103 research outputs found
Coordination protocols for a reliable sensor, actuator, and device network (SADN)
Abstract. A sensor, actuator, and device network (SADN) is composed of three types of nodes, which are sensor, actuator, and actuation device nodes. Sensor nodes and actuator nodes are interconnected in wireless networks as discussed in wireless sensor and actuator networks (WSANs). Actuator nodes and device nodes are interconnected in types of networks, i.e. wireless and wired network. Sensor nodes sense an physical event and send sensed values of the event to actuator nodes. An actuator node makes a decision on proper actions on receipt of sensed values and then issue the action requests to the device nodes. A device node really acts to the physical world. For example, moves a robot arms by performing the action on receipt of the action request. Messages may be lost and nodes may be faulty. Especially, messages are lost due to noise and collision in a wireless network. We propose a fully redundant model for an SADN where each of sensor, actuator, and device functions is replicated in multiple nodes and each of sensor-actuator and actuator-device communication is realized in many-to-many type of communication protocols. Even if some number of nodes are faulty, the other nodes can perform requested tasks. Here, each sensor node sends sensed values to multiple actuator nodes and each actuator node receives sensed values from multiple sensor nodes. While multiple actuator nodes communicate with multiple replica nodes of a device. Even if messages are lost and some number of nodes are faulty, device nodes can surely receive action requests required for sensed values and the actions are performed. In this paper, we discuss a type of semi-passive coordination (SPC) protocol of multiple actuator nodes for multiple sensor nodes. We discuss a type of active coordination protocol for multiple actuator nodes and multiple actuation device nodes. We evaluate the SPC protocol for the sensor-actuator coordination in terms of the number of messages exchanged among actuators
Infant Hip Joint Diagnostic Support System Based on Clinical Manifestations in X-ray Images
Plain X-ray radiography is frequently used for the diagnosis of developmental dislocation of the hip (DDH). The aim of this study was to construct a diagnostic support system for DDH based on clinical findings obtained from the X-ray images of 154 female infants with confirmed diagnoses made by orthopedists. The data for these subjects were divided into 2 groups. The Min-Max method of nonlinear analysis was applied to the data from Group 1 to construct the diagnostic support system based on the measurement of 4 items in X-ray images:the outward displacement rate, upward displacement rate, OE angle, and alpha angle. This system was then applied to the data from Group 2, and the results were compared between the 2 groups to verify the reliability of the system. We obtained good results that matched the confirmed diagnoses of orthopedists with an accuracy of 85.9%
Suppressive effects of 2-methacryloyloxyethyl phosphorylcholine (MPC)-polymer on the adherence of Candida species and MRSA to acrylic denture resin
Objectives: The effects of 2-methacryloyloxyethyl phosphorylcholine (MPC)-polymer on the adherence of microorganisms such as non-Candida albicans Candida (NCAC) and methicillin-resistant Staphylococcus aureus (MRSA), frequently detected in oral infections in immunocompromised and/or elderly people, to denture resin material, are still unclear. Here, we report the effects of MPC-polymer on the adherence of C. albicans, NCAC, and MRSA to acrylic denture resin.
Methods: Sixteen strains of C. albicans, seven strains of C. glabrata, two strains of C. tropicalis, one strain of C. parapsilosis, and six strains of MRSA were used. We cultured the fungal/bacterial strains and examined the cell growth and adherence of fungi/bacteria to mucin-coated acrylic denture resin plates (ADRP) with or without MPC-polymer coating, by scanning electron microscopy. The cell surface hydrophobicity of the fungal/bacterial strains was measured by the adsorption to hydrocarbons.
Results: MPC-polymer did not affect the growth of all strains of Candida species and MRSA, but significantly suppressed adherence to ADRP in most strains of C. albicans and all strains of NCAC and MRSA. A significant positive correlation was found between cell hydrophobicity and the reduction rates of microbial adherence to ADRP treated with 5% of MPC-polymer.
Conclusions: MPC-polymer treatment for acrylic resin material suppresses the adherence of C. albicans, NCAC and MRSA via their hydrophilicity interaction.
Clinical significance: The application of MPC-polymer for denture hygiene is potent to prevent oral candidiasis, denture stomatitis and opportunistic infection, caused by Candida species and MRSA, via suppressing the adherence of those fungus/bacteria
Enhanced Recombinant Protein Productivity by Genome Reduction in Bacillus subtilis
The emerging field of synthetic genomics is expected to facilitate the generation of microorganisms with the potential to achieve a sustainable society. One approach towards this goal is the reduction of microbial genomes by rationally designed deletions to create simplified cells with predictable behavior that act as a platform to build in various genetic systems for specific purposes. We report a novel Bacillus subtilis strain, MBG874, depleted of 874 kb (20%) of the genomic sequence. When compared with wild-type cells, the regulatory network of gene expression of the mutant strain is reorganized after entry into the transition state due to the synergistic effect of multiple deletions, and productivity of extracellular cellulase and protease from transformed plasmids harboring the corresponding genes is remarkably enhanced. To our knowledge, this is the first report demonstrating that genome reduction actually contributes to the creation of bacterial cells with a practical application in industry. Further systematic analysis of changes in the transcriptional regulatory network of MGB874 cells in relation to protein productivity should facilitate the generation of improved B. subtilis cells as hosts of industrial protein production
2-Methacryloyloxyethyl phosphorylcholine (MPC)-polymer suppresses an increase of oral bacteria: a single-blind, crossover clinical trial
Objectives The biocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC)-polymers, which mimic a biomembrane, reduce protein adsorption and bacterial adhesion and inhibit cell attachment. The aim of this study is to clarify whether MPC-polymer can suppress the bacterial adherence in oral cavity by a crossover design. We also investigated the number of Fusobacterium nucleatum, which is the key bacterium forming dental plaque, in clinical samples.
