Miracle-dz/UniFAR-FTUs huggingface dataset:
Synthese von Acyclo‐7‐desazaguanosin durch regiospezifische Phasentransferalkylierung von 2‐Amino‐4‐methoxy‐7H‐pyrrolo[2,3‐d]pyrimidin

Acyclo-7-desazaguanosin (2), ein Strukturanalogon des antiviral hochwirksamen Acycloguanosins (1), wurde synthetisiert. Bei der Phasentransfermethylierung von 2-Amino-4-methoxy-7H-pyrrolo[2,3-d]pyrimidin (4c), die ausschlieslich zum N-7-Methylderivat 5 fuhrt, konnte Regiospezifitat des elektrophilen Angriffs an 4c nachgewiesen werden. Die Konstitutionsermittlung von 5a erfolgte durch Umwandlung in 3,7-Dihydro-7-methyl-4H-pyrrolo[2,3-d]pyrimidin-4-on (5d) uber die Zwischenprodukte 5b und 5c. Die Anwendung der Methylierungsbedingungen auf die Reaktion von 4c mit (2-Acetoxyethoxy)methylbromid fuhrte zu 6a, das zu 6b entacetyliert wurde. Fur das Acyclonucleosid 2 wird aufgrund der mit 1 identische Seitenkette selektive Phoshorylierung durch Thymidinkinasen und damit antivirale Aktivitat erwartet. Synthesis of Acyclo-7-desazaguanosin by Regiospecific Phase-Transfer Alkylation of 2-Amino-4-methoxy-7H-pyrrolo[2,3-d]pyrimidineAcyclo-7-deazaguanosine (2), a structural analogue of the antiviral highly active acycloguanosine (1), has been synthesized. Regiospecificity of the electrophilic attack was shown by phase-transfer methylation of 2-amino-4-methoxy-7H-pyrrolo[2,3-d]pyrimidine (4c) yielding the N-7 methyl derivative 5a exclusively. Elucidation of the structure of 5a resulted from its conversion into 3,7-dihydro-7-methyl-4H-pyrrolo[2,3-d]pyrimidin-4-one via the intermediates 5b and 5c. By applying the methylation conditions on the reaction of 4c with (2-acetoxyethoxy)methyl bromide the protected compound 6a was obtained which was deacetylated to give 6b. The acyclonucleoside 2 is expected to be phosphorylated by thymidine kinases because of the identical side chain compared with 1. Therefore, antiviral activity can be anticipated
CHARACTERIZATION OF ANTIOXIDANT ACTIVITIES OF SOYBEANS AND ASSESSMENT OF THEIR BIOACCESSIBILITY AFTER IN VITRO DIGESTION

Nine Virginia soybeans grown in a single location were compared for their antioxidant properties and isoflavone profiles. The extracts were evaluated for their total phenolic contents (TPC), Oxygen Radical Absorbance Capacity (ORAC), and DPPH radical scavenging activities. In order to evaluate efficient preparation methods for soybean antioxidants, three Virginia-grown soybeans were extracted using different extraction strategies. The extraction techniques included soxhlet extraction, conventional solvent extraction, and ultrasonic-assisted extraction (UAE) with 5 different common solvent systems including 50% and 80% aqueous acetone, 50 and 70% aqueous ethanol, and 80% aqueous methanol. The TPC in the soybean extracts and isoflavone compositions were significantly different among cultivars. Malonylgenistin was the major isoflavone in all soybean seeds, accounting for 75-83% of the total measured isoflavones. The V01-4937 variety had the highest total isoflavone and malonylgenistin contents, followed by V03-5794. The antioxidant activities of the soybean extracts were also significantly different. Overall, the V01-4937 soybean was the variety that stood out from the other tested Virginia soybeans because it had the highest TPC, ORAC value, and isoflavone contents as well as the second highest DPPH scavenging activity. Ultrasonic treatment improved the extraction of soybean phenolics by more than 50% compared to solvent alone. The UAE with 50% aqueous acetone was the most efficient for extraction of phenolic compounds in the soybean seeds. The conventional and UAE with 70% aqueous ethanol extracts had the highest ORAC values, while the soxhlet methanol extracts had the highest DPPH radical scavenging activities. Our results suggest that different extraction technologies have a remarkable effect on soybean antioxidant estimation and the UAE is more appropriate for soybean phenolic extraction because it is less time and solvent consuming than the conventional solvent and soxhlet extractions. The V014937 soybean with the highest TPC was evaluated for its antioxidant activity and isoflavone
Melt Phase Behavior of Poly(oxyethylene)-Poly(oxypropylene) Diblock Copolymers

