Treatment of phenolic wastewater in an anaerobic fluidized bed microbial fuel cell filled with graphene oxide-macroporous adsorption resin as multifunctional carrier.

A novel graphene oxide-modified resin (graphene oxide-macroporous adsorption resin) was prepared and used as a multifunctional carrier in an anaerobic fluidized bed microbial fuel cell (AFB-MFC) to treat phenolic wastewater (PW). The macroporous adsorption resin (MAR) was used as the carrier, graphene oxide was used as the modified material, the conductive modified resin was prepared by loading graphene oxide (GO) on the resin through chemical reduction. The modified resin particles were characterized by scanning electron microscopy (SEM), Raman spectroscopy (RS), specific surface area and pore structure analysis. Graphene oxide-macroporous adsorption resin special model was established using the Amorphous Cell module in Materials Studio (MS), and the formation mechanism of graphene oxide-macroporous adsorption resin was studied using mean square displacement (MSD) of the force module. Molecular dynamics simulation was used to study the motion law of molecular and atomic dynamics at the interface of graphene oxide-macroporous adsorption resin composites. The strong covalent bond between GO and MAR ensures the stability of GO/MAR. When the modified resin prepared in 3.0 mg/mL GO mixture was used in the AFB-MFC, the COD removal of wastewater was increased by 9.1% to 72.44%, the voltage was increased by 84.04% to 405.8 mV, and power density was increased by 765.44% to 242.67 mW/m2.

Immobilization of ferrocene and its derivatives within metal-organic frameworks with high loadings toward efficient oxygen evolution reaction.

The use of an appropriate preparation route is the key to immobilize active molecules into a host matrix with high loadings and stability. Herein, we demonstrate a simple and general strategy to immobilize ferrocene and its derivatives into ZIF-8 with high loadings of up to 4.3% Fe content. The unique host pore structure allows for the stabilization of guest molecules and effectively prevents their leaching. As a result, the obtained electrocatalysts exhibit competitive oxygen evolution reaction (OER) catalytic performance. Optimized Fc-CHO/ZIF-8 requires only a low overpotential of 238 mV to achieve 10 mA cm-2, along with a relatively small Tafel slope of 44.4 mV dec-1. This performance is superior to that of commercial IrO2, suggesting its potential application in electrochemical energy conversion.

Treatment of phenolic wastewater by anaerobic fluidized bed microbial fuel cell using carbon brush as anode: microbial community analysis and m-cresol degradation mechanism.

Anaerobic fluidized bed microbial fuel cell (AFB-MFC) is a technology that combines fluidized bed reactor and microbial fuel cell to treat organic wastewater and generate electricity. The performance and the mechanism of treating m-cresol wastewater in AFB-MFC using carbon brush as biofilm anode were studied. After 48 h of operation, the m-cresol removal efficiency of AFB-MFC, MAR-AFB (fluidized bed bioreactor with acclimated anaerobic sludge), MAR-FB (ordinary fluidized bed reactor with only macroporous adsorptive resin) and AST (traditional anaerobic sludge treatment) were 95.29 ± 0.67%, 85.78 ± 1.81%, 71.24 ± 1.86% and 70.41 ± 0.32% respectively. The maximum output voltage and the maximum power density of AFB-MFC using carbon brush as biofilm anode were 679.7 mV and 166.6 mW/m2 respectively. The results of high-throughput sequencing analysis indicated the relative abundance of dominant electroactive bacteria, such as Trichococcus, Geobacter, and Pseudomonas, on the anode carbon brushes was higher than that of AST, and also identified such superior m-cresol-degrading bacteria as Bdellovibrio, Thermomonas, Hydrogenophaga, etc. Based on the determination of m-cresol metabolites detected by Gas Chromatography-Mass Spectrometry (GC-MS), the possible biodegradation pathway of m-cresol under anaerobic and aerobic conditions in AFB-MFC was speculated. The results showed that m-cresol was decomposed into formic acid-acetic anhydride and 3-methylpropionic acid under the action of electrochemistry, which is a simple degradation pathway without peripheral metabolism in AFB-MFC.

