Purple nutsedge (Cyperus rotundus L.) is one of the world’s resilient upland weeds, primarily spreading through its tubers. Its emergence in rice fields has been increasing, likely due to changing paddy farming practices. This study aimed to investigate how C. rotundus, an upland weed, can withstand soil flooding and become a problematic weed in rice (Oryza sativa L.) fields. The first comparative analysis focused on the survival and recovery characteristics of growing and mature tubers of C. rotundus exposed to soil flooding conditions. Notably, mature tubers exhibited significant survival and recovery abilities in these environments. Based on this observation, further investigation was carried out to explore the morphological structure, non-structural carbohydrates, and respiratory mechanisms of mature tubers in response to prolonged soil flooding. Over time, the mature tubers did not form aerenchyma but instead gradually accumulated lignified sclerenchyma fibers, with lignin content also increasing. After 90 days, the lignified sclerenchyma fibers and lignin contents were 4.0 and 1.1 times higher than those in no soil flooding (CK). Concurrently, soluble sugar content decreased while starch content increased, providing energy storage, and alcohol dehydrogenase (ADH) activity rose to support anaerobic respiration via alcohol fermentation. These results indicated that mature tubers survived in soil flooding conditions by adopting a “low-oxygen quiescence strategy”, which involves morphological adaptations through the development of lignified sclerenchyma fibers, increased starch reserves for energy storage, and enhanced anaerobic respiration. This mechanism likely underpins the flooding tolerance of mature C. rotundus tubers, allowing them to endure unfavorable conditions and subsequently germinate and grow once flooding subsides. This study provides a preliminary explanation of the mechanism by which mature tubers of C. rotundus from the upland areas confer flooding tolerance, shedding light on the reasons behind this weed’s increasing presence in rice fields.

Motivated by the work initiated by Chapman [‘Determinants of Legendre symbol matrices’, Acta Arith. 115 (2004), 231–244], we investigate some arithmetical properties of generalised Legendre matrices over finite fields. For example, letting $a_1,\ldots ,a_{(q-1)/2}$ be all the nonzero squares in the finite field $\mathbb {F}_q$ containing q elements with $2\nmid q$, we give the explicit value of the determinant $D_{(q-1)/2}=\det [(a_i+a_j)^{(q-3)/2}]_{1\le i,j\le (q-1)/2}$. In particular, if $q=p$ is a prime greater than $3$, then

$$ \begin{align*}\bigg(\frac{\det D_{(p-1)/2}}{p}\bigg)= \begin{cases} 1 & \mbox{if}\ p\equiv1\pmod4,\\ (-1)^{(h(-p)+1)/2} & \mbox{if}\ p\equiv 3\pmod4\ \text{and}\ p>3, \end{cases}\end{align*} $$

where $(\frac {\cdot }{p})$ is the Legendre symbol and $h(-p)$ is the class number of $\mathbb {Q}(\sqrt {-p})$.

In order to establish a compact all-optical Thomson scattering source, experimental studies were conducted on the 45 TW Ti: sapphire laser facility. By including a steel wafer, mixed gas, and plasma mirror into a double-exit jet, several mechanisms, such as shock-assisted ionization injection, ionization injection, and driving laser reflection, were integrated into one source. So, the source of complexity was remarkably reduced. Electron bunches with central energy fluctuating from 90 to 160 MeV can be produced. Plasma mirrors were used to reflect the driving laser. The scattering of the reflected laser on the electron bunches led to the generation of X-ray photons. Through comparing the X-ray spots under different experimental conditions, it is confirmed that the X-ray photons are generated by Thomson scattering. For further application, the energy spectra and source size of the Thomson scattering source were measured. The unfolded spectrum contains a large amount of low-energy photons besides a peak near 67 keV. Through importing the electron energy spectrum into the Monte Carlo simulation code, the different contributions of the photons with small and large emitting angles can be used to explain the origin of the unfolded spectrum. The maximum photon energy extended to about 500 keV. The total photon production was 107/pulse. The FWHM source size was about 12 μm.

