Miracle-dz/UniFAR-FTUs huggingface dataset:
Os-complex-based amperometric bienzyme biosensor for continuous determination of lactate in saliva

An amperometric biosensor, constructed through a specific design featuring a bienzyme doped sol–gel and an Os-complex mediator layer, capped with electropolymerized polyphenol semipermeable membranes, is presented for lactate quantification in saliva. The new enzymatic biosensor exhibits impressive linear and low response times in a phosphate buffer solution of pH 7.0, and a linear dependence of the catalytic current upon lactate bulk concentration is obtained between 0.1 and 1.0 mM (r = 0.997). A detection limit of 0.013 mM can be calculated as three times the standard deviation of the blank signal divided by the sensitivity of the sensor. The selectivity of the biosensor is evaluated by adding common interferent species such as ascorbic acid and uric acid to 0.2 mM lactate; current responses for the interferents are nearly negligible compared to that of the lactate, indicating excellent discriminatory selectivity. The lactate biosensor presents remarkable operational stability in 0.2 mM lactate over a 2 h period and good repeatability in a carry-over test by alternating lactate concentrations. The successful application to whole human saliva samples for continuous monitoring of lactate dynamics makes the amperometric bienzyme biosensor hold considerable promise for diverse biomedical and fitness applications.
Strategy against micrometastasis of epithelial cancer: Detection and elimination

Tumor metastasis is generally agreed to be the major cause of cancer death. Over the last few years, studies of new diagnosis techniques and tumor immunotherapy have made great progress. Recent clinical studies on the occult metastases of breast, lung and colorectal cancer all suggested that the detection of micrometastases in bone marrow is prognostically important and provides substantial evidence of tumor dissemination. On the other hand, two kinds of the mAb-based immunotherapy have been approved for the treatment against epithelial cancer. Monoclonal antibody (mAb) 17-1A for colorectal carcinomas and mAb herceptin for breast cancer both have produced good curative effects. Potential therapeutics based on some antibodies with prominent antitumor activity also has shown obvious clinical effect. These studies indicate that detection of micrometastasis in circulatory system and immunotherapy by eliminating metastatic malignant cells suggested a new strategy against the metastatic cancer.
Beyond chemical accuracy: The pseudopotential approximation in diffusion Monte Carlo calculations of the HCP to BCC phase transition in beryllium

Motivated by the disagreement between recent diffusion Monte Carlo calculations and experiments on the phase transition pressure between the ambient and beta-Sn phases of silicon, we present a study of the HCP to BCC phase transition in beryllium. This lighter element provides an oppor- tunity for directly testing many of the approximations required for calculations on silicon and may suggest a path towards increasing the practical accuracy of diffusion Monte Carlo calculations of solids in general. We demonstrate that the single largest approximation in these calculations is the pseudopotential approximation. After removing this we find excellent agreement with experiment for the ambient HCP phase and results similar to careful calculations using density functional theory for the phase transition pressure.
Lead biotransformation potential of allochthonous Bacillus sp. SKK11 with sesame oil cake extract in mine soil

The potential of allochthonous Bacillus sp. SKK11 and sesame oil cake extract for the immobilization of Pb in mine soil was investigated in this study. The isolate SKK11, isolated from a brackish environment and identified as Bacillus sp. based on partial 16S rDNA sequencing, exhibited maximum resistance to Pb (750 mg L−1). Growth kinetic studies revealed that the presence of oil cake extract (2%) increased the biomass of the isolate SKK11. Transmission electron microscopy and X-ray diffraction studies showed that isolate SKK11 transformed Pb either intracellularly or extracellularly. Selective sequential extraction studies showed that the bioremediation decreased 24.9% of the exchangeable fraction in the mine soil in 3 days. However, 75.1% of the exchangeable fraction was not immobilized in the soil. An X-ray diffractogram of the bioremediated soil showed a major decrease (79.0%) in the intensity of the plagioclase mineral peak. Urease, dehydrogenase, amylase, invertase, cellulase, and alkaline phosphatase enzyme activities were increased in the bioremediated mine soil. These results suggest that the isolate Bacillus sp. SKK11 in combination with sesame oil cake extract could be employed for the immobilization of bioavailable Pb in contaminated soil.
High-Performance Carboxylated Polymers of Intrinsic Microporosity (PIMs) with Tunable Gas Transport Properties†

