jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Beatriz Rosales‐Reina | Diego López‐Torres | Guillermo Cruz‐Quesada | Maialen Espinal‐Viguri | César Elosúa | Santiago Reinoso | Julián J. Garrido
Source: Advanced Functional Materials (article, 2024-10-20)
Field: Chemistry — Organic Chemistry

Tuning the Sensitivity of Photonic Sensors Toward Alkanes Through the Textural Properties of Hybrid Xerogel Coatings Abstract This work exemplifies how incorporating organosilane modifiers into silica matrices allows for tuning the optical response of reflection photonic sensors through customizing the textural properties of hybrid xerogel sensing films. Xerogels with propyl molar percentages 0, 5, and 10% are used to construct photonic probes (OFS0pTEOS, OFS5pTEOS and OFS10pTEOS, respectively) by dip‐coating upon optimizing film deposition parameters. The time response of these probes toward a battery of volatile organic compounds (VOCs) comprising species with different functionality, size‐shape, and polarity is systematically analyzed through ON/OFF experiments, revealing that a low propyl content makes the poor‐responding OFS0pTEOS film highly sensitive toward non‐aromatic, large molecules with low‐polar or non‐polar character in OFS5pTEOS. This sensor is particularly sensitive toward alkanes, with globular cyclohexane (cyHex) outperforming elongated n ‐hexane. Variable‐temperature calibration curves obtained from step‐by‐step experiments and adsorption–desorption cycles corroborate these observations and allow hysteresis to be quantified. The response to cyHex closely follows VOC concentration changes with the most stable signal among analytes, leading to well‐defined curves with low‐to‐negligible hysteresis. The isosteric enthalpies of cyHex adsorption are obtained for both the bulk material and the sensor, demonstrating labile adsorbate‐adsorbent interactions ruling the sensor response and becoming more exothermic for larger VOC concentrations. Materials science ; Sensitivity (control systems) ; Nanotechnology ; Photonics ; Optoelectronics ; Electronic engineering Polydiacetylene-based materials and applications ; Conducting polymers and applications ; Advanced Chemical Sensor Technologies
Authors: Adrian Vågberg | Martin Brunzell | Max Widarsson | Patrick Mutter | Andrius Žukauskas | Fredrik Laurell | Valdas Pašiškevičius
Source: EPJ Web of Conferences (article, 2024-01-01)
Field: Chemistry — Spectroscopy

Backward Wave Optical Parametric Oscillator Targeting CO<sub>2</sub> Absorption Lines at 2.7µm The first demonstration of a 2.7 µm CO 2 gas sensing source exploiting a backward wave optical parametric oscillator (BWOPO). Transmission measurements of the backward wave are demonstrated through air with good agreement with simulations. Optical parametric oscillator ; Absorption (acoustics) ; Parametric oscillator ; Parametric statistics ; Physics ; Atomic physics ; Optics ; Telecommunications ; Engineering ; Laser ; Mathematics Spectroscopy and Laser Applications ; Laser Design and Applications ; Solid State Laser Technologies
Source: Pakistan Veterinary Journal (article, 2024-01-01)
Field: Chemistry — Organic Chemistry

Bufalin Promotes Apoptosis and Autophagy Through the JAK-STAT Signaling Pathway inMyeloid Leukemia Myeloid leukemia ; Apoptosis ; Autophagy ; stat ; Signal transduction ; JAK-STAT signaling pathway ; Leukemia ; Cancer research ; Myeloid ; Medicine ; Biology ; Immunology ; Cell biology ; STAT3 ; Biochemistry Quinazolinone synthesis and applications ; Synthesis and biological activity ; Cytokine Signaling Pathways and Interactions
Authors: Levi G. Walls | Merel L. R. van ’t Hoff | Edwin A. Bergin
Source: arXiv (Cornell University) (preprint, 2024-07-31)
Field: Chemistry — Spectroscopy

