27 research outputs found
The Need to generate a Force Time History Towards Life Assessment of a Coil Spring / Y.S. Kong...[et al.]
This paper presents the generation of force time history for coil spring fatigue life predictions using cumulative trapezoidal numerical integration of acceleration time histories. Loading time history was a crucial element for fatigue life prediction but a suitable instrument for the data collection was not always available. Hence, the required force time histories were generated from two relative acceleration time histories. Acceleration time histories from vehicle sprung and un-sprung mass were collected and converted into displacement using cumulative trapezoidal numerical integration approach. Through regarding the spring as a linear component, the force time history was obtained. The force time history together with the spring finite element model were used as the input to fatigue life models for fatigue life prediction. The predicted fatigue lives for the coil spring were 3.12× 10-6, 5.67 × 10-6, 6.97 × 10-6 blocks to failure using Coffin-Manson, Morrow, Smith-Watson-Topper model respectively. The results were validated using measured strain time history where the Morrow and Smith-Watson-Topper models’ results were fitted perfectly using the conservative correlation approach
Methods and results of a search for gravitational waves associated with gamma-ray bursts using the GEO 600, LIGO, and Virgo detectors
Paper producido por "The LIGO Scientific Collaboration and the Virgo Collaboration". (En el registro se mencionan solo algunos autores de las decenas de personas que participan).In this paper we report on a search for short-duration gravitational wave bursts in the frequency range 64 Hz–1792 Hz associated with gamma-ray bursts (GRBs), using data from GEO 600 and one of the LIGO or Virgo detectors. We introduce the method of a linear search grid to analyze GRB events with large sky localization uncertainties, for example the localizations provided by the Fermi Gamma-ray Burst Monitor (GBM). Coherent searches for gravitational waves (GWs) can be computationally intensive when the GRB sky position is not well localized, due to the corrections required for the difference in arrival time between
detectors. Using a linear search grid we are able to reduce the computational cost of the analysis by a factor of Oð10Þfor GBM events. Furthermore, we demonstrate that our analysis pipeline can improve upon the sky localization of GRBs detected by the GBM, if a high-frequency GW signal is observed in coincidence. We use the method of the linear grid in a search for GWs associated with 129 GRBs observed satellite-based gamma-ray experiments between 2006 and 2011. The GRBs in our sample had not been previously analyzed for GW counterparts. A fraction of our GRB events are analyzed using data from GEO 600 while
the detector was using squeezed-light states to improve its sensitivity; this is the first search for GWs using data from a squeezed-light interferometric observatory. We find no evidence for GW signals, either with any individual GRB in this sample or with the population as a whole. For each GRB we place lower bounds on the distance to the progenitor, under an assumption of a fixed GWemission energy of 10−2M⊙c2, with a median exclusion distance of 0.8 Mpc for emission at 500 Hz and 0.3 Mpc at 1 kHz. The reduced computational cost associated with a linear search grid will enable rapid searches for GWs associated with
Fermi GBM events once the advanced LIGO and Virgo detectors begin operation.http://journals.aps.org/prd/abstract/10.1103/PhysRevD.89.122004publishedVersionFil: Aasi, J. LIGO. California Institute of Technology; Estados Unidos de América.Fil: Domínguez, E. Argentinian Gravitational Wave Group; Argentina.Fil: Maglione, C. Argentinian Gravitational Wave Group; Argentina.Fil: Reula, O. Argentinian Gravitational Wave Group; Argentina.Fil: Ortega, W. Argentinian Gravitational Wave Group; Argentina.Fil: Wolovick, N. Argentinian Gravitational Wave Group; Argentina.Fil: Schilman, M. Argentinian Gravitational Wave Group; Argentina.Física de Partículas y Campo
Multimessenger Search for Sources of Gravitational Waves and High-Energy Neutrinos: Results for Initial LIGO-Virgo and IceCube
We report the results of a multimessenger search for coincident signals from
the LIGO and Virgo gravitational-wave observatories and the partially completed
IceCube high-energy neutrino detector, including periods of joint operation
between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010
run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79
strings. We find no significant coincident events, and use the search results
to derive upper limits on the rate of joint sources for a range of source
emission parameters. For the optimistic assumption of gravitational-wave
emission energy of \,Mc at \,Hz with \,ms duration, and high-energy neutrino emission of \,erg
