jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Wonjoong Kim | Gwanho Yoon | Joohoon Kim | Heonyeong Jeong | Yeseul Kim | Hojung Choi | Trevon Badloe | Junsuk Rho | Heon Lee
Source: Microsystems & Nanoengineering (article, 2022-07-04)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Thermally-curable nanocomposite printing for the scalable manufacturing of dielectric metasurfaces Metasurfaces consisting of artificially designed meta-atoms have been popularized recently due to their advantages of amplitude and phase of light control. However, the electron beam lithography method for metasurface fabrication has high cost and low throughput, which results in a limitation for the fabrication of metasurfaces. In this study, nanocomposite printing technology is used to fabricate high-efficiency metasurfaces with low cost. To demonstrate the efficiency of the proposed fabrication method, a metahologram is designed and fabricated using a nanocomposite. The metahologram exhibits conversion efficiencies of 48% and 35% at wavelengths of 532 and 635 nm, respectively. The nanocomposite is composed of polymers with nanoparticles, so durability tests are also performed to evaluate the effects of temperature and humidity on the metasurfaces. The test verifies that at temperatures below the glass transition temperature of the base resin, the nanostructures do not collapse, so the efficiency of the metasurfaces remains almost the same. The surrounding humidity does not affect the nanostructures at all. Hence, the durability of the nanocomposite metasurfaces can be further enhanced by replacing the base resin, and this nanocomposite printing method will facilitate practical metasurface use at low cost. Nanocomposite ; Materials science ; Fabrication ; Dielectric ; Durability ; Lithography ; Nanotechnology ; Optoelectronics ; Nanostructure ; Polymer ; Composite material Metamaterials and Metasurfaces Applications ; Photonic Crystals and Applications ; Liquid Crystal Research Advancements
Authors: Yoshihiko Nishikawa | Misaki Ozawa | Atsushi Ikeda | Pinaki Chaudhuri | Ludovic Berthier
Source: Physical Review X (article, 2022-04-01)
Field: Materials Science — Materials Chemistry

Relaxation Dynamics in the Energy Landscape of Glass-Forming Liquids International audience Relaxation (psychology) ; Spin glass ; Energy landscape ; Statistical physics ; Glass transition ; Population ; Power law ; Exponent ; Field (mathematics) ; Physics ; Theoretical physics ; Condensed matter physics ; Thermodynamics ; Mathematics ; Statistics ; Sociology ; Nuclear magnetic resonance Material Dynamics and Properties ; Theoretical and Computational Physics ; Glass properties and applications
Authors: Takahiro Igarashi | Hahnsung Kim | Phillip Zhe Sun
Source: NMR in Biomedicine (review, 2022-02-10)
Field: Materials Science — Materials Chemistry

Detection of tissue pH with quantitative chemical exchange saturation transfer magnetic resonance imaging Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) has emerged as a novel means for sensitive detection of dilute labile protons and chemical exchange rates. By sensitizing to pH-dependent chemical exchange, CEST MRI has shown promising results in monitoring tissue statuses such as pH changes in disorders like acute stroke, tumor, and acute kidney injury. This article briefly reviews the basic principles for CEST imaging and quantitative measures, from the simplistic asymmetry analysis to multipool Lorentzian decoupling and quasi-steady-state reconstruction. In particular, the advantages and limitations of commonly used quantitative approaches for CEST applications are discussed. Magnetic resonance imaging ; Nuclear magnetic resonance ; Saturation (graph theory) ; Chemistry ; Decoupling (probability) ; Analytical Chemistry (journal) ; Physics ; Medicine ; Radiology ; Chromatography Lanthanide and Transition Metal Complexes ; Advanced MRI Techniques and Applications ; Electron Spin Resonance Studies
Authors: Hui Zhang | Zhen Wang | Qiang Wang | Simone Borri | Iacopo Galli | Angelo Sampaolo | Pietro Patimisco | Vincenzo Spagnolo | Paolo De Natale | Wei Ren
Source: Photoacoustics (article, 2022-12-09)
Field: Chemistry — Spectroscopy

