A two-dimensional body that moves suddenly in a viscous fluid can instantly generate vortices at its sharp edges. Recent work using inviscid flow theory, based on the Birkhoff–Rott equation and the Kutta condition, predicts that the ‘starting vortices’ generated by the sharp and straight edges of a body – i.e. the vortices formed immediately after motion begins – can be one of three distinct self-similar types. We explore the existence of these starting vortices for a flat plate and two symmetric Joukowski aerofoils immersed in a viscous fluid, using high-fidelity direct numerical simulations (DNS) of the Navier–Stokes equations. A lattice Green's function method is employed and simulations are performed for chord Reynolds numbers ranging from 5040 to 45 255. Vortices generated at the leading and trailing edges of the flat plate show agreement with the derived inviscid theory, for which a detailed assessment is reported. Agreement is also observed for the two symmetric Joukowski aerofoils, demonstrating the utility of the inviscid theory for arbitrary bodies. While this inviscid theory predicts an abrupt transition between the starting-vortex types, DNS shows a smooth transition. This behaviour occurs for all Reynolds numbers and is related to finite-time effects – there is a maximal time for which the (self-similar) starting vortices exist. We confirm the inviscid prediction that the leading-edge starting vortex of a flat plate can be suppressed dynamically. This has implications for the performance of low-speed aircraft such as model aeroplanes, micro air vehicles and unmanned air vehicles.

We report an experimental study of the formation and evolution of laminar thermal structures generated by a small heat source, with a focus on their correlation to the thermal boundary layer and effects of heating time $t_{heat}$. The experiments are performed over the flux Rayleigh number ($Ra_f$) range $2.1\times 10^6 \leq Ra_f \leq 3.6\times 10^{7}$ and the Prandtl number ($Pr$) range $28.6 \leq Pr \leq 904.7$. The corresponding Rayleigh number ($Ra= t_{heat}\,Ra_{f}/\tau _0\,Pr$) range is $900 \leq Ra \leq 4\times 10^{4}$, where $\tau _0$ is a diffusion time scale. For thermal structures generated by continuous heating (i.e. starting plumes), their formation process exists three characteristic times that are well reflected by changes in the thermal boundary layer thickness. These characteristic times, denoted as $t_{emit}$, $t_{recover}$ and $t_{static}$, correspond to the moments when the plume emission begins and completes, and when the thermal boundary layer becomes quasi-static, respectively. Their $Ra_f$–$Pr$ dependencies are found to be $t_{emit}/\tau _0\sim Ra_f^{-0.41}\,Pr^{0.41}$, $t_{recover}/\tau _0\sim Ra_f^{-0.48}\,Pr^{0.48}$ and $t_{static}/\tau _0\sim Ra_f^{-0.49}\,Pr^{0.33}$, respectively. Thermal structures generated by finite $t_{heat}$ exhibit similar evolution dynamics once $t_{heat} \ge t_{emit}$, with the accelerating stage behaving like starting plumes and the decay stage like thermals (i.e. a finite amount of buoyant fluids). It is further found that their maximum rising velocity experiences a transition in the $Ra$-dependence from $Ra$ to $(Ra\ln Ra)^{0.5}$ at $Ra \simeq 6000$; and their maximum acceleration reaches the value of starting plumes at $t_{heat}\simeq t_{recover}$, and remains unchanged for larger $t_{heat}$. In particular, the maximum rising velocity for the cases with $t_{heat} = t_{recover}$ follows a scaling relation $Ra_f^{0.37}\,Pr^{-0.37}$, in contrast to the relation $Ra_f^{0.48}\,Pr^{-0.48}$ for starting plumes. This study provides a more comprehensive understanding of laminar thermal structures, which are relevant to a range of processes in nature and laboratory systems such as Rayleigh–Bénard convection.

Metabolic-associated fatty liver disease (MAFLD) has been proposed to replace the term non-alcoholic fatty liver disease (NAFLD) in 2020. The association between micronutrients and MAFLD has not been reported. Therefore, this study aims to explore the association between micronutrients intake and MAFLD. This was a cross-section study based on the National Health and Nutrition Examination Survey (NHANES). The dietary intake of copper, zinc, iron, and selenium was evaluated using the 24-h dietary recall interview. Logistic regression analysis was used to explore the association between micronutrients and MAFLD, and the results were shown as odds ratio (OR) with 95 % confidence intervals (CIs). A total of 5976 participants were finally included for analysis, with 3437 participants in the MAFLD group. After adjusting potential confounders, copper intake at quartile Q3 (OR = 0⋅68, 95 % CI 0⋅50, 0⋅93) and Q4 (OR = 0⋅60, 95 % CI 0⋅45, 0⋅80) was found to be associated with lower odds of MAFLD. Iron intake at Q2 (OR = 0⋅64, 95 % CI 0⋅45, 0⋅92) and Q3 (OR = 0⋅61, 95 % CI 0⋅41, 0⋅91) was associated with the lower odds of MAFLD. Our findings found that high intake of copper and adequate intake of iron were associated with MAFLD, which may provide guidance for the management of MAFLD.

