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81,877 results on '"Chun A"'

1. Element Enterprise Tycoon: Playing Board Games to Learn Chemistry in Daily Life

Author

Tsai, Jen-Che, Chen, Shih-Yeh, Chang, Chun-Yen, and Liu, Shiang-Yao

Abstract

This article reports the design of a scientific board game, named "Element Enterprise Tycoon" (EET), which creates a scenario combining chemical elements, techniques, and products in daily life. The game cards are designed to motivate students not only to retrieve information about chemical elements, but also to be proficient in chemistry. Moreover, the game creates opportunities for group interactions and competitions to engage students in learning chemical elements as they do in regular science curricula. The EET has been field-tested with a group of middle school students to evaluate its applicability. Empirical data show that students improve their understanding of chemistry concepts with a median level of effect size. In particular, students achieve better performance in terms of chemistry-related technique concepts. The follow-up interviews reflect students' positive feedback and attitudes toward science learning through board game playing and their willingness to continue to play the game. It is suggested that learning through science games can indeed help students learn new chemical knowledge.

Published
2020

2. Inquiry-Based Activities and Games That Engage Students in Learning Atomic Orbitals

Author

Xiao Li, Marc Mun~iz, Karlun Chun, Jonathan Tai, Francesca Guerra, and Darrin M. York

Abstract

Atomic orbitals represent an essential construct used to develop chemical bonding models, upon which other more advanced chemistry topics are built. In this article, we share a series of active-learning activities and a gamified approach to develop students' representational competence about atomic orbitals and to engage students in learning the properties of atomic orbitals. These properties are essential for understanding an array of fundamental concepts such as penetration and shielding, relationships such as periodic trends, and models used to describe chemical bonding. The activities employ an inquiry-based approach to engage students in exploring the relationship between atomic orbitals' spatial properties and quantum numbers. The activities guide students to collect data to verify periodic trends and construct electronic configurations. The activities utilize Orbital Explorer Web site for visualization, comparison, and analysis of atomic orbitals. The Orbital Explorer Web site is described in a related Technology Report. The activities and the game are suitable to be conducted in both in-person and remote-teaching settings.

Published
2022
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3. Exploring Students' Understanding of Interactions and Energy across Chemistry and Biology

Author

Noyes, Keenan Chun Hong Lee

Abstract

One of the goals of science education is to help students make sense of the world around them. To that end, it is critical that students understand the central ideas in each discipline like, in chemistry, energy and interactions. These ideas are of particular importance because they are directly related to one another and are relevant across other science disciplines. Unfortunately, researchers have found that students often struggle to develop a deep understanding of these ideas. To uncover better ways to support students' learning, I explored how students understand interactions and energy in both chemistry and biology. In this dissertation, I focused on London dispersion forces (LDFs), a type of intermolecular force (IMF) which occurs between all atoms and molecules. Specifically, I used the lens of causal mechanistic reasoning to think about students' knowledge. That is, how students connect the properties and behaviors of the underlying entities to the overall phenomenon. If we can help students to develop this type of understanding, they may be able to make powerful predictions about new, unfamiliar phenomena in which IMFs play an important role. Additionally, I explored how students thought about the energy changes which result from the formation of LDFs. Lastly, I designed assessments to elicit and characterize explanations of protein-ligand binding, a biological phenomenon governed by IMFs. To explore these questions, I used a mix of qualitative and quantitative techniques. I designed tasks to elicit causal mechanistic responses from students, using students' responses to refine the task design. I also developed coding schemes to characterize students' engagement in causal mechanistic reasoning. Furthermore, I developed and used automated resources to analyze thousands of responses in a matter of minutes. In these studies, I focused primarily on undergraduate students enrolled in Chemistry, Life, the Universe, and Everything (CLUE), a transformed, core-idea centered general chemistry curriculum. From these studies, I found that the majority of CLUE students could leverage electrostatic ideas to explain LDFs, and that a meaningful proportion of those students could provide a full causal mechanistic account. This highlights the importance of emphasizing these interactions, and the mechanism by which they form, throughout the general chemistry course sequence. Additionally, students who used causal mechanistic reasoning to discuss LDFs were more likely to use that same reasoning in the context of the associated changes in potential energy. However, this relationship was weaker among those providing a partially causal mechanistic response. This suggests that more work needs to be done to find ways of supporting students to connect the ideas of interactions and energy. Additionally, in this thesis, I describe the process by which I used iterative design to develop a task eliciting causal mechanistic explanations of a biological phenomenon. In future work, these materials can be used to explore how broader groups of students engage with this task in an effort to foster interdisciplinary coherence. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Published
2022

4. Guiding Students to Understand the Nanoscale Charge Transport by the Mechanically Controllable Break Junction Technique

Author

Ye, Yiling, Tang, Chun, Zhang, Chengyang, Dong, Gang, Liu, Junyang, and Hong, Wenjing

Abstract

Fabrication of molecular devices will meet the demands of the miniaturization of traditional electronic devices. Although microfabrication based on the complementary metal-oxide-semiconductor process can fabricate high-quality single-molecule devices, the cost is high, leading to a challenge to provide a hands-on experiment in the teaching practice of charge transport through single-molecule devices. Here, we demonstrate the low cost and simple procedures associated with a mechanically controllable break junction (MCBJ) technique to fabricate single-molecule devices. On the basis of the MCBJ technique, the conductance of gold-gold atomic contacts and single-molecule junctions can be readily characterized. The teaching practice helps students understand charge transport at the single-molecule level, that is, the quantum tunneling mechanisms. Moreover, the MCBJ technique study provides students the opportunity to develop interdisciplinary thinking, which is vital for understanding, designing, and developing single-molecule electronics.

Published
2021
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5. Rigorous Evidence and Reasoning or Not? A Demonstration of Iron Corrosion to Induce Students' Critical Thinking

Author

Wang, Chun, Chen, Pengwen, Wang, Jingying, and Ling, Yizhou

Abstract

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.

Published
2021
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6. Teaching Electrochemistry with Common Objects: Electrocatalytic Hydrogenation of Acetol with U.S. Coins

Author

Lam, Chun Ho and Jackson, James E.

Abstract

Electrocatalytic hydrogenation of acetol (IUPAC: 1-hydroxy-2-propanone), a species formed upon thermal liquefaction of biomass, can be achieved using inexpensive objects: filter paper, coins, batteries, salts, and water. This simple example demonstrates that "green" chemical transformations can be achieved with familiar items and helps students appreciate that chemistry is all around them. It also illustrates reactivity contrasts between nickel and copper as catalytic metals effecting hydrogenation. Reactions can be completed in 2 to 2.5 h and can be analyzed visually on the basis of a color change or more quantitatively with classic visible wavelength spectrophotometers that can be found in almost any high school or undergraduate institution. Reagents used in the experiment are nontoxic and can be easily disposed of safely.

Published
2020
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7. Bridging Size and Charge Effects of Mesoporous Silica Nanoparticles for Crossing the Blood–Brain Barrier

Author

Yi-Ping Chen, Chih-Ming Chou, Tsu-Yuan Chang, Hao Ting, Julien Dembélé, You-Tai Chu, Tsang-Pai Liu, Chun A. Changou, Chien-Wei Liu, and Chien-Tsu Chen

Subjects
blood–brain barrier, mesoporous silica nanoparticles, zebrafish, doxorubicin, protein corona, Chemistry, QD1-999
Abstract

The blood–brain barrier (BBB) is a highly selective cellular barrier that tightly controls the microenvironment of the central nervous system to restrict the passage of substances, which is a primary challenge in delivering therapeutic drugs to treat brain diseases. This study aimed to develop simple surface modifications of mesoporous silica nanoparticles (MSNs) without external stimuli or receptor protein conjugation, which exhibited a critical surface charge and size allowing them to cross the BBB. A series of MSNs with various charges and two different sizes of 50 and 200 nm were synthesized, which showed a uniform mesoporous structure with various surface zeta potentials ranging from +42.3 to −51.6 mV. Confocal microscopic results showed that 50 nm of strongly negatively charged N4-RMSN50@PEG/THPMP (∼−40 mV) could be significantly observed outside blood vessels of the brain in Tg(zfli1:EGFP) transgenic zebrafish embryos superior to the other negatively charged MSNs. However, very few positively charged MSNs were found in the brain, indicating that negatively charged MSNs could successfully penetrate the BBB. The data were confirmed by high-resolution images of 3D deconvoluted confocal microscopy and two-photon microscopy and zebrafish brain tissue sections. In addition, while increasing the size to 200 nm but maintaining the similar negative charge (∼40 mV), MSNs could not be detected in the brain of zebrafish, suggesting that transport across the BBB based on MSNs occurred in charge- and size-dependent manners. No obvious cytotoxicity was observed in the CTX-TNA2 astrocyte cell line and U87-MG glioma cell line treated with MSNs. After doxorubicin (Dox) loading, N4-RMSN50@PEG/THPMP/Dox enabled drug delivery and pH-responsive release. The toxicity assay showed that N4-RMSN50@PEG/THPMP could reduce Dox release, resulting in the increase of the survival rate in zebrafish. Flow cytometry demonstrated N4-RMSN50@PEG/THPMP had few cellular uptakes. Protein corona analysis revealed three transporter proteins, such as afamin, apolipoprotein E, and basigin, could contribute to BBB penetration, validating the possible mechanism of N4-RMSN50@PEG/THPMP crossing the BBB. With this simple approach, MSNs with critical negative charge and size could overcome the BBB-limiting characteristics of therapeutic drug molecules; furthermore, their use may also cause drug sustained-release in the brain, decreasing peripheral toxicity.

Published
2022
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8. Gender and Ethnicity Differences Manifested in Chemistry Achievement and Self-Regulated Learning

Author

Veloo, Arsaythamby, Hong, Lee Hooi, and Lee, Seung Chun

Abstract

The aim of this study is to examine whether gender and ethnicity differences are manifested in chemistry achievement and self-regulated learning among a matriculation programme students in Malaysia. The result of students' midterm chemistry exam was used as the measure of chemistry achievement. The information of self-regulated learning was collected by using a survey questionnaire that was adapted from the Motivated Strategies and Learning Questionnaire (MSLQ). Random sampling method was utilized to select 358 students of Matriculation Science One-Year Programme. The results of gender differences showed that male students obtained significantly higher achievement in chemistry compared to female counterparts whereas there was no significant gender difference in self-regulated learning. The results of ethnicity differences confirmed that there was a significant difference in chemistry achievement between Malay and Chinese students, Malay and Indian students, respectively. In terms of self-regulated learning, however, a significant difference was found only between Malay and Indian students. The findings suggest that science instructors in higher education institutions utilize the MSLQ to get the information about students' self-regulatory level and motivational level, design a "gender-based initiative" to address the lower science achievement of female students, and be ready to having learning resources and pedagogical practices available for a learning condition with diverse groups of different ethnicities.