Carboxylated polymers of intrinsic microporosity (carboxylated PIMs) are reported as potential high-performance materials for membrane-based gas separation. Carboxylated PIM membranes were prepared by in situ hydrolysis of the nitrile groups of PIM-1 films. Structural characterization was performed by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H NMR). The degree of hydrolysis was determined by carbon elemental analysis. The thermal properties were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Compared with PIM-1, carboxylated PIMs with different degrees of hydrolysis have similar thermal and mechanical properties but show higher selectivity for gas pairs such as O2/N2, CO2/N2, He/N2, and H2/N2 with a corresponding decrease in permeability. Selectivity coupled to high permeability combines to exceed the Robeson upper-bound line for the O2/N2 gas pair. This work demonstrates that significant improvements in gas separati.
Effects of HF cleaning and subsequent heating on the electrical properties of silicon (100) surfaces

Changes in surface‐band bending of both boron‐doped and phosphorus‐doped silicon (100) samples by exposure (40 s) to hydrofluoric acid (HF) with varying HF concentrations were studied by x‐ray photoelectron spectroscopy. Effects of subsequent thermal annealing was investigated by in situ heating in vacuum. Hydrogen termination of the dangling bonds on silicon was found to be an effective means to reduce surface gap states on silicon. Near‐flatband surfaces were observed on both n‐ and p‐Si by the HF exposure when the doping concentration was not less than 1×1016/cm3, and when the HF concentration was not higher than 5%. A higher HF concentration promoted hydrogen diffusion and the formation of an H‐B species in p‐Si. As such, band bending increased on p‐Si. However, the deactivation of boron could be recovered by annealing for less than 1 h at a temperature as low a 120 °C.
Synthesis of Two Coordination Polymer Photocatalysts and Significant Enhancement of Their Catalytic Photodegradation Activity by Doping with Co2+ Ions

The coordination polymers (CPs) [Zn2(tipm)(1,3-BDC)2] (1) and [Co2(tipm)(1,3-BDC)2]·0.5CH3CN (2·0.5CH3CN) were synthesized by the reactions of Zn(NO3)2 or Co(NO3)2 with tetrakis[4-(1-imidazolyl)phenyl]methane (tipm) and benzene-1,3-dicarboxylic acid (1,3-H2BDC) under solvothermal conditions. Compounds 1 and 2 are isostructural and possess complicated three-dimensional frameworks with the Schlafli symbol (4·72)(62·73·12)(4·62·73). Cobalt ions were incorporated into the Zn-based CP framework 1 during solvothermal crystallization to yield [Zn(2–2x)Co2x(tipm)(1,3-BDC)2]·bH2O (x = 2.4 %, b = 0 for 1a, x = 23 %, b = 1 for 2a·H2O). Doped CPs 1a and 2a·H2O exhibited greater catalytic photodegradation of the dye rhodamine B (RhB) than the undoped complexes 1 and 2 and many literature examples.
SEGREGATION OF STRAINS OF BREWING YEAST BY THEIR CARBON ASSIMILATION PATTERNS

The carbon assimilation patterns of different strains of Saccharomyces cerevisiae and Saccharomyces uvarum have been found to be sufficiently different to allow the segregation of 130 strains into 25 distinct groups. These differences offer an additional means of finger-printing commercially used strains and of detecting contamination of these with other strains of brewing yeast.
First-principles studies on facet-dependent photocatalytic properties of bismuth oxyhalides (BiOXs)

The photocatalytic properties were compared for the {001}, {110} and {010} facets of bismuth oxyhalides (BiOXs) through density functional theory (DFT) computations. X-terminated bulk-like {001} facets with clear boundary of [Bi2O2] and halogen slabs result in high thermodynamic stability and efficient separation of photo-induced e−-h+ pairs. Moreover, surface O vacancies, which act as e−-h+ recombination centers, are energetically unfavorable within {001} facets. BiX-terminated {110} and other facets with surface O vacancies introduce deep defect levels to the band gap, which are detrimental to the separation of e−-h+ pairs. These findings can better understand the origin of facet-dependent photocatalytic activities in BiOXs, and provide guidance for the design of high-efficiency photocatalysts.
Dissociative electron attachment study to nitromethane

