jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ventsislav K. Valev
Source:  (article, 2023-03-17)
Field: Chemistry — Spectroscopy

Experimental demonstration of nonlinear chiroptical scattering after its prediction 40 years ago (Conference Presentation) Current drug discovery is facing numerous challenges: antimicrobial resistance, increased risk of future pandemics from globalization, spiralling costs of new drugs, etc. High-throughput (HT) synthesis with robotized operations driven by AI algorithms could help to accelerate drug discovery and development, but it requires miniaturized sample volumes. The majority of new drugs entering the market are chiral. Therefore, new experimental tools are needed to probe chirality in tiny volumes. Solving a 40-years old scientific question, our team reported a new chiral optical effect that probes chirality in tiny volumes across a range of inorganic nanoparticles, randomly distributed in isotropic liquids. Chirality (physics) ; Throughput ; Nanotechnology ; Scattering ; Nanoparticle ; Nonlinear system ; Globalization ; Nonlinear optical ; Isotropy ; Computer science ; Nanomedicine ; Presentation (obstetrics) ; Materials science ; Physics ; Optics ; Medicine ; Telecommunications ; Particle physics ; Political science Molecular spectroscopy and chirality ; Optical and Acousto-Optic Technologies ; Spectroscopy and Quantum Chemical Studies
Authors: Nikhil Vemgal | Elaine Lau | Doina Precup
Source: arXiv (Cornell University) (preprint, 2023-07-15)
Field: Materials Science — Materials Chemistry

An Empirical Study of the Effectiveness of Using a Replay Buffer on Mode Discovery in GFlowNets Reinforcement Learning (RL) algorithms aim to learn an optimal policy by iteratively sampling actions to learn how to maximize the total expected return, $R(x)$. GFlowNets are a special class of algorithms designed to generate diverse candidates, $x$, from a discrete set, by learning a policy that approximates the proportional sampling of $R(x)$. GFlowNets exhibit improved mode discovery compared to conventional RL algorithms, which is very useful for applications such as drug discovery and combinatorial search. However, since GFlowNets are a relatively recent class of algorithms, many techniques which are useful in RL have not yet been associated with them. In this paper, we study the utilization of a replay buffer for GFlowNets. We explore empirically various replay buffer sampling techniques and assess the impact on the speed of mode discovery and the quality of the modes discovered. Our experimental results in the Hypergrid toy domain and a molecule synthesis environment demonstrate significant improvements in mode discovery when training with a replay buffer, compared to training only with trajectories generated on-policy. Reinforcement learning ; Computer science ; Set (abstract data type) ; Sampling (signal processing) ; Class (philosophy) ; Mode (computer interface) ; Advice (programming) ; Quality (philosophy) ; Discovery learning ; Domain (mathematical analysis) ; Machine learning ; Artificial intelligence ; Mathematics ; Human–computer interaction Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Machine Learning and Algorithms
Authors: Shuaixin Fan | Wei-Ping Wu | Lili Fang | Jin Zhu
Source: ChemRxiv (preprint, 2023-02-14)
Field: Chemistry — Organic Chemistry

Catalytic Olefin-Imine Metathesis: Cobalt-Enabled Amidine Olefination with Enaminones Organic metathesis reactions, the transposition/redistribution of molecular fragments between two chemical entities, allow expedient assembly of diverse molecular skeletons and appendages through the merger of whole-piece building blocks. Olefin-imine variant of this chemical process, in particular, can expand the synthetic toolbox for manipulating carbon-carbon and carbon-nitrogen bonds but has thus far been achieved only on a stoichiometric metal-mediated basis. Herein we report the development of a catalytic olefin-imine metathesis reaction, featuring cobalt-catalyzed amidine olefination with enaminones. Comprehensive investigations offer evidence for a mechanistic sequence of exchange of enaminone amine with amidine imine, cobalt-catalyzed cyclization, and ring fragmentation. The reaction provides rapid access to structurally transformed, primary amine-bearing enaminones that can serve as a versatile synthon for further structural diversification. Amidine ; Imine ; Chemistry ; Catalysis ; Combinatorial chemistry ; Amine gas treating ; Salt metathesis reaction ; Alkene ; Cobalt ; Olefin fiber ; Organic chemistry ; Metathesis ; Polymerization ; Polymer Synthetic Organic Chemistry Methods ; Asymmetric Hydrogenation and Catalysis ; Chemical Synthesis and Analysis
Authors: Fatemeh Nasseri | Mohammad Ali Nasseri | M.Z. Kassaee | Issa Yavari
Source: Research Square (preprint, 2023-04-17)
Field: Chemistry — Organic Chemistry

