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Biochar has considerable sorption efficiency for organic pollutants; however, the effect of physicochemical characteristics and their alteration by environmental conditions on the sorption mechanism is still unknown. We investigated the pH-dependent sorption of simazine on Miscanthus biochar produced at two pyrolysis temperatures (400 and 700 °C; hereafter B-400 and B-700) under two different electrolytes and interpreted the sorption mechanism. The surface charge density (SCD) decreased more in B-400 than in B-700 at higher pH due to more deprotonation of acidic functional groups (AFGs), but greater decreases were observed in B-700 than in B-400 from pH 2 to pH 3 as a result of alkali salts deposition. The decrease in KF with increasing pH showed that simazine sorption decreased as van der Waals forces because the surface of biochar carried a greater negative SCD, which repulses simazine molecules due to the enhanced deprotonation of AFGs. At a given pH, KF was lower in CaCl2 than in NaCl due to the formation of larger metal-biochar complexes, resulting in enhanced blocking of pores available for simazine sorption. We believe that knowledge of the pH-dependence of SCD and accessibility of biochar pores could help better interpret the behavior of simazine-like pollutants in soil and aquatic environments.

Introduction: Isocyanates are the raw materials that make up all polyurethane products. Isocyanate is a powerful irritant to the mucosal membrane of the respiratory tract, eyes and skin. Pulmonary symptoms, especially occupational asthma, are predominant manifestations of isocyanate toxicity. Case report: We report mental changes and compartment syndrome complicated with rhabdomyolysis as an extraordinary manifestation of acute isocyanate toxicity observed in a patient during the waterproofing of a water tank. A 58- year-old man recovered consciousness after six hours in the emergency department and complained of severe pain in the lower leg. The results of his laboratory test showed that his serum creatine kinase (15,250 IU/L) level had increased. The tissue pressure in both the lower legs had increased to 180 mmHg/170 mmHg (right/left). We performed fasciotomy on the second day of hospitalization. The patient was provided hyperbaric oxygen (HBO2) therapy of 2.0 ATA for 90 minutes twice a day for seven days. His condition gradually improved over five months, and he did not require amputation. He had a mild neurological disorder in his foot and was transferred to a rehabilitation center five months after hospitalization. Conclusion: It is important to note that when working with isocyanate, non-specific complications such as a change in consciousness as well as compartment syndrome with rhabdomyolysis can occur in a confined space or high-temperature environment. In addition, we found that compartment syndrome caused by isocyanate toxicity can be effectively treated with fasciotomy and HBO2 therapy.

Oxyanions are ubiquitous in soils, organisms and the environment. Due to their unique chemical structure, oxyanions can be easily transferred into other systems. Carbonate (CO32−), nitrate (NO3−), phosphate (PO43−), silicate (SiO42−) and sulfate (SO42−) are the major oxyanions in organisms and the soil environment, whereas arsenate (AsO43−), antimonate (SbO43−), borate (BO33−), selenate (SeO42−), and tellurate (TeO42−) are generally reported as toxic chemicals found at trace levels. Excessive oxyanions leached from soils into water have caused severe environmental problems. Here, we review the factors affecting the structural configuration of oxyanions and organic acids adsorbed on iron oxides and hydroxides. The configuration of oxyanions on iron (hydr)oxides is controlled by surface loading, pH, sample phase, competing ions and organic acids. Under conditions of low surface loading and low pH at the interface in the absence of competing ions, oxyanions with high affinity possibly form a complex with higher denticity. But an increase in pH decreases the number of sorption sites; thus, a transition from a tri- or bidentate complex to monodentate and outer-sphere complexes occurs.

