207 research outputs found

    The Durability of Composite Wood-Steel Systems

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    Nell\u2019ambito della valutazione e del controllo della qualit\ue0 tecnologica in edilizia, la conoscenza del comportamento nel tempo dei prodotti e componenti complessi per l\u2019edilizia, risulta aspetto fondamentale, in particolare per quei prodotti tecnologicamente \u201cinnovativi\u201d per i quali la normativa non prevede ancora prove specifiche per valutarne la durabilit\ue0. In particolare, oggi risulta sempre pi\uf9 diffuso l\u2019impiego di sistemi assemblati o con connessioni tra materiali di diversa natura, tra cui i sistemi legno-acciaio, ottenuti rinforzando le travi in legno lamellare con piastre in acciaio forate, incollati mediante una resina epossidica bicomponente. Tali sistemi, che sono stati gi\ue0 oggetto di sperimentazione sul comportamento a flessione del sistema trave in legno lamellare e solaio collaborante in calcestruzzo, affidano la loro efficacia in riguardo alla resistenza ed alla rigidezza attraverso gli sforzi di taglio e gli spostamenti relativi che in caso di buona collaborazione legno-acciaio sono molto ridotti. Il presente studio si occupa di indagare la durabilit\ue0 delle caratteristiche di aderenza legno-resina-acciaio del sistema, attraverso una sperimentazione condotta su campioni secondo le procedure della normativa ISO 15686. Dopo una prima fase di studio del sistema agenti-azioni-effetti \ue8 stato messo a punto un ciclo di invecchiamento accelerato e sono state effettuate le indagini in laboratorio in camera climatica. Il comportamento della connessione dopo vari livelli di invecchiamento \ue8 stato analizzato attraverso prove meccaniche di resistenza al taglio, azioni cui il sistema \ue8 sottoposto in esercizio, considerando sia le sollecitazioni climatiche che possono condizionare il comportamento dei singoli componenti del sistema: resina, acciaio e legno lamellare, sia il sistema nel suo insieme per cui risulta critico il comportamento all\u2019interfaccia legno-resina e resina-acciaio. I risultati ottenuti hanno fornito indicazioni interessanti sul comportamento del sistema nel tempo. Infatti con l\u2019avanzare dei cicli di invecchiamento si \ue8 manifestata una progressiva riduzione del carico massimo a rottura, mantenendo caratteristiche di rigidezza elevata, con spostamenti relativi ridottissimi anche sui campioni pi\uf9 invecchiati

    Efficacy and Safety of Using High-Flow Nasal Oxygenation in Patients Undergoing Rapid Sequence Intubation.

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    Objective: To assess the efficacy and safety of high-flow nasal oxygen (HFNO) therapy in patients undergoing rapid sequence intubation (RSI) for emergency abdominal surgery. Methods: HFNO of 60 L.min\ue2\u88\u921at an inspiratory oxygen fraction of 1 was delivered 4 min before laryngoscopy and maintained until the patient was intubated, and correct intubation was verified by the appearance of the end-tidal CO2(EtCO2) waveform. Transcutaneous oxygenation (SpO2), heart rate and non-invasive mean arterial pressure were monitored at baseline (T0), after 4 min on HFNO (T1) and at the time of laryngoscopy (T2) and endotracheal intubation (ETI) (T3). An SpO2of <3% from baseline was recorded at any sampled time. The value of EtCO2at T3 was registered after two mechanical breaths. The apnoea time was defined as the time from the end of propofol injection to ETI. RSI was performed with propofol, fentanyl and rocuronium. Results: Forty-five patients were enrolled. SpO2levels showed a statistically significant increase at T1, T2 and T3 compared with those at T0 (p<0.05); median SpO2% (interquartile range) was 97% (range, 96%-99%) at T0, 99% (range, 99%-100%) at T1, 99% (range, 99%-100%) at T2 and 99% (range, 99%-100%) at T3. Minimal SpO2was 96%; no patient showed an SpO2of <3% from baseline; mean EtCO2at the time of ETI was 36\uc2\ub14 mmHg. Maximum apnoea time was 12 min. Conclusion: HFNO is an effective and safe technique for pre-oxygenation in patients undergoing rapid sequence induction of general anaesthesia for emergency surgery

    Tidal Volume Estimation during Helmet Noninvasive Ventilation: an Experimental Feasibility Study

