Miracle-dz/UniFAR-FTUs huggingface dataset:
A three-dimensional co-culture of HepG2 spheroids and fibroblasts using double-layered fibrous scaffolds incorporated with hydrogel micropatterns

We developed a novel methodology of constructing a three-dimensional (3D) heterotypic co-culture system based on double-layered fibrous scaffolds incorporated with hydrogel micropatterns. The combination of electrospinning and hydrogel patterning generated micropatterned fibrous scaffolds consisting of poly(ethylene glycol) (PEG) hydrogel micropatterns and polycarprolactone (PCL) fibers. The thickness of the hydrogel micropatterns and fiber matrices, which were in the ranges of 100 to 250 μm and 20 to 80 μm, respectively, could be controlled by the volume of the hydrogel precursor solution and the collection time used for electrospinning. Because the resultant micropatterned fibrous scaffolds were obtained as a free-standing and bidirectionally-porous sheet, they could be stacked in a double-layered structure in which each scaffold contains different cell types for co-culture studies. As a model system, double-layered scaffolds for the co-culture of HepG2 and fibroblast cells were constructed by placing HepG2-containing scaffolds on top of fibroblast-containing scaffolds. The micropatterned fibrous scaffolds were demonstrated to be suitable for the culture of both HepG2 and fibroblasts cells. In addition, by controlling the micropattern size, HepG2 spheroids of uniform size (187.2 ± 10.7 μm) were formed in the top layer and used for the co-culture studies. According to the co-culture experiment, enhanced albumin secretion was observed from the co-cultured HepG2 cells compared with the single-cultured HepG2 cells, suggesting that micropatterned fibrous scaffolds are a promising tool that can be applied to heterotypic co-culture systems in various tissue engineering applications.
Ab initio evaluation of oxygen diffusivity in LaFeO_3: the role of lanthanum vacancies

Solid oxide fuel cells (SOFCs) are attractive for clean and efficient electricity generation, but high operating temperatures ( T _op > 800 °C) limit their widespread usage. Oxygen ion conducting cathode materials (mixed ion-electron conductors, MIECs), such as La_1− x Sr_xCo_1− y FeyO_3 (LSCF), enable lower T _op by reducing cathode polarization losses. Understanding how composition affects oxygen diffusion in LaFeO_3 is vitally important for designing high-performance LSCF cathodes. To do this, we employ first-principles density functional theory plus U (DFT+U) calculations to show how lanthanum vacancies in LaFeO_3 dramatically change the oxygen diffusion coefficient. Our ab initio results show that A-site substoichiometry is a viable route to increased oxygen diffusion and higher SOFC performance.
Tetranucleotides as a scaffold for diporphyrin arrays

The incorporation of porphyrin-substituted nucleosides into tetranucleotides using phosphoramidite chemistry on solid support is reported. Both diphenyl and tetraphenyl porphyrin nucleosides were used as building blocks. This method allows the synthesis of chiral homo- and heteroporphyrinic arrays, where the composition and thus the physical properties of the array can be modulated simply by reprogramming the DNA synthesizer. The porphyrin arrays are initially isolated in the free-base form. Remetallation to give the zinc-porphyrins can be achieved using standard procedures in solution. The UV-vis spectra of the arrays are reproducible by a superposition of the absorbance spectra of the individual porphyrins, indicating an undisturbed electronic ground state of the porphyrins in the arrays. The same is true for the steady-state emission spectra of the homoporphyrinic arrays, which are not influenced by the presence of the nucleotide strand. In the mixed porphyrin arrays, large differences in the excited-state properties compared to an equimolar mixture of the building blocks are observed by means that the emission of the diphenyl porphyrin moiety is quenched to a large extent, and the overall emission is dominated by the tetraphenyl porphyrin. The covalent connection of the porphyrins via the DNA-derived backbone therefore substantially alters the excited-state and energy-transfer properties of mixed porphyrin systems. The circular dichroism (CD) spectra show induced negative cotton effects in the region of the porphyrin B-band absorption, which is due to the attachment of the chromophores to the chiral oligonucleotide backbone. Addition of a complementary tetra-adenosine did not alter any of the spectroscopic properties, neither in chloroform nor in acetonitrile solutions. Therefore, it can be concluded that no duplex is formed, which is corroborated by 1H NMR spectroscopy.
Monte Carlo simulations of self- and transport-diffusivities of 2-methylhexane in silicalite

