Jellyfish mucin may have potential disease-modifying effects on osteoarthritis

<p>Abstract</p> <p>Background</p> <p>We aimed to study the effects of intra-articular injection of jellyfish mucin (qniumucin) on articular cartilage degeneration in a model of osteoarthritis (OA) created in rabbit knees by resection of the anterior cruciate ligament. Qniumucin was extracted from <it>Aurelia aurita </it>(moon jellyfish) and <it>Stomolophus nomurai </it>(Nomura's jellyfish) and purified by ion exchange chromatography. The OA model used 36 knees in 18 Japanese white rabbits. Purified qniumucin extracts from <it>S. nomurai </it>or <it>A. aurita </it>were used at 1 mg/ml. Rabbits were divided into four groups: a control (C) group injected with saline; a hyaluronic acid (HA)-only group (H group); two qniumucin-only groups (M groups); and two qniumucin + HA groups (MH groups). One milligram of each solution was injected intra-articularly once a week for 5 consecutive weeks, starting from 4 weeks after surgery. Ten weeks after surgery, the articular cartilage was evaluated macroscopically and histologically.</p> <p>Results</p> <p>In the C and M groups, macroscopic cartilage defects extended to the subchondral bone medially and laterally. When the H and both MH groups were compared, only minor cartilage degeneration was observed in groups treated with qniumucin in contrast to the group without qniumucin. Histologically, densely safranin-O-stained cartilage layers were observed in the H and two MH groups, but cartilage was strongly maintained in both MH groups.</p> <p>Conclusion</p> <p>At the concentrations of qniumucin used in this study, injection together with HA inhibited articular cartilage degeneration in this model of OA.</p

Development of a Surgical Site Infection (SSI) Surveillance System, Calculation of SSI Rates and Specification of Important Factors Affecting SSI in a Digestive Organ Surgical Department

We have developed an original system to conduct surgical site infection (SSI) surveillance. This system accumulates SSI surveillance information based on the National N osocomial Infections Surveillance (NNIS) System and the Japanese Nosocomial Infections Surveillance (JNIS) System. The features of this system are as follows: easy input of data, high generality, data accuracy, SSI rate by operative procedure and risk index category (RIC) can be promptly calculated and compared with the current NNIS SSI rate, and the SSI rates and accumulated data can be exported electronically. Using this system, we monitored 798 patients in 24 operative procedure categories in the Digestive Organs Surgery Department of Mazda Hospital, Mazda Motor Corporation, from January 2004 through December 2005. The total number and rate of SSI were 47 and 5.89%, respectively. The SSI rates of 777 patients were calculated based on 15 operative procedure categories and Risk Index Categories (RIC). The highest SSI rate was observed in the rectum surgery of RIC 1 (30%), followed by the colon surgery of RIC3 (28.57%). About 30% of the isolated infecting bacteria were Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli. Using quantification theory type 2, the American Society of Anesthesiology score (4.531), volume of hemorrhage under operation (3.075), wound classification (1. 76), operation time (1.352), and history of diabetes (0.989) increased to higher ranks as factors for SSL Therefore, we evaluated this system as a useful tool in safety control for operative procedures

ACK-less rate adaptation using distributional reinforcement learning for reliable IEEE 802.11bc broadcast WLANs

