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Whilst many studies have explored academic identity construction, very few take a comparative perspective to examine the various ways of constructing academic identities within and across different disciplines. This paper analyses a key policy document used for evaluating academics' performance along with semi-structured interviews with 37 academics from Chemical Sciences, Medical Sciences, Nursing and Education working in a research-intensive New Zealand university. The use of Foucault's theoretical construct of games of truth provides a novel perspective to investigate the ways in which academics in different disciplines play the academic 'game' and how this might affect their construction of an academic identity. Our analysis suggests that the path into academia is a key factor in their trajectory of academic formation. The study suggests three types of 'valid' academics. It problematises the standardised definition and evaluation of academics and offers contextualised, multiple, dynamic and agential understandings of being and becoming set up through the interplay of forces arising from disciplinary, institutional, professional and personal spheres.

Hydrogel is an interesting topic in polymer chemistry, which is closely related to daily life and advanced technology. In this paper, we report an activity to deliver hydrogel chemistry into middle school classrooms by undergraduates as a bridge between professors and students. During the activity, undergraduates act as a bridge to receive knowledge from professors, reprocess it, and finally deliver it to middle school students. The activity comprises a 60 min lecture and a 30 min hands-on experiment and aims to provide a deep understanding of hydrogel. The lecture starts from the jelly, a popular snack for students, in order to introduce hydrogels. Then, the various applications of hydrogels are mentioned to indicate why hydrogel materials are interesting and how hydrogel materials help doctors treat various diseases. Moreover, middle school students expand their minds from everyday applications to advanced technologies by engaging in discussions as well as a hands-on experiment. The survey before and after the activity shows it can play an important role in helping middle school students understand hydrogels and sprout their interest in chemistry. The activity has been successfully held in four local middle schools and more sessions are planned to be held in more middle schools in the near future. Undergraduates also deepened their understanding of hydrogel chemistry and sprouted their interest in scientific research in this activity.

Chemical kinetics is a branch of physical chemistry that constitutes an essential part of undergraduate education. In general, a complex and expensive experimental apparatus is indispensable for observing the kinetics of a chemical process owing to the continuity of chemical reactions. Thus, intuitive visualization of the chemical kinetics using a simple experimental apparatus is challenging. Herein, a portable flow reactor was designed and used to observe the chemical kinetics of a first-order process. Continuous chemical reactions were visualized via the flow reactor as static patterns with color gradients. The thermochromism of the rhodamine B salicylaldehyde hydrazone zinc(II) complex was visualized via the flow reactor and found to follow first-order kinetics. The color gradients of static reaction patterns were analyzed by comparing them with standard color cards, and the kinetic parameters, such as the reaction rate constants at different temperatures and the activation energy, were determined. By performing this experiment, students can learn about flow chemistry, photochromism, and thermochromism. The interesting experimental process and distinct color changes can hold the students' attention. The two calculation methods can help the students better understand the rate equation of a first-order reaction. The experimental apparatus is low cost and commercially available, which is beneficial for the widespread use of this experiment.

An integrated system comprising a commercial high-performance liquid chromatography HPLC (except autosampler) equipped with an external multichannel autofeeding module was developed to accomplish interference-free separation and kinetic tracking for the H[subscript 2]O[subscript 2]-thiourea reaction, which is proposed as a lab experiment for students who have the background of chemical kinetics. Compared to conventional HPLC, the proposed system: (i) provides a similar pedagogical purpose, where students' knowledge in chemistry can be strengthened and improved and (ii) enables online species tracking and kinetic analysis of reactions with the spectral overlap of multiple species, and other interference factors such as turbidity caused by precipitation formation, bubble requirement, or external excitation light for photocatalysis. Additionally, automation of the proposed equipment allows for saving labor and high efficiency. Based on the reliability and accuracy of the proposed system, different species including reactants, intermediates, and products were simultaneously tracked during thiourea oxidation. Both kinetic curves of multiple species and kinetic parameters obtained provide lots of reliable data for fitting and mechanistic analysis. Because the H[subscript 2]O[subscript 2]-thiourea reaction as a lab experiment successfully performed by students with this technology has proven its operability for undergraduates majoring in chemistry, this proposed method is easy to extend to environmental science, pharmacokinetics, and other fields.

The dangers of organic dye pollutants and environmental pollution improvement through photocatalytic degradation are important courses in applied chemistry programs in universities. Zinc oxide (ZnO)-based nanomaterials are potent catalytic agents against organic dyes, but few experiments are available for students to understand their role and mechanism in class. Herein, we designed a comprehensive experiment across 24 class hours for undergraduates to investigate the photodegradation of colored organic dyes, including methylene blue, methyl orange, methyl violet, rhodamine B, basic fuchsin, and thymolphthalein, by a nanocomposite composed of ZnO-coated graphene oxide (ZnO/GO). This nanomaterial was prepared using a facile heating reflux method within 1 h. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction were introduced to students to characterize the synthesized products. Students could observe the time- and dose-dependent degradation as well as the reusability of ZnO/GO. Additionally, the addition of t-butanol, benzoquinone, and triethanolamine, scavengers of hydroxyl radical ([superscript .]OH), superoxide anion ([superscript .]O[superscript 2-]), and hole (h[superscript +]), respectively, to the degradation system allowed them to master the underlying catalytic mechanism of ZnO/GO. This experiment improves students' understanding of the photocatalytic effect of ZnO nanomaterials and stimulates them to engage in the field of applied chemistry and thus is worth recommending to undergraduates.

