jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Sergey V. Sokolkov
Source: Electrochemical Science Advances (article, 2022-02-24)
Field: Chemistry — Electrochemistry

Evolution of the analytical signal in electrochemistry from electrocapillary curve to a digital electrochemical pattern of a multicomponent sample Abstract The number of publications on the electrochemical analysis of liquids increases year by year. The growth of publication activity is largely due to the development of new biosensors and the introduction of nanomaterials into the practice of electrochemical analysis. It is not the task of the author to review the entire array of publications, since the basic principles of electrochemical analysis in most publications remain practically unchanged. The purpose of this critical review is to find answers to two important questions for the development of electroanalysis. First, are all of the used electrochemical methods providing a measurement in the strict metrological sense of this term? That is, do they provide the necessary accuracy, validity, reliability, and reproducibility of the measurement results? Secondly, is electroanalytics capable of meeting the challenge of the information revolution by significantly increasing the information efficiency of each individual measurement? To answer these questions, we will identify the main sources of sensor signal noise by considering the electrochemical sensor as the primary decoder of “chemical information” into an analytical signal. Then we will evaluate the information efficiency of various measurement methods by using the approach of thermodynamics of information processes and considering a sensor as an open thermodynamic system. Electrochemical noise ; Metrology ; Reproducibility ; Computer science ; Reliability (semiconductor) ; SIGNAL (programming language) ; Sample (material) ; Characterization (materials science) ; Electrochemistry ; Nanotechnology ; Analytical Chemistry (journal) ; Electrode ; Materials science ; Chemistry ; Mathematics ; Power (physics) ; Physics ; Statistics ; Thermodynamics ; Environmental chemistry ; Physical chemistry ; Chromatography Electrochemical Analysis and Applications ; Advanced Chemical Sensor Technologies ; Analytical Chemistry and Sensors
Authors: Agus Arip Munawar | Devianti Devianti | Purwana Satriyo | Shahril Anuar Bahari
Source: Acta Technologica Agriculturae (article, 2022-03-01)
Field: Chemistry — Analytical Chemistry

Near Infrared Spectroscopy: Rapid and Simultaneous Approach to Predict the Fixed Carbon, Volatile Matter and Ash Contents in Biochar Produced from Agricultural Residues Abstract Presented paper aimed to employ the near infrared spectroscopy (NIRS) as a rapid and simultaneous method for quality assessment of biochar samples made of agricultural waste materials (chatter bamboo; firewood; coconut shell). Spectral data were obtained in the wavelength range of 1000–2500 nm, while actual fixed carbon, volatile matter and ash contents were observed using standard chemical analysis. Moreover, prediction models were established using two different regression approaches: principal component regression and partial least square regression. Prediction performances were evaluated by assessment of several statistical indicators, such as correlation coefficient and ratio of prediction to deviation index. The results showed that PLS generated a better prediction performance with maximum r coefficient and RPD index – 0.89 and 2.26 for fixed carbon; 0.93 and 2.84 for volatile matter; 0.90 and 2.30 for ash content. Based on the results acquired, it can be concluded that NIRS is usable for the purposes of a rapid and simultaneous approach to biochar quality determination. Biochar ; Partial least squares regression ; Coefficient of determination ; Carbon fibers ; Linear regression ; Environmental science ; Principal component regression ; Principal component analysis ; Firewood ; Correlation coefficient ; Mathematics ; Chemistry ; Statistics ; Waste management Spectroscopy and Chemometric Analyses ; Water Quality Monitoring and Analysis ; Spectroscopy Techniques in Biomedical and Chemical Research
Authors: Tao Cheng | Sen Guo | Zhenggao Pan | Shuxiang Fan | Shucun Ju | Zhenghua Xin | Xin‐Gen Zhou | Fei Jiang | Dongyan Zhang
Source: Agriculture (article, 2022-10-05)
Field: Chemistry — Analytical Chemistry

