Experimental study of modified Tavis-Cummings model with directly-coupled superconducting artificial atoms.

The Tavis-Cummings model is intensively investigated in quantum optics and has important applications in generation of multi-atom entanglement. Here, we employ a superconducting circuit quantum electrodynamic system to study a modified Tavis-Cummings model with directly-coupled atoms. In our device, three superconducting artificial atoms are arranged in a chain with direct coupling through fixed capacitors and strongly coupled to a transmission line resonator. By performing transmission spectrum measurements, we observe different anticrossing structures when one or two qubits are resonantly coupled to the resonator. In the case of the two-qubit Tavis-Cummings model without qubit-qubit interaction, we observe two dips at the resonance point of the anticrossing. The splitting of these dips is determined by Δ λ=2g12+g32, where g1 and g3 are the coupling strengths between Qubit 1 and the resonator, and Qubit 3 and the resonator, respectively. The direct coupling J12 between the two qubits results in three dressed states in the two-qubit Tavis-Cummings model at the frequency resonance point, leading to three dips in the transmission spectrum. In this case, the distance between the two farthest and asymmetrical dips, arising from the energy level splitting, is larger than in the previous case. The frequency interval between these two dips is determined by the difference in eigenvalues (Δ λ=ε 1+-ε 1-), obtained through numerical calculations. What we believe as novel and intriguing experimental results may potentially advance quantum optics experiments, providing valuable insights for future research.

[Research and reflection on the diversified method system of multi-stages and multi-scenarios surveillance and early warning of infectious diseases].

With the outbreak of infectious diseases, more and more attention has been paid to surveillance and early warning work. Timely and accurate monitoring data is the basis of infectious diseases prevention and control. Effective early warning methods for infectious diseases can improve the timeliness and sensitivity of early warning work. This paper briefly introduces the intelligent early warning model of infectious diseases, summarizes the emerging surveillance and early warning methods of infectious diseases, and seeks the possibility of diversified surveillance and early warning in different epidemic stages and different outbreak scenarios of infectious diseases. This paper puts forward the idea of constructing a diversified method system of infectious diseases surveillance and early warning based on multi-stages and multi-scenarios and discusses the future development trend of infectious diseases surveillance and early warning, in order to provide reference for improving the construction level of infectious diseases surveillance and early warning system in China.

[Analysis of work-related musculoskeletal disorders among automobile manufacturing logistics workers in Guangzhou].

Objective: To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in logistics workers of automobile manufacturing enterprises in Guangzhou, and explore their potential categories and influencing factors, so as to provide basis for the prevention and control of WMSDs in logistics workers of automobile manufacturing enterprises. Methods: From April to May 2020, a convenient sampling method was adopted to select 1442 logistics workers in 2 automobile manufacturing enterprises in Guangzhou as the research objects. The incidence of WMSDs among them was investigated by using the Nordic Musculoskeletal Disorders Questionnaire, and the incidence pattern of WMSDs among the subjects was analyzed by the method of potential category analysis. Chi-square test and multiple logistic regression model were used to analyze the influencing factors of the disease. Results: The total prevalence of WMSDs was 42.9% (619/1442). The three parts with high prevalence of WMSDs were neck (23.5%, 339/1442), shoulder (21.3%, 307/1442) and lower back (19.1%, 275/1442). 69.0% (427/619) of the patients showed simultaneous disease in two or more sites. The subjects were divided into four latent groups by the analysis of latent categories: the group with multiple body parts (4.51%), the group with very low or no disease (70.39%), the group with shoulder and neck and upper back (11.37%), and the group with limbs and lower back (13.73%). Multivariate logistic regression showed that compared with the "very low or no disease group", the risk factors of multiple body parts of automotive logistics workers suffering from WMSDs mainly included: Working posture uncomfortable (OR=3.10, 95%CI: 1.44~6.70, P=0.004), often bend and turn (OR=2.36, 95%CI: 1.05~5.29, P=0.037), bend your knees homework for a long time (OR=2.29, 95%CI: 1.17~4.47, P=0.015) ; Working posture uncomfortable (OR=2.26, 95%CI: 1.51~3.38, P<0.001), bending the neck (OR=1.68, 95%CI: 1.03~2.74, P=0.036), neck minister time keep the same position (OR=1.81, 95%CI: 1.22~2.67, P= 0.003) It is a risk factor for shoulder, neck and upper back WMSDs; Risk factors for limb-lower back WMSDs include: Length > 10 years (OR=2.16, 95%CI: 1.24~3.78, P<0.001), the working position uncomfortable (OR=2.38, 95%CI: 1.63~3.48, P<0.001), bending the neck (OR=1.66, 95%CI: 1.03~2.68, P=0.039) . Conclusion: The prevalence rate of WMSDs among logistics workers in automobile manufacturing enterprises is high, which has obvious characteristics of classification and comorbis, and is closely related to individual characteristics such as sufficient rest time and working posture of workers.

