Excess Ions Research Articles

Evaluating groundwater quality and salinity dynamics in the Western-west area of El Minya Governorate, Egypt, based on geochemical modelling and multivariate analysis

In the Western-west area of El Minya Governorate, Egypt, the present study investigates the water quality and salinity of 33 groundwater samples. The primary aim is to conduct a comprehensive evaluation of water purity and gain insights into salinity dynamics. The investigation involves a combination of geochemical analysis and multivariate statistics to reveal significant findings that contribute to our understanding of groundwater characteristics in the region. The collected groundwater samples are analyzed to assess various properties, including pH levels, mineral content, hardness, and salinity. The prevalence of sodium (Na) and chloride (Cl) ions emerges as a noteworthy aspect, implying their derivation from deeper aquifers through mechanisms like upward seepage or reverse ion exchange. The observation is validated through Durov's plot analysis. Concerning the suitability of the water for consumption, the study raises concerns. Apart from magnesium (Mg) ions, all other parameters exceed the acceptable drinking water limits defined by the World Health Organization (WHO), indicating potential health implications related to water quality in the region. Furthermore, outcomes from the saturation index reveal an oversaturation of groundwater with evaporites and carbonates, with halite and sylvite minerals standing as exceptions to this trend. Negative chloroalkaline ratios offer insights into the origins of excessive Na and Cl ions in 72% of the samples, pointing towards processes such as rainy recharging and reverse ion exchange as contributors. Gibbs' chart analysis highlights evaporite dissolution as the predominant process influencing water composition. The study also utilizes principal component analysis, identifying the dissolution of halite as the primary source of Na, K, Cl, and SO4 ions, while the presence of calcium (Ca) and bicarbonate (HCO3) ions originates from the dissolution of carbonate minerals, thereby influencing water hardness and salinity levels. Considering the findings, we recommend the dilution of groundwater with fresh water, assuming the absence of additional contaminants. This step is essential for enhancing water safety for drinking purposes. This research not only advances our understanding of water quality and salinity dynamics in the region but also underscores the imperative for implementing sustainable water resource management strategies. Furthermore, we propose that future investigations delve into the broader environmental ramifications of these discoveries, thus contributing to a more holistic comprehension of the complexities associated with groundwater quality and salinity.

Smartphone-enabled colorimetric determination of silver ions exploiting the peroxidase-mimetic behavior of bowl-shaped Pd3Pt nanocrystals

Excessive silver ions (Ag+) pose significant risks to both human health and the environment, necessitating the rapid and sensitive detection of Ag+ in aqueous systems to ensure public health and environmental safety. In this study, we present a novel and expeditious colorimetric methodology for Ag+ detection, employing bowl-shaped Pd3Pt nanocrystals as an effective probe. The distinctive bowl-like structure of Pd3Pt provides an abundance of catalytic active sites, endowing them with peroxidase-like activity. Upon exposure to hydrogen peroxide, these Pd3Pt nanobowls facilitate the oxidation of the colorless substrate 3,3′,5,5′-tetramethylbenzidine (TMB), resulting in the formation of the blue product oxTMB, which exhibits a pronounced characteristic absorption peak at 652 nm. By virtue of the metal affinity and electrostatic attraction between Ag+ ions and Pd3Pt nanobowls, Ag+ species effectively adsorb onto the nanobowls surface, preferentially occupying the catalytic active sites and impeding the production of the blue oxTMB product. Based on this mechanism, we have established a novel colorimetric approach for the quantitative determination of Ag+, enabling facile Ag+ detection using either a UV–vis absorption spectrometer or a smartphone as the detection instrument. The developed method demonstrates an impressive detectable range spanning 1–100 nmol/L, accompanied by a detection limit of 0.72 nmol/L. Notably, this technique boasts several desirable attributes, including rapid detection, simplified operational procedures, heightened sensitivity, and commendable selectivity. Moreover, we have successfully applied this method to assess Ag+ levels in water samples procured from diverse sources, further attesting to its practical utility and versatility.

Mechanisms of Systemic Osmoregulation in Insects.

