The Interaction between Iron Cyanide and Lead Ions in Pyrite Flotation.

Despite being a major cyanide species in the process water, it is unclear how iron cyanide influences pyritic gold ore flotation as well as how lead ions influence pyritic gold ore flotation in the presence of iron cyanide. This study aims at revealing the interaction of Fe(CN)63- and lead ions in pyrite flotation to investigate the strong depressing effect of Fe(CN)63- on pyritic gold ore flotation and the significant activating effect of lead ions on pyritic gold ore flotation in the presence of Fe(CN)63- using flotation, zeta potential measurement and surface analysis methods. The flotation results showed that upon 5 × 10-5 mol/L Fe(CN)63- addition, pyrite recovery drastically decreased from about 51.3% to 8.6%, while the subsequent addition of 9.5 × 10-4 mol/L lead ions significantly activated pyrite with the recovery increasing from 8.6% to 91%, which demonstrated that Fe(CN)63- strongly depressed pyrite flotation, while lead ions completely activated pyrite in the presence of Fe(CN)63-. Zeta potential measurement, surface analysis using Cryogenic X-ray photoelectron spectroscopy (Cryo-XPS) and electrochemical impedance spectroscopy (EIS) revealed that Fe(CN)63- depression was attributed to the chemical adsorption of Fe(CN)63- on iron sites of pyrite as Prussian Blue (Fe[Fe(CN)6]); however, this hydrophilic layer could be covered totally by lead ions which adsorbed on as lead hydroxide/oxide through electrostatic interactions, which resulted in the significant activation effect of lead ions. The results from this study will lead to improved flotation of gold associated with pyrite in gold flotation plants.

Integrated Solution for As(III) Contamination in Water Based on Crystalline Porous Organic Salts.

A stable crystalline organic porous salt (CPOSs-NXU-1) with 1D apertures has been assembled by the solvothermal method, which shows high-sensitivity "turn-on" fluorescence detection and large-capacity adsorption of As(III) ions in water. The detection limits, saturated adsorption capacity, and removal rate of CPOSs-NXU-1 for As(III) ions in an aqueous solution can reach 74.34 nm (5.57 ppb), 451.01 mg g-1, and 99.6%, respectively, at pH = 7 and room temperature. With the aid of XPS, IR, Raman, and DFT theoretical calculations, it is determined that CPOSs-NXU-1 adsorbed As(III) ions in the form of H2AsO3 - and H3AsO3 through hydrogen bonding between the host and guest. The mechanism for fluorescence sensitization of As(III) ions to CPOSs-NXU-1 is mainly to increase the energy level difference between the ground state and excited state investigated by UV-vis absorption spectra, UV-vis diffuse reflectance spectra, and theoretical calculations. By constructing fluorescent CPOSs, an integrated solution has been achieved to treating As(III) contamination in the water that is equipped with detection and removal. These results blaze a promising path for addressing trivalent arsenic contamination in water efficiently, rapidly, and economically.

Elucidating epigenetic mechanisms governing odontogenic differentiation in dental pulp stem cells: an in-depth exploration.

Epigenetics refers to the mechanisms such as DNA methylation and histone modification that influence gene expression without altering the DNA sequence. These epigenetic modifications can regulate gene transcription, splicing, and stability, thereby impacting cell differentiation, development, and disease occurrence. The formation of dentin is intrinsically linked to the odontogenic differentiation of dental pulp stem cells (DPSCs), which are recognized as the optimal cell source for dentin-pulp regeneration due to their varied odontogenic potential, strong proliferative and angiogenic characteristics, and ready accessibility Numerous studies have demonstrated the critical role of epigenetic regulation in DPSCs differentiation into specific cell types. This review thus provides a comprehensive review of the mechanisms by which epigenetic regulation controls the odontogenesis fate of DPSCs.

Photovoltaic-enhanced water splitting properties of low-temperature-synthesized BiVO4 photoanode films.

