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We present measurements of the 2p-3d transition opacity of a hot molybdenum–scandium sample with nearly half-vacant molybdenum M-shell configurations. A plastic-tamped molybdenum–scandium foil sample is radiatively heated to high temperature in a compact D-shaped gold Hohlraum driven by ∼30 kJ laser energy at the SG-100 kJ laser facility. X rays transmitted through the molybdenum and scandium plasmas are diffracted by crystals and finally recorded by image plates. The electron temperatures in the sample in particular spatial and temporal zones are determined by the K-shell absorption of the scandium plasma. A combination of the IRAD3D view factor code and the MULTI hydrodynamic code is used to simulate the spatial distribution and temporal behavior of the sample temperature and density. The inferred temperature in the molybdenum plasma reaches a average of 138 ± 11 eV. A detailed configuration-accounting calculation of the n = 2–3 transition absorption of the molybdenum plasma is compared with experimental measurements and quite good agreement is found. The present measurements provide an opportunity to test opacity models for complicated M-shell configurations.

A self-consistent and precise method to determine the time-dependent radiative albedo, i.e., the ratio of the reemission flux to the incident flux, for an indirect-drive inertial confinement fusion Hohlraum wall material is proposed. A specially designed symmetrical triple-cavity gold Hohlraum is used to create approximately constant and near-equilibrium uniform radiation with a peak temperature of 160 eV. The incident flux at the secondary cavity waist is obtained from flux balance analysis and from the shock velocity of a standard sample. The results agree well owing to the symmetrical radiation in the secondary cavity. A self-consistent and precise time-dependent radiative albedo is deduced from the reliable reemission flux and the incident flux, and the result from the shock velocity is found to have a smaller uncertainty than that from the multi-angle flux balance analysis, and also to agree well with the result of a simulation using the HYADES opacity.

Experiments and simulations have been carried out to study the colliding process by two lasers irradiating a gold half-hohlraum. Via analyzing the evolutionary x-ray images, radiation fluxes and self-emission spectrum of tracers, influence on the x-ray conversion efficiency and the local plasma temperature $T_{e,i}$ from two gold-plasma plumes have been investigated deeply, which is similar as the configuration in Inertial Confinement Fusion (ICF). Experimental results confirm a region with high electron and ion temperatures $T_{e,i}$ are induced, satisfying the strong collision condition of $\lambda_{i} \lt \Delta{L}$ , where λ _i and $\Delta{L}$ are respectively the ion mean-free path and the gradient length of T _e . It leads to almost $30\%$ increasing of M-band component compared to that from a single laser-irradiation case. Meanwhile ion temperature in this region increases more rapidly than electrons, reaching about $T_i\approx(16\pm4)$ keV ( $T_e\approx(2\pm 0.2)$ keV). Thus, our studies provide the experimental evidence of quantitative x-ray enhancement and a non-equilibrium evolution simultaneously due to the plasma collision for the first time. Besides, two-dimensional simulation results reveal that this process can not be precisely described by the traditional shock-heating model by dissipating the shock energy only to ions. But by distributing the viscous heating between both electrons and ions as theoretically discussed by Miller (2020 Comput. Fluids 210 104672), numerical results can match experiments better. This discovery will be of great importance to improve the precision of prediction for ICF.

ObjectiveTo investigate the effect of physical exercise on sleep quality and the mediating effect of smartphone use behavior in college students.MethodsA cross-sectional study design was adopted. An online survey of 5,075 college students was conducted using the Physical Activity Rating Scale-3, the Pittsburgh Sleep Quality Index, and the Mobile Phone Addiction Tendency Scale.ResultsThe sleep quality of college students was poor, and the proportion of college students with good sleep quality was 23.567%. A significant correlation existed between sleep quality and physical exercise (r = -0.159, P < 0.001) and mobile phone addiction (r = 0.355, P < 0.001). Physical exercise can predict sleep quality in college students (β = -0.011, P < 0.001). Smartphone use plays a part in mediating the process by which physical exercise affects sleep quality.ConclusionChinese college students have poor sleep quality. Physical exercise and smartphone use behavior are important factors affecting the sleep quality of college students. Physical exercise can directly predict the sleep quality of college students and can predict the sleep quality of college students through the mediating effect of smartphone use behavior.