Published
2015

9. Theme-Based Project Learning: Design and Application of Convergent Science Experiments

Author

Chun, Man-Seog, Kang, Kwang Il, and Kim, Young H.

Abstract

This case study aims to verify the benefits of theme-based project learning for convergent science experiments. The study explores the possibilities of enhancing creative, integrated and collaborative teaching and learning abilities in science-gifted education. A convergent project-based science experiment program of physics, chemistry and biology with the theme of environment such as seawater and wetland was designed and applied to science-gifted secondary school students in an international science contest. The program was initiated with integration of physics, chemistry and biology, interrelating both field work and laboratory work. Besides, logical discussion and humanistic writing activities with environmental issues were followed. The participants were tasked to conduct hands-on multi-disciplinary projects for both in the fields and laboratories. The projects involve raising creative and critical thinking through interpreting collected data, predicting outcomes, drawing conclusions, and presenting results. The study shows a model of project-based convergent programs for integrated experimental composition to facilitate collaborative and creative learning as well as to improve students' interests in related subjects. The study discusses ways to raise awareness of benefits from multi-disciplinary approaches through theme-based project learning in science-gifted education.

Published
2015

10. Identifying the Challenging Characteristics of Systems Thinking Encountered by Undergraduate Students in Chemistry Problem-Solving of Gas Laws

Author

Chen, Ya-Chun, Wilson, Kimberley, and Lin, Huann-shyang

Abstract

Systems thinking has been an educational priority for more than a decade, yet its related assessment and teaching strategies have been understudied in the chemistry education research community. Through the lens of systems thinking, this study explores how undergraduate students connect and translate their conceptual representations when they are involved in contextualised problem-solving. The 'Contextualised Problem Solving' (CPS) assessment instrument contains four open-ended questions about gas law. Three different cohorts of students registered in a physical science course (2016 Fall, 2017 Spring, 2017 Fall semesters) participated in the problem-solving component of CPS. The results showed that only 8% of students were capable of higher order systems thinking ability when they engaged in problem solving. Over half of the students failed to retrieve essential concepts in problem situations. Most of the participants demonstrated difficulties in organising related systems' components, understanding the cyclic nature of relationships among systems, and identifying limitations in a specific problem context. By identifying the difficulties and challenges of systems thinking experienced by undergraduate students in solving complex chemistry problems, these findings have the potential to provide fresh insights into effective teaching strategies to promote students' higher order thinking skills.

Published
2019
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11. Demonstrating the Effect of Surfactant on Water Retention of Waxy Leaf Surfaces

Author

Chiu, Yu-Chun, Jenks, Matthew A., Richards-Babb, Michelle, Ratclif, Betsy B., Juvik, John A., and Ku, Kang-Mo

Abstract

We report here the development of an inexpensive and engaging laboratory-based activity that can help students learn about the scientific method and the role of plant epicuticular waxes and surfactant function on waxy plant leaves as real life example in the agricultural industry. Three each of nontreated collard leaves ("Brassica oleraceae" L. Acephala group) and brushed-leaves were sprayed with water to demonstrate hydrophobicity of epicuticular waxes. Another set of three nontreated collard leaves was sprayed with Tween 20 containing water to demonstrate function of surfactant. Then, water retention rate was calculated by subtracting between before and after spray treatments. Water contact angles were measured by ImageJ software from nontreated and brushed-leaves from pictures taken by students' smartphones. This lab activity provides a foundation for instruction on the importance of the plant epicuticular waxes that is the outermost hydrophobic barrier in agrochemical applications and the function of surfactant on waxy leaf surface.

Published
2017
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12. Effects of Type of Exploratory Strategy and Prior Knowledge on Middle School Students' Learning of Chemical Formulas from a 3D Role-Playing Game

Author

Chen, Ming-Puu, Wong, Yu-Ting, and Wang, Li-Chun

Abstract

The purpose of this study was to examine the effects of the type of exploratory strategy and level of prior knowledge on middle school students' performance and motivation in learning chemical formulas via a 3D role-playing game (RPG). Two types of exploratory strategies-RPG exploratory with worked-example and RPG exploratory without worked-example--and two levels of prior knowledge--high prior knowledge and low prior knowledge-were examined in the study. The "5E Instructional Model" was employed as a learning framework in the RPG game design of "The Alchemist's Fort." One hundred and fifteen eighth-grade students from a Taiwanese school voluntarily participated in the 3-week experiment. The results indicate that (1) significant worked-example effect was revealed on knowledge comprehension and marginal worked-example effect occurred on knowledge application; (2) regardless of the type of exploratory strategy employed, learners showed mild positive motivation toward learning chemistry via a 3D RPG game; (3) higher prior-knowledge learners outperformed their lower prior-knowledge peers on performance measures; and (4) high prior-knowledge learners showed a higher degree of motivation in self-efficacy and science learning value than did the low prior-knowledge learners; however, lower prior-knowledge learners revealed higher learning environment stimulation than did their high prior-knowledge peers.

Published
2014
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13. Exploring the Development of College Students' Situational Interest in Learning Science

Author

Lin, Huann-shyang, Hong, Zuway-R, and Chen, Ya-Chun

Abstract

This quasi-experimental study explores how student cumulative situational interest, short-term preference generated by particular conditions such as novel experiences can be developed into better individual interest, an enduring predisposition to engage in certain activity such as chemistry lessons. A continuous intervention of integrating novelty and aesthetic experience into teaching was used for the experimental group ("n"?=?64) while another class of 105 students studying another course of physical science without the intervention of novelty and aesthetics served as a comparison group. The analysis of covariance comparing the two group students' pre-and post-test perceptions of learning science revealed that the experimental group outperformed the comparison group in their perceptions of interest, enjoyment, and aesthetics. The weekly assessment of student situational interest indicated that the experimental group students' situational interests were well maintained by two leading learning activities: demonstrations and hands-on experiments with novelty and aesthetic experience. The above results provide empirical evidence to support the theory of interest development, which proposes that the development goes through a cumulative and progressive procedure.

Published
2013
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14. Measuring the Confidence of 8th Grade Taiwanese Students' Knowledge of Acids and Bases

Author

Jack, Brady Michael, Liu, Chia-Ju, Chiu, Houn-Lin, and Tsai, Chun-Yen

Abstract

The present study investigated whether gender differences were present on the confidence judgments made by 8th grade Taiwanese students on the accuracy of their responses to acid-base test items. A total of 147 (76 male, 71 female) students provided item-specific confidence judgments during a test of their knowledge of acids and bases. Using the correctness of the answer responses, a confidence rating score, an unweighted rating score, and a relative confidence rating score were calculated for each respondent. The correlations between the boys and girls for each score area showed girls as scoring higher than boys in their knowledge of acids and bases, were more confident in this knowledge, and more willing to express different levels of confidence among the test items.

Published
2012
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15. A Computer-Assisted Approach for Conducting Information Technology Applied Instructions

Author

Chu, Hui-Chun, Hwang, Gwo-Jen, and Tsai, Pei Jin

Abstract

The growing popularity of computer and network technologies has attracted researchers to investigate the strategies and the effects of information technology applied instructions. Previous research has not only demonstrated the benefits of applying information technologies to the learning process, but has also revealed the difficulty of applying them effectively. One of the major difficulties is due to the lack of an easy-to-follow procedure for inexperienced teachers to design course content with proper use of suitable information technologies. In this paper, a model for conducting information technology applied instructions is proposed. The novel approach can assist teachers in designing information technology applied course content based on the features of subject materials and the learning status of the students. An experiment on a Chemistry course in a junior high school was conducted to evaluate the performance of our novel approach. (Contains 10 tables and 8 figures.)

Published
2009

16. Fluoride ion sensing with an acridinium borane

Author

Liu, Wei-Chun and Gabbai, Francois P.

Subjects
Borane -- Identification and classification -- Properties, Density functionals -- Usage, Chemical synthesis -- Methods -- Analysis, Spectrum analysis -- Usage, Fluorides -- Identification and classification -- Properties, Chemistry
Abstract

With our continuing interest in the chemistry of cationic horanes, we have synthesized the tetrafluoroborate salt of 1-dimesitylboron-4-(N-methyl-9-acridinium)-phenylene, which acts as a turn-on fluoride anion sensor, visibly changing from yellow to orange upon binding fluoride. To understand this reactivity, we spectroscopically and computationally analyzed the cation and fluoroborate adduct. Ultraviolet-visible spectroscopy and time-dependent density functional theory calculations revealed the basis of the color change to be a low energy redshift in a intramolecular charge transfer band. Electrochemical studies were undertaken to further probe this system. Cyclic voltammetry indicated a reversible one-electron reduction for the cation and a cathodic shift of -0.12 V in the first reduction wave upon fluoride binding. Chemical reduction of the cation yielded the acridine borane radical, which was verified by electron paramagnetic resonance spectroscopy. Key words: boron, carbenium, fluoride ion sensing, acridine radical Notre intérêt constant pour la chimie des boranes cationiques nous a amenés à synthétiser le sel tétrafluoroborate du 1-dimésitylbore-4-(N-méthyl-9-acridinium)-phénylène, qui agit comme détecteur d'anions fluorure activable en changeant visiblement de couleur, passant du jaune à l'orange, lorsqu'il se lie au fluorure. Pour comprendre cette réactivité, nous avons analysé par des méthodes spectroscopiques et computationnelles le cation et l'adduit fluoroborate. La spectroscopic UV-visible et des calculs basés sur la théorie de la fonctionnelle de la densité dépendante du temps (TD-DFT) ont révélé que le changement de couleur était attribuable à un déplacement vers le rouge d'une bande d'absorption de faible énergie qui découle d'un transfert de charge intramoléculaire. Nous avons entrepris des expériences électrochimiques pour étudier davantage ce système. La voltampérométrie cyclique a permis d'établir que le cation subissait une réduction réversible à un électron et a révélér un déplacement cathodique de -0,12 V dans la première onde de réduction lorsque le fluorure se lie au bore. La réduction chimique du cation a donné lieu au radical acridine borane, dont l'identité a été vérifiée par spectroscopic de résonance paramagnétique électronique (RPE). [Traduit par la Rédaction] Mots-clés : bore, carbénium, détection d'ions fluorure, radical acridine, 1. Introduction Fluoride anion recognition has become an attractive research area in recent decades due to concerns regarding this anion's potential toxicity to humans and the environment. (1-3) One conventional [...]