Conjugated Cu-Ni bimetallic complex supported on Fe 3 O 4 @SiO 2 : An efficient nanocatalyst with synergistic performance for the solvent-free Sonogashira, and C-N cross-couplings Abstract Synthesis of a novel Cu-Ni bimetallic system comprising magnetic nanoparticles as the core and 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole (4-ABPT) as a conjugated bridge between nickel and copper species is described. With low Cu and Ni loading (0.06 mol% Ni, 0.08 mol% Cu), the resulting Fe 3 O 4 @SiO 2 @4-ABPT/Cu-Ni is discovered to be a highly efficient catalyst for the Sonogashira and C-N cross-coupling reactions. It is well characterized by FT-IR, XRD, EDX, FE-SEM, TEM, ICP, VSM, TGA/DTG/DTA, and XPS techniques. Fe 3 O 4 @SiO 2 @4-ABPT/Cu-Ni as a nanocatalyst in the Sonogashira and C-N cross-coupling reactions is compatible with a wide range of amines and aryl halides and gives desired coupling products in high to excellent yields under palladium- and solvent-free conditions. The XPS results show that the 4-ABPT as a ligand can adjust electron transfer between Ni and Cu in Fe 3 O 4 @SiO 2 @4-ABPT/Cu-Ni, which promotes the formation and stabilization of Cu + and Ni 3+ species. Electronic interactions and the synergistic effect between these metals increase the selectivity and activity of Fe 3 O 4 @SiO 2 @4-ABPT/Cu-Ni as a catalyst in the Sonogashira and C-N cross-coupling reactions in comparison with its monometallic counterparts. Additionally, the magnetic properties of the Fe 3 O 4 @SiO 2 @4-ABPT/Cu-Ni make it easy to separate from the reaction mixture, and it can be reused several times without a significant loss in its catalytic activity or performance. Bimetallic strip ; Sonogashira coupling ; Catalysis ; Materials science ; X-ray photoelectron spectroscopy ; Nickel ; Copper ; Palladium ; Crystallography ; Inorganic chemistry ; Chemistry ; Chemical engineering ; Organic chemistry ; Metallurgy Catalytic Cross-Coupling Reactions ; Nanomaterials for catalytic reactions ; Cyclopropane Reaction Mechanisms
Authors: Biswa Mohan Sahoo | Varsha Tiwari | Abhishek Tiwari | Bimal Krishna Banik
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2023-03-31)
Field: Chemistry — Organic Chemistry

Essential Oils as Raw Materials in the Synthesis of Anticancer Drugs Roland Institute of Pharmaceutical Sciences, Berhampur-760010, Odisha, India; Pharmacy Academy, IFTM University, Lodhipur Rajput, Moradabad-244102, Uttar Pradesh; Department of Mathematics and Natural Sciences, College of Sciences and Human Studies, Prince Mohammad Bin Fahd University, Al Khobar, Kingdom of Saudi Arabia; drbiswamohansahoo@gmail.com; bimalbanik10@gmail.com; bbanik@pmu.edu.sa Essential Oils as Raw Materials in the Synthesis of Anticancer Drugs Raw material ; Chemistry ; Biochemical engineering ; Nanotechnology ; Materials science ; Organic chemistry ; Engineering Synthesis of β-Lactam Compounds ; Chemical Reactions and Isotopes
Authors: Yucheng Zhou
Source:  (preprint, 2023-12-31)
Field: Materials Science — Ceramics and Composites

