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Green and sustainable power sources for next-generation electronics are being developed. A cellulose paper-based triboelectric nanogenerator (TENG) was fabricated to harness mechanical energy and convert it into electricity. This work proposes a novel approach to modify cellulose paper with natural dyes, including chlorophyll from spinach, anthocyanin from red cabbage, and curcumin from turmeric, to enhance the power output of a TENG. All the natural dyes are found to effectively improve the energy conversion performance of a cellulose paper-based TENG due to their photogenerated charges. The highest power density of 3.3 W/m2 is achieved from the cellulose paper-based TENG modified with chlorophyll, which is higher than those modified with anthocyanin and curcumin, respectively. The superior performance is attributed not only to the photosensitizer properties but also the molecular structure of the dye that promotes the electron-donating properties of cellulose. [ABSTRACT FROM AUTHOR]

The surface of plant fibers was modified by silane coupling agents to prepare plant fiber/polylactic acid (PLA) composites, which can improve the dispersion, adhesion, and compatibility between the plant fibers and the PLA matrix. In this work, three silane coupling agents (KH550, KH560, and KH570) with different molecular structures were used to modify the surface of waste corrugated paper fibers (WFs), and dichloromethane was used as the solvent to prepare the WF/PLA composites. The effects of different silane coupling agents on the microstructure, mechanical properties, thermal decomposition, and crystallization properties of the composites were studied. The mechanical properties of the composites treated with 4 wt% KH560 were the best. Silane coupling agents can slightly improve the melting temperature of the composites, and WFs can promote the crystallization of PLA. The modification of WFs by silane coupling agents can increase the decomposition temperature of the WF/PLA composites. The content and type of silane coupling agent directly affected the mechanical properties of the WF/PLA composites. The interfacial compatibility between the WFs and PLA can be improved by using a silane coupling agent, which can further enhance the mechanical properties of WF/PLA composites. This provides a research basis for the further improvement of the performance of plant fiber/PLA composites. [ABSTRACT FROM AUTHOR]

• A cellulose membrane serves as stationary phase for fractionation of human saliva. • Interaction between red wine and saliva was revealed by a dichromatic analysis. • A non-diffusible salivary fraction showed the highest affinity for wine components. • Diffusion of a diffusible salivary fraction declines due to interaction with wine. • A point of equivalence occurs when a wine/saliva mix shows no diffusible fraction. In-mouth interaction of red wine compounds with salivary proteins is a primary event allegedly responsible for eliciting the mouth-feel sensation of astringency. Those interactions have been currently associated with precipitation of salivary protein/polyphenol complexes. However, such single physicochemical evidence for interaction does not account for the complexity of astringency. This study aimed to develop a paper chromatography method to assess interactions between red wine and the salivary protein fraction using stepwise series of red wine/saliva binary mixtures from 100% wine to 100% saliva ("Alpha and Omega series"). Aliquots of each one of the mixtures were spotted on a cellulose membrane to scrutinize independently the distribution areas of wine components (naturally pink-colored) and salivary protein (stained blue in Coomassie Brilliant R-250). This double target detection revealed interactions between saliva and red wine components along most of the quantitative Alpha and Omega series, a point of equivalence corresponding to maximum interactivity for both complex reactants and a non-diffusible sub-fraction of saliva displaying the highest interactivity. The results indicate a novel way to assess quantitatively physicochemical interactions between red wines and human saliva but also provide new lights to approach the identification of molecular salivary structures involved in triggering astringency. [ABSTRACT FROM AUTHOR]

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Students perceive molecular bonding as an abstract concept; therefore, learning this concept seems uninteresting and difficult. A strategically designed learning object (LO), such as in the form of a simulation, can be used to help students acquire accurate mental images and build appropriate schema in addition to providing a concrete learning experience and encouraging knowledge construction. This paper presents an evaluation of the design and development of the "Making Molecules" simulation through students' perceptions of the previous version and recommendations for improving a future version. Data were collected from two online chemistry courses (N = 159) through an anonymous online survey. Results suggest that students responded positively to the use of the simulation. They reported gaining a better understanding of molecular bonding through an interactive learning experience. One of their recommendations was to include more learning tasks related to complex molecules, expressing an interest in learning more about chemistry. This paper provides insights for educators and instructional designers regarding selection and/or design of an LO for optimizing student learning of complex topics.

Although arynes are usually considered fleeting intermediates, they are highly valuable synthons because they enable the introduction of aromatic rings and the simultaneous formation of new bonds at two sites. Although catalytic reactions using transition metals are excellent method for constructing complex polycyclic aromatic molecules in a single step, the use of asymmetric catalysis for the capture of arynes remains a crucial goal for the progress of aryne chemistry. Catalytic asymmetric reactions of arenes are challenging, requiring sufficient interactions between the neutral and highly reactive short-lived aryne intermediates in a stereo-controlled fashion. In addition, spontaneous decomposition, as well as side reactions, has hindered their development and, until recently, highly enantioselective reactions using arynes had remained elusive. This Review highlights asymmetric reactions using arynes, featuring diastereoselective, enantioselective and catalytic enantioselective reactions., (© 2023. Springer Nature Limited.)

