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The ablation and acceleration of diamond-like high-density carbon foils irradiated by thermal X-ray radiations are investigated with radiation hydrodynamics simulations. The time-dependent front of the ablation wave is given numerically for radiation temperatures in the range of 100–300 eV. The mass ablation rates and ablation pressures can be derived or implied from the coordinates of ablation fronts, which agree well with reported experiment results of high-density carbon with radiation temperatures Trad in the range of 160–260 eV. It is also found that the
scaling law for ablation rates does not apply to Trad above 260 eV. The trajectories of targets and hydrodynamic efficiencies for different target thicknesses can be derived from the coordinates of ablation fronts using a rocket model and the results agree well with simulations. The peak hydrodynamic efficiencies of the acceleration process are investigated for different foil thicknesses and radiation temperatures. Higher radiation temperatures and target thicknesses result in higher hydrodynamic efficiencies. The simulation results are useful for the design of fusion capsules.
Aggressive behaviour is common in animals and typically has lifetime consequences. As younger males have higher residual reproductive value than older males and lose more from injuries than older males do, the propensity for fighting tends to increase with age in many empirical reports and species. However, fighting patterns in those empirical reports cannot confirm the hypothesis that individuals cannot readily inflict injuries on their opponents. To address this shortcoming, a parasitoid wasp species, Anastatus disparis (Hymenoptera: Eupelmidae), was used as an experimental model to explore the characteristics of aggression from a life-history perspective; this wasp exhibits extreme fighting, resulting in contestants experiencing injury and death. Results showed that the energetic costs of fighting to injury significantly shortened life and caused the loss of most mating ability. Inconsistent with general predictions, the frequency and intensity of fighting in A. disparis significantly decreased with male age. Further study results showed significantly more young males were received by and successfully mated with virgin females, and most genes related to energy metabolism were downregulated in aged males. Our study provided supporting evidence that young A. disparis males show more aggression likely because of their resource holding potential and sexual attractiveness decline with age.
The passive oscillations of inverted flags are investigated both experimentally and theoretically in this paper. First, the force and energy distributions of inverted flags, which contain elastic and inertia components, are analysed based on the experimental data. Two main differences between inverted and conventional flags are found: (1) the elastic energy of a conventional flag is concentrated near the free end, while the fixed end of an inverted flag presents the largest elastic energy; and (2) the elastic component is several orders of magnitude greater than the inertia component for an inverted flag, while they are of the same magnitude for a conventional flag. Second, a linear analysis shows that the critical flow velocities obtained from the experiments at small mass ratios are scattered around the theoretical curve of wavenumber
, which is in contrast with
of a conventional flag. For large mass ratios, the mass ratio has a certain influence on the critical velocity rather than being irrelevant. For two parallel inverted flags, both the experimental and theoretical results indicate that the range of the in-phase flapping mode becomes smaller with an increase in the separation distance, and a multiple flapping state may occur. For
parallel inverted flags, the theoretical results show that two of all coupled flapping modes are dominant with most parameters. These findings could contribute to a better understanding of the passive oscillations of inverted flags.
This research utilizes anatase TiO2 incorporated with lithium salt via a simple wet physical method to surface-modified the commercial graphite to form the lithium titanate/graphite composite coated with an amorphous carbon layer on its surface (the double core–shell structure) to enhance its surface conductivity. This double core–shell structure provides a stable specific capacity about 280 mAh/g under the high current density, 2.25 A/g with 15% capacity retention decay. Its intercalation potential is below 1 V that is much lower than that of 1.55 V, the intercalation potential of spinel Li4Ti5O12, to make higher power and energy density for a full cell.