Chemical abundance gradients of organic molecules within a protostellar disk Observations of low-mass protostellar systems show evidence of rich complex organic chemistry. Their low luminosity, however, makes determining abundance distributions of complex organic molecules (COMs) within the water snowline challenging. However, the excitation conditions sampled by differing molecular distributions may produce substantive changes in the resulting emission. Thus, molecular excitation may recover spatial information from spatially unresolved data. By analyzing spatially-unresolved NOrthern Extended Millimeter Array (NOEMA) observations of CH$_3$OH and CH$_3$CN, we aim to determine if CH$_3$OH and CH$_3$CN are distributed differently in the protostellar disk around HOPS-370, a highly-luminous intermediate mass protostar. Rotational diagram analysis of CH$_3$OH and CH$_3$CN yields rotational temperatures of $198 \pm 1.2$ K and $448 \pm 19$ K, respectively, suggesting the two molecules have different spatial distributions. Source-specific 3D LTE radiative transfer models are used to constrain the spatial distribution of CH$_3$OH and CH$_3$CN within the disk. A uniform distribution with an abundance of $4\times10^{-8}$ reproduces the CH$_3$OH observations. In contrast, the spatial distribution of CH$_3$CN needs to be either more compact (within $\sim120$ au versus $\sim240$ au for CH$_3$OH) or exhibiting a factor of $\gtrsim 15$ increase in abundance in the inner $\sim55$ au. A possible explanation for the difference in spatial abundance distributions of CH$_3$OH and CH$_3$CN is carbon-grain sublimation. Abundance (ecology) ; Astrophysics ; Organic molecules ; Astrobiology ; Physics ; Molecule ; Environmental science ; Astronomy ; Chemistry ; Biology ; Ecology Molecular Spectroscopy and Structure ; Pharmacological Effects and Assays ; Analytical Chemistry and Chromatography
Authors: Deepu Kumar | Nguyen The Hoang | Yumin Sim | Youngsu Choi | Kalaivanan Raju | Rajesh Kumar Ulaganathan | Raman Sankar | Maeng‐Je Seong | Kwang‐Yong Choi
Source: arXiv (Cornell University) (preprint, 2024-04-17)
Field: Materials Science — Materials Chemistry

Interplay between magnetic and lattice excitations and emergent multiple phase transitions in MnPSe3-xSx The intricate interplay between spin and lattice degrees of freedom in two-dimensional magnetic materials plays a pivotal role in modifying their magnetic characteristics, engendering hybrid quasiparticles, and implementing functional devices. Herein, we present our comprehensive and in-depth investigations on magnetic and lattice excitations of MnPSe3-xSx (x = 0, 0.5, and 1.5) alloys, utilizing temperature- and polarization-dependent Raman scattering. Our experimental results reveal the occurrence of multiple phase transitions, evidenced by notable changes in phonon self-energy and the appearance or splitting of phonon modes. These emergent phases are tied to the development of long and short-range spin-spin correlations, as well as to spin reorientations or magnetic instabilities. Our analysis of two-magnon excitations as a function of temperature and composition showcases their hybridization with phonons whose degree weakens with increasing x. Moreover, the suppression of spin-dependent phonon intensity in chemically most-disordered MnPSe3-xSx (x = 1.5) suggests that chalcogen substitution offers a control knob of tuning spin and phonon dynamics by modulating concurrently superexchange pathways and a degree of trigonal distortions. Condensed matter physics ; Lattice (music) ; Phase transition ; Physics 2D Materials and Applications ; Organic and Molecular Conductors Research ; Phase-change materials and chalcogenides
Authors: Emmanuel Chinedu Onuoha | Ezekiel Fayiah Hallie | Chima Ikoro
Source: Pharmacologia (article, 2024-10-30)
Field: Chemistry — Inorganic Chemistry

Haematological Assessment of Tender Coconut Water as a Natural Erythropoietic Agent in Wistar Rats Background and Objective: Coconut water has been traditionally recognized for its numerous health benefits, particularly for hydration and its rich nutrient profile.However, its impact on hematological parameters has not been extensively studied.This study aims to investigate Hematological Assessment of Tender Coconut Water as a Natural Erythropoietic Agent in Wistar Rats.Materials and Methods: The 24 Wistar rats were divided into control and treatment groups, with the latter receiving 10, 20 and 30 mL/kg body weight of Malayan green dwarf hybridized immature coconut water.Hematological parameters, including hematocrit, hemoglobin concentration, RBC count, mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC), were assessed.Results: The administration of coconut water resulted in significantly higher hematocrit (p = 0.001), hemoglobin (p = 0.002) and RBC counts (p = 0.006) in the treatment groups compared to the control.However, no significant changes were observed in MCV, MCH or MCHC (p>0.05).Additionally, there was no dose-dependent effect on the hematological parameters among the different treatment groups.Malayan green dwarf hybridized immature coconut water significantly improves hematocrit, hemoglobin and RBC counts in Wistar rats without affecting red cell indices.Conclusion: The effects are consistent across different dosages, indicating its potential as a natural supplement for improving hematological health. Natural (archaeology) ; Traditional medicine ; Toxicology ; Biology ; Medicine ; Geography ; Archaeology Coconut Research and Applications ; Fatty Acid Research and Health ; Advanced Glycation End Products research
Authors: Maria Paula Kwesiga | Roger J. Guillory | Ali Gökhan Demir
Source: Biointerphases (article, 2024-09-01)
Field: Materials Science — Materials Chemistry