A practical experimental method is proposed to investigate thermal transport by characterizing the motion of plasma flows through a x-ray spectroscopic technique using tracers. By simultaneously measuring multiple parameters, namely, the mass-ablation rate, the temporal evolution of plasma flow velocities and trajectories and the temperature, it is possible to observe a variety of physical processes, such as shock wave compression, heating by thermal waves, and plasma thermal expansion, and to determine their relative importance in different phases during the irradiation of CH and Au targets. From a comparison with hydrodynamic simulations, we find significant differences in the motion of the plasma flows between CH and Au, which can be attributed to different sensitivities to the thermal transport process. There are also differences in the ablation and electron temperature histories of the two materials. These results confirm that velocities and trajectories of plasma motion can provide useful evidence in the investigation of thermal conduction, and the approach presented here deserves more attention in the context of inertial confinement fusion and high-energy-density physics.

To investigate the influence of inorganic salt on the photocatalytic degradation, the effects of KBr and KI at various concentrations and pH values on the photocatalytic degradation of dye W-7G using nanoscaled titanium dioxide as photocatalyst in a bubbling fluidized bed photocatalytic reactor (BFBPR) were studied. The results indicated that the degradation apparent rate constant (Kapp) of the system with KI was clearly higher than that with KBr under acidic or alkaline conditions. And the maximum value of Kapp (0.01127) appeared at the KI concentration of 0.075 g L-1 with a pH value of 9.37, meaning the highest degradation efficiency. Furthermore, the possible mechanism of photocatalytic degradation of W-7G in the presence of KBr and KI was proposed, which could provide a theoretical support for the further study of inorganic salt effects on the photocatalytic degradation of dyes.

In order to determine the concentration of melamine, nitrogen-doped carbon dots (NCDs) were synthesized in one step as a fluorescent probe. Uric acid and diethylenetriamine were used as carbon source and nitrogen source, respectively. The experimental results showed that the fluorescence of NCDs can be quenched by mercury ions (Hg2+). Due to the strong coordination affinity between the carbon-nitrogen heterocyclic of melamine and Hg2+, part of Hg2+ coordinated with melamine when melamine was mixed with Hg2+. Then, the fluorescence of the added NCDs was quenched by the remaining Hg2+. Therefore, the concentration of melamine could be determined. The results show that the method has high sensitivity in wide measuring range that the linear ranges are 50–400 μg/L and 800–2500 μg/L, and the R2 is 0.997 and 0.988, respectively, with the limit of detection (LOD) of 21.76 μg/L. The NCDs are easy to fabricate, and the detection method is easy to implement. In this study, a new method for melamine detection was established, and the proposed method for melamine detection can provide some insights for food safety detection.

Nonalcoholic fatty liver disease (NAFLD) is increasingly regarded as a hepatic manifestation of metabolic syndrome. Though with high prevalence, the mechanism is poorly understood. This study aimed to investigate the effects of p21 on free fatty acid (FFA)-induced steatosis in L02 cells. We therefore analyzed the L02 cells with MG132 and siRNA treatment for different expression of p21 related to lipid accumulation and lipotoxicity. Cellular total lipid was stained by Oil Red O, while triglyceride content, cytotoxicity assays, lipid peroxidation markers and anti-oxidation levels were measured by enzymatic kits. Treatment with 1 mM FFA for 48 hr induced magnificent intracellular lipid accumulation and increased oxidative stress in p21 overload L02 cells compared to that in p21 knockdown L02 cells. By increasing oxidative stress and peroxidation, p21 accelerates FFA-induced lipotoxic effect in L02 cells and might provide information about potentially new targets for drug development and treatments of NAFLD.