Parts-per-billion-level detection of hydrogen sulfide based on doubly resonant photoacoustic spectroscopy with line-locking We report on the development of a highly sensitive hydrogen sulfide (H<sub>2</sub>S) gas sensor exploiting the doubly resonant photoacoustic spectroscopy technique and using a near-infrared laser emitting at 1578.128 nm. By targeting the R(4) transition of H<sub>2</sub>S, we achieved a minimum detection limit of 10 part per billion in concentration and a normalized noise equivalent absorption coefficient of 8.9 × 10<sup>-12</sup> W cm<sup>-1</sup> Hz<sup>-1/2</sup>. A laser-cavity-molecule locking strategy is proposed to enhance the sensor stability for fast measurement when dealing with external disturbances. A comparison among the state-of-the-art H<sub>2</sub>S sensors using various spectroscopic techniques confirmed the record sensitivity achieved in this work. Photoacoustic spectroscopy ; Hydrogen sulfide ; Spectroscopy ; Detection limit ; Parts-per notation ; Materials science ; Laser ; Sensitivity (control systems) ; Absorption spectroscopy ; Line (geometry) ; Absorption (acoustics) ; Noise (video) ; Tunable diode laser absorption spectroscopy ; Hydrogen ; Optics ; Analytical Chemistry (journal) ; Optoelectronics ; Tunable laser ; Chemistry ; Sulfur ; Wavelength ; Physics ; Electronic engineering ; Computer science Spectroscopy and Laser Applications ; Atmospheric Ozone and Climate ; Advanced Chemical Sensor Technologies
Authors: Muhammad Haseeb Ur Rehman | Uzma Saleem | Bashir Ahmad | Memoona Rashid
Source: Frontiers in Pharmacology (article, 2022-09-23)
Field: Chemistry — Organic Chemistry

Phytochemical and toxicological evaluation of Zephyranthes citrina Drugs obtained from medicinal plants have always played a pivotal role in the field of medicine and to identify novel compounds. Safety profiling of plant extracts is of utmost importance during the discovery of new biologically active compounds and the determination of their efficacy. It is imperative to conduct toxicity studies before exploring the pharmacological properties and perspectives of any plant. The present work aims to provide a detailed insight into the phytochemical and toxicological profiling of methanolic extract of <i>Zephyranthes citrina</i> (MEZ). Guidelines to perform subacute toxicity study (407) and acute toxicity study (425) provided by the organization of economic cooperation and development (OECD) were followed. A single orally administered dose of 2000 mg/kg to albino mice was used for acute oral toxicity testing. In the subacute toxicity study, MEZ in doses of 100, 200, and 400 mg/kg was administered orally, consecutive for 28 days. Results of each parameter were compared to the control group. In both studies, the weight of animals and their selected organs showed consistency with that of the control group. No major toxicity or organ damage was recorded except for some minor alterations in a few parameters such as in the acute study, leukocyte count was increased and decreased platelet count, while in the subacute study platelet count increased in all doses. In the acute toxicity profile liver enzymes Alanine aminotransferase (ALT), as well as, aspartate aminotransferase (AST) were found to be slightly raised while alkaline phosphatase (ALP) was decreased. In subacute toxicity profiling, AST and ALT were not affected by any dose while ALP was decreased only at doses of 200 and 400 mg/kg. Uric acid was raised at a dose of 100 mg/kg. In acute toxicity, at 2000 mg/kg, creatinine and uric acid increased while urea levels decreased. Therefore, it is concluded that the LD<sub>50</sub> of MEZ is more than 2000 mg/kg and the toxicity profile of MEZ was generally found to be safe. Toxicity ; Phytochemical ; Acute toxicity ; Alkaline phosphatase ; Pharmacology ; Alanine aminotransferase ; Medicine ; Traditional medicine ; Biology ; Enzyme ; Internal medicine ; Biochemistry Chemical synthesis and alkaloids ; Cholinesterase and Neurodegenerative Diseases ; Phytochemistry and Bioactivity Studies
Authors: Lavinia Gambelli | Michail N. Isupov | Rebecca Conners | Mathew McLaren | Annett Bellack | Vicki A. M. Gold | Reinhard Rachel | Bertram Daum
Source: Nature Communications (article, 2022-02-07)
Field: Materials Science — Materials Chemistry

An archaellum filament composed of two alternating subunits Archaea use a molecular machine, called the archaellum, to swim. The archaellum consists of an ATP-powered intracellular motor that drives the rotation of an extracellular filament composed of multiple copies of proteins named archaellins. In many species, several archaellin homologs are encoded in the same operon; however, previous structural studies indicated that archaellum filaments mainly consist of only one protein species. Here, we use electron cryo-microscopy to elucidate the structure of the archaellum from Methanocaldococcus villosus at 3.08 Å resolution. The filament is composed of two alternating archaellins, suggesting that the architecture and assembly of archaella is more complex than previously thought. Moreover, we identify structural elements that may contribute to the filament's flexibility. Protein filament ; Cryo-electron microscopy ; Archaea ; Molecular machine ; Protein subunit ; Operon ; Biology ; Molecular motor ; Flagellum ; Flexibility (engineering) ; Extracellular ; Biophysics ; Cell biology ; Genetics ; Gene Enzyme Structure and Function ; Protein Structure and Dynamics ; Advanced Electron Microscopy Techniques and Applications
Authors: Shanshan Jiang | Zhibo Wen | Sung Soo Ahn | Kejia Cai | Daniel Paech | Charles G. Eberhart | Jinyuan Zhou
Source: NMR in Biomedicine (review, 2022-03-16)
Field: Materials Science — Materials Chemistry

