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The rapid detection of contaminants in water resources is vital for safeguarding the environment, where the use of eco-friendly materials for water monitoring technologies has become increasingly prioritized. In this context, the role of biocomposites in the development of a SERS sensor is reported in this study. Grafted chitosan was employed as a matrix support for Ag nanoparticles (NPs) for the surface-enhanced Raman spectroscopy (SERS). Chitosan (CS) was decorated with thiol and carboxylic acid groups by incorporating S-acetyl mercaptosuccinic anhydride (SAMSA) to yield CS-SAMSA. Then, Ag NPs were immobilized onto the CS-SAMSA (Ag@CS-SAMSA) and characterized by spectral methods (IR, Raman, NIR, solid state 13 C NMR with CP-MAS, XPS, and TEM). Ag@CS-SAMSA was evaluated as a substrate for SERS, where methylene blue (MB) was used as a model dye adsorbate. The Ag@CS-SAMSA sensor demonstrated a high sensitivity (with an enhancement factor ca. 10 8 ) and reusability over three cycles, with acceptable reproducibility and storage stability. The Raman imaging revealed a large SERS effect, whereas the MB detection varied from 1-100 μM. The limits of detection (LOD) and quantitation (LOQ) of the biocomposite sensor were characterized, revealing properties that rival current state-of-the-art systems. The dye adsorption profiles were studied via SERS by fitting the isotherm results with the Hill model to yield the ΔG° ads for the adsorption process. This research demonstrates a sustainable dual-function biocomposite with tailored adsorption and sensing properties suitable for potential utility in advanced water treatment technology and environmental monitoring applications.

In the present study, a homemade mixed-mode ion-exchange sorbent based on silica with embedded graphene microparticles is applied for the selective extraction of 2-aminobenzothiazole (NH 2 BT) followed by determination through liquid chromatography coupled to high-resolution mass spectrometry. The sorbent was evaluated for the solid-phase extraction of NH 2 BT from environmental water samples (river, effluent wastewater, and influent wastewater), and NH 2 BT was strongly retained through the selective cation-exchange interactions. Therefore, the inclusion of a clean-up step of 7 mL of methanol provided good selectivity for the extraction of NH 2 BT. The apparent recoveries obtained for environmental water samples ranged from 62 to 69% and the matrix effect from -1 to -14%. The sorbent was also evaluated in the clean-up step of the organic extract for the extraction of NH 2 BT from organic extracts of indoor dust samples (10 mL of ethyl acetate from pressurized liquid extraction) and fish (10 mL of acetonitrile from QuEChERS extraction). The organic extracts were acidified (adding a 0.1% of formic acid) to promote the cation-exchange interactions between the sorbent and the analyte. The apparent recoveries for fish samples ranged from 22 to 36% depending on the species. In the case of indoor dust samples, the recovery was 41%. It should be highlighted the low matrix effect encountered in such complex samples, with values ranging from -7 to 5% for fish and dust samples. Finally, various samples were analyzed. The concentration in river samples ranged from 31 to 136 ng/L; in effluent wastewater samples, from 55 to 191 ng/L; in influent wastewater samples, from 131 to 549 ng/L; in fish samples, from 14 to 57 ng/g dried weight; and in indoor dust samples, from 

The water environment of large reservoirs is fragility due to effects from hydrological regulation of damming and anthropogenic inputs. As a critical path to quantify the natural chemical weathering and assess environmental risks, solute chemistry of river has been widely focused on. However, the complexed hydrological conditions of large reservoir affect the chemical compositions, and the significance of solute vertical geochemistry as an indicator of chemical weathering and water quality health remains explore. Therefore, the Three Gorges Reservoir (TGR) was selected as a typical study area, which is the world's largest hydropower project and subject to frequent water quality problems. Then, the chemical compositions in stratified water were determined. Ca 2+ (52.8 ± 4.3 mg/L) and HCO 3 - (180.9 ± 8.9 mg/L) were the most abundant ions among cations and anions, respectively. Incremental mean concentration of total major ions followed with the increase of riverine depth and flow direction. An improved inversion model was used to quantify the source contribution, which weathering of dolomite (34%) and calcite (38%) contributed the most to total cations, and the influences of agriculture and sewage discharge were limited. Additional contributions of evaporite and pyrite oxidation were found in analysis of deeper water samples, which also results in 2%-67% difference in estimated CO 2 release flux using data from different depth, indicating additional information about sulfuric acid driven weathering was contained. Finally, the water quality of the reservoir was assessed for irrigation and non-carcinogenic risks. Results showed the stratified water of TGR can be used as a good water source of irrigation. However, NO 3 - (5.1 ± 1.1 mg/L) may have a potential non-carcinogenic risk to children, especially in surface water. To sum up, this study provided an indispensable supplement to the water chemistry archives in the TGR basin, serving as theoretical references for environmental management of large reservoirs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Toxic cations, including heavy metals, pose significant environmental and health risks, necessitating the development of reliable detection methods. This review investigates the techniques and approaches used to strengthen the sensitivity and selectivity of Schiff base fluorescent chemosensors designed specifically to detect toxic and heavy metal cations. The paper explores a range of strategies, including functional group variations, structural modifications, and the integration of nanomaterials or auxiliary receptors, to amplify the efficiency of these chemosensors. By improving selectivity towards targeted cations and achieving heightened sensitivity and detection limits, consequently, these strategies contribute to the advancement of accurate and efficient detection methods while increasing the range of end-use applications. The findings discussed in this review offer valuable insights into the potential of leveraging Schiff base fluorescent chemosensors for the accurate and reliable detection and monitoring of heavy metal cations in various fields, including environmental monitoring, biomedical research, and industrial safety.

Groundwater is a valuable resource for developmental activities, and its demand is growing as surface water becoming scarce. Groundwater demand is increasing, resulting in reduction in water level and deterioration in water quality. A total of 156 groundwater samples were taken from Gaya, a district in Bihar (India), to check the safety of drinking water. The quality of groundwater was assessed using a water quality index (WQI). Analysed samples were assessed using a variety of physicochemical characteristics, and statistical methods principal component analysis (PCA) and cluster analysis (CA) were used as they are effective and efficient. As per the Gibbs, plot majority of the sample falls in the rock-water interaction and some evaporation dominance field. The domination of major cation in the order of Ca 2+  > Mg 2+  > Na + and the major anions followed the order of HCO 3 -  > [Formula: see text]>[Formula: see text]>[Formula: see text]>[Formula: see text]. The KMO's sample adequacy value of 0.703 and the significance level of Bartlett's test of sphericity (0.0001) were indicating that PCA may be implemented. Using the PCA, the three components recovered explained 69.58% of the total variation. Cluster analysis classified the groundwater sample into three cluster based on the similarities among chemical parameters involved in groundwater quality. HCA exhibit less, intermediate, and heavily mineralized groundwater characteristics of groups I, II, and III, respectively. The major parameters affecting the water quality in the study region are TDS, Ca 2+ , Mg 2+ , HCO 3 - , [Formula: see text]. WQI indicates 17% of the sample were found to be of very poor quality and not consumable. The study's findings offer insights and understanding into groundwater pollution regimes. These results used for water quality assessment leading to improved environmental management and planning and in decision-making for water quality management., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