Water is essential to life. Terrestrial insects lose water by evaporation from the body surface and respiratory surfaces, as well as in the excretory products, posing a challenge made more acute by their high surface-to-volume ratio. These losses must be kept to a minimum and be offset by water gained from other sources. By contrast, insects such as the blood-sucking bug Rhodnius prolixus consume up to 10 times their body weight in a single blood meal, necessitating rapid expulsion of excess water and ions. How do insects manage their ion and water budgets? A century of study has revealed a great deal about the organ systems that insects use to maintain their ion and water balance and their regulation. Traditionally, a taxonomically wide range of species were studied, whereas more recent research has focused on model organisms to leverage the power of the molecular genetic approach. Key advances in new technologies have become available for a wider range of species in the past decade. We document how these approaches have already begun to inform our understanding of the diversity and conservation of insect systemic osmoregulation. We advocate that these technologies be combined with traditional approaches to study a broader range of nonmodel species to gain a comprehensive overview of the mechanism underpinning systemic osmoregulation in the most species-rich group of animals on earth, the insects.

Ionically Imprinting-Based Copper (II) Label-Free Detection for Preventing Hearing Loss

Copper is a microelement with important physiological functions in the body. However, the excess copper ion (Cu2+) may cause severe health problems, such as hair cell apoptosis and the resultant hearing loss. Therefore, the assay of Cu2+ is important. We integrate ionic imprinting technology (IIT) and structurally colored hydrogel beads to prepare chitosan-based ionically imprinted hydrogel beads (IIHBs) as a low-cost and high-specificity platform for Cu2+ detection. The IIHBs have a macroporous microstructure, uniform size, vivid structural color, and magnetic responsiveness. When incubated in solution, IIHBs recognize Cu2+ and exhibit a reflective peak change, thereby achieving label-free detection. In addition, benefiting from the IIT, the IIHBs display good specificity and selectivity and have an imprinting factor of 19.14 at 100 μmol·L−1. These features indicated that the developed IIHBs are promising candidates for Cu2+ detection, particularly for the prevention of hearing loss.

The apple lipoxygenase MdLOX3 positively regulates zinc tolerance

Various abiotic stresses, especially heavy metals near factories around the world, limit plant growth and productivity worldwide. Zinc is a light gray transition metal, and excessive zinc will inactivate enzymes in the soil, weaken the biological function of microorganisms, and enter the food chain through enrichment, thus affecting human health. Lipoxygenase (LOX) can catalyze the production of fatty acid derivatives from phenolic triglycerides in plants and is an important pathway of fatty acid oxidation in plants, which usually begins under unfavorable conditions, especially under biotic and abiotic stresses. Lipoxygenase can be divided into 9-LOX and 13-LOX. MdLOX3 is a homolog of AtLOX3 and has been identified in apples (housefly apples). MdLOX3 has a typical conserved lipoxygenase domain, and promoter analysis shows that it contains multiple stress response elements. In addition, different abiotic stresses and hormonal treatments induced the MdLOX3 response. In order to explore the inherent anti-heavy metal mechanism of MdLOX3, this study verified the properties of MdLOX3 based on genetic analysis and overexpression experiments, including plant taproots length, plant fresh weight, chlorophyll, anthocyanins, MDA, relative electrical conductivity, hydrogen peroxide and superoxide anion, NBT\\DAB staining, etc. In the experiment, overexpression of MdLOX3 in apple callus and Arabidopsis effectively enhanced the tolerance to zinc stress by improving the ability to clear ROS. Meanwhile, tomato materials with overexpression of ectopia grew better under excessive zinc ion stress. These results indicated that MdLOX3 had a good tolerance to heavy metal zinc. Homologous mutants are more sensitive to zinc, which proves that MdLOX3 plays an important positive role in zinc stressed apples, which broadens the range of action of LOX3 in different plants.

Elucidating the Role of a Calcium-Binding Loop in an x-Prolyl Aminodipeptidase from Lb. helveticus.

