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Magnesium alloys usually lack “operative deformation slip mechanisms” because of their hexagonal close-packed structure. Therefore, the mechanical behavior of magnesium alloys at different temperatures is dictated by other deformation mechanisms such as twinning, detwinning, secondary twinning, or dynamic recrystallization (DRX). Twinning and DRX can affect the development of grain size and orientation distribution, as well as the deformation behavior of magnesium alloys. The current understanding of the mechanisms and mechanics of these different deformation modes and their implementation in crystal plasticity-based modeling are highlighted in this article. Future directions in the development of constitutive models are also discussed.
We assessed inheritance of resistance to sugarcane brown rust (Puccinia melanocephala) in selfing F1 populations of wild sugarcane germplasm Erianthus rockii ‘Yundian 95-19’ and E. rockii ‘Yundian 95-20’. We tested parent and selfing F1 individuals for the brown rust resistance gene, Bru1, that has been shown to confer resistance to brown rust in sugarcane. The Bru1 gene was not detected in E. rockii ‘Yundian 95-19’, E. rockii ‘Yundian 95-20’ or their selfing F1 individuals, and we found there was segregation of resistance in the two selfing F1 populations (segregation ratio: 3:1). The results confirmed resistance in E. rockii ‘Yundian 95-19’ and E. rockii ‘Yundian 95-20’ to sugarcane brown rust is controlled by a novel, single dominant gene.
Cryoconite is a dark-coloured granular sediment that contains biological and mineralogical components, and it plays a pivotal role in geochemistry, carbon cycling and glacier mass balance. In this work, we collected cryoconite samples from Laohugou Glacier No. 12 (LHG) on the north-eastern Tibetan Plateau during the summer of 2015 and measured the spectral albedo. To explore the impacts of this sediment on surface ablation, the ice melting differences between the cryoconite-free (removed) ice and the intact layers were compared. The results showed that the mean concentrations of black carbon (BC), organic carbon (OC) and total iron (Fe) in the LHG cryoconite were 1.28, 11.18 and 39.94 mg g−1, respectively. BC was found to play a stronger role in solar light adsorption than OC and free Fe. In addition, ice covered by cryoconite exhibited the lowest mean reflectance (i.e., <0.1). Compared with the cryoconite-free ice surface, cryoconite effectively absorbed solar energy and enhanced glacial melting at a rate of 2.27–3.28 cm d−1, and free Fe, BC and OC were estimated to contribute 1.01, 0.99 and 0.76 cm d−1, respectively. This study provides important insights for understanding the role of cryoconite in the glacier mass balance of the northern Tibetan Plateau.
Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a major cause of community-acquired pneumonia in China. Data on epidemiology of paediatric MPP from China are little known. This study retrospectively collected data from June 2006 to June 2016 in Beijing Children's Hospital, Capital Medical University of North China and aims to explore the epidemiological features of paediatric MPP and severe MPP (SMPP) in North China during the past 10 years. A total of 27 498 paediatric patients with pneumonia were enrolled. Among them, 37.5% of paediatric patients had MPP. In this area, an epidemic took place every 2–3 years at the peak, and the positive rate of MPP increased during these peak years over time. The peak age of MPP was between the ages of 6 and 10 years, accounting for 75.2%, significantly more compared with other age groups (χ2 = 1384.1, P < 0.0001). The epidemics peaked in September, October and November (χ2 = 904.9, P < 0.0001). Additionally, 13.0% of MPP paediatric patients were SMPP, but over time, the rate of SMPP increased, reaching 42.6% in 2016. The mean age of paediatric patients with SMPP (6.7 ± 3.0 years old) was younger than that of patients with non-SMPP (7.4 ± 3.2 years old) (t = 3.60, P = 0.0001). The prevalence of MPP and SMPP is common in China, especially in children from 6 to 10 years old. Paediatric patients with SMPP tend to be younger than those with non-SMPP. MPP outbreaks occur every 2–3 years in North China. September, October and November are the peak months, unlike in South China. Understanding the epidemiological characteristics of paediatric MPP can contribute to timely treatment and diagnosis, and may improve the prognosis of children with SMPP.
