jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Qingyang Zhou | Garrett A. Kukier | Igor Gordiy | Roald Hoffmann | Jeffrey I. Seeman | K. N. Houk
Source: The Journal of Organic Chemistry (article, 2023-12-28)
Field: Chemistry — Organic Chemistry

A 21st Century View of Allowed and Forbidden Electrocyclic Reactions In 1965, Woodward and Hoffmann proposed a theory to predict the stereochemistry of electrocyclic reactions, which, after expansion and generalization, became known as the Woodward-Hoffmann Rules. Subsequently, Longuet-Higgins and Abrahamson used correlation diagrams to propose that the stereoselectivity of electrocyclizations could be explained by the correlation of reactant and product orbitals with the same symmetry. Immediately thereafter, Hoffmann and Woodward applied correlation diagrams to explain the mechanism of cycloadditions. We describe these discoveries and their evolution. We now report an investigation of various electrocyclic reactions using DFT and CASSCF. We track the frontier molecular orbitals along the intrinsic reaction coordinate and modeled trajectories and examine the correlation between HOMO and LUMO for thermally forbidden systems. We also investigate the electrocyclizations of several highly polarized systems for which the Houk group had predicted that donor-acceptor substitution can induce zwitterionic character, thereby providing low-energy pathways for formally forbidden reactions. We conclude with perspectives on the field of pericyclic reactions, including a refinement as the meaning of Woodward and Hoffmann's "Violations. There are none!" Lastly, we comment on the burgeoning influence of computations on all fields of chemistry. Pericyclic reaction ; Chemistry ; Atomic orbital ; Computational chemistry ; Theoretical physics ; Physics ; Quantum mechanics ; Electron Organic Chemistry Cycloaddition Reactions ; Chemistry and Chemical Engineering ; Computational Drug Discovery Methods
Authors: Alia Colniță | Vlad Alexandru Toma | Ioana Brezeştean | Muhammad Ali Tahir | Nicoleta Elena Dina
Source: Biosensors (review, 2023-04-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A Review on Integrated ZnO-Based SERS Biosensors and Their Potential in Detecting Biomarkers of Neurodegenerative Diseases Surface-enhanced Raman spectroscopy (SERS) applications in clinical diagnosis and spectral pathology are increasing due to the potential of the technique to bio-barcode incipient and differential diseases via real-time monitoring of biomarkers in fluids and in real-time via biomolecular fingerprinting. Additionally, the rapid advancements in micro/nanotechnology have a visible influence in all aspects of science and life. The miniaturization and enhanced properties of materials at the micro/nanoscale transcended the confines of the laboratory and are revolutionizing domains such as electronics, optics, medicine, and environmental science. The societal and technological impact of SERS biosensing by using semiconductor-based nanostructured smart substrates will be huge once minor technical pitfalls are solved. Herein, challenges in clinical routine testing are addressed in order to understand the context of how SERS can perform in real, in vivo sampling and bioassays for early neurodegenerative disease (ND) diagnosis. The main interest in translating SERS into clinical practice is reinforced by the practical advantages: portability of the designed setups, versatility in using nanomaterials of various matter and costs, readiness, and reliability. As we will present in this review, in the frame of technology readiness levels (TRL), the current maturity reached by semiconductor-based SERS biosensors, in particular that of zinc oxide (ZnO)-based hybrid SERS substrates, is situated at the development level TRL 6 (out of 9 levels). Three-dimensional, multilayered SERS substrates that provide additional plasmonic hot spots in the z-axis are of key importance in designing highly performant SERS biosensors for the detection of ND biomarkers. Nanotechnology ; Context (archaeology) ; Biosensor ; Computer science ; Software portability ; Surface-enhanced Raman spectroscopy ; Miniaturization ; Materials science ; Raman spectroscopy ; Raman scattering ; Physics ; Biology Gold and Silver Nanoparticles Synthesis and Applications ; Advanced biosensing and bioanalysis techniques ; Biosensors and Analytical Detection
Authors: Chun‐Wei Chang | Mei‐Huei Lin | Tsun-Yi Chiang | Chia‐Hui Wu | Tzu-Chun Lin | Cheng‐Chung Wang
Source: Science Advances (article, 2023-10-18)
Field: Chemistry — Organic Chemistry