We report kinetic Monte Carlo (KMC) simulations of self- and transport-diffusivities of 2-methylhexane (2MH) in silicalite. The hopping rates of 2MH along the straight and zig-zag channels were chosen based on the calculations of Smit (Faraday Discuss., 1997, 106, 93). The self-diffusivity tensor was found to exhibit anisotropy and strongly dependent on the occupancy or loading. The degree of anisotropy of the self-diffusivity tensor decreases with loading, a hitherto unreported result. The loading dependence is shown to be due to correlation effects. Such correlation effects, do not however influence the behavior of the transport-diffusivity which exhibits a predictable Langmuirian dependence on loading.
Peierls instabilities in covalent structures I. Electronic structure, cohesion and the Z = 8 – N rule

The vast majority of the molecular, crystalline or liquid structures of groups V, VI and VII of the periodic table and their compounds obey the octet rule (Z = 8 - N). The structure and stability of those structures are discussed in a simple tight-binding approximation. In this framework we show that the Peierls electronic instability of a simple cubic structure leads to the octet rule. This instability does not rely upon the periodicity and consequently may occur in crystalline, amorphous or liquid matter. In a general discussion on the stability of covalent structures, we show that the existence of a Peierls distortion is governed by the balance between the attractive (band) term and the empirical repulsive term. As the hardness of the latter increases when going down the periodic table, this explains why the Peierls distortion is stronger for the light elements.
Nanosilicon‐Coated Graphene Granules as Anodes for Li‐Ion Batteries

IO N Increased concern regarding environmental pollution from combustion power sources combined with the shortage of oil reserves and the growing demand for portable electronics and powered devices has generated considerable research activity to develop Li-ion batteries with greatly enhanced energy density. [ 1 ] Historically, the Li-ion anode has been composed of graphitic carbon. At full lithiation, graphite can intercalate one Li atom per six carbon atoms (LiC 6 ) for a theoretical capacity of 372 mAh · g − 1 . [ 2 ]
Fabrication and Characterization of Integrated Ultrahigh-Density Fe-Pt Alloy Nanowire Arrays on Glass

A method is reported for the fabrication of Fe-Pt binary alloy nanowire arrays embedded in porous alumina films with controlled diameters and high aspect ratios directly on glass substrates by successive anodization and cathodic electrodeposition in a novel bath with a simple composition. Porous alumina films with different pore sizes were initially formed by anodizing aluminum layers sputter-deposited on glass substrates covered with an indium tin oxide (ITO) film. After the insulative barrier layer was removed through a chemical dissolution, the porous alumina nanostructures on ITO/glass were used as template electrodes in dc electrodeposition to deposit Fe-Pt alloy within the nanopores, leading to integrated Fe-Pt nanowire (Φ23-52 nm) arrays on glass with high densities of 1.92-7.85 × 10 1 4 wire per square meter. The as-deposited Fe-Pt nanowires are composed of polycrystalline tetragonal FePt phase with crystal sizes 2-6 nm across. Thermal annealing at 973 K induced the crystal growth of disordered tetragonal FePt phase with appearance of (001) facet and developed the preferential magnetic orientation and enhanced coercivity in perpendicular direction (along the nanowire axis).
pH Adjusting to Reduce Fouling Propensity of Activated Sludge Mixed Liquor in Membrane Bioreactors

The effect of adjusting pH on membrane filterability of activated sludge mixed liquor in membrane bioreactors (MBRs) was studied. The properties of the mixed liquor were analyzed to investigate the mechanisms. The results indicated that moderately adjusting pH was effective to improve the membrane filterability of the mixed liquor. HCl addition provided H+, which reduced the zeta-potential of the colloidal particles. NaOH addition at pH of 8.0–9.0 released some extractable extra-cellular polymeric substances (eEPS) to the supernatant. Re-flocculation occurred. The fouling propensity of the mixed liquor was therefore reduced. Microbial activity was not significantly affected within the pH of 6.0–9.0.
Designable Yolk–Shell Nanoparticle@MOF Petalous Heterostructures