This study characterises the quality of groundwater for the Ludhiana district of Punjab, India by analysing water samples collected from 152 locations spread across 3767 km 2 . The samples were analysed for 18 parameters consisting of pH, EC, TDS, TA, TH, major anions and cations. The parameter values have been used to calculate the drinking water quality index of the study area which suggests that 2.6, 57.9, 32.9, 4 and 2.6% of the samples fall under the excellent, good, poor, very poor and unsuitable categories, respectively. The sequence of abundance for ions (in meq/l) as revealed from the laboratory tests is Na + (37.1%) > Ca 2+ (30.8%) > Mg 2+ (29.1%) > K + (2.8%) for cations and HCO 3 - (80%) > Cl ¯ (8.9%) > CO 3 2- (6.5%) > SO 4 2- (3.9%) > NO 3 - , F - , PO 4 3- (< 1%) for anions. The spatial variability of these parameters has been depicted through the use of interpolation maps. Evaluation of different ionic ratios indicates that carbonate weathering and silicate weathering are both significantly affecting the groundwater chemistry with a slight dominance of carbonate weathering. Also, the ion exchange process is taking place in the area as confirmed by CAI index values. In terms of saturation index, the groundwater is undersaturated with respect to halite, fluorite and sylvite, whereas it is supersaturated for calcite, dolomite and aragonite minerals. The principal components in PCA explained 75.4% of the total variance with 29.1 and 28.3% contributions from PC1 and PC2. Both of these components indicate towards the geogenic and anthropogenic influence on groundwater mineralization of the area. The analysis suggests that groundwater for the study area is suitable for drinking in most of the region expect in a few places. Such a study could be used to understand the current status of groundwater quality in the area, the results of which can be used to prevent further contamination and sustain the resource for the future., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The hydrochemical characteristics were analyzed by mathematical statistics, the hydrochemical types were analyzed by Piper three line diagram, and the sources and influencing factors of main ions in surface water were discussed by Gibbs diagram and ion correlation analysis. The results show that the TDS of surface water in the study area is 109-559 mg·L -1 , and the average value is 318.67 mg·L -1 ; The pH value is 6.81-8.62, and the average value is 7.85. Most of them belong to weakly alkaline water. The surface water cation is mainly Ca 2+ and Mg 2+ , the anion is mainly HCO 3 - and the hydrochemical type is HCO 3 -Ca. Through the correlation analysis of the main ions, it can be seen that TDS has a significant positive correlation with Na + , K + , Mg 2+ , Ca 2+ and HCO 3 - , and these ions contribute to TDS. HCO 3 - has a significant correlation with Na + , K + and Mg 2+ and comes from carbonate rocks. According to the analysis of water-rock model, the hydrochemical genesis of surface water in the study area is mainly controlled by rock weathering, most ions are weathered and dissolved by carbonate rock and evaporated salt rock and a few cations are affected by water ion exchange.

The present study has been carried out to assess the quality of groundwater and surface water resources of Thettiyar watershed, Kerala, India. Sixty-six water samples were collected during pre-monsoon (April, 2019) and monsoon (July, 2019) season, and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness and major cations and anions and microbiological parameters as well. According to the piper diagram's plot, Ca and Mg dominate over Na among the cations, and Cl is the most prevalent anion in groundwater throughout both the studied seasons. The hydrochemical analysis of water samples revealed that all the parameters are within the permissible limit except for pH. For microbiological analysis, the samples were tested for total coliform and fecal coliform. Most of the groundwater samples collected have higher total coliform and fecal coliform (E. coli) content than the recommended count by BIS (2012). The pre-monsoon surface water samples owned a maximum number of 3700 cfu/100 ml (TNTC-too numerous to count) of total coliform and 1400 cfu/100 ml (TNTC) of fecal coliform. In monsoon, the number of total coliform and fecal coliform has increased to 3800 cfu/100 ml and 1900 cfu/100 ml respectively. E. coli and total coliform are effectively correlated with each other in both seasons, in accordance with the statistical study. Domestic, sewage dump, and other household wastes are the main sources of bacterial contamination in the study area, which in turn nourishes contaminant organisms. According to the results, the government or municipality should implement an appropriate system for managing solid waste and should take all necessary measures to clean up the study area., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

In this study, we assessed the capacity of a previously reported engineered liposomal formulation, which had been tested against model membranes mimicking the lipid composition of the HeLa plasma membrane, to fuse and function as a nanocarrier in cells. We used atomic force microscopy to observe physicochemical changes on the cell surface and confocal microscopy to determine how the liposomes interact with cell membranes and released their load. In addition, we performed viability assays using methotrexate as an active drug to obtain proof of concept of the formulation´s capacity to function as a drug delivery-system. The interaction of engineered liposomes with living cells corroborates the information obtained using model membranes and supports the capacity of the engineered liposomal formulation to serve as a potential nanocarrier., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

The aim of the study was to determine the groundwater characteristics of rural and industrial zones in the Kannur region. In 2011, 25 groundwater data were collected from the centre for water resource development management (CWRDM), and in 2019, 25 groundwater samples from rural and near-industrial areas were collected and analysed for major anions (HCO 3 -, CO 3 2- , Cl - , NO 3 - and SO 4 2- ), and cations (TH, Ca 2+ , Mg 2+ , Na + , K + and Fe 2+ ) using APHA standards. To better understand the link between water quality parameters, multivariate statistical analysis approaches such as principal component analysis (PCA), hierarchical cluster analysis (HCA), correlation matrix analysis (CMA), and Pearson correlation bivariate one-tailed analysis (PCBOTA) were used to analyse the inter-relationship of data. The Inverse Distance Weighed (IDW) method was used to generate the spatial distribution of the groundwater quality index (GWQI). In 2011, the water quality index (WQI) value of groundwater samples was excellent at 24.42% and good at 54.14%, which were used for drinking purposes and moderate at 17.22% and poor at 4.22% for irrigation purposes in this study area. In 2019, excellent 21.62%, good 51.56% were used for drinking purpose, and moderate at 18.14%, and poor at 8.68% for irrigation purposes. By comparing the data with BIS and WHO standards, it is clear that groundwater in Kannur district is of good quality. In groundwater samples, the PCA eigen values were reported in 2011 (84.7%) and 2019 (73.4%) for statistical approaches. This study uses HCA and PCBOTA to analyse the elements, resulting in a better understanding of groundwater quality development. GIS based WQI maps were obtained and utilised to gain a better knowledge of the study area's past and present water quality status. We observed that the quality of groundwater in the study region's north-western portion is insufficient for drinking water., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Ismailia Canal is one of the significant streams of the Nile River in Egypt. The study aimed to determine the water quality of Ismailia Canal based on the regional and seasonal variability of physicochemical parameters, irrigation criteria, and the irrigation water quality index (IWQI). It was observed that the physicochemical parameters were within the acceptable FAO irrigation limits. All cations and anions values were within the acceptable FAO limits for irrigation, except the potassium (K + ) concentrations were over the permissible irrigation limits. The one-way analysis of variance (ANOVA) suggested a significant seasonal variation in the canal's water quality concerning all parameters (p value ˂ 0.05). However, the regional variation among various sites was statistically insignificant (p value > 0.05). Statistical analysis was used to calculate the correlation coefficient between different parameters, and the study showed highly significant correlation coefficients between different pairs of water quality parameters. The correlation matrix showed that the pH significantly affected IWQI (r = 0.661). The irrigation criterion values for Ismailia Canal were good, and the WQI levels for irrigation utilization at all studied sites were satisfactory. Deterioration of water quality may occur due to industrial, municipal, and agricultural activities. Drainage water should be treated before being mixed with irrigation water to improve its suitability for irrigation., (© 2022. The Author(s).)

In the current survey, different hydrogeochemical processes governing the geochemistry of aquifers, the usefulness of groundwater for regular consumption, and agricultural purposes were evaluated around the Tummalapalle area. One hundred forty-four borehole locations were chosen to characterize the major physicochemical components of the aquifer water. The analysis results of pH inferred that the groundwater is nominally acidic to basic, and pH ranged from 6.6 to 8.4. The average concentrations of TDS, Ca 2+ , Mg 2+ , total hardness (TH), HCO 3 - , and total alkalinity (TA) are within the allowable limits of potable water quality as prescribed by the Bureau of Indian Standards (BIS) and WHO. However, the average concentrations of Na + , K + , Cl - , and SO 4 2- were all below the permissible limit. All samples were analyzed with the help of Piper and Chadha charts to determine the dominant hydrogeochemical components of groundwater. The dominance of cations in groundwater in this region is in the sequence of Ca 2+  > Na +  > Mg 2+  > K + , followed by anions HCO 3 -  > Cl -  > SO 4 2- . The Gibbs plot analysis suggested the predominance of rock aquifer interaction as the major hydrogeochemical process governing groundwater geochemistry in this region. The water quality index (WQI) of all groundwater samples in the Tummalapalle region was estimated, with 55% of the samples being potable grade. The different irrigation indices were analyzed for the groundwater samples to estimate their desirability for agriculture. The maximum number of water samples was found to be well-suited for cultivation., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A new, simple and sensitive ion chromatography (IC) method for the determination of sodium, potassium, magnesium, calcium and chloride in a parenteral nutrition (PN) solution was developed and validated. Before sample analysis, a sample pretreatment by calcination was applied which could totally remove interference from other constituents of the PN solution. Methanesulfonic acid (MSA) and sodium hydroxide were used as the mobile phase for the determination of cations and anions, respectively. The calibration curves showed good correlation between analyte peak area and concentration (r2 > 0.999). Detection limits ranged from 0.0001 to 0.02 mg/L and quantification limits from 0.0002 to 0.06 mg/L. Relative standard deviation (RSD) values for repeatability and inter-day precision did not exceed 1.0% and the recoveries for all analytes were between 99.1−101.1%. The robustness was verified by using an experimental design.

