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The advantage of alcohol–calcium method on the formation and the stability of vaterite against ethanol–water binary solvents (EWBS) method was studied through comparative experiment. The polymorphs and morphologies of CaCO3 were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that vaterite slowly decreases from 90.4 to 82.5% as increasing aging time from 0 to 1320 min in alcohol–calcium system, while quickly decreases from 46.5% to 0% at the same aging time in EWBS system. The similar variation as reaction temperature was found in both systems. SEM images indicate that calcite presents its typical rhombohedral morphology in both systems, while the morphologies of vaterite particles in two systems are different. In alcohol–calcium system, small vaterite nanoparticles aggregate into spherical microparticles, and these microparticles become porous, loose, and irregular, even incomplete, as increasing aging time and reaction temperature, while in EWBS system, vaterite nanoparticles aggregate into irregular microparticles. The advantage of alcohol–calcium method was discussed from the formation of the complex compound CaCl2·n(C2H5OH) in alcohol and its decomplexation in aqueous medium.
To improve the prenatal diagnosis for anomalous origin of pulmonary artery branches by comparing and analyzing different types of fetal echocardiography features.
Between June 2012 and December 2018, fetal echocardiographic features were analyzed retrospectively from fetuses with a prenatal diagnosis of anomalous origin of pulmonary artery branch. The main points of identification were summarized.
A total of 12 fetuses were diagnosed, including anomalous origin of a pulmonary artery branch from the innominate artery and six cases with unilateral absence of pulmonary artery. The shared characteristic sonographic finding was the lack of confluence at the bifurcation of the main pulmonary artery. The differences between the two conditions are highlighted by the origin of the anomalous vessel. In fetuses with anomalous origin of one pulmonary artery branch, the affected pulmonary artery arose from the posterior wall of the ascending aorta as noted on three vessels and trachea view as well as the long axis of the left ventricular outflow tract. This is in contrast to fetuses with unilateral absence of pulmonary artery, where the origin of affected pulmonary artery arises from the base of the innominate artery via the ipsilateral patent arterial duct as evident on the three vessels and trachea view and the coronal view of innominate (brachiocephalic) artery.
(1) The main similarity is an absence of a confluence at the bifurcation of the main pulmonary artery. (2) The main distinguishing feature is the origin of the anomalous vessel from either the subclavian or directly from the aorta.
The experiment was conducted to investigate the effects of dietary threonine (Thr) on growth performance and muscle growth, protein synthesis and antioxidant-related signalling pathways of hybrid catfish Pelteobagrus vachelli♀ × Leiocassis longirostris♂. A total of 1200 fish (14·19 (se 0·13) g) were randomly distributed into six groups with four replicates each, fed six diets with graded level of Thr (9·5, 11·5, 13·5, 15·4, 17·4 and 19·3 g/kg diets) for 56 d. Results showed (P < 0·05) that dietary Thr (1) increased percentage weight gain, specific growth rate, feed efficiency and protein efficiency ratio; (2) up-regulated growth hormone (GH), insulin-like growth factor 1 (IGF-1), proliferating cell nuclear antigen, myogenic regulation factors (MyoD, Myf5, MyoG and Mrf4) and myosin heavy chain (MyHC) mRNA levels; (3) increased muscle protein content via regulating the protein kinase B/target of rapamycin signalling pathway and (4) decreased malondialdehyde and protein carbonyl contents, increased catalase, glutathione-S-transferase, glutathione reductase and GSH activities, up-regulated mRNA levels of antioxidant enzymes related to NFE2-related factor 2 and γ-glutamylcysteine ligase catalytic subunit. These results suggest that Thr has a potential role to improve muscle growth and protein synthesis, which might be due to the regulation of GH-IGF system, muscle growth-related gene, antioxidative capacity and protein synthesis-related signalling pathways. Based on the quadratic regression analysis of specific growth rate, the Thr requirement of hybrid catfish (14·19–25·77 g) was estimated to be 13·77 g/kg of the diet (33·40 g/kg of dietary protein).
