In this article, Si nanoparticle (NP) films were prepared by pulsed laser ablation (PLA) in the argon atmosphere of 10 Pa at room temperature under different pulse repetition rates from 1 to 40 Hz without the baffle. Different from the conventional PLA method, the substrates were placed below and parallel to the ablated plume axis. The obtained films containing NPs were characterized by scanning electron microscopy and Raman spectrometer. The experimental results under constant laser fluence demonstrate the strong dependence of the mean size and the area number density of NPs on the repetition rate. Specifically, with the increase of pulse repetition rate, the mean size of the NPs in the film first decreases and reaches its minimum at 20 Hz, and then increases after 20 Hz, and decreases again till 40 Hz. The area number density shows the contrary trend versus mean size. The in situ diagnostic results of Langmuir probe denote the ablated Si ion density increases monotonously with the increase of repetition rate, while the temperature is almost constant. Combining with the nucleation probability, the growth/aggregation duration of NPs in the “nucleation region” and the effect of the baffle, the influence of pulse repetition rate on the formation of NPs is addressed. It is found that the repetition rate impacts the growth modes of NPs (i.e., growth and aggregation). 1–20, 20–30, and 30–40 Hz, respectively, correspond to growth-, aggregation-, and growth-controlled rate ranges without the baffle; however, 1–10, 10–20, and 20–40 Hz, respectively, correspond to growth-controlled, aggregation/growth-coexisted, and aggregation-controlled rate ranges with the baffle.

Triploid and pentaploid breeding is of great importance in agricultural production, but it is not always easy to obtain double ploidy parents. However, in fishes, chromosome ploidy is diversiform, which may provide natural parental resources for triploid and pentaploid breeding. Both tetraploid and hexaploid exist in Schizothorax fishes, which were thought to belong to different subfamilies with tetraploid Percocypris fishes in morphology, but they are sister genera in molecule. Fortunately, the pentaploid hybrid fishes have been successfully obtained by hybridization of Schizothorax wangchiachii (♀, 2n = 6X = 148) × Percocypris pingi (♂, 2n = 4X = 98). To understand the genetic and morphological difference among the hybrid fishes and their parents, four methods were used in this study: morphology, karyotype, red blood cell (RBC) DNA content determination and inter-simple sequence repeat (ISSR). In morphology, the hybrid fishes were steady, and between their parents with no obvious preference. The chromosome numbers of P. pingi have been reported as 2n = 4X = 98. In this study, the karyotype of S. wangchiachii was 2n = 6X = 148 = 36m + 34sm + 12st + 66t, while that the hybrid fishes was 2n = 5X = 123 = 39m + 28sm + 5st + 51t. Similarly, the RBC DNA content of the hybrid fishes was intermediate among their parents. In ISSR, the within-group genetic diversity of hybrid fishes was higher than that of their parents. Moreover, the genetic distance of hybrid fishes between P. pingi and S.wangchiachii was closely related to that of their parental ploidy, suggesting that parental genetic material stably coexisted in the hybrid fishes. This is the first report to show a stable pentaploid F1 hybrids produced by hybridization of a hexaploid and a tetraploid in aquaculture.

The aim of the study was to investigate any association between extrauterine growth restriction (EUGR) and intestinal flora of <30-week-old preterm infants. A total of 59 preterm infants were assigned to EUGR (n=23) and non-EUGR (n=36) groups. Intestinal bacteria were compared by using high-throughput sequencing of bacterial rRNA. The total abundance of bacteria in 344 genera (7568 v. 13,760; P<0.0001) and 456 species (10,032 v. 18,240; P<0.0001) was significantly decreased in the EUGR group compared with the non-EUGR group. After application of a multivariate logistic model and adjusting for potential confounding factors, as well as false-discovery rate corrections, we found four bacterial genera with higher and one bacterial genus with lower abundance in the EUGR group compared with the control group. In addition, the EUGR group showed significantly increased abundances of six species (Streptococcus parasanguinis, Bacterium RB5FF6, two Klebsiella species and Microbacterium), but decreased frequencies of three species (one Acinetobacter species, Endosymbiont_of_Sphenophorus_lev and one Enterobacter_species) compared with the non-EUGR group. Taken together, there were significant changes in the intestinal microflora of preterm infants with EUGR compared to preterm infants without EUGR.