The chlorination reaction of aromatic compounds is highly important for the synthesis of pharmaceutical products. As the most common chlorination reagent, chlorine is restricted from undergraduate laboratory experiment training due to its toxicity. In this work, we reported the chlorination of aromatic compounds with chlorine generated from the paired electrolysis of N-chlorosuccinimide. The chlorine in this reaction is produced and consumed in an on-demand manner, ensuring the safety of the reaction, workup, and purification. The reaction is evaluated with 5 undergraduate students with reproducible results and conveys the basic concepts of electrochemical organic synthesis and green synthesis to these students.

The helium-plasma (HePI) ionization mass spectrometry method was used to track the formation of reaction products and consumption of reactants by continually monitoring the vapors in the reaction headspace in real time. Two examples of the application procedure are presented here: a nucleophilic acyl substitution reaction and a 1,4-nucleophilic addition process. For the purposes of the work, a specially constructed helium-plasma ionization (HePI) source was mounted on a single-quadrupole benchtop mass spectrometer. However, any electrospray source is easily convertible to an ambient HePI source. This setup has the potential to be used in the teaching of organic and analytical chemistry laboratories, as well as for demonstrations. Because the procedure requires only the headspace of the reaction vessel to be sampled by an easily prepared Venturi suction device (pump), the experiments can be quickly set up and adapted for any available mass spectrometer equipped with an electrospray source. For sampling, students can be shown how to prepare their own Venturi pumps and conduct reactions at different temperatures.

High-performance liquid chromatography (HPLC) experiments are an important part of the undergraduate analytical instrumentation laboratory courses and usually use commercial C18 silica-packed reversed-phase columns. In this experiment, a simple method of preparing SiO[subscript 2] core-shell packed columns was developed to enable students to master the whole process of HPLC experiment from stationary phase preparation and column packing to separation experiments, just as they do for gas chromatography. Nonporous SiO[subscript 2] particles with a particle size of approximately 2.2 [mu]m were prepared by a three-step dilution reaction using the sol-gel method. The product yield was 92.1%. Monodisperse and spherical SiO[subscript 2] core-shell particles (SiO2@dSiO[subscript 2]) with a particle size of about 2.4 [mu]m were prepared by a one-step hydrothermal method using the prepared SiO2 spheres as the core. The product yield was 83.3%. The prepared SiO[subscript 2]@dSiO[subscript 2] particles were derivatized with n-octadecyldimethylchlorosilane and then packed into a stainless steel chromatography column. A high column efficiency of 83,188 theoretical plates per meter was obtained for fluorene in reversed-phase mode for the separation of a mixture of polycyclic aromatic hydrocarbons. The column efficiency obtained with this method is the same as that of a commercial column packed with fully porous particles of the same particle size. The SiO[subscript 2] core-shell stationary phase preparation method developed in this experiment has the advantages of simple process, high yield, and good repeatability. The experiment can be designed to be completed over a period of 1-3 weeks. Inorganic material synthesis is another important aspect of this experiment.

We describe an iodometric titration method for the determination of ascorbic acid using a microfluidic paper-based analytical device([mu]PAD). The ascorbic acid was detected by measuring the length of the blue band formed in a straight paper channel delimited by wax. This analytical method was designed as a laboratory experiment for under graduates majoring in chemical education. The main objectives of this practice are to introduce [mu]PAD into a preservice teacher's classroom, motivating their passion of learning chemistry, and implementing green chemistry education. Finally, we hope this novel microscale chemistry experiment could be introduced into the chemistry classroom at high schools by these preservice teachers after graduation. A total of 145 preservice chemistry teachers performed this experiment in the fifth semester. They completed this experiment within 3 h; positive feedback from these students indicated that the learning objectives and instructional aims were met.

Teaching through experiments has always been an indispensable teaching method in chemistry and other STEM disciplines. Letting more students have access to experiments at the frontier of scientific research is essential to stimulating students' interest in chemistry. With the advancement of computer technology, virtual simulation experiments (VSEs) provide a new method to perform chemical experiments for the students who might have no resources to conduct an experiment. Here, a VSE of preparation and test analysis of flexible nanochannel membrane materials is designed by our group at Xiamen University in China, which is an interactive learning platform for studying and practicing experiments reported in the latest scientific articles. The objective pursued herein is to equip students with the appropriate tools and strategies required to perform a dangerous or complex chemical experiment. Multiexperimental paths are designed in different experimental modules and steps to meet students' exploration needs. Our platform suits both on- and off-campus undergraduates or graduates with open access. After practicing 5-6 times, students can gain more professional skills and get higher scores in the test section as the feedback. VSE could become a remote-flexible experimental teaching method with a safer process, lower cost, and wider academic community, especially during the pandemic or in the postpandemic era.

There is a long tradition of teaching science through inquiry, with broad agreement about the form it should take. Students should investigate researchable questions; gather and analyse data; and develop and represent evidence-based claims. Authoritative teacher or textbook representations are generally used to guide this learning (Buckley & Boulter, 2000; Bybee, 1997; Furtak et al., 2012; Sell et al., 2006). Parallel to this approach, teachers have also guided students to construct, review and refine their own representations, leading to learning gains. However, this student representation construction approach poses new challenges for teachers. The teacher is expected to elicit and guide students' reasoning about their own represented claims as an orientation to understanding and learning scientific forms of reasoning and their representation. In this paper, drawing on our initial account of this pedagogy, we aim to clarify further this approach's rationale and teacher strategies and underlying purposes in key early stages of exploration in the topics of chemistry and mathematics with a Grade 5 class. An interdisciplinary focus was used to guide students' learning about the science concepts of states of matter, evaporation and the mathematical concepts of formal and informal measurement and data representation. Analysed data included video capture of the teacher's guidance of tasks and classroom discussion, student artefacts and teacher and student interviews. We identify how the teacher framed the task, oriented student inquiry and guided evaluation of students' representations through implicit and explicit instruction.