Published
2023
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17. Analytical discovery of water disinfection byproducts of toxicological relevance: highlighting halobenzoquinones

Author

Craven, Caley B., Blackstock, Lindsay K. Jmaiff, Xie, Jiaojiao, Li, Jinhua, Yuan, Chun-Gang, and Li, Xing-Fang

Subjects
Drinking water -- Analysis -- Composition, Disinfection and disinfectants -- Identification and classification -- Properties, Chemistry
Abstract

Analytical advancement enables discoveries in water research, and challenges in the identification and determination of a wide range of trace level toxic compounds in water drives the development of new analytical platforms and tools. The identification of toxic disinfection byproducts (DBPs) in disinfected drinking water is an excellent example. Water disinfection is necessary to protect the public from waterborne disease. However, an unintentional consequence is the formation of DBPs resulting from reactions of disinfectants with natural organic matter in source water. To date, regulated DBPs do not account for the increased bladder cancer risk estimated in epidemiological studies. The majority of halo-genated DBPs remain unidentified and the discovery of unknown DBPs of toxicological relevance continues to be a major focus of current water research. This review will highlight halobenzoquinones as a class of DBPs that serves as an example of analytical development and toxicological studies. We will feature recent trends and gaps in analytical technologies for identification of unknown DBPs and bioassays for evaluation of the toxicological effects of specific DBPs and their mixtures. Key words: disinfection by-products, HBQs, HPLC-MS, toxicity, real time cell analysis, water disinfection. Les progrès en chimie analytique permettent de réaliser des découvertes dans le domaine de la recherche sur la qualité de l'eau. De fait, les difficultés à identifier et à doser une grande diversité de composés toxiques à l'état de traces dans l'eau stimulent le développement de nouvelles plateformes et de nouveaux outils analytiques. L'identification des sous-produits de désinfection (SPD) toxiques présents dans l'eau potable désinfectée en est un excellent exemple. La désinfection de l'eau est nécessaire pour protéger le public contre les maladies d'origine hydrique. Cependant, les réactions des désinfectants avec la matière organique présente naturellement dans l'eau de source peuvent avoir pour conséquence non intentionnelle la formation de SPD. À l'heure actuelle, l'augmentation du risque de cancer de la vessie estimée dans les études épidémiologiques n'est pas prise en compte dans les réglementations sur les SPD. La majorité des SPD halogénés demeurent non identifiés, et la découverte de SPD inconnus et potentiellement toxiques demeure un centre d'intérêt majeur de la recherche actuelle sur la qualité de l'eau. Le présent article de synthèse s'intéressera aux halobenzoquinones, une classe de SPD, à titre d'exemple des progrès en chimie analytique et d'objet d'études toxicologiques. Nous mettrons en évidence les récentes tendances et les lacunes des technologies analytiques d'identification de SPD inconnus et les essais biologiques pour l'évaluation des effets toxicologiques de certains SPD et mélanges de SPD. [Traduit par la Rédaction] Mots-clés : sous-produits de désinfection, halobenzoquinones (HBQ), HPLC-MS, toxicité, analyse cellulaire en temps réel, désinfection de l'eau., Introduction Water disinfection is necessary to prevent the transmission of waterborne diseases. (1) Different disinfection practices are used to achieve complete inactivation of pathogens in source waters, while minimizing the [...]

Published
2021
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18. Multiplexed and single-cell detection of microRNA with plasmonic nanoparticle assemblies

Author

Ghotra, Gurbrinder, Le, Nguyen H., Hayder, Heyam, Peng, Chun, and Chen, Jennifer I.L.

Subjects
Multichannel communication -- Methods -- Analysis, Nanoparticles -- Spectra -- Properties, Multiplexing -- Methods -- Analysis, MicroRNA -- Identification and classification -- Properties, Digital multiplexing -- Methods -- Analysis, Chemistry
Abstract

We present a label-free, low cost, and miniatured biosensing platform based on the disassembly of core-satellite plasmonic nanoparticle assemblies. The rapid and selective detection of an exemplary nucleic acid biomarker, has-miRNA-210-3p, was achieved via the strand displacement nucleic acid reaction. Target binding leads to dehybridization of the DNA linkers and changes in the scattering properties of nanostructures as monitored by darkfield microscopy. We demonstrate the ability to detect microRNA expunged from single cells and the potential to multiplex discrete assemblies to enable diverse biological applicability. The work may help translate the applicability of microRNA as diagnostic biomarkers, quan-titate their abundance in the microenvironment, and facilitate the study of their correlation or causation to other biomole-cules at the single-cell level. Key words: core-satellite, plasmonic, light scattering, optical sensor, microRNA, biomarker, single-cell analysis, darkfield microscopy, strand displacement. Nous presentons une plateforme de biodetection miniaturisee, sans marquage et peu couteuse fondee sur le desassemblage des architectures noyau-satellite de nanoparticules plasmoniques. Nous sommes parvenus a detecter de maniere rapide et selective un biomarqueur d'acide nucleique representatif, has-miRNA-210-3p, par la reaction d'amplification d'acide nucleique par deplacement de brins. La fixation de la cible entraine la deshybridation des espaceurs de l'ADN et des changements des pro-prietes de diffusion des nanostructures, comme on peut l'observer par microscopie a fond noir. Nous demontrons qu'il est possible de detecter des microARN expulses de cellules uniques et d'observer simultanement plusieurs assemblages discrets, ce qui permet diverses applications en biologie. Ces travaux peuvent contribuer a transposer les microARN dans des applications comme biomarqueurs diagnostiques, a quantifier leur abondance dans le microenvironnement et a faciliter l'etude de leurs correlations ou de leurs liens de causalite avec d'autres biomolecules a l'echelle de la cellule. [Traduit par la Redaction] Mots-cles: noyau-satellite, plasmonique, diffusion de la lumiere, capteur optique, microARN, biomarqueur, analyse monocellulaire, microscopie a fond noir, deplacement de brins., Introduction MicroRNAs (miRNAs) are small non-coding ribonucleic acid molecules involved in the regulation of gene expression and protein output. (1,2) They play critical roles in physiological and pathological processes. The [...]

Published
2021
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19. Steroids with potential anti-inflammatory activity from the roots of Datura metel L

Author

Liu, Yan, Guan, Wei, Yang, Chun-Li, Luo, Yu-Meng, Liu, Yuan, Zhou, Yuan-Yuan, Liu, Li-Na, Yang, Bing-You, and Kuang, Hai-Xue

Subjects
Mitogens, Mass spectrometry, Nitric oxide, Anti-inflammatory drugs, Nuclear magnetic resonance spectroscopy, Chemistry
Abstract

One new [C.sub.21]-steroid, pregnane A (1), and two new anolides daturafolisides X and Y (2 and 3), together with six known with anolides (4-9), were isolated from the roots of Datura metel L. The structures of these compounds were established by 1D and 2D NMR spectra and mass spectroscopy by comparing our results with the literature values. Compounds 1-9 were evaluated for inhibition against nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophages. It was found that the isolated compounds showed the different levels of anti-inflammatory activities with I[C.sub.50] values ranging from 24.2 to 43.4 [micro]mol/L. Key words: Datura metel L., Solanaceae, withanolide, RAW 264.7, anti-inflammatory. Nous avons isole a partir des racines de Datura metel L. un nouveau steroide [C.sub.21], le pregnane A (1), et deux nouveaux withanolides, les daturafolisides X et Y (2 and 3), ainsi que six autres withanolides connus (4-9). Nous avons caracterise la structure de ces composes en comparant les donnees spectroscopiques RMN 1D et 2D a celles de la litterature, ainsi que par spectrometrie de masse. Nous avons evalue la capacite des composes 1 a 9 d'inhiber la production d'oxyde nitrique dans des macrophages RAW 264.7 stimules par des lipopolysaccharides. Nos resultats montrent que les composes isoles presentent differents degres d'activite anti-inflammatoire, caracterises par des valeurs de C[I.sub.50] allant de 24,2 a 43,4 [micro]mol/L. [Traduit par la Redaction] Mots-cles: Datura metel L., Solanaceae, withanolide, RAW 264.7, anti-inflammatoire., Introduction Datura metel L. is a perennial (Solanaceae) that is widely distributed in south provinces of China. (1) The roots of D. metel are acrid and bitter in taste, warm [...]

Published
2020
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20. Au−–Ov–Ti3+: Active site of MO -Au/TiO2 catalysts for the aerobic oxidation of 5-hydroxymethylfurfural

Author

Mengchen Fu, Weiyao Yang, Chenyu Yang, Yiwen Zhang, and Chun Shen

Subjects
Green chemistry, biology, Renewable Energy, Sustainability and the Environment, Inorganic chemistry, Oxide, Active site, engineering.material, Catalysis, Metal, chemistry.chemical_compound, Transition metal, chemistry, Chemisorption, visual_art, engineering, visual_art.visual_art_medium, biology.protein, Noble metal
Abstract

Despite wide applications of noble metal-based catalysts in 5-hydroxymethylfurfural (HMF) oxidation, promoting the catalytic performance at low loading amounts still remains a significant challenge. Herein, a series of metal oxide modified MOx-Au/TiO2 (M = Fe, Co, Ni) catalysts with low Au loading amount of 0.5 wt% were synthesized. Addition of transition metal oxides promotes electron transfer and generation of the Auδ−–Ov–Ti3+ interface. A combination study reveals that the dual-active site (Auδ−-Ov-Ti3+) governs the catalytic performance of the rate-determining step, namely hydroxyl group oxidation. Auδ− site facilitates chemisorption and activation of O2 molecules. At the same time, Ov-Ti3+ site acts as the role of “killing two birds with one stone”: enhancing adsorption of both reactants, accelerating the activation and dissociation of H2O, and facilitating activation of the adsorbed O2. Besides, superoxide radicals instead of base is the active oxygen species during the rate-determining step. On this basis, a FDCA yield of 71.2% was achieved under base-free conditions, complying with the “green chemistry” principle. This work provides a new strategy for the transition metal oxides modification of Au-based catalysts, which would be constructive for the rational design of other heterogeneous catalysts.

Published
2023

21. A purely green approach to low-cost mass production of zeolitic imidazolate frameworks

Author

Dapeng Cao, Hai Li, Bei Liu, Chun Deng, Mingke Yang, Chang-Yu Sun, Wan Chen, Guang-Jin Chen, and Zixuan Huang

Subjects
Filter cake, Solvent, chemistry.chemical_classification, Pilot plant, Aqueous solution, Materials science, Chemical engineering, chemistry, Renewable Energy, Sustainability and the Environment, Salt (chemistry), Environmentally friendly, Catalysis, Zeolitic imidazolate framework
Abstract

Although zeolitic imidazolate frameworks (ZIFs) have bright prospects in wide fields like gas storage/separation, catalysis and medicine, etc., their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique. Here, we report an unconventional method suitable for environmentally friendly and low-cost mass-production of ZIFs. In this method, taking the synthesis of ZIF-8 as an example, ZnO was used instead of Zn(NO3)2 in traditional solvent synthesis methods and CO2 was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole (HMeim) and form water soluble salt ([ZnMeim]+[MeimCOO]-) at room temperature. Then, by removing CO2 through heating or vacuuming, Meim-ions are produced and instantaneously assemble with [ZnMeim]+s to generate ZIF-8 without any by-product. Due to the absence of strong acid anions (such as NO3− and Cl− et al.) in solution, the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely. This method is really green as no waste gas or liquid generates because CO2 and water could be recycled perfectly. It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods. A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced, which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility. It is expected that the new method would open an avenue for commercial applications of ZIFs.

