Development of a theoretical construct for teacher expertise in the Chinese context and identification of its components: A mixed-methods study.

Introduction: Teacher expertise is a vital element of teaching quality. Examining what constitutes teacher expertise has important implications for the theoretical development and practical application of teacher expertise. The present study was conducted to develop a theoretical construct for teacher expertise in the Chinese context, identify its components, and verify the validity of this construct. Methods: This study adopted an exploratory sequential mixed-methods design. To develop a construct for teacher expertise and identify its components, critical incident interviews were conducted with 102 primary and secondary school teachers. Grounded theory analysis was applied to code 621 stories from critical incident interviews. To verify the construct validity and discriminant validity, a survey of 1,041 teachers was conducted in 21 primary schools and 20 secondary schools in Hebei and Shanxi provinces. Confirmative factor analysis, Kruskal-Wallis test, and Mann-Whitney test were used to evaluate the validity of the construct. Results: Knowledge structure, teaching ability, and professional development agency constituted the construct for teacher expertise. This construct had good construct validity and discriminant validity. Knowledge structure could not identify expertise. Teaching ability and professional development agency could differentiate between expert and non-expert teachers. Discussion: Teacher expertise is a complex, multidimensional, and adaptive construct. The construct can be used as a valid and reliable instrument to identify and develop teacher expertise. Moreover, this study expands on prior studies and complements recent theoretical models describing teacher expertise.

Synthesis of polyaspartic acid-capped 2-aminoethylamino acid as a green water treatment agent and study of its inhibition performance and mechanism for calcium scales.

Polyaspartic acid (PASP), a well-known green scale inhibitor for industrial water treatment, might be decomposed with prolonged duration, and its anti-scaling performance against CaCO3 and CaSO4 is diminished at a low concentration (<10 mg L-1) and a high temperature. With semi-ethylenediaminetetraacetic acid (EDTA) tetrasodium salt as the mimicking model, novel phosphorus-free PASP-capped 2-aminoethylamino acid (PASP-ED2A) containing side chains bearing multi-functional groups is rationally designed and successfully prepared via the ring-opening reaction of cheap poly(succinimide) under mild reaction conditions with the assistance of readily available 2-aminoethyl amino acid. The static scale inhibition method is used to evaluate the scale inhibition performance of the as-synthesized PASP derivative. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy are utilized to monitor the crystallization process of calcium carbonate and calcium sulfate scales, and density functional theory calculations are conducted to shed light on the relationship between the molecular structure and scale inhibition mechanism of PASP-ED2A. Results show that the as-prepared PASP-ED2A shows better scale inhibition performance for CaCO3 and CaSO4 than PASP with a low concentration, a high temperature, and an extended duration. Particularly, PASP-ED2A with a concentration of 10 mg L-1 exhibits the best scale inhibition performance for CaCO3; its scale inhibition capacity is about two times as much as that of PASP. The reason lies in that the coordination atoms in the molecular structure of PASP-ED2A can chelate with Ca2+ to inhibit the combination of Ca2+ with anions and prevent the generation of CaCO3 and CaSO4 scales. The PASP-ED2A derivative can more efficiently retard the formation and growth of CaCO3 and CaSO4 crystal nuclei and exerts better inhibition performance against CaCO3 and CaSO4 scales than PASP.

Paternalistic Leadership and Subordinates' Trust in Supervisors: Mediating Effects of Basic Psychological Needs Satisfaction.

Subordinates' trust is critical for a supervisor's exercise of leadership to effectively influence subordinates' work outcomes. However, the optimal approach for facilitating trust is still under debate, between instrumentality-based and motivation-based perspectives. On the basis of self-determination theory (SDT), the current study explored the direct effects of paternalistic leadership on trust in supervisors (TS) and the mediating role of the satisfaction of subordinates' basic psychological needs. In a survey of 1,076 teachers in China, we found that paternalistic leadership affected trust directly, and that subordinates' need for competence, autonomy, and relatedness also mediated the leadership-trust relationship to different degrees. The theoretical and practical implications of these findings are discussed.

