Miracle-dz/UniFAR-FTUs huggingface dataset:
Bacterial bioreporter detects mercury in the presence of excess EDTA

Environmental context Understanding the uptake of mercury by bacteria is essential for predicting the amount of toxic methyl mercury formed in the environment. This study shows that the uptake of mercury by a whole-cell bacterial biosensor as a function of a strong ligand was greater than predicted by chemical speciation measurements or equilibrium calculations. These results call into question the use of chemical measurements and equilibrium modelling for predicting the toxicity of metals to living organisms in the environment and suggest that direct biological methods yield more accurate results. Abstract A whole-cell bacterial reporter was used to probe the bioavailability of mercury in the presence of a strong metal chelator, ethylenediaminetetraacetic acid (EDTA). Strain ARL1 was constructed by inserting a merR::luxCDABE fusion into the chromosome of Escherichia coli. The response of the bioreporter to HgII was monitored as a function of added EDTA. In parallel, square-wave voltammetry (SWV) measurements and thermodynamic calculations using MINEQL were performed to study the chemical speciation of mercury. The amount of electro-labile HgII measured by SWV was similar to the amount of non-complexed HgII predicted from equilibrium calculations. In contrast, the bioavailable fraction measured by the bioreporter was greater than the fraction predicted by either equilibrium calculation or electrochemical analysis. These results suggest that conventional chemical measurements and equilibrium calculations are not necessarily good proxies for predicting the bioavailable metal fraction. Additional factors such as kinetic effects or biological ligand competition must be considered.
Development of Low Density Microspheres of Metformin Hydrochloride Using Ethyl Cellulose and HPMC K4M: In Vitro and in Vivo Characterization

Polymeric floating microspheres of metformin hydrochloride were prepared by a modified solvent evaporation method using ethyl cellulose and HPMC K4M. Microspheres were characterized by SEM, particle size, drug content, in vitro swelling, in vitro buoyancy, in vitro drug release and in vivo X-ray imaging. Formulation D exhibited in vitro swelling, about 48.28 ± 1.03% and the desired floating time and with retention in the upper small intestine of rabbits for 8 h and with release for 12 h. We conclude that ethyl cellulose and HPMC K4M at 0.40:1.50 w/w ratios could be an effective carrier for multiparticulate controlled drug delivery.
Controlling the NO production of an atmospheric pressure plasma jet

The production of NO radicals by an atmospheric pressure plasma jet has been investigated by means of absorption spectroscopy in the mid-infrared region (IR) and optical emission spectroscopy (OES) in the ultraviolet (UV) part of the spectrum. The plasma jet investigated here operates in argon with air admixtures up to 1%. The study shows that OES can be used to characterize the relative NO production at small air admixtures. The Production of NO radicals can be controlled by variation of air admixture. Important to note—especially for operation in ambient conditions—is that a small addition of water vapour strongly affects the production of NO radicals especially at higher air admixtures (greater than 0.2%).
Mechanisms of wafer sawing and impact on wafer properties

Silicon wafer wire‐sawing experiments were realized with different sets of sawing parameters, and the thickness, roughness, and cracks depth of the wafers were measured. The results are discussed in relation to assumptions underlying the rolling–indenting model, which describes the process. It was also found that the silicon surface at the bottom of the sawing groove is different from the wafer surface, implying different sawing conditions in the two positions. Furthermore, the measured parameters were found to vary along the wire direction, between the entrance of the wire in the ingot and its exit. Based on these observations, some improvements for the wire‐sawing model are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Mineralogical characterization of individual growth structures of Mn-nodules with different Ni+Cu content from the central Pacific Ocean