Published
2023

22. Synthesis of the Macrolactone Cores of Maltepolides via a Diene–Ene Ring-Closing Metathesis Strategy

Author

Lars Eric Bendel, Man Ki Sit, Hui Hui Cao, Wei-Min Dai, Wen Zhang, Tsz Chun Yip, and Yan-Dong Wu

Subjects
chemistry.chemical_classification, Double bond, Diene, Stereochemistry, Organic Chemistry, Epoxide, Total synthesis, Conjugated system, Biochemistry, chemistry.chemical_compound, Ring-closing metathesis, chemistry, Biosynthesis, Physical and Theoretical Chemistry, Ene reaction
Abstract

Synthesis of the C19-truncated maltepolide E has been accomplished via a diene–ene RCM strategy without damage to the C11–C14 alkenyl epoxy unit. Upon release of the C17-OH group, it attacked at the C14 position with double bond migration and epoxide ring-opening to furnish the C19-truncated maltepolide A and B as proposed for the biosynthesis of maltepolides. Preliminary cytotoxicity data of the synthesized C19-truncated maltepolides against L929 mouse fibroblast cell line suggest irrelevance of the vinyl epoxide and importance of the conjugated dienyl keto unit for the observed anticancer activity.

Published
2023

23. An approach of auxiliary carbohydrate source on stabilized biohythane production and energy recovery by two-stage anaerobic process from swine manure

Author

Po-Jui Lai, Pin-Yi Liu, Justin Chun-Te Lin, Chen-Yeon Chu, and Alicia Amelia Elizabeth Sinsuw

Subjects
Energy recovery, Anaerobic respiration, Hydraulic retention time, Renewable Energy, Sustainability and the Environment, Chemistry, Chemical oxygen demand, Energy Engineering and Power Technology, Industrial fermentation, Condensed Matter Physics, Pulp and paper industry, Manure, Methane, chemistry.chemical_compound, Fuel Technology, Biogas
Abstract

In this study, a two-stage biohythane production system was used to treat swine manure to solve the high Chemical Oxygen Demand (COD) concentration and verify the total energy recovery between the two-stage and a traditional single-stage system. Experiments were carried out in single-stage methane production, two-stage biohythane production in long Hydraulic Retention Time (HRT), and short HRT. The COD removal efficiency and energy recovery were finally compared between single-stage (CH4 fermenter) and two-stage (H2+ CH4 fermenter) systems. The results showed that the methane production rate of 53.2 ± 2.7 mL/d.L, the COD removal efficiency of 29.6 ± 5.8%, and total energy recovery of 2.9 ± 0.1 kJ/L.d was obtained in the single-stage of methane production system with HRT 11.08 d, pH 7, and temperature 55 °C, respectively. In the two-stage of hydrogen and methane productions system, the hydrogen production rate of 1.8 ± 0.7 mL/d.L, the methane production rate of 65.7 ± 2.5 mL/d.L, the COD removal rate was 97.8 ± 1.7%, and the total energy recovery of 3.6 ± 0.1 kJ/L.d was obtained and stabilized when the sugary wastewater content gradually reduced to 0%. This study shows that the methane production rate increases 20%, COD removal efficiency increases to 97.8 ± 1.7%, and total energy recovery increases 30%. At the same time, the single-stage (CH4 fermenter) switched to a two-stage (H2+ CH4 fermenter) system. The two-stage anaerobic biohythane production system successfully treated the high organic swine manure and obtained a higher energy recovery against the traditional single-stage of the biomethane production system.

Published
2022

24. Sequence types 8, 59, and 45 methicillin resistant Staphylococcus aureus as the predominant strains causing skin and soft tissue infections in Taiwan's prisons and jails

Author

Chun-Yi Lee, Yu Ping Fang, Chia Hsing Sung, Tsung Hua Wu, and Yu Feng Chang

Subjects
Microbiology (medical), General Immunology and Microbiology, business.industry, SCCmec, Mupirocin, General Medicine, biochemical phenomena, metabolism, and nutrition, Sequence types, bacterial infections and mycoses, Antimicrobial, medicine.disease_cause, Methicillin-resistant Staphylococcus aureus, Microbiology, chemistry.chemical_compound, Infectious Diseases, Antibiotic resistance, chemistry, Staphylococcus aureus, Immunology and Allergy, Medicine, Typing, business
Abstract

Background Methicillin-resistant Staphylococcus aureus (MRSA) is the predominant cause of skin and soft tissue infections (SSTIs), which is a problem in prisons and jails. We conducted this study to understand MRSA molecular characteristics among inmates with SSTIs, and we chose MRSA isolates from a community hospital as a comparison. Methods A total of 219 MRSA isolates from three custodial facilities and 134 isolates from a community hospital in Taiwan were collected in the 2017 calendar year. MRSA isolates were investigated molecularly by staphylococcal chromosome cassette mec (SCCmec) type, mupirocin, and chlorhexidine genotypical resistance, and multi-locus sequence typing (ST). Results Of the 219 MRSA isolates from custodial facilities, SCCmec IV was the most prevalent type (65.3%), followed by type VT (32.4%) and type V (1.8%). Regarding sequence types, ST59 (36.4%), 8 (35.3%), and 45 (17.9%) were the leading three predominant types out of 184 selected MRSA isolates, and ST45 MRSA was more prevalent in custodial facilities (p = 0.019). The antimicrobial resistance rates varied for different MRSA strains, with ST45 MRSA having the lowest rates of resistance to most antimicrobials. Overall, 91.5% of isolates carried mupA gene and 25.8% were positive for qacA/B gene, this was independent of the MRSA sequence types. Conclusions ST59, ST8, and ST45 MRSA are the leading three MRSA strains causing SSTIs in Taiwan, 2017, but the molecular distribution varied distinctly between the custodial facilities and hospital settings. The genotypical mupirocin resistance rate is quite high in this study. The frequency of chlorhexidine resistance gene is relatively low, especially in MRSA isolates from custodial facilities.

Published
2022

25. Membrane electrode assembly with additives for proton-exchange membrane water electrolysis in high-voltage operation

Author

Lin Cheng-Lung, Guo-Bin Jung, Chi-Yuan Lee, Chun-Ju Lai, Jyun-Wei Yu, and Shih-Hung Chan

Subjects
Materials science, Electrolysis of water, Renewable Energy, Sustainability and the Environment, Graphene, Membrane electrode assembly, Oxide, Energy Engineering and Power Technology, Proton exchange membrane fuel cell, Carbon nanotube, Condensed Matter Physics, Anode, law.invention, chemistry.chemical_compound, Fuel Technology, Chemical engineering, chemistry, law, Hydrogen production
Abstract

In a proton-exchange membrane water-electrolysis system, performance is greatly affected by the anode materials and operation modes. Moreover, high voltages allow greater hydrogen production as well as the potential of creating ozone for green disinfection. However, after switching off power and restarting, a big decrease in performance drop as well as hydrogen/ozone generation. In this study, different additives—multi-wall carbon nanotubes, surface-modification graphene, reduction graphene oxide, and graphene oxide—are adopted and mixed with PbO2 and to create anode catalyst ink. The characteristics of the anode catalysts are investigated with voltage-current test, interruptive power supply, electrochemical impedance spectroscopy and high voltage accelerating tests. The results show that the anode of MEA with additive, multi-wall carbon nanotubes or multi-wall carbon nanotubes plus surface-modification graphene, lead to twice higher performance. Further, anode of MEA with additive, multi-wall carbon nanotubes, multi-wall carbon nanotubes plus graphene oxide, and multi-wall carbon nanotubes plus reduction graphene oxide, displays better restoration (34–36%↓).

Published
2022

26. Conformational control inhibition of the BCR-ABL1 tyrosine kinase, including the gatekeeper T315I mutant, by the switch-control inhibitor DCC-2036.

Author

Chan, Wayne W, Wise, Scott C, Kaufman, Michael D, Ahn, Yu Mi, Ensinger, Carol L, Haack, Torsten, Hood, Molly M, Jones, Jennifer, Lord, John W, Lu, Wei Ping, Miller, David, Patt, William C, Smith, Bryan D, Petillo, Peter A, Rutkoski, Thomas J, Telikepalli, Hanumaiah, Vogeti, Lakshminarayana, Yao, Tony, Chun, Lawrence, Clark, Robin, Evangelista, Peter, Gavrilescu, L Cristina, Lazarides, Katherine, Zaleskas, Virginia M, Stewart, Lance J, Van Etten, Richard A, and Flynn, Daniel L

Subjects
Animals, Cell Line, Tumor, Cell Proliferation: drug effects, Cell Survival: drug effects, Drug Design, Fusion Proteins, bcr-abl: antagonists & inhibitors, chemistry, Humans, Leukemia, Myelogenous, Chronic, BCR-ABL Positive: drug therapy, Male, Mice, Mice, Inbred BALB C, Mutation, Precursor B-Cell Lymphoblastic Leukemia-Lymphoma: drug therapy, Protein Conformation, Protein Kinase Inhibitors: pharmacology, Protein-Tyrosine Kinases: antagonists & inhibitors, chemistry
Abstract

Acquired resistance to ABL1 tyrosine kinase inhibitors (TKIs) through ABL1 kinase domain mutations, particularly the gatekeeper mutant T315I, is a significant problem for patients with chronic myeloid leukemia (CML). Using structure-based drug design, we developed compounds that bind to residues (Arg386/Glu282) ABL1 uses to switch between inactive and active conformations. The lead "switch-control" inhibitor, DCC-2036, potently inhibits both unphosphorylated and phosphorylated ABL1 by inducing a type II inactive conformation, and retains efficacy against the majority of clinically relevant CML-resistance mutants, including T315I. DCC-2036 inhibits BCR-ABL1(T315I)-expressing cell lines, prolongs survival in mouse models of T315I mutant CML and B-lymphoblastic leukemia, and inhibits primary patient leukemia cells expressing T315I in vitro and in vivo, supporting its clinical development in TKI-resistant Ph(+) leukemia.