The fabrication of photoelectrodes on indium tin oxide (ITO) glass at low temperatures poses a significant challenge due to the inherent instability of ITO at reduced temperatures, while the inexpensive production of high-functionality photoanode technology is a critical determinant facilitating large-scale photovoltaic conversion in water splitting. In this work, highly efficient BiVO4 (BVO) photoanodes with different thicknesses were grown on ITO glass at a low temperature by the sol-gel spin coating method. Pure BVO photoanode, enriched with nanostructures, exhibits a current density of 2.25 mA cm-2 (@1.23 V vs. RHE) under AM-1.5G illumination. The photovoltaic effect induces a continual oxygen evolution reaction at zero bias voltage on the photoanode, resulting in a photocurrent density of 0.04 mA cm-2 at zero bias. This study not only evaluates the feasibility of the large-scale fabrication of a photoanode from economic considerations but also presents potential for water splitting properties of the BVO photoanode.

Platelet Membrane-Coated Curcumin-PLGA Nanoparticles Promote Astrocyte-Neuron Transdifferentiation for Intracerebral Hemorrhage Treatment.

Intracerebral hemorrhage (ICH) is a hemorrhagic disease with high mortality and disability rates. Curcumin is a promising drug for ICH treatment due to its multiple biological activities, but its application is limited by its poor watersolubility and instability. Herein, platelet membrane-coated curcumin polylactic-co-glycolic acid (PLGA) nanoparticles (PCNPs) are prepared to achieve significantly improved solubility, stability, and sustained release of curcumin. Fourier transform infrared spectra and X-ray diffraction assays indicate good encapsulation of curcumin within nanoparticles. Moreover, it is revealed for the first time that curcumin-loaded nanoparticles can not only suppress hemin-induced astrocyte proliferation but also induce astrocytes into neuron-like cells in vitro. PCNPs are used to treat rat ICH by tail vein injection, using in situ administration as control. The results show that PCNPs are more effective than curcumin-PLGA nanoparticles in concentrating on hemorrhagic lesions, inhibiting inflammation, suppressing astrogliosis, promoting neurogenesis, and improving motor functions. The treatment efficacy of intravenously administered PCNPs is comparable to that of in situ administration, indicating a good targeting effect of PCNPs on the hemorrhage site. This study provides a potent treatment for hemorrhagic injuries and a promising solution for efficient delivery of water-insoluble drugs using composite materials of macromolecules and cell membranes.

[Effects of Different Forms of Nitrogen Addition on Soil Physical and Chemical Properties and Microbial Community Structure of Perennial Alpine Cultivated Grassland].

This study aimed to investigate the impact of different nitrogen forms on soil physicochemical properties and microbial community structure in perennial alpine cultivated grasslands, in order to provide scientific basis for developing nitrogen addition strategies for perennial alpine cultivated grasslands. In June 2022, a 4-year-old Qinghai grassland mixed with Poa pratensis Qinghai and Festuca sinensis Qinghai was established at the Bakatai Farm in Gonghe County, Hainan Tibetan Autonomous Prefecture, Qinghai Province. The study was conducted without fertilization as a control (CK), and three different forms of nitrogen treatments were set up, namely, U:urea (amide nitrogen), A:ammonium sulfate (ammonium nitrogen), and N:calcium nitrate (nitrate nitrogen); the nitrogen application rate for each treatment was 67.5 kg·(hm2·a)-1, and the composition and diversity of soil nutrients and microbial communities under different treatments were analyzed. The results showed that the input of exogenous ammonium nitrogen significantly increased NH4+-N content, AP content, and EC; amide nitrogen input significantly increased SOC content and TN content; and nitrate nitrogen input significantly increased NO3--N content, AN content, and TC content. Exogenous nitrogen input changed the structure of soil bacterial and fungal communities, as well as the relative abundance of dominant phyla and genera, but it did not significantly affect the alpha diversity of bacterial and fungal communities. Principal coordinate analysis (PCoA) showed that different forms of nitrogen addition had a significant impact on the Beta diversity of bacterial communities, whereas the impact on fungal communities was not significant. Redundancy analysis (RDA) indicated that nitrogen addition mainly changed the composition and structure of microbial communities through soil ammonium nitrogen. Overall, ammonium nitrogen fertilizer should be given priority in the soil remediation process of perennial cultivated grasslands in the Qinghai Tibet Plateau.