Prolyl aminodipeptidase (PepX) is an α/β hydrolase that cleaves at penultimate N-terminal prolyl peptide bonds. The crystal structure of PepX from Lactobacillus helveticus exhibits a calcium-binding loop within the catalytic domain. The calcium-binding sequence of xDxDxDGxxD within this loop is highly conserved in PepX proteins among lactic acid bacteria, but its purpose remains unknown. Enzyme activity is not significantly affected in the presence of the metal chelator ethylenediaminetetraacetic acid (EDTA), nor in the presence of excess calcium ions. To eliminate calcium binding, D196A and D194A/D196A mutations were constructed within the conserved calcium-binding sequence motif. Enzyme activity and stability of the D196A mutant were comparable to the wild-type enzyme by colorimetric kinetic assays and protein thermal shift assays. However, the D194A/D196A mutant was inactive though it retained native-like structure and thermal stability, contradicting the EDTA and calcium titration results. This suggests calcium binding to PepX may be essential for activity.

Solvent Effects on Structure and Screening in Confined Electrolytes.

Using classical density functional theory, we investigate the influence of solvent on the structure and ionic screening of electrolytes under slit confinement and in contact with a reservoir. We consider a symmetric electrolyte with implicit and explicit solvent models and find that spatially resolving solvent molecules is essential for the ion structure at confining walls, excess ion adsorption, and the pressure exerted on the walls. Despite this, we observe only moderate differences in the period of oscillations of the pressure with the slit width and virtually coinciding decay lengths as functions of the scaling variable σ_{ion}/λ_{D}, where σ_{ion} is the ion diameter and λ_{D} the Debye length. Moreover, in the electrostatic-dominated regime, this scaling behavior is practically independent of the relative permittivity and its dependence on the ion concentration. In contrast, the crossover to the hard-core-dominated regime depends sensitively on all three factors.

Effects of protein aggregation induced by NaCl and temperature on gelation of silkworm (Antheraea pernyi) pupa raw powder

Edible insects have great potential for producing protein-rich ingredients. This study aimed to investigate the effects of protein aggregation induced by NaCl (0–1 M) and temperature (65–95 °C) on gelation of Antheraea pernyi (A. pernyi) pupa raw powder. No thermal aggregates were observed at low temperature (65 °C), on the basis of there being no significant enhancement in turbidity and particle size (P > 0.05), regardless of NaCl concentrations. At elevated temperatures (75–95 °C), protein solutions exhibited significantly higher turbidity and particle size (P < 0.05), accompanied by an initial rise in surface hydrophobicity followed by a decline, alongside declining sulfhydryl. This marks the beginning of massive thermal aggregation driven by molecular forces. In addition, covalent (disulfide bonds) and non-covalent (hydrogen bonding, electrostatic interactions, and hydrophobicity) forces were influenced by NaCl, leading to variability in the protein aggregation and gelation. Correlation analysis indicates that the higher protein aggregation induced by ions was beneficial to the construction of more compact three-dimensional structures, as well as to the rheology, texture, and water-holding capacity of A. pernyi pupa gels. However, excessive salt ions destroyed the gel structure. Our findings will aid the use of A. pernyi pupae as textural ingredients in formula foods.

“Chelation therapy applied to the treatment of oral Peri-implantitis: A hypothesis”

The supporting tissues of dental implants can be affected by peri-implant disease, which encompasses mucositis and peri-implantitis. Mucositis is localized in the soft tissues around dental implants and is reversible. Meanwhile, peri-implantitis is irreversible, presents peri-implant bone loss, and can lead to implant failure. The causes of peri-implantitis are multifactorial, including biofilms, genetics, history of periodontal disease, smoking, obesity, incorrect prosthetic designs, and metal particles and ions. The current strategies for treating peri-implantitis (decontamination of the implant surface, treatment of the infection, regeneration of the lost bone, and modification of risk factors) have obtained inconsistent outcomes, and relapse occurs.In recent years new histological, immunological, and clinical data shows a strong relationship between metallic ions and particles (nano- or micron-sized) and peri-implantitis. In which the metal ions and particles can produce foreign body reactions, diminished cellular response, increased DNA methylation, alteration of the microbiome, and dysbiosis. Therefore, current therapies for oral peri-implantitis do not consider the deposits of metal particles and ions, and this could explain why the peri-implant disease is not entirely under control with conventional treatments.We hypothesize that chelation therapy used to treat oral peri-implantitis could reduce the excess metal ions present in the surrounding peri-implant tissues improving the outcomes of the current treatments against peri-implantitis. Represented by reduced metal ions, lowered inflammatory markers, reduced bone loss and increased implant survival.

