Hemostasis in normotensive and hypertensive men: results of the PROCAM study. The prospective cardiovascular Münster study

BACKGROUND: The greater than normal cardiovascular risk of hypertensive patients could be partly due to an impairment of hemostatic balance found in such individuals. OBJECTIVE: To examine the relationship between hemostatic variables and blood pressures in 1950 apparently healthy male participants in the prospective cardiovascular Münster study aged 40-65 years. METHODS: Blood pressure and other variables were determined, including fibrinogen level, coagulation factor VII clotting activity, protein C level, antithrombin III level, plasminogen activator inhibitor-1 level, euglobulin fibrinolytic activity, and von Willebrand factor level. RESULTS: Age-adjusted mean values of coagulation factor VII clotting activity, plasminogen activator inhibitor-1 level, antithrombin III level, and protein C level in hypertensives and borderline hypertensives were significantly higher than those in normotensive men (e.g. for hypertensive versus normotensive men, coagulation factor VII clotting factor activity 111.5 versus 106.1%, plasminogen activator inhibitor-1 level 5.05 versus 3.22 arbitrary units/ml, and protein C level 111.1 versus 107.0%, P < 0.05-0.01). For most of the hemostatic variables we found positive bivariate correlations to blood pressure (P < or = 0.05). Exceptions were von Willebrand factor level (no correlation to blood pressure), and euglobulin fibrinolytic activity (a negative correlation to systolic blood pressure and no correlation to diastolic blood pressure). Significance persisted in the multiple logistic regression analysis with the exception of the relationships between systolic and diastolic blood pressures and fibrinogen level as well as euglobin fibrinolytic activity after adjustment for age. After adjustment for age and body mass index significance for relationships between systolic blood pressure and coagulation factor VII clotting activity as well as protein C level was also lost. CONCLUSIONS: We conclude that the greater than normal cardiovascular risk of hypertensive patients is partly due to an imbalance in hemostasis.     

Estimating the hydrolytic durability of cured wood adhesives by measuring formaldehyde liberation and structural stability

The durability of different commonly used thermosetting wood adhesives (UF, MUF, MUPF) was determined from the hydrolytically induced mass loss and the amount of liberated formaldehyde. Both methods showed high reproducibility. Different methodical aspects were investigated for further improvement. The hydrolytically induced mass loss and formaldehyde liberation depend on the particle size of the cured resins. Additionally, more severe hydrolytic conditions (time, pH, temperature) caused elevated mass losses and formaldehyde liberations. The hydrolytic stability of the cured resins could be well determined by gravimetric analysis. However, a distinct graduation of the adhesive durability according to formaldehyde liberation appeared to be more difficult. These findings were reinforced by correlating the hydrolytic indicators and wet strength properties of particle boards according to different test methods (V70, V100, EN 321, Werzalit cycle test).     

XRT– Exploring Runtime for .NET Architecture and Applications

XRT– Exploring Runtime – is an exploration framework for programs represented in Microsoft's common intermediate language (CIL). Processing .NET managed assemblies, it provides means for analyzing, rewriting, and executing the rewritten program. Whereas XRT's representation of state allows for arbitrary exploration strategies, it is particularly optimized for transactional exploration, where a transaction may consist of many instruction steps. XRT supports extensions, and one such extension is a module for symbolic exploration which captures the complete domain of safe CIL. Current applications of XRT are in the area of testing, namely parameterized unit testing and state-space exploration for model-based testing. This paper gives an overview of the architecture of XRT and outlines the applications.     

Tribological measures for controlling material flow in sheet-bulk metal forming

Sheet-bulk metal forming (SBMF) is characterized by successive and/or simultaneous occurrence of quite different load conditions regarding stress and strain states. These conditions significantly influence the material flow and thus the geometrical accuracy of the components. To improve the product quality a control of the material flow is required. An appropriate approach is given by locally adapted tribological conditions due to surface modifications of tool and workpiece, so-called tailored surfaces. Within the present study different methods to adapt the surfaces are presented and investigated with respect to their tribological effectiveness in SBMF. In a first step, requirements regarding necessary adaptions of the friction values for two SBMF processes are numerically defined. Based on the requirements different tailored surfaces are presented and analyzed regarding their tribological influence. Finally, the potential of surface modifications to improve SBMF processes is shown.     

