Miracle-dz/UniFAR-FTUs huggingface dataset:
Strontium‐Substituted Calcium Deficient Hydroxyapatite Nanoparticles: Synthesis, Characterization, and Antibacterial Properties

Strontium-substituted apatites have provoked increased interest in recent years for their beneficial effects on osteoporotic bone treatment and replacement. In this study, rod- and acicular-shaped, strontium-substituted calcium deficient hydroxyapatite (CDHA) nanoparticles with (Ca + Sr)/P ratio of 1.61 were synthesized via accelerated microwave processing. The X-ray powder diffraction analysis indicates the synthesized nanoparticles as apatite phase with diffraction patterns similar to those of hydroxyapatite. The hydrodynamic diameter of the particles were observed to be ~200–500 nm and found to increase with strontium substitution along with an increase in the negative zeta potential by dynamic light scattering method, suggesting the particles to be agglomerates in water. The morphology of the nanoparticles was studied using transmission electron microscopy (TEM), where, pure CDHA showed globular and strontium substituted CDHAs showed rod and acicular shape for 5% and 10% Sr substitution, respectively. The average size of the particles in TEM was measured to be 33 nm × 5 nm, 40 nm × 6 nm, and 55 nm × 8 nm (L × W) for pure and strontium-substituted CDHAs, respectively. Inductively coupled plasma spectroscopy, energy dispersive X-ray analysis, and Fourier transform infrared spectroscopy further confirm the substitution of strontium and deficiency of calcium in the synthesized nanoparticles. Thermal stability and in vitro solubility of CDHA nanoparticles were observed to increase with strontium substitution. The MTT [3-(4, 5-Dimethylthiazole-2-yl)-2, 5-diphenyl tetrazolium bromide] assay indicate that the substituted nanoparticles are non-toxic to human periodontal ligament fibroblast (HPDLF) cells. Cell uptake study by fluorescence microscopy using rhodamine-123 and actin/DAPI stained HPDLF cells show cellular localization of the nCDHA, nSr5CDHA, nSr10CDHA nanoparticles without any adverse effects. The strontium-substituted CDHAs showed significant antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria by colony count method. The 10% Sr substituted CDHA show the maximum microbial reduction of around 56% for E. coli and 35% for S. aureus with 1 × 105 cells/mL of respective bacterial culture.
Reduction of perchloroalkanes by ferrioxalate-generated carboxylate radical preceding mineralization by the photo-fenton reaction

Perhalogenated aliphatic compounds in water are difficult to degrade by advanced oxidation processes that rely on hydroxyl radical as the reactive oxidant. We have successfully degraded carbon tetrachloride and hexachloroethane in UV-illuminated (300−400 nm) acidic oxic or anoxic solutions containing Fe(III) and oxalate. Kinetic and product studies were carried out to elucidate the mechanism and role of O2. The initial step is a one-electron reduction of the perhaloalkane by CO2•-, which is generated by photolysis of iron(III) oxalate complexes. The products are lower-chlorinated compounds, several of which are unreactive toward CO2•-. In the presence of O2, the reaction is catalytic in Fe(III) due to the re-oxidation of Fe(II) by oxo-radical intermediates; however, O2 also retards the rate by scavenging CO2•-. After the perhalogenated substrate has been transformed, the system can be made oxidizing by the addition of H2O2, resulting in mineralization of the remaining organochlorine intermediates by a pho.
Influência do conteúdo de umidade de colheita e temperatura de secagem na qualidade do feijão

Considerable losses occur in the post-harvest process of the Brazilian bean production. The objective of this work was to evaluate the bean quality harvested at different moisture contents and dried using different air temperatures in a thin layer dryer. After cleaning and drying, the grains were fumigated and, soon after, conditioned in metallic recipients and kept under laboratory conditions during a period of 90 days. The evaluation of the quality was accomplished by classifying the beans and measuring the electrical conductivity, the color, the breakage susceptibility and the hardening degree of the grains, in intervals of 30 days. It was concluded that grains harvested with moisture content of 18.7% presented the best classification grade and physiological quality of the grains harvested at 20.6 and 18.7% was superior in comparison to grains harvested at 11.7%. The increase of the drying air temperatures did not have effect either upon the type or upon the color classification; however, it reduced the physiological quality of the grains. Regarding the grains storage, it was concluded that the classification grade remained the same; however, the physiological quality of the grains was reduced, and the grains tended to become dark.
Effect of Ultraviolet Germicidal Lamps on Airborne Microorganisms in an Outpatient Waiting Room

