Recent advancements in the use of aerosol-assisted atmospheric pressure plasma deposition

Atmospheric pressure plasma allows for the easy modification of materials' surfaces for a wide range of technological applications. Coupling the aerosol injection of precursors with atmospheric pressure plasma largely extends the versatility of this kind of process; in fact solid and, in general, scarcely volatile precursors can be delivered to the plasma, extending the variety of chemical pathways to surface modification. This review provides an overview of the state of the art of aerosol-assisted atmospheric pressure plasma deposition. Advantages (many), and drawbacks (few) will be illustrated, as well as hints as to the correct coupling of the atomization source with the plasma to obtain specific coatings. In particular, the deposition of different organic, hybrid inorganic-organic and bioactive nanocomposite coatings will be discussed. Finally, it will be shown that, in particular cases, unique core-shell nanocapsules can be obtained

RCC1L (WBSCR16) isoforms coordinate mitochondrial ribosome assembly through their interaction with GTPases

Mitochondrial translation defects can be due to mutations affecting mitochondrial-or nuclear-encoded components. The number of known nuclear genes involved in mitochondrial translation has significantly increased in the past years. RCC1L (WBSCR16), a putative GDP/GTP exchange factor, has recently been described to interact with the mitochondrial large ribosomal subunit. In humans, three different RCC1L isoforms have been identified that originate from alternative splicing but share the same N-Terminus, RCC1LV1, RCC1LV2 and RCC1LV3. All three isoforms were exclusively localized to mitochondria, interacted with its inner membrane and could associate with homopolymeric oligos to different extent. Mitochondrial immunoprecipitation experiments showed that RCC1LV1 and RCC1LV3 associated with the mitochondrial large and small ribosomal subunit, respectively, while no significant association was observed for RCC1LV2. Overexpression and silencing of RCC1LV1 or RCC1LV3 led to mitoribosome biogenesis defects that resulted in decreased translation. Indeed, significant changes in steady-state levels and distribution on isokinetic sucrose gradients were detected not only for mitoribosome proteins but also for GTPases, (GTPBP10, ERAL1 and C4orf14), and pseudouridylation proteins, (TRUB2, RPUSD3 and RPUSD4). All in all, our data suggest that RCC1L is essential for mitochondrial function and that the coordination of at least two isoforms is essential for proper ribosomal assembly

Il sito medievale di Montecorvino (FG) e il suo territorio. Analisi spaziali in ambiente GIS Open Source

Since 2016, the Montecorvino project has studied the topics of intervisibility and of the movement of humans and goods in the area of Monti Dauni (Foggia, South-Eastern Italy) in the late Middle Ages. This has been accomplished through the use of spatial analysis in an Open Source GIS. The use of Digital Terrain Models in a hilly area has been crucial in analyzing the influence of geo-morphological contexts on the genesis and development of settlements. Single and cumulative viewshed analyses have been applied to figure out if and to what extent these settlements could keep sight of each other, their surroundings and the communication routes. By means of a cost surface analysis, some site catchment areas have been defined and the potential and easiest (least costly) paths between some of these settlements have been generated. The results have then been integrated into a much wider research-field, which features archaeological, historical and bibliographical sources of information, to produce a comprehensive and integrated study of the ancient landscapes

Plasma Modification of PCL Porous Scaffolds Fabricated by Solvent Casting/Particulate Leaching for Tissue Engineering

This study points out how the plasma modification of PCL porous scaffolds, produced by Solvent Casting/Particulate Leaching, may enhance their biocompatibility. A C2H4/N2 plasma deposition followed by a H2 plasma treatment was used to increase the hydrophilicity of the whole scaffold to support osteoblast cell proliferation, both outside and inside the scaffold. A better cell growth was obtained on plasma modified scaffolds.JRC.I.4-Nanobioscience

Antimicrobial activity of immobilized lysozyme on plasma-treated polyethylene films.

In this study we tested the antimicrobial activity of polyethylene films modified by means of plasma processes that were followed by the chemical immobilization of lysozyme, an antimicrobial enzyme. To chemically immobilize the enzyme in its active form at the surface of polyethylene, substrates that had been plasma treated under different experimental conditions were soaked in lysozyme solutions at different concentrations. The immobilization of the enzyme was checked, and the antimicrobial activity of the films was investigated by observing the death rate of Micrococcus lysodeikticus cells suspended in phosphate buffer in contact with the films. The results clearly indicate that plasma-treated films loaded with lysozyme are active against the selected microorganism. A modified version of the Gompertz equation was used to quantitatively valuate the dependence of the antimicrobial activity of the films under both plasma treatment conditions and lysozyme concentrations

The Role of Randomly Distributed Well Widths in Disordered GaAs/AlGaAs Superlattices

Numerical and experimental results on the effect of randomness in GaAs/Al0.3Ga0.7As superlattices having a small number of randomly distributed well widths are reported. The numerical results indicate the splitting of the extended state miniband into sub-minibands of localized states having a disorder-induced fine structure. The comparison between the experimental results for low-temperature absorption spectra and the computed joint density of states of the investigated samples confirms the predicted features. The high-temperature photoluminescence intensity of random superlattices is observed to be enhanced with respect to the ordered case

Plasma technology increases the efficacy of prothioconazole against fusarium graminearum and fusarium proliferatum contamination of maize (Zea mays) seedlings

