This work presents the first application of three-dimensional digital image correlation for real-time displacement and strain analysis of a pouch type lithium-ion battery. During the electrochemical ...charge-discharge processes, displacements in the x-, y- and z-directions vary at different states-ofcharge (SOCs) attributed to the expansion and the contraction of the interior structure. The z-displacement is observed to develop and concentrate at the vicinity of the openings of the jelly-roll structure. By resolving the displacement components, the progression and distribution of the surface strains, including principal and von-Mises strains, are computed in the charge-discharge processes. It is shown that the dominant strains are up to 0.12% in the rolling direction of the jelly-roll structure and distribute uniformly on the x-y plane over the surface.
Forming limit curves characterise “mean” failure strains of sheet metals. Safety levels from the curves define the deterministic upper limit of the processing and part design window, which can be ...small for high strength, low formability materials. Effects of heterogeneity of plastic deformation, widely accepted to occur on the microscale, are neglected. Marciniak tests were carried out on aluminium alloys (AA6111-T4, NG5754-O), dual-phase steel (DP600) and mild steel (MS3). Digital image correlation was used to measure the effect of heterogeneity on failure. Heterogeneity, based on strain variance, was modelled with the 2-component Gaussian mixture model, and a framework was proposed to (1) identify the onset of necking and to (2) re-define formability as a probability to failure. The results were “forming maps” in major-minor strain space of contours of constant probability (from probability,
P
= 0 to
P
= 1), which showed how failure risk increased with major strain. The contour bands indicated the unique degree of heterogeneity in each material. NG5754-O had the greatest width (0.07 strain) in plane strain and MS3 the lowest (0.03 strain). This novel characterisation will allow engineers to balance a desired forming window for a component design with the risk to failure of the material.
Introduction of strict glycemic control has increased the risk for hypoglycemia in the intensive care unit. Little is known about the consequences of hypoglycemia in this setting. We examined ...short-term consequences (seizures, coma, and death) of hypoglycemia in the intensive care unit.
All occurrences of hypoglycemia (glucose of <45 mg/dL) in our intensive care unit between September 1, 2002, and September 1, 2004, were identified. Patients with hypoglycemia (n = 156) were matched for time to hypoglycemia with control patients drawn from the at-risk population (nested case control method). Seizures observed within 8 hrs after hypoglycemia were scored. Discharge summaries for cases and controls were reviewed for occurrence of possible hypoglycemia-associated coma and death. A hazard ratio for in-hospital death was calculated with Cox regression analysis.
The hazard ratio for in-hospital death was 1.03 (95% confidence interval, 0.68-1.56; p = .88) in patients with a first occurrence of hypoglycemia relative to the controls without hypoglycemia, corrected for duration of intensive care unit admittance before hypoglycemia, age, sex, and Acute Physiology and Chronic Health Evaluation II score at admission. No cases of hypoglycemia-associated death were reported. Hypoglycemic coma was reported in two patients. Seizures after hypoglycemia were observed in one patient.
In this study, no association between incidental hypoglycemia and mortality was found. However, this data set is too small to definitely exclude the possibility that hypoglycemia is associated with intensive care unit mortality. In three patients with possible hypoglycemia-associated coma or seizures, a causal role for hypoglycemia seemed likely but could not fully be established.
In the present study, WC-12Co coating has been deposited using plasma spray and high velocity oxyfuel spraying (HVOF) and wear performances of these coatings have been compared with electroplated ...hard chrome. Bearing steel and WC-Co balls have been used as rubbing counterparts. The wear is predominantly adhesive for the atmospheric plasma spray (APS) and the electroplated coating. For HVOF coating, wear has been found to occur by localised microfracture. A careful choice of plasma spray parameters yields a coating more wear resistant than the electroplated hard chrome. However, the HVOF coating has always offered the highest wear resistance.