The order-disorder transition of a series of symmetric poly(oxyethylene)-poly(oxypropylene) diblock copolymers was determined via small-angle X-ray scattering (SAXS) and used to determine the Flory-Huggins interaction parameter, χ. The χ parameter was determined using both mean field theory and fluctuation theory, and our results are compared to previously reported values. In addition, we determined the structure of a number of asymmetric diblocks via SAXS and compare the results with the phase diagram predicted by self-consistent mean field theory, allowing for conformational asymmetry.
Synthesis of zinc titanate for Dye Sensitized Solar Cell (DSSC) application

The objectives of the project are to synthesis zinc titanate and characterize the structure for Dye Sensitized Solar Cells (DCCS) application. The porous structure of zinc titanate will increase the light absorption at the longer wavelength of sunlight and increase the efficiency of the DSSC system. Currently, intensive research was done by researcher to increase the efficiency of DSSCs system so that it can be used in industrial scale. There are many factors that effect the efficiency of DSSCs system and one of it is the characteristic of electrode used. The parameters such the surface area, porosity, crystalline grains, and rate of recombination of photoinduced electrone are important in determining the efficiency of DSSCs system. In this project, zinc titanate will be synthesis by two methods that are reflux and impregnation method. The composition of the reactant will be varies to prepare different sample of zinc titanate. The characteristic zinc titanate structure will be tested to identify the best compositon in producing zinc titanate that can be applied in DSSC system. The zinc titanate produced will be tested by using x-ray diffusion (XRD), FTIR, UV-vis, scanning electron microscopy (SEM), and BET analysis. After that, the sample of zinc titanate will be tested in the test cells to determine the electricity generation. Most of the researcher found that the most favorable temperature to synthesis zinc titanate is between 800oC to 945oC. The amount of zinc also needs to be less than titanium to keep the efficiency of DSSCs system high.
Numerical modeling of the turbulent diffusion and chemistry of NOx, O3, isoprene, and other reactive trace gases in and above a forest canopy

A coupled diffusion-chemistry model was developed for the turbulent transport of reactive trace gases in and above a forest canopy. The one-dimensional model was used to study daytime vertical profiles of gaseous concentrations and fluxes and the influences of vertical distributions of solar irradiation and uptake and emission at leaves and the forest floor. The upper boundary of the model was extended to the top of the atmospheric boundary layer to allow adequate coupling at the atmosphere-forest interface. To study the effects of biogenic nonmethane hydrocarbons, chemical reactions for isoprene and its atmospheric oxidation products were linked with reactions for inorganic species and the oxidation of CO and CH4. Isoprene emission rates at various heights in the canopy were calculated as a function of local radiation, temperature, and leaf density distribution. Photolysis rates for photochemical reactions were allowed to vary with height according to the change in solar irradiation in the canopy. Vertical profiles of O3, NO, NO2, NOx, NOy, OH, HNO3, H2O2, and isoprene concentrations and fluxes simulated for a specified deciduous forest were examined with a single set of measured and computed daytime micrometeorological conditions. Results show that for strongly depositing gases like O3, HNO3, and H2O2, deposition velocities appear to be insensitive to chemistry and to have a profile similar to those predicted for a nonreactive case (simulation without chemistry), although the fluxes are influenced by concentration changes caused by chemistry. Simulated profiles of isoprene concentration and flux agree closely with results for the nonreactive case, largely because of the dominant effects of emission and turbulent mixing. Chemical reactions have the most important influence on profiles of NO, NO2, and NOx concentrations and fluxes. With a small and representative NO emission forced at the forest floor, NO concentration decreases quickly with height near the ground and falls to a minimum value near the middle of the canopy because the chemical transformation of NO is fast while photodecomposition of NO2 is weak inside the canopy. As a result, the NO2 concentration becomes higher inside the canopy than above, and an upward NO2 flux occurs near the canopy top despite NO2 deposition in the canopy. The total flux of NOx near the canopy top appears to be downward because of strong downward NO flux. The flux of NOy above the canopy is almost invariant with height as chemical interchanges create no net effect on the total nitrogen flux, although a large flux divergence caused by dry deposition occurs inside the canopy.
Sensory evaluation of rice fortified with iron

