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Astrophysical collisionless shocks are amazing phenomena in space and astrophysical plasmas, where supersonic flows generate electromagnetic fields through instabilities and particles can be accelerated to high energy cosmic rays. Until now, understanding these micro-processes is still a challenge despite rich astrophysical observation data have been obtained. Laboratory astrophysics, a new route to study the astrophysics, allows us to investigate them at similar extreme physical conditions in laboratory. Here we will review the recent progress of the collisionless shock experiments performed at SG-II laser facility in China. The evolution of the electrostatic shocks and Weibel-type/filamentation instabilities are observed. Inspired by the configurations of the counter-streaming plasma flows, we also carry out a novel plasma collider to generate energetic neutrons relevant to the astrophysical nuclear reactions.
We analyzed research themes in the field of disaster medicine in China to provide references for researchers to understand the research status and developing trends of this field.
Published journal articles were retrieved. A social network analysis was conducted to visualize the relations of high-frequency key words. A cluster analysis was used to classify key words. A strategic diagram analysis was conducted to visualize clusters across the entire research field.
We retrieved 3,079 articles, from which 1,749 articles and 8,284 key words were identified after screening. High-frequency key words were classified into 6 clusters. “Medical rescue” had the highest degree and betweenness centralities. Cluster 4 was located in Quadrant I of the strategic diagrams.
“Medical rescue” is the core key word, and it serves a pivotal “bridge” function. “Emergencies” and similar terms are key words with special statuses. “Natural disaster medical rescue” and “fundamental theories of disaster medicine” constitute the primary and secondary core themes, respectively. “On-site emergency treatment techniques” is a marginalized theme. The other themes are emerging themes that offer considerable scope for future development. Generally, the scope and depth of investigations in this field should be improved. (Disaster Med Public Health Preparedness. 2019;13:405-409)
As a promising new way to generate a controllable strong magnetic field, laser-driven magnetic coils have attracted interest in many research fields. In 2013, a kilotesla level magnetic field was achieved at the Gekko XII laser facility with a capacitor–coil target. A similar approach has been adopted in a number of laboratories, with a variety of targets of different shapes. The peak strength of the magnetic field varies from a few tesla to kilotesla, with different spatio-temporal ranges. The differences are determined by the target geometry and the parameters of the incident laser. Here we present a review of the results of recent experimental studies of laser-driven magnetic field generation, as well as a discussion of the diagnostic techniques required for such rapidly changing magnetic fields. As an extension of the magnetic field generation, some applications are discussed.
We present laboratory measurement and theoretical analysis of silicon K-shell lines in plasmas produced by Shenguang II laser facility, and discuss the application of line ratios to diagnose the electron density and temperature of laser plasmas. Two types of shots were carried out to interpret silicon plasma spectra under two conditions, and the spectra from 6.6 Å to 6.85 Å were measured. The radiative-collisional code based on the flexible atomic code (RCF) is used to identify the lines, and it also well simulates the experimental spectra. Satellite lines, which are populated by dielectron capture and large radiative decay rate, influence the spectrum profile significantly. Because of the blending of lines, the traditional
value are not applicable in diagnosing electron temperature and density of plasma. We take the contribution of satellite lines into the calculation of line ratios of He-
lines, and discuss their relations with the electron temperature and density.
Babesiosis is an emerging tick-transmitted zoonosis prevalent in large parts of the world. This study was designed to determine the rates of Babesia microti infection among small rodents in Yunnan province, where human cases of babesiosis have been reported. Currently, distribution of Babesia in its endemic regions is largely unknown. In this study, we cataloged 1672 small wild rodents, comprising 4 orders, from nine areas in western Yunnan province between 2009 and 2011. Babesia microti DNA was detected by polymerase chain reaction in 4·3% (72/1672) of the rodents analyzed. The most frequently infected rodent species included Apodemus chevrieri and Niviventer fulvescens. Rodents from forests and shrublands had significantly higher Babesia infection rates. Genetic comparisons revealed that Babesia was most similar to the Kobe- and Otsu-type strains identified in Japan. A variety of rodent species might be involved in the enzootic maintenance and transmission of B. microti, supporting the need for further serological investigations in humans.