Circ_0001825 promotes osteogenic differentiation in human-derived mesenchymal stem cells via miR-1270/SMAD5 axis.

BACKGROUND: The implication of deregulated circular RNAs in osteoporosis (OP) has gradually been proposed. Herein, we aimed to study the function and mechanism of circ_0001825 in OP using osteogenic-induced human-derived mesenchymal stem cells (hMSCs). METHODS: The content of genes and proteins was tested by quantitative real-time polymerase chain reaction and Western blotting. The osteogenic differentiation in hMSCs were evaluated by ALP activity and Alizarin Red staining, as well as the detection of osteogenesis-related markers. Cell viability and apoptosis were measured by CCK-8 assay and flow cytometry. The binding between miR-1270 and circ_0001825 or SMAD5 (SMAD Family Member 5) was confirmed by using dual-luciferase reporter assay and pull-down assay. RESULTS: Circ_0001825 was lowly expressed in OP patients and osteogenic induced hMSCs. Knockdown of circ_0001825 suppressed hMSC viability and osteogenic differentiation, while circ_0001825 overexpression showed the exact opposite effects. Mechanistically, circ_0001825/miR-1270/SMAD5 formed a feedback loop. MiR-1270 was increased and SMAD5 was decreased in OP patients and osteogenic induced hMSCs. MiR-1270 up-regulation suppressed hMSC viability and osteogenic differentiation, which was reversed by SMAD5 overexpression. Moreover, miR-1270 deficiency abolished the effects of circ_0001825 knockdown on hMSCs. CONCLUSION: Circ_0001825 promoted hMSC viability and osteogenic differentiation via miR-1270/SMAD5 axis, suggesting the potential involvement of circ_0001825 in osteoporosis.

The degree of fracture reduction does not compromise the clinical efficacy of arthroscopic reduction and fixation of tibial posterior cruciate ligament avulsion fractures: A retrospective study.

This study aimed to explore the postoperative outcomes of patients who underwent arthroscopic internal fixation with repositioning sutures for the treatment of posterior cruciate ligament (PCL) avulsion fractures with poorly reduced fracture fragments. It was hypothesized that improperly repositioned fracture fragments might not influence the postoperative clinical outcomes in patients with PCL avulsion fractures treated by arthroscopic sutures. From January 2020 to December 2021, patients admitted to our hospital with PCL avulsion fractures were evaluated. Our inclusion criteria were as follows: diagnosis of PCL avulsion fracture as Meyers & McKeever Type II or Type III; underwent arthroscopic double tunnel suture fixation; and age below 70. Of the patients meeting these criteria, data from 34 individuals were collected by a designated follow-up officer. Based on postoperative imaging, the patients were divided into 2 groups: well fracture reduction and poor fracture reduction groups. Prior to the surgery, the Lysholm score, knee mobility, and international knee documentation committee (IKDC score) were recorded for both groups. At the 3-month post-surgery mark, CT-3D reconstruction was performed. Statistical analysis was conducted on the collected data. For data that conformed to a normal distribution, the t test was applied. For data that didn't conform, we used a non-parametric test. Both groups achieved successful wound healing without encountering any adverse events, such as fracture nonunion infection. Fracture healing was observed in both groups at the 3-month postoperative mark. The average follow-up duration was 13.24 ± 6.18 months. There were no significant differences in Lysholm score, IKDC score, or knee mobility between the well- and poorly-reduced groups at the final follow-up (P > .05). Postoperatively, both groups demonstrated significant improvements in knee function compared to the preoperative scores, with statistically significant differences observed in Lysholm score, IKDC score, and knee mobility (P < .05). Arthroscopic fixation with double-tunnel sutures proved to be a highly effective treatment approach for PCL avulsion fractures, even in cases where the fractures were poorly reduced. Remarkably, there were no significant differences observed in postoperative knee function between the well- and poorly-reduced groups, indicating that both groups achieved favorable outcomes.

Optimization method and experimental research on attitude adjustment scheme of attitude adaptive rescue robot.

