous sample, clogging and impaired cell viability limit such isolation. We have developed the Enrich TROVO system as a novel, nonfluidic technology to sort live cells. The TROVO system combines imaging-based cell selection and photo-crosslinking of (gelatin methacrylate) gelMA-hydrogel to capture cells. After capture, cells are released by enzymatic digestion of the hydrogel and then retrieved for downstream analysis or further cell culturing. The system can capture cells with a recovery rate of 48% while maintaining 90% viability. Moreover, TROVO can enrich rare cells 506-fold with 93% efficiency using single step isolation from a 1:104 cell mixture, and can also capture one target cell from 1 million cells, reaching an enrichment ratio of 9128. In addition, 100% purity and 49% recovery rate can be achieved by a following negative isolation process. Compared to existing technologies, the TROVO system is clog-resistant, highly biocompatible, and can process a wide range of sample sizes.

Glycerol carbonate synthesis via transesterification of enriched glycerol and dimethyl carbonate using a Li-incorporated MCM-41 framework.

Waste crude glycerol was successfully enriched and utilized as an inexpensive source for producing value-added chemicals, such as glycerol carbonate (GC) - a valuable compound with extensive industrial applications. The Li/MCM-41 heterogeneous catalyst was synthesized and used for the transesterification of enriched glycerol and dimethyl carbonate (DMC) to produce GC. The catalyst's physicochemical properties were characterized using thermogravimetric, Hammett indicator, inductively coupled plasma-optical emission spectroscopy, nitrogen adsorption-desorption, X-ray diffractometry, scanning electron microscopy, and Fourier-transform infrared spectroscopy analyses. Reaction conditions were optimized using response surface methodology and analysis of variance, yielding an accurate quadratic model to predict the GC yield under different transesterification variables. The results revealed that 5%Li/MCM-41 served as the optimal catalyst, achieving the highest TOF of 4.72 h-1. The DMC: enriched glycerol molar ratio had the greatest impact on the GC yield, with an R2 = 0.9743 and adjusted R2 = 0.9502. The optimal GC yield (58.77%) with a final purity of 78% was attained at a 5.15 wt% catalyst loading relative to the initial amount of enriched glycerol, DMC: enriched glycerol molar ratio of 4.24 : 1, and a reaction temperature of 86 °C for 165 min. The 5%Li/MCM-41 heterogeneous catalyst could be reused for four cycles with a decreased GC yield from 58.77% to 45.72%. Thus, the Li/MCM-41 catalyst demonstrated a remarkable efficiency and potential as a heterogeneous catalyst for synthesizing GC. This method not only contributes to environmental sustainability by making use of a byproduct from biodiesel production but also aligns with the principles of a circular economy.

A Hydrazone Derivative: Synthesis, Crystal Structure, Supramolecular Assembly Exploration by Hirshfeld Surface Analysis and Computational Study

The diazotization reaction of o-trifluoromethyl aniline from aromatic amines with 5,5-dimethylcyclohexane-1,3-dione was studied, as a result, 2-(2-(o-trifluoromethylphenyl)hydrazono)-5,5-dimethylcyclohexane-1 ,3-dione (THDCD) was synthesized and its structure was confirmed by X-ray diffraction analysis. The solid state assembly is stabilized by numerous intermolecular interactions which are deeply probed by Hirshfeld surface analysis. The enrichment ratio was computed for getting the contact with the highest propensity to form crystal packing interaction. The mechanical response of the crystal is predicted by voids analysis. Moreover, interaction energy calculations were performed at HF/3-21G electron density model to further inspect the supramolecular assembly of the crystal. DFT calculation was conducted using B3LYP level with 6–311++G(d, p) basic set with the help of Gaussian 09W and GaussView 6.0 packages. MEP surface, HOMO-LUMO orbitals, and NBO theory were analyzed via DFT approach. Theoretical method confirms the proposed geometry of THDCD by X-ray analysis.

Numerical Simulation of Stacked Step Flowincentrifugal Force Field for Copper Ore Separation

In this study, the flow field of a stacked step flow device was simulated using Fluent 19.2 software. The simulation results show that: the combination of rotational motion and reverse fluidization of the fluid in the cone of the equipment makes the slurry dispersed and separated in the radial direction, and the upward motion of the fluid can promote the solid phase, especially the smaller particle size and lower density of the silica phase, to realize the separation of the copper phase and the silica phase in the axial direction; the vortex generated by the sudden change of tangential flow velocity at the step can significantly improve the settling efficiency of the copper phase in the upward process. Fluent simulation results show that: when the rotational speed is 50r/min, the feed speed is 0.5m/s, and the reverse fluidization speed is 0.018m/s, the copper recovery rate is 87.70%, and the enrichment ratio is 13.45.