In this study, coatings containing Ca and P elements on Ti6Al4V alloy were fabricated by micro-arc oxidation at different applied voltages. Subsequently, evaluation of the phase structure, morphology, element composition, corrosion mechanism, and tribocorrosion behavior of these coatings was performed. The results showed that the coatings consisted of rutile TiO2 and anatase TiO2. The ratio of rutile/anatase, surface roughness, and hardness increase with the increase of applied voltage. Electrochemical impedance spectroscopy results indicated the corrosion resistance of coatings in simulated body fluid of 400 V > 380 V > 420 V. The open circuit potential of sample 400 V declined during the tribocorrosion test. Sample 420 V possessed the highest wear volume after the tribocorrosion process. The tribocorrosion mechanism of samples 380 and 420 V was mainly confirmed as the wear effect, and the decline of corrosion resistance due to the micro-cracks formed during the abrasive wear of the coating accounts for the tribocorrosion mechanism of sample 400 V.
The present study investigated the effects of condensed tannins (CT) on intestinal immune function in on-growing grass carp (Ctenopharyngodon idella). A total of 540 healthy grass carp were fed six diets containing different levels of CT (0, 10·00, 20·00, 30·00, 40·00 and 50·00 g/kg diet) for 70 d and then challenged with Aeromonas hydrophila for 14 d. The results showed that, compared with the control group, dietary CT (1) induced intestinal histopathological lesions and aggravated enteritis; (2) decreased lysozyme and acid phosphatase activities, complement 3 (C3), C4 and IgM contents and down-regulated the Hepcidin, liver-expressed antimicrobial peptide (LEAP)-2A, LEAP-2B, Mucin2 and β-defensin-1 mRNA levels in the proximal intestine (PI), mid intestine (MI) and distal intestine (DI) (P < 0·05); (3) down-regulated the mRNA levels of anti-inflammatory cytokines transforming growth factor (TGF)-β1, TGF-β2 (not in MI and DI), IL-4/13A (not IL-4/13B), IL-10 and IL-11 partly correlated with target of rapamycin (TOR) signalling; and (4) up-regulated the mRNA levels of pro-inflammatory cytokines interferon-γ2, IL-1β, IL-6, IL-8 (not in PI), IL-12p35, IL-12p40, IL-15 and IL-17D partly related to NF-κB signalling in the intestine of on-growing grass carp. Overall, the results indicated that CT could impair the intestinal immune function, and its potential regulation mechanisms were partly associated with the TOR and NF-κB signalling pathways. Finally, based on the percentage weight gain and enteritis morbidity, the maximum allowable levels of CT for on-growing grass carp (232·22–890·11 g) were estimated to be 18·6 and 17·4 g/kg diet, respectively.
Autonomous ships are gaining in importance and are expected to shape the future of the global shipping industry. This evolutionary shift raises serious issues about compliance with the International Regulations for Preventing Collisions at Sea 1972 (COLREGs). This paper reviews the literature on autonomous ships from the perspective of the obligations of good seamanship imposed by COLREGs. The authors conclude that to facilitate the introduction of autonomous ships, the application barriers presented by COLREGs need to be analysed. With this goal, this paper presents a perspective from navigational practice. Four nautical scientists and two deck officers were invited to give their opinions. The analysis indicates that COLREGs require further elaboration and amendments to eliminate uncertainty of interpretation. In particular, the paper highlights the need to amend the ‘look-out’ rule (COLREGs Rule 5) to permit look-out by ‘computer vision’ alone while, at the same time, preserving the distinction between vessels navigating in restricted visibility and in sight of one another.
The Chinese National Twin Registry (CNTR), initiated in 2001, has now become the largest twin registry in Asia. From 2015 to 2018, the CNTR continued to receive Chinese government funding and had recruited 61,566 twin-pairs by 2019 to study twins discordant for specific exposures such as environmental factors, and twins discordant for disease outcomes or measures of morbidity. Omic data, including genetics, genomics, metabolomics, and proteomics, and gut microbiome will be tested. The integration of omics and digital technologies in public health will advance our understanding of precision public health. This review introduces the updates of the CNTR, including study design, sample size, biobank, zygosity assessment, advances in research and future systems epidemiologic research.
