Se-dopant Modulated Selective Co-Insertion of H+ and Zn2+ in MnO2 for High-Capacity and Durable Aqueous Zn-Ion Batteries.

MnO2 is commonly used as the cathode material for aqueous zinc-ion batteries (AZIBs). The strong Coulombic interaction between Zn ions and the MnO2 lattice causes significant lattice distortion and, combined with the Jahn-Teller effect, results in Mn2+ dissolution and structural collapse. While proton intercalation can reduce lattice distortion, it changes the electrolyte pH, producing chemically inert byproducts. These issues greatly affect the reversibility of Zn2+ intercalation/extraction, leading to significant capacity degradation of MnO2. Herein, we propose a novel method to enhance the cycling stability of δ-MnO2 through selenium doping (Se-MnO2). Our work indicates that varying the selenium doping content can regulate the intercalation ratio of H+ in MnO2, thereby suppressing the formation of ZnMn2O4 by-products. Se doping mitigates the lattice strain of MnO2 during Zn2+ intercalation/deintercalation by reducing Mn-O octahedral distortion, modifying Mn-O bond length upon Zn2+ insertion, and alleviating Mn dissolution caused by the Jahn-Teller effect. The optimized Se-MnO2 (Se concentration of 0.8 at.%) deposited on carbon nanotube demonstrates a notable capacity of 386 mAh g-1 at 0.1 A g-1, with exceptional long-term cycle stability, retaining 102 mAh g-1 capacity after 5000 cycles at 3.0 A g-1.

Behavior analysis and formative assessments in online oral medicine education during the COVID-19 pandemic.

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, traditional teaching methods were disrupted and online teaching became a new topic in education reform and informatization. In this context, it is important to investigate the necessity and effectiveness of online teaching methods for medical students. This study explored stomatology education in China to evaluate the development and challenges facing the field using massive open online courses (MOOCs) for oral medicine education during the pandemic. AIM: To investigate the current situation and challenges facing stomatology education in China, and to assess the necessity and effectiveness of online teaching methods among medical students. METHODS: Online courses were developed and offered on personal computers and mobile terminals. Behavioral analysis and formative assessments were conducted to evaluate the learning status of students. RESULTS: The results showed that most learners had already completed MOOCs and achieved better results. Course behavior analysis and student surveys indicated that students enjoyed the learning experience. However, the development of oral MOOCs during the COVID-19 pandemic faced significant challenges. CONCLUSION: This study provides insights into the potential of using MOOCs to support online professional learning and future teaching innovation, but emphasizes the need for careful design and positive feedback to ensure their success.

Single cell RNA sequencing reveals mesenchymal heterogeneity and critical functions of Cd271 in tooth development.

BACKGROUND: Accumulating evidence suggests that the maxillary process, to which cranial crest cells migrate, is essential to tooth development. Emerging studies indicate that Cd271 plays an essential role in odontogenesis. However, the underlying mechanisms have yet to be elucidated. AIM: To establish the functionally heterogeneous population in the maxillary process, elucidate the effects of Cd271 deficiency on gene expression differences. METHODS: p75NTR knockout (Cd271-/-) mice (from American Jackson laboratory) were used to collect the maxillofacial process tissue of p75NTR knockout mice, and the wild-type maxillofacial process of the same pregnant mouse wild was used as control. After single cell suspension, the cDNA was prepared by loading the single cell suspension into the 10x Genomics Chromium system to be sequenced by NovaSeq6000 sequencing system. Finally, the sequencing data in Fastq format were obtained. The FastQC software is used to evaluate the quality of data and CellRanger analyzed the data. The gene expression matrix is read by R software, and Seurat is used to control and standardize the data, reduce the dimension and cluster. We search for marker genes for subgroup annotation by consulting literature and database; explore the effect of p75NTR knockout on mesenchymal stem cells (MSCs) gene expression and cell proportion by cell subgrouping, differential gene analysis, enrichment analysis and protein-protein interaction network analysis; understand the interaction between MSCs cells and the differentiation trajectory and gene change characteristics of p75NTR knockout MSCs by cell communication analysis and pseudo-time analysis. Last we verified the findings single cell sequencing in vitro. RESULTS: We identified 21 cell clusters, and we re-clustered these into three subclusters. Importantly, we revealed the cell-cell communication networks between clusters. We clarified that Cd271 was significantly associated with the regulation of mineralization. CONCLUSION: This study provides comprehensive mechanistic insights into the maxillary- process-derived MSCs and demonstrates that Cd271 is significantly associated with the odontogenesis in mesenchymal populations.

