Development and validation of scales for speaking self-efficacy: Constructs, sources, and relations.

Speaking is not a compulsory language skill assessed in the English subject of the National College Entrance Examination in China. This explains why, in elementary and secondary schools, less focus has been placed on the development of English-speaking abilities among Chinese students, resulting in their unbalanced mastery of language skills. Although self-efficacy is a crucial factor influencing students' language performance, our understanding of speaking self-efficacy is insufficient in terms of its construct, its sources, and the relationships between the two. We, therefore, constructed psychometrically sound instruments to measure speaking self-efficacy, including the EFL Speaking Self-Efficacy Scale (EFL-SSES) and the EFL Sources of Speaking Self-Efficacy Scale (EFL-SSSES), in accordance with Bandura's 1986 self-efficacy theory. Additionally, we performed path analysis to figure out the relationship between the construct and the sources of speaking self-efficacy. The results revealed the key role of physiological and emotional states and marginal importance of vicarious experience for speaking self-efficacy, advancing our grasp of self-efficacy theory in the speaking domain. Our research sheds valuable light on how to assist researchers and educators in identifying and enhancing students' speaking self-efficacy via a variety of sources.

Molecularly Imprinted Polymer Nanospheres with Hydrophilic Shells for Efficient Molecular Recognition of Heterocyclic Aromatic Amines in Aqueous Solution.

Heterocyclic aromatic amine molecularly imprinted polymer nanospheres with surface-bound dithioester groups (haa-MIP) were firstly synthesized via reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization. Then, a series of core-shell structural heterocyclic aromatic amine molecularly imprinted polymer nanospheres with hydrophilic shells (MIP-HSs) were subsequently prepared by grafting the hydrophilic shells on the surface of haa-MIP via on-particle RAFT polymerization of 2-hydroxyethyl methacrylate (HEMA), itaconic acid (IA), and diethylaminoethyl methacrylate (DEAEMA). The haa-MIP nanospheres showed high affinity and specific recognition toward harmine and its structural analogs in organic solution of acetonitrile, but lost the specific binding ability in aqueous solution. However, after the grafting of the hydrophilic shells on the haa-MIP particles, the surface hydrophilicity and water dispersion stability of the polymer particles of MIP-HSs greatly improved. The binding of harmine by MIP-HSs with hydrophilic shells in aqueous solutions is about two times higher than that of NIP-HSs, showing an efficient molecular recognition of heterocyclic aromatic amines in aqueous solution. The effect of hydrophilic shell structure on the molecular recognition property of MIP-HSs was further compared. MIP-PIA with carboxyl groups containing hydrophilic shells showed the highest selective molecular recognition ability to heterocyclic aromatic amines in aqueous solution.

Preparation of Functionalized Zr-Based MOFs and MOFs/GO for Efficient Removal of 1,3-Butadiene from Cigarette Smoke.

Removal of 1,3-butadiene from cigarette smoke plays an important role in human health and environmental protection. Herein, a series of UiO-66 X% containing different ratios of the -NH2 group was synthesized via the solvothermal method by using terephthalic acid (H2BDC) and 2-aminoterephthalic acid (NH2-BDC) as ligands. Using GO as support, a series of UiO-66-NH2/GO Y% were prepared by controlling the ratio of UiO-66-NH2 and GO. The effects of -NH2 and GO contents on the structure and composition of MOFs were investigated. Finally, the different -NH2 contents of UiO-66 X% and the different GO contents of UiO-66-NH2/GO Y% were applied in 1,3-butadiene removal from cigarette smoke. The results showed that UiO-66 X% with the higher contents of -NH2 showed a higher rate of 1,3-butadiene removal, and UiO-66-NH2/GO Y% with the GO contents of 5% showed the highest removal rate of about 33.85%, which was 25.54% higher than that of activated carbon. In addition, the saturation capacity of the adsorbent materials for 1,3-butadiene was as high as 210.01-239.54 mg/g, showing great potential in reducing harmful components in cigarette smoke and environmental protection.

The Influence of Cognitive, Affective, and Sociocultural Individual Differences on L2 Chinese Speech Performance: A Multiple Indicators Multiple Causes Approach.