The microscopic composition of substances is a piece of essential but abstract knowledge in chemistry. Junior high school students may experience difficulty in mental representation when learning micro concepts, which leads to problems such as unsatisfactory academic performance and low learning motivation. Augmented reality (AR) is an optimal choice for presenting abstract concepts and invisible phenomena. Consequently, this study developed an AR application including three-layer experiential learning activities and integrating multiple external representations (text, pictures, 3D models, operations, etc.). To assess the effect of the AR application on students' knowledge gains, learning motivation, and technology perception, an experiment was conducted with 95 ninth-grade students aged 13-15 years who were randomly assigned to two groups (AR and non-AR). The results show that the AR application helped increase students' knowledge gains. Although there was no significant difference in the retention test between the two groups, scores on the transfer test were significantly higher for the AR group than for the non-AR group. Moreover, the AR application significantly improved students' motivation to learn. Finally, students had a positive perception of AR technology.

Scientific methods have received widespread attention in recent years. Based on the analytical framework derived from Brandon's matrix consisting of four categories of scientific methods, this paper aims to conduct a content analysis to examine how the diversity of scientific methods is represented in college entrance chemistry examination papers from three exam boards in China. It was found that the percentages of the four categories of scientific methods in the examination papers varied significantly from each exam board, highlighting an imbalanced representation of scientific methods. Furthermore, among the four categories of scientific methods, non-manipulative parameter measurement (Non-MPM) accounted for the largest proportion in each examination paper, while the proportion of manipulative hypothesis testing (MHT) was very small, indicating that the practical chemistry items in China are less experimental. At the end of this paper, the implications of the findings and suggestions for further studies are discussed.

Medicinal chemistry is an integrated discipline that primarily concerns the design, discovery, synthesis, identification, and interpretation of biologically active compounds at the molecular level. To assist undergraduates in understanding the core subjects of medicinal chemistry, we introduced a closed-loop education mode combining fundamentals of theoretical and experimental aspects in an undergraduate medicinal chemistry experimental course. Since the "Antibiotics" chapter is an important component in our medicinal chemistry lecture course, the topic "design, synthesis and biological evaluation of [beta]-lactamase inhibitors" was selected to train the students' experimental skills and especially the ability to expand on their acquired learning. The whole course schemes, including course introduction, molecular design, chemical synthesis, biochemical testing, docking simulation, student presentation, and academic writing, were described. The [beta]-lactamase inhibitory activities of synthesized benzoxaborole compounds were discussed on the basis of experimental and computational results. The education experiences regarding course process assessment, teaching management, and student self-evaluation were also summarized. These practices will be useful to solidify medicinal chemistry knowledge, train experimental skills, and improve scientific research ability for undergraduates.

Silver and its compounds have been widely used in experimental teaching, industrial production, and other fields. In these processes, a large amount of wastewater containing silver is usually produced, which might contribute to environmental pollution. Therefore, recycling silver from wastewater not only has good economic value but also meets the requirements of sustainable development, which is also a hot topic emerging in chemical teaching. In this demonstration, polyaniline is used to efficiently recover silver ions from simulated wastewater. Through the regulation of time, temperature, and the morphology of polyaniline particles, a series of silver with rich morphology is obtained, showing the beauty of chemistry and arousing students' interest in chemistry. This demonstration can cultivate audiences awareness of resource recycling and environmental protection and guide them to enjoy the fun of chemistry.

The preparation of ethyl acetoacetate is a distinctive, century-old classic organic chemistry laboratory project. Ethyl acetate and sodium metal (sodium ethoxide) are reacted by Claisen ester condensation to produce the sodium salt of ethyl acetoacetate and then obtain the refined product by acidification as well as washing, drying, and distillation under reduced pressure. This article analyzed the reasons for the low product yield and poor purity of the traditional experimental method and found that ethanol was the key to the final product. The improved experimental method used rotary evaporation and washing with saturated calcium chloride solution to remove ethanol. The new experimental method not only retains the characteristics of the original experiment and improves the product yield, but also adds the interesting phenomenon of pointing water into "ice", which cultivates students' learning interest and innovation and achieves a good teaching effect.

This study established an integrated process for the extraction and enrichment of chlorogenic acid (CGA) from Eucommia ulmoides leaves in a deep eutectic solvent system via ultrasonic wave-enhanced adsorption and desorption practices utilizing macroporous resins. Although deep eutectic solvents (DESs) have the advantages of chemical stability, good dissolving capacity, and nonvolatilization, routine solvent recovery operations are not suitable for subsequent separation in this solvent system. Based on the above characteristics, this study integrated the extraction and enrichment processes, in which DESs extracts directly loaded onto the macroporous adsorption resin, avoiding the loss of target components in solvent recovery and redissolution processes. The screening results of solvents and resin types further showed that choline chloride-malic acid (1:1) was the optimal DES, and the NKA-II resin had high adsorption and elution performance for CGA. The viscosities of the DESs were much higher than those of water and conventional organic solvents; thus, the mass transfer resistance was large, which could also affect the adsorption behaviour of the macroporous resin. The thermal and mechanical effects of ultrasound could effectively enhance the efficiency of the mass transfer, adsorption, and desorption in the DES systems. When compared to no sonication treatment, the CGA adsorption at various ultrasonic powers (120–600 W) was examined. At optimal ethanol concentration (60%), the effect of the ultrasonic treatment on the recovery of the DESs (water eluting process) and the desorption capability of CGA were confirmed. The use of three volumes of water elution could recover the DESs without loss of CGA. The adsorption process significantly differed depending on the ultrasonic settings, and the absorption balance time and experimental adsorption capacity at equilibrium were enhanced. Additionally, the adsorption procedure of the NKA-II macroporous resin for CGA under ultrasonic treatment could be clarified by the pseudo second order kinetic equation and the Freundlich isotherm model. Thermodynamic and dynamic parameters indicated that physical adsorption was the main process of the entire procedure, and it was a spontaneous, exothermic, and entropy-reducing physical adsorption process. This study potentially indicates that the use of ultrasonication, as a high-efficiency, environmentally friendly method, can enhance the features of the macroporous resin to better purify target chemicals from a DES extract.

