jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Wen Zhao | Changjiang Wu | Jian Chen | Shuzhang Qu | Xinwei Li | Wei Wang
Source: Polymers (article, 2024-02-01)
Field: Chemistry — Organic Chemistry

Homogeneous Non-Metallocene Group 4 Metals Ligated with [N,N] Bidentate Ligand(s) for Olefin Polymerization The development of catalysts has significantly advanced the progress of polyolefin materials. In particular, group 4 (Ti, Zr, Hf) non-metallocene catalysts ligated with [N,N] bidentate ligand(s) have garnered increasing attention in the field of olefin polymerization due to their structurally stability and exceptional polymerization behaviors. Ligands containing nitrogen donors are diverse and at the core of many highly active catalysts. They mainly include amidine, guanidinato, diamine, and various N-heterocyclic ligands, which can be used to obtain a series of new polyolefin materials, such as ultrahigh molecular weight polyethylene (UHWMPE), olefin copolymers (ethylene/norbornene and ethylene/α-olefin) with high incorporations, and high isotactic or syndiotactic polypropylene after coordination with group 4 metals and activation by cocatalysts. Herein, we focus on the advancements and applications of this field over the past two decades, and introduce the catalyst precursors with [N,N] ligand(s), involving the effects of ligand structure, cocatalyst selection, and polymerization conditions on the catalytic activity and polymer properties. Polyolefin ; Polymerization ; Metallocene ; Tacticity ; Polymer chemistry ; Norbornene ; Post-metallocene catalyst ; Coordination polymerization ; Ligand (biochemistry) ; Materials science ; Denticity ; Olefin polymerization ; Olefin fiber ; Polyethylene ; Catalysis ; Polymer ; Chemistry ; Organic chemistry ; Solution polymerization ; Crystal structure Organometallic Complex Synthesis and Catalysis ; Carbon dioxide utilization in catalysis ; Synthetic Organic Chemistry Methods
Authors: Zainab Ishfaq | Layla A. Almutairi | M. Yasir Ali | Salhah Hamed Alrefaee | Mohamed Abdelsabour Fahmy | Elsammani Ali Shokralla | Lamiaa G. Alharbe | Adnan Ali | Arslan Ashfaq | A.R. Abd-Elwahed
Source: RSC Advances (article, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Enhanced surface functionalization of 2D molybdenum/tin chalcogenide nanostructures for effective SERS detection of <i>Escherichia coli</i> Surface Enhanced Raman Spectroscopy (SERS) is a highly sensitive analytical technique used for fingerprint recognition of molecular samples. The SERS effect, which enhances Raman scattering signals, has been the subject of extensive research over the past few decades. More recently, the commercialization of portable Raman spectrometers has brought SERS closer to real-world applications. The aim of the study was to enhance their performance, properties, and biocompatibility for potential use as SERS substrates. The synthesis and characterization of MoS<sub>2</sub> and SnS<sub>2</sub> nanoparticles are described, along with the functionalization process using l-cysteine. The detection and identification of <i>Escherichia coli</i> (<i>E. coli</i>) bacteria using MoS<sub>2</sub> and SnS<sub>2</sub> as SERS substrates are also investigated. The results demonstrate the successful functionalization and characterization of the nanostructures, indicating their potential as SERS substrates. The abstract highlights the importance of developing cost-effective and environmentally friendly disposable analysis chips with high accuracy and specificity for practical SERS applications. Chalcogenide ; Surface modification ; Tin ; Molybdenum ; Nanotechnology ; Nanoparticle ; Nanostructure ; Molybdenum disulfide ; Photothermal therapy ; Chemistry ; Escherichia coli ; Materials science ; Combinatorial chemistry ; Inorganic chemistry ; Optoelectronics ; Organic chemistry ; Biochemistry ; Metallurgy Gold and Silver Nanoparticles Synthesis and Applications ; Advanced biosensing and bioanalysis techniques ; Advanced Nanomaterials in Catalysis
Authors: Yawen Yang | Bei Liu | Yufeng Li | Haibin Yin
Source: Journal of Polymer Science (article, 2024-04-06)
Field: Materials Science — Polymers and Plastics

