Binding mechanism of arsenate on rutile (110) and (001) planes studied using grazing-incidence EXAFS measurement and DFT calculation

Characterization of contaminant molecules on different exposed crystal planes is required to conclusively describe its behavior on mineral surfaces. Here, the structural properties and relative stability of arsenate adsorbed on rutile TiO2 (110) and (001) surfaces were investigated using grazing-incidence extended X-ray absorption fine structure (GI-EXAFS) spectra and periodic density functional theory (DFT) calculation. The combined results indicated that arsenate mainly formed inner-sphere bidentate binuclear (BB) and monodentate mononuclear (MM) complexes on both surfaces, but the orientational polar angles of arsenate on the (110) surface were commonly smaller than that on the (001) surface for the two adsorption modes. The DFT calculation showed that the (110) plane had a higher affinity toward arsenate than the (001) plane, suggesting that, for a given adsorption mode (i.e., MM or BB structure), a small polar angle was more favorable for arsenate stabilized on the rutile surfaces

Structure and stability of arsenate adsorbed on α-Al2O3 single-crystal surfaces investigated using grazing-incidence EXAFS measurement and DFT calculation

Direct characterization of contaminants on single-crystal planes is required because the specific adsorption characteristics on different exposed crystal planes constitute their actual behavior at water–mineral interfaces in aquifers. Here, the structure and stability of arsenate on α-Al2O3 (0001) and (View the MathML source112¯0) surfaces were characterized by using a combination of grazing-incidence extended X-ray absorption fine structure (GI-EXAFS) spectra and periodic density functional theory (DFT) calculation. The combined results indicated that arsenate was mainly adsorbed as inner-sphere monodentate and bidentate complexes on both surfaces, but the orientational polar angles on the (0001) surface were commonly 10–20° greater than that on the (View the MathML source112¯0) surface. The DFT calculation showed that the large polar angle was more favorable for arsenate stabilized on the alumina surfaces. Based on the spectroscopic and computational data, the dominant bonding modes of arsenate on the two crystal planes of α-Al2O3 were identified as bidentate binuclear structures, and the (0001) surface displayed a stronger affinity toward arsenate

Molecular dynamics simulations of structural transformation of perfluorooctane sulfonate (PFOS) at water/rutile interfaces

Concentration and salinity conditions are the dominant environmental factors affecting the behavior of perfluorinated compounds (PFCs) on the surfaces of a variety of solid matrices (suspended particles, sediments, and natural minerals). However, the mechanism has not yet been examined at molecular scales. Here, the structural transformation of perfluorooctane sulfonate (PFOS) at water/rutile interfaces induced by changes of the concentration level of PFOS and salt condition was investigated using molecular dynamics (MD) simulations. At low and intermediate concentrations all PFOS molecules directly interacted with the rutile (110) surface mainly by the sulfonate headgroups through electrostatic attraction, yielding a typical monolayer structure. As the concentration of PFOS increased, the molecules aggregated in a complex multi-layered structure, where an irregular assembling configuration was adsorbed on the monolayer structure by the van der Waals interactions between the perfluoroalkyl chains. When adding CaCl2 to the system, the multi-layered structure changed to a monolayer again, indicating that the addition of CaCl2 enhanced the critical concentration value to yield PFOS multilayer assemblies. The divalent Ca2+ substituted for monovalent K+ as the bridging counterion in PFOS adsorption. MD simulation may trigger wide applications in study of perfluorinated compounds (PFCs) from atomic/molecular scale

The Roles of Cultural Capital in Teacher–Student Interactions in China: A Qualitative Study of Students in Higher Vocational Colleges

The theory of cultural capital has long been applied to explain academic achievement. This qualitative study investigated first-year students in higher vocational colleges and, taking this low cultural capital group as an example, explored how cultural capital has affected their past teacher–student interactions. Participants described their experience of interacting with their teachers. We found that these students primarily experienced authoritative and laissez-faire teacher–student interactions. Students’ embodied and institutionalized cultural capital profoundly affected different aspects of the teacher–student interaction. In modern China, vocational and academic education are of the same status, so teachers should modify their evaluations based solely on academic achievement. When interacting with students, teachers should be more understanding and interact in a more student-centred way. Teacher training programmes should also be reformed, and training for teachers in general and vocational schools should be distinguished

Ultrasound-guided internal branch of superior laryngeal nerve block on postoperative sore throat: A randomized controlled trial.

IntroductionUltrasound-guided internal branch of the upper laryngeal nerve block (USG-guided iSLN block) have been used to decrease the perioperative stress response of intubation. It is more likely to be successful than blindly administered superior laryngeal nerve blocks with fewer complications. Here, we evaluated the efficacy of USG-guided iSLN block to treat postoperative sore throat (postoperative sore throat, POST) after extubation.Methods100 patients, aged from 18 to 60 years old, ASA I~II who underwent general anesthesia and suffered from the moderate to severe postoperative sore throat after extubation were randomized into two groups(50 cases per group). Patients in group S received USG-guided iSLN block bilaterally (60mg of 2% lidocaine, 1.5ml each side), whereas those in group I received inhalation with 100 mg of 2% lidocaine and 1mg of budesonide suspension diluted with normal saline (oxygen flow 8 L /min, inhalation for 15 minutes). The primary outcome were VAS scores in both groups before treatment (T0), 10 min (T1), 30 min(T2), 1h(T3), 2 h(T4), 4h(T5), 8h(T6), 24h(T7), and 48h(T8) after treatment. The secondary outcome were satisfaction scores after treatment, MAP, HR, and SPO2 fromT0 to T8. The adverse reactions such as postoperative chocking or aspiration, cough, hoarseness, dyspnea were also observed in both groups.ResultsPatients in group S had significantly lower VAS score than that in group I at points of T1 ~ T6 (P ConclusionCompared with inhalation, USG-guided iSLN block may effectively relieve the postoperative sore throat after extubation under general anesthesia and provided an ideal treatment for POST in clinical work

Combined DFT and IR evidence on metastable-equilibrium adsorption of arsenate on TiO2 surfaces

Adsorption of arsenate on TiO2 surfaces under the same total mass and thermodynamic conditions reached to different final equilibrium states when the reaction was conducted through different pathways. The microscopic structure for equilibrium adsorption samples were significantly affected by the way arsenate was added to the TiO2 suspension (e.g. 1-batch or multi-batch). The As-OTi asymmetric stretching vibration of 3-batch samples shifted to lower wavenumbers; by 15 cm(-1) than that of 1-batch samples. Combined analysis of ATR-FTIR spectroscopy and DFT calculation indicated that the change of reaction pathway altered the ratio of double-corner complex to single-corner complex and, hence, the real equilibrium state that is a mixture of the two surface complexes. (C) 2009 Elsevier Inc. All rights reserved

Additional file 1 of Lipid metabolic reprogramming mediated by circulating Nrg4 alleviates metabolic dysfunction-associated steatotic liver disease during the early recovery phase after sleeve gastrectomy

Additional file 1: Figure S1. Screening flow chart of obese patients who underwent laparoscopic sleeve gastrectomy and healthy control of non-obese volunteers.Figure S2. Conventional Nrg4 knockout mice. Figure S3. Comparisons of clinical parameters among control, pre-SG, and post-SG groups. Figure S4. Comparison of BMI among control, pre-SG, and post-SG groups as well as correlations between adipokines and BMI. Figure S5. Correlations between metabolic parameters and LSR. Figure S6. Comparisons of metabolic parameters among different mice groups respectively at the 2nd and 4th postoperative weeks. Figure S7. Establishment and characterization of Nrg4 overexpression system in liver cell lines