jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Julien Bauland | Louis-Vincent Bouthier | Arnaud Poulesquen | Thomas Gibaud
Source: Journal of Rheology (preprint, 2024-04-11)
Field: Materials Science — Materials Chemistry

Attractive carbon black dispersions: Structural and mechanical responses to shear The rheological behavior of colloidal dispersions is of paramount importance in a wide range of applications, including construction materials, energy storage systems, and food industry products. These dispersions consistently exhibit non-Newtonian behaviors, a consequence of intricate interplays involving colloids morphology, volume fraction, and interparticle forces. Understanding how colloids structure under flow remains a challenge, particularly in the presence of attractive forces leading to cluster formation. In this study, we adopt a synergistic approach, combining rheology with ultra small-angle x-ray scattering, to probe the flow-induced structural transformations of attractive carbon black (CB) dispersions and their effects on the viscosity. Our key findings can be summarized as follows. First, testing different CB volume fractions, in the high shear rate hydrodynamic regime, CB particles aggregate to form fractal clusters. Their size conforms to a power law of the shear rate, ξc∝γ˙−m, with m≃0.5. Second, drawing insights from the fractal structure of clusters, we compute an effective volume fraction ϕeff and find that microstructural models adeptly account for the hydrodynamic stress contributions. We identify a critical shear rate γ∗˙ and a critical volume fraction ϕeff∗, at which the clusters percolate to form a dynamical network. Third, we show that the apparent yield stress measured at low shear rates inherits its properties from the percolation point. Finally, through data scaling and the integration of Einstein’s viscosity equation, we revisit and discuss the Caggioni–Trappe–Spicer model, revealing a significant connection between its empirical parameters and the structural properties of CB dispersions under flow. Carbon black ; Shear (geology) ; Materials science ; Geology ; Composite material Carbon Nanotubes in Composites ; Fiber-reinforced polymer composites ; Cultural Heritage Materials Analysis
Authors: Mohammad Kamruzzaman | Samiul Alam
Source: Heliyon (article, 2024-11-01)
Field: Materials Science — Polymers and Plastics

Influence of stacking sequence on the mechanical properties of banana-glass fiber hybrid laminates for automotive shells The development of composite materials using natural fibers has garnered significant global research interest. Banana fibers, due to their abundant availability and rapid growth cycle, present a promising option for composite material development. When combined with synthetic fibers to form hybrid composites, the resulting material may exhibit significantly improved properties, which is desirable for automotive body manufacturing. The hybrid properties of such composites, however, remain largely unexplored and require thorough evaluation. This study investigates the mechanical performance of hybrid laminated composites fabricated from banana and woven glass fibers bonded with epoxy resin. The composites were produced using non-crimp banana (B) fiber and woven glass (WG) fiber fabrics through the hand lay-up process with four distinct stacking sequences: [WG/B-0⁰/B-0⁰/WG], [WG/B-0⁰/B-45⁰/WG], [WG/B-0⁰/B-60⁰/WG], and [WG/B-0⁰/B-90⁰/WG]. Comprehensive mechanical testing, including tensile, flexural, impact, and hardness tests, along with environmental testing (water diffusion) was conducted in accordance with ASTM standards. Results indicated that the [WG/B-0⁰/B-0⁰/WG] configuration exhibited the highest tensile strength, while the [WG/B-0⁰/B-60⁰/WG] configuration achieved superior flexural strength. The [WG/B-0⁰/B-45⁰/WG] configuration demonstrated the highest impact strength and energy absorption. Rockwell hardness testing revealed that the average hardness numbers for all orientations were approximately 79, which is considered moderate for composite materials. Water absorption tests showed maximum water saturation in [WG/B-0⁰/B-90⁰/WG] of ∼5.5 %, where the other laminates had water saturation between 4.5 and 4.9 %. The microscopic analysis of the [WG/B-0⁰/B-45⁰/WG] laminate suggests fiber-matrix debonding and fiber pull-out as the major cause of failure under tensile and flexural loading. These findings suggest that the hybrid laminated composites, particularly the [WG/B-0⁰/B-0⁰/WG] and [WG/B-0⁰/B-45⁰/WG] configurations, exhibit mechanical properties suitable for automotive body applications. Glass fiber ; Materials science ; Composite material ; Automotive industry ; Stacking ; Sequence (biology) ; Fiber ; Polymer science ; Engineering ; Chemistry ; Organic chemistry Natural Fiber Reinforced Composites ; Mechanical Engineering and Vibrations Research ; Textile materials and evaluations
Authors: Olivier Henrotte | Štěpán Kment | Alberto Naldoni
Source: Nano Letters (article, 2024-07-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Mass Transport Limitations in Plasmonic Photocatalysis The interpretation of mechanisms governing hot carrier reactivity on metallic nanostructures is critical, yet elusive, for advancing plasmonic photocatalysis. In this work, we explored the influence of the diffusion of molecules on the hot carrier extraction rate at the solid-liquid interface, which is of fundamental interest for increasing the efficiency of photodevices. Through a spatially defined scanning photoelectrochemical microscopy investigation, we identified a diffusion-controlled regime hindering the plasmon-driven photochemical activity of metallic nanostructures. Using low-power monochromatic illumination (<2 W cm<sup>-2</sup>), we unveiled the hidden influence of mass transport on the quantum efficiency of plasmonic photocatalysts. The availability of molecules at the solid-liquid interface directly limits the extraction of hot holes, according to their nature and energy, at the reactive spots in Au nanoislands on an ultrathin TiO<sub>2</sub> substrate. An intriguing question arises: does the mass transport enhancement caused by thermal effects unlock the reactivity of nonthermal carriers under steady state? Photocatalysis ; Plasmon ; Nanotechnology ; Materials science ; Mass transport ; Plasmonic nanoparticles ; Optoelectronics ; Chemistry ; Engineering physics ; Physics ; Catalysis Gold and Silver Nanoparticles Synthesis and Applications ; Advanced Photocatalysis Techniques ; Advanced biosensing and bioanalysis techniques
Authors: Roselien Vercauteren | Clémentine Gevers | Jacques Mahillon | Laurent A. Francis
Source: Biosensors (article, 2024-02-17)
Field: Materials Science — Materials Chemistry

Design of a Porous Silicon Biosensor: Characterization, Modeling, and Application to the Indirect Detection of Bacteria The design of a porous silicon (PSi) biosensor is not often documented, but is of the upmost importance to optimize its performance. In this work, the motivation behind the design choices of a PSi-based optical biosensor for the indirect detection of bacteria via their lysis is detailed. The transducer, based on a PSi membrane, was characterized and models were built to simulate the analyte diffusion, depending on the porous nanostructures, and to optimize the optical properties. Once all performances and properties were analyzed and optimized, a theoretical response was calculated. The theoretical limit of detection was computed as 10<sup>4</sup> CFU/mL, based on the noise levels of the optical setup. The experimental response was measured using 10<sup>6</sup> CFU/mL of <i>Bacillus cereus</i> as model strain, lysed by bacteriophage-coded endolysins PlyB221. The obtained signal matched the expected response, demonstrating the validity of our design and models. Biosensor ; Porous silicon ; Analyte ; Detection limit ; Materials science ; Lysis ; Silicon ; Transducer ; Biological system ; Bacillus cereus ; Nanotechnology ; Optoelectronics ; Chemistry ; Chromatography ; Bacteria ; Physics ; Acoustics ; Biology Silicon Nanostructures and Photoluminescence ; Advanced biosensing and bioanalysis techniques ; Nanowire Synthesis and Applications
Authors: Sebastian Zimmermann | Clarissa Schönecker
Source: Journal of Fluid Mechanics (article, 2024-01-05)
Field: Materials Science — Surfaces, Coatings and Films

Analytical models for pressure-driven Stokes flow through superhydrophobic and liquid-infused tubes and annular pipes Analytical expressions for the velocity field and the effective slip length of pressure-driven Stokes flow through slippery pipes and annuli with rotationally symmetrical longitudinal slits are derived. Specifically, the developed models incorporate a finite local slip length and constant shear stress along the slits, and thus go beyond the assumption of perfect slip employed commonly for superhydrophobic surfaces. Thereby, they provide the possibility to assess the influence of both the viscosity of the air or other fluid that is modelled to fill the slits as well as the influence of the micro-geometry of these slits. First, expressions for tubes and annular pipes with superhydrophobic or slippery walls are provided. Second, these solutions are combined to a tube-within-a circular-pipe scenario, where one fluid domain provides a slip to the other. This scenario is interesting as an application to achieve stable fluid–fluid interfaces. With respect to modelling, it illustrates the specification of the local slip length depending on a linked flow field. The comparison of the analytically calculated solutions with numerical simulations shows excellent agreement. The results of this paper thus represent an important instrument for the design and optimization of slippage along surfaces in circular geometries. Mechanics ; Slip (aerodynamics) ; Slippage ; Pressure drop ; Materials science ; Shear stress ; Computational fluid dynamics ; Fluid dynamics ; Physics ; Composite material ; Thermodynamics Surface Modification and Superhydrophobicity ; Fluid Dynamics and Thin Films ; Icing and De-icing Technologies
Authors: Yifu Sun | Peng Lu | Lingyu Zhang | Yu Cao | Lan Bai | Li Ding | Jie Han | Chiyu Zhang | Maguang Zhu | Zhiyong Zhang
Source: Advanced Electronic Materials (article, 2024-10-04)
Field: Materials Science — Materials Chemistry

