1,373 research outputs found

    Lessons learnt from the Sgorigrad and Stava disasters

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    The catastrophic failures of tailings dams at Sgorigrad (Bulgaria) and Stava (Italy) are analyzed, pinpointing the many similarities of the two cases. A description is given about the shortcomings in the construction of these geotechnical structures and the causes of their collapse. Further information is provided about the lessons learnt from these disasters and the activities carried out to keep memory alive and qualify young engineers and geologists on the proper and safe management of tailings dams

    First report on egg-parasitoids of the Asian planthopper Ricania speculum

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    The first findings of egg-parasitoids of the invasive planthopper Ricania speculum (Walker) (Hemiptera Ricaniidae) are presented. Aprostocetus (Ootetrastichus) crino (Walker) (Hymenoptera Eulophidae), a native species until now only associated with Oecanthus spp. (Orthoptera Oecanthidae) eggs, was the most common. Chaetostricha similis (Silvestri) (Hymenoptera Trichogrammatidae) and Polynema sp. (Hymenoptera Mymaridae), which also emerged from R. speculum egg clusters, should be confirmed as parasitoids of this planthopper

    Antiepileptogenic effects of trilostane in the kainic acid model of temporal lobe epilepsy

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    Objective: Epileptogenesis after status epilepticus (SE) has a faster onset in rats treated to reduce brain levels of the anticonvulsant neurosteroid allopregnanolone with the 5α-reductase inhibitor finasteride; however, it still has to be evaluated whether treatments aimed at increasing allopregnanolone levels could result in the opposite effect of delaying epileptogenesis. This possibility could be tested using the peripherally active inhibitor of 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase trilostane, which has been shown repeatedly to increase allopregnanolone levels in the brain. Methods: Trilostane (50 mg/kg) was administered subcutaneously once daily for up to six consecutive days, starting 10 min after intraperitoneal administration of kainic acid (15 mg/kg). Seizures were evaluated by video-electrocorticographic recordings for 70 days maximum, and endogenous neurosteroid levels were assessed by liquid chromatography–electrospray tandem mass spectrometry. Immunohistochemical staining was performed to evaluate the presence of brain lesions. Results: Trilostane did not alter the latency of kainic acid-induced SE onset or its overall duration. When compared to the vehicle-treated group, rats receiving six daily trilostane injections presented a remarkable delay of the first spontaneous electrocorticographic seizure and subsequent tonic–clonic spontaneous recurrent seizures (SRSs). Conversely, rats treated with only the first trilostane injection during SE did not differ from vehicle-treated rats in developing the SRSs. Notably, trilostane did not modify neuronal cell densities or the overall damage in the hippocampus. In comparison to the vehicle group, repeated administration of trilostane significantly decreased the activated microglia morphology in the subiculum. As expected, allopregnanolone and other neurosteroid levels were remarkably increased in the hippocampus and neocortex of rats treated for 6 days with trilostane, but pregnanolone was barely detectable. Neurosteroids returned to basal levels after a week of trilostane washout.. Significance: Overall, these results suggest that trilostane led to a remarkable increase in allopregnanolone brain levels, which was associated with protracted effects on epileptogenesis

    15 GHz quadrature voltage controlled oscillator in 130 nm CMOS technology

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    This paper reports a 15 GHz quadrature voltage controlled oscillator (QVCO) designed in a 130 nm CMOS technology. The phase noise performance of the QVCO and of a phase locked loop (PLL) where the QVCO was inserted were compared with the literature and with telecom standards and commercial products for broadcast satellite applications

    The first record in Italy of Trichogramma cordubense Vargas & Cabello 1985 (Hymenoptera: Trichogrammatidae) emerging from the eggs of Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera: Tortricidae)

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    This study investigated the egg parasitoids of Lobesia botrana (Denis & Schiffermüller, 1775) feeding on Daphne gnidium L. (Malvales, Thymelaeaceae) in the San Rossore-Migliarino-Massaciuccoli Nature Reserve (Tuscany, Italy). Four species of egg parasitoids of the genus Trichogramma spp. were obtained. The parasitization rate gradually increased over the season, reaching its maximum level in September 2015, with a percentage of parasitized eggs close to 55 %. Three of the species obtained were already known as L. botrana parasitoids, whereas the finding of Trichogramma cordubense Vargas & Cabello, 1985 represents the first recording in Italy, as well as the first report of this species among the natural enemies of L. botrana

    P2X7 mRNA expression in non-small cell lung cancer: MicroRNA regulation and prognostic value

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    The human P2X7 receptor is significant and exhibits several functions in neoplasia. At present, little is known with regard to its regulation. P2X7 expression may be regulated post-transcriptionally and putative microRNA (miRNA) binding sites are considered to be involved. The aim of this study was to determine whether miRNAs (miR-21, let-7 g and miR-205) regulate P2X7 mRNA stability. In addition, the impact of P2X7 expression in patients with non-small cell lung cancer (NSCLC) was investigated. P2X7 mRNA and mature Let-7 g, miR-21, and miR-205 expression levels were quantified in 96 NSCLC cases using quantitative reverse transcription polymerase chain reaction. In all samples, epidermal growth factor receptor and K-Ras mutational analysis was also performed. Samples with low P2X7 expression were found to exhibit a higher fold change in miR-21 expression when compared with samples exhibiting high P2X7 expression. Significantly higher miR-21 expression was observed in the tumors of NSCLC patients with a K-Ras mutation when compared with patients who had K-Ras wild-type tumors (P=0.003). Additionally, to evaluate the association between P2X7 expression and prognosis in NSCLC patients, survival analysis was performed using the Kaplan-Meier method. A significant difference in the progression-free survival and overall survival in the NSCLC patients with high P2X7 expression was identified, when compared with that of patients with low expression (P=0.03 and P=0.02, respetively). Therefore, we hypothesized that high levels of miR-21 expression in NSCLC patients with K-Ras mutations may be regulated by a complex circuit, including P2X7 downregulation and together these processes may promote tumor progression