Comparison of domestic infantile type video intubationscope and stethoscope in positioning of double-lumen endobronchial tube / 中国内镜杂志

Objective To compare the effect of the domestic infantile type video intubationscope (VIS) and stethoscope in positioning of double-lumen endobronchial tube (DLT). Methods 100 cases of patients underwent elective thoracic surgery requiring single lung ventilation were randomly divided into two groups: domestic infantile type video intubationscope group (group V) and stethoscope group (group S), with 50 cases in each. After intubating with a DLT, the positions of DLT were judged and adjusted by VIS (group V) and stethoscope (group S) respectively, and then reviewed by fiberoptic bronchoscopy (FOB), the positioning time and accuracy were recorded. Results Comparing with the group S, the positioning time of DLT was significantly shorter and the total positioning accuracy of DLT was significantly higher in group V (P < 0.05). Conclusion It is easy and quickly, high accuracy with domestic infantile type video intubationscope in positioning of DLT, which is worthy of clinical popularization and application.

Comparison of domestic infantile type video intubationscope and stethoscope in positioning of double-lumen endobronchial tube / 中国内镜杂志

Objective To compare the effect of the domestic infantile type video intubationscope (VIS) and stethoscope in positioning of double-lumen endobronchial tube (DLT). Methods 100 cases of patients underwent elective thoracic surgery requiring single lung ventilation were randomly divided into two groups: domestic infantile type video intubationscope group (group V) and stethoscope group (group S), with 50 cases in each. After intubating with a DLT, the positions of DLT were judged and adjusted by VIS (group V) and stethoscope (group S) respectively, and then reviewed by fiberoptic bronchoscopy (FOB), the positioning time and accuracy were recorded. Results Comparing with the group S, the positioning time of DLT was significantly shorter and the total positioning accuracy of DLT was significantly higher in group V (P < 0.05). Conclusion It is easy and quickly, high accuracy with domestic infantile type video intubationscope in positioning of DLT, which is worthy of clinical popularization and application.

Structure-based discovery of highly selective phosphodiesterase-9A inhibitors and implications for inhibitor design.

A new series of phosphodiesterase-9 (PDE9) inhibitors that contain a scaffold of 6-amino-pyrazolopyrimidinone have been discovered by a combination of structure-based design and computational docking. This procedure significantly saved the load of chemical synthesis and is an effective method for the discovery of inhibitors. The best compound 28 has an IC(50) of 21 nM and 3.3 µM, respectively, for PDE9 and PDE5 and about 3 orders of magnitude of selectivity against other PDE families. The crystal structure of the PDE9 catalytic domain in complex with 28 has been determined and shows a hydrogen bond between 28 and Tyr424. This hydrogen bond may account for the 860-fold selectivity of 28 against PDE1B, in comparison with about 30-fold selectivity of BAY73-6691. Thus, our studies suggest that Tyr424, a unique residue of PDE8 and PDE9, is a potential target for improvement of selectivity of PDE9 inhibitors.

[Construction of quantitative real-time PCR detection system of transgenic tomato line Zeneca B,Da,F].

OBJECTIVE: To construct the plasmid reference molecules for detection of transgenic tomato line Zeneca B,Da,F using quantitative real-time PCR(qPCR). METHODS: Three plasmid reference molecules pEasy-T3-APX, pEasy-T3-16A and pEasy-T3-16S were cloned based on reverse genetics, which contain the target fragments of tomato endogenous reference gene apx (ERG-apx), gene-specific sequence of pg(GS-pg) and construct-specific sequence of vectors pJR16S/pJR16A (CS-16S/CS-16A) of Zeneca B,Da,F, respectively. Primers and Taqman probes were designed by Beacon Designer 7.5.The specificity, sensitivity, reproducibility and the limit of detection(LOD) of the qualitative and quantitative PCR system based on the plasmid reference molecules were evaluated. PicoGreen was used to measure the DNA concentration of the plasmid reference molecules. Two sets of samples containing 1% or 0.1% (w/w) pEasy-T3-16A or pEasy-T3-16S mixed with pEasy-T3- APX as background DNA were prepared for evaluating the efficacy of the qPCR system. RESULTS: The target fragments for qPCR detection were anchored, ERG-apx 108 bp, GS-pg 108 bp , CS-16S 109 bp and CS-16A 102 bp. The three plasmid reference molecules were confirmed at the expected sizes by restriction enzyme digestion. The qPCR results showed that the RSD of reproducibility were 0.2% to1.5%, LOD was 25 copies, R2 values for these standard curves were 0.994 ~0.998 and amplification efficiencies were 93.3%~102.4%.The bias between the test and true values of two sets of mixed samples ranged from -9.3% to 14.7% after adjusting by conversion factors(Cf). CONCLUSION: The plasmid reference molecules and qPCR system for qualitative and quantitative detection of transgenic tomato line Zeneca B,Da,F have been established successfully.