Miracle-dz/UniFAR-FTUs huggingface dataset:
Molecular Recognition and Molecular Mechanics of Micelles of Some Model Asphaltenes and Resins

Molecular mechanical calculations of resins and a highly aromatic model asphaltene extracted from the spectroscopic data of a 510 °C residue of a Venezuelan crude showed that the driving interaction in the micelle formation is the attraction between their aromatic planes. The molecular recognition process is completed by the interactions produced by the alkyl and cycloalkyl groups present in these molecules. The complex three-dimensional shape of the alkyl parts of this model asphaltene limits the growth of its micelles through steric interference. The shape of these asphaltene molecules allows the aggregation of only those resins that fit its aromatic regions and show the lowest steric interference with its alkyl groups. This type of molecular recognition may explain why only some resins are able to solubilize specific types of asphaltenes through the formation of stable aggregates. It was found also that the steric interference of the alkyl groups may limit the number of available sites for H bonding an.
Kinetic and mechanistic study of the pressure and temperature dependence of the reaction CH3O + NO

New kinetic measurements for the CH3O + NO reaction have been performed using two different techniques. The discharge flow (DF) technique has been used to investigate the 0.5–5 Torr and 248–473 K pressure and temperature ranges and pulsed laser photolysis (PLP) has been used for the 30–500 Torr and 284–364 K ranges. These new results represent an extension of the pressure and temperature ranges investigated previously. This reaction is known to present two reaction pathways, the association pathway yielding CH3ONO and the disproportionation pathway yielding CH2O+HNO. Based on literature and present experimental data, using the results of ab initio calculations, a multichannel RRKM analysis was developed to interpret the experimental results. This analysis has shown that the disproportionation reaction occurs simultaneously by both a direct hydrogen abstraction reaction, and via the formation of energized CH3ONO* complex in competition with the association reaction. The RRKM analysis, fitted to present and previous data, has yielded a second-order limiting low-pressure value of 2.5 × 10−12 cm3 molecule−1 s−1 at 298 K, with a complex temperature dependence. The limiting high-pressure rate constant derived in the same way is k∞ = (3.4 ± 0.4) × 10−11(T/298)−0.75. The model allows the prediction of CH3O loss rate constants and of the branching ratios in the 1–760 Torr and 220–600 K ranges. For a convenient presentation of the overall rate constant, an analytical expression using the conventional Troe expression with a temperature-dependent addition constant, has been fitted to the results of the RRKM analysis.
Complete UV emission of ZnO nanoparticles in a PMMA matrix

Preparation and photoluminescence (PL) properties of zinc oxide (ZnO) nanoparticles embedded in a lipophilic polymethyl methacrylate (PMMA) matrix are reported in detail with an unbalanced sol–gel route. A high-resolution transmission electron microscope (HRTEM) indicates that ZnO particles are highly crystallized, with a size of 5–6 nm and hexagonal wurtzite structure. During the sol–gel reaction, partial ester groups of R-COOCH3 in PMMA are hydrolyzed to form carboxylic ion groups, which chemisorb on the surface of ZnO nanoparticles to eliminate the defects; thus ZnO nanoparticles in the PMMA matrix exhibit complete ultraviolet (UV) emissions, while emissions in the visible region are fully quenched.
Use of promolecular ASA density functions as a general algorithm to obtain starting MO in SCF calculations

Atomic shell approximation (ASA) constitutes a way to fit first-order density functions to a linear combination of spherical functions. The ASA fitting method makes use of positive definite expansion coefficients to ensure appropriate probability distribution features. The ASA electron density is sufficiently accurate for the practical implementation of quantum similarity measures, as was proved in previous published work. Here, a new application of the ASA density formalism is analyzed, and employed to obtain an initial guess of the density matrix for SCF procedures. The number of cycles needed to assess the convergence criterion in electronic energy calculations appears comparable to or less than those obtained by other means. Several molecular structures of different classes, including organic systems and metal complexes, were chosen as representative test cases. In addition, an ASA basis set for atoms Sc-Kr fitted to an ab initio 6-311G basis set is also presented. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Computer Assisted Fat Blend Recognition Using Regression Analysis and Mathematical Programming

