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The North Qilian orogenic belt in North China has been defined as a subduction–collision zone between the Alxa Block and the Qilian Block. We present petrography, zircon U–Pb geochronology, major- and trace-element geochemistry, and Sr–Nd–Pb–Hf isotope analysis for the Yushigou diabase from the Longshoushan area, which is located SW of the Alxa Block, aiming to understand its petrogenetic link to subduction processes. The Yushigou diabase belongs to the tholeiite series, and shows enrichment in light rare earth and large-ion lithophile elements, and a depletion in heavy rare earth and high-field-strength elements. Laser ablation – inductively coupled plasma – mass spectrometry U–Pb zircon dating yielded an emplacement age of 414 ± 9 Ma, with an ϵHf(t) value in the range of −10.3 to 1.8. The whole-rock initial 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of the diabase range over 16.811–17.157, 15.331–15.422 and 37.768–37.895, respectively. The (87Sr/86Sr)i ratios vary between 0.7086 and 0.7106, and ϵNd(t) values vary between −14.4 and −13.4, which are significantly higher than the ϵHf(t) value (Nd–Hf decoupling). An interpretation of the elemental and isotopic data suggests that the Yushigou diabase was derived from partial melting of an enriched mantle I (EM-I) -type lithospheric mantle in the spinel–garnet transitional zone. Based on the geochemical features and previous regional geological data, we propose that the Silurian magmatism was most likely triggered by slab break-off after the closure of the North Qilian Ocean, and ancient continental materials from the subduction slab metasomatized the overlying lithospheric mantle during exhumation.
Palaeoscolecid worms are widespread in the Palaeozoic period, and are of key importance to understanding the emergence of moulting animals (superphylum Ecdysozoa). However, palaeoscolecids lack a diagnostic set of morphological characters, and as such are unlikely to form a natural (monophyletic) group. Consequently, detailed anatomical study of individual taxa is necessary in order to evaluate the phylogenetic significance of palaeoscolecids. New specimens of Mafangscolex from the Cambrian Stage 3 Xiaoshiba Lagerstätte in Kunming, China, provide the first detailed account of a proboscis in Palaeoscoelcida sensu stricto, a core group of palaeoscolecids characterized by having a tessellating scleritome of phosphatic plates and platelets. The eversible mouthparts of Mafangscolex comprise an armoured, hexaradially symmetrical introvert, a ring of coronal spines and quincuncially arranged pharyngeal armature, with a range of tooth morphologies. Taken together, this configuration strikingly resembles the proboscis arrangement inferred for the ancestral ecdysozoan. The six-fold symmetry represents an important difference from the pentaradial priapulan proboscis. The retention of key aspects of the ancestral ecdysozoan body plan suggests that palaeoscolecids represent a useful window on the earliest stages of ecdysozoan evolution.
A new fast-growing mycobacterium, designated strain QGD101T, was isolated from the sputum of an 84-year-old man suspected of tuberculosis in Wuhan Medical Treatment Center, Hubei, China. This strain was a gram-staining-negative, aerobic, non-spore-forming and catalase-positive bacterium, which was further identified as the NTM by PNB and TCH tests. The moxifloxacin and levofloxacin exhibited strong suppressing function against QGD101T with MIC values of 0.06 and 0.125 µg/ml after drug susceptibility testing of six main antimicrobial agents on mycobacteria. Based on the sequence analysis of 16S rRNA, rpoB, hsp65 and 16S-23S rRNA internal transcribed spacer, the strain QGD101T could not be identified to a species level. Mycobacterium moriokaense ATCC43059T that shared the highest 16S rRNA gene sequence similarity (98%) with strain QGD101T was actually different in genomes average nucleotide identity (78.74%). In addition, the major cellular fatty acids of QGD101T were determined as C18:1ω9c, C16:0 and C18:2ω6c. The DNA G + C content was 64.9% measured by high performance liquid chromatography. Therefore, the phenotypic and genotypic characterisation of this strain led us to the conclusion that it represents a novel species of mycobacteria, for which the name Mycobacterium hubeiense sp. nov. (type strain QGD101T = CCTCCAA 2017003T = KCTC39927T) was proposed. Thus, the results of this study are very significant for the clinical diagnosis of tuberculosis and future personalised medicine.