[The status of projects funded in division of preventive medicine in National Natural Science Foundation of China from the financial year 2007-2021].

It is of great significance to analyze the configuration of programs funded by the National Natural Science Foundation of China using funding data in the field of preventive medicine from 2007 to 2021. The analysis mainly focused on the funding status of the program, funding amount, funded institutions and personnel. A total of 5 349 programs in the discipline of preventive medicine were funded over the last 15 years. The funding amount in this discipline accounted for a relatively low proportion in the total funding amount of the Department of Medical Sciences and this proportion also showed a decreasing trend. Non-infectious disease epidemiology, human nutrition, and health toxicology were the top three subdisciplines of all funded programs in preventive medicine. The proportion of programs led by young scholars was gradually rising over the years, and young scholars were playing an increasingly influential role in scientific research. The funding status among each subdiscipline and institution also varied. The results of this study reflected the thriving of preventive medicine. Meanwhile, some problems and dilemmas were also revealed in its current development. Hopefully, this study could provide valuable information for institutions and preventive medicine researchers to apply for National Natural Science Foundation, and promote the long-term development of preventive medicine in the future.

[Advance on theoretical epidemiology models research of prevention and control of COVID-19].

COVID-19 has brought a significant impact to the global health system, and also opportunities and challenges to epidemiological researches. Theoretical epidemiological models can simulate the process of epidemic in scenarios under different conditions. Therefore, modeling researches can analyze the epidemical trend of COVID-19, predict epidemical risks, and evaluate effects of different control measures and vaccine policies. Theoretical epidemiological modeling researches provide scientific advice for the prevention and control of infectious diseases, and play a crucial role in containing COVID-19 over the past year. In this study, we review the theoretical epidemiological modeling researches on COVID-19 and summarize the role of theoretical epidemiological models in the prevention and control of COVID-19, in order to provide reference for the combination of mathematical modeling and epidemic control.

Topologically Protected Quantum Coherence in a Superatom.

Exploring the properties and applications of topological quantum states is essential to better understand topological matter. Here, we theoretically study a quasi-one-dimensional topological atom array. In the low-energy regime, the atom array is equivalent to a topological superatom. Driving the superatom in a cavity, we study the interaction between light and topological quantum states. We find that the edge states exhibit topology-protected quantum coherence, which can be characterized from the photon transmission. This quantum coherence helps us to find a superradiance-subradiance transition, and we also study its finite-size scaling behavior. The superradiance-subradiance transition also exists in symmetry-breaking systems. More importantly, it is shown that the quantum coherence of the subradiant edge state is robust to random noises, allowing the superatom to work as a topologically protected quantum memory. We suggest a relevant experiment with three-dimensional circuit QED. Our study may have applications in quantum computation and quantum optics based on topological edge states.

[Construction of urban scale-free network model and its epidemiological significance in the prevention and control of COVID-19].