Abstract As a step towards establishing reliable broadcast wireless local area networks (WLANs), this paper proposes acknowledgement (ACK)-less rate adaptation to alleviate reception failures at broadcast recipient stations (STAs) using distributional reinforcement learning (RL). The key point of this study is that the algorithms for learning the strategy of ACK-less rate adaptation are evaluated in terms of the broadcast performance, which is composed of the data rate of the broadcast access point (AP) and the reception success rate at the recipient STAs. ACK-less rate adaptation framework was realized using the received signal strength (RSS) of the uplink frames transmitted by the non-broadcast STAs to the non-broadcast APs, which correlated with the broadcast performance with a confounding effect from the deployment of the broadcast recipient STAs. However, this rate adaptation framework has the problem that it incurs the reception failures at a part of the broadcast recipient STAs, because deep Q-learning used in the previous framework cannot deal with the wide distribution of the broadcast performance. To address this challenge, this paper further discusses the rate adaptation using distributional RL, which approximates the entire distribution of the broadcast performance. The simulations confirmed the following: 1) Using the expected broadcast performance learned by deep Q-learning improved the performance in terms of the Pareto efficiency. 2) Learning the entire distribution of the broadcast performance enabled the broadcast AP to determine the tail of the distribution using risk measure, and to alleviate reception failures while implementing the rate adaptation in the same way as the method that learns only expected broadcast performance

C(sp³)–H Bond Hydroxylation Catalyzed by Myoglobin Reconstituted with Manganese Porphycene

Myoglobin reconstituted with manganese porphycene was prepared in an effort to generate a new biocatalyst and was characterized by spectroscopic techniques. The X-ray crystal structure of the reconstituted protein reveals that the artificial cofactor is located in the intrinsic heme-binding site with weak ligation by His93. Interestingly, the reconstituted protein catalyzes the H₂O₂-dependent hydroxylation of ethylbenzene to yield 1-phenylethanol as a single product with a turnover number of 13 at 25 °C and pH 8.5. Native myoglobin and other modified myoglobins do not catalyze C–H hydroxylation of alkanes. Isotope effect experiments yield KIE values of 2.4 and 6.1 for ethylbenzene and toluene, respectively. Kinetic data, log <i>k</i>_obs versus BDE­(C­(sp³)–H) for ethylbenzene, toluene, and cyclohexane, indicate a linear relationship with a negative slope. These findings clearly indicate that the reaction occurs via a rate-determining step that involves hydrogen-atom abstraction by a Mn­(O) species and a subsequent rebound hydroxylation process which is similar to the reaction mechanism of cytochrome P450

Interference-free AP identification and shared information reduction for tabular Q-learning-based WLAN coordinated spatial reuse

Abstract Access point (AP) coordinated spatial reuse with Q-learning enables efficient spectrum utilization [1]. Although sharing of transmission schedules among APs is necessary for coordination, there is no mechanism to identify the APs with which the schedules are to be shared, resulting in excess information being shared among APs. In this study, we propose a scheme to identify the interference-free APs that are not required for sharing of information by comparing Q-values. A simple simulation demonstrates that this scheme successfully reduces shared information without throughput degradation

Manganese(V) Porphycene Complex Responsible for Inert C–H Bond Hydroxylation in a Myoglobin Matrix

A mechanistic study of H₂O₂-dependent C–H bond hydroxylation by myoglobin reconstituted with a manganese porphycene was carried out. The X-ray crystal structure of the reconstituted protein obtained at 1.5 Å resolution reveals tight incorporation of the complex into the myoglobin matrix at pH 8.5, the optimized pH value for the highest turnover number of hydroxylation of ethylbenzene. The protein generates a spectroscopically detectable two-electron oxidative intermediate in a reaction with peracid, which has a half-life up to 38 s at 10 °C. Electron paramagnetic resonance spectra of the intermediate with perpendicular and parallel modes are silent, indicating formation of a low-spin Mn^V-oxo species. In addition, the Mn^V-oxo species is capable of promoting the hydroxylation of sodium 4-ethylbenzenesulfonate under single turnover conditions with an apparent second-order rate constant of 2.0 M^–1 s^–1 at 25 °C. Furthermore, the higher bond dissociation enthalpy of the substrate decreases the rate constant, in support of the proposal that the H-abstraction is one of the rate-limiting steps. The present engineered myoglobin serves as an artificial metalloenzyme for inert C–H bond activation via a high-valent metal species similar to the species employed by native monooxygenases such as cytochrome P450