jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Hao Zha | Qing Wang | Xinping Wang | Daniele Cangialosi | Biao Zuo
Source: Macromolecules (article, 2021-02-12)
Field: Materials Science — Materials Chemistry

Enhanced Free Surface Mobility Facilitates the Release of Free-Volume Holes in Thin-Film Polymer Glasses The concept of free volume underpins the variations in polymer dynamics. Annihilation of free-volume holes through diffusion to surfaces has been proposed to determine the vitrification of the confined polymers. In this work, we assessed the hole diffusion dynamics in glassy thin poly (ethylene terephthalate) films with various thicknesses using a strategy based on covering the film surface with crystals of different sizes, which allows for changing the hole diffusion efficiency, thus tuning the glass transition temperature of the thin film (Tgfilm). The apparent activation energy for hole diffusion (Ea,hole) in the thin films was elucidated by modeling the correlation between Tgfilm and surface coverage of crystals using the free-volume hole diffusion model. Our results demonstrated a trend of linear decrease in Ea,hole with the increasing inverse film thickness (h–1), suggesting that the presence of a free surface with faster dynamics promotes hole diffusion in thin films. This finding demonstrates that the free volume release in thin films and thus the confined polymer dynamics can be modulated by changing the free surface properties of the films. Thin film ; Diffusion ; Free surface ; Materials science ; Polymer ; Glass transition ; Volume (thermodynamics) ; Vitrification ; Chemical physics ; Surface diffusion ; Nanotechnology ; Thermodynamics ; Composite material ; Chemistry ; Physical chemistry ; Physics Material Dynamics and Properties ; Liquid Crystal Research Advancements ; Rheology and Fluid Dynamics Studies
Authors: Hongxue Qi | Xianjun Niu | Haipeng Wu | Xiuping Liu | Yong‐Qiang Chen
Source: Journal of Chemistry (article, 2021-12-24)
Field: Chemistry — Inorganic Chemistry

Adsorption of Chromium (VI) by Cu (I)-MOF in Water: Optimization, Kinetics, and Thermodynamics To investigate the adsorption behavior of Cu (I)-MOF material for chromium (VI) in water, the parameters of influencing adsorption were optimized and found as follows: the optimal pH was 6 for the adsorption of Cr (VI) by the Cu (I)-MOF, the optimal amount of adsorbent was 0.45 g·L−1, and the adsorption saturation time was within 180 min. Subsequently, the kinetics results were fitted by four models such as pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. Among them, the adsorption of chromium (VI) was more inclined to the pseudo-first-order model (Radj2 = 0.9230). Then, the isotherm data were fitted by Langmuir and Freundlich models. The results indicated that Langmuir isotherm was the excellent match model (Radj2 = 0.9827). It belongs to a monolayer adsorption, and the maximum adsorption capacity was 95.92 mg·g−1. Subsequently, the thermodynamic parameters of the adsorption were calculated as follows: enthalpy change (ΔHθ) was −8.583 kJ·mol−1, entropy change (ΔSθ) was −8.243 J·mol−1 K−1, and the Gibbs function change (ΔGθ) was less than zero in the temperature range of 288–328 K, indicating that the reaction was spontaneous. Finally, both the spectra of infrared and XPS supported the adsorption mechanism that belonged the ion exchange. The spectra of XRD and SEM images shown that the structure of Cu (I)-MOF remained stable for at least 3 cycles. In conclusion, Cu (I)-MOF material has a high adsorption capacity, good water stability, low cost, and easy to prepare in large quantities in practical application. It will be a promising adsorbent for the removal of Cr (VI) from water. Chemistry ; Adsorption ; Chromium ; Freundlich equation ; Enthalpy ; Langmuir adsorption model ; Langmuir ; Thermodynamics ; Kinetics ; Gibbs free energy ; Monolayer ; Saturation (graph theory) ; Diffusion ; Physical chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Adsorption and biosorption for pollutant removal ; Nanomaterials for catalytic reactions
Authors: Prakash Parthasarathy | Hamish R. Mackey | Sabah Mariyam | Shifa Zuhara | Tareq Al‐Ansari | Gordon McKay
Source: Frontiers in Materials (article, 2021-01-29)
Field: Materials Science — Polymers and Plastics