Materials and methods This study was a randomized, placebo-controlled, single-blind, crossover study, with two treatment periods separated by a 2-week washout period. We conducted clinical trial with 20 healthy subjects to evaluate the effect of 5% MPC-polymer mouthwash after 5 h on oral microflora. PBS was used as a control. The bacterial number in the gargling sample before and after intervention was counted by an electronic bacterial counter and a culture method. DNA amounts of total bacteria and F. nucleatum were examined by q-PCR.
Results The numbers of total bacteria and oral streptcocci after 5 h of 5% MPC-polymer treatment significantly decreased, compared to the control group. Moreover, the DNA amounts of total bacteria and F. nucleatum significantly decreased by 5% MPC-polymer mouthwash.
Conclusions We suggest that MPC-polymer coating in the oral cavity may suppress the oral bacterial adherence.
Clinical relevance MPC-polymer can be a potent compound for the control of oral microflora to prevent oral infection
ロイテリン関連化合物の歯周病原因菌への抗菌および抗バイオフィルム効果
OBJECTIVE: Lactobacillus reuteri is one of the probiotics that possesses preventive effects on oral infections including dental caries and periodontal disease. Reuterin is a bacteriocin-like compound produced by L. reuteri and plays an important role in the probiotic effects. However, it is difficult to obtain reuterin due to the general lability of its aldehyde moiety. Therefore, fourteen stable reuterin-related compounds (RRCs) were chemically synthesized. Here, we investigated the effects of RRCs on periodontopathic bacteria.
MATERIALS AND METHODS: The antibacterial activity of RRCs on pathogenic microorganisms including periodontopathic bacteria was determined. Moreover, the effects of RRCs on biofilm formation by Fusobacterium nucleatum were examined by a crystal violet biofilm formation assay. Cytotoxicity of RRCs was evaluated by a lactate dehydrogenase assay using oral keratinocytes.
RESULTS: Among synthesized RRCs, RRC-04, -05, -09, -10, -12, -13, and -14, exhibited antibacterial activities against periodontopathic bacteria. RRCs, except for RRC-06, -07, -08, and -11, significantly suppressed biofilm formation to 60-80 % of the control. Most RRCs, except for RRC-12 and -13, were not cytotoxic to human oral keratinocytes.
CONCLUSIONS: The synthesized RRCs can be potent novel oral care products for the prevention of periodontitis without adverse effects
Validation of radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas: Japanese Orthopaedic Association Committee on Musculoskeletal Tumors Cooperative Study
AbstractBackgroundThe radiographic evaluation of the response to preoperative chemotherapy for bone and soft tissue sarcomas is based mostly on the change in primary tumor size before and after chemotherapy, as is done for many solid cancers. Its prognostic correlation, however, has hardly been validated.MethodsWe conducted a retrospective validation study of the Japanese Orthopaedic Association (JOA) radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas as a JOA Committee on Musculoskeletal Tumors cooperative study. A total of 125 consecutive patients with high-grade bone (n = 77) and soft tissue (n = 48) sarcomas treated with neoadjuvant chemotherapy and definitive surgery in 25 tertiary referral hospitals were selected for the study. We investigated the correlation between the tumor size-based radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas provided by the JOA Committee on Musculoskeletal Tumors (hereafter called the JOA criteria) and the patients’ overall survival using the Kaplan-Meier method and the log-rank test.ResultsThe JOA criteria correlated relatively well with survival for malignant bone tumors (mostly comprising osteosarcoma and Ewing’s sarcoma) but not for soft tissue sarcomas, suggesting that the tumor size-based radiographic evaluation criteria for the response to preoperative chemotherapy in patients with soft tissue sarcomas is invalid.ConclusionsThe JOA criteria, based on the change in primary tumor size, is valid for malignant bone tumors but invalid for soft tissue sarcomas. Other new evaluation modalities of the response to preoperative chemotherapy using innovative functional imaging techniques are needed for soft tissue sarcomas
Randomized, crossover questionnaire survey of acceptabilities of controlled-release mesalazine tablets and granules in ulcerative colitis patients
Background/Aims Oral mesalazine is an important treatment for ulcerative colitis (UC), and non-adherence to mesalazine increases the risk of relapse. Controlled-release (CR) mesalazine has 2 formulations: tablets and granules. The relative acceptabilities of these formulations may influence patient adherence; however, they have not been compared to date. This study aimed to evaluate the acceptabilities of the 2 formulations of CR mesalazine in relation to patient adherence using a crossover questionnaire survey. Methods UC patients were randomly assigned to 2 groups in a 1:1 ratio. Patients in each group took either 4 g of CR mesalazine tablets or granules for 6 to 9 weeks, and then switched to 4 g of the other formulation for a further 6 to 9 weeks. The acceptability and efficacy were evaluated by questionnaires, and adherence was assessed using a visual analog scale. The difference in acceptabilities between the 2 formulations and its impact on adherence were assessed. Results A total of 49 patients were prospectively enrolled and 33 patients were included in the analysis. Significantly more patients found the tablets to be less acceptable than the granules (76% vs. 33%, P=0.0005). The granules were preferable to the tablets when the 2 formulations were compared directly (73% vs. 21%, P=0.004), for their portability, size, and numbers of pills. The adherence rate was slightly better among patients taking the granules (94% vs. 91%) during the observation period, but the difference was not significant (P=0.139). Conclusions CR mesalazine granules are more acceptable than tablets, and may therefore be a better option for long-term medication
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