Radek Kuchta

Design of a Pressure Sensor Based on Optical Fiber Bragg Grating Lateral Deformation

This paper describes steps involved in the design and realization of a new type of pressure sensor based on the optical fiber Bragg grating. A traditional pressure sensor has very limited usage in heavy industrial environments, particularly in explosive or electromagnetically noisy environments. Utilization of optics in these environments eliminates all surrounding influences. An initial motivation for our development was the research, experimental validation, and realization of a complex smart pressure sensor based on the optical principle. The main benefit of this solution consists of increasing sensitivity, resistance to electromagnetic interference, dimensions, and potential increased accuracy.

New Role for L-Arginine in Regulation of Inducible Nitric-Oxide-Synthase-Derived Superoxide Anion Production in Raw 264.7 Macrophages

Dietary supplementation with L-arginine was shown to improve immune responses in various inflammatory models. However, the molecular mechanisms underlying L-arginine effects on immune cells remain unrecognized. Herein, we tested the hypothesis that a limitation of L-arginine could lead to the uncoupled state of murine macrophage inducible nitric oxide synthase and, therefore, increase inducible nitric-oxide-synthase-derived superoxide anion formation. Importantly, we demonstrated that L-arginine dose- and time dependently potentiated superoxide anion production in bacterial endotoxin-stimulated macrophages, although it did not influence NADPH oxidase expression and activity. Detailed analysis of macrophage activation showed the time dependence between LPS-induced iNOS expression and increased O2∙− formation. Moreover, downregulation of macrophage iNOS expression, as well as the inhibition of iNOS activity by NOS inhibitors, unveiled an important role of this enzyme in controlling O2∙− and peroxynitrite formation during macrophage stimulation. In conclusion, our data demonstrated that simultaneous induction of NADPH oxidase, together with the iNOS enzyme, can result in the uncoupled state of iNOS resulting in the production of functionally important levels of O2∙− soon after macrophage activation with LPS. Moreover, we demonstrated, for the first time that increased concentrations of L-arginine further potentiate iNOS-dependent O2∙− formation in inflammatory macrophages.

New Location-Based Authentication Techniques in the Access Management

In this paper, new space-time authentication techniques are proposed. Location-based authentication is a new direction in development of authentication techniques. At the first part advantages of location-based authentication are introduced. In the second chapter the main aspects of using user’s position information are discussed, as user’s mobility and user’s privacy. The main part of the paper is focused on introducing of two new proposed authentication techniques. The first technique called STAT I (Space-Time Authentication Technique) uses GPS system for a position determination. The second technique (STAT II) uses proprietary communication technology IQRF for a position determination. Both newly designed authentication techniques use a pocket device described in the final section of the paper.

Wireless temperature data logger

Knowledge of temperature course during a certain time is needed in scientific, medical and industrial applications. In some applications, however, the recorded temperature course should be read wirelessly. This paper describes main principles applied in a set of mobile temperature data logger and portable reader/writer with wireless transfer of digitized temperature values. A mobile temperature data logger with RFID features was designed for applications, where portability and wireless data transfer is inevitable. Communicating reader/writer can be mounted on the wall or can be portable, too. Two main modes of operation during temperature data logging may be remotely chosen for a tag. Mode 1 - standard storing of data in preprogrammed regular acquisition time intervals (100 milliseconds up to 2 hours) with number of samples limited only by a data EEPROM memory size. Mode 2 - more memory size reducing method, when only breaking lower and upper temperature limits initiates storing the date and time stamp. However, the following date and time stamp is stored only when the temperature returns back into the temperature band between lower and upper temperature predefined limits. This mode 2 corresponds with a structure of data stored in data EEPROM memory. Enhanced mode can be set when the maximum or minimum temperature between breaking and returning points of a sampling temperature course is stored, too. This is a typical example for monitoring of food transport, where the time stamp and maximum temperature after breaking the limit are proofs to define the offender who damaged the transported goods.