Published
2011

27. Comparison of Surgical or Medical Castration-Related Cardiotoxicity in Patients with Prostate Cancer

Author

Zhih-Cherng Chen, Chun-Yen Chiang, Yi Chen Chen, Wei-Ting Chang, Nan-Chun Wu, Chon-Seng Hong, Kun-Lin Hsieh, Wei-Chih Kan, Michael Chen, Chung-Han Ho, and Jhih-Yuan Shih

Subjects
Male, endocrine system, medicine.medical_specialty, Antineoplastic Agents, Hormonal, Urology, Taiwan, Androgen deprivation therapy, Prostate cancer, chemistry.chemical_compound, Postoperative Complications, Risk Factors, Surgical castration, medicine, Humans, In patient, Cardiotoxicity, business.industry, Prostatic Neoplasms, Androgen Antagonists, medicine.disease, Castration, chemistry, Cardiovascular Diseases, business, Orchiectomy, Bilateral orchiectomy, hormones, hormone substitutes, and hormone antagonists, Hormone
Abstract

Androgen deprivation therapy (ADT) includes bilateral orchiectomy or long-acting gonadotropin-releasing hormone (GnRH) agonists/antagonists. It remains controversial with respect to ADT associated cardiovascular outcomes. Hereby, we compared the risk of major adverse cardiovascular and cerebrovascular events (MACCEs) in patients with prostate cancer receiving either surgical castration or GnRH therapies.Using the Taiwan Cancer Registry and Taiwan's National Health Insurance Research Database, we identified 8,413 patients receiving GnRH therapies compared with 694 receiving surgical castration from 2008 to 2017. The median followup duration was 3 years.The crude incidences of 3-year mortality and MACCEs were 19.90% vs 26.51% and 8.23% vs 8.65% in patients receiving GnRH therapies or surgical castration, respectively. After adjusting for age, cancer stage and comorbidities, despite no significant differences in MACCEs between groups there was a slight increase in the incidence of acute myocardial infarction (AMI) in patients receiving surgical castration compared with those receiving GnRH therapies. The mortality adjusted hazard ratios of MACCEs and AMI among patients receiving surgical castration were 1.11- and 1.8-fold higher than those receiving GnRH therapies. Notably, in subgroup analysis regarding cancer stage, patients with cancer stage IV showed the most significantly increasing risk of AMI in those receiving surgical castration compared with GnRH therapies.Collectively, we indicated an increased risk of AMI in patients with prostate cancer, especially in patients receiving surgical castration rather than those receiving GnRH therapies. Our findings highlight concerns regarding the cardiac safety of surgical castration compared with GnRH therapies.

Published
2022

28. Nationwide surveillance of antimicrobial resistance in invasive isolates of Streptococcus pneumoniae in Taiwan from 2017 to 2019

Author

Ting Shu Wu, Chun-Yu Lin, Yu-Hui Chen, Zhi-Yuan Shi, Wang-Huei Sheng, Chang Pan Liu, Chi-Ying Lin, Hung-Jen Tang, Yu Lin Lee, Pei-Lan Shao, Shu Hsing Cheng, Po-Liang Lu, Chun Ming Lee, Yen-Hsu Chen, Muh Yong Yen, Wen Sen Lee, Yu Te Tsai, Fu Der Wang, Yao Shen Chen, Shu Hui Tseng, Po-Ren Hsueh, Wen Chien Ko, Lih Shinn Wang, Min-Chi Lu, and Chao Nan Lin

Subjects
Ertapenem, Microbiology (medical), medicine.medical_specialty, Taiwan, Levofloxacin, Microbial Sensitivity Tests, Penicillins, medicine.disease_cause, Meropenem, Pneumococcal Infections, chemistry.chemical_compound, Vancomycin, Moxifloxacin, Internal medicine, Drug Resistance, Bacterial, Streptococcus pneumoniae, medicine, Humans, Immunology and Allergy, Aged, General Immunology and Microbiology, Meningitis, Pneumococcal, business.industry, Ceftriaxone, Doripenem, Linezolid, General Medicine, Anti-Bacterial Agents, Infectious Diseases, chemistry, business, medicine.drug
Abstract

Background/purpose Streptococcus pneumoniae causes pneumonia and other invasive diseases, and is a leading cause of mortality in the elderly population. The present study aimed to provide current antimicrobial resistance and epidemiological profiles of S. pneumoniae infections in Taiwan. Methods A total of 252 nonduplicate S. pneumoniae isolates were collected from patients admitted to 16 hospitals in Taiwan between January 2017 and December 2019, and were analyzed. The minimum inhibitory concentration of antibiotics was determined using the Vitek 2 automated system for antimicrobial susceptibility testing. Furthermore, epidemiological profiles of S. pneumoniae infections were analyzed. Results Among the strains analyzed, 88% were recognized as invasive pneumococcal strains. According to the Clinical and Laboratory Standards Institute criteria for non-meningitis, the prevalence of penicillin-non-susceptible S. pneumoniae demonstrated a declining trend from 43.6% in 2017 to 17.2% in 2019. However, the rate of penicillin-non-susceptible S. pneumoniae was 85.7% based on the criteria for meningitis. Furthermore, the prevalence of ceftriaxone-non-susceptible S. pneumoniae was 62.7% based on the criteria for meningitis. Isolates demonstrated higher susceptibility toward doripenem and ertapenem than toward meropenem and imipenem. An increased rate of non-susceptibility toward levofloxacin was observed in southern Taiwan (15.1%) and elderly patients (≥65 years; 11.4%). Most isolates were susceptible to vancomycin and linezolid. Conclusion Empirical treatment with ceftriaxone monotherapy for pneumococcal meningitis should be carefully monitored owing to its high non-susceptibility rate. The susceptibility rates of most isolates to penicillin (used for treating non-meningitis pneumococcal diseases), carbapenems (ertapenem and doripenem), respiratory quinolones (moxifloxacin and levofloxacin), vancomycin, and linezolid suggested the potential of these antibiotics in treating pneumococcal diseases in Taiwan.

Published
2022

30. Ionic Liquids-Assisted Solvent Extraction of Precious Metals from Chloride Solutions

Author

Jae-chun Lee, Kurniawan Kurniawan, Sookyung Kim, Viet Tu Nguyen, and Banshi D. Pandey

Subjects
MECHANISM, Technology, Engineering, Chemical, SELECTIVE EXTRACTION, Science & Technology, PALLADIUM, PLATINUM-GROUP METALS, Chemistry, Analytical, precious metals, Filtration and Separation, RECOVERY, solvent extraction, AQUEOUS-SOLUTION, Analytical Chemistry, Ionic liquids, Chemistry, Applied, Chemistry, Engineering, PD(II), Physical Sciences, HYDROCHLORIC-ACID SOLUTIONS, SEPARATION, GOLD, cation extraction
Abstract

ispartof: SEPARATION AND PURIFICATION REVIEWS vol:52 issue:3 pages:242-261 status: accepted

Published
2023

31. Kasugamycin Is a Novel Chitinase 1 Inhibitor with Strong Antifibrotic Effects on Pulmonary Fibrosis

Author

Jae-Hyun Lee, Chang-Min Lee, Joyce H. Lee, Mun-Ock Kim, Jin Wook Park, Suchitra Kamle, Bedia Akosman, Erica L. Herzog, Xue Yan Peng, Jack A. Elias, and Chun Geun Lee

Subjects
Pulmonary and Respiratory Medicine, Pulmonary Fibrosis, Clinical Biochemistry, Kasugamycin, Bleomycin, chemistry.chemical_compound, Mice, In vivo, Transforming Growth Factor beta, Pulmonary fibrosis, medicine, Animals, Humans, Molecular Biology, Lung, Original Research, biology, business.industry, Chitinases, Interstitial lung disease, Cell Biology, Transforming growth factor beta, Fibroblasts, medicine.disease, Mice, Inbred C57BL, Aminoglycosides, chemistry, biology.protein, Cancer research, Antifibrotic Agents, business, Myofibroblast, Transforming growth factor
Abstract

RationalePulmonary fibrosis is a devastating lung disease with few therapeutic options. Chitinase 1 (CHIT1), an 18 glycosyl hydrolase family member, contributes to the pathogenesis of pulmonary fibrosis through regulation of Transforming Growth Factor (TGF)-β signaling and effector function. Therefore, CHIT1 is a potential therapeutic target of pulmonary fibrosis.ObjectivesThis study aimed to identify and characterize a druggable CHIT1 inhibitor with strong antifibrotic activity and minimal toxicity for therapeutic application to pulmonary fibrosis.MethodsExtensive screening of small molecule libraries identified the aminoglycoside antibiotic Kasugamycin as a potent CHIT1 inhibitor.Measurements and Main ResultsElevated levels of CHIT1 were detected in the lungs of patients with pulmonary fibrosis. In vivo bleomycin- and TGF-β-stimulated murine models of pulmonary fibrosis, Kasugamycin showed impressive anti-fibrotic effects in both preventive and therapeutic conditions. In vitro studies also demonstrated that Kasugamycin inhibits fibrotic macrophage activation, fibroblast proliferation and myofibroblast transformation. Null mutation of transforming growth factor beta associated protein 1 (TGFBRAP1), a recently identified CHIT1 interacting signaling molecule, phenocopied antifibrotic effects of Kasugamycin in in vivo lungs and in vitro fibroblasts responses. Kasugamycin inhibits physical association between CHIT1 and TGFBRAP1, suggesting that antifibrotic effect of Kasugamycin is mediated through regulation of TGFBRAP1, at least in part.ConclusionsThese studies demonstrate that Kasugamycin is a novel CHIT1 inhibitor with strong antifibrotic effect that can be further developed as an effective and safe therapeutic drug for pulmonary fibrosis.

Published
2023

32. Plasma ceramides are associated with outcomes in acute ischemic stroke patients

Author

Ching-Hua Lee, Hsi-Chun Chao, Ching-Hua Kuo, Tsung-Heng Lee, Chih-Ning Cheng, Sung-Chun Tang, and Jiann-Shing Jeng

Subjects
Oncology, Medicine (General), medicine.medical_specialty, Sphingosine-1-phosphate, Acute ischemic stroke, Ceramides, Prognostic markers, 03 medical and health sciences, chemistry.chemical_compound, R5-920, 0302 clinical medicine, Internal medicine, medicine, Stroke, Eukaryotic cell, Mass spectrometry, Stroke scale, business.industry, Confounding, General Medicine, Plasma levels, medicine.disease, Sphingolipid, chemistry, 030220 oncology & carcinogenesis, lipids (amino acids, peptides, and proteins), 030211 gastroenterology & hepatology, business
Abstract

Background/Purpose: Sphingolipids are major constituents of eukaryotic cell membranes and play key roles in cellular regulatory processes. Our recent results in an experimental stroke animal model demonstrated changes in sphingolipids in response to acute ischemic brain injury. This study aimed to investigate the plasma levels of sphingosine-1-phosphate (S1P) and ceramides in acute ischemic stroke (AIS) patients and their associations with functional outcomes. Methods: Plasma samples were collected from patients with AIS at

Published
2022

33. Globo H Is a Promising Theranostic Marker for Intrahepatic Cholangiocarcinoma

Author

Chiao-En Wu, Li-Chun Lai, Fei-Yun Lo, Jung-Tung Hung, Alice L. Yu, Chien-Wei Lee, John Yu, Chau-Ting Yeh, Yenlin Huang, Tsai-Hsien Hung, Chun-Nan Yeh, Yi-Hsiu Chung, and John K Tung

