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This paper aimed to provide a holistic view of research that investigated online learning in higher education around the globe during COVID-19 utilizing a bibliometric analysis. The researchers used co-citation analysis and text mining afforded by VOSviewer to document and analyze research patterns and topics reported in peer-reviewed documents published between January 2020 and August 2021. Findings of this study indicated that scholars from 103 countries or regions from the Global North and Global South investigated a wide array of topics, such as use of various technologies and strategies, redesigned curriculum, student perceptions and psychological impacts of the pandemic-imposed online learning. Many researchers applied technology acceptance theories and structural equation modeling to investigate factors associated with adoption and impacts of the pandemic-imposed online learning. Of the large quantity of research, medical education and chemical education were the most investigated disciplines. Inquiry-based learning, discovery learning, hands-on learning and collaborative learning emerged as instructional approaches frequently discussed or utilized across the target studies. This paper discussed (a) ongoing and emerging challenges to online higher education, (b) placing innovative pedagogies at the forefront of online learning, and (c) rapid, but imbalanced distribution of evolving literature based on the findings.

Nuclear chemistry and radiochemistry is a branch of chemistry that has high experimental risks, has high research costs, and is subject to certain prejudices. However, it has an extremely important influence on the development of human life. It is particularly important to emphasize the general education of nuclear chemistry and radiochemistry without compromising the quality of the teaching. The introduction of the general education mode into nuclear chemistry and radiochemistry overcomes the shortcomings of narrow audiences. However, single theoretical courses are limited to a slide-based lecture. Although the audience for general education is wide, it is difficult to carry out related experiments because of safety responsibility and teaching funds. In this work, VR technology was first applied to the general education of nuclear chemistry and radiochemistry, and the audiences of the course were not limited to students who major in chemistry. The research results showed that not only did the VR platform effectively improve students' learning confidence, but also the effect of teacher-student interaction and the usability of VR equipment were recognized. This work may bring enlightenment to the popularization of nuclear chemistry and radiochemistry through new media technology.

Evidence-based reasoning and critical thinking are two crucial scientific abilities of students, sharing a close relationship with each other critical thinking is not just randomly refuting but a logical-reasoning thinking based on solid evidence. However, in real teaching circumstances of experiment classes, students easily directly accept the conclusions they have been given, without critical thinking and full comprehension of the relationship between experimental evidence and the resulting conclusions. In this work, a demonstration experiment of iron corrosion was developed. More than teaching the knowledge of specific chemical reactions in the case, the experiment was designed for the further purpose of stimulating students' critical thinking. During implementation, instead of showing the well-designed experiment scheme directly, the teacher first showed the preliminary outline and then revealed the process of revising the outline gradually to become the final rigorous scheme. In each step, students were asked to seek evidence and flaws in the reasoning process that appeared in the experiment, as the basis for subsequent revisions. After three revisions, teachers and students agreed that the evidence and reasoning process of the scheme were sufficiently rigorous. The performance of the students during the class showed that the students' attitude toward the demonstration experiment has changed from passive acceptance to active reflection and questioning. The feedback from students after class showed that students' awareness of evidence-based reasoning and critical thinking has been enhanced.

This study developed a complexometric titration simulation program based on LabVIEW. With built-in approximation and rigorous algorithms, the program can easily simulate and plot a single or a group of complexometric titration curves. On the basis of this program, we developed and implemented an online course to guide undergraduates to (i) compare the differences between the two titration types EDTA (Y) to Metal (M) and M to Y, (ii) explore the influencing factors of a titration jump, (iii) explore the conditions for an accurate titration, and (iv) find evidence for the existence of complexometric equilibrium. Questionnaires from 25 students were used for evaluation. The results showed that the program had high usability, practicability, effectiveness, and user behavior intention. Besides, 92% of the students were willing to use it more in the future and 11 students completed the test with an average score of 124.6 (full score of 150), and the average score of the modules corresponding to each learning goal was high, indicating that the students had achieved satisfactory learning outcomes.

