3,214 research outputs found

    Development and demonstration of flueric sounding rocket motor ignition

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    An analytical and experimental program is described which established a flueric rocket motor ignition system concept incorporating a pneumatic match with a simple hand pump as the only energy source. An evaluation was made of this concept to determine the margins of the operating range and capabilities of every component of the system. This evaluation included a determination of power supply requirements, ignitor geometry and alinement, ignitor/propellant interfacing and materials and the effects of ambient temperatures and pressure. It was demonstrated that an operator using a simple hand pump for 30 seconds could ignite BKNO3 at a standoff distance of 100 m (330 ft) with the only connection to the ignitor being a piece of plastic pneumatic tubing

    Ignition of sounding rocket motors with hand-pumped air

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    Method demonstrates inexpensive, safe, and foolproof concept for solid propellant rocket motors, using simple handpump to deliver air. Flueric ignition was accomplished using system without stored energy and with complete absence of electrical energy and wiring

    Overview of the cerebellar function in anticipatory postural adjustments and of the compensatory mechanisms developing in neural dysfunctions

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    This review aims to highlight the important contribution of the cerebellum in the Anticipatory Postural Adjustments (APAs). These are unconscious muscular activities, accompanying every voluntary movement, which are crucial for optimizing motor performance by contrasting any destabilization of the whole body and of each single segment. Moreover, APAs are deeply involved in initiating the displacement of the center of mass in whole-body reaching movements or when starting gait. Here we present literature that illustrates how the peculiar abilities of the cerebellum (i) to predict, and contrast in advance, the upcoming mechanical events; (ii) to adapt motor outputs to the mechanical context, and (iii) to control the temporal relationship between task-relevant events, are all exploited in the APA control. Moreover, recent papers are discussed which underline the key role of cerebellum ontogenesis in the correct maturation of APAs. Finally, on the basis of a survey of animal and human studies about cortical and subcortical compensatory processes that follow brain lesions, we propose a candidate neural network that could compensate for cerebellar deficits and suggest how to verify such a hypothesis

    PARP inhibitors affect growth, survival and radiation susceptibility of human alveolar and embryonal rhabdomyosarcoma cell lines

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    PARP inhibitors (PARPi) are used in a wide range of human solid tumours but a limited evidence is reported in rhabdomyosarcoma (RMS), the most frequent childhood soft-tissue sarcoma. The cellular and molecular effects of Olaparib, a specific PARP1/2 inhibitor, and AZD2461, a newly synthesized PARP1/2/3 inhibitor, were assessed in alveolar and embryonal RMS cells both as single-agent and in combination with ionizing radiation (IR)

    Lymph node ratio predicts efficacy of postoperative radiation therapy in nonmetastatic Merkel cell carcinoma: A population-based analysis

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    Background: After radical resection of a nonmetastatic Merkel cell carcinoma (M0 MCC), postoperative radiation therapy (RT) is recommended as it improves survival. However, the role of RT in specific subgroups of M0 MCC is unclear. We sought to identify whether there is a differential survival benefit from RT in specific M0 MCC patient subgroups. Methods: M0 MCC patients from the Surveillance, Epidemiology, and End Results (SEER) database registry were collected. The best prognostic age, tumor size, and lymph node ratio (LNR, ratio between positive lymph nodes and resected lymph nodes) cutoffs were calculated. The primary endpoint was overall survival (OS). Results: A total of 5644 M0 MCC patients (median age 77 years, 62% male) were included: 4022 (71%) node-negative (N0) and 1551 (28%) node-positive (N+). Overall, 2682 patients (48%) received RT. Age > 76.5 years, tumor size >13.5 mm, and LNR >0.215 were associated with worse OS. RT was associated with longer OS in the M0 MCC, N0, and N+ group and independently associated with a 25%, 27%, and 26% reduction in the risk for death, respectively. RT benefit on survival was increased in tumor size >13.5 mm in the N0 group and LNR >0.215 in the N+ group. No OS benefit from RT was observed in T4 tumors (N0 and N+ groups). Conclusions: RT was associated with improved survival in M0 MCC, irrespective of the nodal status. LNR >0.215 is a useful prognostic factor for clinical decision-making and for stratification and interpretation of clinical trials

    Indexed left atrial volume, C-reactive protein and erythrocyte sedimentation rate as predictors of recurrence of non-valvular atrial fibrillation after successful cardioversion