Under the threat of the COVID-19 pandemic, an interdisciplinary project about the brewing and analysis of traditional Chinese rice wine was performed at home by junior students of the chemistry major at Huanggang Normal University under the remote guidance of teachers during the spring lockdown semester of 2020. Students were exposed to the concepts of yeast metabolism, analytical testing, and sensory evaluation in terms of real project study and completed a series of hands-on activities at home using readily available materials, utensils, and self-made devices. In the spring semester of 2021, experiments were conducted in the general lab with other students in the same program to compare the results of the two groups of students. The results were that the "home" results were credible, the students were trained not only in laboratory skills but also in analytical and communication skills, and, significantly, the majority of students enjoyed the content and activities. This paper illustrates an effective experimental design procedure that can be conducted at home or in the laboratory in response to uncertain changes, such as a pandemic lockdown.

Medicinal chemistry, as the core curriculum of the pharmaceutical engineering major, contains complex knowledge systems and scattered knowledge points. A medicinal chemistry course covers more than 50kinds of drugs divided into 11 categories including antibiotics, antiparasitic drugs, anesthetics, nonsteroidal anti-inflammatory drugs, and nervous system drugs. This places a substantial learning burden on students and seriously affects their learning interest and initiative. On the basis of the innovative curriculum reform of "student-centered" learning and with the aim of improving the quality of instruction provided in medicinal chemistry courses, a novel "student-centered team-based learning" (SCTBL) method was developed to cope with these challenges on the basis of our long-term teaching experience. This paper introduces the essence of the team-based learning method and explores the application of SCTBL in the process of teaching medicinal chemistry, which consists of three stages: preclass, in-class, and postclass. The results show that introducing the SCTBL method into medicinal chemistry instruction is conducive to improving students' learning enthusiasm and initiative, which is of great significance to the development of medicinal chemistry education.

Representations constitute an important part of chemistry knowledge. This paper revisits the notion of the term, symbolic, in the chemistry triangle proposed by Johnstone using the theoretical lens of social semiotics. In doing so, this paper proposes a framework of chemistry learning that highlights representational re-description and coordination as key mechanisms for facilitating connections among the three domains of knowledge: chemical phenomenon (perceptual-experiential level), macroscopic (theoretical-descriptive level) and submicroscopic (theoretical-explanatory level). This paper illustrates how this framework can be used to explore student meaning making of changes of state by examining students' interactions with the phenomena of melting and boiling and with the multiple representations of the phases of matter introduced in the classroom. The findings revealed the opportunities and challenges which emerged from student meaning making with multiple representations in the process of developing an understanding of the submicroscopic view of phase change. It also highlighted the support needed to facilitate such meaning making through representational re-description and coordination in order for students to develop a deep understanding of the logical connections between the particular model and the macroscopic patterns of the observed phenomena.

The water extraction and ethanol precipitation method is an extraction method based on the solubility characteristics of polysaccharides that offers wide applicability in the extraction and separation of plant polysaccharides. However, this method leads to large amounts of proteins, nucleic acids, pigments, and other impurities in the polysaccharides products, which makes downstream purification complicated and time-consuming. In this study, a green, high-density natural deep eutectic solvents was used for the high-purity extraction and separation of polysaccharides from Astragalus membranaceus (Fisch) Bge. var. Mongholicus (Bge.) Hsiao roots under ultrasound-assisted conditions. In this study, 16 different natural deep eutectic solvents were designed to screen the best solvent for extracting Astragalus polysaccharides (APSs). Based on the yield and recovery of APSs, a natural deep eutectic solvents composed of choline chloride and oxalic acid with a molar ratio of 1:2 was selected. The related factors affecting polysaccharides extraction and solvent precipitation were investigated. To improve the operating methodology, single-factor trials, a Plackett-Burman design, and a Box-Behnken design were used. The optimal extraction process conditions were obtained as follows: water content of 55%, liquid–solid ratio of 24 mL/g, ultrasonic irradiation time of 54 min, ultrasonic irradiation temperature of 50 °C, ultrasonic irradiation power of 480 W, ethanol precipitation time of 24 h, and ethanol concentration of 75%. Under optimal extraction conditions, the recovery of APSs was 61.4 ± 0.6 mg/g. Considering the special matrix characteristics of A. membranaceus var. Mongholicus roots, physical-technology-based ultrasonic waves promote penetration, and the mass transfer function also solves the bottleneck of high-viscosity deep eutectic solvents in the extraction stage. In comparison with the conventional method, the proposed method based on deep eutectic solvents isolation can significantly increase APSs recovery, which is beneficial to simplifying the process of polysaccharides purification by using solvent properties to separate extracts and reduce impurities in APSs.

Ionic liquids (ILs) begin to be applied in more broad scopes and even in medicine steadily, so it is very necessary to study their biocompatibility, bioactivity, and influence on blood. For the first time, the main effects of popular imidazolium ILs with common anions and alkylated cations on rabbit blood were explored and compared comprehensively. A series of key indices and characteristic methods were applied in this systematic study. The thrombolytic properties in vitro of these ILs and their interactions with two kinds of serum albumins were also studied. This study provides key data and lays foundation for further applications of ILs and risk assessments in related fields.

