97 research outputs found

    The Modeling of Anisotropic Fuselage Lining Material

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    In this paper a theoretical model that can account for the effect of lining anisotropy on sound transmission through fuselage structures is developed. The model allows for anisotropic flow resistivity, tortuosity and elastic moduli. Implicit to the theory is a characteristic dispersion relation of sixth order that yields the allowed wave numbers for wave propagation in anisotropic elastic porous media. In addition, explicit expressions for field variables such as displacements and stresses appropriate for anisotropic foams are derived. Predictions of random incidence sound transmission loss for double panels with anisotropic linings have been performed. To verify the prediction, the theoretical results have been compared with random incidence transmission loss measurements

    Clinical and organizational factors associated with mortality during the peak of first COVID-19 wave: the global UNITE-COVID study

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    Purpose: To accommodate the unprecedented number of critically ill patients with pneumonia caused by coronavirus disease 2019 (COVID-19) expansion of the capacity of intensive care unit (ICU) to clinical areas not previously used for critical care was necessary. We describe the global burden of COVID-19 admissions and the clinical and organizational characteristics associated with outcomes in critically ill COVID-19 patients. Methods: Multicenter, international, point prevalence study, including adult patients with SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) and a diagnosis of COVID-19 admitted to ICU between February 15th and May 15th, 2020. Results: 4994 patients from 280 ICUs in 46 countries were included. Included ICUs increased their total capacity from 4931 to 7630 beds, deploying personnel from other areas. Overall, 1986 (39.8%) patients were admitted to surge capacity beds. Invasive ventilation at admission was present in 2325 (46.5%) patients and was required during ICU stay in 85.8% of patients. 60-day mortality was 33.9% (IQR across units: 20%–50%) and ICU mortality 32.7%. Older age, invasive mechanical ventilation, and acute kidney injury (AKI) were associated with increased mortality. These associations were also confirmed specifically in mechanically ventilated patients. Admission to surge capacity beds was not associated with mortality, even after controlling for other factors. Conclusions: ICUs responded to the increase in COVID-19 patients by increasing bed availability and staff, admitting up to 40% of patients in surge capacity beds. Although mortality in this population was high, admission to a surge capacity bed was not associated with increased mortality. Older age, invasive mechanical ventilation, and AKI were identified as the strongest predictors of mortality

    Co-infection and ICU-acquired infection in COIVD-19 ICU patients: a secondary analysis of the UNITE-COVID data set

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    Background: The COVID-19 pandemic presented major challenges for critical care facilities worldwide. Infections which develop alongside or subsequent to viral pneumonitis are a challenge under sporadic and pandemic conditions; however, data have suggested that patterns of these differ between COVID-19 and other viral pneumonitides. This secondary analysis aimed to explore patterns of co-infection and intensive care unit-acquired infections (ICU-AI) and the relationship to use of corticosteroids in a large, international cohort of critically ill COVID-19 patients.Methods: This is a multicenter, international, observational study, including adult patients with PCR-confirmed COVID-19 diagnosis admitted to ICUs at the peak of wave one of COVID-19 (February 15th to May 15th, 2020). Data collected included investigator-assessed co-infection at ICU admission, infection acquired in ICU, infection with multi-drug resistant organisms (MDRO) and antibiotic use. Frequencies were compared by Pearson's Chi-squared and continuous variables by Mann-Whitney U test. Propensity score matching for variables associated with ICU-acquired infection was undertaken using R library MatchIT using the "full" matching method.Results: Data were available from 4994 patients. Bacterial co-infection at admission was detected in 716 patients (14%), whilst 85% of patients received antibiotics at that stage. ICU-AI developed in 2715 (54%). The most common ICU-AI was bacterial pneumonia (44% of infections), whilst 9% of patients developed fungal pneumonia; 25% of infections involved MDRO. Patients developing infections in ICU had greater antimicrobial exposure than those without such infections. Incident density (ICU-AI per 1000 ICU days) was in considerable excess of reports from pre-pandemic surveillance. Corticosteroid use was heterogenous between ICUs. In univariate analysis, 58% of patients receiving corticosteroids and 43% of those not receiving steroids developed ICU-AI. Adjusting for potential confounders in the propensity-matched cohort, 71% of patients receiving corticosteroids developed ICU-AI vs 52% of those not receiving corticosteroids. Duration of corticosteroid therapy was also associated with development of ICU-AI and infection with an MDRO.Conclusions: In patients with severe COVID-19 in the first wave, co-infection at admission to ICU was relatively rare but antibiotic use was in substantial excess to that indication. ICU-AI were common and were significantly associated with use of corticosteroids

    Point-of-care testing and treatment of sexually transmitted and genital infections to improve birth outcomes in high-burden, low-resource settings (WANTAIM): a pragmatic cluster randomised crossover trial in Papua New Guinea.