Conventional mobile phone colorimetry usually utilizes the RGB color mode to measure concentration of solutions, but the paper entitled "Determining the Amount of Copper(II) Ions in a Solution Using a Smartphone" proposes the use of hue ("H") to measure the concentration. It is pointed out that the "H" value increases with the increase of copper nitrate concentration. However, our experimental results show that the "H" value does not change with the concentration, which indicates that the amount of copper ions in a solution cannot be determined by "H" values. The errors in the paper may come from the deficiencies of materials and methods, resulting in large deviations.

The Briggs-Rauscher reaction is a popular demonstration to illustrate chemical oscillations in laboratories, classrooms, and public seminars because of its simplicity and visual appeal. Here, we adapt the Briggs-Rauscher reaction to present reaction-diffusion-convection patterns in the undergraduate general or physical chemistry laboratory. By maintaining the ratio between malonic acid and potassium iodate concentrations as 0.2 in an uncovered Petri dish, sequential patterns (transient dendritic patterns and rotating dendritic patterns) can be observed, which are induced by the interaction of reaction, diffusion, and convection. This beautiful demonstration captures students' attention and inspires reflection and discussion about similar phenomena in nature as well as the wealth of behaviors in systems far from equilibrium.

The topic of chemistry safety was included at the margins of traditional chemistry education in China. In order to understand the concerns of the safety issues based on the new chemistry curriculum in the mainland China secondary school, this study analyzed old and new secondary chemistry curriculum standards via the Natural Language Processing & Information Platform (NLPIR). Results show that the frequency of chemistry-safety-related words increased in the new curriculum standards. Evidence that the safety content is enriched and enhanced can also be found in the new textbook. In addition, content analysis of lesson plans from Jiangsu teaching contests reveals that the chemistry teachers (CTs) pay more attention to the safety risk of experiments, but they generally ignore the consideration of risks from the perspective of the uncertainty of chemical reactions.

The practice and research on online chemistry education have received great attention in the context of the COVID-19 pandemic worldwide. This paper describes the teaching practice of online learning based on three online courses for pre-service chemistry teachers. To adapt online teaching requirements, we reshaped the structure of the physical chemistry course, for example, adjusting the assessment approaches, and reinforcing long-distance instruction. Besides, we also shared the course of training chemistry teaching skills online publicly, and provided multiple learning approaches after class. Moreover, we introduced chemistry education research based on website data in an educational research methods course and shared ideas through the technology platform.

To promote the integration of aesthetic education into chemistry education, this study designed activities to photograph precipitation reaction experiments with a smartphone, thereby combining experimental inquiry with artistic creation across disciplines. These activities were divided into (i) perceiving, (ii) appreciating, (iii) exploring, and (iv) creating the beauty of chemistry. The participants first used macrophotography to capture the details and small changes of a precipitation reaction to obtain an impression of beauty. Then, they managed to understand, appreciate, and evaluate the beauty of the precipitation reaction from an artistic vision (admiring chemistry like an artist). Next, the students explored the fascinating phenomenon from a chemical perspective and looked for its inherent laws. Finally, they consistently improved the experimental and photographic methods and created works of scientific photography. These activities are suitable for students from primary school to college, and even for the general public. The experiments can be completed in only 1 min, but several hours can be spent to improve the results. In the end, most students are able to take high-quality photographs of precipitation reactions.

This paper proposes an experiment in which students build microdevices for conveniently electrolyzing water and use image recognition and processing technology to measure the volume of gas generated during the reaction in a noncontact way. Taking advantage of three ratio relationships between (i) gas volume and the area of bubbles, (ii) the factual size and the size on the picture, and (iii) the area on the picture and the pixel number, the experiment converts the measurement of trace gas volume into measurement of bubbles' pixel number on the picture, which simplifies the complex problem. The device includes pencil refills as the electrodes, compressing the reaction space in the interval between two glass slides to squeeze the gas generated into flat-cylinder shaped bubbles with a fixed height. The students use a smartphone to take pictures and use software to process the images. Briefly, edges of bubbles are recognized and enhanced by PowerPoint, followed by a cutout process by Photoshop to get the bubbles' image without the background; a histogram tool is then used for analyzing the pixel number of bubbles to finally get the volume of hydrogen and oxygen. Results of the survey among participating students proved the pedagogical effectiveness of this project.

