362 research outputs found

    Design of a large span-distributed load flying-wing cargo airplane with laminar flow control

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    A design study was conducted to add laminar flow control to a previously design span-distributed load airplane while maintaining constant range and payload. With laminar flow control applied to 100 percent of the wing and vertical tail chords, the empty weight increased by 4.2 percent, the drag decreased by 27.4 percent, the required engine thrust decreased by 14.8 percent, and the fuel consumption decreased by 21.8 percent. When laminar flow control was applied to a lesser extent of the chord (approximately 80 percent), the empty weight increased by 3.4 percent, the drag decreased by 20.0 percent, the required engine thrust decreased by 13.0 percent, and the fuel consumption decreased by 16.2 percent. In both cases the required take-off gross weight of the aircraft was less than the original turbulent aircraft

    Preliminary design characteristics of a subsonic business jet concept employing laminar flow control

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    Aircraft configurations were developed with laminar flow control (LFC) and without LFC. The LFC configuration had approximately eleven percent less parasite drag and a seven percent increase in the maximum lift-to drag ratio. Although these aerodynamic advantages were partially offset by the additional weight of the LFC system, the LFC aircraft burned from six to eight percent less fuel for comparable missions. For the trans-atlantic design mission with the gross weight fixed, the LFC configuration would carry a greater payload for ten percent fuel per passenger mile

    Preliminary design characteristics of a subsonic business jet concept employing an aspect ratio 25 strut braced wing

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    The advantages of replacing the conventional wing on a transatlantic business jet with a larger, strut braced wing of aspect ratio 25 were evaluated. The lifting struts reduce both the induced drag and structural weight of the heavier, high aspect ratio wing. Compared to the conventional airplane, the strut braced wing design offers significantly higher lift to drag ratios achieved at higher lift coefficients and, consequently, a combination of lower speeds and higher altitudes. The strut braced wing airplane provides fuel savings with an attendant increase in construction costs

    Efficacy and Safety of Q10 Ubiquinol With Vitamins B and E in Neurodevelopmental Disorders: A Retrospective Chart Review

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    Increased oxidative stress and defective mitochondrial functioning are shared features among many brain disorders. The aim of this study was to verify retrospectively the clinical efficacy and safety of a metabolic support therapy with Q10 ubiquinol, vitamin E and complex-B vitamins in various neurodevelopmental disorders. This retrospective chart review study included 59 patients (mean age 10.1 ± 1.2 y.o., range 2.5–39 years; M:F = 2.47:1), diagnosed with Autism Spectrum Disorder (n = 17), Autism Spectrum Disorder with co-morbid Intellectual Disability (n = 19), Intellectual Disability or Global Developmental Delay (n = 15), Attention-Deficit/Hyperactivity Disorder (n = 3) and Intellectual Disability in Phelan-McDermid syndrome due to chr. 22q13.33 deletion (n = 5). After a minimum of 3 months of therapy, a positive outcome was recorded in 45/59 (76.27%) patients, with Clinical Global Impression—Improvement scores ranging between 1 (“very much improved”) and 3 (“minimally improved”). The most widespread improvements were recorded in cognition (n = 26, 44.1%), adaptative functioning (n = 26, 44.1%) and social motivation (n = 19, 32.2%). Improvement rates differed by diagnosis, being observed most consistently in Phelan-McDermid Syndrome (5/5, 100%), followed by Intellectual Disability/Global Developmental Delay (13/15, 86.7%), Autism Spectrum Disorder with co-morbid Intellectual Disability (15/19, 78.9%), Autism Spectrum Disorder (11/17, 64.7%) and ADHD (1/3, 33.3%). No significant adverse event or side effect leading to treatment discontinuation were recorded. Mild side effects were reported in 18 (30.5%) patients, with the most frequent being increased hyperactivity (9/59, 15.3%). This retrospective chart review suggests that metabolic support therapy with Q10 ubiquinol, vitamin E and complex-B vitamins is well tolerated and produces some improvement in the majority of patients with neurodevelopmental disorders, especially in the presence of intellectual disability. Randomized controlled trials for each single neurodevelopmental disorder are now warranted to conclusively demonstrate the efficacy of these mitochondrial bioenergetic and antioxidant agents and to estimate their therapeutic effect size

