Splitter-Based Sensors Realized via POFs Coupled by a Micro-Trench Filled with a Molecularly Imprinted Polymer.

An optical-chemical sensor based on two modified plastic optical fibers (POFs) and a molecularly imprinted polymer (MIP) is realized and tested for the detection of 2-furaldehyde (2-FAL). The 2-FAL measurement is a scientific topic of great interest in different application fields, such as human health and life status monitoring in power transformers. The proposed sensor is realized by using two POFs as segmented waveguides (SW) coupled through a micro-trench milled between the fibers and then filled with a specific MIP for the 2-FAL detection. The experimental results show that the developed intensity-based sensor system is highly selective and sensitive to 2-FAL detection in aqueous solutions, with a limit of detection of about 0.04 mg L-1. The proposed sensing approach is simple and low-cost, and it shows performance comparable to that of plasmonic MIP-based sensors present in the literature for 2-FAL detection.

3D-printed biosensors in biomedical applications exploiting plasmonic phenomena and antibody self-assembled monolayers.

In this work, a 3D-printed plasmonic chip based on a silver-gold bilayer was developed in order to enhance the optical response of the surface plasmon resonance (SPR) probe. More specifically, numerical and experimental results were obtained on the 3D-printed SPR platform based on a silver-gold bilayer. Then, the optimized probe's gold plasmonic interface was functionalized with a specific antibody directed against the p27Kip1 protein (p27), an important cell cycle regulator. The 3D-printed plasmonic biosensor was tested for p27 detection with good selectivity and a detection limit of 55 pM. The biosensor system demonstrated performance similar to commercially available ELISA (enzyme-linked immunoassay) kits, with several advantages, such as a wide detection range and a modular and simple-based architecture. The proposed biosensing technology offers flexible deployment options that are useful in disposable, low-cost, small-size, and simple-to-use biochips, envisaging future applications in experimental and biomedical research.

Analysis of Plasmonic Sensors Performance Realized by Exploiting Different UV-Cured Optical Adhesives Combined with Plastic Optical Fibers.

Polymer-based surface plasmon resonance (SPR) sensors can be used to realize simple, small-size, disposable, and low-cost biosensors for application in several fields, e.g., healthcare. The performance of SPR sensors based on optical waveguides can be changed by tuning several parameters, such as the dimensions and the shape of the waveguides, the refractive index of the core, and the metal nanofilms used to excite the SPR phenomenon. In this work, in order to develop, experimentally test, and compare several polymer-based plasmonic sensors, realized by using waveguides with different core refractive indices, optical adhesives and 3D printed blocks with a trench inside have been used. In particular, the sensors are realized by filling the blocks' trenches (with two plastic optical fibers located at the end of these) with different UV-cured optical adhesives and then covering them with the same bilayer to excite the SPR phenomenon. The developed SPR sensors have been characterized by numerical and experimental results. Finally, in order to propose photonic solutions for healthcare, a comparative analysis has been reported to choose the best sensor configuration useful for developing low-cost biosensors.

Clinical outcomes and prognostic factors in non-cirrhotic non-neoplastic patients with portal vein thrombosis: A single-centre experience.

INTRODUCTION: The knowledge of natural history and prognostic factors of portal vein thrombosis (PVT) is still based on a limited number of studies. AIM: To describe our single-center experience with 79 consecutive non-neoplastic non-cirrhotic patients with PVT (15 recent/64 chronic PVT). RESULTS: Among patients with recent PVT, 7 received anticoagulation alone, 4 systemic thrombolysis, 3 direct thrombolysis through a TIPS and 1 TIPS alone. Portal recanalization was achieved in 11 patients. In patients with chronic PVT, the rate of variceal progression was high (20% at one year and 50% at two years). The thrombotic involvement of splenic and superior mesenteric veins was the only risk factor for variceal enlargement. The cumulative bleeding rates were 10% at one year and 20% at two years. A multisegmental thrombosis and large varices at entry and a previous variceal bleeding were the independent predictors for variceal bleeding. The cumulative rate of new thrombotic events was 14% at one year and 18% at two years. Eight patients died, 2 because of thrombotic events. There were no bleeding-related deaths. Two-year cumulative survival rate was 90%. CONCLUSIONS: Our study supports the importance of anticoagulation especially when a more extended thrombosis is present. Moreover, in patients with chronic PVT, the timing of follow-up endoscopy should be based on the extension of thrombosis and not, as in cirrhosis, on the size of varices at first endoscopy.

Detection of 2-Furaldehyde in Milk by MIP-Based POF Chips Combined with an SPR-POF Sensor.

An innovative optical-chemical sensor has been used to detect the 2-furaldehyde (2-FAL) in milk. The proposed sensing approach exploits the refractive index changing in a microstructured chip based on a plastic optical fiber (POF) with orthogonal micro-holes containing a specific molecularly imprinted polymer (MIP). This POF-MIP chemical chip modifies the surface plasmon resonance (SPR) phenomena excited in another sensor chip realized in POFs (SPR-POF) and connected in series. The proposed sensor configuration exploits MIP receptors avoiding any modification of the gold film of the SPR platform. This work reports the performance, particularly the high sensitivity and low detection limit, in complex matrices such as buffalo milk fortified with 2-FAL and in different commercial kinds of cow milk thermally treated for pasteurization. The measurements were carried out in about ten minutes by dropping the solution under-test on the planar D-shaped POF surface of the chemical chip. In contrast, on the gold surface of the SPR-POF platform, a water drop is always placed to excite the SPR phenomenon, which is modulated by the chemical chip via MIP-2-FAL binding. Furthermore, the experimental results demonstrated the pros and cons of the proposed sensor system. Thanks to the high sensitivity of the sensor system, the detection of 2-FAL in the diluted milk sample (1:50) was achieved. The dilution is required to reduce the interferent effect of the complex matrix.