Background: Dental disorders are commonly encountered in companion animals and diagnosed with dental radiography (DTR) and computed tomography (CT). No study has been reported previously that compares dental measurements from DTR and CT in companion animals with periodontitis-related bone loss. The purpose was to compare the DTR and CT of bony defects in cats and dogs with dental disease.Methods: This is a retrospective study and the records of Jeonbuk Animal Medical Center were reviewed between June 2019 and October 2020. All patients underwent both modalities. In DTR, bisecting angle technique was used. In CT, slice thickness was applied at either 0.5 mm or 1.0 mm depending on the size of the patients. Bony defects of dentoalveolar structures were measured.Result: Eight dogs and eight cats with dental disease were included. All measurements in both cats and dogs were smaller in DTR than in CT. Additionally, CT with thin slice thickness provided more sufficient and accurate information for dental diagnosis. Conclusively, CT examination for dental disease showed to be superior in the assessment of periodontitis-related bone lesions by obtaining precise images without distortion and overlap and can possibly substitute DTR in cats and small dogs.

Biochar has received great attention as a biosorbent, but explanations of the underlying sorption mechanisms are still unclear. Here, batch sorption of cadmium (Cd(II)) and arsenate (As(V)) to Miscanthus biochar at different pH values and pyrolysis temperatures and the sorption mechanisms were comprehensively investigated. The maximum sorption capacities for both Cd(II) and As(V) were observed under alkaline conditions. Physisorption was identified as a common sorption mechanism for both Cd(II) and As(V) irrespective of pH; however, inner-sphere complexation with acidic functional groups (AFGs) and crystallized precipitation as otavite predominate at higher pH values for Cd(II), while hydrophobic attraction of arsenite and metallic As and electrostatic bridging with multivalent ions at deprotonated AFGs are presumed to be dominant sorption mechanisms for As(V). Inner-sphere complexes of Cd(II) (98.6%) and electrostatic bridging complexes of As(V) (89.5%) were the dominant sorption forms for B400, while inner-sphere complexes (45.9%) and precipitates (50.5%) of Cd(II) and physisorption and hydrophobic interactions of As (63.7%) were abundant. The results challenge the widely held notion that the sorption of anions decreases as pH increases, while that of cations increases with increasing pH. This unexpected phenomenon can be explained by reduction of As(V) and by the difference in the charge densities between As(V) and basic functional groups of the biochar. Such biochar-induced reduction would cause an unexpected risk of exposing human health and ecosystems to reduceable pollutants. These findings contribute to a better explanation for the environmental fate and behavior of inorganic pollutants in biochar applications.

A novel alkali diffusion reactor using ceramic porous media (ceram-ADR) was designed for the long-term remediation of acid mine drainage (AMD) without external energy. The filling material was newly applied to improve the ceram-ADR for intensive long-term treatment of acidity and metals in AMD. Activated carbon (AC), polyurethane (PU), or MgO-incorporated polyurethane (PU-MgO) were inserted as filling materials into ceram-ADR. NaHCO

The Republic of Azerbaijan suffers from low agricultural productivity caused by soil salinization and erosion, and limited and insufficient soil data are available for economic and political reasons. In this study, soil salinity and heavy metal levels were assessed. Environmental risk assessment was conducted to evaluate the potential risk posed by soils to human health. Soil guideline values were proposed to monitor soil pollution in the Republic of Azerbaijan. Water extraction and spatial variability analysis were conducted to understand soil salinization and heavy metal pollution. Among the 20 studied elements, the elements Ca, Cl, and S and the heavy metals Cr, Ni, and Pb were classified as problematic on the basis of the geoaccumulation index, and As was also identified as posing a possible risk on the basis of the potential ecological risk index. Based on the developed soil guideline values for agricultural soil, the As, Cr, and Ni in the soil samples exceeded their respective guidelines by 31.3, 41.8, and 61.6%, respectively. Water extraction results confirmed that 99% of the leached ions were cationic salts, and the most problematic ion was Na, followed by Ca, Cl, and S. The extractability values of Cr and Ni were significantly lower than those of other heavy metals, which implies that their actual leaching potential may be overestimated. The linear regression and spatial variability analysis confirmed that leachable salts have accumulated in lowland areas due to the capillary rise of water and evaporation, but the distribution of heavy metals confirmed that As, Cr, and Ni were abundant in agricultural soils. Our results clearly showed that heavy metal soil contamination and high salinity levels are major problems that should be considered when assessing food safety and health hazards in the Mugan Plain of Azerbaijan. Therefore, future studies should be performed for additional environmental risk assessment, detailed hazard identification, and health risk assessment.

