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Many exclusive c→d/sℓ+νℓ(ℓ=e,μ,τ) transitions have been well measured, and they can be used to test the theoretical calculations. Motivated by this, we study the D→P/V/Sℓ+νℓ decays induced by the c→d/sℓ+νℓ transitions with the SU(3) flavor symmetry approach, where P denotes the pseudoscalar meson, V denotes the vector meson, and S denotes the scalar meson with a mass below 1 GeV. The different decay amplitudes of the D→Pℓ+νℓ, D→Vℓ+νℓ or D→Sℓ+νℓ decays can be related by using the SU(3) flavor symmetry and by considering the SU(3) flavor breaking. Using relevant data, we predict the not yet measured or not yet well measured processes in the D→P/V/Sℓ+νℓ decays. We find that the SU(3) flavor symmetry approach works well in the D→P/Vℓ+νℓ decays. Many branching ratios of the D→Sℓ+νℓ decays are predicted by using the data of the Ds+→f0(980)e+νe and D→S(S→P1P2)ℓ+νℓ decays, in addition, the two quark and the four quark scenarios for the light scalar mesons are analyzed. The SU(3) flavor symmetry predictions of the D→Sℓ+νℓ decays need to be further tested, and our predictions of the D→Sℓ+νℓ decays are useful for probing the structure of light scalar mesons. Our results in this work could be used to test the SU(3) flavor symmetry approach in the semileptonic D decays by the future experiments at BESIII, LHCb and BelleII.

In eukaryotes, histone acetylation and deacetylation play an important role in the regulation of gene expression. Histone acetylation levels are reversibly regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). Increasing evidence highlights histone acetylation plays essential roles in the regulation of gene expression in plant response to environmental stress. In this review, we discussed the recent advance of histone acetylation in the regulation of abiotic stress responses including temperature, light, salt and drought stress. This information will contribute to our understanding of how plants adapt to environmental changes. As the mechanisms of epigenetic regulation are conserved in many plants, research in this field has potential applications in improvement of agricultural productivity. [ABSTRACT FROM AUTHOR]

Abstract The complexity of the intrinsic oxygen evolution reaction (OER) mechanism, particularly the precise relationships between the local coordination geometry of active metal centers and the resulting OER kinetics, remains to be fully understood. Herein, we construct a series of 3 d transition metal-incorporated cobalt hydroxide-based nanobox architectures for the OER which contain tetrahedrally coordinated Co(II) centers. Combination of bulk- and surface-sensitive operando spectroelectrochemical approaches reveals that tetrahedral Co(II) centers undergo a dynamic transformation into highly active Co(IV) intermediates acting as the true OER active species which activate lattice oxygen during the OER. Such a dynamic change in the local coordination geometry of Co centers can be further facilitated by partial Fe incorporation. In comparison, the formation of such active Co(IV) species is found to be hindered in CoOOH and Co-FeOOH, which are predominantly containing [CoIIIO6] and [CoII/FeIIIO6] octahedra, respectively, but no mono-μ-oxo-bridged [CoIIO4] moieties. This study offers a comprehensive view of the dynamic role of local coordination geometry of active metal centers in the OER kinetics.

Abstract Background Babesia is a tick-borne protozoan blood parasite that can cause hemolytic anemia, thrombocytopenia, lethargy and splenomegaly in giant pandas. Methods We evaluated the efficacy and safety profile of a therapeutic regimen combining atovaquone and zithromycin in the context of babesiosis in giant pandas that have been naturally infected. The examined pandas underwent clinical and laboratory analyses, including hematology, biochemistry and thyroid hormone profiles. Upon diagnosis, the giant pandas were administered a compounded treatment consisting of atovaquone oral suspension (15 mg/kg, PO, q8 h), azithromycin tablets (10 mg/kg, PO, q24 h) and Enteral Nutritional Suspension (TPF) as a fat-rich supplement (0.5 ml/kg, PO, q8 h) for a 10-day period. Results The combination treatment increased the red blood cell count, hemoglobin levels and hematocrit in the pandas within a short period, while also reducing parasite levels below the PCR detection threshold. Conclusions Our study suggested that atovaquone and azithromycin combination therapy is highly effective for emergency treatment of Babesia sp. infection in giant pandas. Graphical Abstract

The giant panda is a critical species for biodiversity conservation, yet the majority of its subpopulations are at high risk of extinction. To effectively guide conservation efforts and avert local extinctions, ongoing genetic monitoring is crucial. This study, focusing on the vital Daxiangling giant panda population in southwest China, utilized non-invasive genetic sampling and microsatellite markers to assess the genetic diversity and evaluate the impact of releasing captive-bred individuals on population viability. Our findings indicate that conservation efforts have reduced genetic differentiation between subpopulations (FST = 0.035). Although the Daxiangling population is small, it has moderate genetic diversity, suggesting potential adaptability. However, the future risks posed by small population size and inbreeding are still significant over the next century. To maintain 90 % of current genetic diversity, the Daxiangling population should have at least 80 individuals with a balanced sex ratio. Releasing the existing three female wild-training giant pandas can slightly boost the current genetic diversity, but the long-term survival probability is low (42.9 %). The interval of releases (every 5, 2, or 1 year) has little impact on long-term dynamics of population size, whereas the sex of released individuals does have a significant impact. Additionally, the duration of releases (spanning 20, 30, 50 or 100 years) also has notable effects on future population prospects. The most effective strategy to increase population size (to over 80 individuals), maintain the genetic diversity (above 90 %), and ensure a high survival probability (above 98 %) is to release at least one female panda annually for 50 years or two females annually for 30 years. These findings provide critical guidance for the future conservation of the Daxiangling giant panda population.