Schistosomiasis, a parasite infectious disease caused by Schistosoma japonicum, often leads to egg granuloma and fibrosis due to the inflammatory reaction triggered by egg antigens released in the host liver. This study focuses on the role of the egg antigens CP1412 protein of S. japonicum (SjCP1412) with RNase activity in promoting liver fibrosis. In this study, the recombinant egg ribonuclease SjCP1412, which had RNase activity, was successfully prepared. By analysing the serum of the population, it has been proven that the anti-SjCP1412 IgG in the serum of patients with advanced schistosomiasis was moderately correlated with liver fibrosis, and SjCP1412 may be an important antigen associated with liver fibrosis in schistosomiasis. In vitro, the rSjCP1412 protein induced the human liver cancer cell line Hep G2 and liver sinusoidal endothelial cells apoptosis and necrosis and the release of proinflammatory damage-associated molecular patterns (DAMPs). In mice infected with schistosomes, rSjCP1412 immunization or antibody neutralization of SjCP1412 activity significantly reduced cell apoptosis and necroptosis in liver tissue, thereby reducing inflammation and liver fibrosis. In summary, the SjCP1412 protein plays a crucial role in promoting liver fibrosis during schistosomiasis through mediating the liver cells apoptosis and necroptosis to release DAMPs inducing an inflammatory reaction. Blocking SjCP1412 activity could inhibit its proapoptotic and necrotic effects and alleviate hepatic fibrosis. These findings suggest that SjCP1412 may be served as a promising drug target for managing liver fibrosis in schistosomiasis japonica.

Adsorption of nanoparticles on minerals affects the fate and transport of nanoparticles directly and is of great significance to many fields, including research into ore deposits, geochemistry, the environment and mineral materials. Whereas many previous studies have been conducted under the equilibrium pH and low solid (mineral) to liquid (nanoparticle suspension) ratio conditions, adsorption processes under initial pH and high solid/liquid ratio conditions may represent many important yet underexamined complex scenarios. To fill in this research gap, the adsorption of gold nanoparticles on illite was investigated experimentally at a relatively high solid/liquid ratio of 5 g L–1 and the effects of initial pH, ionic strength, citrate concentration, temperature and illite particle size were evaluated. The adsorbed amount of gold nanoparticles (from <5% to nearly 100%) increased with increasing ionic strength, temperature and citrate concentration and decreased with increasing pH and illite particle size. The presence of illite resulted in the dynamic evolution of the pH of the suspension, which, along with solution chemistry parameters, controlled the electrostatic interaction of illite and gold nanoparticles. The adsorption results, scanning electron microscopy observations and surface properties of illite suggest that the negatively charged gold nanoparticles were adsorbed predominantly on the positive illite edges through electrostatic interaction. The electrostatic attraction between illite and gold nanoparticles appeared to be strong, supported by the minor amount of desorption. These research findings are expected to provide a valuable reference regarding many critical issues in the geosciences as well as for industrial applications.

Placental trophoblastic cells play important roles in placental development and fetal health. However, the mechanism of trophoblastic cell fusion is still not entirely clear. The level of Tspan5 in the embryo culture medium was detected using enzyme-linked immunosorbent assay (ELISA). Fusion of BeWo cells was observed by immunofluorescence. Cell fusion-related factors and EMT-related factors were identified by qRT-PCR and western blotting. Notch protein repressor DAPT was used to verify the role of Tspan5 in BeWo cells. The expression of Tspan5 was significantly increased in embryo culture medium. The fusion of BeWo cells was observed after treatment with forskolin (FSK). Cell fusion-related factors (i.e. β-hCG and syncytin 1/2) and Tspan5 were significantly increased after FSK treatment. In addition, FSK treatment promoted EMT-related protein expression in BeWo cells. Knockdown of Tspan5 inhibited cell fusion and EMT-related protein levels. Notch-1 and Jagged-1 protein levels were significantly upregulated, and the EMT process was activated by overexpression of Tspan5 in FSK-treated BeWo cells. Interestingly, blocking the Notch pathway by the repressor DAPT had the opposite results. These results indicated that Tspan5 could promote the EMT process by activating the Notch pathway, thereby causing cell fusion. These findings contribute to a better understanding of trophoblast cell syncytialization and embryonic development. Tspan5 may be used as a therapeutic target for normal placental development.

Negative symptoms are an important symptom dimension in schizophrenia that are often least responsive to antipsychotic medications. We revisit the current practice of identifying ‘primary’ negative symptoms and suggest that its concept would benefit from a further elaboration of their timing of emergence in relation to the dynamic neurobiological changes to enhance their utility in clinical decision-making and research.

To explore the effect of yield stress on the secondary breakup of gel drops, experimental and theoretical investigations are carried out by employing a high-speed camera. A unique hemline-type breakup, as a modified behaviour of sheet-thinning breakup, occurs when the air velocity increases to a high region. The edges of the drops constantly deform into thin membranes when the high-velocity air skims over the gel drops. These membranes vibrate vertically, and breaking points occur at high amplitudes, causing the formation of reticular fragments. The results of linear stability analysis indicated that the yield stress of the gel drops has an influence on the formation and breakup of the gel membranes. The breakup regime map and breakup times are also studied.