Abstract The mineralogy of manganese nodules from the German license area in the eastern Clarion and Clipperton Zone (CCZ) of the central Pacific Ocean was studied using X‑ray diffraction. Their individual nanometer to micrometer thick genetically different (hydrogenetic/diagenetic) layer growth structures were investigated using high-resolution transmission electron microscopy. Relationships between the mineral phases and metal content (e.g., Ni+Cu) were assessed with electron microprobe analyzer. The main manganese phase detected in nodules of this study was vernadite, a nanocrystalline and turbostratic phyllomanganate with hexagonal layer symmetry. In layer growth structures of hydrogenetic origin, Fe-vernadite dominates. Layer growth structures of suboxic-diagenetic origin contain three vernadite forms, which are the main Ni and Cu carriers. These Mn-phases were identified on the basis of their structural layer-to-layer distances (7 and 10 Å) and on their capacity to retain these distances when heated. The first form is 7 Å vernadite, which is minor component of the nodules. The second is a thermally unstable ~10 Å vernadite collapsing between room temperature and 100 °C, and the third is a thermally stable ~10 Å vernadite collapsing between 100 and 300 °C. Todorokite was neither detected in bulk nodules nor in any of the individual suboxic-diagenetic growth structures. Because the mineralogical composition of the nodule is quite homogeneous (only different vernadite-types), it is suggested that the content of Ni and Cu in the individual growth structures is controlled by their availability in the environment during individual growth phases. A profile through a CCZ nodule revealed that the thermal stability of the vernadites change from younger (thermally unstable vernadites, collapsing <100 °C) to older growth structures (thermally stable 10 Å vernadites, collapsing >100 °C) of the nodule accompanied with changes in type and amount of interlayer cations (e.g., Mg, Na, Ca, K). The stability of the vernadites is probably due to re-organization and incorporation of metals within the interlayer of the crystal structure.
Influence of architecture on the Raman spectra of acid-treated carbon nanostructures

Raman spectroscopy was used to characterise 11 varieties of carbon nanostructures (CNSs) consisting on seven varieties of commercial multi-walled carbon nanotubes, two types of carbon nanofibres and two types of lab-synthesised single-walled carbon nanotubes. The Raman spectra of these CNSs provided information on the structural ordering of the as-received (or as-synthesised) material. Additionally, the CNSs were chemically treated by two mixtures of nitric and sulphuric acids at markedly different concentrations and then characterised by Raman spectroscopy. The features of the G and D Raman bands of the CNSs were used to assess structural modifications and generation of defects induced by the acid treatments. Changes in the Raman spectra before and after acidic treatment depend strongly on the initial intensity ratio of the G to D bands and the architecture (number of layers or diameter) of the CNSs.
Electronic structure symmetry of interfaces between pentacene and metals

We examined the electronic structure of the interfaces formed between pentacene and various metals: Au, Ag, and Ca, using photoemission spectroscopy. For all interfaces, we observed the formation of an interface dipole that varied linearly with the measured metal work function. We observed that the behavior of the interfaces of Ca with pentacene was symmetric with respect to whether Ca was deposited on pentacene or vice versa. On the other hand, the interfaces of Au and Ag with pentacene were asymmetric. For both Au and Ag we saw indications that upon metal deposition, metal penetration resulted in a metallic surface with a work function significantly different from that of pure Au or Ag. This also resulted in different interface dipoles for these interfaces.
Pressure-induced semimetallic behavior of calcium from ab initio calculations

A loss of metallic properties in fcc calcium under high pressure is studied ab initio using the density functional theory (DFT) and GW approximation. It is found that a more correct description of many-electron effects given by GW method does not provide significant changes in the behavior of electronic spectrum in comparison with DFT approach. We note that the obtained width of (pseudo)gap is highly sensitive to the k-point sampling used for density of states calculation. The analysis of fcc calcium's band structure at p ~ 20 GPa shows that the crossing of bands at the Fermi level is removed if the spin-orbit coupling is taken into account.
Distribution granulométrique d'aérosols d'uranium dans l'industrie française de fabrication du combustible

