Durability testing at one atmosphere of advanced catalysts and catalyst supports for automotive gas turbine engine combustors, part 1

The durability of catalysts and catalyst supports in a combustion environment was experimentally demonstrated. A test of 1000 hours duration was completed with two catalysts, using diesel fuel and operating at catalytically supported thermal combustion conditions. The performance of the catalysts was determined by monitoring emissions throughout the test, and by examining the physical condition of the catalyst core at the conclusion of the test. The test catalysts proved to be capable of low emissions operation after 1000 hours diesel aging, with no apparent physical degradation of the catalyst support

Hop (Humulus lupulus L.): Suitability of Traditional Cultivars to a Low-Trellis Farming System in a Semiarid Environment

Humulus lupulus is a dioecious twining herb, with an outstanding vertical development capacity. Hop plants are usually grown on trellises up to 4.5 to 6.0 m high, whose management requires intense use of water, fertilizers, pesticides, and labor. In semiarid Mediterranean areas, where native resources are often scarce, the adoption of low-trellis farming systems could be a sustainable option for hop cultiva-tion. With the aim of evaluating hop suitability to low-trellis cultivation in a Mediter-ranean environment, in 2018 and 2019 three traditional hop genotypes ('Cascade', 'Chinook', and 'Nugget') were grown, and their development rate was evaluated and put in relation with the plants' cone, root, and biomass yield. Moreover, organic (fragmented pine bark) and synthetic [black polyethylene (PE) plastic film] mulches were applied on the same cultivars, and both epigeal and hypogeal development were evaluated. The results showed that the faster the growth in the first two phases of plant elongation (up to 50% of the height of the upper wire), the lower the yield in both cones and total epigeal biomass. A fast growth rate was instead associated with a higher hypogeal biomass production. Mulching was able to significantly affect the hypogeal biomass, specifically for cv. Cascade, where the use of synthetic mulching allowed significant root biomass increases. The analysis of the results obtained showed that hop's suitability to a low-trellis farming system is highly variable among varieties in the semiarid Mediterranean environment

Propagation of Artemisia arborescens L. by stem-cutting: adventitious root formation under different conditions

Artemisia arborescens L. has gained a strong importance worldwide due to its many industrial uses and it has been recently considered as ornamental plant. A major constraint to its widespread cultivation is represented, by far, by the scarce availability of high-quality plant material for field establishment; hence, development of a fast and effective methods for its vegetative propagation is needed. An experiment was conducted to assess the effects of different harvest periods, NAA, and rooting substrates on rooting of stem cuttings of A. arborescens. Semi hardwood cuttings were collected from wild plants in February, April, and November. Half of the material was treated with 0.4% NAA and placed on different mixtures of sphagnum peat and perlite (2 : 1, 1 : 1, and 1 : 2 v/v) under mist. After 40 days the percentage of rooted cuttings was significantly influenced by the harvest period as cuttings collected in February showed the highest rooting rate, and numerous alive but not rooted cuttings evidenced callus formation. In contrast, the use of different rooting substrates as well as NAA addition did not show any significant effect on rooting capacity. The best results, in terms of root number (4.2) and root length (8.8 cm), were achieved on cuttings grown in a 1 : 1 v/v sphagnum peat : perlite mixture, without NAA application

Arbuscular mycorrhizal fungi altered the hypericin, pseudohypericin, and hyperforin content in flowers of Hypericum perforatum grown under contrasting P availability in a highly organic substrate