Arsenate and phosphate have similar properties due to their electrochemical structures, but their environmental impacts are unique. The abundance and competition of arsenate and phosphate determine their bioavailability and leachability; thus, it is essential to understand their fate in the soil environment. In this study, the effects of pH and surface loading on the competitive adsorption of arsenate and phosphate on four iron (hydr)oxides were evaluated by employing the Langmuir isotherm, competitive sorption ratio (CSR), and competition effect (CE). The stability and transformation of the iron (hydr)oxides were also assessed. Various adsorption patterns were observed in the single and mixed treatments by controlling the addition of oxyanions, pH, surface loading, and type of iron (hydr)oxides. Arsenate was preferentially adsorbed at a low pH, whereas phosphate showed the opposite trend. The CEAs(V),P(V) was close to zero at low surface density (no competition) and sequentially changed to negative or positive values with increasing surface density, indirectly indicating the sequential development of promotive and competitive effects. Transformation in goethite was identified at a high pH with the presence of oxyanions, except that no transformation was observed upon the addition of oxyanions and with pH change. However, the stability of the iron (hydr)oxides decreased at a low pH and with the presence of phosphate, arsenate, or both. The hematite showed a significant promotive effect regardless of the pH. Our study revealed that the pH, surface loading, and type of iron (hydr)oxides are intercorrelated and simultaneously affect the adsorption characteristics of oxyanions and the stability of iron (hydr)oxides.

Biochar has received considerable attention as an eco-friendly bio-sorbent; however, multifarious characteristics caused by pyrolysis and feedstock pose difficulties in its application. We characterized the pH-dependent sorption of the pesticide simazine on Miscanthus biochar produced at two pyrolysis temperatures (400 and 700 °C; hereafter B-400 and B-700). The specific surface-area (SSA) of the micro- and nanopores, elemental composition, surface acidity and infrared spectra were determined. The SSA was greater in B-700 than in B-400, and the former had greater SSA in micro-pores and lower SSA in nanopores than the latter. During pyrolysis, the single-bond structures of the feedstock were converted to aromatic structures, and further pyrolysis led to ligneous structures. Alterations in pore structure and concave-up Scatchard plot corroborated the presence of two sorption mechanisms: electrostatic attractions (Ses) and hydrophobic attractions (Shp). Decreases in maximum sorption in the qmax-L with increasing pH was due to decreased Ses via deprotonation of carboxylic groups on biochar, while those in the qmax-H with increasing pyrolysis temperature were due to decreased Shp, resulting from pore structure deformation. We believe that our approach, which addresses the pH-dependence of charge density of sorbate and sorbent, could contribute to a better understanding of the behavior of simazine.

The structural configuration of arsenate on iron (hydr)oxide determines its leachability and bioavailability in the soil environment. It is important to understand how the stability of iron hydroxide and the structural configuration of arsenate complexes vary in response to changes in environmental conditions. Therefore, we investigated the effects of drying, pH and surface loadings on the stability of goethite and the structural configuration of arsenate through batch experiments and TEM and XAS measurements with DFT calculation. As a result, we observed no significant transformation of goethite under most conditions, but TEM confirmed the partial formation of bernalite in the presence of arsenate at a pH of 10, and the bernalite showed 2.18 times higher arsenate sorption than the goethite. The linear combination fitting of the EXAFS spectra with DFT calculations revealed that tridentate and bidentate complexes were dominant under low surface loading and pH conditions in the sedimented samples, while monodentate complexes were abundant under high surface loading and pH conditions. Based on our results, we conclude that the formation of arsenic-rich colloids could account for mobilization in the soil environment, and the density of available sorption sites combined with the concentration of solute could cause the change in structural configuration.

