Branching of High-Current Relativistic Electron Beam in Porous Materials.

Propagation of high-current relativistic electron beam (REB) in plasma is relevant to many high-energy astrophysical phenomena as well as applications based on high-intensity lasers and charged-particle beams. Here, we report a new regime of beam-plasma interaction arising from REB propagation in medium with fine structures. In this regime, the REB cascades into thin branches with local density a hundred times the initial value and deposits its energy 2 orders of magnitude more efficiently than that in homogeneous plasma, where REB branching does not occur, of similar average density. Such beam branching can be attributed to successive weak scatterings of the beam electrons by the unevenly distributed magnetic fields induced by the local return currents in the skeletons of the porous medium. Results from a model for the excitation conditions and location of the first branching point with respect to the medium and beam parameters agree well with that from pore-resolved particle-in-cell simulations.

Coherent Subcycle Optical Shock from a Superluminal Plasma Wake.

We propose exploiting the superluminal plasma wake for coherent Cherenkov radiation by injecting a relativistic electron beam (REB) into a plasma with a slowly varying density up-ramp. Using three-dimensional particle-in-cell and far-field time-domain radiation simulations, we show that an isolated subcycle pulse is coherently emitted towards the Cherenkov angle by bubble-sheath electrons successively at the rear of the REB-induced superluminal plasma wake. A theoretical model based on a superluminal current dipole has been developed to interpret such coherent radiation, and agrees well with the simulation results. This radiation has ultrashort attosecond-scale duration and high intensity, and exhibits excellent directionality with ultralow angular divergence and stable carrier envelope phase. Its intensity increases with the square of the propagation length and its central frequency can be easily tuned over a wide range, from the far infrared to the ultraviolet.

[Impact of COVID-19 on primary percutaneous coronary intervention in patients with acute ST segment elevation myocardial infarction in Beijing].

Objective: To investigate the impact of COVID-19 on treatment of patients with acute ST segment elevation myocardial infarction(STEMI) undergoing primary percutaneous coronary intervention(PPCI). Methods: This was a multicenter retrospective study. STEMI patients undergoing PPCI from January 1, 2019 to December 31, 2021 were selected, based on the data of Xinnaolvsetongdao App. Clinical data and treatment time indicators, including symptom to first medical contact (S-FMC), symptom to door (StoD), first medical contact to ECG (FMC-ECG), first medical contact to guide wire (FMC-W), door to balloon (DtoB) and total ischemic time in 2019, 2020 and 2021 were compared. STEMI patients aged<60 years were sub-grouped as the young and middle-aged group, and STEMI patients aged≥60 years were sub-grouped as the elderly group. Results: A total of 7 435 (3 305 in 2019, 1 796 in 2020 and 2 334 in 2021) STEMI patients aged (59.6±12.6) years undergoing PPCI were included in this analysis. There were 5 990 males. For STEMI patients with PPCI in 2019, 2020 and 2021, FMC-ECG was 3 (1, 5) min, 3(1, 7) min and 4 (1, 7) min. FMC-W was 73 (56, 87) min, 78 (62, 95) min and 77 (62, 87) min. DtoB was 73 (56, 85) min, 78 (62, 95) min and 77 (62, 86) min. Total ischemic time was 189 (130, 273) min, 196 (138, 295) min and 209 (143, 276) min. FMC-ECG, FMC-W, DtoB and total ischemic time were longer in 2020 and 2021 than in 2019 (all P<0.05). The proportions of patients with FMC-ECG≤10 min (88.4% (1 588/1 796) vs. 92.7% (3 064/3 305), P<0.05), FMC-W≤120 min (87.9% (1 579/1796) vs. 91.7% (3 030/3 305), P<0.05) and DtoB≤90 min (72.3% (1 298/1 796) vs. 80.8% (2 672/3 305), P<0.05) were lower in 2020 than in 2019, whereas no differences were observed in the proportions of patients with FMC-ECG≤10 min (91.3% (2 131/2 334) vs. 92.7% (3 064/3 305), P=0.054), FMC-W≤120 min (92.0% (2 148/2 334) vs. 91.7% (3 030/3 305), P=0.635) and DtoB≤90 min (80.0% (1 867/2 334) vs. 80.8% (2 672/3 305), P=0.424) in 2021 compared with 2019. In the subgroup analysis, the proportions of patients with FMC-ECG≤10 min, FMC-W≤120 min and DtoB≤90 min were lower in the elderly group than in young and middle-aged group in 2019 (all P<0.05). The proportions of patients with FMC-W≤120 min and DtoB≤90 min were lower in the elderly group than in young and middle-aged group in 2021(all P<0.05). No differences were observed in the proportions of patients with FMC-ECG≤10 min, FMC-W≤120 min and DtoB≤90 min between the two group in 2020 (all P>0.05). Conclusions: Affected by the COVID-19, there is a reduction in the number of PPCI cases and treatment delays in STEMI patients, especially in the elderly. After adjusting the treatment strategy and widely applying the Xinnaolvsetongdao APP, the above indicators are significantly improved in 2021 as compared with 2020.