Foam fluids are widely used in petroleum engineering, but long-standing foam stability problems have limited the effectiveness of their use. The study explores the synergistic effects and influencing factors of SiO2 nanoparticles (SiO2-NPs) with different wettability properties and three different surfactants. The paper investigates the foaming performance of different types of surfactants and analyzes and compares the stability of foam after adding hydrophilic and hydrophobic SiO2-NPs from macroscopic as well as microscopic perspectives, and the effects of temperature and inorganic salts on the stability of mixed solutions. The experimental results show that: 1) hydrophilic nanoparticles can significantly enhance the foam stability of amphoteric surfactants, with a small increase in the foam stability of anionic and cationic surfactants; 2) The concentration of nanoparticles did not have a significant effect on the stability of the cationic surfactants and this conclusion was verified in the experimental results of the surface tension measured below;3) The cationic surfactants showed better temperature resistance at temperatures of 50–90 °C. Both amphoteric surfactant solutions with the addition of hydrophilic SiO2-NPs or hydrophobic SiO2-NPs significantly improved the temperature resistance of the foam at high temperatures. The anionic surfactant solution with hydrophobic SiO2-NPs did not enhance the solution temperature resistance; 4) The surface tension of the surfactant solution gradually increases with increasing concentration of hydrophilic or hydrophobic SiO2-NPs and then levels off; 5) the hydrophilic SiO2-NPs had a significant effect on the salt tolerance of the anionic and amphoteric surfactant solutions. The salt tolerance of cationic surfactant solutions with hydrophobic SiO2-NPs was better than that of surfactants with hydrophilic SiO2-NPs.

In this work, we introduce the VR[superscript 2]E[superscript 2]C system for Virtual Reality Remote Education for Experimental Chemistry. It aims to increase scientific literacy about remote education of theoretical and experimental chemistry among the public and high school students. It provides a laboratory option for students with disabilities who are keen on chemistry experiments but have limited mobility. VR[superscript 2]E[superscript 2]C provides three modes to accomplish the training: users can choose to control the intelligent robot to finish the experimental operations by instruction or choose to watch the experiments automatically conducted by VR[superscript 2]E[superscript 2]C. The experimental results can be delivered to users in real time or later. This system provides remote education for safe and high fault-tolerant experimental topics, demonstrating how the latest VR and robotics technology could benefit traditional chemical education.

This article introduces a novel experiment that involves vitrimers, a new type of polymer, in polymer chemistry and physics lab courses for undergraduate students. Vitrimers are permanently cross-linked networks that can be reprocessed under certain external stimuli. Therefore, they combine the advantages of traditional thermoplastics (excellent reprocess ability) with thermosets (outstanding mechanical properties and environmental stability). They can be regarded as a kind of "special thermoset", which moves this industry toward a more sustainable path, as they are conducive to decreasing thermosetting wastes, reducing environmental pollution, and cutting down the waste of resources. From this lab class, students obtained more experience in the preparation and characterization of polymers. They also learned the concepts of dynamic chemistries and vitrimers and gained a better understanding of the advantages and limitations of thermosets and thermoplastics, as well as a strategy for making a reprocess able thermoset polymeric material. It also fostered students' interest in functional materials and inspired them to design other functional materials. Moreover, this experimental setup is convenient and safe for implementation and dissemination in most undergraduate laboratory classes.

The rhizoma of Polygonatum odoratum (PO) is used to treat yin injuries of the lung and stomach in traditional Chinese medicine. The chemical constituents of this herb are steroidal saponins, homoisoflavanones, and alkaloids. Xiangyuzhu (XPO) and Guanyuzhu (GPO) are available in the market as two specifications of the commodity. Nonetheless, systematic research on the identification and comparison of chemical constituents of these two commercial specifications is yet lacking. Herein, an integrated method combing ultra-high-performance liquid chromatography-quadruple time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) with ultra-high-performance liquid chromatography-charged aerosol detection (UHPLC-CAD) was employed for the comprehensively qualitative and quantitative analyses of PO. A total of 62 compounds were identified by UHPLC-Q-TOF/MS, among which 13 potential chemical markers were screened out to distinguish two commercial specifications. Subsequently, the absolute determination method for polygodoraside G, polygonatumoside F, and timosaponin H1 was established and validated by UHPLC-CAD. The contents of the three compounds were 13.33–236.24 μg/g, 50.55–545.04 μg/g, and 13.34–407.83 μg/g, respectively. Furthermore, the ratio of timosaponin H1/polygodoraside G could be applied to differentiate the two specifications. Samples with a ratio 5 are considered GPO. Therefore, the above results provide a valuable means for the quality control of PO.

The Joint Safety Team (JST) was conceived in 2012 by the Departments of Chemical Engineering and Materials Science and Chemistry at the University of Minnesota and the Dow Chemical Company as a model student-led safety organization. The JST initiative was aimed at improving academic safety through four core areas: compliance, awareness, resources, and education. Since its inception, the JST has taken great strides to develop a culture of peer-led safety at Minnesota. We describe the evolution of the structure of the organization over the last 8 years and the innovative methodologies employed by the JST to educate and evaluate safety in academic laboratories. The continuous efforts of the student members of the JST have enabled the organization to be recognized as a leader in peer-to-peer safety. The Minnesota model of "inform and reform" is now being adopted at other academic institutions to develop safety organizations emulating the JST.

This study examined participatory simulation-based learning of teaching in a virtual reality (VR) supported learning environment and its affordance for alternative perspectives taking. This VR-supported, embodiment-integrated learning environment is designed to enable collaborative and contextualized microteaching practicing by university teaching assistants. A total of 42 chemistry teaching assistants participated in a 3-hour teaching training session, during which they were randomly assigned to a VR-supported simulation group and a live simulation group. The study found teaching knowledge development for all participants after simulation-based training. The live simulation participants better performed in the post-session knowledge test than the VR simulation participants. Qualitative data indicated a multitude of challenges and opportunities in VR simulation-based learning, including a concurrent, yet, inequivalent experience of the "diving-in" and "stepping-out" learning perspectives during virtual collaborative role-playing in a hybrid learning space.