Demonstrating the impact of molecular weight on the glass transition temperature of poly-methyl methacrylate using molecular dynamics simulations Demonstrating the impact of molecular weight on the glass transition temperature of Glass transition ; Molecular dynamics ; Methyl methacrylate ; Poly(methyl methacrylate) ; Materials science ; Dynamics (music) ; Chemical physics ; Polymer chemistry ; Chemical engineering ; Polymer ; Chemistry ; Computational chemistry ; Composite material ; Physics ; Copolymer Glass properties and applications ; Adsorption, diffusion, and thermodynamic properties of materials ; Material Dynamics and Properties
Authors: Alexa Guglielmelli | Liliana Valente | Giovanna Palermo | Giuseppe Strangi
Source: arXiv (Cornell University) (preprint, 2023-06-29)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Unveiling Chirality: Exploring Nature's Blueprint for Engineering Nanostructured Materials Chirality, the property of asymmetry, is of great importance in biological and physical phenomena. This prospective offers an overview of the emerging field of chiral bioinspired plasmonics and metamaterials, aiming to uncover nature's blueprint for engineering nanostructured materials. These materials possess unique chiral structures, resulting in fascinating optical properties and finding applications in sensing, photonics, and catalysis. The first part of the prospective focuses on the design and fabrication of chiral metamaterials that mimic intricate structures found in biological systems. By employing self-assembly and nanofabrication techniques, researchers have achieved remarkable control over the response to light, opening up new avenues for manipulating light and controlling polarization. Chiral metamaterials hold significant promise for sensing applications, as they can selectively interact with chiral molecules, allowing for highly sensitive detection and identification. The second part delves into the field of plasmonics nanostructures, which mediate enantioselective recognition through optical chirality enhancement. Plasmonic nanostructures, capable of confining and manipulating light at the nanoscale, offer a platform for amplifying and controlling chirality-related phenomena. Integrating plasmonic nanostructures with chiral molecules presents unprecedented opportunities for chiral sensing, enantioselective catalysis, and optoelectronic devices. By combining the principles of chiral bioinspired plasmonics and metamaterials, researchers are poised to unlock new frontiers in designing and engineering nanostructured materials with tailored chiroptical properties. Metamaterial ; Nanotechnology ; Chirality (physics) ; Plasmon ; Blueprint ; Materials science ; Photonics ; Enantioselective synthesis ; Nanostructure ; Physics ; Chemistry ; Optoelectronics ; Engineering ; Catalysis ; Chiral anomaly Metamaterials and Metasurfaces Applications ; Polydiacetylene-based materials and applications
Authors: Hadi Poerwono | Marcellino Rudyanto
Source: Borneo Journal of Pharmacy (article, 2023-11-30)
Field: Chemistry — Organic Chemistry

Bibliometric Study of Microwave-Assisted Synthesis of Flavanone Derivatives This study aims to describe various studies related to synthesizing flavanone derivatives using the microwave-assisted method with a bibliometric approach. Metadata information was collected from Scopus on June 30th, 2023, with three keywords (microwave-assisted OR microwave, synthesis, and flavanone) searched for article titles, abstracts, and keywords. Analysis and research mapping were carried out with VOSviewer. Of the 33 articles relevant for analysis, 15 keyword clusters were obtained, most of which contained a list of flavanone derivatives. Interestingly, none of these clusters contain keywords for well-known compounds from the flavanone group, such as pinostrobin, pinocembrin, or hesperetin. In other words, there is an excellent opportunity to obtain novelty for microwave-assisted derivatization studies of flavanones. The chances of publication of these studies are greater in Chemistry of Heterocyclic Compounds (Springer Nature), Oriental Journal of Chemistry (Scientific Publishers), and Tetrahedron Letters (Elsevier), each with three documents. Meanwhile, most researchers on this topic come from India with 13 documents. This information allows researchers on this topic to determine potential flavanones that have the opportunity to be derivatized by the microwave-assisted method. Flavanone ; Chemistry ; Hesperetin ; Computer science ; Organic chemistry ; Flavonoid Synthesis and biological activity ; Synthesis of Organic Compounds ; Bioactive natural compounds
Authors: Zenan Shi | Shouwei Liao | Yanying Wei | Libo Li
Source:  (preprint, 2023-11-19)
Field: Materials Science — Materials Chemistry

Theoretical insights into He/CH4 separation by MXene nanopore Natural gas is currently the main industrial source of helium, thus He/CH4 separation has become increasing important, where two-dimensional materials have been considered to be a potential solution, but the gas transport mechanism within nanopores is not yet clear. Here, both non-equilibrium molecular dynamics (NEMD) and equilibrium MD (EMD) were employed to study the transport of He/CH4 through nanopores of different MXenes with various pore diameters (d), nanopores’ density and functional groups, which shows two main transport mechanisms, molecular sieving or Knudsen diffusion. Small d is found to be crucial for the molecular sieving mechanism and consequently, high He/CH4 selectivity (SHe/CH4). The density profiles of He/CH4 along permeation direction from EMD simulations were used to predict SHe/CH4 and permeance for the gas passing through different nanopores, yielding results well agreeing with NEMD simulations. This work provides theoretical insights into gas transport in MXene nanopore for future nanopore designing engineering. Nanopore ; Permeance ; Molecular dynamics ; Permeation ; Gas separation ; Chemical physics ; Knudsen number ; Materials science ; Nanotechnology ; Membrane ; Chemistry ; Computational chemistry ; Thermodynamics ; Physics MXene and MAX Phase Materials ; Graphene research and applications ; Membrane Separation and Gas Transport
Authors: Sonali Yadav | Sudha Vishwakarma | Samreen shaikh | Mohammad Wais
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2023-01-14)
Field: Chemistry — Analytical Chemistry