Experimental and molecular dynamics study on thermal‐mechanical properties of epoxy shape memory polymers Abstract Experimental and molecular dynamics simulations were employed to investigate epoxy shape memory polymers' thermal‐mechanical properties and shape memory characteristics, utilizing polyether amine and modified hexanediamine as curing agents following the material prerequisites for variable stiffness fixtures. Glass transition temperature and Young's modulus of epoxy shape memory polymers are characterized by dynamic mechanical analysis. The consistency of the glass transition temperature between the simulation model and the experimental findings verified the accuracy of the molecular dynamics simulation. The uniaxial tensile simulation revealed that non‐bond energy predominantly exerts its influence in stretch. After reaching the yield stress, the weight fraction of the curing agent affects the generation of internal pores, with the yield stress of systems exhibiting substantial pores being minor. Systems characterized by a higher weight fraction of curing agents are more prone to pore formulation. Simulation of shape memory properties demonstrates that the entropy resulting from differences in molecular weight impacts the simulated system's shape fixation ratio and shape recovery ratio. Epoxy ; Polymer ; Molecular dynamics ; Materials science ; Thermal ; Composite material ; Shape-memory polymer ; Dynamics (music) ; Polymer science ; Polymer chemistry ; Computational chemistry ; Chemistry ; Thermodynamics ; Physics Polymer composites and self-healing ; Photochromic and Fluorescence Chemistry ; Photopolymerization techniques and applications
Authors: Kevin O’Toole | Mark M. McGrath | David W. Hatchett
Source: Mechanika (article, 2024-04-04)
Field: Materials Science — Materials Chemistry

Transient characterisation and analysis of shape memory alloy wire bundles for the actuation of finger joints in prosthesis design Most current lower arm/hand prosthesis designs incorporate relatively bulky, heavy dc motors that produce substantial noise when performing actuation which rendersthem uncomfortable for the end-user. The engineering challenge is to produce more effective powered upper limb prosthetic solutions. Identification, characterisation and testing of actuation methods with better force to weight ratios are essential pre-requisites for this. The main aim of this work is to carry out a comprehensive study to establish conclusively the feasibility of employing Shape Memory Alloys (SMA’s) in the actuation of prosthetic finger designs. A comprehensive review of existing literature has been undertaken in order to establish the maximum grip forces at each phalanx of the human hand under different loading conditions. An experiment was developed in conjunction with this review to estimate the time response of the hand during a gripping/releasing action. These results, in combination with physical dimensions, will be used to drive the design of a prosthetic limb. A test rig has been developed which can facilitate complete transient and steady-state characterisation of a range of SMA wire diameters and bundle configurations. Anumber of different configurations were tested, each configuration having a different combination of 150 μm and 300 μm diameter nitinol wires. A data acquisition systemwas used to capture and retain data pertaining to the full characterisation of the bundles and in particular the strain and force capabilities of the various arrangements. A direct comparison is made between the actuator capabilities and the requirements of a working limb for basic gripping actions. This work will contribute to the development of an improved powered prosthetic solution. Shape-memory alloy ; Transient (computer programming) ; Prosthesis ; Materials science ; Alloy ; Structural engineering ; Actuator ; Mechanical engineering ; Composite material ; Computer science ; Engineering ; Electrical engineering ; Artificial intelligence Shape Memory Alloy Transformations
Authors: Hye Jin Jeong | Cyrus Picou | Keunhong Jeong | Jean K. Chung
Source: ACS Chemical Biology (article, 2024-07-22)
Field: Chemistry — Organic Chemistry

Oxidation Kinetics of Fluorescent Membrane Lipid Peroxidation Indicators The oxidation of the cellular membrane through lipid peroxidation (LPO) is linked to aging and disease. Despite the physiological importance, the chemical mechanisms underlying LPO and oxidative reactions in membranes in general remain incompletely understood, and challenges exist in translating LPO inhibitor efficacies from in vitro to in vivo. The complexity of LPO, including multiple oxidation reactions in complex membrane environments and the difficulty in quantifying reaction kinetics, underlies these difficulties. In this work, we developed a robust and straightforward method for quantifying the oxidation rate kinetics of fluorescent molecules and determined the oxidation kinetics of widely fluorophores used as indicators of membrane LPO, diphenylhexatriene (DPH), BODIPY-C11, and Liperfluo. The measurement is initiated by lipoxygenase, which provides chemical specificity and enables a straightforward interpretation of oxidation kinetics. Our results reveal that the membrane composition significantly impacts the observed kinetics oxidation in DPH and BODIPY-C11 but not Liperfluo. Reaction mechanisms for their lipid peroxide-induced oxidation are proposed. This work provides a foundation for the quantitative analysis of LPO with fluorescence and extricating the complexity of oxidation reactions within membranes. Kinetics ; Lipid peroxidation ; Fluorescence ; Biophysics ; Chemistry ; Membrane ; Lipid oxidation ; Biochemistry ; Biology ; Oxidative stress ; Antioxidant Free Radicals and Antioxidants ; Electrochemical Analysis and Applications ; Electrochemical sensors and biosensors
Authors: Rong Song | Dingyi Shen | Dongyan Liu | Jingyi Liang | Zimei Zhang | Jingmei Tang | Liang Chen | Bo Li | Li Jia | Xidong Duan
Source: Nano Research (article, 2024-12-16)
Field: Materials Science — Materials Chemistry