We investigated the performance of attenuated total reflectance--Fourier-transform infrared (ATR-FTIR) spectroscopy to rapidly identify intentional additives in a variety of items commonly handled by consumers and workers. We investigated ortho-phthalate esters, specific alternative plasticizers, and flame retardants in food contact materials and consumer products. We also investigated bisphenol A (BPA) and bisphenol S (BPS) developers in thermal paper purchase receipts. Applications include regulatory compliance screening and product deformulation. We compared FTIR results with mass spectrometry measurements. Samples were analyzed either intact or after a simple liquid-phase extraction using small amounts of nonhalogenated solvents. These methods greatly reduced the time and expense of identifying intentionally added phthalates and other plasticizers compared with more sensitive methods. Similarly, BPA and BPS were readily identified in receipts and organophosphorus flame retardants were identified in child car seats. In some samples, FTIR detected novel or unexpected additives not detected by conventional targeted methods. These approaches are useful for screening diverse product samples for intentional additives with a relatively portable instrument while generating very low volumes of spent solvent. [ABSTRACT FROM AUTHOR]

• It is shown that the commented paper has severe errors. • The analysis of the diffraction pattern was made without success. • The chemical composition of the studied crystals is unknown. My comments concern the errors in the crystallographic part of the commented paper. Moreover, the true chemical composition of the studied sample is different than BaNaFeWO 6 as proposed by authors. Therefore, the subsequent data on other measurements may have no scientific value. [ABSTRACT FROM AUTHOR]

In this paper, we describe a dynamic-model as a strategy to teach DNA transcription and translation in an active way. This activity aims to provide learning beyond memorisation through the simulation of molecular processes, stimulating the elaboration of questions and hypotheses by students. The dynamic consists of four steps, starting with different problem situations which provide a context and encouragement to start the activity. The next steps connect these problems with DNA transcription and translation, requiring the active participation of students to simulate these processes through a construction of a model based on an iron board and representations of cellular structures, enzymes and genetic sequences fixed in magnets. An implementation experience of this dynamic, applied to 21 undergraduate veterinary students at a public university in the city of Curitiba, Paraná State, Brazil, is also described. Data from pre and post-questionnaires suggest knowledge about DNA transcription and translation was improved and some previous mistakes were clarified. Among the positive aspects that were cited by the students, the words visualisation and playful were more frequent, which reflect the didactic aspects of the dynamic. Some points of attention are discussed throughout the paper, as well as educational implications associated with the material and its potential to promote active learning.

This paper addresses policy effects of international mobility in developing countries. It proposes a multilevel approach to study research training policies, specifically focusing on international mobility schemes as capacity-building instruments, where effects need to be identified at both individual and organizational levels. The paper asserts that current categorizations of country efforts to build a solid scientific base should consider transference of effects in domestic research contexts. Using a survey and interview-based study of a mobility policy in Mexico, and nanotechnology-related disciplines and sectors, this paper's findings suggest that mobility policies are crucial in creating high-quality individual research skills, but that their impact on building domestic research capacity may be modest. This paper contributes to the evaluation literature on national research training programs and their influence on research capacity in two ways. First, it mobilizes a multilevel analytical approach to examine the effects of policies on individuals and organizations, offering a broader conceptualization of impact. Second, by introducing these individual and organizational effects, the paper provides insights into how effects are enacted and transferred.

Forest-based industries produce huge quantities of bark during their primary processing activities. In Nordic pulp and paper industries, where a wet debarking process is used for bark removal, toxic debarking water and bark press water are produced as a by-product. However, polyphenols represent an important fraction of the debarking water and bark press water. These polyphenolic compounds are of commercial interest in chemical specialty sectors since polyphenols have been proven to have diverse health benefits, and after collecting them from waste sources, they can act as alternatives to oil-based chemicals. Determining the economic potential of polyphenolic compounds, identifying their molecular structure, and determining the antioxidant capacity of these compounds present in debarking water and bark can support the identification of their potential applications. The results show that water extractions from bark have a lower efficiency than (partial) alcoholic extractions. Nevertheless, a considerable amount of low-molecular polyphenolic compounds, which are of interest for high-end applications, was found in all extracts. Bark press water has a highly versatile range of polyphenolic compounds and showed some antioxidant activity, making it a great source for the collection of polyphenolic compounds, in contrast to debarking water, which had a much lower polyphenolic content and low antioxidant activity. [ABSTRACT FROM AUTHOR]

Teaching chemistry and biology students about biologics design remains challenging despite its increasing importance in pharmaceutical development. Monoclonal antibodies, commonly called mAbs, are the most popular biologics. They have been developed into drugs to treat various diseases in the past decades. Multiple challenges exist for designing proper formulations to stabilize mAbs, such as preventing aggregation and mitigating viscosity. Molecular modeling and simulations can improve pharmaceutical products by examining the interactions between mAbs and other compounds, such as excipients. To introduce students to biopharmaceuticals, eight students at the Stevens Institute of Technology participated in a semester-long course to learn the challenges of pharmaceutical development and different computational skills to study biologics design. The students started with a limited background in this field. Throughout one semester, they were introduced to various literature and software tools for modeling antibodies and studying their interactions with excipients. This paper aims to develop a course structure to be replicated at other universities and institutions to teach biopharmaceutical development to students.