This paper introduces a safe, interesting, convenient, and low-cost experiment. The products of galvanic cells and electrolytic cells are compressed into specimens that are placed on a slide to stretch the metal dendrites in one plane and ensure they are not easily destroyed by external factors. The details and growth process of the metal dendrites can be clearly observed with the naked eye and optical microscopy, which arouses interest from students and allows them to enjoy the beautiful images while obtaining a large amount of macroscopic information. By allowing the students to observe the macroscopic phenomena and the corresponding microscopic changes among the microparticles, it is possible for them to explain the morphological origins and growth rates of the metal dendrites, which deepens their understanding of the reactions that occur in galvanic and electrolytic cells.

In this study, we reviewed 76 journal articles on employing drawing assessment as a research tool in science education. Findings from the systematic review suggest four justifications for using drawing as a type of research tool, including assessment via drawing as (a) an alternative method considering young participants' verbal or writing abilities, and affective or economic reasons, (b) a unique method that can reveal aspects not easily measured by other methods, (c) a major method that reflects characteristics of science subjects, and (d) a formative assessment to diagnose students' ideas to benefit their learning. Furthermore, five research trends of studies using drawing as assessment tools are identified, including: (a) students' conceptions of scientists from the Draw-a-Scientist-Test (DAST) and evolving studies, (b) students' understanding or mental models of science concepts, (c) participants' conceptions of science learning or teaching, (d) students' inquiry abilities and modelling skills via drawing, and (e) technology to support drawing. For each trend, we synthesised and commented on the current findings. A framework conceptualising phases and issues when designing research and instruments employing drawing assessments is proposed. The review provides insights into the design and future direction of research employing drawing assessments in science education.

Technology-enhanced learning has attracted increasing attention of educational community focused on improvement of traditional classroom learning. Augmented immersive reality (AIR) technologies enhance users' perception of reality by augmenting it with computer-generated components such as audio, video, 2/3-D graphics, GPS data, etc. The AIR introduces new dimensions of learning experience that ensure better attention, focus, and entertainment, thereby boosting students' motivation and attainment. This work presents an award winning AIR-based educational mobile system, code-named AIR-EDUTECH, that was developed to help high school students learn chemistry. The AIR-EDUTECH introduced new AIR features to help students better understand and learn basic concepts of molecular chemistry. It offers immersive 3D visualization and visual interaction with the examined structures that provides a broader and more retentive knowledge and improves intuition around forming basic chemical reactions. The system was introduced and tested in a field study with 45 students in the 11th grade chemistry class, and its impact was evaluated by the formal assessment quiz along with the feedback from survey conducted after the trial. Collected data have been subjected to an in-depth multi-modal quantitative analysis that revealed that AIR-EDUTECH stimulated significant improvements in understanding and retention of the taught content as well as turned learning chemistry into a fun, interesting and interactive experience. It also uncovered a hidden structure of taught knowledge dependencies and highlighted the role that AIR technology could play in reinforcing the retention of critical knowledge that may otherwise widen student knowledge gaps.

Integrating knowledge across disciplines has been shown to be a challenging, and yet it is a necessary skill that university students need to develop. Students who are able to connect different concepts, perspectives, and angles of a given topic are generally more engaged and have better understanding. However, designing lesson plans or assignments that integrate knowledge across disciplines is a challenge to most instructors. This paper describes our effort to provide an interdisciplinary and independent assignment that couples topics from a Physical Chemistry course with skills taught in an Introductory Computing course. It was shown that such an interdisciplinary assignment, though done independently, can help to boost students' learning. However, it helps only in the understanding of certain aspects of the topics. We present the design of the assignment and the lessons learned for other instructors willing to adopt this kind of interdisciplinary approach.

Purpose: Argumentative practices are central to science education, and have recently been emphasised to promote students' reasoning skills and to develop student's understanding of scientific concepts. This study examines the mastery of scientific argumentation, based on the concept of neutralisation, among secondary level science students, when engaged in individual and group argumentations. Methodology: 356 form four science students were first randomly assigned to an argumentative condition, after their lesson on acids and bases, presented using the developed instructional materials. Each individual or group was then asked to answer an Open-ended Scientific Argumentation Test (OSAT). Discussions during group argumentations were observed and recorded. All the answers provided in the OSAT were then analysed based on their accuracy, the triplet relationship in chemistry and for the presence of argumentation elements. Observations from the group argumentations were transcribed and assessed. Findings: The results show that in both argumentative conditions, most of the arguments constructed tend to consist of the elements of claim and evidence. The results also show that students who work in groups outperform students who work individually. As individuals, most of the arguments presented tend to be simple with reasoning at a macro-level. As groups, the arguments presented are more complex, where justifications are provided at the sub-micro and symbolic levels, and with fewer misconceptions. That is because group argumentation participants have the opportunity to share ideas, detect and correct each other's mistakes, seek explanations and explain ideas. Significance: The study implies that group argumentation enhances students' argumentation and reasoning skills and improves their mastery of scientific concepts. In addition, this study also investigates students' performance from the Malaysian perspective.