    Identification and synthesis of new sex-specific components of olive fruit fly (Bactrocera oleae) female rectal gland, through original Negishi reactions on supported catalysts

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    In the present study, eleven new sex-specific components extracted from female rectal gland of olive fruit flies were synthesized and identified. The quantitative determination of those components by GC and GC/EI-MS, at different moments of the insect life span, highlighted the growing trend of their secretion. While for the synthesis of saturated esters, conventional transesterification methods could be adopted, for the synthesis of unsaturated components, a Negishi cross-coupling between organozinc halides and (Z)-1-bromo-1-alkenes was developed. To the extent of our knowledge, this reaction represents the first example of supported-catalyst promoted Negishi coupling, between an alkylzinc reagent and an alkenyl halide

    Investigation on the microbiological hazards in an artisanal salami produced in Northern Italy and its production environment in different seasonal periods

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    In the present study, the occurrence of Listeria monocytogenes, Staphylococcus aureus, Salmonella spp. and Escherichia coli VTEC was investigated in two batches of artisanal Italian salami tested in winter and summer. Moreover, enumerations of total bacterial count, lactic acid bacteria and Enterobacteriaceae were performed as well as monitoring of water activity and pH. Samples were taken from raw materials, production process environment, semi-finished product and finished products. The results revealed an overall increase of total bacterial count and lactic acid bacteria during the ripening period, along with a decrease of Enterobacteriaceae, pH and water activity. No significant difference was observed between the two batches. The enterobacterial load appeared to decrease during the maturation period mainly due to a decrease in pH and water activity below the limits that allow the growth of these bacteria. E. coli VTEC, Salmonella spp. or L. monocytogenes were not detected in both winter and summer batches. However, Klebsiella pneumoniae was detected in both summer and winter products. Except for one isolate, no biological hazards were detected in the finished salami, proving the efficacy of the ripening period in controlling the occurrence of microbiological hazard in ripened salami. Further studies are required to assess the virulence potential of the Klebsiella pneumoniae isolates

    Augmentation of endogenous neurosteroid synthesis alters experimental status epilepticus dynamics

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    Neurosteroids can modulate γ-aminobutyric acid type A receptor-mediated inhibitory currents. Recently, we discovered that the neurosteroids progesterone, 5α-dihydroprogesterone, allopregnanolone, and pregnanolone are reduced in the cerebrospinal fluid of patients with status epilepticus (SE). However, it is undetermined whether neurosteroids influence SE. For this reason, first we evaluated whether the inhibitor of adrenocortical steroid production trilostane (50 mg/kg) could modify the levels of neurosteroids in the hippocampus and neocortex, and we found a remarkable increase in pregnenolone, progesterone, 5α-dihydroprogesterone, and allopregnanolone levels using liquid chromatography tandem mass spectrometry. Second, we characterized the dynamics of SE in the presence of the varied neurosteroidal milieu by a single intraperitoneal kainic acid (KA; 15 mg/kg) injection in trilostane-treated rats and their controls. Convulsions started in advance in the trilostane group, already appearing 90 minutes after the KA injection. In contrast to controls, convulsions prevalently developed as generalized seizures with loss of posture in the trilostane group. However, this effect was transient, and convulsions waned 2 hours before the control group. Moreover, electrocorticographic traces of convulsions were shorter in trilostane-treated rats, especially at the 180-minute (P < .001) and 210-minute (P < .01) time points. These findings indicate that endogenous neurosteroids remarkably modulate SE dynamics

    Braconinae parasitoids (Hymenoptera, Braconidae) emerged from larvae of Lobesia botrana (Denis & Schiffermüller) (Lepidoptera, Tortricidae) feeding on Daphne gnidium L.

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    The Bracon Fabricius, 1804 species, B. admotus Papp, 2000, and three species of the genus Habrobracon Ashmead, 1895, H. concolorans (Marshall, 1900), H. hebetor (Say, 1836) and H. pillerianae Fischer, 1980, were obtained from the larvae of Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera, Tortricidae) living on Daphne gnidium Linnaeus, 1753 (Thymelaeaceae) in the natural reserve of Migliarino-San Rossore- Massaciuccoli (Pisa - Central Italy). Bracon admotus, Habrobracon concolorans and H. pillerianae were found for the first time to be associated with L. botrana, while H. hebetor was reared for the first time from the larvae of Cryptoblabes gnidiella (Milliere, 1867) (Lepidoptera, Pyralidae, Phycitinae). Bracon admotus and H. pillerianae are new fauna to Italy and Western Europe. A key is proposed for the determination of Habrobracon species reared from L. botrana and related Palaearctic species of this genus. Bracon (Habrobracon) lineatellae Fisher, 1968 is considered as a valid species
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