Constructed coastal marsh regulates land-born nitrogen (N) loadings through salinity-dependent microbial N transformation processes. A hypothesis that salinity predominantly controls N removal in marsh was tested through incubation in a closed system with added-15NH4+ using sediments collected from five sub-marshes in Shihwa marsh, Korea. Time-course patterns of concentrations and 15N–atom% of soil-N pools were analyzed. Sediments having higher salinity and lower soil organic-C and acid-extractable organic-N exhibited slower rates of N mineralization and immobilization, nitrification, and denitrification. Rates of denitrification were not predicted well by sediment salinity but by its organic-C, indicating heterotrophic denitrification. Denitrification dominated N-loss from this marsh, and nitrogen removal capacity of this marsh was estimated at 337 kg N day−1 (9.9% of the daily N-loadings) considering the current rooting depth of common reeds (1.0 m). We showed that sediment N removal decreases with increasing salinity and can increase with increasing organic-C for heterotrophic denitrification.

The Mugan Plain is the most productive area in the Republic of Azerbaijan, but a previous study confirmed trace metal and metalloid (TMM) contamination with Cr, Ni and Pb, and the potential ecological risk of As was estimated. However, no industrial activity was previously reported in this area; thus, a source apportionment model using positive matrix factorization (PMF) was employed to identify pollution sources, and a human health risk assessment was conducted to evaluate noncarcinogenic and carcinogenic risks. Surface soil samples were collected from 349 sites, and six major elements (Si, Ca, Cl, P, S and Sr) and 8 TMMs (As, Cd, Cr, Co, Cu, Ni, Pb and Zn) were analyzed by X-ray fluorescence and employed for further apportionment and risk assessment. As a result, the PMF model showed 7 factors, assigned to natural activity (12.9%), dry riverbed (13.6%), surface accumulation (3.1%), desalinization activity (3.2%), residential activity (12.3%), fossil fuel combustion (35.5%) and agricultural activity (19.3%). The PMF model characterized certain areas with desalinization activity in the previous Soviet period and with surface accumulation of salt, and these findings were confirmed by additional field surveys and historical Landsat satellite images. The risk assessment results showed that there was no risk for the adults, while for children, there was a noncarcinogenic risk, but no carcinogenic risk. Dermal contact was estimated to be the primary pathway, and Ni and As were identified as the most problematic TMMs for noncarcinogenic and carcinogenic risks, respectively. According to the results, fossil fuel combustion associated with heating and vehicle transportation was estimated to be the main source of pollution, contributing 42.6% of the noncarcinogenic and 48.0% of the carcinogenic risks. These results can provide scientific guidance to understand and prevent the risk of TMMs on the Mugan Plain.

A sparse population of neurons active during a learning event has been identified as memory engram cells. However, cells that are recruited to support memory when experience is repeated have been scarcely explored. Evidence from previous studies provides contradictory views. To address these questions, we employed learning-dependent cell labeling in the lateral amygdala (LA) and applied electrophysiological recording, spine imaging, and optogenetic tools to the labeled neurons with or without retraining. We found that engram cells established from original fear learning became dispensable for memory retrieval specifically with relearning, and this correlated with a reduction of synaptic transmission and loss of dendritic spines in these neurons. Despite such decreased connectivity, direct activation of these neurons resulted in fear-memory recall. We further identified that repeated memory was encoded in neurons active during relearning. These results suggest a shift in neuronal ensembles encoding fear memory in the LA by relearning through disconnection of the existing engram neurons established from original experience.

