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Intense attosecond light sources are required for investigating ultrafast electron dynamics, such as that in molecules and atoms, etc. However, so far the achievable photon energy remains at the keV level, thereby limiting their range of applications. For instance, probing intranuclear dynamics requires photon energies in the gamma-ray regime. We propose here a scheme for generating intense attosecond gamma-ray pulses by irradiating a thin solid-density foil with intense vortex laser. In the interaction, the laser driven-foil electrons are differentially accelerated within a quarter-wave field and become highly bunched. Three-dimensional particle-in-cell simulations show that they can efficiently (with ∼ 30 % energy conversion efficiency) radiate ultrashort ( ∼ 400 as), high-flux ( > 10 10 photons per pulse), and ultrabrilliant (up to 1027 photons s−1 mm−2 mrad−2 per 0.1% BW at 1 MeV photon energy) gamma rays. With an x-ray driving laser, the scheme can even produce isolated bright sub-attosecond gamma-ray pulses that are useful for time-resolved nuclear spectroscopy and many other areas. [ABSTRACT FROM AUTHOR]

Background: Because of the close relationship between seed coat color and forage seed quality, it is of great significance to reveal the effect of seed coat color on seed germination and seedling growth under drought stress. Methods: We explore the effect of different seed coat colors (yellow, dark brown) on the seed germination and seedling growth of alfalfa under simulated drought stress (polyethylene glycol (PEG-6000) with eight osmotic potentials: 0 MPa, -0.1 MPa, -0.2 MPa, -0.3 MPa, -0.4 MPa, -0.6 MPa, -0.8 MPa, -1.0 MPa). Result: Under control conditions, the germination rate and germination energy of yellow seeds (91.6% and 91.2%, respectively) were higher than dark brown seeds (46.2% and 42.0%). The maximum seed germination rate and germination energy were observed in the -0.1MPa treatment for both yellow and dark brown seeds and were higher than control by 1.53% and 0.66% (yellow) and 9.96%, 14.76% (dark brown), respectively. The root length and seedling growth of two kinds of seeds were significantly inhibited when drought intensity increased. In summary, the germination and seedling growth traits of yellow seeds were much better than dark brown ones. Agronomically, selecting seed with high proportions of yellow coat color is more beneficial for seed storage and establishment of new alfalfa grasslands. [ABSTRACT FROM AUTHOR]

Precision spectroscopy of molecular hydrogen can be used to test the quantum electrodynamics theory and determine the proton-to-electron mass ratio in a four-body system. Cavity-enhanced double-resonance spectroscopy is proposed to determine highly-excited rotation-vibration energies of HD with high precision. As a demonstration, the V-type comb-locked cavity-assisted double resonance (COCA-DR) spectroscopy of HD is measured by pumping the P(1) (2-0) line and probing the R(1) line in the same overtone band. The sum value of the two transition frequencies is determined to be 426 889 423 917 (26) kHz, representing a new test of theoretical calculations. [ABSTRACT FROM AUTHOR]

Vaccine-induced mucosal immunity and broad protective capacity against various severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants remain inadequate. Formyl peptide receptor-like 1 inhibitory protein (FLIPr), produced by Staphylococcus aureus , can bind to various Fcγ receptor subclasses. Recombinant lipidated FLIPr (rLF) was previously found to be an effective adjuvant. In this study, we developed a vaccine candidate, the recombinant Delta SARS-CoV-2 spike (rDS)-FLIPr fusion protein (rDS-F), which employs the property of FLIPr binding to various Fcγ receptors. Our study shows that rDS-F plus rLF promotes rDS capture by dendritic cells. Intranasal vaccination of mice with rDS-F plus rLF increases persistent systemic and mucosal antibody responses and CD4/CD8 T-cell responses. Importantly, antibodies induced by rDS-F plus rLF vaccination neutralize Delta, Wuhan, Alpha, Beta, and Omicron strains. Additionally, rDS-F plus rLF provides protective effects against various SARS-CoV-2 variants in hamsters by reducing inflammation and viral loads in the lung. Therefore, rDS-F plus rLF is a potential vaccine candidate to induce broad protective responses against various SARS-CoV-2 variants.IMPORTANCEMucosal immunity is vital for combating pathogens, especially in the context of respiratory diseases like COVID-19. Despite this, most approved vaccines are administered via injection, providing systemic but limited mucosal protection. Developing vaccines that stimulate both mucosal and systemic immunity to address future coronavirus mutations is a growing trend. However, eliciting strong mucosal immune responses without adjuvants remains a challenge. In our study, we have demonstrated that using a recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike-formyl peptide receptor-like 1 inhibitory protein (FLIPr) fusion protein as an antigen, in combination with recombinant lipidated FLIPr as an effective adjuvant, induced simultaneous systemic and mucosal immune responses through intranasal immunization in mice and hamster models. This approach offered protection against various SARS-CoV-2 strains, making it a promising vaccine candidate for broad protection. This finding is pivotal for future broad-spectrum vaccine development., Competing Interests: M.S.H., S.J.L., C.L.Liao, and H.W.C. are named on patent applications related to lipidated FLIPr and the use thereof in vaccines.