Time-resolved x-ray self-emission imaging was used to study the dynamic evolution of a laserproduced gold plasma tamped by plastic (CH), and a significant plasma collapse was observed during the laser irradiation. The plasma collapse, a kind of transverse contraction, has been ascribed to the radial compression caused by the different radiative cooling rates and thus different pressures between the central high-Z gold plasma and the surrounding low-Z CH plasma, and this has been reproduced by numerical simulations using the two-dimensional radiation-hydrodynamics code Multi2D. The experimental results represent an observation of the radiative cooling induced plasma jet within a 1 ns laser pulse duration, much more quickly than those reported previously. In addition, our experiment design may offer a method to study the radiative cooling rates of high-Z plasmas. The measured cooling rate is a factor of 2 higher than the theoretical result [Post et al., At. Data Nucl. Data Tables 20, 397 (1977)], but is within the stated calculational uncertainty. [ABSTRACT FROM AUTHOR]

We describe an experimental technique to measure the drive symmetry of M-band radiation on the capsule in hohlraum. M-band radiation from the corona of the laser-produced gold plasma, especially the laser spot regions in the cavity, was used to pump x-ray fluorescence of a thin layer of Sitracer coated on a solid CH-ball. The fluorescence images were time resolvedly recorded by an x-ray framing camera and the drive asymmetry due to M-band radiation was deduced from these fluorescence images. Moreover, a Si-doped gold cavity was used with the initial purpose of maximizing the fluorescence signal through resonance transitions. Since the Si-plasma expands more rapidly than the gold-plasma, the evolution of drive asymmetry was accelerated in Si-doped hohlraum. [ABSTRACT FROM AUTHOR]

The enhancement of laser to x-ray conversion efficiencies using low density gold targets [W. L. Shang, J. M. Yang, and Y. S. Dong, Appl. Phys. Lett. 102, 094105 (2013)] is demonstrated. Laser to x-ray conversion efficiencies with 6.3% and 12% increases are achieved with target densities of 1 and 0.25 g/cm³, when compared with that of a solid gold target (19.3 g/cm³). Experimental data and numerical simulations are in good agreement. The enhancement is caused by larger x-ray emission zone lengths formed in low density targets, which is in agreement with the simulation results. [ABSTRACT FROM AUTHOR]

A design of secondary hohlraum radiation source with laser focal spots blocked is introduced. The hard x-ray radiation such as the gold M-band emission and hot electrons from the coronal plasma were designed to be shielded using a cylindrical shield. Three-dimensional view factor analysis was carried out to optimize the shield structure to achieve higher radiation temperature. An experiment was performed at Shenguang III prototype laser facility to verify the design. Velocity Interferometer System for Any Reflector was used to measure the shock wave speed in a threestepped Al sample driven by this radiation source and the peak radiation temperature of the radiation source was estimated to be about 90 eV. [ABSTRACT FROM AUTHOR]

In the hohlraum used in laser indirect-drive inertial confinement fusion experiments, hydrodynamic processes of radiation-ablated high-Z plasma have a great effect on laser injection efficiency, radiation uniformity, and diagnosis of hohlraum radiation field from diagnostic windows (DW). To study plasma filling in the DWs, a laser-irradiated Ti disk was used to generate 2-5 keV narrow energy band X-ray as the intense backlighter source, and laser-produced X-ray in a hohlraum with low-Z foam tamper was used to heat a small hole surrounded by gold wall with 150 μm in diameter and 100 μm deep. The hydrodynamic movement of the gold plasma in the small hole was measured by an X-ray framing camera and the results are analyzed. Quantitative measurement of the plasma areal density distribution and evolution in the small hole can be used to assess the effect of plasma filling on the diagnosis from the DWs. [ABSTRACT FROM AUTHOR]

Hydrodynamic processes of radiation-ablated high-Z plasmas have great influence on the x-ray radiation transport both in a high-Z tube with low-Z foam filling and in a low-Z filling indirect drive cavity. Using the intense x-ray radiation to heat a low-Z foam-tamped high-Z gold plate from a half cavity, the hydrodynamic moving process of the x-ray-ablated gold plasma has been studied by an imaging method with Ti He-α line emission as the backlighter source. The hydrodynamic trajectory of the x-ray-heated gold plasma was obtained and the average trajectory velocity of (36.5±1.2) km/s was derived. The experimental trajectory was compared with the simulations using the one-dimensional (1D) RDMG [P. Gu et al., Sci. China, Ser. G 48, 345 (2005)] and two-dimensional (2D) LARED-R [K. Lan et al., Laser Part. Beams 23, 275 (2005)] codes separately. It is shown that the 2D LARED-R code simulated the measured plasma trajectory much better than the 1D RDMG code due to the fact that the lateral x-ray radiation loss was taken into account in the 2D LARED-R but not in the 1D RDMG simulations. [ABSTRACT FROM AUTHOR]

