The delafossites are a class of layered metal oxides that are notable for being able to exhibit optical transparency alongside an in-plane electrical conductivity, making them promising platforms for ...the development of transparent conductive oxides. Pressure-induced polymorphism offers a direct method for altering the electrical and optical properties in this class, and although the copper delafossites have been studied extensively under pressure, the silver delafossites remain only partially studied. We report two new high-pressure polymorphs of silver ferrite delafossite, AgFeO
, that are stabilized above ∼6 and ∼14 GPa. In situ X-ray diffraction and vibrational spectroscopy measurements are used to examine the structural changes across the two phase transitions. The high-pressure structure between 6 and 14 GPa is assigned as a monoclinic
2/
structure that is analogous to the high-pressure phase reported for AgGaO
. Nuclear resonant forward scattering reveals no change in the spin state or valence state at the Fe
site up to 15.3(5) GPa.
The delafossites are a class of layered metal oxides that are notable for being able to exhibit optical transparency alongside an in-plane electrical conductivity, making them promising platforms for ...the development of transparent conductive oxides. Pressure-induced polymorphism offers a direct method for altering the electrical and optical properties in this class, and although the copper delafossites have been studied extensively under pressure, the silver delafossites remain only partially studied. We report two new high-pressure polymorphs of silver ferrite delafossite, AgFeO2, that are stabilized above ∼6 and ∼14 GPa. In situ X-ray diffraction and vibrational spectroscopy measurements are used to examine the structural changes across the two phase transitions. The high-pressure structure between 6 and 14 GPa is assigned as a monoclinic C2/c structure that is analogous to the high-pressure phase reported for AgGaO2. Nuclear resonant forward scattering reveals no change in the spin state or valence state at the Fe3+ site up to 15.3(5) GPa.
By means of numerical simulation, the special phenomenon of zonal disintegration of surrounding rock mass around the diversion tunnels of Jinping II Hydropower Station is analyzed in this paper. In ...order to model the growth and coalescence of cracks within rock mass in Jinping II Hydropower Station, the weak-element is adopted. When cracks coalesce, failure of deep crack-weakened rock masses occurs and fractured zone is formed. The present result is different from the one obtained by the traditional elasto-plastic theory. The numerical results show that the slip-line zonal fracture is created within rock mass around the diversion tunnels in Jinping II Hydropower Station. Meanwhile, the magnitude and distributions of fractured zones are determined by numerical simulation. It is shown that the present results are in good agreement with the one observed by model tests. Through sensitivity analysis, the effects of stress condition, cohesion and the angle of internal friction on the phenomenon of zonal disintegration is determined.
Coronal mass ejections (CMEs) are frequently associated with filament eruptions. Theoretical studies propose that both magnetic reconnection and ideal magnetohydrodynamic instability of magnetic flux ...ropes can convert coronal magnetic energy into the filament/CME kinetic energy. Numerical simulations and analytical considerations demonstrate that both mechanisms can have significant contributions to the filament/CME acceleration. Many observational studies support that reconnection plays an important role during the acceleration, while it remains open how to resolve observationally the contribution of the ideal instability to the acceleration. On the other hand, it is difficult to separate and compare their contributions through observations as both mechanisms often work in a close time sequence. In this Letter, the above issues are addressed by analyzing the eruption process of a quiescent filament. The filament started to rise from ∼00:00 UT on 2011 December 25, 20 minutes earlier than the starting time of the flare impulsive phase (∼00:20 UT), and reached the maximum velocity at the flare peak time (∼00:50 UT). We divide the acceleration process into two stages, corresponding to the pre-flare and flare impulsive phases, respectively. The analysis indicates that an ideal flux-rope instability is dominant in the first stage, while reconnection below the flux rope becomes important during the second stage, and both mechanisms may have comparable contributions to the net acceleration of the filament.
We report magnetotransport measurements of PrSb in high magnetic fields. Our results show that PrSb exhibits large magnetoresistance at low temperatures. Meanwhile angle-dependent magnetoresistance ...measurements were used to probe the Fermi surface via Shubnikov–de Haas oscillations. We found that the angular dependence of the oscillation frequency of the α branch can be explained well by a model for a two-dimensional-like Fermi surface, whereas the effective mass of this branch as a function of angle shows a fourfold signature. The evolution of the Fermi surface with increasing magnetic field also was studied up to 32 T. A continuous increase in the oscillation frequency up to 14 T is observed before it becomes constant at higher fields. Meanwhile our analysis of the residual Landau index from the high-field data reveals a zero Berry phase and therefore trivial topology of the Fermi surface.
