Transition of recollision trajectories from linear to elliptical polarization.

Using a classical ensemble method, we revisit the topic of recollision and nonsequential double ionization with elliptically polarized laser fields. We focus on how the recollision mechanism transitions from short trajectories with linear polarization to long trajectories with elliptical polarization. We propose how this transition can be observed by meansuring the carrier-envelop-phase dependence of the correlated electron momentum spectra using currently available few-cycle laser pulses.

[Comparative study of different methods of blood purification treatment of paraquat intoxication].

OBJECTIVE: To investigate the different effect of three methods of blood purification for paraquat poisoning patients:hemoperfusion (HP), hemoperfusion combined with hemodialysis (HP + HD), hemoperfusion combined with continuous veno-venous hemofiltration (HP + CVVH). METHODS: 72 cases of paraquat poisoning patients were divided into three groups after giving conventional therapy HP group, HP + HD group, HP + CVVH group. Compared the rate of decline concentrations of paraquat in blood, the liver and the kidney damage between before and after blood purification and contrast the mortality in three groups after different method of blood purification. RESULTS: The rate of decline concentrations of paraquat in blood of the HP + HD group and HP + CVVH group were both significantly greater than the HP group, but this result of HP + HD group has no significant difference compared with HP + CVVH group; Among the three groups of patients after 72 hours, the degree of dysfunction of liver of the HP + HD group and HP + CVVH group were both significantly lower than the HP group, whilely the degree of dysfunction of kidney of the HP + HD group was significantly lower than the HP group and the HP + CVVH group. The survival time of the HP + HD group and the HP + CVVH group were significant linger than the HP group, but the comparison among the three groups had no significant difference in mortality. CONCLUSION: Three blood purification methods can effectively remove paraquat absorbed into the blood, and the hemoperfusion combined with hemodialysis or continuous veno-venous hemofiltration can effectively reduce the degree of damage of liver and kidney and also can prolong survival time, but did not significantly improve the survival rate of patients.

Correlated multielectron dynamics in mid-infrared laser pulse interactions with neon atoms.

The multielectron dynamics in nonsequential triple ionization (NSTI) of neon atoms driven by mid-infrared (MIR) laser pulses is investigated with the three-dimensional classical ensemble model. In consistent with the experimental result, our numerical result shows that in the MIR regime, the triply charged ion longitudinal momentum spectrum exhibits a pronounced double-hump structure at low laser intensity. Back analysis reveals that as the intensity increases, the responsible triple ionization channels transform from direct (e, 3e) channel to the various mixed channels. This transformation of the NSTI channels leads to the results that the shape of ion momentum spectra becomes narrow and the distinct maxima shift towards low momenta with the increase of the laser intensity. By tracing the triply ionized trajectories, the various ionization channels at different laser intensities are clearly identified and these results provide an insight into the complex dynamics of the correlated three electrons in NSTI.

Correlated electron dynamics in nonsequential double ionization of molecules by mid-infrared fields.

The electron dynamics in strong field nonsequential double ionization (NSDI) of nitrogen molecules by mid-infrared (MIR) laser pulses is investigated with the three-dimensional classical ensemble model. The numerical results show that in the MIR regime, the correlated behavior of the two electrons from NSDI is independent on the molecular alignment, contrary to the case in the near-infrared (NIR) regime where the electron correlations exhibit a strong alignment dependence. In consistent with the experimental results, our numerical results show that the longitudinal momentum spectrum of the doubly charged ion evolves from a wide single-hump structure at NIR regime into a double-hump structure when wavelength enters the MIR regime. This double-hump structure becomes more pronounced as the wavelength further increases. The responsible microscopic electron dynamics of NSDI at the MIR regime is explored by back analysis of the classical trajectories.

Classical simulations of electron emissions from H2+ by circularly polarized laser pulses.

With the classical fermion molecular dynamics model (FMD), we investigated electron emissions from H(2)(+) by circularly polarized laser pulses. The obtained electron momentum distribution clearly shows an angular shift relative to the expected direction for H(2)(+) aligned parallel to the polarization plane, which is in good agreement with the recent experimental result. By tracing the classical trajectory, we provide direct evidence for the electron delayed emission with respect to the instant when the electric field is parallel to the molecular axis, which was regarded as the origin of the angular shift in the electron momentum distribution. Furthermore, we find that the angular shift decreases with increasing the laser wavelength.