Dissociative electron attachment (DEA) to CH3NO2 in the gas phase was studied in the electron energy range from zero up to 10 eV with an energy resolution of 140 meV. For the most intense negative fragments NO2−, O−, OH−, CN−, CNO− estimates for the absolute partial cross sections were obtained for the first time [σ(NO2)≈10−21 m2 at 0.62 eV, σ(O−)≈10−23 m2 at 5.4 eV, σ(OH−)≈10−24 m2 at 4 eV, σ(CN−)≈10−24 m2 at 1.7 eV, and σ(CNO−)≈10−25 m2 at 4 eV]. In the case of OH−, CN−, and CNO−, ion formation at very low electron energies (≈0 eV) has been observed in contrast to previous studies. The formation of OH− and CNO− at these low electron energies is explained in terms of DEA to vibrationally excited molecules. Analyzing measured partial cross sections, the standard enthalpy of formation of the CH3NO (nitroso-methane) and the CNO radical has been estimated, as ΔfHg∘(CH3NO)=129±30 kJ/mol and ΔfHg∘(CNO)=323±30 kJ/mol, respectively.
Thermal Stability of Pt/Al 2O 3 Catalysts Prepared by SolGel

Abstract A series of Pt/Al 2 O 3 catalysts were prepared using a sol–gel method. The influence of several parameters used in the synthesis including: metal content, identity of the metal precursor, and the water/alkoxide ratio on the structural properties of the fresh (dried) and calcined samples were studied. It was found that the BET surface area decreased with an increase in the platinum content. A surface area of 500 m 2 /g was obtained following calcination at 773 K. The structure of fresh samples as determined by FTIR corresponded to that of a pseudoboehmite structure. Samples prepared using a water/alkoxide ratio (H 2 O/ATB) of 9 showed a well-defined, uniform pore size distribution following calcination at 773 K. Metal dispersions comparable to those obtained using impregnation methods were obtained. Aging studies (calcination at 873 K for 24 h) performed on these catalysts, exhibited sintering behavior which were similar to Pt/Al 2 O 3 catalysts prepared by other methods. The sample prepared using a H 2 O/ATB ratio of 9 had the highest surface area and was more thermally resistant towards metal sintering. A bimodal metal particle size distribution was observed: some particles exhibited sintering while others of similar size showed a greater thermal stability to sintering. The sample having the largest surface area and the highest thermal stability following thermal treatment was a consequence of a more condensed structure and a higher pore roughness obtained after drying the gel. This enabled the formation of an alumina structure which was more amorphous and limited aggregation of platinum particles due to surface diffusion within the pore structure.
Interfacial morphology of low-voltage anodic aluminium oxide

X-ray reflectivity (XRR) and neutron reflectivity (NR), as well as ultra-smallangle X-ray scattering (USAXS), are used to examine the in-plane and surfacenormal structure of anodic films formed on aluminium alloy AA2024 and pure aluminium. Aluminium and alloy films up to 3500 A thick were deposited on Si wafers by electron beam evaporation of ingots. Porous anodic aluminium oxide (AAO) films are formed by polarizing at constant voltage up to 20 V noble to the open circuit potential. The voltage sweet spot (5 V) appropriate for constant-voltage anodization of such thin films was determined for both alloy and pure Al. In addition, a new concurrent voltage- and current-control protocol was developed to prepare films with larger pores (voltages higher than 5 V), but formed at a controlled current so that pore growth is slow enough to avoid stripping the aluminium substrate layer. USAXS shows that the pore size and interpore spacing are fixed in the first 10 s after initiation of anodization. Pores then grow linearly in time, at constant radius and interpore spacing. Using a combination of XRR and NR, the film density and degree of hydration of the films were determined from the ratio of scattering length densities. Assumingmore » a chemical formula Al2O3xH2O, it was found that x varies from 0.29 for the native oxide to 1.29 for AAO grown at 20 V under concurrent voltage and current control. The average AAO film density of the porous film at the air surface is 2.45 (20) g cm3. The density of the barrier layer at the metal interface is 2.9 (4) g cm3, which indicates that this layer is also quite porous« less
Effects of aromatic spacers on film morphology and device memory performance based on imidazole–π–triphenylamine derivatives