Influence of metal oxides on biocompatibility of additively manufactured NiTi In order to properly satisfy biomedical constraints for cardiovascular applications, additively manufactured NiTi scaffolds required further process and metallurgical engineering. Additively manufactured NiTi materials for cardiovascular use will have to undergo surface finishing in order to minimize negative surface interactions within the artery. In this study, we sought to understand biocompatibility from chemically etched additively manufactured NiTi scaffolds by laser powder bed fusion (LPBF). Although two distinct oxide films were created in the surface etching process (labeled CP-A and CP-B), no qualitative changes in microroughness were seen between the two conditions. CP-A possessed significantly less Ni at the surface (0.19 at. %) than the CP-B group (3.30 at. %), via x-ray photoelectron spectroscopy, alongside a concomitant shift in the O1 s peak presentation alluding to a greater formation of a Ni based oxide in the CP-B group. Our live dead staining revealed significant toxicity and reduced cellular attachment for the CP-B group, in addition to inducing more cell lysis (20.9 ± 5.1%), which was significantly increased when compared to CP-A (P < 0.01). Future practices of manufacturing NiTi scaffolds using LPBF should focus on producing surface films that are not only smooth, but free of cytotoxic Ni based oxides. Biocompatibility ; Nickel titanium ; X-ray photoelectron spectroscopy ; Oxide ; Chemistry ; Metal ; Metallurgy ; Etching (microfabrication) ; Chemical engineering ; Materials science ; Nanotechnology ; Shape-memory alloy ; Nuclear chemistry Shape Memory Alloy Transformations ; Additive Manufacturing Materials and Processes ; High Entropy Alloys Studies
Authors: Nandita Singh
Source: resMilitaris (article, 2024-03-01)
Field: Materials Science — Materials Chemistry

Analysis of Thermoluminescence Glow Curves of X-ray irradiated CaSO4:Dy phosphor This research article presents a detailed analysis of the thermoluminescence (TL) glow curves exhibited by calcium sulphate doped with dysprosium (CaSO4:Dy) crystals following X-ray irradiation. TL is a phenomenon where certain materials emit light when heated after being exposed to ionizing radiation. CaSO4:Dy is known for its thermoluminescent properties, making it a valuable material in dosimetry and radiation monitoring applications. The investigation of the glow curve characteristics of CaSO4:Dy crystals by CGCD deconvolution at different heating rates reveals both consistent trends and noteworthy differences. The activation energy (E) consistently varies from 0.8 to 1.5 eV, and the value of frequency factor (s) ranges from 2.38E+08 to 7.76E+11. The order of kinetics (b) exhibits variation between 1 and 2, suggesting a complex interplay of thermoluminescent mechanisms influenced by the heating rate. Thermoluminescence ; Phosphor ; Irradiation ; Materials science ; X-ray ; Radiochemistry ; Optics ; Chemistry ; Optoelectronics ; Luminescence ; Physics ; Nuclear physics Luminescence Properties of Advanced Materials ; Solid-state spectroscopy and crystallography ; Radiation Detection and Scintillator Technologies
Authors: Shaikh Taufiq Khalil Ahema
Source:  (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Study of La³⁺ Substitution in Y₃Fe₅O₁₂ Nanoparticles by Sol-Gel Route In this study, La-substituted yttrium iron garnet nanoparticles with compositions Y₃₋ₓLaₓFe₅O₁₂ (x = 0.0 and 0.2) were successfully synthesized using the sol-gel method. X-ray diffraction (XRD) analysis confirmed the formation of a pure cubic garnet phase, with a slight increase in lattice constant upon La substitution. The average crystallite sizes were calculated using the Debye-Scherrer formula and Williamson-Hall method, showing minor variation due to doping. FTIR spectra revealed characteristic Fe–O vibrational modes, supporting the garnet structure. Field emission scanning electron microscopy (FE-SEM) showed spherical, agglomerated nanoparticles, with particle sizes increasing from 35.26 nm to 39.74 nm after La doping. Energy dispersive X-ray spectroscopy (EDS) confirmed the elemental composition, indicating successful incorporation of La³⁺ ions. The results demonstrate that La substitution effectively influences the structural and morphological properties of YIG nanoparticles, making them suitable for potential applications in magneto-dielectric and microwave devices. Substitution (logic) ; Materials science ; Nanoparticle ; Sol-gel ; Chemical engineering ; Nanotechnology ; Computer science ; Engineering Catalytic Processes in Materials Science
Authors: Étienne Derat | Géraldine Masson | Aurélie Claraz
Source: Angewandte Chemie (article, 2024-04-30)
Field: Chemistry — Organic Chemistry