We developed a comprehensive training module for the undergraduates majoring in chemical education with a simple microfluidic experiment. The students were required to read a scientific reference offered by the instructor, then design and implement a microfluidic experiment for real sample analysis by making some modifications to the method described in the reference. Finally, the students were required to evaluate the analytical results with a standard method and write an experimental report. This reading-designing-implementing-evaluating-writing (RDIEW) module aims to enhance the students' experimental skills as well as their abilities at designing experiments and reading English scientific literature. More importantly, the concept of microfluidic analysis was successfully introduced to the undergraduates majoring in chemical education by this training module, which may facilitate the introduction of microfluidic devices to chemistry courses at high schools. This 1 week (3 h per day) module was developed for the undergraduates majoring in chemical education at the sixth semester. The feedback from the students indicated that the learning objectives of this training module were met.

Lock-in amplifiers (LIAs) are commonly used in chemistry laboratories to improve noise-to-signal ratios. Constructing and testing a suitably designed LIA provide undergraduate students with an excellent opportunity to learn about theory, construction, and applications of LIA. In particular, students can learn about time-dependent behavior and various components, from resistors (R) and capacitors (C) to packaged microchips such as demodulators and phase shifters. We provide here design and performance characteristics of a two- (Vx, Vy) channel LIA based on balanced modulator/demodulators (AD630). The LIA includes configurable resistor-capacitor (RC) high-pass and low-pass filters, various op-amp circuits, and a phase-shifter. Various configurations of resistors/capacitors, as well as salt solutions and isopropanol/pentane mixtures, are used as samples to measure conductance or capacitance to test both V[subscript x] and V[subscript y] channels of the LIA. The results are consistent with behaviors expected theoretically. The LIAs yield excellent noise/signal ratios with peak-to-peak values that are <0.2% and that compare favorably with commercial LIA performance.

This communication describes a method to detect aluminum in gastric drugs by the naked eye using a microfluidic paper-based analytical device ([mu]PAD). Aluminum ions react with chrome azurol S (CAS) and cetyltrimethylammonium bromide (CTAB) to form a colored complex, which generates a colored band on the [mu]PAD. A printed ruler can be used to measure the length of the colored band on an individual paper channel for the quantification of an aluminum ion. The [mu]PAD system was designed for use in a modern instrumental analysis course taken by students majoring in Food Quality and Safety. This analytical protocol could also be modified to be used as a demonstration or laboratory experiment in a high school chemistry course with some simplifications to the procedures.

The magnetoelastic generator (MEG) is a fundamentally new platform technology to convert mechanical motions into electrical signals for sensing, therapeutics, and energy applications. Here, we present a protocol for fabricating and characterizing the MEG for personalized muscle physiotherapy when integrated into a wearable textile patch. We describe the steps for fabricating such a textile MEG, including the magnetomechanical coupling (MC) and magnetic induction (MI) layers, and characterizing their magnetoelastic and electrical properties. We then detail procedures for monitoring muscle biomechanical activities and muscle physiotherapy application. For complete details on the use and execution of this protocol, please refer to Xu et al.1.

A new bacterium capable of heterotrophic nitrogen removal was isolated and identified as Oligella sp. XS68. The strain exhibited efficient heterotrophic nitrogen removal capabilities, with a low accumulation of nitrification products. Single-factor experiments indicated that efficient nitrogen removal and growth of the strain XS68 occurred with sodium succinate as the carbon source, C/N ratio 15, pH 6.0–9.0, temperature 30–37 °C, and shaking speed 160–200 rpm. The removal efficiency of ammonium nitrogen could achieve 98 % within 96 h when the initial nitrogen concentration was 421.3 mg L-1. These findings demonstrate that XS68 is a promising candidate for nitrogen removal in wastewater treatments.

The methanol–toluene alkylation process over zeolites catalysts offers a promising route for the production of p-xylene from low-cost feedstocks. Herein, we present a catalyst by preparing a core-shell aluminosilicate zeolite with an epitaxial silicalite-1 shell that passivates acid sites on the exterior surfaces. The para-selectivity was obviously increased due to the inhibition of the unselective isomerization of p-xylene over the external acid sites, and the open porous structure of the silicalite-1 shell ensured the mass transfer of reactants and products. Meanwhile, the carbon deposition was suppressed over HZSM-5@silicalite-1 catalysts, as a result of the decreased external acid sites. Furthermore, pulse chromatographic experiments revealed that the silicalite-1 coating could also improve the separation efficiency of p-xylene over o-xylene and m-xylene, due to the steric hindrance and extended diffusion path, resulting in a higher selectivity for p-xylene compared to that of the parent HZSM-5. The HZSM-5@4%S-1 catalyst showed the highest p-xylene selectivity (>80%) and methanol efficiency (66%), with good catalytic stability throughout the 170 h reaction time.

CRISPR-Cas systems empower prokaryotes with adaptive immunity against invasive mobile genetic elements. At the first step of CRISPR immunity adaptation, short DNA fragments from the invaders are integrated into CRISPR arrays at the leader-proximal end. To date, the mechanism of recognition of the leader-proximal end remains largely unknown. Here, in the Sulfolobus islandicus subtype I-A system, we show that mutations destroying the proximal region reduce CRISPR adaptation in vivo. We identify that a stem-loop structure is present on the leader-proximal end, and we demonstrate that Cas1 preferentially binds the stem-loop structure in vitro. Moreover, we demonstrate that the integrase activity of Cas1 is modulated by interacting with a CRISPR-associated factor Csa3a. When translocated to the CRISPR array, the Csa3a-Cas1 complex is separated by Csa3a binding to the leader-distal motif and Cas1 binding to the leader-proximal end. Mutation at the leader-distal motif reduces CRISPR adaptation efficiency, further confirming the in vivo function of leader-distal motif. Together, our results suggest a general model for binding of Cas1 protein to a leader motif and modulation of integrase activity by an accessory factor.