COVID-19 is a public health emergency currently. In this study, a scale-free network model is established based on the Spring Migration data in 2020.The cities is clustered into three different modules. The epidemic of the cities in the black module was the most serious, followed by the red and the cyan. The black module contains 9 cities in Zhejiang province and 8 cities in Guangdong province, most of them located in the southeast coastal economic belt. These cities should be the key cities for epidemic prevention and control.

Clinical and pathologic predictors of central lymph node metastasis in papillary thyroid microcarcinoma: a retrospective cohort study.

OBJECTIVE: To identify the clinical and pathological predictors of central lymph node metastasis (CLNM) in patients with clinically lymph node-negative papillary thyroid microcarcinoma (PTMC). MATERIALS AND METHODS: Data pertaining to 541 clinically lymph node-negative PTMC patients who underwent thyroid surgery at the Shanghai General Hospital between January 2010 and December 2013 were retrospectively analyzed. According to histopathological evidence of central lymph node involvement, patients were divided into central lymph node metastasis (CLNM)-positive and CLNM-negative groups; risk factors for CLNM were identified statistically. RESULTS: LNM was found in 148 (27.4%) patients. Gender (P = 0.002), age (P < 0.001), tumor size (P < 0.001), multifocality (P < 0.001), and extrathyroidal extension (P < 0.001) were significantly different between CLNM-positive and CLNM-negative groups. On multivariate analyses, male sex (odds ratio [OR] = 2.656), age <45 years (OR = 4.184), tumor size >0.575 cm (OR = 2.105), gross extrathyroidal extension (OR = 14.605) and multifocality (OR = 2.084) were independent risk factors for CLNM. Among patients who did not have any of these five risk factors, only 3.9% were found to have CLNM. CONCLUSIONS: A relatively high prevalence of CLNM was observed in patients with clinically lymph node-negative PTMC. CLNM was associated with male sex, younger age, larger tumor size, extrathyroidal extension and multifocal PTMC.

Correlated Emission Lasing in Harmonic Oscillators Coupled via a Single Three-Level Artificial Atom.

A single superconducting artificial atom can be used for coupling electromagnetic fields up to the single-photon level due to an easily achieved strong coupling regime. Bringing a pair of harmonic oscillators into resonance with the transitions of a three-level atom converts atomic spontaneous processes into correlated emission dynamics. We present the experimental demonstration of two-mode correlated emission lasing in harmonic oscillators coupled via a fully controllable three-level superconducting quantum system (artificial atom). The correlation of emissions with two different colors reveals itself as equally narrowed linewidths and quenching of their mutual phase diffusion. The mutual linewidth is more than 4 orders of magnitude narrower than the Schawlow-Townes limit. The interference between the different color lasing fields demonstrates that the two-mode fields are strongly correlated.

Hepatitis C virus infection and risk factors in the general population: a large community-based study in eastern China, 2011-2012.

Limited information is available on the prevalence of hepatitis C virus (HCV) in the general population in China. A community-based epidemiological study was conducted in three counties in eastern China. A total of 149 175 individuals were investigated in 60 communities in three counties in Jiangsu province, eastern China, of whom 1175 subjects [0·79%, 95% confidence interval (CI) 0·74-0·83] were HCV antibody positive. The prevalence was low in children (0·09%, 95% CI 0·04-0·17), but increased progressively from adolescents (0·20%, 95% CI 0·15-0·28) to adults aged ⩾21 years (95% CI 0·15-1·64). Women had a higher prevalence of HCV infection than men in most age groups. In a multilevel regression analysis, age, sex, education, occupation, blood transfusion [odds ratio (OR) 2·91, 95% CI 1·09-5·37], invasive testing (OR 1·28, 95% CI 1·14-1·61), and dental therapy (OR 2·27, 95% CI 1·41-3·42) were associated with HCV infection. In conclusion, although the prevalence of HCV in this population was lower than reported from national levels, the total reservoir of infection is significant and warrants public health measures, such as health education to limit the magnitude of the problem.