Informed by Segalowitz's (Cognitive bases of second language fluency, Routledge, 2010) L2 speech production model and MacIntyre et al.'s (Mod Lang J 82(4):545-562, 1998. https://doi.org/10.1111/j.1540-4781.1998.tb05543.x ) L2 willingness to communicate model, this study sought to understand the influence of cognitive, affective and sociocultural individual differences on advanced learners' L2 Chinese speech performance. A total of 240 advanced L2 Chinese learners in China participated in the study. The participants' perceptions of the impact of cognitive, affective, and sociocultural factors on their L2 Chinese speech performance were measured by an adapted questionnaire. A speaking test, following the Hanyu Shuiping Kouyu Kaoshi (HSKK, an international standardized L2 Chinese speaking proficiency test for non-native speakers), was employed to evaluate the participants' L2 Chinese speech performance. The results of multiple indicators multiple causes (MIMIC) analysis show that (1) cognitive factors such as cognitive fluency, expression practice strategy, and assistance strategy, (2) affective factors such as speaking self-efficacy, speaking anxiety, and speaking motivation, and (3) sociocultural factors such as attitudes toward target language class and attitudes toward target language culture jointly influence advanced L2 Chinese learners' speech performance. Results and implications of the present study are discussed for enhancing learners' L2 Chinese speech performance.

Novice Chinese as a foreign language teachers' identity construction in primary schools in New Zealand from positioning and affordance perspectives.

While there has been an increase in research on Chinese as a foreign language (CFL) teachers' identity worldwide, limited attention has been drawn to CFL teachers' positioning and affordances to interpret their identity construction in an overseas context. To fill the gap, this study investigated seven novice CFL teachers' identity construction as Chinese language teachers in primary schools in New Zealand from positioning and affordance perspectives. Retrospective semi-structured interviews were adopted to understand how the novice CFL teachers were positioned, how they positioned themselves, and what affordances they perceived to be influential to their Chinese language teacher identity construction. The findings showed that the novice CFL teachers' identity construction was subject to the social, institutional, and individual levels of being positioned, self-positioning, and affordances. Specifically, (1) consistent self-positioning at the social, institutional, and individual levels could largely determine the novice CFL teachers' identity construction; (2) inconsistency of identities between being positioned and self-positioning at the social, institutional, and individual levels might weaken the novice CFL teachers' identity construction; (3) affordances as opportunities at the social, institutional, and individual levels could strengthen the novice CFL teachers' identity construction, whereas affordances as challenges could not. The study concluded with implications and limitations to inform future research.

A Multidimensional Perspective on Individual Differences in Multilingual Learners' L2 Chinese Speech Production.

To date, research has been undertaken to reveal factors contributing to learners' second/foreign language (L2) speaking and/or learning at particular points in time in separate studies from cognitive, affective, and socio-cultural perspectives as individual variables. Nonetheless, little research has concurrently investigated L2 speaking with the same cohort of learners as participants from these perspectives in a single study, to obtain comprehensive and systematic understandings of how the three dimensions of factors work together in influencing individuals' L2 speaking. This study, utilizing Segalowitz's (2010) L2 speech production framework as the theoretical lens, examined a group of L2 Chinese multilinguals' perceptions toward their speech performance and production ability development, attempting to comprehensively and systematically uncover the factors influencing L2 speaking from the three perspectives mentioned above. We collected data through focus groups and semi-structured interviews from 17 advanced level L2 Chinese multilinguals. The findings of the study revealed that factors that influenced the L2 Chinese multilinguals' speech performance and their development of such an ability included the following: (1) age of acquisition, cognitive fluency, learning styles, and speaking strategies; (2) motivation, anxiety, speaking self-efficacy, and willingness-to-communicate; (3) L2 cultural interest, L2 communities, and L2 classes; and (4) multilingualism. We conclude that the development of L2 Chinese speech production ability could be the result of the synergies gained from the cognitive, affective, and socio-cultural dimensions of L2 learning and use. Insights into L2 Chinese teachers and learners in terms of how to support and sustain the improvement of L2 Chinese speech production ability are also discussed.

Preparation of PolyHIPE Scaffolds for 3D Cell Culture and the Application in Cytotoxicity Evaluation of Cigarette Smoke.

Polystyrene-based polyHIPE (polymerized high internal phase emulsion) materials were prepared by the copolymerization of styrene and divinylbenzene in the continuous phase of a HIPE. The resultant polyHIPE materials were found to have an open-cellular morphology and high porosity, and the polyHIPE structure could be well adjusted by varying the water/oil (W/O) ratio and the amount of emulsifier in the HIPE. Cell culture results showed that the resultant polyHIPE materials, which exhibited larger voids and connected windows as well as high porosity, could promote cell proliferation on the 3D scaffold. A 3D cell cytotoxicity evaluation system was constructed with the polystyrene-based polyHIPE materials as scaffolds and the cigarette smoke cytotoxicity was evaluated. Results showed that the smoke cytotoxicity against A549 cells is much lower in the 3D cell platform compared to the traditional 2D system, showing the great potential of the polyHIPE scaffolds for 3D cell culture and the cytotoxic evaluation of cigarette smoke.