[Phenotypic and genomic characterization for Salmonella isolates recovered from meat products in Beijing wholesale markets, 2014-2015].

Objective: To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods: A total of 336 Salmonella strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results: The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, ß-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates. Conclusion: Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.

Nanoscale Electrostatic Modulation of Mega-Ampere Electron Current in Solid-Density Plasmas.

Transport of high-current relativistic electron beams in dense plasmas is of interest in many areas of research. However, so far the mechanism of such beam-plasma interaction is still not well understood due to the appearance of small time- and space-scale effects. Here we identify a new regime of electron beam transport in solid-density plasma, where kinetic effects that develop on small time and space scales play a dominant role. Our three-dimensional particle-in-cell simulations show that in this regime the electron beam can evolve into layered short microelectron bunches when collisions are relatively weak. The phenomenon is attributed to a secondary instability, on the space- and timescales of the electron skin depth (tens of nanometers) and few femtoseconds of strong electrostatic modulation of the microelectron current filaments formed by Weibel-like instability of the original electron beam. Analytical analysis on the amplitude, scale length, and excitation condition of the self-generated electrostatic fields is clearly validated by the simulations.

[The safety and efficacy of Firesorb bioresorbable scaffold in first-in-man study for coronary artery disease: the four-year outcomes].

Objective: To evaluate the 4-year clinical outcomes of patients following Firesorb bioresorbable scaffold (BRS) implantation. Methods: The study reported the 4-year follow-up results of the FUTURE I study. FUTURE I was a prospective, single-center, open-label, first-in-man study which evaluated the feasibility, preliminary safety, and efficacy of Firesorb stent in the treatment of coronary artery stenosis. A total of 45 patients with single de novo lesions in native coronary arteries ,who hospitalized in Fuwai Hospital from January to March 2016 were enrolled. After successfully stent implantation these patients were randomized in a 2∶1 ratio into cohort 1 (n=30) or cohort 2 (n=15). The patients in cohort 1 underwent angiographic, IVUS or OCT examination at 6 months and 2 years; and cohort 2 underwent angiographic, IVUS or OCT at 1 and 3 years. All patients underwent clinical follow-up at 1, 6 months and 1 year and annually thereafter up to 5 years. The primary endpoint was target lesion failure (TLF, including cardiac death, target vessel myocardial infarction, and ischemia-driven target lesion revascularization). Secondary endpoints included patient-oriented composite endpoint (PoCE, defined as composite of all death, all miocardial infarction, or any revascularization). Results: A total of 45 patients were enrolled and implanted with Firesorb BRS, including 35 males (77.8%), and the age was (54.4±9.3) years. At 4 years, 10 patients in cohort 1 were reexamined by coronary angiography and OCT examination. Among them, 2 patients' stents were completely degraded and absorbed. Compared with the OCT images of the other 8 patients in cohort 2 at 3 years, the degree of stent degradation was increased, and no stent adherence was found. The 4-year clinical follow-up rate was 100%. In 4-year clinical following up, 2 patients suffered PoCE (4.4%): 1 patient underwent non-target vessel revascularization the day after index procedure and target vessel revascularization (Non-target lesion revascularization) at 2-year imaging follow-up; the other patient underwent target lesion revascularization during imaging follow-up at 4 years but not due to ischemic driven. There was no scaffold thrombosis or TLF events through 4 years. Conclusions: Four years after the implantation, complete degradation and absorption of the Firsorb stent are evidenced in some patients. Firesorb stent is feasible and effective in the treatment of patients with non-complex coronary lesions.

[The progress of research on the immune pathogenesis and biomarkers in optic neuritis related to neuromyelitis optica].

