Contrasting effects of MgAl- and MgFe-based layered double hydroxides on phosphorus mobilization and microbial communities in sediment.

The effects of two types of layered double hydroxides (LDH) in-situ treatment on sediment phosphorus (P) mobilization and microbial community's structure were studied comparatively. The results presented that magnesium/aluminum-based (MA) and magnesium/iron (MF)-based LDH displayed great phosphate uptake ability in aqueous solution in a broad pH range of 3-8. The maximum phosphate sorption capacity of MA was 64.89 mg/g, around four times greater than that of MF (14.32 mg/g). Most of phosphate bound by MA and MF is hard to re-liberate under reduction and ordinary pH (5-9) conditions. In the in-situ remediation, the MA and MF capping/amendment both prevented P migration from the sediment to the overlying water (OL-water) under long-term anaerobic conditions, and MA had a better interception efficiency compared to MF in the same application mode. MA amendment significantly reduced mobile P (Mob-P) content in sediment and could remain its stable Mob-P inactivation capacity over a wide pH range. On the contrary, MF amendment increased Mob-P content in sediment and exhibited a variable ability to inactivate Mob-P under elevated pH conditions. MF can decrease Mob-P content at pH of 7 and 11 but increase Mob-P content at pH of 8-10. Under resuspension conditions, MA and MF capping groups still maintained low P levels in OL-water, while MA capping simultaneously showed a certain degree of resistance to sediment resuspension, but it had a weaker stabilizing effect for sediment than MF. Microbial community analysis manifested neither MA nor MF addition observably altered the sediment microbial diversity, but impacted the functional microorganisms' abundance and reshaped the microbial community's structure, intervening the sediment-P stabilization. Viewed from environmental friendliness, control efficiency, stability of P fixation capacity, and application convenience, MA capping wrapped by fabric is more suitable for addressing internal P loading in eutrophic lakes and holds great potential application.

Immobilization of phosphorus in water-sediment system by iron-modified attapulgite, calcite, bentonite and dolomite under feed input condition: Efficiency, mechanism, application mode effect and response of microbial communities and iron mobilization.

Four kinds of iron-based materials, i.e., iron-modified attapulgite, calcite, bentonite and dolomite (abbreviated as Fe-ATP, Fe-CA, Fe-BT and Fe-DOL, respectively) were prepared and used to immobilize the phosphorus in the system of overlying water (O-water) and sediment under the feed input condition, and their immobilization efficiencies and mechanisms were investigated. The influence of application mode on the immobilization of phosphorus in the water-sediment system by Fe-ATP, Fe-CA, Fe-BT and Fe-DOL was researched. The effects of Fe-ATP, Fe-CA, Fe-BT and Fe-DOL on the concentration of labile iron in the water-sediment system and the microbial communities in sediment were also studied. The results showed that the Fe-ATP, Fe-CA, Fe-BT and Fe-DOL addition all can effectively immobilize the soluble reactive phosphorus (SRP), dissolved total phosphorus (DTP) and diffusive gradients in thin-films (DGT)-labile phosphorus in O-water under the feed input condition, and also had the ability to inactivate the DGT-labile phosphorus in the top sediment. Although the change in the application mode from the one-time addition to the multiple addition reduced the inactivation efficiencies of SRP and DTP in O-water in the early period of application, it increased the immobilization efficiencies in the later period of application. Although Fe-ATP, Fe-CA, Fe-BT and Fe-DOL had a certain releasing risk of iron into the pore water, they had negligible risk of iron release into O-water. The addition of Fe-ATP, Fe-CA, Fe-BT or Fe-DOL reshaped the sediment bacterial community structure and can affect the microorganism-driven phosphorus cycle in the sediment. Results of this work suggest that Fe-ATP, Fe-CA, Fe-BT and Fe-DOL are promising phosphorus-inactivation materials to immobilize the phosphorus in the water-sediment system under the feed input condition.

False Tendons in the Left Ventricle: Implications for Successful Ablation of Left Posterior Fascicular Tachycardias.

BACKGROUND: The anatomical substrate for left posterior fascicular ventricular tachycardia (LPF-VT) is still unclear. OBJECTIVES: The purpose of this study is to describe the endocavitary substrate of the re-entrant loop of LPF-VT. METHODS: A total of 26 consecutive patients with LPF-VT underwent an electrophysiology study and radiofrequency ablation. RESULTS: Intracardiac echocardiography imaging observed a 100% prevalence of false tendons (FTs) at the left posterior septal region in all patients, and 3 different types of FTs could be classified according to their location. In 22 patients, a P1 potential could be recorded via the multielectrode catheter from a FT. In 4 patients without a recorded P1 during LPF-VT, the earliest P2 potentials were recorded from a FT in 3 patients, and from a muscular connection between 2 posteromedial papillary muscles in 1 patient. Catheter ablation focused on the FTs with P1 or earliest P2 (in patients without P1) was successful in all 26 patients. After 19 ± 8.5 months of follow-up, no patients had recurrence of LPF-VT. CONCLUSIONS: FTs provide an electroanatomical substrate for LPF-VT and a "culprit FT" may be identified as the critical structure bridging the macro-re-entrant loop. Targeting the "culprit FT" is a novel anatomical ablation strategy that results in long-term arrhythmia-free survival.