The present research has been performed to analyze the chemical behavior of rainwater of the Shaune Garang catchment (32.19° N, 78.20° E) in the Baspa basin, located at a high elevation (4221 m above mean sea level) in the Himachal Himalaya, India. During the study period, sixteen rainwater samples were collected from the Shaune Garang catchment at five different sites. The volume-weighted mean (VWM) pH value of rainwater ranged between 4.59 and 6.73, with an average value of 5.47 ± 0.69, indicating the alkaline nature of rainfall. The total ionic strength in the rainwater ranged from 113.4 to 263.3 µeq/l with an average value of 169.1 ± 40.4 µeq/l. The major dominant cations were Ca 2+ (43.10%) and Na + (31.97%) and anions were Cl - (37.68%), SO 4 2- (28.71%) and NO 3 - (23.85%) in rainwater. The ionic ratios were calculated among all the ions. The fraction of (NO 3 -  +Cl - ) with SO 4 2- was measured as 2.3, which specifies sour faces of rainwater due to HNO 3 , H 2 SO 4 , and HCl. A multivariate statistical assessment of rainwater chemistry through Principal Component Analysis (PCA) shows the significance of four factors controlling 78.37% of the total variance, including four-component (PC1 explained 27.89%, PC2 explained 24.98%, PC3 explained 14.64%, PC4 explained 10.85%). However, the individual contribution of Factor 1(PC1) explains 27.89% of the total variance (78.37%) and displays a strong optimistic loading for Ca 2+ and Cl - . Further, high loading of Ca 2+ and NO 3 - and moderate loading of SO 4 2- signify the contribution of burning fossil fuel and soil dust. Anthropogenic and natural pollutants influence the composition of rainwater in the pristine Himalayas due to local and long-distance transportation. The study area receives precipitation from the West and North-West, transporting dust and fossil fuel emissions from the Thar Desert and Northwestern countries., (© 2022. The Author(s).)

In this study,the water samples were collected from 31 sites of Tawang, Arunachal Pradesh, India (North-Eastern Himalaya), during the winter season to check the suitability of water for drinking and irrigation purposes.The study scientifically demonstrates the estimation of Water quality index (WQI) andhydrogeochemical characteristics of surface water samples by utilizing multivariate statistical methods. The main water quality parameters considered for this study were TDS, conductivity, salinity, pH, hardness, cations and anions. WQI was calculated in order to find out the deviation in the water quality parameters particularly with respect to BIS permissible limits.The major influencing factors responsible for the variation in these parameters were derived by using Principal component analysis (PCA) and Correlation matrix.To check the suitability of water for drinking purpose, hydrogeochemical facies and rock water interaction was derived by using well established methods such as Piper Plot (determine water type), WQI (Quality monitoring), and saturation index (for mineral dissolution). The results revealed that the silicate weathering was the main ionic source in comparison to carbonate weathering which is due to the higher dissolution capacity of silicate minerals.The results of the scattered plot between (Ca 2+  + Mg 2+ )-(HCO 3 - + SO 4 2 -) versus (Na +  + K + )-Cl- (meq/L) highlighted thation exchange occurs between Mg 2+ and Ca 2+ ofsurface water with Na + and K + of rock /soil. This means that calcium ion was getting adsorbed, and sodium ion was getting released. The Ca 2+ -Mg 2+ -HCO 3 -, Na + -HCO 3 -and Na + -Cl- type of surface water suggested permanent and temporary hardness respectively in the studied region. The dominant cations of this study were Na + and Ca 2+ while the dominant anions were HCO 3 - and SO 4 2 -. In order to check the suitability of water sources for irrigation, parameters like, Magnesium hazard (MH), Total hardness (TH), Permeability Index (PI), Kelly Index (KI), Sodium adsorption rate (SAR), Sodium percentage (Na%), and Residual sodium carbonate (RSC) were determined. The results showed that 93% of the samples had PI score < 75, which indicates the suitability of the water for irrigation. Also the WQI calculation showed an average WQI value of 82.49, amongst which 61% samples were in the range of 0-50 being considered as good for drinking, while 39% were catageorised as unsuitable for drinking showing a value of > 50. Hence the above findings reveal that geogenic activities play a major role in influencing the water quality of Tawang region. Hence suitable water treatment technologies or methods might be used to eliminate thenon desirable elements and minerals present in surface water., (© 2022. The Author(s).)

In spite of the fact that rock weathering performs an essential task in the evolution of the Earth's surface, the quantitative assessment between pH and rates of chemical weathering remain unclear. This study aims to characterize the chemical weathering rate of purple rocks and then develops a model to calculate the release rates of cations (K + , Na + , Ca 2+ and Mg 2+ ) under various pH conditions. Two types of purple rock were sampled from the Shaximiao Group (J 2 s) and Penglaizhen Group (J 3 p), and a series of laboratory experiments were performed by soaking the purple rocks in solutions with pHs from 2.5 to 7.0, over 24 treatment cycles. The results showed that the release rates of cations apparently increased as the pH decreased. The release of Ca 2+ was the dominant process of chemical weathering in J 3 p under various pH treatments, while K + and Na + were remarkably high in J 2 s (with the exception of the pH 2.5 treatment). Quantitative analysis revealed that the rate of cation release was significantly related to the H + concentration (p < 0.001) and the air temperature (p < 0.001). The relationship between cation release and acidity was found to be an exponential function. Our results suggested that solution acidity serves as an important driving force for cation release rates from purple rocks and that environmental acidification would enhance rock weathering., (© 2022. The Author(s).)

We evaluate stability of cesium (Cs) and other alkali-metal cation complexes of lichen metabolites in both gas and aqueous phases to discuss why lichens can retain radioactive Cs in the thalli over several years. We focus on oxalic acid, (+)-usnic acid, atranorin, lecanoric acid, and protocetraric acid, which are common metabolite substances in various lichens including, e.g., Flavoparmelia caperata and Parmotrema tinctorum retaining Cs in Fukushima, Japan. By performing quantum chemical calculations, their gas-phase complexation energies and aqueous-solution complexation free energies with alkali-metal cations are computed for their neutral and deprotonated cases. Consequently, all the molecules are found to energetically favor cation complexations and the preference order is Li[Formula: see text]Na[Formula: see text]K[Formula: see text]Rb[Formula: see text]Cs[Formula: see text] for all conditions, indicating no specific Cs selectivity but strong binding with all alkali cations. Comparing complexation stabilities among these metabolites, lecanoric and protocetraric acids seen in medullary layer are found to keep higher affinity in their neutral case, while (+)-usnic acid and atranorin in upper cortex exhibit rather strong affinity only in deprotonated cases through forming stable six atoms' ring containing alkali cation chelated by two oxygens. These results suggest that the medullary layer can catch all alkali cations in a wide pH range around the physiological one, while the upper cortex can effectively block penetration of metal ions when the metal stress grows. Such insights highlight a physiological role of metabolites like blocking of metal-cation migrations into intracellular tissues, and explain long-term retention of alkali cations including Cs in lichens containing enough such metabolites to bind them.

