jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Mohamed Sy | Emad Al Ibrahim | Aamir Farooq
Source: ACS Omega (article, 2024-09-04)
Field: Chemistry — Spectroscopy

VOC-Certifire: Certifiably Robust One-Shot Spectroscopic Classification via Randomized Smoothing Spectroscopic methods are advantageous for gas detection with applications ranging from safety to operational efficiency. Despite the potential of laser-based sensors, real-world challenges, such as noise, interference and unseen conditions, hinder the accurate identification of species. The use of conventional machine learning (ML) models is constrained by extensive data requirements and their limited adaptability to new conditions. Although augmentation-based strategies have proven to improve the robustness of machine learning models, they still do not offer a complete defense. To address these challenges, this study focuses on three primary goals: first, to detect pressure-induced spectral broadening using simple yet effective augmentations; second, to bypass the need for extensive data sets by deploying a one-shot learning approach that can identify up to 12 volatile organic compounds (VOCs); and third, to provide a provable certification for the one-shot learning model predictions via randomized smoothing. To assess the effectiveness of our proposed augmentations and randomized smoothing, we perform a comparative study with four distinct models: VOC-net, VOC-lite, VOC-plus, and VOC-certifire. Remarkably, the one-shot learning model proposed herein, VOC-certifire, delivers predictions that match the baseline model VOC-net. The VOC-certifire predictions not only exhibit robustness and reliability but are also certified within a predefined norm radius. Such a certification is particularly useful for gas detection, where the robustness, precision and consistency are key to well-informed decision-making. Robustness (evolution) ; Smoothing ; Computer science ; Machine learning ; Artificial intelligence ; Interpretability ; Data mining ; Computer vision Spectroscopy and Laser Applications ; Advanced Chemical Sensor Technologies ; Spectroscopy Techniques in Biomedical and Chemical Research
Authors: Ama tul Zahra | Jamoliddin Razzokov | Muhammad Kashif | Umedjon Khalilov | Haipeng Li | Kun Luo | Aamir Shahzad | Guogang Ren | G. Reza Vakili-Nezhaad
Source: ACS Omega (article, 2024-11-28)
Field: Materials Science — Materials Chemistry

Strained Mechanical and Fracture Analyses of Armchair-Chiral-Zigzag-Based Carbon Nanotubes Using Molecular Dynamics Simulations Carbon nanotubes (CNTs) have emerged as one of the most capable and interesting materials in recent decades and have extraordinary mechanical properties (MPs) and resourceful applications in bioengineering and medicine. Equilibrium molecular dynamics simulations have been performed to investigate the structural and MPs of armchair, chiral, and semiconducting and metallic zigzag single-walled CNTs (SWCNTs) under varying temperature <i>T</i> (K) and compressive and tensile strains ±γ (%) with reactive bond-order potential. New results elaborate on the buckling and deformation mechanisms of the SWCNTs through deep analyses of density profiles, radial distribution functions, structural visualizations, and stress-strain interactions. Density profile and structural visualizations of SWCNTs provide the understanding of atomic arrangements and structural changes under varying ±γ (%) strains. The structure of SWCNT configurations is changed at varying ±γ (%) and <i>T</i> (K) and radial distribution functions present the appropriate peaks for buckling and deformation states. It has been shown that the mechanical responses of different chirality of the SWCNTs clarify the variations in tensile strength in terms of <i>T</i> (K) and chirality. Stress-strain analyses reveal that the metallic zigzag and armchair SWCNTs have superior tensile strength as compared to chiral ones, having the lowest tensile strength. Simulation results show that yield strength, ultimate tensile strength, and Young's modulus are higher for metallic zigzag and armchair SWCNTs at room <i>T</i> (K) and overall decrease with increasing <i>T</i> (K). However, the ultimate strain of semiconducting zigzag and armchair SWCNTs is higher as compared to other configurations, and it reflects the MPs of SWCNTs have to shed light on potential applications in nanotechnology and material sciences. Zigzag ; Carbon nanotube ; Molecular dynamics ; Materials science ; Fracture (geology) ; Nanotechnology ; Carbon fibers ; Chemical physics ; Computational chemistry ; Composite material ; Chemistry ; Geometry ; Mathematics Carbon Nanotubes in Composites ; Graphene research and applications ; Boron and Carbon Nanomaterials Research
Authors: Muhammet Büyükbayram | Sonay Gürer | Yeşim Çat | Oğuzhan Canayakın | Cevher Altuğ | Akın Sağırlı
Source: Flavour and Fragrance Journal (article, 2024-02-29)
Field: Materials Science — Materials Chemistry