St. John’s Wort (Hypericum perforatum) is a perennial herb able to produce water-soluble active ingredients (a.i.), mostly in flowers, with a wide range of medicinal and biotechnological uses. However, information about the ability of arbuscular mycorrhizal fungi (AMF) to affect its biomass accumulation, flower production, and concentration of a.i. under contrasting nutrient availability is still scarce. In the present experiment, we evaluated the role of AMF on growth, flower production, and concentration of bioactive secondary metabolites (hypericin, pseudohypericin, and hyperforin) of H. perforatum under contrasting P availability. AMF stimulated the production of aboveground biomass under low P conditions and increased the production of root biomass. AMF almost halved the number of flowers per plant by means of a reduction of the number of flower-bearing stems per plant under high P availability and through a lower number of flowers per stem in the low-P treatment. Flower hyperforin concentration was 17.5% lower in mycorrhizal than in non-mycorrhizal plants. On the contrary, pseudohypericin and hypericin concentrations increased by 166.8 and 279.2%, respectively, with AMF under low P availability, whereas no effect of AMF was found under high P availability. These results have implications for modulating the secondary metabolite production of H. perforatum. However, further studies are needed to evaluate the competition for photosynthates between AMF and flowers at different nutrient availabilities for both plant and AM fungus

Variability of morphological descriptors in Sicilian oat (Avena sativa L.) populations

Due to its rusticity and feasibility of use, oat (Avena sativa L.) represents a crucial agronomic and economic resource for many semiarid environments. Presently, the recourse to new commercial varieties has caused a dramatic lowering of areas covered with the traditional local genotypes, and a severe risk of genetic erosion is emerging. To deepen the knowledge about the autochthonous oat populations, an activity of collection and cataloging across semiarid cropping areas was carried out. Sixteen oat populations were collected from different areas of Sicily and put in a field study for two consecutive years (2014 and 2015) in the experimental farm “Sparacia” (Cammarata, Italy). In both years and all populations, 21 morphological characters, related to different aspects of the whole plant or plant parts, were measured as described in the guidelines Community Plant Variety Office—Office Communautaire des Varietes Vegetales (CPVO-OCVV) (rif. CPVO-TP/020/2). Multivariate analysis (MA) was applied to assess the similarity/dissimilarity level among populations, also evaluating the relative discriminatory importance of each selected plant character. Although a strong variability between years did not allow perfect discrimination among genotypes, an association between oat groups emerged based on their prevalent utilization form. Among categorical characters, measurements on glumes and grain provided the best characterization of the populations in both years

Milk Thistle (Silybum Marianum L.) as a Novel Multipurpose Crop for Agriculture in Marginal Environments: A Review

Milk thistle (Silybum marianum (L.) Gaertn.) is a versatile crop that has adapted to the broadly different soil and environmental conditions throughout all continents. To date, the fruits (\u201cseeds\u201d) of the plant are the only reliable source of silymarin, which, given its recognized therapeutic effects and its many present and potential uses, has led to a significant re-discovery and enhancement of the crop in recent years. Overall, although many studies have been carried out globally on the bioactivity, phytochemistry, and genetics of milk thistle, few and discontinuous research activity has been conducted on its basic agronomy as well as on the farm opportunities offered by the cultivation of this species. However, the multiple potential uses of the plant and its reduced need for external inputs suggest that milk thistle can perfectly fit among the most interesting alternative crops, even for marginal environments. The growing interest in natural medicine, the increasing popularity of herbal dietary supplements, and the multiple possibilities for livestock feeding are all arguments supporting the idea that in many rural areas, this crop could represent a significant tool for enhancing and stabilizing farm income. However, several issues still have to be addressed. The species retains some morphological and physiological traits belonging to non-domesticated plants, which make the application of some common agronomic practices challenging. Furthermore, the lack of reliable field data devoted to the definition of suitable cropping protocols represents a major constraint on the spread of this crop among farmers. This review has therefore focused on updating information on the main morphological and phytochemical traits of the crop and its agronomic characteristics and novel uses. Several gaps in technical knowledge have been addressed, and further goals for experimental activity have been outlined in order to guide farmers eager to cope with the cultivation of such a challenging and resource-rich crop

Biochar enhances root development and aloin content of mature leaves in containerized Aloe arborescens Mill