Scientific argumentation has been greatly emphasized in the National Science Standard due to its ability to enhance students' understanding of scientific concepts. This study investigated the mastery level of scientific argumentation, based on Toulmin's Argumentation Model (TAP), when students engage in individual and group argumentations. A total of 120 students were selected and were first randomly divided into two groups to answer the Scientific Argumentation Test (ScAT). One group of students answered individually, while the other group was allowed to collaborate among group members. The Student Semi Structured Interview (SSSI) and Teacher Semi Structured Interview (TSSI) were also conducted on a selected group of students and their teachers to gather additional information to support the ScAT data. The findings showed that there is a significant difference in the mastery level of scientific argumentation between groups and individuals. Students who participated in group argumentation tend to perform better than those who participated in individual argumentation. However, the mastery level of scientific argumentation for both groups of students was generally unsatisfactory. Therefore, the teaching and learning of science in Malaysian schools need to emphasize more on group argumentative activities to enhance students' mastery of scientific argumentation, which will also their reasoning capabilities and scientific knowledge.

This study explored relationships between students' attitudes toward science and their preferred versus actual experience of cooperative, constructivist-oriented, or direct instruction. The sample consisted of 1334 Chinese middle school students in physics and chemistry classrooms. Results showed that students report experiencing more direct instruction, very little constructivist-oriented instruction, and a moderate amount of cooperative instruction. Attitudes toward science were positively related to cooperative teaching strategies like group work in class or developing small-group projects. There was no significant effect of constructivist-oriented instruction or of direct instruction on students' attitudes. Whereas previous studies demonstrated positive impacts of constructivist teaching on student understanding of science concepts, student attitude toward school science appears to be more related to social interaction or cooperation. Lack of any statistically significant differential effect from constructivist-oriented instruction might also be related to the overall low incidence of such instruction experienced by our sample.

The purpose of this study is to evaluate the technological acceptance of Chemistry students, and the opinions of Chemistry lecturers and laboratory assistants towards the use of remote laboratory in Chemistry education. The convergent parallel design mixed method was carried out in this study. The instruments involved were questionnaire and interview protocol. A total of 81 Chemistry students, five Chemistry lecturers and two Chemistry laboratory assistants from Universiti Pendidikan Sultan Idris (UPSI) were chosen as respondents in this study. For the quantitative approach, the data from the questionnaire were analysed using descriptive statistics to evaluate students' technological acceptance of remote laboratory. For the qualitative approach, the responses from the interviews were analysed to evaluate the lecturers and laboratory assistants' opinions towards the use of remote laboratory by using coding and grouping methods. Quantitatively, the student respondents had given the mean scores ranging from 2.97 to 3.30 for the attitude towards use (ATU), perceived ease of use (PEOU), behavioural intention (BI), and perceived usefulness (PU). Qualitatively, the respondents accepted the implementation of remote laboratory in Chemistry education based on its several advantages such as flexibility, cost efficiency, and risk-free environment. However, some disadvantages of remote laboratory such as lack of skills and experience and Internet connection problem were also voiced out by the respondents. Overall, the results from this study showed that the students, lecturers and laboratory assistants had positive responses towards the technological acceptance of remote laboratory in Chemistry education. Thus, remote laboratory could be developed and introduced to Chemistry education in UPSI.