The fatty acid profile of a fat blend depends on the blend composition and the corresponding profiles of the constituent raw materials. In principle, the composition of a blend can then be determined via these fatty acid profiles. Two approaches have been applied to tackle this blend estimation problem. In the regression analysis approach the identification part of the problem is handled in a brute force manner: all possible combinations of raw materials are considered. Combinations giving sufficiently close fits to the fatty acid profile with meaningful, positive regression coefficients are retained. The acceptable solutions are sorted in order of increasing complexity and decreasing precision yielding a survey that may help the expert in reaching a final decision. In the alternative Mixed Integer Programming approach the identification problem is solved more efficiently using a branch-and-bounds search strategy. This allows much larger problems to be considered with up to 40 different raw materials. The two methods are compared and directions for further improvements are indicated. Computergestutzte Erkennung von Fettmischungen mittels Regressionsanalyse und mathematischer Programme Das Fettsaureprofil einer Fettmischung ist von den beteiligten Fetten und deren Fettsaurezusammensetzung abhangig. Im Prinzip kann die Zusammensetzung einer Fettmischung uber das Gesamt-Fettsaureprofil bestimmt werden. Zur Losung dieser Aufgabe wurden zwei verschiedene Wege beschritten. Die Anwendung der Regressionsanalyse versucht, das Problem mit einem „Kraftakt” zu losen: alle moglichen Kombinationen von Fettrohstoffen werden herangezogen und jene, deren berechnete Profile einigermasen mit dem analytisch bestimmten Fettsaureprofil ubereinstimmen und sinnvolle positive Regressionskoeffizienten liefern, zur weiteren Betrachtung ausgewahlt. Annehmbare Losungen werden nach ansteigender Komplexitat und abnehmender Genauigkeit geordnet. Dies hilft dem Fachmann, eine endgultige Entscheidung zu treffen. Mit dem alternativen „Mixed Integer”-Programm wird das Problem mittels einer „Verzweigungs-Begrenzungs-Strategie” wirksamer gelost. Dieses Verfahren ermoglicht die Bearbeitung umfangreicher Aufgaben mit bis zu 40 verschiedenen Fettrohstoffen. Die beiden Methoden werden verglichen und Anweisungen fur weitere Verbesserungen gegeben.
Evidence for Specific Glucocorticoid Binding Sites on the Cell Membrane by Fluorescence Correlation Spectroscopy

Fluorescence correlation spectroscopy (FCS) was used to study the diffusion behavior of the glucocorticoid dexamethasone on the cell membrane of the mouse pituitary cell line AtT-20 to investigate the putative membrane glucocorticoid receptor (mGR). This putative membrane receptor is thought to mediate glucocorticoid effects independent from protein synthesis and the well-known intracellular glucocorticoid receptor (iGR), the so-called “nongenomic” effects. The high spatial resolution of the FCS technique allowed for focusing exclusively on the cell membrane; measurements were taken on living cells in solution after incubation with 60 nM fluoresceindexamethasone for 1 h without manipulation of the cells. FCS measurements were performed by moving the position of the laser focus in 1 μm steps through a single cell. In a scan through the cell a component typical for a receptor-bound ligand (diffusion constant 3 x 10-10 cm2 sec-1) becomes apparent in the autocorrelation function (ACF) at the position of the cell membrane whereas another component (diffusion constant 2 x 10-8 cm2 sec-1) typical for a ligand diffusing in the cytosol becomes predominant in the ACF curves inside the cell. After pre-incubation with unlabeled dexamethasone in 1000-fold excess the “receptor-typical” component on the cell membrane was absent. This result is the first direct evidence for the existence of a mGR on a living cell.
Thermoresponsive self‐assembled nanovesicles based on amphiphilic triblock copolymers and their potential applications as smart drug release carriers