Mode I and mode II fracture toughness of E-glass non-crimp fabric/carbon nanotube (CNT) modified polymer based composites

In this study, mode I and mode II interlaminar fracture toughness, and interlaminar shear strength of E-glass non-crimp fabric/carbon nanotube modified polymer matrix composites were investigated. The matrix resin containing 0.1 wt.% of amino functionalized multi walled carbon nanotubes were prepared, utilizing the 3-roll milling technique. Composite laminates were manufactured via vacuum assisted resin transfer molding process. Carbon nanotube modified laminates were found to exhibit 8% and 11% higher mode II interlaminar fracture toughness and interlaminar shear strength values, respectively, as compared to the base laminates. However, no significant improvement was observed for mode I interlaminar fracture toughness values. Furthermore, Optical microscopy and scanning electron microscopy were utilized to monitor the distribution of carbon nanotubes within the composite microstructure and to examine the fracture surfaces of the failed specimens, respectively.     

Chemical characterization and classification of pollen

We report on the in situ characterization of tree pollen molecular composition based on Raman spectroscopy. Different from purification-based analysis, the nondestructive approach allows (i) to analyze various classes of molecules simultaneously at microscopic resolution and (ii) to acquire fingerprint-like chemical information that was used for the classification of pollen from different species. Hierarchical cluster analysis of spectra from fresh pollen samples of 15 species partly related at the genus level and family level indicates separation of species based on the complete Raman spectral signature and yields classification in accord with biological systematics. The results have implications for the further elucidation of pollen biochemistry and also for the development of chemistry-based online pollen identification methods.     

ECG-triggered non-enhanced MR angiography of peripheral arteries in comparison to DSA in patients with peripheral artery occlusive disease

Object

The purpose of this study was to evaluate peripheral non-enhanced-MRA (NE-MRA) acquired with a 3D Turbo Spin Echo sequence with electrocardiographt (ECG) triggering in comparison to Digital Subtraction Angiography (DSA) as the gold standard in symptomatic peripheral artery occlusive disease (PAOD) patients.

Materials and methods

This IRB approved prospective study included 23 PAOD patients from whom three patients had to be excluded. The remaining 20 subjects were included in the analysis (15 male; mean age 62.4 ± 15.3 years). The patients first underwent DSA followed by NE-MRA on a 1.5-T whole body scanner within 24 h after the DSA study. A NATIVE (Non-contrast Angiography of the Arteries and Veins) SPACE (Sampling Perfection with Application Optimized Contrast by using different flip angle Evolution) sequence at four levels (pelvis, upper leg, knee region and lower leg) was acquired. For evaluation purposes, subtracted standardized MIP (maximum intensity projection) images were generated from the NE-MRA data sets. Qualitative assessment of NE-MRA images in reference to the corresponding DSA images, as well as blinded stenosis grading of preselected segments in NE-MRA images were performed by two experienced readers. Image quality in 95 corresponding arterial segments was rated from 1 (good) to 4 (inadequate) directly comparing the NE-MRA with the corresponding DSA segment as the gold standard. Blinded stenosis grading consisted of 66 preselected stenoses rated from 1 (<10 %) to 4 (>90 %) in NE-MRA which were compared to the grade in the corresponding DSA.

Results

The mean image quality of NE-MRA in comparison to DSA was 2.7 ± 1.1 (reader 1) and 3.0 ± 1.0 (reader 2). The kappa value indicating interobserver agreement was 0.34; readers 1 and 2 rated the image quality as good in 21 % and 3 %, sufficient in 19 % and 41 %, limited in 29 % and 14 % and inadequate in 31 % and 42 %, respectively. Stenosis graduation revealed significantly higher grades in NE-MRA (reader 1: 3.0 ± 0.7, p < 0.001 and reader 2: 3.1 + 0.8, p < 0.001) compared to DSA (mean value DSA 2.7 ± 0.8). The kappa value indicating interobserver agreement concerning stenosis grading was 0.59.

Conclusion

NE-MRA revealed a relatively high number of inadequate quality segments. This is in line with recently published comparable studies of the similar SPACE NE-MRA techniques. Further advance of NE-MRA techniques remains desirable for patients with PAOD.