Char Products From Bamboo Waste Pyrolysis and Acid Activation Bamboo is found worldwide but is especially concentrated in tropical and subtropical areas with the major producing nations being China, Indonesia and Thailand with an annual production of 12 million tonnes. It has found uses in many applications such as: furniture, flooring, roofing, fencing, interior design and scaffolding in the construction industry. In this study, discarded waste bamboo furniture was used in the ground form as the raw material feedstock for the production of a series of biochars and activated carbons. The biochars were produced at different temperatures, namely, 723, 823, 923, 1,023, 1,123 and 1223 K, in a muffle furnace inerted with nitrogen and for different pyrolysis times. The product chars yields were 20–30% by weight of the raw material, surface areas were 100–350 m 2 /g. Other tests include elemental analysis, helium displacement density, pH, ICP-AES on a leachate sample. Four of the different temperature samples of biochar were used to adsorb the basic dye methylene blue and were shown to possess high adsorption capacities. Then, the same bamboo raw material powder was treated with acid and pyrolysed/activated in a nitrogen atmosphere at the same range of temperatures to produce activated carbons; these were characterized using similar test methods to the biochars. The yields are in the range 20–40% by weight of the raw material feedstock and the BET surface areas are in the range 200–600 m 2 /g. Three of the different temperature activated carbons were used to adsorb methylene blue and the results were compared with the biochar results. All the adsorption experimental isotherm results were analyzed using conventional isotherm equations. The benefits and cost implications of both biochar and activated carbon routes are discussed. The methylene blue adsorption capacities are extremely attractive in the range 0.42–1.12 mmol/g (150–300 mg/g char product) and extend to over 2.35 mmol/g (700 mg/g) for the bamboo derived activated carbons. The micropore and mesopore volumes have been determined under the various char and activated carbon experimental conditions and coupled with the surface areas; these results have been used to explain the trends in the methylene blue adsorption capacities. Raw material ; Bamboo ; Pyrolysis ; Biochar ; Char ; BET theory ; Pulp and paper industry ; Muffle furnace ; Activated carbon ; Waste management ; Adsorption ; Materials science ; Biomass (ecology) ; Nitrogen ; Nuclear chemistry ; Chemistry ; Organic chemistry ; Composite material ; Calcination ; Agronomy ; Catalysis Polymer Nanocomposites and Properties ; Natural Fiber Reinforced Composites ; Carbon Nanotubes in Composites
Authors: Zhaoying Sun | Tao Feng | Zhihui Zhou | Hongdan Wu
Source: e-Polymers (article, 2021-01-01)
Field: Materials Science — Biomaterials

Removal of methylene blue in water by electrospun PAN/β-CD nanofibre membrane Abstract The polyacrylonitrile (PAN) nanofiber membrane prepared by the electrospinning technology was used as the matrix, and β-cyclodextrin (β-CD) was introduced into it to synthesize the composite nanofiber membrane. Taking methylene blue as the object, the adsorption performance of nanofiber membranes for dyes in the aqueous solution was studied. The structure, morphology, and specific surface area of the nanofiber membrane were characterized using FTIR, SEM, BET, XRD, and EDS. Meantime, the adsorption equilibrium was also explored. After being modified by cyclodextrin, a large number of cavity structures and hydrophobic binding sites were provided for the nanofiber membrane, and the adsorption performance was significantly improved. The results showed that the maximum adsorption capacity of the PAN/β-CD blend nanofiber membrane (at 25℃) for methylene blue was 108.66 mg g −1 . The effects of pH, adsorption time, ion concentration, and adsorbent dosage on the adsorption capacity were also investigated. In addition, by fitting with the adsorption model, the adsorption process was more complex with the quasi-secondary adsorption kinetics and Langmuir isotherm adsorption model. Electrospinning ; Adsorption ; Polyacrylonitrile ; Nanofiber ; Langmuir adsorption model ; Membrane ; Methylene blue ; Chemical engineering ; Aqueous solution ; Materials science ; Methyl blue ; Polymer chemistry ; Chemistry ; Organic chemistry ; Composite material ; Polymer ; Photocatalysis ; Catalysis Electrospun Nanofibers in Biomedical Applications ; Adsorption and biosorption for pollutant removal ; Graphene and Nanomaterials Applications
Authors: Gerardo F. Goya | Álvaro Mayoral | E. Winkler | Roberto D. Zysler | Carolina Bagnato | Mariana Raineri | Jesús Antonio Fuentes-García | Enio Lima
Source: Journal of Applied Physics (article, 2021-11-15)
Field: Materials Science — Materials Chemistry