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    Indexed left atrial volume, C-reactive protein and erythrocyte sedimentation rate as predictors of recurrence of non-valvular atrial fibrillation after successful cardioversio

    NGS transcriptomic analysis uncovers the possible resistance mechanisms of olive to Spilocea oleagina leaf spot infection

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    Spilocea oleagina is a dangerous obligate fungal pathogen of olive, feared in the Mediterranean countries, causing Peacock's eye or leaf spot infection, which can lead to a serious yield loss of approximately 20% or higher depending on climatic conditions. Coping with this disease is much more problematic for organic farms. To date, knowledge on the genetic control of possible mechanisms of resistance/low susceptibility is quite limited. In this work, comparative transcriptomic analysis (RNA-seq) was conducted in leaf tissues of a low susceptible cultivar Koroneiki and a high susceptible cultivar Nocellara del Belice, both tested in the field using the NaOH test, considering two stages-"zero sign of disease" and "evident sign of infection". Cultivars showed a very large number of differentially expressed genes (DEGs) in both stages. 'Koroneiki' showed an extensive hormonal crosstalk, involving Abscisic acid (ABA) and ethylene synergistically acting with Jasmonate, with early signaling of the disease and remarkable defense responses against Spilocea through the over-expression of many resistance gene analogs or pathogenesis-related (PR) genes: non-specific lipid-transfer genes (nsLTPs), LRR receptor-like serine/threonine-protein kinase genes, GDSL esterase lipase, defensin Ec-AMP-D2-like, pathogenesis-related leaf protein 6-like, Thaumatin-like gene, Mildew resistance Locus O (MLO) gene, glycine-rich protein (GRP), MADS-box genes, STH-21-like, endochitinases, glucan endo-1,3-beta-glucosidases, and finally, many proteinases. Numerous genes involved in cell wall biogenesis, remodeling, and cell wall-based defense, including lignin synthesis, were also upregulated in the resistant cultivar, indicating the possible role of wall composition in disease resistance. It was remarkable that many transcription factors (TS), some of which involved in Induced Systemic Resistance (ISR), as well as some also involved in abiotic stress response, were found to be uniquely expressed in 'Koroneiki', while 'Nocellara del Belice' was lacking an effective system of defense, expressing genes that overlap with wounding responses, and, to a minor extent, genes related to phenylpropanoid and terpenoid pathways. Only a Thaumatin-like gene was found in both cultivars showing a similar expression. In this work, the genetic factors and mechanism underlying the putative resistance trait against this fungal pathogen were unraveled for the first time and possible target genes for breeding resistant olive genotypes were found

    Indexed left atrial volume is superior to left atrial diameter in predicting nonvalvular atrial fibrillation recurrence after successful cardioversion: a prospective study.

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    BACKGROUND: Although indexed left atrial volume (iLAV) is the most accurate measure of left atrial size, it has not been evaluated prospectively as predictor of recurrence of atrial fibrillation (AFib) after successful cardioversion (CV). METHODS: We prospectively selected 76 patients (mean age 66.1 ± 13.6 years, 65.8% men) with AFib who underwent successful CV. Baseline clinical and echocardiographic characteristics were obtained before CV. LAV was measured using Simpson's method and indexed to body surface area. All patients were scheduled for follow-up visit at 1, 6, 12 months, and then annually. A 24-hour Holter ECG was performed within 6 months and each time the patients reported symptoms suggestive of arrhythmia. RESULTS: The 52 patients (68.4%) with AFib recurrence had larger iLAV (35.5 ± 8.9 mL/m(2) vs 27.0 ± 6.7 mL/m(2) , P < 0.001). Anteroposterior LA diameter was not associated with AFib relapse (OR 1.08, 95% CI: 0.96-1.21, P = 0.09). Each unit increase in iLAV was associated with a 1.15-fold increased risk of recurrence (OR 1.15, 95% CI: 1.06-1.25, P < 0.001). In a multivariable model, iLAV remained the only independent predictor of relapse (adjusted OR 1.14, 95% CI: 1.02-1.28, P = 0.02). The area under ROC curves, generated to compare LA diameter, and iLAV as predictors of AFib recurrence were 0.56 (SE 0.07) versus 0.78 (SE 0.05), respectively (P = 0.003). CONCLUSION: This is the first prospective study to show that larger iLAV, as a more accurate measure of LA remodeling than anteroposterior diameter, is strongly and independently associated with a higher risk of AFib recurrence after CV
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