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Let x_1, x_2, ..., x_n be n points on the sphere S^2. Determining the value \inf \sum _{1\leq k

In Lin (Calc. Var. Partial Differential Equations 60:196, 2021), the first author proved the Steiner's projection inequality and the Petty projection inequality for sets of finite perimeter but didn't characterize their cases of equality. In this paper, we characterize the case of equality in the Steiner's projection inequality. Moreover, we give a new proof of the equality case in the Petty projection inequality, which was characterized by Wang (Adv. Math. 230:2457–2473, 2012). [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to examine the associations between body composition and temporal eating patterns, including time of first eating occasion, time of last eating occasion, eating window, and eating jet lag (the variability in meal timing between weekdays and weekends).A total of 131 participants were included in the study. Temporal eating pattern information was collected through consecutive 7-day eat timing questionnaires and photographic food records. Body composition was assessed by bioelectrical impedance analysis. Multiple linear regression models were used to evaluate the relationships of temporal eating patterns with body composition, and age was adjusted. Eating midpoint was additionally adjusted in the analysis of eating window.On weekdays, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with lower body fat percentage. On weekends, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with higher FFMI. Longer first eating occasion jet lag was associated with lower lean mass.Our study suggested that earlier and more regular eating patterns may have a benefit on body composition.Methods: The aim of this study was to examine the associations between body composition and temporal eating patterns, including time of first eating occasion, time of last eating occasion, eating window, and eating jet lag (the variability in meal timing between weekdays and weekends).A total of 131 participants were included in the study. Temporal eating pattern information was collected through consecutive 7-day eat timing questionnaires and photographic food records. Body composition was assessed by bioelectrical impedance analysis. Multiple linear regression models were used to evaluate the relationships of temporal eating patterns with body composition, and age was adjusted. Eating midpoint was additionally adjusted in the analysis of eating window.On weekdays, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with lower body fat percentage. On weekends, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with higher FFMI. Longer first eating occasion jet lag was associated with lower lean mass.Our study suggested that earlier and more regular eating patterns may have a benefit on body composition.Results: The aim of this study was to examine the associations between body composition and temporal eating patterns, including time of first eating occasion, time of last eating occasion, eating window, and eating jet lag (the variability in meal timing between weekdays and weekends).A total of 131 participants were included in the study. Temporal eating pattern information was collected through consecutive 7-day eat timing questionnaires and photographic food records. Body composition was assessed by bioelectrical impedance analysis. Multiple linear regression models were used to evaluate the relationships of temporal eating patterns with body composition, and age was adjusted. Eating midpoint was additionally adjusted in the analysis of eating window.On weekdays, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with lower body fat percentage. On weekends, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with higher FFMI. Longer first eating occasion jet lag was associated with lower lean mass.Our study suggested that earlier and more regular eating patterns may have a benefit on body composition.Conclusion: The aim of this study was to examine the associations between body composition and temporal eating patterns, including time of first eating occasion, time of last eating occasion, eating window, and eating jet lag (the variability in meal timing between weekdays and weekends).A total of 131 participants were included in the study. Temporal eating pattern information was collected through consecutive 7-day eat timing questionnaires and photographic food records. Body composition was assessed by bioelectrical impedance analysis. Multiple linear regression models were used to evaluate the relationships of temporal eating patterns with body composition, and age was adjusted. Eating midpoint was additionally adjusted in the analysis of eating window.On weekdays, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with lower body fat percentage. On weekends, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with higher FFMI. Longer first eating occasion jet lag was associated with lower lean mass.Our study suggested that earlier and more regular eating patterns may have a benefit on body composition. [ABSTRACT FROM AUTHOR]

For sets of finite perimeter, k -codimensional projection bodies are introduced. The corresponding k -codimensional projection inequalities are investigated and their equality cases are characterized. [ABSTRACT FROM AUTHOR]

Objective To analyzed the DKK1 expression in early osteogenic and adipogenic differentiation of BMSCs in rats and to explore its regulating mechanism. Methods DKK1 gene expression in early adipogenic and osteogenic differentiation was detected using real4ime PCR. And the DKK1 expression was also detected after hormone treatment. Results The expression level of DKK1 gene after 6, 12, 24, and 48h adipogenic induction was higher than that in control group and the difference was significant (P < 0. 01). The expression level of DKK1 gene after 0. 5 and 6h osteogenic induction was obviously lower than that in control group and the difference was significant (P < 0. 05). The expression level of DKK1 gene of BMSCs after 3, 6, 12, and 24 h hormone treatment was higher than in control group (P < 0. 05). Conclusion DKK1 plays an important role in early osteogenic and adipogenic differentiation by BMSCs. The hormone affects osteogenic and adipogenic differentiation by regulating the expression of DKK1. [ABSTRACT FROM AUTHOR]

Background: Insomnia is common in patients undergoing maintenance hemodialysis (MHD). Long-term use of sedative-hypnotic agents is often correlated with increasing adverse effects. Auricular acupressure therapy (AAT) applied to specific auricular acupoints for managing insomnia has achieved favorable outcomes in a hemodialysis unit. This pilot study was performed to demonstrate the potential of AAT for insomnia in MHD patients and to prepare for a future randomized controlled trial. Methods: Eligible patients were enrolled into this descriptive pilot study and received AAT designed to manage insomnia for 4 weeks. Questionnaires that used the Pittsburgh sleep quality index (PSQI) were completed at baseline, after a 4-week intervention, and 1 month after completion of treatment. Sleep quality and other clinical characteristics, including sleeping pills taken, were statistically compared between different time points. Results: A total of 22 patients were selected as eligible participants and completed the treatment and questionnaires. The mean global PSQI score was significantly decreased after AAT intervention ( p<0.05). Participants reported improved sleep quality ( p<0.01), shorter sleep latency ( p<0.05), less sleep disturbance ( p<0.01), and less daytime dysfunction ( p=0.01). They also exhibited less dependency on sleep medications, indicated by the reduction in weekly estazolam consumption from 6.98±4.44 pills to 4.23±2.66 pills ( p<0.01). However, these improvements were not preserved 1 month after treatment. Conclusion: In this single-center pilot study, complementary AAT for MHD patients with severe insomnia was feasible and well tolerated and showed encouraging results for sleep quality. [ABSTRACT FROM AUTHOR]

