A thin film of well-ordered anatase TiO
2
nanotubes prepared by anodic oxidation of titanium metal were synthesised and used as adsorbent medium for the purification of water from aqueous uranium and ...lead. The amount of subtracted metal ions was quantified by using X-ray photoelectron spectroscopy at the surface of the reacted TiO
2
surface. Batch experiments for the sorption of U and Pb at the surface of the titania substrate were carried out in separated solution equilibrated with air of uranyl acetate and lead nitrate, in the pH range 3–9. For uranium, the experiments were also repeated in anoxic (N
2
) atmosphere. The amount of metal ions adsorbed onto the titania medium was quantified by measurements of the surface coverage expressed in atomic percent, by recording high-resolution XPS spectra in the Ti2
p
, U4
f
and Pb4
f
photoelectron regions. Adsorption of the uranyl species in air atmosphere as a function of pH showed an adsorption edge near pH 4 with a maximum at pH 7. At higher pH the presence of very stable uranyl–carbonate complexes prevented any further adsorption. Further adsorption increased until pH 8.5 was obtained when the uranyl solution was purged from dissolved CO
2
. Lead ion showed a sorption edge at pH 6, with a maximum uptake at pH 8. The results showed that the uptake of uranium and lead on the selected titania medium is remarkably sensitive to the solution pH. This study demonstrates the reliability of this type of material for treating water polluted with heavy metals as well as leachates from radioactive nuclear wastes.
SUMMARYThe domestication of ostriches and commercialisation of ostrich farming started in South Africa in the 19th century for the production and harvesting of feathers. Ostrich feathers were the ...primary product of farmed ostriches until the collapse of the feather market in 1914. Because ostrich feathers are not used for flying, they have different attributes than other bird feathers, which makes them unique and valued. This review summarises knowledge regarding ostrich feather production and research since the feather industry has again become an important contributor to the farmers’ income in South Africa, which supplies most of the ostrich feathers used worldwide. Wing feathers on ostriches grow at a rate of 2.5 to 5 cm per week, which varies based on the bird’s age and nutritional status. Adult birds can produce 380–400 g of white plume. Factors such as good husbandry practices, age, sex, breed, nutrition and climate can affect feather production. In addition, genetic selection can be used to increase feather quantity and quality because the heritability of these feather production variables is significant and in the low to moderate range. Developments in these disciplines are summarised, and recommendations for future research are made.
Although experimental results proved the feasibility of using time-varying magnetic field as a contactless cells permeabilization method, the underlying mechanism is still poorly understood. In this ...study a numerical analysis of the time-dependent transmembrane potential (TMP) at cell membranes during permeabilization by time-varying magnetic fields was proposed, and a first quantification of mechanical stress induced by the magnetic and electric fields, hypothesized to play an important role in the permeabilization mechanism, was carried out. Methods: Starting from the simulation of real in vitro experimental conditions, the analysis was widened quantifying the influence of pulse frequency, cell dimension and distance of the cell from the magnetic field source. The mechanical pressure on cell membrane due to the interaction between free charges and induced electric field and due to the gradient of the magnetic field was quantified in all those conditions in which the TMP values were not high enough to cause membrane permeabilization. Results: TMP values induced by typical in-vitro experimental conditions were far below the values needed for membrane permeabilization, with a strong dependence on pulse frequency and distance of the cell from the coil. Conclusion: The preliminary assessment of the mechanical pressure on cell membrane showed that stress values evaluated in conditions in which TMP values were too low to cause membrane permeabilization were comparable to those known to influence the pores opening mechanisms. Results represent a significant step towards a better comprehension of the mechanism underlying cell membrane permeabilization by time-varying magnetic fields.
•Transmembrane potential (TMP) at cell membrane during time-varying magnetic fields permeabilization was quantified.•The mechanical stress induced by the magnetic and electric fields on cell membrane was quantified.•TMP values induced by in-vitro experimental conditions were far below the values needed for membrane permeabilization.•Mechanical pressure on cell membrane showed stress values comparable to those known to influence pores opening mechanisms.•Results represent an important step towards a better comprehension of mechanisms underlying cell membrane permeabilization.