Alanyl-glutamine (Ala-Gln), a highly soluble and stable glutamine dipeptide, is known to improve gut integrity and function. The aim of this study was to evaluate whether dietary Ala-Gln supplementation could improve growth performance, intestinal development and digestive-absorption function in weaned piglets. A total of 100 purebred Yorkshire piglets weaned at 21 days of age were assigned randomly to four dietary treatment groups and fed a basal diet (control group) or a basal diet containing 0.15%, 0.30% and 0.45% Ala-Gln, respectively. Compared with the control group, piglets fed the Ala-Gln diets had higher average daily gain and lower feed : gain and diarrhea rate (P < 0.05). Moreover, dietary Ala-Gln supplementation increased villous height and villous height : crypt depth ratio in duodenum and jejunum (P < 0.05), as well as the activities of maltase and lysozyme in jejunum mucosa (P < 0.05). In addition, a decrease in serum diamine oxidase activity and crypt depth in duodenum and jejunum was observed in piglets fed the Ala-Gln diets (P < 0.05). Serum cytosolic phospholipase A2 (cPLA2) concentration and gene expression of cPLA2, Na+-dependent glucose transporter 1, glucose transporter 2 and peptide transporter 1 in jejunum were increased by feeding Ala-Gln diets relative to control diet (P < 0.05). These results indicated that feeding Ala-Gln diet has beneficial effects on the growth performance of weaned piglets, which associated with maintaining intestinal morphology and digestive-absorption function.

Muons produced by the Bethe–Heitler process from laser wakefield accelerated electrons interacting with high $Z$ materials have velocities close to the laser wakefield. It is possible to accelerate those muons with laser wakefield directly. Therefore for the first time we propose an all-optical ‘Generator and Booster’ scheme to accelerate the produced muons by another laser wakefield to supply a prompt, compact, low cost and controllable muon source in laser laboratories. The trapping and acceleration of muons are analyzed by one-dimensional analytic model and verified by two-dimensional particle-in-cell (PIC) simulation. It is shown that muons can be trapped in a broad energy range and accelerated to higher energy than that of electrons for longer dephasing length. We further extrapolate the dependence of the maximum acceleration energy of muons with the laser wakefield relativistic factor $\unicode[STIX]{x1D6FE}$ and the relevant initial energy $E_{0}$ . It is shown that a maximum energy up to 15.2 GeV is promising with $\unicode[STIX]{x1D6FE}=46$ and $E_{0}=1.45~\text{GeV}$ on the existing short pulse laser facilities.

Relativistic collisionless shock charged particle acceleration is considered as a possible origin of high-energy cosmic rays. However, it is hard to explore the nature of relativistic collisionless shock due to its low occurring frequency and remote detecting distance. Recently, there are some works attempt to solve this problem by generating relativistic collisionless shock in laboratory conditions. In laboratory, the scheme of generation of relativistic collisionless shock is that two electron–positron pair plasmas knock each other. However, in laboratory, the appropriate pair plasmas have been not generated. The 10 PW laser pulse maybe generates the pair plasmas that satisfy the formation condition of relativistic collisionless shock due to its ultrahigh intensity and energy. In this paper, we study the positron production by ultraintense laser high Z target interaction using numerical simulations, which consider quantum electrodynamics effect. The simulation results show that the forward positron beam up to 1013/kJ can be generated by 10 PW laser pulse interacting with lead target. The estimation of relativistic collisionless shock formation shows that the positron yield satisfies formation condition and the positron divergence needs to be controlled. Our results indicate that the generation of relativistic collisionless shock by 10 PW laser facilities in laboratory is possible.

