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In the paper, the finite element model of the wheelset-track system is established, and the explicit transient dynamic analysis method is used to study the dynamic response. The research results show that when the mass eccentric wheelset rolls on the rails, the eccentric mass will increase the wheel-rail contact force, and the peak changes of the vertical contact force are more than those of the lateral force peak changes. As the speed increases, the mass eccentric wheelset will increase the vertical vibration energy of the wheelset-track system and make the vibration energy in the middle-high frequency range increase significantly. When the speed v = 300 km/h, the corresponding vibration frequency f = 534.82 Hz becomes very prominent, which is close to the passing frequency of high-order wheel polygonal wear. At the same time, with the increase of the dynamic unbalance U , the overall vibration energy of the wheelset-track system presents an increasing trend, but it has little effect on the main frequency of unstable vibration. Finally, the larger the eccentric phase difference of the wheelset mass, the more the main frequency of unstable vibration exists in the middle-high frequency region, which is easy to cause high-order wheel polygonal wear.

Against the backdrop of consolidating the achievements of poverty alleviation and promoting rural revitalization, whether digital village construction can alleviate the risk of rural families returning to poverty and then help long-term poverty prevention needs systematic and scientific empirical investigation. Using data from the 2020 China Rural Revitalization Survey (CRRS), this paper analyzes the impact of digital village construction on rural household poverty vulnerability and explores its potential channels. The results show that (1) digital village construction can significantly alleviate the poverty vulnerability of rural households. (2) Improving entrepreneurial activity is an effective way for digital village construction to affect the risk of rural households returning to poverty. (3) Digital village construction has a greater effect on reducing the poverty vulnerability of households in the eastern and the plains regions, and it is necessary to be vigilant against the emergence of the “digital divide”. Based on these findings, this paper proposes policy recommendations to prevent the risk of rural areas returning to poverty through digital village construction, which achieves sustainable poverty reduction and rural revitalization goals.

The Fragile X-related disorders (FXDs) are Repeat Expansion Diseases resulting from an expansion of a CGG-repeat tract at the 5' end of the FMR1 gene. The mechanism responsible for this unusual mutation is not fully understood. We have previously shown that mismatch repair (MMR) complexes, MSH2/MSH3 (MutSβ) and MSH2/MSH6 (MutSα), together with Polβ, a DNA polymerase important for base excision repair (BER), are important for expansions in a mouse model of these disorders. Here we show that MLH1/MLH3 (MutLγ), a protein complex that can act downstream of MutSβ in MMR, is also required for all germ line and somatic expansions. However, exonuclease I (EXO1), which acts downstream of MutL proteins in MMR, is not required. In fact, a null mutation in Exo1 results in more extensive germ line and somatic expansions than is seen in Exo1+/+ animals. Furthermore, mice homozygous for a point mutation (D173A) in Exo1 that eliminates its nuclease activity but retains its native conformation, shows a level of expansion that is intermediate between Exo1+/+ and Exo1-/- animals. Thus, our data suggests that expansion of the FX repeat in this mouse model occurs via a MutLγ-dependent, EXO1-independent pathway, with EXO1 protecting against expansion both in a nuclease-dependent and a nuclease-independent manner. Our data thus have implications for the expansion mechanism and add to our understanding of the genetic factors that may be modifiers of expansion risk in humans.

We propose and experimentally demonstrate a high efficient circularly polarizing dichroism waveplate (CPDW) using a Si-based all-dielectric 2Dchiral metasurface. We demonstrate that the CPDW exhibits a unique dichroism in that it functions as a transmissive quarter waveplate for one of either left-or right-handed circularly polarized incident lightand a reflective mirror for the opposite polarization. The circular polarization dichroism (CPD = I RCP  − I LCP ) in transmission at wavelength ~1.5 μm reaches 97% and the extinction ratio (ER = I RCP /I LCP ) is as high as 345:1. Experimental fabrications and measurements of the proposed all-dielectric metasurface are implemented and found to be in excellent agreement with the simulations. The proposed all-dielectric chiral metasurface is of advantages of high-dichroism, easy-fabrication and standard semiconductor fabrication techniques compatible, which could lead to enhanced security in fiber and free-space communications, as well as imaging and sensing applications for circularly polarized light with a highly integrated photonic platform.