Study of Photo-transformation of Ag Nanoparticles under Green LEDs Light Source and their Changes Induced by Z-scan Technique

Background: The study of metallic nanoparticles is important since they present nonlinear optical properties crucial for modern photonic science and technology. Moreover, their mechanical, chemical, and optical properties are different from those presented with respect to volumetric material. Said properties can be adjusted by controlling the size and shape of the studied nanoparticles, and various methodologies have been developed to obtain nanoparticles by chemical and physical means. Methods: Spherical nanoparticles were synthesized by chemically reducing silver nitrate, sodium borohydride, and sodium citrate precursors. Different amounts of silver nitrate were added to the original spherical nanoparticles and then exposed to a green LED light source to convert the spherical nanoparticles to triangular prisms. The changes in the samples were monitored using absorption spectra obtained with a UV-Vis spectrophotometer. The nonlinear refractive index was determined with Z-scan measurements, and a scanning electron microscope was used to observe the silver nanoparticles before and after laser irradiation. Results: The absorption spectra show a band of around 418 nm for the original spherical nanoparticles, which shifted to blue after the irradiation with green LED light. Furthermore, a new band was obtained, centered around 565 nm, which indicates the presence of triangular prisms. From SEM images, it was confirmed that the spherical nanoparticles were transformed into triangular nanoprisms. The non-linear (negative) refractive index depends on the shape and number of nanoparticles; however, using the Z-scan technique caused photo-melting and photofragmentation of the triangular prisms, which was corroborated by SEM images. Conclusion: These results suggest that the shape and amount of AgNPs can be controlled with excess silver ions and irradiation time. In addition, the Z-scan technique causes photo-melting and photo-fragmentation of AgNPs, and their nonlinear refraction index is negative due to thermal origin.

Magnetic phase diagram of Ge1–x–y(SnxMny)Te multiferroic semiconductors: Coexistence of ferromagnetic and cluster glass ordering

Noncentrosymmetric IV-VI semiconductors doped with magnetic ions offer exciting possibilities such as carrier mediated ferromagnetism, ferroelectric-controlled spin texture and integration of semiconducting features with ferromagnetic order. Also, coupling between more than one ferroic orders and giant Rashba spin splitting can be studied to develop materials for spintronic applications. In that context, we report the structural and magnetic results of polar α–GeTe doped with Sn and Mn from x = 0.185–0.841 and y = 0.02–0.086, respectively. The magnetic results of Ge1–x–y(SnxMny)Te (GSMT) crystals identify Mn-clustering effect with scaling parameter, R = 0.033 for x ≈ 0.2 and y = 0.06. The excessive Sn ions are assumed to drive the inception of short range ferromagnetic clusters. For the crystals revealing glassy magnetic behavior, the irreversibility temperature, Tirr shifts at high dc magnetic field which is well described by de Almeida-Thouless equation, δTirr ∝ HΦ/2 yielding Φ values of 1.55 and 1.7 that validates the formation of Mn clusters. The spin relaxation time, τ0 ∼ 10–9 s, activation energy, Ea/kB ∼ 5 TF where TF is freezing temperature and Vogel-Fulcher temperature, T0 ∼ TF also signify intracluster interactions. Also, the Mn-hole magnetic exchange constant, Jpd drops from 0.24 eV for the samples with smaller Sn content of x ≈ 0.2 to 0.16 eV for Sn rich alloy with x ≈ 0.8. Consequently, we present a magnetic phase diagram for GSMT bulk crystals as a function of Mn ions.

Integrating GIS and irrigation water quality index approaches for identifying groundwater irrigation potential zones in Central Gujarat, India.