[Display omitted] • Synthesis and characterization of a phenothiazine-linked pyridine acetonitrile compound (PZ-PY) through Knoevenagel condensation reaction. • Confirmation of PZ-PY's molecular structure via single-crystal X-ray diffraction, revealing a monoclinic crystal system with a P2 1 /c space group. • Absorbance and emission spectra of PZ-PY receptor at 431 nm and 608 nm, respectively. • PZ-PY's exceptional ability to recognize and bind cyanide ions, a toxic environmental chemical, with significant photophysical properties. • Confirmation of binding stoichiometry (1:1) through various analytical methods including Job's and HRMS spectroscopy. Determination of a relatively low limit of detection for cyanide ions (8.79 × 10 -8 M). • For practical application, the I3 receptor was investigated through the test strips, solid state, bioimaging (A547 cell line), detection of cyanide in diverse water samples and food samples. A phenothiazine-linked pyridine acetonitrile with a cyanoethylene bond PZ-PY has been synthesized by Knoevenagel condensation reaction and characterized by spectroscopic and analytical techniques. The structure of PZ-PY was confirmed through single-crystal X-ray diffraction studies; revealing its monoclinic crystal system with a P2 1 /c space group. The absorption maximum and emission spectrum of the PZ-PY receptor were observed at 431 and 608 nm respectively. Cyanide anion is one of the most prevalent chemicals in the environment, its toxic nature poses a constant threat to human daily life. The PZ-PY receptor's recognition of cyanide ions is associated with remarkable photophysical properties. The binding stoichiometry of PZ-PY-CN- was confirmed by Job's plot, B-H studies, 1H NMR titration, TD-DFT, and ESI-mass spectroscopy. The relatively low limit of detection was determined to be 8.79 × 10 -8 M in a linear range between 0 and 120 µL. PZ-PY receptor exhibits an aggregation-caused quenching (ACQ) nature with the increase in water fraction; it is stable between pH 2 to 11. Moreover, the practical applicability of PZ-PY was investigated through the test strip, solid-state, bioimaging (A547 cell line), detection of cyanide in diverse water samples (tap water, distilled water, and lake water), and food samples (sprouted potatoes, bitter almonds, and cassava). [ABSTRACT FROM AUTHOR]

• The degradation of Chinese handmade papers produced by different raw materials was systematically studied at microscopic multiscale structures. • The effect of fiber raw materials on the degradation kinetics of paper cellulose and the variation of cellulose molecular/supramolecular structure was studied. • The correlation between the types of fiber raw materials and the durability of Chinese handmade papers was discussed. As the carriers of paper-based cultural relics, ancient handmade papers have greatly promoted the development of human culture, knowledge and civilization. Chinese papermakers wisely selected a broad variety of plants to make papers with better properties and longer lifetime. However, the correlation between the types of fiber raw materials and the durability of handmade papers is still unclear. Herein, six handmade papers classified as bark paper, bamboo paper and grass paper were selected to study their aging behavior and degradation mechanism. Optical microscope and fiber quality analyzer were used to characterize the fiber morphology and length distribution of papers. The degradation kinetics of six handmade papers were systematically studied under accelerated aging condition. On molecular scale, the degradation rate, variation of pH, oxidation degree, chromaticity, and content of reducing carbonyl groups were discussed for bark, bamboo and grass papers. On supramolecular scale, the crystallinity, energy and distance of hydrogen bonds for paper cellulose were quantitatively calculated. For six handmade papers, most of the degradation occurs in the amorphous region of cellulose, leading to the cleavage of glycosidic bonds, the generation of oxidized groups, and the variation of H-bonds arrangement. Owing to the specific molecular and supramolecular structures of cellulose in bast fiber, bark papers have longer lifetime and better durability than bamboo and grass papers. The results of this work will improve the understanding of paper degradation mechanism at microscopic multiscale structures, and provide the scientific foundation for the preparation of handmade papers with better durability. [ABSTRACT FROM AUTHOR]

