Integrated "Two-in-One" Strategy for High-Rate Electrocatalytic CO2 Reduction to Formate.

The electrochemical CO2 reduction reaction (ECR) is a promising pathway to producing valuable chemicals and fuels. Despite extensive studies reported, improving CO2 adsorption for local CO2 enrichment or water dissociation to generate sufficient H* is still not enough to achieve industrial-relevant current densities. Herein, we report a "two-in-one" catalyst, defective Bi nanosheets modified by CrOx (Bi-CrOx), to simultaneously promote CO2 adsorption and water dissociation, thereby enhancing the activity and selectivity of ECR to formate. The Bi-CrOx exhibits an excellent Faradaic efficiency (≈100 %) in a wide potential range from -0.4 to -0.9 V. In addition, it achieves a remarkable formate partial current density of 687 mA cm-2 at a moderate potential of -0.9 V without iR compensation, the highest value at -0.9 V reported so far. Control experiments and theoretical simulations revealed that the defective Bi facilitates CO2 adsorption/activation while the CrOx accounts for enhancing the protonation process via accelerating H2O dissociation. This work presents a pathway to boosting formate production through tuning CO2 and H2O species at the same time.

Effect of Orthodontic Treatment on the Outcomes of Endodontically Treated Teeth: A Cone-Beam Computed Tomography Analysis.

INTRODUCTION: Often there is the need of moving endodontically treated teeth. Orthodontic movement may have no effect on the prognosis of teeth with root canal treatment (RCT). To verify this subject, we evaluated the effect of orthodontic movement on the prognosis of RCT teeth using cone-beam computed tomography (CBCT) and further explored the influence of orthodontic movement on the prognosis of RCT teeth with and without apical periodontitis (AP). METHODS: This retrospective study was conducted by evaluating 169 RCT teeth of 100 patients who had undergone fixed orthodontic treatment. AP was assessed and classified using the CBCT periapical index. Univariate analysis of RCT outcome was performed for the total RCT group, RCT without AP group and RCT with AP group. Multivariate logistic regression was performed for the total RCT group and RCT without AP group, respectively, but not for the RCT with AP group. Variables related to the prognosis of RCT were included, such as age, gender, tooth position, RCT quality, coronal restoration quality, periodontal condition, orthodontic traction distance, and orthodontic rotation angle. RESULTS: The orthodontic traction distance and rotation angle were not significantly correlated to the RCT outcomes, regardless of the presence of AP. Among the total RCT group, teeth with unqualified RCT (odds ratio = 3.42, P = .004) and inadequate coronal restoration (odds ratio = 4.40, P = .031) had a lower success rate. Of the 97 RCT teeth without AP, unqualified RCT was a risk factor for treatment failure (odds ratio = 3.55, P = .041). Of the 72 RCT teeth with AP, the univariate analysis showed that RCT quality were significantly related to the outcome (P = .042). CONCLUSIONS: Orthodontic movement had no effect on the prognosis of RCT teeth regardless of the presence of AP.

Outcomes and prognostic factors of apical periodontitis by root canal treatment and endodontic microsurgery-a retrospective cohort study.

BACKGROUND: The aim of this study was to analyze the outcome and prognostic factors of root canal treatment (RCT) and endodontic microsurgery (EMS) in the treatment of apical periodontitis (AP), respectively, and to compare the outcome and prognostic factors between initial RCT and nonsurgical retreatment (re-RCT) for AP. METHODS: Patients with AP were recruited from the Stomatology Department of Peking University Third Hospital from January 2016 to December 2019. Data were collected by medical records review. Univariate analysis of treatment outcome was performed for the total RCT group, initial RCT group, re-RCT group and EMS group, respectively. Multivariate logistic regression was performed for the three RCT groups, respectively, but not for the EMS group. RESULTS: The overall success of treatment for AP was 73.8%. The success rate of RCT in 229 cases was 70.7%, while that of EMS in 34 cases was 94.1%. The failure of RCT was significantly higher for elderly patients [odds ratio (OR) =1.025, P=0.013], teeth with incomplete fracture (OR =7.082, P=0.013), teeth with a greater crown root ratio (OR =1.198, P=0.029), teeth treated by a general dentist (OR =2.16, P=0.042) and teeth with unqualified treatment (OR =2.841, P=0.002). Of the 166 teeth treated by initial RCT, the success was 68.1%. A greater crown root ratio (OR =1.333, P=0.004) was identified as a risk factor for treatment. Of the 63 teeth treated by re-RCT, the success was 77.8%. A lower success was observed in teeth with unqualified treatment (OR =5.291, P=0.018). With regard to EMS, the univariate analysis showed that none of the variables were significantly related to the outcome. CONCLUSIONS: For AP treated by RCT, age, incomplete tooth fracture, crown root ratio, doctor classification and unqualified treatment had a strong impact on determining outcome. For initial RCT, crown root ratio was a significant outcome predictor, while for re-RCT, unqualified treatment was a strong statistically significant factor. No significant difference was found between the success of initial RCT and re-RCT for AP.