Novel polyepinephrine-modified NaYF 4 :Yb,Tm upconversion luminescent nanoparticles (UCNP@PEP) were prepared via the self-polymerization of epinephrine on the surfaces of the UCNPs for selective sensing of Fe 3+ inside a cell and for intracellular imaging. The proposed UCNP@PEP probe is a strong blue light emitter (λ max  = 474 nm) upon exposure to an excitation wavelength of 980 nm. The probe was used for detecting Fe 3+ owing to the complexation reaction between UCNP@PEP and Fe 3+ , resulting in reduced upconversion luminescence (UCL) intensity. The proposed probe has a detection limit of 0.2 μM and a good linear range of 1-10 μM for sensing Fe 3+ ions. Moreover, the UCNP@PEP probe displays high cell viability (90%) and is feasible for intracellular imaging. The ability of the probe to sense Fe 3+ in a human serum sample was tested and shows promising output for diagnostic purposes. The prepared UCNP@PEP probe was characterized by using UV-visible (UV-Vis) absorption spectrometry, fluorescence (FL) spectrometry, field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR).

Environmental monitoring is one of the most dynamically developing branches of chemical analysis. In this area, the use of multidimensional techniques and methods is encouraged to allow reliable determinations of metal ions with portable equipment for in-field applications. In this regard, this study presents, for the first time, the capabilities of a polymer inclusion membrane (PIM) sensor to perform cadmium (II) determination in aqueous solutions by in situ visible (VIS) and Mid- Fourier transform infrared spectroscopy (MID-FTIR) analyses of the polymeric films, using a partial least squares (PLS) chemometric approach. The influence of pH and metal content on cadmium (II) extraction, the characterization of its extraction in terms of the adsorption isotherm, enrichment factor and extraction equilibrium were studied. The PLS chemometric algorithm was applied to the spectral data to establish the relationship between cadmium (II) content in the membrane and the absorption spectra. Furthermore, the developed MID-FTIR method was validated through the determination of the figures of merit (accuracy, linearity, sensitivity, analytical sensitivity, minimum discernible concentration difference, mean selectivity, and limits of detection and quantitation). Results showed reliable calibration curves denoting systems' potentiality. Comparable results were obtained in the analysis of real samples (tap, bottle, and pier water) between the new MID-FTIR-PLS PIM based-sensor and F-AAS.

The abuse of tetracycline arises the risk of antibiotic resistance genes and has been paid much attention. To understand the potential bioavailability of tetracycline (TC) in soil environments, this study explored the behaviors of TC adsorbing to six types of soils sampled from different regions of China. Moreover, the solution pH and existence of Cd 2+ effect on TC sorption to soils were investigated to understand the influential factors affecting TC sorption. The results showed that the soil properties and sorption capacity of TC varied significantly with different soils. The sorption capacity of TC to soils might be largely affected by cation exchange capacity (CEC) and soil organic carbon (SOC), while the sorption rate, interaction strength and equilibrium sorption binding might be affected by soil pH, pH PZC , soil inorganic carbon (SIC) and H content. The result of solution pH effect suggested that the predominant sorption mechanism for acid soils might be hydrophobic interactions between soils and H 2 TC 0 , and the cation exchange was possibly proposed as the primary mechanism for TC sorption to alkaline soils. Furthermore, the presence of Cd 2+ might increase TC sorption to acid soil, while reduce TC sorption to alkaline soil. It is expected that this study may provide important information for predicting the potential fate of TC (or similar antibiotics) in different soils, and thus helping to assess the bioavailability of TC in soils., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

In this work, lignin fractionation is proposed as an effective approach to reduce the heterogeneity of lignin and improve the adsorption and recycle performances of lignin as a cationic dye adsorbent. By stepwise dissolution of enzymatic hydrolysis lignin in 95% and 80% ethanol solutions, three lignin subdivisions (95% ethanol-soluble subdivision, 80% ethanol-soluble subdivision, and 80% ethanol-insoluble subdivision) were obtained. The three lignin subdivisions were characterized by gel permeation chromatography (GPC), FTIR, 2D-NMR and scanning electron microscopy (SEM), and their adsorption capacities for methylene blue were compared. The results showed that the 80% ethanol-insoluble subdivision exhibited the highest adsorption capacity and its value (396.85 mg/g) was over 0.4 times higher than that of the unfractionated lignin (281.54 mg/g). The increased adsorption capacity was caused by the enhancement of both specific surface area and negative Zeta potential. The maximum monolayer adsorption capacity of 80% ethanol-insoluble subdivision by adsorption kinetics and isotherm studies was found to be 431.1 mg/g, which was much higher than most of reported lignin-based adsorbents. Moreover, the 80% ethanol-insoluble subdivision had much higher regeneration yield (over 90% after 5 recycles) compared with the other two subdivisions. Consequently, the proposed fractionation method is proved to be a novel and efficient non-chemical modification approach that significantly improves adsorption capacity and recyclability of lignin.

The study investigates transformation mechanism of ions on different waters in Alpine region through analyzed the hydrochemical characteristics of the major ions of precipitation, glacier and snow meltwater, supra-permafrost water and river water in permafrost regions in the Tibetan Plateau under climate warming. The results showed that, The relation between recharge and discharge was the major ways for ionic transformation of each water body. Precipitation and glacier and snow meltwater are the main input sources for ionic transformation, and river water is the final output source. Different water bodies had different ionic concentrations and different hydrochemical types. However, different water bodies in different months (from June to September) also had different hydrochemical types. The water - rock interaction, reactions for ions, dilution effect and other effect for ions played an important role in the process of ion transformation. The increasing of temperature would lead to the accelerated melting of glaciers, permafrost and snow in the alpine regions, so the amount of supra-permafrost water and glacier and snow meltwater will increase, which leads to the increase of runoff. Meanwhile, the increase of temperature makes evaporation stronger. The strong of evaporation will accelerate the transformation of liquid water to gaseous water. Moreover, ion translation and water conversion are synchronous. Accordingly, ions are also accelerating transformation in the process of accelerated transformation of water body. Climate change is not only the main driving force for multiphase water transformation, but also the main driving force for the ion transformation of various water bodies., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Laser-induced breakdown spectroscopy, coupled with advanced chemometric methods, was used to quantitate multiple elements in a seaweed-based fertilizer. The influence of important parameters was determined using partial least squares regression (PLSR), support vector regression (SVR) and random forest (RF) optimizations. Optimal results for Mg, K and P were obtained using PLSR, whereas RF yielded the best results for Mn, Cu, Sr and Ca. The best predictions for Ba levels were obtained with SVR. The lowest root mean square errors in the prediction sets for Mn, Cu, Sr, Ba, Mg, K, P and Ca were 48.27 µg/g, 36.90 µg/g, 0.37 mg/g, 40.32 µg/g, 1.99 mg/g, 2.03 mg/g, 4.81 mg/g and 14.08 mg/g, respectively, with average relative standard deviations of 13.65%, 2.68%, 19.80%, 5.17%, 3.32%, 2.98%, 1.82% and 5.81%. The results showed that the optimal multivariate model depended on the specific element being analyzed. The proposed method provides a rapid means of determining multielement concentrations in seaweed-based fertilizers.

The Opuntia ficus indica (L.) (OFI) is used as a nutritional and pharmaceutical agent in various dietary and value added products. This study underlines the possible use of native prickly pear cladode powder as a functional ingredient for health-promoting food production. To summarise, chemical characterization of polyphenols, minerals and soluble dietary fibre was performed; furthermore, the antioxidant activity and bioaccessibility of polyphenols and minerals were assessed. Eleven compounds between phenolic acids and flavonoids were identified, with piscidic acid and isorhamnetin derivatives being the most abundant. Opuntia's dietary fibre was mainly constituted of mucilage and pectin, and was composed of arabinose, galactose, glucose, mannose, rhamnose, and xylose sugars. The polyphenols' bioaccessibility was very high: piscidic acid at 200%, eucomic and ferulic acids >110% and flavonoids from 89% to 100%. The prickly pear cladode powder is also a source of minerals, as cations (calcium, sodium, potassium and magnesium) and anions (sulphate and chloride), with high magnesium bioaccessibilty (93%). OFI powder showed good capacity of radical scavenging measured by DPPH and ABTS methods, with 740 and 775 μmol Trolox/100 g OFI, respectively. Finally, the presented results allow the consideration of this natural product as a source of several essential nutrients, with a possible use in the food industry as a functional ingredient.