Controllable integration of nanoparticles (NPs) and metal–organic frameworks (MOFs) is crucial for expanding the applications of MOF-based materials. In this study, we demonstrate the facile encapsulation of presynthesized NPs into carboxylic acid based MOFs using NPs@metal oxide core–shell nanostructures as the self-template. The shell dissolved gradually in the mildly acidic growth solution created by dissociation of the ligands and thus directing the growth of the MOF crystals by providing metal ions. With protection of the metal oxide shell, various NPs (Au NPs, Au nanorods, Pd nanocubes, and Pt-on-Au dendritic NPs) could be encapsulated easily without being aggregated or dissolved in the reaction mixture. Importantly, instead of forming the exact replicate of the self-template, the obtained NP@MOF heterostructures exhibited a yolk–shell morphology with a central cavity and a certain degree of mesoporosity. The formation of the well-defined yolk–shell structure was demonstrated to be dependent on both.
Detection of photosynthetic activity under cadmium stress by measurement of the red and far-red chlorophyll fluorescence

In this work it is shown that, with a new spectroscopic method based on ultraviolet light emitting diode-induced fluorescence spectroscopy (UV-LED IFS), the photosynthetic activity of an intact attached leaf can be measured in a non-destructive way within a few seconds. The effects of cadmium (Cd) toxicity on the photosynthetic activity of tomato plants (Solanum lycopersicum) were studied using various CdCl2 (cadmium chloride) concentrations. The Cd treatment decreases the photosynthetic activity, measured via a decline of the variable chlorophyll (chl) fluorescence decrease ratio (R Fd) values, calculated at 690 and 730 nm. The chl fluorescence ratios of intensity (FIR) and band area were also calculated. It was found that the R Fd(690) and R Fd(730) values decreased whereas the FIR increased from 1 μM Cd treatment and this behaviour is enhanced with the increasing of Cd concentrations. At 10 and 25 μM Cd, the decrease in R Fd values was associated with a strong decline in the chlorophyll-a + chlorophyll-b (chl-a + b). The chl-a + b decline could also be followed via an increase of the chl fluorescence ratio F 690/F 730. Our study demonstrates that the UV-LED IFS is a promising technique for early detection of Cd stress (from 1 μM) in tomato plants, before visual symptoms appear.
Hydroxy-steroids. Part IV. The preparation and spectra of steroid olefins

Convenient preparations have been developed for a series of steroidal mono-olefins free from oxygenated substituents: this Series includes representatives of all but one of the possible endocyclic olefins. The infrared, nuclear magnetic resonance, and ultraviolet spectra of the compounds were examined with particular attention to the relative power and scope of the different techniques in structural diagnosis.
Relating Qualitative Analysis to Equilibrium Principles

Qualitative analysis in the general chemistry laboratory provides an excellent opportunity to help students make connections between ionic equilibrium topics covered in the lecture course and physical reality. Although laboratory manuals generally provide ample discussion of the equilibrium principles upon which the procedures are based, students' attention tends to be focused mostly on techniques, the reactions involved, and physical observations. A lack of understanding of the underlying principles often results in students being unable to make simple modifications to the procedure. This Mathcad document is intended to be used in a prelab activity for qualitative analysis experiments (based on modules ANAL364-366 of the Modular Laboratory Program in Chemistry, Palmyra, PA 17078), which are done toward the end of the general chemistry laboratory course at Nicholls State University. Mathcad is introduced at the beginning of the course and is routinely used throughout the semester for data analysis; handou.
Synthesis of carbon nanofibres over nanoporous Ni–MgO catalyst: influence of the bimetallic Ni–(Cu, Co, Mo) MgO catalysts

In this study, methane decomposition was conducted over monometallic Ni and bimetallic Ni–(Cu, Co, Mo) catalysts based on nanoporous MgO support to produce CO x -free hydrogen and carbon nanofibres (CNFs). The MgO support was prepared by the sol–gel method and the catalysts were prepared by incipient wetness impregnation. The molar ratio of Ni to Mg was found to be around 0.76 and the molar ratios of transition metals Cu, Mo and Co to Ni were found to be around 0.23, 0.15 and 0.25, respectively. The methane decomposition reactions were performed at temperature of 570°C over a nanoporous catalyst sample using the chemical vapour deposition technique in a fixed bed reactor. The X-ray diffraction pattern of the air-reduced catalysts confirmed the presence of metallic oxides as solid solution in the calcined samples. The maximal carbon and hydrogen yields, 3.62 gC/gNi and 36.16 were obtained with the Ni–MgO catalyst, respectively, during 1 h of reaction time. The Ni–Cu–MgO catalyst exhibited pronounced catalytic activity for several hours time-on-stream with accumulated carbon and hydrogen yields of 5.85 gC/gNi and 58.39 , respectively, during 1 h of reaction time. However, adding Mo to the Ni-based catalyst increased the activity of the catalyst only by a slight increase (3.90 gC/gNi·1h). Scanning and transmission electron microscope images of solid carbon showed hollow core herringbone structure of CNFs formed by a tip-growth mechanism.
Enzymatic hydrocyanation of a sterically hindered aldehyde. Optimization of a chemoenzymatic procedure for (R)-2-chloromandelic acid