Next generation of nanozymes: A perspective of the challenges to match biological performance Nanomaterials with enzyme-like activity have been the spotlight of scientific and technological efforts to substitute natural enzymes, not only in biological research but also for industrial manufacturing, medicine, and environment healing. Notable advancements in this field along the last years relied on to the rational design of single-atom active sites, knowledge of the underlying atomic structure, and realistic ab initio theoretical models of the electronic configuration at the active site. Thus, it is plausible that a next generation of nanozymes still to come will show even improved catalytic efficiency and substrate specificity. However, the dynamic nature of the protein cage surrounding most active sites in biological enzymes adds a flexible functionality that possess a challenge for nanozyme's mimicking of their natural counterparts. We offer a perspective about where the main strategies to improve nanozymes are headed and identify some of the big challenges faced along the road to better performance. We also outline some of the most exciting bio-inspired ideas that could potentially change this field. Nanotechnology ; Biochemical engineering ; Computer science ; Field (mathematics) ; Perspective (graphical) ; Natural (archaeology) ; Engineering ; Artificial intelligence ; Materials science ; Biology Advanced Nanomaterials in Catalysis ; Nanocluster Synthesis and Applications ; Carbon and Quantum Dots Applications
Authors: Noor Akbar | Jasra Gul | Ruqaiyyah Siddiqui | Muhammad Raza Shah | Naveed Ahmed Khan
Source: Antibiotics (article, 2021-08-11)
Field: Chemistry — Organic Chemistry

Moxifloxacin and Sulfamethoxazole-Based Nanocarriers Exhibit Potent Antibacterial Activities Antibiotic resistance is a major concern given the rapid emergence of multiple-drug-resistant bacteria compared to the discovery of novel antibacterials. An alternative strategy is enhancing the existing available drugs. Nanomedicine has emerged as an exciting area of research, showing promise in the enhanced development of existing antimicrobials. Herein, we synthesized nanocarriers and loaded these with available clinically approved drugs, namely Moxifloxacin and Sulfamethoxazole. Bactericidal activity against Gram-negative (<i>Serratia marcescens</i>, <i>Pseudomonas aeruginosa</i>, <i>Klebsiella pneumoniae</i>, and <i>Salmonella enterica</i>) and Gram-positive (methicillin-resistant <i>Staphylococcus aureus</i>, <i>Streptococcus pneumoniae</i>, and <i>Bacillus cereus</i>) bacteria was investigated. To characterize the nanocarriers and their drug-loaded forms, Fourier-transform infrared spectroscopy, dynamic light scattering, and atomic force microscopy were utilized. Antibacterial assays and hemolysis assays were carried out. Moreover, lactate dehydrogenase assays were performed to determine cytotoxicity against human cells. The results depicted the successful formation of drug-nanocarrier complexes. The potent antibacterial activities of the drug-loaded nanocarriers were observed and were significantly enhanced in comparison to the drugs alone. Hemolysis and cytotoxicity assays revealed minimal or negligible cytotoxic effects against human red blood cells and human cells. Overall, metronidazole-based nanocarriers loaded with Moxifloxacin and Sulfamethoxazole showed enhanced bactericidal effects against multiple-drug-resistant bacteria compared with drugs alone, without affecting human cells. Our findings show that drug-loaded nanocarriers hold promise as potent chemotherapeutic drugs against multiple-drug-resistant bacteria. Nanocarriers ; Moxifloxacin ; Antimicrobial ; Microbiology ; Chemistry ; Hemolysis ; Bacillus cereus ; Pharmacology ; Antibiotics ; Drug ; Bacteria ; Medicine ; Biology ; Immunology Antimicrobial agents and applications ; Antimicrobial Peptides and Activities ; Antibiotic Resistance in Bacteria
Authors: Shaojie Yang | Shuodong Wu | Wanlin Dai | Liwei Pang | Yaofeng Xie | Tengqi Ren | Xiaolin Zhang | Shiyuan Bi | Yuting Zheng | Jingnan Wang | Yang Sun | Zhuyuan Zheng | Jing Kong
Source: Frontiers in Pharmacology (review, 2021-12-16)
Field: Chemistry — Organic Chemistry

Tetramethylpyrazine: A Review of Its Antitumor Potential and Mechanisms Cancer remains a major public health threat. The mitigation of the associated morbidity and mortality remains a major research focus. <i>From a molecular biological perspective</i>, cancer is defined as uncontrolled cell division and abnormal cell growth caused by various gene mutations. Therefore, there remains an urgent need to develop safe and effective antitumor drugs. The antitumor effect of plant extracts, which are characterized by relatively low toxicity and adverse effect, has attracted significant attention. For example, increasing attention has been paid to the antitumor effects of tetramethylpyrazine (TMP), the active component of the Chinese medicine Chuanqiong, which can affect tumor cell proliferation, apoptosis, invasion, metastasis, and angiogenesis, as well as reverse chemotherapeutic resistance in neoplasms, thereby triggering antitumor effects. Moreover, TMP can be used in combination with chemotherapeutic agents to enhance their effects and reduce the side effect associated with chemotherapy. Herein, we review the antitumor effects of TMP to provide a theoretical basis and foundation for the further exploration of its underlying antitumor mechanisms and promoting its clinical application. Tetramethylpyrazine ; Pharmacology ; Medicine ; Traditional medicine ; Computational biology ; Biology ; Alternative medicine ; Pathology Synthesis and Biological Evaluation ; Synthesis and biological activity ; Quinazolinone synthesis and applications
Authors: Jasmine Chase | Maria Arizaleta | Benjamin M. Tutolo
Source: Minerals (article, 2021-01-22)
Field: Materials Science — Biomaterials