Nanomaterials with enzyme-like characteristics (also called nanozymes) have attracted increasing attention in the area of analytical chemistry. Nevertheless, most of the nanozymes used for analytical applications are oxidoreductase mimics, and their enzyme-like activities are usually demonstrated by using chromogenic and/or fluorogenic substrates. Herein, the phosphatase mimetic activity of cerium oxide nanoparticles (nanoceria) was investigated by using CDP-star as the chemiluminescent (CL) substrate. Interestingly, we found that the phosphatase mimetic activity of nanoceria can be remarkably inhibited by the addition of Al 3+ . Based on this finding, a highly sensitive and selective CL method for Al 3+ detection is proposed. The CL intensity of the nanoceria/CDP-star system decreased with the increasing Al 3+ concentrations in the range from 30 nM to 3.5 μM. A detection limit as low as 10 nM was obtained. Finally, the CL detection of intracellular Al 3+ was achieved, demonstrating the utility of the CL method in complex biological samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A novel method was developed for the simultaneous determination of inorganic anions (Cl - , SO 4 2- and ClO 3 - ) and cations (K + , Ca 2+ , Na + , Mg 2+ and Li + ) in wine by capillary electrophoresis-indirect ultraviolet detection (CE-UV) with dual-opposite end injection using 1-ethyl-3-methylimidazolium p -toluenesulfonate ([EMIm]TS) as the background electrolyte.[EMIm]TS acted as the running electrolyte and probe, generating the background signals for cations and anions under indirect UV light, consequently simplifying the electrophoretic medium. Under the optimal experimental conditions, baseline separation was achieved for the eight inorganic ions within 6.5 min. The linear ranges of the eight inorganic ions were 0.005-0.7 g/L, with correlation coefficients ( R 2 ) of 0.963-0.995. The limits of detection (LODs) were between 1.2 and 12.5 mg/L at a signal-to-noise ratio of 3 ( S/N =3). Eight inorganic ions were detected in three different brands of wines obtained from supermarket. Good recoveries of 90.1%-110.5% at three spiked levels (0.05, 0.2 and 0.4 g/L) were achieved with a low relative standard deviations (RSDs) ( n =5) of 1.1%-4.8%. The proposed method is robust and reliable for the sensitive and rapid analysis of the inorganic anions and cations, and it has potential in evaluating the quality of wine.

Understanding factors influencing groundwater quality is critical to the development of best management practices at the large watershed scale. In this study, the shallow groundwater (10-20 m depth) in the Su-Xi-Chang region, eastern China, was investigated as part of a monitoring program from 2007 to 2008 to analyze the regional groundwater quality as well as the hydrogeochemical processes and their controlling factors. Conventional physicochemical water parameters (pH, turbidity, electrical conductivity, dissolved oxygen, total phosphorus), major cations (Na + , Ca 2+ , Mg 2+ and NH 4 + ) and anions (Cl - , NO 3 - and SO 4 2- ) were measured. Hydrochemical methods and multivariate statistical methods were applied to analyze the hydrogeochemical signatures, origins, the similarities among the variables and to identify the main pollution sources in the groundwater. The results showed that (1) the concentrations of TDS (224.89-1086.70 mg/L) and turbidity (0.1-18.60 NTU) were higher than the class II groundwater quality standards in China and the WHO drinking water standards, (2) there were extremely high concentrations of ammonia (0.01-32.90 mg/L), with a mean value of 0.72 mg/L and (3) the nitrate concentrations (average value of 22.07 mg/L) exceeded the class III groundwater quality standards. The study also provided evidence that weathering, dissolution of carbonate, halite and silicate and cation exchange were the possible primary hydrogeochemical control mechanisms in the groundwater. The sources of ammonia, total phosphorus, sulfates and nitrates included rock-water interactions and anthropogenic activities. The groundwater administration of pollution sinks and sources, long-term legal frameworks and economic incentives should be improved to optimize watershed scale management in the context of rapid development in China.

The detection of heavy metals such as Hg 2+ and Ag + is important and urgent. In this work, - NO 2 /- NH 2 /C=S boron dipyrromethene small molecular derivatives were synthesized at first. Then they were incorporated into polymer chains. The macromolecular fluorescent probes were obtained via Sonogashira reaction using the small molecular probes as building blocks. The as-prepared small-molecule fluorescent probe BO3 exhibits high sensing performance for Hg 2+ . By introducing it into macromolecules, the sensing ability still remains, and even more, the recognition performance is improved. The macromolecular fluorescent probes P1, P2, and P3 also have high recognition ability for Ag + with a binding ratio of 2:1 (metal ion to probe ratio). Through the study of the sensing mechanism and the recycling experiments, it is found that the probes responded by the photo-induced electron transfer mechanism and can be recycled and reused. At the same time, BO3, P2, and P3 show excellent recognition performance for Hg 2+ in living cells and zebrafish. Living cell imaging experiments indicated that these fluorescent probes had good cell membrane permeability and low cytotoxicity, and could realize bioimaging of Hg 2+ . Therefore, the application value of these fluorescent probes could be enlarged. Graphical abstract.

The impact of electrolytes on the adsorption of emerging pollutants: pharmaceuticals onto layered materials: a raw clay mineral and its nonionic and cationic organoclay derivatives was studied. The selected pharmaceuticals: amoxicillin, norfloxacin, sulfamethoxazole, metoprolol, carbamazepine, and trimethoprim show different electric charges: zwitterionic, anionic, cationic and neutral and hydrophobic character (different LogP). Without any salts, the set of complementary data obtained by UV and infrared spectroscopies, X-ray diffraction points out the importance of the electric charge which represents a key parameter in both the spontaneity and feasibility of the adsorption. In contrast, the hydrophobicity of the analytes plays a minor role but determines the magnitude of the adsorbed amount of pharmaceuticals onto organoclays. With a dual hydrophilic and hydrophobic behavior, nonionic organoclay appears to be the most polyvalent material for the removal of the pharmaceuticals. In the presence of electrolytes (NaCl at a concentration of 1 × 10 -2  mol L -1 ), both nonionic and cationic organoclays show a decrease of their efficiencies, whereas the adsorption is particularly enhanced for Na-Mt except for the cationic species (trimethoprim and metoprolol). Thus, in realistic experimental conditions close to those of natural effluents, raw clay mineral appears as the most appropriate sorbent for the studied pharmaceuticals while it raises the question of the usefulness of organoclays in water remediation strategy., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In many parts of the world, wastewater irrigation has become a common practice because of freshwater scarcity and to increase resource reuse efficiency. Wastewater irrigation has positive impacts on livelihoods and at the same time, it has adverse impacts related to environmental pollution. Hydrochemical processes and groundwater behaviour need to be analyzed for a thorough understanding of the geochemical evolution in the wastewater irrigated systems. The current study focuses on a micro-watershed in the peri-urban Hyderabad of India, where farmers practice intensive wastewater irrigation. To evaluate the major factors that control groundwater geochemical processes, we analyzed the chemical composition of the wastewater used for irrigation and groundwater samples on a monthly basis for one hydrological year. The groundwater samples were collected in three settings of the watershed: wastewater irrigated area, groundwater irrigated area and upstream peri-urban area. The collected groundwater and wastewater samples were analyzed for major anions, cations and nutrients. We systematically investigated the anthropogenic influences and hydrogeochemical processes such as cation exchange, precipitation and dissolution of minerals using saturated indices, and freshwater-wastewater mixtures at the aquifer interface. Saturation indices of halite, gypsum and fluorite are exhibiting mineral dissolution and calcite and dolomite display mineral precipitation. Overall, the results suggest that the groundwater geochemistry of the watershed is largely controlled by long-term wastewater irrigation, local rainfall patterns and water-rock interactions. The study results can provide the basis for local decision-makers to develop sustainable groundwater management strategies and to control the aquifer pollution influenced by wastewater irrigation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

