Electrospun silk fibroin fibers for storage and controlled release of human platelet lysate

Human platelet lysate (hPL) is a pool of growth factors and cytokines able to induce regeneration of different tissues. Despite its good potentiality as therapeutic tool for regenerative medicine applications, hPL has been only moderately exploited in this field. A more widespread adoption has been limited because of its rapid degradation at room temperature that decreases its functionality. Another limiting factor for its extensive use is the difficulty of handling the hPL gels. In this work, silk fibroin-based patches were developed to address several points: improving the handling of hPL, enabling their delivery in a controlled manner and facilitating their storage by creating a device ready to use with expanded shelf life. Patches of fibroin loaded with hPL were synthesized by electrospinning to take advantage of the fibrous morphology. The release kinetics of the material was characterized and tuned through the control of fibroin crystallinity. Cell viability assays, performed with primary human dermal fibroblasts, demonstrated that fibroin is able to preserve the hPL biological activity and prolong its shelf-life. The strategy of storing and preserving small active molecules within a naturally-derived, protein-based fibrous scaffold was successfully implemented, leading to the design of a biocompatible device, which can potentially simplify the storage and the application of the hPL on a human patient, undergoing medical procedures such as surgery and wound care. Statement of Significance: Human platelets lysate (hPL) is a mixture of growth factors and cytokines able to induce the regeneration of damaged tissues. This study aims at enclosing hPL in a silk fibroin electrospun matrix to expand its utilization. Silk fibroin showed the ability to preserve the hPL activity at temperature up to 60 \ub0C and the manipulation of fibroin's crystallinity provided a tool to modulate the hPL release kinetic. This entails the possibility to fabricate the hPL silk fibroin patches in advance and store them, resulting in an easy and fast accessibility and an expanded use of hPL for wound healing

Development of a sampling plan for Myzus persicae (Hemiptera : Aphidoidea) and its predator Macrolophus costalis (Hemiptera : Miridae) on tobacco

A tobacco field in Greece was sampled during the 2001 and 2002 growing seasons to assess the seasonal trends in densities and spatial distributions of the aphid Myzus persicae (Sulzer) and its predatory mirid Macrolophus costalis (Fieber). On repeated occasions between June Oust after the transplantation) and September Oust before harvest), 20 tobacco leaves (10 from the upper and 10 from the lower plant part) were taken from randomly chosen plants. These leaves were sampled for aphids and mirids. In both years, the highest aphid densities were recorded during July and August, while aphid numbers were low in September. In contrast, the majority of M costalis individuals were found during September when aphid numbers were low. Significantly more M persieae individuals were found in the upper part of the plants, whereas significantly more M costalis individuals were found in the lower part of the plants. As indicated by Taylor's Power Law estimates, both species were aggregated in their spatial distributions among sampling units (leaves). Wilson and Room's model, based on the Taylor's estimates, was used to calculate the mean number of aphids and mirids, from the proportion of sampling units (leaves) that had gt 0 individuals of each species. This model provided a satisfactory fit of the data for both the aphid and the mirid. In addition, Wilson and Room's model was successfully used to predict the mean number of aphids and mirids in a series of samples that were carried out in the same area between June and September 2003 for model validation. Finally, equations are given for the calculation of precision in estimating the mean number of aphids or mirids per sampling unit, and the required sample size for a given level of precision

Mortality and suppression of progeny production of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) in seven different grains treated with an enhanced diatomaceous earth formulation

DEBBM, an enhanced diatomaceous earth (DE) formulation consisting of a mixture of DE and the plant extract bitterbarkomycin, was applied to seven different grains (wheat, barley, oats, rye, triticale, paddy rice and maize) at two dose rates 50 ppm and 150 ppm. Unsexed, 7d old adults of Sitophilus oryzae (Coleoptera: Curculionidae) and Tribolium confusum (Coleoptera: Tenebrionidae) were exposed to the DEBBM treated commodities and their mortality was assessed after 7d and 14d of exposure at 25 oC and 65% r.h. Furthermore, progeny production of the tested species per treated commodity was also assessed. Sitophilus oryzae appeared to be more susceptible than T. confusum to DEBBM. Performance of DEBBM was better in barley, wheat and oats compared to the remainder of the tested commodities. DEBBM performed better in rye and triticale than in paddy rice against both species although in many cases, significant differences among these grains were not recorded. Despite that DEBBM reached its highest efficacy levels on barley, wheat, and oats it did not suppress progeny production of the treated species in any of the grains. A significant reduction in progeny production of the treated species was recorded in the DEBBM treated grains in comparison with the untreated ones. This reduction in progeny production was expressed more vigorously to S. oryzae rather than T. confusum. In commodities with high DEBBM performance such as barley, oats or wheat, > 9-fold less progeny of S. oryzae were recorded at 150 ppm of DEBBM than in the untreated commodities. Although significantly less progeny of T. confusum were recorded in DEBBM treated grains than untreated grains, progeny suppression of this species was neither dose nor commodity dependant. Keywords: Diatomaceous earth, Bitterbarkomycin, Tribolium, Sitophilus, Mortality, Commodit