comparable to the isotropic gamma-ray energy of gamma-ray bursts, we limit the
source rate below \,Mpcyr. We also examine
how combining information from gravitational waves and neutrinos will aid
discovery in the advanced gravitational-wave detector era
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication
Topological and Topographical Optimization of Automotive Spring Lower Seat
Abstract The design of a suspension system emphasizes weight reduction in this high-computation technology era. Understanding that the reduction of suspension mass can lead to cost and material reduction is important; moreover, the riding performance of the vehicle should be improved. Topology and topography structure optimization for the spring lower seat is performed to reduce the weight of a passenger car spring lower seat design under stress and structure compliance constraints. Topology optimization is performed to identify the density of the required elements, whereas topography optimization is utilized to strengthen the structure of the lower seat by applying bead parameters in the model. Based on topology optimization, the mass of the model is improved by a reduction of 36.5%. Topography optimization is subsequently performed to fine-tune the topology-optimized model. Beads are added to the model to strengthen the stiffness of the structure. The topography-optimized model has successfully increased compliance by 27% compared with the sole topological optimized design. With the combination of topology and topography optimization techniques, the weight of coil spring lower seat has been successfully reduced while preserving the strength. Suitable sheet materials are proposed to match the optimized coil spring lower seat design
Olive Biophenols Reduces Alzheimer's Pathology in SH-SY5Y Cells and APPswe Mice
Alzheimer's disease (AD) is a major neurodegenerative disease, associated with the hallmark proteinacious constituent called amyloid beta (Aβ) of senile plaques. Moreover, it is already established that metals (particularly copper, zinc and iron) have a key role in the pathogenesis of AD. In order to reduce the Aβ plaque burden and overcome the side effects from the synthetic inhibitors, the current study was designed to focus on direct inhibition of with or without metal-induced Aβ fibril formation and aggregation by using olive biophenols. Exposure of neuroblastoma (SH-SY5Y) cells with Aβ42 resulted in decrease of cell viability and morphological changes might be due to severe increase in the reactive oxygen species (ROS). The pre-treated SH-SY5Y cells with olive biophenols were able to attenuate cell death caused by Aβ42, copper- Aβ42, and [laevodihydroxyphenylalanine (l-DOPA)] l-DOPA-Aβ42-induced toxicity after 24 h of treatment. Oleuropein, verbascoside and rutin were the major anti-amyloidogenic compounds. Transgenic mice (APPswe/PS1dE9) received 50 mg/kg of oleuropein containing olive leaf extracts (OLE) or control diet from 7 to 23 weeks of age. Treatment mice (OLE) were showed significantly reduced amyloid plaque deposition (
Olive Biophenols Reduces Alzheimer’s Pathology in SH-SY5Y Cells and APPswe Mice
Alzheimer’s disease (AD) is a major neurodegenerative disease, associated with the hallmark proteinacious constituent called amyloid beta (Aβ) of senile plaques. Moreover, it is already established that metals (particularly copper, zinc and iron) have a key role in the pathogenesis of AD. In order to reduce the Aβ plaque burden and overcome the side effects from the synthetic inhibitors, the current study was designed to focus on direct inhibition of with or without metal-induced Aβ fibril formation and aggregation by using olive biophenols. Exposure of neuroblastoma (SH-SY5Y) cells with Aβ42 resulted in decrease of cell viability and morphological changes might be due to severe increase in the reactive oxygen species (ROS). The pre-treated SH-SY5Y cells with olive biophenols were able to attenuate cell death caused by Aβ42, copper- Aβ42, and [laevodihydroxyphenylalanine (l-DOPA)] l-DOPA-Aβ42-induced toxicity after 24 h of treatment. Oleuropein, verbascoside and rutin were the major anti-amyloidogenic compounds. Transgenic mice (APPswe/PS1dE9) received 50 mg/kg of oleuropein containing olive leaf extracts (OLE) or control diet from 7 to 23 weeks of age. Treatment mice (OLE) were showed significantly reduced amyloid plaque deposition (p < 0.001) in cortex and hippocampus as compared to control mice. Our findings provide a basis for considering natural and low cost biophenols from olive as a promising candidate drug against AD. Further studies warrant to validate and determine the anti-amyloid mechanism, bioavailability as well as permeability of olive biophenols against blood brain barrier in AD
Thigh-length compression stockings and DVT after stroke
Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease