Voltammetric Sensor Based on Waste-Derived Carbon Nanodots for Enhanced Detection of Nitrobenzene

Carbon dots (CDs) samples were synthesized from orange peel waste (OPW) via a simple and eco-friendly hydrothermal carbonization (HTC) and electrochemical (EC) bottom-up synthesis integrated approach. The comprehensive chemical-physical characterization of CDs samples, carried out by various techniques such as TEM, EDX, XRD, FT-IR, underlined their morphological and microstructural features. The CDs exhibited attractive electrochemical properties, and thus an electrochemical sensor by modifying a screen printed carbon electrode (CDs/SPCE) for the detection of nitrobenzene (NB) in water was developed. Electroanalytical performances of CDs/SPCE sensor using differential pulse voltammetry (DPV) demonstrated its high sensitivity (9.36 μAμM^(-1)cm(^-2)) towards NB in a wide linear dynamic range (0.1–2000 μM) and a low limit of detection (LOD=13 nM). The electrochemical sensor also shown high selectivity, long-term stability, and repeatability. This paper might open the way to a new synergistic HTC-EC approach for the synthesis of CDs from waste biomass material and their advanced application in highly efficient electrochemical sensors

Production of cytokines at the operation site

Background and aim: Cytokines are part of a family of molecules involved in the initiation, control and termination of the events that occurs in wound healing process. Aim of this study was to evaluate the production of some cytokines [interleukin (IL)-6, IL-10, IL-1a, IL-1ra, interferon (IFN)-g] in the drainage wound fluid from patients undergoing incisional hernia repair. Methods: Ten female patients with abdominal midline incisional hernia undergoing to surgical repair were included in this study. In all cases a closed suction drain was placed in the wound below the fascia and it was removed on the 4 th postoperative day. Wound fluid was collected on the 1st , 2 nd, 3rd and 4th day and its amount in each time was recorded. The production of IL-6, IL-10, IL-1a, IL-1ra and IFN-g were evaluated as quantity produced in 24 hour. Results: In all patients the amount of drain fluid from surgical wound was highest on the 1st day after surgery, afterwards there is a significant reduction. The production of all cytokines evaluated was highest on the 1st day decreasing on the 2nd day except for IL-1a that not show any modification. The produciton of IL-1ra, IL-6, IL-1a and IL-10 was significantly reduced on the 3rd and 4th postoperative day in comparison with the respectively values recorded on the 1st day, whereas IFN-g levels were similar. Conclusions: The dosage of cytokines in the drain fluid led us to better evaluated the events that follow surgical wound and their analysis offers further information in the role of cytokines in healing process, with the goal to get supportive treatments to promote the best evolution

On the Electroanalytical Detection of Zn Ions by a Novel Schiff Base Ligand-SPCE Sensor

A novel bidentate Schiff base (L) is here proposed for the detection of Zn ions in water. The structure of the synthesized Schiff base L was characterized by FT-IR, 1H NMR and 13C NMR. Optical characteristics were addressed by UV-Visible spectroscopy and Photoluminescence (PL) measurements. PL demonstrated that L displays a “turn-off” type fluorescence quenching in the presence of Zn2+ ion in aqueous solution, indicating its ability to preferentially coordinate this ion. Based on these findings, an L-M (where M is a suitable membrane) modified screen-printed carbon electrode (SPCE) was developed to evaluate the electrochemical behavior of the Schiff base (L) with the final objective of undertaking the electroanalytical determination of Zn ions in water. Using various electrochemical techniques, the modified L-M/SPCE sensor demonstrates high sensitivity and selectivity to Zn ions over some common interferents ions, such as Ca2+, Mg2+, K+, Ni++ and Cd++. The potentiometric response of the L-M/SPCE sensor to Zn ions was found to be linear over a relatively wide concentration range from 1 μM to 100 mM

Differential requirements for antigen or homeostatic cytokines for proliferation and differentiation of human Vgamma9Vdelta2 naive, memory and effector T cell subsets.

We have compared four human subsets of Vgamma9Vdelta2 T cells, naive (T(naive), CD45RA(+)CD27(+)), central memory (T(CM), CD45RA(-)CD27(+)), effector memory (T(EM), CD45RA(-)CD27(-)) and terminally differentiated (T(EMRA), CD45RA(+)CD27(-)), for their capacity to proliferate and differentiate in response to antigen or homeostatic cytokines. Cytokine responsiveness and IL-15R expression were low in T(naive) cells and progressively increased from T(CM) to T(EM) and T(EMRA) cells. In contrast, the capacity to expand in response to antigen or cytokine stimulation showed a reciprocal pattern and was associated with resistance to cell death and Bcl-2 expression. Whereas antigen-stimulated cells acquired a T(CM) or T(EM) phenotype, IL-15-stimulated cells maintained their phenotype, with the exception of T(CM) cells, which expressed CD27 and CD45RA in various combinations. These results, together with ex vivo bromodeoxyuridine incorporation experiments, show that human Vgamma9Vdelta2 memory T cells have different proliferation and differentiation potentials in vitro and in vivo and that T(EMRA) cells are generated from the T(CM) subset upon homeostatic proliferation in the absence of antigen

Production of VEGF and b-FGF in the drainage fluid from patients undergoing incisional hernia repair

Wound healing is a complex process involving interaction between different cell types, such as growth factors. Among these, vascular endothelial growth factors (VEGF) and basic fibroblast growth factors (b-FGF) are the most important. The aim of this study was to assess the production of VEGF and b-FGF in wound drainage fluid from patients undergoing incisional abdominal hernia repair. Ten female patients with abdominal midline incisional hernia undergoing surgical repair were included in this study. In all cases a closed suction drain was placed in the wound below the fascia and removed on postoperative day 4. Wound fluid was collected on the I, II, III and IV day and its amount at each time was recorded. VEGF and b-FGF production were evaluated as the quantity produced in 24 hours. In all patients the amount of drainage fluid from the surgical wound was highest on the I day after surgery, after which there was a significant reduction. VEGF production increased progressively after the operation proving significantly higher only on the IV day. The amount of b-FGF, in contrast, was higher on the I day, decreasing thereafter on the following postoperative days. Analysis of the production of growth factors in the drainage fluid has enabled us to better assess the events that occur following surgical wounds and has confirmed the physiology of the healing process and the possible use of these factors in modulating positive healing