Employing atomic-scale simulations, the response of a high-angle grain boundary (GB), the soft/hard GB, against external loading was systematically investigated. Under tensile loading close to the hard orientation, strain-induced dynamic recrystallization was observed to initiate through direct soft-to-hard grain reorientation, which was triggered by stress mismatch, inhibited by surface tension from the soft-hard GB, and proceeded by interface ledges. Such grain reorientation corresponds with expansion and contraction of the hard grain along and perpendicular to the loading direction, respectively, accompanied by local atomic shuffling, providing relatively large normal strain of 8.3% with activation energy of 0.04 eV per atom. Tensile strain and residual dislocations on the hard/soft GB facilitate the initiation of dynamic recrystallization by lowering the energy barrier and the critical stress for grain reorientation, respectively.
Metal chalcogenides have attracted great attention because of their broad applications. It has been well acknowledged that microstructure can alter the intrinsic properties and performance of metal chalcogenides. The structure–property–performance relationships can be investigated at atomic scale with scanning transmission and transmission electron microscopy (STEM and TEM). Nevertheless, careful specimen preparation is paramount for accurate analyses and interpretations. In this work, we compare the effects of a variety of well-established TEM specimen preparation methods on the observed microstructure of an ingot stoichiometric lead telluride (PbTe). Most importantly, from aberration corrected STEM and first principles calculations, we discovered that argon (Ar) ion milling can lead to surface irradiation damage in the form of Pb vacancy clusters and self-interstitial atom (SIA) clusters. The SIA clusters appear as orthogonal nanoscale features when characterized along the <001> crystal orientation of the rock salt structured PbTe. This obfuscates the interpretation of the intrinsic microstructure of metal chalcogenides, especially lead chalcogenides. We demonstrate that with sufficiently low energy (300 eV) Ar ion cleaning or appropriate high-temperature annealing, the surface damage layer can be properly cleaned and the orthogonal nanoscale features are significantly reduced. This reveals the materials’ intrinsic structure and can be used as the standard protocol for future TEM specimen preparation of lead-based chalcogenide materials.
The utilization of medical resources in China is unbalanced and insufficient. In order to find a way to maximize their utilization to face challenges in the upcoming decade, this study aims to investigate the elderly's first choice of health institutions when they were ill in the Zhejiang and Qinghai provinces, and to explore the potential pathways related to their choices, respectively.
The data used in this study was from cross-sectional surveys in Zhejiang and Qinghai. According to the Anderson Health Service Utilization Model, we applied structural equation modeling to explore the complex pathways from socioeconomic status (SES), accessibility, and health status to the elderly's first choice of health institutions.
The proportion of the elderly who selected community health institutions (CHI) as their first choice of medical institutions in Qinghai was higher than in Zhejiang. The Zhejiang model revealed a significantly negative direct effect of SES and significantly positive direct effects of accessibility to CHI and health status on the choice of institutions, and a significantly positive indirect effect of SES on choice of institutions, through the mediating factor of health status. SES played an important role in the Zhejiang model in direct and indirect ways. In the Qinghai model, only SES and accessibility to CHI had significantly direct effects on the choice of institutions, with accessibility to CHI having the biggest effects. SES had a significant and positive indirect impact on choice of institutions, through the factor of accessibility to CHI.
A better understanding of the complex pathways from factors to elderly's choices of health institutions was essential, which may inform priorities for maximizing the utilization of CHI further and prepare to face challenges in the new decade. Through this research method, policymakers could explore the specific pathways based on their own economic and societal status.
China has made great achievements in health insurance coverage and healthcare financing. Nonetheless, the rate of catastrophic health expenditure (CHE) in China was 13 percent in 2008, which is higher than in some other countries. There are differences among the provinces in China in terms of the lifestyles, customs, prevalent medical conditions, and health consciousness of their populations. This study aimed to compare the proportion of households with CHE and the factors influencing this expenditure between the Zhejiang and Qinghai province in China.
Data were derived from household surveys conducted in Zhejiang and Qinghai. Sampling was based on a multi-stage, stratified random cluster method. Households with CHE were defined as those with an out-of-pocket payment for health care that was at least 40 percent of the household income. Univariate and multivariate logistic regression analyses were used to identify the factors associated with CHE.
