Virological evaluation of natural and modified attapulgite against porcine epidemic diarrhoea virus.

BACKGROUND: The Porcine Epidemic Diarrhea Virus (PEDV) has caused significant economic losses in the global swine industry. As a potential drug for treating diarrhea, the antiviral properties of attapulgite deserve further study. METHODS: In this study, various methods such as RT-qPCR, Western blot, viral titer assay, Cytopathic Effect, immunofluorescence analysis and transmission electron microscopy were used to detect the antiviral activity of attapulgite and to assess its inhibitory effect on PEDV. RESULTS: When exposed to the same amount of virus, there was a significant decrease in the expression of the S protein, resulting in a viral titer reduction from 10-5.613 TCID50/mL to 10-2.90 TCID50/mL, which represents a decrease of approximately 102.6 folds. Results of cytopathic effect and indirect immunofluorescence also indicate a notable decrease in viral infectivity after attapulgite treatment. Additionally, it was observed that modified materials after acidification had weaker antiviral efficacy compared to powdered samples that underwent ultrasonic disintegration, which showed the strongest antiviral effects. CONCLUSION: As a result, Attapulgite powders can trap and adsorb viruses to inhibit PEDV in vitro, leading to loss of viral infectivity. This study provides new materials for the development of novel disinfectants and antiviral additives.

Analysis of the effect of cations on protein conformational stability using solid-state nanopores.

The conformation of proteins is closely related to their biological functions, and it is affected by many factors, including the type of cations in solution. However, it is difficult to detect the conformational changes of a protein in situ. As a single-molecule sensing technology, nanopores can convert molecular structural information into analyzable current signals within a reasonable time range. Herein, we detect and analyze the effects of two different types of monovalent cations (Na+ and Li+) on a model protein bovine serum albumin (BSA) conformation using SiNx nanopores with different diameters. The quantitative analysis results show that the excluded volume of BSA in LiCl salt solutions is larger than the value in NaCl solution, indicating that Li+ is more prone to unfolding the proteins and making them unstable. This study demonstrated that nanopores enable the in situ detection of the structure of proteins at the single-molecule level and provide a new approach for the quantitative analysis of proteins.

Unravelling performance of honeycomb structures as drug delivery systems for the isoniazid drug using DFT-D3 correction dispersion and molecular dynamic simulations.

In this study, the potential of aluminum nitride (h-AlN), boron nitride (h-BN) and silicon carbide (h-SiC) nanosheets as the drug delivery systems (DDS) of isoniazid (INH) was scrutinized through density functional theory (DFT) and molecular dynamic (MD) simulations. We performed DFT periodic calculations on the geometry and electronic features of nanosheets adsorbed with INH by the DFT functional (DZP/GGA-PBE) employed in the SIESTA code. In the energetically favorable model, an oxygen atom of the C-O group of the INH molecule interacts with a Si atom of the h-SiC at 2.077 Å with an interaction energy of -1.361 eV. Charge transfer (CT) calculation by employing the Mulliken, Hirshfeld and Voronoi approaches reveals that the monolayers and drug molecules act as donors and acceptors, respectively. The density of states (DOS) calculations indicate that the HOMO-LUMO energy gap (HLG) of the h-SiC nanosheet declines significantly from 2.543 to 1.492 eV upon the adsorption of the INH molecule, which causes an electrical conductivity increase and then produces an electrical signal. The signal is linked to the existence of INH, demonstrating that h-SiC may be an appropriate sensor for INH sensing. The decrease in HLG for the interaction of INH and h-SiC is the uppermost (up to 41%) representing the uppermost sensitivity, whereas the sensitivity trend is σ(h-SiC) > σ(h-AlN) > σ(h-BN). Quantum theory of atoms in molecules (QTAIM) investigations is employed to scrutinize the nature of the INH/nanosheet interactions. The QTAIM analysis reveals that the interaction of the INH molecule and h-SiC has a partially covalent nature, while INH/h-AlN model electrostatic interaction occurs in the system and noncovalent and electrostatic interaction for the INH/h-BN model. Finally, the state-of-the-art DFT-MD simulations utilized in this study can mimic ambient conditions. The results obtained from the MD simulation show that it takes more time to bond the INH drug and h-SiC, and the INH/h-SiC system becomes stable. The results of the current research demonstrate the potential of h-SiC as a suitable sensor and drug delivery platform for INH drugs to remedy tuberculosis.