Synthesis of wafer-scale monolayer MoS <sub>2</sub> on sapphire: Unlocking the influence of key growth parameters Large-scale synthesis of high-quality two-dimensional (2D) semiconductors, such as molybdenum disulfide (MoS<sub>2</sub>), is a prerequisite for their lab-to-fab transition. It is crucial to systematically explore and understand the influence of key synthetic conditions on the nucleation, uniformity, and quality of MoS<sub>2</sub> wafers. Here, we report the epitaxial growth of high-quality and uniform monolayer MoS<sub>2</sub> films on 2-in c-plane sapphire by chemical vapor deposition (CVD) method under optimized growth conditions (0–1 mg NaCl, adequate S/Mo ratio, and the addition of 0–1 sccm O<sub>2</sub>). We systematically explore the influence of critical synthetic conditions on the nucleation, and stitching of MoS<sub>2</sub> domains over the wafer scale, including the dosage of the alkali metal salt NaCl additive, the evaporation temperature of MoO<sub>3</sub>, the distance between MoO<sub>3</sub> and the substrate, and the flow rate of O<sub>2</sub>. Among them, the dosage of NaCl and the S/Mo ratio have important influences on the quality and film coverage of MoS<sub>2</sub>, while the flow rate of O<sub>2</sub> plays a key role in controlling the nucleation density and domain size. We further discovered that a-plane sapphire could easily guide the unidirectional growth of MoS<sub>2</sub> without the need for other specific synthetic conditions compared with c-plane and m-plane sapphire. The field-effect transistors (FETs) fabricated from the full-coverage films show an average and the highest mobilities of 28.5 and around 45 cm<sup>2</sup>·V<sup>−1</sup>·s<sup>−1</sup>, respectively. Monolayer ; Wafer ; Materials science ; Key (lock) ; Nanotechnology ; Scale (ratio) ; Sapphire ; Optoelectronics ; Engineering physics ; Computer science ; Engineering ; Physics ; Optics 2D Materials and Applications ; MXene and MAX Phase Materials ; Ichthyology and Marine Biology
Authors: Renjie Niu | Jiale Du | Wenqing He | Liwen Liu | Jie Chao
Source: Nano Research (article, 2024-12-17)
Field: Materials Science — Electronic, Optical and Magnetic Materials

DNA-based plasmonic nanostructures with tailored optical responses Plasmonic nanostructures, particularly those composed of noble metals such as gold and silver, have garnered extensive attention due to their exceptional physical and chemical properties, which are highly advantageous for optical sensing applications. The unique characteristics of DNA enable the precise spatial arrangement and functionalization of nanoparticles, allowing for the tailoring of optical characteristics within plasmonic systems. This review encompasses the development of DNA nanotechnology and its application in constructing plasmonic nanostructures featuring diverse geometric configurations. It emphasizes the tailored optical responses of these structures, including surface-enhanced Raman scattering (SERS), fluorescence enhancement, and chirality. The review concludes with a discussion of the opportunities and challenges facing DNA-based plasmonic nanostructures. Plasmon ; Nanotechnology ; Nanostructure ; Materials science ; DNA ; Optoelectronics ; Chemistry Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Advanced biosensing and bioanalysis techniques
Authors: L Krog | Shinji Kihara | Pablo Mota‐Santiago | Vito Foderà | Kārlis Bērziņš | Ben J. Boyd
Source: Journal of Colloid and Interface Science (article, 2024-12-07)
Field: Chemistry — Spectroscopy