Electrochemically‐Driven 1,4‐Aryl Migration via Radical Fluoromethylation of N‐Allylbenzamides: a Straightforward Access to Functionalized β‐Arylethylamines Abstract An electrochemical radical Truce Smiles rearrangement of N‐allylbenzamides is documented herein. The selective 1,4‐aryl migration was triggered by the radical fluoromethylation of the alkene providing a direct route to fluoro derivatives of the highly privileged β‐arylethylamine pharmacophore. This practical transformation utilizes readily available starting materials and employs an electrical current to drive the oxidative process under mild reaction conditions. It accommodates a variety of migratory aryl groups with different electronic properties and substitution patterns. Careful selection of the protecting group on the nitrogen atom of the N‐allylbenzamide is crucial to outcompete the undesired 6‐ endo cyclization and achieve high level of selectivity towards the 1,4‐aryl migration. DFT calculations support the reaction mechanism and unveil the origin of selectivity between the two competitive pathways. Aryl ; Chemistry ; Combinatorial chemistry ; Aryl radical ; Organic chemistry Radical Photochemical Reactions ; Fluorine in Organic Chemistry ; Catalytic C–H Functionalization Methods
Authors: Gbadebo Taofeek Yusuf | Sukhwinder Singh | Alexandros Askounis | Zlatka Stoeva | Fideline Tchuenbou‐Magaia
Source: arXiv (Cornell University) (preprint, 2024-06-09)
Field: Materials Science — Materials Chemistry

Integrative Mobility Model For Grain-Boundary-Limited Transport In Thermoelectric Compounds Grain-boundary-limited charge transport remains a key bottleneck in polycrystalline thermoelectric materials, where reduced carrier mobility degrades electrical conductivity and suppresses the power factor. Here we present a semi-empirical mobility model that integrates three dominant grain-boundary mechanisms: (i) weighted mobility linked to carrier effective mass and concentration, (ii) thermionic emission across grain-boundary barriers, and (iii) geometric suppression arising from a finite mean free path ($\ell$). The model is validated against a diverse set of polycrystalline thermoelectric materials -- including Bi$_2$Te$_3$, PbTe, Mg$_2$Si, and SnSe -- showing excellent agreement with experiment ($R^2 = 0.93$--0.99) and yielding physically consistent parameters: $0 \lesssim Φ_{\mathrm{GB}} \lesssim 0.15$ eV and $\ell \approx 15$--60 nm. The model captures the non-monotonic mobility trends produced by the interplay between barrier activation and phonon scattering. We further apply the model to Al-doped ZnO, revealing that combined grain-boundary passivation (reducing $Φ_{\mathrm{GB}}$ from 0.15 eV to 0.05 eV) and moderate grain growth (increasing $\ell$ from 5 nm to 25 nm) can raise the power factor by $\sim 6\times$ (from $\sim 4$ to $\sim 26$ mW\,m$^{-1}$\,K$^{-2}$) and the electronic quality factor $B$ by nearly $7\times$ (from $\sim 0.15$ to $&gt;1.0 \times 10^{-3}$ m$^2$\,V$^{-1}$\,s$^{-1}$\,kg$^{3/2}$), approaching values achieved in leading chalcogenide thermoelectrics. The model therefore provides a transparent and practical framework for grain-boundary engineering in oxide-based thermoelectrics. Grain boundary ; Thermoelectric effect ; Materials science ; Engineering physics ; Nanotechnology ; Metallurgy ; Engineering ; Physics ; Microstructure ; Thermodynamics Advanced Thermoelectric Materials and Devices ; Solidification and crystal growth phenomena
Authors: Maizia Abdelhakim | Abdelkader Hocine | Ghania Habbar | Levent Aydın | Bezazi Abderrezak | Abdelkader Louza | Omar Bouledroua | Basil Ibrahim
Source: STUDIES IN ENGINEERING AND EXACT SCIENCES (article, 2024-12-17)
Field: Materials Science — Polymers and Plastics