ABSTRACT
The Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS), which has covered about 642 sq. deg. in five bands from 100 to 500 $\mu \rm m$, allows a blind flux-limited selection of ...blazars at sub-mm wavelengths. However, blazars constitute a tiny fraction of H-ATLAS sources and therefore identifying them is not a trivial task. Using the data on known blazars detected by the H-ATLAS, we have defined a locus for 500 $\mu$m selected blazars and exploited it to select blazar candidates in the H-ATLAS fields. Candidates and known blazars in the H-ATLAS equatorial and South Galactic Pole fields were followed up with the Australia Telescope Compact Array (ATCA) or with the Karl G. Jansky Very Large Array (VLA), and matched with existing radio- and mm-catalogues to reconstruct the spectral behaviour over at least six orders of magnitude in frequency. We identified a selection approach that, combining the information in the sub-mm and radio domains, efficiently singles out genuine blazars. In this way, we identified a sample of 39 blazars brighter than $S_{500\mu \rm m} = 35\,$mJy in the H-ATLAS fields. Tests made cross-matching the H-ATLAS catalogues with large catalogues of blazar candidates indicate that the sample is complete. The derived counts are compared with model predictions finding good consistency with the C2Ex model and with estimates based on ALMA data.
Dilution rate, dilution temperature and storage time have been recognized as vital steps in the processing of semen for storage before artificial insemination. The objective of this study was to ...determine optimal dilution and dilution temperature with an ostrich-specific semen extender for chilled storage. Four preselected ostrich (Struthio camelus var. domesticus) males, known for their ease of collection and specific semen quality parameters, were collected using the “dummy” female method. Dilution of 384 semen samples, at rates of 1:1, 1:2, 1:4 and 1:8 semen/diluent ratio with a diluent set at 5, 21 and 38 °C was performed and stored for 48 h at 5 °C. In vitro sperm function tests were conducted to evaluate treated semen during different storage intervals of 1, 5, 24 and 48 h. Motility and kinematic parameters were measured by the Sperm Class Analyzer®, the percentage live sperm measured by fluorescence SYBR14®/PI (LIVE/DEAD®), the percentage of sperm able to resist the hypo-osmotic swelling (HOS) stress test and sperm morphology determined by Nigrosin-Eosin staining. Progressive motility (PMOT), motility (MOT), sperm kinematics, LIVE and HOS were best (P < 0.05) maintained at a higher dilution of 1:4–1:8. The beneficial effect (P < 0.05) of a higher dilution temperature (21 °C) was prominent in terms of PMOT at a higher dilution. Storage of chilled semen at 5 °C requires dilution, at interpolated rates of 1:6–1:7, together with an extender temperature of 21 °C, to maintain optimal sperm function with minimal loss over a 48 h storage period.
•An interpolated dilution rate of 1:6–1:7 maintained sperm function best.•Sperm cell membrane integrity was most affected by dilution rate.•Higher dilution temperatures of 21 °C were optimal for 24 h storage at 5 °C.•Ostrich sperm demonstrated a degree of thermal sensitivity with higher cooling rates.
We tested a group of ten post-acute right-hemisphere damaged patients. Patients had no neglect according to paper-and-pencil cancellation tasks. They were administered computer-based single- and ...dual-tasks, requiring to orally name the position of appearance (e.g. left vs. right) of briefly-presented lateralized targets. Patients omitted a consistent number of contralesional targets (≈ 40%) under the single-task condition. When required to perform a concurrent task which recruited additional attentional resources (dual-tasks), patients' awareness for contralesional hemispace was severely affected, with less than one third of contralesional targets detected (≈ 70% of omissions). In contrast, performance for ipsilesional (right-sided) targets was close to ceiling, showing that the deficit unveiled by computer-based testing selectively affected the contralesional hemispace. We conclude that computer-based, attention-demanding tasks are strikingly more sensitive than cancellation tasks in detecting neglect, because they are relatively immune to compensatory strategies that are often deployed by post-acute patients.