Background Dental diseases are common in dogs and cats, and accurate measurements of dentoalveolar structure are important for planning of treatment. The information that the comparison computed tomography (CT) with dental radiography (DTR) is not yet reported in veterinary medicine. Objectives The purpose of this study was to compare the DTR with CT of dentoalveolar structures in healthy dogs and cats, and to evaluate the CT images of 2 different slice thicknesses (0.5 and 1.0 mm). Methods We included 6 dogs (2 Maltese and 1 Spitz, Beagle, Pomeranian, mixed, 1 to 8 years, 4 castrated males, and 2 spayed female) and 6 cats (6 domestic short hair,8 months to 3 years, 4 castrated male and 2 spayed female) in this study. We measured the pulp cavity to tooth width ratio (P/T ratio) and periodontal space of maxillary and mandibular canine teeth, maxillary fourth premolar, mandibular first molar, maxillary third premolar and mandibular fourth premolar. Results P/T ratio and periodontal space in the overall dentition of both dogs and cats were smaller in DTR compared to CT. In addition, CT images at 1.0 mm slice thickness was generally measured to be greater than the images at 0.5 mm slice thickness. Conclusions The results indicate that CT with thin slice thickness provides more accurate information on the dentoalveolar structures. Additional DTR, therefore, may not be required for evaluating dental structure in small-sized dogs and cats.

The Republic of Azerbaijan has suffered from low agricultural productivity caused by soil salinization and erosion, and limited and insufficient soil data are available for economic and political reasons. In this study, soil elemental composition and heavy metal levels were assessed by comparing the results of XRF and ICP-OES analyses for the first time. Leachability assessment and spatial variability analysis were conducted to understand the soil salinization properties, and 632 surface soil samples categorized as agricultural (Ag) or salt-affected (SA) soils from the Mugan Plain were collected and analyzed. Based on our observations, the elemental concentrations of Ca, Fe, Cl and S were high among 20 elements compared with the median values for world soils. Apatite, calcite, gypsum, quartz, olivine, microcline and jarosite were proposed as possible mineral structures. The heavy metal guidelines suggested by the neighboring country of Georgia would be appropriate for assessing heavy metal contamination, and Ni and Pb were the most concerning elements. Leachability assessment confirmed that 99 % of the cationic ions were cationic salts and Na was the most problematic ion. Analysis of the electrical conductivity and sum of leachates showed that the exchange of interlayer cations, dissolution of minerals with low dissolution rates, transformation of metal (hydr)oxides and additional precipitation would be the reasons for this disparity. More leachable salts were accumulated in the lowland area, which is due to water movement and high evaporation. The spatial analysis results confirmed the reciprocal relationship between total Ca and total Fe and between total Fe and DW-leached Fe. This result indicates that less-stable iron complexes are prevalent in SA soils, while stable iron complexes are found in Ag soils. We believe that this approach can provide a foundation for the international study of Azerbaijani soil by sharing soil and salinization data with researchers worldwide and can help to diminish or solve agricultural problems in both Azerbaijan and neighboring countries suffering from soil salinization.

Ginseng has been shown to produce a cognitive improvement effect. The key molecular components in ginseng that produce pharmacological effects are ginsenosides. Previous studies reported a memory improvement effect of a few major ginsenosides. However, the identity of specific minor ginsenosides mediating such function remains unknown. Here, we report that a minor ginsenoside F1 improves memory function in APPswe/PSEN1dE9 (APP/PS1) double-transgenic Alzheimer’s disease (AD) model mice. After 8-wk oral administration of F1 jelly, we observed that spatial working memory, but not context-dependent fear memory, was restored in AD mice. To search for a possible underlying molecular and cellular mechanism, we investigated the effect of F1 on Aβ plaque. We observed F1 administration reduced the Aβ plaque area and density in the cortex, but not in the hippocampus of AD mice. Next, we tested for the effect of F1 on the expression level of key molecules involved in learning and memory. Results from Western blot assay revealed that an abnormally reduced level of a phosphorylated form of CREB in the hippocampus of AD mice was restored to a normal level by F1 administration. Moreover, in the same animals, BDNF level was augmented in the cortex. Our results, therefore, suggest that minor ginsenoside F1 constitutes a promising target to develop therapeutic agents for AD. Electronic supplementary material The online version of this article (10.1186/s13041-019-0495-7) contains supplementary material, which is available to authorized users.