The idiopathic optic neuritis (ION) which is related to neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD) is called optic neuritis related to neuromyelitis optica (NMO-ON). Because of the high rates of blindness, disability and fatality of NMO, the heterogeneous clinical presentation, severity of neurologic disability following relapses, and variability of therapeutic responses, reliable and sensitive biomarkers for onset, relapse, and progression in NMO are urgently needed. Currently, detecting aquaporin-4 (AQP4) antibodies (AQP4-IgG or NMO-IgG) in serum is employed as the major supporting approach for the diagnosis of seropositive NMO, however, AQP4-IgG seronegativity in 10% to 25% of NMO patients suggests that there are several other factors involved in NMO immunopathogenesis. Collaborative international studies hold great promise for establishing and validating biomarkers of NMO. This article discusses known and potential biomarkers for NMO. The biomarkers of NMO maybe the potential biomarkers of NMO-ON, for ION is the initial presentation and the earliest stage. (Chin J Ophthalmol, 2019, 55:228-233).

Quadrichromatic LED based mobile phone camera visible light communication.

A quadrichromatic light-emitting diode (QLED) based visible light communication for mobile phone camera is proposed to improve data rate and enhance illumination effect at the same time. Different from color intensity modulation (CIM), we propose and use color ratio modulation (CRM) in CMOS image sensor based visible light communication to improve data rate. According to the spectral power distribution (SPD) of the QLED and the spectral response of the complementary-metal-oxide-semiconductor (CMOS) image sensor, color multiple-input multiple-output (CMIMO) channel model is set up first to obtain optimal 16-CRM constellation design. Taking full consideration of the high quality of color rendering index (CRI), tunable color temperature (CT), we design a specific data packet structure to realize illumination requirements. A decoding strategy is also addressed for demapping at the receiver. The experimental results demonstrate that the proposed scheme can realize a downlink data rate of 13.2kbit/s, meanwhile, the optical signal source is illumination compatible.

Digital expression analysis of the genes associated with salinity resistance after overexpression of a stress-responsive small GTP-binding RabG protein in peanut.

The Rab protein family is the largest family of the small GTP-binding proteins. Among them, the RabG genes are known to be responsive to abiotic stresses, but the molecular mechanisms of the stress responses mediated by RabG genes in plants is poorly understood. To investigate the molecular mechanism of AhRabG gene in peanut, transgenic plants overexpressing the AhRabG gene (S6) with relatively higher salinity resistance than the non-transgenic plants (S7) were obtained. Digital gene expression (DGE) sequencing was performed with the leaves of S6 and S7 plants before and after salinity-stress treatment. The AhRabG gene in peanut was found to be involved in a few pathways such as "photosynthesis", "oxidative phosphorylation", "AMPK signaling pathway", "plant hormone signal transduction", etc. A total of 298 differentially expressed genes (DEGs) were found to be upregulated or downregulated at five sampling time points based on the comparison between S6 and S7 plants. Among them, 132 DEGs were responsive to salinity stress in S6 and/or S7 after salinity-stress treatment. These 132 DEGs included genes encoding various transcription factors and proteins involved in resistance to salinity stress such as MYB, AP2, RING-H2 zinc finger proteins, late embryogenesis abundant (LEA) proteins, dehydration-responsive protein RD22, peroxidases, CBL-interacting protein kinases, calcium-binding proteins, and others. The information from this study will be useful for further studies on elucidating the mechanism of salinity resistance conferred by RabG genein peanut.

Intense circularly polarized attosecond pulse generation from relativistic laser plasmas using few-cycle laser pulses.

We have investigated the polarization of attosecond light pulses generated from relativistic few-cycle laser pulse interaction with the surface of overdense plasmas using particle-in-cell simulation. Under suitable conditions, a desired polarization state of the generated attosecond pulse can be achieved by controlling the polarization of the incident laser. In particular, an elliptically polarized laser pulse of suitable ellipticity can generate an almost circularly polarized attosecond pulse without compromising the harmonic generation efficiency. The process is thus applicable as a new tabletop circularly-polarized XUV radiation source for probing attosecond phenomena with high temporal resolution.

Cloning and functional analysis of the chitinase gene promoter in peanut.