Effect of ellagic acid on body weight, nutrient digestibility, fecal microbiota, and urolithin A metabolism in Thoroughbred horses.

This study aimed to investigate the effects of ellagic acid (EA) supplementation on body weight (BW), nutrient digestibility, fecal microbiota, blood biochemical indices, and urolithin A metabolism in 1-yr-old Thoroughbred horses. A group of 18 1-yr-old Thoroughbred horses, with an average weight of 339.00 ±â€…30.11 kg, were randomly allocated into three groups of six horses each (three males and three females). The control group (n = 6) received only the basal diet, whereas test groups I (n = 6) and II (n = 6) were fed the basal diet supplemented with 15 mg/kg BW/d and 30 mg/kg BW/d of EA, respectively, for 40-d. The results showed that test group I and II horses had a significant increase in total weight gain by 49.47% and 62.74%, respectively, compared to the control group. The digestibility of various components in the diets of the test group horses was improved, including dry matter, organic matter, gross energy, neutral detergent fiber, acid detergent fiber, and calcium. Additionally, the digestibility of crude protein and phosphorus (P) in test group II horses increased significantly by 10.96% and 33.56% (P < 0.05), respectively. Moreover, EA supplementation significantly increased the fecal abundance of Firmicutes, Bacteroidetes (P < 0.05), Fibrobacterota, p-251-o5, Desemzia incerta (P < 0.05), and Fibrobacter sp. (P < 0.05), while reducing the abundance of Proteobacteria, Pseudomonadaceae, Pseudomonas, and Cupriavidus pauculus (P < 0.05 or P < 0.01). Fecal samples from test group II showed 89.47%, 100%, and 86.15% increases in the concentrations of acetic acid, valeric acid, and total volatile fatty acids, respectively. In addition, the plasma levels of total protein, and globulin increased significantly in test groups I (7.88% and 11.35%, respectively) and II (13.44% and 16.07%, respectively) compared to those in the control group (P < 0.05). The concentration of urolithin A in fecal and urine samples was positively correlated with increasing doses of EA. These findings suggest that supplemental feeding of EA improved nutrient digestibility, blood biochemical indices, and fecal microbiota in 1-yr-old Thoroughbred horses, promoting growth and development.

Ellagic acid (EA), a plant-derived feed additive, has beneficial physiological effects, including antioxidant and anti-inflammatory properties as well as intestinal microbiota regulation. Young Thoroughbred horses exhibit rapid growth and require ample nourishment. However, the underdeveloped functional anatomy of their gastrointestinal tract restricts the rate of feed utilization. Therefore, improving digestive tract function in horses at this stage promotes intestinal homeostasis, improves antioxidant and anti-inflammatory capabilities, and supports rapid growth and health. This study revealed that supplemental feeding of 1-yr-old Thoroughbred horses with EA improved nutrient digestibility and fecal floral diversity, leading to enhanced growth performance. The optimal dose was 30 mg/kg body weight.

Effect of capping mode on control of phosphorus release from sediment by lanthanum hydroxide.

The use of in situ active capping to control phosphorus release from sediment has attracted more and more attentions in recent years. It is important to identify the effect of capping mode on the control of phosphorus release from sediment by the in situ active capping method. In this study, the impact of capping mode on the restraint of phosphorus migration from sediment into overlying water (OW) by lanthanum hydroxide (LH) was studied. Under no suspended particulate matter (SPM) deposition condition, LH capping effectively restrained the liberation of endogenous phosphorus into OW during anoxia, and the inactivation of diffusive gradient in thin film-unstable phosphorus (UPDGT) and mobile phosphorus (PMobile) in the topmost sediment served as a significant role in the restraint of endogenous phosphorus migration into OW by LH capping. Under no SPM deposition, although the transformation of capping mode from the single high dose capping to the multiple smaller doses capping had a certain negative impact on the restraint efficiency of endogenous phosphorus liberation to OW by LH in the early period of application, it increased the stability of phosphorus in the static layer in the later period of application. Under SPM deposition condition, LH capping had the capability to mitigate the risk of endogenous phosphorus liberation into OW under anoxia conditions, and the inactivation of UPDGT and PMobile in the topmost sediment was a significant mechanism for the control of sediment phosphorus liberation into OW by LH capping. Under SPM deposition condition, the change in the covering mode from the one-time high dose covering to the multiple smaller doses covering decreased the efficiency of LH to limit the endogenous phosphorus transport into OW in the early period of application, but it increased the performance of LH to restrain the sedimentary P liberation during the later period of application. The results of this work suggest that the multiple LH capping is a promising approach for controlling the internal phosphorus loading in freshwater bodies where SPM deposition often occurs in the long run.