Near-Infrared Model and Its Robustness as Affected by Fruit Origin for ‘Dangshan’ Pear Soluble Solids Content and pH Measurement Soluble solid content (SSC) and acidity (pH) are two important factors indicating the fruit quality of pears and can be measured by near-infrared spectroscopy (NIRS). However, the robustness of these measurements as affected by different origins of pears remains largely unknown. In this study, we developed an NIRS method to measure ‘Dangshan’ pear (Pyrus spp.) SSC and pH and evaluated the robustness of this non-destructive detection method by examining the effects of pears from three different origins in 2019 and 2020. First, the Kennard–Stone method was used to divide the calibration set of the 2020 pear samples from different orchards. The partial least squares (PLS) model was used to establish the local origin and hybrid origin models to predict the pears’ SSC and pH. Second, a combination of competitive adaptive reweighted sampling (CARS), successive projections algorithm (SPA), and uninformative variable elimination (UVE) was implemented to construct spectral prediction models based on effective variables for assessing the pears’ SSC and pH from local and hybrid origins. The results showed that the local origin detection model produced large errors in predicting the SSC and pH of pears from different origins, and the model, established based on the pear samples of three origins, performed better than the local origin and other hybrid origin models. Finally, the model could be effectively simplified using 70 and 52 characteristic variables selected by the CARS method. Pear samples harvested from three different orchards in 2019 were used as an independent set to verify the validity of the selected characteristic variables. The results showed that the predicted R2p for the SSC and pH measurements of pears of three different origins were more than 0.9 and 0.85, respectively. This finding indicates that the difference in the origin of pears has an important influence on the quantitative inversion of pear SSC and pH measurements, and the combination of the hybrid origin model constructed based on the characteristic variables can improve the prediction accuracy. These findings provide an important theoretical basis for the development of rapid detection devices for the measurements of pears’ SSC and pH. PEAR ; Partial least squares regression ; Robustness (evolution) ; Mathematics ; Pyrus communis ; Chemistry ; Pera ; Statistics ; Botany ; Horticulture ; Biological system ; Biology Spectroscopy and Chemometric Analyses ; Essential Oils and Antimicrobial Activity ; Horticultural and Viticultural Research
Authors: Noureddine Boumdouha | ZITOUNI SAFIDINE | ACHRAF BOUDIAF
Source: TURKISH JOURNAL OF CHEMISTRY (article, 2022-01-01)
Field: Materials Science — Polymers and Plastics

A new study of dynamic mechanical analysis and the microstructure of polyurethanefoams filled Polyurethane foams have good shock-absorbing properties. This article discusses the study of the physical, dynamic analysis, and microstructure of filled polyurethane foams (PUR). We used mineral fillings nanoparticles of titanium dioxide (TiO<sub>2</sub>) and calcium carbonate (C1) to support and strengthen the foam cell structure to develop shock absorption and thermal resistance properties. Dynamic mechanical analysis (DMA) and compression tests compared the mechanic characterization results with different modelling approaches. For studies of physicochemical properties, we used differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). We deduced the flame retardancy mechanism. It appears that a detailed description of the characteristics of viscosity and yield stress must take into consideration the filler's size in comparison to the cell wall's size. The effect of size distribution on the foam's microstructure was given by scanning electron microscopy (SEM). Half-open spherical cells were shown to be reduced in size with filling. The filler diffusion in polyurethane foams was used to model the composite foam. We observed that crystalline filler particles were uniformly distributed in the matrix, indicating that the total size is related to the density and is a crucial metric for the level of reinforcement. Thermogravimetric analysis ; Microstructure ; Differential scanning calorimetry ; Polyurethane ; Composite material ; Scanning electron microscope ; Dynamic mechanical analysis ; Materials science ; Chemistry ; Polymer Flame retardant materials and properties ; Polymer composites and self-healing ; Polymer Nanocomposites and Properties
Authors: Benjamin Le Droumaguet | Mohamed Guerrouache | Benjamin Carbonnier
Source: Macromolecular Rapid Communications (review, 2022-06-14)
Field: Chemistry — Organic Chemistry