This study examines the verbal interactions among a group of pre-service teachers as they engaged in scientific discussions in a medicinal chemistry course. These discussions were part of the course that encompassed an explicit instruction of scientific argumentation structures as well as an applied component, whereby the pre-service teachers learned the content of medicinal chemistry through cases developed using the strategy of competing theories. By adopting a case study approach using sociocultural framework of learning, we examined the interactions between the pre-service teachers using video data. We describe 12 possible forms of interactions during discussions--(1) seeking clarification, (2) figuring out loud, (3) sharing information, (4) agreement, (5) asking questions, (6) providing explanations, (7) raising strategic and procedural issues, (8) stating claims, (9) disagreement, (10) sharing perspectives, (11) offering alternatives, and (12) persuasion. The pre-service teachers engaged in figuring out aloud and seeking clarifications frequently, and used persuasion least in their discussions. To clarify their ideas and thoughts, pre-service teachers commonly rebut their counterparts and used warrants to support their own assertions. A similar pattern was also observed when figuring their thoughts out loud. Our findings suggest that pre-service teachers were able to carry out rebuttals in the argumentation process. However, the quality and function of their rebuttals can be improved by deepening their understanding of the subject matter knowledge and the science argumentation structure. Implications are discussed.

Abstract The oxidation of phenolic compounds is one of the most important reactions prevalent in various biological processes, often explicitly coupled with proton transfers (PTs). Quantitative descriptions and molecular-level understanding of these proton-coupled electron transfer (PCET) reactions have been challenging. This work reports a direct observation of PCET in photodetachment (PD) photoelectron spectroscopy (PES) of hydrogen-bonded phenolic (ArOH) nitrate (NO3 −) complexes, in which a much slower rising edge provides a spectroscopic signature to evidence PCET. Electronic structure calculations unveil the PCET processes to be isomer-specific, occurred only in those with their HOMOs localized on ArOH, leading to charge-separated transient states ArOH•+ ·NO3 − triggered by ionizing phenols while simultaneously promoting PT from ArOH•+ to NO3 −. Importantly, this study showcases that gas-phase PD-PES is a generic means enabling to identify PCET reactions with explicit structural and binding information.

Abstract Molybdenum sulfide (MoS2) and modified MoS2 with different percentages of CdS (10%, 30%, and 50% CdS@MoS2) were successfully synthesized and characterized. The photocatalytic performance of the MoS2 and CdS@MoS2 was evaluated by degrading brilliant green (BG), methylene blue (MB), and rhodamine B (RhB) dyes under visible light irradiation. Amongst the synthesized photocatalysts, 50% CdS@MoS2 exhibited the highest photocatalytic activity, degrading 97.6%, 90.3%, and 75.5% of BG, MB, and RhB dyes, respectively within 5 h. The active species involved in the degradation processes were investigated. All trapping agents inhibited BG and MB degradation to a similar extent, indicating that all of the probed active species play an important role in the degradation of BG and MB. In contrast, h+ and O2 •− were found to be the main reactive species in the photocatalytic RhB degradation. A potential mechanism for the photocatalytic degradation of dyes using CdS@MoS2 has been proposed. This work highlights the potential of CdS@MoS2 as a photocatalyst for more efficient water remediation applications.

Photoelectrochemical (PEC) water splitting presents a promising approach for harnessing solar energy and converting it into hydrogen energy. However, the limited water oxidation activity of semiconductor photoanodes has severely hampered the overall conversion efficiency. In this study, a hollow dodecahedral structure of NiCo-LDH (HD-NiCo-LDH) was designed using the metal-organic framework ZIF-67 as a precursor. HD-NiCo-LDH was employed to modify the BiVO4 photoanode, serving as an oxygen evolution cocatalyst. HD-NiCo-LDH can enhance light absorption, accelerate photogenic hole extraction, promote photogenic charge separation and improve the kinetics of water oxidation reaction. Significantly, the unique hollow dodecahedral structure of HD-NiCo-LDH possesses a larger specific surface areas, which provides additional active sites for the water oxidation reaction and facilitates the adsorption of water molecules. The photocurrent density of the optimized HD-NiCo-LDH/BiVO4 photoanode reaches 4.54 mA/cm2 at 1.23 V vs. RHE, which is 3.3 times greater than the bare BiVO4 photoanode. This presented work introduces an innovative design concept for photoanodes supported by oxygen evolution cocatalysts with multi-active sites.