Thermoalkaliphilic GH11 xylanases are largely favored for paper pulp biobleaching process. The present work aimed to comparatively investigate the molecular phylogeny, amino acid sequences, molecular structure, and enzyme–substrate interaction of six thermoalkaliphilic GH11 xylanases from different bacterial species (Oxalobacteraceae bacterium xylanase = ObXyl, Sphingomonas sp. xylanase = SsXyl, Hymenobacter sp. xylanase = HsXyl, Amycolatopsis vastitatis xylanase = AvXyl, Lentzea deserti xylanase = LdXyl, Streptomyces rubellomurinus xylanase = SrXyl). For this purpose, six bacterial thermoalkaliphilic GH11 xylanase sequences derived from unreviewed protein entries of UniProt/TrEMBL database were analyzed for their phylogenetic relationships and sequence similarities. Also, 3D predicted structures of the enzymes were built and computationally validated by different bioinformatics tools. The enzyme–substrate interactions were investigated by molecular docking analysis using various substrates. Phylogenetic analysis showed that six enzymes were grouped into two different clusters: the first cluster included ObXyl, SsXyl, and HsXyl, whereas the second cluster had AvXyl, LdXyl, and SrXyl. Multiple sequence alignment showed that the second cluster xylanases possessed longer N-terminal regions indicating higher thermostability, compared to the first cluster xylanases. The structural analyses showed that six predicted structures were largely conserved. Molecular docking results indicated that binding efficiency to xylotriose, xylotetraose, and xylopentaose was higher in second cluster enzymes than that in first cluster enzymes, exhibiting mostly above -8.0 kCal/mol of binding energy. Arginine in B8 β-strand was commonly involved in substrate interactions in all the second cluster xylanases, different from the first cluster ones. Thus, the present work predicted that the thermoalkaliphilic xylanases in the second cluster might be greater potential candidates for the paper pulp bleaching process. [ABSTRACT FROM AUTHOR]

Primary aromatic amines (PAAs) are a class of hazardous substances where many compounds are classified as carcinogen, mutagen, and reproduction toxin (CMR). PAAs can be taken up by dermal exposure. In the polyurethane industry, a valid and trustworthy method for the quantification of PAAs in the presence of isocyanates that could interfere is of great interest, especially on workplaces where a regular contact to PAAs cannot be excluded. The aim of this work is the development, validation, and verification of a novel sampling device to quantify selectively the PAA load on work surfaces. We describe the synthesis of Cell-ßALA-PEMSA analytical papers and their characterization by infrared spectroscopy and thermogravimetric analysis. The recovery of TDA and MDA spiked on these filters is satisfactory. An excellent selectivity of Cell-ßALA-PEMSA papers towards PAAs in the presence of isocyanates of almost 100% was found by wipe tests of amine/isocyanate contaminated surfaces. First positive field tests were achieved at certain areas in a Polyurethane Technical Application Department where surface contamination with PAAs was expected, and the Cell-ßALA-PEMSA analytical papers were superior to an established method of surface sampling. However, recovery of these amines from surfaces shows a large variability, and more work is required to address influencing surface properties. [ABSTRACT FROM AUTHOR]

Visuospatial thinking is considered crucial for understanding of three-dimensional spatial concepts in STEM disciplines. Despite their importance, little is known about the underlying cognitive processing required to spatially reason and the varied strategies students may employ to solve visuospatial problems. This study seeks to identify and describe how and when students use imagistic or analytical reasoning when making pen-on-paper predictions about molecular geometry and if particular reasoning strategies are linked to greater accuracy of responses. Student reasoning was evidenced through penon-paper responses generated by high attaining, high school students (N = 10) studying Valence Shell Electron Pair Repulsion (VSEPR) Theory in their final year of chemistry. Through analysis and coding of students' open-ended paper-based responses to an introductory task, results revealed that students employed multiple reasoning strategies, including analytical heuristics and the spontaneous construction of external diagrammatic representations to predict molecular geometry. Importantly, it was observed that despite being instructed on the use of VSEPR theory to find analytical solutions, some students exhibited preference for alternative reasoning strategies drawing on prior knowledge and imagistic reasoning; showing greater accuracy with 3D diagrammatic representations than students who used the algorithmic method of instruction. This has implications for both research and practice as use of specific reasoning strategies are not readily promoted as a pedagogical approach nor are they given credit for in national examinations at school level.

Three D‐A type blue‐light TADF materials with AIE characteristic have been calculated at atomic level in this paper. The design materials base on carbazole as donor groups and benzenyl‐trifluoride/ cyanobenzene as accept groups. Geometry optimization shows that low binding energy of studied molecules is favorable for synthesis and the optimized molecular structures are highly distorted. Electronic structure analysis proved strong interactions of both inter‐C‐N and C‐C bonds between molecular fragments, and the electronic reconstruction trend and bonding strength are basically consistent for the same type of atom pairs. Frontier molecular orbitals and population analysis demonstrated that HOMO and LUMO are successfully isolated to the receptor and donor. DSCN‐CAZ has the lowest energy due to lower LUMO level. Simulated UV‐Vis spectrum explores that the absorption peak of TADF molecules stand at 253nm‐335 nm and their corresponding excited states all occur pi‐pi* excitation. ESP Surface analysis finds that cyanobenzene fragments were an important factor affecting the stability of the designed TADF molecules. The geometry, electronic structure and optics properties of design materials have been revealed, providing a theoretical basis for developing blue‐light TADF materials with AIE properties. [ABSTRACT FROM AUTHOR]