Positron generation by an ultra-short ultra-intense laser in an indirect manner has been studied with two-dimensional particle-in-cell (PIC) and Monte Carlo (MC) simulations. In this generation scheme, positrons are produced with energetic electrons accelerated by an ultra-shot laser pulse propagating through an underdense plasma. The dependence of the positron beam properties on the plasma length and secondary target (converter) thickness was investigated in detail. The simulation results reveal that the positron yield is strongly correlated with the total energy of laser-accelerated electrons; both the temperature and divergence of the positron beam are sensitive to the plasma length; and the positron beam has a pulse duration comparable to the incident electron beam. In addition, it is indicated that even with the optimal converter thickness, only a small fraction (11.4%) of positrons can escape out and most of the detected positrons originate from the back edge of the converter. [ABSTRACT FROM AUTHOR]

Energetic electron bunches with more than 20 nC charge are generated from 100 TW level laser pulse interaction with 2% critical density plasma. Three-dimensional particle-in-cell simulations show that the unexpected high bunch-charge can be attributed to the multiple intensity peaks of the laser pulse and the resulting multiple-bubble wake structure. This charge is one of the highest among experiments on electron-bunch generation by laser-plasma interaction. Such highly charged ultra-short electron bunches are crucial for producing sufficiently bright Bremsstrahlung x-rays required in high-resolution flash radiography of large samples. [ABSTRACT FROM AUTHOR]

The Monte Carlo transport code Geant4 has been used to study positron production in the transport of laser-produced hot electrons in solid targets. The dependence of the positron yield on target parameters and the hot-electron temperature has been investigated in thick targets (mm-scale), where only the Bethe-Heitler process is considered. The results show that Au is the best target material, and an optimal target thickness exists for generating abundant positrons at a given hot-electron temperature. The positron angular distributions and energy spectra for different hot electron temperatures were studied without considering the sheath field on the back of the target. The effect of the target rear sheath field for positron acceleration was studied by numerical simulation while including an electrostatic field in the Monte Carlo model. It shows that the positron energy can be enhanced and quasi-monoenergetic positrons are observed owing to the effect of the sheath field. [ABSTRACT FROM AUTHOR]

In this paper, we consider optimal linear sensor fusion for obtaining a remote state estimate of a linear process based on the sensor data transmitted over lossy channels. There is no local observability guarantee for any of the sensors. It is assumed that the state of the linear process is collectively observable. We transform the problem of finding the optimal linear sensor fusion coefficients as a convex optimization problem which can be efficiently solved. Moreover, the closed-form expression is also derived for the optimal coefficients. Simulation results are presented to illustrate the performance of the developed algorithm. [ABSTRACT FROM AUTHOR]

Momordica charantia L. is a kind of vegetable with medicinal value. As the main component of the vegetable, Momordica charantia polysaccharides (MCPs) mainly consist of galactose, galacturonic acid, xylose, rhamnose, mannose and the molecular weight range is 4.33 × 103–1.16 × 106 Da. MCPs have been found to have various biological activities in recent years, such as anti-oxidation, anti-diabetes, anti-brain injury, anti-obesity, immunomodulatory and anti-inflammation. In this review, we systematically summarized the extraction methods, structural characteristics and physicochemical properties of MCPs. Especially MCPs modulate gut microbiota and cause the alterations of metabolic products, which can regulate different signaling pathways and target gene expressions to exert various functions. Meanwhile, the potential structure-activity relationships of MCPs were analyzed to provide a scientific basis for better development or modification of MCPs. Future researches on MCPs should focus on industrial extraction and molecular mechanisms. In East Asia, Momordica charantia L. is used as both food and medicine. It is not clear whether MCP has its unique biological effects. Further study on the difference between MCPs and other food-derived polysaccharides will be helpful to the development and potential application of Momordica charantia L. [ABSTRACT FROM AUTHOR]

The incidence of CKD seriously endangers people's health. Researchers have proposed that improving the intestinal barrier damage in CKD may be an effective target for delaying the progression of CKD. Rhubarb can effectively improve the intestinal barrier and renal fibrosis, which may be related to the regulation of gut dysbiosis, but the mechanism needs to be further studied. Short-chain fatty acids (SCFAs) are important metabolites of the gut microbiota and play an important role in maintaining the intestinal barrier. The purpose of this study was to investigate whether rhubarb enema regulates the production of short-chain fatty acid-related gut microbiota and improves the intestinal barrier damage of CKD. 5/6 nephrectomy rats were used as the animal model, sevelamer was used as the positive control group, and the sham operation rats were used as the control group. After 4 weeks of enema treatment, the general clinical indicators, short-chain fatty acid levels, renal pathology, intestinal tissue pathology, intestinal tight junction protein, and changes in gut microbiota were detected. The results showed that rhubarb enema can increase the level of short-chain fatty acids in the 5/6 nephrectomy model rats, improve the intestinal barrier damage, inhibit the decrease of intestinal tight junction proteins, reduce inflammation levels, improve kidney pathology, reduce blood creatinine levels, and regulate the intestinal tract, the abundance, and composition of the flora. Further correlation analysis showed that rhubarb enema increased the level of short-chain fatty acids in 5/6 nephrectomy model rats, which may be related to the 7 strains that may regulate the production of short-chain fatty acids. This study indicated that rhubarb enema can improve the intestinal barrier damage of 5/6 nephrectomy model rats and improve CKD, which may be related to the regulation of short-chain fatty acid-producing gut microbiota. [ABSTRACT FROM AUTHOR]

