12 research outputs found

    Enhanced Phosphate Removal by Nanosized Hydrated La(III) Oxide Confined in Cross-linked Polystyrene Networks

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    A new nanocomposite adsorbent La-201 of extremely high capacity and specific affinity toward phosphate was fabricated and well characterized, where hydrated La­(III) oxide (HLO) nanoclusters were immobilized inside the networking pores of the polystyrene anion exchanger D-201. La-201 exhibited enhanced phosphate adsorption in the presence of competing anions (chloride, sulfate, nitrate, bicarbonate, and silicate) at greater levels (up to molar ratio of 20), with working capacity 2–4 times higher than a commercial Fe­(III) oxide-based nanocomposite HFO-201 in batch runs. Column adsorption runs by using La-201 could effectively treat ∼6500 bed volumes (BV) of a synthetic feeding solution before breakthrough occurred (from 2.5 mg P/L in influent to <0.5 mg P/L in effluent), approximately 11 times higher magnitude than that of HFO-201. The exhausted La-201 could be regenerated with NaOH–NaCl binary solution at 60 °C for repeated use without any significant capacity loss. The underlying mechanism for the specific sorption of phosphate by La-201 was revealed with the aid of STEM-EDS, XPS, XRD, and SSNMR analysis, and the formation of LaPO<sub>4</sub>·<i>x</i>H<sub>2</sub>O is verified to be the dominant pathway for selective phosphate adsorption by the immobilized nano-HLO. The results indicated that La-201 was very promising in highly efficient removal of phosphate from contaminated waters

    Elucidating the active ingredients and potential anti-inflammatory mechanism of Qingwei Huanglian Wan

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    Qingwei Huanglian Wan (QHW) is a traditional Chinese medicine used for treating inflammation. As the compositions of QHW preparations are complex and varied, it has proven difficult to identify the active ingredients in QHW and control the quality. In this study, high-performance liquid chromatography (HPLC) fingerprints, network pharmacology, molecular docking, and the Griess method were used to screen for and verify the potential active ingredients of QHW. First, sixteen batches of QHW were studied as two groups using multivariate statistical analysis. Thirteen peaks were detected in the HPLC results to establish a fingerprint similarity model, and six chemical constituents (phellodendrine hydrochloride, geniposide, berberine hydrochloride, baicalin, wogonoside, and glycyrrhizic acid) were identified. Among these six constituents, four components (glycyrrhizic acid, berberine hydrochloride, baicalin, and wogonoside) were considered as potential active ingredients. Second, network pharmacology, molecular docking, and the Griess method were used to further elucidate the potential active ingredients. There was no significant difference in the NO content of the active ingredients administration group (dose converted into the medium-dose group) and medium-dose QHW administration group. Then, the contents of berberine hydrochloride, baicalin, wogonoside, and glycyrrhizic acid were determined using the HPLC method. This study provides a comprehensive and reliable strategy for the quality control of QHW preparations and identifies potential active ingredients in QHW. Our methodology may also be useful for studying other traditional Chinese medicines. Elucidating the active ingredients and potential anti-inflammatory mechanism of Qingwei Huanglian Wan</p

    Phosphorus Binding by Lanthanum Modified Pyroaurite-like Clay: Performance and Mechanisms

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    In situ immobilization of phosphorus (P) by using P binding agents is a facile and effective strategy for eutrophication control. Currently, the most successful commercial agent (Phoslock, a lanthanum modified bentonite, LMB) still suffers low P removal efficiency from natural waters of complex chemistry, largely due to the competitive complexation of the active La species by humic substances (HAs) and bicarbonate. Herein, we describe an attempt to address these issues by intercalating La into Mg/Fe layered double hydroxides, a pyroaurite-like anionic clay, to obtain a hybrid agent (denoted L-CMF-1.0) of phosphate capacity five times higher than that of LMB. More attractively, the binding stability and capacity of L-CMF-1.0 toward P were significantly enhanced in the presence of HAs and bicarbonate, resulting in a high La usage (P/La ratio at ∼1.30). A continuous P immobilization test in the simulated natural waters validates that the addition of L-CMF-1.0 at 0.12 g/L could result in an efficient P removal from 580 μg/L to <100 μg/L within 38 days, outperforming LMB within 10 days only under otherwise identical conditions. Such improvement results from the rational design of the agent structure, i.e., the host, not only contributes to the direct P uptake but also provides a flexible nanoshelter microenvironment to favor the specific La–P interaction under complex solution chemistry. This work is believed to shed new light on the rational design of P binding agent for enhanced eutrophication control

    Arsenate Adsorption by Hydrous Ferric Oxide Nanoparticles Embedded in Cross-linked Anion Exchanger: Effect of the Host Pore Structure

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    Three composite adsorbents were fabricated via confined growth of hydrous ferric oxide (HFO) nanoparticles within cross-linked anion exchangers (NS) of different pore size distributions to investigate the effect of host pore structure on the adsorption of As­(V). With the decrease in the average pore size of the NS hosts from 38.7 to 9.2 nm, the mean diameter of the confined HFO nanoparticles was lessened from 31.4 to 11.6 nm as observed by transmission electron microscopy (TEM), while the density of active surface sites was increased due to size-dependent effect proved by potentiometric titration. The adsorption capacity of As­(V) yielded by Sips model was elevated from 24.2 to 31.6 mg/g via tailoring the pore size of the NS hosts, and the adsorption kinetics was slightly accelerated with the decrease of pore size in background solution containing 500 mg/L of Cl<sup>–</sup>. Furthermore, the enhanced adsorption of As­(V) was achieved over a wide pH range from 3 to 10, as well as in the presence of competing anions including Cl<sup>–</sup>, SO<sub>4</sub><sup>2–</sup>, HCO<sub>3</sub><sup>–</sup>, NO<sub>3</sub><sup>–</sup> (up to 800 mg/L), and PO<sub>4</sub><sup>3–</sup> (up to 10 mg P/L). In addition, the fixed-bed working capacity increased from 2200 to 2950 bed volumes (BV) owing to the size confinement effect, which did not have adverse effect on the desorption of As­(V) as the cumulative desorption efficiency reached 94% with 10 BV of binary solution (5% NaOH + 5% NaCl) for all the three adsorbents. Therefore, this study provided a promising strategy to regulate the reactivity of the nanoparticles via the size confinement effect of the host pore structure