CrFeNiTix (x = 0.2, 0.3, 0.4, 0.5, and 0.6 molar ratio) compositionally complex alloys were fabricated by vacuum arc melting to investigate the microstructure, hardness, and compressive properties. The results revealed that CrFeNiTix alloys consisted of the principal face-centered cubic (FCC) phase and body-centered cubic (BCC) solid solution, with an amount of (Ni, Ti)-rich hexagonal close-packed phase. CrFeNiTix alloys exhibited the typical dendrite. Ti0.2 and Ti0.3 alloys were composed of FCC and BCC solid solutions in the dendrite, as well as ε (Ni3Ti) and R (Ni2.67Ti1.33) phases in the inter-dendrite, simultaneously. For Ti0.4, Ti0.5, and Ti0.6 alloys, (Fe, Cr)-rich solid solution separated out and ε phase transformed into R phase gradually. Meanwhile, TEM analysis indicated that Ti0.4 alloy matrix consisted of the principal FCC phase containing (Ni, Ti)-rich intragranular nanoprecipitates. The hardness values of CrFeNiTix alloys were increased with the addition of Ti content and the high compressive strength of CrFeNiTix alloys was maintained, which was attributed to the solid solution strengthening and precipitation hardening.
Brain structural connectome comprise of a minority of efficiently interconnected rich club nodes that are regarded as ‘high-order regions’. The remission of major depressive disorder (MDD) in response to selective serotonin reuptake inhibitor (SSRI) treatment could be investigated by the hierarchical structural connectomes’ alterations of subnetworks.
Fifty-five MDD patients who achieved remission underwent diffusion tensors imaging (DTI) scanning from 3 cohorts before and after 8-weeks antidepressant treatment. Five hierarchical subnetworks namely, rich, local, feeder, rich-feeder and feeder-local, were constructed according to the different combinations of connections and nodes as defined by rich club architecture. The critical treatment-related subnetwork pattern was explored by multivariate pattern analysis with support vector machine to differ the pre-/post-treatment patients. Then, relationships between graph metrics of discriminative subnetworks/ nodes and clinical variables were further explored.
The feeder-local subnetwork presented the most discriminative power in differing pre-/post- treatment patients, while the rich-feeder subnetwork had the highest discriminative power when comparing pre-treatment patients and controls. Furthermore, based on the feeder connection, which indicates the information transmission between the core and non-core architectures of brain networks, its topological measures were found to be significantly correlated with the reduction rate of 17-item Hamilton Rating Scale for Depression.
Although pathological lesion on MDD relied on abnormal core organization, disease remission was association with the compensation from non-core organization. These results suggested that the dysfunctions arising from hierarchical subnetworks are compensated by increased information interactions between core brain regions and functionally diverse regions.
Seed reserves play vital roles in seed germination and seedling growth and their variation may be related to various environment factors, plant traits and phylogenetic history. Here, the evolutionary correlation associated with seed mass and altitude and carbon (C), nitrogen (N) and phosphorus (P) allocation of seeds among 253 alpine herbaceous plants was tested. In this study, phylogeny had strong limitations on nutrient allocation of seeds across species, and species from younger phylogenetic groups tended to have higher N and P contents, which might be considered as the evolutionary selection of seed plants. Higher seed N and P content would help seedlings to gain more survival chance and stronger competitive capacity, and their progeny would be more likely to be preserved. When phylogeny was considered, altitude only had a significant positive effect on P content, but the negative effects on seed mass were all expressed. The independent effects of altitude and seed mass suggest that the nutrient allocation of seeds might be affected by both environment and plant traits. In addition, altitude and seed mass displayed partial overlapping effects on nutrient allocation of seeds. The negative effects of seed mass were affected slightly by altitude, whereas altitude only had a significant positive effect on P content when seed mass was controlled. Above all, seed P content showed obvious and general correlations with seed mass, altitude and age of clade, which indicated that higher seed P content might be an adaptive selection of species associated with growth and survival of progeny.