Smart Platform for Wireless Communication - Case Study

This paper presents main features of a new IQRF wireless communication platform. This platform was developed and designed for home and industrial automation. Some basic functions of OS, development tools and basic modules are described. A case study is discussed at the end of the paper. This is a case study of a sensor network created around a core coordinator and a set of temperature wireless units.

Wireless and Wired Temperature Data System

Knowledge of temperature course during a certain time is needed in scientific, medical and industrial applications. In some applications, however, the recorded temperature course should be read wirelessly. This paper describes main principles applied in a set of mobile temperature data logger and portable interrogator with wireless transfer of digitized temperature values.

Asymmetric dimethyl arginine induces pulmonary vascular dysfunction via activation of signal transducer and activator of transcription 3 and stabilization of hypoxia-inducible factor 1-alpha

Pulmonary hypertension (PH), associated with imbalance in vasoactive mediators and massive remodeling of pulmonary vasculature, represents a serious health complication. Despite the progress in treatment, PH patients typically have poor prognoses with severely affected quality of life. Asymmetric dimethyl arginine (ADMA), endogenous inhibitor of endothelial nitric oxide synthase (eNOS), also represents one of the critical regulators of pulmonary vascular functions. The present study describes a novel mechanism of ADMA-induced dysfunction in human pulmonary endothelial and smooth muscle cells. The effect of ADMA was compared with well-established model of hypoxia-induced pulmonary vascular dysfunction. It was discovered for the first time that ADMA induced the activation of signal transducer and activator of transcription 3 (STAT3) and stabilization of hypoxia inducible factor 1α (HIF-1α) in both types of cells, associated with drastic alternations in normal cellular functions (e.g., nitric oxide production, cell proliferation/Ca(2+) concentration, production of pro-inflammatory mediators, and expression of eNOS, DDAH1, and ICAM-1). Additionally, ADMA significantly enhanced the hypoxia-mediated increase in the signaling cascades. In summary, increased ADMA may lead to manifestation of PH phenotype in human endothelial and smooth muscle cells via the STAT3/HIF-1α cascade. Therefore this signaling pathway represents the potential pathway for future clinical interventions in PH.

IQRF Smart Wireless Platform for Home Automation: A Case Study

This paper presents the main features of a new IQRF wireless communications platform. The platform was designed and developed for home and industrial automation. Some basic functions of operating systems, development tools and basic modules are described. On a case study a basic home automation application is discussed. The new proprietary wireless communication platform IQRF was developed. Its advantages, the guidelines of using it, and currently available development tools are described in the article.

IQMESH Implementation in IQRF Wireless Communication Platform

There are a lot of attempts to define a universal protocol for low power wireless communication based on mesh network topologies. This paper describes one such approach, IQMESH protocol, its advantages, strengths, also limitations and specific implementations. IQRF is an intelligent platform for wireless communication and control designed primarily to fulfill requests coming from building automation and telemetry industries, based on IQMESH protocol. IQMESH utilizes several unique and patented features, it is light and would be easily ported even to the smallest 8 bit microcontrollers.

Implementation of Intrusion Detection System for Automation Devices within Virtual Automation Network

Security incidents are becoming more serious and more common not only in computer networks, but also in automation networks. Automation devices are still more and more based on computers and they have the same weak points like standard computers. Actual trends in automation networks are among others wide automation networks covering several manufacture divisions or remote controlling of automation networks through the Internet. Necessity of the remote connection to the automation networks covers all security vulnerabilities and risks which originate from the Internet. Analogically the automation network can be secured by the conventional way through firewalls and VPN tunnels. For this reason new automation firewall device was designed. The VAN firewall includes messaging system for logging all events and alerts. As a basis for VAN (Virtual Automation Network) firewall messaging system IDMEF (Intrusion Detection Message Exchange Format) is used. This paper describes the intrusion detection system and its implementation within the VAN.