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Nozzle shape greatly affects the activity of cells and growth factors inside bio-ink, which is easy to be ignored. In this research, the finite element simulation software based on fluid dynamics theory was used to simulate the extrusion flow behavior of the bio-ink inside the printing needle. By establishing the flow models of two commonly used needles (cylindrical and conical needles), taking sodium alginate solution as bio-ink, the extrusion flow behavior of bio-ink inside the printing needle was simulated. Following, taking steady pressure, flow rate, and fluid shear stress as the research objectives, the response effects of nozzle geometry parameters, including shape, size, and feeding pressure, on the flow behavior of bio-ink were analyzed. Finally, a method based on the idea of integration for evaluating the cumulative damage to the active substances inside bio-ink has been proposed. Results show that the wall shear stress is the main stress suffered by bio-ink in the bio-printing process. Smaller inlet pressure and larger nozzle outlet diameter are beneficial for reducing wall shear stress. Compared with the cylindrical nozzle, although the maximum wall shear stress of the conical nozzle is higher than that of the cylindrical nozzle under the same inlet pressure and outlet nozzle diameter, the time of bio-ink subjected to the wall shear stress is shorter. The cumulative damage of the cylindrical nozzle is 29.65 Pa·s, and that of the conical nozzle is 18.25 Pa·s, which indicates that the conical nozzle has better biofriendliness and less damage to the active substance inside the bio-ink. [ABSTRACT FROM AUTHOR]

Background Cardiovascular disease is the primary cause of death and Disease burden of Chinese residents, and the situation of prevention and control is grim. Management of risk factors for cardiovascular disease is an important foundation for preventing cardiovascular disease. However, there is currently limited research on the influencing risk factors of cardiovascular disease risk in elderly patients with chronic disease in primary care using single lead wearable electrocardiogram devices both domestically and internationally, and previous studies have not ranked the importance of variables containing different quantities of risk in patients from a holistic perspective. Objective The aim of this study is to analyze the influencing factors of the comprehensive risk of cardiovascular disease in elderly patients with chronic disease aged 65 and above in primary care in Ningxia, and to provide objective basis and assistance for the comprehensive prevention and control of cardiovascular disease in primary care. Methods From December 2021 to September 2022, totally 3 039 patients over 65 years old with hypertension, diabetes and coronary heart disease, including at least one chronic disease, from 26 primary care health center in Ningxia were selected as the research subjects. According to the analysis of the 72 hour electrocardiogram, there were 632 cases in the normal group and 2 407 cases in the risk group. Analyze the basic information of two groups of patients to determine the best λ Value, draw a model, and use LASSO regression and multivariate Logistic regression to analyze the comprehensive risk factors of cardiovascular disease in elderly patients with chronic diseases; and rank the variables that affect the overall risk of cardiovascular disease and include different numbers of risks among patients. Results The differences in age, gender, BMI, education level, occupation, urban-rural distribution, smoking, exercise, coronary heart disease combined with diabetes, hypertension combined with coronary heart disease and diabetes between the two groups of patients were statistically significant (P

To examine the effects of childhood parent-child separation with varying duration and form on later cognitive performance and psychopathological problems over a 6-year period, we use data from the China Family Panel Study (CFPS), which is an ongoing, prospective nationally representative study across 25 provinces in China. Of the 4033 children aged 4-10 years followed in 2012, 3522 children with complete data on separation from fathers and mothers were included. In 2018, 2560 participants were followed and interviewed to assess cognitive performance, behavioral problems as well as depressive symptoms at age 10-16 years. A total of 3522 children (mean [SD] age at baseline, 6.9 [2.0] years) were included. About 17.9% and 13.3% had separated from father and mother over 11 months or more in the year prior to the survey. Prolonged separation from parents was associated with lower scores in vocabulary (maternal: adjusted [beta] = -1.64, P = 0.002; paternal: adjusted [beta] = -1.58, P < 0.001) and mathematics performance (maternal: adjusted [beta] = -1.10, P = 0.009; paternal: adjusted [beta] = -0.94, P = 0.004) over a 6-year period. Prolonged maternal separation was associated with 0.34-point higher internalizing behaviors (P < 0.001) and 0.21-point higher externalizing behaviors (P = 0.009), as well as 0.89-point higher depressive symptoms (P = 0.018), while prolonged paternal separation was associated with 0.23-point higher internalizing behaviors (P = 0.005) and 0.76-point higher depressive symptoms (P = 0.011). The finding demonstrates substantial negative impacts of childhood paternal and maternal separations on cognitive and mental well-being during adolescence, which might be dependent on the "stress-dose" (duration of separation) and urban-rural residence.