Pariicle size distribution of uranium aerosols measured in the French nuclear fuel cycle. Introduction of the new recommendations of ICRP, and more precisely the new respiratory tract mode1 of ICRP 66, led us to focus on some specfic parameters related to uranium aerosols coliected at different workplaces, in particular the particle size distribution, including the activity median aerodynamic diameter (AMAD), and the associated geometric standard deviation op. This study reports on aU the AMAD and as results on different uranium aerosols which have been coliected during the last 10 years within 4 uranium cycle facilities. The measured AMAD size range is 5.1 to 7.6 pn, with an average value of 55 pm and an average og of 2.6. Influence of AMAD values upon respiratory tract deposit, dose per unit intake (DPUI) and annual iimit on intake (ALI), was investigated, as weU as the effect of associated parameters such as density or respiratory flow rate.
Influence of Water Stress on Japanese Mint

ABSTRACT Changes in plant growth and development, micronutrient accumulation, and essential oil yield and composition were studied in Japanese mint (Mentha arvensis L. cv. MS 77) growing under selected water stresses from deficiency to sufficiency. Water stress resulted in significant reductions in CO2 exchange rate, total assimilatory area, fresh and dry matter, chlorophyll, carotenoids, Fe, Mn, Zn, and essential oil yield. Some changes in essential oil composition were observed, but these changes generally were not correlated with water stress.
Removal of Metal Contaminants from Saline Waters at Low Temperature by an Iminodiacetic Acid Ion‐Exchange Resin, Thala Valley Tip, Casey Station, Antarctica

Abstract Effects of salinity and low temperature on the removal of dissolved contaminant metals from water by an iminodiacetic acid (IDA) ion‐exchange resin, Amberlite IRC748, were investigated under batch equilibrium conditions. As expected for ions retained by chelation, the efficiency of the resin was reduced with low temperature. The efficiency of the resin increased with salinity: increasing salinity (from 0% seawater) reduces protonation of the resin, lowering solution pH into the optimum pH range for the retention of contaminant metal ions. Selectivities of the divalent matrix cations, Ca2+ and Mg2+, were decreased with increasing salinity: this is attributed to a shift to an ion‐exchange retention mechanism for these ions, which is favoured at lower solution pH. At low salinity, the selectivity for Ca2+ and Mg2+ was decreased at low temperature, however at higher salinities, selectivity was unaffected by low temperature. This is consistent with the proposal of a shift from a chelation to an ion‐exchange mechanism for these ions.
Near‐Freezing Temperature Storage (−2C) for Extension of Shelf Life of Chilled Yellow‐Feather Broiler Meat: A Special Breed in Asia

As a special breed in Asia, yellow-feather broilers have high nutrition and can deteriorate easily under chilled conditions. The present work evaluated the effect of different storage temperatures (−2, 1 and 4C) on the shelf life of chilled yellow-feather chicken under modified atmosphere packaging (CO2/N2: 80%/20%). The total viable counts reached the limit value (7.0 log colony-forming unit [cfu]/g) after 28 and 12 days of storage at 1 and 4C, whereas it did not exceed 7.0 log cfu/g during the whole −2C storage period. The samples stored at −2C had the lowest total volatile basic nitrogen content and maintained the best sensory quality and lowest drip loss among the three groups. The shelf lives of samples stored at −2 and 1C were significantly extended for 16 days compared with traditional chilling at 4C. Our results provide practical information on shelf life extension of chilled yellow-feather broiler meat, which provide benefits to the industry to reduce unnecessary food waste. Practical Applications As a special species in Asia, yellow-feather broiler meat has more distinctive flavor, and is thereby favored by consumers. As a result of rapid deterioration, it is imperative to develop a novel preservation technology for chilled yellow-feather chicken. In this work, we determined the quality changes of the shelf life of chilled yellow-feather chicken half-carcass with high CO2-modified atmosphere packaging stored at −2, 1 and 4C. The shelf lives of samples stored at −2 and 1C were significantly extended for 16 days compared with traditional chilling at 4C. Our results will provide practical information to extend the shelf life of chilled yellow-feather broiler meat, which will be of benefit to the poultry industry to reduce unnecessary food waste.
Effect of alkalinity on the structure of phenol–formaldehyde resol resins

