Study of the driving factors of the abnormal influenza A (H3N2) epidemic in 2022 and early predictions in Xiamen, China.

BACKGROUND: Influenza outbreaks have occurred frequently these years, especially in the summer of 2022 when the number of influenza cases in southern provinces of China increased abnormally. However, the exact evidence of the driving factors involved in the prodrome period is unclear, posing great difficulties for early and accurate prediction in practical work. METHODS: In order to avoid the serious interference of strict prevention and control measures on the analysis of influenza influencing factors during the COVID-19 epidemic period, only the impact of meteorological and air quality factors on influenza A (H3N2) in Xiamen during the non coronavirus disease 2019 (COVID-19) period (2013/01/01-202/01/24) was analyzed using the distribution lag non-linear model. Phylogenetic analysis of influenza A (H3N2) during 2013-2022 was also performed. Influenza A (H3N2) was predicted through a random forest and long short-term memory (RF-LSTM) model via actual and forecasted meteorological and influenza A (H3N2) values. RESULTS: Twenty nine thousand four hundred thirty five influenza cases were reported in 2022, accounting for 58.54% of the total cases during 2013-2022. A (H3N2) dominated the 2022 summer epidemic season, accounting for 95.60%. The influenza cases in the summer of 2022 accounted for 83.72% of the year and 49.02% of all influenza reported from 2013 to 2022. Among them, the A (H3N2) cases in the summer of 2022 accounted for 83.90% of all A (H3N2) reported from 2013 to 2022. Daily precipitation(20-50 mm), relative humidity (70-78%), low (≤ 3 h) and high (≥ 7 h) sunshine duration, air temperature (≤ 21 °C) and O3 concentration (≤ 30 µg/m3, > 85 µg/m3) had significant cumulative effects on influenza A (H3N2) during the non-COVID-19 period. The daily values of PRE, RHU, SSD, and TEM in the prodrome period of the abnormal influenza A (H3N2) epidemic (19-22 weeks) in the summer of 2022 were significantly different from the average values of the same period from 2013 to 2019 (P < 0.05). The minimum RHU value was 70.5%, the lowest TEM value was 16.0 °C, and there was no sunlight exposure for 9 consecutive days. The highest O3 concentration reached 164 µg/m3. The range of these factors were consistent with the risk factor range of A (H3N2). The common influenza A (H3N2) variant genotype in 2022 was 3 C.2a1b.2a.1a. It was more accurate to predict influenza A (H3N2) with meteorological forecast values than with actual values only. CONCLUSION: The extreme weather conditions of sustained low temperature and wet rain may have been important driving factors for the abnormal influenza A (H3N2) epidemic. A low vaccination rate, new mutated strains, and insufficient immune barriers formed by natural infections may have exacerbated this epidemic. Meteorological forecast values can aid in the early prediction of influenza outbreaks. This study can help relevant departments prepare for influenza outbreaks during extreme weather, provide a scientific basis for prevention strategies and risk warnings, better adapt to climate change, and improve public health.

Economic burden of measles and its influencing factors in Fujian, China.

BACKGROUND: Measles is a highly-contagious, serious diseases that can lead to potentially fatal illness, disability and death . We conducted an investigation to calculate the economic burden of measles cases from 2018 to 2019 and to analyze factors that influenced the total costs of measles cases in Fujian Province, China. METHODS: We investigated confirmed cases of measles by telephone interview, from 2018 to 2019, including demographic characteristics, therapeutic measures, self-treatment and nutritional supplement expenditure, transportation fees, and lost wages. Medical expenses in the hospitals were obtained from the hospital service charge system. RESULTS: A total of 131 measles cases were investigated, the average direct cost, indirect cost, and total cost were $518, $284, and $802, respectively. The total cost was 15.5% of Annual Per Capita Disposable Income of Households ($5 162) in Fujian. Hospitalization (OR = 98.6, 95%CI: 21.1 ~ 460.6) and complication (OR = 8.7, 95%CI: 1.3 ~ 58.0) significantly influenced the total cost according to binary logistic regression, and an outbreak of measles may pose a significant threat to household finances in a short term. CONCLUSIONS: The economic burden of measles was high when compared with Annual Per Capita Disposable Income of Households. The resurgence of measles and measles outbreaks increased economic burden of household finances.

Hydrophobicity-driven unfolding of Trp-cage encapsulated between graphene sheets.

Understanding the interaction between proteins and graphene not only helps elucidate the behaviors of proteins in confined geometries, but is also imperative to the development of a plethora of graphene-based biotechnologies, such as the graphene liquid cell transmission electron microscopy. To discuss the overall geometrical-thermal effects on proteins, we performed molecular dynamics simulations of hydrated Trp-cage miniprotein sandwiched between two graphene sheets and in the bulk environment at the temperatures below and above its unfolding temperature. The structural fluctuations of Trp-cage were characterized using the backbone root mean square displacement and the radius of gyration, from which the free energy landscape of Trp-cage was further constructed. We observed that at both temperatures the confined protein became adsorbed to the graphene surfaces and exhibited unfolded structures. Residue-specific analyses clearly showed the preference for the graphene to interact with the hydrophobic regions of Trp-cage. These results suggested that the conformation space accessible to the protein results from the competition between the thermodynamic driving forces and the geometrical restraints. While confinement usually tends to restrict the conformation of proteins by volume exclusion, it may also induce the unfolding of proteins by hydrophobic interactions.

Impact of Shape Persistence on the Porosity of Molecular Cages.

Porous materials provide a plethora of technologically important applications that encompass molecular separations, catalysis, and adsorption. The majority of research in this field involves network solids constructed from multitopic constituents that, when assembled either covalently or ionically, afford macromolecular arrangements with micro- or meso-porous apertures. Recently, porous solids fabricated from discrete organic cages have garnered much interest due to their ease of handling and solution processability. Although this class of materials is a promising alternative to network solids, fundamental studies are still required to elucidate critical structure-function relationships that govern microporosity. Here, we report a systematic investigation of the effects of building block shape-persistence on the porosity of molecular cages. Alkyne metathesis and edge-specific postsynthetic modifications afforded three organic cages with alkynyl, alkenyl, and alkyl edges, respectively. Nitrogen adsorption experiments conducted on rapidly crystallized and slowly crystallized solids illustrated a general trend in porosity: alkynyl > alkenyl > alkyl. To understand the molecular-scale origin of this trend, we investigated the short and long time scale molecular motions of the molecular cages using ab initio molecular dynamics (AIMD) and classical molecular dynamics (MD) simulations. Our combined experimental and computational results demonstrate that the microporosity of molecular cages directly correlates with shape persistence. These findings discern fundamental molecular requirements for rationally designing porous molecular solids.

Dynamic Odd-Even Effect in Liquid n-Alkanes near Their Melting Points.

n-Alkanes are the textbook examples of the odd-even effect: The difference in the periodic packing of odd- and even-numbered n-alkane solids results in odd-even variation of their melting points. However, in the liquid state, in which this packing difference is not obvious, it seems natural to assume that the odd-even effect does not exist, as supported by the monotonic dependence of the boiling points of n-alkanes on the chain length. Herein, we report a surprising odd-even effect in the translational diffusional dynamic properties of n-alkanes in their liquid states. To measure the dynamics of the molecules, we performed quasi-elastic neutron scattering measurements near their melting points. We found that odd-numbered n-alkanes exhibit up to 30 times slower dynamics than even-numbered n-alkanes near their respective melting points. Our results suggest that, although n-alkanes are the simplest hydrocarbons, their dynamic properties are extremely sensitive to the number of carbon atoms.