Rodents and shrews are major reservoirs of various pathogens that are related to zoonotic infectious diseases. The purpose of this study was to investigate co-infections of zoonotic pathogens in rodents and shrews trapped in four provinces of China. We sampled different rodent and shrew communities within and around human settlements in four provinces of China and characterised several important zoonotic viral, bacterial, and parasitic pathogens by PCR methods and phylogenetic analysis. A total of 864 rodents and shrews belonging to 24 and 13 species from RODENTIA and EULIPOTYPHLA orders were captured, respectively. For viral pathogens, two species of hantavirus (Hantaan orthohantavirus and Caobang orthohantavirus) were identified in 3.47% of rodents and shrews. The overall prevalence of Bartonella spp., Anaplasmataceae, Babesia spp., Leptospira spp., Spotted fever group Rickettsiae, Borrelia spp., and Coxiella burnetii were 31.25%, 8.91%, 4.17%, 3.94%, 3.59%, 3.47%, and 0.58%, respectively. Furthermore, the highest co-infection status of three pathogens was observed among Bartonella spp., Leptospira spp., and Anaplasmataceae with a co-infection rate of 0.46%. Our results suggested that species distribution and co-infections of zoonotic pathogens were prevalent in rodents and shrews, highlighting the necessity of active surveillance for zoonotic pathogens in wild mammals in wider regions.

Trematodes of the genus Ogmocotyle are intestinal flukes that can infect a variety of definitive hosts, resulting in significant economic losses worldwide. However, there are few studies on molecular data of these trematodes. In this study, the mitochondrial (mt) genome of Ogmocotyle ailuri isolated from red panda (Ailurus fulgens) was determined and compared with those from Pronocephalata to investigate the mt genome content, genetic distance, gene rearrangements and phylogeny. The complete mt genome of O. ailuri is a typical closed circular molecule of 14 642 base pairs, comprising 12 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes and 2 non-coding regions. All genes are transcribed in the same direction. In addition, 23 intergenic spacers and 2 locations with gene overlaps were determined. Sequence identities and sliding window analysis indicated that cox1 is the most conserved gene among 12 PCGs in O. ailuri mt genome. The sequenced mt genomes of the 48 Plagiorchiida trematodes showed 5 types of gene arrangement based on all mt genome genes, with the gene arrangement of O. ailuri being type I. Phylogenetic analysis using concatenated amino acid sequences of 12 PCGs revealed that O. ailuri was closer to Ogmocotyle sikae than to Notocotylus intestinalis. These data enhance the Ogmocotyle mt genome database and provide molecular resources for further studies of Pronocephalata taxonomy, population genetics and systematics.

The provenance and tectonic setting of the Lower–Middle Triassic clastic sediments from the Napo basin, South China, have been examined here using detrital modes, whole-rock geochemistry and detrital zircon U–Pb ages. Field investigations indicate that these sediments consist of fan delta, slope and turbidity fan facies with dominantly southward palaeocurrent directions. Detrital modes and geochemical characteristics of the clastic rocks indicate that they were derived from mixed magmatic arc and Palaeozoic successions in a continental island arc setting, with no significant sediment recycling. The U–Pb age spectra of sandstone detrital zircons from different stratigraphic positions are similar, with one major group (300–230 Ma), two subordinate groups (400–320 Ma and 480–420 Ma, respectively) and two scattered groups (1200–800 Ma and 2000–1700 Ma, respectively). Thus, we consider that the north late Permian – Middle Triassic volcanic rocks and the uplifted Palaeozoic sedimentary/volcanic sequences constituted the predominant sources. The detritus derived from the late Permian Emeishan mafic rocks is subordinate and limited. The pre-Devonian zircons are likely sedimentary-recycled or magmatic-captured instead of directly derived from the early Palaeozoic orogen (e.g. Yunkai massif) and Neoproterozoic Jiangnan orogen because of the topographic barrier of a magmatic arc and carbonate platform. Considering the spatial and temporal distribution characteristics of the volcanic arc and ophiolite, we suggest that the Triassic Napo basin was a fore-arc basin within a continental island arc setting, which developed in response to the northward subduction of the Babu–Cao Bang branch ocean beneath the South China Block.