Investigation and Improvement of the Bias Temperature Instability in Carbon Nanotube Transistors Abstract Carbon nanotube (CNT) is widely regarded as a promising candidate for constructing sub‐10 nm field‐effect transistors (FETs). However, limited attention is carried out on the reliability of CNT FETs, which is critical for practical application. In this work, the bias temperature instability (BTI) effect in top‐gate CNT FETs is thoroughly investigated under a wide range of environment temperatures from 200 to 400 K for the first time. Notably, the threshold voltage (V th ) shifts induced by BTI are measured down to 0.38 V, which is ≈2–3 times smaller than those reported in previous studies. In addition, by optimizing the device fabrication process, the reliability of the BTI effects in CNT FETs can be further improved. The optimized CNT FET exhibits a Normalized BTI shift down to ≈0.10 V/(MV cm −1 ), which represents the most reliable top‐gate nano‐devices to date. Materials science ; Carbon nanotube ; Transistor ; Instability ; Nanotechnology ; Carbon nanotube field-effect transistor ; Carbon nanotube quantum dot ; Nanotube ; Negative-bias temperature instability ; Engineering physics ; Optoelectronics ; Field-effect transistor ; MOSFET ; Electrical engineering ; Voltage ; Mechanics Carbon Nanotubes in Composites ; Advancements in Semiconductor Devices and Circuit Design ; Diamond and Carbon-based Materials Research
Authors: Nahla Said M. Ibrahim | Hanan H. Kadry | Ashraf F. Zaher | Khaled O. Mohamed
Source: Chemical Papers (article, 2024-02-12)
Field: Chemistry — Organic Chemistry

Review: synthesis and anticancer activity of pyrimido[4,5-b]quinolines in the last twenty years Abstract Pyrimido[4,5- b ]quinoline is a vital structural motif. The synthesis of pyrimido[4,5- b ]quinolines has been a challenging topic in medicinal chemistry. A wide range of starting materials have been employed to achieve this nucleus such as quinoline derivatives and isatins. Multi-component one-pot synthestic approaches were employed either by using barbituric or thiobarbituric acid, amines and aldehydes or from 6-aminouracils, aldehydes and cyclohexanone derivatives. Recent synthetic strategies and many green chemistry techniques have improved pyrimido[4,5- b ]quinolines synthesis over the last twenty years. Among the many reported biological activities of pyrimido[4,5- b ]quinolines, anticancer activity attracted research attention over the past couple of decades. Many derivatives have shown promising anticancer activity on different cancer cell lines such as MCF-7, A549, K562 and others. They also demonstrated activity on different enzymes and receptors such as tyrosine kinases, tyrosyl-DNA Phosphodiesterase II and HDM2 ubiquitin ligase (E3) that promote apoptosis, repair DNA damage, and induce cell cycle arrest. This review critically examines the recent synthetic approaches employed for the synthesis of pyrimido[4,5- b ]quinolines and explores their reported anticancer activities. Quinoline ; Chemistry ; Quinoxaline ; Pharmacophore ; K562 cells ; Cyclohexanone ; Combinatorial chemistry ; Biochemistry ; Apoptosis ; Organic chemistry ; Catalysis Synthesis and biological activity ; Quinazolinone synthesis and applications ; Phenothiazines and Benzothiazines Synthesis and Activities
Authors: Xiaolan Huang | Jeffrey R. Harmer | Gerhard Schenk | Gordon Southam
Source: Frontiers in Chemistry (article, 2024-02-08)
Field: Materials Science — Materials Chemistry

