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Radiocarbon (14C) has become a unique and powerful tracer in source apportionment of atmospheric carbonaceous particles. In this study, the Asia Pacific Economic Cooperation summit (APEC) held in Beijing in 2014 was used as a demonstration to research the source apportionment of atmosphere PM2.5. We used a 200 kV single stage accelerator mass spectrometer recently completed at China Institute of Atomic Energy (CIAE). The PM2.5 samples related to above case were collected, and the characteristics of radiocarbon in organic carbon (OC) and elemental carbon (EC) in samples were analyzed using the AMS. The results show that the Before-APEC pollution emission mode is different from the During-APEC and After-APEC pollution emission modes. For Before-APEC, During-APEC and After-APEC, the average values of fossil carbon fraction of OC are 0.463, 0.431 and 0.615, respectively, and those of EC are 0.644, 0.561 and 0.687. The fossil source contributions of traffic activities using fossil fuels to OC and EC are 15.8 % and 21.9 %, respectively. The fossil source contributions of industrial activities to OC and EC are 38.0 % and 8.2 %, respectively. It is about 7–10 days that is needed to take to regenerate the PM2.5 pollution caused by human activities.
Echinococcus granulosus sensu stricto (s.s.), Echinococcus multilocularis and Echinococcus canadensis are the common causes of human echinococcosis in China. An accurate species identification tool for human echinococcosis is needed as the treatments and prognosis are different among species. The present work demonstrates a method for the simultaneous detection of these three Echinococcus species based on multiplex polymerase chain reaction (mPCR). Specific primers of this mPCR were designed based on the mitochondrial genes and determined by extensive tests. The method can successfully detect either separated or mixed target species, and generate expected amplicons of distinct size for each species. Sensitivity of the method was tested by serially diluted DNA, showing a detection threshold as less as 0.32 pg for both E. granulosus s.s. and E. canadensis, and 1.6 pg for E. multilocularis. Specificity assessed against 18 other parasites was found to be 100% except weakly cross-react with E. shiquicus. The assay was additionally applied to 69 echinococcosis patients and 38 healthy persons, confirming the high reliability of the method. Thus, the mPCR described here has high application potential for clinical identification purposes, and can further provide a useful tool for evaluation of serology and imaging method.
The Weibel instability and the induced magnetic field are of great importance for both astrophysics and inertial confinement fusion. Because of the stochasticity of this magnetic field, its main wavelength and mean strength, which are key characteristics of the Weibel instability, are still unobtainable experimentally. In this paper, a theoretical model based on the autocorrelation tensor shows that in proton radiography of the Weibel-instability-induced magnetic field, the proton flux density on the detection plane can be related to the energy spectrum of the magnetic field. It allows us to extract the main wavelength and mean strength of the two-dimensionally isotropic and stochastic magnetic field directly from proton radiography for the first time. Numerical calculations are conducted to verify our theory and show good consistency between pre-set values and the results extracted from proton radiography.
Oxidative stress is closely related to metabolic disorders, which can lead to various diseases. Nuclear factor E2-related factor 2 (Nrf2) is a central regulator of oxidative stress. Sodium butyrate (NaB) has been shown to alleviate oxidative stress and insulin resistance, yet how Nrf2 is involved in the action of NaB remains unclear. In the present study, rats were rendered obese by feeding a high-fat diet for 9 weeks. NaB (300 mg/kg), which was gavaged every 2 d for 7 weeks, significantly alleviated high-fat diet-induced oxidative stress and insulin resistance. Additionally, the insulin signalling pathway in the liver was activated by NaB, associated with significant activation of Nrf2, superoxide dismutase and glutathione. Furthermore, hepatic up-regulation of Nrf2 in NaB-treated rats was associated with reduced protein content of histone deacetylase 1 and increased histone H3 acetyl K9 (H3K9Ac) modification on the Nrf2 promoter. The actions of NaB were completely abolished when Nrf2 was knocked down in vitro. Taken together, NaB acts as a histone deacetylase inhibitor to up-regulate Nrf2 expression with enhanced H3K9Ac modification on its promoter. NaB-induced Nrf2 activation stimulates transcription of downstream antioxidant enzymes, thus contributing to the amelioration of high-fat diet-induced oxidative stress and insulin resistance.