Immunomodulation of adipose-derived mesenchymal stem cells on peripheral blood mononuclear cells in colorectal cancer patients with COVID-19.

BACKGROUND: Accumulating evidence has shown that adipose tissue-derived mesenchymal stem cells (ADSCs) are an effective therapeutic approach for managing coronavirus disease 2019 (COVID-19); however, further elucidation is required to determine their underlying immunomodulatory effect on the mRNA expression of T helper cell-related transcription factors (TFs) and cytokine release in peripheral blood mononuclear cells (PBMCs). AIM: To investigate the impact of ADSCs on the mRNA expression of TFs and cytokine release in PBMCs from colorectal cancer (CRC) patients with severe COVID-19 (CRC+ patients). METHODS: PBMCs from CRC+ patients (PBMCs-C+) and age-matched CRC patients (PBMCs-C) were stimulated and cultured in the presence/absence of ADSCs. The mRNA levels of T-box TF TBX21 (T-bet), GATA binding protein 3 (GATA-3), RAR-related orphan receptor C (RORC), and forkhead box P3 (FoxP3) in the PBMCs were determined by reverse transcriptase-polymerase chain reaction. Culture supernatants were evaluated for levels of interferon gamma (IFN-γ), interleukin 4 (IL-4), IL-17A, and transforming growth factor beta 1 (TGF-ß1) using an enzyme-linked immunosorbent assay. RESULTS: Compared with PBMCs-C, PBMCs-C+ exhibited higher mRNA levels of T-bet and RORC, and increased levels of IFN-γ and IL-17A. Additionally, a significant decrease in FoxP3 mRNA and TGF-ß1, as well as an increase in T-bet/GATA-3, RORC/FoxP3, IFN-γ/IL-4, and IL-17A/TGF-ß1 ratios were observed in PBMCs-C+. Furthermore, ADSCs significantly induced a functional regulatory T cell (Treg) subset, as evidenced by an increase in FoxP3 mRNA and TGF-ß1 release levels. This was accompanied by a significant decrease in the mRNA levels of T-bet and RORC, release of IFN-γ and IL-17A, and T-bet/GATA-3, RORC/FoxP3, IFN-γ/IL-4, and IL-17A/TGF-ß1 ratios, compared with the PBMCs-C+alone. CONCLUSION: The present in vitro studies showed that ADSCs contributed to the immunosuppressive effects on PBMCs-C+, favoring Treg responses. Thus, ADSC-based cell therapy could be a beneficial approach for patients with severe COVID-19 who fail to respond to conventional therapies.

HIF-2α/TFR1 mediated iron homeostasis disruption aggravates cartilage endplate degeneration through ferroptotic damage and mtDNA release: A new mechanism of intervertebral disc degeneration.

Backgroud: Iron overload is a prevalent condition in the elderly, often associated with various degenerative diseases, including intervertebral disc degeneration (IDD). Nevertheless, the mechanisms responsible for iron ion accumulation in tissues and the mechanism that regulate iron homeostasis remain unclear. Transferrin receptor-1 (TFR1) serves as the primary cellular iron gate, playing a pivotal role in controlling intracellular iron levels, however its involvement in IDD pathogenesis and the underlying mechanism remains obscure. Methods: Firstly, IDD mice model was established to determine the iron metabolism associated proteins changes during IDD progression. Then CEP chondrocytes were isolated and treated with TBHP or pro-inflammatory cytokines to mimic pathological environment, western blotting, immunofluorescence assay and tissue staining were employed to explore the underlying mechanisms. Lastly, TfR1 siRNA and Feristatin II were employed and the degeneration of IDD was examined using micro-CT and immunohistochemical analysis. Results: We found that the IDD pathological environment, characterized by oxidative stress and pro-inflammatory cytokines, could enhance iron influx by upregulating TFR1 expression in a HIF-2α dependent manner. Excessive iron accumulation not only induces chondrocytes ferroptosis and exacerbates oxidative stress, but also triggers the innate immune response mediated by c-GAS/STING, by promoting mitochondrial damage and the release of mtDNA. The inhibition of STING through siRNA or the reduction of mtDNA replication using ethidium bromide alleviated the degeneration of CEP chondrocytes induced by iron overload. Conclusion: Our study systemically explored the role of TFR1 mediated iron homeostasis in IDD and its underlying mechanisms, implying that targeting TFR1 to maintain balanced iron homeostasis could offer a promising therapeutic approach for IDD management. The translational potential of this article: Our study demonstrated the close link between iron metabolism dysfunction and IDD, indicated that targeting TfR1 may be a novel therapeutic strategy for IDD.