Unraveling the promoter effect and the roles of counterion exchange in glycosylation reaction The stereoselectivity of glycosidic bond formation continues to pose a noteworthy hurdle in synthesizing carbohydrates, primarily due to the simultaneous occurrence of S<sub>N</sub>1 and S<sub>N</sub>2 processes during the glycosylation reaction. Here, we applied an in-depth analysis of the glycosylation mechanism by using low-temperature nuclear magnetic resonance and statistical approaches. A pathway driven by counterion exchanges and reaction byproducts was first discovered to outline the stereocontributions of intermediates. Moreover, the relative reactivity values, acceptor nucleophilic constants, and Hammett substituent constants (σ values) provided a general index to indicate the mechanistic pathways. These results could allow building block tailoring and reaction condition optimization in carbohydrate synthesis to be greatly facilitated and simplified. SN2 reaction ; Glycosidic bond ; Glycosylation ; Chemistry ; Substituent ; Counterion ; Reaction rate constant ; Nucleophile ; Acceptor ; Carbohydrate chemistry ; Reactivity (psychology) ; Nucleophilic substitution ; Stereoselectivity ; Computational chemistry ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Catalysis ; Kinetics ; Biochemistry ; Ion ; Enzyme Carbohydrate Chemistry and Synthesis ; Glycosylation and Glycoproteins Research ; Microbial Metabolites in Food Biotechnology
Authors: Xiankun Zhang | Hang Zhao | Xiaofu Wei | Yanzhe Zhang | Zheng Zhang | Yue Zhang
Source: National Science Open (article, 2023-04-12)
Field: Materials Science — Materials Chemistry

Two-dimensional transition metal dichalcogenides for post-silicon electronics Rapid advancements in information technology push the explosive growth in data volume, requiring greater computing-capability logic circuits. However, conventional computing-capability improving technology, which mainly relies on increasing transistor number, encounters a significant challenge due to the weak field-effect characteristics of bulk silicon-based semiconductors. Still, the ultra-thin layered bodies of two-dimensional transition metal dichalcogenides (2D-TMDCs) materials enable excellent field-effect characteristics and multiple gate control ports, facilitating the integration of the functions of multiple transistors into one. Generally, the computing-capability improvement of the transistor cell in logic circuits will greatly alleviate the challenge in transistor numbers. In other words, only using a small number, or even just one, 2D-TMDCs-based transistors to conduct the sophisticated logic operations that can be realized by many traditional transistors. In this review, from material selection, device structure optimization, and circuit architecture design, we discuss the developments, challenges, and prospects for 2D-TMDCs-based logic circuits. Transition metal ; Silicon ; Electronics ; Materials science ; Nanotechnology ; Metallurgy ; Engineering physics ; Engineering ; Chemistry ; Electrical engineering ; Catalysis 2D Materials and Applications ; Graphene research and applications ; Nanowire Synthesis and Applications
Authors: Hengnian Qi | Zihong Huang | Zeyu Sun | Qizhe Tang | Guangwu Zhao | Xuhua Zhu | Chu Zhang
Source: Frontiers in Plant Science (article, 2023-10-23)
Field: Chemistry — Analytical Chemistry

Rice seed vigor detection based on near-infrared hyperspectral imaging and deep transfer learning Vigor is one of the important factors that affects rice yield and quality. Rapid and accurate detection of rice seed vigor is of great importance for rice production. In this study, near-infrared hyperspectral imaging technique and transfer learning were combined to detect rice seed vigor. Four varieties of artificial-aged rice seeds (Yongyou12, Yongyou1540, Suxiangjing100, and Longjingyou1212) were studied. Different convolutional neural network (CNN) models were built to detect the vigor of the rice seeds. Two transfer strategies, fine-tuning and MixStyle, were used to transfer knowledge among different rice varieties for vigor detection. The experimental results showed that the convolutional neural network model of Yongyou12 classified the vigor of Yongyou1540, Suxiangjing100, and Longjingyou1212 through MixStyle transfer knowledge, and the accuracy reached 90.00%, 80.33%, and 85.00% in validation sets, respectively, which was better or close to the initial modeling performances of each variety. MixStyle statistics are based on probabilistic mixed instance-level features of cross-source domain training samples. When training instances, new domains can be synthesized, which increases the domain diversity of the source domain, thereby improving the generalization ability of the trained model. This study would help rapid and accurate detection of a large varieties of crop seeds. Hyperspectral imaging ; Transfer of learning ; Convolutional neural network ; Artificial intelligence ; Computer science ; Generalization ; Pattern recognition (psychology) ; Machine learning ; Agronomy ; Mathematics ; Biology Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Spectroscopy Techniques in Biomedical and Chemical Research
Authors: Jun Zhang | Zihao Liu | Yaoyuan Pu | Jiajun Wang | Binman Tang | Limin Dai | Shuihua Yu | Ruqing Chen
Source: Processes (review, 2023-02-21)
Field: Chemistry — Analytical Chemistry