Abstract The effectiveness of 254-nm ultraviolet radiation for inactivating airborne microorganisms (and thereby reducing the spread of respiratory infections such as tuberculosis) was evaluated by collecting air samples in an occupied 90-m3 room equipped with four 15-W wall-mounted germicidal lamps. The indoor concentration of airborne bacteria was positively associated with the number of people present, the concentration of bacteria in the ventilation supply air, and the relative humidity, but was negatively associated with operation of the germicidal lamps and with the number of open windows. A generalized linear model suggested that use of the lamps reduced culturable airborne bacteria by 14 to 19 percent. This degree of air disinfection was calculated to be the equivalent of between 1.5 and 2 air changes per hour (ACHeq). This equivalent ventilation was in addition to the 1 to 2.5 ACH that open windows provided and the 8 ACH that the mechanical ventilation system supplied. The microbicidal effect of .
Simultaneous enhancement of charge generation quantum yield and carrier transport in organic solar cells

Bulk heterojunction (BHJ) organic solar cells and photodiodes require optimised active layer structures for both charge carrier photo-generation and extraction to occur efficiently. The most efficient polymer:fullerene devices comprising narrow optical gap donor polymers invariably have a high fullerene fraction. In such circumstances photo-generated carrier extraction is compromised, as charge transport is often unbalanced with electron transport in the fullerene dominating. In this current work we study the high efficiency blend system poly(2,5-{2-octyldodecyl}-3,6-diketopyrrolopyrrole-alt-5,5-{2′,5′-di[thien-2-yl]thieno[3,2-b]thiophene}) (DPP–DTT):phenyl-C71-butyric acid methyl ester (PC70BM). We show that by manipulating the packing of the (DPP–DTT) chains, large hole mobilities >0.02 cm2 V−1 s−1 can be obtained in a simple polymer-only diode. More importantly, when blended with PC70BM in a 1 : 3 ratio the hole mobility was found to increase to 0.2 cm2 V−1 s−1. This is the first case of a polymer:fullerene solar cell where the charge carrier transport is limited by the electron mobility of the fullerene rather than the hole mobility of the donor material. Photophysical measurements reveal that the charge generation quantum yield is also enhanced when the DPP–DTT chains are optimally packed. The simultaneous improvement of the charge transport properties and charge generation quantum yield delivers an order of magnitude increase in the power conversion efficiency.
Does the G·G*syn DNA mismatch containing canonical and rare tautomers of the guanine tautomerise through the DPT? A QM/QTAIM microstructural study

We have established that the asynchronous concerted double proton transfer (DPT), moving with a time gap and without stable intermediates, is the underlying mechanism for the tautomerisation of the G·G*syn DNA base mispair (C1 symmetry), formed by the keto and enol tautomers of the guanine in the anti- and syn-configurations, into the G*·G*syn base mispair (C1), formed by the enol and imino tautomers of the G base, using quantum-mechanical calculations and Bader's quantum theory of atoms in molecules. By constructing the sweeps of the geometric, electron-topological, energetic, polar and natural bond orbital properties along the intrinsic reaction coordinate of the G·G*syn↔G*·G*syn DPT tautomerisation, the nine key points, that are critical for the atomistic understanding of the tautomerisation reaction, were set and comprehensively analysed. It was found that the G·G*syn mismatch possesses pairing scheme with the formation of the O6···HO6 (7.01) and N1H···N7 (6.77) H-bonds, whereas the G*·G*syn mismatch – of the O6H···O6 (10.68) and N1···HN7 (9.59 kcal mol−1) H-bonds. Our results highlight that these H-bonds are significantly cooperative and mutually reinforce each other in both mismatches. The deformation energy necessary to apply for the G·G*syn base mispair to acquire the Watson–Crick sizes has been calculated. We have shown that the thermodynamically stable G*·G*syn base mispair is dynamically unstable structure with a lifetime of 4.1 × 10−15 s and any of its six low-lying intermolecular vibrations can develop during this period of time. These data exclude the possibility to change the tautomeric status of the bases under the dissociation of the G·G*syn mispair into the monomers during DNA replication. Finally, it has been made an attempt to draw from the physico-chemical properties of all four incorrect purine–purine DNA base pairs a general conclusion, which claims the role of the transversions in spontaneous point mutagenesis.
Simulation and Optimization of Evaporative Gas Turbine with Chemical Absorption for Carbon Dioxide Capture