An Al–3% B master alloy has been subjected to equal channel angular pressing (ECAP). The grain refining performance and fading resistance of an Al–3% B master alloy on a commercial purity Al (CPA) have been evaluated. The effect of the number of ECAP passes on the size and the distribution of the AlB2 particles, the grain size of CPA ingots with and without adding the Al–3% B master alloy subjected to ECAP have been investigated. The mean size of AlB2 particles was significantly reduced from ∼34 to ∼12 μm after four ECAP passes. Fine blocky AlB2 particles were uniformly distributed in the Al matrix. It has been revealed that when it was inoculated by the Al–B master alloy subjected to ECAP, the grain size of α-Al was decreased from ∼1200 to ∼180 μm after four ECAP passes, beyond that, the grain size tends to be saturated. It has been proved that grain refinement efficiency and fading resistance of the Al–3% B master alloy subjected to ECAP in CPA ingots was enhanced.
Evaluating quality traits is important to the selection of elite lines in Brassica napus L. In this study, the quality traits of 488 global collections of B. napus L were evaluated for two consecutive years under central Chinese growing conditions, and a series of phenotypic data was obtained. The measured total glucosinolate content (GLC) and erucic acid content (ERU) values for 95.5% of the accessions were consistent with the original values, and large variations in quality traits were found among these accessions, thus enabling selection for these characters. In general, Chinese accessions tended to have a higher oil content (OC) than foreign accessions, while compared with winter and spring accessions, semi-winter accessions tended to have the highest OC. The mean GLC and ERU of Chinese rapeseed accessions showed gradual downward trends over time, and the genotypic variation in ERU accounted for 98.44% of the total variation, which was the highest among all 10 of the quality traits. Additionally, the heritability for ERU was largest among all 10 of the quality traits. Significant correlations were observed between different traits; OC had significantly (P < 0.01) negative correlation coefficients with oleic acid content, whereas OC had significantly (P < 0.01) positive correlation coefficients with ERU. Principal component analysis revealed that there was no clear boundary among materials of different geographic origins and different ecotypes according to the first two principal coordinates, respectively. This information about variations in quality traits revealed in this study could identify parents for improved rapeseed breeding.
Nitrogen is an essential element for biological activity, and nitrogen isotopic compositions of geological samples record information about both marine biological processes and environmental evolution. However, only a few studies of N isotopes in the early Cambrian have been published. In this study, we analysed nitrogen isotopic compositions, as well as trace elements and sulphur isotopic compositions of cherts, black shales, carbonaceous shales and argillaceous carbonates from the Daotuo drill core in Songtao County, NE Guizhou Province, China, to reconstruct the marine redox environment of both deep and surface seawater in the study area of the Yangtze shelf margin in the early Cambrian. The Mo–U covariation pattern of the studied samples indicates that the Yangtze shelf margin area was weakly restricted and connected to the open ocean through shallow water flows. Mo and U concentrations, δ15Nbulk and δ34Spy values of the studied samples from the Yangtze shelf margin area suggest ferruginous but not sulphidic seawater and low marine sulphate concentration (relatively deep chemocline) in the Cambrian Fortunian and early Stage 2; sulphidic conditions (shallow chemocline and anoxic photic zone) in the upper Cambrian Stage 2 and lower Stage 3; and the depression of sulphidic seawater in the middle and upper Cambrian Stage 3. Furthermore, the decreasing δ15N values indicate shrinking of the marine nitrate reservoir during the middle and upper Stage 3, which reflects a falling oxygenation level in this period. The environmental evolution was probably controlled by the changing biological activity through its feedback on the local marine environment.
Right pulmonary artery–left atrial fistula is a rare congenitalcardiac anomaly, and only a few articles published so far have reported the diagnosis and treatment of right pulmonary artery–left atrial fistula. In this study, we report three cases of successful transcatheter closure or surgical repair of right pulmonary artery–left atrial fistula.
The purpose of the present study was to examine the influence of maternal pre-pregnancy BMI and gestational weight gain (GWG) on initiation and duration of infant breast-feeding in a prospective birth cohort study.
Breast-feeding information was collected at 1, 3, 6 and 12 months postpartum. The association of pre-pregnancy BMI and GWG with delayed lactogenesis II and termination of exclusive breast-feeding was assessed with logistic regression analysis. The risk of early termination of any breast-feeding during the first year postpartum was assessed with Cox proportional hazards models.