Inorganic Fe-O and Fe-S oxidoreductases: paradigms for prebiotic chemistry and the evolution of enzymatic activity in biology Oxidoreductases play crucial roles in electron transfer during biological redox reactions. These reactions are not exclusive to protein-based biocatalysts; nano-size (<100 nm), fine-grained inorganic colloids, such as iron oxides and sulfides, also participate. These nanocolloids exhibit intrinsic redox activity and possess direct electron transfer capacities comparable to their biological counterparts. The unique metal ion architecture of these nanocolloids, including electron configurations, coordination environment, electron conductivity, and the ability to promote spontaneous electron hopping, contributes to their transfer capabilities. Nano-size inorganic colloids are believed to be among the earliest 'oxidoreductases' to have 'evolved' on early Earth, playing critical roles in biological systems. Representing a distinct type of biocatalysts alongside metalloproteins, these nanoparticles offer an early alternative to protein-based oxidoreductase activity. While the roles of inorganic nano-sized catalysts in current Earth ecosystems are intuitively significant, they remain poorly understood and underestimated. Their contribution to chemical reactions and biogeochemical cycles likely helped shape and maintain the balance of our planet's ecosystems. However, their potential applications in biomedical, agricultural, and environmental protection sectors have not been fully explored or exploited. This review examines the structure, properties, and mechanisms of such catalysts from a material's evolutionary standpoint, aiming to raise awareness of their potential to provide innovative solutions to some of Earth's sustainability challenges. Electron transfer ; Redox ; Nanotechnology ; Chemistry ; Biogeochemical cycle ; Catalysis ; Electron transport chain ; Abiogenesis ; Nanoparticle ; Earth (classical element) ; Biochemical engineering ; Astrobiology ; Environmental chemistry ; Materials science ; Biology ; Biochemistry ; Physics ; Organic chemistry Advanced Nanomaterials in Catalysis ; Electrochemical sensors and biosensors ; Microbial Fuel Cells and Bioremediation
Authors: Julia Matysik | Olga Długosz | Marcin Banach
Source: The Journal of Physical Chemistry B (article, 2024-08-09)
Field: Materials Science — Materials Chemistry

Development of Nanozymatic Characteristics in Metal-Doped Oxide Nanomaterials Nanozymes are nanoscale materials that exhibit enzymatic-like activity, combining the benefits of nanomaterials with biocatalytic effects. The addition of metals to nanomaterials can enhance their nanozyme activity by mimicking the active sites of enzymes, providing structural support and promoting redox activity. In this study, nanostructured oxide and silicate-phosphate nanomaterials with varying manganese and copper additions were characterized. The objective was to assess the influence of metal modifications (Mn and Cu) on the acquisition of the nanozymatic activity by selected nanomaterials. An increase in manganese content in each material enhanced proteolytic activity (from 20 to 40 mUnit/mg for BG-Mn), while higher copper addition in glassy materials increased activity by 40%. Glassy materials exhibited approximately twice the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radical activity (around 40 μmol/mL) compared to that of oxide materials. The proteolytic and antioxidant activities discussed in the study can be considered indicators for evaluating the enzymatic properties of the nanomaterials. Observations conducted on nanomaterials may aid in the development of materials with enhanced catalytic efficiency and a wide range of applications. Nanomaterials ; Doping ; Materials science ; Metal ; Nanotechnology ; Oxide ; Metallurgy ; Optoelectronics Advanced Nanomaterials in Catalysis ; Nanoplatforms for cancer theranostics ; Nanoparticles: synthesis and applications
Authors: Rana R. Haikal | Noha El Salakawy | Alaa Ibrahim | Shaimaa L. Ali | Wael Mamdouh
Source: Nanoscale Advances (article, 2024-01-01)
Field: Chemistry — Inorganic Chemistry