Programmable magnetic field-free manipulation of perpendicular magnetization switching is essential for the development of ultralow-power spintronic devices. However, the magnetization in a centrosymmetric single-layer ferromagnetic film cannot be switched directly by passing an electrical current in itself. Here, we demonstrate a repeatable bulk spin-orbit torque (SOT) switching of the perpendicularly magnetized CoPt alloy single-layer films by introducing a composition gradient in the thickness direction to break the inversion symmetry. Experimental results reveal that the bulk SOT-induced effective field on the domain walls leads to the domain walls motion and magnetization switching. Moreover, magnetic field-free perpendicular magnetization switching caused by SOT and its switching polarity (clockwise or counterclockwise) can be reversibly controlled in the IrMn/Co/Ru/CoPt heterojunctions based on the exchange bias and interlayer exchange coupling. This unique composition gradient approach accompanied with electrically controllable SOT magnetization switching provides a promising strategy to access energy-efficient control of memory and logic devices. A major challenge of spintronics is achieving magnetic field free electrical control of magnetisation. Here, Xie et al. achieve perpendicular magnetisation switching in a CoPt alloy, breaking inversion symmetry by varying the composition of the alloy in the growth direction.

Expansion of a CGG-repeat tract in the 5' untranslated region of the FMR1 gene causes the fragile X-related disorders (FXDs; aka the FMR1 disorders). The expansion mechanism is likely shared by the 35+ other diseases resulting from expansion of a disease-specific microsatellite, but many steps in this process are unknown. We have shown previously that expansion is dependent upon functional mismatch repair proteins, including an absolute requirement for MutLγ, one of the three MutL heterodimeric complexes found in mammalian cells. We demonstrate here that both MutLα and MutLβ, the two other MutL complexes present in mammalian cells, are also required for most, if not all, expansions in a mouse embryonic stem cell model of the FXDs. A role for MutLα and MutLβ is consistent with human GWA studies implicating these complexes as modifiers of expansion risk in other Repeat Expansion Diseases. The requirement for all three complexes suggests a novel model in which these complexes co-operate to generate expansions. It also suggests that the PMS1 subunit of MutLβ may be a reasonable therapeutic target in those diseases in which somatic expansion is an important disease modifier.

(1) Background: Poverty eradication is the common goal and challenge of human development. Livelihood capital is the basis for poor families to escape poverty and is also the key to enhancing the ability for sustainable development. (2) Methods: Using data from the 2018 China Family Panel Studies (CFPS), this paper empirically examines the impact of livelihood capital on poverty alleviation. In addition, the mediating effect of land transfer is explored. (3) Results: The results show that human, physical, financial, and social capital all have a significant positive impact on poverty alleviation, while natural capital has a significant negative impact on poverty alleviation. Moreover, land transfer plays a partial mediating role in the relationship between livelihood capital and poverty alleviation. (4) Conclusions: Based on the above findings, we suggest that the government formulate targeted poverty alleviation policies according to rural households’ livelihood capital endowment characteristics, reasonably guide the land flow, and achieve sustainable poverty reduction.