Attapulgite-enhanced ε-poly-l-lysine for heightened antibacterial efficiency against Pseudomonas syringae pv. Tomato.

ε-Poly-l-lysine (ε-PL) is an effective antimicrobial peptide for controlling fungal plant diseases, exhibiting significant antifungal activity and safety. Despite its known efficacy, the potential of ε-PL in combating plant bacterial diseases remains underexplored. This study evaluated the effectiveness of ε-PL and its nanomaterial derivative in managing tomato bacterial spot disease caused by Pseudomonas syringae pv. tomato. Results indicated that ε-PL substantially inhibited the growth of Pseudomonas syringae pv. tomato. Additionally, when ε-PL was loaded onto attapulgite (encoded as ATT@PL), its antibacterial effect was significantly enhanced. Notably, the antibacterial efficiency of ATT@PL containing 18.80 µg/mL ε-PL was even close to that of 100 µg/mL pure ε-PL. Further molecular study results showed that, ATT@PL stimulated the antioxidant system and the salicylic acid signaling pathway in tomatoes, bolstering the plants disease resistance. Importantly, the nanocomposite demonstrated no negative effects on both seed germination and plant growth, indicating its safety and aligning with sustainable agricultural practices. This study not only confirmed the effectiveness of ε-PL in controlling tomato bacterial spot disease, but also introduced an innovative high antibacterial efficiency ε-PL composite with good bio-safety. This strategy we believe can also be used in improving other bio-pesticides, and has high applicability in agriculture practice.

Detection of Biomolecules Using Solid-State Nanopores Fabricated by Controlled Dielectric Breakdown.

Nanopore sensor technology is widely used in biomolecular detection due to its advantages of low cost and easy operation. In a variety of nanopore manufacturing methods, controlled dielectric breakdown has the advantages of a simple manufacturing process and low cost under the premise of ensuring detection performance. In this paper, we have made enhancements to the applied pulses in controlled dielectric breakdown and utilized the improved dielectric breakdown technique to fabricate silicon nitride nanopores with diameters of 5 to 15 nm. Our improved fabrication method offers the advantage of precise control over the nanopore diameter (±0.4 nm) and enhances the symmetry of the nanopore. After fabrication, we performed electrical characterization on the nanopores, and the IV characteristics exhibited high linearity. Subsequently, we conducted detection experiments for DNA and protein using the prepared nanopores to assess the detection performance of the nanopores fabricated using our method. In addition, we also give a physical model of molecule translocation through the nanopores to give a reasonable explanation of the data processing results.

Salivary, acidic and enzymatic degradation of resin composite subjected to different finishing and polishing systems.