A series of thermoresponsive triblock copolymers, methoxy poly(ethylene oxide)-b-poly(e-caprolactone)-b-poly(N-isopropylacrylamide) (mPEO-b-PCL-b-PNIPAM), with different PCL and PNIPAM block lengths, were synthesized by a combination of ring opening polymerization and reversible addition-fragmentation chain transfer polymerization techniques. The triblock copolymers undergo self-assembly in aqueous solutions forming stable nanovesicles of various sizes with a lipid membrane structure similar to body cells as revealed by transmission electron microscopy. The nanovesicle is thermoresponsive, that is, its size is tunable using the temperature as a switch: shrinks at a temperature above the lower critical solution temperature (LCST) and expands at a temperature below the LCST. The corresponding LCST of the triblock copolymers is adjustable by varying the PNIAM segment length as well as the PCL segment length and covers a range from 33.9 to 41.0°C in water. The diameter of nanovesicles for mPEO3k-b-PCL5k-b-PNIPAM13.2k is about 177.7 nm below the LCST and 138.9 nm above the LCST, as determined by dynamic light scattering. It was demonstrated using indomethacin, a popular anti-inflammation medicine, that the triblock copolymers can effectively act as a drug release carrier under the right human physiological conditions, that is, store the drug at a lower temperature and release it at a higher temperature, possibly targeting at the lesion sites of human body. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41361.
An optical-fiber sensor based on time-gated fluorescence for detecting water content in organic solvents

In this paper, the authors proposed an optical-fiber sensor based on time-gated fluorescence with high sensitivity for water content determination in organic solvents, and a type of europium ion fluorescent chelate (EIFC) with a long fluorescence lifetime was synthesized and used as the fluorescent indicator. Covalent immobilization was used to solve the problem caused by the leakage of fluorescent dye during the fabrication process of the proposed sensor. The EIFC was photo-copolymerized with 2-hydroxy-2-methyl-1-phenyl-1-propanone, triethylene glycol dimethacrylate, acrylamide, and (2-hydroxyethyl)methacrylate on a silanized glass slide, yielding the optode membrane. With increasing water content in the organic solvents, the time-gated fluorescence intensity of the optode membrane decreased obviously. The time-gated fluorescence intensity of the optode membrane changed as a linear function of the water content. For ethanol and acetonitrile this change was in the range of 0.20–10.0% (v/v), and for 1,4-dioxane it was in the range of 0.20–4.0% (v/v). The limits of detection were 0.031%, 0.016%, and 0.012% for ethanol, acetonitrile, and 1,4-dioxane, respectively. The optical-fiber sensor exhibited satisfactory reproducibility, reversibility, response times, and practicability. The lifetime of the prepared optode membrane was at least one month.
Convergence rates for variational regularization of statistical inverse problems

We consider inverse problems with statistical (noisy) data. By applying regularization methods one can approximate the true solution of the inverse problem by a regularized solution. In this thesis we show convergence rates of the regularized solution to the true solution as the noise tends to zero under so called source conditions on the true solution. Recently variational source conditions (VSCs) have become increasingly popular, due to their generality. However, they have the disadvantage that they only give optimal rates for low smoothness of the true solution. For this reason a second order VSC has been introduced in the literature, but it still has the problem that it can only make use of limited smoothness. A major contribution of this work is that we introduce VSCs of arbitrary order on Hilbert spaces which cover convergence rates of arbitrary order. For more general Banach spaces we introduce a third order VSC with which we show the new result that Bregman iterated Tikhonov regularization can have improved convergence rates compared to noniterated Tikonov regularization. A special focus of this work lies on statistical noise models such as Gaussian white noise and Poisson data. We show that also in these settings VSCs can yield order optimal convergence rates in expectation. Further we introduce variants of the second order VSC that yield new higher order convergence rates for Poisson data. In addition to these major contributions this work also contains a new proof of upper and lower bounds for Bregman divergences, which are a crucial tool in our convergence analysis.
Measuring health‐related quality of life in adolescent and young adult cancer survivors with the National Institutes of Health Patient‐Reported Outcomes Measurement Information System®: Comparing adolescent, emerging adult, and young adult survivor perspectives

Our knowledge of symptom burden and functioning among adolescent and young adult (AYA; diagnosed ages 15–39) cancer survivors has been hindered by variability in health‐related quality of life (HRQOL) measurement associated with developmental and disease heterogeneity among AYAs. We aimed to examine the variability in domain‐specific aspects of HRQOL as a function of cancer type and developmental stage to clarify commonalities and differences using the NIH Patient‐Reported Outcome Measurement Information System®.
CdSe Nanotube Arrays on ITO via Aligned ZnO Nanorods Templating