Identification of Transgenic Agricultural Products and Foods Using NIR Spectroscopy and Hyperspectral Imaging: A Review Spectroscopy and its imaging techniques are now popular methods for quantitative and qualitative analysis in fields such as agricultural products and foods, and combined with various chemometric methods. In fact, this is the application basis for spectroscopy and spectral imaging techniques in other fields such as genetics and transgenic monitoring. To date, there has been considerable research using spectroscopy and its imaging techniques (especially NIR spectroscopy, hyperspectral imaging) for the effective identification of agricultural products and foods. There have been few comprehensive reviews that cover the use of spectroscopic and imaging methods in the identification of genetically modified organisms. Therefore, this paper focuses on the application of NIR spectroscopy and its imaging techniques (including NIR spectroscopy and hyperspectral imaging techniques) in transgenic agricultural product and food detection and compares them with traditional detection methods. A large number of studies have shown that the application of NIR spectroscopy and imaging techniques in the detection of genetically modified foods is effective when compared to conventional approaches such as polymerase chain reaction and enzyme-linked immunosorbent assay. Hyperspectral imaging ; Chemical imaging ; Imaging spectroscopy ; Spectral imaging ; Spectroscopy ; Imaging spectrometer ; Identification (biology) ; Biotechnology ; Environmental science ; Remote sensing ; Computer science ; Artificial intelligence ; Spectrometer ; Biology ; Geography ; Ecology ; Physics Spectroscopy and Chemometric Analyses ; Identification and Quantification in Food ; Listeria monocytogenes in Food Safety
Authors: Yiran Wang | Matthew L. Nisbet | Kendall R. Kamp | Emily Hiralal | Romain Gautier | P. Shiv Halasyamani | Kenneth R. Poeppelmeier
Source: Journal of the American Chemical Society (article, 2023-07-24)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Beyond π–π Stacking: Understanding Inversion Symmetry Breaking in Crystalline Racemates The design of noncentrosymmetric (NCS) solid state materials, specifically how to break inversion symmetry between enantiomers, has intrigued chemists, physicists, and materials scientists for many years. Because the chemical complexity of molecular racemic building units is so varied, targeting these materials is poorly understood. Previously, three isostructural racemic compounds with a formula of [Cu(H<sub>2</sub>O)(bpy)<sub>2</sub>]<sub>2</sub>[MF<sub>6</sub>]<sub>2</sub>·2H<sub>2</sub>O (bpy = 2,2'=bipyridine; M = Ti, Zr, Hf) were shown to crystallize in the NCS space group <i>Pna</i>2<sub>1</sub>, of polar, achiral crystal class <i>mm</i>2. In this work, we synthesized five new racemic compounds with the formula [Cu(H<sub>2</sub>O)(dmbpy)<sub>2</sub>]<sub>2</sub>[MF<sub>6</sub>]<sub>2</sub>·<i>x</i>H<sub>2</sub>O (dmbpy = 4,4'/5,5'-dimethyl-2,2'-bipyridine; M = Ti, Zr, Hf). Single crystal X-ray diffraction reveals that the five newly synthesized compounds feature equimolar combinations of Δ- and Λ-Cu(dmbpy)<sub>2</sub>(H<sub>2</sub>O)<sup>2+</sup> complexes that are assembled into packing motifs similar to those found in the reported NCS structure but all crystallize in centrosymmetric (CS) space groups. Seven structural descriptors were created to analyze the intermolecular interactions on the assembly of Cu racemates in the CS and NCS structures. The structural analysis reveals that in the CS structures, the inversion center results from parallel heterochiral π-π stacking interactions between adjacent Cu racemates regardless of cation geometries, hydrogen bonding networks, or interlayer architectures, whereas in the NCS structure, nonparallel heterochiral π-π interactions between the adjacent Cu racemates preclude an inversion center. The parallel heterochiral π-π interactions in the CS structures can be rationalized by the restrained geometries of the methyl-substituted ligands. This work demonstrates that the introduction of nonparallel stacking can suppress the formation of an inversion center for an NCS racemate. A conceptual framework and practical approach linking the absence of inversion symmetry in racemates is presented for all NCS crystal classes. Chemistry ; Stacking ; Crystallography ; Isostructural ; Crystal structure ; Enantiomer ; Hydrogen bond ; Intermolecular force ; Space group ; Bipyridine ; Supramolecular chemistry ; Crystal engineering ; Molecule ; Stereochemistry ; Diffraction ; X-ray crystallography ; Organic chemistry Crystal Structures and Properties ; Metal-Organic Frameworks: Synthesis and Applications ; Polyoxometalates: Synthesis and Applications
Authors: Yijun Zhang | Fabrice Morlet‐Savary | Michael Schmitt | Bernadette Graff | Alexandre Rico | Malika Ibrahim‐Ouali | Frédéric Dumur | Jacques Lalevée
Source: Dyes and Pigments (article, 2023-03-09)
Field: Chemistry — Organic Chemistry