The contamination of maize by Fusarium species able to produce mycotoxins raises great concern worldwide since they can accumulate these toxic metabolites in field crop products. Further-more, little information exists today on the ability of Fusarium proliferatum and Fusarium graminearum, two well know mycotoxigenic species, to translocate from the seeds to the plants up to the kernels. Marketing seeds coated with fungicide molecules is a common practice; however, since there is a growing need for reducing chemicals in agriculture, new eco-friendly strategies are increasingly tested. Technologies based on ionized gases, known as plasmas, have been used for decades, with newer material surfaces, products, and approaches developed continuously. In this research, we tested a plasma-generated bilayer coating for encapsulating prothioconazole at the surface of maize seeds, to protect them from F. graminearum and F. proliferatum infection. A minimum amount of chemical was used, in direct contact with the seeds, with no dispersion in the soil. The ability of F. graminearum and F. proliferatum species to translocate from seeds to seedlings of maize has been clearly proven in our in vitro experiments. As for the use of plasma technology, the combined use of the plasma-generated coating with embedded prothioconazole was the most efficient approach, with a higher reduction of the infection of the maize seminal root system and stems. The debated capability of the two Fusarium species to translocate from seeds to seedlings has been demonstrated. The plasma-generated coating with embedded prothioconazole resulted in a promising sustainable approach for the protection of maize seedlings

Intra-instar larval cannibalism in Anopheles gambiae (s.s.) and Anopheles stephensi (Diptera: Culicidae)

BACKGROUND: Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1) has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4) of Anopheles gambiae (s.s.) and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size) on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. RESULTS: Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s.) than in An. stephensi. In both species the total number of cannibalistic events increased from 0-24 to 0-48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. CONCLUSIONS: The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s.) and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior and lower cannibalism rate. The understanding of cannibalistic behavior and the factors affecting it is of utmost importance for malaria vectors, as nutrition during larval development can strongly affect the fitness of adult female mosquitoes and ultimately their vector ability

Use of Modified 3D Scaffolds to Improve Cell Adhesion and Drive Desired Cell Responses.

In the most common approach of tissue engineering, a polymeric scaffold with a well-defined architecture has emerged as a promising platform for cells adhesion and guide their proliferation and differentiation into the desired tissue or organ. An ideal model for the regeneration should mimic clinical conditions of tissue injury, create a permissive microenvironment for diffusion of nutrients, gases and growth factors and permit angiogenesis. In this work, we used a 3D support made of synthetic resorbable polylactic acid (PLLA), which has considerable potential because of its well-known biocompatibility and biodegradability. One of the factors that influence cell adhesion to the scaffold is its porosity degree, but surface properties represent the main driving forces that influence the composition and orientation of proteins that will be absorbed onto material surfaces. We used scaffolds in which it was possible to control pore size and that had undergone on type-I collagen treatment, to mimic the extra cellular matrix, or plasma enhanced chemical vapor deposition (PE-CVD) combined with plasma treatment, in order to modify surface chemistry of the material. Our results show different cell affinity in non-treated scaffolds compared to type-I collagen or plasma modified ones. These surface changes are of considerable interest for tissue engineering and other areas of biomaterials science, where it can be useful to improve the surface of biomedical polymers to facilitate the colonization of the structure by the cells and obtain a more rapid regeneration or tissue replacement.In the most common approach of tissue engineering, a polymeric scaffold with a well-defined architecture has emerged as a promising platform for cells adhesion and guide their proliferation and differentiation into the desired tissue or organ. An ideal model for the regeneration should mimic clinical conditions of tissue injury, create a permissive microenvironment for diffusion of nutrients, gases and growth factors and permit angiogenesis. In this work, we used a 3D support made of synthetic resorbable polylactic acid (PLLA), which has considerable potential because of its well-known biocompatibility and biodegradability. One of the factors that influence cell adhesion to the scaffold is its porosity degree, but surface properties represent the main driving forces that influence the composition and orientation of proteins that will be absorbed onto material surfaces. We used scaffolds in which it was possible to control pore size and that had undergone on type-I collagen treatment, to mimic the extra cellular matrix, or plasma enhanced chemical vapor deposition (PE-CVD) combined with plasma treatment, in order to modify surface chemistry of the material. Our results show different cell affinity in non-treated scaffolds compared to type-I collagen or plasma modified ones. These surface changes are of considerable interest for tissue engineering and other areas of biomaterials science, where it can be useful to improve the surface of biomedical polymers to facilitate the colonization of the structure by the cells and obtain a more rapid regeneration or tissue replacement. Copyright © 2012, AIDIC Servizi S.r.l

The use of high aspect ratio photoresist (SU-8) for super-hydrophobic pattern prototyping

In this work we present a reliable technique for the production of large areas of high aspect-ratio patterns and describe their use as model super-hydrophobic systems. The high thickness and straight sidewalls possible with SU-8 were used to generate dense patterns of small pillars. These photoresist patterns could be used directly, without the need for micromoulding. A method is given allowing resist thickness to be varied over a wide range and a bottom antireflective layer was used to simplify patterning on reflective substrates. This patterning technique allows rapid testing of wetting theories, as pattern size and depth can be varied simply and samples can be produced in sufficient numbers for laboratory use. We show how the static contact angle of water varies with pattern height for one sample-pattern and how static and dynamic contact angles vary with dimension using high aspect-ratio patterns