Effects of multiple factors on particle size selectivity under artificial extreme rainfall events on simulated Gobi surface

Understanding multiple-factor effects on particle size selectivity by extreme rainfall events in Ala-Shan Gobi desert is of great significance for better estimation of potential Asian dust emission sources. Artificial rainfall simulation experiments were used to investigate the particle size selectivity characteristics by extreme rainfall events under different rainfall intensities (20 mm h−1 and 40 mm h−1), slope gradients (3° and 15°) and gravel coverages (0, 30%, and 60%). Moreover, the relations of clay content (Clc), silt content (Sic), fine particle (< 50 μm) content (Fic) and enrichment ratio of fine particles (ER<50) with multiple factors were regressed and validated. Results show that rainfall intensity significantly (P < 0.05) affect runoff and sediment yield processes, but slope gradient was a dominant factor that changed particle size distribution (PSD). The selectivity of fine particles was higher at low rainfall intensity (20 mm h−1), gentle slope (3°) and moderate gravel coverage (30%), with ER<50 reaching 6.14, which dominate the potential Asian dust emission sources. The interaction were discussed and classified into ‘Synergy’ and ‘Trade-off’. Clc and Fic showed negative exponential relationship with rainfall intensity and slope gradient, but positive exponential relationship with gravel coverage. While Sic and ER<50 showed negative power function relationship with rainfall intensity, slope gradient and gravel coverage. These findings could help to understand the effects of multiple factors on potential sources of Asian dust emission under extreme rainfall events in Gobi region of northwestern China and provide basic science reference for the prediction of dust emission in this region.

Comprehensive performance evaluation of six bioaerosol samplers based on an aerosol wind tunnel

Choosing a suitable bioaerosol sampler for atmospheric microbial monitoring has been a challenge to researchers interested in environmental microbiology, especially during a pandemic. However, a comprehensive and integrated evaluation method to fully assess bioaerosol sampler performance is still lacking. Herein, we constructed a customized wind tunnel operated at 2–20 km/h wind speed to systematically and efficiently evaluate the performance of six frequently used samplers, where various aerosols, including Arizona test dust, bacterial spores, gram-positive and gram-negative bacteria, phages, and viruses, were generated. After 10 or 60 min of sampling, the physical and biological sampling efficiency and short or long-term sampling capabilities were determined by performing aerodynamic particle size analysis, live microbial culturing, and a qPCR assay. The results showed that AGI-30 and BioSampler impingers have good physical and biological sampling efficiencies for short-term sampling. However, their ability to capture aerosols at low concentrations is restricted. SASS 2300 and BSA-350 wet-wall cyclones had excellent enrichment ratios and high microbial cultivability in both short-term and long-term sampling; however, they were not suitable for quantitative studies of aerosols. Polycarbonate filter samplers showed outstanding performance in physical and long-term sampling but lacked the ability to maintain microbial activity, which can be improved by gelatin filter samplers. However, limitations remain for some fragile microorganisms, such as E. coli phage PhiX174 and coronavirus GX_P2V. In addition, the effects of wind speed and direction should be considered when sampling particles larger than 4 µm. This study provides an improved strategy and guidance for the characterization and selection of a bioaerosol sampler for better measurement and interpretation of collected ambient bioaerosols.

Effects of microtopography shaping on characteristics of eroded sediment particles of a dump slope in an opencast coal mine in China