Using a ZnO nanorod array as the template, vertically aligned CdSe nanotubes have been demonstrated on indium tin oxide (ITO) glass in large scale. The wall thickness of the nanotube is tunable and can be increased until the formation of a continuous porous CdSe network. Detailed morphological and structural characterizations of the samples during the nanotube array formation reveal a growth mechanism that can be generally applied to a wide range of materials. In particular, we found that preferable CdSe nucleation and growth on the side surface ({1010} planes) of the ZnO nanorods in the array is critical to the later formation of a tubular structure with controllable wall thickness.
Sapphire (0001) Surface, Clean and with d -Metal Overlayers

We present local density-functional results for structural and electronic properties of Al{sub 2}O {sub 3}(0001) , clean and with Pt and Ag adsorption. Significant surface relaxations penetrate to the third oxygen layer, 5.2 {Angstrom} below the surface. The dominant mechanism of metal adhesion is polarization and is relatively weak ({approx_equal} 0.4 and 0.6 eV/atom for Ag and Pt, respectively); however, isolated metal atoms bind up to 5{times} as strongly with an ionic bond induced by the surface Madelung potential. {copyright} {ital 1999} {ital The American Physical Society}
Extractives from Guttiferae. Part II. The isolation and structure of four polyhydroxyxanthones in Symphonia globulifera L.

Four xanthones isolated from Symphonia globulifera L. , have been shown to be 1,7-dihydroxyxanthone (euxanthone), 1,5,6-trihydroxyxanthone, 1,3,5,6-tetrahydroxyxanthone, and 1,3,6,7-tetrahydroxyxanthone. Experiments leading to the synthesis of 1,7-dihydroxyxanthone are described.
Empirical Correlations for Estimating Filtrate Volume of Water Based Drilling Fluids

Abstract Standard American Petroleum Institute (API) filter press is generally used for identifying the filtrate volume of drilling fluids and works only at very low pressures. In fact, during a drilling operation, at downhole conditions, the pressures encountered are significantly higher than what is used during standard API filter press tests. A relationship between the well-known fluid properties and the filtrate volume test is developed. In this study, experiments have been conducted for different water-clay mixtures with varying concentrations at different pressure values by using standard API filter press and HP&HT (high-pressure high-temperature) filter press. The relationship between physical and chemical properties of water-clay mixtures and filtrate volume is analyzed. An empirical correlation has been developed for estimating filtrate volume using basic information of the mud (i.e., rotational viscometer readings, density, pressure, cation exchange capacity, and chemical composition). The developed correlation can estimate filtrate volume with an error less than 20% for a wide range of pressure values.
Prediction of potential prognostic biomarkers in metastatic prostate cancer based on a competing endogenous RNA regulatory network

Background Recently, studies on competing endogenous RNA (ceRNA) networks were becoming prevalent, and circular RNAs (circRNA) have crucial implications for the development and progression of carcinoma. However, studies relevant to metastatic prostate cancer (mPCa) are scanty. Methods RNA-Seq data was obtained from MiOncoCirc database and Gene Expression Omnibus (GEO). Differential expression patterns of RNAs were examined using R packages. Circular RNA Interactome, miRTarBase, miRDB and TargetScan were applied to predicting the corresponding relation between circRNAs, miRNAs and mRNAs. The Gene Ontology (GO) annotations were performed to present related GO terms, and Gene Set Enrichment Analysis (GSEA) tools were applied for pathway annotations. Moreover, survival analysis was conducted for hub genes. Results We found 820 circRNAs, 81 miRNAs and 179 mRNAs, which were distinguishingly expressed between primary prostate cancer (PCa) and mPCa samples. A ceRNA network including 45 circRNAs, 24 miRNAs and 56 mRNAs was constructed. Besides, the protein-protein interaction (PPI) network was built up, and 10 hub genes were selected by using CytoHubba application. Among the 10 hub genes, survival analysis showed ITGA1, LMOD1, MYH11, MYLK, SORBS1 and TGFBR3 were significantly connected with disease-free survival (DFS). Conclusion The circRNA-mediated ceRNA network provides potential prognostic biomarkers for metastatic prostate cancer .
Raman Spectral Studies of Cadmium–Nitrite Interactions in Aqueous Solutions and Crystals