The asymmetric synthesis of (R)-o-chloromandelic acid, a key intermediate for the anti-thrombotic agent clopidogrel, via the almond meal catalyzed hydrocyanation of 2-chlorobenzaldehyde and subsequent acidic hydrolysis was developed into an industrially viable procedure. The use of a minimum amount of water consistent with enzyme activity and a slow feed of the reactants were the keys to obtaining (R)-2-chloromandelonitrile in a high (98%) yield and satisfactory (90%) enantiomeric excess. Acidic hydrolysis of the nitrile followed by crystallization from toluene afforded enantiopure (ee > 99%) (R)-2-chloromandelic acid.
Structure Analysis of Intercalated Zirconium Phosphate Using Molecular Simulation

Molecular simulation supported by X-ray diffraction and IR spectroscopy has been used to analyse the structure of α-zirconium phosphate intercalated by ethanol, Zr(HPO4)2.2C2H5OH. Molecular-mechanics simulations using the Crystal Packer module in the Cerius2 modelling environment revealed the crystal packing in the interlayer, i.e. the positions of ethanol with respect to the Zr(HPO4)2 layers and the layer stacking in the intercalated structure. The average interlayer distance d\,=\,14.03 (13) A obtained by modelling is in agreement with the experimental d value of 14.05 (4) A obtained from the X-ray diffraction analysis. The disorder in the Zr(HPO4)2.2C2H5OH structure found by molecular simulation has been confirmed by the character of the X-ray diffraction pattern.
Kinetics study of photocatalytic process for treatment of phenolic wastewater by TiO2 nano powder immobilized on concrete surfaces

In this study, kinetics of photocatalytic degradation of phenolic wastewater in immobilized photocatalytic reactor was investigated. Immobilization of titanium dioxide (TiO2) nano powders on concrete surfaces were accomplished with epoxy concrete sealer. Kinetics of photocatalytic reactions has been proposed to follow the Langmuir–Hinshelwood model in different initial phenol concentration, pH, and UV lamp intensity. First-order reaction kinetics with respect to the pollutant concentration was obtained for the reaction. Effect of UV lamp intensity showed that kinetic constants were proportional to the power of 0.73–1 of the photonic flow. In all cases kinetic constant increases as pH of the system reached up to 12 units. Several reaction intermediates were identified using the GC/Mass analysis. Products at the initial stage of the reaction were aromatic compounds, contained hydroquinone, benzoquinone, and catechol. These intermediates underwent further photocatalytic oxidation to aliphatic compounds and finally into CO2 and H2O after 4 h. Kinetic constants of intermediate compounds were determined using mathematical–chemical equations and nonlinear regression. Data showed that the differences between the mathematical model and Langmuir–Hinshelwood model for the kinetic constant was less than 5%.
Growth mechanism of nanoparticles: theoretical calculations and experimental results

We report a combined theoretical and experimental study on the growth mechanism of silver and gold nanoparticles. We introduce for the first time the grand-canonical Monte Carlo method to study the growth/dissolution steps of nanoparticle growth mediated by seeds. In particular we found that small changes on the chemical potential, i.e. the activity of the metal ions, produce significant changes on the size and morphologies of the nanoparticles. We have found very good agreements between simulated structures with those observed experimentally by means of scanning electron microscopy.
Effects of biomass co-combustion with coal on functional speciation and mobility of heavy metals in industrial ash.