• Evolution of molecular structure of handmade papers in aging process is traced by two-dimensional correlation spectroscopy. • Quantitative changes of molecular and supramolecular structures of Kaihua handmade papers in aging process are presented. • The degradation mechanism of Kaihua handmade paper in dry-heat and wet-heat aging process is revealed. • Correlations between the microstructural evolution and macroscopic deterioration are explained. Valued for its toughness and durability, Kaihua paper has been famous in China since the Qing Dynasty. It attracts great attention on the extension of paper life. Understanding of the complex degradation behavior of handmade paper under various aging conditions is an essential precondition for preparing long-life handmade paper. However, it is still difficult to explain the reactions sequence of cellulose microstructure and its relationship with the macroscopic deterioration of handmade paper. Herein, different types of Kaihua handmade papers, produced by various raw materials and crafts, were artificially aged. The evolution of their multi-scale structures in dry-heat (DH) and wet-heat (WH) conditions was explored systematically. Two-dimensional correlation spectroscopy (2D-COS) distinguished possible carbonyl vibrations involving hydrolysis and oxidation of cellulose and gave sequential changes of various carbonyl groups, illustrating different evolutionary behaviors of molecular structure of papers in DH and WH aging process. The energy and distance of hydrogen bond, crystal size and microfiber accessibility were quantitatively calculated during the degradation of cellulose. In addition, correlations between microstructural evolution and macroscopic deterioration of handmade papers involving reduced mechanical properties and yellowing were revealed. The current results will help to establish a platform for the multi-scale detection of handmade paper and improve the understanding of the degradation mechanism of handmade paper under different reaction paths. It also provides useful foundation on the preparation of long-life paper and the conservation of paper-based culture relics. [ABSTRACT FROM AUTHOR]

The hot exciton mechanism has joined TTA and TADF as one of the three fundamental theories widely recognized for overcoming the spin statistics constraint in FOLEDs. Although there has been many research and application of hot exciton materials in OLED, the relationship between the molecular structure and its performance of hot exciton material is still unclear. In this work, we performed a high-throughput quantum chemistry calculation for screening hot exciton materials. Ten thousand different molecules are calculated for the electronic donor or acceptor for hot exciton material molecule. Ten hot exciton material molecules were designed based on predicted properties, while other molecular properties were also analyzed. This research represents a significant opportunity to enhance our comprehension of the interplay between material structure and performance and could potentially accelerate the design of hot exciton materials. [ABSTRACT FROM AUTHOR]

In common with many other countries, the Iranian science curriculum does not introduce primary children to atoms and molecules but instead leaves the teaching of these concepts until high school. This paper challenges this practice and describes the changes in elementary Iranian children's understanding of atoms and molecules following a 10-h teaching intervention about basic atomic-molecular theory, derived from recently published Australian research. The participants involved in this study are a group of 25 Iranian children aged 9 to 12 years old, who participated in a vacation summer school where they were taught about the structure of atoms and molecules. Thematic and content analysis of children's written responses and drawings before and after the intervention reveal significant changes in their conceptual thinking. The results also show the extent to which the children can generate microscopic representations of the states of matter from their understanding of atoms and molecules.

In this paper, we will explore the relation between molecular structure and functions displayed by biochemical molecules in complex physiological processes by using tools from the philosophy of science and the philosophy of scientific practice. We will argue that biochemical functions are weakly emergent from molecular structure by using an account of weak. In order to explore this thesis, we will consider the role of vitamin B12 in contributing to the process of erythropoiesis. The structure of the paper is the following: First, we will consider biochemical functions and why they cannot be easily reduced to their chemical realisers. We will suggest weak emergence as an alternative while also accounting for the relevance of the context, in our case, systemic and organisational. The paper will conclude by considering (1) how the usage of tools from the philosophy of science, such as weak emergence, can aid our understanding of the relations between the components of complex phenomena, such as erythropoiesis, and (2) how the philosophy of scientific practice sheds light on the explanatory role of processes that are dynamically stabilised and the different levels of organisation implied. [ABSTRACT FROM AUTHOR]

Atomic/molecular visualization for human sight is usually generated by a software that reproduces a 3D reality on a 2D screen. Although Virtual Reality (VR) software was originally developed for the gaming industry, now it is used in academia for chemistry teaching. This work reviews the scientific literature on 3D visualization in stereoscopic vision, the VR. VR has the capability to simulate reality since we do not observe these real particles, but it reproduces their shapes and movements digitally. The aim of this study is to present the applications of this technology and to show the function of VR in the field of chemistry and the potential for implementation of VR in research and educational settings. The review is based on 219 articles and meeting papers, between 2018 and 2020, obtained from Web of Science (WoS). A series of registers from the WoS repository was analyzed and assigned to three groups, an analysis of 2D support software, analysis of research on Virtual Reality (VR), and research on Virtual Laboratories (VL). The research on advanced atomic/molecular simulation reveals discrepancies regarding the VR effectiveness of Chemistry teaching. Novel Virtual Reality Laboratory (VRL) methodologies are emerging that have a high impact on educational and research scenarios. VL and VRL entail several advantages and drawbacks, such as the implementation of new methodologies, the increase in the students' motivation, the growth of new spaces for collaborative online interaction, and the interaction with physical structure of any impossible, dangerous, or not feasible elements. Finally, the article compares the main features and the learning outcomes of the VRL and the traditional laboratory.