PURPOSE: To evaluate the effect of different finishing and polishing systems on the surface roughness of a resin composite subjected to simulated saliva-, acid-, and enzyme-induced degradation. METHODS: 160 specimens (n= 40) were fabricated with Filtek Z350 XT nanofilled composite and analyzed for average surface roughness (Ra). The specimens were finished and polished using: AD - Al2O3-impreginated rubberized discs (medium, fine, and superfine grit, Sof-Lex); SD - silicon carbide and Al2O3-impregnated rubberized discs (coarse, medium and fine grit, Jiffy,); MB - 12- and 30-multiblade burs. The control group (CT) (n= 40) comprised specimens with a Mylar-strip-created surface. Specimens from each group were immersed in 1 mL of one of the degradation methods (n= 10): artificial saliva (ArS: pH 6.75), cariogenic challenge (CaC: pH 4.3), erosive challenge (ErC: 0.05M citric acid, pH 2.3) or enzymatic challenge (EzC: artificial saliva with 700 µg/mL of albumin, pH 6.75). The immersion period simulated a time frame of 180 days. Ra measurements were also performed at the post-polishing and post-degradation time points. The data were evaluated by three-way ANOVA for repeated measures and the Tukey tests. RESULTS: There was significant interaction between the finishing/polishing system and the degradation method (P= 0.001). AD presented the greatest smoothness, followed by SD. After degradation, CT, AD and SD groups became significantly rougher, but not the MB group, which presented no difference in roughness before or after degradation. CT and AD groups showed greater roughness in CaC, ErC and EzC than in ArS. The SD group showed no difference in roughness when the specimens were polished with CaC, EzC or ArS, but those treated with ErC had greater roughness. In the MB group, the lower roughness values were found after using CaC and EzC, while the higher values were found using ErC or ArS. CLINICAL SIGNIFICANCE: As far as degradation resistance of nanofilled composite to hydrolysis, bacterial and dietary acids and enzymatic reactions is concerned, restorations that had been finished and polished with Al2O3-impregnated discs had the smoothest surfaces.

The effect of various surface treatments on the repair bond strength of denture bases produced by digital and conventional methods.

There is limited information on the repairability of prostheses produced with digital technology. This study aims to evaluate various surface treatments on flexural bond strength of repaired dentured base resins produced by digital and conventional methods. A total of 360 samples were prepared from one heat-polymerized, one CAD/CAM milled and one 3D printed denture base materials. All of the test samples were subjected to thermocycling (5-55 °C, 5000 cycles) before and after repair with auto-polymerizing acrylic resin. The test samples were divided into five subgroups according to the surface treatment: grinding with silicon carbide (SC), sandblasting with Al2O3 (SB), Er:YAG laser (L), plasma (P) and negative control (NC) group (no treatment). In addition, the positive control (PC) group consisted of intact samples for the flexural strength test. Surface roughness measurements were performed with a profilometer. After repairing the test samples, a universal test device determined the flexural strength values. Both the surface topography and the fractured surfaces of samples were examined by SEM analysis. The elemental composition of the tested samples was analyzed by EDS. Kruskal-Wallis and Mann-Whitney U tests were performed for statistical analysis of data. SB and L surface treatments statistically significantly increased the surface roughness values of all three materials compared to NC subgroups (p < 0.001). The flexural strength values of the PC groups in all three test materials were significantly higher than those of the other groups (p < 0.001). The repair flexural strength values were statistically different between the SC-SB, L-SB, and NC-SB subgroups for the CAD/CAM groups, and the L-SC and L-NC subgroups for the 3D groups (p < 0.001). The surface treatments applied to the CAD/CAM and heat-polymerized groups did not result in a statistically significant difference in the repair flexural strength values compared to the NC groups (p > 0.05). Laser surface treatment has been the most powerful repair method for 3D printing technique. Surface treatments led to similar repair flexural strengths to untreated groups for CAD/CAM milled and heat-polymerized test samples.

Purification and preparation of pure SiC with silicon cutting waste.

Recycling silicon cutting waste (SCW) plays a pivotal role in reducing environmental impact and enhancing resource efficiency within the semiconductor industry. Herein SCW was utilized to prepare SiC and ultrasound-assisted leaching was investigated to purify the obtained SiC and the leaching factors were optimized. The mixed acids of HF/H2SO4 works efficiently on the removal of Fe and SiO2 due to that HF can react with SiO2 and Si and then expose the Fe to H+. The assistance of ultrasound can greatly improve the leaching of Fe, accelerate the leaching rate, and lower the leaching temperature. The optimal leaching conditions are HF-H2SO4 ratio of 1:3, acid concentration of 3 mol/L, temperature of 50 °C, ultrasonic frequency of 45 kHz and power of 210 W, and stirring speed of 300 rpm. The optimal leaching ratio of Fe is 99.38%. Kinetic analysis shows that the leaching process fits the chemical reaction-controlled model.

Electrochemically produced nano-TiO2-coated SiC membranes for photocatalytic water treatment: Preparation, characterization, and hydroxyl radical formation.

Photocatalytically active ceramic flat sheet membranes based on a nanostructured titanium dioxide (TiO2) coating were produced for photocatalytic water treatment. The nano-TiO2 layer was produced by a novel combination of magnetron sputtering of a thin titanium layer on silicon carbide (SiC) membranes, followed by electrochemical oxidation (anodization) and subsequent heat treatment (HT). Characterization by Raman spectra and field emission scanning electron microscopy proved the presence of a nanostructured anatase layer on the membranes. The influence of the titanium layer thickness on the TiO2 formation process and the photocatalytic properties were investigated using anodization curves, by using cyclovoltammetry measurements, and by quantifying the generated hydroxyl radicals (OH•) under UV-A irradiation in water. Promising photocatalytic activity and permeability of the nano-TiO2-coated membranes could be demonstrated. A titanium layer of at least 2 µm was necessary for significant photocatalytic effects. The membrane sample with a 10 µm Ti/TiO2 layer had the highest photocatalytic activity showing a formation rate of 1.26 × 10-6 mmol OH• s-1. Furthermore, the membranes were tested several times, and a decrease in radical formation was observed. Assuming that these can be attributed to adsorption processes of the reactants, initial experiments were carried out to reactivate the photocatalyzer.

Acid modified attapulgite loaded with bacillomycin D for mold inhibition and mycotoxin removal.

Molds and mycotoxins pose severe threats to health. Bacillomycin D (BD) can effectively inhibit mold growth. Attapulgite (ATP) can provide a good carrier for antimicrobial agents. Natural ATP was acid-modified to obtain H-ATP. It was used to load BD to obtain a novel composite material (H-ATP-BD). The results showed H-ATP had better adsorption performance than ATP. BD was adsorbed up to 93.13 % by adding 30 mg H-ATP and stirring at 40 ℃ for 120 min. Fourier transform infrared spectra (FTIR), size and zeta potential, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results confirmed successful loading of BD onto H-ATP. The composite showed good inhibition of Aspergillus and adding 0.6 % H-ATP-BD composite was effective in removing 89.06 % of aflatoxin B1 (AFB1) at 50 °C. Model fitting indicated that AFB1 removal was a spontaneous exothermic reaction. This research will lay the foundation for the development of efficient and green antimicrobial and toxin-reducing materials.

Quaternized chitosan/polyvinyl alcohol anion exchange membrane enhanced by functionalized attapulgite clay with an ionic "chain-ball" surface structure.

Biomass chitosan has garnered considerable interest for alkaline anion exchange membranes (AEMs) due to its eco-friendly and sustainable characteristics, low reactant permeability and easily modifiable nature, but it still faces the trade-off between high hydroxide conductivity and sufficient mechanical properties. Herein, a novel functionalized attapulgite clay (f-ATP) with a unique ionic "chain-ball" surface structure was prepared and incorporated with quaternized chitosan (QCS)/polyvinyl alcohol (PVA) matrix to fabricate high-performance composite AEMs. Due to the strengthened interfacial bonding between f-ATP nanofillers and the QCS/PVA matrix, composite membranes are synergistically reinforced and toughened, achieving peak tensile strength and elongation at break of 24.62 MPa and 33.8 %. Meanwhile, abundant ion pairs on f-ATP surface facilitate ion transport in the composite AEMs, with the maximum OH- conductivity of 46 mS cm-1 at 80 °C and the highest residual IEC of 83 % after alkaline treatment for 120 h. Moreover, the assembled alkaline direct methanol fuel cell exhibits a remarkable power density of 49.3 mW cm-2 at 80 °C. This work provides a new strategy for fabricating high-performance anion exchange membranes.

Mercapto-functionalized palygorskite modified the growth of Ligusticum Chuanxiong and restrained the Cd migration in the soil-plant system.

