Connections between Reachability and Time Optimality

This paper presents the concept of an equivalence relation between the set of optimal control problems. By leveraging this concept, we show that the boundary of the reachability set can be constructed by the solutions of time optimal problems. Alongside, a more generalized equivalence theorem is presented together. The findings facilitate the use of solution structures from a certain class of optimal control problems to address problems in corresponding equivalent classes. As a byproduct, we state and prove the construction methods of the reachability sets of three-dimensional curves with prescribed curvature bound. The findings are twofold: Firstly, we prove that any boundary point of the reachability set, with the terminal direction taken into account, can be accessed via curves of H, CSC, CCC, or their respective subsegments, where H denotes a helicoidal arc, C a circular arc with maximum curvature, and S a straight segment. Secondly, we show that any boundary point of the reachability set, without considering the terminal direction, can be accessed by curves of CC, CS, or their respective subsegments. These findings extend the developments presented in literature regarding planar curves, or Dubins car dynamics, into spatial curves in $\mathbb{R}^3$. For higher dimensions, we confirm that the problem of identifying the reachability set of curvature bounded paths subsumes the well-known Markov-Dubins problem. These advancements in understanding the reachability of curvature bounded paths in $\mathbb{R}^3$ hold significant practical implications, particularly in the contexts of mission planning problems and time optimal guidance.Comment: Submitted to Automatic

Association between harmful alcohol use and periodontal status according to gender and smoking

BACKGROUND: the aim of this study is to assess the association of harmful alcohol use based on the alcohol use disorders identification test (AUDIT) score with periodontal status according to gender and smoking in a representative sample of Korean adults. METHODS: This study analyzed 5,291 participants older than 19 years whose data of harmful alcohol use and periodontal status were available. Harmful alcohol use was defined by the WHO guidelines for the administration of AUDIT. The periodontal status was assessed by the Community Periodontal Index (CPI). Multivariate logistic regression analysis was performed with adjustment for socio-demographic variables, oral and general health behavior, oral health status and systemic conditions. All analyses considered a complex sampling design, and multivariate analysis was also performed in the subgroups. RESULTS: Multivariate logistic regression analysis revealed a marginal association between harmful alcohol use and higher CPI in the total sample. The adjusted odds ratio (OR) of harmful alcohol use was 1.16 (0.97 to 1.38) for higher CPI. Higher CPI was significantly associated with harmful alcohol use in men (OR: 1.28; 95% CI: 1.03-1.60) and non-smokers (OR: 1.29; 95% CI: 1.06-1.57). CONCLUSION: Periodontal status is significantly associated with harmful alcohol use in men and non-smokers in a representative sample of Korean adults

The role of adjuvant pelvic radiotherapy in rectal cancer with synchronous liver metastasis: a retrospective study

<p>Abstract</p> <p>Background</p> <p>Synchronous liver metastases are detected in approximately 25% of colorectal cancer patients at diagnosis. The rates of local failure and distant metastasis are substantial in these patients, even after undergoing aggressive treatments including resection of primary and metastatic liver tumors. The purpose of this study was to determine whether adjuvant pelvic radiotherapy is beneficial for pelvic control and overall survival in rectal cancer patients with synchronous liver metastasis after primary tumor resection.</p> <p>Methods</p> <p>Among rectal cancer patients who received total mesorectal excision (TME) between 1997 and 2006 at Yonsei University Health System, eighty-nine patients diagnosed with synchronous liver metastasis were reviewed. Twenty-seven patients received adjuvant pelvic RT (group S + R), and sixty-two patients were managed without RT (group S). Thirty-six patients (58%) in group S and twenty patients (74%) in group S+R received local treatment for liver metastasis. Failure patterns and survival outcomes were analyzed.</p> <p>Results</p> <p>Pelvic failure was observed in twenty-five patients; twenty-one patients in group S (34%), and four patients in group S+R (15%) (<it>p </it>= 0.066). The two-year pelvic failure-free survival rates (PFFS) of group S and group S+R were 64.8% and 80.8% (<it>p </it>= 0.028), respectively, and the two-year overall survival rates (OS) were 49.1% and 70.4% (<it>p </it>= 0.116), respectively. In a subgroup analysis of fifty-six patients who received local treatment for liver metastasis, the two-year PFFS were 64.9% and 82.9% (<it>p </it>= 0.05), respectively; the two-year OS were 74.1% and 80.0% (<it>p </it>= 0.616) in group S (n = 36) and group S+R (n = 20), respectively.</p> <p>Conclusions</p> <p>Adjuvant pelvic RT significantly reduced the pelvic failure rate but its influence on overall survival was unclear. Rectal cancer patients with synchronous liver metastasis may benefit from adjuvant pelvic RT through an increased pelvic control rate and improved quality of life.</p

