Investigations on nucleophilic layers made with a novel plasma jet technique

In this work a novel plasma jet technique is used for the deposition of nucleophilic films based on (3-aminopropyl)trimethoxysilane at atmospheric pressure. Film deposition was varied with regard to duty cycles and working distance. Spectral ellipsometry and chemical derivatization with 4-(trifluoromethyl)benzaldehyde using ATR- FTIR spectroscopy measurements were used to characterize the films. It was found that the layer thickness and the film composition are mainly influenced by the duty cycle

A novel plasma jet with RF and HF coupled electrodes

In order to achieve low processing temperature and efficient coatings deposition for manufacturing applications, a novel torch has been developed that couples in a double DBD design high frequency (HF ~17 kHz) and radio frequency (RF ~27 MHz) excitations. The design allows to obtain a stable RF plasma also in reactive processes and with the possibility to control on the treated substrates ions flux and surface charging, avoiding the micro-discharges. The plasma has been electrically and optically characterized by emission spectroscopy

Towards a better understanding of gold electroless deposition in track-etched templates

The template method for preparing nanomaterials entails synthesis of tubular or fibrillar nanostructures within the pores of a microporous membrane. If the holes are completely filled, solid nanowires result, while a partial filling with a continuous coating gives rise to nanotubes. This paper focused on the study of the parameters controlling electroless gold deposition in track-etched polycarbonate membranes. The structure and morphology of the obtained nanomaterials are examined and compared by a variety of electron microscopies and atomic force microscopy and examined in relation to electrochemical and spectrophotometric results. As far as nanotubes are concerned, problems with obtaining such a nanostructure are observed, in particular when membranes with pore diameters equal to or smaller than 30 nm are used. In the case of nanowires, defects related to fabrication problems are evidenced when they are used to prepare nanoelectrode ensembles (NEEs), because defects dramatically influence their voltammetric behavior. The role of deposition time and pH on gold nucleation and growth is studied in detail. We demonstrate that these parameters indeed determine the formation of nanowires versus nanotubes. In all cases the deposit is started by the formation of gold nuclei on the walls of the previously activated membrane. Then the nuclei grow, until they are bound together to produce the final nanomaterial. A significantly better control of the deposition is achieved by separating the nuclei formation step from the growth process. At pH 10 the nuclei growth is more regular but slower, whereas at pH 12 the process is faster but their size distribution is wider. At pH 10 the formation of nanotubes is better controlled, whereas at pH 12 continuous nanofibers are more quickly formed

Gefitinib in patients with progressive high-grade gliomas: a multicentre phase II study by Gruppo Italiano Cooperativo di Neuro-Oncologia (GICNO)

To investigate the role of gefitinib in patients with high-grade gliomas (HGGs), a phase II trial (1839IL/0116) was conducted in patients with disease recurrence following surgery plus radiotherapy and first-line chemotherapy. Adult patients with histologically confirmed recurrent HGGs following surgery, radiotherapy and first-line chemotherapy, were considered eligible. Patients were treated with gefitinib (250 mgday−1) continuously until disease progression. The primary end point was progression-free survival at 6 months progression-free survival at 6 months (PFS-6). Tissue biomarkers (epidermal growth factor receptor (EGFR) gene status and expression, phosphorylated Akt (p-Akt) expression) were assessed. Twenty-eight patients (median age, 55 years; median ECOG performance status, 1) were enrolled; all were evaluable for drug activity and safety. Sixteen patients had glioblastoma, three patients had anaplastic oligodendrogliomas and nine patients had anaplastic astrocytoma. Five patients (17.9%, 95% CI 6.1–36.9%) showed disease stabilisation. The overall median time to progression was 8.4 (range 2–104+) weeks and PFS-6 was 14.3% (95% CI 4.0–32.7%). The median overall survival was 24.6 weeks (range 4–104+). No grade 3–4 gefitinib-related toxicity was found. Gefitinib showed limited activity in patients affected by HGGs. Epidermal growth factor receptor expression or gene status, and p-Akt expression do not seem to predict activity of this drug

Bismuth modified gold nanoelectrode ensemble for stripping voltammetric determination of lead

The preparation of bismuth modified ensembles of gold nanoelectrodes (Bi-NEE) is described for the first time. Bi-NEEs are characterized and successfully applied for anodic stripping voltammetric measurement of trace Pb(II). Optimization of the experimental parameters provided low detection limits of 60 ng L−1 and 30 ng L−1 by using in-situ and ex-situ bismuth film deposition, respectively, after a 3 min accumulation step

Are food-deceptive orchid species really functionally specialized for pollinators?

Food-deceptive orchid species have traditionally been considered pollination specialized to bees or butterflies. However, it is unclear to which concept of specialization this assumption is related; if to that of phenotypic specialization or of functional specialization. The main aim of this work was to verify if pollinators of five widespread food-deceptive orchid species (Anacamptis morio (L.) R.M. Bateman, Pridgeon & M.W. Chase, Anacamptis pyramidalis (L.) Rich., Himantoglossum adriaticum H. Baumann, Orchis purpurea Huds. and Orchis simia Lam.) predicted from the phenotypic point of view matched with the observed ones. We addressed the question by defining target orchids phenotypic specialization on the basis of their floral traits, and we compared the expected guilds of pollinators with the observed ones. Target orchid pollinators were collected by conducting a meta-analysis of the available literature and adding unpublished field observations, carried out in temperate dry grasslands in NE Italy. Pollinator species were subsequently grouped into guilds and differences in the guild spectra among orchid species grouped according to their phenotype were tested. In contradiction to expectations derived from the phenotypic point of view, food-deceptive orchid species were found to be highly functionally generalized for pollinators, and no differences in the pollinator guild spectra could be revealed among orchid groups. Our results may lead to reconsider food-deceptive orchid pollination ecology by revaluating the traditional equation orchid-pollination specialization