Applications of chemical exchange saturation transfer magnetic resonance imaging in identifying genetic markers in gliomas Chemical exchange saturation transfer (CEST) imaging is an important molecular magnetic resonance imaging technique that can image numerous low-concentration biomolecules with water-exchangeable protons (such as cellular proteins) and tissue pH. CEST, or more specially amide proton transfer-weighted imaging, has been widely used for the detection, diagnosis, and response assessment of brain tumors, and its feasibility in identifying molecular markers in gliomas has also been explored in recent years. In this paper, after briefing on the basic principles and quantification methods of CEST imaging, we review its early applications in identifying isocitrate dehydrogenase mutation status, MGMT methylation status, 1p/19q deletion status, and H3K27M mutation status in gliomas. Finally, we discuss the limitations or weaknesses in these studies. Isocitrate dehydrogenase ; Magnetic resonance imaging ; Glioma ; Nuclear magnetic resonance ; Molecular imaging ; Biomolecule ; Chemistry ; Cancer research ; Biology ; Medicine ; Genetics ; Biochemistry ; Radiology ; Physics ; In vivo ; Enzyme Lanthanide and Transition Metal Complexes ; Magnetism in coordination complexes ; Advanced MRI Techniques and Applications
Authors: Hye‐Young Heo | Yee Kai Tee | George Harston | Richard Leigh | Michael A. Chappell
Source: NMR in Biomedicine (review, 2022-03-23)
Field: Materials Science — Materials Chemistry

Amide proton transfer imaging in stroke Amide proton transfer (APT) imaging, a variant of chemical exchange saturation transfer MRI, has shown promise in detecting ischemic tissue acidosis following impaired aerobic metabolism in animal models and in human stroke patients due to the sensitivity of the amide proton exchange rate to changes in pH within the physiological range. Recent studies have demonstrated the possibility of using APT-MRI to detect acidosis of the ischemic penumbra, enabling the assessment of stroke severity and risk of progression, monitoring of treatment progress, and prognostication of clinical outcome. This paper reviews current APT imaging methods actively used in ischemic stroke research and explores the clinical aspects of ischemic stroke and future applications for these methods. Penumbra ; Stroke (engine) ; Ischemic stroke ; Acidosis ; Medicine ; Magnetic resonance imaging ; Internal medicine ; Ischemia ; Radiology Lanthanide and Transition Metal Complexes ; Advanced MRI Techniques and Applications ; Electron Spin Resonance Studies
Authors: Hind Hajjaoui | Malika Khnifira | Amal Soufi | Mohamed Abdennouri | Savaş Kaya | Recep Akkaya | Noureddine Barka
Source: Journal of Molecular Liquids (article, 2022-08-08)
Field: Materials Science — Polymers and Plastics

Experimental, DFT and MD simulation studies of Mordant Black 11 dye adsorption onto polyaniline in aqueous solution Freundlich equation ; Polymerization ; Adsorption ; Polyaniline ; Aqueous solution ; Langmuir ; Emulsion polymerization ; In situ polymerization ; Endothermic process ; Monolayer ; Materials science ; Chemistry ; Chemical engineering ; Analytical Chemistry (journal) ; Physical chemistry ; Organic chemistry ; Polymer ; Nanotechnology Conducting polymers and applications ; Electrochemical sensors and biosensors ; Adsorption and biosorption for pollutant removal
Authors: Karl Grantham | Muhetaer Mukaidaisi | Hsu Kiang Ooi | Mohammad Sajjad Ghaemi | Alain Tchagang | Yifeng Li
Source: IEEE Computational Intelligence Magazine (article, 2022-04-13)
Field: Materials Science — Materials Chemistry

