293 research outputs found
Timing for treatment of HCV recurrence after liver transplantation: the earlier the better.
HCV is the leading cause of death from liver disease and is the most common indication for a liver transplantation. Although HCV is a widespread health problem, disease management is particularly challenging in several key subpopulations, including liver transplant recipients. HCV recurrence after liver transplantation constituted a major challenge for the physicians during the last years. The recommended standard of care before the advent of new regimen was the treatment of confirmed recurrent disease, based either on persistent, unexplained elevated alanine aminotransferase levels or on histologically confirmed fibrosis, once rejection, biliary obstruction, and vascular damage have been ruled out. Moreover, early therapy (including interferon) has been associated with high rates of adverse effects, an increased risk of graft rejection, and higher proportions of patients requiring dose reductions. We are now facing a "new era" of direct antiviral agents that is already changing the approach to HCV burden in the post liver transplantation setting. Available data on treatment of HCV recurrence with the new antiviral drugs showed sustained virological response that ranges between 60 to 100%. In this comment we have focused on both the utility of non invasive test to evaluate the fibrosis progression and on timing of antiviral therapy for HCV recurrence. This article is protected by copyright. All rights reserved
Cancer-Associated Thrombosis in Cirrhotic Patients with Hepatocellular Carcinoma.
It is common knowledge that cancer patients are more prone to develop venous thromboembolic complications (VTE). It is therefore not surprising that patients with hepatocellular carcinoma (HCC) present with a significant risk of VTE, with the portal vein being the most frequent site (PVT). However, patients with HCC are peculiar as both cancer and liver cirrhosis are conditions that can perturb the hemostatic balance towards a prothrombotic state. Because HCC-related hypercoagulability is not clarified at all, the aim of the present review is to summarize the currently available knowledge on epidemiology and pathogenesis of non-malignant thrombotic complications in patients with liver cirrhosis and HCC. They are at increased risk to develop both PVT and non-splanchnic VTE, indicating that both local and systemic factors can foster the development of site-specific thrombosis. Recent studies have suggested multiple and often interrelated mechanisms through which HCC can tip the hemostatic balance of liver cirrhosis towards hypercoagulability. Described mechanisms include increased fibrinogen concentration/polymerization, thrombocytosis, and release of tissue factor-expressing extracellular vesicles. Currently, there are no specific guidelines on the use of thromboprophylaxis in this unique population. There is the urgent need of prospective studies assessing which patients have the highest prothrombotic profile and would therefore benefit from early thromboprophylaxis
Misiones: how to support an approach to sustainable tourism
Sviluppare il turismo internazionale è un obiettivo ricorrente nei paesi emergenti, che comporta però il rischio di gravi limiti alla sua sostenibilità . Si valutano le prime esperienze di uno sviluppo che non eroda le caratteristiche ambientali e culturali di una provincia argentina che si affaccia al mercato turistico mondiale
6-channel CMOS-based instrument for optical absorption spectroscopy and chemical identification
A multichannel portable instrument for on-chip optical absorption spectroscopy is presented. The system can house photonic chips having up to 6 sensing sites operating in parallel, allowing real-time simultaneous detection of multiple chemicals. A 6-channel CMOS lock-in front-end performs the amplification and demodulation of the signals from the integrated light detectors, while an FPGA is chosen for signal acquisition and analysis. A digital real-time ratiometric processing cancels out the effect of laser power fluctuations to achieve high sensitivity in monitoring the presence of the analytes, as demonstrated with the detection of an acetone sample. Compact size for portability, real-time parallel detection and flexible FPGA processing make this system suitable for environmental investigations on many different pollutants, both in the near- and mid-infrared wavelength range
Drop-out rate from the liver transplant waiting list due to HCC progression in HCV-infected patients treated with direct acting antivirals.
BACKGROUND & AIM: concerns about an increased hepatocellular carcinoma (HCC) recurrence rate following directly acting antiviral (DAA) therapy in cirrhotic patients with a prior complete oncological response have been raised. Data regarding the impact of HCV-treatment with DAAs on waiting list drop-out rates in patients with active HCC and HCV-related cirrhosis awaiting liver transplantation (LT) are lacking.
MATERIALS AND METHODS: HCV-HCC patients listed for LT between January 2015 and May 2016 at Padua Liver Transplant Centre were considered eligible for the study. After enrollment patients were divided into 2 groups, depending on whether they underwent DAAs treatment while awaiting LT or not. For each patient clinical, serological and virological data were collected. HCC characteristics were radiologically evaluated at baseline and during follow-up (FU). For transplanted patients, pathological assessment of the explants was performed and recurrence-rates were calculated.