In this study, groundwater irrigation potential zones are identified by measuring an integrated irrigation water quality index using a GIS platform in the Vishwamitri River Basin (VRB) region, Gujarat, India. Classification of different irrigation potential zones is about the collective paraphernalia of thematic maps, namely, electrical conductivity (EC), sodium adsorption ratio (SAR), Na+, Cl-, and HCO3-, which principally regulate the groundwater quality for irrigation. The EC, SAR, and chloride values are > 3000 µS/cm, > 9meq/L, and > 10meq/L, respectively, indicating 98.78%, 41.78%, and 84.88% of the total area, respectively, belong to groundwater both hazardous and unsuitable for irrigation. Similarly, 39.55% of the total area is unsuitable for irrigation due to its high Na+ concentration. The permeability, porosity, and infiltration risk usually appear when excessive sodium ions reduce the rate of flow of irrigation water which moves in the lower soil zones. Similarly, high bicarbonate and chloride concentrations have been denoted to hamper the development of several crops causing symptoms analogous to lime-induced chlorosis due to toxic effects of the salt. The final irrigation potential map is marked by four levels, such as "most suitable," "moderately suitable," "moderately unsuitable," and "unsuitable for irrigation." Approximately, 56.69% of the total VRB region are covered with unsuitable for irrigation purposes. In such areas, irrigation must be avoided in usual conditions, and the halophytes, namely, Khati palak (Atriplex stocksii), Lamb's quarters (Chenopodium album), and Rudravanti (Cressa cretica) should be recommended with high soil permeability and proper drainage facilities. The soil must be highly permeable for groundwaters with high salinity and sodicity. Based on this study, policymakers and environmental managers can estimate the resource implications for drinking and irrigation.

Construction of Lung Adenocarcinoma Prognosis Model and Drug Sensitivity Analysis Based on Cuproptosis Related Genes

Lung cancer is one of the most common malignant tumors in the world, and the current lung cancer screening and treatment strategies are constantly improving, but its 5-year survival rate is still very low, which seriously endangers human health. Therefore, it is critical to explore new biomarkers to provide personalized treatment and improve the prognosis. Cuproptosis is a newly discovered type of cell death, which is due to the accumulation of excess copper ions in the cell, eventually leading to cell death, which has been suggested by studies to be closely related to the occurrence and development of lung adenocarcinoma (LUAD). Based on The Cancer Genome Atlas (TCGA) database, this study explored the association between cuproptosis-related genes (CRGs) and LUAD prognosis, established a prognostic risk model, and analyzed the interaction between CRGs and LUAD immune cell infiltration. The RNA-seq data of LUAD tissue and paracancerous or normal lung tissue were downloaded from the TCGA database; the RNA-seq data of normal lung tissue was downloaded from the Genotype-tissue Expression (GTEx) database, and the data of 462 lung adenocarcinoma cases were downloaded from the Gene Expression Omnibus repository (GEO) as verification. T the risk score model to assess prognosis was constructed by univariate Cox and Lasso-Cox regression analysis, and the predictive ability of the model was evaluated by receiver operating characteristic (ROC) curve and calibration curve. Immune-related and drug susceptibility analysis was further performed on high- and low-risk groups. A total of 1656 CRGs and 1356 differentially expressed CRGs were obtained, and 13 CRGs were screened out based on univariate Cox and Lasso-Cox regression analysis to construct a prognostic risk model, and the area under the curves (AUCs) of ROC curves 1-, 3- and 5- year were 0.749, 0.740 and 0.689, respectively. Further study of immune-related functions and immune checkpoint differential analysis between high- and low-risk groups was done. High-risk groups were more sensitive to drugs such as Savolitinib, Palbociclib, and Cytarabine and were more likely to benefit from immunotherapy. The risk model constructed based on 13 CRGs has good prognostic value, which can assist LUAD patients in individualized treatment, and provides an important theoretical basis for the treatment and prognosis of LUAD.

Developing machine-learned potentials to simultaneously capture the dynamics of excess protons and hydroxide ions in classical and path integral simulations.

