jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: K. Shiv Kumar | Ajit Kumar Dash | Hasna Sabreen H | Manvi Verma | Vivek Kumar | Kenji Watanabe | Takashi Taniguchi | Gopalakrishnan Sai Gautam | Akshay Singh
Source: arXiv (Cornell University) (preprint, 2023-12-22)
Field: Materials Science — Materials Chemistry

Towards a comprehensive understanding of the low energy luminescence peak in 2D materials An intense low-energy broad luminescence peak (L-peak) is usually observed in 2D transition metal dichalcogenides (TMDs) at low temperatures. L-peak has earlier been attributed to bound excitons, but its origins are widely debated with direct consequences on optoelectronic properties. To decouple the contributions of physisorbed and chemisorbed oxygen, organic adsorbates, and strain on L-peak, we measured a series of monolayer (ML) MoS2 samples (mechanically exfoliated (ME), synthesized by oxygen-assisted chemical vapour deposition (O-CVD), hexagonal boron nitride (hBN) covered and hBN encapsulated). Emergence of L-peak below 150 K and saturation of photoluminescence (PL) intensity with laser power confirm bound nature of L-peak. Anomalously at room temperature, O-CVD samples show high A-exciton PL (c.f. ME), but reduced PL at low temperatures, which is attributed to strain-induced direct-to-indirect bandgap change in low defect O-CVD MoS2. Further, L-peak redshifts dramatically ~ 130 meV for O-CVD samples (c.f. ME). These observations are fully consistent with our predictions from density functional theory (DFT) calculations, considering effects of both strain and defects, and supported by Raman spectroscopy. In ME samples, charged oxygen adatoms are identified as thermodynamically favourable defects which can create in-gap states, and contribute to the L-peak. The useful effect of hBN is found to originate from reduction of charged oxygen adatoms and hydrocarbon complexes. This combined experimental-theoretical study allows an enriched understanding of L-peak and beneficial impact of hBN, and motivates collective studies of strain and defects with direct impact on optoelectronics and quantum technologies. Photoluminescence ; Exciton ; Luminescence ; Materials science ; Oxygen ; Raman spectroscopy ; Monolayer ; Chemical vapor deposition ; Saturation (graph theory) ; Density functional theory ; Redshift ; Analytical Chemistry (journal) ; Chemical physics ; Nanotechnology ; Condensed matter physics ; Chemistry ; Optoelectronics ; Computational chemistry ; Optics ; Physics 2D Materials and Applications ; Ga2O3 and related materials ; Advanced biosensing and bioanalysis techniques
Authors: Guilherme Almeida | Lara van der Poll | Wiel H. Evers | Emma Szoboszlai | Sander J. W. Vonk | Freddy T. Rabouw | Arjan J. Houtepen
Source: ChemRxiv (preprint, 2023-07-13)
Field: Materials Science — Materials Chemistry

Size-Dependent Optical Properties of InP Colloidal Quantum Dots Indium phosphide colloidal quantum dots (CQDs) are the main alternative for toxic and restricted Cd based CQDs for lighting and display applications. Here we systematically report on the size-dependent optical absorption, ensemble and single particle photoluminescence (PL) and biexciton lifetimes of core-only InP CQDs. This systematic study is enabled by improvements in the synthesis of InP CQDs to yield a broad size series of monodisperse core-only InP CQDs with narrow absorption and PL linewidth and significant PL quantum yield Laser linewidth ; Photoluminescence ; Indium phosphide ; Quantum dot ; Materials science ; Absorption (acoustics) ; Quantum yield ; Yield (engineering) ; Core (optical fiber) ; Optoelectronics ; Indium ; Biexciton ; Nanotechnology ; Optics ; Laser ; Gallium arsenide ; Physics ; Composite material Quantum Dots Synthesis And Properties ; Silicon Nanostructures and Photoluminescence ; Chalcogenide Semiconductor Thin Films
Authors: Guilherme Almeida | Lara M. van der Poll | Wiel H. Evers | Emma Szoboszlai | Sander J. W. Vonk | Freddy T. Rabouw | Arjan J. Houtepen
Source: ChemRxiv (preprint, 2023-07-13)
Field: Materials Science — Materials Chemistry