Bi2O3 Nanosheets Grown on Carbon Nanofiber with Inherent Hydrophobicity for High-Performance CO2 Electroreduction in a Wide Potential Window.

The ever-increasing concern for adverse climate changes has propelled worldwide research on the reduction of CO2 emission. In this regard, CO2 electroreduction (CER) to formate is one of the promising approaches to converting CO2 to a useful product. However, to achieve a high production rate of formate, the existing catalysts for CER fall short of expectation in maintaining the high formate selectivity and activity over a wide potential window. Through this study, we report that Bi2O3 nanosheets (NSs) grown on carbon nanofiber (CNF) with inherent hydrophobicity achieve a peak formate current density of 102.1 mA cm-2 and high formate Faradaic efficiency of >93% over a very wide potential window of 1000 mV. To the best of our knowledge, this outperforms all the relevant achievements reported so far. In addition, the Bi2O3 NSs on CNF demonstrate a good antiflooding capability when operating in a flow cell system and can deliver a current density of 300 mA cm-2. Molecular dynamics simulations indicate that the hydrophobic carbon surface can repel water molecules to form a robust solid-liquid-gas triple-phase boundary and a concentrated CO2 layer; both can boost CER activity with the local high concentration of CO2 and through inhibiting the hydrogen evolution reaction (HER) by reducing proton contacts. This water-repelling effect also increases the local pH at the catalyst surface, thus inhibiting HER further. More significantly, the concept and methodology of this hydrophobic engineering could be broadly applicable to other formate-producing materials from CER.

Mechanisms of diabetes mellitus induced with FK506 in SD rats models.

BACKGROUND: Tacrolimus causes post-transplant diabetes mellitus, however the pathogenetic mechanisms remain controversial. In this study we probed into the mechanisms of tacrolimus-induced diabetes mellitus in rats. METHODS: Glucose levels were determined on whole blood samples using a glucose oxidase method. Levels of serum insulin and C-peptide were measured with ELISA. Histological damage of ultra-structure and apoptosis of beta cells of the pancreas were assayed with electric microscope and tunnel methods respectively.--Ultra-structure were assayed with electric microscope and apoptosis of beta cells of the pancreas were assayed with tunnel methods. Immunohistochemistry was utilized to detect the sum of insulin receptors of hepatic cells. RESULTS: Compared to control group, insulin and C peptide levels in serum decreased in rats of diabetes mellitus models induced with FK506(P<0.05). Compared to the control group, the sum of apoptosis body in pancreatic islets increased in rats of diabetes mellitus models induced with FK506 (P<0.05). Compared to the control group, electron microscopy showed cytoplasm swelling and vacuolization, and marked decrease or absence of dense-core secretory granules in beta cells in rats with diabetes mellitus induced with FK506.Compared to the control group, expression of insulin receptor of hepatic cell decreased in rats of diabetes mellitus models induced with FK506 (P<0.05). CONCLUSION: Pathogenetic mechanisms of rats of diabetes mellitus models induced with FK506 including reduction of secretion of insulin in beta cells of pancreatic islets, damages of ultra-structure of beta cells of pancreatic islets, increasing of apoptosis of beta cells of pancreatic islets and decreasing of expression of insulin receptors in hepatic cells.

[Correlations between SNP of LALBA gene and economic traits in Inner Mongolian white cashmere goat].