The effect of hot streaks from a gas turbine combustor on the thermodynamic load of internally air-cooled nozzle guide vanes (NGVs) and shrouds has been numerically investigated under flight conditions. The study follows two steps: one for the high-fidelity 60° combustor sector with simplified ten NGVs and three thermocouples attached; and the other for the NGV sectors where each sector consists of one high-fidelity NGV (probe NGV) and nine dummy NGVs. The first step identifies which NGV has the highest thermal load and provides the inlet flow boundary conditions for the second step. In the second step, the flow fields and thermal loads of the probe NGVs are resolved in detail.
With the systematically validated physical models, the two-phase flowfield of the combustor-NGVs sector has been successfully simulated. The predicted mean and maximum temperature at the combustor sector exit are in excellent agreement with the experimental data, which provides a solid basis for the hot-streak effect investigation. The results indicate that the second NGV, looking upstream from left, has the highest thermal load. Its maximum surface temperature is 8.4% higher than that for the same NGV but with the mean inlet boundary conditions, and 14.1% higher than the ninth NGV. The finding is consistent with the field-observed NGV damage pattern. To extend the service life of these vulnerable NGVs, some protection methods should be considered.
Goosegrass is considered one of the worst agricultural weeds worldwide. Understanding its life cycle will provide useful management information. Field experiments with six emergence times (April, May, June, July, August, and September) were conducted at Anyang, China in 2015 and 2017 to clarify the growth and reproduction of goosegrass emerging at different times within a season. The result showed that plant height, dry weight, average weight per inflorescence, total inflorescence weight, average seed number per inflorescence, and total number of seeds per plant were relatively low in the April cohort, peaked with the May or June emergence cohort, and decreased thereafter. However, the earliest emergence of goosegrass in April had the highest total number of inflorescences. The plants of the May cohort produced the greatest number of seeds: 225,954 and 322,501 seeds per plant in 2015 and 2017, respectively. Delayed emergence resulted in less seed production; most plants that emerged in September did not flower or set seed. The 1,000-seed weight did not vary among the emergence cohorts. The reproductive investment was lowest for plants of the May cohort and then increased as emergence time was delayed to June, July, and August. Fresh mature seed of all emergence cohorts was extremely dormant and had low germination only up to 6% from August to November, and high germination (44% to 93%) in December. The information gained from this study indicates that weed management strategies should focus on the early-emerged seedlings such as the April and May cohorts, so as to effectively prevent goosegrass seed production, minimize the weed seed replenishment into the soil seed bank, and reduce the infestation in subsequent seasons.
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.
Schizophrenia is a complex mental disorder with high heritability and polygenic inheritance. Multimodal neuroimaging studies have also indicated that abnormalities of brain structure and function are a plausible neurobiological characterisation of schizophrenia. However, the polygenic effects of schizophrenia on these imaging endophenotypes have not yet been fully elucidated.
To investigate the effects of polygenic risk for schizophrenia on the brain grey matter volume and functional connectivity, which are disrupted in schizophrenia.
Genomic and neuroimaging data from a large sample of Han Chinese patients with schizophrenia (N = 509) and healthy controls (N = 502) were included in this study. We examined grey matter volume and functional connectivity via structural and functional magnetic resonance imaging, respectively. Using the data from a recent meta-analysis of a genome-wide association study that comprised a large number of Chinese people, we calculated a polygenic risk score (PGRS) for each participant.
The imaging genetic analysis revealed that the individual PGRS showed a significantly negative correlation with the hippocampal grey matter volume and hippocampus–medial prefrontal cortex functional connectivity, both of which were lower in the people with schizophrenia than in the controls. We also found that the observed neuroimaging measures showed weak but similar changes in unaffected first-degree relatives of patients with schizophrenia.
These findings suggested that genetically influenced brain grey matter volume and functional connectivity may provide important clues for understanding the pathological mechanisms of schizophrenia and for the early diagnosis of schizophrenia.
This study aimed to investigate endoscopic revision septoplasty with semi-penetrating straight and circular incisions in patients for whom septoplasty was unsuccessful.