To improve the space attitude adjustment efficiency of the robot designed in this study, the average water level height variation of each ballast tank during the rescue process and the ballast water filling mass before the rescue process are taken as optimization variables, the minimal ballasting time during rescue process as the optimisation objective, and the heel and trim inclination angle, and stability in the rescue process as the constraint conditions. For the first time, an optimization method of a rescue robot space attitude adjustment scheme based on a dynamic programming algorithm is proposed. Relevant experiments and data collection were carried out with a model robot with a physical ratio of 1:2. MATLAB simulation and model robot experimental results show that compared with an empirical scheme, the total deployment time and ballast water total allocation mass are reduced by 11.07% and 30.79%, respectively, and the heel and trim angle variation stability is increased by 4.18% and 8.67%, respectively. The optimization model and algorithm are beneficial to improve the space attitude adjustment efficiency and stability of the rescue robot in this paper, and it is also easier to transfer to other fields of ballast water allocation, which has strong practical engineering significance.

More reactive oxygen species generation facilitated by highly dispersed bimodal gold nanoparticle on the surface of Bi2WO6 for enhanced photocatalytic degradation of ofloxacin in water.

An essential strategy to eliminate emerging contamination in water is to initiate more reactive oxygen species (ROS) in the catalytic systems. 0.14 wt.% Au loaded Bi2WO6 (Bi2WO6/Au-400 °C) was fabricated after 400 °C annealing with the assistance of glutathione for Au atom anchoring and stabilization on Bi2WO6 surface. Bimodal Au size distribution of highly dispersed small size clusters (0.5 ± 0.1 nm) and large size nanoparticles (6.3 ± 1.0 nm) simultaneously existed on Bi2WO6 nanosheets in Bi2WO6/Au-400 °C, which were verified through high resolution transmission electron microscopy (HR-TEM). 95% of ofloxacin (OFX) was degraded over Bi2WO6/Au-400 °C in 180 min under visible light irradiation with a reaction constant of 24.5 × 10-3 min-1, which showed 3.0 and 2.5-fold enhancement compared with bare Bi2WO6 and unimodal Bi2WO6/Au-500 °C (annealed at 500 °C, Au NPs (8.6 ± 1.0 nm)), respectively. The enhanced catalytic activity originated from the additional ROS production that initiated by photo-induced electron transported from small Au clusters to large Au NPs through the conduction band of Bi2WO6. Moreover, it still maintained a good stability after five cycling performance and the total cost of 10 g Bi2WO6/Au-400 °C was estimated to be 6.78 $. Lower-content of bimodal Au NPs decorated Bi2WO6 catalyst possesses high efficiency to degrade pollutant and lower cost, which provides a promising alternative in practical environmental remediation by photocatalysis.

Fe3O4@S-doped ZnO: A magnetic, recoverable, and reusable Fenton-like catalyst for efficient degradation of ofloxacin under alkaline conditions.

In this study, an efficient and reusable heterogeneous Fenton catalyst Fe3O4@S-doped ZnO magnetic composite was synthesized for the degradation of ofloxacin (OFX) under alkaline conditions without external energy input. The Fe3O4@S-doped ZnO exhibited excellent catalytic activity toward ofloxacin degradation within 120 min. Using 0.25 g/L of catalyst and 5.0 mL/L of H2O2 under optimized conditions, the catalyst was effective in pH values ranging from 5.2 to 9.0. The catalytic performance at optimal conditions was in accordance with a pseudo-first-order kinetics model. The reaction constant of Fe3O4@S-doped ZnO (0.0354 min-1) was three times than that of Fe3O4@ZnO (0.0124 min-1) under alkaline conditions (pH 8.2). The reactive oxygen species were the ·OH and O2·-, with ·OH dominating in the degradation of OFX. It is proposed that the catalyst acts as a Lewis acid, creating an acidic microenvironment on the catalyst's surface and widening the pH range of the Fenton reaction to alkaline conditions. Additionally, the catalyst was stable and reusable after six cycles of use. The Fenton-like Fe3O4@S-doped ZnO catalyst overcomes the problem of the narrow pH of the reaction system, thus providing promising environmental applications.

