116 research outputs found

    Dephasing of ultracold cesium 80D5/280D_{5/2}-Rydberg Electromagnetically Induced Transparency

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    We study Rydberg electromagnetically induced transparency (EIT) of a cascade three-level atom involving 80D5/2D_{5/2} state in a strong interaction regime employing a cesium ultracold cloud. In our experiment, a strong coupling laser couples 6P3/2P_{3/2} to 80D5/2D_{5/2} transition, while a weak probe, driving 6S1/2S_{1/2} to 6P3/2P_{3/2} transition, probes the coupling induced EIT signal. At the two-photon resonance, we observe that the EIT transmission decreases slowly with time, which is a signature of interaction induced metastability. The dephasing rate γOD\gamma_{\rm OD} is extracted with optical depth OD = γODt\gamma_{\rm OD}t. We find that the optical depth linearly increases with time at onset for a fixed probe incident photon number RinR_{\rm in} before saturation. The dephasing rate shows a nonlinear dependence on RinR_{\rm in}. The dephasing mechanism is mainly attributed to the strong dipole-dipole interactions, which leads to state transfer from nD5/2nD_{5/2} to other Rydberg states. We demonstrate that the typical transfer time τ0(80D)\tau_{0(80D)} obtained by the state selective field ionization technique is comparable with the decay time of EIT transmission τ0(EIT)\tau_{0({\rm EIT})}. The presented experiment provides a useful tool for investigating the strong nonlinear optical effects and metastable state in Rydberg many-body systems.Comment: 7 pages, 5 figure

    CO2 Hydrogenation on Metal-Organic Frameworks-Based Catalysts: A Mini Review

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    Conversion of carbon dioxide (CO2) into value-added fuels and chemicals can not only reduce the emission amount of CO2 in the atmosphere and alleviate the greenhouse effect but also realize carbon recycling. Through hydrogenation with renewable hydrogen (H2), CO2 can be transformed into various hydrocarbons and oxygenates, including methanol, ethanol, methane and light olefins, etc. Recently, metal-organic frameworks (MOFs) have attracted extensive attention in the fields of adsorption, gas separation, and catalysis due to their high surface area, abundant metal sites, and tunable metal-support interface interaction. In CO2 hydrogenation, MOFs are regarded as important supports or sacrificed precursors for the preparation of high-efficient catalysts, which can uniformly disperse metal nanoparticles (NPs) and enhance the interaction between metal and support to prevent sintering and aggregation of active metal species. This work summarizes the recent process on hydrogenation of CO2 to methanol, methane and other C2+ products over various MOFs-based catalysts, and it will provide some dues for the design of MOFs materials in energy-efficient conversion and utilization

    Dephasing of ultracold cesium 80í µí°· 5/2 -Rydberg Electromagnetically Induced Transparency

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    We study Rydberg electromagnetically induced transparency (EIT) of a cascade three-level atom involving 80í µí°· 5/2 state in a strong interaction regime employing a cesium ultracold cloud. In our experiment, a strong coupling laser couples 6í µí± 3/2 to 80í µí°· 5/2 transition, while a weak probe, driving 6í µí± 1/2 to 6í µí± 3/2 transition, probes the coupling induced EIT signal. At the two-photon resonance, we observe that the EIT transmission decreases slowly with time, which is a signature of interaction induced metastability. The dephasing rate í µí»¾ OD is extracted with optical depth OD = í µí»¾ OD í µí±¡. We find that the optical depth linearly increases with time at onset for a fixed probe incident photon number í µí± in before saturation. The dephasing rate shows a nonlinear dependence on í µí± in. The dephasing mechanism is mainly attributed to the strong dipole-dipole interactions, which leads to state transfer from í µí±í µí°· 5/2 to other Rydberg states. We demonstrate that the typical transfer time í µí¼ 0(80í µí°·) obtained by the state selective field ionization technique is comparable with the decay time of EIT transmission í µí¼ 0(EIT). The presented experiment provides a useful tool for investigating the strong nonlinear optical effects and metastable state in Rydberg many-body systems

    Dephasing of ultracold cesium 80D5/2-Rydberg electromagnetically induced transparency

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    We study Rydberg electromagnetically induced transparency (EIT) of a cascade three-level atom involving 80D5/2 state in a strong interaction regime employing a cesium ultracold cloud. In our experiment, a strong coupling laser couples 6P3/2 to 80D5/2 transition, while a weak probe, driving 6S1/2 to 6P3/2 transition, probes the coupling induced EIT signal. At the two-photon resonance, we observe that the EIT transmission decreases slowly with time, which is a signature of interaction induced metastability. The dephasing rate γOD is extracted with optical depth OD = γODt. We find that the optical depth linearly increases with time at onset for a fixed probe incident photon number Rin before saturation. The dephasing rate shows a nonlinear dependence on Rin. The dephasing mechanism is mainly attributed to the strong dipole-dipole interactions, which leads to state transfer from nD5/2 to other Rydberg states. We demonstrate that the typical transfer time τ0(80D) obtained by the state selective field ionization technique is comparable with the decay time of EIT transmission τ0(EIT). The presented experiment provides a useful tool for investigating the strong nonlinear optical effects and metastable state in Rydberg many-body systems

    Association between admission-blood-glucose-to-albumin ratio and clinical outcomes in patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention

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    IntroductionIt is unclear whether admission-blood-glucose-to-albumin ratio (AAR) predicts adverse clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) who are treated with percutaneous coronary intervention (PCI). Here, we performed a observational study to explore the predictive value of AAR on clinical outcomes.MethodsPatients diagnosed with STEMI who underwent PCI between January 2010 and February 2020 were enrolled in the study. The patients were classified into three groups according to AAR tertile. The primary outcome was in-hospital all-cause mortality, and the secondary outcomes were in-hospital major adverse cardiac events (MACEs), as well as all-cause mortality and MACEs during follow-up. Logistic regression, Kaplan–Meier analysis, and Cox proportional hazard regression were the primary analyses used to estimate outcomes.ResultsAmong the 3,224 enrolled patients, there were 130 cases of in-hospital all-cause mortality (3.9%) and 181 patients (5.4%) experienced MACEs. After adjustment for covariates, multivariate analysis demonstrated that an increase in AAR was associated with an increased risk of in-hospital all-cause mortality [adjusted odds ratio (OR): 2.72, 95% CI: 1.47–5.03, P = 0.001] and MACEs (adjusted OR: 1.91, 95% CI: 1.18–3.10, P = 0.009), as well as long-term all-cause mortality [adjusted hazard ratio (HR): 1.64, 95% CI: 1.19–2.28, P = 0.003] and MACEs (adjusted HR: 1.58, 95% CI: 1.16–2.14, P = 0.003). Receiver operating characteristic (ROC) curve analysis indicated that AAR was an accurate predictor of in-hospital all-cause mortality (AUC = 0.718, 95% CI: 0.675–0.761) and MACEs (AUC = 0.672, 95% CI: 0.631–0.712).DiscussionAAR is a novel and convenient independent predictor of all-cause mortality and MACEs, both in-hospital and long-term, for STEMI patients receiving PCI

    Influenza vaccine uptake among children and older adults in China: a secondary analysis of a quasi-experimental study.

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    BACKGROUND: Influenza vaccination is the key to prevent influenza-related disease, especially among high-risk populations. However, influenza vaccine uptake in China is low. This secondary analysis of a quasi-experimental trial aimed to understand factors associated with influenza vaccine uptake among children and older people stratified by funding context. METHODS: A total of 225 children (aged 0.5-8 years) and 225 older people (aged 60 years or above) were recruited from three clinics (rural, suburban and urban) in Guangdong Province. Participants were allocated into two groups based on funding contexts: a self-paid group (N = 150, 75 children and 75 older adults) in which participants paid full price for their vaccination; and a subsidized group (N = 300, 150 children and 150 older adults) in which varying levels of financial support was provided. Univariate and multivariable logistic regressions were conducted stratified by funding contexts. RESULTS: Overall, 75.0% (225/300) of participants in the subsidized group and 36.7% (55/150) in the self-paid group got vaccinated. Older adults had lower vaccination rates than children in both funding groups, while both age groups showed much higher uptake in the subsidized group than in the self-paid group (aOR = 5.96, 95% CI: 3.77-9.42, p = 0.001). In the self-paid group, having prior influenza vaccination history of children (aOR:2.61, 95%CI: 1.06-6.42) or older people (aOR:4.76, 95%CI: 1.08-20.90) was associated with increased influenza vaccine uptake compared to those who had no prior vaccination experiences in the family. While in the subsidized group, participants who got married or lived with partners (aOR = 0.32, 0.10-0.98) had lower vaccination uptake than single ones. Trust in providers' advice (aOR = 4.95, 95%CI:1.99, 12.43), perceived effectiveness of the vaccine (aOR: 12.18, 95%CI: 5.21-28.50), and experienced influenza-like illnesses in the family in the past year (aOR = 46.52, 4.10, 533.78) were associated with higher vaccine uptake. CONCLUSIONS: Older people had suboptimal vaccine uptake compared to children in both contexts and need more attention to enhance influenza vaccination. Tailoring interventions to different vaccine funding contexts may help improve influenza vaccination: In self-paid context, motivating people to accept their first ever influenza vaccination may be a promising strategy. In subsidized context, improving public confidence in vaccine effectiveness and providers' advice would be useful

    ZMYND10 Is Mutated in Primary Ciliary Dyskinesia and Interacts with LRRC6

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    Defects of motile cilia cause primary ciliary dyskinesia (PCD), characterized by recurrent respiratory infections and male infertility. Using whole-exome resequencing and high-throughput mutation analysis, we identified recessive biallelic mutations in ZMYND10 in 14 families and mutations in the recently identified LRRC6 in 13 families. We show that ZMYND10 and LRRC6 interact and that certain ZMYND10 and LRRC6 mutations abrogate the interaction between the LRRC6 CS domain and the ZMYND10 C-terminal domain. Additionally, ZMYND10 and LRRC6 colocalize with the centriole markers SAS6 and PCM1. Mutations in ZMYND10 result in the absence of the axonemal protein components DNAH5 and DNALI1 from respiratory cilia. Animal models support the association between ZMYND10 and human PCD, given that zmynd10 knockdown in zebrafish caused ciliary paralysis leading to cystic kidneys and otolith defects and that knockdown in Xenopus interfered with ciliogenesis. Our findings suggest that a cytoplasmic protein complex containing ZMYND10 and LRRC6 is necessary for motile ciliary function

    A genome-wide investigation of microsatellite mismatches and the association with body mass among bird species

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    Mutation rate is usually found to covary with many life history traits of animals such as body mass, which has been readily explained by the higher number of mutation opportunities per unit time. Although the precise reason for the pattern is not yet clear, to determine the universality of this pattern, we tested whether life history traits impact another form of genetic mutation, the motif mismatches in microsatellites. Employing published genome sequences from 65 avian species, we explored the motif mismatches patterns of microsatellites in birds on a genomic level and assessed the relationship between motif mismatches and body mass in a phylogenetic context. We found that small-bodied species have a higher average mismatches and we suggested that higher heterozygosity in imperfect microsatellites lead to the increase of motif mismatches. Our results obtained from this study imply that a negative body mass trend in mutation rate may be a general pattern of avian molecular evolution

    How do helpers slow senescence in a Tibetan cooperatively breeding bird?

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    Abstract Sociality is known to be capable of slowing individual senescence, but it is unclear whether the effect differs for reproduction versus survival in a sex‐specific manner. Here we predict that social benefits are directed toward (1) somatic maintenance in harsh environments where high survival prospects of adults over young intensify the trade‐off between current and future reproduction, and (2) females that invest more in reproduction and have a greater marginal effect if their survival is improved by reducing the cost of reproduction. These two predictions are tested with cooperatively breeding Tibetan ground tits (Pseudopodoces humilis). Across the lifetime, both mothers and fathers with helpers did not differ in brood size at fledging from their counterparts without helpers. The presence of helpers reduced survival senescence of both parents, but mothers benefited more than fathers from receiving help. Consequently, the inherent sex difference in life span and along with lifetime reproductive success, as expressed in breeders of never‐receiving help, became no longer obvious. The model of social modulation for senescence should facilitate the persistence of cooperative breeding in challenging environments
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