Design, synthesis, olfactory evaluation and molecular docking study of Isoxazoline carboxylate derivatives as fragrance molecules Abstract In this research, a wide range of aldoxime derivatives with aromatic and aliphatic substituents were synthesized as precursors to nitrile oxide in cycloaddition reactions. The aldoximes were synthesized with good to high yields and showed a lack of diastereoselectivity, as confirmed by 1 H NMR measurements. These aldoximes were then utilized as precursors of nitrile oxide in 1,3‐dipolar cycloaddition reactions and were treated with dipolarophilic reagents, namely methyl methacrylate (MMA) and glycidyl methacrylate (GMA), to produce isoxazoline carboxylate derivatives with high regioselectivity. The obtained compounds were characterized using various techniques, including NMR, FT‐IR, GC–MS and TOF‐LCMS analyses. The study also targets the molecular docking analysis, using Autodock 4.2.6 software, targeting the OR51E2 protein. This protein has drawn recent attention, with the hypothesis that propionic acid activates OR51E2, making it a suitable candidate for the carboxylate group within the obtained isoxazoline skeleton. Through these multifaceted investigations, this research contributes to the design and development of fragrant molecules with potential applications in the fragrance industry, offering a promising avenue for future olfactory innovations. Chemistry ; Nitrile ; Cycloaddition ; Regioselectivity ; Carboxylate ; Molecule ; Combinatorial chemistry ; 1,3-Dipolar cycloaddition ; Docking (animal) ; Organic chemistry ; AutoDock ; Click chemistry ; Catalysis Photochromic and Fluorescence Chemistry ; Olfactory and Sensory Function Studies ; Biochemical Analysis and Sensing Techniques
Authors: N. Engel | Tim Hoffmann | Florian F. Behrendt | Phil Liebing | Christine Weber | Michael Gottschaldt | Ulrich S. Schubert
Source: Macromolecules (article, 2024-03-12)
Field: Materials Science — Biomaterials

Cryogels Based on Poly(2-oxazoline)s through Development of Bi- and Trifunctional Cross-Linkers Incorporating End Groups with Adjustable Stability 1,4-Bis(iodomethyl)benzene and 1,3,5-tris(iodomethyl)benzene were used as initiators for the cationic ring-opening polymerization (CROP) of 2-ethyl-2-oxazoline (EtOx) and its copolymerization with <i>tert</i>-butyl (3-(4,5-dihydrooxazol-2-yl)propyl)carbamate (BocOx) or methyl 3-(4,5-dihydrooxazol-2-yl)propanoate (MestOx). Kinetic studies confirmed the applicability of these initiators. Termination with suitable nucleophiles resulted in two- and three-armed cross-linkers featuring acrylate, methacrylate, piperazine-acrylamide, and piperazine-methacrylamide as polymerizable ω-end groups. Matrix-assisted laser desorption/ionization mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy confirmed the successful attachment of the respective ω-end groups at all initiation sites for every prepared cross-linkers. Except for acrylate, each ω-end group remained stable during deprotection of BocOx containing cross-linkers. The cryogels were prepared using EtOx-based cross-linkers, as confirmed by solid-state NMR spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Stability tests revealed a complete dissolution of the acrylate-containing gels at pH = 14, whereas the piperazine-acrylamide-based cryogels featured excellent hydrolytic stability. Chemistry ; Polymer chemistry ; Oxazoline ; Copolymer ; Acrylate ; Piperazine ; Thermogravimetric analysis ; Methacrylamide ; Cationic polymerization ; Methacrylate ; Ethyl acrylate ; Methyl acrylate ; Polymerization ; Nucleophilic aromatic substitution ; Acrylamide ; Nucleophilic substitution ; Polymer ; Organic chemistry biodegradable polymer synthesis and properties ; Advanced Polymer Synthesis and Characterization ; Photopolymerization techniques and applications
Authors: Mir Sahanur Ali | Mir Sahidul Ali | Subhasish Mallick | Shubhranshu Bhandari | Mir Intaj Ali | Subhenjit Hazra | Bodhishatwa Roy | Sanatan Chattopadhyay | Srikanta Karmakar | Dipankar Chattopadhyay
Source: Scientific Reports (article, 2024-09-14)
Field: Materials Science — Materials Chemistry