Raman spectra of aqueous solutions containing Cd2+ and NO2− clearly reveal the presence of solvated nitrite ion and of complexes. A band at 861 cm−1 is characteristic of the latter. The free nitrite concentration was measured from the intensity of the 817 cm−1 line and the average ligand number was evaluated for solutions with composition prescribed by the mole-ratio method. Four cumulative formation constants were deduced: β1 = 61.6; β2 = 993; β3 = 2390; β4 = 1899. Evidence that nitrite chelates Cd2+ through the two oxygen atoms is presented. The diagnostic spectral evidence consists of a high intensity, high frequency deformation mode and low intensity N—O stretching Raman bands with frequencies almost identical to those of the solvated nitrite ion. Data are also presented for solid Cd(NO2)2 and Kx−2Cd(NO2)x(x = 3,4,5).
Sulfonated Polyethersulfone (SPES) – Charged Surface Modifying Macromolecules (cSMMs) Blends as a Cation Selective Membrane for Fuel Cells

Polyethersulfone (PES) was sulfonated by chlorosulfonic acid and concentrated sulfuric acid. The pure sulfonated PES (SPES) and modified SPES membranes were prepared by blending with different charged surface modifying macromolecules (cSMMs) namely, SPES/DEG‐HBS, SPES/PEG‐HBS, and SPES/PPG‐HBS. Membranes were characterized for their morphology, physical properties, and electrochemical properties in order to evaluate these membranes as cation exchange membranes. The blended membranes showed an increase in hydrophilicity, water uptake, and proton conductivity compared to the pure SPES membranes. The highest values of water uptake and proton conductivity were obtained for the SPES/PPG‐HBS blended membrane. Morphological studies revealed that the nodule size and surface roughness also influenced the water uptake, apart from the additional –SO3H group. Among the modified membranes, the SPES/DEG‐HBS blended membrane exhibited a lower methanol permeability value of 8.895 × 10−8 cm2 s−1 than the corresponding SPES membrane. The other two cSMM blended membranes showed higher methanol permeability values than SPES but still a smaller value than Nafion 117. The highest selectivity ratio (i.e., ratio of proton conductivity to methanol permeability) was obtained with the SPES/DEG‐HBS cSMM blended membrane. These results showed that the SPES/cSMM blended membranes have promise for possible use as a cation exchange membrane in fuel cells and electrolyzer applications.
Nanoscopic templates using self-assembled cylindrical diblock copolymers for patterned media

We demonstrated a process to create nanoscopic templates for the nanofabrication of patterned media using thin films of diblock copolymers. The self-assembled monolayers (SAMs) technique is used as a means to chemically modify the topographically confined trench surfaces to manipulate the wetting behavior of cylindrical diblock copolymers and perpendicularly oriented cylindrical poly (styrene-block-methyl methacrylate) (PS-b-PMMA) copolymers are obtained. Through optimizing the annealing conditions, long-range ordering in trenches is achieved after annealing at 170°C for about 24h. The ordering is strongly dependent on the line-edge-roughness (LER) of the trenches and the number of defects in the copolymer films inside the trenches. Efforts to decrease the various defects in the copolymer films and improve the trench LER are still in progress. With our approach, a negative phase 20nm nanoporous SiO2 template and a positive phase 20nm Ta nanodot template based on the self-assembled cylindrical PS-b-PMMA bl.
Pharmacokinetics and Bio-distribution of New Gd-complexes of DTPA-bis (amide) (L3) in a Rat Model

Magnetic resonance imaging (MRI) is a powerful, noninvasive diagnostic imaging modality that provides high-quality anatomic images and other physiologic data (1, 2). Advancement of the MRI technique has prompted the development of contrast agent, which is administered to the patient to enhance image contrast between normal and diseased tissue or to indicate the status of organ function or blood flow (3, 4). The development of new MRI contrast agents offers intriguing challenges for investigators in the chemical, physical, and biological sciences, including the design and synthesis of stable, non-toxic, and tissue-specific metal complexes and the understanding of their effect on relaxation behavior in solution and in tissues. MR image contrast is mainly generated by the relaxation differences of water protons in adjacent tissues. Gadolinium (III) ion has a large magnetic moment, which can alter the relaxation rate of surrounding protons to enhance image contrast (5). Gd (III) is known to possess the highest paramagnetism of all metal ions; to date, Gd (III) complexes incorporating INTRODUCTION