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    Classical trigeminal neuralgia (TN) is a severe neuropathic facial pain disorder associated with increased risks of anxiety and depression. Converging evidence suggests that chronic pain pathophysiology involves dysfunctional pain-related and emotion-related networks. However, whether these systems are also among the culprit networks for TN remains unclear. Here, we aimed to assess TN-related anatomical and functional brain anomalies in pain-related and emotion-related networks. We investigated differences in gray matter (GM) volume and the related resting-state functional connectivity (rsFC) between 29 classical TN patients and 34 matched healthy controls. Relationships between brain measurement alterations, clinical pain and emotional states were identified. A longitudinal observation was further conducted to determine whether alterations in the brain could renormalize following pain relief. Reduced GM volumes in the bilateral amygdala, periaqueductal gray (PAG) and right insula were found in TN patients compared with healthy control subjects. Whole-brain rsFC analyses with the four above-mentioned anatomical regions as seeds identified three significantly altered functional circuits, including amygdala-DLPFC, amygdala-mPFC and amygdala-thalamus/putamen circuitry. The amygdala-DLPFC and amygdala-mPFC circuits were associated with clinical pain duration and emotional state ratings, respectively. Further longitudinal analysis found that rsFC strength abnormalities in two fronto-limbic circuits (left amygdala/left DLPFC and right amygdala/right PFC) were resolved after pain relief. Together, structural and functional deficits in pain-related and emotion-related networks were associated with TN patients, as demonstrated by our multimodal results. Pain relief had protective effects on brain functional connectivity within fronto-limbic circuits. Our study provides novel insights into the pathophysiology of TN, which may ultimately facilitate advances in TN intervention.</p

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    No full text
    Classical trigeminal neuralgia (TN) is a severe neuropathic facial pain disorder associated with increased risks of anxiety and depression. Converging evidence suggests that chronic pain pathophysiology involves dysfunctional pain-related and emotion-related networks. However, whether these systems are also among the culprit networks for TN remains unclear. Here, we aimed to assess TN-related anatomical and functional brain anomalies in pain-related and emotion-related networks. We investigated differences in gray matter (GM) volume and the related resting-state functional connectivity (rsFC) between 29 classical TN patients and 34 matched healthy controls. Relationships between brain measurement alterations, clinical pain and emotional states were identified. A longitudinal observation was further conducted to determine whether alterations in the brain could renormalize following pain relief. Reduced GM volumes in the bilateral amygdala, periaqueductal gray (PAG) and right insula were found in TN patients compared with healthy control subjects. Whole-brain rsFC analyses with the four above-mentioned anatomical regions as seeds identified three significantly altered functional circuits, including amygdala-DLPFC, amygdala-mPFC and amygdala-thalamus/putamen circuitry. The amygdala-DLPFC and amygdala-mPFC circuits were associated with clinical pain duration and emotional state ratings, respectively. Further longitudinal analysis found that rsFC strength abnormalities in two fronto-limbic circuits (left amygdala/left DLPFC and right amygdala/right PFC) were resolved after pain relief. Together, structural and functional deficits in pain-related and emotion-related networks were associated with TN patients, as demonstrated by our multimodal results. Pain relief had protective effects on brain functional connectivity within fronto-limbic circuits. Our study provides novel insights into the pathophysiology of TN, which may ultimately facilitate advances in TN intervention.</p

    Evolving Role of Ca<sup>2+</sup> on the Long-Term Phosphate Adsorption-Regeneration Performance of Nanoconfined Hydrated Lanthanum Oxides: Short-Term Enhancement and Long-Term Inhibition

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    Phosphorus (P) advanced treatment by adsorption reduces the risk of eutrophication in natural waters and reservoirs. The impact of ubiquitous Ca2+ on long-term P removal is critical in assessing the regeneration efficiency of one adsorbent, which is a vital indicator for cost-effectiveness. Given the critical role of lanthanum (La)-based composite materials in P removal, in this study, we unravel the long-term evolving role of Ca2+ on phosphate removal by nanosized hydrated lanthanum oxides (HLO) confined in cross-linked polystyrene beads (HLO@201) over 20 adsorption-regeneration cycles and fixed-bed column runs, with a combination of macroscopic adsorption experiments, microscopic structural investigation, and theoretical calculations. The role of Ca2+ gradually evolves from positive (5–70% higher than Ca2+-free group) to negative (18–41% lower than the Ca2+-free group) with ongoing cyclic runs of HLO@201, which is distinctive from the bulky HLO. The presence of Ca2+ enhances P uptake by HLO@201 possibly through La–P–Ca–P multiple complexation and Ca–P precipitation (i.e., hydroxyapatite, HAP) inside the polymeric host, which creates an antagonistic effect with HLO over time. The formed Ca–P precipitates may accumulate and encapsulate on the surface of HLO nanoparticles, which induce the formation of irreversible LaPO4·xH2O under nanoconfinement that deplete the active adsorptive sites. A two-step (acid wash + NaOH) regeneration method can partially recover the P removal performance of HLO@201. We envision that this study could be a cautionary tale for advanced treatment of P by adsorption, to inspire re-evaluation on the long-term performance of adsorption processes
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