The objective of this study was to examine sensory differences between conventional rice and iron-fortified Ultra Rice rice (UR) and determine consumer acceptance. Differences between both types of rice were analyzed using the Duo-Trio Test on 37 non-trained judges. The Acceptance Test evaluated general rice appearance, color, aroma and taste by 43 non-trained judges, using a 7-point hedonic scale with extremes ranging from “really disliked” and “really liked. ” There were no significant differences between the analyzed samples of conventional rice and UR rice using Duo-Trio Test. Mean values from the Acceptance Test for the evaluated attributes (general appearance, color, aroma e taste) were 5.6 and 5.9, corresponding to “liked” and “really liked” according to the hedonic scale, respectively. The iron did not alter the sensory characteristics of the final product, and the iron-fortified rice was well accepted.
Inception and development prebreakdown cavities in water

The shadow observation results of slow streamer inception and development in deionized water are presented. The propagation features of two different types of positive slow streamers are observed. The first is usual for water and hydrocarbon liquids. The other starts from near the electrode and can transform into a tree-like streamer due to a larger gas content which originates from the electrode. Evidence for the gaseous nature of the slow streamers is presented. Comparison of the observation data with Rayleigh and Watson models suggests the involvement of microbubbles in the first type of positive and the negative streamers.
Annealing Studies on Hydrogenated Amorphous Silicon-Tin Films

Hydrogenated amorphous Si-Sn (a-Si1-xSnx:H) films were prepared by radio-frequency sputtering of the planarmagnetron type, and optical absorption, infrared absorption, Raman scattering, electron spin resonance and conductivity measurements were carried out on these films. Annealing experiments revealed that the a-Si1-xSnx:H films had a low crystallization temperature, a low evolution temperature of H atoms and a low degradation temperature for the photoconductivity, compared with a-Si:H films. The incorporation of N into these films was found to improve the thermat stability without a large increase in the optical gap, although it decreased the photoconductivity.
Excess Heat during the Electrolysis of a Light Water Solution of K2CO3 with a Nickel Cathode

In this paper experimental results of differential heat loss calorimetry measurements during the electrolysis of light water solutions of K{sub 2}CO{sub 3} and Na{sub 2}CO{sub 3} with a nickel cathode are presented. A significant increase in temperature with every watt input, compared with the calibration experiment, is observed during the electrolysis of K{sub 2}CO{sub 3}. This effect is not observed when Na{sub 2}CO{sub 3} is electrolyzed. No trivial explanation (in terms of chemical reactions, change in heat transfer properties, etc.) of this effect has been found so far. If the nontriviality of the observed overcoming of the energy breakeven barrier is further confirmed, this phenomenon may find application as an important new energy source.
Effect of antioxidant on peroxide modification of LLDPE

A commercial linear low density polyethylene (1-hexene comonomer) was reacted with dicumyl peroxide at appropriate levels to initiate chain extension without crosslinking. The peroxide modification was carried out both in the presence and absence of a common hindered phenolic antioxidant. Thermal treatment of the resin was also completed with and without antioxidant present to evaluate the contribution of classical thermooxidative degradation to the peroxide modification process. In terms of pure thermal degradation, the phenolic antioxidant was found to be effective in prevention of reduction of molecular weights at the high end of the molecular weight distribution, as reflected in changes in M z . At the low end of the distribution, the opposite effect is seen, where the removal of the antioxidant actually allows an increase in the value of M n , through chain coupling reactions. Processing of the resin with addition of the organic peroxide significantly increases the molecular weights of both antioxidant containing and antioxidant free resins. Increasing the reaction temperature increases the rate of degradative chain scission and nonenlarging disproportionation reactions. At low temperatures, the presence of the antioxidant acts negatively with respect to chain enlargement reactions, and an overall reduction is seen in the efficiency of the peroxide in its role of increasing molecular weights. As the reaction temperature is increased, chain scission reactions become more predominant, and the antioxidant free resin shows very substantial decreases in molecular weight. Retention of the antioxidant at higher reaction temperatures is beneficial to maintaining high molecular weights, both with and without peroxide present. As in the peroxide free case, branching is essentially unchanged by the absence of antioxidant in peroxide modification. © 1995 John Wiley & Sons, Inc.
Structural study on a sulfido-bridged dinuclear organotin(IV) complex with weak Sn ··· Sn bonding

