Ethylene production affects blueberry fruit texture and storability

Ethylene, produced endogenously by plants and their organs, can induce a wide array of physiological responses even at very low concentrations. Nevertheless, the role of ethylene in regulating blueberry (Vaccinium spp.) ripening and storability is still unclear although an increase in ethylene production has been observed in several studies during blueberry ripening. To overcome this issue, we evaluated the endogenous ethylene production of a Vaccinium germplasm selection at different fruit ripening stages and after cold storage, considering also textural modifications. Ethylene and texture were further assessed also on a bi-parental full-sib population of 124 accessions obtained by the crossing between "Draper" and "Biloxi", two cultivars characterized by a different chilling requirement and storability performances. Our results were compared with an extensive literature research, carried out to collect all accessible information on published works related to Vaccinium ethylene production and sensitivity. Results of this study illustrate a likely role of ethylene in regulating blueberry shelf life. However, a generalisation valid for all Vaccinium species is not attainable because of the high variability in ethylene production between genotypes, which is strictly genotype-specific. These differences in ethylene production are related with blueberry fruit storage performances based on textural alterations. Specifically, blueberry accessions characterized by the highest ethylene production had a more severe texture decay during storage. Our results support the possibility of tailoring ad hoc preharvest and postharvest strategies to extend blueberry shelf life and quality according with the endogenous ethylene production level of each cultivar

Active debris removal: overview and figures of merit of debris grabbing strategies

During the last two decades the problem of space debris and safe access to Low Earth Orbit has been one of the most controversial and discussed issue in the space community. Along with mitigation actions (e.g. the 25-year Post Mission Disposal rule currently adopted by most agencies), analyses of the current situation and future projections have shown the necessity of active debris removal (ADR) operations aimed to a direct intervention in relatively short time as a remediation action. Apart from the problem of considering the potential political and legal consequences of dealing with spent space objects, many methods have been proposed for the despinning and grabbing phases of ADR missions, but in spite of the variety in the ideas and concepts on the ground, not all of them are ready to be sent to space. Starting from an overview on the different approaches proposed for in-orbit grabbing of uncooperative targets, this work analyses the current status of the solutions designed so far, both in terms of technical readiness and methodological maturity, and identifies the characteristics that can be used as a metric for the quality and feasibility of those systems. From these figures of merit, different scenarios will be simulated to obtain additional supporting data in order to validate the results of the preliminary analyses

A roadmap for the characterization of energy metabolism in human cardiomyocytes derived from induced pluripotent stem cells

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are an increasingly employed model in cardiac research and drug discovery. As cellular metabolism plays an integral role in determining phenotype, the characterization of the metabolic profile of hiPSC-CM during maturation is crucial for their translational application. In this study we employ a combination of methods including extracellular flux, 13C-glucose enrichment and targeted metabolomics to characterize the metabolic profile of hiPSC-CM during their maturation in culture from 6 weeks, up to 12 weeks. Results show a progressive remodeling of pathways involved in energy metabolism and substrate utilization along with an increase in sarcomere regularity. The oxidative capacity of hiPSC-CM and particularly their ability to utilize fatty acids increased with time. In parallel, relative glucose oxidation was reduced while glutamine oxidation was maintained at similar levels. There was also evidence of increased coupling of glycolysis to mitochondrial respiration, and away from glycolytic branch pathways at later stages of maturation. The rate of glycolysis as assessed by lactate production was maintained at both stages but with significant alterations in proximal glycolytic enzymes such as hexokinase and phosphofructokinase. We observed a progressive maturation of mitochondrial oxidative capacity at comparable levels of mitochondrial content between these time-points with enhancement of mitochondrial network structure. These results show that the metabolic profile of hiPSC-CM is progressively restructured, recapitulating aspects of early post-natal heart development. This would be particularly important to consider when employing these cell model in studies where metabolism plays an important role

Rapid disease progression in patient with mismatch-repair deficiency pituitary ACTH-secreting adenoma treated with checkpoint inhibitor pembrolizumab

Secreting pituitary adenomas are tumors for which few treatment options are available, including surgical treatment and management of hormonal imbalance due to altered pituitary secretion. In case of inoperable relapse, radiotherapy or chemotherapeutic treatment can be considered; the effectiveness of these treatments, however, remains limited. In the immunotherapy era, it is necessary to select patients who can benefit from immunotherapeutic treatment. Mismatch repair deficiency is strongly associated with responsiveness to anti-PD-1 in other cancers and can be detected using immunohistochemistry for MLH1, MSH2, MHS6, and PMS2. In this case report, we report a case of rapid disease progression to pembrolizumab in a patient with a MMRd pituitary adrenocorticotropic hormone (ACTH)-secreting adenoma. For the best of our knowledge, we described for the first time, a poor efficacy of pembrolizumab in a patient with ACTH-secreting pituitary adenoma having mismatch repair deficiency probably caused by high levels of cortisol in this patient. Prospective study should be performed to assess the activity of immune checkpoint inhibitor alone or in association with temozolomide in this subsetting of pituitary adenomas

Variability of biological effects of silicas: different degrees of activation of the fifth component of complement by amorphous silicas.

A biogenic and a pyrogenic amorphous silica were incubated in normal human plasma and compared on a per unit surface basis for their ability to split C5 molecules and yield small C5a peptides. Since C5a peptides induce selective chemotactic attraction of polymorphonuclear leukocytes (PMN), measurement of PMN-induced chemotaxis was used as an index of C5 activation. Though to a lesser extent than the crystalline forms, amorphous silicas can promote the cleavage of C5 protein and generation of C5a-like fragment. The biogenic silica, which differs from the pyrogenic variety in particle shape, level of contaminants, and degree of surface hydrophilicity, besides specific surface, induced a greater response. Both silicas activated C5 through a process which seems to involve multiple events similar to those induced by crystalline silica. C5 molecules are adsorbed and hydroxyl radicals are generated through Haber Weiss cycles catalyzed by the redox-active iron present at the particle surface either as trace impurities or chelated from plasma by silanol groups. In turn, these radicals convert native C5 to an oxidized C5-like form C5(H2O2). Finally, C5(H2O2) is cleaved by protease enzymatic action of plasma kallikrein activated by the same silica dusts, yielding a product, C5a(H2O2), having the same functional characteristic as C5a

Nanosatellites: Space and Ground Technologies, Operations and Economics

Nanosatellites: Space and Ground Technologies, Operations and Economics comprehensively presents the latest research on the fast-developing area of nanosatellites. Divided into three distinct sections, the book begins with a brief history of nanosatellites and introduces nanosatellites technologies and payloads, also explaining how these are deployed into space. The second section provides an overview of the ground segment and operations, and the third section focuses on the regulations, policies, economics, and future trends. Key features: Payloads for nanosatellites Nanosatellites components design Examines the cost of development of nanosatellites. Covers the latest policies and regulations. Considers future trends for nanosatellites. Nanosatellites: Space and Ground Technologies, Operations and Economics is a comprehensive reference for researchers and practitioners working with nanosatellites in the aerospace industry