    Behavioral Restriction Determines Left Attentional Bias: Preliminary Evidences From COVID-19 Lockdown

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    During the COVID-19 lockdown, individuals were forced to remain at home, hence severely limiting the interaction within environmental stimuli, reducing the cognitive load placed on spatial competences. The effects of the behavioral restriction on cognition have been little examined. The present study is aimed at analyzing the effects of lockdown on executive function prominently involved in adapting behavior to new environmental demands. We analyze non-verbal fluency abilities, as indirectly providing a measure of cognitive flexibility to react to spatial changes. Sixteen students (mean age 20.75; SD 1.34), evaluated before the start of the lockdown (T1) in a battery of psychological tasks exploring different cognitive domains, have been reassessed during lockdown (T2). The assessment included the modified Five-Point Test (m-FPT) to analyze non-verbal fluency abilities. At T2, the students were also administered the Toronto Alexithymia Scale (TAS-20). The restriction of behaviors following a lockdown determines increased non-verbal fluency, evidenced by the significant increase of the number of new drawings. We found worsened verbal span, while phonemic verbal fluency remained unchanged. Interestingly, we observed a significant tendency to use the left part of each box in the m-FPT correlated with TAS-20 and with the subscales that assess difficulty in describing and identifying feelings. Although our data were collected from a small sample, they evidence that the restriction of behaviors determines a leftward bias, suggesting a greater activation of the right hemisphere, intrinsically connected with the processing of non-verbal information and with the need to manage an emotional situation

    Detection of SARS-COV N2 Gene: Very low amounts of viral RNA or false positive?

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    Background: The detection of a low amount of viral RNA is crucial to identify a SARS-CoV-2 positive individual harboring a low level of virus, especially during the convalescent period. However, the detection of one gene at high Cycle threshold (Ct) has to be interpreted with caution. In this study we address this specific issue and report our real-life experience. Study design: A total of 1639 nasopharyngeal swabs (NPS) were analyzed with Xpert® Xpress SARS-CoV-2. Positive samples showing high Ct values (Ct>35) were concentrated by centrifugation and re-tested with Cepheid or other methods (RealStar SARS-CoV2 RT-PCR, Altona Diagnostics; GeneFinder COVID-19 Plus RealAmp Kit, Elitech). Results: 1599 (97.5%) negative samples, 36 (2.3%) positive samples and 4 (0.2%) presumptive positive samples were detected. In 17 out of 36 positive patients, very low viral RNA copies were suspected since positivity was detected at high Ct. We confirmed positivity for patients who showed both E and N genes detected and for patients with only N detected but with Ct <39. On the contrary, samples with only gene N detected with Ct values >39 were found negative. NPS taken 24 hours after the first collection confirmed the negativity of the 12 samples. Clinical data sustained these results since only 2 of these 12 patients showed COVID-19-like symptoms. Conclusions: These data support our consideration that detection of the N2 gene at high Ct needs to be interpreted with caution, suggesting that collaboration between virologists and clinicians is important for better understanding of results

    Analysis of viral nucleic acids in duodenal biopsies from adult patients with active celiac disease: in search for an etiological relationship

