Electrostatically stabilized hybrids of carbon and maghemite nanoparticles: electrochemical study and application.

Binary hybrids have been investigated for the past few decades due to the emerging properties of nanoparticle composites. Electrostatically stabilized core-shell nanostructures composed of surface active magnetic nanoparticles (SAMNs) and differently charged carbon nanomaterials display specific electrochemical properties. In this work, a set of binary hybrids that include a new class of magnetic nanoparticles is presented and the electrochemical features of the hybrids are reported. Gallic acid derived carbon dots (GA-CDs), PEG derived graphene dots (PEG-GDs), and quaternized carbon dots (Q-CDs) characterized by different charged groups were used for the preparation of different complexes with SAMNs. Thus, a set of six binary nanomaterials was obtained, and characterized by electrochemical impedance spectroscopy, cyclic voltammetry and chronoamperometry, demonstrating significant differences in the charge transfer resistance, capacitive current, electrochemical performance, and reversibility with respect to the isolated subunits. Among them, the combination of Q-CDs with an excess of SAMNs led to a Q-CD@SAMN hybrid, which displayed peculiar electrocatalytic properties attributable to the influence of the strong electrostatic interactions exerted by Q-CDs on the SAMN surface. Notwithstanding their small fraction (around 1% w/w), Q-CDs oriented the electrocatalysis of SAMNs toward the selective electro-oxidation of polyphenols at low applied potentials (+0.1 V vs. SCE). Finally, the Q-CD@SAMN hybrid was used for the development of a coulometric sensor for polyphenols, composed of a simple carbon paste electrode in a small volume electrochemical flow cell (1 µL), and used for the complete direct electro-oxidation of polyphenols from plant extracts.

Liver Regeneration Induced By Extracorporeal Portal Vein Arterialization in a Swine Model of Carbon Tetrachloride Intoxication.

INTRODUCTION: This study aimed to determine whether a controlled portal blood arterialization by a liver extracorporeal device (L.E.O2 NARDO) is effective in treating acute hepatic failure (AHF) induced in swine by carbon tetrachloride (CCl4) administration. MATERIALS AND METHODS: Sixteen swine with AHF induced by intraperitoneal injection of CCl4 in oil solution were randomly divided into 2 groups: animals that received L.E.O2 NARDO treatment 48 hours after the intoxication (study group; n = 8); and animals that were sham operated 48 hours after the intoxication (control group; n = 8). Blood was withdrawn from the iliac artery and reversed in the portal venous system by an interposed extracorporeal device. Each treatment lasted 6 hours. The survival was assessed at 5 days after L.E.O2 NARDO treatment or sham operation. In both groups blood samples were collected for biochemical analysis at different study time and liver biopsies were performed 48 hours after intoxication and at humane killing. RESULTS: In the study group decreased transaminases levels and a more rapid international normalized ratio (INR) recover were detected as compared with the control group. Six animals of the study group (75%) versus 1 animal (12.5%) of the control group survived at 5 days after surgery with a statistically significant difference (P < .05). Liver biopsies performed at humane killing showed damaged areas of the livers reduced in the study group compared with biopsies of the control group. CONCLUSIONS: Arterial blood supply in the portal system through the L.E.O2 NARDO device is easily applicable, efficacious, and safe in a swine model of AHF induced by CCl4 intoxication.

Complications and graft survival in kidney transplants with vascular variants: our experience and literature review.

INTRODUCTION: In the literature several reconstructive techniques for vascular anastomoses in case of kidney graft vascular variants are reported. This article reports our experience in kidney transplants with vascular anomalies. MATERIALS AND METHODS: Between January 1996 and June 2012, 154 cadaveric kidney transplantations were performed at our center. In 35 case, vascular variants were found. Among the arterial variants we observed 27 double arteries, 2 cases with 3 arteries, and 1 case with 4 arteries. All cases of Venous variants were double veins. Based on the type of reconstructive technique used, we divided transplants into group A (n = 22) separate multiple arterial anastomoses; group B (n = 8) anastomosis on the aortic patch; group C (n = 4) single anastomosis in case of 2 arteries with a common ostium at the aortic origin. The venous variants were treated with ligation of the vein of smaller caliber. RESULTS: Kidney preparation to the back table lasted on average 50 minutes with no significant differences between the 3 groups and no significant timing increase compared to renal transplants without vascular anomalies (mean warm ischemia 40 minutes, range 30-60 minutes). The mean cold ischemia time was limited to 16 hours from the removal and the mean warm ischemia was 50 minutes (range 30-70 minutes). There were no differences in timing between group C and single anastomoses, whereas groups A and B showed mean warm ischemia time was slightly increased compared to group C (P < .05). There were no significant differences in terms of delayed upturn of graft function and graft survival between groups A, B, and C and compared to transplants without vascular anomalies. CONCLUSIONS: In our series we observed similar results performing the reimplantation on aortic patch and separate multiple arterial anastomoses. Considering our experience, we believe that vascular variants are not an indication to exclude a graft for transplantation.

Laparoscopic placement of "self-locating catheter": our experience and a review of literature.

Among the available devices for peritoneal dialysis, the Di Paolo self-locating catheter (SLC) represents a milestone using to its ability to ensure a permanent reliable means of access to the peritoneum. Our experience included 20 laparoscopic peritoneal catheter placements from 2008 to 2011. We performed the laparoscopic surgical technique using 3 trocars: 2 10 mm and 1 5 mm. The technique allows catheter introduction into the pouch of Douglas under direct vision. Among 20 treated patients, 1 died due to causes unrelated to peritoneal dialysis; 1 underwent transplantation, and 1 was switched to hemodialysis because of ultrafiltration failure. The complications included 2 catheter displacements, only 1 of them needing repositioning by open laparotomy, and 1 case of peritonitis. No infection in the subcutaneous tunnel or obstruction and malfunction occurred among our patients. The Di Paolo SLC is similar to Tenckhoff catheter but includes a small tungsten cylinder at the tip that engenders continuous gravity in the peritoneal cavity, producing a reduced risk of dislocation. In a large series of cases, Di Paolo et al. reported a 0.8% dislocation rate after SLC placement compared with 12% using Tenckhoff catheters. They also demonstrated a reduced risk of other complications, such as peritonitis, infection, obstruction, and failure. These data have been confirmed by other authors with smaller case series. Thus, introduction of the SLC and improved surgical techniques result in better efficiency of peritoneal dialysis.