74 research outputs found
40-Gb/s systems on G.652 fibers: comparison between periodic and all-at-the-end dispersion compensation
In the literature, two system solutions have been proposed to overcome high dispersion problems typical of G.652 fibers at high bit rates (40 Gb/s): they are periodic and all-at-the-end dispersion compensation. We carry out an exhaustive comparison between the two methods that, up to this moment, have been studied separately. In the first part, we introduce a simplified model on strong dispersion management (DM) with intrachannel four-waves mixing (IFWM) and intrachannel cross-phase modulation (IXPM). We then carry out extensive numerical simulations of a complete system in order to verify the results as a function of the input average power and of the input pulsewidth. Finally, we tackle a typical system aspect, i.e., the influence of nonlinear effects on dispersion compensating fibers (DCFs)
Optimisation of in-building optical networks
A single in-building optical fibre network can efficiently deliver wired and wireless services. Point-topoint architectures using POF are attractive for small buildings; for large buildings SMF-based all-optical bus architectures using weighted tap couplers are preferable
A look into the future of in-building networks: roadmapping the fiber invasion
Optical fiber-based in-building network solutions can outperform in the near future copper- and radiobased solutions both regarding performance and costs. POF solutions are maturing, and can already today be cheaper than Cat-5e solutions when ducts are shared with electricity cabling. Advanced signal modulation techniques allow high-capacity services over POF. With their extra features of multi-wavelength transport and routing, fiber solutions offer a higher network throughput and flexibility, and improved sustainability
Optimisation of in-building optical networks
Abstract A single in-building optical fibre network can efficiently deliver wired and wireless services. Point-topoint architectures using POF are attractive for small buildings; for large buildings SMF-based all-optical bus architectures using weighted tap couplers are preferable
Lymphatic and Immune Cell Cross-Talk Regulates Cardiac Recovery After Experimental Myocardial Infarction
Objective: Lymphatics play an essential pathophysiological role in promoting fluid and immune cell tissue clearance. Conversely, immune cells may influence lymphatic function and remodeling. Recently, cardiac lymphangiogenesis has been proposed as a therapeutic target to prevent heart failure after myocardial infarction (MI). We investigated the effects of gene therapy to modulate cardiac lymphangiogenesis post-MI in rodents. Second, we determined the impact of cardiac-infiltrating T cells on lymphatic remodeling in the heart. Approach and Results: Comparing adenoviral versus adeno-associated viral gene delivery in mice, we found that only sustained VEGF (vascular endothelial growth factor)-C(C156S)therapy, achieved by adeno-associated viral vectors, increased cardiac lymphangiogenesis, and led to reduced cardiac inflammation and dysfunction by 3 weeks post-MI. Conversely, inhibition of VEGF-C/-D signaling, through adeno-associated viral delivery of soluble VEGFR3 (vascular endothelial growth factor receptor 3), limited infarct lymphangiogenesis. Unexpectedly, this treatment improved cardiac function post-MI in both mice and rats, linked to reduced infarct thinning due to acute suppression of T-cell infiltration. Finally, using pharmacological, genetic, and antibody-mediated prevention of cardiac T-cell recruitment in mice, we discovered that both CD4(+)and CD8(+)T cells potently suppress, in part through interferon-gamma, cardiac lymphangiogenesis post-MI. Conclusions: We show that resolution of cardiac inflammation after MI may be accelerated by therapeutic lymphangiogenesis based on adeno-associated viral gene delivery of VEGF-C-C156S. Conversely, our work uncovers a major negative role of cardiac-recruited T cells on lymphatic remodeling. Our results give new insight into the interconnection between immune cells and lymphatics in orchestration of cardiac repair after injury.Peer reviewe
Nitric oxide production and monoamine oxidase activity in cancer patients during interferon-α therapy
Both increased and decreased nitric oxide (NO) synthesis have been reported in patients treated with interferon-α (IFN-α). Animal studies showed that IFN-α administration results in increased levels of biogenic amines, subsequent activation of monoamine oxidases (MAOs), and finally in a change in NO production due to the H2O2 generated by MAOs. We examined the potential relationship between NO production in plasma and MAO-B activity in platelets of 43 cancer patients during 8 weeks of treatment with IFN-α. NO synthesis was quantitated by measuring both the ratio of citrulline and arginine (CIT/ARG-ratio) and total nitrite/nitrate (NOx) levels. Compared to baseline, MAO activity and NOx increased, while the CIT/ARG-ratio decreased. No associations were found between NOx, MAO and CIT/ARG-ratio. Only few associations were observed between changes in the biochemical parameters and changes in psychopathology induced by IFN-α, of which the association between changes in CIT and lassitude was the most consistent. The results suggest that peripheral NO production and MAO activity are unrelated to each other, and that peripheral changes in these biochemical parameters induced by IFN-α are unlikely to contribute to definite psychiatric disturbance
Access network evolution: optical fibre to the subscribers and impact on the metropolitan and home networks
Impact of hybrid EDFA-distributed Raman amplification on a 4x40 Gbit/s WDM optical communication system
The impact of hybrid erbium-doped fiber,amplifier-(EDFA) distributed Raman amplification on a high bit rate wavelength-division-multiplexed optical communication system is studied by Means of a reliable simulation model that takes into account noise properties of Raman amplification. Pure Raman amplification allows the decrease of the mean input power of about 6 dB, keeping the bit error. rate at the, same level. The best performance, however, is obtained for loss compensation provided by hybrid EDFA/Raman amplifiers, due to the reduction of nonlinear distortion
Statistical description of optical system performances due to random coupling on the principal states of polarization
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