Subjects
Male, RC799-869, law.invention, Cholangiocarcinoma, Rats, Sprague-Dawley, chemistry.chemical_compound, In vivo, law, Risk Factors, medicine, Animals, Humans, Antigens, Tumor-Associated, Carbohydrate, Polymerase chain reaction, Intrahepatic Cholangiocarcinoma, Tumor microenvironment, Hepatology, biology, business.industry, Cancer, Antibodies, Monoclonal, Original Articles, Diseases of the digestive system. Gastroenterology, medicine.disease, Prognosis, Disease Models, Animal, chemistry, Bile Duct Neoplasms, biology.protein, Cancer research, Immunohistochemistry, Original Article, Antibody, Thioacetamide, business
Abstract

Recent studies support the development of cancer therapeutics to target Globo H-ceramide, the most prevalent tumor-associated carbohydrate antigen in epithelial cancers. Herein, we evaluated the expression of Globo H and its prognostic significance in intrahepatic cholangiocarcinoma (ICC) and conducted preclinical studies to assess the antitumor activity of Globo H-specific antibody in thioacetamide (TAA)-induced ICC in rats. Globo H-ceramide in tumor specimens was detected by immunohistochemistry (IHC) and mass spectrometry. Antitumor efficacy of anti-Globo H mAbVK9 was evaluated in TAA-induced ICC in rat. Natural killer (NK) cells and their related genes were analyzed by IHC and quantitative real-time polymerase chain reaction. Data mining revealed that B3GALT5 and FUT2, the key enzymes for Globo H biosynthesis, were significantly up-regulated in human ICC. In addition, Globo H expression was detected in 41% (63 of 155) of ICC tumor specimens by IHC staining, and validated by mass spectrometric analysis of two IHC-positive tumors. Patients with Globo H positive tumors had significantly shorter relapse-free survival (RFS) and overall survival (P = 0.0003 and P = 0.002, respectively). Multivariable Cox regression analysis identified Globo H expression as an independent unfavorable predictor for RFS (hazard ratio: 1.66, 95% confidence interval: 1.08-2.36, P = 0.02) in ICC. Furthermore, gradual emergence of Globo H in liver tissues over 6 months in TAA-treated rats recapitulated the multistage progression of ICC in vivo. Importantly, administration of anti-Globo H mAbVK9 in rats bearing TAA-induced ICC significantly suppressed tumor growth with increased NK cells in the tumor microenvironment. Conclusion: Globo H is a theranostic marker in ICC.

Published
2022

34. Hypoglycemic and Hypolipidemic Effects of Malonyl Ginsenosides from American Ginseng (Panax quinquefolius L.) on Type 2 Diabetic Mice

Author

Zhi Liu, Chun-Yuan Qu, Jia-Xin Li, Yan-Fang Wang, Wei Li, Chong-Zhi Wang, Dong-Sheng Wang, Jia Song, Guang-Zhi Sun, and Chun-Su Yuan

Subjects
Chemistry, General Chemical Engineering, General Chemistry, QD1-999, Article
Abstract

American ginseng (Panax quinquefolius L.) is popularly consumed as traditional herbal medicine and health food for the treatment of type 2 diabetes mellitus (T2DM). Malonyl ginsenosides (MGR) are the main natural ginsenosides in American ginseng. However, whether the malonyl ginsenosides in P. quinquefolius (PQ-MGR) possess antidiabetic effects has not been explored yet. In this study, the antidiabetic effects and the underlying mechanism of PQ-MGR in high-fat diet/streptozotocin (HFD/STZ)-induced T2DM mice were investigated. The chemical composition was analyzed by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Our results showed that 14 malonyl ginsenosides were identified in the PQ-MGR. Among them, the content of m-Rb1 represented about 77.4% of the total malonyl ginsenosides. After a 5-week experiment, the PQ-MGR significantly reduced the fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), nonesterified fatty acid (NEFA), alanine transaminase (ALT), and aspartate transaminase (AST) levels and improved glucose tolerance and insulin resistance. Furthermore, Western blot analysis demonstrated that the protein expressions of p-PI3K, p-AKT, p-AMPK, p-ACC, PPARγ, and GLUT4 in the liver and skeletal muscle were significantly upregulated after PQ-MGR treatment. In contrast, the protein expressions of p-IRS1 and p-JNK were significantly downregulated. Our results revealed that PQ-MGR could ameliorate glucose and lipid metabolism and insulin resistance in T2DM via regulation of the insulin receptor substrate-1/phosphoinositide3-kinase/protein-kinase B (IRS1/PI3K/Akt) and AMP-activated protein kinase/acetyl-CoA carboxylase (AMPK/ACC) pathways. These findings suggest that PQ-MGR may be used as an antidiabetic candidate drug for T2DM treatment.

Published
2021

35. Enhanced Production of Formic Acid in Electrochemical CO2 Reduction over Pd-Doped BiOCl Nanosheets

Author

Mei-Ying Chung, Mei-Chun Tseng, Peng-Jen Chen, Jeng-Lung Chen, Sheng-Yu Chen, Wei-Hung Chiang, Chun Hong Kuo, Pin-An Hsieh, and Lian-Ming Lyu

Subjects
Materials science, Formic acid, Doping, chemistry.chemical_element, Crystal structure, Electrochemistry, Catalysis, Bismuth, Tetragonal crystal system, chemistry.chemical_compound, chemistry, Chemical engineering, General Materials Science, Palladium
Abstract

Bismuth oxyhalides (BiOX, X = F, Cl, Br, I) are emerging energy materials because of their remarkable catalytic activity. The BiOX compounds usually have a tetragonal type crystal structure with unique layered morphology consisting of [X-Bi-O-Bi-X] sheets. Although the BiOX nanosheets exposed with {001} facets perform superior photoactivity, there is lack of understanding about their capability in the electrochemical CO2 reduction reaction (CO2RR). Herein, we adopt wet-chemical syntheses to make 2D BiOCl and Pd-doped BiOCl nanosheets for CO2RR. In the results, formic acid is the only one kind of product converted from CO2 along with H2 gas from water reduction over both BiOCl and Pd-doped BiOCl nanosheets. By thorough analyses with ex situ and in situ spectroscopy, the results reflect that (1) metallic Bi0 atoms generated by the applied negative potentials serve as the catalytic sites for the hydrogen evolution reaction (HER) and CO2RR and (2) the existence of doped Pd ions in the BiOCl structure reduces the barrier of charge transfer over the nanosheets, which enhances HER and CO2RR activities. We believe that the observations are important references for making catalysts toward CO2RR performance.

Published
2021

36. Influence of sulfate on the generation of bitumen components from kerogen decomposition during catagenesis

Author

Fujie Jiang, Qingyong Luo, Qi-Sheng Ma, Yong-Chun Tang, Chun-Lin Zhang, Wen Qi, Huan-Zhen Hu, Zi Wang, and Jia Wu

Subjects
chemistry.chemical_classification, Thermal decomposition, Energy Engineering and Power Technology, Mineralogy, Geology, Geotechnical Engineering and Engineering Geology, Catagenesis (geology), chemistry.chemical_compound, Geophysics, Fuel Technology, Hydrocarbon, chemistry, Source rock, Geochemistry and Petrology, Kerogen, Petroleum, Economic Geology, Sulfate, Asphaltene
Abstract

High-quality source rocks in saline lacustrine or marine sedimentary environments often show early peak petroleum generation and enhanced hydrocarbon yields, which have conventionally been attributed to organosulfur-enhanced thermal decomposition of kerogen. However, there is increasing awareness that the coexisting inorganic salts, particularly sulfates, might also contribute to the acceleration of petroleum generation. In this study, we investigated the influence of sulfates on the thermal decomposition of kerogen sampled from the Pingliang Formation in the Ordos Basin. Our results demonstrate that the kerogen samples mixed with sulfate generate more hydrocarbons with a lower peak production temperature than their sulfate-free counterparts. Detailed chemical analysis revealed that the presence of sulfates significantly facilitated the generation of resins and asphaltenes at temperatures below 350 °C, corresponding in our simulations to the early stage of petroleum generation (Easy%Ro

Published
2021

37. N-linoleyltyrosine exerts neuroprotective effects in APP/PS1 transgenic mice via cannabinoid receptor-mediated autophagy

Author

Qi-xue Zheng, Yi Zhou, Liu-ping Gong, Chun-mei Long, Ying-chun Zeng, Yuan-ting Liu, and Sha Liu

Subjects
Cannabinoid receptor, Morris water navigation task, Mice, Transgenic, RM1-950, Pharmacology, Hippocampus, Partial agonist, Neuroprotection, APP/PS1 transgenic mice, Receptor, Cannabinoid, CB2, Amyloid beta-Protein Precursor, chemistry.chemical_compound, Receptor, Cannabinoid, CB1, Alzheimer Disease, Presenilin-1, Cannabinoid receptor type 2, Autophagy, Animals, Receptors, Cannabinoid, Receptor, Spatial Memory, Amyloid beta-Peptides, Chemistry, N-linoleyltyrosine, Anandamide, Mice, Inbred C57BL, Disease Models, Animal, Neuroprotective Agents, Tyrosine, Molecular Medicine, lipids (amino acids, peptides, and proteins), Therapeutics. Pharmacology, Psychomotor Performance
Abstract

Anandamide (AEA) analogs show fair effects in counteracting the deterioration of Alzheimer's disease (AD). Our previous studies demonstrated that AEA analog-N-linoleyltyrosine (NITyr) exerted significant activities. In our current research, the role and mechanisms of NITyr were assessed in APP/PS1 mice mimicking the AD model. NITyr improved motor coordination in the rotarod test (RRT) and ameliorated spatial memory in the Morris water maze (MWM) but did not increase spontaneous locomotor activity in the open field test (OFT). In addition, NITyr protected neurons against β-amyloid (Aβ) injury via hematoxylin-eosin (HE) and Nissl staining. Moreover, the related biochemical indexes showed that NITyr reduced the levels of Aβ40 and Aβ42 in the hippocampus but did not affect the expression of p-APP and β-secretase 1 (BACE1). Furthermore, the autophagy inhibitor 3-methyladenine (3 MA) attenuated the effect of NITyr on animal behaviors and neurons. Meanwhile, NITyr upregulated the expression levels of LC3-II and Beclin-1, which were weakened by AM630 (an antagonist of CB2 receptor and a weak partial agonist of CB1 receptors). AM630 also weakened the role of NITyr in animal behaviors. Thus, NITyr improved behavioral impairment and neural loss by inducing autophagy mainly mediated by the CB2 receptor, and weakly mediated by the CB1 receptor.