A Series of Data-Driven Hypotheses for Inferring Biogeochemical Conditions in Alkaline Lakes and Their Deposits Based on the Behavior of Mg and SiO2 Alkaline (pH &gt; 8.5) lakes have been common features of Earth’s surface environments throughout its history and are currently among the most biologically productive environments on the planet. The chemistry of alkaline lakes favors the deposition of aluminum-poor magnesian clays (e.g., sepiolite, stevensite, and kerolite) whose chemistry and mineralogy may provide a useful record of the biogeochemistry of the lake waters from which they were precipitated. In this forward-looking review, we present six data-driven, testable hypotheses devoted to furthering our understanding of the biogeochemical conditions in paleolake waters based on the geochemical behavior of Mg and SiO2. In the development of these hypotheses, we bring together a compilation of modern lake water chemistry, recently published and new experimental data, and empirical, thermodynamic, and kinetic relationships developed from these data. We subdivide the hypotheses and supporting evidence into three categories: (1) interpreting paleolake chemistry from mineralogy; (2) interpreting the impact of diatoms on alkaline lake sedimentation; and (3) interpreting depositional mineralogy based on water chemistry. We demonstrate the need for further investigation by discussing evidence both for and against each hypothesis, which, in turn, highlights the gaps in our knowledge and the importance of furthering our understanding of the relevant geological and biological systems. The focused testing of these hypotheses against modern occurrences and the geologic record of alkaline lakes can have profound implications for the interpretation of the paleo-biogeochemistry and paleohabitability of these systems on Earth and beyond. Biogeochemistry ; Biogeochemical cycle ; Earth science ; Geology ; Geologic record ; Biogeosciences ; Earth system science ; Chemistry ; Geochemistry ; Environmental chemistry ; Oceanography Clay minerals and soil interactions ; Groundwater and Isotope Geochemistry ; Geochemistry and Elemental Analysis
Authors: Fei Wang | Cheng Zhang | Anzhong Tan | Haiyun Chen | Sifan Weng | Qirong Xie | Chunmei Li | Zhixiong Cai | Xuejuan Wan
Source: Polymer (article, 2021-03-27)
Field: Materials Science — Polymers and Plastics

Photothermal and magnetocaloric-stimulated shape memory and self-healing via magnetic polymeric composite with dynamic crosslinking Materials science ; Copolymer ; Nanocomposite ; Monomer ; Composite number ; Photothermal effect ; Shape-memory alloy ; Self-healing ; Chemical engineering ; Methyl methacrylate ; Magnetic refrigeration ; Methacrylate ; Photothermal therapy ; Composite material ; Nanotechnology ; Polymer Polymer composites and self-healing ; Photochromic and Fluorescence Chemistry ; Marine Sponges and Natural Products
Authors: Daniel S. King | Donald G. Truhlar | Laura Gagliardi
Source: The Journal of Physical Chemistry Letters (article, 2021-08-10)
Field: Materials Science — Materials Chemistry

Machine-Learned Energy Functionals for Multiconfigurational Wave Functions We introduce multiconfiguration data-driven functional methods (MC-DDFMs), a group of methods which aim to correct the total or classical energy of a qualitatively accurate multiconfigurational wave function using a machine-learned functional of some featurization of the wave function such as its density, on-top density, or both. On a data set of carbene singlet-triplet energy splittings, we show that MC-DDFMs are able to achieve near-benchmark performance on systems not used for training with a robust degree of active-space independence. Beyond demonstrating that the density and on-top density hold the information necessary to correct the singlet-triplet energy splittings of multiconfigurational wave functions, this approach shows great promise for the development of functionals for MC-PDFT because corrections to the classical energy appear to be more transferable to types of molecules not included in the training data than corrections to total energies such as those yielded by CASSCF or NEVPT2. Wave function ; Singlet state ; Density functional theory ; Physics ; Energy (signal processing) ; Statistical physics ; Benchmark (surveying) ; Function (biology) ; Quantum mechanics ; Excited state Machine Learning in Materials Science ; Advanced Chemical Physics Studies ; Computational Drug Discovery Methods
Authors: Yuan Tian | Dezhen Xue | Ruihao Yuan | Yumei Zhou | Xiangdong Ding | Jun Sun | Turab Lookman
Source: Physical Review Materials (article, 2021-01-08)
Field: Materials Science — Materials Chemistry