Vortex creep activation energies and depinning currents in CaKFe4As4 and Ba0.6K0.4Fe2As2 revealed by AC susceptibility measurements.

Systematic ac susceptibility measurements have been carried out to study the vortex dynamics in CaKFe4As4 and Ba0.6K0.4Fe2As2 single crystals under various temperatures, dc magnetic fields, ac field frequencies and amplitudes. The field-temperature phase diagrams were shown, and the characteristics of irreversibility line were also derived. The specific expressions of activation energy on the parameters of temperature (T), current density (J), and dc magnetic field (H) are obtained according to these data. The results indicate that both superconductors have similar functional expressions of activation energy and flux pinning behaviors. Though both CaKFe4As4 and Ba0.6K0.4Fe2As2 superconductors exhibit very strong flux pinning ability, the vortex pinning potential in CaKFe4As4 is slightly smaller than that in Ba0.6K0.4Fe2As2, which may result from its distorted FeAs4-tetrahedron in CaKFe4As4. The depinning critical current densities at the limit of low temperature and low field were also extrapolated, yielding the corresponding values of J c0(0) ∼ 1.0 × 108 and 2.2 × 108 A cm-2 for CaKFe4As4 and Ba0.6K0.4Fe2As2 superconductors, respectively, which suggest potential applications.

Reduced expression of microRNA-199a-3p is associated with vascular endothelial cell injury induced by type 2 diabetes mellitus.

The aim of the present study was to investigate the function and mechanism of action of microRNA (miRNA or miR)-199a-3p in vascular endothelial cell injury induced by type 2 diabetes mellitus (T2DM). A total of 36 patients with T2DM (26 males and 10 females; mean age, 52.5±7.0 years) and 20 healthy subjects (10 males and 10 females; mean age, 55.6±4.5 years) were included in the present study. Peripheral blood samples were obtained from all participants and total RNA was extracted Reverse transcription-quantitative polymerase chain reaction was performed to determine the expression of miR-199a-3p. Following the transfection of human umbilical vein endothelial cells (HUVECs) with a negative control (NC) miRNA or miR-199a-3p mimics, cell proliferation was assessed using a Cell Counting kit-8 assay. Cell migration was investigated using Transwell assays and flow cytometry was performed to detect the apoptosis of HUVECs. HUVECs were infected with Ad-GFP-LC3B and laser-scanning confocal microscopy was performed to observe autophagosomes in HUVECs. Western blotting was used to measure the expression of proteins associated with autophagy and the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor (NF)-κB signaling pathway. MiR-199a-3p was downregulated in peripheral blood from patients with T2DM compared with healthy subjects. Transfection with miR-199a-3p mimics promoted the proliferation and migration of HUVECs. However, miR-199a-3p overexpression inhibited the apoptosis of HUVECs. MiR-199a-3p facilitated HUVEC autophagy by affecting autophagy-associated signaling pathways. Furthermore, miR-199a-3p regulated the biological functions of HUVECs via the PI3K/AKT/NF-κB signaling pathway. The results of the present study suggest that miR-199a-3p expression was reduced in patients with T2DM compared with healthy subjects and may be associated with vascular endothelial cell injury. In addition, miR-199a-3p promoted the proliferation, migration and autophagy of HUVECs, potentially by regulating the PI3K/AKT/NF-κB signaling pathway. Therefore, miR-199a-3p may function as protector of vascular endothelia.

Nonsequential double ionization with mid-infrared laser fields.

Using a full-dimensional Monte Carlo classical ensemble method, we present a theoretical study of atomic nonsequential double ionization (NSDI) with mid-infrared laser fields, and compare with results from near-infrared laser fields. Unlike single-electron strong-field processes, double ionization shows complex and unexpected interplays between the returning electron and its parent ion core. As a result of these interplays, NSDI for mid-IR fields is dominated by second-returning electron trajectories, instead of first-returning trajectories for near-IR fields. Some complex NSDI channels commonly happen with near-IR fields, such as the recollision-excitation-with-subsequent-ionization (RESI) channel, are virtually shut down by mid-IR fields. Besides, the final energies of the two electrons can be extremely unequal, leading to novel e-e momentum correlation spectra that can be measured experimentally.