We propose a positron acceleration scheme in which a laser-driven positron beam is injected into a solid target hit by a laser beam and accelerated in the sheath field on the target back side. The positron beam injection and acceleration in the target have been investigated with numerical simulation. The feasibility of such an acceleration scheme was proved according to the simulation results, which show that a 10 MeV positron beam can be accelerated up to 30 MeV. The dependency of the positron beam properties on the positron injection location, injection time, and target thickness was studied. Related acceleration details were obtained and analyzed. The acceleration scheme provides a method in positron energy controlling and its related applications. [ABSTRACT FROM AUTHOR]

The physics of shock-induced ejection is a crucial phenomenon in the field of shock compression science and technology. Limited by loading methods, the previous research primarily focused on the physics of ejecta induced by single shockwave, with few data available on multiple shockwave loading conditions. To solve this problem, we proposed a double shockwave production method based on the high-intensity laser facility, which allows the interval time between the shock waves to be adjusted in the nanosecond to microsecond timescale. Meanwhile, we applied loading techniques to study the ejection behavior of metal tin and integrated photonic doppler velocimetry and high-energy x-ray radiography technology to observe the ejection process. By comparing the experimental results for single and double shockwave, the multiple shock-induced ejection features have been clearly confirmed. Our experimental results provide valuable insight into the behavior of ejecta under multiple shockwave loading conditions, which is of great significance for deepening our understanding of the ejection mechanism. [ABSTRACT FROM AUTHOR]

Background: Patients on maintenance hemodialysis (MHD) frequently complain of insomnia. Poor sleep quality impairs their quality of life and adversely affects long-term outcome. Previously we applied auricular acupressure therapy (AAT) for MHD patients with insomnia and yielded favorable results. AAT probably improves sleep quality by stimulating the vagus nerve and inhibiting sympathetic overactivity. However, the efficacy of AAT for insomnia in this population is still lacking. The proposed randomized controlled trial (RCT) will evaluate the efficacy and safety of AAT for improvement of sleep quality in MHD patients with insomnia.Methods/design: The proposed study is a multi-center, double-blind (participants and assessors), parallel-group RCT. A total of 112 participants with insomnia will be recruited from six hemodialysis centers in Guangzhou, China, and randomly allocated in a 1:1 ratio to receive auricular acupressure on either active points (AA group) or control points (points irrelevant to insomnia management, SAA group). The treatment will last for 8 weeks prior to a follow-up period of 12 weeks. Evaluation by blinded assessors at baseline, at 8 weeks (end of treatment) as well as at 4-week, 8-week and 12-week follow-ups (after intervention) will include Pittsburgh Sleep Quality Index (PSQI) scores and average weekly dose of hypnotics. The primary endpoint is clinical response rate (percentage of participants who reach a reduction of PSQI global score ≥ 3 in each group) at 8 weeks from baseline. Secondary endpoints include the changes in PSQI scores over time from baseline, as well as the changes in weekly dose of hypnotics.Discussion: This paper describes the rationale and design of a double-blind RCT that aims to determine the efficacy and safety of AAT for insomnia of hemodialysis patients. If successful, this project will provide evidence of the efficacy and safety of AAT for insomnia of hemodialysis patients.Trial Registration: ClinicalTrials.gov , Identifier: NCT03015766 . Registered on 22 December 2016. [ABSTRACT FROM AUTHOR]

Background: Limited literature has addressed the impact of nut consumption in mitigating frailty. This study aimed to investigate the association between nut consumption and frailty among Americans aged above 60 years, employing two 24‐h dietary recalls for analysis. Methods: The data sets of the National Health and Nutrition Examination Survey (NHANES) (2003–2018) and the Food Patterns Equivalents Database were utilised for a weighted multiple logistic regression model to evaluate the association between nut consumption and frailty in elderly adults. Furthermore, a restricted cubic spline model was employed to investigate the nonlinear relationship between nut intake and frailty. Besides, stratified and interaction analyses were conducted to explore the sensitivity of nut consumption in reducing the risk of frailty in diverse subgroups. Results: The research study comprised 10,033 individuals aged 60 years or above, of whom 3591 were classified as frailty and 5302 consumed nuts. In the multivariate logistic regression analysis that adjusted for covariates, the weighted multivariate adjusted odds ratios demonstrated that the prevalence of frailty was lower in the nut intake group than in nonconsumers. The stratified analysis indicated that nearly all subgroups who consumed nuts had a significantly lower risk of frailty compared to nonconsumers, and an interaction was observed between nut intake and nonhypertensive populations. The optimal threshold for nut intake to decrease the risk of frailty was identified as 1.02 ounces. Conclusions: The study concluded that nut consumption has a constructive impact on averting frailty in elderly adults, particularly in nonhypertensive individuals. Nut intake of ~1.02 ounces per day is advantageous in improving the quality of life in elderly adults. Key points: This study investigated the impact of nut consumption on frailty among American seniors aged over 60.A lower prevalence of frailty was observed in nut consumers in the National Health and Nutrition Examination Survey database.Almost all subgroups consuming nuts reaped advantages, with nonhypertensive individuals markedly standing out.Optimal nut intake to reduce frailty risk was found to be ~1.02 ounces daily. [ABSTRACT FROM AUTHOR]