Efficient fenton-like degradation of ofloxacin over bimetallic Fe-Cu@Sepiolite composite.

An effective method for increasing the utilization efficiency of active components in heterogeneous Fenton-like catalysts was provided. 1.5 at.% Fe-Cu bimetal on 1D sepiolite (Sep) (D-FeCu@Sep) with high dispersion and reduced chemical valence was prepared via complexation-carbonization process of glutathione. 93% of ofloxacin (OFX, a typical antibiotic of emerging concern) was degraded over D-FeCu@Sep without any extra energy input at the optimum conditions (100 mL 10 mg/L OFX, pH 5.0, 3.0 g/L catalyst and 0.03 M H2O2), which was enhanced by 2.3, 3.0 and 1.7 times compared with aggregated Fe-Cu on Sep (A-FeCu@Sep), monometallic Fe on Sep (D-Fe@Sep) and Fe-Cu on blocky Celite (D-FeCu@Celite), respectively. Moreover, it exhibited an excellent performance at a wide working pH range from acidic to neutral conditions (pH 3.2-7.2) with a satisfied stability. Based on the characterizations of X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy (TEM), hydrogen temperature-programmed reduction (H2-TPR) and electrochemical impedance spectroscopy (EIS), the proposed complexation-carbonization process of glutathione played an important role in the good Fenton performance of D-FeCu@Sep. The complexation of Fe and Cu ion by glutathione favors the high dispersion of Fe-Cu active component, afterward the reduced chemical valence results from carbonization process of glutathione. Moreover, the 1D nanofibrous structure of D-FeCu@Sep could greatly increase the surface electron transfer efficiency compared with D-FeCu@Celite. This study provides a method alternative to the heterogeneous Fenton chemistry by increasing the utilization efficiency of active components.

Novel Colorimetric Method for Simultaneous Detection and Identification of Multimetal Ions in Water: Sensitivity, Selectivity, and Recognition Mechanism.

Accurate recognition and speciation analysis of heavy-metal ions in complex hydrological environments is always a serious challenge. In this work, we proposed a small-molecule-based ultrasensitive colorimetric detection strategy and successfully applied it to the accurate detection of Fe2+, Fe3+, Co2+, and Hg2+ in groundwater through the specific recognition of multiple ligands of different metal ions. The detection limits for Hg2+, Co2+, Fe2+, and Fe3+ are calculated to be 6.51, 0.34, 0.49, and 1.01 ppb, respectively, which are far below the drinking water standards and superior to most of the reported colorimetric sensors. Remarkably, the speciation analysis of Fe2+/Fe3+ also has been successfully realized by a one-step method without complex pretreatment. The speciation and concentration of Fe2+ and Fe3+ in actual water samples can be accurately identified and monitored. In addition, as an attempt of visual onsite detection, we have developed a simple test strip, which has been applied to visual monitoring of four metal ions with the detection limit estimated by the naked eye to be as low as ppb level. This proposed colorimetric method realizes the rapid, sensitive, and portable multiple metal ions recognition and Fe2+/Fe3+ speciation analysis, displaying great potential for onsite rapid water quality analysis.

Oxygen Vacancy Promoted Heterogeneous Fenton-like Degradation of Ofloxacin at pH 3.2-9.0 by Cu Substituted Magnetic Fe3O4@FeOOH Nanocomposite.

To develop an ultraefficient and reusable heterogeneous Fenton-like catalyst at a wide working pH range is a great challenge for its application in practical water treatment. We report an oxygen vacancy promoted heterogeneous Fenton-like reaction mechanism and an unprecedented ofloxacin (OFX) degradation efficiency of Cu doped Fe3O4@FeOOH magnetic nanocomposite. Without the aid of external energy, OFX was always completely removed within 30 min at pH 3.2-9.0. Compared with Fe3O4@FeOOH, the pseudo-first-order reaction constant was enhanced by 10 times due to Cu substitution (9.04/h vs 0.94/h). Based on the X-ray photoelectron spectroscopy (XPS), Raman analysis, and the investigation of H2O2 decomposition, •OH generation, pH effect on OFX removal and H2O2 utilization efficiency, the new formed oxygen vacancy from in situ Fe substitution by Cu rather than promoted Fe3+/Fe2+ cycle was responsible for the ultraefficiency of Cu doped Fe3O4@FeOOH at neutral and even alkaline pHs. Moreover, the catalyst had an excellent long-term stability and could be easily recovered by magnetic separation, which would not cause secondary pollution to treated water.