Biodegradable All-Polymer Field-Effect Transistors Printed on Mater-Bi

The growing demand of disposable electronics raises serious concerns for the corresponding increase in the amount of electronic waste, with severe environmental impact. Organic and flexible electronics have been proposed long ago as a more sustainable and energy-efficient technological platform with respect to established ones. Yet, such technology is leading to a drastic increase of plastic waste if common approaches for flexible substrates are followed. In this scenario, biodegradable solutions can significantly limit the environmental impact, actively contributing to eliminate the waste streams (plastic or electronic) associated with disposal of devices. However, achieving suitably scalable processes to pattern mechanically robust organic electronics onto largely available biodegradable substrates is still an open challenge. In this work, all-organic and highly flexible field-effect transistors, inkjet printed onto the biodegradable and compostable commercial substrate Mater-Bi, are demonstrated. Because of the thermal instability of Mater-Bi, no annealing steps are applied, producing devices with limited carrier mobility, yet showing correct n-type behavior and robustness to bending and crumpling. The degradation behavior of the final system shows unaltered biodegradability level according to ISO 14851. These results represent a promising step toward sustainable flexible and large-area electronics, combining energy and materials efficient processes with largely available biodegradable substrates

Life Cycle Assessment of a Circular Economy Process for Tray Production via Water-Based Upcycling of Vegetable Waste

With one-third of food being wasted at the various steps of the value chain, there is a large amount of biomass constantly being discarded, also wasting the resources consumed for its production. Several strategies have been proposed to use this biomass as a source of raw materials for the production of plastic alternatives, but the environmental impact parameters have rarely been estimated to understand if the proposed process provides an overall benefit. The purpose of this paper is to analyze, through an experimental laboratory campaign, the production process of a vegetable biocomposite material obtained by valorization of biomass from two sources: unsold vegetables from a wholesale market and carrot pomace obtained as a byproduct of juicing. The obtained biocomposite films were thermoformed into trays to replace the traditional plastic food containers made principally with PET. Different scenarios for the lab-scale production of trays were evaluated by testing two water-based processing methods for the two types of biomass used. In order to understand which of the four scenarios was the least impactful, the global warming potential, the cumulative energy demand, and the water scarcity index were used as indicators. Among the different lab-scale processing scenarios for the upscaling of vegetable waste, the least impactful was starting from the unsold/discarded vegetables collected at the wholesale market that were processed via water-based hydrolysis catalyzed by formic acid. Impact parameters were comparable or better than two traditional polymers (PET and HDPE) and two biopolymers (PLA and biopolymer from starch), showing that this process has excellent potential, from an environmental point of view, of substituting plastic packaging

Top Management Team Diversity: A systematic Review

Empirical research investigating the impact of top management team (TMT) diversity on executives’ decision making has produced inconclusive results. To synthesize and aggregate the results on the diversity-performance link, a meta-regression analysis (MRA) is conducted. It integrates more than 200 estimates from 53 empirical studies investigating TMT diversity and its impact on the quality of executives’ decision making as reflected in corporate performance. The analysis contributes to the literature by theoretically discussing and empirically examining the effects of TMT diversity on corporate performance. Our results do not show a link between TMT diversity and performance but provide evidence for publication bias. Thus, the findings raise doubts on the impact of TMT diversity on performance

Patterned structures of in situ size controlled CdS nanocrystals in a polymer matrix under UV irradiation.

A method of in situ formation of patterns of size controlled CdS nanocrystals in a polymer matrix by pulsed UV irradiation is presented. The films consist of Cd thiolate precursors with different carbon chain lengths embedded in TOPAS polymer matrices. Under UV irradiation the precursors are photolyzed, driving to the formation of CdS nanocrystals in the quantum size regime, with size and concentration defined by the number of incident UV pulses, while the host polymer remains macroscopically/microscopically unaffected. The emission of the formed nanocomposite materials strongly depends on the dimensions of the CdS nanocrystals, thus, their growth at the different phases of the irradiation is monitored using spatially resolved photoluminescence by means of a confocal microscope. X-ray diffraction measurements verified the existence of the CdS nanocrystals, and defined their crystal structure for all the studied cases. The results are reinforced by transmission electron microscopy. It is proved that the selection of the precursor determines the efficiency of the procedure, and the quality of the formed nanocrystals. Moreover it is demonstrated that there is the possibility of laser induced formation of well-defined patterns of CdS nanocrystals, opening up new perspectives in the development of nanodevices