Size-Dependent Optical Properties of InP Colloidal Quantum Dots Indium phosphide colloidal quantum dots (CQDs) are the main alternative for toxic and restricted Cd based CQDs for lighting and display applications. Here we systematically report on the size-dependent optical absorption, ensemble and single particle photoluminescence (PL) and biexciton lifetimes of core-only InP CQDs. This systematic study is enabled by improvements in the synthesis of InP CQDs to yield a broad size series of monodisperse core-only InP CQDs with narrow absorption and PL linewidth and significant PL quantum yield Laser linewidth ; Photoluminescence ; Indium phosphide ; Quantum dot ; Materials science ; Quantum yield ; Absorption (acoustics) ; Yield (engineering) ; Core (optical fiber) ; Optoelectronics ; Indium ; Biexciton ; Particle size ; Nanotechnology ; Optics ; Laser ; Chemistry ; Gallium arsenide ; Physics ; Physical chemistry ; Composite material Quantum Dots Synthesis And Properties ; Silicon Nanostructures and Photoluminescence ; Chalcogenide Semiconductor Thin Films
Authors: Danrui Ni | Haozhe Wang | Xianghan Xu | Weiwei Xie | R. J. Cava
Source: arXiv (Cornell University) (preprint, 2023-11-07)
Field: Chemistry — Inorganic Chemistry

The Pressure-Stabilized Polymorph of Indium Triiodide A layered rhombohedral polymorph of indium (III) triiodide is synthesized at high pressure and temperature. The unit cell symmetry and approximate dimensions are determined by single crystal X-ray diffraction. Its R-3 crystal structure, with a = 7.217 Å, and c = 20.476 Å, is refined by the Rietveld method on powder X-ray diffraction data. The crystal structure is based on InI6 octahedra sharing edges to form honeycomb lattice layers, though with considerable stacking variations. Different from ambient pressure InI3, which has a monoclinic molecular structure and a light-yellow color, high pressure InI3 is layered and has an orange color. The band gaps of both the monoclinic and rhombohedral variants of InI3 are estimated from diffuse reflectance measurements. Monoclinic crystal system ; Crystallography ; Triiodide ; Crystal structure ; Stacking ; Materials science ; Indium ; Octahedron ; Diffraction ; Powder diffraction ; Rietveld refinement ; Polymorphism (computer science) ; Chemistry ; Optics ; Metallurgy ; Physics ; Physical chemistry Inorganic Chemistry and Materials ; Inorganic Fluorides and Related Compounds ; Crystal Structures and Properties
Authors: Yinan Zhang | Zilin Wang | Xiang Guo | Xue-Jing Lin | Hao-Yi Duan | Nan Wang | Shuichang Zhang | Wei-Ru Cheng | Fan-Di Xu | Minhaj Ahmad | Zhu-Ling Guo
Source: International Journal of Gastroenterology (article, 2023-08-10)
Field: Chemistry — Organic Chemistry

