Titration procedures for nasal CPAP: Automatic CPAP or prediction formula?

Background: The best method for titration Of continuous positive airway pressure (CPAP) therapy in obstructive sleep apnea (OSA) syndrome has not yet been established. The 90th or 95th percentiles of the pressure titrated over time by automatic CPAP (A-CPAP) have been recommended as reference for prescribing therapeutic fixed CPAP (F-CPAP). We compared A-CPAP to F-CPAP. which was determined by a common prediction formula. Methods: Forty-five patients who were habituated to F-CPAP underwent titration polysomnography. In a double-blind randomized order, each patient used an A-CPAP device in the autotitration and in the fixed pressure mode during one half of the night. Apnea-hypopnea index (AHI) and pressure profiles were primary outcomes. Bias and precision were additionally assessed for both CPAP modes. Results: No significant differences in various sleep parameters or in subjective sleep quality evaluation were found. The AHI was effectively lowered in both CPAP modes (A-CPAP 7.7 [10.8] events/h versus F-CPAP 5.4 (9.0] events/h, p = 0.061). Comparison of group means showed that F-CPAP closely paralleled mean (Pmean) and median (P50). but not the 95th percentile (P95) pressure. of A-CPAP. While bias was lowest for Pmean and P50. there was a lack of precision in all A-CPAP pressure categories. Conclusions: We confirm that F-CPAP set by prediction formula is not worse in terms of AHI control than A-CPAP. On average. F-CPAP parallels Pmean and P50 but not P95. However. due to imprecise matching. individual F-CPAP values cannot be derived front Pmean or P50

Creation of a type IIS restriction endonuclease with a long recognition sequence

Type IIS restriction endonucleases cleave DNA outside their recognition sequences, and are therefore particularly useful in the assembly of DNA from smaller fragments. A limitation of type IIS restriction endonucleases in assembly of long DNA sequences is the relative abundance of their target sites. To facilitate ligation-based assembly of extremely long pieces of DNA, we have engineered a new type IIS restriction endonuclease that combines the specificity of the homing endonuclease I-SceI with the type IIS cleavage pattern of FokI. We linked a non-cleaving mutant of I-SceI, which conveys to the chimeric enzyme its specificity for an 18-bp DNA sequence, to the catalytic domain of FokI, which cuts DNA at a defined site outside the target site. Whereas previously described chimeric endonucleases do not produce type IIS-like precise DNA overhangs suitable for ligation, our chimeric endonuclease cleaves double-stranded DNA exactly 2 and 6 nt from the target site to generate homogeneous, 5′, four-base overhangs, which can be ligated with 90% fidelity. We anticipate that these enzymes will be particularly useful in manipulation of DNA fragments larger than a thousand bases, which are very likely to contain target sites for all natural type IIS restriction endonucleases

Risks and safety in the operation of railway vehicles

The need for continuous improvement of product quality, reliability and safety arises from product specifications, government regulatory requirements, agency recommendations, legal implications and above all a company’s desire to improve its market position and customer satisfaction. These issues require product manufacturers to perform risk analyses that identify and minimize part/system failures throughout the product‘s life cycle. The FMEA methodology is one of the risk analysis techniques recommended by international standards. It is a systematic process to identify potential failures to fulfil the intended function, to identify possible failure causes so the causes can be eliminated, and to locate the failure consequences so the consequences can be reduced. As an example, FMECA of railway freight tank wagon has been done on which the most critical parts and are addressed, consequently measures to reduce the risk of failure mode in operation are proposed

Implementation of FMEA method in maintenance of semi-trailer combination

The paper deals with the proposal of new maintenance system on a semi-trailer combination. Analysis of wear and damage of air brake system components used on the semi-trailer combination based on Real experience from practice and creation of the FMEA analysis of the system using software support are presented. The need for continuous improvement of product quality, reliability and safety arises from product specifications, government regulatory requirements, agency recommendations, legal implications and above all a company’s desire to improve its market position and customer satisfaction. These issues require product manufacturers to perform risk analyses that identify and minimize part/system failures throughout the product‘s life cycle. The FMEA methodology is one of the risk analysis techniques recommended by international standards. It is a systematic process to identify potential failures to fulfil the intended function, to identify possible failure causes so the causes can be eliminated, and to locate the failure consequences so the consequences can be reduced

Potential of possible tilting body trains usage in Slovakia from the energy consumption and travel time point of view

An important role of the railways at the moment is to increase the speed of passenger traffic. This task is because of inter-national agreements as well as the need to keep the competitiveness of railways in the transport market. The paper presents the opportunity to increase travel speed of passenger transport with using tilting body vehicles. For the selected section of the ŽSR lines travel times for vehicles with classic designs and tilting body vehicles were calculated. From their comparison a remarkable reduction of driving times showed up. Energy consumption of classical design vehicles and Pendolino type trains on the existing section of Slovak railway, considering the current speed limits and the theoretical speed limits for trains with tilting technology was assessed

FMEA analysis of combustion engine and assignment occurrence index for risk valuation

The need for continuous improvement of product quality, reliability and safety arises and above all a company’s desire to improve its market position and customer satisfaction. These issues require product manufacturers to perform risk analyses that identify and minimize part/system failures throughout the product‘s life cycle. In the paper we will apply the Failure Modes and Effects Analysis (FMEA) for analysis of combustion engine failures. We analyzed 15 different types of cars in which the 2.0 TDI was equipped. On the basis of the obtained data, we evaluated the most disturbing parts of the combustion engine and on these elements we determined the probability of occurrence of a fault which is one of the factors determining the Risk Priority Number (RPN)

Examining the condition of the ball and the ball track on the heavy machine ZP6600

The article deals with the examination of the state of the ball track at the heavy machine ZP 6600/Z79. This kind of machines are located in Doly Bílina. Article presents results of material exams which were taken on given samples and it describes the progress and results of the numeric calculations for the state of tenseness. The material tests were realized in an external cooperation. The numeric simulation of the tenseness was made in the VÚHU a. s. on the 3D model of the contact by a method of the ultimate elements. The used method works with the ending parts at the bottom of part of the ball track when it touches the ball. To determine the internal and contact forces in the ball and the bottom part of the ball track we used the software called COSMOS/DesignStar ver. 6.0. The result was an evidence for the decision about the depth of the turned layer of the material in order to create a new groove of the bottom part of the ball track