One-third of the global population aged 15 years and older engages in insufficient physical activities, which affects health. However, the health risks posed by sedentary behaviors are not well known. The mean daily duration of sedentary behavior is 8.3 hours among the Korean population and 7.7 hours among the American adult population. Sedentary lifestyles are spreading worldwide because of a lack of available spaces for exercise, increased occupational sedentary behaviors such as office work, and the increased penetration of television and video devices. Consequently, the associated health problems are on the rise. A sedentary lifestyle affects the human body through various mechanisms. Sedentary behaviors reduce lipoprotein lipase activity, muscle glucose, protein transporter activities, impair lipid metabolism, and diminish carbohydrate metabolism. Furthermore, it decreases cardiac output and systemic blood flow while activating the sympathetic nervous system, ultimately reducing insulin sensitivity and vascular function. It also alters the insulin-like growth factor axis and the circulation levels of sex hormones, which elevates the incidence of hormone-related cancers. Increased sedentary time impairs the gravitostat, the body's weight homeostat, and weight gain, adiposity, and elevated chronic inflammation caused by sedentary behavior are risk factors for cancer. Sedentary behaviors have wide-ranging adverse impacts on the human body including increased all-cause mortality, cardiovascular disease mortality, cancer risk, and risks of metabolic disorders such as diabetes mellitus, hypertension, and dyslipidemia; musculoskeletal disorders such as arthralgia and osteoporosis; depression; and, cognitive impairment. Therefore, reducing sedentary behaviors and increasing physical activity are both important to promote public health.

Copolymers composed of diketopyrrolopyrrole and phenylene units with different numbers of fluorine subsitution are synthesized. When the effect of the number of fluorine substitution on the n-channel transporting property is investigated, the polymer with four fluorine substitutions exhibits the best n-type charge-transporting behavior with an electron mobility of 2.36 cm(2) V(-1) s(1).

The life span of intestinal epithelial cells (IECs) is short (3–5 days), and its regulation is thought to be important for homeostasis of the intestinal epithelium. We have now investigated the role of commensal bacteria in regulation of IEC turnover in the small intestine. The proliferative activity of IECs in intestinal crypts as well as the migration of these cells along the crypt-villus axis were markedly attenuated both in germ-free mice and in specific pathogen–free (SPF) mice treated with a mixture of antibiotics, with antibiotics selective for Gram-positive bacteria being most effective in this regard. Oral administration of chloroform-treated feces of SPF mice to germ-free mice resulted in a marked increase in IEC turnover, suggesting that spore-forming Gram-positive bacteria contribute to this effect. Oral administration of short-chain fatty acids (SCFAs) as bacterial fermentation products also restored the turnover of IECs in antibiotic-treated SPF mice as well as promoted the development of intestinal organoids in vitro. Antibiotic treatment reduced the phosphorylation levels of ERK, ribosomal protein S6, and STAT3 in IECs of SPF mice. Our results thus suggest that Gram-positive commensal bacteria are a major determinant of IEC turnover, and that their stimulatory effect is mediated by SCFAs.

BackgroundObesity is a global epidemic. Behavior change monitoring using a smartphone application (app) can support weight management in obese patients. These apps must undergo usability testing, which is an important step in mobile healthcare app development. The current study aimed to develop a mobile app for behavioral monitoring and to test its usability including technical effectiveness, user efficiency, and user satisfaction for obese adults.MethodsDevelopment of the Dr. Youth app components included information on behavioral monitoring indicators and their obesity subtypes. The usability of the app was tested with 50 obese adults in a university hospital. Participants were asked to complete eight tasks for evaluating the technical effectiveness of the app. The time to complete each task was measured to test user efficiency. To explore user satisfaction, each participant completed the System Usability Scale (SUS). Descriptive statistics were used to examine the mean user efficiency and SUS scores.ResultsFifty adults (14 men and 36 women, aged 20–59 years) who are obese (body mass index ≥25 kg/m2) were recruited. The mean age of participants was 42.6 years (standard deviation [SD], 10.8 years); their mean body mass index was 29.6 kg/m2 (SD, 5.7 kg/m2). The tasks were completed with a 99% success rate. The overall mean SUS score was 76.65 (SD, 15.43).ConclusionThe Dr. Youth app shows acceptable technical effectiveness, user efficiency, and user satisfaction. Future study is warranted to establish the app’s clinical efficacy.

Widdrol is an odorant compound isolated from Juniperus chinensis. We previously reported that widdrol induces Gap 1 (G1) phase cell cycle arrest and leads to apoptosis in human colon adenocarcinoma HT29 cells. It was also reported that this cell cycle arrest is associated with the induction of checkpoint kinase 2 (Chk2), p53 phosphorylation and cyclin dependent kinase (Cdk) inhibitor p21 expression. In this paper, we investigated the molecular mechanisms of widdrol on the activation of G1 DNA damage checkpoint at early phase when DNA damages occurred in HT29 cells. First of all, we examined that widdrol breaks DNA directly or not. As the results of DNA electrophoresis and formation of phosphorylated histone H2AX (γH2AX) foci in HT29 cells, widdrol generates DNA double-strand breaks directly within 0.5 h both in vitro and in vivo. Based on this result, the change of proteins related in checkpoint pathway was examined over a time course of 0.5-24 h. Treatment of HT29 cells with widdrol elicits the following: (1) phosphorylation of Chk2 and p53, (2) reduction of cell division cycle 25A (Cdc25A) expression, (3) increase of Cdk inhibitor p21 expression, and (4) decrease of the levels of Cdk2 and cyclin E expression in a time-dependent manner. Moreover, only the expression level of mini-chromosome maintenance 4 (MCM4) protein, a subunit of the eukaryotic DNA replicative helicase, is rapidly down-regulated in HT29 cells treated with widdrol over the same time course, but those of the other MCM proteins are unchanged. Overall, our results indicated that widdrol breaks DNA directly in HT29 cells, and this DNA damage results in checkpoint activation via Chk2-p53-Cdc25A-p21-MCM4 pathway and finally cells go to G1-phase cell cycle arrest and apoptosis.