Photoinitiation behavior of phenothiazines containing two oxime ester functionalities (OXEs) in free radical photopolymerization and 3D printing application Photoinitiator ; Photopolymer ; Moiety ; Photochemistry ; Stereolithography ; Chemistry ; Polymer chemistry ; Materials science ; Organic chemistry ; Polymerization ; Polymer Photopolymerization techniques and applications ; Advanced Polymer Synthesis and Characterization
Authors: Binal Y. Patel | Hiren K. Patel
Source: Heliyon (article, 2023-09-01)
Field: Chemistry — Analytical Chemistry

Current approaches toward the removal of methylene blue dye from synthetic textile effluent using bacterial treated agricultural waste absorbent through statistical design Massive amounts of wastewater are produced by the textile industry, and this waste needs to be appropriately managed. Agricultural waste wheat straw (WS), a biosorbent that is both economically available and environmentally acceptable, was used in this work to treat textile effluent. Microbial treated modification approaches were utilized for WS to study the dye removal from textile wastewater. Total 15 different isolates were screened for the dye degradation ability from Surat textile industrial effluent. The most significant deterioration was seen in PPSUHB3 when compared to other isolates. The amount of methylene blue dye removal was examined using the isolate PPSUHB3 due to its high efficiency. Based on 16s rDNA sequencing, it was predicted that the isolate PPSUHB3 was <i>Bacillus licheniformis</i>, having great capacity to degrade dye & wheat straw by producing efficient enzyme. The isolate showed the highest decolorization % of MB dye during optimization with WS absorbent which was verified using FTIR and SEM. The dye removal process parameters were statistically optimized using a central composite design (CCD). Wheat straw with particle sizes of 180-250 mm was discovered to be a possible adsorbent for the removal of colour. The maximum removal of MB (55.89%) was obtained using a statistical experimental design at pH 6.36, Temperature 44.6 °C, and Bacteria Concentration 3.04%. The created model is highly significant, according to the ANOVA, which found an R2 value of 0.9812 for it. The validation experiment revealed that the experimental and projected results were strikingly similar. The study found that using bacterial treated wheat straw as an adsorbent may remove wastewater that contains colours at a low cost. Effluent ; Methylene blue ; Textile ; Agriculture ; Agricultural waste ; Waste management ; Pulp and paper industry ; Wastewater ; Environmental science ; Waste treatment ; Engineering ; Environmental engineering ; Chemistry ; Materials science ; Biology ; Organic chemistry ; Ecology ; Composite material Dye analysis and toxicity ; Adsorption and biosorption for pollutant removal ; Dyeing and Modifying Textile Fibers
Authors: Xudong Wang | Wen Zhou | Hangming Zhang | Shehzad Ahmed | Tiankuo Huang | Riccardo Mazzarello | E. Ma | Wei Zhang
Source: npj Computational Materials (article, 2023-08-07)
Field: Materials Science — Materials Chemistry