This article studied the integration of an evaporative gas turbine (EvGT) cycle with chemical absorption for CO2 capture. Two systems of EvGT cycle without CO2 capture and EvGT cycle with CO2 capture were simulated and optimized. The impacts of key parameters such as the water/air ratio (W/A), the stripper pressure, and the flue-gas condensing temperature were studied regarding the electrical efficiency and CO2 reduction. Simulation results show that (1) there always exists an optimum point of W/A for both EvGT and EvGT combined with CCS; (2) although lowering the stripper pressure would lower the heat quality requirement of reboiler, it increases the quantity more obviously. Therefore increasing the operating pressure of stripper would help to increase the total electrical efficiency; but the efficiency improvement becomes smaller if stripper pressure is high; (3) adding a flue-gas condenser to condense out the excessive water is another method to increase the total electrical efficiency. There is also an optimum point of condensing temperature considering the concentration of mono ethanol amine (MEA) and inlet temperature of stripper; and (4) comparatively the combined cycle has a higher gross electricity generation and electrical efficiency than the EvGT cycle no matter if combined with CO2 capture or not.
Electronic Structure and Optical Properties of AFeO2 (A = Ag, Cu) within GGA Calculations

The electronic structure of delafossite type oxides AFeO2 (A = Ag, Cu) has been calculated using the full potential linearized augmented plane wave (FP-LAPW) method within the local spin density approximation (LSDA), Perdew−Burke−Ernzerhof (PBE-GGA), and Engel−Vosko (EV-GGA) generalized-gradient approximations. It was found that the EV-GGA provides a more realistic description of the electronic structure and the optical properties of AFeO2 than PBE-GGA or LSDA. The influence of electron correlations has been considered within the PBE-GGA+U and LSDA+U methods. The effective Hubbard U, Ueff, has been derived on the basis of an ab initio constraint calculation and by comparison with X-ray emission spectra. The energy band gap of AFeO2 within the PBE-GGA+U is found as a charge-transfer gap between O-2p to Fe-3d states. The theoretical optical band gaps Δ0 = 1.30, Δ1 = 2.06, and Δ2 = 3.20 eV for CuFeO2 are quite compatible with experimental data. We have predicted an optical band gap Δ0 = 1.90 eV for AgFeO2, a.
Hydrothermal Synthesis, Crystal Structure, and Characterization of Two New Metal Diphosphonates with a 3D Pillared Layered Structure

Two new metal diphosphonates with a 3D pillared layered framework, [Zn2L]·2H2O (1) and [Sb(HL)(H2O)]·H2O (2) (H4L = H2O3PCH2NC4H8NCH2PO3H2), were synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction as well as IR spectroscopy, elemental analyses, and thermogravimetric analyses. For compound 1, each ZnO3N tetrahedron is in turn corner-sharing through three CPO3 tetrahedra from three different phosphonate ligands to form two-dimensional inorganic layers in the ab plane. In compound 2, the inorganic puckered layers are composed of pseudo-octahedral bipyramidal SbO5 and CPO3 tetrahedra in the bc plane. The overall structure of both compounds may be described in terms of alternating inorganic infinite layers and organic pillars{–CH2N(C2H4)2NCH2–} to form a 3D pillared layered structure.
Efeito da aplicação de silicato de cálcio no crescimento, no estado nutricional e na produção de matéria seca de mudas de maracujazeiro

Objetivou-se, com este trabalho, avaliar os efeitos da aplicacao de um residuo industrial (silicato de calcio) ao substrato de producao das mudas de maracujazeiro, como material corretivo, no desenvolvimento, na producao de materia seca e no estado nutricional das plantas. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos e quatro repeticoes. As doses de silicato de calcio foram aplicadas objetivando-se elevar a percentagem de saturacao com bases 25, 50, 75 e 100%, correspondendo a 0,45; 0,90; 1,35 e 1,80 g por vaso, respectivamente, alem da testemunha sem aplicacao. A unidade experimental foi constituida por vasos com 2 dm3 de substrato de um Latossolo Vermelho distrofico. Apos 80 dias da semeadura avaliaram-se: a altura, o numero de folhas, o diâmetro do caule e a materia seca da parte aerea e das raizes e, tambem, os teores de macro e micronutrientes. O residuo de silicato de calcio mostrou-se como corretivo de acidez do solo e como fonte de Ca, embora ineficiente fonte de Mg. O maior crescimento das mudas de maracujazeiro esteve associado a saturacao por bases do solo de 58%, a concentracao de Ca do solo de 19 mmolc dm-3 e teores de Ca na parte aerea de 12,0 g kg-1.
De‐excitation rates for excited xenon molecules