Published
2021

38. Fuzzy optimization design of multicomponent refinery hydrogen network

Author

Qixin Zhang, Xuantong Lu, Chun Deng, Xiao Feng, Jui-Yuan Lee, and Jian Liu

Subjects
Optimal design, chemistry.chemical_classification, Environmental Engineering, Hydrogen, business.industry, General Chemical Engineering, Hydrogen sulfide, Separator (oil production), chemistry.chemical_element, General Chemistry, Maximization, Reuse, Biochemistry, Refinery, chemistry.chemical_compound, Hydrocarbon, chemistry, Environmental science, Process engineering, business
Abstract

Hydrogen and light hydrocarbon components are essential resources of the refinery. The optimization of the refinery hydrogen system and recovery of the light hydrocarbon components contained in the gas streams are key strategies to reduce the operating costs for sustainable development. Many research efforts have been focused on the optimization of single impurity hydrogen network, and the flowrates of the hydrogen sources and sinks are assumed to be constant. However, their flowrates vary along with the quality of crude oil and refinery processing plans. A general superstructure of multicomponent refinery hydrogen network is proposed, which considers four components, namely H2, H2S, CH4 and C 2 + , as well as the flowrate variations of hydrogen source and hydrogen sink. The mathematical model based on the superstructure is developed with objective functions, including the minimization of total annualized cost and the maximization of overall satisfaction of the hydrogen network. Moreover, the model considers the removal of hydrogen sulfide and the recovery of light hydrocarbon components (i.e., C 2 + ) in the optimization. To verify the applicability of the proposed mathematical model, a simplified industrial case study with four scenarios is solved. The optimization results show that the economic benefit can be maximized by considering both the direct reuse of gas streams from high-pressure separator (HP gas stream) and from low-pressure separator (LP gas stream) and the recovery of the light hydrocarbon streams. The fuzzy optimization method can be used to guide the optimal design of the refinery hydrogen system with multi-period variable flowrates.

Published
2022

39. Highly effective liquid and solid phase extraction methods to concentrate radioiodine isotopes for radioiodination chemistry

Author

Christopher Davis, Chun Li, Ruirui Nie, Norman Guzzardi, Barbara Dworakowska, Pragalath Sadasivam, John Maher, Eric O. Aboagye, Zhi Lu, Ran Yan, and Imperial College Healthcare NHS Trust- BRC Funding

Subjects
Biochemistry & Molecular Biology, Medicinal & Biomolecular Chemistry, Chemistry, Medicinal, 0305 Organic Chemistry, Biochemistry, Biochemical Research Methods, Analytical Chemistry, Iodine Radioisotopes, radioiodination, Chlorides, Drug Discovery, Humans, Radiology, Nuclear Medicine and imaging, Pharmacology & Pharmacy, Thyroid Neoplasms, Spectroscopy, Science & Technology, Chemistry, Analytical, Solid Phase Extraction, Organic Chemistry, Water, Iodides, REAGENT, radioiodine, Chemistry, Physical Sciences, phase transfer reagent, 1115 Pharmacology and Pharmaceutical Sciences, Radiopharmaceuticals, Life Sciences & Biomedicine, iodotriazole, Copper
Abstract

Radioactive iodine isotopes play a pivotal role in radiopharmaceuticals. Large-scale production of multi-patient dose of radioiodinated nuclear medicines requires high concentration of radioiodine. We demonstrate that tetrabutylammonium chloride and methyltrioctylamonium chloride are effective phase transfer reagents to concentrate iodide-124, iodide-125 and iodide-131 from the corresponding commercial water solutions. The resulting concentrated radioiodide, in the presence of either phase transfer reagent, does not hamper the chemical reactivity of aqueous radioiodide in the copper (II)-mediated one-pot three-component click chemistry to produce radioiodinated iodotriazoles.

Published
2022

40. The Value of Preoperative Plasma VEGF Levels in Urothelial Carcinoma of the Bladder Treated with Radical Cystectomy

Author

Hadi Mostafaei, Pawel Rajwa, Francesco Soria, Péter Nyirády, Frederik König, Pierre I. Karakiewicz, Shahrokh F. Shariat, Douglas S. Scherr, Satoshi Katayama, Yair Lotan, Benjamin Pradere, Shin Egawa, Keiichiro Mori, Nico C. Grossmann, Abdulmajeed Aydh, Fahad Quhal, Jeremy Yuen-Chun Teoh, Reza Sari Motlagh, Martin Haydter, Eva Compérat, Victor M. Schuettfort, Ekaterina Laukhtina, and Marco Moschini

Subjects
Vascular Endothelial Growth Factor A, Oncology, Carcinoma, Transitional Cell, medicine.medical_specialty, Chemotherapy, Bladder cancer, Proportional hazards model, Angiogenesis, business.industry, Urology, medicine.medical_treatment, Urinary Bladder, Cystectomy, medicine.disease, Vascular endothelial growth factor, chemistry.chemical_compound, Urinary Bladder Neoplasms, chemistry, Internal medicine, medicine, Humans, Biomarker (medicine), business, Pathological
Abstract

BACKGROUND Elevated preoperative plasma levels of the angiogenesis-related marker VEGF have been associated with worse oncological outcomes in various malignancies. OBJECTIVE To investigate the predictive/prognostic role of VEGF in patients with urothelial carcinoma of the bladder (UCB) treated with radical cystectomy (RC). DESIGN, SETTING, AND PARTICIPANTS VEGF plasma levels were measured preoperatively in 1036 patients with UCB who underwent RC. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The correlation between plasma VEGF levels and pathological and survival outcomes was assessed using logistic regression and Cox regression analyses. Discrimination was assessed using the concordance index (C index). The clinical net benefit was evaluated using decision curve analysis (DCA). RESULTS AND LIMITATIONS Patients with higher pretreatment plasma VEGF levels had poorer recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) according to log-rank tests (all p 0.05). Preoperative plasma VEGF levels were independently associated with RFS, CSS, and OS in preoperative and postoperative multivariable models. However, in all cases the C index increased by

Published
2022

41. Nuclear magnetic resonance spectroscopy-based urinalysis for a young girl with extreme hypoglycaemia

Author

Ka-chung Wong, Tsz-ki Ling, Grace Wing-kit Poon, Nike Kwai-Cheung Lau, Anne Mei-kwun Kwok, Chun-yiu Law, and Ching-Wan Lam

Subjects
Magnetic Resonance Spectroscopy, Urinalysis, medicine.diagnostic_test, Chemistry, media_common.quotation_subject, Nuclear magnetic resonance spectroscopy, Hypoglycemia, Pathology and Forensic Medicine, Nuclear magnetic resonance, medicine, Humans, Female, Girl, media_common
Published
2022

42. Valeriaquinone A, a unique anthraquinone–coumarin hybrid with selective inhibition of PTP1B from Knoxia valerianoides

Author

Chun-Hua Wang, Wei Cong, Yan Jiang, Ren-Yong Yang, Feng Zhao, Gui-Ge Hou, and Zhaoxia Qu

Subjects
biology, Stereochemistry, Allosteric regulation, General Chemistry, Selective inhibition, Coumarin, biology.organism_classification, Inhibitory postsynaptic potential, Knoxia, Anthraquinone, chemistry.chemical_compound, chemistry, Cytotoxic T cell, IC50
Abstract

Available online xxx Valeriaquinone A (1), an unprecedented anthraquinone–coumarin hybrid, was isolated from the roots of Knoxia valerianoides. Its structure was determined by extensive spectroscopic analyses and X-ray diffraction. The plausible biosynthetic pathways for 1 were proposed. Compound 1 exhibited strong protein tyrosine phosphatase 1B (PTP1B) inhibition with high selectivity (> 30 fold) over homologous T cell protein tyrosine phosphatase (TCPTP) potentially by binding to an allosteric site predicted by kinetic analysis and molecular docking. Moreover, compound 1 showed significant cytotoxic activities against three human hepatoma cell lines (HepG2, QGY-7703, and SMMC-7721) with half maximal inhibitory concentration (IC50) values of 1.39 ± 0.2, 10.34 ± 2.09, and 5.56 ± 0.47 µmol/L, respectively.

Published
2022

43. Cassane diterpenoids from Caesalpinia pulcherrima and their anti-inflammatory and α-glycosidase inhibitory activities

Author

Xiu-Mei Chen, Shi-Chun Zong, Jin-Ming Gao, Chun-Huan Li, Young Ho Kim, Jia-Yun Wang, Xin Yun, Zi-Han Zhang, and Wang Lu

Subjects
biology, Chemistry, medicine.drug_class, Stereochemistry, Organic Chemistry, Plant Science, Fabaceae, Inhibitory postsynaptic potential, Caesalpinia pulcherrima, biology.organism_classification, Biochemistry, Anti-inflammatory, Analytical Chemistry, α glycosidase, medicine, IC50, Biological evaluation
Abstract

Three undescribed cassane-type diterpenoids (CAs), caesalpulcherrins K-M (1–3), together with three known ones (4–6) were isolated from the aerial parts of Caesalpinia pulcherrima (L.) Sw (Fabaceae). Their structures were elucidated via analysis of NMR (1 D and 2 D) and HRESIMS data. The character for caesalpulcherrin K possessing the olefin bond at C-11 and C-12 in its cassane skeleton was observed, which belonged to a small group among more than 450 CAs. That is, only fifteen derivatives have been reported up to now, to our knowledge. Biological evaluation revealed that compounds 1–6 exhibited moderate anti-inflammatory activity, with an IC50 value from 6.04 ± 0.34 to 8.92 ± 0.65 μM. Furthermore, compounds 5 and 6 exhibited significant α-glucosidase inhibitory activity at 10 μM.

Published
2021

44. Microglial ERK-NRBP1-CREB-BDNF signaling in sustained antidepressant actions of (R)-ketamine

Author

Qianqian Cao, Shilin Luo, Ji-chun Zhang, Chun Yang, Jiaxu Chen, Lujuan He, Kenji Hashimoto, Qi Qi, and Wei Yao

Subjects
MAPK/ERK pathway, Dendritic spine, biology, Microglia, Kinase, Chemistry, Pharmacology, CREB, Cellular and Molecular Neuroscience, Psychiatry and Mental health, medicine.anatomical_structure, Neurotrophic factors, biology.protein, medicine, Receptor, Molecular Biology, Astrocyte
Abstract

(R,S)-ketamine elicits rapid-acting and sustained antidepressant actions in treatment-resistant patients with depression. (R)-ketamine produces longer-lasting antidepressant effects than (S)-ketamine in rodents; however, the precise molecular mechanisms underlying antidepressant actions of (R)-ketamine remain unknown. Using isobaric Tag for Relative and Absolute Quantification, we identified nuclear receptor-binding protein 1 (NRBP1) that could contribute to different antidepressant-like effects of the two enantiomers in chronic social defeat stress (CSDS) model. NRBP1 was localized in the microglia and neuron, not astrocyte, of mouse medial prefrontal cortex (mPFC). (R)-ketamine increased the expression of NRBP1, brain-derived neurotrophic factor (BDNF), and phosphorylated cAMP response element binding protein (p-CREB)/CREB ratio in primary microglia cultures thorough the extracellular signal-regulated kinase (ERK) activation. Furthermore, (R)-ketamine could activate BDNF transcription through activation of CREB as well as MeCP2 (methyl-CpG binding protein 2) suppression in microglia. Single intracerebroventricular (i.c.v.) injection of CREB-DNA/RNA heteroduplex oligonucleotides (CREB-HDO) or BDNF exon IV-HDO blocked the antidepressant-like effects of (R)-ketamine in CSDS susceptible mice. Moreover, microglial depletion by colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX3397 blocked the antidepressant-like effects of (R)-ketamine in CSDS susceptible mice. In addition, inhibition of microglia by single i.c.v. injection of mannosylated clodronate liposomes (MCLs) significantly blocked the antidepressant-like effects of (R)-ketamine in CSDS susceptible mice. Finally, single i.c.v. injection of CREB-HDO, BDNF exon IV-HDO or MCLs blocked the beneficial effects of (R)-ketamine on the reduced dendritic spine density in the mPFC of CSDS susceptible mice. These data suggest a novel ERK-NRBP1-CREB-BDNF pathways in microglia underlying antidepressant-like effects of (R)-ketamine.