New Sedatives and Analgesic Drugs for Gastrointestinal Endoscopic Procedures

Procedural sedation has become increasingly common in endoscopy. Sedatives and analgesics induce anxiolysis and amnesia. In addition, an appropriate level of sedation is necessary for safe procedures including therapeutic endoscopy. Midazolam and propofol are the most commonly used drugs in sedative endoscopy. In recent years, the need to ascertain the safety and effectiveness of sedation has increased in practice. Therefore, new sedatives and analgesic drugs for optimal sedative endoscopy, have recently emerged. This article reviews the characteristics of sedatives and analgesics, and describes their clinical use in gastrointestinal endoscopy

Direct activation of Transient Receptor Potential Vanilloid 1(TRPV1) by Diacylglycerol (DAG)

The capsaicin receptor, known as transient receptor potential channel vanilloid subtype 1 (TRPV1), is activated by a wide range of noxious stimulants and putative ligands such as capsaicin, heat, pH, anandamide, and phosphorylation by protein kinase C (PKC). However, the identity of endogenous activators for TRPV1 under physiological condition is still debated. Here, we report that diacylglycerol (DAG) directly activates TRPV1 channel in a membrane-delimited manner in rat dorsal root ganglion (DRG) neurons. 1-oleoyl-2-acetyl-sn-glycerol (OAG), a membrane-permeable DAG analog, elicited intracellular Ca2+ transients, cationic currents and cobalt uptake that were blocked by TRPV1-selective antagonists, but not by inhibitors of PKC and DAG lipase in rat DRG neurons or HEK 293 cells heterologously expressing TRPV1. OAG induced responses were about one fifth of capsaicin induced signals, suggesting that OAG displays partial agonism. We also found that endogenously produced DAG can activate rat TRPV1 channels. Mutagenesis of rat TRPV1 revealed that DAG-binding site is at Y511, the same site for capsaicin binding, and PtdIns(4,5)P2binding site may not be critical for the activation of rat TRPV1 by DAG in heterologous system. We propose that DAG serves as an endogenous ligand for rat TRPV1, acting as an integrator of Gq/11-coupled receptors and receptor tyrosine kinases that are linked to phospholipase C

A two-photon fluorescent probe for lysosomal zinc ions

The selective detection of zinc ions in lysosomes over that in cytosol is achieved with a fluorescent probe, which enabled the fluorescence imaging of endogenous zinc ions in lysosomes of NIH 3T3 cells as well as mouse hippocampal tissues by two-photon microscopy under excitation at 900 nm.open

In-stent restenosis-prone coronary plaque composition: A retrospective virtual histology-intravascular ultrasound study

  Background: The mechanism of in-stent restenosis (ISR) is multifactorial, which includes biological, mechanical and technical factors. This study hypothesized that increased inflammatory reaction, which is known to be an important atherosclerotic process, at a culprit lesion may lead to higher restenosis rates. Methods: The study population consisted of 241 patients who had undergone percutaneous coronary intervention with virtual histology-intravascular ultrasound (VH-IVUS) and a 9-month follow-up coronary angiography. Compared herein is the coronary plaque composition between patients with ISR and those without ISR. Results: Patients with ISR (n = 27) were likely to be older (66.2 ± 9.5 years vs. 58.7 ± 11.7 years, p = 0.002) and have higher levels of high-sensitivity C-reactive protein (hs-CRP, 1.60 ± 3.59 mg/dL vs. 0.31 ± 0.76 mg/dL, p &lt; 0.001) than those without ISR (n = 214). VH-IVUS examination showed that percent necrotic core volume (14.3 ± 8.7% vs. 19.5 ± 9.1%, p = 0.005) was higher in those without ISR than those with ISR. Multivariate analysis revealed that hs-CRP (odds ratio [OR] 3.334, 95% con­fidence interval [CI] 1.158–9.596, p = 0.026) and age (OR 3.557, 95% CI 1.242–10.192, p = 0.018) were associated with ISR. Conclusions: This study suggests that ISR is not associated with baseline coronary plaque composition but is associated with old age and increased expression of the inflammatory marker of hs-CRP. (Cardiol J 2018; 25, 1: 7–13