Willingness to vaccinate against herpes zoster in Chinese urban population: a mixed-methods study.

OBJECTIVE: Although the herpes zoster vaccine has been available in mainland China since June 2020, residents' knowledge of herpes zoster and the herpes zoster vaccine is poor, and vaccination rates are low, especially among the elderly, who are at high risk for herpes zoster. This study assessed willingness to be vaccinated against herpes zoster and factors associated with vaccination among urban residents in China. METHODS: A mixed-methods study was conducted in community health centres from August 2022 to September 2022. We used convenience sampling to select 2864 residents from 9 Chinese cities for the quantitative study and 67 adults for the qualitative study. A structured questionnaire was used for the quantitative study, and data were collected through face-to-face interviews. Multinomial logistic regression was used to analyse factors associated with willingness to vaccinate. Qualitative data were analysed using thematic analysis of barriers to herpes zoster vaccination. RESULTS: A total of 2864 eligible respondents were included in the study. Of these, 42.67% intended to receive the herpes zoster vaccine, 21.44% refused and 35.89% were hesitant. The results of the quantitative and qualitative analyses showed that the factors associated with respondents' willingness to be vaccinated against herpes zoster included: personal characteristics such as gender, age and income; knowledge and attitudes about herpes zoster and the vaccine; vaccine characteristics such as efficacy, safety and price; and other factors such as pain tolerance and accessibility to vaccination. CONCLUSION: The low willingness to vaccinate, especially among the elderly, is mainly related to their poor knowledge and negative attitude towards the infection and vaccination. Therefore, health education about herpes zoster, immunisation promotion, and improvement of accessibility and affordability would be valuable in China.

Direct economic burden attributable to age-related diseases in China: An econometric modelling study.

Background: Aging is a strong risk factor for many chronic diseases. However, the economic burden attributable to age-related diseases remains unclear. We aimed to calculate the economic burden attributable to age-related diseases in China. Methods: We used an econometric modelling approach from the China Health and Retirement Longitudinal Survey (CHARLS), which is based on a longitudinal observational data set from middle-aged and older adults aged 45+ in 2011, 2013, and 2015. Results: We calculated the total direct economic burden attributable to age-related diseases for outpatient and inpatient services among adults aged 45 and above in China, which was approximately 288.368 billion US dollars (US$), US$379.901 billion, and US$616.809 billion in 2011, 2013, and 2015, respectively, taking up 19.48%, 21.11% and 32.03% of the overall health care expenses in the same year. The proportion of dyslipidemia was the largest, followed by hypertension in all the three years; hearing problems accounted for the lowest proportion. Conclusions: The alarming upward trend in age-related economic burden in China calls for urgent interventions to prevent or slow down the accumulation of damage associated with age-related diseases.

Unfolding of a diblock chain and its anomalous diffusion induced by active particles.

We study the structural and dynamical behavior of an A-B diblock chain in the bath of active Brownian particles (ABPs) by Brownian dynamics simulations in two dimensions. We are interested in the situation that the effective interaction between the A segments is attractive, while that between the B segments is repulsive. Therefore, in thermal (nonactive) equilibrium, the A block "folds" into a compact globule, while the B block is in the expanded coil state. Interestingly, we find that the A block could "unfold" sequentially like unknitting a sweater, driven by the surrounding ABPs when the propelling strength on them is beyond a certain value. This threshold value decreases and then levels off as the length of the B block increases. We also find a simple power-law relation between the unfolding time of the A block and the self-propelling strength and an exponential relation between the unfolding time and the length of the B block. Finally, we probe the translational and rotational diffusion of the chain and find that both of them show "super-diffusivity" in a large time window, especially when the self-propelling strength is small and the A block is in the folded state. Such super-diffusivity is due to the strong asymmetric distribution of ABPs around the chain. Our work provides new insights into the behavior of a polymer chain in the environment of active objects.

Globule-stretch transition of a self-attracting chain in the repulsive active particle bath.

Folding and unfolding of a chain structure are often manipulated in experiments by tuning the pH, temperature, single-molecule forces or shear fields. Here, we carry out Brownian dynamics simulations to explore the behavior of a single self-attracting chain in a suspension of self-propelling particles (SPPs). As the propelling force increases, the globule-stretch (G-S) transition of the chain occurs due to the enhanced disturbance from the SPPs. Two distinct mechanisms of the transition in the limits of low and high rotational diffusion rates of SPPs have been observed: shear-induced stretching at a low rate and collision-induced melting at a high rate. The G-S and S-G (stretch-globule) curves form a hysteresis loop at the low rate, while they merge at the high rate. Besides, we find that two competing effects result in a non-monotonic dependence of the G-S transition on SPP density at the low rate. Our results suggest an alternative approach to manipulating the folding and unfolding of (bio)polymers by utilizing active agents.

Beating of grafted chains induced by active Brownian particles.

We study the interplay between active Brownian particles (ABPs) and a "hairy" surface in two-dimensional geometry. We find that the increase of propelling force leads to and enhances inhomogeneous accumulation of ABPs inside the brush region. Oscillation of chain bundles (beating like cilia) is found in company with the formation and disassembly of a dynamic cluster of ABPs at large propelling forces. Meanwhile chains are stretched and pushed down due to the effective shear force by ABPs. The decrease of the average brush thickness with propelling force reflects the growth of the beating amplitude of chain bundles. Furthermore, the beating phenomenon is investigated in a simple single-chain system. We find that the chain swings regularly with a major oscillatory period, which increases with chain length and decreases with the increase of propelling force. We build a theory to describe the phenomenon and the predictions on the relationship between the period and amplitude for various chain lengths, and propelling forces agree very well with simulation data.

Polymer-Nucleic Acid Interactions.

Gene therapy is an important therapeutic strategy in the treatment of a wide range of genetic disorders. Polymers forming stable complexes with nucleic acids (NAs) are non-viral gene carriers. The self-assembly of polymers and nucleic acids is typically a complex process that involves many types of interaction at different scales. Electrostatic interaction, hydrophobic interaction, and hydrogen bonds are three important and prevalent interactions in the polymer/nucleic acid system. Electrostatic interactions and hydrogen bonds are the main driving forces for the condensation of nucleic acids, while hydrophobic interactions play a significant role in the cellular uptake and endosomal escape of polymer-nucleic acid complexes. To design high-efficiency polymer candidates for the DNA and siRNA delivery, it is necessary to have a detailed understanding of the interactions between them in solution. In this chapter, we survey the roles of the three important interactions between polymers and nucleic acids during the formation of polyplexes and summarize recent understandings of the linear polyelectrolyte-NA interactions and dendrimer-NA interactions. We also review recent progress optimizing the gene delivery system by tuning these interactions.