The leaves of the medicinal plant Aloe arborescens Mill. Asphodelaceae) contain significant amounts of bioactive metabolites, including aloin (a mixture of the two diastereoisomers, aloin A and aloin B), aloesin, isoaloeresin D, and aloenin A. The presence of these metabolites varies considerably depending on the plant’s growth conditions, including the used growing substrate. In recent years, there has been growing interest in using biochar for potted plants cultivation. However, there is currently no available information regarding the suitability of biochar for the containerized cultivation of A. arborescens. A pot experiment was conducted with the hypothesis that biochar could influence the growth and phytochemistry of A. arborescens. The growing medium was supplied with increasing proportions of biochar (1: 100% commercial substrate; 2: mixed 50%(v/v) substrate; 3: 100% conifers wood biochar). Over the course of three years, the plants were closely monitored, and several key growth parameters were measured, including plant height, stem diameter, number and weight of leaves, and the number of suckers. After the first year, the content of selected active metabolites wasassessed. This evaluation also involved a comparison of the respective levels in the leaves taken from the apical, median, and basal sections of the stem. The leaves collected from the median section of plants were found to be larger and exhibited the highest percentage of spikes, epidermis, and gel on fresh weight. As a general trend, it was observed that in plants cultivated within the highest amount of biochar, the leaves collected from the intermediate stem portion contained the highest quantity of secondary metabolites

Engineered membranes for residual cell trapping on microfluidic blood plasma separation systems. A comparison between porous and nanofibrous membranes

Blood-based clinical diagnostics require challenging limit-of-detection for low abundance, circulating molecules in plasma. Micro-scale blood plasma separation (BPS) has achieved remarka-ble results in terms of plasma yield or purity, but rarely achieving both at the same time. Here, we proposed the first use of electrospun polylactic-acid (PLA) membranes as filters to remove residual cell population from continuous hydrodynamic-BPS devices. The membranes hydrophilicity was improved by adopting a wet chemistry approach via surface aminolysis as demonstrated through Fourier Transform Infrared Spectroscopy and Water Contact Angle analysis. The usability of PLA-membranes was assessed through degradation measurements at extreme pH values. Plasma purity and hemolysis were evaluated on plasma samples with residual red blood cell content (1, 3, 5% hematocrit) corresponding to output from existing hydrodynamic BPS systems. Commercially available membranes for BPS were used as benchmark. Results highlighted that the electrospun membranes are suitable for downstream residual cell removal from blood, permitting the collection of up to 2 mL of pure and low-hemolyzed plasma. Fluorometric DNA quantification revealed that electrospun membranes did not significantly affect the concentration of circulating DNA. PLA-based electrospun membranes can be combined with hydrodynamic BPS in order to achieve high volume plasma separation at over 99% plasma purity

Physical and biological properties of electrospun poly(d,l-lactide)/nanoclay and poly(d,l-lactide)/nanosilica nanofibrous scaffold for bone tissue engineering

Electrospun scaffolds exhibiting high physical performances with the ability to support cell attachment and proliferation are attracting more and more scientific interest for tissue engineering applications. The inclusion of inorganic nanoparticles such as nanosilica and nanoclay into electrospun biopolymeric matrices can meet these challenging requirements. The silica and clay incorporation into polymeric nanofibers has been reported to enhance and improve the mechanical properties as well as the osteogenic properties of the scaffolds. In this work, for the first time, the physical and biological properties of polylactic acid (PLA) electrospun mats filled with different concentrations of nanosilica and nanoclay were evaluated and compared. The inclusion of the particles was evaluated through morphological investigations and Fourier transform infrared spectroscopy. The morphology of nanofibers was differently affected by the amount and kind of fillers and it was correlated to the viscosity of the polymeric suspensions. The wettability of the scaffolds, evaluated through wet contact angle measurements, slightly increased for both the nanocomposites. The crystallinity of the systems was investigated by differential scanning calorimetry highlighting the nucleating action of both nanosilica and nanoclay on PLA. Scaffolds were mechanically characterized with tensile tests to evaluate the reinforcing action of the fillers. Finally, cell culture assays with pre-osteoblastic cells were conducted on a selected composite scaffold in order to compare the cell proliferation and morphology with that of neat PLA scaffolds. Based on the results, we can convince that nanosilica and nanoclay can be both considered great potential fillers for electrospun systems engineered for bone tissue regeneration