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    BACKGROUND AND AIM: Celiac Disease (CD) is a multisystemic chronic inflammatory autoimmune disease which develops in genetically predisposed subjects and it is triggered by the ingestion of gluten. After the interaction between HLA-DQ2/DQ8 and gluten-derived peptides, lymphocytes T CD4+ start a specific immune response which ends in a chronic inflammation and mucosal damage. CD pathogenesis is complex and not entirely understood, probably due to an alteration in the gastrointestinal immune system or to its aberrant regulation. Furthermore, many environmental and immune factors could be involved, particularly viral infections. The aim of the study was to observe possible relationships between CD and infections from HHV-6 A/B, EBV, CMV, adenovirus and rotavirus. MATERIAL AND METHODS: Thirty-nine adult patients (aged 18-65 yrs) have been enrolled: specifically, 24 duodenal biopsies from active CD patients and 15 biopsies from non-CD patients were analyzed. CD diagnosis has been performed by means of serological antibodies, histology of duodenal biopsies and duodenal biopsy organ culture. Viral nucleic acids were extracted from duodenal biopsies and then amplified using Real-Time PCR technique. RESULTS: HHV-6B was found in 62.5% of CD patients and in 73.3% of non-CD patients (p=0.13). EBV was found in 4.5% of CD patients and 6.7% of non-CD patients (p=0.35). Nucleic acids from HHV-6A, CMV, adenovirus and rotavirus were not detected in any group. HHV-6B viral load in CD patients was higher than in non-CD patients, but data were not statistically significant (p=0.54). CD patients with HHV-6B viral load >50000 copies/ml resulted to be younger and had lower anti-tTG antibody titers found at organ culture than patients with lower HHV-6B viral load (p>0.05). CONCLUSIONS: There seems to be no difference in viral load and/or in the detection of viruses between CD and non-CD patients. Thus, our data do not support the possible relationship between CD and viral infections, although a larger population is needed to confirm our study results

    Sperm cryopreservation during the SARS-CoV-2 pandemic

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    Purpose: Sperm cryopreservation is fundamental in the management of patients undergoing gonadotoxic treatments. Concerns have risen in relation to SARS-CoV-2 and its potential for testicular involvement, since SARS-CoV-2-positive cryopreserved samples may have unknown effects on fertilization and embryo safety. This study therefore aimed to analyze the safety of sperm cryopreservation for cancer patients after the onset of the pandemic in Italy, through assessment of the risk of SARS-CoV-2 exposure and viral RNA testing of semen samples. Methods: We recruited 10 cancer patients (mean age 30.5 ± 9.6 years) referred to our Sperm Bank during the Italian lockdown (from March 11th to May 4th 2020) who had not undergone a nasopharyngeal swab for SARS-CoV-2 testing. Patients were administered a questionnaire on their exposure to COVID-19, and semen samples were taken. Before cryopreservation, SARS-CoV-2 RNA was extracted from a 150 Âµl aliquot of seminal fluid in toto using QIAamp viral RNA kit (Qiagen) and amplified by a real time RT PCR system (RealStar SARS-CoV2 RT PCR, Altona Diagnostics) targeting the E and S genes. Results: The questionnaire and medical interview revealed that all patients were asymptomatic and had had no previous contact with COVID-19 infected patients. All semen samples were negative for SARS-CoV-2 RNA. Conclusion: This preliminary assessment suggests that a thorough evaluation (especially in the setting of a multidisciplinary team) and molecular confirmation of the absence of SARS-CoV-2 in seminal fluid from asymptomatic cancer patients may assist in ensuring the safety of sperm cryopreservation

    Endovascular Management of Juxtarenal and Pararenal Abdominal Aortic Aneurysms: Role of Chimney Technique

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    The use of chimney technique in endovascular repair of abdominal aortic aneurysms (ChEVAR) has had a secondary role. Although it was first developed in an emergent/urgent setting, the publication of various important studies has helped overcome scepticism towards this technique in elective procedures. This paper reviews current evidence about ChEVAR, focusing on clinical results, technical notes and comparisons with other techniques. The new ChEVAR findings show favourable mid- and long-term clinical outcomes, even in elective patients. These results, comparable to those related to fenestrated endografts, have been achieved through standardisation in planning and materials. An adequate endograft oversizing associated to the right aortic neck length is fundamental to avoid ChEVAR-related complications, such as type 1a endoleaks. These data indicate that ChEVAR, compared to other complex endovascular treatments, has comparable outcomes along with features that could make it an essential option in every clinical settin
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