The transport of excess protons and hydroxide ions in water underlies numerous important chemical and biological processes. Accurately simulating the associated transport mechanisms ideally requires utilizing abinitio molecular dynamics simulations to model the bond breaking and formation involved in proton transfer and path-integral simulations to model the nuclear quantum effects relevant to light hydrogen atoms. These requirements result in a prohibitive computational cost, especially at the time and length scales needed to converge proton transport properties. Here, we present machine-learned potentials (MLPs) that can model both excess protons and hydroxide ions at the generalized gradient approximation and hybrid density functional theory levels of accuracy and use them to perform multiple nanoseconds of both classical and path-integral proton defect simulations at a fraction of the cost of the corresponding abinitio simulations. We show that the MLPs are able to reproduce abinitio trends and converge properties such as the diffusion coefficients of both excess protons and hydroxide ions. We use our multi-nanosecond simulations, which allow us to monitor large numbers of proton transfer events, to analyze the role of hypercoordination in the transport mechanism of the hydroxide ion and provide further evidence for the asymmetry in diffusion between excess protons and hydroxide ions.

Interactive effects of silicon and potassium on photosynthesis and physio-biochemical traits of rice (Oryza sativa L.) leaf mesophyll under ferrous iron toxicity

Iron toxicity originated from excess ferrous ion (Fe2+) availability within plant growth medium remains a potent stress severely limiting rice productivity via alteration of photosynthetic and metabolic processes. Silicon (Si) or potassium (K) individually can enhance plant tolerance to abiotic stresses, including metal toxicity. However, their combined mitigation effects lack proper exploration even though greater alleviation potential could possibly be achieved. The objective of the present study was to evaluate the potential of combined application of Si and K in mitigating Fe2+ toxicity impairments to rice leaf mesophyll tissue. The experiment was laid out in a factorial combination of two Fe2+ levels (0 and 300 mg L−1), two Si levels (0 and 56 mg L−1), and two K levels (0 and 200 mg L−1) following a completely randomized design. Excess Fe2+ impaired leaf mesophyll performance by negatively affecting all tested parameters; however, Si and K significantly reduced those impairments. The integrated application of Si and K resulted in the maximum mitigation effects as high as 23%, 27%, 14%, 40%, 25%, 37%, 24%, 48%, 34%, 28%, 41%, and 15% for total chlorophyll content, maximum quantum yield of photosystem II, membrane stability index, relative cell death, lipid peroxidation, total protein content, free proline content, total polyphenol content, hydrogen peroxide content, total antioxidant activity, net photosynthetic rate, and plant biomass, respectively, compared with the control, with 29% decrease in Fe content and 4.2-fold and 1.7-fold respective increase in Si and K content of rice leaf mesophyll. Silicon or K enhanced photosynthetic performance by boosting antioxidant activity, proline content, and polyphenol content, thereby reducing oxidative damages from Fe2+-generated free radicals like hydrogen peroxide; however, K was comparatively more effective than Si. The combined application of Si and K resulted in significantly better Fe2+ toxicity alleviation response over their sole application for the maximum studied traits. The findings would contribute to the present understanding of Fe2+ toxicity alleviation and help in strategizing crop management practices for sustainable rice production in Fe2+-toxic lowlands.

Quantifying the relationship between spreading depolarization and perivascular cerebrospinal fluid flow

Recent studies have linked spreading depolarization (SD, an electro-chemical wave in the brain following stroke, migraine, traumatic brain injury, and more) with increase in cerebrospinal fluid (CSF) flow through the perivascular spaces (PVSs, annular channels lining the brain vasculature). We develop a novel computational model that couples SD and CSF flow. We first use high order numerical simulations to solve a system of physiologically realistic reaction–diffusion equations which govern the spatiotemporal dynamics of ions in the extracellular and intracellular spaces of the brain cortex during SD. We then couple the SD wave with a 1D CSF flow model that captures the change in cross-sectional area, pressure, and volume flow rate through the PVSs. The coupling is modelled using an empirical relationship between the excess potassium ion concentration in the extracellular space following SD and the vessel radius. We find that the CSF volumetric flow rate depends intricately on the length and width of the PVS, as well as the vessel radius and the angle of incidence of the SD wave. We derive analytical expressions for pressure and volumetric flow rates of CSF through the PVS for a given SD wave and quantify CSF flow variations when two SD waves collide. Our numerical approach is very general and could be extended in the future to obtain novel, quantitative insights into how CSF flow in the brain couples with slow waves, functional hyperemia, seizures, or externally applied neural stimulations.