Two imidazole–π–triphenylamine derivatives TPAPPI and TPATPI, connected via different aromatic spacers (i.e., phenyl or thienyl), were synthesized. The photophysical and electrochemical properties, and memory behaviors of the two donor–π–acceptor molecules were comparatively investigated. The replacement of phenyl with thienyl leads to a much better nanoscale morphology after thermal treatment, as characterized by atomic force microscopy (AFM). Sandwich devices based on TPAPPI and TPATPI both exhibited the nonvolatile WORM characteristic but the TPATPI-based device showed a higher ON/OFF ratio and a lower switching voltage. Simulation results showed that the insertion of the thienyl spacer between the donor and acceptor moieties leads to smaller torsion between the imidazole ring and TPA moiety, which indicates a smaller charge transfer barrier and a higher extent of charge transfer (CT). This comparative study of tuning the properties of conjugated D–π–A molecules via aromatic π-spacers may be an alternative approach for the design and study of future high-performance memory devices based on new D–π–A type materials.
Variability in the acquisition of allomorphs : The Dutch diminutive and past tense

What factors influence the acquisition of allomorphs? Most allomorphs are phonological variant forms of morphemes and stem from the phonological characteristics of the noun or verb. Earlier studies have found variability in the acquisition of allomorphs and various explanations have been given for this. However, a multifactorial understanding that brings together and clarifies the relationships between these explanations is still missing. In four studies the development of the Dutch past tense and diminutive allomorphs are investigated in adults, typically developing children, and children with reading difficulties using a production and judgement task. Associations between children’s sensitivity to allomorphy and complexity of the phonological characteristics of the stem, children’s phonological processing skills, type and phonotactic frequencies of the (stem+) allomorph, and children’s vocabulary size are investigated. Type frequency and vocabulary size certainly play a role in the sense that children need enough input to be able to abstract the morphophonological patterns based on the phonological characteristics of the stem. However, children need to be able to deal with these phonological characteristics before they can actually generalize over the different morphophonological patterns. Children’s phonological processing skills and the complexity of the phonological stem characteristics appear therefore to have a stronger influence and to be more direct causes of the protracted acquisition of some allomorphs. The better children’s phonological processing skills and the less complex the phonological characteristics, the better children will be able to abstract the phonological patterns and choose the appropriate allomorph.
Improved catalytic activity of PrMO3 (M = Co and Fe) perovskites: synthesis of thermally stable nanoparticles by a novel hydrothermal method

A novel and simple hydrothermal synthesis method using metal cyano complex precursors was demonstrated to synthesize nano-sized PrCoO3 and PrFeO3 perovskites. It was possible to achieve significantly improved catalytic properties, but more importantly with thermal stability and purity of perovskite phases in their nanoparticle form. These materials were characterized by means of X-ray powder diffraction, FE-SEM, HR-TEM as well as H2-TPR analysis, and evaluated for their catalytic activity towards CO oxidation reaction. Both the nanoperovskites were able to retain their morphology achieved through hydrothermal treatment, even after high temperature calcination. The catalytic activity of these materials was also compared with conventionally synthesised materials using a solid state method, as well as those reported in the literature. The superior catalytic activity of the PrCoO3 catalyst for CO oxidation over the PrFeO3 catalyst is mainly because of its better redox properties and may also be due to preferential adsorption of CO on PrCoO3 perovskite at low temperature. However, the marked improvement in catalytic activity for both nanoperovskites was primarily due to their improved surface area and better reducibility, which can be attributed to their nanoform. It appears possible to control the particle size as well as the shape of perovskites using this improved synthesis method, while more importantly, it was possible to reduce sintering and agglomeration of perovskites. While the method has potential to apply for synthesis of several other mixed oxide materials in nanoform, it will be important to investigate other physical properties of such thermally stable nanoperovskites.
Analysis of penicillin and its β-lactamase hydrolysis products in milk using capillary zone electrophoresis