Urban city in China.
Women with infants from the Ma’anshan Birth Cohort Study (n 3196).
The median duration of any breast-feeding in this cohort was 7·0 months. Pre-pregnancy obese women had higher risks of delayed lactogenesis II (risk ratio=1·89; 95 % CI 1·04, 3·43) and early termination of any breast-feeding (hazard ratio=1·38; 95 % CI 1·09, 1·75) adjusted for potential maternal and infant confounders, when compared with normal-weight women. No differences in breast-feeding initiation or duration of exclusive breast-feeding according to pre-pregnancy BMI were found. Moreover, GWG was not associated with any poor breast-feeding outcomes.
The present study indicated that pre-pregnancy obesity increases the risks of delayed lactogenesis II and early termination of any breast-feeding in Chinese women.
Blue-ice areas (BIAs) and their geographical distribution in Antarctica were mapped using Landsat-7 ETM+ images with 15 m spatial resolution obtained during the 1999–2003 austral summers and covering the area north of 82.5° S, and a snow grain-size image of the MODIS-based Mosaic of Antarctica (MOA) dataset with 125 m grid spacing acquired during the 2003/04 austral summer from 82.5°S to the South Pole. A map of BIAs was created with algorithms of thresholds based on band ratio and reflectance for ETM+ data and thresholds based on snow grain size for the MOA dataset. The underlying principle is that blue ice can be separated from snow or rock by their spectral discrepancies and by different grain sizes of snow and ice. We estimate the total area of BIAs in Antarctica during the data acquisition period is 234 549 km2, or 1.67% of the area of the continent. Blue ice is scattered widely over the continent but is generally located in coastal or mountainous regions. The BIA dataset presented in this study is the first map covering the entire Antarctic continent sourced solely from ETM+ and MODIS data. This dataset can potentially benefit other studies in glaciology, meteorology, climatology and paleoclimate, meteorite collection and airstrip site selection.
This paper presents a novel metamaterial constructed with wires, spheres and hollow slabs (WSHS), which simultaneously exhibits negative permittivity and permeability. An electromagnetic wave simulation is performed based on the proposed metamaterial and shows that a negative refractive index is achieved for this metamaterial. Adjusting the lattice constant of the unit cell is an easy way to manipulate the frequency of negative index of this structure. A left-hand material prism is designed composed of metamaterial unit cells and the simulation on the proposed prism proves the left-hand behavior of the designed metamaterial.
Our aim is to screen miRNAs and genes related to tetralogy of Fallot and construct a co-expression network based on integrating miRNA and gene microarrays. We downloaded the gene expression profile GSE35490 (miRNA) and GSE35776 (mRNA) of tetralogy of Fallot from the Gene Expression Omnibus database, which includes eight normal and 15 disease samples from infants, and screened differentially expressed miRNAs and genes between normal and disease samples (cut-off: p < 0.05; FDR < 0.05; and log FC > 2 or log FC < −2); in addition, we downloaded human miRNA and their targets, which were collected in the miRNA targets prediction database TargetScan, and selected ones that also appeared in our differentially expressed miRNAs and their predicted targets (score >0.9) and then made a relationship of diff_miRNAs and diff_genes of our results. Finally, we uploaded all the diff_target genes into String, constructed a co-expression network regulated by diff_miRNAs, and performed functional analysis with the software DAVID. Comparing normal and disease lesion tissue, we got 32 and 875 differentially expressed miRNAs and genes, respectively, and found hsa-miR-124 with 34 diff_target genes and hsa-miR-138 with two diff_target genes. Then we constructed a co-expression network that contains 231 pairs of genes. Genes in the network were enriched into 14 function clusters, and the most significant one is protein localisation. We screened the tetralogy of Fallot-related hsa-miR-124 and hsa-miR-138 with their direct and indirect differentially expressed target genes, and found that protein localisation is the significant cause affecting tetralogy of Fallot. Our approach may provide the groundwork for a new therapy approach to treating tetralogy of Fallot.
