Lipoprotein lipase activity is decreased in a large cohort of patients with coronary artery disease and is associated with changes in lipids and lipoproteins

Lipoprotein lipase (LPL) is crucial in the hydrolysis of triglycerides (TG) in TG-rich lipoproteins in the formation of HDL particles. As both these lipoproteins play an important role in the pathogenesis of atherosclerotic vascular disease, we sought to assess the relationship between post-heparin LPL (PH-LPL) activity and lipids and lipoproteins in a large, well-defined cohort of Dutch males with coronary artery disease (CAD). These subjects were drawn from the REGRESS study, totaled 730 in number and were evaluated against 75 healthy, normolipidemic male controls. Fasting mean PH-LPL activity in the CAD subjects was 108 46 mU/ml, compared to 138 44 mU/ml in controls (P < 0.0001). When these patients were divided into activity quartiles, those in the lowest versus the highest quartile had higher levels of TG (P < 0.001), VLDLc and VLDL-TG (P = 0.001). Conversely, levels of TC, LDL, and HDLc were lower in these patients (P = 0.001, P = 0.02, and P = 0.001, respectively). Also, in this cohort PH-LPL relationships with lipids and lipoproteins were not altered by apoE genotypes. The frequency of common mutations in the LPL gene associated with partial LPL deficiency (N291S and D9N carriers) in the lowest quartile for LPL activity was more than double the frequency in the highest quartile (12.0% vs. 5.0%; P = 0.006). By contrast, the frequency of the S447X LPL variant rose from 11.5% in the lowest to 18.3% (P = 0.006) in the highest quartile. This study, in a large cohort of CAD patients, has shown that PH-LPL activity is decreased (22%; P = 0.001) when compared to controls; that the D9N and N291S, and S447X LPL variants are genetic determinants, respectively, in CAD patients of low and high LPL PH-LPL activities; and that PH-LPL activity is strongly associated with changes in lipids and lipoproteins

ЭФФЕКТИВНОСТЬ ИСПОЛЬЗОВАНИЯ МОЛОЧНО-КИСЛОЙ ДОБАВКИ В КОРМЛЕНИИ ЦЫПЛЯТ-БРОЙЛЕРОВ

The article reveals aspects of developing animal indexes and productivity of broilers when applying lacto-acid additive. The paper applies experimental data and shows efficiency of lacto-acid additive applying in ratios of broilers. The research is aimed at estimation of lacto-acid efficiency when applying it in feed ratios together with activated feeds. The research focuses on estimating different ways of lacto-acid additive applying and its influence on broilers productivity; defining the appropriate rate of additive in poultry feeding; revealing economic efficiency of lacto-acid additive applying in feeding young birds. The authors declare efficient amount of lacto-acid additive is 0.2 % of ratio mass. They note average daily liveweight gain increases on 2.5 % and overall liveweight gain on 3 %; feed consumption pro 1 kg of body weight is reduced. The article proves applying of 0.2 % lacto-acid additive together with activated feeds reduces feed consumption pro 1 kg of body weight gain; when specialists apply 0.3 % of lacto-acid additive this leads to increasing of feed consumption on 10 %. When birds receive granular lacto-acid additive, this increases average daily liveweight gain on 2.5 % and overall liveweight gain on 6.1 % and reduces feed consumption on 06.6 % and 6.6 % correspondently. The authors conclude feeding broilers with granular lacto-acid additive allows increasing production profitability.Рассматриваются вопросы улучшения зоотехнических показателей и продуктивности цыплят-бройлеров при введении молочно-кислой добавки. На основе экспериментальных данных установлена эффективность введения молочно-кислой добавки (МКД) в рационы цыплят-бройлеров с активированным кормом (АВК). Оптимальное количество МКД составляет 0,2% от массы рациона. При этом увеличивается среднесуточный и абсолютный прирост на 2,5 и 3% соответственно, снижаются затраты корма на 1 кг прироста живой массы. Применение МКД совместно с АВК в количестве 0,2% снижает затраты корма на 1 кг прироста, а увеличение ее доли до 0,3% приводит к увеличению затрат корма на 10%. Потребление птицей МКД в гранулированном виде способствовало увеличению среднесуточного и абсолютного прироста живой массы на 2,5–6,1% и снижению затрат кормов на 0,6–6,6% соответственно. Скармливание МКД в гранулированном виде позволяет повысить рентабельность производства