The time decay of the density of excited xenon molecules (Xe2*) in the lowest bound diatomic states was monitored by observing the photons (1730 ± 100 A) emitted in transitions to the repulsive ground state. Mutual ionizing collisions of the excited diatomic states are responsible for the initial decay at high excited‐state density. The measured rate for this process is (3.5 ± 1.4) × 10−10 cm3 sec−1. At lower excited‐state densities, the decay of Xe2* is controlled by spontaneous emission [(20 ± 8) × 106 sec−1], collisional deactivation [(3,3 ± 1.3) × 10−18 cm2], and electronic recombination.
Reduced Amylose Effects on Bread and White Salted Noodle Quality

ABSTRACT Amylose content in wheat endosperm is controlled by three Wx loci, and the proportion of amylose decreases with successive accumulation of Wx null alleles at the three loci. The proportion of amylose is believed to influence end-use quality of bread and Asian noodles. The objectives of this study were to determine influence of the allelic difference at Wx-B1 locus on bread quality, bread firmness, and white salted noodle texture in a spring wheat cross segregating for the Wx-B1 locus and in a set of advanced spring wheat breeding lines differing in allelic state at the Wx- B1 locus. In addition, we examined the relationship between amylose content and flour swelling properties on bread and noodle traits. Fifty-four recombinant inbred lines of hard white spring wheat plus parents were grown in replicated trials in two years, and 31 cultivars and breeding lines of hard spring wheat were grown in two locations. Bread and white salted noodles were processed from these trials. The presence of the Wx-B.
Synthesis and characterisation of porphyrin nanotubes obtained by ionic self-assembly

In this work, the porphyrin nanotubes were built by ionic self-assembly in acidic aqueous solution of two oppositely charged non-metal porphyrins, namely, the anionic meso-tetra (4-sulfonatophenyl) porphine dihydrochloride (TPPS4) and cationic meso-tetra (4-pyridyl) porphine (T4MPyP). The electrostatic forces between these porphyrin blocks contribute to the formation of porphyrin aggregates in the form of nanosheets and nanotubes, enhance the structural stability of these nanostructures. The nanosheets thickness approximately varies in the range of 3-15 nm and the sheets diameter up to 1 micron. Using the TEM and SEM, it was revealed that the mechanism of nanotubes formation is based on the wrapping of nanosheets in multiwall cigar-like structures. The porphyrin nanotubes obtained are hollow structures with a length from 200 nm up to 1,000 nm and have a diameter in the range of 50-140 nm with 20-40 nm thick walls. TEM images confirm a hollow tubular structure of the aggregates.
Counting perfect colourings of plane regular tilings

Abstract A first step in investigating colour symmetries of periodic and nonperiodic patterns is determining the number of colours which allow perfect colourings of the pattern under consideration. A perfect colouring is one where each symmetry of the uncoloured pattern induces a global permutation of the colours. Two cases are distinguished: Either perfect colourings with respect to all symmetries, or with respect to orientation preserving symmetries only (no reflections). For the important class of colourings of regular tilings (and some Laves tilings) of the Euclidean or hyperbolic plane, this mainly combinatorial question is addressed here using group theoretical methods.
Biosorption of Chromium(VI) and Lead(II): Role of Spirulina platensis in the Treatment of Industrial Effluent

ABSTRACT Biosorption is the process of removal of any chemical molecules by the treatment of biological material. Industrialization resulted in the discharge of various toxic heavy metals into water bodies, which poses serious health hazards to humans and animals. In the present study, live Spirulina platensis was used as a biosorbent for the removal of the heavy metals chromium (Cr(VI)) and lead (Pb(II)) from the aqueous samples. S. platensis were cultured in the presence of different concentrations of heavy metals. The growth of the algal cells was found to be decreased by 59% and 36% in media containing 50 ppm Cr(VI) and Pb(II), respectively. To assess the biosorption of heavy metals, at different time intervals, the spent culture media were used to detect Cr(VI) by atomic absorption spectroscopy method and Pb(II) by 4-(2-pyridylazo)resorcinol indicator method. Results suggested that there was a significant uptake of Cr(VI) and Pb(II) from the medium by S. platensis, with corresponding decrease of metals in the medium. When metal salt solutions or industrial effluent samples were passed through the column containing immobilized live S. platensis in calcium alginate beads, the concentration of Cr(VI) was found to be reduced drastically. The present study indicates the application of S. platensis for the bioremediation of heavy metals from the samples obtained from industrial effluents.
X-ray photoelectron spectroscopic studies of some iodine compounds