AbstractThe properties of sediment particles are crucial research areas for understanding soil erosion on dump slopes. In this study, the slope of the southern dump of the ATB opencast coal mine in the Pingshuo mining area in Shanxi Province, China, was selected to conduct microtopographical shaping and artificial rainfall simulation experiments. Three different gradients of rainfall intensity, 20, 50, and 80 mm·h−1, were set. The main component of rainwater was water (chemistry H2O) by a rainfall duration of 30 min. A Microtrac S3500 laser particle size analyzer was used to measure the collected erosion sediment particles. This study conducted level benches and fish‐scale pits microtopography shaping on the slope of the waste dump. The dimensions of the level bench design were 1, 2, and 1 m for the step width, for the step length, and between each level bench, respectively. The fish‐scale pits were 60 cm (length), 40 cm (width), and 30 cm (depth). The horizontal and row spacing of each fish‐scale pit was 1 m, and an unshaped terrain was used as the control group. Through dynamic monitoring and statistical analysis of the data, the impacts of rainfall intensity and microtopography shaping mode on the features of the eroded sediment particles were analyzed. Fine silt particles (53%) were lost as a result of the surface erosion of the slope. The mean starting periods of sediment particle loss decreased with the increase in rainfall intensity (589 s &gt; 402 s &gt; 305 s). Additionally, the clay and silt particle enrichment ratios decreased (ER &gt;1), whereas the sand particle enrichment ratios increased (ER &lt;1). The level benches had a stronger interception effect on fine sediment, whereas the fish‐scale pits had a weaker interception effect on sediment particles under heavy rain. The distribution properties of erosion sediment particles on a slope can be assessed using fractal dimension as an index. This study is significant for understanding the erosion mechanism of eroded sediment particles on dump slopes and provides a scientific foundation for soil erosion control on opencast coal mine dump slopes in the Loess Plateau. These results highlight the potential for the level bench to effectively delay the occurrence of runoff and greatly enhance the interception of sediment particles.

Source apportionment and source-specific risk assessment of bioavailable metals in river sediments of an anthropogenically influenced watershed in China

Integrated source analysis and risk assessment of metals facilitate the development of targeted risk management strategies. However, previous studies usually addressed total concentration rather than bioavailability, and consequently overestimated metal risk, especially natural source-related risk. In this study, a source-specific risk assessment was conducted by integrating the source analysis of bioavailable metals in surface sediments. Moreover, risk assessment was performed using two bioavailability-based indices: the total availability risk index (TARI) and a modified index of mean probable effect concentration quotients (mPEC-Q). A representative river watershed in eastern China was selected as the study area. Findings revealed that the total concentrations of Pb, Cu, Zn, Cr, and Ni in the sediments were 1.4–2.2 times higher than the local soil background values. Using a modified community bureau of reference (BCR) sequential extraction procedure, the dominant fraction for Pb, Cu, Zn, and Cr in the studied area was found to be the residual fraction, constituting 53.63–62.44% of the total concentrations. This suggested that a significant portion of the metals potentially originated from natural sources. Nevertheless, the concentration enrichment ratio (CER) indicated that anthropogenic sources contributed significantly, accounting for 67.84–87.68% of bioavailable metals. The positive matrix factorization (PMF) model further identified three different sources of bioavailable metals, with a descending concentration contribution sequence of industrial sources (37.61%), mixed traffic and natural sources (33.17%), and agricultural sources (29.22%). Both the TARI and mPEC-Q index values indicated that the bioavailable metals generally posed a moderate risk, and Ni was the priority pollutant. Industrial sources contributed the most to the total risk, although the contribution from TARI-based assessment (37.27%) was lower than that from the mPEC-Q assessment (46.43%). This study provides an example of the consideration of metal bioavailability in the context of source-specific risk assessments to develop more reasonable management strategies.

A novel strategy by combining foam fractionation with high-speed countercurrent chromatography for the rapid and efficient isolation of antioxidants and cytostatics from Camellia oleifera cake

Camellia oleifera cake is a by-product, which is rich in functional chemical components. However, it is typically used as animal feed with no commercial value. The purpose of this study was to isolate and identify compounds from Camellia oleifera cake using a combination of foam fractionation and high-speed countercurrent chromatography (HSCCC) and to investigate their biological activities. Foam fractionation with enhanced drainage through a hollow regular decahedron (HRD) was first established for simultaneously enriching flavonoid glycosides and saponins for further separation of target compounds. Under suitable operating conditions, the introduction of HRD resulted in a threefold increase in enrichment ratio with no negative effect on recovery. A novel elution-extrusion countercurrent chromatography (EECCC) coupled with the consecutive injection mode was established for the successful simultaneous isolation of flavonoid glycosides and saponins. As a result, 38.7 mg of kaemferol-3-O-[2-O-D-glucopyranosyl-6-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside (purity of 98.17%, FI), 70.8 mg of kaemferol-3-O-[2-O-β-D-xylopyranosyl-6-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside (purity of 97.52%, FII), and 560 mg of an oleanane-type saponin (purity of 92.32%, FIII) were separated from the sample (900 mg). The present study clearly showed that FI and II were natural antioxidants (IC50 < 35 μg/mL) without hemolytic effect. FIII displayed the effect of inhibiting Hela cell proliferation (IC50 < 30 μg/mL). Further erythrocyte experiments showed that this correlated with the extremely strong hemolytic effect of FIII. Overall, this study offers a potential strategy for efficient and green isolation of natural products, and is beneficial to further expanding the application of by-products (Camellia oleifera cake) in food, cosmetics, and pharmacy.