The prevalence of chronic kidney disease (CKD) is gradually increasing in the elderly population. At the same time, frailty has become one of the research hotspots in the field of geriatrics. Bibliometric analyses help to understand the direction of a field. Therefore, this study aimed to analyze the status and emerging trends of frailty in CKD patients. The Web of Science Core Collection (WoSCC) database was screened for relevant literature published between 1 January 2000 and 31 December 2021. Next, publications were analyzed for information including authors, journals, cited references, citing journals, institutions, countries and regions, high-frequency keywords and co-citations using VOSviewer, Microsoft Excel, and R software. A total of 2223 articles were obtained, from which 613 relevant articles were selected based on title and abstract screening. There was an upward trend in the number of annual publications and Johansen KL was considered the most contributing author in the field. The Clinical Journal of the American Society of Nephrology was the most productive research journal. Johns Hopkins University is the most published organization. The United States is the global leader in the field and contributes the most to research. Research hotspots focus on epidemiological studies of frailty and frailty intervention. This study presents a comprehensive bibliometric analysis of CKD and frailty research. Key findings highlight the current focus on early screening and assessment of frailty in CKD patients, as well as physical function interventions in frail patients. [ABSTRACT FROM AUTHOR]

X-ray source based on the Thomson scattering of laser interacting with energetic electron beams features high photon energy, small spot size, and good collimation. However, the photon number is insufficient for practical application because of the small cross section of the Thomson scattering. To solve this problem, here, we replace a traditional Gaussian laser pulse with a flying focus laser pulse to extend interaction length and restrain nonlinear effects. Simulation results show that the scattered photon number can be increased by about 25 and 2 times for high and low energy lasers, respectively. In particular, a 1010 photon number can be generated with a 10 J flying focus laser pulse, and the energy spread can also be greatly reduced for high energy laser, from a broad spectrum to a monoenergetic peak. Combining these two advantages, the peak spectrum brightness of x ray is 3 × 108 photons/keV at 240 keV, which is about three orders of magnitude more than the traditional case. [ABSTRACT FROM AUTHOR]

The integrating current transformer (ICT) is a magnetic sensor widely used to precisely measure the charge of an ultra-short-pulse charged particle beam generated by traditional accelerators and new laser-plasma particle accelerators. In this paper, we present a new method to calculate the beam charge in an ICT based on circuit analysis. The output transfer function shows an invariable signal profile for an ultra-short electron bunch, so the function can be used to evaluate the signal quality and calculate the beam charge through signal fitting. We obtain a set of parameters in the output function from a standard signal generated by an ultra-short electron bunch (about 1 ps in duration) at a radio frequency linear electron accelerator at Tsinghua University. These parameters can be used to obtain the beam charge by signal fitting with excellent accuracy. [ABSTRACT FROM AUTHOR]

Background: Xerostomia is one of the most common complaints in maintenance hemodialysis (MHD) patients. This problem contributes to excess fluid intake and results in poor survival outcome. Based on Traditional Chinese Medicine (TCM) theory and literature studies, the authors have been practicing auricular acupressure therapy (AAT) to help patients with xerostomia. This pilot study was conducted to demonstrate the potential of AAT for xerostomia in MHD patients. Methods: Eligible subjects who agreed to participate in this study were recruited and provided with AAT for 4 weeks. The Summated Xerostomia Inventory (SXI), as well as measurement of inter-dialytic weight gain (IDWG), daily inter-dialytic weight gain (daily IDWG), percentage of inter-dialytic weight gain (IDWG%), blood pressure, and biochemical parameters, were completed at baseline and after a 4-week intervention. Results: A total of 26 eligible participants were recruited. Of them, 10 men and 16 women ( Mage = 52.92 ± 11.80 years; dialysis vintage 81.86 ± 46.05 months) completed the study. After the 4-week AAT intervention, the SXI scores were significantly decreased compared with baseline (from 10.08 ± 2.26 to 9.04 ± 2.14; p < 0.05). However, the IDWG, daily IDWG, IDWG%, blood pressure, and biochemical parameters did not change significantly after the intervention. Conclusion: This study provides preliminary evidence that AAT may be effective in reducing xerostomia intensity for MHD patients. [ABSTRACT FROM AUTHOR]

Background: Osteoporosis is a major public health problem. Dietary inflammatory preference and body mass index (BMI) are emerging factors that tends to affect bone health. There is limited evidence regarding the joint influence of BMI and dietary status on the bone health. This study aimed to investigate the relationship between dietary inflammatory index (DII) and bone health among adults under different levels of BMI utilizing the National Health and Nutrition Examination Survey (NHANES). Methods: Data were collected from 2005–2010, 2013–2014 to 2017–2018 in NHANES. In total, 10,521 participants who aged ≥ 20 years and had complete data for dietary intake interview, bone mineral density (BMD) and bone mineral content (BMC) were included. DII was performed to evaluate the dietary inflammatory potential based on dietary intake interview. We evaluated bone health by femoral neck BMD and BMC measured by dual energy X-ray absorptiometry. Weighted multivariable linear regression and BMI-stratified subgroup analysis were performed. Results: The average DII score for 10,521 participants was 1.24 ± 0.04, mean femoral neck BMD was 0.82 ± 0.00 g/cm2 and mean BMC was 4.37 ± 0.01 g. In the fully adjusted model, there was a negative correlation between DII with BMD (β = − 0.016, P < 0.001) and BMC (β = − 0.011, P < 0.001) in the most anti-inflammatory diet. Using BMI-stratified subgroup analysis, this correlation became more evident in both the overweight (BMD: β = − 0.024, P < 0.001; BMC: β = − 0.058, P = 0.042) and obese groups (BMD: β = − 0.015, P = 0.049; BMC: β = − 0.009, P = 0.042), while this correlation was opposite in DII tertile 2 (middle DII score) in the underweight group (BMD: β = 0.047, P = 0.038; BMC: β = 0.274, P = 0.010). Conclusion: Relationship between higher consumption of pro-inflammatory and increased risk of lower BMD and BMC was only existed in overweight and obese participants. [ABSTRACT FROM AUTHOR]

