Electromagnetically Induced Transparency in the Strongly Relativistic Regime.

Stable transport of laser beams in highly overdense plasmas is of significance in the fast ignition of inertial confinement fusion, relativistic electron generation, and powerful electromagnetic emission, but hard to realize. Early in 1996, Harris proposed an electromagnetically induced transparency (EIT) mechanism, analogous to the concept in atomic physics, to transport a low-frequency (LF) laser in overdense plasmas aided by a high-frequency pump laser. However, subsequent investigations show that EIT cannot occur in real plasmas with boundaries. Here, our particle-in-cell simulations show that EIT can occur in the strongly relativistic regime and result in stable propagation of a LF laser in bounded plasmas with tens of its critical density. A relativistic three-wave coupling model is developed, and the criteria and frequency passband for EIT occurrence are presented. The passband is sufficiently wide in the strongly relativistic regime, allowing EIT to work sustainably. Nevertheless, it is narrowed to nearly an isolated point in the weakly relativistic regime, which can explain the quenching of EIT in bounded plasmas found in previous investigations.

[Immunological mechanism of Ermiao Powder improving inflammation in rats with collagen-induced arthritis through α7nAChR-JAK2/STAT3 pathway].

This study investigated the immunological mechanisms of Ermiao powder in the treatment of rheumatoid arthritis rats through the alpha 7 nicotinic acetylcholine receptor(α7nAChR)-Janus kinases 2(JAK2)/signal transducer and activator of transcription 3(STAT3) signaling pathway. A total of 56 female Wistar rats were randomly divided into the normal group(HG, n=8), collagen-induced arthritis(CIA) model group(CM, n=8), vagotomy group(VA, n=8), sham group(SH, n=8), Ermiao Powder treatment model group(EM, n=8), Ermiao Powder treatment for vagotomy group(EV, n=8) and Ermiao Powder treatment for sham group(ES, n=8). Following the establishment of CIA models in all groups except the HG group, the rats underwent unilateral vagotomy and sham operation(only the vagus nerve was separated). Drug treatment was started 7 days after surgery and continued for 35 days. The body weight and joints of rats were recorded, the pathological changes of the spleen of rats were observed, the contents of interleukin-6(IL-6), interleukin-1ß(IL-1ß) and tumor necrosis factor-α(TNF-α) in serum were detected by enzyme-linked immunosorbent assay(ELISA), and the mRNA and protein expression of α7nAChR-JAK2/STAT3 pathway core genes in spleen were detected by qRT-PCR, Western blot and immunohistochemistry. RESULTS:: showed that CM group(compared with HG group) and VA group(compared with CM group and SH group) had significantly decreased body weight(P<0.05, P<0.01), increased arthritis score(P<0.05, P<0.01), swollen ankle joints with deformity, and increased and enlarged lymph nodes in the spleen. There were also notable increases in the serum levels of IL-6, IL-1ß and TNF-α(P<0.05, P<0.01), and in the mRNA expressions of JAK2 and STAT3 in the spleen(P<0.05, P<0.01). The protein levels of phosphorylated JAK2(p-JAK2)/JAK2 and phospho-STAT3(p-STAT3)/STAT3 were significantly increased(P<0.05, P<0.01), and the number of JAK2, p-JAK2, STAT3 and p-STAT3 cells increased(P<0.05, P<0.01). EM group(compared with CM group) and ES group(compared with SH group) exhibited significantly increased body weight(P<0.01), decreased arthritis scores(P<0.05, P<0.01), reduced swelling of ankle joint, and decreased number and volume of lymph nodes in the spleen. Furthermore, serum levels of IL-6, IL-1ß, and TNF-α decreased(P<0.05, P<0.01), the mRNA expression of JAK2 and STAT3 in spleen decreased(P<0.05, P<0.01), the protein levels of p-JAK2/JAK2 and p-STAT3/STAT3 decreased(P<0.05, P<0.01), and the number of JAK2, p-JAK2, STAT3 and p-STAT3 cells decreased(P<0.05, P<0.01), whereas the mRNA and protein expressions of α7nAChR were significantly increased(P<0.01). Compared with the VA group, there was no significant differences in weight gain and arthritis scores in the EV group. The number of lymph nodes in the spleen was not significantly reduced and the volume was still large, suggesting the inflammation was not significantly improved. The serum levels of IL-6, IL-1ß and TNF-α were not significantly different, and there were no significant differences in α7nAChR, JAK2, and STAT3 mRNA expression in the spleen. The protein expression levels of p-JAK2/JAK2 and α7nAChR in spleen were lower(P<0.05, P<0.01), while p-STAT3/STAT3 protein expression was not significantly different. Besides, the two groups had no significant difference in the number of JAK2, p-JAK2, STAT3, and p-STAT3 cells. The results suggested that unilateral vagotomy promoted the increase of phosphorylated JAK2 and STAT3 expressions and exacerbated inflammation. In contrast, Ermiao Powder alleviated the inflammation in rheumatoid arthritis rats by activating the α7nAChR-mediated JAK2/STAT3 pathway through the vagus nerve, suggesting that the α7nAchR-JAK2/STAT3 pathway may be a potential target for the treatment of rheumatoid arthritis.