GelMA-based hydrogel biomaterial scaffold: A versatile platform for regenerative endodontics.

Endodontic therapy, while generally successful, is primarily limited to mature teeth, hence the pressing need to explore regenerative approaches. Gelatin methacryloyl (GelMA) hydrogels have emerged as pivotal biomaterials, promising a bright future for dental pulp regeneration. Despite advancements in tissue engineering and biomaterials, achieving true pulp tissue regeneration remains a formidable task. GelMA stands out for its injectability, rapid gelation, and excellent biocompatibility, serving as the cornerstone of scaffold materials. In the pursuit of dental pulp regeneration, GelMA holds significant potential, facilitating the delivery of stem cells, growth factors, and other vital substances crucial for tissue repair. Presently, in the field of dental pulp regeneration, researchers have been diligently utilizing GelMA hydrogels as engineering scaffolds to transport various effective substances to promote pulp regeneration. However, existing research is relatively scattered and lacks comprehensive reviews and summaries. Therefore, the primary objective of this article is to elucidate the application of GelMA hydrogels as regenerative scaffolds in this field, thereby providing clear direction for future researchers. Additionally, this article provides a comprehensive discussion on the synthesis, characterization, and application of GelMA hydrogels in root canal therapy regeneration. Furthermore, it offers new application strategies and profound insights into future challenges, such as optimizing GelMA formulations to mimic the complex microenvironment of pulp tissue and enhancing its integration with host tissues.

In-situ observation of silk nanofibril assembly via graphene plasmonic infrared sensor.

Silk nanofibrils (SNFs), the fundamental building blocks of silk fibers, endow them with exceptional properties. However, the intricate mechanism governing SNF assembly, a process involving both protein conformational transitions and protein molecule conjunctions, remains elusive. This lack of understanding has hindered the development of artificial silk spinning techniques. In this study, we address this challenge by employing a graphene plasmonic infrared sensor in conjunction with multi-scale molecular dynamics (MD). This unique approach allows us to probe the secondary structure of nanoscale assembly intermediates (0.8-6.2 nm) and their morphological evolution. It also provides insights into the dynamics of silk fibroin (SF) over extended molecular timeframes. Our novel findings reveal that amorphous SFs undergo a conformational transition towards ß-sheet-rich oligomers on graphene. These oligomers then connect to evolve into SNFs. These insights provide a comprehensive picture of SNF assembly, paving the way for advancements in biomimetic silk spinning.

Association between muscular tissue desaturation and acute kidney injury in older patients undergoing major abdominal surgery: a prospective cohort study.

PURPOSE: Present study was designed to investigate the association between muscular tissue desaturation and acute kidney injury (AKI) in older patients undergoing major abdominal surgery. METHOD: A total of 253 patients (≥ 65 years old) who underwent abdominal surgery with expected duration ≥ 2 h were enrolled. Muscular tissue oxygen saturation (SmtO2) was monitored at quadriceps and bilateral flanks during surgery. Muscular desaturation was defined as SmtO2 < 90% baseline lasting for > 60 s. The primary outcome was the incidence of AKI within postoperative 7 days. The association between muscular desaturation and AKI was analyzed by multivariable logistic regression model. The secondary outcomes indicated the other complications within postoperative 30 days. RESULTS: Among 236 patients, 44 (18.6%) of them developed AKI. The incidence of muscular desaturation at quadriceps was 28.8% (68/236). Patients with muscular desaturation had higher incidence of AKI than those without desaturation (27.9% [19/68], vs. 14.9% [25/168], P = 0.020). After adjustment of confounders, multivariable analysis showed that muscular desaturation at quadriceps was significantly associated with an increased risk of AKI (OR = 2.84, 95% CI 1.21-6.67, P = 0.016). Muscular desaturations at left and right flank were also associated with an increased risk of AKI (OR = 6.38, 95% CI 1.78-22.89, P = 0.004; OR = 8.90, 95% CI 1.42-45.63; P = 0.019, respectively). Furthermore, patients with muscular desaturation may have a higher risk of pulmonary complications, sepsis and stroke at 30-day follow-up. CONCLUSION: Muscular desaturation was associated with postoperative AKI in older patients undergoing major abdominal surgery which may serve as a predictor of AKI.