Deep Evolutionary Learning for Molecular Design In this paper, a prototypical deep evolutionary learning (DEL) process is proposed to integrate deep generative model and multi-objective evolutionary computation for molecular design. Our approach enables <xref ref-type="disp-formula" rid="deqn1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(1)</xref> evolutionary operations in the latent space of the generative model, rather than the structural space, to generate promising novel molecular structures for the next evolutionary generation, and <xref ref-type="disp-formula" rid="deqn2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(2)</xref> generative model fine-tuning using newly generated high-quality samples. Thus, DEL implements a data-model co-evolution concept which improves both sample population and generative model learning. Experiments on public datasets indicate that the sample population obtained by DEL exhibits improvement on property distributions, and dominates samples generated by other baseline molecular optimization algorithms. Furthermore, comparisons with a range of deep generative models show that DEL is beneficial for improving sample populations. Generative model ; Generative grammar ; Artificial intelligence ; Evolutionary algorithm ; Population ; Computer science ; Evolutionary computation ; Sample (material) ; Deep learning ; Machine learning ; Mathematics Machine Learning in Materials Science ; Advanced Multi-Objective Optimization Algorithms ; Computational Drug Discovery Methods
Authors: Radwa Mohamed Abdelaziz | Azza El‐Maghraby | Wagih A. Sadik | Abdel‐Ghaffar Maghraby El‐Demerdash | Eman A. Fadl
Source: Scientific Reports (article, 2022-04-19)
Field: Materials Science — Biomaterials

Biodegradable cellulose nanocrystals hydrogels for removal of acid red 8 dye from aqueous solutions Abstract Biodegradable cellulose nanocrystals hydrogels (CNCsH) were synthesized from cellulose nanocrystals (CNCs) which were prepared from office wastepaper (OWP) by a chemical crosslinking method using epicholorohydrin (ECH) as a cross-linker. CNCsH were tested for their swelling behavior and biodegradability and the point of zero charge had been determined. The ability of CNCsH for removing the Acid Red 8 (AR8) anionic dye from its aqueous solution was evaluated. The different parameters affecting removal of the dye, such as pH, initial concentration of dye, content of CNCs, temperature and adsorbent dosage were investigated. The optimum conditions for 68% removal efficiency were pH = 1, initial concentration of dye = 10 ppm, contact time = 105 min, CNCs content = 5% and CNCsH dosage = 0.5 g at 30 °C. The adsorption isotherms, kinetics, and thermodynamic parameters have been studied. The results showed an appropriate fit for Langmuir adsorption isotherm and pseudo-second order kinetics model with an adsorption capacity of 17.12 mg/g. According to the obtained values of thermodynamic parameters, the removal of Acid red 8 by CNCs hydrogels was exothermic spontaneous process. Self-healing hydrogels ; Cellulose ; Aqueous solution ; Chemistry ; Chemical engineering ; Polymer chemistry ; Organic chemistry Advanced Cellulose Research Studies ; Adsorption and biosorption for pollutant removal ; Nanomaterials for catalytic reactions
Authors: Samuel Leguizamon | Nicolas T. Monk | Madison T. Hochrein | Elizabeth Zapien | Alana Yoon | Jeffrey C. Foster | Leah Appelhans
Source: Macromolecules (article, 2022-09-12)
Field: Chemistry — Organic Chemistry

Photoinitiated Olefin Metathesis and Stereolithographic Printing of Polydicyclopentadiene Recent progress in photoinitiated ring-opening metathesis polymerization (photoROMP) has enabled the lithographic production of patterned films from olefinic resins. Recently, we reported the use of a latent ruthenium catalyst (HeatMet) in combination with a photosensitizer (2-isopropylthioxanthone) to rapidly photopolymerize dicyclopentadiene (DCPD) formulations upon irradiation with UV light. While this prior work was limited in terms of catalyst and photosensitizer scope, a variety of alternative catalysts and photosensitizers are commercially available that could allow for tuning of thermomechanical properties, potlifes, activation rates, and irradiation wavelengths. Herein, 14 catalysts and 8 photosensitizers are surveyed for the photoROMP of DCPD and the structure–activity relationships of the catalysts examined. Properties relevant to stereolithography additive manufacturing (SLA AM)-potlife, irradiation dose required to gel, conversion-are characterized to develop catalyst and photosensitizer libraries to inform development of SLA AM resin systems. Two optimized catalyst/photosensitizer systems are demonstrated in the rapid SLA printing of complex, multidimensional pDCPD structures with microscale features under ambient conditions. Photosensitizer ; Catalysis ; Dicyclopentadiene ; Stereolithography ; Polymerization ; Chemistry ; Materials science ; Photochemistry ; Nanotechnology ; Chemical engineering ; Organic chemistry ; Polymer ; Composite material Synthetic Organic Chemistry Methods ; Advanced Polymer Synthesis and Characterization ; Photopolymerization techniques and applications
Authors: Martin Grootveld
Source: Frontiers in Nutrition (review, 2022-01-05)
Field: Chemistry — Organic Chemistry