Effect of common ions aging treatment on adsorption of phosphate onto and control of phosphorus release from sediment by lanthanum-modified bentonite.

The objective of this work was to explore the influence of combined aging treatment using Na+, Ca2+, Cl-, HCO3- and SO42- on the adsorption of phosphate (HiPO4i-3) onto and the restraint of internal phosphorus (P) migration into overlying water (OW) by lanthanum modified bentonite (LMB). To achieve this aim, the adsorption characteristics and mechanisms of HiPO4i-3 onto the raw and aged LMBs (named as R-LMB and A-LMB, respectively) were comparatively studied, and the effects of R-LMB and A-LMB treatments (addition and capping) on the migration of P from sediment to OW were comparatively investigated. The results showed that the combined aging treatment of R-LMB with Na+, Ca2+, Cl-, HCO3- and SO42- inhibited the adsorption of HiPO4i-3. Similar to R-LMB, the precipitation of HiPO4i-3 with La3+ to form LaPO4 and the ligand exchange between CO32- and HiPO4i-3 to form the inner-sphere lanthanum-phosphate complexes are the important mechanisms for the HiPO4i-3 uptake by A-LMB. The R-LMB addition and capping can be effective in the suppression of endogenous P release to OW under hypoxia conditions. The inactivation of diffusive gradient in thin film-unstable P (DGT-UP) and potentially mobile P (PM-P) in sediment acted as a key role in the restraint of internal P release to OW by the R-LMB addition, and the immobilization of DGT-UP and PM-P in the topmost sediment played a key role in the interception of endogenous P migration into OW by the R-LMB capping. Although the Na+/Ca2+/Cl-/HCO3-/SO42- combined aging treatment had a certain negative effect on the efficiencies of LMB addition and capping to hinder the liberation of P from sediment into OW, the A-LMB addition and capping still can be effective in the control of sediment internal phosphorus pollution to a certain degree. The results of this work indicate that LMB has a high potential to be used as a capping/amendment material to control internal phosphorus pollution.

Control of phosphorus release from sediment by hydrous zirconium oxide combined with calcite, bentonite and zeolite.

This study investigated the effectiveness and mechanism for the control of internal phosphorus (P) liberation from sediment by hydrous zirconium oxide (HZrO2) combined with calcite, bentonite and zeolite. The results suggested that coexisting calcite, calcium-modified bentonite (CaBT) and calcium-modified zeolite (CaZ) all had the ability to promote the adsorption of phosphate (PO43-) onto HZrO2. The mechanisms of PO43- elimination by HZrO2/calcite mixture involved the adsorption of PO43- on calcite, the precipitation of PO43- with Ca2+, and the inner-sphere complexation of PO43- with HZrO2. The amendment of sediment with HZrO2/calcite, HZrO2/CaBT or HZrO2/CaZ mixture can effectively prevent the sedimentary P release, and the immobilization of mobile P in the sediment and the uptake of dissolved reactive P (DRP) from the interstitial water by the amendment material played a key role in the control of P release from sediment by the combined amendment. Capping sediment with HZrO2/calcite, HZrO2/CaBT or HZrO2/CaZ mixture also can effectively intercept sediment P release, and the formation of P static layer attributed to the uptake of interstitial water DRP and DGT (diffusive gradient in thin-films)-unstable P in the upper sediment by the capping material was a key to the inhibition of sedimentary P migration into the overlying water by the combined capping. The great majority of P immobilized by the HZrO2/calcite, HZrO2/CaBT or HZrO2/CaZ combined covering layer is stable P and it has a low re-releasing risk under dissolved oxygen-deficit and pH 5-9 condition. The stability of P bound by the combined covering layer was larger than that by the single HZrO2 covering layer. The results of this research show that the combined use of HZrO2 and calcite, HZrO2 and CaBT, or HZrO2 and CaZ as a capping material has great potential in the reduction of sediment P loading.

Circ_0004585 Facilitates Tumorigenesis of Colorectal Cancer Via Modulating the miR-338-3p/ZFX Axis and Activating the MEK/ERK Pathway.