Functional Porous Carboxymethyl Cellulose/Cellulose Acetate Composite Microspheres: Preparation, Characterization, and Application in the Effective Removal of HCN from Cigarette Smoke.

To selectively reduce the yield of hydrogen cyanide (HCN) in the cigarette smoke, functional porous carboxymethyl cellulose/cellulose acetate (CMC/CA) composite microspheres were prepared via the double emulsion-solvent evaporation method. Cupric ions, which have a high complexing ability toward HCN, were introduced to the CMC/CA composite microspheres during the fabrication process via an in situ ion cross-link method. The microspheres were characterized using nitrogen adsorption, mercury intrusion porosimetry, and scanning electron microscopy (SEM). The microspheres have a predominantly macroporous structure indicating weak physisorption properties, but sufficient functional cupric ion groups to selectively adsorb HCN. With these CMC/CA microspheres as filter additives, the smoke yield of HCN could be reduced up to 50%, indicating the great potential of these microspheres as absorbents for removing HCN from cigarette smoke.

pH-Sensitive Polyampholyte Microgels of Poly(Acrylic Acid-co-Vinylamine) as Injectable Hydrogel for Controlled Drug Release.

pH-sensitive polyampholyte microgels of poly(acrylic acid-co-vinylamine) (P(AA-co-VAm)) were developed as an injectable hydrogel for controlled drug release. The microgels of P(AA-co-VAm) were prepared via inverse suspension polymerization of acrylic acid and N-vinylformamide followed by hydrolysis of poly(N-vinylformamide) (PNVF) chains of the resultant microgels under basic condition. The pH-sensitivity of the P(AA-co-VAm) microgels in zeta potential and swelling ratio were investigated using a zeta potential analyzer and optical microscope. The results showed that both the zeta potential and the swelling ratio of the microgels were highly affected by the solution pH. By changing the pH of P(AA-co-VAm) microgel dispersion, the interparticle interaction and the swelling ratio of the microgels could be well adjusted and a colloidal hydrogel could be fabricated at moderate pH, showing a pH-triggered reversible fluid-gel transition. Using the polyampholyte P(AA-co-VAm) microgels as an injectable hydrogel drug release system, a sustained drug release could be achieved, indicating the great potentials of the pH-sensitive P(AA-co-VAm) microgels for controlled drug delivery.

Investigation of the chromatographic regulation properties of benzyl groups attached to bridging nitrogen atoms in a calixtriazine-bonded stationary phase.

Two reversed-phase/anion-exchange mixed-mode stationary phases for high-performance liquid chromatography using calixtriazines as chromatographic ligands were investigated with Tanaka test solutes, monosubstituted benzenes, aromatic positional isomers, and inorganic anions. Calixtriazine as a chromatographic ligand has been reported previously, but the benzylated nitrogen-bridged calixtriazine-bonded silica gel reported in this study is new. The experimental data showed that the calixtriazine platform is a unique chromatographic selector because its multiple active sites are available for different solutes and its chromatographic selectivity could be tuned by introducing substituent on the bridging nitrogen atoms present in the calixtriazine matrix. The synergistic effects of aromatic rings, nitrogen atoms, benzyl groups, and tunable cavity in the host molecule influenced the separation selectivity by multiple retention mechanisms. Such hybrid stationary phases provide more versatility and have great potential in the analysis of complex samples. Moreover, the synthetic protocols presented herein may provide an alternative understanding on macrocyclic host-guest chemistry, leading to new and selective separation media.

Profiling Perceptual Learning Styles of Chinese as a Second Language Learners in University Settings.

This study revisited Reid's (1987) perceptual learning style preference questionnaire (PLSPQ) in an attempt to answer whether the PLSPQ fits in the Chinese-as-a-second-language (CSL) context. If not, what are CSL learners' learning styles drawing on the PLSPQ? The PLSPQ was first re-examined through reliability analysis and confirmatory factor analysis (CFA) with 224 CSL learners. The results showed that Reid's six-factor PLSPQ could not satisfactorily explain the CSL learners' learning styles. Exploratory factor analyses were, therefore, performed to explore the dimensionality of the PLSPQ in the CSL context. A four-factor PLSPQ was successfully constructed including auditory/visual, kinaesthetic/tactile, group, and individual styles. Such a measurement model was cross-validated through CFAs with 118 CSL learners. The study not only lends evidence to the literature that Reid's PLSPQ lacks construct validity, but also provides CSL teachers and learners with insightful and practical guidance concerning learning styles. Implications and limitations of the present study are discussed.

Distribution of toxic chemicals in particles of various sizes from mainstream cigarette smoke.