The association between milk consumption and the metabolic syndrome remains inconclusive, and data from Chinese populations are scarce. We conducted a cross-sectional study to investigate the association between milk consumption and the metabolic syndrome and its components among the residents of Suzhou Industrial Park, Suzhou, China. A total of 5149 participants were included in the final analysis. A logistic regression model was applied to estimate the OR and 95 % CI for the prevalence of the metabolic syndrome and its components according to milk consumption. In addition, the results of our study were further meta-analysed with other published observational studies to quantify the association between the highest v. lowest categories of milk consumption and the metabolic syndrome and its components. There was no significant difference in the odds of having the metabolic syndrome between milk consumers and non-milk consumers (OR 0·86, 95 % CI 0·73, 1·01). However, milk consumers had lower odds of having elevated waist circumference (OR 0·78, 95 % CI 0·67, 0·92), elevated TAG (OR 0·83, 95 % CI 0·70, 0·99) and elevated blood pressure (OR 0·85, 95 % CI 0·73, 0·99). When the results were pooled together with other published studies, higher milk consumption was inversely associated with the risk of the metabolic syndrome (relative risk 0·80, 95 % CI 0·72, 0·88) and its components (except elevated fasting blood glucose); however, these results should be treated with caution as high heterogeneity was observed. In summary, the currently available evidence from observational studies suggests that higher milk consumption may be inversely associated with the metabolic syndrome.
Freshwater habitats in China are potentially suitable for invasive alien turtle species and, consequently, raising turtles in aquaculture facilities and the trade in turtles this supplies pose risks to habitats and native wetland communities when exotic turtles escape or are released deliberately. Online trade (e-commerce) is making an increasing contribution to turtle sales in China, seemingly driving demand and thus potentially exacerbating the risk of release. We document the scale and spatial pattern of online sales of non-native turtles over 90 days on China's Taobao.com e-commerce site. The majority of sales were in the ecologically sensitive middle and lower Yangtze river basin (82.35% of > 840,000 slider turtles Trachemys scripta elegans, and 68.26% of > 100,000 snapping turtles, Chelydridae spp.). These species are native to the Americas. Concurrently, over 2008–2018, we found 104 mentions of feral turtle issues listed on Baidu News where, among the 53 prefectures mentioned, issues with invasive turtle populations also focused predominantly in the middle and lower Yangtze river basin. Although circumstantial, this association suggests that the substantial online sale of alien turtles could be having detrimental effects in China's Yangtze river basin. It is important to safeguard these wetland habitats, which are of global importance, by improving policies for detecting and regulating invasive alien turtle issues and by warning consumers about the ecological hazard of their purchases.
Asia Minor bluegrass (Polypogon fugax Nees ex Steud.) is a problem grass weed of winter crops in China, where a population has become resistant to aryloxyphenoxypropionate (APP) herbicides. The mechanism of resistance is due to an Ile-2041-Asn mutation of the ACCase gene. Screen house experiments were conducted to study the growth, fecundity characteristics, and competitive ability of this aryloxyphenoxypropionate-resistant (APP-R) biotype compared with a susceptible (APP-S) biotype. When grown under noncompetitive conditions, the APP-R P. fugax developed more rapidly than the APP-S plants, with earlier tiller and panicle emergence and seed shedding; the APP-R P. fugax set seeds nearly 12 d earlier than the APP-S biotype. APP-R and APP-S biotypes had similar aboveground dry weight before the flowering stage. Fecundity of the APP-R biotype was similar to the APP-S biotype (8.57 g seeds plant−1 and 0.17 g seeds panicle−1 versus 8.22 g seeds plant−1 and 0.13 g seeds panicle−1, respectively). Ultimately, the relatively slower-developing APP-S P. fugax had 50% more shoot dry weight than the APP-R plants. Relative competitiveness among the APP-R and APP-S P. fugax biotypes was investigated through replacement series experiments. No difference in competitive ability was measured between APP-R and APP-S biotypes on the basis of shoot dry weight before the tillering stage. These results indicate that there is no apparent fitness penalty for the APP-R P. fugax. The shorter growth cycle of APP-R with no apparent fitness penalty suggests that growers will need begin weed control earlier and possibly include vegetative crops with an even shorter growth cycle in their rotations.
Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.
Low urinary iodine concentration (UIC) is associated with dyslipidaemia in adults but is not well characterised in adolescents. Because dyslipidaemia is a cardiovascular risk factor, identifying such an association in adolescents would allow for the prescription of appropriate measures to maintain cardiovascular health. The present study addresses this question using data in the 2001–2012 National Health and Nutrition Examination Survey for 1692 adolescents aged 12–19 years. Primary outcomes were UIC, cardiometabolic risk factors and dyslipidaemia. Data for subjects categorised by low and normal UIC and by sex were analysed by univariate and multivariate logistic regression. Treating UIC as the independent variable, physical activity level, apoB and lipid profiles differed significantly between subjects with low and normal UIC. Subjects with low UIC had a significantly greater risk of elevated total cholesterol (TC) (95 % CI 1·37, 2·81), elevated non-HDL (95 % CI 1·33, 2·76) and elevated LDL (95 % CI 1·83, 4·19) compared with those with normal UIC. Treating UIC as a dependent variable, the risk of low UIC was significantly greater in those with higher apoB (95 % CI 1·52, 19·08), elevated TC (≥4·4mmol/l) (95 % CI 1·37, 2·81) and elevated non-HDL (≥3·11mmol/l) (95 % CI 1·33, 2·76) than in those with normal UIC. These results show that male and female adolescents with low UIC tend to be at greater risk of dyslipidaemia and abnormal cardiometabolic biomarkers, though the specific abnormal parameters differed between sexes. These results may help to identify youth who would benefit from interventions to improve their cardiometabolic risk.
Muscle fibre types can transform from slow-twitch (slow myosin heavy chain (MyHC)) to fast-twitch (fast MyHC) or vice versa. Leucine plays a vital effect in the development of skeletal muscle. However, the role of leucine in porcine myofibre type transformation and its mechanism are still unclear. In this study, effects of leucine and microRNA-27a (miR-27a) on the transformation of porcine myofibre type were investigated in vitro. We found that leucine increased slow MyHC protein level and decreased fast MyHC protein level, increased the levels of phospho-protein kinase B (Akt)/Akt and phospho-forkhead box 1 (FoxO1)/FoxO1 and decreased the FoxO1 protein level. However, blocking the Akt/FoxO1 signalling pathway by wortmannin attenuated the role of leucine in porcine myofibre type transformation. Over-expression of miR-27a decreased slow MyHC protein level and increased fast MyHC protein level, whereas inhibition of miR-27a had an opposite effect. We also found that expression of miR-27a was down-regulated following leucine treatment. Moreover, over-expression of miR-27a repressed transformation from fast MyHC to slow MyHC caused by leucine, suggesting that miR-27a is interdicted by leucine and then contributes to porcine muscle fibre type transformation. Our finding provided the first evidence that leucine promotes porcine myofibre type transformation from fast MyHC to slow MyHC via the Akt/FoxO1 signalling pathway and miR-27a.
Leucine, one of the branched-chain amino acids, is the only amino acid to regulate protein turnover in skeletal muscle. Leucine not only increases muscle protein synthesis, but also decreases muscle protein degradation. It is well documented that leucine plays a positive role in differentiation of murine muscle cells. However, the role of leucine on porcine myoblast differentiation and its mechanism remains unclear. In this study, porcine myoblasts were induced to differentiate with differentiation medium containing different concentrations of leucine, and wortmannin was used to interdict the activity of protein kinase B (Akt). We found that leucine increased the number of myosin heavy chain-positive cells and creatine kinase activity. Moreover, leucine increased the mRNA and protein levels of myogenin and myogenic determining factor (MyoD). In addition, leucine increased the levels of phosphorylated Akt/Akt and phosphorylated Forkhead box O1 (P-FoxO1)/FoxO1, as well as decreased the protein level of FoxO1. However, wortmannin, a specific repressor of PI3K/Akt signalling pathway, attenuated the positive role of leucine on porcine myoblast differentiation. Our results suggest that leucine promotes porcine myoblast differentiation through the Akt/FoxO1 signalling pathway.