Published
2021

45. Copper-Catalyzed (4+1) Cascade Annulation of Terminal Alkynes with 2-(Tosylmethyl)anilines: Synthesis of 2,3-Disubstituted Indoles

Author

Chun-Fang Liu, Lin-Han Pang, Xu Bao, Xiao-Min Ge, Chun-An Fan, Xu Yan, Xian-Tao An, and Qing Zhang

Subjects
Annulation, Terminal (electronics), Cascade, Chemistry, Organic Chemistry, Synthon, Copper catalyzed, Physical and Theoretical Chemistry, Biochemistry, Combinatorial chemistry
Abstract

A novel strategy based on Cu-catalyzed (4+1) cascade annulation of terminal alkynes as one-carbon synthons with 2-(tosylmethyl)anilines has been developed for the expeditious synthesis of 2,3-disubstituted indoles, in which in situ generations of aza-o-quinone methides and alkynyl-copper(I) species are involved. This annulation provides an effective method for the assembly of synthetically and structurally interesting 2,3-disubstituted indoles.

Published
2021

46. Auger Electron Spectroscopy Analysis of the Thermally Induced Degradation of MAPbI3 Perovskite Films

Author

Jun-Xian Li, Man-Ying Wang, Pei-Chen Huang, Wei-Chun Lo, and Wei-Chun Lin

Subjects
Auger electron spectroscopy, Materials science, General Chemical Engineering, Photovoltaic system, Energy conversion efficiency, Halide, General Chemistry, Article, Chemistry, Chemical engineering, Degradation (geology), Thermal stability, QD1-999, Perovskite (structure)
Abstract

Organometal halide perovskites are highly promising materials for photovoltaic applications due to the rapid growth of power conversion efficiency in recent years. However, thermal stability is still a major hurdle for perovskite solar cells toward commercialization. Herein, we first explore the slow thermal response of the CH3NH3PbI3 perovskite crystal investigated via Auger electron spectroscopy (AES). AES image mapping directly observes the evolution of morphology and elemental distribution over time. The AES small spot analysis demonstrates the precise initial degradation position of perovskite with both information regarding physical changes in crystals and chemical changes in elemental bonding at the nanometer scale. X-ray photoelectron spectroscopy (XPS) was used to confirm the surface chemical bonding and composition of the perovskite crystals. This work provides the first insights into the physical and chemical changes of perovskites investigated by AES upon long-term exposure to heat under ambient conditions.

Published
2021

47. A New Acenaphthylene and Bioactive Constituents of Salvia arisanensis

Author

Jih Jung Chen, Chien Ming Huang, Ping-Jyun Sung, Chien Liang Lin, Chun-Lin Chen, Chun-Hao Chang, Chang-Syun Yang, Chieh-Yang Cheng, Tsung-Hsien Chang, and Ming-Jen Cheng

Subjects
biology, Stereochemistry, Plant Science, General Chemistry, Salvia, biology.organism_classification, Acenaphthylene, General Biochemistry, Genetics and Molecular Biology, Carnosol, Ferruginol, chemistry.chemical_compound, chemistry, Ic50 values, Derivative (chemistry)
Abstract

A new acenaphthylene derivative, salviarisanal (1), has been isolated from the aerial part of Salvia arisanensis, together with six known compounds, carnosol (2), 16-hydroxycarnosol (3), ferruginol (4), cryptotanshinone (5), salvileucantholide (6), and dugesin B (7). The structure of the new compound 1 was determined through spectroscopic and MS analyses. Among the isolates, cryptotanshinone (5) exhibited cytotoxicities with IC50 values of 5.38, 7.16, 4.84, and 9.10 μM, respectively, against DLD-1, CCRF-CEM, HL-60, and IMR-32 cell lines. 16-Hydroxycarnosol (3) also exhibited cytotoxicities with IC50 values of 7.42 and 6.73 μM, respectively, against DLD-1 and IMR-32 cell lines. In addition, salviarisanal (1), carnosol (2), 16-hydroxycarnosol (3), and ferruginol (4) showed potent inhibition with IC50 values of 18.45, 30.33, 27.58, and 35.05 μM, respectively, against LPS-induced NO generation.

Published
2021

48. Bisphenol <scp>A</scp> induced apoptosis via oxidative stress generation involved <scp>Nrf2</scp> / <scp>HO</scp> ‐1 pathway and mitochondrial dependent pathways in human retinal pigment epithelium ( <scp>ARPE</scp> ‐19) cells

Author

Yu-Hsiang Kuan, Yun-Wei Chiang, Chia-Che Chang, Wen-Ying Chen, Chun-Hung Su, Han-Yin Sun, Chun-Jung Chen, Chuan-Mu Chen, and Shih-Pin Chen

Subjects
endocrine system, biology, urogenital system, Chemistry, Health, Toxicology and Mutagenesis, Cytochrome c, AMPK, General Medicine, Management, Monitoring, Policy and Law, Mitochondrion, Toxicology, medicine.disease_cause, Cell biology, Heme oxygenase, Superoxide dismutase, Apoptosis, biology.protein, medicine, Apoptotic signaling pathway, hormones, hormone substitutes, and hormone antagonists, Oxidative stress
Abstract

Bisphenol A (BPA) is an estrogen-like compound, and an environmental hormone, that is commonly used in daily life. Therefore, it may enter the human body through food or direct contact, causing BPA residues in blood and urine. Because most studies focused on the analysis of BPA in reproductive cells or tissues, regarding evidence the effect of BPA on human retinal pigment epithelium (ARPE-19) cells unavailable. Accordingly, the present study explored the cytotoxicity of BPA on ARPE-19 cells. After BPA treatment, the expression of Bcl-XL an antiapoptotic protein, in the mitochondria decreased, and the expression of Bax, a proapoptotic protein increased. Then the mitochondrial membrane potential was affected. BPA changed in mitochondrial membrane potential led to the release of cytochrome C, which activated caspase-9 to promote downstream caspase-3 leading to cytotoxicity. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase 1 (HO-1) pathway play a major role in age-related macular degeneration. Our results showed that expression of HO-1 and Nrf2 suppressed by BPA. Superoxide dismutase and catalase, which Nrf2 downstream antioxidants, were degraded by BPA. AMP-activated kinase (AMPK), which can regulate the phosphorylation of Nrf2, and the phosphorylation of AMPK expression was reduced by BPA. Finally, BPA-induced ROS generation and cytotoxicity were reduced by N-acetyl-l-cysteine. Taken together, these results suggest that BPA induced ARPE-19 cells via oxidative stress, which was associated with down regulated Nrf2/HO-1 pathway, and the mitochondria dependent apoptotic signaling pathway.

Published
2021

49. Gm364 coordinates MIB2/DLL3/Notch2 to regulate female fertility through AKT activation

Author

Teng Zhang, Chun-Xiang Zhou, Na-Na Zhang, Liang-Jian Chen, Zi-Bin Wang, Qing-Yuan Sun, Dong Zhang, Cong-Rong Li, Zhen-Bo Wang, Yi-Chun Guan, Xin Wang, Yang Wang, Zheng-Rong Xia, Cui-Lian Zhang, Zhi-Xia Yang, and Yan-Ru Li

Subjects
biology, Chemistry, Cell Biology, Oocyte, Transmembrane protein, Cell biology, Ubiquitin ligase, medicine.anatomical_structure, Cytoplasm, medicine, biology.protein, Receptor, Molecular Biology, Integral membrane protein, Protein kinase B, Intracellular
Abstract

Many integral membrane proteins might act as indispensable coordinators in specific functional microdomains to maintain the normal operation of known receptors, such as Notch. Gm364 is a multi-pass transmembrane protein that has been screened as a potential female fertility factor. However, there have been no reports to date about its function in female fertility. Here, we found that global knockout of Gm364 decreased the numbers of primordial follicles and growing follicles, impaired oocyte quality as indicated by increased ROS and γ-H2AX, decreased mitochondrial membrane potential, decreased oocyte maturation, and increased aneuploidy. Mechanistically, Gm364 directly binds and anchors MIB2, a ubiquitin ligase, on the membrane. Subsequently, membrane MIB2 ubiquitinates and activates DLL3. Next, the activated DLL3 binds and activates Notch2, which is subsequently cleaved within the cytoplasm to produce NICD2, the intracellular active domain of Notch2. Finally, NICD2 can directly activate AKT within the cytoplasm to regulate oocyte meiosis and quality.

Published
2021

50. Creation of a rat lymphedema model using extensive lymph node dissection and circumferential soft tissue resection: Is this a reliable model?

Author

Chi-Wei Huang, Jung-Ju Huang, Jia-Wei Liu, Yung-Chun Chang, Hui-Yi Hsiao, and Frank Chun-Shin Chang

Subjects
Male, medicine.medical_specialty, Resection, chemistry.chemical_compound, medicine, Animals, Lymphedema, Lymph node, High-power field, Groin, business.industry, Lymphography, Soft tissue, medicine.disease, Rats, Surgery, body regions, Dissection, medicine.anatomical_structure, chemistry, Rats, Inbred Lew, Lymph Node Excision, Lymph Nodes, business, Indocyanine green
Abstract

INTRODUCTION The medical demand for lymphedema treatment is huge since the disease mechanism remains unclear, and management are difficult. Our purpose was to develop a reliable lymphedema model mimicking the clinical scenario and allows a microsurgical approach. MATERIALS AND METHODS Male Lewis rats weighing 400 to 450 g were used to create lymphedema with groin and popliteal lymph node dissection and creation of 5 mm circumferential skin defect (n = 6). A skin incision was made and closed primarily for control group (n = 5). Evaluation included indocyanine green (ICG) lymphangiography 1 and 2 months postoperatively, volume difference between bilateral hindlimbs measured using micro-CT, and the skin was harvested for histological evaluation 2 months postoperatively. RESULTS Larger volume differences present in the lymphedema group (17.50 ± 7.76 vs. 3.73 ± 2.66%, p

Published
2021

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