We report on facile synthesis and characterization of phosphate-functionalized polymer dots (PDs) by doping tributyl phosphate (TBP) in a semiconducting polymer poly[9,9-dioctylfluorenyl-2,7-diyl)-co-1,4-benzo-{2,10-3}-thiadiazole)] (PFBT). Then, the prepared TBP@PFBT PDs were used to develop a very high sensitive probe for detection Fe 3+ , Cu 2+ ions and Cytochrome c based on aggregation induced fluorescence off mechanism. The PDs exhibited a linear dynamic range for Fe 3+ from 0.1 to 2 nM with a detection limit of 30 pM and for Cu 2+ from 2.0 to 50.0 nM with a detection limit of 0.35 nM. Meanwhile, this probe showed a linear dynamic range for Cyt c from 175 to 1750 pM with a detection limit of 32.7 pM. The TBP@PFBT PDs is a simple, one-step, fast, non-invasive, label-free, and inexpensive probe that is capable of online apoptosis monitoring response to drugs with an ever-present opportunity to contribute in a variety of in-vitro and in-vivo biological applications. We also obtained sharp, specific 2D and 3D imaging results for early stage apoptosis in breast cancer cells. Moreover, this technique possesses the advantage of rapid determination of Fe 3+ ion in biological or environmental samples. Importantly, this label-free assay provides short determination time of only a few min, easy operation and very low LOD allowing 100-4000 times increased in sensitivity over previously reported probes, together with high selectivity without need to using biorecognition elements like enzymes, antibodys and/or aptamers. Such excellent features make the TBP@PFBT PDs an excellent probe for successful apoptosis imaging in live cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A study was conducted to evaluate the effects of feeding an acidogenic diet with a low dietary cation-anion difference (DCAD) on acid-base balance, blood, milk, and urine Ca concentrations of sows during lactation. A total of 30 multiparous sows (parity: 4.5 ± 2.9, Smithfield Premium Genetic, Rose Hill, NC) were allotted to 1 of 2 dietary treatments: CON (control diets were corn-soybean meal based with a calculated DCAD of 170 and 226 mEq/kg during late gestation and lactation, respectively) or ACI (acidogenic diets had a DCAD 100 mEq/kg lower than the control diets). The lower DCAD was achieved by the addition of an acidogenic mineral. The DCAD was calculated as mEq (Na + K - Cl)/kg diet. Sows had a daily access to 2-kg feed from day 94 of gestation to parturition and ad libitum access to feed during lactation. Blood and urine pH and Ca, serum macrominerals, serum biochemistry, Ca-regulating hormones, and milk composition were measured. Sows in ACI had a lower (P < 0.05) blood pH than sows in CON at day 1 of lactation. Sows in ACI had a lower (P < 0.05) urine pH at day 108 of gestation, days 1, 9, and 18 of lactation compared with sows in CON. Sows in ACI had greater (P < 0.05) concentrations of serum total Ca at days 1 and 18 of lactation than sows in CON. There was a greater (P < 0.05) concentration of colostrum Ca in ACI than in CON. There was no difference in urine Ca concentration between treatments during lactation. Concentrations of parathyroid hormone and 1,25-dihydroxycholecalciferol were not different between treatments at either day 1 or 18 of lactation. Sows in ACI tended to have a smaller (P = 0.086) concentration of total alkaline phosphatase in serum at day 18 of lactation compared with sows in CON. At day 1 of lactation, the concentration of serum Cl in ACI was greater (P < 0.05) than that in CON. Feed intake, BW loss, and litter performance were not different between treatments. Collectively, feeding an acidogenic diet with a low DCAD to sows can induce a mild metabolic acidosis at farrowing, reduce the urine pH consistently, and increase serum total Ca and colostrum Ca concentrations during lactation but without altering the parathyroid hormone and 1,25-dihydroxycholecalciferol levels during lactation., (© The Author(s) 2019. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Capillary electrophoresis (CE) is excellent at separating all the ions in a sample but is rarely used as a result of its detection issue and easy loss of very fast ions by common one-end injection methods. Herein we propose a newly developed method aimed at simultaneous determination of positive and negative ions with a home-made CE device, featuring bi-end injection and contactless conductivity detection at the middle. By simply using 2.5 M acetic acid as a running buffer, the method can separate 37 ions (3 inorganic anions, 8 inorganic cations, 10 biogenic amines, and 16 amino acids) per run, with linearity between 10 and 2000 μM (R 2  > 0.99), limit of detection of 1.0-16.6 μM, and limit of quantification of 2.3-31.7 μM. The recovery measured by spiking standards into samples at high, middle, and low levels was between 73% and 110%. The intra- and interday repeatability of the 37 analytes ranged from 0.69% to 8.97% and from 0.68% to 11.04%, respectively. The proposed method was evaluated by analysis of 21 beers and, in addition to acquiring the concentration information, the brands of the tested beers were distinguished. This method is of high throughput, fast, and cost-effective. It could be a promising tool for ionomic analysis. Graphical abstract ᅟ.

In this study, we investigated the lipopolysaccharide (LPS)-neutralizing and angiogenic activities of cationic peptides derived from the traditional Japanese fermented product Natto, which is made by fermenting cooked soybeans using Bacillus subtilis. Initially, we prepared 20 fractions of Natto extracts with various isoelectric points (pI's) using ampholyte-free isoelectric focusing (autofocusing). Cationic peptides were then purified from fractions 19 and 20, whose pH values were greater than 12, using reversed-phase high-performance liquid chromatography, and were identified using matrix-assisted laser/desorption ionization-time-of-flight mass spectroscopy. Among the 13 identified cationic peptides, seven (KFNKYGR, FPFPRPPHQK, GQSSRPQDRHQK, QRFDQRSPQ, ERQFPFPRPPHQK, GEIPRPRPRPQHPE, and EQPRPIPFPRPQPR) had pI's greater than 9.5, positive net charges, and differing molecular weights. These peptides were then chemically synthesized and applied to chromogenic LPS-neutralizing assays using Limulus amebocyte lysates, and 50% effective (neutralizing) concentrations of 2.6-5.5 μM were demonstrated. In addition, tube formation assays in human umbilical vein endothelial cells revealed angiogenic activities for all but one (GEIPRPRPRPQHPE) of these seven cationic peptides, with increases in relative tube lengths of 23-31% in the presence of peptides at 10 μM. Subsequent experiments showed negligible hemolytic activity of these peptides at concentrations of up to 500 μM in mammalian red blood cells. Collectively, these data demonstrate that six cationic peptides from Natto extracts, with the exception of GEIPRPRPRPQHPE, have LPS-neutralizing and angiogenic activities but do not induce hemolysis., (Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

An analytical method for concurrent analysis of inorganic anions and cations has been developed using a capillary electrophoresis (CE)-capacitively coupled contactless conductivity detector (C 4 D) system. Although hydrodynamic and electrokinetic injection techniques have been widely used in CE, we employed a capillary filling method (CFM) for the analysis of inorganic ions. The procedure is relatively simple and has the advantage that CMF does not require pressure control and vial exchange. Three anions (chloride, sulfate, nitrate) and five cations (ammonium, potassium, sodium, magnesium, calcium) were successfully separated and detected at ppm levels within 80 s using a 9 mM histidine/15 mM malic acid (pH 3.6) containing 50 mM N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate as background electrolyte. Applying this analytical condition, the electroosmotic flow is negligible and anions and cations were migrated concurrently to different polarities according to their electrophoretic mobility. Obtained raw data showed stepwise increases in detected conductivity due to the migration of sample components, which expresses as peak profiles by differentiation of electropherograms. The RSD values of the peak area and migration times for the anions and cations were satisfactory and were less than 5.15 and 2.04%, respectively. The developed method was applied for the analysis of inorganic anions and cations in commercial mineral waters, tap water, urine, and exhaled breath condensate. These results indicate that the CE-C 4 D system with CFM is suitable for the rapid analysis of inorganic anions and cations in various samples.

Intracellular monovalent ions have been shown to be important for cell proliferation, however, mechanisms through which ions regulate cell proliferation is not well understood. Ion transporters may be implicated in the intracellular signaling: Na + and Cl - participate in regulation of intracellular pH, transmembrane potential, Ca 2+ homeostasis. Recently, it is has been suggested that K + may be involved in "the pluripotency signaling network". Our study has been focused on the relations between K + transport and stem cell proliferation. We compared monovalent cation transport in human mesenchymal stem cells (hMSCs) at different passages and at low and high densities of culture as well as during stress-induced cell cycle arrest and revealed a decline in K + content per cell protein which was associated with accumulation of G1 cells in population and accompanied cell proliferation slowing. It is suggested that cell K + may be important for successful cell proliferation as the main intracellular ion that participates in regulation of cell volume during cell cycle progression. It is proposed that cell K + content as related to cell protein is a physiological marker of stem cell proliferation and may be used as an informative test for assessing the functional status of stem cells in vitro.

