jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tomoki Yamashita | Hiori Kino | Koji Tsuda | Takashi Miyake | Tamio Oguchi
Source: Science and Technology of Advanced Materials Methods (article, 2022-03-23)
Field: Materials Science — Materials Chemistry

Hybrid algorithm of Bayesian optimization and evolutionary algorithm in crystal structure prediction We propose a highly efficient searching algorithm in crystal structure prediction. The searching algorithm is a hybrid of the evolutionary algorithm and Bayesian optimization. The evolutionary algorithm is widely used in crystal structure prediction, and the Bayesian optimization is one of the selection-type algorithms we have developed. We have performed simulations of crystal structure prediction to compare the success rates of the random search, evolutionary algorithm, Bayesian optimization, and hybrid algorithm for up to ternary systems such as Si, Y2Co17, Al2O3, and CuGaS2, using the CrySPY code. These results demonstrate that the evolutionary algorithm can generate structures more efficiently than random structure generation, and the Bayesian optimization can efficiently select potential candidates from a large number of structures. Moreover, the hybrid algorithm, which has the advantages of both, is proved to be the most efficient searching algorithm among them. Algorithm ; Evolutionary algorithm ; Computer science ; Bayesian optimization ; Bayesian probability ; Crystal structure prediction ; Hybrid algorithm (constraint satisfaction) ; Artificial intelligence ; Crystal structure ; Probabilistic logic Machine Learning in Materials Science ; Crystallization and Solubility Studies ; X-ray Diffraction in Crystallography
Authors: Daniel Huang | Chong Teng | Junwei Lucas Bao | Jean-Baptiste Tristan
Source: Journal of Mathematical Chemistry (article, 2022-03-29)
Field: Materials Science — Materials Chemistry

mad-GP: automatic differentiation of Gaussian processes for molecules and materials Automatic differentiation ; Differentiable function ; Python (programming language) ; Gaussian process ; Computer science ; Gaussian ; Algorithm ; Surrogate model ; Kernel (algebra) ; Mathematical optimization ; Applied mathematics ; Mathematics ; Physics ; Discrete mathematics ; Mathematical analysis Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Protein Structure and Dynamics
Authors: Muhamad Furkan Mat Salleh | Rose Amnah Abd Rauf | Rohaida Mohd Saat | Mohamad Hisyam Ismail
Source: Asian Journal of University Education (article, 2022-04-30)
Field: Chemistry — Physical and Theoretical Chemistry

Novice Chemistry Teachers’ Instructional Strategies in Teaching Mixed-Ability Classrooms This qualitative study sought to explore Malaysian novice chemistry teachers' experiences in teaching mixed-ability students during their teaching practicum, focusing on their instructional strategies for dealing with those learners in the class. The researchers employed purposive sampling to select 12 trainee teachers to be involved in semi-structured interviews. The data collected were analysed using the constant comparative method. As a result, two themes emerged regarding participants' instructional strategies: the whole-class approach and adjustment to the learners' needs. This paper discusses the first theme, which consists of three sub-themes: active learning activities, the use of stimulating learning materials, and assessment practice. Even though novice chemistry teachers primarily engaged mixed-ability students through whole-class instruction, the study found they emphasised active classroom engagement and collaboration between students in their classroom. Besides, they did consider students' interests and preferences when selecting activities and materials for their lessons. However, the study found that novice teachers mainly did not utilise the data from the formative assessments to inform their decisions in differentiating instruction for mixed-ability learners in class. Though there are differences in students' ability in class, the teachers generally opted for a 'one-size-fits-all' strategy for all students in most lessons. The study recommends that teacher training institutions and related stakeholders provide adequate training for novice chemistry teachers to improve their knowledge and skills in practising differentiated instruction. Class (philosophy) ; Formative assessment ; Practicum ; Mathematics education ; Nonprobability sampling ; Psychology ; Qualitative research ; Teaching method ; Theme (computing) ; Qualitative property ; Chemistry ; Pedagogy ; Computer science ; Medicine ; Sociology Various Chemistry Research Topics ; Innovative Teaching Methods
Authors: Laila A. Jaragh-Alhadad | Mayada S. Ali | Moustafa S. Moustafa | Gamaleldin I. Harisa | Fars K. Alanazi | Sadashiva S. Karnik
Source: Journal of Molecular Structure (article, 2022-07-11)
Field: Chemistry — Organic Chemistry