A coaxial-output rolled strip pulse-forming line (RSPFL) with a dry structure is researched for the purpose of miniaturization and all-solid state of pulse-forming lines (PFL). The coaxial-output RSPFL consists of a coaxial-output electrode (COE) and a rolled strip line (RSL). The COE is characterized by quasi-coaxial structure, making the output pulse propagate along the axial direction with a small output inductance. The RSL is rolled on the COE, whose transmission characteristics are analyzed theoretically. It shows that the RSL can be regarded as a planar strip line when the rolling radius of the strip line is larger than 60 times of the thickness of the insulation dielectric layer of RSL. CST modeling was carried out to simulate the discharging characteristic of the coaxial-output RSPFL. It shows that the coaxial-output RSPFL can deliver a discharging pulse with a rise time <6 ns when the impedance of the RSL matches that of the COE, which confirms the theoretical analysis. A prototype of the coaxial-output RSPFL was developed. A 49-kV discharging pulse on a matched load was achieved when it was charged to 100 kV. The discharging waveform has a pulse width of 32 ns, with a rise time of 6 ns, which is consistent with the simulation waveform. An energy-storage density of 1.9 J/L was realized in the coaxial-output RSPFL. By the method of multi-stage connection in series, a much higher output voltage is convenient to be obtained.
Health system reform is considered a tough issue worldwide. Great efforts have been made toward health system building and strengthening. However, it is still unclear which health system is appropriate for different countries. This study aimed to systematically compare the characteristics of the establishment periods between eighty-eight counties of National Health Service (NHS) and Social Health Insurance (SHI).
Forty-eight NHS countries and forty SHI countries with data availability were selected. The establishment years of current health systems and other eighteen indicators in economics, society, population and health during establishment periods were collected. Comparison between NHS and SHI was conducted by descriptive analysis of every indicator.
Most NHS countries were established during the cold war, while SHI had been set up since the cold war ended. The median of gross domestic product (GDP) per capita, urbanization rate and aging rate of SHI were USD 1535 in current dollars, 58.2 percent and 9.8 percent, respectively; compared with USD 1387, 41.2 percent and 4.7 percent, respectively of NHS. NHS countries had a smaller total population, lower mortality rate and elderly dependency ratio, while the birth rate and children's dependency ratio were higher. SHI countries showed a higher life expectancy and lower mortality rate in infants and children. NHS countries spent less in total health expenditure and a lower proportion of GDP. The median health expenditure per capita of SHI and NHS were USD 188 and USD 131 in current dollars, respectively. There was little difference among maternal mortality rates, and public and private health expenditure proportions.
NHS and SHI countries had different characteristics during the health system establishment periods. NHS was established earlier than SHI overall, so that SHI revealed higher levels in economic and social development. Health outcomes of NHS countries were slightly lower than SHI ones, while health expenditure was more in SHI countries. Specific social, economic, demographic and health conditions should be considered when countries are building their own health systems.
We investigate theoretically the field-free orientation of CO molecules induced by a single-cycle THz laser pulse train. It is shown that the molecular orientation can be obviously enhanced by applying the pulse train. The laser intensity and pulse number have some effects on the molecular orientation. The high degree of field-free molecular orientation |⟨cosθ⟩|max=0.9246 is obtained at temperature T=0 K. The variations of the maximum orientation degree with the experimentally available pulse number and peak intensity are given. Temperature T has a considerable influence on the field-free molecular orientation. The maximal field-free molecular orientation at T=0, 10, 20 and 30 K for N=14 and E0=1.8 MV/cm are |⟨cosθ⟩|max=0.9188, 0.7338, 0.6055 and 0.5154 in order, and the corresponding effective duration times of molecular orientation are Δt=0.759, 0.432, 0.297 and 0.117 ps.