Coupled with the social practice of female hypergamy, the male surplus within the never-married population means that today's Chinese marriage market is extremely tight in particular for men from a rural background and the least privileged socio-economic categories. Drawing on quantitative data from a survey conducted in 2014–2015, this article sheds light on the situation of single men who are past prime marriage age in three rural districts of Shaanxi particularly affected by this phenomenon. It compares single men's characteristics to those of their married counterparts and offers insights into the heterogeneity of single men with the aim of challenging some commonly accepted assumptions about bachelorhood in rural China. Results suggest a strong internalization of the various characteristics, centred on being able to offer social mobility to a potential wife, that a man is expected to have to be attractive to women in a context where women have more choice in mate selection. We conclude that mate selection is highly marked by class, social norms, social interactions, health, generation and age, and requires the mobilization of certain amounts of individual, social and economic resources. Unwanted bachelorhood would thus be better understood using an intersectional approach rather than mainly in numeric terms.
In January 2016, static GPS measurements were carried out in a 30 × 30 km2 area centered around Kunlun station at Dome Argus (Dome A), East Antarctica, to acquire high-precision 3-D geodetic coordinates at 49 sites. By comparing the coordinates with previous GPS measurements in 2008 and 2013 at the same sites, we constructed a detailed and long-term record of the ice-surface velocity field, 2008–2016, around Dome A. During this time span, the estimated ice-surface velocity ranges from 0.8 ± 0.3 to 28.7 ± 1.6 cm a−1, with a mean of 10.4 ± 0.3 cm a−1. From 2013 to 2016, the surface elevation of most Dome A areas exhibits a rising trend, and the maximum increase of snow surface elevation is 84.8 cm. The mean snow surface elevation change rate at Dome A is estimated to be 6.6 ± 0.7 cm a−1. The difference of 1.0 cm a−1 between the snow surface change rate derived from GPS and pole-height change rate from surface mass balance is suspected to be a result of a combination of firn densification and basal melt under Dome A.
Although it is crucial to improve the treatment status of people with severe mental illness (SMI), it is still unknown whether and how socioeconomic development influences their treatment status.
To explore the change in treatment status in people with SMI from 1994 to 2015 in rural China and to examine the factors influencing treatment status in those with SMI.
Two mental health surveys using identical methods and ICD-10 were conducted in 1994 and 2015 (population ≥15 years old, n = 152 776) in the same six townships of Xinjin County, Chengdu, China.
Compared with 1994, individuals with SMI in 2015 had significantly higher rates of poor family economic status, fewer family caregivers, longer duration of illness, later age at first onset and poor mental status. Participants in 2015 had significantly higher rates of never being treated, taking antipsychotic drugs and ever being admitted to hospital, and lower rates of using traditional Chinese medicine or being treated by traditional/spiritual healers. The factors strongly associated with never being treated included worse mental status (symptoms/social functioning), older age, having no family caregivers and poor family economic status.
Socioeconomic development influences the treatment status of people with SMI in contemporary rural China. Relative poverty, having no family caregivers and older age are important factors associated with a worse treatment status. Culture-specific, community-based interventions and targeted poverty-alleviation programmes should be developed to improve the early identification, treatment and recovery of individuals with SMI in rural China.
To examine urban–rural disparity in childhood stunting, wasting and malnutrition at national and subnational levels in Chinese primary-school children in 2010 and 2014.
Data were obtained from two nationwide cross-sectional surveys conducted in 2010 and 2014. Malnutrition was classified using the Chinese national ‘Screening Standard for Malnutrition of Children’.
All twenty-seven mainland provinces and four municipalities of mainland China.
Children aged 7–12 years (n 215 214; 107 741 in 2010 and 107 473 in 2014) from thirty-one provinces.
Stunting, wasting and malnutrition prevalence were 1·9, 12·3 and 13·7 % in 2010, but decreased to 1·0, 9·4 and 10·2 % in 2014, respectively. The prevalence of stunting, wasting and malnutrition in both urban and rural children was higher in western provinces, while lower in eastern provinces. Although the prevalence of wasting and malnutrition was higher in rural children than their urban counterparts, the urban–rural disparity in both wasting and malnutrition decreased from 2010 to 2014 (prevalence OR: wasting, 1·35 to 1·16; malnutrition, 1·50 to 1·27). A reversal occurred in 2014 in several eastern provinces where the prevalence of wasting and malnutrition in urban children surpassed their rural peers. The urban–rural disparity was larger in western provinces than eastern provinces.