Sulfonamide derivatives mediate breast and lung cancer cell line killing through tubulin inhibition Tubulin plays essential roles in cell signaling, division, proliferation, and other cellular functions. Tubulin is a potential target for anticancer agents. The classical tubulin inhibitors have a low therapeutic index, multi-drug resistance, and induced tubulin gene mutations. Therefore, the discovery of alternative tubulin inhibitors is critical for cancer therapy. The study aimed to synthesize sulfonamide derivatives to combat breast and lung cancer by tubulin inhibition mediated mechanism. In the present work sulfonamide derivatives were synthesized and physicochemically characterized in terms of melting points, magnetic measurements, IR,1H NMR, 13C NMR, thermogravimetric analysis, and molecular weights. Moreover, the cytotoxicity and western blot analysis were investigated using MCF7, and A549 cell lines as surrogate models for breast and lung cancer. The present results showed that the modified sulfonamides agents elicited cytotoxicity against breast cancer cell line MCF7 as well as A549 cell lines with IC50 values below 1.8 µM. Among the designed sulfonamide derivatives the 4-iodo-N-(3-((2-methyl-5-(trifluoromethyl) benzyl) oxy)-4-(N-methylmethylsulfonami-do) phenyl) benzamide is the most effective cytotoxic agent against MCF7 and A549 cell lines. These data demonstrated that sulfonamide agents have excellent anti-cancer activity targeting tubulin in both cancer cell lines. Tubulin ; Chemistry ; Cytotoxicity ; Sulfonamide ; Cell culture ; Cancer research ; Lung cancer ; A549 cell ; Cytotoxic T cell ; Pharmacology ; Cell ; Stereochemistry ; In vitro ; Biochemistry ; Microtubule ; Internal medicine ; Biology ; Cell biology ; Medicine Synthesis and biological activity ; Enzyme function and inhibition ; Cancer Mechanisms and Therapy
Authors: Niranjan Sitapure | Joseph Sang‐Il Kwon
Source: Digital Chemical Engineering (article, 2022-12-16)
Field: Materials Science — Materials Chemistry

A Unified Approach for modeling and control of crystallization of quantum dots (QDs) Recently, quantum dots (QDs) have garnered significant attention due to their superior photoelectronic properties, and widespread applications in high-resolution displays and solar cells. Generally, the optoelectronic properties of QDs are majorly dictated by their bandgap energy (related to their size). Thus, there is a large impetus on accurate modeling and control of size of QD nanocrystals. Unfortunately, unlike traditional protein or sugar crystallization, there are very few models that describe QD crystallization. That said, the existing few QD models are based on computationally demanding multiscale modeling approaches, which (a) makes extrapolation to different QD systems highly resource-intensive; and (b) makes them unsuitable for direct implementation in a controller framework. To address these challenges, we present a unified QD crystallization modeling and control framework. Specifically, mass-energy balance equations, population balance equations (PBEs), and crystallization kinetics are decomposed into a matrix of first-order ordinary differential equations (ODEs) that can be easily computed using native python solvers. Further, a model predictive controller (MPC) module is designed for set-point tracking of crystal size distribution (CSD). Also, unlike the multiscale QD models from the literature, the developed PBE-based QD model has high computational efficiency, and can be directly incorporated within the MPC without the requirement of a surrogate model. Then, to demonstrate the developed unified framework’s capabilities, batch crystallization of CdTe QDs is taken as a case study. It was observed that the simulation results are in good agreement with the experimental results, and the MPC shows effective set-point tracking performance for regulating size of QD crystals. Quantum dot ; Computer science ; Model predictive control ; Ode ; Python (programming language) ; Crystallization ; Ordinary differential equation ; Population balance equation ; Population ; Materials science ; Nanotechnology ; Mathematics ; Physics ; Differential equation ; Applied mathematics ; Control (management) ; Artificial intelligence Quantum Dots Synthesis And Properties ; Perovskite Materials and Applications ; Spectroscopy and Quantum Chemical Studies
Authors: Hutdia Putri Murni | Minda Azhar | Ellizar Ellizar | Umar Kalmar Nizar | Guspatni Guspatni
Source: Journal of Turkish Science Education (article, 2022-10-01)
Field: Chemistry — Physical and Theoretical Chemistry