Iron isotope evidence in continental intraplate basalts for mantle lithosphere imprint on heterogenous asthenospheric melts

Iron isotope studies on ocean island basalts (OIBs) and mid-ocean ridge basalts (MORBs) have disclosed the contribution of pyroxenite lithologies in the generation of basaltic magmas. Whether Fe isotopic compositions of continental intraplate basalts can be applied to trace lithological heterogeneity within the mantle source regions remains poorly investigated. To explore the systematics of stable Fe isotopes as a potential probe of lithological heterogeneity in the source of continental intraplate basalts, we present twenty-four Fe isotope data on a suite of well-characterized Cenozoic basalts from SE China. The samples show a large range of Fe isotope values (δ56Fe = +0.09‰ to +0.20‰), which correlate with SiO2, CaO/Al2O3, Ti/Eu, Hf/Hf*, Zr/Nb, Dy/Yb, La/Yb, Nb/Y, K/La, Sr/Ce, δ66Zn and estimated equilibrium pressures. The samples with the highest δ56Fe values represent early-stage low-silica basalts with moderately enriched Sr-Nd isotope ratios and high δ66Zn values, while the late-stage high-silica basalts display a broad δ56Fe decrease with increasing 87Sr/86Sr and with decreasing εNd and δ66Zn. We demonstrate that the heaviest Fe isotope signatures cannot be derived from a pure peridotite source and require a pyroxenite component in the source. Combined with other geochemical proxies, we show that the heaviest basalt compositions are consistent with low-degree melts produced by the adiabatic decompression of a carbonated pyroxenite-bearing asthenospheric mantle. Mixing of these hybrid melts with melt produced from in-situ melting of the subduction-modified sub-continental lithospheric mantle (SCLM) reproduces the Fe-isotope variability of the late-stage basalts. Our results demonstrate the significance of lithological heterogeneity in the mantle source of continental intraplate basalts and highlight the subsequent imprint of mantle lithosphere in the evolution of their Fe isotope compositions. Finally, this study exemplifies the potential of the Fe-Zn stable isotope pair for mantle geochemistry; coupled with traditional radiogenic isotopes and major and trace element concentrations, they formed an efficient tool to trace the nature and contribution of the mantle source components in the formation of intraplate basalts.

The enigmatic enrichment of potassium and magnesium in runoff and floodwater in the Negev: Do biocrusts hold the key?

Regardless of lithology and plant cover, chemical composition of floodwater in the Negev show a consistent enrichment in K+ and Mg2+ ions, which could not have been explained by the rock or clay minerals or (due to the scarcity of plants) by plant decomposition. Hypothesizing that rock-dwelling (lithobionts) or soil (loess)-dwelling biocrusts may shed light on the phenomena, we conducted sprinkling experiments in the Negev Highlands. Sprinkling was conducted on 4 types of lithobionts: cyanobacteria which inhabit the south-facing bedrock (ENC), epilithic lichens, inhabiting the inclined (EPIi) and the flat (EPIf) north-facing bedrocks, and endolithic lichens (ENL) inhabiting south-facing boulders. Additional sprinkling took place on two types of soil biocrusts, a mixed crust composed of cyanobacteria, lichens and mosses at the north-facing footslope and a cyanobacterial crust at the more xeric south-facing footslope. The runoff water (of 5 and for 4 plots for each lithobiont and soil biocrust type, respectively) was analyzed for the ionic composition of Na+, K+, Mg2+, Ca2+, NH4+, Cl−, SO42−, and NO3−, whereas HCO3− was calculated. In comparison to rainwater, all habitats (except for K+ in ENL) showed high enrichment ratios (ERs) in K+ and Mg2+, which, unlike the high ERs of the other ions (such as SO42− that may stem from gypsum dissolution), could not have been explained by the rock lithology, clay or dust composition. It is suggested that following wetting, K+, serving for osmoregulation of cells, is released by the crust organisms, being thus responsible for K+ enrichment, while chlorophyll degradation is responsible for Mg2+ enrichment. It is suggested that rock- and soil-dwelling microorganisms may explain K+ and Mg2+ enrichment in runoff and floodwater and subsequently in groundwater of the Negev, and possibly in other arid zones worldwide, affecting in turn the quality of irrigation and drinking water.

