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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.
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.
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.
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.
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.
The long-lived radioisotope 59Ni is of interest in various research fields including neutron dosimetry, radioactive waste management, and astrophysics. In order to achieve the sensitivity required for such applications, the technique of accelerator mass spectrometry (AMS) 59Ni measurement has been developed at the AMS facility at China Institute of Atomic Energy (CIAE). Based on the AE-Q3D detection system in the CIAE AMS facility, the interference in 59Ni counting from the isobar 59Co has been reduced by a factor of 8 × 106. A series of laboratory reference samples and a blank sample were measured to check the performance of 59Ni measurement. A detection sensitivity of about 5 × 10−13 (59Ni/Ni) has been obtained.
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.
In this paper, we discuss the competition between the stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) instabilities under the strong damping condition. Based on a five-wave interaction model, relations of the stationary backscattering reflectivity between SRS and SBS are deduced in the case of homogeneous plasmas. Developments of the two coexistent instabilities are simulated with different parameters. The density and the temperature of plasma are found to be important in determining which instability dominates the backscattering in the regime of competition. Furthermore, the influence of inhomogeneous condition to the pattern of competition is analyzed. Numerical results consist with our theoretical results.
To determine the association between major dietary patterns characterized by factor analysis and risk of depression and anxiety symptoms among adolescents.
Diet and symptoms of depression and anxiety were assessed in a cross-sectional survey among students attending junior high school. Dietary patterns were derived from a self-reported FFQ, which consisted of thirty-eight items. Anthropometric measurements were also performed.
Four junior high schools in Bengbu city, China.
A random sample of 5003 adolescents, 11–16 years of age (mean 13·21 years).
Three major dietary patterns were identified in the study based on factor analysis: ‘snack’, ‘animal food’ and ‘traditional’. The prevalence of depression symptoms, anxiety disorders and the coexistence of both were 11·2 % (560/5003), 14·6 % (732/5003) and 12·6 % (629/5003), respectively. After adjustment for potential confounders, adolescents in the highest tertile of snack dietary pattern scores had a higher odds for ‘pure’ psychological symptoms (‘depression without anxiety’, OR = 1·64; 95 % CI 1·30, 2·06; and ‘anxiety without depression’, OR = 1·87; 95 % CI 1·51, 2·31) compared with coexisting depression and anxiety (OR = 1·93; 95 % CI 1·54, 2·43). Similar to snacks, high consumption of animal foods was associated with a higher risk of psychological symptoms. Compared with low consumption, adolescents in the highest tertile of traditional dietary pattern scores had lower odds for ‘pure’ depression (OR = 0·38; 95 % CI 0·30, 0·49), ‘pure’ anxiety (OR = 0·85; 95 % CI 0·69, 1·04) and coexisting anxiety and depression (OR = 0·50; 95 % CI 0·39, 0·63).
Data from Chinese secondary-school adolescents validated findings from adult populations. Dietary patterns should be considered as important predictors of depression and anxiety among adolescents in further studies.
Signal-In-Space Error (SISE) is important for the system integrity of GNSS. Real-time monitoring SISE has been one of the effective solutions used for improving GNSS system-level integrity. As one of the typical solutions, the Galileo integrity concept uses Signal-In-Space Accuracy (SISA) and Signal-In-Space Monitoring Accuracy (SISMA) respectively to transmit the quality of SIS and the integrity alarming information to users. As an important component of the Galileo Integrity Concept, Worst User Location (WUL) is of great importance for the computation of SISA and SISMA. An improved WUL algorithm based on a geometrical model is given in this paper, which needs no iterative search and is simple when compared with the existing models. The WUL accuracy requirement is discussed based on an analysis of the magnitude of the orbit errors and SIS ranging resolution and error. The conclusion is that, considering the metre-level orbital error observed in the orbit determination process, as long as the orientation error of the WUL is less than three degrees, the projection error of SISE can be kept to centimetre levels. This will satisfy the requirements of most users. The algorithm is further optimised to omit the non-linear iterative parts based on the above assumption. The optimisation reduces computation load and enhances the real-time capability. GPS raw measurements are used to validate the correctness and reliability of the algorithms.
A new species, Primula fenghwaiana C.M.Hu & G.Hao (Primulaceae), from Yunnan, China, is described and illustrated. Primula petelotii W.W.Sm., a species previously known only from one collection from Vietnam, is for the first time found in China. An addendum to the description for this incompletely known species is given.
The current induced magnetic dynamics of a nano-scale pseudo-spin-valve (PSV) structure was theoretically studied. The spin relaxation mechanisms and the influence of ferromagnetic/nonmagnetic (FM/NM) interfaces on the current polarization were investigated, and a modified magnetic dynamic equation was developed. Both the free layer's local magnetic moments and itinerant electrons' spins were regarded as a macro-spin, whose movement was resulted from two items: spin relaxation due to the magnetic damping and spin accumulation due to the polarized current. The injected current not only produces a spin transfer torque, but also alters the effective magnetic field, and thus affects the damping. Therefore, the damping is nonlinear and correlated to the current. Based on the analysis of the competition between magnetic damping and spin accumulation, the dynamic behaviors of magnetization switching and oscillation can be explained.