The organic light-emitting (OLE) materials have attracted great interest due to their potential applications in sensors, biodetectors and OLE devices. However, highly efficient emission from organic solids is still a great challenge because of the aggregation-caused quenching effect. In this article, a three-dimensional (3D) organic-inorganic hybrid nanoparticle, based on polyhedral oligomeric silsesquioxane (POSS), was precisely fabricated via click chemistry with high yield, and its structure was characterized by Fourier transform infrared spectroscopy, 1H, and 29Si nuclear magnetic resonance spectroscopies, and Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry, respectively. The resultant 3D organic-inorganic nanohybrid showed significantly enhanced emission in solid film (Φfilm 80%) with a slight red-shift as compared with its organic counterpart, (Φfilm 14%), which exhibits a large red-shift in solid film, due to the deaggregation effect of POSS. Simultaneously, the resultant nanohybrid also exhibited good film formability, excellent spectrum and thermal stability (>250 °C) due to the introduction of POSS.
SONG (Stellar Observations Network Goup) is a low-cost ground based international collaboration aimed at two cutting edge problems in contemporary astrophysics in the time-domain: 1) Direct diagnostics of the internal structure of stars and 2) looking for and studying extra solar planets, possibly in the habitable zone. The general plan is to set up a network of 1m telescopes uniformly distributed in geographic latitude (in both hemispheres). China jointed the collaboration (initiated by Danish astronomers) at the very beginning. In addition to SONG's original plan (http://song.phys.au.dk), the Chinese team proposed a parallel photometry subnet work in the northern hemisphere, namely 50BiN (50cm Binocular Network, previously known as mini-SONG), to enable a large field photometric capability for the network, therefore maximising the potential of the network platform. The network will be able to produce nearly continuous time series observations of a number of selected objects with high resolution spectroscopy (SONG) and accurate photometry (50BiN), and to produce ultra-high accuracy photometry in dense field to look for micro-lensing events caused by planetary systems. This project has great synergy with Chinese Astronomical activities in Antarctica (Dome A), and other similar networks (e.g. LCOGT). The plan and current status of the project are overviewed in this poster.
In this study, novel Si2Sb2Te6 phase change material is investigated in detail for the phase change memory application using transmission electron microscopy and X-ray photoelectron spectroscopy. The phenomenon that Te diffuses to the film surface during phase switching and successively evaporates out has been confirmed. The phase change memory cells employing Si2Sb2Te6 and Si3Sb2Te3 materials are fabricated and programmed. For the Si2Sb2Te6-based cell a data endurance of 5×105 cycles is achieved with a failure mode resembling reset stuck, which can be attributed to the migration of Tellurium during the operation cycles. It means that a thermally stable material system of SixSb2Te3 is preferred for the PCM applications.
The techniques used to detect genetically modified organisms (GMO), including qualitative polymerase chain reaction (PCR), quantitative PCR, enzyme-linked immunosorbent assay (ELISA) and many others, are systematically described and discussed. The application progress of GMO in species-specific detection, endogenous genes, standard substances and restraining factors influencing detection are reviewed. The ongoing problems and development prospects of detection techniques of GMO are also pointed out.
Eupatorium adenophorum (crofton weed) is one of the most widespread invasive species in China. Its genetic diversity and population structure in China were analysed by amplified fragment length polymorphism (AFLP). Three primer pairs were selected for the analysis and 490 bands were produced from 62 E. adenophorum populations selected from five major geographic areas. A total of 328 of the bands showed polymorphism [percentage of polymorphic bands (PPB)=59.4%]. Diversity levels of populations were relatively high (mean expected heterozygosity=0.154, mean Shannon index=0.241). At the regional level, the AMOVA indicated that about 70.25% of variation in the data set was from genotypic variations within populations, whereas 8.04% of the variation was due to regional differences, and the remaining 21.71% to differences among populations within the provincial regions. Cluster analysis based on the unweighted pair-group method using the method of arithmetic averages (UPGMA) grouped the majority of E. adenophorum populations into four main clusters, which correspond to their geographic regions. It is concluded that E. adenophorum spread mainly by wind or water and its genetic diversity level in newly invaded areas was lower than that in formerly colonized areas.