NOVEL APPROCHES FOR OPHTHALMIC DRUG DELIVERY SYSTEM This review's goal is to provide readers with an up-to-date summary of what is currently known about ocular medication delivery. The unusual architecture and physiology of the eye have presented a significant barrier to drug delivery scientists. The rapid precorneal drug loss caused by nasolacrimal drainage, tear turnover, and drug dilution leading to low bioavailability is one of the main issues with conventional ocular dose forms. These efforts resulted in the creation of innovative drug delivery dosage forms such as mucoadhesive formulation, liposomes, occuserts, and nanoparticles. In terms of increasing medication bioavailability, lowering toxicity, and reducing dosing frequency, controlled drug delivery systems have significant benefits over conventional dosage forms. Drug delivery may be greatly enhanced in the future by developing non-invasive sustained drug delivery systems and examining the viability of topical application to deliver drugs to the posterior segment. Drug delivery ; Drug ; Medicine ; Computer science ; Optometry ; Pharmacology ; Nanotechnology ; Materials science Analytical Methods in Pharmaceuticals
Authors: Hadi Wazni | Mehrnoosh Sadrzadeh
Source: arXiv (Cornell University) (preprint, 2023-12-01)
Field: Materials Science — Materials Chemistry

Towards Transparency in Coreference Resolution: A Quantum-Inspired Approach Guided by grammatical structure, words compose to form sentences, and guided by discourse structure, sentences compose to form dialogues and documents. The compositional aspect of sentence and discourse units is often overlooked by machine learning algorithms. A recent initiative called Quantum Natural Language Processing (QNLP) learns word meanings as points in a Hilbert space and acts on them via a translation of grammatical structure into Parametrised Quantum Circuits (PQCs). Previous work extended the QNLP translation to discourse structure using points in a closure of Hilbert spaces. In this paper, we evaluate this translation on a Winograd-style pronoun resolution task. We train a Variational Quantum Classifier (VQC) for binary classification and implement an end-to-end pronoun resolution system. The simulations executed on IBMQ software converged with an F1 score of 87.20%. The model outperformed two out of three classical coreference resolution systems and neared state-of-the-art SpanBERT. A mixed quantum-classical model yet improved these results with an F1 score increase of around 6%. Coreference ; Computer science ; Natural language processing ; Sentence ; Artificial intelligence ; Machine translation ; Classifier (UML) ; Pronoun ; Quantum ; Linguistics ; Resolution (logic) ; Physics ; Quantum mechanics Machine Learning in Materials Science ; Quantum Computing Algorithms and Architecture ; Topic Modeling
Authors: Marco T. Passia | Niklas Bormann | Jas S. Ward | Kari Rissanen | Carsten Bolm
Source: Angewandte Chemie (article, 2023-05-04)
Field: Chemistry — Organic Chemistry

Synthesis of <i>N</i>‐Monosubstituted Sulfondiimines by Metal‐free Iminations of Sulfilimium Salts Abstract Sulfondiimines are marginalized entities among nitrogen‐containing organosulfur compounds, despite offering promising properties for applications in various fields including medicinal and agrochemical. Herein, we present a metal‐free and rapid synthetic procedure for the synthesis of N ‐monosubstituted sulfondiimines that overcomes current limitations in their synthetic accessibility. Particularly, S , S ‐dialkyl substrates, which are commonly difficult to convert by existing methods, react well with a combination of iodine, 1,8‐diazabicyclo[5.4.0]undec‐7‐en (DBU), and iminoiodinanes (PhINR) in acetonitrile (MeCN) to furnish the corresponding sulfondiimines in yields up to 85 % (25 examples). Valuable “free” N H‐ N ′H‐sulfondiimines can then be accessed by N ‐deprotection under mild reaction conditions. Several experimental observations suggest a mechanistic pathway diverging from the common radical‐based iodine/iminoiodinane mechanism. Based on the experimental results in combination with data obtained by 1 H NMR spectroscopy, ESI mass spectrometry, and crystallographic analysis we propose a direct amination from PhINNs and a reaction path via a cationic iodonitrene. Chemistry ; Acetonitrile ; Amination ; Cationic polymerization ; Combinatorial chemistry ; Organosulfur compounds ; Nuclear magnetic resonance spectroscopy ; Organic chemistry ; Sulfur ; Catalysis Synthesis and Catalytic Reactions ; Sulfur-Based Synthesis Techniques ; Catalytic C–H Functionalization Methods
Authors: Beatriz Mouriño | Kevin Maik Jablonka | Andres Ortega‐Guerrero | Berend Smit
Source: ChemRxiv (preprint, 2023-02-06)
Field: Materials Science — Materials Chemistry