The Nihewan Basin is a key region for studying the Palaeolithic archaeology of East Asia. However, because of the lack of suitable dating methods and representative lithic technologies in this region, the ‘Middle Palaeolithic’ sites in this basin have been designated based mainly on stratigraphic correlation, which may be unreliable. In this study, three Palaeolithic sites, Motianling, Queergou and Banjingzi, which have been assigned previously to the ‘Middle Palaeolithic’, are dated based on luminescence dating of K-feldspar grains. Our results show that the cultural layers at Motianling, Queergou and Banjingzi have ages of 315 ± 13, 268 ± 13 and 86 ± 4 ka (corresponding to Marine Isotope Stages 9, 8 and 5), respectively, suggesting that Motianling and Queergou should be assigned to the Lower Palaeolithic, while the age of Banjingzi is consistent with a Middle Palaeolithic attribution. Our results suggest that reassessing the age of ‘Middle Palaeolithic’ sites in the Nihewan Basin, and elsewhere in North China, is crucial for understanding the presence or absence of the Middle Palaeolithic phase in China. Our dating results also indicate that the Sanggan River developed sometime between about 270 and 86 ka ago.
Three important low valent transition metal oxides were synthesized in supercritical methanol by using inorganic metal salts as precursors. X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and x-ray photoelectron spectroscopy were applied to analyze the composition, structure, and morphology of the products. Results showed that Cu2O, MoO2, and V2O3 were obtained successfully under a supercritical condition of 240 °C and 9.0 MPa. MoO2 and V2O3 displayed sphere-like morphology with average particle sizes of 20–40 and 20–50 nm, respectively. Cu2O particles displayed edge-truncated cubic morphology with a particle size of 2.5 μm. Formation mechanism proposed that high valent metal oxides (CuO, MoO3, and V2O5) were formed firstly in supercritical methanol by the decomposing of precursors and then reduced to target products by free hydroxyl anions. In addition, methanol performed important roles not only as a reaction medium but also as a reducing agent under supercritical fluid conditions.
In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed. On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection (MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced.
The Qiangtang Metamorphic Belt (QMB) was considered to have either formed in situ by amalgmation of the North and South Qiangtang blocks or been underthrust from the Jinsha suture and exhumed in the interior of a single ‘Qiangtang Block’. A new Sphaeroschwagerina fusuline fauna discovered in the Raggyorcaka Lake area supports the interpretation that the North and South Qiangtang blocks were separated by a wide ocean during Asselian (Early Permian) time, indicating that the QMB was formed by the suturing of the Palaeotethys Ocean along the Longmu Co-Shuanghu suture.
A method to design the composite insulation structures in pulsed power systems is proposed in this paper. The theoretical bases for this method include the Weibull statistical distribution and the empirical insulation formula. A uniform formula to describe the reliability (R) for different insulation media such as solid, liquid, gas, vacuum, and vacuum surface is derived. The dependence curves of the normalized applied field on R are also obtained. These curves show that the normalized applied field decreases rapidly as R increases but the declining rates corresponding to different insulation media are different. In addition, if R is required to be higher than a given level, the normalized applied field should be smaller than a certain value. In practical design, the common range of the applied fields for different insulation media should be chosen to meet a global reliability requirement. In the end, the proposed method is demonstrated with a specific coaxial high-voltage vacuum insulator.
Meningiomas account for approximately 24-30% of primary intracranial neoplasms. Histopathologic grade and degree of resection are two major prognostic factors. The aim of this study was to determine the factors associated with the prognosis of meningioma.
We used immunohistochemistry to analyze the expression levels of Vav3, SPARC, p-Akt, cyclin D1, and Ki-67 in 287 meningiomas of all grades.
The expression of Vav3, SPARC, p-Akt, cyclin D1, and Ki- 67 significantly increased with meningioma grade (p<0.01), and was higher in brain-invasive meningiomas compared to non-invasive meningiomas (WHO grade I) (p<0.05). Furthermore, the expression of Vav3, p-Akt, and Ki-67 was higher in recurrent meningiomas compared to non-recurrent meningiomas (WHO grade I) (p<0.05).
The expression of Vav3, SPARC, p-Akt, cyclin D1, and Ki-67 in meningiomas appears to correlate with meningioma invasiveness, aggressiveness, and recurrence.