Flour whiteness (FW) is an important factor in assessing flour quality and determining the end product quality. It is an integrated sensory indicator reflecting flour colour and is negatively correlated with protein content. In order to dissect the genetic relationship between FW and its five related traits at the quantitative trait locus (QTL)/gene level, a recombinant inbred line population was evaluated under three environments. Quantitative trait loci for FW were analysed by unconditional and conditional QTL mapping. Four unconditional additive QTLs and 16 conditional additive QTLs were detected across the three environments. Of these QTLs, only one major additive QTL (Qfw1D1-1) was consistently identified using both unconditional and conditional QTL analysis. This QTL was independent of flour colour a* (a function of red-green with a positive a* for redness and negative for greenness) and b* (a green-blue value with positive value for yellowness and negative for blueness) and was only slightly affected by flour protein content. A minor additive QTL (Qfw4A-4) was also detected using these two QTL mapping methods, being independent of flour colour a* and b*. Five unconditional and ten conditional epistatic minor QTLs were detected, from which only one pair (Qfw3A-10/Qfw6B-6) was identified by both unconditional and conditional QTL mapping, also independent of flour colour a* and b*. The major QTL (Qfw1D1-1) identified in the current study for the first time can be used for improving wheat FW in marker-assisted breeding.

This paper focuses on the attitude dynamics and control of liquid filled spacecraft, and the large amplitude fuel slosh dynamics is included by using an improved moving pulsating ball model. The moving pulsating ball model is an equivalent mechanical model that is capable of imitating the whole liquid reorientation process, specifically for the occurrence of large amplitude slosh. This model is improved by incorporating a static capillary force and an effective mass factor. The improvements on this model are validated with previously published experiment results. The spacecraft attitude maneuver is implemented by the momentum transfer technique, and the feedback control strategy is designed based on Lyapunov theory. The effects of liquid viscosity, tank location and desired steady time on sloshing torque and control torque are investigated. The attitude control strategy applied in this paper is proved to be applicable for the coupled liquid filled spacecraft system. The obtained conclusions are useful to aid in liquid filled spacecraft overall design.

Escherichia albertii is a newly emerging enteric pathogen that has been associated with gastroenteritis in humans. Recently, E. albertii has also been detected in healthy and sick birds, animals, chicken meat and water. In the present study, the prevalence and characteristics of the eae-positive, lactose non-fermenting E. albertii strains in retail raw meat in China were evaluated. Thirty isolates of such strains of E. albertii were identified from 446 (6·73%) samples, including duck intestines (21·43%, 6/28), duck meat (9·52%, 2/21), chicken intestines (8·99%, 17/189), chicken meat (5·66%, 3/53), mutton meat (4·55%, 1/22) and pork meat (2·44%, 1/41). None was isolated from 92 samples of raw beef meat. Strains were identified as E. albertii by phenotypic properties, diagnostic PCR, sequence analysis of the 16S rRNA gene, and housekeeping genes. Five intimin subtypes were harboured by these strains. All strains possessed the II/III/V subtype group of the cdtB gene, with two strains carrying another copy of the I/IV subtype group. Pulsed-field gel electrophoresis showed high genetic diversity of E. albertii in raw meats. Our findings indicate that E. albertii can contaminate various raw meats, posing a potential threat to public health.