Chitinase is an important pathogenesis-related protein in plants, and it can accumulate when induced by salicylic acid (SA) or other elicitors. Here, we found that chitinase mRNA levels were 4.5-times greater when peanut seedlings were sprayed with 1.5 mM SA, as compared to water. The upstream promoter sequence of the chitinase gene was cloned by TAIL-PCR and the potential cis-regulatory elements in this promoter were predicted by the cis-element databases PLACE and plantCARE. Elements in the promoter related to SA induction and disease resistance response included AS-1, GT1-motif, GRWAAW, TGTCA, W-box, and WB-box. The full-length promoter (P) and a series of 5'-deleted promoters (P1-P5) were cloned and then substituted for the 35S promoter of pCAMBIA1301-xylA, which carries the xylose isomerase gene as the selectable marker and GUS as the reporter gene. Six plant expression vectors (pCAMBIA1301-xylA-P-pCAMBIA1301-xylA-P5) were obtained. The six expression vectors were then transferred into onion epidermal cells and peanut plants by Agrobacterium-mediated transformation. Both the full-length and deleted promoters resulted in GUS staining of the onion epidermis cells when induced by SA. In onion epidermis cells, GUS enzyme activity was greater after SA induction. In transgenic peanut plants, GUS mRNA levels were greater after SA induction. Consideration of the cis-regulatory elements predicted by PLACE and plantCARE suggested that AS-1, GRWAAW, and W-box are positive regulatory elements in P2 and P3 and that GT1-motif and TGTCA are negative regulatory elements between P and P2.

Association between the TRAIL single nucleotide polymorphism rs1131580 and type 2 diabetes mellitus in a Han Chinese population.

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is expressed in different tissues and cells, including the pancreas and lymphocytes, and it can selectively induce apoptosis in tumor cells but not in most normal cells. TRAIL plays critical roles in type 1 diabetes mellitus, and is involved in type 2 diabetes mellitus (T2DM). We recently discovered the association of nonalcoholic fatty liver disease, a risk factor for T2DM, with a single nucleotide polymorphism (SNP) in the TRAIL (TNFSF10) gene at site 1595C/T (rs1131580), indicating the possible association of T2DM with this TRAIL polymorphism. The aim of this study was to investigate the relationship of the TRAIL SNP at site 1595C/T (rs1131580) with T2DM susceptibility and the biometabolic parameters of T2DM in a Han Chinese population. The polymerase chain reaction-restriction fragment length polymorphism method was used to genotype SNP rs1131580 in 292 patients with T2DM and 266 healthy controls. We found that the frequency of the CC genotype and that of the C allele of rs1131580 were significantly higher in T2DM patients than in the control group. Additionally, the triglyceride and serum creatinine levels of T2DM patients with the CC genotype were significantly higher than those of patients with the TT genotype. Thus, the CC genotype of the TRAIL SNP at 1595C/T (rs1131580) confers increased susceptible to T2DM in a Han Chinese population from Shandong Province. These data suggest that the CC genotype at this SNP is related to diabetic severity and it might be a candidate for the prognostic assessment of T2DM.

Experimental confirmation of driving pressure boosting and smoothing for hybrid-drive inertial fusion at the 100-kJ laser facility.

In laser-driven inertial confinement fusion, driving pressure boosting and smoothing are major challenges. A proposed hybrid-drive (HD) scheme can offer such ideal HD pressure performing stable implosion and nonstagnation ignition. Here we report that in the hemispherical and planar ablator targets installed in the semicylindrical hohlraum scaled down from the spherical hohlraum of the designed ignition target, under indirect-drive (ID) laser energies of ~43-50 kJ, the peak radiation temperature of 200 ± 6 eV is achieved. And using only direct-drive (DD) laser energies of 3.6-4.0 kJ at an intensity of 1.8 × 1015 W/cm2, in the hemispherical and planar targets the boosted HD pressures reach 3.8-4.0 and 3.5-3.6 times the radiation ablation pressure respectively. In all the above experiments, significant HD pressure smoothing and the important phenomenon of how a symmetric strong HD shock suppresses the asymmetric ID shock pre-compressed fuel are demonstrated. The backscattering and hot-electron energy fractions both of which are about one-third of that in the DD scheme are also measured.

Dysregulation of microRNA-204 mediates migration and invasion of endometrial cancer by regulating FOXC1.

MicroRNAs (miRNAs) regulate mRNA stability and protein expression, and certain miRNAs have been demonstrated to act either as oncogenes or tumor suppressors. Differential miRNA expression signatures have been documented in many human cancers but the role of miRNAs in endometrioid endometrial cancer (EEC) remains poorly understood. This study identifies significantly dysregulated miRNAs of EEC cells, and characterizes their impact on the malignant phenotype. We studied the expression of 365 human miRNAs using Taqman low density arrays in EECs and normal endometriums. Candidate differentially expressed miRNAs were validated by quantitative real-time PCR. Expression of highly dysregulated miRNAs was examined in vitro through the effect of anti-/pre-miRNA transfection on the malignant phenotype. We identified 16 significantly dysregulated miRNAs in EEC and 7 of these are novel findings with respect to EEC. Antagonizing the function of miR-7, miR-194 and miR-449b, or overexpressing miR-204, repressed migration, invasion and extracellular matrix-adhesion in HEC1A endometrial cancer cells. FOXC1 was determined as a target gene of miR-204, and two binding sites in the 3'-untranslated region were validated by dual luciferase reporter assay. FOXC1 expression was inversely related to miR-204 expression in EEC. Functional analysis revealed the involvement of FOXC1 in migration and invasion of HEC1A cells. Our results present dysfunctional miRNAs in endometrial cancer and identify a crucial role for miR-204-FOXC1 interaction in endometrial cancer progression. This miRNA signature offers a potential biomarker for predicting EEC outcomes, and targeting of these cancer progression- and metastasis-related miRNAs offers a novel potential therapeutic strategy for the disease.

Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction.

Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson et al. [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fanlike electron outflow region including three well-collimated electron jets appears. The (>1 MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS.

Tunable radiation source by coupling laser-plasma-generated electrons to a periodic structure.

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV/m field strength can be achieved by using appropriate grating parameters.

CHD5 Downregulation Associated with Poor Prognosis in Epithelial Ovarian Cancer.

BACKGROUND: The CHD5 gene located on 1p36 encodes a protein-chromodomain helicase DNA-binding protein 5. CHD5 has been shown to be a tumor suppressor gene candidate. This study investigated the involvement of CHD5 in ovarian cancer and its clinicopathological significance. METHODS: CHD5 expression in ovarian cancer and its counterpart were determined by quantitative RT-PCR. The correlation of CHD5 expression to clinicopathological features of the tumor was analyzed. RESULTS: CHD5 expression was downregulated by at least twofold in 32 of 72 (41%) invasive epithelial ovarian carcinomas when compared to 12 controls in Hong Kong Chinese women. CHD5 downregulation was correlated to clinical status (p < 0.05), but not to patient age, tumor type and grade, recurrence and clinical stage (p > 0.05). Survival analysis showed that patients with CHD5 downregulation in their tumors were associated with shorter disease-free and total survival times compared to those without CHD5 downregulation (p < 0.05). Cox proportional-hazards regression analysis indicated that downregulation of CHD5 is an independent adverse prognostic factor in ovarian cancer. CONCLUSION: This study shows that CHD5 is downregulated in a certain number of ovarian cancers and appears to be an adverse predictor candidate of ovarian cancer disease-free and total survival.

Quasimonoenergetic proton bunch generation by dual-peaked electrostatic-field acceleration in foils irradiated by an intense linearly polarized laser.

It is found that stable proton acceleration from a thin foil irradiated by a linearly polarized ultraintense laser can be realized for appropriate foil thickness and laser intensity. A dual-peaked electrostatic field, originating from the oscillating and nonoscillating components of the laser ponderomotive force, is formed around the foil surfaces. This field combines radiation-pressure acceleration and target normal sheath acceleration to produce a single quasimonoenergetic ion bunch. A criterion for this mechanism to be operative is obtained and verified by two-dimensional particle-in-cell simulation. At a laser intensity of ∼5.5×10(22) W/cm(2), quasimonoenergetic GeV proton bunches are obtained with ∼100 MeV energy spread, less than 4° spatial divergence, and ∼50% energy conversion efficiency from the laser.

Generating quasi-single-cycle relativistic laser pulses by laser-foil interaction.

A scheme for producing nearly single-cycle relativistic laser pulses is proposed. When a laser pulse interacts with an overdense thin foil, because of self-consistent nonlinear modulation, the latter will be more transparent to the more intense part of the laser, so that a transmitted pulse can be much shorter than the incident pulse. Using two-dimensional particle-in-cell simulation and analytical modeling, it is found that a transmitted pulse of duration 4 fs and peak intensity 3 x 10{20} W/cm{2} can be generated from a circularly polarized laser pulse. The intensity of the resulting pulse is only limited by that of the incident pulse, since this scheme involves only laser-plasma interaction.

Laser-driven inertial ion focusing.

A Hohlraum-like configuration is proposed for realizing a simple compact source for neutrons. A laser pulse enters a tiny thin-shelled hollow-sphere target through a small opening and is self-consistently trapped in the cavity. The electrons in the inner shell-wall region are expelled by the light pressure. The resulting space-charge field compresses the local ions into a thin layer that becomes strongly heated. An inward expansion of ions into the shell cavity then occurs, resulting in the formation at the cavity center of a hot spot of ions at high density and temperature, similar to that in inertial electrostatic confinement.