Considering the ever-growing usage of trivalent salts in water treatment, for example, lanthanum salts in rare earth, AlCl 3 and FeCl 3 , the effects of different trivalent cations on the bacterium Escherichia coli (E. coli) ATCC 11775 strain have been studied in aqueous solutions. From colony incubation studies, the colony-forming unit (CFU) densities were found to decrease significantly in the presence of even low levels (10 -5  mol/L) of lanthanum chloride. This level of reduction in CFU number is comparable to the results obtained using the known bacteriocidal cationic surfactant, C 14 TAB. By comparison, exposure of the cells to low levels of trivalent ion, aluminum and chromium ion solutions produced only modest reductions in CFU density. The results from the incubation studies suggest that the bacteriostatic mechanism of La 3+ ions has similarities to that of the cationic surfactant, and different to that of the other trivalent ions. Size distribution and zeta potential measurements of E. coli cells and phospholipid vesicles in the presence of trivalent cations solutions suggested significant cell shrinkage probably caused by membrane disruption., (© 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

A new nucleic acid-based fluorescence sensor is reported for simultaneous detection of Pb2+, Ag+, and Hg2+ based on the specific catalytic activity of Pb2+ for a particular DNAzyme, specific regulation of Ag+ on "C-Ag+-C" complex, and stable complex formed by Hg2+ and rhodamine B isothiocyanate (RBITC). Three fluorescence dyes, aminomethylcoumarin acetic acid (AMCA), 5-carboxyfluorescein (FAM), and RBITC, were modified on the probes and served as fluorescent donors. Upon DNA interaction with these metal ions and AuNP fluorescence quenching effect on the fluorescence dyes,the fluorescencerecovery of RBITC and the fluorescencequenching of AMCA and FAM were monitored to detect Hg2+, Pb2+, and Ag+, separately, without the need of using any masking reagents. This sensor exhibited high sensitivity and selectivity. The limit of detection (LOD) is 0.48 nM for Pb2+, 0.23 nM for Ag+, and 0.17 nM for Hg2+. Finally, this sensor was successfully applied for simultaneous detection of Pb2+, Ag+, and Hg2+ in real sample.

Accurate quantification of cations and anions remains a major diagnostic tool in understanding diseased states. The current technologies used for these analyses are either unable to quantify all ions due to sample size/volume, instrument setup/method, or are only able to measure ion concentrations from one physiological sample (liquid or solid). Herein, we adapted a common analytical chemistry technique, ion chromatography and applied it to measure the concentration of cations; sodium, potassium, calcium, and magnesium (Na + , K + , Ca 2+ , and Mg 2+ ) and anions; chloride, and acetate (Cl - , - OAc) from physiological samples. Specifically, cations and anions were measured in liquid samples: serum, urine, and cerebrospinal fluid, as well as tissue samples: liver, cortex, hypothalamus, and amygdala. Serum concentrations of Na + , K + , Ca 2+ , Mg 2+ , Cl - , and - OAc (mmol/L): 138.8 ± 4.56, 4.05 ± 0.21, 4.07 ± 0.26, 0.98 ± 0.05, 97.7 ± 3.42, and 0.23 ± 0.04, respectively. Cerebrospinal fluid concentrations of Na + , K + , Ca 2+ , Mg 2+ , Cl - , and - OAc (mmol/L): 145.1 ± 2.81, 2.41 ± 0.26, 2.18 ± 0.38, 1.04 ± 0.11, 120.2 ± 3.75, 0.21 ± 0.05, respectively. Tissue Na + , K + , Ca 2+ , Mg 2+ , Cl - , and - OAc were also measured. Validation of the ion chromatography method was established by comparing chloride concentration between ion chromatography with a known method using an ion selective chloride electrode. These results indicate that ion chromatography is a suitable method for the measurement of cations and anions, including acetate from various physiological samples., (© 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.)

The treatment of cesium-contaminated wastewater has become one of the biggest issues. The selective Cs + removal from wastewater containing competitive alkali metal ions such as Na + is desired to reduce the volume of sludge. Therefore, the present work focused on water-soluble calix[4]arene-bis-crown-6 (W-BisC6) to selectively capture Cs + . For characterization of the complex, UV-vis spectroscopy is commonly used, however, due to the limited availability of information it can be hard to quickly identify the specific structures of some complexes. In this work, the electrospray ionization time of flight spectrometry (ESI-TOF-MS) is successfully utilized to identify the number and type of cations in W-BisC6-cation complexes. ESI-TOF-MS accurately recognized 4 types of complex (W-BisC6-Na + , W-BisC6-Cs + , W-BisC6-2Na + , W-BisC6-Na + -Cs + ), and the experimental and simulated results were almost perfectly matched. It also revealed the difficulty of W-BisC6-2Cs + complex formation under the present conditions. Thus, this technique is significantly helpful for rapid identification of the specific structures of complexes during Cs + -contaminated wastewater treatment., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Graphene quantum dot (GQD) has been attractive in analytical science field due to its low toxicity, stable photoluminescence. Herein, nitrogen-doped GQD (N-GQD) was prepared by a facile solvothermal treatment of GO using dimethylformamide, and exhibited a green emission with 23.1% quantum yield. The N-GQD probe showed a selective and sensitive fluorescence enhancement response to Al 3+ , the mechanism might be the formation of a complex between Al 3+ and N-GQD constrained the photo-induced electron transfer (PET) process of N-GQD itself. With Benesi-Hildebrand equation, the binding constant and molar ratio between N-GQD and Al 3+ was calculated to be 4.6 × 10 4 Lmol -1 and 1:1 respectively. The pK a value of N-GQD was also determined to be 4.4 by capillary electrophoresis. In pH 4.0 PBS solution, there was a good linear relation between the fluorescence intensity and the logarithm of concentration of Al 3+ in the range of 2.5-75μmolL -1 , the limit of detection (3σ) was 1.3μmolL -1 . This "Off - On" fluorescence method had been applied to accurate quantification of aluminum in hydrotalcite tablets. What's more, the fluorescence switch property of N-GQD was explored by alternate addition of Al 3+ and EDTA. The probe was also utilized for detection Al 3+ in living cells due to its excellent biocompatibility., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Peat is an excellent material for metal sorption since it naturally contains different kinds of functional groups that can sorb metal cations from water. The main objective of this work was to test low-cost treatment (acid and alkali) methods for natural peat, which would improve the settling properties of peat particles while maintaining its metal removal efficiency. Particularly, the poor settling properties of peat hinder its practical application. The study revealed that NaOH-treated peat (0.1M) had excellent settling properties and could be applied in wastewater applications having mixing and settling systems without a settling aid. The superior leaching of humic and fulvic acids in alkaline treatment caused a change in morphology, making it a harder and sticky material. Moreover, the NaOH-treated (0.1M) peat was proven to be the most efficient material for nickel removal followed by the HCl-treated (0.2M) peat, citric acid-treated (0.16M) peat and water-treated peat. A higher temperature and longer time slightly increased the Ni removal efficiency with NaOH-treated peat material. The settling of HCl-treated peat was studied further using polyacrylamide flocculants (cationic, neutral, anionic). Cationic flocculants performed best and the cationic charge density also had an effect on the flocculation performance of peat particles. This study provides further evidence that peat can be applied in the treatment of metal-containing wastewaters., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The objectives were to investigate the effects that maternal diets containing negative dietary cation-anion differences (DCAD) fed in the last 42 d of gestation may have on the acid-base status, hematology, mineral and energy metabolism, growth, and health of calves. The experiment was a randomized block design with a 2 × 2 factorial arrangement of 2 levels of negative DCAD (-70 or -180 mEq/kg) and 2 feeding durations (the last 21 d prepartum and the last 42 d prepartum). Bulls and heifers (n = 60) born to these dams were weighted at birth and fed 3.8 L of colostrum for their first feeding, and only heifers (n = 44, 9-12/treatment) were kept thereafter. Heifer body weight was also recorded at 21 d, 42 d, 62 d, 3 mo, and 6 mo of age. Blood was collected at birth, before colostrum feeding, and at 1, 2, 3, 21, and 42 d of age and assayed for minerals, metabolites, and cell counts. Heifers born to dams fed the last 42 d prepartum weighed 2.8 and 4.8 kg less at birth and 62 d, respectively, compared with calves born to dams fed the last 21 d prepartum; however, body weight at 3 and 6 mo of age was similar. Concentrations of ionized calcium did not differ among treatments at birth, but heifers born to -180 DCAD dams had increased blood concentrations at 3 d of age, whereas those born to -70 DCAD dams did not. At birth, heifers born to -180 DCAD dams experienced a subtle and transient metabolic acidosis (pH = 7.33 ± 0.02; pCO 2 = 53.0 ± 2.4 mmHg; HCO 3 - = 27.6 ± 0.7 mmol/L) compared with the more evident metabolic acidosis observed in those born to -70 DCAD cows (pH = 7.28 ± 0.02; pCO 2 = 59.3 ± 2.4 mmHg; HCO 3 - = 27.8 ± 0.7 mmol/L). Heifers born to -180 DCAD dams had reduced concentrations of β-hydroxybutric acid and nonesterified fatty acids compared with those born to -70 DCAD dams. Efficiency of IgG transfer from colostrum into blood and serum concentrations did not differ among treatments. There was no relationship between measures of metabolic acidosis and measures of efficiency of IgG absorption. Percentage of lymphocytes and neutrophils was altered by maternal treatments; however, treatments did not affect calf morbidity. Extending the duration of feeding up to 42 d or reducing the level of negative DCAD to -180 mEq/kg in maternal diets exerted a transient metabolic acidosis in the calves and slightly affected measures of mineral, energy metabolism, and growth., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