Two phenol-formaldehyde resol resin series with different methylation-and condensation-stage alkalinities were studied. The first series was impregnation resins having a methylation alkalinity between 0.5 and 1.5 wt % and a condensation alkalinity of 1.5 wt %. The second series was adhesive resins with a methylation alkalinity between 0.5 and 3.5 wt % and a condensation alkalinity of 6.0 wt %. The chemical structure was analyzed by 13 C-NMR spectroscopy, and reactivity, by differential scanning calorimetry (DSC). The methylation alkalinity was found to affect the distribution of the structural groups of both phenol-formaldehyde impregnation and adhesive resins, but not to the same extent as did the total condensation alkalinity. Also, the results of the DSC analysis illustrate best the reactivity differences due to the condensation alkalinity.
Copper cathode erosion by an electric arc - the causes of the variations of the erosion rate with the electrode gap

In this paper we present a study concerning the influence of the electrode gap on the erosion of a copper cathode under the sole action of an electric arc in air at atmospheric pressure. The causes of the variations of the erosion rate with this parameter are studied. It is shown that, certainly, the variations of the erosion rates with the electrode gap should be imputed to two factors: the arc mobility which changes strongly with the electrode gap and a `supplementary' heating of the cathode surface due to interactions that occur at small electrode gap values between the cathode surface and the anode plasma jets.
Blends of poly(ethylene terephthalate) and poly(butylene terephthalate)

Commercial grade poly(ethylene terephthalate), (PET, intrinsic viscosity = 0.80 dL/g) and poly(butylene terephthalate), (PBT, intrinsic viscosity = 1.00 dL/g) were melt blended over the entire composition range using a counterrotating twin-screw extruder. The mechanical, thermal, electrical, and rheological properties of the blends were studied. All of the blends showed higher impact properties than that of PET or PBT. The 50:50 blend composition exhibited the highest impact value. Other mechanical properties also showed similar trends for blends of this composition. The addition of PBT increased the processability of PET. Differential scanning calorimetry data showed the presence of both phases. For all blends, only a single glass-transition temperature was observed. The melting characteristics of one phase were influenced by the presence of the other. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 75–82, 2005
Capillary levelling as a probe of thin film polymer rheology

While measuring the rheology of bulk polymer systems is routine, when the size of a system becomes comparable to molecular dimensions, properties of flow are hard to measure and poorly understood. We present the results of experiments that are easily performed and can probe the rheological properties of polymer films that are mere tens of nanometres in thickness. Glassy bilayer polymer films are prepared with height profiles well approximated by a step function. Upon annealing such stepped bilayer films above the glass transition, the height profiles broaden due to gradients in the Laplace pressure. By varying the molecular weights of the stepped films, we control the rate at which the broadening takes place. A scaling relation derived in the lubrication approximation is used to show that the rate of broadening is consistent with that expected from polymer rheology in the bulk, thus validating the technique as a uniquely versatile rheological probe for thin polymer films.
Anomalous Behavior of Sound Velocity and Attenuation in Liquid Fe-Ni-S

The compressional wave velocity in molten iron containing 5 percent nickel and 10 percent sulfur increased with increasing temperature. This anomalous behavior was determined to be attributable to the presence of sulfur, which conditions the formation of large molecular units in the liquid. Temperature-induced breakup of macromolecular units resulted in greater packing efficiency and an increased velocity. Ten percent sulfur increased attenuation by one to two orders of magnitude compared with liquid iron. Such behavior at outer core pressures and temperatures would constrain the velocity gradient in the outer core and would enable the discrimination of potential light alloying elements.
Iron and calcium translocation from pure gypsum and iron-amended gypsum by two brown rot fungi and a white rot fungus