Contribution of the “Click Chemistry” Toolbox for the Design, Synthesis, and Resulting Applications of Innovative and Efficient Separative Supports: Time for Assessment The last two decades have seen the rapid expansion of click chemistry methodology in various domains closely related to organic chemistry. It has notably been widely developed in the area of surface chemistry, mainly because of the high-yielding character of reactions of the "click" type. Especially, this powerful chemical reaction toolbox has been adapted to the preparation of stationary phases from the corresponding chromatographic supports. A plethora of selectors can thus be immobilized on either organic, inorganic, or hybrid stationary phases that can be used in different chromatographic modes. This review first highlights the few different chemical ligation strategies of the "click" type that are up to now mainly devoted to the development of functionalized supports for separation sciences. Then, it gives in a second part an up-to-date survey of the different studies dedicated to the preparation of click chemistry-based chromatographic supports while highlighting the powerful and versatile character of the "click" ligation strategy for the design, synthesis, and developments of more and more complex systems that can find promising applications in the area of analytical sciences, in domains as varied as enantioselective separation, glycomics, proteomics, genomics, metabolomics, etc. Click chemistry ; Toolbox ; Glycomics ; Computer science ; Chemistry ; Nanotechnology ; Combinatorial chemistry ; Proteomics ; Materials science ; Programming language Click Chemistry and Applications ; Monoclonal and Polyclonal Antibodies Research ; Chemical Synthesis and Analysis
Authors: Jaina A. Bhayani | Maria Josefina Iglesias | Romina I. Minen | Antonela E. Cereijo | Miguel A. Ballícora | Alberto Á. Iglesias | Matías D. Asención Diez
Source: Frontiers in Microbiology (article, 2022-04-27)
Field: Materials Science — Materials Chemistry

Carbohydrate Metabolism in Bacteria: Alternative Specificities in ADP-Glucose Pyrophosphorylases Open Novel Metabolic Scenarios and Biotechnological Tools We explored the ability of ADP-glucose pyrophosphorylase (ADP-Glc PPase) from different bacteria to use glucosamine (GlcN) metabolites as a substrate or allosteric effectors. The enzyme from the actinobacteria <i>Kocuria rhizophila</i> exhibited marked and distinctive sensitivity to allosteric activation by GlcN-6P when producing ADP-Glc from glucose-1-phosphate (Glc-1P) and ATP. This behavior is also seen in the enzyme from <i>Rhodococcus</i> spp., the only one known so far to portray this activation. GlcN-6P had a more modest effect on the enzyme from other Actinobacteria (<i>Streptomyces coelicolor</i>), Firmicutes (<i>Ruminococcus albus</i>), and Proteobacteria (<i>Agrobacterium tumefaciens</i>) groups. In addition, we studied the catalytic capacity of ADP-Glc PPases from the different sources using GlcN-1P as a substrate when assayed in the presence of their respective allosteric activators. In all cases, the catalytic efficiency of Glc-1P was 1-2 orders of magnitude higher than GlcN-1P, except for the unregulated heterotetrameric protein (GlgC/GgD) from <i>Geobacillus stearothermophilus</i>. The Glc-1P substrate preference is explained using a model of ADP-Glc PPase from <i>A. tumefaciens</i> based on the crystallographic structure of the enzyme from potato tuber. The substrate-binding domain localizes near the N-terminal of an α-helix, which has a partial positive charge, thus favoring the interaction with a hydroxyl rather than a charged primary amine group. Results support the scenario where the ability of ADP-Glc PPases to use GlcN-1P as an alternative occurred during evolution despite the enzyme being selected to use Glc-1P and ATP for α-glucans synthesis. As an associated consequence in such a process, certain bacteria could have improved their ability to metabolize GlcN. The work also provides insights in designing molecular tools for producing oligo and polysaccharides with amino moieties. Streptomyces coelicolor ; Allosteric regulation ; Biochemistry ; Enzyme ; Biology ; Bacteria ; Substrate (aquarium) ; Chemistry ; Mutant Enzyme Structure and Function ; Glycosylation and Glycoproteins Research ; Enzyme Production and Characterization
Authors: Lingyu Guo | Chu Han | Liangyuan Ren | Wenchao Yang | Annan Yin
Source: Metals (article, 2022-03-28)
Field: Materials Science — Materials Chemistry

Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field Study The columnar-to-equiaxed transition (CET) is commonly observed in laser welds. It is able to prevent the growth of large columnar grains and consequently improve the mechanical properties of welded joints. In this paper, the CET behaviors at different locations in the laser weld of an Al–Mg alloy are observed experimentally and studied systematically. In order to describe the dynamic CET behaviors, an integrated phase-field (PF) model coupled with transient thermal conditions and a Gaussian heterogeneous nucleation model is developed. Investigations on columnar growth under steady conditions are performed first. In particular, the effects of thermal conditions, i.e., solidification rate and temperature gradient, on the constitutionally undercooled degree and region ahead of the solidification front are quantitatively studied. In a laser weld, it is found that the CET behaviors vary significantly along the thickness direction. Our PF simulation results indicate that the CET depends strongly on the locally transient thermal conditions in the fusion zone. The transient thermal conditions affect CET behaviors by dynamically adjusting the constitutionally undercooled degree and region during the solidification process. The predicted CET behaviors under transient conditions exhibit reasonably good agreements with corresponding experimental results. Equiaxed crystals ; Materials science ; Nucleation ; Transient (computer programming) ; Temperature gradient ; Welding ; Thermal ; Laser ; Phase transition ; Phase (matter) ; Weld pool ; Mechanics ; Alloy ; Composite material ; Condensed matter physics ; Optics ; Thermodynamics ; Chemistry ; Physics ; Arc welding Solidification and crystal growth phenomena ; Aluminum Alloy Microstructure Properties ; Metallurgy and Material Forming
Authors: Zhen‐Nan Shen | Yuxuan Xu | Chenyu Wang | Bo Qiao
Source: ChemPhotoChem (article, 2022-02-13)
Field: Materials Science — Materials Chemistry

Fine‐Tuning the Thermal Relaxation Dynamics of Indigo‐Based Photoswitches Using Selective Non‐Covalent Interactions Without Chemical Modification Abstract Understanding the thermal relaxation dynamics of photoswitches is of crucial importance when considering application scenarios. Strategies for regulating the thermal relaxation rates of photoswitches have been mostly limited to modifying the chemical structures. Herein we demonstrate a complementary method of manipulating the thermal relaxation rate of indigo‐based photoswitches that does not require chemical modification. We used indigo‐based photoswitches in aprotic solvents as a model system to demonstrate this strategy. Our method creates a deactivated pathway that extends the thermal relaxation half‐life by selectively stabilizing the parent structure of the metastable Z ‐isomer via non‐covalent interaction. In addition, by establishing a quantitative kinetic model, we showed that controlling the strength of such selective stabilization enables fine‐tuning of the thermal relaxation rates to precisely access to targeted values. Covalent bond ; Relaxation (psychology) ; Thermal ; Metastability ; Chemical physics ; Chemistry ; Chemical modification ; Nanotechnology ; Materials science ; Physical chemistry ; Thermodynamics ; Organic chemistry ; Physics Photochromic and Fluorescence Chemistry ; Photoreceptor and optogenetics research ; Supramolecular Self-Assembly in Materials
Authors: Archana V. Raveendran | Chinna Ayya Swamy P
Source: New Journal of Chemistry (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Fine-tuning the acceptor–donor ability of star shaped triarylborane–triphenylamine conjugates: synthesis, characterization and anion binding studies A modest approach to design and synthesize functionalized triarylborane–triarylamine based donor–acceptor systems, compounds 1–3 , and the investigation of the photophysical, solvatochromic, solid state emissive and anion binding properties. Chemistry ; Triphenylamine ; Acceptor ; Combinatorial chemistry ; Conjugate ; Characterization (materials science) ; Star (game theory) ; Ion ; Stereochemistry ; Photochemistry ; Nanotechnology ; Organic chemistry Luminescence and Fluorescent Materials ; Organoboron and organosilicon chemistry ; Molecular Sensors and Ion Detection
Authors: Hsin‐Wei Su | Junfeng Zhou | Seiyoung Yoon | Junpeng Wang
Source: Chemistry - An Asian Journal (article, 2022-12-19)
Field: Materials Science — Biomaterials