In search of Covalent Organic Framework photocatalysts: A DFT-based screening approach Covalent organic frameworks (COFs) stand out as prospective organic-based photocatalysts given their intriguing optoelectronic properties, such as visible light absorption and high charge-carrier mobility. The CURATED COFs is a database of reported experimental COFs that until now remained mostly unexplored for photocatalysis. In this work, we screen the CURATED COFs database for discovering potential photocatalysts using a set of DFT-based descriptors that cost-effectively assesses visible light absorption, preliminary thermodynamic feasibility of the desired pair of redox reactions, charge separation, and charge-carrier mobility. The workflow can shortlist 13 COFs as prospective candidates for water splitting, and identify materials (Nx-COF, x=0-3) that have been reported as candidates for Hydrogen evolution reaction (HER). Overall, our strategy tackles the challenge of having too many COFs to explore by channeling the focus of future research to a selective group of COFs while elucidating insights into the structure design for a desired photocatalytic process. Workflow ; Photocatalysis ; Covalent bond ; Absorption (acoustics) ; Charge carrier ; Nanotechnology ; Materials science ; Water splitting ; Computer science ; Visible spectrum ; Redox ; Chemistry ; Biochemical engineering ; Catalysis ; Optoelectronics ; Database ; Organic chemistry ; Engineering Covalent Organic Framework Applications ; Advanced Photocatalysis Techniques ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Tumelo H. Tabane | Bareki S. Batlokwa
Source: Journal of Drug Delivery and Therapeutics (article, 2023-11-15)
Field: Materials Science — Biomaterials

A comparative evaluation of two approaches for loading a therapeutic agent into custom fabricated electrospun nanofiber based innovative wound bandages In this work, we evaluated two different approaches; the pvpi_blended and the pvpi_soaked approaches, of loading a model therapeutic agent, povidone-iodine (pvpi), into innovatively fabricated, electrospun poly-Ɛ-caprolactone (PCL) nanofiber based wound bandages. The two loading approaches were compared based on the critical parameters that an excellent wound dressing material must possess; loading capacity, therapeutic agent releasing behavior and wettability. From the results, the pvpi_blended approach PCL nanofiber mats with their higher calculated pvpi loading capacities of 97.0% outperformed the pvpi_soaked approach PCL nanofiber mats with 61.2%. They further outclassed the soaked_approach mats when it came to pvpi release time, recording a longer prolonged time of 98 min compared to shorter, faster time of 18 min for the release of 50% or more of pvpi for both. Furthermore, it was found out that the presence of the hydrophilic pvpi within the structure of the prepared PCL nanofiber mats bandages, altered the natural hydrophobicity of the pure PCL mats to slightly hydrophilic making them compatible with the hydrophilic wound exudates and their excellent absorbers. Additionally, the pvpi_loaded PCL nanofiber mat bandages exhibited favorable morphological attributes such as smooth surfaces, nano sized fibers with estimated diameters of 350 nm and high surface area to volume ratio, that supported high performance efficiency of the prepared materials. Overall, the blended presented itself as an approach of choice for incorporating medication when developing medicated nanofiber-based bandages such as the ones in this study, which are potential replacements of the conventional drug wasting, micro-structured cotton bandages.&#x0D; Keywords: Electrospinning, Nanostructured bandages, Electrospun nanofiber bandages, Innovative drug delivery bandages, Smart bandages, Blended approach, Chronic wounds. Nanofiber ; Materials science ; Electrospinning ; Nanotechnology ; Wound dressing ; Biomedical engineering ; Composite material ; Medicine ; Polymer Electrospun Nanofibers in Biomedical Applications ; Advanced Sensor and Energy Harvesting Materials ; Polymer Nanocomposite Synthesis and Irradiation