This perspective paper analyses the possibilities and challenges of using cheminformatics as a context for STEM education. The objective is to produce theoretical insights through a SWOT analysis of an authentic educational cheminformatics project where future chemistry teachers engineered a physical 3D model using cheminformatics software and a 3D printer. In this article, engineering is considered as the connective STEM component binding technology (cheminformatics software and databases), science (molecular visualizations), and mathematics (graph theory) together in a pedagogically meaningful whole. The main conclusion of the analysis is that cheminformatics offers great possibilities for STEM education. It is a solution-centered research field that produces concrete artifacts such as visualizations, software, and databases. This is well-suited to STEM education, enabling an engineering-based approach that ensures students' active and creative roles. The main challenge is a high content knowledge demand, derived from the multidisciplinary nature of cheminformatics. This challenge can be solved via training and collaborative learning environment design. Although the work with educational cheminformatics is still in its infancy, it seems a highly promising context for supporting chemistry learning via STEM education.

It is widely argued that Nanoscience and Nanotechnology (NST) is going to affect several aspects of our life. Therefore, students need to develop their nanoliteracy to cope with the everyday issues related to NST. Although there is an increasing interest in introducing NST content to primary school students, the theoretical frameworks for interpreting their learning are still an open issue. ?o fill this research gap, this paper presents a Teaching Learning Sequence (TLS) about NST content that focuses on students' learning from the perspective of the Framework Theory and the Conceptual Change. The TLS is developed in six units, including concepts related to the size of objects, the observation tools, the lotus effect, the applications of NST as well as the models. The participants (N = 60) were 6th grade primary school students. ? questionnaire was used to capture the students' progress one week and three months after implementing the TLS. The results provided evidence that shows that students' conceptions were closer to scientific ones after implementing the TLS. Results are discussed in the light of the Framework Theory and the Conceptual Change. Educational implications for teaching and learning NST concepts at the primary school level are also discussed.

Oxidation number (ON) is taught as an electron-counting concept for redox reactions in chemistry curriculum. The molecular formula method, the Lewis formula method, and the structural formula method have all been used to determine ON. However, the task of assigning ON still poses problems for some teachers and students. This paper explores a new method, the fragmentation method, which is a visual approach for counting the individual ON of any atom according to its structural formula. The critical step is to break the carbon-heteroatom bond into organic fragments and inorganic fragments. The individual ON of carbon atoms and heteroatoms can be determined by the bond cleavages in the organic and biological compounds. The mean ON of carbons can be calculated by the arithmetic mean of all individual ON of carbons in a molecule or molecular ion. The step-by-step operating procedures and examples are provided. When comparing corresponding molecules in organic conversions, the change of individual ON of atoms can be used as a tool for determining the number of transferred electrons. Furthermore, a reaction site can be identified by their changes of individual ON, chemical composition, and bond order in metabolic redox reactions.

In the fall of 2009 and in the spring of 2012, supported by the National Institute of General Medical Sciences (NIGMS) in the National Institutes of Health (NIH), we designed a course "Phylogenetic Analysis and Molecular Evolution" (PAME), the first cross-listed course across three different colleges (College of Arts and Sciences, College of Engineering, and College of Agriculture). This course was the first at the author's university. The course will be made available to graduate students and advanced undergraduate students in biology and computer science, and undergraduate student in statistics and mathematics at regional universities and colleges. The graduate students will learn how to gather sequence data, use bioinformatics tools, and analyze biological data using mathematics and statistics throughout the project. In this paper, we propose an online course on PAME facilitated with the statistical software RStudio on Amazon Web Service (AWS).

This study focuses on post-induction mentoring as a vehicle for science teachers' training in implementing a nanotechnology teaching-learning sequence. Five mentors and 15 mentee-teachers participated in a 9-months long mentoring programme. Qualitative methods of analysis were used to examine the content of the mentoring conversations and the employed mentoring practices. Our findings indicate that the focus of the mentoring conversations was mainly set on the necessary strategies for teaching nanotechnology and secondarily on the resolution of organisational issues that arose. As regards the mentoring activities, mentors tended to address the arisen issues by giving advice, sharing their knowledge and teaching materials and by modelling the conduct of the lessons. The paper highlights the contribution of mentoring to the professional growth of post-induction teachers mainly in terms of broadening their teaching repertoire on nanotechnology issues.