TfR1 mediated iron metabolism dysfunction as a potential therapeutic target for osteoarthritis.

OBJECTIVE: Transferrin receptor-1 (TfR1) plays important roles in controlling cellular iron levels, but its role in OA pathology is unknown. Herein we aim to investigate the role of TfR1 in OA progression and its underlying mechanisms. METHODS: TfR1 expression in cartilage during OA development were examined both in vivo and in vitro. Then IL-1ß was used to induce chondrocytes degeneration in vitro and TfR1 siRNA was used for observing the effect of TfR1 in modulating iron homeostasis, mitochondrial function and degrading enzymes expression. Also the inhibitor of TfR1 was exploited to analyze the protective effect of TfR1 inhibition in vivo. RESULTS: TfR1 is elevated in OA cartilage and contributes to OA inflammation condition. Excess iron not only results in oxidative stress damage and sensitizes chondrocytes to ferroptosis, but also triggers c-GAS/STING-mediated inflammation by promoting mitochondrial destruction and the release of mtDNA. Silencing TfR1 using TfR1 siRNA not only reduced iron content in chondrocytes and inhibited oxidative stress, but also facilitated the mitophagy process and suppressed mtDNA/cGAS/STING-mediated inflammation. Importantly, we also found that Ferstatin II, a novel and selective TfR1 inhibitor, could substantially suppress TfR1 activity both in vivo and in vitro and ameliorated cartilage degeneration. CONCLUSION: Our work demonstrates that TfR1 mediated iron influx plays important roles in chondrocytes degeneration and OA pathogenesis, suggesting that maintaining iron homeostasis through the targeting of TfR1 may represent a novel therapeutic strategy for the treatment of OA.

Electron/infrared-phonon coupling in ABC trilayer graphene.

Stacking order plays a crucial role in determining the crystal symmetry and has significant impacts on electronic, optical, magnetic, and topological properties. Electron-phonon coupling, which is central to a wide range of intriguing quantum phenomena, is expected to be intricately connected with stacking order. Understanding the stacking order-dependent electron-phonon coupling is essential for understanding peculiar physical phenomena associated with electron-phonon coupling, such as superconductivity and charge density waves. In this study, we investigate the effect of stacking order on electron-infrared phonon coupling in graphene trilayers. By using gate-tunable Raman spectroscopy and excitation frequency-dependent near-field infrared nanoscopy, we show that rhombohedral ABC-stacked trilayer graphene has a significant electron-infrared phonon coupling strength. Our findings provide novel insights into the superconductivity and other fundamental physical properties of rhombohedral ABC-stacked trilayer graphene, and can enable nondestructive and high-throughput imaging of trilayer graphene stacking order using Raman scattering.

Clinical outcomes of endodontic microsurgery in complicated cases with large or through-and-through lesions: a retrospective longitudinal study.