The soft scales (Hemiptera: Coccoidea: Coccidae) are a group of sap-sucking plant parasites, many of which are notorious agricultural pests. The quarantine and economic importance of soft scales necessitates rapid and reliable identification of these taxa. Nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene (barcoding region) and 28S rDNA were generated from 340 individuals of 36 common soft scales in China. Distance-based [(best match, Automated Barcode Gap Discovery (ABGD)], tree-based (neighbor-joining, Bayesian inference), Klee diagrams, and general mixed Yule coalescent (GMYC) models were used to evaluate barcoding success rates in the data set. Best match showed that COI and 28S sequences could provide 100 and 95.52% correct identification, respectively. The average interspecific divergences were 19.81% for COI data and 20.38% for 28S data, and mean intraspecific divergences were 0.56 and 0.07%, respectively. For COI data, multiple methods (ABGD, Klee, and tree-based methods) resulted in general congruence with morphological identifications. However, GMYC analysis tended to provide more molecular operational taxonomic units (MOTUs). Twelve MOTUs derived from five morphospecies (Rhodococcus sariuoni, Pulvinaria vitis, Pulvinaria aurantii, Parasaissetia nigra, and Ceroplastes rubens) were observed using the GMYC approach. In addition, tree-based methods showed that 28S sequences could be used for species-level identification (except for Ceroplastes ceriferus – Ceroplastes pseudoceriferus), even with low genetic variation (<1%). This report demonstrates the robustness of DNA barcoding for species discrimination of soft scales with two molecular markers (COI and 28S) and provides a reliable barcode library and rapid diagnostic tool for common soft scales in China.

This study was conducted to determine the effects on intestinal function, anti-inflammatory role and possible mechanism of polyethylene glycosylated (PEGylated) porcine glucagon-like peptide-2 (pGLP-2), a long-acting form of pGLP-2, in weaning piglets challenged with Escherichia coli lipopolysaccharide (LPS). We divided 18 weaned piglets on day 21 into three groups (control, LPS and LPS+PEG-pGLP-2; n=6). The piglets from the LPS+PEG-pGLP-2 group were injected with PEG-pGLP-2 at 10 nmol/kg BW from 5 to 7 days of the trials daily. On 8th day, the piglets in the LPS and LPS+PEG-pGLP-2 groups were intraperitoneally administered with 100 µg LPS/kg. The control group was administered with the same volume of saline solution. The piglets were then sacrificed on day 28. Afterwards, serum, duodenum, jejunum and ileum samples were collected for analysis of structural and functional endpoints. LPS+PEG-pGLP-2 treatment increased (P<0.05) lactase activities in the duodenum and the jejunum compared with LPS treatment. LPS+PEG-pGLP-2 treatment also significantly increased sucrase activity in the jejunum compared with LPS treatment. Furthermore, LPS treatment increased (P<0.05) the mRNA expression levels of interleukin (IL)-8, tumour necrosis factor-α (TNF-α) and IL-10 in the ileum compared with the control treatment. By contrast, LPS+PEG-pGLP-2 treatment decreased (P<0.05) the mRNA expression levels of IL-8, IL-10 and TNF-α in the ileum compared with the LPS treatment. LPS treatment also increased (P<0.05) the mRNA expression level of GLP-2 receptor (GLP-2R) and the percentage of GLP-2R-positive cells in the ileum; by comparison, these results were (P<0.05) reduced by LPS+PEG-pGLP-2 treatment. Moreover, LPS+PEG-pGLP-2 treatment increased (P<0.05) the content of serum keratinocyte growth factor compared with the control group and the LPS group. The protective effects of PEG-pGLP-2 on intestinal digestive function were associated with the release of GLP-2R mediator (keratinocyte growth factor) and the decrease in the expressions of intestinal pro-inflammatory cytokines.

Ten leading varieties of winter wheat released during 1950–2009 in North China were tested in a free-air temperature increase (FATI) facility. The FATI facility mimicked the local air temperature pattern well, with an increase of 1·1 °C in the daily mean temperature. For all the tested varieties, warming caused a significant reduction in the total length of wheat growth period by 5 days and especially in the pre-anthesis period, where it was reduced by 9 days. However, warming increased wheat biomass production and grain yield by 8·4 and 11·4%, respectively, on an average of all the tested varieties. There was no significant difference in the warming-led reduction in the entire growth period among the tested varieties. Interestingly, the warming-led increments in biomass production and grain yield increased along with the variety release year. Significantly higher warming-led increases in post-anthesis biomass production and 1000-grain weight were found in the new varieties compared to the old ones. Meanwhile, a significant improvement in plant productivity was noted due to wheat breeding during the past six decades, while no significant difference in the length of entire growth period was found among the varieties released in different eras. The results demonstrate that historical wheat breeding might have enhanced winter wheat productivity and adaptability through exploiting the positive effects rather than mitigating the negative impacts of warming on wheat growth in North China.