Ligusticum Chuanxiong is an essential medicinal and edible plant, but it is highly susceptible to the enrichment of soil Cadmium (Cd), which seriously affects its medical safety. However, the control of Cd uptake by Ligusticum Chuanxiong is little reported. In this study, we reported that a green Mercapto-functionalized palygorskite (MPAL) effectively promoted Ligusticum Chuanxiong growth, and restrained the Cd uptake by Ligusticum Chuanxiong both in the mildly contaminated soil (M-Soil) and severely contaminated soil (S-Soil). The experimental results demonstrated that the application of MPAL significantly increased the biomass and antioxidant enzyme activity of Ligusticum Chuanxiong. In the M-Soil, the Cd content in the roots, stems, and leaves of Ligusticum Chuanxiong decreased markedly by 82.46-86.66%, 64.17-71.73%, and 64.94-76.66%, respectively, after the MPAL treatment. In the S-Soil, MPAL application decreased the Cd content in roots, stems, and leaves by 89.43-98.92%, 24.19-86.22%, and 67.14-77.90%, respectively. Based on Diethylenetriamine Pentaacetic Acid (DTPA) extraction, the immobilization efficiency of MPAL for Cd in soils ranged from 22.01% to 77.04%. Additionally, the HOAc extractable Cd was transformed into reducible and oxidizable fractions. Furthermore, MPAL enhanced the activities of soil alkaline phosphatase, and urease, but decreased sucrase activity. Environmental toxicological analysis indicated that MPAL reduced the potential ecological risk of Cd in the soil. These findings revealed that MPAL can effectively reduce Cd accumulation in Ligusticum Chuanxiong and promote plant growth, suggesting its potential as a viable amendment for remediating Cd-contaminated soils.

Effect of layer thickness and polishing on wear resistance of additively manufactured occlusal splints.

OBJECTIVE: To evaluate the effect of polishing and layering thickness on the wear resistance of 3D-printed occlusal splint materials. METHODS: Specimens with 3 different layer thicknesses (50, 75, 100 µm) were produced in the form of a disc 3 mm thick using V-Print splint resin on a 3D-printer with digital light processing technology. (n = 16 for each thickness) All specimens were washed and cured according to the manufacturer's instructions. Half of the specimens of each layer thickness were polished with silicon carbide papers. All specimens were subjected to 120.000 cycles of a chewing simulator for 2-body wear tests. Before and after the wear test, the specimens were scanned with a laser scanner, and the images were overlaid using a 3D analysis program and the volume loss was calculated. The wear patterns of the specimens were examined under a scanning electron microscope. Statistical evaluation was performed using a Shapiro-Wilk test, 2-way ANOVA, 1-way ANOVA, and Tukey post hoc test (α = 0.05). RESULTS: While polishing had a significant effect (p = 0.003) on the wear volume of the occlusal splints, layer thickness (p = 0.105) and their interaction between polishing and layer thickness (p = 0.620) did not significantly affect the wear volume. Regardless of the polishing, the lowest mean wear was observed for D50 (0.064 mm3), followed by D75 (0.078 mm3), and D100 (0.096 mm3). However, a significant difference was observed only between polished D50 and unpolished D100. CONCLUSION: The polished 3D-printed occlusal splint resin showed higher wear resistance than the unpolished one, regardless of the layer thickness. CLINICAL SIGNIFICANCE: Since different layer thicknesses of 50 µm and greater had no effect on the wear resistance of the material, a layer thickness of 100 µm may be preferred for faster printing. However, polishing occlusal splints may reduce the amount of wear and improve clinical performance.

Pesticide loaded nanohydrogel based on attapulgite and gelatin with improved foliar adhesion.