Evaluating <i>Trans</i>‐Benzocyclobutene‐Fused Cyclooctene as a Monomer for Chemically Recyclable Polymer Chemically recyclable polymers offer a promising solution to address the issues associated with the unsustainable use of plastics by converting the traditional linear plastic economy into a circular one. Central to developing chemically recyclable polymers is to identify the appropriate monomers that enable practical conditions for polymerization and depolymerization and ensure useful stability and material properties. Our group has recently demonstrated that trans-cyclobutane-fused cyclooctene (tCBCO) meets the abovementioned requirements and is a promising candidate for developing chemically recyclable polymers. Herein, encouraged by the success with tCBCO, we investigate the thermodynamics of polymerization of a relevant system, trans-benzocyclobutene-fused-cyclooctene, which can be viewed as tCBCO with an additional benzene ring. The study shows that introducing an additional benzene ring favors polymerization and disfavors depolymerization, and the effect is predominantly entropic. The benzo-effect can be leveraged to fine-tune the thermodynamics of polymerization and depolymerization to facilitate the chemical recycling of polymers. Depolymerization ; Polymerization ; Polymer ; Benzocyclobutene ; Monomer ; Cyclooctene ; Materials science ; Polymer chemistry ; Polymer science ; Chemistry ; Organic chemistry ; Catalysis biodegradable polymer synthesis and properties ; Chemistry and Chemical Engineering
Authors: David DiMeglio | Xinqi Zhou | Tatiana Wirth | Frederik Brøndsted | Lauren Lesiak | Fang Yuan | Mehrdad Shadmehr | Cliff I. Stains
Source: Chemistry - A European Journal (article, 2022-10-25)
Field: Chemistry — Organic Chemistry

Experimentally Calibrated Computational Prediction Enables Accurate Fine‐Tuning of Near‐Infrared Rhodamines for Multiplexing A significant barrier inhibiting multiplexed imaging in the near-infrared (NIR) is the extensive trial and error associated with fine-tuning NIR dyes. In particular, the need to synthesize and experimentally evaluate dye derivatives in order to empirically identify those that can be used in multiplexing applications, requires a large investment of time. While coarse-tuning efforts benefit from computational prediction that can be used to identify target dye structures for synthetic campaigns, errors in computational prediction remain too large to accurately parse modifications aimed at fine-tuning changes in dye absorbance and emission. To address this issue, we screened different levels of theory and identified a time-dependent density functional theory (TD-DFT) approach that can rapidly, as opposed to synthesis and experimental evaluation, estimate absorbance and emission. By calibrating these computational estimations of absorbance and emission to experimentally determined parameters for a panel of existing NIR dyes, we obtain calibration curves that can be used to accurately predict the effect of fine-tuning modifications in new dyes. We demonstrate the predictive power of this calibrated dataset using seven previously unreported dyes, obtaining mean percent errors in absorbance and emission of 2.2 and 2.8 %, respectively. This approach provides a significant timesavings, relative to synthesis and evaluation of dye derivatives, and can be used to focus synthetic campaigns on the most promising dye structures. The new dyes described herein can be utilized for multiplexed imaging, and the experimentally calibrated dataset will provide the dye chemistry community with a means to rapidly identify fine-tuned NIR dyes in silico to guide subsequent synthetic campaigns. Absorbance ; Multiplexing ; Near-infrared spectroscopy ; Calibration ; Computer science ; Biological system ; Materials science ; Optics ; Telecommunications ; Physics Radical Photochemical Reactions ; Free Radicals and Antioxidants ; Luminescence Properties of Advanced Materials
Authors: Daniel Sánchez‐deAlcázar | Andoni Rodriguez‐Abetxuko | Ana Beloqui
Source: ACS Applied Materials & Interfaces (article, 2022-06-08)
Field: Materials Science — Materials Chemistry

Metal–Organic Enzyme Nanogels as Nanointegrated Self-Reporting Chemobiosensors A fluorometric glucose biosensor based on fine-tuned chemoenzymatic nanohybrids is herein proposed. The successful integration of an engineered glucose oxidase enzyme and an optically responsive polymeric nanogel in a single entity has led to the fabrication of a highly efficient glucose chemobiosensor. The optical responsiveness has been achieved by the loading of preactivated polymeric hydrogel with fluorescent lanthanide, i.e., cerium (III), cations. A comprehensive investigation of the responsiveness of the biomaterial revealed the interplay between the oxidation state of the cerium lanthanide and the fluorescence emission of the polymer. Finally, a full structural, chemical, and biochemical characterization of the reported system supports the chemobiosensors as robust, specific, and sensitive materials that could be utilized to faithfully quantify the amount of glucose in tear fluids. Glucose oxidase ; Materials science ; Biosensor ; Cerium ; Lanthanide ; Fluorescence ; Nanogel ; Nanotechnology ; Polymer ; Biomaterial ; Combinatorial chemistry ; Chemical engineering ; Organic chemistry ; Drug delivery ; Chemistry Advanced Nanomaterials in Catalysis ; Electrochemical sensors and biosensors ; Molecular Sensors and Ion Detection