Patients in this study (n = 14) had a deviation of the nasal septum after septoplasty. Pre-operative and post-operative assessments were performed using a visual analogue scale and nasal endoscope. Semi-penetrating straight and circular incisions in front of the caudal septum and at the margin of the nasal septal cartilage–bone defect, respectively, were made. The mucoperichondrium and mucoperiosteum were bilaterally dissected until interlinkage with the cartilage–bone defect was achieved. Mucous membranes within the circular incision as well as the right mucoperichondrium and mucoperiosteal flaps were protected by pushing them to the right. This exposed the osteocartilaginous framework and allowed correction of the residual deviation. The patients were followed up for 30–71 months.
For nasal obstruction and headaches, a significant improvement was noted in post-operative compared to pre-operative visual analogue scale scores. No patients had septal deviations, saddle nose, false hump nose or contracture of the nasal columella.
The technique allowed exposure of the septal osteocartilaginous framework and a broad operational vision, which enabled successful correction of various deformities of the nasal septum.
Anti-solvent treatment assisted crystallization is currently one of the most widely used methods to obtain high-quality perovskite films ascribed to its great operability. However, choosing a proper anti-solvent toward high-quality perovskite film for perovskite solar cells (PSCs) remains elusive. In this study, we qualitatively evaluate the impact of anti-solvent treatment on the grain growth and phase composition of perovskite by X-ray diffraction, scanning electron microscope, Fourier transform infrared spectrometer, and UV-vis absorption measurement, etc. The results demonstrate that the chemical groups in anti-solvents also affect the formation of perovskites, and anti-solvents with a low boiling point and good polarity contribute to the superior efficiency and reproducibility of PSCs. The device prepared using ether as an anti-solvent exhibits the best power conversion efficiency of 18.47%. The results indicate a new path toward selecting an ideal anti-solvent to improve the performance of PSCs.
To obtain information on changes in glacier mass balance in the central Nyainqentanglha Range, a comprehensive study was carried out based on digital-elevation models derived from the 1968 topographic maps, the Shuttle Radar Topography Mission DEM (2000) and TerraSAR-X/TanDEM-X (2013). Glacier area changes between 1968 and 2016 were derived from topographic maps and Landsat OLI images. This showed the area contained 715 glaciers, with an area of 1713.42 ± 51.82 km2, in 2016. Ice cover has been shrinking by 0.68 ± 0.05% a−1 since 1968. The glacier area covered by debris accounted for 11.9% of the total and decreased in the SE–NW directions. Using digital elevation model differencing and differential synthetic aperture radar interferometry, a significant mass loss of 0.46 ± 0.10 m w.e. a−1 has been recorded since 1968; mass losses accelerated from 0.42 ± 0.20 m w.e. a−1 to 0.60 ± 0.20 m w.e. a−1 between 1968–2000 and 2000–2013, with thinning noticeably greater on the debris-covered ice than the clean ice. Surface-elevation changes can be influenced by ice cliffs, as well as debris cover and land- or lake-terminating glaciers. Changes showed spatial and temporal heterogeneity and a substantial correlation with climate warming and decreased precipitation.
In this article, we propose two asymmetry measures for stock returns. Unlike the popular skewness measure, our measures are based on the distribution function of the data rather than just the third central moment. We present empirical evidence that the greater upside asymmetries calculated using our new measures imply lower average returns in the cross section of stocks. In contrast, when using the skewness measure, the relationship between asymmetry and returns is inconclusive.
The timing of the Holocene summer monsoon maximum (HSMM) in northeastern China has been much debated and more quantitative precipitation records are needed to resolve the issue. In the present study, Holocene precipitation and temperature changes were quantitatively reconstructed from a pollen record from the sediments of Tianchi Crater Lake in northeastern China using a plant functional type-modern analogue technique (PFT-MAT). The reconstructed precipitation record indicates a gradual increase during the early to mid-Holocene and a HSMM at ~5500–3100 cal yr BP, while the temperature record exhibits a divergent pattern with a marked rise in the early Holocene and a decline thereafter. The trend of reconstructed precipitation is consistent with that from other pollen records in northeastern China, confirming the relatively late occurrence of the HSMM in the region. However, differences in the onset of the HSMM within northeastern China are also evident. No single factor appears to be responsible for the late occurrence of the HSMM in northeastern China, pointing to a potentially complex forcing mechanism of regional rainfall in the East Asian monsoon region. We suggest that further studies are needed to understand the spatiotemporal pattern of the HSMM in the region.