Background: Colorectal cancer (CRC) is a common malignant tumor in the digestive tract. Circular RNAs (circRNAs) have been identified as crucial regulators of tumorigenesis. However, the role and potential mechanism of circ_0004585 in CRC are poorly understood. Methods: The expression of circ_0004585, microRNA-338-3p (miR-338-3p), and zinc finger protein X-linked (ZFX) was detected by quantitative real-time PCR and Western blot. Cell proliferation, cell cycle arrest, apoptosis, and angiogenesis were evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), 5-Ethynyl-2'-deoxyuridine (EdU), flow cytometry and tube formation assays. Western blot assay was applied to detect the expression of epithelial-mesenchymal transition (EMT)-related proteins and MEK/ERK signaling pathway-related proteins. A xenograft model was used to analyze tumor growth in vivo. The targeted relationship between miR-338-3p and circ_0004585/ZFX was verified by a dual-luciferase reporter assay. Results: Circ_0004585 and ZFX were up-regulated, while miR-338-3p was down-regulated in CRC tissues and cells. Silencing of circ_0004585 inhibited proliferation, angiogenesis, and EMT and triggered apoptosis in CRC cells. Consistently, circ_0004585 depletion blocked tumor growth in vivo. Circ_0004585 contributed to CRC cell development via sequestering miR-338-3p. Also, miR-338-3p hindered the malignant progression of CRC cells by targeting ZFX. Circ_0004585 activated MEK/ERK pathway via regulating ZFX. Conclusion: Circ_0004585 facilitated CRC progression through modulating miR-338-3p/ZFX/MEK/ERK pathway, which might provide a potential therapeutic target for CRC. Supplementary Information: The online version contains supplementary material available at 10.1007/s12195-022-00756-6.

Comparison of magnetite, hematite and goethite amendment and capping in control of phosphorus release from sediment.

The characteristics and mechanism of phosphate adsorption onto magnetite, hematite and goethite were comparatively studied, and the effects of magnetite, hematite and goethite amendment and capping on endogenous phosphorus (P) liberation from sediment into overlying water (OW) were comparatively investigated. The adsorption of phosphate onto magnetite, hematite and goethite mainly obeyed the inner-sphere complexation mechanism, and the phosphate adsorption capacity decreased in the order of magnetite > goethite > hematite. The magnetite, hematite and goethite amendment all can decrease the risk of endogenous Prelease into OW under anoxic conditions, and the inactivation of diffusion gradients in thin films-labile P in sediment made a great contribution to the restraint of endogenous P release into OW by the magnetite, hematite and goethite amendment. The efficiency of endogenous P release restraint by the iron oxide addition decreased in the order of magnetite > goethite > hematite. The magnetite, hematite and goethite capping all can be effective for the suppression of endogenous P release from sediment into OW under anoxic conditions, and most of P immobilized by the magnetite, hematite and goethite capping layers is relatively or very stable. The results obtained from this work suggest that magnetite is more suitably used a capping/amendment material to prevent P release from sediment than hematite and goethite, and magnetite capping is a promising approach for hindering sedimentary P release into OW.

Combined amendment and capping of sediment with ferrihydrite and magnetite to control internal phosphorus release.

This study developed novel active capping systems with recycling convenience using ferrihydrite (Fh) combined with magnetite (Mag), and investigated the effectiveness and mechanism for the restriction of endogenous phosphorus movement from sediment into overlying water (OW) by the combined use of Fh and Mag. The Fh/Mag combined amendment effectively hindered endogenous phosphorus release from sediment to OW in dissolved oxygen (DO)-deficit environment, and the immobilization of diffusion gradient in thin film-labile phosphorus (LPDGT) and mobile phosphorus in the sediment played a key role in the control of endogenous phosphorus liberation by the Fh/Mag combined amendment. Combined capping sediment with Fh and Mag effectively hindered endogenous phosphorus release from sediment to OW in anoxic environment, and the inactivation of LPDGT in the upper sediment played a key part in the control of sediment phosphorus release by the Fh/Mag mixture capping. The stability of phosphorus immobilized by the Fh/Mag combined covering layer was related to its construction way, and the majority (around 90%) of P immobilized to the Fh/Mag mixture covering layer had low risk of release in common pH (5-9) and DO-deficit environments. The Fh/Mag mixture amendment or capping did not increase the risk of sediment iron release, and it also did not produce a large impact on the diversity and richness of bacterial community in the sediment. The combined utilization of Fh and Mag as a composite amendment or capping material to prevent the internal phosphorus from being moved to OW can make full use of their respective advantages. The Fh/Mag mixture capping wrapped by permeable fabric has high potential to reduce the risk of endogenous phosphorus from sediment into OW due to its advantages of high internal phosphorus release suppression efficiency, environmental friendliness, application convenience and sustainability.