Ordered mesoporous carbons (OMCs) are appealing alternatives to conventional porous activated carbon applied to electronic energy storage and conversion devices. Nitrogen-doped OMC (NOMC) was prepared with a soft-template strategy directly using task-specific ionic liquid with dicyanamide anion as the nitrogen dopant, and utilized as supercapacitors for the first time. Compared with pristine OMC, NOMC showed excellent electrochemical capacitive behavior in 6 M KOH electrolyte. NOMC possessed a high specific capacitance of 427 F/g at a current density of 1 A/g and exhibited a stable cycle life (almost 98% retained at a current density of 5 A/g after 2000 cycles). The outstanding capacitive performance of NOMC was ascribed to the synergetic effects of its bimodal mesoporous structure, large specific surface area (1919 m2/g), and nitrogen doping (3.52 wt%), which help to accelerate the ion diffusion, increase the surface charge storage, and intensify pseudo-capacitive reactions.
The effect of nitrogen gas addition in Ar-based double-layer shielding gas on the impact toughness of welded ultra-ferritic stainless steel during an autogenous gas tungsten arc welding (GTAW) process was investigated. The nitrogen behavior was proposed. The microstructure, mechanical properties, and fracture surface morphology of the weld metals have been evaluated. More equiaxed crystals, refined grain, narrow HAZ width, and increased microhardness were produced with nitrogen addition. Experimental findings indicated that nitrogen diffused into HAZ and dissolved into weld pool. The solute distribution was changed thus bringing significant constitutional supercooling and decreased temperature gradient of weld pool, which contributed to fine microstructure. Impact toughness at room temperature was enhanced from 2J to 9J (welds), 5J–13J (HAZ). Ductile fracture zone was produced about 0.3–0.5 mm thickness distance from the weld surface. A significant increased impact toughness of weld metal was due to the refinement of microstructure and element addition.
In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed. On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection (MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced.
miR-124, a brain-specific microRNA, was originally considered as a key regulator in neuronal differentiation and the development of the nervous system. Here we showed that miR-124 expression was suppressed in patients with epilepsy and rats after drug induced-seizures. Intrahippocampal administration of a miR-124 duplex led to alleviated seizure severity and prolonged onset latency in two rat models (pentylenetetrazole- and pilocarpine-induced seizures), while miR-124 inhibitor led to shortened onset latency in pilocarpine-induced seizure rat models. Moreover, the result of local field potentials (LFPs) records further demonstrated miR-124 may have anti-epilepsy function. Inhibition of neuronal firing by miR-124 was associated with the suppression of mEPSC, AMPAR- and NMDAR-mediated currents, which were accompanied by decreased surface expression of NMDAR. In addition, miR-124 injection resulted in decreased activity and expression of cAMP-response element-binding protein1 (CREB1). a key regulator in epileptogenesis. A dual-luciferase reporter assay was used to confirm that miR-124 targeted directly the 3′UTR of CREB1 gene and repressed the CREB1 expression in HEK293T cells. Immunoprecipitation studies confirmed that the CREB1 antibody effectively precipitated CREB1 and NMDAR1 but not GLUR1 from rat brain hippocampus. These results revealed a previously unknown function of miR-124 in neuronal excitability and provided a new insight into molecular mechanisms underlying epilepsy.
A defect in the intestinal barrier is one of the characteristics of Crohn's disease (CD). The tight junction (TJ) changes and death of epithelial cells caused by intestinal inflammation play an important role in the development of CD. DHA, a long-chain PUFA, has been shown to be helpful in treating inflammatory bowel disease in experimental models by inhibiting the NF-κB pathway. The present study aimed at investigating the specific effect of DHA on the intestinal barrier function in IL-10-deficient mice. IL-10-deficient mice (IL-10− / −) at 16 weeks of age with established colitis were treated with DHA (i.g. 35·5 mg/kg per d) for 2 weeks. The severity of their colitis, levels of pro-inflammatory cytokines, epithelial gene expression, the distributions of TJ proteins (occludin and zona occludens (ZO)-1), and epithelial apoptosis in the proximal colon were measured at the end of the experiment. DHA treatment attenuated the established colitis and was associated with reduced infiltration of inflammatory cells in the colonic mucosa, lower mean histological scores and decreased levels of pro-inflammatory cytokines (IL-17, TNF-α and interferon-γ). Moreover, enhanced barrier function was observed in the DHA-treated mice that resulted from attenuated colonic permeability, rescued expression and corrected distributions of occludin and ZO-1. The results of the present study indicate that DHA therapy may ameliorate experimental colitis in IL-10− / − mice by improving the intestinal epithelial barrier function.