A dinuclear anionic complex, Bu4N[Me2SnCl(S)ClSnMe2Br], has been synthesized in chloroform solution by reacting (Me2SnS)3, Me2SnCl2, and Bu4NBr. Attempts to isolate the anionic complex using tetramethylammonium cation were unsuccessful. The anion possesses two five-coordinate tin(IV) units bridged by sulfide and bromide. X-ray diffraction study revealed the possibility of a weak Sn–Sn bond in the complex. Theoretical (DFT) studies have been carried out to analyze the nature of metal–metal interaction in the complex.
STUDIES ON THE DECOMPOSITION OF PLANT MATERIAL IN SOIL. V. THE EFFECTS OF PLANT COVER AND SOIL TYPE ON THE LOSS OF CARBON FROM14C LABELLED RYEGRASS DECOMPOSING UNDER FIELD CONDITIONS

Summary Ryegrass uniformly labelled with 14C was allowed to decompose for 10 years under field conditions in a range of contrasting soils. The amount of organic matter already in a soil had no effect on the retention of labelled C by that soil, nor had a variation in soil pH of from 4.9 to 8.1. Decomposition was initially slower in a strongly acid soil (pH 3.7) but by the end of 5 years the difference between this soil and the others had almost disappeared. The more clay in a soil, the greater the retention of labelled C over the whole 10 year period; this was true of both strongly acid and near-neutral soils. More labelled organic matter was leached from a soil containing 7.6% clay than from one with 17.5% clay, but the amount thus lost was insufficient to account for the difference in retention of C by the two soils. The decomposition of labelled plant material was faster in bare soil than in soil growing grass but the ‘protection’ thus given to the labelled C by the growing grass ended when the grass was removed. In bare soil about one third of the labelled ryegrass C was left after one year but thereafter decomposition became very much slower and about one eighth of the labelled C still remained in the soil after 10 years. The decay curve can be represented by a two compartment model, in which about 70% of the ryegrass C decomposed by a first order process of half life 0.25 years and the remainder by a similar process of half-life 8 years.
Ablative Heat Transfer in a Shrinking Packed-Bed of ZnO Undergoing Solar Thermal Dissociation

A transient heat transfer model is formulated for a shrinking packed-bed of reacting ZnO particles exposed to concentrated solar irradiation. The model combines conduction, convection, and radiation heat transfer with simultaneous sintering and reaction kinetics. Validation is accomplished in terms of temperatures and dissociation rates experimentally measured using a solar-driven thermogravimeter with ZnO packed-bed samples subjected to solar flux concentration ratios in the range 1225–2133 suns and surface temperatures in the range 1834–2109 K. Operating conditions are typical of an ablation regime controlled by the rate of radiative heat transfer to the first layers of ZnO undergoing endothermic dissociation.
Antioxidant activity of medicinal spices and aromatic herbs

Essential oils of many plants besides having a strong and pleasant aroma also are biologically active as an antioxidant. They have an important economic role in the medical and pharmaceutical industries, aromatherapy and cosmetology, production of natural food flavorings and as natural preservative. A variety of free radical scavenging antioxidants are found in dietary sources like fruits, vegetables, aromatic herbs, spices etc. The antioxidant role of aromatic principles also have medicinal effects and play important roles in long term health, reduction in the risk of chronic and degenerative diseases and preventing cellular damage, when included in regular diet. Considering the highly significant medicinal role of antioxidant, in the present investigation, effort is made to find out the antioxidant capacity of hexane extracts of 15 aromatic herbs and spices. Antioxidant activity screening assays implemented here is % DPPH radical scavenging activity (RSA). All the plant extracts have shown an excellent activity. The highest activity recorded in the present assay is with Ocimum sanctum extract 76.608 ± 0.063 % for DPPH radical scavenging activity.
1H chemical shifts in NMR: Part 19 . Carbonyl anisotropies and steric effects in aromatic aldehydes and ketones