To understand the clinical epidemiology and molecular characteristics of human bocavirus (HBoV) infection in children with diarrhoea in Guangzhou, South China, we collected 1128 faecal specimens from children with diarrhoea from July 2010 to December 2012. HBoV and five other major enteric viruses were examined using real-time polymerase chain reaction. Human rotavirus (HRV) was the most prevalent pathogen, detected in 250 (22·2%) cases, followed by enteric adenovirus (EADV) in 76 (6·7%) cases, human astrovirus (HAstV) in 38 (3·4%) cases, HBoV in 17 (1·5%) cases, sapovirus (SaV) in 14 (1·2%) cases, and norovirus (NoV) in 9 (0·8%) cases. Co-infections were identified in 3·7% of the study population and 23·5% of HBoV-positive specimens. Phylogenetic analysis revealed 14 HBoV strains to be clustered into species HBoV1 with only minor variations among them. Overall, the detection of HBoV appears to partially contribute to the overall detection gap for enteric infections, single HBoV infection rarely results in severe clinical outcomes, and HBoV sequencing data appears to support conserved genomes across strains identified in this study.

The survival behaviour of Vibrio cholerae in cholera epidemics, together with its attributes of virulence-associated genes and molecular fingerprints, are significant for managing cholera epidemics. Here, we selected five strains representative of V. cholerae O1 and O139 involved in cholera events, examined their survival capacity in large volumes of water sampled from epidemic sites of a 2005 cholera outbreak, and determined virulence-associated genes and molecular subtype changes of the surviving isolates recovered. The five strains exhibited different survival capacities varying from 17 to 38 days. The virulence-associated genes of the surviving isolates remained unchanged, while their pulsotypes underwent slight variation. In particular, one waterway-isolated strain maintained virulence-associated genes and evolved to share the same pulsotype as patient strains, highlighting its role in the cholera outbreak. The strong survival capacity and molecular attributes of V. cholerae might account for its persistence in environmental waters and the long duration of the cholera outbreak, allowing effective control measures.

Fertilizer application can play an important role in soil organic carbon (SOC) retention and dynamics. The mechanisms underlying long-term accumulation and protection of SOC in intensive maize cropping systems, however, have not been well documented for cool high-latitude rainfed areas. Based on a 23-year fertilization experiment under a continuous maize cropping system at Gongzhuling, Jilin Province, China, the effects of fertilization regimes on SOC content and soil aggregate-associated carbon (C) composition were investigated. Results showed that, within the 0–1·0 m soil profile, SOC contents decreased significantly with soil depth in all treatments. In the topsoil layer (0–0·2 m), SOC concentrations in balanced inorganic fertilizers plus farmyard manure (MNPK), fallow system (FAL) and balanced inorganic fertilizers plus maize straw residue (SNPK) treatments were significantly greater than initial levels by 61·0, 34·1 and 20·1%, respectively. The MNPK and SNPK treatments increased SOC content by 50·7 and 12·4% compared to the unfertilized control in the topsoil layer, whereas no significant differences were found between balanced inorganic nitrogen, phosphorus and potassium fertilizers (NPK) and the unfertilized control treatment. There were no significant differences in aggregate-size distribution among the unfertilized control, NPK and MNPK treatments, whereas the SNPK treatment significantly enhanced the formation of micro-aggregates (53–250 μm) and decreased the formation of silt+clay aggregates (<53 μm) compared to the unfertilized control, NPK and MNPK treatments. Moreover, SOC concentrations in all aggregate fractions in the MNPK treatment were the highest among treatments. Furthermore, the MNPK treatment significantly increased SOC stock in micro- and silt+clay aggregates, which may slow down C decomposition in the soil. These results indicate that long-term manure amendment can benefit SOC sequestration and stability in the black soil of Northeast China.