Abundant prior research has compared effects of physical and virtual manipulatives on students' conceptual learning. However, most prior research has been based on conceptual salience theory; that is, it has explained mode effects by the manipulative's capability to draw students' attention to conceptually relevant (visual or haptic) features. Yet, research based on embodied schema theory suggests that other mechanisms, which do not rely on students' explicit attention to specific features, also affect students' learning from manipulatives. This paper presents a study that contrasts predictions by different theoretical perspectives by comparing multiple versions of physical and virtual manipulatives. Specifically, we conducted a lab experiment with 119 undergraduate students who learned about 3 concepts related to atomic structure using 1 of 4 versions of energy diagram manipulatives. The 4 versions varied the representation mode (i.e., physical vs. virtual) and the actions students used to manipulate the representation (i.e., via actions that draw attention or activate embodied schemas). We assessed students' learning via reproduction and transfer posttests and interviews that measured the quality of students' explanation and the gestures they used while explaining the concepts. Our results suggest that embodied schema theory accounts for effects on the reproduction posttest, whereas conceptual salience theories account for effects on the transfer posttest. Further, when physical manipulatives offered relevant haptic cues, we found an advantage of physical manipulatives on transfer. We interpret these results based on the complexity of embodied schema and conceptual salience learning mechanisms and the complexity of the assessment tasks.

Background: In the digital environment, users' academic reading behaviour has changed, working with many articles simultaneously to search, filter, scan, link, annotate and analyse content fragments. The semantic enhancement environment has been widely set with semantic technologies to offer additional and handy support for users and thus facilitate the reading process. Despite many efforts devoted to developing a semantic enhancement environment, less attention has been paid to its actual effects. Objectives: This study aims to explore the effects of a semantic enhancement environment. Methods: Elaborating on cognitive load theory and focusing on academic reading, this study compared users' cognitive load and reading effect under the semantic enhancement environment and plain text environment and verified the three hypotheses. Results and conclusions: Through experiments and statistical analysis, this study found that, under a semantic enhancement environment, users had their cognitive load reduced and their reading effect improved. Consequently, a semantic enhancement environment promotes academic reading. Takeaways: This study adds to previous literature on semantic publishing by empirically corroborating the conducive effects of semantic enhancement environment in academic reading. Additionally, it justifies semantic publishing and provides a reference for the future design of semantically enhanced reading environments. Lay Description: What is already known about this topic?: The effects of a semantic enhancement environment are open to discuss.Academic reading is fundamental to researches and hence needs promotion.Limited studies investigated the effects of a semantic enhancement environment on academic reading.Publishers require effective reading environment designs. What this paper adds?: This study constructed a semantic enhancement reading environment to conduct a reading experiment.The experiment tested cognitive load, by using WP scale, and reading effects, by answer time and answer score.Semantic enhancement environment reduces users' cognitive load, promotes users' reading effects, and bolsters users' understanding of academic reading materials, especially in microstructure content.The design of semantic enhancement reading environments needs to fully consider the features of reading materials and give users a controllable way of interaction. The implications of study findings for practitioners: Compared to plain text environment, semantic enhancement environment is preferred in academic reading.Publishers are encouraged to add semantic enhancements to their publications.This study discussed how to design an effective learning and reading environment from the perspectives of reading resources, media forms of resources, and interaction modes. [ABSTRACT FROM AUTHOR]

One of the more difficult concepts introduced in the first-year undergraduate course, general chemistry, is that of chirality. Typically, left and right hands are the common, macroscopic objects of reference used to demonstrate the quality of being nonsuperimposable, followed by the use of a mirror and molecular models, to illustrate molecular enantiomers. While this approach works well as an introduction, and the handedness model becomes more useful in organic chemistry where absolute R- and S-configuration assignment becomes necessary, it does not help the general chemistry student to determine molecular chirality or "handedness" at this basic level. Much of the difficulty stems from the representation of 3-dimensional (3-D) structures on the 2-dimensional (2-D) paper plane. While detailed flowcharts exist for molecules of varying orbital hybridization and geometry, these are more suited to advanced students in inorganic chemistry and are not designed to be mentally retained or learned. Additionally, the process of determining R- and S-configurations for carbon tetrahedral centers in organic chemistry is more complex as ligands must be ranked according to Cahn-Ingold-Prelog (CIP) rules. Previous publications have addressed this topic thoroughly. A simple method is presented here (called clocking) which introduces the concept of chirality for general chemistry and primes the way for more complex chirality assignments in higher level courses.

This paper describes the design and implementation of a course-based undergraduate research experience (CURE) sequence in chemistry that links a lower-division, organic chemistry course to an upper-division, analytical chemistry course. The focus of student research is on blood preservation using trehalose derivatives in order to mimic the tardigrade, a microscopic extremophile, which produces sugar molecules to survive desiccation and freezing. Students created a library of modified sugar molecules in the organic CURE and then evaluated the behavior of those molecules within membranes in the analytical CURE. The CURE sequence has been run with three student cohorts which were selected to match the demographics of all students in the course. This article details the student selection process, the course design, the faculty implementation, and revisions. Fidelity of the CURE is demonstrated with survey results. We also describe adaptation of the research courses to accommodate the COVID-19 restrictions.