BACKGROUNDS: Pesticides have been widely applied to promote plant growth due to their high insecticidal efficiency. However, most pesticides easily slip from the leaf surface due to the low foliar adhesion, leading to significant damage to the environment and human health. Increasing foliar adhesion of pesticides has been a major challenge. Nanomaterial technology, which can deliver pesticide active ingredients, offers a new opportunity to increase pesticides efficacy with higher foliar adhesion. RESULTS: In this study, we prepared the pesticide loaded nanohydrogel ALP@Ge-g-P(AA-co-AM)/ATP by grafting attapulgite and gelatin onto P(AA-co-AM), and loading the pesticide alphacypermethrin synchronously via the emulsion solvent evaporation method. The size of the new nanohydrogel was 20.5 nm and the pesticide loading capacity was 21.5%. Compared to P(AA-co-AM), the water absorbency of Ge-g-P(AA-co-AM)/ATP increased by 54.3% in 120 min, while the water retention increased from 4.27% to 38.7% after 48 h. Washout experiments and contact angle results suggested that the nanohydrogel, with a contact angle of 44.8° indicating good wettability, can resist rain flush and increase foliar adhesion naturally. CONCLUSIONS: Overall, the preparation of pesticide loaded nanohydrogel is simple. Experiments demonstrated the pesticide loaded nanohydrogel has high efficiency and strong foliar adhesion. This makes it a promising candidate for spraying application and reducing pollution levels. © 2024 Society of Chemical Industry.

Selective biosorption of Li+ in aqueous solution by lithium ion-imprinted material on the surface of chitosan/attapulgite.

The extraction of Li+ from liquid lithium resources is a pivotal focus of current research endeavors. Attapulgite (ATP), characterized by its distinctive layered structure and inherent ion exchange properties, emerges as an exceptional material for fabricating lithium-ion sieve. Ion-imprinted chitosan/ATP composite materials are successfully synthesized, demonstrating efficacy in selectively absorbing Li+. The results emphasize the rich functional groups present in H-CTP-2, enhancing its absorbability and selectivity, with an adsorption capacity of 37.56 mg•g-1. The adsorption conforms to the Langmuir and pseudo-second-order kinetic model. Li+ coordination involves amino and hydroxyl group, indicating a chemisorption process. Furthermore, the substantial pore structure and significant specific surface area of ATP significantly promote Li+ adsorption, suggesting its participation not only in chemisorption but also in physical adsorption. The fabricated ion-imprinted materials boast substantial adsorption capacity, exceptional selectivity, and rapid kinetics, highlighting their potential for effectively separating Li+ from aqueous solution.

Enhanced efficiencies on purifying acid mine drainage in constructed wetlands based on synergistic adsorption of attapulgite-soda residue composites and microbial sulfate reduction.

Constructed wetlands (CWs) are a promising approach for treating acid mine drainage (AMD). However, the extreme acidity and high loads of heavy metals in AMD can easily lead to the collapse of CWs without proper pre-treatment. Therefore, it is considered essential to maintain efficient and stable performance for AMD treatment in CWs. In this study, pre-prepared attapulgite-soda residue (ASR) composites were used to improve the substrate of CWs. Compared with CWs filled with gravel (CWs-G), the removal efficiencies of sulfate and Fe, Mn, Cu, Zn Cd and Pb in CWs filled with ASR composites (CWs-ASR) were increased by 30% and 10-70%, respectively. These metals were mainly retained in the substrate in stable forms, such as carbonate-, Fe/Mn (oxide)hydroxide-, and sulfide-bound forms. Additionally, higher levels of photosynthetic pigments and antioxidant enzyme activities in plants, along with a richer microbial community, were observed in CWs-ASR than in CWs-G. The application of ASR composites alleviated the adverse effects of AMD stresses on wetland plants and microorganisms. In return, the increased bacteria abundance, particularly SRB genera (e.g., Thermodesulfovibrionia and Desulfobacca), promoted the formation of metal sulfides, enabling the saturated ASR adsorbed with metals to regenerate and continuously capture heavy metals. The synergistic adsorption of ASR composites and microbial sulfate reduction maintained the stable and efficient operation of CWs. This study contributes to the resource utilization of industrial alkaline by-products and promotes the breakthrough of new techniques for low-cost and passive treatment systems such as CWs.