Effect of sediment burial depth on the control of sedimentary phosphorus release by iron/aluminum co-modified calcite and strategy for overcoming the negative effect of sediment burial.

After placing an active capping material on surface sediments, the capping layer will be buried by the newly formed sediment. In this research, the influence of sediment burial depth on the performance of iron/aluminum co-modified calcite (FeAlCAL) to suppress sedimentary phosphorus (P) release into overlaying water (OL-water) was studied. Furthermore, in order to find out the strategy for overcoming the negative effect of sediment burial, the efficiencies and mechanisms of three different FeAlCAL treatments (one-time FeAlCAL capping with 3 cm sediment burial, multiple FeAlCAL capping with 1 cm sediment burial, and amendment of top 3 cm sediment with FeAlCAL) in the inhibition of sediment P release were contrastively studied. The results showed that with the increase of sediment burial depth, the efficiency of FeAlCAL to block the release of sediment P into OL-water gradually decreased until the FeAlCAL lost the ability to hinder sediment-P release. In contrast to the one-time FeAlCAL capping in the presence of 3 cm sediment burial, the multiple FeAlCAL capping in the presence of 1 cm sediment burial and amendment of top 3 cm sediment with FeAlCAL both effectively prevented the release of P from sediment into OL-water. All results of this work suggest that although sediment burial can negatively affect the ability of FeAlCAL in the inhibition of sediment P release into OL-water and the negative effect becomes stronger as the sediment burial depth increases, the transformation of the application mode of FeAlCAL from one-time capping to multiple capping or from capping to amendment can overcome the negative influence of sediment burial.

Effect of application mode (capping and amendment) on the control of cadmium release from sediment by apatite/calcite mixture and its phosphorus release risk.

In this research, the influence of application mode (capping and amendment) on the control of cadmium (Cd) liberation from sediment by apatite/calcite mixture and its phosphorus release risk were investigated. The results showed that calcite addition had a limited effect on the speciation of Cd in sediment, but apatite addition had a significant impact on the fractionation of Cd in sediment. Apatite amendment could effectively immobilize the most readily mobilized Cd by transferring the acid-soluble fraction to the reducible and residual fractions. Apatite addition also could effectively reduce the concentration of toxicity characteristic leaching procedure (TCLP)-leachable Cd in sediment, and apatite had a much higher reduction efficiency of TCLP-leachable Cd than calcite. Apatite/calcite mixture capping could reduce the risk of Cd liberation from sediment into the overlying water, and the controlling efficiency of apatite/calcite mixture capping was higher than that of apatite/calcite mixture amendment. The effect of apatite/calcite mixture addition on the concentration of reactive soluble phosphorus (SRP) in the overlying water was limited. The introduction of calcite into the apatite capping layer could lower the risk of phosphorus release from apatite to the overlying water as compared to single apatite capping. However, the apatite/calcite mixture capping layer still had a relatively high risk of phosphorus liberation into the overlying water. Results of this work suggest that apatite/calcite mixture has a high potential to be used as a capping material to control Cd release from sediment from the perspective of controlling efficiency and application convenience.

Dual-mode detection of dopamine based on 0D/2D/2D CuInS2/ZnS quantum dot-black phosphorous nanosheet-TiO2 nanosheet nanocomposites.

In this work, we designed new dual-mode "turn-on" electrochemical (EC) and photoelectrochemical (PEC) sensors for the detection of dopamine (DA) based on 0D/2D/2D CuInS2/ZnS quantum dot (QD)-black phosphorous nanosheet (BPNS)-TiO2 nanosheet (TiO2NS) nanocomposites. QDs can not only improve the photocurrent of the developed PEC sensors, but also provide the electrochemical signal in the EC detection. BPNSs as p-type semiconductor with high conductive properties work as electron acceptors and are utilized to improve the sensitivity of the DA PEC and EC sensors. Under irradiation of visible light or the applied voltage, DA is both excited and releases electrons, realizing "turn-on" detection. The PEC sensors have a linear range of 0.1-100 µM with a lower detection limit of 0.028 µM. For the EC detection, BPNSs can accelerate electron transfer which attribute to its excellent conductivity. In the range of 1-200 µM, the working curve of DA detection by the EC sensors was established and the detection limit is 0.88 µM. Comparing the two methods, the PEC sensors have a lower detection limit, and the EC sensors have a wider monitoring range. The dual-mode sensors of EC and PEC pave an effective way for the detection in biological and medical fields.

Contrasting effect of zirconium-, iron-, and zirconium/iron-modified attapulgites capping and amendment on phosphorus mobilization in sediment.