Per the well‐known resistance of hepatitis B virus to nucleoside/nucleotide analogs, alternative treatment options with higher resistance barriers have been approved for use in both treatment‐naïve and lamivudine‐resistant hepatitis B virus infections. This phase I study was conducted in adults with normal and impaired renal function to evaluate the effect of renal impairment on the pharmacokinetics of besifovir, a prodrug of an acyclic nucleotide phosphonate, that is mainly cleared via renal excretion. An open‐label, single‐dose parallel‐group clinical study was conducted in subjects with normal renal function and mild, moderate, and severe renal impairment. Subjects received a single oral dose of besifovir dipivoxil 150 mg, and serial blood and urine samples were collected for up to 72 hours after dosing to assess the pharmacokinetic characteristics of besifovir. The extent of plasma exposure of besifovir, detected as its major and active metabolites, LB80331 and LB80317, respectively, increased with worsening renal function. Compared to the subjects with normal renal function, the mean areas under the concentration‐time curves of LB80331 increased by 1.5‐, 2.5‐, and 4.5‐fold in subjects with mild, moderate, and severe impairment, respectively. LB80317 showed a 1.8‐, 3.2‐, and 6.2‐fold increase in subjects with mild, moderate, and severe renal impairment compared to those with normal function. The ratios of LB80331 renal clearance and the average estimated glomerular filtration rate of each renal impairment group with respect to the normal group were similar. The increase in plasma exposure and decrease in renal clearance suggest the need to adjust dosage regimens in patients with moderate to severe renal impairment. [ABSTRACT FROM AUTHOR]

In the heterogeneous reservoirs, CO2 flooding easily leads to CO2 gas channeling, which can seriously affect sweeping efficiency and reduce oil recovery. After thoroughly investigating the advantages and shortcomings of various CO2 plugging technologies, this paper focuses on the feasibility of improving conventional water-alternating gas (WAG) through CO2-responsive gel materials. Based on the different chemical reaction mechanisms between the unique chemical structure and CO2, changes in the material's physical and chemical properties can respond to CO2. The feasibility of utilizing these property changes for CO2-responsive plugging is explored. Various CO2-responsive gels and gel nanoparticles have been extensively researched in different fields, such as energy, medicine, and biology. This paper surveys the molecular structures, chemical compositions, response mechanisms, and changes of these CO2-responsive gels, aiming to draw insights into the carbon dioxide-enhanced oil recovery (CO2-EOR) field. Finally, the key issues and future development direction of CO2-responsive plugging gels were analyzed. [ABSTRACT FROM AUTHOR]

• A new tetraphenylethene midified quinolone derivative TPE-QL was designed and prepared. • TPE-QL exhibited highly twisted conformation, high fluorescence quantum and AIE behaviors. • TPE-QL showed mechanochromic behavior by changing the emitting color from blue-green upon grinding. A simple tetraphenylethene (TPE) modified quinoline derivative TPE-QL was designed and prepared. It possessed donor-acceptor molecular structure and highly twisted conformation, which could be proved by spectral studies and theoretical calculatiuons. Due to the introduction of TPE unit, TPE-QL exhibited typical aggregation-induced emission (AIE) characteristic. Interestinly, TPE-QL also showed obvious fluorescence response to mechanical force by changing the emission wavelength from 440 nm to 485 nm upon grinding. Moreover, reversible mechanochromic behavior was detected after repeated grinding and fuming treatment. This work not only discovered a new AIE-active mechanochromic material, but also provided possibility for its application in the filed of ink-free rewritable papers for security decumentation purposes. [Display omitted] [ABSTRACT FROM AUTHOR]

The structural formula of a chemical compound is a shorthand, diagrammatic representation of a molecular structure, showing how atoms can be arranged in two dimensions of space. Often named Kekulé structures after August Kekulé, an early architect of structural arrangements in organic chemistry, these diagrams put forward a geometry of relations, enumerated through lines, symbols, vertices, and patterns (Rocke 1981). While suggestive of something substantial, the diagram often functions in the planular, and is therefore skeletal. For scientists, skeletal structures are not altogether representative of chemical constitutions, but of chemical arrangements (Hepler-Smith 2015). That is, they are analogous with formulas; not respective forms themselves. From this perspective, there is a severance of contextual placement, but not of performative function. As a presupposition to this construct, it seems that skeletal structures can be read as compositions and translations, but not as epitaphs or reincarnations. Following Deleuze's and Guattari's premise that the diagram constructs something 'yet to come' (2013:164), Victoria Sharples' 'Epitaphic Readings: Diagrams as (Re)incarnations' presents skeletal structures as epitaphic readings; as accounts of something passed, and further to this as matter re-incarnate. Skeletal structures provide a genesis for this paper and are the seeming conclusion to Ash (2018–2020), an interdisciplinary study on which this article builds. For Ash, three pieces of Nepalese Lokta paper were placed on the surface of the sacred and contaminated Bagmati River downstream from Pashupatinath Temple: an open-pyre cremation site in Kathmandu. Once dried, the substrates were analysed using Gas Chromatography-Mass Spectrometry (GC-MS); an analytical approach for forensic substance identification. Through the intersection of science and spirituality, this paper meditates on the potential 'afterlives' of Ash. Functioning in a space between active-passive and organic-machinic, the GC-MS diagrams function as epitaphic readings making that which has passed present, marking an arrival and re-incarnation of matter. [ABSTRACT FROM AUTHOR]