The morphology of quiescent galaxies has been found to be correlated with the activity of their central super massive black hole. In this work, we use data from the first data release of the LOFAR ...Two-Metre Sky Survey (LoTSS DR1) and the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) to select more than 15 000 quiescent galaxies at
z
< 0.3 to investigate the connection between radio-loud active galactic nuclei (RLAGNs) and the morphology of their host galaxy. Taking advantage of the depth of LoTSS, we find that the fraction of RLAGNs with
L
150 MHz
> 10
21
W Hz
−1
at fixed stellar mass, velocity dispersion, or surface mass density does not depend on the galaxy projected axis ratio (
q
). However, the high-power (
L
150 MHz
> 10
23
W Hz
−1
) RLAGNs are more likely to be found in massive, round galaxies, while the low- and intermediate-power (
L
150 MHz
≤ 10
23
W Hz
−1
) RLAGNs have similar distributions of
q
to non-RLAGN galaxies. We argue that our results support the picture that high-power RLAGNs are more easily triggered in galaxies with a merger-rich history, while low-power RLAGNs can be triggered in galaxies growing mainly via secular processes. Our work also supports the idea that the low-luminosity RLAGN may be sufficient for maintenance-mode feedback in low-mass quiescent galaxies with disc-like morphology, which is based on a simple extrapolation from the observed energy balance between cooling and RLAGN-induced cavities in massive clusters. We find no significant difference between the
q
distributions of RLAGNs likely to be found in clusters and those likely not found in clusters after controlling the radio luminosity and stellar mass of the two samples, indicating that the environment does not significantly influence the morphology–RLAGN correlation.
Inhibition of phosphodiesterase 4 (PDE4) is a promising pharmacological strategy for the treatment of cerebral ischemic conditions. To increase the relevance and increase the translational value of ...preclinical studies, it is important to conduct experiments using different animal species and strains, different animal models, and to evaluate long-term functional outcomes after cerebral ischemia. In the present study, the effects of the selective PDE4 inhibitor roflumilast were evaluated in vivo and in vitro. Balb/c mice were subjected to bilateral common carotid artery occlusion (BCCAO) and tested during 21 days in multiple behavioral tasks to investigate the long-term effects of roflumilast on functional recovery. The effects of roflumilast were also investigated on hippocampal cell loss, white matter injury, and expression of neuroinflammatory markers. Roflumilast prevented cognitive and emotional deficits induced by BCCAO in mice. Roflumilast also prevented neurodegeneration and reduced the white matter damage in the brain of ischemic animals. Besides, roflumilast decreased Iba-1 (microglia marker) levels and increased Arginase-1 (Arg-1; microglia M2 phenotype marker) levels in the hippocampus of these mice. Likewise, roflumilast suppressed inducible nitric oxide synthase (microglia M1 phenotype marker) expression and increased Arg-1 levels in a primary mouse microglia culture. These findings support evidence that PDE4 inhibition by roflumilast might be beneficial in cerebral ischemic conditions. The neuroprotective effects of roflumilast appear to be mediated by a decrease in neuroinflammation.
Core-shell magnetoelectric nanoparticles (MENPs) have recently gained popularity thanks to their capability in inducing a local electric polarization upon an applied magnetic field and
vice versa
. ...This work estimates the magnetoelectrical behavior, in terms of magnetoelectric coupling coefficient (αME), via finite element analysis of MENPs with different shapes under either static (DC bias) and time-variant (AC bias) external magnetic fields. With this approach, the dependence of the magnetoelectrical performance on the MENPs geometrical features can be directly derived. Results show that MENPs with a more elongated morphology exhibits a superior αME if compared with spherical nanoparticles of similar volume, under both stimulation conditions analyzed. This response is due to the presence of a larger surface area at the interface between the magnetostrictive core and piezoelectric shell, and to the MENP geometrical orientation along the direction of the magnetic field. These findings pave a new way for the design of novel high-aspect ratio magnetic nanostructures with an improved magnetoelectric behaviour.
PDF