A capillary zone electrophoresis method was established for simultaneous analysis of penicillin G and penicillin acid in milk. Milk samples were deproteinized and the analytes were extracted with acetonitrile. Separation of target compounds was performed through electrophoresis. Under optimum conditions, the proposed method demonstrated good correlation coefficients (R > 0.9953), precision (<6.2%), accuracy (89.2–96.8%), and limits of detection and quantification of penicillin G and penicillin acid (LOD, 0.01 and 0.5 μg mL−1, LOQ, 0.04 to 1.7 μg mL−1, respectively). The proposed method for the determination of penicillin and penicillin acid in milk is rapid, convenient and low-cost, and can measure β-lactamase activity in milk. The thermal stabilities of penicillin G, penicillin acid, and β-lactamases in milk were satisfactory when the temperature was lower than 303 K. When the temperature was higher than 353 K for 5 h, β-lactamase tended to be inactivated completely. When the temperature was 373 K, penicillin G and penicillin acid were easily degraded.
Influence of polymer gate dielectrics on n-channel conduction of pentacene-based organic field-effect transistors

This work elucidates the way polymer gate dielectrics affect the accumulation and transport of charge carriers in the active layer of organic field-effect transistors (OFETs). Incorporating a poly(vinyl alcohol) polymer interfacial film and another cross-linked poly(4-vinyl phenol) layer as a double-layer gate dielectric causes the pentacene-based OFETs to exhibit effective n-channel conduction of a saturated, apparent pinch-off drain-source current with the electron mobility of ∼0.012cm2V−1s−1. The formation of an n channel in the pentacene layer is supported by the increased capacitance that is identified by the quasistatic capacitance-voltage measurements of devices with the metal-insulator-semiconductor configuration, biased at a positive gate voltage, in the n-type accumulation regime.
Density of interface states, electron traps, and hole traps as a function of the nitrogen density in SiO2 on SiC

Nitridation of the SiO2/SiC interface yields a reduction in interface state density, immunity to electron injection, as well as increased hole trapping. It is shown that the accumulation of nitrogen at the oxide/semiconductor interface is solely responsible for these three effects. The evolution of the density of interface states, electron traps, and hole traps is measured in metal-oxide-semiconductor capacitors as a function of the nitrogen content which is varied by adjusting the gate oxide NO annealing time. A rate equation is derived to model the change in the interface state density, observed at various energy levels, in terms of nitrogen binding cross-sections. While the generation of acceptor interface states upon electron injection is suppressed after minimum N incorporation, the density of oxide hole traps appears to scale linearly with the amount of nitrogen. The origin and the properties of the N-induced hole traps resembles those of the defects responsible for enhanced negative bias temperatur.
Synthesis of 2, 5-Dichloro-2, 5-dimethylhexane by an SN1 reaction

This laboratory experiment was developed to provide a safe, economical, and effective way to instruct undergraduate organic chemistry students about the unimolecular nucleophilic substitution (SN1) reaction. Students treat 2,5-dimethyl-2,5-hexanediol with excess concentrated hydrochloric acid to synthesize 2,5-dichloro-2,5-dimethylhexane, assess solubility of the starting material and the product in different solvents, and determine purity with thin-layer chromatographic analysis. The experiment was performed by approximately 97 students. The effectiveness of the laboratory was assessed by two separate methods: a qualitative postlab student self-assessment and a quantitative prelab and postlab three-point quiz. For the qualitative student self-assessment, the students stated that they acquired an improved understanding of the SN1 reaction from the experiment. The average on the quantitative prelab and postlab quiz increased from 0.80 ± 0.86 to 1.69 ± 1.02 and demonstrated a statistically significant impro.
Composition of heavy petroleums. 3. An improved boiling point-molecular weight relation

The first two papers in this series (Energy Fuels 1987, 1, 2; 1998, 2, 597) introduced the concept of extended atmospheric equivalent boiling point (AEBP) to molecular distillates of petroleum residues. In this paper we describe three correlations between AEBP and M n (number average molecular weight) by means of a third variable, where the latter may be (a) specific gravity, (b) H/C ratio, or (c) refractive index. These correlations, we believe, are better than earlier ones between mid-boiling point, molecular weight (MW), and specific gravity. By applying them to atmospheric residue fractions obtained by moelcular distillation we have doubled the range from a previous upper limit of less than 450 to 950 MW, or from about 1000 o to over 1300 o F AEBP