Practical Strategy for Arsenic(III) Electroanalysis without Modifier in Natural Water: Triggered by Iron Group Ions in Solution.

Significant progress has been made in nanomaterial-modified electrodes for highly efficient electroanalysis of arsenic(III) (As(III)). However, the modifiers prepared using some physical methods may easily fall off, and active sites are not uniform, causing the potential instability of the modified electrode. This work first reports a promising practical strategy without any modifiers via utilizing only soluble Fe3+ as a trigger to detect trace-level As(III) in natural water. This method reaches an actual detection limit of 1 ppb on bare glassy carbon electrodes and a sensitivity of 0.296 µA ppb-1 with excellent stability. Kinetic simulations and experimental evidence confirm the codeposition mechanism that Fe3+ is preferentially deposited as Fe0, which are active sites to adsorb As(III) and H+ on the electrode surface. This facilitates the formation of AsH3, which could further react with Fe2+ to produce more As0 and Fe0. Meanwhile, the produced Fe0 can also accelerate the efficient enrichment of As0. Remarkably, the proposed sensing mechanism is a general rule for the electroanalysis of As(III) that is triggered by iron group ions (Fe2+, Fe3+, Co2+, and Ni2+). The interference analysis of coexisting ions (Cu2+, Zn2+, Al3+, Hg2+, Cd2+, Pb2+, SO42-, NO3-, Cl-, and F-) indicates that only Cu2+, Pb2+, and F- showed inhibitory effects on As(III) due to the competition of active sites. Surprisingly, adding iron power effectively eliminates the interference of Cu2+ in natural water, achieving a higher sensitivity for 1-15 ppb As(III) (0.487 µA ppb-1). This study provides effective solutions to overcome the potential instability of modified electrodes and offers a practical sensing platform for analyzing other heavy-metal anions.

Ambient air pollution exposure and risk of chronic kidney disease: A systematic review of the literature and meta-analysis.

Ambient air pollution has been identified as one of the leading causes of global burden of disease. The relationship between ambient air pollution exposure and risk of chronic kidney disease (CKD) has stimulated increasing scientific interest in the past few years. However, evidence from human epidemiological studies is still limited and inconsistent. We performed an updated systematic review and meta-analysis to clarify the potential association comprehensively. Selected electronic databases were searched for related English language studies until March 1, 2020 with a final follow-up in December 31, 2020. Risk of bias assessment for individual studies were assessed using the OHAT (Office of Health Assessment and Translation) risk-of-bias rating tool. Confidence rating and level-of-evidence conclusions were developed for bodies of evidence for a given ambient air pollutant. Summary effect estimates were calculated using random-effects meta-analyses when three or more studies are identified for the same air pollutant-CKD combination. A total of 13 studies were finally identified in our study. The meta-analytic estimates (ORs) for risk of CKD were 1.15 (95% CI: 1.07, 1.24) for each 10 µg/m3 increase in PM2.5, 1.25 (95% CI: 1.11, 1.40) for each 10 µg/m3 increase in PM10, 1.10 (95% CI: 1.03, 1.17) for each 10 ppb increase in NO2, 1.06 (95% CI: 0.98, 1.15) for each 1 ppb increase in SO2 and 1.04 (95% CI: 1.00, 1.08) for each 0.1 ppm increase in CO, respectively. The level of evidence was appraised as moderate for four of the five tested air pollutant-CKD combinations using an adaptation of the GRADE (Grading of Recommendations Assessment, Development and Evaluation) tool. In conclusion, this study suggests that certain ambient air pollutant exposure was significantly associated with an increased risk of CKD. Given the limitations, the results of this study should be interpreted with caution, and further well-designed epidemiological studies are needed to draw a definite evidence of a causal relationship.