The shrinking urban–rural disparity and the reversal in wasting and malnutrition suggest that the malnutrition situation has improved during the post-crisis period, especially in the western provinces. Region-specific policies and interventions can be useful to sustainably mitigate malnutrition in Chinese children, especially in rural areas and the western provinces.
Direct numerical simulation is conducted to uncover the response of a supersonic turbulent boundary layer to streamwise concave curvature and the related physical mechanisms at a Mach number of 2.95. Streamwise variations of mean flow properties, turbulence statistics and turbulent structures are analysed. A method to define the boundary layer thickness based on the principal strain rate is proposed, which is applicable for boundary layers subjected to wall-normal pressure and velocity gradients. While the wall friction grows with the wall turning, the friction velocity decreases. A logarithmic region with constant slope exists in the concave boundary layer. However, with smaller slope, it is located lower than that of the flat boundary layer. Streamwise varying trends of the velocity and the principal strain rate within different wall-normal regions are different. The turbulence level is promoted by the concave curvature. Due to the increased turbulence generation in the outer layer, secondary bumps are noted in the profiles of streamwise and spanwise turbulence intensity. Peak positions in profiles of wall-normal turbulence intensity and Reynolds shear stress are pushed outward because of the same reason. Attributed to the Görtler instability, the streamwise extended vortices within the hairpin packets are intensified and more vortices are generated. Through accumulations of these vortices with a similar sense of rotation, large-scale streamwise roll cells are formed. Originated from the very large-scale motions and by promoting the ejection, sweep and spanwise events, the formation of large-scale streamwise roll cells is the physical cause of the alterations of the mean properties and turbulence statistics. The roll cells further give rise to the vortex generation. The large number of hairpin vortices formed in the near-wall region lead to the improved wall-normal correlation of turbulence in the concave boundary layer.
The evolution of fatigue performance and surface mechanical properties of AISI 304 stainless steel induced by the electropulsing-assisted ultrasonic surface rolling process (EP-USRP) was systematically investigated by integrating instrumented indentation, scanning electron microscopy with electron backscatter diffraction, and transmission electron microscopy. The results indicate that higher hardness, greater strength, finer ultra-refined grains, and higher residual compressive stress are formed within the strengthened layer compared with the original ultrasonic surface rolling process (USRP). EP-USRP with the optimized experimental parameters can produce a higher average rotating bending fatigue strength for AISI 304 stainless steel than USRP. Anomalously and noteworthily, all fatigue specimens treated by EP-USRP showed an incomplete fracture, revealing a higher reservation of safety in practical engineering applications. The further modified structure strengthening and stress strengthening induced by EP-USRP are likely the primary intrinsic reasons for the observed phenomena. Furthermore, the influence mechanism of EP-USRP was discussed scrupulously.
The hot deformation behavior of Ti–6Al–4V alloy with starting fully lamellar microstructure was investigated by conducting isothermal hot compression tests at the temperature of 700–1000 °C and strain rate of 0.001–10 s−1. The deformation activation energy is calculated to be 342 kJ/mol at temperatures from 750 to 850 °C, whereas the higher apparent activation energy of 610 kJ/mol is obtained at a high temperature regime of 900–1000 °C. The relationship between the dynamic softening behavior and deformation parameters was analyzed by power dissipation efficiency η, which shows an increasing trend as the deformation temperature increases and strain rate decreases, respectively. Processing maps were constructed. The instability flow is dominated by the presence of adiabatic shear bands, and the dynamic softening is mainly caused by a combination effect of dynamic recrystallization and dynamic recovery. Moreover, straining is found to have a positive effect on lowering the phase transformation temperature.
A compact dual-wideband (DWB) bandpass filter utilizing open-shorted coupled lines (OSCL) is proposed in this paper. The introduction of the folded structure not only reduces the overall size but also contribute to the split of the transmission zero (TZ), which improves the selectivity effectively. Six transmission poles and five TZs are realized utilizing the shorted-circuit stub and OSCL. The characteristic of the flexible adjustment method of TZs guarantees an independently wide adjustable range of the bandwidth. For demonstration, a DWB filter (3 dB bandwidth 120 and 28%, respectively) is designed and fabricated. The filter is compact and has the characteristics of extraordinary wide bandwidth, low insertion loss, as well as high selectivity.