The outbreak of COVID-19 has spread worldwide, causing great damage to the global economy. Raman spectroscopy is expected to become a rapid and accurate method for the detection of coronavirus. A classification method of coronavirus spike proteins by Raman spectroscopy based on deep learning was implemented. A Raman spectra dataset of the spike proteins of five coronaviruses (including MERS-CoV, SARS-CoV, SARS-CoV-2, HCoVHKU1, and HCoV-OC43) was generated to establish the neural network model for classification. Even for rapidly acquired spectra with a low signal-to-noise ratio, the average accuracy exceeded 97%. An interpretive analysis of the classification results of the neural network was performed, which indicated that the differences in spectral characteristics captured by the neural network were consistent with the experimental analysis. The interpretative analysis method provided a valuable reference for identifying complex Raman spectra using deep-learning techniques. Our approach exhibited the potential to be applied in clinical practice to identify COVID-19 and other coronaviruses, and it can also be applied to other identification problems such as the identification of viruses or chemical agents, as well as in industrial areas such as oil and gas exploration. [ABSTRACT FROM AUTHOR]

The origin of He + ions in picosecond intense laser–gas interaction was experimentally and numerically investigated. A nanosecond laser pulse was used to modulate the plasma condition, which helps to distinguish the origin of the helium ions with different charge states. By comparing the energy spectra of He 2 + and He + ions in the experiments with/without plasma shaping, we found neither ion–atom nor electron–ion recombination is responsible for the He + generation, which is supported by two-dimensional hydrodynamic simulations and theoretical calculations. [ABSTRACT FROM AUTHOR]

Fusion reactions in a plasma environment are fundamental issues with general interest in high energy density sciences. The reaction rate in an astro-system, which may differ from cold matter, is an important subject in the ambiguous problems of elemental abundance. In addition, the stopping of charged particle in plasma has a considerable impact on the design of nuclear fusion reactors as it is related to the α-particle heating process and ion-driven fast ignition, but still needs better understanding. In this research, an experiment on laser-driven D–D fusion reactions (D + D → 3He + n) has been carried out to investigate the effects of ion stopping power in plasma on fusion reactivities. The neutron yields, plasma density, and deuteron energy loss in the plasma have been measured simultaneously, and the plasma temperature has been analyzed from simulations. It is experimentally demonstrated that the fusion reaction yield is closely correlated with ion beam transportation in the plasma. As a cold target heated to plasma, the reaction probabilities from a deuteron beam and deuterated target interactions can be enhanced or suppressed, which is ascribed to the deuteron stopping power variation in the plasma. The results show the importance of considering the temperature adjusted ion stopping power to correctly model the fusion reaction yields. This work has an impact on understanding the fusion reactions in plasma environment, which is also likely to help achieve higher neutron yields. [ABSTRACT FROM AUTHOR]

The radiography of gamma-ray is one of the most important non-destructive testing in many fields. However, the spot size is always in millimeter scale for the generation of gamma-ray by conventional way. As the development of laser wakefield acceleration, the electron beam with small divergence and spot size can be generated easily in the experiment by tens of terawatt ultra-short laser pulse. Based on this electron beam, gamma-ray with micro spot size is generated and the properties are measured and tested in detail experimentally. The experiment demonstrates that the spot size of this gamma-ray is always smaller than 200 μm, no matter the conversion target thickness, and can be as small as about 40 μm when the conversion target thickness of 0.2 mm is used. The spatial resolution of this gamma-ray is much better than 2.5 LP/mm, the fitting temperature (which is relative to the average energy of gamma-ray) is between 5 MeV and 8 MeV, and the maximum yield per shot of the gamma-ray can be up to 9.1 × 109 photons (energy higher than 1 MeV). High-resolution radiography shows that the areal density of the gamma-ray radiography can be up to 51.3 g/cm2 (stainless steel thickness equivalent is about 6.5 cm). Such micro-spot gamma-ray can play an important role in the high-resolution radiography of high areal density objects. [ABSTRACT FROM AUTHOR]

Objectives: To assess the feasibility and acceptability of a randomized controlled trial compared auricular acupressure (AA) on specific acupoints with AA on non-specific acupoints for treating maintenance hemodialysis (MHD) patients with insomnia. Methods: Sixty three (63) eligible subjects were randomly assigned into either AA group received AA on specific acupoints (n=32), or sham AA (SAA) group received AA on points irrelevant to insomnia treatment (n=31) for eight weeks. All participants were followed up for 12 weeks after treatments. The primary outcome was clinical response at eight weeks after randomization, defined as a reduction of Pittsburgh Sleep Quality Index (PSQI) global score by 3 points and more. Results: Fifty-eight (58) participants completed the trial and five dropped out. Twenty participants in AA group (62.5%) and ten in SAA group (32.3%) responded to the eight-week interventions (χ2 = 5.77, P = 0.02). PSQI global score declined 3.75 ± 4.36 (95%CI -5.32, -2.18) and 2.26 ± 3.89 (95%CI -3.68, -0.83) in AA group and SAA group respectively. Three participants died during the follow-up period. No evidence supported their deaths were related to the AA intervention. No other adverse event was observed. Conclusion: Feasibility and logistics of patient recruitment, randomization procedure, blinding approach, interventions application and outcome assessment had been tested in this pilot trial. The preliminary data appeared to show a favorable result on AA treatment. A full-scale trial is warranted. Trial Registration: Chinese Clinical Trial Registry . [ABSTRACT FROM AUTHOR]