OBJECTIVES: To investigate the clinical outcomes of endodontic microsurgery in complicated cases presenting with large or through-and-through lesions. MATERIALS AND METHODS: We retrospectively collected and analyzed preoperative, intraoperative, and follow-up data from 143 complicated cases that underwent endodontic microsurgery. Clinical outcomes were assessed in terms of tooth survival and surgery success. Cox regression analysis was used to evaluate the survival rate and identify associated risk factors. Additionally, the success rate was compared across different postoperative periods, and potential factors contributing to surgical failure were identified through binary logistic regression. RESULTS: The overall survival and success rates were 93.0% and 91.7%, respectively. The Cox regression model identified four risk factors affecting tooth survival, including apicoectomy of four teeth (HR = 35.488; P = 0.0002), an open apex observed on preoperative radiographs (HR = 6.300; P = 0.025), the performance of guided tissue regeneration technique (HR = 8.846; P = 0.028), and a palatal surgical approach (HR = 8.685; P = 0.030). The success rate demonstrated an initial increase in the early postoperative period (from 0.5 to 2 years; P = 5.8124e-30), followed by stabilization (from 2 to 9 years; P = 0.298). Surgery success rate significantly declined when apicoectomy involved four teeth (OR = 109.412; P = 0.002). CONCLUSIONS: Endodontic microsurgery demonstrates satisfactory outcomes in complicated cases, maintaining a stable success rate after two years. However, tooth survival and surgery success are significantly compromised when apicoectomy involves four teeth. Factors such as guided tissue regeneration, an open apex, and the palatal surgical approach are associated with an increased risk of tooth extraction. CLINICAL RELEVANCE: Despite achieving acceptable outcomes in complicated cases, endodontic microsurgery is adversely affected by the apicoectomy of four teeth.

HSPA8-mediated stability of the CLPP protein regulates mitochondrial autophagy in cisplatin-resistant ovarian cancer cells.

Currently, platinum agents remain the mainstay of chemotherapy for ovarian cancer (OC). However, cisplatin (DDP) resistance is a major reason for chemotherapy failure. Thus, it is extremely important to elucidate the mechanism of resistance to DDP. Here, we establish two DDP-resistant ovarian cancer cell lines and find that caseinolytic protease P (CLPP) level is significantly downregulated in DDP-resistant cell lines compared to wild-type ovarian cancer cell lines (SK-OV-3 and OVcar3). Next, we investigate the functions of CLPP in DDP-resistant and wild-type ovarian cancer cells using various assays, including cell counting kit-8 assay, western blot analysis, immunofluorescence staining, and detection of reactive oxygen species (ROS) and apoptosis. Our results show that CLPP knockdown significantly increases the half maximal inhibitory concentration (IC 50) and mitophagy of wild-type SK-OV-3 and OVcar3 cells, while CLPP overexpression reduces the IC 50 values and mitophagy of DDP-resistant SK-OV-3 and OVcar3 cells. Next, we perform database predictions and confirmation experiments, which show that heat shock protein family A member 8 (HSPA8) regulates CLPP protein stability. The dynamic effects of the HSPA8/CLPP axis in ovarian cancer cells are also examined. HSPA8 increases mitophagy and the IC 50 values of SK-OV-3 and OVcar3 cells but inhibits their ROS production and apoptosis. In addition, CLPP partly reverses the effects induced by HSPA8 in SK-OV-3 and OVcar3 cells. In conclusion, CLPP increases DDP resistance in ovarian cancer by inhibiting mitophagy and promoting cellular stress. Meanwhile, HSPA8 promotes the degradation of CLPP protein by regulating its stability.

Microwave-assisted synthesis of Co-free Li[Li0.2Ni0.2Mn0.6]O2 cathodes with a spinel-layered coherent structure for high-power Li-ion batteries.

Li- and Mn-rich layered oxides (LMLOs) are regarded as the most promising cathode materials for Li-ion batteries (LIBs), but they suffer from poor rate capability. Herein, a promising and practical method (i.e. a hydroxide coprecipitation method in combination with a microwave heating process) is developed to controllably synthesize cobalt-free Li[Li0.2Ni0.2Mn0.6]O2 with a layered/spinel heterostructure (LLNMO-LS). The cathode made of the LLNMO-LS delivers an excellent electrochemical performance, demonstrating a discharge capacity of 147 mA h g-1 at 10C.

Compensating losses in polariton propagation with synthesized complex frequency excitation.