We described a simple method for detection of Fe on a thread-based analytical device. Fe reacts with 1,10-phenanthroline to form a colored band on a cotton thread; the length was measured to quantify the contents of Fe using a ruler. This method has the advantages of easy operation, low cost, easy fabrication, and reduced sample/reagent consumption. Furthermore, this method is free of any electronic equipment such as camera and digital scanner. These features make this method suitable as a laboratory experiment in universities and colleges. This laboratory experiment is designed as one of selected experiments of the Comprehensive Chemistry Experiment course for the students majoring in chemistry, for the sixth and seventh semester. The students enjoyed fabricating the thread-based analytical device and used it to detect the contents in unknown samples. This laboratory experiment could be completed within 3 h.

The IQ67 Domain (IQD) gene family plays important roles in plant developmental processes and stress responses. Although IQDs have been characterized in model plants, little is known about their functions in wheat (Triticum aestivum), especially their roles in the regulation of seed dormancy and germination. Here, we identified 73 members of the IQD gene family from the wheat genome and phylogenetically separated them into six major groups. Gene structure and conserved domain analyses suggested that most members of each group had similar structures. A chromosome positional analysis showed that TaIQDs were unevenly located on 18 wheat chromosomes. A synteny analysis indicated that segmental duplications played significant roles in TaIQD expansion, and that the IQD gene family underwent strong purifying selection during evolution. Furthermore, a large number of hormone, light, and abiotic stress response elements were discovered in the promoters of TaIQDs, implying their functional diversity. Microarray data for 50 TaIQDs showed different expression levels in 13 wheat tissues. Transcriptome data and a quantitative real-time PCR analysis of wheat varieties with contrasting seed dormancy and germination phenotypes further revealed that seven genes (TaIQD4/-28/-32/-58/-64/-69/-71) likely participated in seed dormancy and germination through the abscisic acid-signaling pathway. The study results provide valuable information for cloning and a functional investigation of candidate genes controlling wheat seed dormancy and germination; consequently, they increase our understanding of the complex regulatory networks affecting these two traits.

The production of biochemicals requires the use of microbial strains with efficient substrate conversion and excellent environmental robustness, such as Weizmannia coagulans species. So far, the genomes of 47 strains have been sequenced. Herein, we report a comparative genomic analysis of nine strains on the full repertoire of Carbohydrate-Active enZymes (CAZymes), secretion systems, and resistance mechanisms to environmental challenges. Moreover, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) immune system along with CRISPR-associated (Cas) genes, was also analyzed. Overall, this study expands our understanding of the strain’s genomic diversity of W. coagulans to fully exploit its potential in biotechnological applications.

The reaction process of copper-aluminum displacement in agar gel was observed at the microscopic level with a stereomicroscope; pine-like branches of copper crystals growing from aluminum surface into gel at a constant rate were observed. Students were asked to make hypotheses on the pattern formation and design new research approaches to prove their hypotheses. Results of the experiments designed by students well proved the existence of microcells in reaction system, which caused continuous growth of copper branches. The whole experimental teaching process motivated students by stimulating their interest and enthusiasm.

The interaction between a shock wave and solid particles involves complex gas–solid two-phase flow, which is widely used in industrial processes. Theoretical analysis, an experimental test, and simulation were combined to investigate the interaction process between a shock wave and quartz sand particles. The variation of physical parameters of the two phases during the interaction process was considered theoretically. Then, a novel vertical shock tube generator was employed to record the pressure attenuation and dispersion process of solid particles. Finally, the complex gas–solid two-phase flow was simulated based on the computational fluid dynamics method. The results showed that a nonequilibrium state was formed during the interaction process and momentum exchange generated, resulting in a drag force of the shock wave on the particles. The shock intensity obviously attenuated after the shock wave passed through the solid particles, and this part of the energy was work on the solid particles to drive their dispersion. A three-dimensional annular vortex was generated around the solid particles due to the entrainment effect of airflow. Under the shock wave action of 1.47 Ma, the three types of solid particles with average diameters of 2.5, 0.95, and 0.42 mm presented different motion laws. The particles with smaller size were easier to disperse, and the cloud that formed was larger and more uniform.

In order to study the effect of initial defects on fatigue crack propagation law, a test method to identify fatigue crack propagation rate and path based on load waveform variation was presented, and a new test device was designed to apply fatigue pulsation loads to multiple wires for bridge cables simultaneously in this paper. To simplify the corrosion defect formation process, a machine-cut notch was used to describe the initial defect on the steel wire surface. Firstly, fatigue crack propagation tests were conducted on the surface notched steel wire specimens. By using crack front marking technique, the “beach-like patterns” visible to the naked eyes on the cross sections of the steel wires were formed, and the process of fatigue crack propagation can be tracked and reproduced. Then Autodesk Computer Aided Design (AutoCAD) software was used to describe the morphology of “beach-like patterns” and accurately measure the depth and width of cracks. Finally, the influence of initial defect morphology on fatigue crack propagation rate was investigated according to the relationship between fatigue cracks depth and cyclic loading numbers. The results show that the test device designed in this paper can effectively realize the synchronous fatigue crack propagation test of multiple wires, and significantly shorten the fatigue test period. By observing and analyzing the change of load waveform, the moment of fatigue crack propagation can be directly and accurately determined. The larger the depth, the smaller the width and the sharper the morphology of initial defect, the faster the crack propagation rate and the shorter the life of notched wire specimens under the combined action of fatigue loads and corrosive medium.