Dual parameter smart sensor for nitrogen and temperature sensing based on defect-engineered 1T-MoS2 In general, defects are crucial in designing the different properties of two-dimensional materials. Therefore large variations in the electric and optical characteristics of two-dimensional layered molybdenum disulphide might be attributed to defects. This study presents the design of a temperature and nitrogen sensor based on few-layer molybdenum disulfide sheets (FLMS), which was developed from bulk MoS<sub>2</sub> (BMS) through an exfoliation approach. The produced sulfur defect, molybdenum defect, line defect, and plane defect were characterized by scanning transmission electron microscopy (STEM), which substantially impacts the sensing characteristics of the resulting FLMS. Our theoretical analysis validates that the sulfur vacancies of the MoS<sub>2</sub> lattice improve sensing performance by promoting effective charge transfer and surface interactions with target analytes. The FLMS-based sensor showed a high sensitivity for detecting nitrogen gas with a detection limit (LOD) of ~ 0.18 ppm. Additionally, temperature-detecting capabilities were assessed over various temperatures, showing outstanding stability and repeatability. To the best of our knowledge, this material is the first of its kind, demonstrating visible N<sub>2</sub> gas sensing with chromic behaviour. Dual (grammatical number) ; Dual role ; Computer science ; Nitrogen ; Materials science ; Chemistry ; Combinatorial chemistry 2D Materials and Applications ; Gas Sensing Nanomaterials and Sensors ; MXene and MAX Phase Materials
Authors: Gottfried Zimmermann | László Sturz | C. Pickmann | Elke Schaberger-Zimmermann | András Roósz | Arnold Rónaföldi | Zsolt Veres | Charles‐André Gandin | G. Reinhart | Henri Nguyen-Thi | Nathalie Mangelinck‐Noël | Sh. McFadden | Gerd‐Ulrich Grün | W.H. Sillekens
Source: Materialia (article, 2024-07-10)
Field: Materials Science — Materials Chemistry

Structures in grain-refined directionally solidified hypoeutectic Al-Cu alloys: Benchmark experiments under microgravity on-board the International Space Station Benchmark solidification experiments were successfully performed under microgravity conditions on-board the International Space Station (ISS) within the ESAprogramme CETSOL (Columnar-to-Equiaxed Transition in SOLidification Processing). Cylindrical samples of grain-refined Al-4wt.%Cu, Al-10wt.%Cu and Al-20wt.%Cu alloys were directionally solidified in a gradient furnace to investigate columnar and equiaxed dendritic growth structures as well as the columnar to equiaxed transition under diffusive conditions. The determination of temperature gradients; interface velocities; and cooling rates at liquidus, solidus, and eutectic front positions provides well-defined thermal experimental characterization. The evaluation of the flight samples demonstrates that no significant macrosegregation along the sample axis occurred and no radial effects were observed. Therefore, purely diffusive solidification behaviour without any residual melt convection can be assumed for these microgravity experiments. The analyses of the microstructure in longitudinal cross-sections show dendritic structures without any pore formation and the averaged eutectic fraction is largely constant along the sample. The samples of refined Al-4wt.%Cu alloy show a sharp CET from columnar dendrites to a fine equiaxed steady-state grain structure whereas in the samples of refined Al-10wt.%Cu and Al-20wt.%Cu alloy, only equiaxed dendritic grain growth is observed. A quantitative analysis of the equiaxed grain morphology shows, that the shapes of the equiaxed dendrites depend on the applied temperature gradient, but the grain sizes in radial and longitudinal directions are identical. Therefore, a fully equiaxed dendritic growth structure without dendrite elongation was obtained. Compared to experiments in microgravity with non-refined Al-Cu alloys the average equiaxed grain size is about three times smaller. Materials science ; Eutectic system ; Metallurgy ; Space (punctuation) ; International Space Station ; Benchmark (surveying) ; Alloy ; Aerospace engineering ; Engineering ; Computer science Solidification and crystal growth phenomena ; Aluminum Alloy Microstructure Properties ; Crystallization and Solubility Studies
Authors: Jianrui Sun | Jinglan Li | Ruirui Ren | Linlin Yao | Tong Li | Jiangfeng Yuan | Dahong Wang
Source: Foods (article, 2024-04-27)
Field: Materials Science — Biomaterials