The 1H chemical shifts of benzaldehyde, 2‐chloro‐, 2‐hydroxy‐ and 2‐methoxybenzaldehyde, acetophenone, 2‐methoxy‐ and 2‐hydroxyacetophenone, indanone, anthraquinone, fluorenone, anthrone, α‐tetralone, 2,4,6‐trimethylacetophenone, 9‐acetylanthracene, 9‐anthranaldehyde and benzosuberone were obtained and completely assigned in CDCl3 and DMSO solution. In anthrone a keto–enol tautomerism (anthrone–9‐hydroxyanthracene) was observed by NMR in hydrogen bonding solvents but not chloroform. The percentage of enol is linearly dependent on the Kamlett β hydrogen bonding parameter of the solvent, and not the solvent relative permittivity. The chemical shift data allowed the determination of the carbonyl substituent chemical shifts (SCS) in these molecules. These were analysed in terms of the carbonyl electric field, magnetic anisotropy and steric effects for long‐range protons together with a model (CHARGE7) for the calculation of the two‐ and three‐bond effects. The SCS of the carbonyl bond was reproduced with an asymmetric magnetic anisotropy acting at the midpoint of the carbonyl bond with values of Δχpar and Δχperp of 6.36 and −11.88 (10−30 cm3 molecule−1) plus a steric term from the oxygen atom and the CO electric field effect. The short‐range effects of the carbonyl group on the aldehyde proton were modelled using the appropriate β functions in the CHARGE routine. For the 9‐substituted anthracenes the Hückel π calculation was modified to account for the 1H chemical shifts of the H‐10 protons. This model gave a comprehensive calculation of the 1H chemical shifts of these aromatic aldehydes and ketones. For the data set of 129 chemical shifts ranging from δ 2.5 to 11.5 the r.m.s. error of the observed vs calculated shifts was 0.094 ppm. The CO anisotropy and oxygen shielding differ appreciably from the corresponding values for the aliphatic aldehydes and ketones but are similar to the values for the CO group of amides, illustrating the effect of conjugation on these parameters. The model was used in the conformational analysis of some related compounds. In 2‐chlorobenzaldehyde the chemical shift calculations support a non‐planar molecule with the aldehyde–ring dihedral angle in the trans conformer of ca 25°. In the strained seven‐membered ring of benzosuberone, the model was used to test calculated geometries. The ab initio geometry at the B3LYP(6–31++G(d,p)) level gave the best agreement with the observed shifts. Copyright © 2002 John Wiley & Sons, Ltd.
Ionic Liquid-Based, Liquid-Junction-Free Reference Electrode

In this paper, we describe a new type of polymer membrane-based reference electrode (RE) based on ionic liquids (ILs), in both liquid-contact (LCRE) and solid-contact reference electrode (SCRE) forms. The ILs used were bis(trifluoromethane sulfonyl)amid with 1-alkyl-3-methyl-imidazolium as well as phosphonium and ammonium cations. In addition to their charge stabilisation role, it was found that the ILs also functioned as effective plasticizers in the PVC matrix. The LCREs and SCREs were prepared using the same design as their corresponding indicator electrodes. LCREs were prepared by casting in glass rings while SCREs were prepared on platforms made using screenprinting technology, with poly(3-octylthiophene-2,5 diyl) (POT) as the intermediate polymer. After potentiometric characterization of the response mechanism, the practical performance of the REs was studied using potentiometric titrations (Pb 2 + and pH), and characterised using cyclic voltammetry and impedance spectroscopy. All results were compared via parallel experiments in which the novel RE was substituted by a conventional double junction Ag/ AgCl reference electrode. The mechanism of response is most likely based on a limited degree of partitioning of IL ions into the sample thereby defining aquo-membrane interfacial potential. Despite their simple nature and construction, the REs showed excellent signal stability, and performed well in the analytical experiments. The identical mode of fabrication to that of the equivalent indicator (or Ion-Selective Electrode, ISE) will facilitate mass-production of both indicator and reference electrode using the same fabrication line, the only difference being the final capping membrane composition.