Impaired helix 12 dynamics due to proline 892 substitutions in the androgen receptor are associated with complete androgen insensitivity

Human Molecular Genetics (2006) 15, 921–931;     

Balance of prostacyclin and thromboxane in offspring of parents with premature coronary arterial disease.

6-keto-prostaglandin F1a and thromboxane B2 were determined in order to obtain more information about the prostacyclin synthesis and thromboxane A2 release in 3- to 18-year-old healthy children and in offspring of parents who have had an acute myocardial infarction before the age of 45. The authors demonstrated a reduction of plasma prostacyclin synthesis in children with a positive family history of premature coronary arterial disease. Thromboxane levels in the affected adolescent boys were significantly lower compared with the controls. The ratio of thromboxane:prostacyclin in endangered children did not show a significant difference from that of healthy controls. These data indicate that prostaglandins are a definitive marker for identifying cardiovascular risk children. It must be supposed that in adolescence, only in boys, with a positive family history of premature coronary arterial disease, a compensatory mechanism exists to protect them from developing an imbalance in the regulation of prostaglandins.     

Evaluation of myocardial function in patients with end-stage heart failure during support with the Jarvik 2000 left ventricular assist device.

In 2 patients with the Jarvik 2000 left ventricular assist device (LVAD), we assessed left ventricular systolic function through pressure-volume loops and E(max) at the beginning and end of the support period to potentially predict the possibility of pump removal without transplantation. Immediately before LVAD implantation and explantation, pressure and volume measurements were made with catheters and echocardiography, respectively, the E(max) being calculated from the slope of the pressure-volume loops, and the left ventricular ejection fraction (LVEF) being estimated by echocardiography. Transplantation was performed after 14 and 62 days, respectively, during which the LVEF increased by 75% (from 12% to 21%) in Patient 1 and remained unchanged (from 16% to 18%) in Patient 2, whereas the E(max) increased from 0.63 and 0.42 mm Hg/ml, respectively, to 1.31 and 1.07 mm Hg/ml, reflecting a 107% and 155% improvement. In these 2 cases, the E(max) was a more reliable indicator of intrinsic myocardial contractility than was the LVEF.     

Multiple-bandwidth photoacoustic tomography

Photoacoustic tomography, also referred to as optoacoustic tomography, employs short laser pulses to generate ultrasonic waves in biological tissues. The reconstructed images can be characterized by the convolution of the structure of samples, the laser pulse and the impulse response of the ultrasonic transducer used for detection. Although the laser-induced ultrasonic waves cover a wide spectral range, a single transducer can receive only part of the spectrum because of its limited bandwidth. To systematically analyse this problem, we constructed a photoacoustic tomographic system that uses multiple ultrasonic transducers simultaneously, each at a different central frequency. The photoacoustic images associated with the different transducers were compared and analysed. The system was tested by imaging both mouse brains and phantom samples. The vascular vessels in the brain were revealed by all of the transducers, but the image resolutions differed. The higher frequency detectors provided better image resolution while the lower frequency detectors delineated the major structural traits with a higher signal-noise ratio.     

A novel technique for laser-assisted revascularization: an in vitro pilot study

Lasers in Medical Science - The common limitation of surgical revascularization procedures for severe tissue ischemia due to cardiovascular diseases is the need to interrupt blood flow during the...     

The concordance and discordance of cardiovascular risk factors in a group of twin children

The cross-sectional study of epidemiological screening type has permitted to evaluate some cardiovascular risk factors in two groups of monozygotic (MZ) and dizygotic (DZ) twins born between 1975-1990, in the town of Ia?i. In the 89 MZ pairs and 112 DZ pairs, certain constitutional and behavioural cardiovascular risk factors have presented values of prevalence with statistical signification (p < 0.05) in terms of their age, sex, the urbanisation time and the educational level of their parents. In risk factors existence or absence to both of the twins have put into evidence, to the MZ, most enhanced values of concordance as regards: overweight (66.6%), excessive consumption of salt (56.9%), food with atherogenic risk (50.9%). The concordance values have been less in DZ compared to MZ concerning all the risk factors excepting compartmental type A (77.7%). By analysing the concordance variants, an preponderant influence of the environment has been noted in the studied MZ and heredity and environment influence in DZ. By measuring the arterial blood pressure values at the twins and the twins parents, a prevalence of the essential arterial hypertension is noticed to both of the twins, 6.2% in MZ pairs and 6.9% in DZ ones.     

Infill Density Influence on Mechanical and Thermal Properties of Short Carbon Fiber-Reinforced Polyamide Composites Manufactured by FFF Process

In three-dimensional (3D) printing, one of the main parameters influencing the properties of 3D-printed materials is the infill density (ID). This paper presents the influence of ID on the microstructure, mechanical, and thermal properties of carbon fiber-reinforced composites, commercially available, manufactured by the Fused Filament Fabrication (FFF) process. The samples were manufactured using FFF by varying the infill density (25%, 50%, 75%, and 100%) and were subjected to tensile tests, three-point bending, and thermal analyses by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). It was shown that the samples with 100% ID had the highest values of both tensile, 90.8 MPa, and flexural strengths, 114 MPa, while those with 25% ID had the lowest values of 56.4 MPa and 62.2 MPa, respectively. For samples with infill densities of 25% and 50%, the differences between the maximum tensile and flexural strengths were small; therefore, if the operating conditions of the components allow, a 25% infill density could be used instead of 50%. After DSC analysis, it was found that the variation in the ID percentage determined the change in the glass transition temperature from 49.6 °C, for the samples with 25% ID, to 32.9 °C, for those with 100% ID. TGA results showed that the samples with IDs of 75% and 100% recorded lower temperatures of onset degradation (approximately 344.75 °C) than those with infill densities of 25% and 50% (348.5 °C, and 349.6 °C, respectively).     

Aluminide Diffusion Coatings on IN 718 by Pack Cementation

This paper addressed the issues of both direct and indirect synthesis of Ni aluminides by pack cementation (pure Ni and IN 718 superalloy). On the Al-Ni diffusion twosome under pressure, at temperatures below and above the Al melting temperature, the appearance and evolution of diffusion porosity because of the Kirkendall–Frenkel effect manifestation was highlighted. It has been confirmed that, as the temperature rises above the Al melting temperature, the porosity decreases. Nickel-based superalloys, and in particular IN 718, significantly increase their performance by increasing the aluminides proportion in the top diffusion coating. This is made possible by changing the value of the Al and Ni weight percentage ratio in this area (noted as Al/Ni). In the case of the diffusion twosome between IN 718 and pack aluminizing mixtures, having in their composition as active components Al powder, Ferroaluminum (FeAl40) or mixtures of Al and Fe powders, at processing temperatures above the Al melting temperature, by modifying the active component of the mixture, substantial changes in the Al/Ni values were observed, as well as in the maximum %Al in the diffusion coating and of its thickness. It was found that, when switching from Al to FeAl40 or powder mixture (Al + Fe), the Al/Ni value changes between 3.43 and 1.01, from initial subunit values. The experiments confirmed that the highest %Al in the top aluminized diffusion coating, for IN 718, was obtained if the powder mixture contained 66.34 wt.% Al.