Effect of Chitosan and Hyperbranched Poly-L-Lysine Treatment on Quality of Cucumber (Cucumis sativus L.) during Storage To enhance the storage time of cucumbers, this research investigated the impact of chitosan (CS) and hyperbranched poly-L-lysine (HBPL) on the quality and nutritional attributes of cucumbers when stored at a temperature of 25 °C. The results demonstrated that sensory evaluation scores for cucumbers treated with a CS-HBPL combination were significantly higher than the control (CK), CS, and HBPL groups. On the 18th day of storage, cucumbers in the CK group exhibited significant decay and softening; however, there was a decrease in hardness observed in the CS-HBPL group and no decay or noticeable sour taste was detected. Furthermore, compared to the CK group, treatment with CS-HBPL effectively delayed cucumber decay and weight loss rate while significantly inhibiting decreases in cucumber hardness and growth of surface microorganisms. Additionally, it substantially reduced losses of soluble protein content as well as vitamin C (Vc), reducing sugars, and total phenolic compounds within cucumbers, which were 4.7 mg/g, 4.7 mg/g, 0.94 mg/g, and 0.52 mg/kg, respectively. Moreover, compared to the CK group, combined treatment with CS-HBPL significantly inhibited malondialdehyde (MDA) accumulation and reducing relative electrolyte permeability within cucumbers, which were 1.45 μmol·g<sup>-1</sup>FW and 29.82%. Furthermore, it notably enhanced activities of superoxide dismutase (SOD) and catalase (CAT), while exerting a significant inhibitory effect on polyphenol oxidase (PPO). In summary, the combined CS-HBPL treatment successfully prolonged cucumber shelf life at room temperature, enabling new possibilities for extending cucumber shelf life. Cucumis ; Chitosan ; Lysine ; Chemistry ; Food science ; Horticulture ; Biology ; Organic chemistry ; Biochemistry ; Amino acid Nanocomposite Films for Food Packaging ; Advances in Cucurbitaceae Research ; Food and Agricultural Sciences
Authors: Mario Rojas-Rodríguez | Sandra Rico‐Martínez | Pedro Prádanos | Cristina Álvarez | Larissa Alexandrova | Young Moo Lee | Ángel E. Lozano | Carla Aguilar‐Lugo
Source: Macromolecules (article, 2024-08-06)
Field: Materials Science — Polymers and Plastics

Thermally Rearranged (TR) Polybenzoxazoles from <i>o</i>-Substituted Precursor Polyimides with Phenyl Pendant Groups: Synthesis, Properties, and Thermal Rearrangement Conditions A series of polyimides (PIs) was synthesized from 6FDA and two <i>o</i>-OH substituted diamines having bulky pendant phenyl, Ph, and trifluoromethyl, CF<sub>3</sub>, groups as precursors for thermally rearranged polybenzoxazole, TR-PBO, membranes. One diamine had two pendant Ph substituents; in the other, the substituents were Ph and CF<sub>3</sub>. Applying azeotropic and chemical cyclizations allowed the obtention of four <i>o</i>-hydroxy (<i>o</i>-OH) or/and <i>o</i>-acetoxy (<i>o</i>-OAc) substituted PIs depending on the imidization method. The PIs were labeled as 3Ph-OH, 4Ph-OH, or 3Ph-OAc and 4PH-OAc, respectively. Thermal rearrangements of all four precursors were investigated in the interval from 350 to 450 °C. The conversions to TR-PBO increased with temperature, and almost quantitative conversions were obtained at temperatures close to 450 °C, although <i>o</i>-OH substituted PIs reached conversions slightly higher than those of <i>o</i>-OAc PIs at a given temperature. The TR-polymers' fractional free volume (FFV) also increased with conversion but was higher for the <i>o</i>-OAc substituted precursors. Despite the high TR-PBO conversions, self-supported uniform TR membranes with reasonable mechanical properties were obtained, except for 4Ph-OH. Gas separation behavior of the membranes significantly improved after the thermal treatment, and the final CO<sub>2</sub>/CH<sub>4</sub> permselectivities lay between the 1991 and 2008 Robeson upper bounds. Particularly, TR-membranes derived from <i>o</i>-OAc precursors and with pendant CF<sub>3</sub> group demonstrated better gas transport properties with values of <i>P</i> <sub>(CO2)</sub> = 1121 barrer and α<sub>CO2/CH4</sub> = 29 for 3Ph-OAc derived membrane, which positioned it beyond the 2008 upper limit. Polymer chemistry ; Thermal ; Chemistry ; Physics Synthesis and properties of polymers ; Membrane Separation and Gas Transport ; Epoxy Resin Curing Processes
Authors: James F. Amaku | Kabir O. Oyedotun | Nobanathi Wendy Maxakato | Kovo G. Akpomie | Emmanuel Sunday Okeke | Chijioke Olisah | Alhadji Malloum | Kayode Adesina Adegoke | Joshua O. Ighalo | Jeanet Conradie | Chinemerem R. Ohoro
Source: Chemistry Africa (article, 2024-01-23)
Field: Chemistry — Analytical Chemistry