This paper examines learning of science in 15 grade nine classrooms by analyzing the type of talk that teachers engaged in. Using transcripts from audio recordings that are part of the Singapore Corpus of Research in Education database, annotations were carried out on the phrases of teacher talk using Mortimer and Scott's framework for meaning making in science classrooms. Interpreted from a sociocultural view of science learning and based on text coverage per 1,000 words spoken by teachers and students, we analyzed the content of instruction and found that (1) teachers in all three sub-disciplines of science used the least number of words to make statements of generalizations, with chemistry teachers privileging description more than physics and biology teachers, while physics teachers use more words for explanation when compared with biology and chemistry teachers and (2) teachers from all three sub-disciplines depended more on empirical justification than theoretical justifications. These findings suggest that most scientific stories in Singaporean grade nine classrooms are dependent on specific contexts and that the nature and organization of knowledge in each sub-discipline defines the features that teachers use in the classrooms to talk knowledge into being. We discuss our findings on whether science curriculum should be framed as "separate subjects" or if they should be developed as "integrated science" and draw implications to science teacher education and the conduct of high stakes public placement examinations.

Solvothermal reactions of Ba(NO3)2 with 1,3,5-benzenetricarboxylic acid gave rise to a new coordination polymer of [Ba6(BTC)4(H2O)9]}n (1 H3BTC = benzenetricarboxylic acid). The complex 1 was characterized soundly by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis (EA), single-crystal X-ray diffraction (SCXRD), and thermogravimetric analysis (TGA). The framework of 1 has high thermal stability and shows intense luminescence at room temperature. Hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) have good biocompatibility, based on the chemical synthesis method, the HA/CMCS hydrogel was prepared. With exosomes as drug models, we further synthesized novel exosome-loaded metal gel particles and evaluated their effects on oxidative stress in human dermal fibroblasts.

Due to the complexity and diversity of the chemical composition of traditional Chinese medicines (TCMs), the identification of components of TCMs can effectively guarantee the quality of TCMs and be of great significance for the development and utilization of TCMs. In this study, the ultra-high performance liquid chromatography-quadrupole-electrostatic field Orbitrap mass spectrometry (UHPLC-Q-Orbitrap/MS) was used to comprehensively analyze the chemical composition of Danggui Sini Granules. The UHPLC separation was performed on a SUPELCO C18 column (100 mm×4.6 mm×2.7 μm), and the column temperature was 30 ℃, the injection volume was 5 μL. The mobile phase was consisted of 0.1% formic acid aqueous solution (A) and acetonitrile (B) with the flow rate of 0.5 mL/min. MS data was collected under positive and negative ion modes. A self-constructed database of organic acids, flavonoids, phthalides, triterpenoids, saponins and other compounds was established by searching online databases. Rapid identification of the constituents of Danggui Sini Granules based on precise m/z and secondary fragment ion information in combination with literature data was achieved, and the herbal sources of the compounds were attributed. Seventy-two compounds are identified from Danggui Sini Granules, including 20 flavonoids, 15 organic acids, 11 saponins, 9 terpenoids, 5 phthalides, 1 phenylpropanoid, 1 aldehyde, 1 nucleoside, 1 lignan and 8 other compounds. Among them, the organic acids and phthalides are mainly from Angelicae Sinensis Radix, the flavonoids are mainly from Glycyrrhizae Radix et Rhizoma, the saponins are mainly from Akebiae Caulis, the terpenoids are mainly from Paeoniae Radix Rubra, the nucleosides are mainly from Jujubae Fructus, and other compounds are mainly from Asari Radix et Rhizoma and Cinnamomi Cortex. The results showed that the chemical composition of this compound preparation is rich and structurally diverse, which not only provides data support for comprehensive understanding of its chemical composition, but also a preliminary research basis for clarifying the material basis of its pharmacological action. However, there are still some unknown species whose specific structures have not been clarified. The structural identification and differentiation of these compounds are somewhat limited in the absence of sufficient controls, and can be followed up with deeper separation and identification by techniques such as nuclear magnetic resonance mass spectrometry (NMR-MS).