Low-frequency Raman spectroscopy as a new tool for understanding the behaviour of ionisable compounds in dispersed mesophases The intensity of the VDOS signal of MO + OA mesophases scaled with phase-specific transformations, such as from the bi-continuous cubic Im3¯m phase (V<sub>2</sub>) or lamellar-based vesicles to the reversed hexagonal p6m phase (H<sub>2</sub>). For NG subtle changes in the lattice parameter of the V<sub>2</sub> phase of NG + MO mesophases coincided with the apparent dissociation constant (pK<sub>a</sub><sup>app</sup>) of NG, however, slight variations between the pK<sub>a</sub><sup>app</sup> of NG determined by equilibrated samples analysed using SAXS and non-equilibrated samples analysed using LFR suggest structural hysteresis upon changes in the protonation state of NG. This approach offers an efficient method for studying the phase behaviour of lipid systems under varying pH and potentially other conditions such as temperature. Raman spectroscopy ; Spectroscopy ; Chemistry ; Chemical engineering ; Nuclear magnetic resonance spectroscopy ; Organic chemistry ; Materials science ; Analytical Chemistry (journal) ; Nanotechnology ; Physics ; Engineering ; Optics Analytical Chemistry and Chromatography ; Surfactants and Colloidal Systems ; Porphyrin and Phthalocyanine Chemistry
Authors: Despoina Langari | Fani Th. Mantzouridou
Source: Exploration of Foods and Foodomics (article, 2024-09-26)
Field: Chemistry — Organic Chemistry

Analytical aspects of metagenomic and volatilomic approaches that advance table olive integrity research Table olives are one of the most widespread fermented foods in the Mediterranean area, presenting an exponential increase in global consumption in the latest years. As a fermented product, its microbiota consists of a complex ecosystem, the composition of which depends on a multitude of factors and affects the quality attributes of the final product. The swiftly developing and constantly evolving field of omics technologies is being applied to unravel the profile of the microbial ecosystem and enable a deeper understanding of the fermentation process. In particular, the use of amplicon metagenomics facilitates the thorough analysis of the microbiota involved as it encompasses both culturable and unculturable microorganisms. Volatilomics aims at the identification and quantification of the volatile metabolites formed during fermentation with a direct involvement in the safety and quality evaluation of the food product. The integration of metagenomic and volatilomic data, through the application of bioinformatics can enhance the understanding of the interplay between the microbial profile and volatilome, resulting in a more comprehensive view of the system. This review summarized the overall amplicon metagenomics and volatilomics analytical approaches, along with the currently available bioinformatics tools for the data analysis in the field of table olives. Emphasis is given to the integration of amplicon metagenomic and volatilomic data employed to characterize the diversity of microbial populations and reveal the relationships between them and the volatile compounds. The latter may provide an extensive view of the microbial community dynamics, which is key in table olive fermentation and the microbiota’s functional properties. The potentiality to evaluate their effect in shaping the quality and unique features of the final product is highlighted. Metagenomics ; Table (database) ; Computational biology ; Biology ; Computer science ; Biochemical engineering ; Engineering ; Data mining ; Genetics Edible Oils Quality and Analysis ; Horticultural and Viticultural Research ; Fermentation and Sensory Analysis
Authors: Katherine Graham | Vincent J. Grisolia | Nicholas B. Borotto
Source: Journal of the American Society for Mass Spectrometry (article, 2024-06-26)
Field: Chemistry — Spectroscopy