Recent developments in analytics using infrared spectroscopy have enabled us to identify the adsorption mechanism at interfaces, but such methods are applicable only for simple systems. In this study, the preferential adsorption of phosphate on binary goethite and maghaemite was investigated. As a result, monodentate and bidentate complexes were the major complexes on goethite and maghaemite, respectively. A shrinking effect in goethite and a swelling effect in maghaemite were identified, and environmental perturbations caused a significant decrease in the integrated absorbance of phosphate complexes on maghaemite, while no effect was observed on goethite, which implies that different adsorption mechanisms were involved. Based on the results, a bridging complex was proposed, and the swelling effect is explained by the negatively charged maghaemite surface resulting from the bidentate complex. The isolation of phosphate by the shrinking effect explains the low phosphate bioavailability in the soil environment, while the colloidal properties of the bidentate complex on maghaemite are the reason for colloidal mobilization. To the best of our knowledge, this study not only addresses the shrinking and swelling properties of iron (hydr)oxide nanoparticles but also demonstrates preferential adsorption on binary sorbents using in situ ATR-FTIR for the first time.

Figure S1. Uncropped western blot images for hippocampus samples related with Fig. 3a. (PDF 126 kb)

Constructed coastal marsh regulates land-born nitrogen (N) loadings through salinity-dependent microbial N transformation processes. A hypothesis that salinity predominantly controls N removal in marsh was tested through incubation in a closed system with added

The effect of bentonite and sand, as natural capping agents, on the fluxes of nutrients and trace metals across the sediment-water interface was studied through sediment incubation, and the ecotoxicological impact was assessed by using Daphnia magna. Bentonite and sand were layered on the sediment at 15, 75, and 225 mg cm(-2), and the concentration of cations, nutrients, and trace metals was measured. Sediment incubation showed that bentonite reduced the N flux but increased the P flux as a result of dissolution of non-crystalline P from bentonite, while sand slightly decreased the N fluxes but not the P flux. The concentration of Na increased in the overlying water with increasing application rates of bentonite, while that of Ca decreased. However, regardless of the rate of sand application, concentrations of all cation species remained unchanged. The concentration of As and Cr increased with bentonite application rate but decreased with sand. Both capping materials suppressed fluxes of Cd, Cu, Ni, and Zn compared to control, and the extent of suppression was different depending on the trace metal species and capping agents used. During sediment incubation, the survival rate of D. magna significantly decreased in bentonite suspension but began to decrease at the end in sand suspension. Sediment capping of mildly polluted sediments by using bentonite and sand lowered the level of nutrients and trace metals. However, unexpected or undesirable side effects, such as influxes of P and As from bentonite to the overlying water and a possibility of toxic impacts to aquatic ecosystems, were observed, suggesting that capping agents with an adequate assessment of their side effects and toxicity should be predetermined for site-specific sediment management strategies.

The cosolvency model was not applicable for predicting the sorption of organic carboxylic acids. The reason of inapplicability was investigated by analyzing the solubility (Sm) and sorption (Km) of benzoic acid, 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4,6-trichlorophenol (2,4,6-TCP). The Sm and Km by two iron-rich soils was measured as a function of methanol volume fraction (fc), electrolyte compositions, and pHapp. For 2,4,6-TCP, the Km of both neutral and anion species was well-explainable by the cosolvency model, exemplifying the knowledge of cosolvency power (σ) being sufficient to describe its sorption. However, for benzoic acid and 2,4-D, the Km of organic anions increased with fc, illustrating the organic carboxylate to be responsible for the deviation. The Sm of organic anions was not affected by the ionic valence (Ca2+ vs. K+) of liquid phase. Among hydrophilic quantities of the 2,4-D sorption, the fraction of anion exchange increased with fc while the fraction of Ca-bridge decreased in the same range. Adding solvent in soil–water system is likely to render soil surface charge more positive, fortifying the anion exchange, but opposing the formation of Ca-bridging. Therefore, it can be concluded that the positive Km–fc relationship is due to the anion exchange of organic carboxylate with positively charged soil surface, whose contribution is >50% of overall sorption at solvent-free system and becomes greater with fc up to 82%.