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    We performed a bench (BS) and human (HS) study to test the hypothesis that estimation of tidal volume (VT) during noninvasive helmet pressure support ventilation (nHPSV) would be possible using a turbine driven ventilator (TDV) coupled with an intentional leak single-limb vented circuit. During the BS a mannequin was connected to a lung simulator (LS) and at different conditions of respiratory mechanics, positive end expiratory pressure (PEEP) levels and leaks (30, 50 and 80 L/min). All differences were within the 95% limits of agreement (LoA) in all conditions in the Bland-Altman plot. The overall bias (difference between VT measured by TDV and LS) was 35 ml (95% LoA 10 to 57 ml), 15 ml (95% LoA -40 to 70 ml), 141 ml (95% LoA 109 to 173 ml) in the normal, restrictive and obstructive conditions. The bias at different leaks flow in normal condition was 29 ml (95% LoA 19 to 38 ml). In the HS four healthy volunteers using nHPSV had a pneumotachograph (P) inserted through a mouthpiece to measure subject's VT.The bias showed a scarce clinical relevance. In conclusions, VT estimation seems to be feasible and accurate in all conditions but the obstructive one. Additional leaks seem not to affect VT reliability

    Spatial correlation between dust and Hα emission in dwarf irregular galaxies

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    Using a sample of dwarf irregular galaxies selected from the ALFALFA blind H i-survey and observed using the VIMOS IFU, we investigate the relationship between Hα emission and Balmer optical depth (τb{\tau }_{{\rm{b}}}). We find a positive correlation between Hα luminosity surface density and Balmer optical depth in 8 of 11 at ≥0.8σ significance (6 of 11 at ≥1.0σ) galaxies. Our spaxels have physical scales ranging from 30 to 80 pc, demonstrating that the correlation between these two variables continues to hold down to spatial scales as low as 30 pc. Using the Spearman's rank correlation coefficient to test for correlation between ΣHα{{\rm{\Sigma }}}_{{\rm{H}}\alpha } and τb{\tau }_{{\rm{b}}} in all the galaxies combined, we find ρ=0.39\rho =0.39, indicating a positive correlation at 4σ significance. Our low stellar-mass galaxy results are in agreement with observations of emission line regions in larger spiral galaxies, indicating that this relationship is independent of the size of the galaxy hosting the emission line region. The positive correlation between Hα luminosity and Balmer optical depth within spaxels is consistent with the hypothesis that young star-forming regions are surrounded by dusty birth-clouds

    A case of severe dermatitis in a patient with Polycythemia Vera during cytoreductive therapy

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    Polycythemia Vera (PV) is a Philadelphia-negative chronic myeloproliferative neoplasm (MPN) mainly characterized by erythrocytosis. In this report we describe a case of severe cutaneous toxicity in patients with PV treated with hydroxyurea. A 72-year-old woman diagnosed with PV with V617F mutation of JAK2 performed more than 10 years before and treated with hydroxyurea plus phlebotomies and low-dose ASA for about 7 years addressed our center for the appearance of serious dermatitis at the face symptomatic for severe itch. The patient underwent a dermatology visit with diagnosis of desquamative dermatitis due to iatrogenic cause related to the use of hydroxyurea. HU was stopped for a month with no improvement after a month of wash-out. Ruxolitinib was prescribed at a dose of 20 mg per day, in order to control hypercytosis and considering the severe intolerance to hydroxyurea. Ruxolitinib allowed not only to reduce the haematocrit, reaching the target value of 45%, and control thrombocytosis, but also to switch off the severe itch and to completely resolve skin toxicity

    Deriving a multivariate CO-to-H2_2 conversion function using the [CII]/CO(1-0) ratio and its application to molecular gas scaling relations