Mobility-Assisted Pseudo-MS<sup>3</sup> Sequencing of Protein Ions The sequencing of intact proteins within a mass spectrometer has many benefits but is frequently limited by the fact that tandem mass spectrometry (MS/MS) techniques often generate poor sequence coverages when applied to protein ions. To overcome this limitation, exotic MS/MS techniques that rely on lasers and radical chemistry have been developed. These techniques generate high sequence coverages, but they require specialized instrumentation, create products through multiple dissociation mechanisms, and often require long acquisition times. Recently, we demonstrated that protein ions can be dissociated in a trapped ion mobility spectrometry (TIMS) device prior to mobility separation in a commercial timsTOF. All generated product ions were distributed throughout the mobility dimension, and this separation enabled deconvolution of complex tandem mass spectra and could enable facile pseudo-MS<sup>3</sup> interrogation of generated product ions with the downstream quadrupole and collision cell. A second activation step improves sequence coverage because the most labile bonds have been depleted during the first dissociation and subsequent dissociation events are more evenly distributed throughout the product ion backbone. In this work, we explore the potential of this mobility-assisted pseudo-MS<sup>3</sup> (MAP) method on a commercial timsTOF and timsTOF Pro 2. We demonstrate that while MAP only generates 92% of the sequence coverage of the most effective MS/MS technique, it accomplished this feat in 1.5 min and could be facilely integrated with liquid chromatographic separations. Chemistry ; Mass spectrometry ; Tandem mass spectrometry ; Ion-mobility spectrometry ; Ion ; Tandem ; Top-down proteomics ; Dissociation (chemistry) ; Analytical Chemistry (journal) ; Chromatography ; Protein mass spectrometry ; Physical chemistry Mass Spectrometry Techniques and Applications ; Advanced Proteomics Techniques and Applications ; Analytical Chemistry and Chromatography
Authors: Weizhao Gu | Simone Lamon | Haoyi Yu | Hui Zhang | Haibo Ding | Miṅ Gu | Qiming Zhang
Source: Advanced Optical Materials (article, 2024-10-24)
Field: Materials Science — Materials Chemistry

Thermo‐Optical Sub‐Micrometer Ultrahigh Luminescence Emission Tuning in Hybrid Organic–Inorganic Upconversion Nanocomposites for Data Storage and Anticounterfeiting Abstract Nanophotonics techniques, driven by optical microscopy, enable high‐capacity data recording and readout, yet ensuring data security demands versatile, multi‐stimuli activatable media. Lanthanide ion‐doped upconversion nanoparticles hold promise for these applications by fine‐tuning upconversion luminescence emission. While chemical methods customize this emission with meticulous adjustments, optical methods face challenges such as high laser beam intensities, setup complexity, and wavelength limitations. Efficiently modulating upconversion luminescence emission requires multi‐stimuli methods or integrating upconversion nanoparticles with responsive materials. Here, dual‐stimulus thermo‐optical activation and optical microscopy are used to achieve sub‐micrometer ultrahigh upconversion luminescence emission tuning in newly developed hybrid organic–inorganic upconversion nanocomposites for high‐capacity and secure data storage and anticounterfeiting. Thermal stimulus (activation I) facilitates a 102‐fold increase in absorption, promoting the formation of an inorganic network and complex. Optical stimulus via focused 460‐nm femtosecond laser beam irradiation (activation II) enhances absorption by fivefold through sub‐micrometer photo‐polymerization bit recording. The method achieves a 92% decrease of 450‐nm upconversion luminescence emission intensity after activation I and over 90% quenching of this emission after activation II, enabling sub‐micrometer bit readout under 980‐nm continuous‐wave excitation laser beam irradiation. This work demonstrates the potential for high‐capacity and secure data storage, anticounterfeiting, high‐security encryption, and high‐resolution display. Materials science ; Photon upconversion ; Nanocomposite ; Luminescence ; Aggregation-induced emission ; Optoelectronics ; 3D optical data storage ; Micrometer ; Nanotechnology ; Optics ; Fluorescence Luminescence Properties of Advanced Materials ; Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics
Authors: Eliza K. Hanson | Samuel W. Foster | Christopher Piccolo | James P. Grinias
Source: Journal of Chromatography Open (article, 2024-10-30)
Field: Chemistry — Spectroscopy

Considerations for method development and method translation in capillary liquid chromatography: A tutorial HPLC continues to be one of the most widely used measurement techniques for chemical analysis. Capillary LC, which utilizes narrow diameter columns operated at lower flow rates than analytical-scale LC, continues to gain adoption based on its reduced mobile phase consumption and increased sensitivity when coupled to MS detection. This tutorial offers practical insights into the most critical aspects of translating analytical-scale separations to the capillary scale. The selection of pumping systems, detectors, and the potential for performance loss due to extra-column effects are examined within the context of separations using columns with inner diameters ≤ 0.3 mm. Column choices within this diameter range are also detailed, both in terms of stationary phase support options and general commercial availability. The impact of these various factors on the effective development/translation of LC methods down to flow rates under 10 μL/min is described to provide readers with a basis for implementing these strategies within their own analytical workflows. Translation (biology) ; Chromatography ; Capillary action ; Computer science ; Chemistry ; Materials science ; Biochemistry Analytical Chemistry and Chromatography ; Microfluidic and Capillary Electrophoresis Applications ; Chromatography in Natural Products