Mesoporous Fe3O4 nanoparticles coated with ZnO nanocrystals were successfully synthesized by a simple solution method at low temperature. The transmission electron microscopy analysis indicates that the mesoporous Fe3O4 nanoparticles are monodispersed with a mean diameter of 160 nm and the thickness of ZnO layer is 15 nm approximately. The porosity of the products was further substantiated by the nitrogen (N2) sorption measurement. The N2 adsorption-desorption isotherm curve can be identified as type IV, which is a characteristic of mesopores. Electromagnetic (EM) wave absorption properties of the as-prepared Fe3O4@ZnO mesoporous spheres-wax composites were investigated at a room temperature in the frequency range of 0.5∼18 GHz. Interestingly, the Fe3O4@ZnO mesoporous spheres exhibit an enhanced EM wave absorption due to the mesoporous structure. The multiple absorbing mechanisms result from the interface polarization induced by the special core/shell and mesoporous structures as well as dipole polarization of both Fe3O4 and ZnO. The results demonstrate that the Fe3O4@ZnO mesoporous spheres are attractive candidates for a new kind of EM wave absorption materials with wide absorption frequency band.
A study of 7,388 consecutive patients after hepatic resection between 2011 and 2012 identified hepatolithiasis, cirrhosis, and intraoperative blood transfusion as the only independent risk factors of both incisional and organ/space surgical site infection (SSI). Patients with these conditions should be cared for with caution to lower SSI rates.
Approximately 50 % of patients with inflammatory bowel disease (IBD) suffer from anaemia, with Fe deficiency being the most common cause. CD52 monoclonal antibody (mAb) targets the cell surface CD52 and is effective in depleting lymphocytes through cytolytic effects in vivo. The aim of the present study was to investigate the therapeutic effect of anti-mouse CD52 mAb on Fe-deficient anaemia in IBD. IL-10 knockout mice (IL-10− / −) of 12 weeks with established colitis were treated with anti-mouse CD52 mAb once per week for 2 weeks. Severity of colitis, blood T lymphocytes, blood Hb, haematocrit, plasma erythropoietin (EPO), serum Fe concentration, transferrin saturation, splenic Fe stores, expression of liver hepcidin mRNA, Western blotting of the phosphorylated form of Smad1/5/8 and total Smad1 were measured at the end of the experiment. IL-10− / − mice treated with CD52 mAb showed a reduction in the percentage of CD4+ and CD4+CD45+ T cells in blood and weight loss typically associated with colonic inflammation, serum levels of EPO, the expression of liver hepcidin mRNA and total Smad1 protein, while they showed an increase in Hb concentrations, haematocrit, levels of serum Fe, transferrin saturation and splenic Fe stores. The present results indicated that anti-CD52 therapy may ameliorate Fe-deficient anaemia by reducing colonic inflammation. These findings may open novel horizons in the treatment of patients with IBD by resetting of immunological homeostasis in the gut by depleting the activated T cells in the gut mucosa.
It is found that there is an upper-limit critical power for self-guided propagation of intense lasers in plasma in addition to the well-known lower-limit critical power set by the relativistic effect. Above this upper-limit critical power, the laser pulse experiences defocusing due to expulsion of local plasma electrons by the transverse ponderomotive force. Associated with the upper-limit power, a lower-limit critical plasma density is also found for a given laser spot size, below which self-focusing does not occur for any laser power. Both the upper-limit power and the lower-limit density are derived theoretically and verified by two-dimensional particle-in-cell simulations. The present study provides new guidance for experimental designs, where self-guided propagation of lasers is essential.
The protective effects of fruits and vegetables against CHD have been suggested by many epidemiological studies among Western populations. However, prospective data are lacking for Asian populations. In the present study, we examined the associations of fruit and vegetable intake with CHD incidence among 67 211 women (aged 40–70 years) and 55 474 men (aged 40–74 years) living in Shanghai, China. Food intake was assessed using validated FFQ through in-person interviews. Coronary events (non-fatal myocardial infarction or fatal CHD) were identified by biennial home visits and further confirmed by medical record review. During a mean follow-up period of 9·8 and 5·4 years, 148 events in women and 217 events in men were documented and verified. After adjustment for potential confounders, women in the highest quartile of total fruit and vegetable intake (median 814 g/d) had a hazard ratio (HR) of 0·62 (95 % CI 0·38, 1·02) for CHD (P for trend = 0·04) compared with those in the lowest quartile (median 274 g/d). This association was primarily driven by fruits (HR for the highest v. the lowest intake in women: 0·62, 95 % CI 0·37, 1·03). The strength of the association was attenuated after further controlling for history of diabetes or hypertension. For men, no significant association was found for fruit and vegetable intake when analysed either in combination or individually. The present findings suggest that a high consumption of fruits may reduce CHD risk in Chinese women.