Aqueous Phase Removal of Tartrazine Abstract In this study, published articles on the adsorptive removal of tartrazine from the aqueous phase were reviewed. Adsorbents sustaining both intercalating and photodegradation characteristics were also assessed. Besides collating available information on adsorbents employed for tartrazine removal, experimental conditions (solution temperature, pH, dosage, initial concentration, and agitation period) relating to the adsorptive removal of tartrazine were discussed. Deduction from kinetic, isotherms and thermodynamics data acquired from different adsorbents were assessed. Granular activated carbon and chitosan adsorbents had the least and highest tartrazine removal capacity. Lower solution pH majorly favoured the adsorption of tartrazine. On the other hand, increased dosage, contact time, initial concentration, and solution temperature generally enhanced the adsorptive uptake of tartrazine. Pseudo-second-order kinetics model was observed to typically describe the kinetic data. Freundlich and Langmuir isotherm models were popularly observed to best describe the tartrazine adsorption equilibrium. The uptake of tartrazine was generally spontaneous with the exception of a few nanocomposites. Meanwhile, π-π stacking, hydrogen bonding, Van der Waals forces and electrostatic interactions were proposed as possible mechanisms for the adsorption of tartrazine from wastewater. Adsorbents demonstrated good regeneration tendency with NaOH. Hence, it was concluded that the batch adsorption technique is economically viable and should be scaled up for industrial applications. Meanwhile, future work on tartrazine adsorption should employ real wastewater samples, regenerate adsorbents for reuse, design and execute a pilot scale assessment, employ column adsorption technique and formulate policy to regulate effluent discharge. Tartrazine ; Aqueous solution ; Phase (matter) ; Chemistry ; Environmental science ; Chromatography ; Organic chemistry Dye analysis and toxicity ; Adsorption and biosorption for pollutant removal ; Electrochemical sensors and biosensors
Authors: Syeda Khair-ul-Bariyah | Muhammad Sarfraz | Muhammad Sohail Arshad | Amir Waseem | Hidayat Ullah Khan | Shahnaz Khan | Ahsan Sharif | Zahoor H. Farooqi | Ejaz Ahmed
Source: Heliyon (article, 2024-07-20)
Field: Chemistry — Organic Chemistry

Synthesis of 2-aminothiazole sulfonamides as potent biological agents: Synthesis, structural investigations and docking studies A simplified synthetic approach involving sulfonylation followed by amino group alkylation produced new 2-aminothiazole derivatives. UV/Vis, infrared, and NMR spectroscopies confirmed their structures. Compounds <b>36</b>, <b>22</b>, <b>34</b>, and <b>35</b> showed strong inhibition against Jack bean and Bacillus Pasteurii urease, with IC<sub>50</sub> values from 14.06 to 20.21 μM/mL. Compounds <b>20</b>, <b>26</b>, <b>21</b>, <b>29</b>, <b>30</b>, <b>31</b>, and <b>32</b> exhibited potent inhibitory effects against α-glucosidase and α-amylase, with IC<sub>50</sub> values between 20.34 and 37.20 μM/mL. Compounds <b>33</b>, <b>26</b>, and <b>27</b> demonstrated potent DPPH scavenging, with IC<sub>50</sub> values around 34.4-39.2 μM/mL. FMO analysis showed compounds <b>21</b>, <b>22</b>, <b>24</b>, and <b>25</b> having parallel aromatic ring systems due to π cloud interactions, while compounds <b>32</b> and <b>38</b> had distinct electronic density distributions. Compound <b>22</b> had HOMO and LUMO energy gaps of 5.805 eV, with bromo and fluoro substitutions in compounds <b>21</b> and <b>24</b> slightly increasing the gaps to 6.089 eV and 6.078 eV, respectively. Nitro groups in compounds <b>25</b> and <b>32</b> reduced the gaps to 0.384 eV and 1.187 eV. All compounds demonstrated high gastrointestinal absorption, non-permeability to the blood-brain barrier, and optimal skin permeation (Log Kp between -5.83 and -6.54 cm/s). Compounds <b>22</b>, <b>24</b>, and <b>38</b> had promising QED scores of 0.719, 0.707, and 0.860, respectively, with synthetic accessibility scores from 2.057 to 2.517. ADMET predictions indicated minimal toxicity, cardiovascular safety, and significant inhibitory potential for CYP enzymes. Strong in silico binding affinities (binding energies -5.75 to -7.63 kcal/mol) and metabolic stability suggest these derivatives are promising candidates for further drug development. Docking (animal) ; Chemistry ; Combinatorial chemistry ; Computational biology ; Stereochemistry ; Pharmacology ; Biology ; Medicine Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Enzyme function and inhibition