Abundant platform-bearing gondolellid conodonts, including Scythogondolella mosheri (Kozur and Mostler), Sc. phryna Orchard and Zonneveld, and Sc. cf. milleri (Müller), have been discovered from the Yiwagou Section of Tewo, together with Novispathodus waageni waageni (Sweet) and Nv. w. eowaageni Zhao and Orchard. This is the first report of Smithian platform-bearing gondolellids from the Paleo-Tethys region. In addition, Eurygnathodus costatus Staesche, E. hamadai (Koike), Parafurnishius xuanhanensis Yang et al., and the genera Pachycladina Staesche, Parachirognathus Clark, and Hadrodontina Staesche have also been recovered from Dienerian to Smithian strata at Yiwagou Section. Three conodont zones are established, in ascending order: Eurygnathodus costatus-E. hamadai Assemblage Zone, Novispathodus waageni-Scythogondolella mosheri Assemblage Zone, and the Pachycladina-Parachirognathus Assemblage Zone.
The platform-bearing gondolellids were globally distributed just after the end-Permian mass extinction, but the formerly abundant Clarkina Kozur disappeared in the late Griesbachian. Platform-bearing gondolellids dramatically decreased to a minimum of diversity and extent in the Dienerian before recovering in the Smithian. Scythogondolella Kozur, probably a thermophilic and eurythermic genus, lived in all latitudes at this time whereas other genera did not cope with Smithian high temperatures and so became restricted to the high-latitude regions. However, the maximum temperature in the late Smithian likely caused the extinction of almost all platform-bearing gondolellids. Finally, the group returned to equatorial regions and achieved global distribution again in the cooler conditions of the late Spathian. We conclude that temperature (and to a lesser extent oxygen levels) exerted a strong control on the geographical distribution and evolution of platform-bearing gondolellids in the Early Triassic.
Cerebrovascular disease is the most common cause of death in China, and the incidence of ischemic stroke (240 per 100,000 people) is higher than that of hemorrhagic stroke (82 per 100,000 people). More than 80 percent of strokes can be prevented by early control of risk factors. Therefore, identifying and managing high-risk groups is a top priority in preventing stroke. The CHA2DS2-VASc score is a key prediction tool for stratifying stroke risk in individuals with atrial fibrillation (AF) as follows: zero score is low risk; one is intermediate risk; and two is high risk. The present study was undertaken to evaluate the accuracy of the CHA2DS2-VASc scoring system for stratifying ischemic stroke risk in the non-AF population.
We searched PubMed, EMBASE, and the Cochrane Library in June 2018 for relevant diagnostic studies. Study selection, data extraction, and quality assessment (using the QUADAS-2 criteria) were performed independently by two authors. Methodological variation across the selected studies precluded meta-analysis, so the results were synthesized narratively.
Seven prospective studies involving 50,652 patients (6,760 with ischemic stroke) were included. The treatment threshold ranged from two to four across the studies. Three studies reported diagnostic accuracy at a threshold of two, with a sensitivity above 0.8 and a specificity ranging from 0.32 to 0.68. The diagnostic odds ratio was greater than two (seven studies). The two studies using a treatment threshold of four reported a sensitivity of 0.59 to 0.76 and a specificity of 0.43 to 0.69. One study used a threshold of three, with a sensitivity of 0.79 and a specificity of 0.39.
The CHA2DS2-VASc score may be used to predict ischemic stroke in the non-atrial fibrillation population. Treatment thresholds greater than two provide more optimal diagnostic accuracy, although the predictive performance of the CHA2DS2-VASc score may be better in patients with chronic obstructive pulmonary disease but not AF.