Empirical Research on the Anti-Inflammatory, Antibacterial, and Mucosal Protective Effects of Agarwood Based on the Oral and Intestinal Microenvironment Objective: To investigate the effects of chemical substances contained in agarwood on the body's inflammatory response, oxidative stress, oral and intestinal micro-ecology, as well as their role in various mucosal diseases, such as recurrent aphthous ulcer (RAU) and inflammatory bowel disease (IBD). Materials and Methods: By reviewing and summarizing literature from the past decade on agarwood and its related chemical components composition, as well as their effects on RAU and IBD, we explore the role of agarwood in the body and its relationship with mucosal-related diseases. Results: The Specific components in agarwood, such as sesquiterpenes, flavonoids, etc., can regulate the body's inflammatory response and oxidative stress levels through various signaling pathways, thereby affecting the mucosal status of the oral and intestinal cavity, such as influencing the expression of tight junction proteins between epithelial cells to restore mucosal barrier permeability. Conclusion: Agarwood can down-regulate the inflammatory response by inhibiting various signaling pathways, mainly NF-κB, reduce oxidative stress by decreasing ROS expression, improve the mucosal barrier in the oral and intestinal cavity, and simultaneously impact the improvement of oral and intestinal micro-ecology. It plays a certain controlling role in mucosal-damaged diseases such as IBD and RAU, laying the foundation for the transformation, development, and upgrading of the agarwood industry. Agarwood ; Medicine ; Pathology Wood and Agarwood Research ; Traditional Chinese Medicine Analysis ; Biological Stains and Phytochemicals
Authors: Rania Sheet | Salim Mohammed | M Mamani | J Farfn | F Reyes | S Rath | B Vuran | H Ulusoy | G Sarp | E Yilmaz | U Morgl | H Lu | H Zhang | Y Li | F Gan | Y Pang | Z Lv | J Sun | C Yang | X Shen | R Gil | C Amorim | M Montenegro | A Arajo | L Faria | A Lima | F Arajo | T Lisboa | M Matos | X Hu | Y Xu | X Cui | W Li | X Huang | N Alassaf | F Zankanah | A Hamody | S Dikran | Al-Abbasi Kmh | N Othman | Al-Ashow Jr | M Abd | A Mahmood | R Ali | Hjs Hawezy | M Abdullah | E Tella | M Taherunnisa | G Deepthi | B Choragudi | I Hameedi | L Mari | M Bakir | Msa Aziz | R Sheet | S Mohammed | W Thanasarakhan | S Kruanetr | R Deming | B Liawruangrath | S Wangkarn | Kms Fahelelbom | N Ahmed | S Edress | H Yaseen | M Valcarcel Cases | A Lopez-Lorente | M Lopez-Jimenez | S Sultan | I Alzamil | N Alarfaj
Source: Medical & Clinical Research (article, 2023-08-30)
Field: Chemistry — Analytical Chemistry

Colourimetric Method for Assaying Tetracycline Hydrochloride in Pharmaceutical Formulations via Zirconium Complex Formation This paper includes development of a sensitive, accurate and precise direct spectrophotometric approach to estimate tetracycline hydrochloride in the bulk solution and in its pharmaceutical preparations. The method was based on the reaction of tetracycline hydrochloride with zirconium (IV) in presence of acetate buffer solution at pH3.6 to form a yellow complex with a highest absorption peak at 398 nm. The resulting complex conforms Beer's law to cover the concentration in the range of 0.5 to 12.5 µg/ml with a good determination coefficient (r2 =0.9989), molar absorptivity of 2.7798×104 l/mol.cm and Sandell's sensitivity of 0.0173 μg/cm2 . The Limits of detection (LOD) and quantitation (LOQ) were equal to 0.019 and 0.063μg/ml, respectively. A relative standard deviation (precision) was evaluated to be better than 0.91% depending on the concentration levels, whereas the value of recovery percentage were in the range of 97.20% to 103.82%. The approach was useful to the analysis of tetracycline hydrochloride in capsules and skin ointment. The statistic factors t-test and F-test values have also been investigated and revealed that the experimental "t" and "F" results were less than the theoretical results at confidence level of 95% Molar absorptivity ; Tetracycline Hydrochloride ; Tetracycline ; Chromatography ; Chemistry ; Relative standard deviation ; Detection limit ; Absorption (acoustics) ; Zirconium ; Hydrochloride ; Materials science ; Organic chemistry ; Antibiotics Analytical Methods in Pharmaceuticals ; Analytical Chemistry and Chromatography ; Drug-Induced Adverse Reactions
Authors: Nicolae Herişanu | Bogdan Marinca | Vasile Marinca
Source: Romanian Journal of Technical Sciences - Applied Mechanics (article, 2023-12-14)
Field: Materials Science — Materials Chemistry