Neurosyphilis (NS) may present with neuropsychiatric disorders characterized by cognitive impairment, personality disorders, and confusion, among others. Very few studies have focused on neuropsychiatric disorders secondary to NS in elderly people.
A retrospective chart review was performed to characterize the psychiatric findings, clinical signs and symptoms, laboratory findings, and brain magnetic resonance imaging results of ten elderly inpatients with NS.
In these ten patients, the most common presenting symptoms included a wide variety of psychiatric manifestations. The serum rapid plasma regain (RPR) and Treponema pallidum particle agglutination assay (TPPA) of the ten patients were positive, with positive CSF TPPA and RPR rates of 100% and 60%, respectively. In addition, 90% of the patients demonstrated abnormal imaging, including cerebral atrophy, infarct ischemic stroke, and hydrocephalus.
Our findings support the importance of serological tests for syphilis as a routine component of the evaluation of patients with clinically evident neurological or psychiatric symptoms. If the serology is positive, all of the patients should be examined with a lumbar puncture. Moreover, psychiatric illnesses secondary to NS in the elderly also deserve medical attention.
The driving mechanism of solar flares and coronal mass ejections is a topic of ongoing debate, apart from the consensus that magnetic reconnection plays a key role during the impulsive process. While present solar research mostly depends on observations and theoretical models, laboratory experiments based on high-energy density facilities provide the third method for quantitatively comparing astrophysical observations and models with data achieved in experimental settings. In this article, we show laboratory modeling of solar flares and coronal mass ejections by constructing the magnetic reconnection system with two mutually approaching laser-produced plasmas circumfused of self-generated megagauss magnetic fields. Due to the Euler similarity between the laboratory and solar plasma systems, the present experiments demonstrate the morphological reproduction of flares and coronal mass ejections in solar observations in a scaled sense, and confirm the theory and model predictions about the current-sheet-born anomalous plasmoid as the initial stage of coronal mass ejections, and the behavior of moving-away plasmoid stretching the primary reconnected field lines into a secondary current sheet conjoined with two bright ridges identified as solar flares.
This study was conducted to investigate the pattern of DNA methylation in vitrified–thawed mouse oocytes and their in vitro fertilized early embryos. Firstly, mouse oocytes at metaphase II (MII) stage of meiosis were allocated randomly into three groups: (1) untreated (control); (2) exposed to vitrification solution without being plunged into liquid nitrogen (toxicity); or (3) vitrified by open-pulled straw (OPS) method (vitrification). Oocytes from all three groups were fertilized subsequently in vitro. The level of DNA methylation in the MII oocytes and their early embryos was then examined by immunofluorescence using an anti-5-methylcytosine (anti-5-MeC) monoclonal antibody and fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG. Developmental rates to 2-cell embryos (62.28%) and blastocysts (43.68%) of the vitrified–thawed oocytes were lower (P < 0.01) than those of fresh oocytes (81.47%, 61.99%) and vitrification solution treated (79.20%, 60.04%) oocytes. DNA methylation (as reflected by 5-MeC fluorescence intensity) in the vitrification group was less (P < 0.01) for MII oocyte and 2- to 8-cell stages compared with that in the control and toxicity groups. Accordingly, a reduction in global genomic methylation due to vitrification of MII oocytes may result in compromised in vitro developmental potential in early mouse embryos.
Energetic electron beam generation from a thin foil target by the ponderomotive force of an ultra-intense circularly polarized laser pulse is investigated. Two-dimensional particle-in-cell (PIC) simulations show that laser pulses with intensity of 1022–1023 Wcm−2 generate about 1–10 GeV electron beams, in agreement with the prediction of one-dimensional theory. When the laser intensity is at 1024–1025 Wcm−2, the beam energy obtained from PIC simulations is lower than the values predicted by the theory. The radiation damping effect is considered, which is found to become important for the laser intensity higher than 1025 Wcm−2. The effect of laser focus positions is also discussed.