Efficient estimation of material property curves and surfaces via active learning The relationship between material properties and independent variables such as temperature, external field, or time is usually represented by a curve or surface in a multidimensional space. Determining such a curve or surface requires a series of experiments or calculations which are often time and cost consuming. A general strategy uses an appropriate utility function to sample the space to recommend the next optimal experiment or calculation within an active learning loop. However, knowing what optimal sampling strategy to use to minimize the number of experiments is an outstanding problem. We compare a number of strategies based on directed exploration on several materials problems of varying complexity using a Kriging-based model. These include one-dimensional curves such as the fatigue life curve for 304L stainless steel and the Liquidus line of the Fe-C phase diagram, surfaces such as the Hartmann 3 function in three-dimensional space and the fitted intermolecular potential for Ar-SH, and a four-dimensional data set of experimental measurements for ${\mathrm{BaTiO}}_{3}$-based ceramics. We also consider the effects of experimental noise on the Hartmann 3 function. We find that directed exploration guided by maximum variance provides better performance overall, converging faster across several data sets. However, for certain problems, the tradeoff methods incorporating exploitation can perform at least as well, if not better than maximum variance. Thus, we discuss how the choice of the utility function depends on the distribution of the data, the model performance and uncertainties, additive noise, as well as the budget. Function (biology) ; Property (philosophy) ; Liquidus ; Surface (topology) ; Sampling (signal processing) ; Curve fitting ; Set (abstract data type) ; Data point ; Active learning (machine learning) Machine Learning in Materials Science ; Model Reduction and Neural Networks ; Gaussian Processes and Bayesian Inference
Authors: Xiao Xiao | Jürgen Brillo | Jonghyun Lee | R. W. Hyers | Douglas M. Matson
Source: npj Microgravity (article, 2021-10-05)
Field: Materials Science — Materials Chemistry

Impact of convection on the damping of an oscillating droplet during viscosity measurement using the ISS-EML facility Oscillating droplet experiments are conducted using the Electromagnetic Levitation (EML) facility under microgravity conditions. The droplet of molten metal is internally stirred concurrently with the pulse excitation initiating shape oscillations, allowing viscosity measurement of the liquid melts based on the damping rate of the oscillating droplet. We experimentally investigate the impact of convection on the droplet's damping behavior. The effective viscosity arises and increases as the internal convective flow becomes transitional or turbulent, up to 2-8 times higher than the intrinsic molecular viscosity. The enhanced effective viscosity decays when the stirring has stopped, and an overshoot decay pattern is identified at higher Reynolds numbers, which presents a faster decay rate as the constraint of flow domain size becomes influential. By discriminating the impact of convection on the viscosity results, the intrinsic viscosity can be evaluated with improved measurement accuracy. Viscosity ; Mechanics ; Levitation ; Overshoot (microwave communication) ; Convection ; Turbulence ; Reynolds number ; Physics ; Thermodynamics ; Materials science Solidification and crystal growth phenomena ; Fluid Dynamics and Heat Transfer ; Electrohydrodynamics and Fluid Dynamics
Authors: Karmveer Yadav | Syed Azmal Ali | Ashok Kumar Mohanty | Eshwarmoorthy Muthusamy | Kesavan Subaharan | Gautam Kaul
Source: Journal of Nanobiotechnology (article, 2021-02-12)
Field: Materials Science — Materials Chemistry

MSN, MWCNT and ZnO nanoparticle-induced CHO-K1 cell polarisation is linked to cytoskeleton ablation Based on the incubation and concentration of NPs, our work provides evidence for the activation of Rac-Rho signalling pathway to alter cytoskeleton dynamics. Our results assist as a sensitive early molecular readout for nanosafety assessment. Cell biology ; Cytoskeleton ; Chemistry ; Lamellipodium ; Chinese hamster ovary cell ; Actin cytoskeleton ; Cortactin ; Endocytic cycle ; Cell ; Biophysics ; Endocytosis ; Biology ; Biochemistry Nanoparticles: synthesis and applications ; Advanced Proteomics Techniques and Applications ; Cellular Mechanics and Interactions