RESULTS: twenty-three patients treated with DAAs and 23 controls were enrolled. HCC characteristics at time of LT-listing were comparable between the 2 groups. Median FU was 10 and 7 months, respectively, during which 2/23 (8.7%) and 1/23 (4.3%) drop-out events due to HCC-progression were registered (p = 0.9). No significant differences in terms of radiological progression were highlighted (p = 0.16). Nine out of 23 cases (39%) and 14/23 (61%) controls underwent LT, and histopathological analysis showed no differences in terms of median number and total tumor volume of HCC nodules, tumor differentiation or microvascular invasion. During post-LT FU, 1/8 DAAs treated patient (12,5%) and 1/12 control (8,3%) experienced HCC recurrence (p = 0.6).
CONCLUSIONS: Viral eradication does not seem to be associated with an increased risk of drop-out due to neoplastic progression in HCV-HCC patients awaiting LT
Establishing Multiple Chip-to-Chip Orthogonal Free-Space Optical Channels using Programmable Silicon Photonics Meshes
Two silicon photonics programmable meshes of Mach-Zehnder interferometers are used to automatically establish chip-to-chip orthogonal free-space communication links. Optimum channels with mutual isolation of more than 30dB are found even in case of a misaligned link or in presence of an obstacle in the path
Multimode Free Space Optical Link Enabled by SiP Integrated Meshes
A silicon photonic mesh of tuneable Mach-Zehnder Interferometers (MZIs) is employed to receive two spatially-overlapped Hermite-Gaussian beams modulated at 10 Gbit/s, sharing the same wavelength and state of polarization. The mesh automatically self-configures, separating and sorting the two beams out without any excess loss
Lecturas
Esta sección contiene reseñas de los siguientes libros:
* Rubin, Barry. Istanbul intrigues. Bogazici University Press, Istanbul. 2002. Pp. 334.
* Gungomus Kona, Gamza. Disertation on Central Asia and Cooperation Strategy Models. Yeditepe University, Estambul TurquÃa. 2003. Pp. 479.
* Devlet, Nadir. Empires in Eurasia. From Chingiz Khan to 20° century. Yeditepe University Yayinlari SAYI: 8, Estambul TurquÃa. 2002. Pp. 106.
* Pétric, Boris-Mathieu. Power, gift-exchanges, networks in the Post-soviet Uzbekistan. Presses Universitaires de France, Paris. 2002. Pp. 202.
* Ertürk, Korkut A. (ed.). Rethinking Central Asia. NonEurocentric Studies in History, Social Structure and Identity. Ithaca Press Garnet Publishing Ltd. Reading, RG1 4QS, UK. Impreso en LÃbano. 2001. Pp. 202.
* Gorshenina, Svetlana. Explorateurs en Asie Centrale: Voyageurs et aventuriers de Marco Polo a Ella Maillart. Geneve, Olizane. 2003. Pp. 544.
* Foltz, Richard C. Religions of the Silk Road. Overland Trade and Cultural Exchange from Antiquity to the Fifteenth Century. Macmillan Press Ltd. Harrisonburg, VA. EE.UU. 2002. Pp. 186.
* Rumer, Boris. Central Asia. A Gathering Storm? M. E. Sharpe, Armonk, New York. London, England. 2002. Pp. 442.
* Cisneros, Andrés y Piñeiro Iñiguez, Carlos. Del ABC al MERCOSUR La integración latinoamericana en la
doctrina y praxis del peronismo Buenos Aires, Grupo Editor Latinoamericano, 2002, 603 páginas.
* Alice, Mauricio. La evaluación de la eficacia de la OEA en crisis democráticas en el continente. Las posiciones argentinas. Nuevo Hacer. Grupo Editor Latinoamericano. 2002.Instituto de Relaciones Internacionales (IRI
Separating arbitrary free-space beams with an integrated photonic processor
Free-space optics naturally offers multiple-channel communications and sensing exploitable in many applications. The different optical beams will, however, generally be overlapping at the receiver, and, especially with atmospheric turbulence or other scattering or aberrations, the arriving beam shapes may not even be known in advance. We show that such beams can be still separated in the optical domain, and simultaneously detected with negligible cross-talk, even if they share the same wavelength and polarization, and even with unknown arriving beam shapes. The kernel of the adaptive multibeam receiver presented in this work is a programmable integrated photonic processor that is coupled to free-space beams through a two-dimensional array of optical antennas. We demonstrate separation of beam pairs arriving from different directions, with overlapping spatial modes in the same direction, and even with mixing between the beams deliberately added in the path. With the circuit’s optical bandwidth of more than 40 nm, this approach offers an enabling technology for the evolution of FSO from single-beam to multibeam space-division multiplexed systems in a perturbed environment, which has been a game-changing transition in fiber-optic systems
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