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Objective. Previous studies have found that some ventricular remodeling is accompanied by increased matrix metalloproteinase-9 (MMP-9) in vivo, and MMP-9 inhibitors can reduce ventricular remodeling. However, there is still no direct evidence that MMP-9 causes ventricular remodeling. In this study, MMP-9 was injected into rats to observe whether MMP-9 caused ventricular remodeling, thereby providing direct evidence of MMP-9-induced ventricular remodeling. Methods. Forty-eight eight-week-old male Wistar rats were randomly divided, by weight, into control, low-, medium-, and high-dose MMP-9 groups and were administered normal saline or recombinant rat MMP-9 0.7, 1.4, or 2.1 ng/g, respectively, via intraperitoneal injection, twice per week. On the 28th day, six rats were randomly selected from each group (Stage I). The remaining rats continued receiving injections until the 56th day (Stage II). Echocardiography was performed to observe cardiac structure and function, and the left ventricular mass index (LVWI) was calculated. Myocardial pathological changes and the collagen volume fraction (CVF) were observed by HE and VG staining in myocardial tissue. MMP-9 levels in serum were tested using ELISA. Myocardial MMP-9 levels were measured using Western blots, and the myocardial expression levels of MMP-9 mRNA were assessed using RT-PCR. Results. During Stage I, serum MMP-9 and myocardial MMP-9 mRNA levels are increased; hypertrophic cardiomyocytes, disorderly arrangement of fibers, and endochylema dissolution are observed in the medium- and high-dose groups. The left ventricular weight index (LVWI) and myocardial MMP-9 increased, and the collagen volume fraction (CVF) reduced in the high-dose group. In Stage II, the left ventricular end-diastolic volume (LVEDV) and diameter (LVIDd) are higher, and CVF decreased in the medium- and high-dose groups. Myocardial pathological lesions intensified. Serum MMP-9 in the model groups and myocardial MMP-9 in the medium- and high-dose groups are increased. Conclusions. Injection of MMP-9 can lead to ventricular remodeling. [ABSTRACT FROM AUTHOR]

Dynamic physical examination data can provide both cross-sectional and time-series characteristics of cardiovascular health. However, most physical examination databases containing health and disease information have not been fully utilized in China. Hence, this study aimed to analyze dynamic physical examination indicators for cardiovascular health to provide evidence for precise prevention and control of cardiovascular diseases in the primary prevention domain among healthy population with different demographic characteristics in Shanghai. Three-year continuous data were collected from the physical examination center of a hospital in Shanghai from 2018 to 2020, which included a total of 14,044 participants with an average age of 46.51±15.57 years. The cardiovascular status of overall healthy individuals may have a decreasing trend, which is manifested as a significant year-on-year decrease in high-density lipoprotein cholesterol; a significant year-on-year increase in total cholesterol, low-density lipoprotein cholesterol, and blood glucose levels; and a possible increasing trend of diastolic blood pressure, body mass index, and triglycerides. Healthy population with different sex and age groups have various sensitives to cardiovascular physical examination indicators. To conduct more accurate cardiovascular health management and health promotion for key populations in primary prevention, focusing on the dynamic trends of blood pressure, blood lipids, blood glucose, and body mass index in men and changes in total cholesterol in women over time is especially important. The age group of 50–69 years is key for better prevention and control of cardiovascular health. [ABSTRACT FROM AUTHOR]

• The liquid film was in the form of many slant streams in the middle region of the annular channel. • Four types of droplet impact outcomes were observed in the annular channel. • The impact outcomes were shown to undergo a transition from bouncing to coalescence as the droplet Weber number increased. • The transition boundary from bouncing to coalescence was 2500 under different liquid volume fractions. The separation of the gas and liquid in the gas-liquid cyclone separator is achieved through the swirling flow. The liquid film flow characteristics and the dynamics of droplets impacting the liquid film are very important for the separation performance, but these phenomena have not been well understood in the swirling flow. In this work, an experiment was conducted to investigate the liquid film flow and droplet impingement in the annular channel of the gas-liquid cyclone separator. Three regions of the annular channel could be divided based on the film flow patterns, which were the inlet region, the annular region, and the outlet region; and four typical droplet impact outcomes could be observed, which were splashing, coalescence, bouncing, and jet breakup. According to the characteristics of the liquid film and the outcome of droplet liquid film impingement, if the droplet splashing in the inlet region could be weakened and the length of the annular region was lengthened, it would be beneficial for gas-liquid separation. The impact outcomes were shown to undergo a transition from bouncing to coalescence as the droplet Weber number increased. Droplet coalescence was affected by the disturbance of gas flow and the evenness of the liquid film, so when the superficial velocity of the gas flow was fixed, the transition boundary was constant whatever the liquid volume fraction in the channel, and when the Reynolds number of the gas flow increased, the transition boundary of droplet Weber number increased first and then decreased. This work may provide a basis for a comprehensive understanding of the liquid film flow pattern and droplet behavior in the cyclone separator, and the results have the potential to be applied in other multiphase studies. [ABSTRACT FROM AUTHOR]