Radiation flow through gold-doped hydrocarbon foam is investigated and a model is presented to calculate effective opacity for an inhomogeneous, pressure-equilibrated gold/foam mixture based on the Levermore-Pomraning method for binary stochastic media. The effective opacity dependance on the size of the gold particles and the foam temperature are studied. The results suggest that when the mixture temperature is lower than 250 eV, the opacity difference between the 5 &mgr;m particle mix case and the atomic mix case is large enough to induce a significant discrepancy in radiation transport, which is confirmed by the hydrodynamic simulation. [ABSTRACT FROM AUTHOR]

X-ray streak cameras are extensively used to study transient x-ray processes in experiments carried out on various laser facilities at the Research Center of Laser Fusion. Precise calibration and clear description of the sweep speed of the x-ray streak camera are vital for obtaining precise temporal information to understand the fast physics phenomena. An x-ray streak camera named wide-slit x-ray streak camera has been calibrated using a small-scale laser facility with pulse duration of 8 ps. Sweep speeds on most part of the output screen (charge coupled device) are obtained. These calibration results can be used to correct the nonlinearity of sweep speed in measurement of temporal processes. [ABSTRACT FROM AUTHOR]

As an important x-ray source, enhancement of x-ray emissions from laser-produced plasmas is significant for various applications. Due to less expanding kinetic loss, gold foam with low initial density can have an enhanced x-ray conversion efficiency compared with solid-density gold. However, low-Z impurities within gold foam targets will diminish the enhancement remarkably, and should be tightly controlled. This paper presents an experimental study of a high brightness laser plasma soft x-ray source, based on a g gold foam target with negligible impurities irradiated by nanosecond laser pulses with power density around 3  ×  10 W at the Shenguang II laser facility. A conversion efficiency, from multi-eV to multi-keV, of % is achieved in the x-ray emissions—about 21% relative enhancement compared with a solid-density gold target, and the highest conversion efficiency for Au foam planar targets yet. Good agreement has been achieved between the semi-analytical model prediction and the experimental results. [ABSTRACT FROM AUTHOR]

Fluorescence imaging of surrogate Si-doped CH targets has been used to provide a measurement for drive condition of high-energy x-ray (i.e. M-band x-ray) drive symmetry upon the capsule in hohlraum on Shenguang-II laser facility. A series of experiments dedicated to the study of photo-pumping and fluorescence effect in Si-plasma are presented. To investigate the feasibility of fluorescence imaging in Si-plasma, an silicon plasma in Si-foil target is pre-formed at ground state by the soft x-ray from a half-hohlraum, which is then photo-pumped by the K-shell lines from a spatially distinct laser-produced Si-plasma. The resonant Si photon pump is used to improve the fluorescence signal and cause visible image in the Si-foil. Preliminary fluorescence imaging of Si-ball target is performed in both Si-doped and pure Au hohlraum. The usual capsule at the center of the hohlraum is replaced with a solid Si-doped CH-ball (Si-ball). Since the fluorescence is proportional to the photon pump upon the Si-plasma, high-energy x-ray drive symmetry is equal to the fluorescence distribution of the Si-ball. [ABSTRACT FROM AUTHOR]

The K-shell emission spectra of laser-produced aluminum plasma are measured by a space-resolved spectrometer consisting of a flat crystal spectrometer with a 20 um wide space-resolved slit. By using the approximation of the steady collisional-radiative equilibrium model, the interstage line intensity ratios of Ly-a resonance line to He-a resonance line are given as a function of electron temperature. The spectra profiles are decomposed to resonance line and the overlapped high-order satellites manifold. Thus reliable electron temperature is deduced from the interstage line intensity ratios of the decomposed resonance lines. The results of spaced-resolved temperature are compared with the hydrodynamic simulations. The diagnostics of electron temperature for laser-produced plasma is developed. [ABSTRACT FROM AUTHOR]