To accurately estimate the risk of inhaling cigarette smoke containing toxic chemicals, it is important that the distribution of these chemicals is accurately measured in cigarette smoke aerosol particles of various sizes. In this study, a single-channel smoking machine was directly coupled to an electrical low-pressure impactor. The particles of mainstream cigarette smoke were collected using 12 polyester films, and the particulate matter (PM) was characterized. Nicotine, tobacco-specific N-nitrosamines (TSNAs, including NNN, NAT, NAB, and NNK), polycyclic aromatic hydrocarbons (PAHs, including benzo(a)pyrene (BaP), benzo(a)anthracene, and chrysene), and heavy metals (including Cr, As, Cd, and Pb) present in the particles of different sizes were analyzed by GC, HPLC-MS/MS, GC/MS, or ICP-MS, respectively. The results demonstrated that the nicotine, TSNAs, PAHs, and heavy metals in mainstream cigarette smoke were dispersed over a particle size ranging from 0.1 µm to 2.0 µm, and the concentration of these toxic chemicals initially increased and then decreased the particle size grew. The distribution of nicotine was uniform for the PM in the size ranges of less than 0.1 µm, 0.1-1.0 µm, and 1.0-2.0 µm, TSNAs and heavy metals in particles of less 0.1 µm were more abundant, and PAHs in fine particles were also more abundant.

A chemometric-assisted method based on gas chromatography-mass spectrometry for metabolic profiling analysis.

An automatic and efficient data analysis method for comprehensive metabolic profiling analysis is urgently required. In this study, a new chemometric-assisted method for metabolic profiling analysis (CAMMPA) was developed to discover potentially valuable metabolites automatically and efficiently. The proposed method mainly consists of three stages. First, automatic chromatographic peak detection is performed based on the total ion chromatograms of samples to extract chromatographic peaks that can be accurately quantified. Second, a novel peak-shift alignment technique based on peak detection results is implemented to resolve time-shift problems across samples. Consequently, aligned results, including aligned chromatograms, and peak area tables, among others, can be successfully obtained. Third, statistical analysis using results from unsupervised and supervised classification results, together with ANOVA and partial least square-discriminate analysis, is performed to extract potential metabolites. To demonstrate the proposed technique, a complex GC-MS metabolic profiling dataset was measured to identify potential metabolites in tobacco plants of different growth stages as well as different plant tissues after maturation. Results indicated that the efficiency of the routine metabolic profiling analysis procedure can be significantly improved and potential metabolites can be accurately identified with the aid of CAMMPA.

Novel reduction-sensitive micelles for triggered intracellular drug release.

Novel reduction-sensitive micelles based on poly(ethylene oxide)-b-poly(N-methacryloyl-N'-(t-butyloxycarbonyl)cystamine) (PEO-b-PMABC) diblock copolymers were developed and applied for triggered intracellular drug release. PEO-b-PMABC block copolymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of MABC with dithioester-capped PEO as macroRAFT agent. Gel permeation chromatography (GPC) and (1)H NMR analysis showed that the copolymers have controlled compositions and molecular weights, indicating the living nature of polymerization. These copolymers were self-assembled into micelles. The physicochemical characteristics and reduction-sensitivity of the resultant micelles were investigated by fluorescence measurement, transmission electron microscopy (TEM), and dynamic light scattering (DLS). The results showed that PEO-b-PMABC micelles are stable at normal physiologic condition but readily cleaved into free copolymers under reducing environment. In vitro release of doxorubicin (DOX) and cell experiments showed that the drug-loaded PEO-b-PMABC micelles accomplished much faster drug release under reducing condition and higher anticancer efficacy as compared to the control without reduction-sensitivity, indicating great potential of PEO-b-PMABC micelles for efficient intracellular drug delivery.

Thermosensitive nanoparticles self-assembled from PCL-b-PEO-b-PNIPAAm triblock copolymers and their potential for controlled drug release.

Thermosensitive nanoparticles with a core-shell structure were prepared by self-assembly of PCL-b-PEO-b-PNIPAAm triblock copolymers, which were synthesized by anionic ring-opening polymerization and reversible addition fragmentation chain transfer (RAFT) polymerization. At temperatures above the lower critical solution temperature (LCST), the collapse of PNIPAAm chains in the outer shell and in the core of nanoparticle caused a decrease in size, while the constantly hydrophilic PEO chains in the shell endowed nanoparticles with excellent stability in water. The release of doxorubicin from these nanoparticles showed that both the length of PNIPAAm chains and temperature have great influence on drug release, which indicates the great potential of thermosensitive nanoparticles as drug carriers.