Vibrio parahaemolyticus is the causative agent of food-borne gastroenteritis disease. Once consumed, human acid gastric fluid is perhaps one of the most important environmental stresses imposed on the bacterium. Herein, for the first time, we investigated Vibrio parahaemolyticus CHN25 response to artificial gastric fluid (AGF) stress by transcriptomic analysis. The bacterium at logarithmic growth phase (LGP) displayed lower survival rates than that at stationary growth phase (SGP) under a sub-lethal acid condition (pH 4.9). Transcriptome data revealed that 11.6% of the expressed genes in Vibrio parahaemolyticus CHN25 was up-regulated in LGP cells after exposed to AGF (pH 4.9) for 30 min, including those involved in sugar transport, nitrogen metabolism, energy production and protein biosynthesis, whereas 14.0% of the genes was down-regulated, such as ATP-binding cassette (ABC) transporter and flagellar biosynthesis genes. In contrast, the AGF stress only elicited 3.4% of the genes from SGP cells, the majority of which were attenuated in expression. Moreover, the number of expressed regulator genes was also substantially reduced in SGP cells. Comparison of transcriptome profiles further revealed forty-one growth-phase independent genes in the AGF stress, however, half of which displayed distinct expression features between the two growth phases. Vibrio parahaemolyticus seemed to have evolved a number of molecular strategies for coping with the acid stress. The data here will facilitate future studies for environmental stresses and pathogenicity of the leading seafood-borne pathogen worldwide.

A hands-on activity based on general electrochemistry concepts with the aim at introducing design science elements is presented. The main goals of the activity are to reinforce electrochemical principles while fostering innovation in the students through the assembly and optimization of a voltaic device and subsequent evaluation by powering several light emitting diodes. The voltaic device consists of metal clips that function as electrodes prepared from Cu and Al metal sheets immersed in rice wine in a paint box, which works as the electrolyte. The active learning activity highlights the historical context of energy storage devices, and can be used as a tool for fostering "outside-the-box" thinking in the students, as well as encouraging team collaboration. This active learning activity is suitable for high school students with a background in chemistry, for undergraduate engineering and architecture students, and for general undergraduate students enrolled in an introductory general chemistry course, regardless of their interest in design science.

We examined the use of problem solving videos (PSVs) as a substitute for general chemistry exam review sessions. We investigated student perceptions of course aspects regarding usefulness for supporting their learning of chemistry content. We also examined "how" students used the PSVs to further their learning. Students ranked the PSVs as more useful than other course components such as the textbook and exam review sessions. Weekly lectures, back tests, and online homework assignments were also ranked highly. A majority of our students viewed the PSVs, multiple views were common, and PSVs were mainly viewed for exam preparation. YouTube statistics corroborated this finding in that numbers of PSV views were maximal 4 days prior to and through each exam day. Students found step-by-step explanations and ability to control their own learning to be more helpful features of the PSVs. Shifting content to out-of-class video viewing frees up in-class time for tasks that promote learning at the higher levels of Bloom's taxonomy (e.g., active learning, group work).

The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the cooling curves of phenol-t-butanol mixtures are measured and the phase diagram of this system is found to give three eutectic points and two congruent melting points. The laboratory provides the students a practical way to investigate a complex system with their own efforts and teamwork spirit.

In this paper, a silicon-based terahertz wideband filter was designed using rigorous couple wave theory to achieve high diffraction efficiency and wideband filtering performance. The optimal parameters, such as filter period, duty ratio, and groove depth, are given. The design value and tolerance analysis were carried out to obtain the allowable deviation range of each structural parameter of the filter. The device was fabricated and tested for performance. The experimental results were consistent with the design results, proving the feasibility of the design method and can be applied in terahertz, communication, imaging, and other fields.

Obesity and its associated metabolic disorders are spreading at a fast pace throughout the world; thus, effective therapeutic approaches are necessary to combat this epidemic. Obesity develops when there is a greater caloric intake than energy expenditure. Promoting energy expenditure has recently attracted much attention as a promising approach for the management of body weight. Thermogenic adipocytes are capable of burning fat to dissipate chemical energy into heat, thereby enhancing energy expenditure. After the recent re-discovery of thermogenic adipocytes in adult humans, much effort has focused on understanding the molecular mechanisms, especially the epigenetic mechanisms, which regulate thermogenic adipocyte development and function. A number of chromatin signatures, such as histone modifications, DNA methylation, chromatin accessibilities, and interactions, have been profiled at the genome level and analyzed in various murine and human thermogenic fat cell systems. Moreover, writers and erasers, as well as readers of the epigenome are also investigated using genomic tools in thermogenic adipocytes. In this review, we summarize and discuss the recent advance in these studies and highlight the insights gained into the epigenomic regulation of thermogenic program as well as the pathogenesis of human metabolic diseases.

Many of the instruments developed for research use by the chemistry education community are relatively new. Because psychometric evidence dictates the validity of interpretations made from test scores, gathering and reporting validity and reliability evidence is of utmost importance. Therefore, the purpose of this study was to investigate what "counts" as psychometric evidence within this community. Using a methodology based on concepts described and operationalized in the "Standards for Educational and Psychological Testing," instruments first published in the "Journal" between 2002 and 2011, and follow-up publications reporting the use of these instruments, were examined. Specifically, we investigated the availability of evidence based on test content, response processes, internal structure, relations to other variables, temporal stability, and internal consistency. Findings suggest that our peer review and reporting practices value some types of evidence while neglecting others. Results of this study serve as an indication of the need for the chemistry education research community to view gathering psychometric evidence as a collective activity and to report such evidence at the level of detail appropriate to inform future research. (Contains 3 tables and 1 figure.)