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    Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and bacterial vaginosis have been associated with adverse maternal and perinatal outcomes, but there is conflicting evidence on the benefits of antenatal screening and treatment for these conditions. We aimed to determine the effect of antenatal point-of-care testing and immediate treatment of C trachomatis, N gonorrhoeae, T vaginalis, and bacterial vaginosis on preterm birth, low birthweight, and other adverse maternal and perinatal outcomes compared with current standard of care, which included symptom-based treatment without laboratory confirmation. In this pragmatic cluster randomised crossover trial, we enrolled women (aged ≥16 years) attending an antenatal clinic at 26 weeks' gestation or earlier (confirmed by obstetric ultrasound), living within approximately 1 h drive of a study clinic, and able to provide reliable contact details at ten primary health facilities and their catchment communities (clusters) in Papua New Guinea. Clusters were randomly allocated 1:1 to receive either the intervention or control (standard care) in the first phase of the trial. Following an interval (washout period) of 2-3 months at the end of the first phase, each cluster crossed over to the other group. Randomisation was stratified by province. Individual participants were informed about trial group allocation only after completing informed consent procedures. The primary outcome was a composite of preterm birth (livebirth before 37 weeks' gestation), low birthweight (<2500 g), or both, analysed according to the intention-to-treat population. This study is registered with ISRCTN Registry, ISRCTN37134032, and is completed. Between July 26, 2017, and Aug 30, 2021, 4526 women were enrolled (2210 [63·3%] of 3492 women in the intervention group and 2316 [62·8%] of 3687 in the control group). Primary outcome data were available for 4297 (94·9%) newborn babies of 4526 women. The proportion of preterm birth, low birthweight, or both, in the intervention group, expressed as the mean of crude proportions across clusters, was 18·8% (SD 4·7%) compared with 17·8% in the control group (risk ratio [RR] 1·06, 95% CI 0·78-1·42; p=0·67). There were 1052 serious adverse events reported (566 in the intervention group and 486 in the control group) among 929 trial participants, and no differences by trial group. Point-of-care testing and treatment of C trachomatis, N gonorrhoeae, T vaginalis, and bacterial vaginosis did not reduce preterm birth or low birthweight compared with standard care. Within the subgroup of women with N gonorrhoeae, there was a substantial reduction in the primary outcome

    Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study

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    Background Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave. Methods This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs. Results Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; p = 0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; p ≤ 0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; p = 0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; p = 0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; p = 0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI − 0.47, 1.37, p = 0.34) and hospital (adj. difference 1.4 days; 95% CI − 0.62, 2.35, p = 0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, p = 0.24) when adjusted for covariates. Conclusions Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility. Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)

    Urfa, İstanbul and Aleppo in Nâbî's Poems [Nâbî'ni·n şi·i·rleri·nde Urfa, İstanbul, Halep]

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    Nâbî who lived in the second half of the seventeenth century; has been known as the founder and the most important representative of profound style old Turkish poetry, namely hikemi şiir during his time and after. Urfa, Aleppo and İstanbul are the three important cities where Nâbî lived. He was born in Urfa where he spent his childhood years and then he came to İstanbul at the age of his twenties. Among the cities where Nâbî lived; Aleppo is the most important place since he spent most of his life and gained his literary personality there. In other words, Aleppo played an important role for gaining his literary reputation through which he ranked his literary place in our history as the most important poet in hikemi şiir. The Divan he arranged in Aleppo and also Hayriye he wrote the didactic mesnevi for his son there; are among his important works. He was twice in İstanbul for sometimes before he went to and after he left Aleppo. He died in İstanbul. On the other hand, as İstanbul had a various beauties and benefits the city charmed him even though he lived in Aleppo. As a matter of fact, İstanbul helped him as being an Ottoman bureaucrat, a gentleman and also shaping him a respectful poet among the literary figures of that time. His Divan and the work Hayriye contain important information related to his experience he gained especially in Aleppo and İstanbul. In this article Nâbî's life story will be traced by means of above mentioned three cities, first through Urfa and then especially Aleppo and İstanbul by Nâbî's utterance in his Divan and Hayriye

    Transmitting boundary conditions suitable for analysis of dam-reservoir interaction and wave load problems

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    Transmitting boundary conditions (tbcs) are developed, suitable for both boundary and finite element analyses, for the radiation of waves propagating in horizontal direction along a compressible inviscid fluid layer. The derivation of the proposed tbcs uses a completely continuum approach and is based on the spectral properties of radiating waves. The formulation is presented in Fourier space and accommodates the effects due to surface waves, as well as, due to the radiation of waves in viscoelastic foundation. The proposed tbcs may be used in the analyses of both dam-reservoir systems and wave load problems of floating or submerged bodies. Here, for assessment, they are used in the analyses of two simple benchmark problems. The results indicate that, when used in conjunction with boundary element analysis, the proposed tbcs not only improve the prediction of BEM, but also reduce the computational load of the analysis. (C) 2003 Elsevier Science Inc. All rights reserved
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