Abstract Aldo-keto reductase 1C3 (AKR1C3) is a protein upregulated in prostate cancer, hematological malignancies, and other cancers where it contributes to proliferation and chemotherapeutic resistance. Androgen receptor splice variant 7 (ARv7) is the most common mutation of the AR receptor that confers resistance to clinical androgen receptor signalling inhibitors in castration-resistant prostate cancer. AKR1C3 interacts with ARv7 promoting stabilization. Herein we report the discovery of the first-in-class AKR1C3 Proteolysis-Targeting Chimera (PROTAC) degrader. This first-generation degrader potently reduced AKR1C3 expression in 22Rv1 prostate cancer cells with a half-maximal degradation concentration (DC50) of 52 nM. Gratifyingly, concomitant degradation of ARv7 was observed with a DC50 = 70 nM, along with degradation of the AKR1C3 isoforms AKR1C1 and AKR1C2 to a lesser extent. This compound represents a highly useful chemical tool and a promising strategy for prostate cancer intervention.

In the realm of public health, the rising threat caused by bacteria resistant to many drugs is a critical concern. In this work, we used the aqueous extract of mangosteen leaves to create zinc oxide (ZnO) nanoparticles (NPs) in an environmentally friendly manner. Through various analytical methods, we thoroughly characterized these biogenic ZnO NPs, including UV−visible, Fourier transform infrared, X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray powder diffraction, field emission-scanning electron microscopy with energy dispersive X-ray and high resolution-transmission electron microscopy. ZnO NPs showed distinctive properties among different characterization techniques, including a small energy bandgap of 2.80 eV, a porous, a minimum crystalline size of 16.99 nm, an average particle size of 14.21 nm, and a spherical nanostructure. Additionally, we performed preliminary antibacterial experiments to assess ZnO NPs, copper oxide (CuO) NPs, and ZnO–CuO nanocomposites for antibacterial activity. Interestingly, ZnO NPs showed significant potential in suppressing the growth of Staphylococcus aureus ATCC BAA-1026, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, and Klebsiella pneumoniae ATCC 13883, with decreasing order of minimum inhibitory concentrations: S. aureus = B. subtilis (15.63 μg·mL−1) > E. coli (62.50 μg·mL−1) > K. pneumoniae (125.00 μg·mL−1). These results highlight the potential of biogenic NPs, particularly ZnO NPs, as effective agents against multi-drug-resistant bacteria.

Abstract Nod-like receptor protein 3 (NLRP-3), is an intracellular sensor that is involved in inflammasome activation, and the aberrant expression of NLRP3 is responsible for diabetes mellitus, its complications, and many other inflammatory diseases. NLRP3 is considered a promising drug target for novel drug design. Here, a pharmacophore model was generated from the most potent inhibitor, and its validation was performed by the Gunner-Henry scoring method. The validated pharmacophore was used to screen selected compounds databases. As a result, 646 compounds were mapped on the pharmacophore model. After applying Lipinski's rule of five, 391 hits were obtained. All the hits were docked into the binding pocket of target protein. Based on docking scores and interactions with binding site residues, six compounds were selected potential hits. To check the stability of these compounds, 100 ns molecular dynamic (MD) simulations were performed. The RMSD, RMSF, DCCM and hydrogen bond analysis showed that all the six compounds formed stable complex with NLRP3. The binding free energy with the MM-PBSA approach suggested that electrostatic force, and van der Waals interactions, played a significant role in the binding pattern of these compounds. Thus, the outcomes of the current study could provide insights into the identification of new potential NLRP3 inflammasome inhibitors against diabetes and its related disorders.

Abstract Halogenation of pyrrole requires strong electrophilic reagents and often leads to undesired polyhalogenated products. Biocatalytic halogenation is a highly attractive approach given its chemoselectivity and benign reaction conditions. While there are several reports of enzymatic phenol and indole halogenation in organic synthesis, corresponding reports on enzymatic pyrrole halogenation have been lacking. Here we describe the in vitro functional and structural characterization of PrnC, a flavin-dependent halogenase that can act on free-standing pyrroles. Computational modeling and site mutagenesis studies identified three key residues in the catalytic pocket. A moderate resolution map using single-particle cryogenic electron microscopy reveals PrnC to be a dimer. This native PrnC can halogenate a library of structurally diverse pyrrolic heterocycles in a site-selective manner and be applied in the chemoenzymatic synthesis of a chlorinated analog of the agrochemical fungicide Fludioxonil.