In this research, the sorption characteristics and mechanism of phosphate on zirconium-modified attapulgite (Zr-ATP), iron-modified attapulgite (Fe-ATP), and zirconium/iron co-modified attapulgite (Zr/Fe-ATP) prepared by a simple impregnation method were studied, and the impacts of Zr-ATP, Fe-ATP, and Zr/Fe-ATP amendment and capping on the migration of phosphorus (P) from sediments to overlying waters were investigated. The results showed that Zr-ATP and Zr/Fe-ATP possessed stronger adsorption ability for phosphate in aqueous solution than Fe-ATP. The ligand replacement of the hydroxyl group with the phosphate anion to form the inner-sphere phosphate complex played a crucial role in the adsorption process of phosphate on Zr-ATP, Fe-ATP, and Zr/Fe-ATP. Most of the phosphate ions bound by Zr-ATP and Zr/Fe-ATP were in the form of caustic soda solution-extractable inorganic P (NaOH-IP) and residual P (Res-P), and it is hard for these P species to be re-released into water under the circumstances of reducing environment and normal pH (5-9). The ratio of mobile P to total P of Fe-ATP loaded with phosphate was much higher than those of Zr-ATP and Zr/Fe-ATP loaded with phosphate, indicating that Fe-ATP-bound phosphate has a higher re-releasing risk than Zr-ATP-bound and Zr/Fe-ATP-bound phosphate. Zr-ATP, Fe-ATP, and Zr/Fe-ATP amendment all can reduce the releasing risk of P from sediments to overlying waters. The amendment of sediment with Zr-ATP and Zr/Fe-ATP can both induce the conversion of redox-sensitive P (BD-P) to NaOH-IP and Res-P in the sediment, making the phosphorus in the sediment more stable. However, the amendment of sediment with Fe-ATP can only induce the conversion of HCl-P to NaOH-IP in the sediment and had a negligible effect on the inorganic P activity in the sediment. Zr-ATP, Fe-ATP, and Zr/Fe-ATP capping all can reduce the risk of P release from sediment into the overlying water, and Zr-ATP and Zr/Fe-ATP capping had a better reduction efficiency of internal P liberation to the overlying water than Fe-ATP capping. Zr-ATP, Fe-ATP, and Zr/Fe-ATP capping all can give rise to the reduction of pore water SRP and diffusive gradient in thin-film (DGT)-labile P in the upper sediment. This is beneficial to the control of P releasing from sediment into the overlying water by the Zr-ATP, Fe-ATP, and Zr/Fe-ATP capping. The findings of this work suggest that Zr-ATP and Zr/Fe-ATP are promising active capping or amendment materials for internal P loading management in surface water bodies.

Effectiveness and mechanism of aluminum/iron co-modified calcite capping and amendment for controlling phosphorus release from sediments.

The effectiveness and mechanism of aluminum/iron co-modified calcite (Al/Fe-CA) for the control of phosphorus (P) liberation from sediments was investigated. The results showed that Al/Fe-CA possessed good sorption performance for phosphate, and the maximum phosphate sorption capacity for Al/Fe-CA could reach 27.0 mg/g. The major mechanisms involved the surface adsorption of phosphate on calcite, the precipitation between phosphate and Ca2+ leached from calcite, and the ligand exchange between Al/Fe-bound hydroxyl groups and phosphate to form the Al-O-P and Fe-O-P inner-sphere complexes. The re-releasing risk of Al/Fe-CA-bound P under the circumstances of normal pH (5-9) and reducing environment was very low. Al/Fe-CA addition could significantly reduce the risk of P releasing from sediment to overlying water (OL-water), and the inactivation of mobile P, reactive soluble P (SRP) and diffusive gradient in thin-films (DGT)-labile P in sediment by Al/Fe-CA had a great part in the suppression of sediment-P liberation to OL-water by the Al/Fe-CA amendment. Al/Fe-CA capping and fabric-wrapped Al/Fe-CA capping both could greatly reduce the risk of P releasing from sediment into OL-water, and the formation of a static layer with low concentrations of SRP and DGT-labile P in the upper sediment was the key to sustaining a high P controlling efficiency. When the applied mode of Al/Fe-CA varied from capping to amendment, although the inactivation efficiency of DGT-labile P in the overlying water and upper sediment by Al/Fe-CA would decrease to a certain degree, the inactivation efficiency of DGT-labile P in the lower sediment by Al/Fe-CA would increase. Results of this study suggest that Al/Fe-CA has the high potential to be used as an active capping or amendment material for the management of internal P loading in surface water bodies.

[Effect of the Combined Use of Denitrifying Bacteria, Calcium Nitrate, and Zirconium-Modified Zeolite on the Mobilization of Nitrogen and Phosphorus in Sediments and Evaluation of Its Nitrate-Nitrogen Releasing Risk].