PCR-SSCP and DNA sequencing methods were conducted to detect single nucleotide polymorphism of alpha-lactalbumin (LALBA) gene in 452 Inner Mongolian white cashmere goats (IMWC). Correlations between SNP of goat LALBA gene and economic traits, e.g., cashmere yield, cashmere thickness, length and weight, were analyzed. The SSCP in P2 primer locus, which was caused by the point mutation M63868:g.1897T>C in the exon 3 of LALBA gene was detected. At this locus, the genotype TT and allele T were predominant in the IMWC population, which agreed with Hardy-Weinberg equilibrium. Moreover, there was a significant correlation between polymorphism of goat M63868:g.1897 locus and cashmere yield of IMWC (P=0.017). The individuals with genotype TC had more cashmere yield than those with geontype TT. Hence, genotype TC of LALBA gene can be used as a molecular marker for breeding superior cashmere yield in goat marker-assisted selection.

[Determination of se in blood and tissue of animal samples by normal ICP-MS and ICP-MS with octupole reaction system].

The Se in the blood and tissue of animal samples was determined by ICP-MS instrument. The method was not only proved simple and rapid, but also showed satisfying precision and low detection limit. The optimum conditions of ICP-MS for the method were investigated. Results by the digestion method, the isotopes selection, and the difference between the normal ICP-MS without ORS (Octopole Reaction System) and the ICP-MS with ORS were compared, which afford reference to the determination of the same kinds of sample. The standard materials were determined to proved the reliability of the normal ICP-MS and the ORS-ICP-MS methods. The ORS-ICP-MS can effectively remove the interference based on polyatomic ions, so the the detection limits were lowed, and the accuracy was improved. The detection limits of the method for normal ICP-MS is 0.024 ng x g(-1) and that for ORS-ICP-MS is 0.004 6 ng x g(-1), the RSDs are between 1.8% and 5.5%, and the recoveries of the method are in the range of 90.8%-107.2%.

[Basic principle and impact factors of soil vapor extraction (SVE) technology for remediation of contaminated soils by volatile and semivolatile organics].

Because soil vapor extraction (SVE) is an effective, economic, and environmentally benign technology to remediate soils contaminated by volatile and semivolatile organics, it has been widely used in the remediation of these soils. The objectives of this paper were to introduce the basic principle of SVE and general steps of constructing SVE engineering, discuss major impact factors on remediation efficiency of SVE technology, and describe three kinds of enhanced SVE technologies. Finally, study and application progress of SVE technologies in China was introduced.

[Release and transform of lead from the glass of cathode ray tube (CRT) following its entrance in the soil].

The objective of this study was to investigate the release and transform Pb from the CRT glass following its entrance into the soil environment. A long-term incubation of soil mixed with CRT glass particles and sequential selective dissolution technology were used. Results indicated that the addition of CRT glass particle to the soil led to the increase in the total concentration of Pb in the soil from 28.4 mg/kg to 8 634.4 mg/kg. In details,the concentrations of Pb in the soluble and exchangeable form (EXC-Pb) and bound to the carbonate minerals (CARB-Pb) and manganese and iron oxides (RO-Pb) were 0.20-0.98 mg/kg, 20.1-103.6 mg/kg, and 26.7-54.3 mg/kg, respectively. The sum of these three fractions of Pb was 48.6-155.2 mg/kg. In the EXC, CARB, and RO dissolution steps, the concentrations of Pb directly released from the surface of the CRT glass particles were only (0.038 +/- 0.025), (7.55 +/- 3.13), (7.55 +/- 3.13) mg/kg, respectively. Hence, the released Pb from the CRT glass was mostly bound to the carbonate minerals and manganese and iron oxides in the soil. The decrease of pH from 8.0-8.3 to 7.1-7.5 did not significantly affect the chemical forms of Pb in the soil. The release rates of Pb from the CRT glass to the EXC, CARB, and RO forms were 0.15/t, 21.1/t, and 3.8/t mg x (kg x d)(-1), respectively (t is incubation time in unit of d). The CARB-Pb or RO-Pb might transform to EXC-Pb when pH or Eh of soil decreases, thus entrance of CRT glass particles in the soil environment may pose an ecological risk.