Surface plasmon polaritons and phonon polaritons offer a means of surpassing the diffraction limit of conventional optics and facilitate efficient energy storage, local field enhancement and highsensitivity sensing, benefiting from their subwavelength confinement of light. Unfortunately, losses severely limit the propagation decay length, thus restricting the practical use of polaritons. While optimizing the fabrication technique can help circumvent the scattering loss of imperfect structures, the intrinsic absorption channel leading to heat production cannot be eliminated. Here, we utilize synthetic optical excitation of complex frequency with virtual gain, synthesized by combining the measurements made at multiple real frequencies, to compensate losses in the propagations of phonon polaritons with dramatically enhanced propagation distance. The concept of synthetic complex frequency excitation represents a viable solution to the loss problem for various applications including photonic circuits, waveguiding and plasmonic/phononic structured illumination microscopy.

Dissolved organic matter accelerates microbial degradation of 17 alpha-ethinylestradiol in the presence of iron mineral.

Dissolved organic matter (DOM) and iron minerals widely existing in the natural aquatic environment can mediate the migration and transformation of organic pollutants. However, the mechanism of interaction between DOM and iron minerals in the microbial degradation of pollutants deserves further investigation. In this study, the mechanism of 17 alpha-ethinylestradiol (EE2) biodegradation mediated by humic acid (HA) and three kinds of iron minerals (goethite, magnetite, and pyrite) was investigated. The results found that HA and iron minerals significantly accelerated the biodegradation process of EE2, and the highest degradation efficiency of EE2 (48%) was observed in the HA-mediated microbial system with pyrite under aerobic conditions. Furthermore, it had been demonstrated that hydroxyl radicals (HO•) was the main active substance responsible for the microbial degradation of EE2. HO• is primarily generated through the reaction between hydrogen peroxide secreted by microorganisms and Fe(II), with aerobic conditions being more conducive. The presence of iron minerals and HA could change the microbial communities in the EE2 biodegradation system. These findings provide new information for exploring the migration and transformation of pollutants by microorganisms in iron-rich environments.

Limitations and Management of Dynamic Navigation System for Locating Calcified Canals Failure.

Nonsurgical endodontic teeth treatment with severe pulp canal obliteration poses challenges, primarily locating canals. By combining 3-dimensional reconstruction and spatial location registration, the dynamic navigation technique uses an optical tracking system to guide the clinician to drill in real time according to the predesigned path until access to the canal is established. Several in vitro studies and case reports have shown that calcified canal location with dynamic navigation system (DNS) is more accurate and efficient, yet the technique has limitations. In 4 cases with 7 teeth, this work presents manipulation process and clinical outcomes of DNS helping in calcified canal location. We performed handpiece adaptation and elucidated the failure to locate the canals with DNS in 2 teeth, resulting in canal geometry alteration and canal path deviation. Subsequently, the more experienced endodontist located the canals by combining cone-beam computed tomographic imaging and dental operating microscopy. All patients were completely asymptomatic after treatment. At the 1-year follow-up visit, the bone healing of periapical lesions progressed well according to the periapical radiography or cone-beam computed tomographic imaging. These findings indicate that DNS is a promising technique for locating calcified canals; however, it needs to be refined before clinical use.

Accelerating structure reconstruction to form NiOOH in metal-organic frameworks (MOFs) for boosting the oxygen evolution reaction.

Structural reconstruction of electrocatalysts to generate metal hydroxide/oxyhydroxide species is critical for an efficient oxygen evolution reaction (OER), but the controllable regulation of the reconstruction process still remains a challenge. Given the designable nature of metal-organic frameworks (MOFs), herein, we have reported a localized structure disordering strategy to accelerate the structural reconstruction of Ni-BDC to generate NiOOH for boosting the OER. The Ni-BDC nanosheets were modified by Fe3+ and urea to form cracks, which could promote the accessibility of the Ni sites by the electrolyte and thus promote the reconstruction to form NiOOH. In addition, the interaction between Ni2+ and Fe3+ allows the electron flow from Ni2+ to Fe3+, further enhancing the NiOOH generation. As a result, the optimized sample exhibits excellent OER activity with a small overpotential of 251 mV at 10 mA cm-2, which is superior to most of the MOF-based OER catalysts reported previously. This work provides a controllable strategy to regulate the structural reconstruction for promoting the OER, which could provide important guidance for the development of more efficient OER electrocatalysts.