A simple analytical method for quantitative determination of an anionic surfactant in aqueous solutions without liquid-liquid extraction is described. The method is based on the formation of a green-colored ion associate between sodium dodecylbenzenesulfonate (SDBS) and cationic dye, Brilliant Green (BG) in acidic medium. Spectral changes of the dye by addition of SDBS are studied by visible spectrophotometry at maximum wave length of 627 nm. The interactions and micellar properties of SDBS and cationic dye are also investigated using surface tension method. The pH, the molar ratio ([BG]/[SDBS]), and the shaking time of the solutions are considered as the main parameters which affect the formation of the ion pair. Determination of AS in distilled water gives a significant detection limit up to 3 × 10 -6  M. The response surface methodology (RSM) is applied to study the absorbance. A Box-Behnken is a model designed to the establishment of responses given by parameters with great probability. This model is set up by using the three main parameters at three levels. Analysis of variance shows that only two parameters affect the absorbance of the ion pair. The statistical results obtained are interesting and give us real possibility to reach optimum conditions for the formation of the ion pair. As the proposed method is free from interferences from major constituents of water, it has been successfully applied to the determination of anionic surfactant contents in wastewaters samples collected from Algiers bay.

This article aims to establish the judicious use of iron-binding chemistry of microbial chelators in order to functionalize the surface of iron nanoparticles to develop non-toxic nanobiosensor. Anchoring a simple siderophore 2,3-dihydroxybenzoylglycine (H 3 L), which bears catechol and carboxyl functionalities in tandem, on to the surface of Fe 3 O 4 nanoparticles has developed a unique nanobiosensor HL-FeNPs which showed highly selective and sensitive detection of Al 3+ in 100% water at physiological pH. The biosensor HL-FeNPs, with 20nM limit of detection, behaves reversibly and instantly. In-vivo bio-imaging in live brine shrimp Artemia confirmed that HL-FeNPs could be used as fluorescent biomarker for Al 3+ in live whole organisms. Magnetic nature of the nanosensor enabled HL-FeNPs to remove excess Al 3+ by using external magnet. To our knowledge, the possibility of microbial chelator in the practical development of Al 3+ selective nanobiosensor is unprecedented., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A soil resampling approach has detected an early stage of recovery in the cation chemistry of spruce forest soil due to reductions in acid deposition. That approach is limited by the lack of soil data and archived soil samples prior to major increases in acid deposition during the latter half of the 20th century. An alternative approach is the dendrochemical analysis of dated wood to detect temporal changes in base cations back into the 19th century. To infer environmental change from dendrochemical patterns of essential base cations, internal factors that affect cation chemistry such as the maturation of sapwood and the spread of wood infection need to be recognized. Potassium concentration was a useful marker of these internal maturation and infection that could affect the concentration of essential base cations in wood. Dendrochemical patterns in samples of red spruce in the eastern United States and Norway spruce in northwestern Russia were used to determine how internal changes in base cations can be separated from external changes in root-zone soil to date major changes in the availability of essential base cations associated with a changing environment., (Published by Elsevier Ltd.)

A novel type of suspension array for multiplex detection of heavy metal ions with photonic crystal hydrogel microspheres was reported. The photonic crystal hydrogel microspheres have close-packed photonic crystal particles as their encoding units and ssDNA-functionalized hydrogel as the sensing units. The developed microspheres were successfully applied in multiplex detection of heavy metal ions., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this paper, the cheap, easily obtained small antibiotic molecule of vancomycin was employed as reducer/stabilizer for facile one-pot synthesis of water exhibited a bluish fluorescence emission at 410nm within a short synthesis time about 50min. Based on the strong fluorescence quenching due to electron transfer mechanism by the introduction of ferric ions(Fe 3+ ), the Van-AuNCs were interestingly designed for sensitive and selective detecting Fe 3+ with a limit of 1.4μmol L -1 in the linear range of 2-100μmol L -1 within 20min. The Van-AuNCs based method was successfully applied to determine Fe 3+ in tap water, lake water, river water and sea water samples with the quantitative spike recoveries from 97.50-111.14% with low relative standard deviations ranging from 0.49-1.87%, indicating the potential application of this Van-AuNCs based fluorescent sensor for environmental sample analysis., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Precipitation samples have been collected by the National Atmospheric Deposition Program's (NADP) National Trends Network (NTN) using the Aerochem Metrics Model 301 (ACM) collector since 1978. Approximately one-third of the NTN ACM collectors have been replaced with N-CON Systems, Inc. Model ADS 00-120 (NCON) collectors. Concurrent data were collected over 6 years at 12 NTN sites using colocated ACM and NCON collectors in various precipitation regimes. Linear regression models of the colocated data were used to adjust for relative bias between the collectors. Replacement of ACM collectors with NCON collectors resulted in shifts in 10-year seasonal precipitation-weighted mean concentration (PWMC) trend slopes for: cations (-0.001 to -0.007 mgL -1 yr -1 ), anions (-0.009 to -0.028 mgL -1 yr -1 ), and hydrogen ion (+0.689 meqL- 1 yr -1 ). Larger shifts in NO 3 - and SO 4 -2 seasonal PWMC trend slopes were observed in the Midwest and Northeast US, where concentrations are generally higher than in other regions. Geospatial analysis of interpolated concentration rasters indicated regions of accentuated variability introduced by incorporation of NCON collectors into the NTN., (Published by Elsevier Ltd.)

Heavy metal detection is a key topic in analytical chemistry. DNA-based metal recognition has advanced significantly producing many specific metal ligands, such as thymine for Hg 2+ and cytosine for Ag + . For practical applications, however, robust sensors that can work in a diverse range of salt concentrations need to be developed, while most current sensing strategies cannot meet this requirement. In this work, 2-aminopurine (2AP) is used as a fluorescence label embedded in the middle of four 10-mer DNA homopolymers. 2AP can be quenched up to 98% in these DNA without an external quencher. The interaction between 2AP and all common metal ions is studied systematically for both free 2AP base and 2AP embedded DNA homopolymers. With such low background, Hg 2+ induces up to 14-fold signal enhancement for the poly-T DNA, and Ag + enhances up to 10-fold for the poly-C DNA. A detection limit of 3nM is achieved for both metals. With these four probes, silver and mercury can be readily discriminated from the rest. A comparison with other signaling methods was made using fluorescence resonance energy transfer, graphene oxide, and SYBR Green I staining, respectively, confirming the robustness of the 2AP label. Detection of Hg 2+ in Lake Huron water was also achieved with a similar sensitivity. This work has provided a comprehensive fundamental understanding of using 2AP as a label for metal detection, and has achieved the highest fluorescence enhancement for non-protein targets., (Copyright © 2016 Elsevier B.V. All rights reserved.)