Against the backdrop of global warming and rising sea levels, storm surge disasters occur frequently, often forming complex chains of events that lead to severe crises. However, systematic research on storm surge disaster chains is scarce. To characterize these chains, this research proposes a storm surge disaster chain analysis system based on complex networks and Bayesian networks. The system consists of three modules: evaluation, prediction, and measurement. The evaluation module uses a complex network model to quantitatively analyze the vulnerability, key nodes, and critical transmission paths of the disaster chain complex network. The prediction module establishes a Bayesian network-based model to forecast the complex network evolution process, forecasting the occurrence probability and loss scenarios of the disaster events. The measurement module measures and calculates the chain effect based on the dependence relationship and loss degree of the disaster event loss scenario. The results elucidate that most key nodes are primary and secondary disasters such as seawater flooding, flooding, dam damage, rainstorm, and house damage. Meanwhile, edges such as the sea wave–seawater flooding and house damage–human casualties have a critical impact on the storm surge disaster chain complex network. Key evolutionary paths such as strong winds–human casualties and over-warning tide level–social influence need to be focused on. Disaster reduction strategies such as maintaining dams, reinforcing houses, and removing disaster-bearing body can effectively break the chain and mitigate disasters. This research has a reference value for the scientific understanding of storm surge disaster chains and can serve as a scientific basis for comprehensive disaster reduction, disaster preparedness, and disaster relief.

To assess the impact of vaccines on clinical outcomes among hospitalized COVID-19-infected patients requiring oxygen supplementation during the Beijing Omicron outbreak. We conducted a retrospective cohort study at Beijing Chaoyang Hospital, Capital Medical University, from November 15, 2022, to March 31, 2023. Vaccination statuses were categorized into 3 doses, 2 doses, and unvaccinated (0 dose). The primary outcome was 28-day all-cause mortality. Secondary outcomes included poor outcomes, intensive care unit admission, cardiovascular thromboembolism events, and hospital readmission. Among the included patients, 117 were 2 doses, 285 received booster doses, and 503 were unvaccinated. After propensity score inverse probability weighting, the 3 doses group showed a significantly lower 28-day all-cause mortality compared to the unvaccinated group (inverse probability of treatment weighting-adjusted HR: 0.64, 95% CI: 0.50–0.81). No significant difference was observed in all-cause mortality between the 2 doses and unvaccinated groups. No significant differences were observed in secondary outcome analyses when comparing the 3 doses or 2 doses group to the unvaccinated group. Subgroup analysis revealed significant benefits of booster vaccination in patients with shorter symptom duration, lower Charlson Comorbidity Index, and without immunosuppression status. Our study highlights the significant reduction in all-cause mortality among hospitalized Omicron-infected patients who received a third dose vaccine. These findings underscore the importance of prioritizing booster vaccinations, especially among the elderly. Further research is warranted to confirm and extend these observations.

The performance of the chemical fuel determines the altitude, range and longevity of spacecraft in air and space exploration. Promising alternatives (e.g., hypergolic ionic liquids or high-energy composites) with high-energy density, heat of formation and fast initial rate are considered as potential chemical fuels. As the high-energy density material, hexanitrohexaazaisowurtzitane (CL-20) often serves as secondary explosive with poor self-propagating combustion behaviors. Herein, 90% loading CL-20 microspheres with uniform particle sizes are precisely prepared by microfluid method, which exhibit unique hierarchical structure. The morphology, thermal behaviors, as well as combustion performance were further investigated. The results demonstrated that as-prepared spherical particles exhibit prominent thermal compatibility, and the enhanced self-sustaining combustion performance. This work provides an efficient method achieving the uniform high-energy density particles with excellent self-sustaining combustion performance. [ABSTRACT FROM AUTHOR]

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Abstract Multi‐stable structures can be reconfigured with fewer, lightweight, and less accurate actuators. This is because the attraction domain in the multi‐stable energy landscape provides both reconfiguration guidance and shape accuracy. Additionally, such structures can generate impulsive motion due to structural instability. Most multi‐stable units are planar structures, while spatial linkages can generate complex 3D motion and hold a more promising potential for applications. This study proposes a generalized approach to design a type of intrinsically multi‐stable spatial (IMSS) linkages with multiple prescriptible configurations, which are structurally compatible, and naturally stable at these states. It reveals that all over‐constrained mechanisms can be transformed into multi‐stable structures with the same design method. Single‐loop bi‐stable 4R and quadra‐stable 6R spatial linkages modules with intrinsic non‐symmetric stable states, which are transformed from fundamental kinematic linkage mechanisms unit such as Bennett and Bricard linkages, are designed to illustrate the basic idea and the superiority over the ordinary methods. Multi‐loop assembly by these IMSS linkage modules shows potential for practical applications that are required for the deployability and impulsivity of reconfiguration. Two preliminary design cases of a deployable tube and an impulsive gripper are experimentally presented to validate this applicability. Further promisingly, this design method of IMSS linkages paves the way for morphing platforms with lightweight actuation, high shape accuracy, high stiffness, and prescribed impulsive 3D motion.