Planar amorphous silicon carbide microelectrode arrays for chronic recording in rat motor cortex.

Chronic implantation of intracortical microelectrode arrays (MEAs) capable of recording from individual neurons can be used for the development of brain-machine interfaces. However, these devices show reduced recording capabilities under chronic conditions due, at least in part, to the brain's foreign body response (FBR). This creates a need for MEAs that can minimize the FBR to possibly enable long-term recording. A potential approach to reduce the FBR is the use of MEAs with reduced cross-sectional geometries. Here, we fabricated 4-shank amorphous silicon carbide (a-SiC) MEAs and implanted them into the motor cortex of seven female Sprague-Dawley rats. Each a-SiC MEA shank was 8 µm thick by 20 µm wide and had sixteen sputtered iridium oxide film (SIROF) electrodes (4 per shank). A-SiC was chosen as the fabrication base for its high chemical stability, good electrical insulation properties, and amenability to thin film fabrication. Electrochemical analysis and neural recordings were performed weekly for 4 months. MEAs were characterized pre-implantation in buffered saline and in vivo using electrochemical impedance spectroscopy and cyclic voltammetry at 50 mV/s and 50,000 mV/s. Neural recordings were analyzed for single unit activity. At the end of the study, animals were sacrificed for immunohistochemical analysis. We observed statistically significant, but small, increases in 1 and 30 kHz impedance values and 50,000 mV/s charge storage capacity over the 16-week implantation period. Slow sweep 50 mV/s CV and 1 Hz impedance did not significantly change over time. Impedance values increased from 11.6 MΩ to 13.5 MΩ at 1 Hz, 1.2 MΩ-2.9 MΩ at 1 kHz, and 0.11 MΩ-0.13 MΩ at 30 kHz over 16 weeks. The median charge storage capacity of the implanted electrodes at 50 mV/s was 58.1 mC/cm2 on week 1 and 55.9 mC/cm2 on week 16, and at 50,000 mV/s, 4.27 mC/cm2 on week 1 and 5.93 mC/cm2 on week 16. Devices were able to record neural activity from 92% of all active channels at the beginning of the study, At the study endpoint, a-SiC devices were still recording single-unit activity on 51% of electrochemically active electrode channels. In addition, we observed that the signal-to-noise ratio experienced a small decline of -0.19 per week. We also classified observed units as fast and slow repolarizing based on the trough-to-peak time. Although the overall presence of single units declined, fast and slow repolarizing units declined at a similar rate. At recording electrode depth, immunohistochemistry showed minimal tissue response to the a-SiC devices, as indicated by statistically insignificant differences in activated glial cell response between implanted brains slices and contralateral sham slices at 150 µm away from the implant location, as evidenced by GFAP staining. NeuN staining revealed the presence of neuronal cell bodies close to the implantation site, again statistically not different from a contralateral sham slice. These results warrant further investigation of a-SiC MEAs for future long-term implantation neural recording studies.

Insight into hemostatic performance and mechanism of natural mixed-dimensional Attapulgite clay.

Clay minerals have attracted wide attention as biomedical materials due to the unique crystal structure, abundant morphology and good biocompatibility. However, the relevant studies on the abundant natural mixed clay deposits were scarcely reported. Herein, the hemostatic performance of natural mixed-dimensional attapulgite clay (MDAPT) composed of one-dimensional attapulgite and multiple two-dimensional clay were systematically investigated based on the structural evolution using oxalic acid for different time. The results of hemostatic evaluation showed that MDAPT leached by oxalic acid with 1 h presented the shortest clotting time (134 ± 12.17 s), a 15.09 % and 41.74 % reduction of relative hemoglobin absorbance at 180 s and 120 s when compared with the control group, respectively, and an increase of 19.45 % of the blood clotting index in vitro, as well as MDAPT obtained the shortest bleeding time (158.5 ± 6.9 s), nearly 66 % and 31 % reduction blood loss as compared to the blank group and the YNBY group in vivo. This improvement was primarily ascribed to the synergistic effect of lamellar non-expandable illite, and nano rod-like attapulgite. Furthermore, the rapid hemostasis of MDAPT was also due to the joint effect of superhydrophobic property toward blood, minimizing blood loss, surface negative charge, metal ions from MDAPT structural skeleton, promoting an average increase of 21 % for platelet activation. The results suggested that MDAPT could be served as a promising efficient inorganic hemostatic materials, which provided a feasible strategy to realize the high-valued utilization of natural mixed clay resources.