Nonlinear forced vibration of a nanobeam resting on Winkler-Pasternak elastic foundation and subjected to a mechanical impact The nonlinear governing equations of nanobeam taking into consideration its curvature, resting on an elastic Winkler-Pasternak foundation and based on non-local Euler-Bernoulli beam theory is analyzed. The equation of motion and the boundary conditions are modeled within the framework of a simple supported nanobeam which accounts the presence of a mechanical impact and nonlinear von-Karman strain. The resulting nonlinear differential equations are reduced to only one differential equation which is studied by means of the Optimal Auxiliary Functions Method (OAFM). An explicit analytical solution is proposed for a complex problem. The main quality of our technique consists in the existence of some auxiliary functions derived from the expressions of the solution for the initial linear equation and the form of nonlinear term calculated from the above solution of the linear equation. The convergence-control parameters present in the auxiliary functions are evaluated by a rigorous mathematical procedure. The obtained solutions are in very good agreement with the numerical solution. Nonlinear system ; Mathematical analysis ; Mathematics ; Boundary value problem ; Vibration ; Curvature ; Differential equation ; Timoshenko beam theory ; Beam (structure) ; Equations of motion ; Classical mechanics ; Physics ; Geometry Nonlocal and gradient elasticity in micro/nano structures ; Composite Structure Analysis and Optimization ; Thermoelastic and Magnetoelastic Phenomena
Authors: Josua Grawitter | Holger Stark
Source: arXiv (Cornell University) (preprint, 2023-10-30)
Field: Materials Science — Surfaces, Coatings and Films

Steering droplets on substrates with plane-wave wettability patterns and deformations Motivated by strategies for targeted microfluidic transport of droplets, we investigate how sessile droplets can be steered toward a preferred direction using travelling waves in substrate wettability or deformations of the substrate. To perform our numerical study, we implement the boundary-element method to solve the governing Stokes equations for the fluid flow field inside the moving droplet. In both cases we find two distinct modes of droplet motion. For small wave speed the droplet surfes with a constant velocity on the wave, while beyond a critical wave speed a periodic wobbling motion occurs, the period of which diverges at the transition. These observation can be rationalized by the nonuniform oscillator model and the transition described by a SNIPER bifurcation. For the travelling waves in wettability the mean droplet velocity in the wobbling state decays with the inverse wave speed. In contrast, for travelling-wave deformations of the substrate it is proportional to the wave speed at large speed values since the droplet always has to move up and down. To rationalize this behavior, the nonuniform oscillator model has to be extended. Since the critical wave speed of the bifurcation depends on the droplet radius, this dependence can be used to sort droplets by size. Mechanics ; Inclined plane ; Wetting ; Bifurcation ; Critical speed ; Physics ; Substrate (aquarium) ; RADIUS ; Classical mechanics ; Materials science ; Nonlinear system ; Acoustics ; Thermodynamics Surface Modification and Superhydrophobicity ; Fluid Dynamics and Thin Films ; Adhesion, Friction, and Surface Interactions
Authors: Satadru Chakraborty | Anuradha Deshmukh | Pooja Kesari | Prasenjit Bhaumik
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-02-16)
Field: Materials Science — Materials Chemistry