In this work, the influence of an integrated method based on calcium nitrate, denitrifying bacteria, and zirconium-modified zeolite (CN+DB+ZZ) on the transport and transformation of nitrogen (N) and phosphorus (P) in sediments was investigated, and the risk of nitrate release from the calcium nitrate-injected sediment was evaluated. The effects of the single calcium nitrate injection (CN), calcium nitrate, and denitrifying bacteria combined treatment (CN+DB) and the combined treatment using calcium nitrate injection and zirconium-modified zeolite capping (CN+ZZ) on the mobilization of N and P in sediment were compared, and the nitrate releasing risk of these methods was also evaluated. The results indicated that although CN treatment could effectively control the P release from the sediment, this method could not effectively control the release of ammonium-nitrogen from sediment and has a high risk of releasing nitrate-nitrogen. The CN+DB combined method not only could effectively control the liberation of sedimentary P but also reduce the risk of nitrate-nitrogen release from the calcium nitrate-injected sediment compared with the single CN method. However, the CN+DB combined method could not effectively control the release of ammonium-nitrogen from the sediment. The CN+ZZ combined treatment not only could effectively prevent the release of sedimentary P but could also greatly reduce the release of ammonium-nitrogen from the sediment. However, the CN+ZZ combined method could result in a substantial release of nitrate-nitrogen from the calcium nitrate-injected sediment. The CN+DB+ZZ combined technology could effectively control the release of P from sediment as well as greatly reduce the risk of ammonium-nitrogen release from the sediment. Furthermore, the CN+DB+ZZ combined method resulted in a significant reduction of nitrate-nitrogen released from the calcium nitrate-injected sediment compared with the CN and CN+ZZ treatment methods. The prevention of the dissolution of the P-bound iron oxide/hydroxide in the sediment, the reduction of redox-sensitive P in sediment, and the improvement of the phosphate and ammonium adsorption abilities of sediment by the CN+DB+ZZ combined method is critical to control the release of phosphorus and ammonium-nitrogen from sediment using this method. Results of this study reveal that the CN+DB+ZZ combined technology could be a promising method for the control of phosphorus and ammonium-nitrogen release from sediments.

Suppression of phosphorus release from sediment using lanthanum carbonate as amendment.

The performance of lanthanum carbonate (LC) pertaining to the adsorption of phosphate (HwPO4w-3) was investigated, and the possible adsorption mechanism was elucidated. The stabilization of HwPO4w-3 adsorbed to LC was evaluated. The influence of LC addition on the upward transport of phosphorus (P) from sediment to overlying water (OL-W) was studied, and the adsorption performance of HwPO4w-3 on the LC-amended sediment was explored. The results of this work indicated that LC performed well in the elimination of HwPO4w-3 from water in the pH range of 4 to 11, and the commercial and self-prepared LC samples afforded the maximum HwPO4w-3 adsorption capacities of 57.9 and 99.4 mg P/g, respectively, at pH 7. The presence of coexisting species including chloride, bicarbonate, and sulfate had a small influence on the HwPO4w-3 adsorption onto LC. The main HwPO4w-3 adsorption mechanism of LC at pH 7 was the ligand exchange reaction between carbonate and HwPO4w-3 forming the inner-sphere La-phosphate complexation. The self-synthesized LC exhibited much higher HwPO4w-3 adsorption performance than the commercial LC. The overwhelming majority (> 97.0%) of HwPO4w-3 adsorbed to LC primarily existed in the form of muriatic acid-extractable P, which has relatively low re-releasing risk. The addition of LC into sediment could significantly prevent the release of P from the sediment solid into the OL-W, thereby leading to a lower concentration level of reactive soluble P (RSP) in the OL-W compared with no LC treatment. The addition of LC into sediment could greatly improve the HwPO4w-3 uptake ability for the sediment, and the enhancement of HwPO4w-3 adsorption onto the sediment by the added LC increased as the increase of the amendment dosage and the initial HwPO4w-3 concentration. All results suggest that LC could serve as a promising amendment material for the control of sedimentary P release.

Qingxin Kaiqiao Fang Inhibits Aß 25-35-Induced Apoptosis in Primary Cultured Rat Hippocampal Neuronal Cells via the p38 MAPK Pathway: An Experimental Validation and Network Pharmacology Study.