The significance of nonobstructive sinusoidal dilatation of the liver: Impaired portal perfusion or inflammatory reaction syndrome.

UNLABELLED: Sinusoidal dilatation found in the absence of an impaired sinusoidal blood outflow has been so far of unclear significance. Sinusoidal dilatation may actually be a nonspecific feature of impaired portal venous blood inflow, whatever the cause, or a feature of severe systemic inflammatory reaction syndrome, whatever the cause. Sinusoidal dilatation is mainly located in the centrilobular area even in the absence of an outflow block. A predominantly periportal location is specifically found in oral contraceptive users, associated with an inflammatory condition. There is strong evidence for the association of sinusoidal dilatation and oxaliplatin-based chemotherapy but not for estroprogestative steroids or thiopurine derivatives. Exposure to anabolic androgen steroids appears to cause sinusoidal changes different from a mere sinusoidal dilatation. CONCLUSION: There is evidence of activation of the interleukin-6 and vascular endothelial growth factor pathways in sinusoidal dilatation, but the mechanisms linking the activation of these pathways with the microvascular changes must be identified.

Small hepatic veins Budd-Chiari syndrome.

Budd-Chiari syndrome is a rare disorder characterized by hepatic venous outflow obstruction at any level from the small hepatic veins to the atrio-caval junction, in the absence of heart failure or constrictive pericarditis. Various imaging modalities are available for investigating the gross hepatic vascular anatomy but there are rare forms of this disease where the obstruction is limited to the small intrahepatic veins, with normal appearance of the large hepatic veins at imaging. In this cases only a liver biopsy can demonstrate the presence of a small vessels outflow block. We report two cases of small hepatic veins Budd-Chiari syndrome.

Transjugular intrahepatic portosystemic shunt with expanded-polytetrafuoroethylene-covered stents in non-cirrhotic patients with portal cavernoma.

AIMS: To evaluate the feasibility and efficacy of Transjugular intrahepatic portosystemic shunt (TIPS) in non-cirrhotic patients with symptomatic portal hypertension secondary to portal cavernoma. METHODS: Our cohort includes 13 consecutive patients. Eleven were considered for Transjugular intrahepatic portosystemic shunt placement for complications not manageable by medical/endoscopic treatment and two because of the need of oral anticoagulation in presence of high-risk varices. Expanded-polytetrafluoroethylene-covered stents were used in all. RESULTS: One of the 13 patients was excluded because of a thrombosis of the superior cava and jugular veins. In 10 patients, Transjugular intrahepatic portosystemic shunt was successfully implanted [83.3%; 95% confidence interval: 52-98%]. One patient had an early shunt dysfunction with recurrence of variceal bleeding which required an emergency surgical shunt. Late shunt dysfunction occurred in two patients, successfully treated with angioplasty and re-stenting. Two patients experienced an episode of encephalopathy. CONCLUSIONS: Transjugular intrahepatic portosystemic shunt is feasible in most of the patients with portal cavernoma and should be considered in those with severe complications uncontrolled by conventional therapy. The use of Transjugular intrahepatic portosystemic shunt to achieve a lifelong anticoagulation therapy in selected patients with high-risk varices may be another possible indication. These patients should be referred to selected Units with large experience in Transjugular intrahepatic portosystemic shunt placement.

Improving the inhibitory control task to detect minimal hepatic encephalopathy.

BACKGROUND & AIMS: Quantification of the number of noninhibited responses (lures) in the inhibitory control task (ICT) has been proposed for the diagnosis of minimal hepatic encephalopathy (MHE). We assessed the efficacy of ICT compared with recommended diagnostic standards. METHODS: We studied patients with cirrhosis and healthy individuals (controls) who underwent the ICT at 2 centers (center A: n=51 patients and 41 controls, center B: n=24 patients and 14 controls). Subjects were evaluated for MHE by psychometric hepatic encephalopathy score (PHES). Patients from center B also were assessed for MHE by critical flicker frequency and spectral electroencephalogram analyses. RESULTS: Patients with cirrhosis had higher ICT lures (23.2+/-12.8 vs 12.9+/-5.8, respectively, P<.01) and lower ICT target accuracy (0.88+/-0.17 vs 0.96+/-0.03, respectively, P<.01) compared with controls. However, lures were comparable (25.2+/-12.5 vs 21.4+/-13.9, respectively, P=.32) among patients with/without altered PHES (center A). There was a reverse, U-shaped relationship between ICT lure and target accuracy; a variable adjusting lures was devised based on target accuracy (weighted lures at center B). This variable differed between patients with and without MHE. The variable weighted lures was then validated from data collected at center A by receiver operator characteristic curve analysis; it discriminated between patients with and without PHES alterations (area under the curve=0.71+/-0.07). However, target accuracy alone was as effective as a stand-alone variable (area under the curve=0.81+/-0.06). CONCLUSIONS: The ICT is not useful for the diagnosis of MHE, unless adjusted by target accuracy. Testing inhibition (lures) does not seem to be superior to testing attention (target accuracy) for the detection of MHE.