A novel singlet oxygen involved peroxymonosulfate activation mechanism for degradation of ofloxacin and phenol in water.

This study proposed a new and previously unconsidered reaction mechanism in the activation of peroxymonosulfate. We report that singlet oxygen (1O2) rather than ˙OH or SO4˙- was the dominant reactive oxygen species towards the efficient degradation of ofloxacin and phenol, demonstrating a promising application in real wastewater treatment.

Facile synthesis of hierarchical dendrite-like structure iron layered double hydroxide nanohybrids for effective arsenic removal.

The highly dispersed iron layered double hydroxide (Fe-LDH) nanoplates supported on sepiolite (SEP) nanofibers have been successfully prepared via in situ co-precipitation of an iron salt precursor. The as-obtained hierarchical dendrite-like Fe-LDH/SEPs possess high specific area, and exhibit excellent removal ability for arsenic, demonstrating promising potential in environment applications.

A ratiometric fluorescence nanosensor for highly selective and sensitive detection of selenite.

The instant and on-site detection of selenium still remains a challenge for environmental monitoring and medical prevention. We herein developed a ratiometric fluorescent nanosensor for accurate and on-site sensing of SeO3(2-) by linking the recognition molecule 3,3'-diaminobenzidine (DAB) onto the surface of carboxyl group modified CdTe@SiO2. The fluorescence of DAB on the surface of silica nanospheres could be selectively and efficiently enhanced by SeO3(2-) through a surface chelating reaction between DAB and SeO3(2-). Thus, in the presence of SeO3(2-), the nanosensor would show two characteristic fluorescence emissions of Se-DAB and CdTe QDs under a single excitation wavelength. The selectivity and the optimal conditions for the detection of SeO3(2-) were carefully investigated. The ratio of F530/F635 linearly increased with increasing SeO3(2-) concentration in the range of 0 to 2.5 µM and the detection limit reaches as low as 6.68 nM (0.53 ppb). This developed nanosensor has the capability of on-site detection in an aqueous system without any separation step. The Se concentrations in selenium-rich food were detected and the results were consistent with the values determined by ICP-AES.

Carbon doped molybdenum disulfide nanosheets stabilized on graphene for the hydrogen evolution reaction with high electrocatalytic ability.

Fabricating a cost effective hydrogen evolution reaction catalyst without using precious metal elements is in crucial demand for environmentally-benign energy production. In this work, the thin and edge-rich molybdenum disulfide nanosheets, with carbon doped in the interlayers and decorated on graphene, were developed by a facile solvothermal process. The as-synthesized nanohybrids exhibited high catalytic ability for the hydrogen evolution electrochemical reaction with an onset overpotential of 0.165 mV and a Tafel slope of 46 mV dec(-1). Furthermore, the prepared nanohybrids also showed better durability and stability. Our work may lead to a potential method for in situ production of metal carbide-sulphur hybrid nanomaterials with promising applications for the hydrogen evolution reaction.

Novel MoSe2 hierarchical microspheres for applications in visible-light-driven advanced oxidation processes.

Advanced oxidation processes as a green technology have been adopted by combining the semiconductor catalyst MoSe2 with H2O2 under visible radiation. And novel three-dimensional self-assembled molybdenum diselenide (MoSe2) hierarchical microspheres from nanosheets were produced by using organic, selenium cyanoacetic acid sodium (NCSeCH2COONa) as the source of Se. The obtained products possess good crystallinity and present hierarchical structures with the average diameter of 1 µm. The band gap of MoSe2 microspheres is 1.68 eV and they present excellent photocatalytic activity under visible light irradiation in the MoSe2-H2O2 system. This effective photocatalytic mechanism was investigated in this study and can be attributed to visible-light-driven advanced oxidation processes.