A technique of flat crystal x-ray spectrometer for quantitative spectral measurement is described. For the flat crystal spectrograph geometry, the quantitative reduction of relating the CCD counts back to the photon flux from the x-ray source is established. The absolute calibrations of the integral diffraction coefficients of the crystal and the CCD sensitivity make it possible to measure absolute photons flux within the energy range of 2000-5000 eV. The uncertainty analysis of the calibrations is carried out to obtain the energy resolved uncertainties of crystal and CCD. Thus, the experimental spectra with spectral resolved intensity uncertainties are available. Then, a performing experiment of laser-produced Ti plasma is carried out and the absolute x-ray spectra with intensity uncertainty less than 8.5% are obtained. The technique is promising for absolute spectral measurement of high temperature plasmas in a kilo-electron-volt region. [ABSTRACT FROM AUTHOR]

Integral diffraction coefficients of the crystal are the essential data of a crystal spectrometer which is extensively used to measure quantitative x-ray spectra of high temperature plasmas in kilo-electron-volt region. An experimental method has been developed to measure the integral diffraction coefficients of crystals on beamline 4B7 of Beijing Synchrotron Radiation Facility. The integral diffraction coefficients of several crystals including polyethylene terephthalate (PET), thallium acid phthalate (TlAP) and rubidium acid phthalate (RAP) crystals have been measured in the x-ray energy range 2100-5600 eV and compared with the calculations of the 'Darwin Prins' and the 'Mosaic' models. It is shown that the integral diffraction coefficients of these crystals are between the calculations of the 'Darwin Prins' and the 'Mosaic' models, but more close to the 'Darwin Prins' model calculations. [ABSTRACT FROM AUTHOR]

Background: Betatrophin is a novel adipokine that provokes pancreatic β-cell proliferation and is involved in lipid metabolism. Aims: This study aims to evaluate the role of serum betatrophin in metabolic syndrome (MetS). Methods: A hospital-based, age-/gender-matched case control study was conducted. The serum betatrophin level was evaluated by enzyme- linked immunosorbent assay. Serum concentrations of 12 adipokines were measured to assess their associations with serum betatrophin, using commercial Adipokine Magnetic Bead Panel kits. Statistical analyses included bivariate correlation, receiver operating characteristic (ROC) curve, and multivariate stepwise linear regression. Results: Serum betatrophin showed a higher level in MetS patients (997.36 ± 475.92 pg/ml, p = 0.001) compared with controls (735.35 ± 526.51 pg/ml). Compared with the lowest tertile, the highest tertile of serum betatrophin level indicated an association with higher risk of MetS (adjusted odds ratio = 3.521, 95% confidence interval [CI] [1.191-10.413], p = 0.023). ROC curve of betatrophin was developed to predict the presence of MetS (area under ROC = 0.682 [95% CI, 0.597-0.767], p < 0.001). Furthermore, betatrophin correlated with several parameters, e.g. age (r = 0.286, p < 0.001), body mass index (r = 0.160, p = 0.046), waist-to-hip ratio (r = 0.241, p = 0.002), high-density lipoprotein cholesterol (r = -0.167, p = 0.037), low-density lipoprotein cholesterol (r = -0.195, p = 0.015), fasting plasma glucose (r = 0.266, p = 0.001), hemoglobin A1C (r = 0.314, p < 0.001), homeostasis model assessment of insulin resistance (r = 0.272, p = 0.001), and various adipokines, e.g. resistin (r = 0.571, p < 0.001), interleukin-8 (r = 0.435, p < 0.001), tumor necrosis factor-α (r = 0.295, p = 0.011) and lipocalin-2 (r = 0.346, p = 0.003). Conclusions: This study supports that serum betatrophin plays an important role in MetS, involving the regulations of glucose and lipid metabolism and inflammation. [ABSTRACT FROM AUTHOR]