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    We present Herschel PACS observations of the [CII] 158 micron emission line in a sample of 24 intermediate mass (9<logM_\ast/M_\odot<10) and low metallicity (0.4< Z/Z_\odot<1.0) galaxies from the xCOLD GASS survey. Combining them with IRAM CO(1-0) measurements, we establish scaling relations between integrated and molecular region [CII]/CO(1-0) luminosity ratios as a function of integrated galaxy properties. A Bayesian analysis reveals that only two parameters, metallicity and offset from the star formation main sequence, Δ\DeltaMS, are needed to quantify variations in the luminosity ratio; metallicity describes the total dust content available to shield CO from UV radiation, while Δ\DeltaMS describes the strength of this radiation field. We connect the [CII]/CO luminosity ratio to the CO-to-H2_2 conversion factor and find a multivariate conversion function αCO\alpha_{CO}, which can be used up to z~2.5. This function depends primarily on metallicity, with a second order dependence on Δ\DeltaMS. We apply this to the full xCOLD GASS and PHIBSS1 surveys and investigate molecular gas scaling relations. We find a flattening of the relation between gas mass fraction and stellar mass at logM_\ast/M_\odot<10. While the molecular gas depletion time varies with sSFR, it is mostly independent of mass, indicating that the low LCO_{CO}/SFR ratios long observed in low mass galaxies are entirely due to photodissociation of CO, and not to an enhanced star formation efficiency.Comment: Submitted to MNRAS, this version after referee comments. 21 page

    Hodgkin's disease presenting below the diaphragm. The experience of the Gruppo Italiano Studio Linfomi (GISL)

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    Background and Objective. Infradiaphragmatic Hodgkin\ub4s disease is rare, making up 5-12% of cases in clinical stages I and II; consequently, several questions concerning prognosis and treatment strategy remain to be answered. The aim of this study was to analyze the clinical and prognostic characteristics and outcome of his condition. Methods. A series of 282 patients with CS I-II Hodgkin\ub4s disease (HD) was investigated. In 31 patients the disease was confined below the diaphragm (BDHD), and in the remaining above the diaphragm (ADHD). The presenting features and outcomes were compared in the two groups. Results. The BDHD group was older (p < 0.0002), had a higher frequency of males (p < 0.08) and a different histological subtype group distribution (p < 0.0001). Stage II BDHD patients had a worse overall survival rate (OS) than stage II ADHD patients (68.8% vs 86.6% at 8 years, p < 0.01) if age is not considered; patients with more than 40 years of age, in fact, had the same survival rates as those with ADHD. BDHD patients with intra-abdominal disease alone had worse prognostic factors and OS (p = 0.12) than patients with inguinal-femoral nodes. Interpretation and Conclusions. Although BDHD patients present distinct features, they have the same OS and relapse-free survival rate as age-adjusted ADHD patients. According to our experience patients with stage I peripheral BDHD respond well to radiotherapy-based regimens. Those with stage II and or intra-abdominal disease are more challenging; chemotherapy or a combined therapy seem to be more suitable approaches for these patients

    Clinical implications of discordant early molecular responses in CML patients treated with imatinib

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    A reduction in BCR-ABL1/ABL1IS transcript levels to &lt;10% after 3 months or &lt;1% after 6 months of tyrosine kinase inhibitor therapy are associated with superior clinical outcomes in chronic myeloid leukemia (CML) patients. In this study, we investigated the reliability of multiple BCR-ABL1 thresholds in predicting treatment outcomes for 184 subjects diagnosed with CML and treated with standard-dose imatinib mesylate (IM). With a median follow-up of 61 months, patients with concordant BCR-ABL1/ABL1IS transcripts below the defined thresholds (10% at 3 months and 1% at 6 months) displayed significantly superior rates of event-free survival (86.1% vs. 26.6%) and deep molecular response (≥ MR4; 71.5% vs. 16.1%) compared to individuals with BCR-ABL1/ABL1IS levels above these defined thresholds. We then analyzed the outcomes of subjects displaying discordant molecular transcripts at 3-and 6-month time points. Among these patients, those with BCR-ABL1/ABL1IS values &gt;10% at 3 months but &lt;1% at 6 months fared significantly better than individuals with BCR-ABL1/ABL1IS &lt;10% at 3 months but &gt;1% at 6 months (event-free survival 68.2% vs. 32.7%; p &lt; 0.001). Likewise, subjects with BCR-ABL1/ABL1IS at 3 months &gt;10% but &lt;1% at 6 months showed a higher cumulative incidence of MR4 compared to patients with BCR-ABL1/ABL1IS &lt;10% at 3 months but &gt;1% at 6 months (75% vs. 18.2%; p &lt; 0.001). Finally, lower BCR-ABL1/GUSIS transcripts at diagnosis were associated with BCR-ABL1/ABL1IS values &lt;1% at 6 months (p &lt; 0.001). Our data suggest that when assessing early molecular responses to therapy, the 6-month BCR-ABL1/ABL1IS level displays a superior prognostic value compared to the 3-month measurement in patients with discordant oncogenic transcripts at these two pivotal time points
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