<i>Toxoplasma gondii</i> aspartic protease 5 ( <i>Tg</i> ASP5): Understanding structural details and inhibition mechanism Abstract Toxoplasma gondii , a worldwide prevalent parasite, is responsible for causing toxoplasmosis by infecting almost all warm-blooded animals, including humans. To establish a successful infection, the parasite exports a series of effector proteins which modulates the host immune system; Golgi-resident T. gondii aspartyl protease 5 ( Tg ASP5) plays an essential role in the maturation and export of these effector proteins. This is the first report of the detailed structural investigation of the Tg ASP5 mature enzyme. Molecular modeling and all-atom simulation provided in-depth knowledge of the active site architecture of Tg ASP5. The analysis of the binding mode of TEXEL substrate highlighted the importance of the active site residues forming the pocket; the Ser505, Ala776 and Tyr689 in the S2 binding pocket provide the specificity towards Arg at the P2 position. Our study also provides insights into the binding mode of the known inhibitor RRL Statine. Screening the known aspartic protease inhibitors against Tg ASP5 active site and performing 100 ns all-atom molecular dynamic simulations, MM-PBSA binding energy calculations provided the best nine inhibitor protein complexes. Besides that, Principal Component Analysis (PCA) was employed to identify the change in protein dynamics with respect to the substrate and ligand binding. Tg ASP5 is essential for the fitness and virulence of the parasite; inhibiting this enzyme can be a possible therapeutic strategy against toxoplasmosis. Our study put forth the inhibitors which can act as initial scaffolds for developing potent mechanistic inhibitors against Tg ASP5. Toxoplasma gondii ; Effector ; Active site ; Biology ; Protease ; Golgi apparatus ; Binding site ; Toxoplasmosis ; Proteases ; Biochemistry ; Enzyme ; Cell biology ; Genetics ; Virology ; Antibody Enzyme Structure and Function ; Protein Structure and Dynamics ; Toxoplasma gondii Research Studies
Authors: Seda Ulusoy | Mikhail Feygenson | Thomas Thersleff | Toni Uusimäki | Mario Valvo | Alejandro G. Roca | J. Nogués | Peter Svedlindh | Germán Salazar‐Alvarez
Source: ChemRxiv (preprint, 2023-11-02)
Field: Materials Science — Materials Chemistry

Correlating magnetism and structural properties of chemically-lithiated Fe3–δO4 We have investigated the chemical lithiation in 70 nm cubic-shaped magnetite nanoparticles with varying degree of lithiation x = 0, 0.5, 1, 1.5. The induced changes on structure and magnetic properties were investigated with X-ray scattering techniques along with electron microscopy and magnetic measurements. The results indicate that a structural transformation from spinel to rock salt phase occurs above a critical limit for the lithium concentration (xc), which is determined to be between 0.5< xc≤1 for Fe3–δO4. Magnetization measurements confirm the formation of the LiFeO2 phase with its distinct antiferromagnetic behaviour. Upon lithiation, exchange bias measurements reveal a shift in the hysteresis loops with an asymmetry, which can be attributed to the formation of mosaic-like LiFeO2 subdomains and cationic disorder. The combined structural, spectral-imaging and magnetization characterization techniques enabled us to identify the phases and their distribution during in the lithiation process. Spinel ; Antiferromagnetism ; Magnetism ; Magnetization ; Hysteresis ; Magnetite ; Materials science ; Lithium (medication) ; Phase (matter) ; Exchange bias ; Cationic polymerization ; Condensed matter physics ; Chemistry ; Magnetic field ; Physics ; Metallurgy ; Magnetic anisotropy Magnetic Properties and Synthesis of Ferrites ; Advancements in Battery Materials ; Magnetic properties of thin films
Authors: Tehreem Tahir | Awais Rasheed | Sadaf Kayani | Asim Shahzad
Source: Research Square (preprint, 2023-07-11)
Field: Chemistry — Analytical Chemistry

High-Throughput Digital Imaging Analysis Of Historical Wheat Cultivars From Pakistan Cultivar ; Throughput ; Computer science ; Horticulture ; Biology ; Telecommunications Spectroscopy and Chemometric Analyses ; Wheat and Barley Genetics and Pathology ; Genetic Mapping and Diversity in Plants and Animals
Authors: Amun Amri
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2023-03-19)
Field: Materials Science — Materials Chemistry