Single shot gamma-induced positron annihilation spectroscopy (GiPS) based on a laser wakefield accelerator is proposed. In this spectroscopy, a large number of gamma rays generated by laser-wakefield accelerated electrons are injected into a sample in a very short time (<2 ps), and the positron lifetime is detected by measuring the time profile of the annihilation radiation (511 keV gamma ray) from the sample. The processes including gamma-ray production, shielding, annihilation generation, and annihilation detection were simulated by using the Monte Carlo method. The results show that up to 1010 gamma rays with a duration of 1.4 ps can be produced per shot with a 45 TW laser system. A Cherenkov radiator PbF2 was used to detect the annihilation radiation, and its optimal thickness of 15 mm was obtained. A whole process simulation with optimized parameters was conducted. A low statistical fluctuation lifetime spectrum can be produced, which confirms the feasibility of single shot GiPS with a typical 45 TW laser system. [ABSTRACT FROM AUTHOR]

The spectrum of laser–plasma generated X-rays is very important, it characterizes electron dynamics in plasma and is basic for applications. However, the accuracies and efficiencies of existing methods to diagnose the spectrum of laser–plasma based X-ray pulse are not very high, especially in the range of several hundred keV. In this study, a new method based on electron tracks detection to measure the spectrum of laser–plasma produced X-ray pulses is proposed and demonstrated. Laser–plasma generated X-rays are scattered in a multi-pixel silicon tracker. Energies and scattering directions of Compton electrons can be extracted from the response of the detector, and then the spectrum of X-rays can be reconstructed. Simulations indicate that the energy resolution of this method is approximately 20% for X-rays from 200 to 550 keV for a silicon-on-insulator pixel detector with 12 μ m pixel pitch and 500 μ m depletion region thickness. The results of a proof-of-principle experiment based on a Timepix3 detector are also shown. [ABSTRACT FROM AUTHOR]

This paper studies a design problem of how a group of wireless sensors are selected and scheduled to transmit data efficiently over a multi-hop network subject to energy considerations, when the sensors are observing multiple independent discrete-time linear systems. Each time instant, a subset of sensors is selected to transmit their measurements to a remote estimator. We formulate an optimization problem, in which a network schedule is searched to minimize a linear combination of the averaged estimation error and the averaged transmission energy consumption. It is shown that the optimal network schedule forms a tree with root at the gateway node. From this observation, we manage to separate the optimization problem into two subproblems: tree planning and sensor selection. We solve the sensor selection subproblem by a Markov decision process, showing that the optimal solution admits a periodic structure when the transmission cost is sufficiently low. Efficient algorithms are proposed and they are shown to reduce the computational complexity of the original optimization problem. Numerical studies illustrate the effectiveness of the proposed algorithms, and show that they are scalable to large networks. [ABSTRACT FROM AUTHOR]

The metal–nonmetal transition is of fundamental interest in contemporary physics. We present a combination of the optical reflectivity measurement of an expanded gold fluid produced by gold L-band x-rays from a Hohlraum and the corresponding ab initio calculations to study the metal–nonmetal transition. The averaged density and temperature of the reflective layer are derived from 1D radiation hydrodynamic simulations constrained by matching the expansion velocity obtained from the fringe shift. A sharp change in time-resolved reflectivity occurs at one third of the initial density, near where the metal–nonmetal transition is predicted to occur. The reflectivity calculated based on the Helmholtz equations with the dielectric function from the density functional theory calculations is compared with the experimental measurement. Disagreement of reflectivity between calculation and measurement probably originates from the energy shift of the dielectric function due to the inaccurate Kohn–Sham eigenvalue. More accurate methods on calculating the dielectric function are still needed to improve the calculated reflectivity. [ABSTRACT FROM AUTHOR]

A chirped laser pulse indicates that the laser frequency changes over the duration of the pulse: a positively (negatively) chirped pulse implies that the laser frequency increases (decreases) with time. In this paper, we use a simplified, fully relativistic hydrodynamic approach to simulate the influence of chirp on the propagation of a femtosecond relativistic laser pulse in underdense plasma. Based on this simplified cold‐fluid model, the influence of chirp on the main dynamics of the laser pulse, such as self‐steepening, red‐shift in the leading edge, variation of the frequency chirp, and the generated wakefields can be studied self‐consistently. The simulation results show that a pulse with a positive chirp results in a larger increment in the intensity parameter a0 when propagating a certain distance into an underdense plasma compared with an un‐chirped and a negatively chirped pulse, which is largely because of a much greater forward shift of the peak amplitude and more severe pulse self‐steepening effect due to the frequency red‐shift at the leading edge when exciting a plasma wave. The ponderomotive force, which relates to the first‐order differential of the laser pulse intensity envelope, is expected to be stronger for a positively chirped pulse because of its steeper leading edge and larger intensity parameter a0. As a result, the wakefield driven by the positively chirped laser pulse is more intense than that driven by an un‐chirped and a negatively chirped laser pulse, which is confirmed by our self‐consistent hydrodynamic simulation. [ABSTRACT FROM AUTHOR]

This study is devoted to the high-energy X-ray radiography investigation on the ejecta physics of laser shock-loaded tin. The ejecta were generated via laser shock loaded tin under sequential shock-breakout pressures by high-power nanosecond lasers. A high-energy X-ray (50∼200keV) source was created to radiograph the high dense ejecta. Due to its strong penetration, high-quality radiograph images were obtained with detailed inner information and topology structure of ejecta. The areal density distribution and total mass of ejecta were further inferred. It was found that the ejecta from laser shock-loaded tin under sequential pressures show obvious difference in density distribution between the samples in a solid state and in a melt-on-release state. In addition, the total mass of ejecta was demonstrated to increase sharply when the breakout pressure is larger than the onset of melt-on-release for tin. Such increase inferred a solid-liquid phase transition of ejecta production mechanism. [ABSTRACT FROM AUTHOR]