Multiscale simulations of growth-dominated Sb2Te phase-change material for non-volatile photonic applications Abstract Chalcogenide phase-change materials (PCMs) are widely applied in electronic and photonic applications, such as non-volatile memory and neuro-inspired computing. Doped Sb 2 Te alloys are now gaining increasing attention for on-chip photonic applications, due to their growth-driven crystallization features. However, it remains unknown whether Sb 2 Te also forms a metastable crystalline phase upon nanoseconds crystallization in devices, similar to the case of nucleation-driven Ge-Sb-Te alloys. Here, we carry out ab initio simulations to understand the changes in optical properties of amorphous Sb 2 Te upon crystallization and post annealing. During the continuous transformation process, changes in the dielectric function are highly wavelength-dependent from the visible-light range towards the telecommunication band. Our finite-difference time-domain simulations based on the ab initio input reveal key differences in device output for color display and photonic memory applications upon tellurium ordering. Our work serves as an example of how multiscale simulations of materials can guide practical photonic phase-change applications. Photonics ; Chalcogenide ; Materials science ; Nucleation ; Crystallization ; Amorphous solid ; Dielectric ; Metastability ; Annealing (glass) ; Photonic crystal ; Chalcogenide glass ; Optoelectronics ; Ab initio ; Tellurium ; Phase-change memory ; Nanotechnology ; Chemistry ; Physics ; Crystallography ; Thermodynamics Phase-change materials and chalcogenides ; Chalcogenide Semiconductor Thin Films ; Nonlinear Optical Materials Studies
Authors: Tao Feng | Wei Guo | Wei Li | Zhenghua Meng | Yao Zhu | Feng Zhao | Weicheng Liang
Source: Materials (article, 2023-07-11)
Field: Materials Science — Polymers and Plastics

Unveiling Sustainable Potential: A Life Cycle Assessment of Plant–Fiber Composite Microcellular Foam Molded Automotive Components The development and utilization of new plant-fiber composite materials and microcellular foam molding processes for the manufacturing of automotive components are effective approaches when achieving the lightweight, low-carbon, and sustainable development of automobiles. However, current research in this field has mainly focused on component performance development and functional exploration, with a limited assessment of environmental performance, which fails to meet the requirements of the current green and sustainable development agenda. In this study, based on a life cycle assessment, the resource, and environmental impacts of plant-fiber composite material automotive components and microcellular foam molding processes were investigated. Furthermore, a combined approach to digital twinning and life cycle evaluation was proposed to conduct resource and environmental assessments and analysis. The research results indicate that under current technological conditions, resource and environmental issues associated with plant-fiber composite material automotive components are significantly higher than those of traditional material components, mainly due to differences in their early-stage processes and the consumption of electrical energy and chemical raw materials. It is noteworthy that electricity consumption is the largest influencing factor that causes environmental issues throughout the life cycle, especially accounting for more than 42% of indicators such as ozone depletion, fossil resource consumption, and carbon dioxide emissions. Additionally, the microcellular foam molding process can effectively reduce the environmental impact of products by approximately 15% and exhibits better overall environmental performance compared to chemical foaming. In future development, optimizing the forming process of plant-fiber composite materials, increasing the proportion of clean energy use, and promoting the adoption of microcellular foam injection molding processes could be crucial for the green and sustainable development of automotive components. Composite number ; Materials science ; Composite material ; Automotive industry ; Fiber ; Life-cycle assessment ; Engineering Natural Fiber Reinforced Composites ; Polymer Foaming and Composites ; biodegradable polymer synthesis and properties
Authors: Louise F. Dow | Alfie M. Case | Megan P. Paustian | Braeden Pinkerton | Princess Simeon | Paul C. Trippier
Source: RSC Medicinal Chemistry (review, 2023-01-01)
Field: Chemistry — Organic Chemistry

The evolution of small molecule enzyme activators There is a myriad of enzymes within the body responsible for maintaining homeostasis by providing the means to convert substrates to products as and when required. Physiological enzymes are tightly controlled by many signaling pathways and their products subsequently control other pathways. Traditionally, most drug discovery efforts focus on identifying enzyme inhibitors, due to upregulation being prevalent in many diseases and the existence of endogenous substrates that can be modified to afford inhibitor compounds. As enzyme downregulation and reduction of endogenous activators are observed in multiple diseases, the identification of small molecules with the ability to activate enzymes has recently entered the medicinal chemistry toolbox to afford chemical probes and potential therapeutics as an alternative means to intervene in diseases. In this review we highlight the progress made in the identification and advancement of non-kinase enzyme activators and their potential in treating various disease states. Small molecule ; Enzyme ; Chemistry ; Biophysics ; Biochemistry ; Biology Click Chemistry and Applications ; Histone Deacetylase Inhibitors Research ; Enzyme function and inhibition