Very-few-layer graphene obtained from facile two-step shear exfoliation in aqueous solution A defect-free graphene with 1–3 layers (very-few-layer graphene, VFLG) has been successfully produced using a facile and environmentally friendly two-step shear exfoliation method in rotating-blade mixer (kitchen blender) and in high shear rotor–stator mixer. An aqueous solution containing an inexpensive and safe anionic surfactant of sodium lauryl sulphate (SLS) was deployed as the working fluid. Raman spectroscopy (RS) and Raman imaging (RI), density functional theory (DFT) simulation, transmission electron microscopy and high-resolution transmission electron microscopy (TEM-HRTEM), as well as Fouriertransform infrared spectroscopy (FTIR) analyses were used to characterize the samples. Some configurations of mixer setting were applied, and the exfoliation mechanisms were discussed. RS analysis revealed that the exfoliation process in rotating-blade mixer continued by high shear in rotor–stator mixer for 3 h had produced VFLG dominated by a single layer of graphene. The Lorentzian peak fitting of 2D band was well-fitted by a single Lorentzian component at Raman shift of 2651.317 cm 1. The produced VFLG endured the lowest peak intensity ratio of D and G bands (ID/IG) of 0.146 which corresponded with the highest lateral size. RI analysis showed that produced VFLG had edge chirality of armchairs and zigzag terminations. TEM-HRTEM confirmed the presence of VFLG with the highest mean lateral size of ~375.4 nm. DFT calculations provided pertinent optical/electronic properties of graphene in terms of Raman Spectra, density of states (DOS) curve and nuclear magnetic resonance (NMR) shielding tensor. FTIR analysis showed that the exfoliation process did not cause any oxidation, sulphonation, or functional defects on the VFLG. The turbulence and hydrodynamic force in liquid were the critical factors in the exfoliation processes. High-quality VFLG, with a facile, inexpensive, and environmentally friendly synthesis process, rendered this process to be a promising route for large-scale high-quality graphene production. Exfoliation joint ; Graphene ; Aqueous solution ; Materials science ; Layer (electronics) ; Shear (geology) ; Chemical engineering ; Composite material ; Nanotechnology ; Chemistry ; Organic chemistry Graphene research and applications ; Graphene and Nanomaterials Applications ; Advancements in Photolithography Techniques
Authors: Chan Mi Bang | Khaliunaa Tseveen | Gwang Hyeon Lee | Gil Jong Seo | Hong Kong
Source: Journal of Animal Reproduciton and Biotechnology (article, 2023-09-26)
Field: Materials Science — Polymers and Plastics

Identification of CNVs and their association with the meat traits of Hanwoo Background: Copy number variation (CNV) can be identified using next-generation sequencing and microarray technologies, the research on the analysis of its association with meat traits in livestock breeding has significantly increased in recent years. Hanwoo is an inherent species raised in the Republic of Korea. It is now considered one of the most economically important species and a major food source mainly used for meat (Hanwoo beef). Methods: In this study, CNVs and the relationship between the obtained CNV regions (CNVRs) can be identified in the Hanwoo steer samples (n = 473) using Illumina Hanwoo SNP 50K bead chip and bioinformatic tools, which were used to locate the required data and meat traits were investigated. The PennCNV software was used for the identification of CNVs, followed by the use of the CNV Ruler software for locating the different CNVRs. Furthermore, bioinformatics analysis was performed. Results: We found a total of 2,575 autosomal CNVs (933 losses, 1,642 gains) and 416 CNVRs (289 gains, 111 losses, and 16 mixed), which were established with ranged in size from 2,183 bp to 983,333 bp and 10,004 bp to 381,836 bp, respectively. Upon analyzing the restriction of minor alleles frequency > 0.05 for meat traits association, 6 CNVRs in the carcass weight, 2 CNVRs in the marbling score, 3 CNVRs in the backfat thickness, and 2 CNVRs in the longissimus muscle area were related to the meat traits. In addition, we identified an overlap of 347 CNVRs. Moreover, 3 CNVRs were determined to have a gene that affects meat quality. Conclusions: Our results confirmed the relationship between Hanwoo CNVR and meat traits, and the possibility of overlapping candidate genes, annotations, and quantitative trait loci that results depended on to contribute to the greater understanding of CNVs in Hanwoo and its role in genetic variation among cattle livestock. Hanwoo ; Identification (biology) ; Biology ; Genetic association ; Association (psychology) ; Genetics ; Gene ; Single-nucleotide polymorphism ; Genotype ; Food science ; Psychology ; Ecology Textile materials and evaluations ; Consumer Perception and Purchasing Behavior ; Healthcare and Venom Research