Synergistic antioxidant and antibacterial effects of a Zn-ascorbate metal–organic framework loaded with marjoram essential oil Antimicrobial resistance (AMR) has become an immense threat to public health leading to an urgent need for development of new technologies to tackle such a challenge. Plant-based drugs, specifically essential oils (EOs) and plant extracts, have shown significant potential as effective green antimicrobial agents. However, they suffer from high volatility and low thermal stability resulting in their inefficient utilization in commercial settings. Among the various nanoencapsulation technologies reported, metal-organic frameworks (MOFs) have been recently investigated as potential nanocarriers of EOs in attempt to enhance their stability. Herein, we report the utilization of Zn-ascorbate MOF for the encapsulation of marjoram essential oil (MEO) with synergistic antioxidant and antibacterial activities. The prepared composite was thoroughly characterized <i>via</i> a number of techniques and its antibacterial performance was investigated against various strains of Gram-negative and Gram-positive bacteria. The results demonstrated that the antioxidant activity originated from the ascorbic acid ligand (l-Asc), while the antibacterial activity originated from Zn<sup>2+</sup> ions as well as encapsulated MEO. Ascorbic acid ; Chemistry ; Antioxidant ; Antibacterial activity ; Essential oil ; Food science ; Metal ions in aqueous solution ; Bacteria ; Metal ; Nuclear chemistry ; Organic chemistry ; Biology Metal-Organic Frameworks: Synthesis and Applications ; Electrochemical Analysis and Applications ; Thermal and Kinetic Analysis
Authors: Alexandru Șandor | Ionel Fizeșan | Ioana Ionuț | Gabriel Marc | Cristina Moldovan | Ilioara Oniga | Adrian Pı̂rnău | Laurian Vlase | Andreea-Elena Petru | Ioana Macașoi | Ovidiu Oniga
Source: Biomolecules (article, 2024-02-12)
Field: Chemistry — Organic Chemistry

Discovery of A Novel Series of Quinazoline–Thiazole Hybrids as Potential Antiproliferative and Anti-Angiogenic Agents Considering the pivotal role of angiogenesis in solid tumor progression, we developed a novel series of quinazoline-thiazole hybrids (<b>SA01-SA07</b>) as antiproliferative and anti-angiogenic agents. Four out of the seven compounds displayed superior antiproliferative activity (IC<sub>50</sub> =1.83-4.24 µM) on HepG2 cells compared to <b>sorafenib</b> (IC<sub>50</sub> = 6.28 µM). The affinity towards the VEGFR2 kinase domain was assessed through in silico prediction by molecular docking, molecular dynamics studies, and MM-PBSA. The series displayed a high degree of similarity to <b>sorafenib</b> regarding the binding pose within the active site of VEGFR2, with a different orientation of the 4-substituted-thiazole moieties in the allosteric pocket. Molecular dynamics and MM-PBSA evaluations identified <b>SA05</b> as the hybrid forming the most stable complex with VEGFR2 compared to <b>sorafenib</b>. The impact of the compounds on vascular cell proliferation was assessed on EA.hy926 cells. Six compounds (<b>SA01-SA05, SA07</b>) displayed superior anti-proliferative activity (IC<sub>50</sub> = 0.79-5.85 µM) compared to <b>sorafenib</b> (IC<sub>50</sub> = 6.62 µM). The toxicity was evaluated on BJ cells. Further studies of the anti-angiogenic effect of the most promising compounds, <b>SA04</b> and <b>SA05,</b> through the assessment of impact on EA.hy296 motility using a wound healing assay and in ovo potential in a CAM assay compared to <b>sorafenib</b>, led to the confirmation of the anti-angiogenic potential. Thiazole ; Hybrid ; Quinazoline ; Biology ; Combinatorial chemistry ; Chemistry ; Stereochemistry ; Botany Quinazolinone synthesis and applications ; Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and biological activity
Authors: Mamoalosi A. Selepe
Source: ChemMedChem (review, 2024-08-02)
Field: Chemistry — Organic Chemistry

Isoflavone Derivatives as Potential Anticancer Agents: Synthesis and Bioactivity Studies Isoflavones are phenolic natural compounds with a C<sub>6</sub>C<sub>3</sub>C<sub>6</sub> framework. They possess a plethora of biological activities that are associated with putative benefits to human health. In particular, the cancer chemopreventive and chemotherapeutic potential of isoflavones has attracted the interest of researchers. Several isoflavone derivatives have been synthesised and probed for their anticancer activities. The isoflavone analogues are mainly synthesised by molecular hybridisation and other strategies that enable diversification through early or late-stage functionalisation of A-, B- and C-rings of the isoflavones. This has resulted in the discovery of isoflavone analogues with improved antiproliferative activities against several cancer cells and different mechanisms of action. In this review, the synthesis of isoflavone derivatives and their anticancer activity studies are discussed. Chemistry ; Pharmacology ; Combinatorial chemistry ; Anticancer drug ; Stereochemistry ; Biology ; Drug Synthesis and biological activity