The objective of this research is to investigate the plasma pharmacokinetics and bio-distribution of liposomal daunorubicin plus tamoxifen in breast cancer murine models through intravenous ...administration. Daunorubicin and tamoxifen plasma levels in pharmacokinetics studies were determined using HPLC. Biodistributions of various carriers loaded with a cyanine dye (cy7) were evaluated using in vivo imaging. After administration, free daunorubicin and tamoxifen were rapidly cleared out from the blood following a two-compartment kinetic model. The clearances and AUC (0-∞) of daunorubicin were (means ± SD): 0.028 ± 0.005 L h
kg
and 367.489 ± 56.979 μg mL
h
(liposomes), and 2.235 ± 0.347 L h
kg
and 4.546 ± 0.704 μg mL
h
(free drug). By ex vivo imaging 24 h after injection, the fluorescence intensity of liposomal cy7 plus tamoxifen in tumor region was obviously higher than that of free liposomal cy7. In conclusion, tamoxifen can improve pharmacokinetics profile of liposomal daunorubicin with enhanced therapy for breast cancer.
In-plane uniaxial magnetic anisotropy (UMA) has been carefully studied for the same amorphous Co 56 Fe 24 B 20 (CoFeB) film deposited on different orientational GaAs substrates. It was noted that a ...strong uniaxial anisotropy field (H k ) of ~270 Oe could be achieved with CoFeB film grown on GaAs(001) substrate, which is much larger than the largest value (150 Oe) reported before. In contrast, H k was <;20 Oe when the same CoFeB film was deposited on (110) or (111) GaAs substrate. The angular dependence of H k also behaved quite differently in these CoFeB films. Based on the surface morphology of the CoFeB/GaAs films, the possible mechanisms responsible for the different behavior of UMA were briefly discussed in terms of bond-orientational anisotropy model and random anisotropy model.
The present study was undertaken to evaluate the influence of rumen-protected folic acid (RPFA) on slaughter performance, visceral organ and gastrointestinal tract coefficients, and meat quality in ...lambs. Sixty-six lambs from 120 Hu ewes were selected based on body weight and maternal diets and then assigned to six groups using a randomised block experimental design in a 3 × 2 factorial arrangement. The first factor was folic acid (FA) as RPFA in the maternal diet (0 mg/kg (M0F), 16 mg/kg (M16F) or 32 mg/kg (M32F) on DM basis). The second factor was FA in the lambs’ diet from weaning until slaughter (0 mg/kg (OC) or 4·0 mg/kg (OF)). The results indicated that the addition of 16 mg/kg FA to the maternal diet increased pre-slaughter weight (PSW), dressing and meat percentage, the reticulum and omasum coefficients, length of the jejunum and ileum, tail fat and perirenal fat coefficient and a* value of the meat colour. The addition of RPFA to the lambs’ diet increased PSW, dressing and meat percentage, eye muscle area, abomasum weight, weight and length of the small intestine, but reduced the coefficients of tail fat. An M × O interaction was observed for the weights of heart, lungs, rumen and total stomach, weight and coefficient of omental fat and the girth rib value. Collectively, RPFA in the maternal and lambs’ diet improved slaughter performance and meat quality by stimulating the morphological development of the gastrointestinal tract and the distribution of fat in the body.
The S-phase checkpoint plays an essential role in regulation of the ribonucleotide reductase (RNR) activity to maintain the dNTP pools. How eukaryotic cells respond appropriately to different levels ...of replication threats remains elusive. Here, we have identified that a conserved GSK-3 kinase Mck1 cooperates with Dun1 in regulating this process. Deleting MCK1 sensitizes dun1Δ to hydroxyurea (HU) reminiscent of mec1Δ or rad53Δ. While Mck1 is downstream of Rad53, it does not participate in the post-translational regulation of RNR as Dun1 does. Mck1 phosphorylates and releases the Crt1 repressor from the promoters of DNA damage-inducible genes as RNR2-4 and HUG1. Hug1, an Rnr2 inhibitor normally silenced, is induced as a counterweight to excessive RNR. When cells suffer a more severe threat, Mck1 inhibits HUG1 transcription. Consistently, only a combined deletion of HUG1 and CRT1, confers a dramatic boost of dNTP levels and the survival of mck1Δdun1Δ or mec1Δ cells assaulted by a lethal dose of HU. These findings reveal the division-of-labor between Mck1 and Dun1 at the S-phase checkpoint pathway to fine-tune dNTP homeostasis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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