Two Eu(III) central silica hybrids as ratiometric turn-on luminescent sensors for Al3+ ions

Aluminum ion is considered as an important ecological pollution because of its wide application in industry. In addition, excessive aluminum ion in water and food will cause great harm to human body. Therefore, it is very important to develop highly sensitive and selective sensors for the detection of aluminum ions. In this work, two kinds of β - diketone ligands (4, 4, 4-trifluoro-1-(2-naphthyl)–1, 3-butanedione (NTA) and 2-thiophenyltrifluoroacetone (TTA)), which have good energy matching with europium ion, are selected as the first ligands, and they are covalently grafted onto the silica network through reactions with triethoxysilyl propyl isonitrile, and then p-bromobenzotripyridine (L) is used as the second ligand. Finally two rare earth europium organic–inorganic hybrid materials, Eu(NTA-Si)3L and Eu(TTA-Si)3L, were obtained by coordination reaction and hydrolytic copolycondensation. Their luminescent properties and cation sensing properties were further studied. Two kinds of rare earth europium organic–inorganic hybrid materials not only display excellent photoluminescence properties, but also have excellent performance in the detection of aluminum ions in THF solution.

Carbon quantum dots in-situ relieve humic acids inhibition on methanogens while significantly increasing the abundance of Methanosarcinaceae

Monophenols form humic acids (HA) through polycondensation reaction in the anaerobic digestion (AD) process, which will inhibit AD process. Currently, metal ions are the option for in-situ relieving HA inhibition during AD, but excess metal ions are harmful to microorganisms. In this study, carbon quantum dots (CQDs, a non-metallic materials) were proposed to relieve HA inhibition in-situ. We investigated the effect of HA on AD acidification and methanation stage, and synthesized CQDs using sodium citrate (s-CQDs) and p-phenylenediamine (p-CQDs) as precursors to relieve the HA inhibition in-situ. Results showed that s-CQDs (3.0 g/L) significantly increased the cumulative CH4 yield from AD of ethanol with 1.0 g/L HA (1.9 times higher than that without s-CQDs). Microbiological analysis indicated the most dominant methanogen was Methanosarcinaceae, with richness of 89.7%. Compared to the HA inhibition system, the relative abundance of Methanosarcinaceae increased by 87.5%. The analysis of interaction mechanism between CQDs and HA indicated that s-CQDs has an in-situ binding effect to HA by reacting with -OH, CC, and -COOH. This study provided a novel means for in-situ relieving HA inhibition, and illustrated the interaction mechanism between CQDs and HA, which will guide the application in production of bioenergy.

Spectral Quality Assessment Strategy Based on the 13C-Isotopic Pattern for the Fourier Transform Ion Cyclotron Resonance Mass Spectra of Dissolved Organic Matter.

The interpretation of data and optimization spectral acquisition of dissolved organic matter (DOM) by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) have been challenging due to the varied instrument performances among laboratories and the complex chemical characteristics of DOM. However, a universal spectral optimization strategy for FT-ICR MS spectra is still unavailable. The results of this study showed that the number, intensity, and resolving power of all assigned peaks increased with the ion accumulation time (IAT) and DOM concentrations within a reasonable range. The space-charge effect induced by the excess ions in the ICR cell can deteriorate the data quality of the FT-ICR MS spectra, which could be inspected by examining the mass errors and intensity deviation of the monoisotopic and 13C-isotopic peaks based on the 13C-isotopic pattern. The maximum absolute mass error and 13C-isotopic pattern-based intensity deviation are two critical criteria for inspecting the space-charge effect, which was suggested to be 2.0 ppm and 20%, respectively. Therefore, a novel strategy based on the 13C-isotopic pattern has been proposed in this study to optimize the FT-ICR MS spectra of DOM based on their wide occurrence of monoisotopic and 13C-isotopic signals. This optimization strategy has laid the fundamentals for the method development of FT-ICR MS and could be extended to different FT-ICR MS instruments and various organic complex mixtures.