A total of 1,598 households were included: 995 in Zhejiang and 603 in Qinghai. The average rates of CHE in Zhejiang and Qinghai were 10 percent and 31 percent, respectively. The economic status of a household influenced the likelihood of experiencing CHE; households headed by an employed person were less likely to experience CHE. In contrast, households that included outpatients or individuals with chronic diseases had a higher risk of experiencing CHE across the two provinces. Poorer or uninsured households in Zhejiang were more likely to experience CHE, as were households in Qinghai that included outpatients or were headed by a person from a minority nationality.
This study highlighted the importance of promoting economic development, expanding employment, and adjusting policies to better protect individuals with chronic diseases and outpatients from the risk of CHE. The Chinese government should pay more attention to actual conditions in different provinces to ensure that policy decisions incorporate local knowledge.
Previous studies show inconsistent associations between α-linolenic acid (ALA) and risk of CHD. We aimed to examine an aggregate association between ALA intake and risk of CHD, and assess for any dose–response relationship. We searched the PubMed, EMBASE and Web of Science databases for prospective cohort studies examining associations between ALA intake and CHD, including composite CHD and fatal CHD. Data were pooled using random-effects meta-analysis models, comparing the highest category of ALA intake with the lowest across studies. Subgroup analysis was conducted based on study design, geographic region, age and sex. For dose–response analyses, we used two-stage random-effects dose–response models. In all, fourteen studies of thirteen cohorts were identified and included in the meta-analysis. The pooled results showed that higher ALA intake was associated with modest reduced risk of composite CHD (risk ratios (RR)=0·91; 95 % CI 0·85, 0·97) and fatal CHD (RR=0·85; 95 % CI 0·75, 0·96). The analysis showed a J-shaped relationship between ALA intake and relative risk of composite CHD (χ2=21·95, P<0·001). Compared with people without ALA intake, only people with ALA intake <1·4 g/d showed reduced risk of composite CHD. ALA intake was linearly associated with fatal CHD – every 1 g/d increase in ALA intake was associated with a 12 % decrease in fatal CHD risk (95 % CI −0·21, −0·04). Though a higher dietary ALA intake was associated with reduced risk of composite and fatal CHD, the excess composite CHD risk at higher ALA intakes warrants further investigation, especially through randomised controlled trials.
Equity is the core of primary care. The issue of equity in health has become urgent and China has attached increasing attention to it. With rapid economic development and great change of the policy on medical insurance, the pattern of equity in health has changed a lot. Reform of healthcare in Zhejiang province is at the forefront of China; studies on Zhejiang are of great significance to the whole country. This paper aims to measure the equity in health from the perspectives of health needs and health seeking behavior, and provides suggestions for decision making.
A household survey was conducted in August 2016. A sample of 1000 households, 2807 individuals in Zhejiang was obtained with the multi-stage stratified cluster sampling method. Descriptive analysis and Chi-square test were adopted in the analysis. The value of concentration index was used to measure the equity.
This study finds that the poor have more urgent health needs and poorer health situation compared with the rich. The utilization of outpatient services was almost equal, whilst the utilization of hospitalization was pro-rich (the rich use more).Individuals with employer-based medical insurance use more outpatient services than those with rural and urban medical insurance. Compared to the rich, there were more people in the poorer income groups who didn't use inpatient services due to financial difficulties.
The issue of equity in health has attracted broad attention in the world, and China is no exception. We measured and analyzed the equity of health needs and absent rate of health services. We find that the poor have more urgent health needs and high absent rate of inpatient services compared with the rich. Income level and medical insurance may well explain the equity of outpatient and inequity of hospitalization. In view of the pro-rich inequity of hospitalization, more financial protection should be provided for the poor.