Steady regime of radiation pressure acceleration with foil thickness adjustable within micrometers under a 10-100 PW laser.

Quasimonoenergetic GeV-scale protons are predicted to be efficiently generated via radiation pressure acceleration (RPA) when the foil thickness is matched with the laser intensity, e.g., L_{mat} of several nm to 100 nm for 10^{19}-10^{22}Wcm^{-2} available in laboratory. However, nonmonoenergetic protons with much lower energies than predicted were usually observed in RPA experiments because of too small foil thickness which cannot support insufficient laser contrast and foil surface roughness. Besides the technical problems, we here find that there is an upper-limit thickness L_{up} derived from the requirement that the laser energy should dominate over the ion source energy in the effective laser-proton interaction zone, and L_{up} is lower than L_{mat} with the intensity below 10^{22}Wcm^{-2}, which causes inefficient or unsteady RPA. As the intensity is enhanced to ≥10^{23}Wcm^{-2} provided by 10-100 PW laser facilities, L_{up} can significantly exceed L_{mat}, and therefore RPA becomes efficient. In this regime, L_{mat} acts as a lower-limit thickness for efficient RPA, so the matching thickness can be extended to a continuous range from L_{mat} to L_{up}; the range can reach micrometers, within which foil thickness is adjustable. This makes RPA steady and meanwhile the above technical problems can be overcome. Particle-in-cell simulation shows that multi-GeV quasimonoenergetic proton beams can be steadily generated and the fluctuation of the energy peaks and the energy conversation efficiency remains stable although the thickness is taken in a larger range with increasing intensity. This work predicts that near future RPA experiments with 10-100 PW facilities will enter a new regime with a large range of usable foil thicknesses that can be adjusted to the interaction conditions for steady acceleration.

[Microbial Mechanisms of Removal of Phthalic Acid Esters in Purple Soils Revealed Using Metagenomic Analysis].

The removal mechanisms of phthalic acid esters (PAEs) have attracted much attention because of their endocrine-disrupting properties and persistence in environmental media. In order to reveal the removal mechanism of PAEs and involved keystone taxa and functional genes, purple soils were polluted by di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP), respectively, along a gradient of 0, 5, 10, and 20 mg·kg-1 and cultured for 90 days in the dark. The results showed that the degradation dynamics of DBP and DEHP were well-fitted by the first-order kinetic model, and the half-life of DBP and DEHP ranged from 17.0 to 38.2 days. The degradation rate of DBP (5 mg·kg-1) was the fastest, and that of DEHP (20 mg·kg-1) was the slowest. The soil samples of the seventh day and the fifteenth day were analyzed using metagenomic sequencing. NMDS and cluster analysis showed that there was a significant difference between the bacterial community structure of soil samples from the seventh day and the fifteenth day. The relative abundance of Actinobacteria increased from the seventh day to the fifteenth day. The smaller the half-life of DBP or DEHP, the higher the relative abundance of Actinobacteria in the different treatments. In addition, Streptomyces was the dominant genus in all polluted soils. Co-occurrence network analysis elucidated that Pandoraea was a keystone genus of the soil bacterial communities, which could be used to indicate the pollution levels of DBP and DEHP. The results of KEGG annotation demonstrated that Pandoraea was responsible for benzoate degradation, quorum sensing, ABC transporters, and the two-component system and could promote the intercellular communications and the microbial growth and proliferation and maintain the stability of the community structure. Therefore, the degradation rate of DBP and DEHP in purple soils depended on their initial content and their own properties. Actinobacteria played an important role in the PAEs degradation, and Pandoraea played a major part in promoting PAEs degradation and regulating the stability of the structure and function of degrading bacterial communities.

Cytotoxic xanthanolide sesquiterpenes from the fruits of Xanthium italicum Moretti.

One previously undescribed xanthanolide sesquiterpene dimer pungiolide P (1), possessing an unprecedented scaffold with a 5/7/5/7/5 ring system skeleton and its intermediate pungiolide Q (2), ten xanthanolide sesquiterpenes (3-12), two eudesmene sesquiterpene derivatives (13-14), one phenylpropionic acid derivative (15), together with eleven known compounds (16-26) were obtained from the fruits of Xanthium italicum Moretti. A possible biosynthetic pathway for pungiolide P (1) was also proposed, which was supported by its bio-synthetic intermediate (2). Compounds 1, 4-5, 18-21, and 25 exhibited cytotoxic activity against a variety of human cancer cell lines. Furthermore, compounds 1, 4-5, could cause blockage of the cell cycle in the G2/M phase and induce apoptosis in H460 cells. Notably, pungiolide P (1) exhibited significantly superior cytotoxicity compared to previously reported compounds, providing valuable insights for natural anti-tumor sources.