Abstract Wood-degrading fungi commonly grow in contact with calcium (Ca)-containing building materials and may import Ca and iron (Fe) from soil into forest woody debris. For brown rot fungi, imported Ca2+ may neutralize oxalate, while Fe3+ may facilitate Fenton-based degradation mechanisms. We previously demonstrated, in two independent trials, that degradation of spruce by wood-degrading fungi was not promoted when Ca or Fe were imported from gypsum or metallic Fe, respectively. Here, we tested pine wood with lower endogenous Ca than the spruce blocks used in prior experiments, and included a pure gypsum treatment and one amended with 1% with FeSO4. Electron microscopy with microanalysis verified that brown rot fungi Serpula himantioides and Gloeophyllum trabeum and the white rot fungus Irpex lacteus grew on gypsum and produced iron-free Ca-oxalate crystals away from the gypsum surface. Wood cation analysis verified significant Fe import by both brown rot isolates in Fe-containing treatments. Wood degradation was highest in Fe-gypsum-containing treatments for all three fungi, although only wood degraded by I. lacteus had significant Ca import. We suggest that Fe impurities may not exacerbate brown rot, and that both brown and white rot fungi may utilize Ca-containing materials.
A Review of Atmospheric Mercury in the Polar Environment

This paper is an overview of Hg measurements made in the Arctic and Antarctic regions, with an emphasis on the evaluation of the methodological approaches employed in both sampling and analysis between different Hg species as well as the fundamental aspects of their behavior. There have been numerous efforts to measure the concentrations of different Hg species, including gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate mercury (Hg(p)) in polar environments. The mean concentration value for GEM, if evaluated on the basis of numerous studies conducted previously, was moderately higher in the Arctic region (1.56 ng m−3) than the Antarctic counterpart with the limited data sets (1.08 ng m−3). The mean GEM concentration in the Arctic environment varied moderately between different locations so that the highest mean values occurred in sub-Arctic locations with a complicated climatology (e.g., Kuujjuarapik, Quebec: 1.80 ng m−3), while the lowest one was recorded in Pallas, Finland (1.26 ng m−3). A comparison of temporal patterns between different studies also indicates that rather dynamic variations occur due to the effects of certain phenomenon, known as atmospheric mercury depletion events (AMDE). During such depletion events, the GEM concentrations frequently dropped below 1.0 ng m−3, while the RGM and Hg(p) exhibited oposing trends. The distribution of GEM in polar environments is, however, fairly comparable in spatial scale, while those of RGM and Hg(p) vary fairly dynamically in such respects. Evidence suggests that the distribution of Hg species at each measurement site in the polar environments is affected more effectively by site-specific meteorological conditions.
Determination of phenolic diterpene antioxidants in rosemary (Rosmarinus officinalis L.) with different methods of extraction and analysis.

The extraction from rosemary (Rosmarinus officinalis L.) of the phenolic diterpene antioxidants (PDAs), carnosic acid and carnosol, by sonication or Soxhlet extraction with acetone (with or without active charcoal bleaching) are compared with fractionated SFE extraction obtained by varying the dissolving power of supercritical carbon dioxide through the addition of methanol. For the further analysis of the PDAs, the results obtained by reversed-phase HPLC linked to a UV detector are compared with those produced when an evaporative light scattering detector or a particle beam interface linked to an MS were employed. Copyright © 2000 John Wiley & Sons, Ltd.
Interactions between silver nanoparticles and polyvinyl alcohol nanofibers

The interaction of polyvinylalcohol (PVA) nanofibers with silver (Ag) nanoparticles (mean diameter 8nm) has been modeled using density functional theory (DFT) calculations. The physical adsorption of PVA through the hydroxyl group, to the Ag, and its corresponding molecular orientation was compared with experimental results obtained from surface-enhanced Raman scattering (SERS) studies of the same material. A good agreement was found between the computational model of the vibrational spectrum of the adsorbate and the experimentally observed SERS. In general, aliphatic capping molecules are used to passivate the surface of Ag55 nanocrystals (55 = atomic number of Ag). In this study, a DFT simulation was employed to show binding energies and electron contour map analyses of Ag55 with PVA. Here we show that the PVA interacts with the Ag nanoparticle's surface, through the OH group, thereby contributing significantly to the increase in SERS activity.