Disclosing the diagnosis of Alzheimer's disease (AD) to a patient is controversial. There is significant stigma associated with a diagnosis of AD or dementia in China, but the attitude of the society toward disclosure of such a diagnosis had not been formally evaluated prior to our study. Therefore, we aimed to evaluate the attitude toward disclosing an AD diagnosis to patients in China with cognitive impairment from their caregivers, and the factors that may affect their attitude.
We designed a 17-item questionnaire and administered this questionnaire to caregivers, who accompanied patients with cognitive impairment or dementia in three major hospitals in Shanghai, China. The caregiver's attitude toward disclosing the diagnosis of AD as evaluated by the questionnaire was compared to that of disclosing the diagnosis of terminal cancer.
A majority (95.7%) of the 175 interviewed participants (mean 14.2 years of education received) wished to know their own diagnosis if they were diagnosed with AD, and 97.6% preferred the doctor to tell their family members if they were diagnosed with AD. If a family member of the participants suffered from AD, 82.9% preferred to have the diagnosis disclosed to the patient. “Cognitive impairment” was the most accepted term by caregivers to disclose AD diagnosis in Chinese.
This study suggests most of the well-educated individuals in a Chinese urban area favored disclosing the diagnosis when they or their family members were diagnosed with AD.
In this paper, a three-dimensional (3D) model as a new module of LAP3D code is presented to study the crossed-beam energy transfer (CBET) process. This model is not limited by the paraxial approximation and can be used to deal with a large crossing angle case. Besides, this model is also appropriate for the multi-ion species conditions and even multi-beams problems, which will be very helpful in relevant experiment analysis and the target design. In our 3D simulations, we take the overlapped beams with a 60° crossing angle as an example, and observe obvious energy transfer process, which indicates CBET process might occur between the incident laser beams with a large crossing angle when the matching condition is satisfied. This large crossing angle CBET process also can change the spatial shape of the beam spot, and may have some potential important influence on other laser–plasma interaction instabilities and the energy symmetry in hohlraum.
This paper describes an optimized magnetic wheel solution for use in a novel grit-blasting robot intended to be used on the hulls of ships. The grit-blasting robot was designed for conducting surface operations on newly-built ships in dry yards. It can be adapted to curvatures of up to 0.833 m−1; can achieve a total payload of 120 kg and can also be steered. The proposed magnetic wheel solution for robots with such payloads and surface adaptability has not been seen in previous work.
As the magnetic force acting on a magnetic wheel is very sensitive to the working conditions, a mathematical model was built to derive the exact force requirements taking into account the mechanical structure of the robot and its disposition on the ship's hull. In this paper, the design of the wheels was optimized based on the model. Wheels were manufactured according to the optimized results and a prototype robot was constructed. The design was then validated using locomotion tests.
The NASA Kepler satellite has provided unprecedented high duty-cycle, high-precision light curves for a large number of stars by continuously monitoring a field of view in Cygnus-Lyra region, leading to great progress in both discovering exoplanets and characterizing planet-hosting stars by means of asteroseismic methods. The asteroseismic survey allows the investigation of stars covering the whole H-R diagram. However, the low precision of effective temperatures and surface gravities in the KIC catalogue and the lack of information on chemical composition, metallicity and rotation rate prevent asteroseismic modeling, requiring spectroscopic observations for thousands of asteroseismic targets in the Kepler field in a homogeneous way.
To evaluate the genetic diversity (GD) of wild and cultivated soybeans and determine the genetic relationships between them, in this study, 127 wild soybean accessions and 219 cultivated soybean accessions were genotyped using 74 simple sequence repeat (SSR) markers. The results of the study revealed that the GD of the wild soybeans exceeded that of the cultivated soybeans. In all, 924 alleles were detected in the 346 soybean accessions using 74 SSRs, with an average of 12.49 alleles per locus. In the 219 cultivated soybean accessions, 687 alleles were detected, with an average of 9.28 alleles per locus; in the 127 wild soybean accessions, 835 alleles were detected, with an average of 11.28 alleles per locus. We identified 237 wild-soybean-specific alleles and 89 cultivated-soybean-specific alleles in the 346 soybean accessions, and these alleles accounted for 35.28% of all the alleles in the sample. Principal coordinates analysis and phylogenetic analysis based on Nei's genetic distance indicated that all the accessions could be classified into two major clusters, corresponding to wild and cultivated soybeans. These results will increase our understanding of the genetic differences and relationships between wild and cultivated soybeans and provide information to develop future breeding strategies to improve soybean yield.