Northeastern China is a region of high tick abundance, multiple tick-borne pathogens and likely human infections. The spectrum of diseases caused by tick-borne pathogens has not been objectively evaluated in this region for clinical management and for comparison with other regions globally where tick-transmitted diseases are common. Based on clinical symptoms, PCR, indirect immunofluorescent assay and (or) blood smear, we identified and described tick-borne diseases from patients with recent tick bite seen at Mudanjiang Forestry Central Hospital. From May 2010 to September 2011, 42% (75/180) of patients were diagnosed with a specific tick-borne disease, including Lyme borreliosis, tick-borne encephalitis, human granulocytic anaplasmosis, human babesiosis and spotted fever group rickettsiosis. When we compared clinical and laboratory features to identify factors that might discriminate tick-transmitted infections from those lacking that evidence, we revealed that erythema migrans and neurological manifestations were statistically significantly differently presented between those with and without documented aetiologies (P < 0.001, P = 0.003). Twelve patients (6.7%, 12/180) were co-infected with two tick-borne pathogens. We demonstrated the poor ability of clinicians to identify the specific tick-borne disease. In addition, it is necessary to develop specific laboratory assays for optimal diagnosis of tick-borne diseases.
In this paper, a triple-wideband bandpass filter (BPF) with controllable bandwidths based on two multi-mode stub-loaded resonators (MMSLRs) and a triple-mode resonator is presented. The MMSLR is loaded with two identical folded open-ended stubs and a T-shaped stub. Each passband of the tri-band BPF is formed by four resonant modes, which provide sufficient bandwidths to meet various application requirement. By adjusting the lengths of open-ended stubs, three passband bandwidths can be controlled individually. The center frequencies of the triple-wideband BPF are allocated at 2.7, 3.67, and 5.44 GHz, with the 3 dB fractional bandwidths (FBWs) of 20.1, 14.7, and 26.3%. Among the three passbands, the highest one covers the 5 G WiFi band (5.15–5.85 GHz). The measured results of the proposed filter exhibit excellent agreement with simulated results.
High-precision underwater positioning must eliminate the influence of refraction artefacts. Since a Time Of Arrival - Global Navigation Satellite System Intelligent Buoys (TOA-GIB) system does not measure incident beam angles, common refraction correction methods cannot be directly used for refraction artefacts. An Equivalent Sound Speed (ESS) iteration method is proposed and is based on the transformation relations between depth, the ESS gradient and the incident beam angle. On this basis, a TOA/AOA-GIB system without a real-time Sound Speed Profile (SSP) is proposed to estimate the target position and the ESS gradient as unknown parameters. The results from a simulation experiment show that the positioning accuracy of a TOA/AOA-GIB system is better than 0·07% of water depth when the accuracy of the incident beam angle is 0·1°.
Invasive smooth cordgrass (Spartina alterniflora Loisel) eradication is important for the health of many coastal ecosystems. An integrated regime of continuous submergence after clear mowing, with three interval levels between mowing and submergence (5, 10, and 15 d) and three submergence depths (20, 30, and 50 cm), was implemented in cofferdams enclosing invader populations along a Chinese coast. In July of the following year, after the roots of mowed S. alterniflora had been submerged for 12 mo, some ramets grew under the regime with an interval of 15 d and the regime with a submergence depth of 20 cm, but no ramets occurred under the regimes with submergence depths of 30 or 50 cm and intervals of 5 or 10 d. Four crab species were documented: Helice tridens tientsinensis Rathbun, Sesarma dehaani H. Milne-Edwards, Ocypode stimpsoni Ortmann, and Chiromantes haematocheir de Haan. Biomass and abundance values of crab species in the cofferdams were similar to those in the mudflats but different from those in smooth cordgrass populations. Thus, the treatment of submergence after mowing, which was implemented in the cofferdams, can control S. alterniflora and provide a mudflat-like habitat that promotes crab recovery if this treatment uses the proper combination of submergence depth and interval between mowing and submergence.