The parasite Fasciola hepatica is an important zoonotic parasite. The development of an animal model of F. hepatica's life cycle is critical for studying the biological characteristics of the parasite in snails and mammals. Eggs of F. hepatica of bovine origin were cultured, and metacercariae were obtained after infection of Galba pervia snails. The life cycle system of F. hepatica was initiated in 2 different animals by orally infecting rabbits, SD rats and Kunming mice with the metacercariae. The animals' survival after infection, parasite migration in the animals and pathological damage to the liver were observed. We discovered that rabbits died due to acute suppurative hepatitis 60–69 days after infection, and eggs were found in the feces on day 63 of infection. The liver of SD rats showed punctate lesions on day 3 of infection, and further changes occurred as the infection progressed. However, liver repair was observed at week 9. SD rats survived for more than a year after infection and continued the F. hepatica life cycle. The liver lesions in Kunming mice after infection were similar but more severe than those in SD rats. Death was observed on the 31st post-infection day. We discovered that while rabbits, SD rats and Kunming mice can all be used as animal models of F. hepatica, SD rats are more suitable experimental animals in terms of tolerance and pathological response.

The findings regarding the associations between red meat, fish and poultry consumption, and the metabolic syndrome (Mets) have been inconclusive, and evidence from Chinese populations is scarce. A cross-sectional study was performed to investigate the associations between red meat, fish and poultry consumption, and the prevalence of the Mets and its components among the residents of Suzhou Industrial Park, Suzhou, China. A total of 4424 participants were eligible for the analysis. A logistic regression model was used to estimate the OR and 95 % CI for the prevalence of the Mets and its components according to red meat, fish and poultry consumption. In addition, the data of our cross-sectional study were meta-analysed under a random effects model along with those of published observational studies to generate the summary relative risks (RR) of the associations between the highest v. lowest categories of red meat, fish and poultry consumption and the Mets and its components. In the cross-sectional study, the multivariable-adjusted OR for the highest v. lowest quartiles of consumption was 1·23 (95 % CI 1·02, 1·48) for red meat, 0·83 (95 % CI 0·72, 0·97) for fish and 0·93 (95 % CI 0·74, 1·18) for poultry. In the meta-analysis, the pooled RR for the highest v. lowest categories of consumption was 1·20 (95 % CI 1·06, 1·35) for red meat, 0·88 (95 % CI 0·81, 0·96) for fish and 0·97 (95 % CI 0·85, 1·10) for poultry. The findings of both cross-sectional studies and meta-analyses indicated that the association between fish consumption and the Mets may be partly driven by the inverse association of fish consumption with elevated TAG and reduced HDL-cholesterol and, to a lesser extent, fasting plasma glucose. No clear pattern of associations was observed between red meat or poultry consumption and the components of the Mets. The current findings add weight to the evidence that the Mets may be positively associated with red meat consumption, inversely associated with fish consumption and neutrally associated with poultry consumption.

Environmental hypoxia exposure causes fertility problems in human and animals. Compelling evidence suggests that chronic hypoxia impairs spermatogenesis and reduces sperm motility. However, it is unclear whether paternal hypoxic exposure affects fertilization and early embryo development. In the present study, we exposed male mice to high altitude (3200 m above sea level) for 7 or 60 days to evaluate the effects of hypoxia on sperm quality, zygotic DNA methylation and blastocyst formation. Compared with age-matched controls, hypoxia-treated males exhibited reduced fertility after mating with normoxic females as a result of defects in sperm motility and function. Results of in vitro fertilization (IVF) experiments revealed that 60 days’ exposure significantly reduced cleavage and blastocyst rates by 30% and 70%, respectively. Immunohistochemical staining of pronuclear formation indicated that the pronuclear formation process was disturbed and expression of imprinted genes was reduced in early embryos after paternal hypoxia. Overall, the findings of this study suggested that exposing male mice to hypoxia impaired sperm function and affected key events during early embryo development in mammals.

Robots of next-generation physically interact with the world rather than be caged in a controlled area, and they need to make contact with the open-ended environment to perform their task. Compliant robot links offer intrinsic mechanical compliance for addressing the safety issue for physical human–robot interactions (pHRI). However, many important research questions are yet to be answered. For instance, how do system parameters, for example, mechanical compliance, motor torque, impact velocities, and so on, affect the impact force? how to formulate system impact dynamics of compliant robots, and how to size their geometric dimensions to maximize impact force reduction. In this paper, we present a parametric study of compliant link (CL) design for safe pHRI. We first present a theoretical model of the pHRI system that is comprised of robot dynamics, an impact contact model, and dummy head dynamics. After experimentally validating the theoretical model, we then systematically study the effects of CL parameters on the impact force in more detail. Specifically, we explore how the design and actuation parameters affect the impact force of pHRI system. Based on the parametric studies of the CL design, we propose a step-by-step process and a list of concrete guidelines for designing CL with safety constraints in pHRI. We further conduct a simulation case study to validate this design process and design guidelines.