Evidence-Based Challenges to the Continued Recommendation and Use of Peroxidatively-Susceptible Polyunsaturated Fatty Acid-Rich Culinary Oils for High-Temperature Frying Practises: Experimental Revelations Focused on Toxic Aldehydic Lipid Oxidation Products In this manuscript, a series of research reports focused on dietary lipid oxidation products (LOPs), their toxicities and adverse health effects are critically reviewed in order to present a challenge to the mindset supporting, or strongly supporting, the notion that polyunsaturated fatty acid-laden frying oils are "safe" to use for high-temperature frying practises. The generation, physiological fates, and toxicities of less commonly known or documented LOPs, such as epoxy-fatty acids, are also considered. Primarily, an introduction to the sequential autocatalytic peroxidative degradation of unsaturated fatty acids (UFAs) occurring during frying episodes is described, as are the potential adverse health effects posed by the dietary consumption of aldehydic and other LOP toxins formed. In continuance, statistics on the dietary consumption of fried foods by humans are reviewed, with a special consideration of French fries. Subsequently, estimates of human dietary aldehyde intake are critically explored, which unfortunately are limited to acrolein and other lower homologues such as acetaldehyde and formaldehyde. However, a full update on estimates of quantities derived from fried food sources is provided here. Further items reviewed include the biochemical reactivities, metabolism and volatilities of aldehydic LOPs (the latter of which is of critical importance regarding the adverse health effects mediated by the inhalation of cooking/frying oil fumes); their toxicological actions, including sections focussed on governmental health authority tolerable daily intakes, delivery methods and routes employed for assessing such effects in animal model systems, along with problems encountered with the Cramer classification of such toxins. The mutagenicities, genotoxicities, and carcinogenic potential of aldehydes are then reviewed in some detail, and following this the physiological concentrations of aldehydes and their likely dietary sources are considered. Finally, conclusions from this study are drawn, with special reference to requirements for (1) the establishment of tolerable daily intake (TDI) values for a much wider range of aldehydic LOPs, and (2) the performance of future nutritional and epidemiological trials to explore associations between their dietary intake and the incidence and severity of non-communicable chronic diseases (NCDs). Polyunsaturated fatty acid ; Food science ; Lipid oxidation ; Chemistry ; French fries ; Fatty acid ; Organic chemistry ; Antioxidant Edible Oils Quality and Analysis ; Phytochemicals and Antioxidant Activities ; Essential Oils and Antimicrobial Activity
Authors: Ethan F. Bull-Vulpe | Marc Riera | Sigbjørn Løland Bore | Francesco Paesani
Source: Journal of Chemical Theory and Computation (article, 2022-09-16)
Field: Materials Science — Materials Chemistry

Data-Driven Many-Body Potential Energy Functions for Generic Molecules: Linear Alkanes as a Proof-of-Concept Application We present a generalization of the many-body energy (MB-nrg) theoretical/computational framework that enables the development of data-driven potential energy functions (PEFs) for generic covalently bonded molecules, with arbitrary quantum mechanical accuracy. The "nearsightedness of electronic matter" is exploited to define monomers as "natural building blocks" on the basis of their distinct chemical identity. The energy of generic molecules is then expressed as a sum of individual many-body energies of incrementally larger subsystems. The MB-nrg PEFs represent the low-order <i>n</i>-body energies, with <i>n</i> = 1-4, using permutationally invariant polynomials derived from electronic structure data carried out at an arbitrary quantum mechanical level of theory, while all higher-order <i>n</i>-body terms (<i>n</i> > 4) are represented by a classical many-body polarization term. As a proof-of-concept application of the general MB-nrg framework, we present MB-nrg PEFs for linear alkanes. The MB-nrg PEFs are shown to accurately reproduce reference energies, harmonic frequencies, and potential energy scans of alkanes, independently of their length. Since, by construction, the MB-nrg framework introduced here can be applied to generic covalently bonded molecules, we envision future computer simulations of complex molecular systems using data-driven MB-nrg PEFs, with arbitrary quantum mechanical accuracy. Proof of concept ; Computer science ; Energy (signal processing) ; Theoretical computer science ; Data science ; Mathematics Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Advanced Chemical Physics Studies