A number of iodine compounds are studied as solids, in particular some iodine-oxygen and iodine-chlorine compounds and the tri-iodide ion. The chlorine 2p electron binding energy for I2Cl6 can be resolved into two peaks of intensity ratio 2:1 corresponding to terminal and bridging chlorine atoms. The iodine 3d electron binding energy for the tri-iodide ion may be resolved into peaks corresponding to different iodine atoms. The experimental results are compared with CNDO calculations, using both a 5s, 5p(sp model) and a 5s, 5p and 5d(spd model) basis set, in the framework of the ground and relaxation potential models (GPM and RPM). The CNDO calculations (spd model) give good agreement with previously published charges for xenon compounds, and the spd model, but not the sp model, is found to give good agreement with the experimental results for iodine compounds. The RPM model is found to be an improvement over the GPM model. The overall bond orders obtained with the spd model charges and charges based on Pauling electronegativities are compared for the isoelectronic series SiO4–4, PO3–4, SO2–4, ClO–4, and the trends found to be in the opposite directions. For ClO–4, Pauling charges give particularly poor agreement with experiment.
Conversion of light to electricity by cis-X2bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) charge-transfer sensitizers (X = Cl-, Br-, I-, CN-, and SCN-) on nanocrystalline titanium dioxide electrodes

cis-X 2 Bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) complexes (X=Cl - , Br, I - , CN - , and SCN - ) were prepared and characterized with respct to their absorption, luminescence, and redox behavior. They act as efficient charge-transfer sensitizers for nanocrystalline TiO 2 films (thickness 8-12 μm) of very high internal surface area (roughness factor ca. 1000), prepared by sintering of 15-30-nm colloidal titania particles on a conducting glass support. The performance of cis-di(thiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) (1) was found to be outstanding and is unmatched by any other known sensitizer
Carbon dioxide enrichment decreases critical nitrate and nitrogen concentrations in wheat

Abstract Atmospheric carbon dioxide (CO2) levels are increasing. In a glasshouse experiment with wheat grown at 5 levels of nitrate (NO3) supply, CO2 enrichment (1500 cm3/m3) substantially decreased critical concentrations of N03‐N and total‐N in stem bases and leaves. For example, critical NO3‐N concentrations in stem bases at Feekes Stages 1.5, 5, and 10.3, were 4.5, 2.0, and 2.0 mg/g dry wt, respectively, for CO2‐enriched plants, compared with 7.5, 6.2 and 6.4 mg/g dry wt, respectively, for control plants grown at the ambient level of CO2. However, concentrations of NO3‐N in the rooting medium required to produce maximum dry matter accumulation by CO2‐enriched plants were similar to those of control plants at the three growth stages. Critical concentrations of NO3‐N and total‐N declined with time in stem bases and leaves of plants grown at both ambient and elevated CO2 levels, but the decline was greater for CO2‐enriched plants. It was concluded that diagnostic criteria based on current critical N conc.
Dual length morphological model for bulk‐heterojunction, polymer‐based solar cells

We present a dual length morphological model for the active layer of bulk-heterojunction, polymer-based solar cells using results from neutron and X-ray scattering techniques. Two critical characteristic lengths are found in the mixtures composed of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). A characteristic length at 15 nm is the local characteristic of the P3HT crystals and PCBM agglomerations, which is independent of the bulk composition upon relaxation by thermal annealing. Conversely, a larger bicontinuous structure described by Teubner–Strey model with phase distances between 23 and 35 nm forms only after thermal annealing, which is highly correlated to the bulk compositions. These results suggest phase separation between the polymer and fullerene can only be partially manipulated by simple processing techniques such as coating conditions and annealing, and a more rigorous design of the morphology should be implemented in the future. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym. Phys. 2014, 52, 387–396