ENDOTHELIAL DYSFUNCTION – A KEY FACTOR IN ATHEROSCLEROSIS PATHOGENESIS

Endothelial dysfunction (ED) is currently considered as a key factor in atherosclerosis pathogenesis, and is manifested in disbalance between endothelial vasodilatators and vasoconstrictors. It has been demonstrated that virtually all atherogenic risk factors (RFs) act via ED. Therefore, ED parameters could be used as markers of early vascular atherosclerosis in people with atherogenic RFs. Early pathogenetic therapy in this group, as well as the treatment of the patients with confirmed atherosclerosis, could significantly improve prognosis

Endothelial dysfunction role in atherosclerosis pathogenesis

According to modern views, the key component in atherosclerosis pathogenesis is endothelial dysfunction (ED), manifesting in dysbalance between main endothelial functions: vasodilatation and vasoconstriction, proliferation inhibition and promotion, antithrombotic and prothrombotic, antioxidant and prooxidant functions. Endothelial effects are mediated through vasoactive agents’ release – vasodilatators (NO, prostacyclin, bradykinin) and vasoconstrictors (endothelin, free oxygen radicals, thromboxan A2 , angiotensin II). It has been demonstrated that virtually all atherosclerosis risk factors (RF) realize their negative effects via ED. Therefore, endothelial function parameters could be used as early atherosclerosis markers in individuals with atherosclerosis RF, at pre-clinical stage. Pathogenetic therapy, administered early or in already verified atherosclerosis, could improve patients’ prognosis substantially

1.55 μm directly modulated CCIG lasers fabricated by surface-defined lateral feedback gratings

To combine low-cost fabrication and high-speed data communication like 100 GBit/s, multi-section DBR lasers are developed with nanoimprint compatible surface defined gratings. This laser design has the potential to enhance the modulation bandwidth by exciting a higher order optical mode, the so-called photon-photon resonance (PPR). ICP-RIE etching was used to transfer the e-beam exposed surface pattern in one step into the semiconductor. High aspect ratios of > 1:15, vertical trenches with a width of about 140 nm and an etch depth of > 2 μm were obtained for the lateral gratings. Three-section DBR lasers are fabricated on an MOVPE grown 1.5 μm InP laser material exhibiting CW threshold currents of 94 mA for a 0.9 mm long device. A side mode suppression ratio of > 50 dB could be achieved demonstrating a high enough coupling strength of the lateral gratings. The influence of different operation conditions (currents, temperature) and dependence on the grating period on threshold current and emission wavelength are studied and will be discussed in this paper. First high frequency measurements in operation conditions without PPR enhancement show a - 3dB bandwidth of about 15 GH