Early identification of patients with bipolar disorder during their first depressive episode is beneficial to the outcome of the disorder and treatment, but traditionally this has been a great challenge to clinicians. Recently, brain-derived neurotrophic factor (BDNF) has been suggested to be involved in the pathophysiology of bipolar disorder and major depressive disorder (MDD), but it is not clear whether BDNF levels can be used to predict bipolar disorder among patients in their first major depressive episode.
To explore whether BDNF levels can differentiate between MDD and bipolar disorder in the first depressive episode.
A total of 203 patients with a first major depressive episode as well as 167 healthy controls were recruited. After 3 years of bi-annual follow-up, 164 patients with a major depressive episode completed the study, and of these, 21 were identified as having bipolar disorder and 143 patients were diagnosed as having MDD. BDNF gene expression and plasma levels at baseline were compared among the bipolar disorder, MDD and healthy control groups. Logistic regression and decision tree methods were applied to determine the best model for predicting bipolar disorder at the first depressive episode.
At baseline, patients in the bipolar disorder and MDD groups showed lower BDNF mRNA levels (P<0.001 and P = 0.02 respectively) and plasma levels (P = 0.002 and P = 0.01 respectively) compared with healthy controls. Similarly, BDNF levels in the bipolar disorder group were lower than those in the MDD group. These results showed that the best model for predicting bipolar disorder during a first depressive episode was a combination of BDNF mRNA levels with plasma BDNF levels (receiver operating characteristics (ROC) = 0.80, logistic regression; ROC = 0.84, decision tree).
Our findings suggest that BDNF levels may serve as a potential differential diagnostic biomarker for bipolar disorder in a patient's first depressive episode.
Flexible electronics and microsystems are an emerging technology with a tremedous impact to the future electronics and information technology and widespread applications. Various devices and microsystems have been developed. Surface acoustic wave (SAW) devices are a type of essential device for electronics, microsensors and microsystems; however there is no activity on the development of flexible SAW devices yet. This paper reports the development of flexible SAW devices on cheap, bendable and disposable plastic films. Flexible SAW devices with resonant frequency of 198.1 MHz and 447 MHz for the Rayleigh and Lamb waves respectively have been obtained with a large transmission signal up to 18dB. The flexible SAW devices have also demonstrated their ability for acoustic streaming with a velocity up to 3.4 cm/s and for particle concentration. The results have clearly demonstrated that the flexible SAW devices have great potential for applications in electronics and microsystems.
The influence of Zn on the adsorption and desorption of Cry1Ab toxin from Bacillus thuringiensis (Bt) on palygorskite and montmorillonite was studied. The adsorption of the toxin gradually increased with increasing Zn concentration from 0 to 1.0 mmol L–1, and then decreased with further increase in Zn concentration. The adsorption isotherms of the toxin in the absence and presence of Zn were well described by the Langmuir equation (R2 > 0.9810–0.9991). The separation factor (RL) decreased with increase of Zn concentration, suggesting that the irreversibility of the adsorption increases. The XRD results showed that the treatment by Tris buffer or Zn(NO3)2 solution caused an expansion of the interlayer space of montmorillonite but did not affect palygorskite. The IR spectra suggest that Zn was likely to be combined with amino groups on the surface of the toxin. The presence of Zn during the adsorption of the toxin decreased desorption, suggesting that the residual risk of toxin would be exacerbated if soil is polluted by zinc.