Stochastic sensitivity analysis of micromechanical properties of unidirectional layer with natural fibers - hydrogen pipeline application The primary objective of this study is to predict the sensitivity of the mechanical properties in unidirectional layers of bio-composites. Four bio-sourced fibers were investigated: PALF (Pineapple leaf fiber), Date palm, Alfa, and Hemp fiber. In order to conduct this sensitivity analysis, three models were implemented. The first model utilizes analytical approaches based on four theoretical methods: Halpin-Tsai, Chamis, Hashin-Rosen, and the Rule of Mixtures (ROM). The second model is based on the finite element method (FEM) applied to the unit cell of bio-layer composites. After validating the analytical and numerical results with experimental data, a coupled methodology combining probabilistic stochastic analysis and FEM was employed to determine the sensitivity of all mechanical properties of the natural fiber-based layers. These bio-layers are designed for use in manufacturing the layers and skins of sandwich composite hydrogen transportation pipelines. The probabilistic stochastic approach, utilizing the Monte Carlo method, enables the execution of the sensitivity analysis. The results indicate that uncertainties in the micromechanical characteristics of fibers, the fiber volume fraction, and the fibers' radius are the most significant factors affecting the stiffness of the layer or the multi-layered structure in longitudinal and transversal directions. These findings provide valuable insights for designers to estimate the volume ratio and select the types of components or fibers to manufacture reliable and economically viable Bio-Composites layers with high resistance and quality. Pipeline (software) ; Sensitivity (control systems) ; Materials science ; Layer (electronics) ; Natural (archaeology) ; Composite material ; Biological system ; Geology ; Mechanical engineering ; Engineering ; Electronic engineering Natural Fiber Reinforced Composites ; Textile materials and evaluations ; Material Properties and Processing
Authors: Arthur Grimaud | Maša Babović | Frederik Haugaard Holck | Ole N. Jensen | Veit Schwämmle
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2024-04-21)
Field: Chemistry — Spectroscopy

How to deal with internal fragment ions? 1 Abstract Tandem mass spectrometry of peptides and proteins generates mass spectra of their gas-phase fragmentation product ions, including N-terminal, C-terminal, and internal fragment ions. Whereas N- and C-terminal ions are routinely assigned and identified using computational methods, internal fragment ions are often difficult to annotate correctly. They become particularly relevant for long peptides and full proteoforms where the peptide backbone is more likely to be fragmented multiple times. Internal fragment ions potentially offer tremendous information regarding amino acid sequences and positions of post-translational modifications of peptides and intact proteins. However, their practical application is challenged by the vast number of theoretical internal fragments that exist for long amino acid sequences, leading to a high risk of false-positive annotations. We analyze the mass spectral contributions of internal fragment ions in spectra from middle-down and top-down experiments and introduce a novel graph-based annotation approach designed to manage the complexity of internal fragments. Our graph-based representation allows us to compare multiple candidate proteoforms in a single graph, and to assess different candidate annotations in a fragment ion spectrum. We demonstrate cases from middle-down and top-down data where internal ions enhance amino acid sequence coverage of polypeptides and proteins and accurate localization of post-translational modifications. We conclude that our graph-based method provides a general approach to process complex tandem mass spectra, enhance annotation of internal fragment ions, and improve proteoform sequencing and characterization by mass spectrometry. Tandem mass spectrometry ; Fragmentation (computing) ; Fragment (logic) ; Ion ; Mass spectrometry ; Chemistry ; Tandem ; Peptide sequence ; Graph ; Computer science ; Computational biology ; Combinatorial chemistry ; Algorithm ; Biology ; Biochemistry ; Materials science ; Gene ; Theoretical computer science ; Chromatography Mass Spectrometry Techniques and Applications ; Advanced Proteomics Techniques and Applications ; Ion-surface interactions and analysis
Authors: Benjamin List | Kateryna Kryvous
Source: Synfacts (article, 2024-03-13)
Field: Chemistry — Inorganic Chemistry

Catalytic Enantioselective Wagner–Meerwein Rearrangement of Alkenyl Cycloalkanes Key words IDPi catalysis - aliphatic hydrocarbons - Wagner–Meerwein rearrangement Chemistry ; Enantioselective synthesis ; Catalysis ; Cope rearrangement ; Organic chemistry ; Cycloalkane Asymmetric Hydrogenation and Catalysis ; Axial and Atropisomeric Chirality Synthesis ; Synthetic Organic Chemistry Methods