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We aimed to investigate the fluid–solid–ice coupling mechanism as structures break through ice into water. Using LS–DYNA finite element software, a numerical simulation method is established, based on the ALE flow–solid coupling method, and the penalty function contact algorithm, which describes the structure–ice–water coupling interaction. The Eulerian algorithm is used to describe the air and water domains, while the Lagrange method is applied to the wedge and ice structure. The mechanical properties of ice are characterized using the elastic–plastic failure strain model. The feasibility of simulating the entry of structures into water via the ALE method is demonstrated by comparing the experimental and simulation results of wedges entering into water. The applicability of the ice material model in simulating collision–induced breakup is verified by comparing a simulation of a rigid plate hitting a spherical head of ice, with results from the ISO standard. The effects of water during icebreaking are assessed by simulating a wedge breaking through ice into water, as well as through ice without water. Additionally, the ice breakup and motion response of the wedge under different working conditions are compared by varying the wedge mass and icebreaking speed.

Objectives: We conducted a retrospective cohort study of medical records from a large, Maryland, U.S.-based cohort of pediatric primary care patients for potential associations between antibacterial, antifungal and antiviral prescriptions and subsequent suicidal thoughts and/or behaviors. Methods: Using first suicide-related diagnosis as the outcome and prior prescription of antibacterial, antifungal, and/or antiviral use as the exposure, we employed a series of multivariate Cox proportional hazards models. These models examined the hazard of developing newly recognized suicidal thoughts and/or behaviors, controlling for age, sex, race, insurance, number of encounters during the study period, prior mood disorder diagnosis and number of chronic health conditions. We constructed the same series of models stratified by the groups with and without a prior recorded mental or behavioral health diagnosis (MBHD). Results: Suicidal thoughts and/or behaviors were associated with the previous prescription of an antibacterial, antifungal and/or antiviral medication (HR 1.31, 95 %‐CI 1.05–1.64) as well as the total number of such medications prescribed (HR 1.04, 95 %‐CI 1.01–1.08), with the strongest relationship among patients with three or more medications (HR 1.44, 95 %‐CI 1.06–1.96). Among individual medications, the strongest association was with antibacterial medication (HR 1.28, 95 %‐CI 1.03–1.60). Correlations were strongest among the subgroup of patients with no previous (MBHD). Interpretation: Infections treated with antimicrobial medications were associated with increased risks of a suicide-related diagnosis among patients who had not had a previous mental or behavioral health diagnosis. This group should be considered for increased levels of vigilance as well as interventions directed at suicide screening and prevention. Funding: National Institutes of Health, Stanley Medical Research Institute.

ObjectiveChlamydia trachomatis (CT) infection is one of the most common sexually transmitted infections (STIs) worldwide. This study aimed to provide prevalence and associated factors data among patients seeking clinic-based STI services for estimating the disease burden of CT.Study design and methodA cross-sectional survey was conducted among patients attending clinics for STI services. Patients' social-demographic and behavioral information was collected and CT infection was determined by nucleic acid amplification test (NAAT) with self-collected urine specimens. Associated factors were identified using logistic regression.ResultsAmong the 8,324 participants, the overall prevalence was 9.0% with 10.7% for males and 8.3% for females respectively. Multivariate analysis showed that aged < 24 [adjusted odds ratio (aOR) = 1.27, 95% confidence interval (CI) = 1.01–1.59], being unmarried (aOR = 1.64, 95%CI = 1.35–2.00), having junior high school or below education level (aOR = 1.47, 95%CI = 1.13–1.91), having no access to health insurance (aOR = 1.27, 95%CI = 1.07–1.51), and being positive for Neisseria gonorrhoeae (NG, aOR = 4.49, 95%CI = 3.25–6.21) were significantly associated with CT infection.ConclusionWe found that CT infection is prevalent among patients seeking clinic-based STI services in Southern China. Targeted interventions could be implemented for patients with a higher risk of CT infection including those aged < 24, being unmarried, having junior high school or below education level, having no access to health insurance, and being positive for NG. In addition, routine CT screening could be considered a public health strategy by the government.

Abstract The notion that local heritage can be defined by the ‘collective memory’ of a city may be considered as being simplistic nowadays. Heritage is increasingly recognised as knowledge, a cultural product or even a political resource set within specific social circumstances. The local heritage underpins various ways of relating our past with our present and future, which are often much more complicated than we can imagine. The evolution of the conservation of Shanghai’s modern heritage architecture shows this complexity. By tracing more than 50 years’ progress in historic preservation, this paper shows how historical buildings from Shanghai’s early modern period were selected as urban heritage in the changing socio-political contexts of different time periods. Starting with how the first modern buildings were listed in a new Chinese narrative in the 1950s, this paper focuses on the great ideological changes and progress Shanghai achieved after China’s reform and opening policy since the 1980s. Emphasising the great significance of the establishment of local legislation for historic preservation as an extension of the national system, examples of the great enrichment of Shanghai’s local heritage are presented through multiple narratives and interpretations of Shanghai’s modern history. In a deeper observation of various practices and complicated contradictions, the historic preservation of Shanghai’s modern heritage architecture is shown to be a process of continuing to reconstruct the relationships between city and the State, the city and the world, as well as the city’s past, present and future in a pluralist society.