Supramolecular Structure, Hirshfeld Surface Analysis, Morphological Study and DFT Calculations of the Triphenyltetrazolium Cobalt Thiocyanate Complex

Polymorphism is a prevalent occurrence in pharmaceutical solids and demands thorough investigation during product development. This paper delves into the crystal growth and structure of a newly synthesized polymorph (TPT)2[CoII(NCS)4], (1), where TPT is triphenyl tetrazolium. The study combines experimental and theoretical approaches to elucidate the 3D framework of the crystal structure, characterized by hydrogen-bonded interactions between (TPT)+ cations and [Co(NCS)4]2− anions. Hirshfeld surface analysis, along with associated two-dimensional fingerprints, is employed to comprehensively investigate and quantify intermolecular interactions within the structure. The enrichment ratio is calculated for non-covalent contacts, providing insight into their propensity to influence crystal packing interactions. Void analysis is conducted to predict the mechanical behavior of the compound. Utilizing Bravais-Friedel, Donnay-Harker (BFDH), and growth morphology (GM) techniques, the external morphology of (TPT)2[CoII(NCS)4] is predicted. Experimental observations align well with BFDH predictions, with slight deviations from the GM model. Quantum computational calculations of the synthesized compounds is performed in the ground state using the DFT/UB3LYP level of theory. These calculations assess the molecule’s stability and chemical reactivity, including the computation of the HOMO-LUMO energy difference and other chemical descriptors. The study provides a comprehensive exploration of the newly synthesized polymorph, shedding light on its crystal structure, intermolecular interactions, mechanical behavior, and external morphology, supported by both experimental and computational analyses.

High-efficiency foam fractionation of anthocyanin from perilla leaves using surfactant-free active Al2O3 nanoparticle as collector and frother: Performance and mechanism.

Anthocyanin (ACN) is a natural pigment with significant industrial applications. However, foam fractionation of ACN from perilla leaves extract presents theoretical challenges due to its limited surface activity and foaming capacity. This work developed a surfactant-free active Al2O3 nanoparticle (ANP) as a collector and frother, which was modified with adipic acid (AA). The ANP-AA efficiently collected ACN through the electrostatic interaction, condensation reaction, and hydrogen bonding, with a Langmuir maximum capacity of 129.62mg/g. Moreover, ANP-AA could form a stable foam layer by irreversibly adsorbing on the gas-liquid interface, reducing surface tension, and alleviating liquid drainage. Under the appropriate conditions of ANP-AA 400mg/L and pH 5.0, we achieved a high ACN recovery of 95.68% with an enrichment ratio of 29.87 after ultrasound-assisted extraction of ACN from perilla leaves. Additionally, the recovered ACN displayed promising antioxidant properties. These findings hold significant importance in the food, colorant, and pharmaceutical industries.

LC-MS/MS method for quantitative profiling of ketone bodies, α-keto acids, lactate, pyruvate and their stable isotopically labelled tracers in human plasma: An analytical panel for clinical metabolic kinetics and interactions

An important area within clinical research is in vivo metabolism of ketone bodies (β-hydroxybutyrate and acetoacetate) and in connection metabolites that may affect their production and/or cellular transport such as the keto-acids from the branched-chain amino acids, lactate and pyruvate. To determine in vivo metabolite turnover, availability of accurate and sensitive methods for analyzing the plasma concentrations of these metabolites and their stable isotopically labeled enrichments is mandatory. Therefore, the present study describes a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous analysis of ketone bodies, α-keto acids, lactate, pyruvate, and their tracer enrichments in humans using 2 different derivatization techniques with 4-bromo-N-methylbenzylamine and O-benzylhydroxylamine as derivatization reagents, and 1-ethyl-3-dimethylaminopropyl carbodiimide as coupling compound followed by a single LC-MS/MS run. The method was validated for matrix effects, linearity, accuracy, precision, recovery, stability, and enrichment (ratio) analysis of a stable isotopically labelled analytes (tracers) continuously infused in humans divided by the unlabeled endogenous analyte (tracee) that makes it possible to quantify the analyte in vivo synthesis and degradation rates. The applied parallel derivatization procedure yielded good sensitivity for all analytes of interest and their tracers. Despite the double derivatization method, mixing the ethyl acetate portions at the final stage made it possible to simultaneously analyze all compounds in a single LC-MS/MS run. Moreover, the liquid chromatography method was optimized to robustly quantify the keto acids derived from leucine (α-keto-isocaproic acid) and isoleucine (α-keto-β-methylvaleric acid), the compounds with similar chemical structure and identical molecular weights. The presented method is designed and validated for human plasma. However, care should be taken in blood sampling and processing procedures as well as quick freezing and storage at −80 °C due to the instability of especially acetoacetate.