Using repeat GPS measurements during 2005–16, we calculated and updated two-dimensional high-resolution decadal ice surface velocity estimates along the traverse route from Zhongshan Station to and around Dome Argus, East Antarctica. Along the 71 sites of the transect, the magnitudes of ice velocity increased from near 0 in Dome Argus to 1, 10 and ~100 m a−1 at the sites DT416, DT333 and LT980, respectively. The comparison between GPS and interferometric synthetic aperture radar (InSAR) derived results agree well when the magnitude of the ice surface velocities is faster than 5 m a−1, and disagree for slower flow velocities. A scale value 1.15 and 0.12 can be applied to InSAR derived results over this region with ice surface velocity larger and <5 m a−1, respectively. We attributed the cause of the discrepancy to the insensitivity of InSAR to the magnitude of low ice surface velocities, thus confirming the importance of GPS fieldwork-based ground truth high-resolution ice velocity estimates to constrain ice-sheet dynamics.
Comparable corpora serve as an important substitute for parallel resources in cases of under-resourced language pairs. Previous work mostly aims to find a better strategy to exploit existing comparable corpora, while ignoring the variety in corpus quality. The quality of comparable corpora affects a lot its usability in practice, a fact that has been justified by several studies. However, researchers have not been able to establish a widely accepted and fully validated framework to measure corpus quality. We will thus investigate in this paper a comprehensive methodology to deal with the quality of comparable corpora. To be exact, we will propose several comparability measures and a quantitative strategy to test those measures. Our experiments show that the proposed comparability measure can capture gold-standard comparability levels very well and is robust to the bilingual dictionary used. Moreover, we will show in the task of bilingual lexicon extraction that the proposed measure correlates well with the performance of the real world application.
Randomised controlled trials comparing low- v. high-fat diets on cardiometabolic risk factors in people with overweight or obesity have shown inconsistent results, which may be due to the mixed metabolic status of people with excess adiposity. The role of dietary fat manipulation in modifying cardiometabolic indicators in people with overweight or obese without metabolic disturbance is unclear. Thus, meta-analysis was conducted to compare low- v. high-fat diets on cardiometabolic indicators in people who are overweight or obese without metabolic disturbance in the present study. Databases were searched until October 2016. The pooled effects of outcomes with heterogeneity were calculated with a random-effects model, heterogeneities were analysed by subgroup and meta-regression. As a result, twenty studies with 2106 participants were included in the meta-analysis. Total cholesterol and LDL-cholesterol levels were lower following low-fat diets compared with high-fat diets: weighted mean difference (WMD) was −7·05 mg/dl (−0·18 mmol/l; 95 % CI −11·30, −2·80; P=0·001) and −4·41 mg/dl (−0·11 mmol/l; 95 % CI −7·81, −1·00; P=0·011), respectively. Conversely, significant higher level of TAG (WMD: 11·68 mg/dl (0·13 mmol/l), 95 % CI 5·90, 17·45; P<0·001) and lower level of HDL-cholesterol (WMD: −2·57 mg/dl (−0·07 mmol/l); 95 % CI −3·85, −1·28; P<0·001) were found following low-fat diets compared with high-fat diets. In conclusion, dietary fat manipulation has a significant influence on blood lipid levels in people with overweight or obesity without metabolic disturbances.
Diabetic nephropathy (DN) is a major cause of chronic kidney disease. We aimed to investigate the effect of the low-protein diets (LPD) supplemented with ketoacids (LPD+KA) in KKAy mice, an early type 2 DN model. KKAy mice were treated with normal protein diet (NPD), LPD or LPD+KA from 12 to 24 weeks of age. A period of 12-week treatment with LPD significantly reduced albuminuria as compared with that observed after NPD treatment. Treatment with LPD+KA further reduced albuminuria as compared with that observed with LPD treatment alone. Moreover, LPD treatment reduced mesangial expansion, thickness of glomerular basement membrane and the severity of the podocyte foot process effacement in KKAy mice; these effects were more pronounced in KKAy mice treated with LPD+KA. Both LPD and LPD+KA treatments slightly reduced total body weight, but had no significant effect on kidney weight and blood glucose concentrations when compared with NPD-treated KKAy mice. LPD treatment slightly attenuated oxidative stress in kidneys as compared with that observed in NPD-treated KKAy mice; however, LPD+KA treatment remarkably ameliorated oxidative stress in diabetic kidneys as shown by decreased malondialdehyde concentrations, protein carbonylation, nitrotyrosine expression and increased superoxide dismutase expression. Nutritional therapy using LPD+KA confers additional renal benefits as compared with those of LPD treatment alone in early type 2 DN through inhibition of oxidative stress.