Innovative treatment of industrial effluents through combining ferric iron and attapulgite application.

The escalation of industrial activities has escalated the production of pharmaceutical and dyeing effluents, raising significant environmental issues. In this investigation, a hybrid approach of Fenton-like reactions and adsorption was used for deep treatment of these effluents, focusing on effects of variables like hydrogen peroxide concentration, catalyst type, pH, reaction duration, temperature, and adsorbent quantity on treatment effectiveness, and the efficacy of acid-modified attapulgite (AMATP) and ferric iron (Fe(III))-loaded AMATP (Fe(III)-AMATP) was examined. Optimal operational conditions were determined, and the possibility of reusing the catalysts was explored. Employing Fe3O4 as a heterogeneous catalyst and AMATP for adsorption, CODCr was reduced by 78.38-79.14%, total nitrogen by 71.53-77.43%, and phosphorus by 97.74-98.10% in pharmaceutical effluents. Similarly, for dyeing effluents, Fe(III)-AMATP achieved 79.87-80.94% CODCr, 68.59-70.93% total nitrogen, and 79.31-83.33% phosphorus reduction. Regeneration experiments revealed that Fe3O4 maintained 59.48% efficiency over three cycles, and Fe(III)-AMATP maintained 62.47% efficiency over four cycles. This work offers an economical, hybrid approach for effective pharmaceutical and dyeing effluent treatment, with broad application potential.

Rapidly reducing cadmium from contaminated farmland soil by novel magnetic recyclable Fe3O4/mercapto-functionalized attapulgite beads.

Reducing cadmium (Cd) content from contaminated farmland soils remains a major challenge due to the difficulty in separating commonly used adsorbents from soils. This study synthesized novel millimeter-sized magnetic Fe3O4/mercapto-functionalized attapulgite beads (MFBs) through a facile one-step gelation process incorporating alginate. The MFBs inherit the environmental stability of alginate and enhance its mechanical strength by hybridizing Fe3O4 and clay mineral components. MFBs can be easily separated from flooded soils by magnets. When applied to 12 Cd-polluted paddy soils and 14 Cd-polluted upland soils, MFBs achieved Cd(II) removal rates ranging from 16.9% to 62.2% and 9.8%-54.6%, respectively, within a 12-h period. The MFBs predominantly targeted the exchangeable and acid soluble, and reducible fractions of Cd, with significantly enhanced removal efficiencies in paddy soils compared to upland soils. Notably, MFBs exhibited superior adsorption performance in soils with lower pH and organic matter (OM) content, where the bioavailability and mobility of Cd are heightened. The reduction of Cd content by MFBs is a sustainable and safe method, as it permanently removes the bioavailable Cd from soil, rather than temporarily reducing its bioavailability. The functional groups such as -SH, -OH, present in attapulgite and alginate of MFBs, played a crucial role in Cd(II) adsorption. Additionally, attapulgite and zeolite provided a porous matrix structure that further enhanced Cd(II) adsorption. The results of X-ray photoelectron spectroscopy suggested that both chemical precipitation and surface complexation contributed to Cd(II) removal. The MFBs maintained 87.6% Cd removal efficiency after 5 regeneration cycles. The surface of the MFBs exposed new adsorption sites and increased the specific surface area during multiple cycles with Cd-contaminated soil. This suggests that MFBs treatment with magnetic retrieval is a potentially effective pathway for the rapid removal of Cd from contaminated farmland soils.