Aim: To analyze the benefits and harms of pancreatic cancer screening in familial high-risk individuals (HRIs)., Methods: Studies were identified by searching PubMed, EBSCO, ClinicalTrials.gov and the Cochrane database from database inception to June 2014. We also obtained papers from the reference lists of pertinent studies and systematic reviews. English-language trials and observational studies were searched. The key words used as search terms were "screening" and "surveillance". Cost-effectiveness, diagnostic rate, survival rate, mortality and adverse events were the outcomes of interest. Age, sex, lifestyle and other confounding factors were also considered. However, anticipating only a few of these studies, we also included observational studies with or without control groups. We also included studies concerning the anxiety associated with pancreatic cancer risk and other psychological changes in familial HRIs. We extracted details on study design, objectives, population characteristics, inclusion criteria, year of enrollment, method of screening, adjusted and unadjusted mortality, cost-effectiveness and adverse events from the included studies. Studies were assessed using the Reporting of Observational studies in Epidemiology (STROBE) checklist., Results: Sixteen studies on pancreatic cancer screening were included. Five studies included control groups, nine were observational studies without control groups, and the other two studies investigated the worry associated with pancreatic cancer risk. We found that pancreatic cancer screening resulted in a high curative resection rate (60% vs 25%, P = 0.011), longer median survival time (14.5 mo vs 4 mo, P < 0.001), and higher 3-year survival rate (20% vs 15.0%, P = 0.624). We also found that familial HRIs had a higher diagnostic rate of pancreatic tumors than controls (34% vs 7.2%, P < 0.001). In patients who underwent regular physical examinations, more stage I pancreatic cancers were observed (19% vs 2.6%, P = 0.001). In addition, endoscopic ultrasonography, which was the main means of detection, diagnosed 64.3% of pancreatic cancers. In comparison, endoscopic retrograde cannulation of the pancreas, magnetic resonance imaging, and computed tomography diagnosed 28.6%, 42.9%, and 21.4%, respectively. For mass lesions, instant surgery was recommended because of the beneficial effects of post-operative chemotherapy. However, in patients with intraductal papillary mucinous neoplasms, we did not find a significant difference in outcome between surgery and follow-up without treatment. Moreover, pancreatic cancer screening in familial HRIs had a greater perceived risk of pancreatic cancer (P < 0.0001), higher levels of anxiety regarding pancreatic cancer (P < 0.0001), and increased economic burden., Conclusion: Pancreatic cancer screening in familial HRIs is associated with a higher detection rate and longer survival, although screening may influence psychological function and increase the economic burden.

Aim: To investigate whether Helicobacter pylori (H. pylori) infection is associated with glycemic control and whether hyperglycemia is modified by eradication therapy., Methods: The databases of PubMed, Cochrane Library, Chinese BioMedicine Web Base and Chinese Science and Technology Journals were searched from inception to June 2014. Studies examining the association between H. pylori infection and glycemic control and/or the effect of eradication treatment on glycemic control in diabetic humans were eligible for inclusion. Meta-analyses were conducted using the Review Manager software version 5.2. The outcome measures are presented as weighed mean differences (WMDs) with 95% confidence intervals (CIs). Statistical heterogeneity was assessed by the Cochran Q test and the I(2) statistic., Results: A total of 21 relevant publications were identified. A meta-analysis of 11 studies with 513 patients with diabetes mellitus (DM) showed significantly lower glycosylated hemoglobin (HbA1c) levels in the H. pylori-negative than H. pylori-positive DM participants (WMD = 0.43, 95%CI: 0.07-0.79; P = 0.02). In children and adolescents with type 1 DM (T1DM), there was a positive association between H. pylori infection and HbA1c level (WMD = 0.35, 95%CI: 0.05-0.64; P = 0.02), but there was no difference in those with type 2 DM (T2DM, WMD = 0.51, 95%CI: -0.63-1.65; P = 0.38). A meta-analysis of six studies with 325 T2DM participants showed a significant difference in the fasting plasma glucose levels between H. pylori-positive and H. pylori-negative participants (WMD = 1.20, 95%CI: 0.17-2.23; P = 0.02). Eradication of H. pylori did not improve glycemic control in the T2DM participants in a three-month follow-up period (HbA1c decrease: WMD = -0.03, 95%CI = -0.14-0.08; P = 0.57; fasting plasma glucose decrease: WMD = -0.06, 95%CI: -0.36-0.23; P = 0.68). Glycemic control was significantly better in T1DM participants who were not reinfected than in those who were reinfected (HbA1c: WMD = 0.72, 95%CI: 0.32-1.13: P = 0.00)., Conclusion: H. pylori infection is associated with poorer glycemic control in T1DM patients, but eradication may not improve glycemic control in DM in a short-term follow-up period.