Metal Replacement Causing Interference in Stripping Analysis of Multiple Heavy Metal Analytes: Kinetic Study on Cd(II) and Cu(II) Electroanalysis via Experiment and Simulation.

Although it has been recognized that the interference between heavy metal ions (HMIs) becomes a severe problem for the simultaneous electroanalysis of multiple HMIs, the factor leading to the interference is still difficult to identify, due to the limited understanding of the electroanalytic kinetics. In this work, a kinetic model is built for the electroanalysis of HMIs, and the electroanalytic results are simulated for Cd(II), Cu(II), and their mixture as examples for the interference investigation. The mutual interference between Cd and Cu is observed on the glassy carbon electrode. By applying the kinetic model, the replacement of deposited Cd by Cu(II) at the codeposition stage is regarded as the main reason for the interference, and the corresponding suggestion for selecting suitable electrode materials to avoid such interference is also provided.

Massive haemorrhage in liver transplantation: Consequences, prediction and management.

From its inception the success of liver transplantation has been associated with massive blood loss. Massive transfusion is classically defined as > 10 units of red blood cells within 24 h, but describing transfusion rates over a shorter period of time may reduce the potential for survival bias. Both massive haemorrhage and transfusion are associated with increased risk of mortality and morbidity (need for dialysis/surgical site infection) following liver transplantation although causality is difficult to prove due to the observational design of most trials. The blood loss associated with liver transplantation is multifactorial. Portal hypertension secondary to cirrhosis results in extensive collateral circulation, which can bleed during hepatectomy particular if portal pressures are increased. Avoiding volume loading and maintenance of a low central venous pressure together with the use of vasopressors have been shown to reduce blood loss and transfusion during liver transplantation, but may increase the risk of renal impairment post-operatively. Coagulation defects may be present pre-transplant, but haemostasis is often re-balanced due to a deficit in both pro- and anti-coagulation factors. Further derangement of haemostasis may develop in the anhepatic and neohepatic phases due to absent hepatic metabolic function, hyperfibrinolysis and platelet sequestration in the donor liver. Point-of-care tests of coagulation such as the viscoelastic tests rotation thromboelastometry/thromboelastometry allow and more accurate and rapid assessment of these derangements in coagulation and guide the use of factor replacement and antifibrinolytics. Transfusion protocols guided by these tests have been shown to reduce transfusion rates compared with conventional coagulation tests, but have not shown improvements in mortality or morbidity. Pre-operative factors associated with massive transfusion include previous surgery, re-do transplantation, the aetiology and severity of liver disease. Intra-operatively the use of piggy-back technique and avoiding veno-veno bypass has been shown to reduced blood loss.

[Experimental study of PVPP/silicone composite automatic expanded material as implants].

OBJECTIVE: To study the feasibility of Polyvinylpolypyrrolidone (PVPP)/silicone composite automatic expanded material as implants. METHODS: The PVPP hydrogel was mixed with silicone through the location at the high temperature. Implants with different ratio of PVPP to silicone were placed under the back and nose skin in 24 New Zealand rabbits. The surrounding tissue reaction, material and skin expansion were observed and compared with those with pure silicone implants. RESULTS: The study lasted for 200 days. Compared with pure silicone implants, the composite material could expand automatically and stop expanding at about 2 weeks after implantation. Histological study showed similar inflectional and foreign body reaction around the composite material and the pure silicone. CONCLUSIONS: Compared with pure silicone, the PVPP/silicone composite implant has the advantage of automatic expansion, so as to expand the soft tissue.