Ultraintense laser driven fast electrons play an increasingly important role in many applications. To predict and optimize the fast electron transport efficiency, we introduce a one-dimensional analytical model including resistive effects to estimate the transport efficiency as a function of transport distance and a key parameter named the penetration path. Based on the model, the transport efficiency of fast electrons with the same penetration coefficient can be calculated for different characteristic parameters including the target thickness and laser intensity. A double-layer Kα fluorescence measurement of fast electron transport efficiency is proposed to eliminate the influence of in-target electrons refluxing from the relative Kα photon yield of the rear and front sides of the target. By fixing the transport distance, we have experimentally measured the penetration path and the efficiency of planar Al2O3 targets, in good accordance with Monte Carlo simulations. The results show that the beam energy can be reduced to 25% in a penetration path of tens of microns. This measurement method provides a feasible route to characterize and compare the fast electron transport in various targets and laser conditions, making it possible to modulate and optimize the transport efficiency in actual research studies, which is of great significance in fast ignition, X-ray emission, positron–electron pair production, and many other applications. [ABSTRACT FROM AUTHOR]

The injecting time of the picosecond laser in an indirect-drive integrated fast ignition experiment was measured by using an x-ray streak camera. Despite overlapping spatially and temporally in experiments, the soft x-ray signal from the nanosecond laser ablating the inner wall of an Au hohlraum and the hard x-ray signal from the bremsstrahlung radiation of hot electrons generated by a picosecond laser were separated by different image processes by filtering and collimating the two signals differently. The time sequence between the two x-ray signals was analyzed to extract the injection time of the picosecond laser relative to the hohlraum emission. By tracking the neutron yield as a function of the injection time of the picosecond laser, a clear positive correlation between the neutron yield enhancement and the derived injection times was exhibited. The heating effect of the picosecond laser was confirmed. It is concluded that this method could be used to measure the injecting time and validate the picosecond laser injection. [ABSTRACT FROM AUTHOR]

The dynamic fragmentation of shock-loaded high-Z metal is of considerable importance for both basic and applied science. The areal density and mass-velocity distribution of dynamic fragmentation are crucial factors in understanding this issue. Experimental methods, such as pulsed X-ray radiography and proton radiography, have been utilized to obtain information on such factors; however, they are restricted to a complex device, and the spatial resolution is in the order of 100 μm. In this work, we present the high-quality radiography of the dynamic fragmentation of laser shock-loaded tin, with good two-dimensional (2D) spatial resolution. Dynamic fragmentation is generated via high-intensity ns-laser shock-loaded tin. A high-energy X-ray source in the 50–200 keV range is realized by the interaction of a high-intensity ps-pulse with an Au microwire target, attached to a low-Z substrate material. A high 2D resolution of 12 μm is achieved by point-projection radiography. The dynamic-fragmentation radiography is clear, and the signal-to-noise ratio is sufficiently high for a single-shot experiment. This unique technique has potential application in high-energy density experiments. [ABSTRACT FROM AUTHOR]

A multi-channel Thomson parabola spectrometer was designed and employed to diagnose ion beams driven by intense laser pulses. Angular-resolved energy spectra for different ion species can be measured in a single shot. It contains parallel dipole magnets and wedged electrodes to fit ion dispersion of different charge-to-mass ratios. The diameter and separation of the entrance pinhole channels were designed properly to provide sufficient resolution and avoid overlapping of dispersed ion beams. To obtain a precise energy spectral resolving, three-dimensional distributions of the electric and magnetic fields were simulated. Experimental measurement of energy-dependent angular distributions of target normal sheath accelerated protons and deuterons was demonstrated. This novel compact design provides a comprehensive characterization for ion beams. [ABSTRACT FROM AUTHOR]

An ultraintense femtosecond laser pulse was used, for the first time, to produce a strong magnetic field with controlled shapes by interactions with a capacitor-coil target with high efficiency. The temporal evolution of the strong magnetic field was obtained by the time-gated proton radiography method. A comparison of high-resolution radiographic images of proton deflection and particle-track simulations indicates a peak magnetic field of ∼20 T. The energy conversion efficiency from the ultraintense laser pulse to the magnetic field is as high as ∼10%. A simple model of the ultraintense laser-driven capacitor-coil target gives a relationship between the magnetic field strength and the electron temperature produced by the laser. Our results indicate that magnetic fields of tens of tesla could be stably produced by most of the existing ultraintense laser facilities. It potentially opens new frontiers in basic physics which require strong magnetic field environments. [ABSTRACT FROM AUTHOR]

Background The Spalt-Like Transcription Factor 4 (SALL4) is reported to regulate cell proliferation, migration and invasion. However, the roles of SALL4 in osteoblast differentiation are unclear. This study was aimed to explore the underlying mechanism of SALL4 in osteoporosis. Methods Firstly, the expression of SALL4 was assessed in vivo and in vitro at various stages of development of rats (E14, E20, postnatal 2, 4, and 9 day) or different incubation time (0, 6, 9, 12 and 15 day) of C2C12 and MC3T3-E1 cells. Then, alkaline phosphatase (ALP) activities and positive cells percentages were respectively detected after oeSall4 or siSall4 transfection. Cell differentiation related markers and chondrogenesis-related genes expressions in C2C12 cells were tested by western blot assay and qRT-PCR. Finally, the connection and interaction between SALL4 and NOTCH2 were studied. Results The results showed that SALL4 expression was increased in vivo and in vitro with the growth of rats or the incubation of cells. SALL4 overexpression promoted osteoblast differentiation; on the contrary, SALL4 knockdown inhibited osteoblast differentiation. Moreover, SALL4 participated in the middle and late stages of cell differentiation. Then, SALL4 and NOTCH2 interacted with each other. NOTCH2 expression was decreased both in vivo and in vitro , and negatively regulated by SALL4. Besides, SALL4 overexpression suppressed NOTCH2 target genes expressions and nuclear entry, while deactivated NOTCH2 signaling. Conclusions Our study found that SALL4 played very important roles in the process of osteoblast differentiation by deactivating NOTCH2 signaling. These findings might provide a new insight for treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