Qingxin kaiqiao fang (QKF), a traditional Chinese medicine compound, has been applied to treat Alzheimer's disease (AD) for many years and has exhibited remarkable effects. However, the underlying mechanism is still not explicit. The current study aims to investigate whether QKF exerts an antiapoptotic role through the p38 MAPK pathway in the course of AD. Network pharmacology analysis was applied to study the effective components, possible therapeutic targets, and AD-related pathway of QKF. Further, the AD cell model was established using amyloid-beta (Aß)25-35 peptide and primary hippocampal neuronal cells extracted from newborn Sprague-Dawley rats. Microtubule-associated protein-2 (MAP-2) imaging was used to detect the morphology of hippocampal neurons. Western blot (WB) analysis was applied to detect the protein expression levels of p38 MAPK, p-p38 MAPK, Bcl-2, Bax, caspase-3, and cleaved caspase-3. Cell viability and apoptosis were determined using cell counting kit-8 (CCK-8) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assays, respectively. SB203580 and U46619 were used to detect changes in cell morphology, cell viability, and apoptosis upon inhibiting or activating p38 MAPK. Our present work showed that QKF protects hippocampal neuronal morphology, enhances cell viability, and reduces the number of TUNEL-positive cells. In addition, our results showed that QKF increased the expression levels of antiapoptotic proteins and decreased the expression of proapoptotic proteins. QKF at 25 mg·mL-1 best inhibited neuronal apoptosis among the three doses of QKF by suppressing p38 MAPK activity. Collectively, QKF plays an antiapoptotic role via the p38 MAPK pathway.

Control of internal phosphorus release from sediments using magnetic lanthanum/iron-modified bentonite as active capping material.

The non-magnetic capping materials are difficult to be recycled from the water bodies after their application, leading to the increase in the cost of the sediment remediation. To address this issue, a capping material, i.e., magnetic lanthanum/iron-modified bentonite (M-LaFeBT) was prepared by loading lanthanum onto a magnetic iron-modified bentonite (M-FeBT) and used to control the internal phosphorus (P) loading in this study. To determine the capping efficiency and mechanism of M-LaFeBT, the impact of M-LaFeBT and M-FeBT capping on the mobilization of P in sediments was investigated, and the stabilization of P bound by the M-LaFeBT and M-FeBT capping layers was evaluated. Results showed that M-LaFeBT possessed good magnetic property with a saturated magnetization of 14.9 emu/g, and exhibited good phosphate adsorption ability with a maximum monolayer sorption capacity (QMAX) of 14.3 mg P/g at pH 7. Moreover, M-LaFeBT capping tremendously reduced the concentration of soluble reactive P (SR-P) in the overlying water (OL-water), and the reduction efficiencies were 94.7%-97.4%. Furthermore, M-LaFeBT capping significantly decreased the concentration of SR-P in the pore water and DGT (diffusive gradient in thin films)-labile P in the profile of OL-water and sediment. Additionally, most of P bound by the M-LaFeBT capping layer (approximately 77%) was stable under natural pH and reducing conditions. The phosphate adsorption ability for M-LaFeBT was much higher than that for M-FeBT, and the QMAX value for the former was 4.86 times higher than that for the latter. M-LaFeBT capping gave rise to a higher reduction of DGT-labile concentration in the profile of OL-water and sediment than M-FeBT capping. The P adsorbed by the M-LaFeBT capping layer was more stable than that by the M-FeBT capping layer. Results of this study demonstrate that M-LaFeBT is promising for utilization as an active capping material to intercept sedimentary P release into OL-water.

Qingxin Kaiqiao Recipe Improves Cognitive Performance, Inhibits Apoptosis, and Reduces Pathological Deposits in APP/PS1 Double Transgenic Mice via the PI3K/Akt Pathway.

The traditional Chinese medicine of Qingxin Kaiqiao Recipe (QKR) is effective in the treatment of Alzheimer's disease (AD). This study aims to investigate whether QKR improves the cognitive ability and takes neuroprotective effect on APP/PS1 double transgenic mice via the PI3K/Akt pathway. APP/PS1 double transgenic mice were randomly divided into a model, donepezil-treated, or QKR-treated group (L-QKR: 4.75 mg/kg/d, M-QKR: 9.5 mg/kg/d, and H-QKR: 19 mg/kg/d, respectively). Wild-type C57/BL6J mice were used as the control group. Morris water maze (MWM) was used to test the ability of spatial navigation and memorization; terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) assay was applied to test the apoptosis; amyloid protein granule deposition was detected via Methenamine silver staining; Western blot (WB) analysis, immunohistochemistry, and RT-PCR were applied to measure the expression of Aß and corresponding indicators of the PI3K/Akt pathway. Compared with the model group, QKR significantly relieved the cognitive impairment, reduced the deposition of senile plaques, decreased the expression of GSK-3α and Aß, and increased the expression of p-PI3K, p-Akt, and IDE. In addition, the number of TUNEL-positive cells decreased after treatment using QKR. The current study proved that QKR, especially at the high dose tested, exerted a protective effect on improving learning and memory, inhibiting apoptosis, and reducing the process of pathological degeneration in the hippocampus of AD mice.