SEDIMENTOLOGY, PALAEOGEOGRAPHY AND DIAGENESIS OF THE UPPER PERMIAN (Z2) HAUPTDOLOMIT FORMATION ON THE SOUTHERN MARGIN OF THE MID NORTH SEA HIGH AND IMPLICATIONS FOR RESERVOIR PROSPECTIVITY

This paper provides an updated understanding of the reservoir stratigraphy, sedimentology, palaeogeography and diagenesis of the Upper Permian Hauptdolomit Formation of the Zechstein Supergroup (“Hauptdolomit”) in a study area on the southern margin of the Mid North Sea High. The paper is based on the examination and description of core and cuttings data from 25 wells which were integrated with observations based on existing and new 3D seismic.Based on thin‐section petrography of cuttings and core from the wells studied, it is evident that Hauptdolomit microfacies are distributed in a relatively predictable way, and well‐defined platform interior, platform margin, slope and basin settings can be distinguished. Platform margins are typically characterised by the development of ooid shoals and, to a lesser‐extent, by microbial build‐ups. High‐energy back‐shoal settings are characterised by a more complex combination of peloid grainstones, thrombolitic and microbial build‐ups, and fine crystalline dolomites. Lower energy lagoons which developed further behind the platform margin are characterised by a variety of microfacies types; fine crystalline dolomites are common in this setting as well as peloidal facies and local microbial build‐ups. Intertidal and supratidal settings are typified by increased proportions of anhydrite and the development of laminated microbial bindstones (stromatolites). Platform margins are in general relatively steep and pass into slope and basinal settings. Only a few wells have penetrated Hauptdolomit successions deposited in a slope setting, and these successions are characterised by a range of resedimented shallow‐water facies together with low‐energy laminated dolomicrites and fine crystalline dolomites. Slope zones in the study area are interpreted from seismic data to be typically 1‐1.5 km in width. Basinal Hauptdolomit deposits have been strongly affected by post‐depositional diagenesis and are dedolomitised to variable degrees. The original depositional facies are rarely preserved.Diagenetic studies show that dolomitisation has affected almost the entire Hauptdolomit Formation throughout the study area in both basinal and platform settings. The dolomite is considered to result from seepage‐reflux processes and is an early diagenetic phase. Mouldic porosity is present in many facies types as a result of dissolution, especially in ooid grainstones, thrombolitic build‐ups and peloidal facies. The dissolution cannot be associated with any one diagenetic phase but was most likely a result of the dolomitisation process itself. Stable isotope analyses indicate that all dolomites were precipitated from Permian marine‐derived pore fluids. Fluid inclusion analyses of dolomite cements indicate that cementation continued into the burial realm. Anhydrite cementation occurs in two phases: early anhydrite precipitation was associated with dolomitisation, and can be distinguished from a later, pore‐filling cement which is highly detrimental to reservoir quality.The Hauptdolomit succession in basinal wells (and in some slope wells) in the study area has undergone significant dedolomitisation. Dedolomitisation was a shallow burial process which affected precursor dolomites, whereby excess calcium from the transition of gypsum to anhydrite during burial combined with CO2 and organic acids derived from basinal sediments. The process was triggered by excess calcium reacting with excess carbonate ions from dissolution.3D seismic volumes supplemented by numerous 2D lines were available in the study area and allowed an interpretation to be made of Hauptdolomit gross depositional settings; platform margins and base‐of‐slope polygons were mapped, with the greatest confidence in areas of 3D seismic. The basin, slope and platform settings were distinguished using seismic data integrated with the results of micro‐facies analysis and incorporating seismic‐to‐well ties. The data shows that large parts of the study area are characterised by the presence of polyhalites within the overlying (Z2) Stassfurt Halite Formation, which may create particular seismic geometries at the Hauptdolomit slope. These are interpreted to be intra‐Stassfurt Halite features, providing an alternative model to the thickened, prograded Hauptdolomit which has been suggested in previous publications.Because few wells drilled in the study area had the Hauptdolomit as the primary target, cores were limited but significant data was obtained from cuttings analyses. More than 400 thin sections were evaluated, allowing depositional models based on microfacies observations to be developed, verifying the seismic‐scale observations.