Timber Resources of the Am ur Region and tha Problem of their Effective Utilization

Scientific Reference

Validation of the FEM model of the Mi-24 tail boom and vertical stabilizer

The scope of this work was the validation process of the numerical model of the Mi-24 helicopter tail boom and vertical stabilizer. In order to obtain a detailed geometry of the actual structure the sophisticated reversed engineering techniques were used. The measurement was performed using two separate techniques: one based on digitalphotogrammetry and other based on a three dimensional laser scanning with ATOSIII scanner. The numerical model was created with use of the obtained geometry, available technical documentation and detailed inspection of the structure. The obtained FEM model was validated using strain measurements of the real structure during characteristic flight maneuvers. A system of foil strain gauges was installed on the tail boom in previously selected locations. Calibration process, using known loads, was performed in order to determine response of the measurement system. To enable a quick and reasonable comparison of results from the experiment and calculations a special element was introduced in the FEM model. Their task was to monitor local strains in places corresponding to those where the strain gauges were installed. Detailed analysis of results confirmed, that after some minor modifications, the developed finite element model represents the actual structure reasonably well. Particular attention was paid to the representation of the boundary conditions and how to implement loads, which can significantly affect the obtained results. The analysis carried through confirms, that the presented validation technique, based on strain measurements, allows verifying a complicated numerical model in a relative cheap, fast and reliable way

Analysis of residual strength of a helicopter tail boom

The aim of this work is to determine the residual strength of a Mi-24 helicopter's tail boom with a structural damage. The idea of this work has come from the fact that these helicopters are operated on a battlefleld and often suffer such damages. It may be crucial to make a quick estimation whether any particular damage can cause a critical failure to the whole structure. The scope of this work covers static loading of the structure during landing. The analysis has been based on a numerical model that makes use of the Finite Element Method. The model has been developed using reverse engineering techniques. Structural discontinuities have been modelled in characteristic sections where stress concentrations occur. Boundary conditions and loads applied have been chosen to simulate normal and hard landings. Two failure criteria have been chosen: one based on the Crack Tip Opening Angle (CTOA) method that enables very efficient verification, and the second concerning the tail boom tip dislocation, taken from the helicopter,s alignment manual. The specific load history has been designed to enable detection of tail boom tip dislocation due to plastic strain in the vicinity of damage tips after the hard landing

Preliminary Verification of Selected Solutions for Crack Detection

Throughout its service life an aircraft is subjected to varying loads. Because of those periodically appearing stresses, undesirable and irreversible changes in structure may occur. As a consequence, cracks are formed, which reduce aircraft structural strength, significantly affecting structural integrity. For that reason, intensive research works are carried out around the world to develop innovative and reliable methods for detection of cracks initiation and propagation. This paper presents two methods of crack detection. One of them uses wireless polymer gages for determining deformation in a test region. The other one uses electrical, resistive ladder sensors for detection of cracks and their length determination

Fatigue Life Estimation of the Tail Boom and Vertical Stabilizer of MI-24 Helicopter

The aim of this work was to estimate fatigue life of the Mi-24 helicopter tail boom and vertical stabilizer sheathing. The analysis was based on a numerical model of the helicopter airframe crucial to obtain stress fields under defined loads and to estimate fatigue life. In order to do so, the load spectrum, specific for Polish army helicopters, was obtained by means of strain gauge measurements during a series of experimental flights. Data collected during flights was post-processed to create a characteristic ten hour spectrum that would statistically represent the flight profile for Polish Army Mi-24 helicopters. The third crucial element of the analysis was the safe S-N curve that was created on the basis of 2024-T3 aluminum S-N curve. Two factors were introduced in order to change the curve in a way that would guarantee a higher level of certainty that the outcome is not overrated. As a result of this analysis the total fatigue life was estimated including the list of critical locations in which fatigue damage is prone to occur. These regions are going to be carefully examined during scheduled inspections

Simulating Crack Propagation of a Selected Structural Component of the PZL-130 Orlik TC-II Aircrafts

This paper presents the process of estimating crack propagation within a selected structural component of the PZL-130 Orlik TC-II using a numerical model. The model is based on technical drawings and measurements of the real structure. The proper definition of the geometry, including the location and size of the gap between elements, is significant for mesh generation. During the simulation process the gap is combined node by node. Each time, the strain energy release rate (G) is calculated. The stress intensity factor and geometry correction factor are defined for consecutive crack lengths, and used further on to estimate crack propagation