Three levels of chemical representation-integrated and structured inquiry-based reaction rate module: Its effect on students’ mental models Previous studies showed that structured inquiry-based learning is suitable for novice learners, chemical multiple representations facilitate meaningful learning, and modules are organized and complete learning materials for students. Modules designed with a structured inquiry-based model and completed with chemical multiple representations could be media to help students learn. This study aims to determine the effects of the structured inquiry-based reaction rate module that is integrated within three levels of chemical representation on senior high school students' mental models and learning outcomes. The study used a Posttest Control and Experimental Group Design where the research subjects were 137 students from two different ranks of public senior high schools in the city of Padang, Indonesia. Research instruments used were learning achievement test and two-tier diagnostic test as well as a semi-structured interview sheet. T-test results of the research hypotheses showed that the mean of the mental models and learning outcomes of students in the experimental class were significantly higher than those of students in the control class at both low-ranked and high-ranked schools. The integration of three levels of chemical representation on reaction rate topic in a structured inquirybased module during learning affects mental models which they then relate to the learning outcomes of both low and high achiever students in senior high schools. Representation (politics) ; Mental representation ; Computer science ; Psychology ; Cognition ; Psychiatry ; Political science Various Chemistry Research Topics
Authors: Andreas Traberg | Fernanda E. Pinto | Anders C. N. Hansen | Merete Hædersdal | Catharina M. Lerche | Christian Janfelt
Source: Pharmaceuticals (article, 2022-12-19)
Field: Chemistry — Spectroscopy

Quantitative Mass Spectrometry Imaging of Bleomycin in Skin Using a Mimetic Tissue Model for Calibration The aim of Quantitative mass spectrometry imaging (Q-MSI) is to provide distribution analysis and quantitation from one single mass-spectrometry-based experiment, and several quantitation methods have been devised for Q-MSI. Mimetic tissue models based on spiked tissue homogenates are considered one of the most accurate ways to perform Q-MSI, since the analyte is present in a well-defined concentration in a sample matrix highly similar to the one of the unknown sample to be analyzed. The delivery of drugs in skin is among the most frequent types of pharmaceutical MSI studies. Here, a mimetic tissue model is extended for use on the skin, which, due to its high collagen content, is different from most other tissue as the homogenates become extremely viscous. A protocol is presented which overcomes this by the addition of water and the handling of the homogenate at an elevated temperature where the viscosity is lower. Using a mimetic tissue model, a method was developed for the quantitative imaging of bleomycin in skin. To compensate for the signal drift and the inhomogeneities in the skin, an internal standard was included in the method. The method was tested on skin from a pig which had had an electropneumatic injection of bleomycin into the skin. Quantification was made at several regions in a cross section of the skin at the injection site, and the results were compared to the results of a quantitative LC-MS on a neighboring tissue biopsy from the same animal experiment. The overall tissue concentration determined by the LC-MS was within the range of the different regions quantified by the Q-MSI. As the model provides the results of the same order of magnitude as a LC-MS, it can either be used to replace LC-MS in skin studies where MSI and LC-MS are today carried out in combination, or it can add quantitative information to skin studies which are otherwise carried out by MSI alone. Analyte ; Bleomycin ; Mass spectrometry imaging ; Mass spectrometry ; Quantitative analysis (chemistry) ; Matrix (chemical analysis) ; Chromatography ; Chemistry ; Pig skin ; Tissue sample ; Biomedical engineering ; Medicine ; Surgery Mass Spectrometry Techniques and Applications ; Analytical Chemistry and Chromatography ; Microfluidic and Capillary Electrophoresis Applications
Authors: Hang Su | Fei Zhao
Source: Applied Sciences (article, 2022-04-30)
Field: Materials Science — Surfaces, Coatings and Films

Recent Advances in Intrinsically Fluorescent Polydopamine Materials Fluorescence nanoparticles have gained much attention due to their unique properties in the sensing and imaging fields. Among the very successful candidates are fluorescent polydopamine (FPDA) nanoparticles, attributed to their simplicity in tracing and excellent biocompatibility. This article aims to highlight the recent achievements in FPDA materials, especially on the part of luminescence mechanisms. We focus on the intrinsic fluorescence of PDA and will not discuss fluorescent reaction with a fluorometric reagent or coupling reaction with a fluorophore, which may cause more in vivo interferences. We believe that intrinsic FPDA presents great potential in bioapplications. Fluorophore ; Fluorescence ; Nanotechnology ; Biocompatibility ; Materials science ; Chemistry ; Optics ; Physics Polymer Surface Interaction Studies ; Quantum Dots Synthesis And Properties ; Advanced biosensing and bioanalysis techniques
Authors: Rouven Britz | Gianluca Rizzello | Paul Motzki
Source: Advanced Engineering Materials (article, 2022-04-05)
Field: Materials Science — Materials Chemistry

High‐Speed Antagonistic Shape Memory Actuator for High Ambient Temperatures This work presents the development of an innovative shape memory alloy (SMA) actuator principle, which allows high‐speed switching cycles through the decoupling of antagonistically arranged SMA wires. Being optimized for the use at high ambient temperatures up to 65 °C, a possible application area is the active venting of injection molds where it can be used to expel air, which is trapped during the injection mold process. The patented actuator principle is based on a decoupled agonist–antagonist SMA‐spring system and allows a high‐speed closing movement by a compact and lightweight design. Another innovation compared to conventional antagonistic SMA actuator systems is the integrated fail‐safe mechanism, which guarantees a defined closed state in case of power failure. Subsequently, in the motivation the need for active venting valves for injection molding is first described. Second, the novel actuator principle is introduced, and the development of an electronics concept is discussed. Finally, the design process, assembly, and validation of two iterations of the actuator prototype are presented. The final prototype validation measurements showcase high performance by valve strokes of 1 mm within 100 ms at ambient temperature of 65 °C. Actuator ; SMA* ; Decoupling (probability) ; Materials science ; Shape-memory alloy ; Mechanical engineering ; Process (computing) ; Computer science ; Control engineering ; Engineering ; Composite material Shape Memory Alloy Transformations ; Polymer composites and self-healing
Authors: Sara ZERROUKI | Samia MEZHOUD | Ayse SAHİN YAĞLIOĞLU | Chawki Bensouıcı | Mehmet NURİ ATALAR | Ibrahim DEMİRTAS | Souad AMEDDAH | Ratiba MEKKIOU
Source: Journal of Research in Pharmacy (article, 2022-01-01)
Field: Chemistry — Analytical Chemistry

Antioxidant, anticancer activities, and HPLC-DAD analyses of the medicinal halophyte Limoniastrum guyonianum Dur. extracts Although notable medicinal value and biological activities such as antioxidant, antibacterial, antimicrobial and antifungal of Limoniastrum guyonianum have been reported, identification and quantification of phytoconstituents of CHCl3, EtOAC, and n-BuOH extracts from the aerial parts of the halophyte medicinal plant from Algerian Sahara was not well investigated for biological and anticancer activity in spite of their great interest. Therefore, the aim of this study was to investigate the antioxidant and anticancer activities of L. guyonianum. The phytoconstituents of CHCl3, EtOAC, and n-BuOH extracts were screened using HPLC-DAD. Total phenolic and flavonoid contents were quantified, antioxidant activity, using DPPH radical scavenging activity, ABTS + decolorization, cupric reducing power, and anticancer activity against human cervical adenocarcinoma (HeLa) cell line were investigated and quantified. The results showed the presence of chlorogenic, gallic, syringic, p-coumaric, trans ferulic, o-coumaric acids, and quercetin in significant varying quantities. Chlorogenic acid was present in the greatest quantity (344.027-422.711mg/g of extract) as well as quercetin in CHCl3 extract. It is important to note the absence of caffeic acid and o-coumaric acid from EtOAc and CHCl3 extracts, respectively. The content of phenolic and flavonoid were higher in EtOAc extract (9344,38mgGAE and 218.336.36mgQE/gof extract), respectively. EtOAc extract possesses a strong antioxidant effect in vitro, while the CHCl3 extract proved to be the most active againstHeLa cell lines (IC50= 50.3690.020g/ml). The findings in this studydemostrate the potential use of these compounds in medicine and importance of this species, which have largely been used in folk medicine for several diseases' treatment. Halophyte ; Antioxidant ; Traditional medicine ; Chemistry ; High-performance liquid chromatography ; DPPH ; Biology ; Chromatography ; Medicine ; Biochemistry ; Ecology Chromatography in Natural Products
Authors: Elżbieta Regulska | Philip Hindenberg | Adrian Espineira‐Gutierrez | Carlos Romero‐Nieto
Source: Chemistry - A European Journal (article, 2022-10-10)
Field: Chemistry — Organic Chemistry