Background Salmonella has been considered as one of the most important foodborne pathogens that threatened breeding industry and public health. To investigate the prevalence and characterization of Salmonella isolated from duck farms and a slaughterhouse in Shandong province, a total of 49 Salmonella strains were isolated from 2342 samples from four duck farms and one duck slaughterhouse in Jinan and Tai’an, Shandong province, China. Results Among the isolates, S . Enteritidis (20/49, 40.8%) and S . Anatum (10/49, 20.4%) were the most prevalent, and high resistance rates were detected for erythromycin (49/49, 100.0%) and nalidixic acid (47/49, 95.9%). Class I integrons were detected in 17 isolates (34.7%17/49), which contained gene cassettes aadA7 + aac3-Id (15/17) and aadA5 + dfrA17 (2/17). Eleven different kinds of resistance genes were detected while bla TEM (36/49, 73.5%) was the most prevalent, followed by sul2 (14/49, 28.6%). Thirteen virulence genes were tested, and all of the strains carried invA, hilA and sipA . Multilocus sequence typing (MLST) results showed that seven sequence types (STs) were identified; ST11 was the most prevalent ST (20/49, 40.8%), followed by ST2441 (10/49, 20.4%). There was a strong correlation between STs and serovars. The results of pulsed field gel electrophoresis(PFGE) showed that 39 PFGE patterns were generated from 49 Salmonella strains. PFGE patterns were mostly diverse and revealed high similarity between the isolates from the same sampling sites. Conclusions The presence of Salmonella infections among duck farms revealed that ducks could also be potential reservoirs for Salmonella . The high resistance rates against commonly used antimicrobials suggested a need for more reasonable use of antimicrobials, as well as for investigating substitutes for antimicrobials.

Dust aerosols significantly impact the global climate, ecological environment and human health. Clarifying the distribution changes, sources, and transport routes of dust aerosols along the China–Pakistan Economic Corridor is important for assessing regional atmospheric environments and ensuring sustainable development. This study uses MODIS aerosol data, meteorological reanalysis data from 2003 to 2023, and the HYSPLIT model to reveal the characteristics and trends of aerosols and dust aerosols, quantify the distributions of dust sources, and estimate dust emissions. Results reveal ①Dust aerosols exhibit significant seasonal variations: summer (0.66)> spring (0.58)> autumn (0.37)> winter (0.29), and high-value areas are concentrated in eastern and southern Pakistan. The proportion of areas with increasing dust aerosol optical depth (DAOD) is 2.92%. ②Pakistan’s Balochistan and Sindh Provinces, and China’s Xinjiang Kashgar Region, are the main dust sources. Dust emissions from natural surfaces are high in spring, while those from anthropogenically influenced surfaces are peak in summer. ③In spring, air mass transport pathways are dominated by short-distance southeastward transport (75%), while long-distance northeastward transport occurs across all four seasons.

Ilex rotunda Thunb. is a prestigious ornamental tree renowned for its vibrant red fruits, yet the molecular mechanisms governing its fruit color variation remain poorly understood. The discovery of a rare yellow-fruited natural bud sport cultivar, ‘Peace Time’, provides an ideal model to investigate these processes compared to the wild-type red fruit. In this study, we integrated physiological evaluations, untargeted metabolomics, and de novo transcriptomics across multiple fruit developmental stages to elucidate the basis of this color transition. Our results demonstrated that the yellow phenotype is characterized by high lightness and yellowness values, driven by the profound suppression of anthocyanin biosynthesis. Biochemical and transcriptomic profiling revealed that DFR (dihydroflavonol 4-reductase), a critical “gatekeeper” gene, experiences severe transcriptional silencing in the yellow-fruited cultivar. This enzymatic bottleneck triggers a “passive substrate overflow,” redirecting shared precursors toward the parallel flavonol branch, resulting in the substantial accumulation of specific flavonols, including rutin and isoquercitrin. Furthermore, correlation network analysis highlighted a putative dual regulatory module associated with this metabolic reprogramming: the down-regulation of the putative activator bHLH30 coupled with the robust up-regulation of the putative repressor bHLH51, together likely contributing to the silencing of DFR transcription. These findings provide a comprehensive “dual-module” and “passive overflow” framework for fruit coloration in I. rotunda, highlighting a remarkable metabolic plasticity that reshapes this cultivar’s phytochemical profile and offers vital insights for future ornamental breeding.