ITGB1 (Integrin β1, CD29) is a member of the integrin family and has a role as a major adhesion receptor. Gastric cancer (GC) is an important cause of mortality worldwide, especially in China. As a potential cancer enhancer, the role ITGB1 plays in GC progression remains unclear. In the current study, our assay on the databases of tumoassociated gene expression and interaction found that the high expression of ITGB1 was closely correlated with the poor prognosis of GC patients. To explore the roles, ITGB1 plays in GC progression, and an ITGB1-deleted cell line (ITGB1−/−SGC7901) was generated using the CRISPR/Cas9 method. The tumor malignancy-associated cell behaviors and microstructures were detected, imaged, and analyzed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), wound healing, transwell, scanning electron microscopy, laser scanning confocal microscopy, and others. The results indicated that ITGB1 deletion decreased the GC cell proliferation and motility, and inhibited motility-relevant microstructures, such as pseudopodia and filopodia, markedly in ITGB1-deleted SGC7901 cells. The analysis of STRING database and western blots indicated that ITGB1 contributes to the malignancy of GC mediated by Src-mediated FAK/PI3K/Akt signaling pathways. Taken together, the results showed that ITGB1 may be a potential targeting marker for GC diagnosis and therapy in the future.

Donkeys facilitated trade and transport in much of the ancient world, but were seldom used in elite or leisure activities. While Tang Dynasty (AD 618–907) texts indicate that noble women played polo riding donkeys, this has never been documented archaeologically. Here, the authors present the first archaeological evidence of the significance of donkeys for elite Tang women through analyses of donkey remains recovered from the tomb of a Tang noblewoman in Xi'an, China. These findings broaden our understanding of the donkey's historic roles beyond simple load bearing.

Wire-shaped supercapacitors (WSSCs) hold great promise in portable and wearable electronics. Herein, a novel kind of high-performance coaxial WSSCs has been demonstrated and realized by scrolling porous carbon dodecahedrons/Al foil film electrode on vertical FeOOH nanosheets wrapping carbon fiber tows (FeOOH NSs/CFTs) yarn electrode. Remarkably, ionogel is utilized as solid-state electrolyte and exhibits a high thermal/electrochemical stability, which effectively ensures the great reliability and high operating voltage of coaxial WSSCs. Benefiting from the intriguing configuration, the coaxial WSSCs with superior flexibility act as efficient energy storage devices and exhibit low resistance, high volumetric energy density (3.2 mW h/cm3), and strong durability (82% after 10,000 cycles). Importantly, the coaxial WSSCs can be effectively recharged by harvesting sustainable wind source and repeatedly supply power to the lamp without a decline of electrochemical performance. Considering the facile fabrication technology with an outstanding performance, this work has paved the way for the integration of sustainable energy harvesting and wearable energy storage units.

Annexin A2 (ANXA2) is reported to be associated with cancer development. To investigate the roles ANXA2 plays during the development of cancer, the RNAi method was used to inhibit the ANXA2 expression in caco2 (human colorectal cancer cell line) and SMMC7721 (human hepatocarcinoma cell line) cells. The results showed that when the expression of ANXA2 was efficiently inhibited, the growth and motility of both cell lines were significantly decreased, and the development of the motility relevant microstructures, such as pseudopodia, filopodia, and the polymerization of microfilaments and microtubules were obviously inhibited. The cancer cell apoptosis was enhanced without obvious significance. The possible regulating pathway in the process was also predicted and discussed. Our results suggested that ANXA2 plays important roles in maintaining the malignancy of colorectal and hepatic cancer by enhancing the cell proliferation, motility, and development of the motility associated microstructures of cancer cells based on a possible complicated signal pathway.

Bi0.5Na0.5TiO3 (BNT)-based lead-free materials are important for piezoelectric actuator, and several researchers have studied the effect of B-site complex ion doping on strain in (Bi0.5Na0.5)TiO3–SrTiO3. In this work, a paraelectric perovskite Sr(Zn1/3Nb2/3)O3 (SZN) with B-site complex structure was introduced into 0.80(Bi0.5Na0.5)TiO3–0.20SrTiO3 (BNTST) to investigate the phase structure and electrical properties as well as the field-induced strain behavior. The results showed that SZN substitution decreases the rhombohedrality 90-γ and induces the transition from dominant ferroelectric to nonergodic relaxor by shifting its TF-R to lower temperatures. Moreover, the field-induced ferroelectric domains cannot remain stable at room temperature when SZN substitution is large than 1.0 mol%. These behaviors induced the transition between nonergodic relaxor and ergodic relaxor, which contributed to its large strain and related properties. In this work, this material gave the largest bipolar strain of 0.43% and large normalized unipolar strain of 505 pm/V at the SZN content of 2 mol% under 8 kV/mm, and showed good temperature stability up to 100 °C. The above encouraging results may be helpful for further investigation of BNTST-based ternary systems in search of a potential Pb-free piezoelectric material.