Synthesis, Post‐Functionalization and Properties of Diphosphapentaarenes Linearly-fused polyarenes are an important class of compounds with high relevance in materials science. While modifying the shape and size represents a common means to fine-tune their properties, the precise placement of heteroatoms is a strategy that is receiving an increasing deal of attention to overcome the intrinsic limitations of all-carbon structures. Thus, linearly-fused diphosphaarenes recently emerged as a novel family of molecules with striking optoelectronic properties and outstanding stability. However, the properties of diphosphaarenes are far from being benchmarked. Herein, we report the synthesis, phosphorus post-functionalization and properties of new diphosphapentaarene derivatives. We describe their synthetic limitations and unveil their potential for optoelectronic applications. Surface modification ; Heteroatom ; Nanotechnology ; Materials science ; Molecule ; Combinatorial chemistry ; Computer science ; Chemistry ; Organic chemistry ; Ring (chemistry) ; Physical chemistry Synthesis and Properties of Aromatic Compounds ; Organoboron and organosilicon chemistry ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
Authors: Huilong Zhu | Junhao Xing | Changhui Wu | Chenhong Wang | Weijun Yao | Xiaowei Dou
Source: Organic Letters (article, 2022-06-30)
Field: Chemistry — Organic Chemistry

Rhodium-Catalyzed Chemodivergent Pyridylation of Alkynes with Pyridylboronic Acids The pyridylation of alkynes with pyridylboronic acids is realized under rhodium catalysis. Chemodivergent pyridylation products, including alkenylpyridines produced via the hydropyridylation pathway and cyclopenta[<i>c</i>]pyridines produced via the pyridylation/cyclization pathway, were selectively produced by fine-tuning the reaction conditions. A mechanistic study revealed that 1,4-rhodium migration to the pyridine ring was involved as the key step in the chemodivergent synthesis. Rhodium ; Chemistry ; Catalysis ; Pyridine ; Ring (chemistry) ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry Catalytic C–H Functionalization Methods ; Catalytic Cross-Coupling Reactions ; Cyclopropane Reaction Mechanisms
Authors: An‐An Zhang | Duan‐Hui Si | Haibo Huang | Lei Xie | Zhi‐Bin Fang | Tian‐Fu Liu | Rong Cao
Source: Angewandte Chemie (article, 2022-04-20)
Field: Chemistry — Inorganic Chemistry

Partial Metalation of Porphyrin Moieties in Hydrogen‐Bonded Organic Frameworks Provides Enhanced CO<sub>2</sub> Photoreduction Activity Abstract In natural photosynthesis, the architecture of multiproteins integrates more chromophores than redox centers and simultaneously creates a well‐controlled environment around the active site. Herein, we demonstrate that these features can be emulated in a prototype hydrogen‐bonded organic framework (HOF) through simply varying the proportion of metalated porphyrin in the structure. Further studies demonstrate that changing the metalloporphyrin content not only realizes a fine tuning of the photosensitizer/catalyst ratio, but also alters the microenvironment surrounding the active site and the charge separation efficiency. As a result, the obtained material achieves the challenging overall CO 2 reduction with a high HCOOH production rate (29.8 μmol g −1 h −1 , scavenger free), standing out from existing competitors. This work unveils that the degree of metalation is vital to the catalytic activity of the porphryinic framework, presenting as a new strategy to optimize the performance of heterogeneous catalysts. Metalation ; Porphyrin ; Catalysis ; Chemistry ; Chromophore ; Photochemistry ; Redox ; Hydrogen production ; Combinatorial chemistry ; Inorganic chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; CO2 Reduction Techniques and Catalysts ; Advanced Photocatalysis Techniques
Authors: Madhuri Beena Sreekumar | Nandhakumar Annadurai | Saranya Jayaram | Suma Sarojini
Source: Topics in Catalysis (article, 2022-11-01)
Field: Chemistry — Organic Chemistry

Industrial Applications of Hybrid Nanocatalysts and Their Green Synthesis Nanomaterial-based catalyst ; Nanotechnology ; Biochemical engineering ; Materials science ; Nanoparticle ; Engineering Nanomaterials for catalytic reactions ; Advanced Photocatalysis Techniques ; TiO2 Photocatalysis and Solar Cells