Objective: To investigate the impact of COVID-19 on treatment of patients with acute ST segment elevation myocardial infarction(STEMI) undergoing primary percutaneous coronary intervention(PPCI). Methods: This was a multicenter retrospective study. STEMI patients undergoing PPCI from January 1, 2019 to December 31, 2021 were selected, based on the data of Xinnaolvsetongdao App. Clinical data and treatment time indicators, including symptom to first medical contact (S-FMC), symptom to door (StoD), first medical contact to ECG (FMC-ECG), first medical contact to guide wire (FMC-W), door to balloon (DtoB) and total ischemic time in 2019, 2020 and 2021 were compared. STEMI patients aged<60 years were sub-grouped as the young and middle-aged group, and STEMI patients aged≥60 years were sub-grouped as the elderly group. Results: A total of 7 435 (3 305 in 2019, 1 796 in 2020 and 2 334 in 2021) STEMI patients aged (59.6±12.6) years undergoing PPCI were included in this analysis. There were 5 990 males. For STEMI patients with PPCI in 2019, 2020 and 2021, FMC-ECG was 3 (1, 5) min, 3(1, 7) min and 4 (1, 7) min. FMC-W was 73 (56, 87) min, 78 (62, 95) min and 77 (62, 87) min. DtoB was 73 (56, 85) min, 78 (62, 95) min and 77 (62, 86) min. Total ischemic time was 189 (130, 273) min, 196 (138, 295) min and 209 (143, 276) min. FMC-ECG, FMC-W, DtoB and total ischemic time were longer in 2020 and 2021 than in 2019 (all P <0.05). The proportions of patients with FMC-ECG≤10 min (88.4% (1 588/1 796) vs. 92.7% (3 064/3 305), P <0.05), FMC-W≤120 min (87.9% (1 579/1796) vs. 91.7% (3 030/3 305), P <0.05) and DtoB≤90 min (72.3% (1 298/1 796) vs. 80.8% (2 672/3 305), P <0.05) were lower in 2020 than in 2019, whereas no differences were observed in the proportions of patients with FMC-ECG≤10 min (91.3% (2 131/2 334) vs. 92.7% (3 064/3 305), P =0.054), FMC-W≤120 min (92.0% (2 148/2 334) vs. 91.7% (3 030/3 305), P =0.635) and DtoB≤90 min (80.0% (1 867/2 334) vs. 80.8% (2 672/3 305), P =0.424) in 2021 compared with 2019. In the subgroup analysis, the proportions of patients with FMC-ECG≤10 min, FMC-W≤120 min and DtoB≤90 min were lower in the elderly group than in young and middle-aged group in 2019 (all P <0.05). The proportions of patients with FMC-W≤120 min and DtoB≤90 min were lower in the elderly group than in young and middle-aged group in 2021(all P <0.05). No differences were observed in the proportions of patients with FMC-ECG≤10 min, FMC-W≤120 min and DtoB≤90 min between the two group in 2020 (all P >0.05). Conclusions: Affected by the COVID-19, there is a reduction in the number of PPCI cases and treatment delays in STEMI patients, especially in the elderly. After adjusting the treatment strategy and widely applying the Xinnaolvsetongdao APP, the above indicators are significantly improved in 2021 as compared with 2020.

Objective: To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods: A total of 336 Salmonell a strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results: The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, β-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates. Conclusion: Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.