Comparative studies of industrial fly ash from coal and biomass co-combustion (50%: mixture of sunflower pellets, wood chips, and straw briquettes) and coal ash were conducted. The functional speciation of metals (Pb, Cd, Zn, Cu) and mobility of chemical fractions of ash (soluble in water, exchangeable, soluble in acids pH5, oxide, pseudosulfide, residual) were carried out with a 6-stage sequential extraction and singlestage mineralization methods. It was found that the addition of biomass to coal results in ash containing more Zn, a decrease in the content of Cd, and no major changes in total content of Pb and Cu. A mixture of sunflower pellets, wood chips, and straw briquettes added to coal as biomass results in an increase of the ash fractions: exchangeable (Pb), pseudosulfide (Pb, Cu), oxide and residual (Zn), reduction in ash fractions: soluble in acid pH5 (Pb, Cd, Zn), oxide (Cu), pseudosulfide (Zn), residual (Cd). Biomass co-combusted with coal (50/50 m/m) improves the ash by reduction of the environmental mobility of Pb, Cd and Zn, but does not cause major changes in the mobility of Cu in relation to coal ash.
Opinion Dynamics on Complex Networks

Social media has emerged as a significant source of information for people. As agents interact with each other through social media platforms, they create numerous complex social networks. Within these networks, information spread among agents and their opinions may be altered by their neighbors' influence. This paper explores opinion dynamics on social networks, which are influenced by complex network structure, confirmation bias, and specific issues discussed. We propose a novel model based on previous models to simulate how public opinion evolves from consensus to radicalization and to polarization. We also analyze how agents change their stance under their neighbors' impact. Our model reveals the emergence of opinion groups and shows how different factors affect opinion dynamics. This paper contributes to the understanding of opinion dynamics on social networks and their possible applications in finance, marketing, politics, and social media.
Influence of surface electrokinetics on organosilane adsorption

The time-dependent adsorption of propyltrimethoxysilane (PTMS) in aqueous solution on four substrates (aluminium, zinc, iron and chromium oxide) has been investigated using x-ray photoelectron spectroscopy. Oscillations in the adsorption isotherm as a function of adsorption time in solution have been observed for all of the substrates studied. The adsorption of PTMS is shown to depend strongly upon the isoelectric point of the surface oxide. The closer the isoelectric point is to the solution pH, the more rapid is the initial adsorption rate of silane on the surface. Models are proposed to explain the influence that the electrokinetics of the surface has upon the adsorption mechanism.
Heat transfer coefficients in coiled stirred‐tank systems

Les mesures experimentales sont effectuees en regime transitoire et permanent dans un seul ou deux appareils agites en serie, en utilisant des agitateurs a palettes plates. On fait varier la temperature, les debits et la vitesse d'agitation pour des nombres de Reynolds variant de 19000 a 77000. Les resultats experimentaux sont en bon accord avec les valeurs theoriques predites. On obtient les memes valeurs en regime transitoire et permanent
Determination of the stoichiometry of CuxInySez by total-reflection XRF

A rapid and accurate total-reflection XRF method was developed in order to determine the absolute stoichiometry of ternary compounds of the type Cu∶In∶Se. The method was used to determine the composition of the synthesised compounds CuxInyS ez(CIS). Three compounds were synthesised with different atomic proportions x∶y∶z; 1∶3∶5, 2∶4∶7 and the no stoichiometric phase 1∶2.5∶4.75. The results obtained showed a systematic deficiency of In and an increment of Se with respect to the stoichiometric formula.
Novel poly(l‐lactide)/poly(d‐lactide)/poly(tetrahydrofuran) multiblock copolymers with a controlled architecture: Synthesis and characterization

Novel poly(L-lactide) (PLLA)/poly(D-lactide) (PDLA)/poly(tetrahydrofuran) (PTHF) multiblock copolymers with designed molecular structure were synthesized by a two-stage procedure. Well-defined PDLA-PLLA-PTHF-PLLA-PDLA pentablock copolymers were prepared by sequential ring opening polymerization of L- and D-lactides starting from PTHF glycol, with the length of the (equimolar) PLLA and PDLA blocks being varied. Then, these dihydroxyl-terminated pentamers were transformed into multiblock copolymers by melt chain-extension with hexamethylene diisocyanate-being the first time that the coupling of pentablock units is reported. The successful formation of macromolecular chains with a multiblock and well-defined architecture was demonstrated by 1H NMR spectroscopy. The thermal properties and structuring of the resulting materials were investigated by means of DSC and WAXD measurements and DMA analysis. Stereocomplexation was found to be promoted during solution and melt crystallization. This approach affords materials combining the high rigidity and strength (other than improved thermal resistance) of the hard stereocomplex crystallites with the flexibility imparted by the soft block, whereby their properties can be finely tailored through the composition of the basic pentablock units without limitations on the final molecular weight. The adopted reaction conditions make this process highly appealing in view of the possibility to perform it in extruder.