Positron production by ultra-intense laser-accelerated electrons has been studied with two-dimensional particle-in-cell and Monte Carlo simulations. The dependence of the positron yield on plasma density, plasma length, and converter thickness was investigated in detail with fixed parameters of a typical 100 TW laser system. The results show that with the optimal plasma and converter parameters a positron beam containing up to 1.9 × 1010 positrons can be generated, which has a small divergence angle (10°), a high temperature (67.2 MeV), and a short pulse duration (1.7 ps). [ABSTRACT FROM AUTHOR]

An extensive comparison of the properties of positron beams produced by an ultra-intense femtosecond laser in direct and indirect schemes has been performed with two-dimensional particle-in-cell and Monte Carlo simulations. It is shown that the positron beam generated in the indirect scheme has a higher yield (1010), a higher temperature (28.8 MeV), a shorter pulse duration (5 ps), and a smaller divergence (8°) than in the direct case (109 yield, 4.4 MeV temperature, 40 ps pulse duration, and 60° divergence). In addition, it was found that the positron/gamma ratio in the indirect scheme is one order of magnitude higher than that in the direct one, which represents a higher signal/noise ratio in positron detection. Nevertheless, the direct generation method still has its own unique advantage, the so-called target normal sheath acceleration, which can result in quasi-monoenergetic positron beams that may serve in some specialized applications. [ABSTRACT FROM AUTHOR]

The hybrid pixel detector Timepix3 allows the measurement of the time and energy deposition of an event simultaneously in each 55 μ m pixel, which makes Timepix3 a promising approach for a compact Compton camera. However, the angular resolution of Compton camera based on this kind of detector with high pixel density is usually degraded in imaging of MeV gamma-ray sources, because the diffusion of energetic Compton electron or photoelectron could trigger many pixels and lead to an inaccurate measurement of interaction position. In this study, an electron track algorithm is used to reconstruct the electron track and determine the interaction point. An demonstrative experiment was carried out, showing that the effect of this algorithm was significant. The angular resolution measures of a single layer Compton camera based on Timepix3 was enhanced to 12 degrees (FWHM) in imaging of a 60Co gamma-ray source. [ABSTRACT FROM AUTHOR]

For high-energy gain of electron acceleration by a laser wakefield, a stable or guiding propagation of an ultrashort, high-intensity laser pulse in a gas-target plasma is of fundamental importance. Preliminary experiments were carried out for the propagation of 30-fs, ~100-TW laser pulses of intensities ~1019W/cm2 in plasma of densities ~1019/cm3. Self-guiding length of nearly 1.4 mm was observed in a gas jet and 15 mm in a hydrogen-filled capillary. Fluid-dynamics simulations are used to characterize the two types of gas targets. Particle-in-cell simulations indicate that in the plasma, after the pulse's evolution of self-focusing and over-focusing, the high-intensity pulse could be stably guided with a beam radius close to the plasma wavelength. At lower plasma densities, a preformed plasma channel of a parabolic density profile matched to the laser spot size would be efficient for guiding the pulse. [ABSTRACT FROM PUBLISHER]

Objective: To investigate whether the 5/6 nephrectomized (5/6Nx) rats' 12-week serum could lead to tubular epithelialto- mesenchymal transition (EMT) and its molecular mechanism, so as to probe the potential stimulation from circulation in chronic progressive kidney disease. Methods: A total of 24 Sprague Dawley (SD) rats were randomly divided into two groups: sham operation group (sham group) and 5/6Nx group. Rats were killed 12 weeks after surgery to obtain 5/6Nx rats' 12-week serum. Then we detected the expression of E-cadherin in renal tubular epithelial cells of the remaining kidney and we investigated whether the 12th week serum of 5/6Nx rats could cause HK-2 (human kidney proximal tubular cell line) cells to transdifferentiate into fibroblasts. Results: Our data confirmed that E-cadherin expression decreased significantly in the remaining kidney at 12 weeks, and the 5/6Nx rats’ 12-week serum could suppress E-cadherin protein and mRNA expression (p < 0.05). We also found that the 5/6Nx rats' 12-week serum could upregulate ZEB1, β-catenin, and wnt3 protein expression (p < 0.05). Conclusions: Our results demonstrated that the 5/6Nx rats' 12-week serum could suppress the expression of E-cadherin in HK-2 cells. It was partially through modulating the increase of ZEB1. The loss of E-cadherin could lead β-catenin to localize to the cytoplasm and nucleus, and feed into the Wnt signaling pathway. It means that the pathogenic serum in chronic kidney disease (CKD) plays an important role in the loss of renal function and turns to be a new avenue of research with potential clinical implications. [ABSTRACT FROM AUTHOR]

Laser interaction with a nanobrush target plasma is investigated at the SILEX-I laser facility [X. F. Wei et al., J. Phys. Conf. Ser. 112, 032010 (2008)] with a laser of intensity 7.9×1018 W/cm2. Highly collimated fast electron beams with yields of more than three times higher than that from the planar target can be produced. Two-dimensional particle-in-cell simulation confirms that a layered surface structure can increase the efficiency of laser energy absorption, and the resulting fast electrons are tightly collimated and guided by the plasma layers to a cross section of about the laser spot size. [ABSTRACT FROM AUTHOR]