ObjectivesThe aim of this multicentre COVID-PREDICT study (a nationwide observational cohort study that aims to better understand clinical course of COVID-19 and to predict which COVID-19 patients ...should receive which treatment and which type of care) was to determine the association between atrial fibrillation (AF) and mortality, intensive care unit (ICU) admission, complications and discharge destination in hospitalised COVID-19 patients.SettingData from a historical cohort study in eight hospitals (both academic and non-academic) in the Netherlands between January 2020 and July 2021 were used in this study.Participants3064 hospitalised COVID-19 patients >18 years old.Primary and secondary outcome measuresThe primary outcome was the incidence of new-onset AF during hospitalisation. Secondary outcomes were the association between new-onset AF (vs prevalent or non-AF) and mortality, ICU admissions, complications and discharge destination, performed by univariable and multivariable logistic regression analyses.ResultsOf the 3064 included patients (60.6% men, median age: 65 years, IQR 55–75 years), 72 (2.3%) patients had prevalent AF and 164 (5.4%) patients developed new-onset AF during hospitalisation. Compared with patients without AF, patients with new-onset AF had a higher incidence of death (adjusted OR (aOR) 1.71, 95% CI 1.17 to 2.59) an ICU admission (aOR 5.45, 95% CI 3.90 to 7.61). Mortality was non-significantly different between patients with prevalent AF and those with new-onset AF (aOR 0.97, 95% CI 0.53 to 1.76). However, new-onset AF was associated with a higher incidence of ICU admission and complications compared with prevalent AF (OR 6.34, 95% CI 2.95 to 13.63, OR 3.04, 95% CI 1.67 to 5.55, respectively).ConclusionNew-onset AF was associated with an increased incidence of death, ICU admission, complications and a lower chance to be discharged home. These effects were far less pronounced in patients with prevalent AF. Therefore, new-onset AF seems to represent a marker of disease severity, rather than a cause of adverse outcomes.
PurposeThe purpose of the study was to evaluate the efficacy and safety of intravitreal pirfenidone for inhibition of proliferative vitreoretinopathy (PVR) in a model of penetrating ocular ...injury.Patients and methodsPenetrating trauma was induced on the retina of rabbit and treated either with 0.1 ml of phosphate-buffered saline (PBS) or 0.1 ml of 0.5% pirfenidone, and development of PVR was evaluated clinically and graded after 1 month. Histopathology and immunohistochemistry with transforming growth factor beta (TGFβ), alpha smooth muscle actin (αSMA), and collagen-1 were performed to assess the fibrotic changes. Expression of cytokines in the vitro-retinal tissues at different time points following pirfenidone and PBS injection was examined by RT-PCR. Availability of pirfenidone in the vitreous of rabbit at various time points was determined by high-performance liquid chromatography following injection of 0.1 ml of 0.5% pirfenidone. In normal rabbit eye, 0.1 ml of 0.5% pirfenidone was injected to evaluate any toxic effect.ResultsClinical assessment and grading revealed prevention of PVR formation in pirfenidone-treated animals, gross histology, and histopathology confirmed the observation. Immunohistochemistry showed prevention in the expression of collagen-I, αSMA, and TGFβ in the pirfenidone-treated eyes compared to the PBS-treated eyes. Pirfenidone inhibited increased gene expression of cytokines observed in control eyes. Pirfenidone could be detected up to 48 h in the vitreous of rabbit eye following single intravitreal injection. Pirfenidone did not show any adverse effect following intravitreal injection; eyes were devoid of any abnormal clinical sign, intraocular pressure, and electroretinography did not show any significant change and histology of retina remained unchanged.ConclusionThis animal study shows that pirfenidone might be a potential therapy for PVR. Further clinical study will be useful to evaluate the clinical application of pirfenidone.
To evaluate the association between overweight and obesity on the clinical course and outcomes in patients hospitalized with COVID-19.
Retrospective, observational cohort study.
We performed a ...multicenter, retrospective, observational cohort study of hospitalized COVID-19 patients to evaluate the associations between overweight and obesity on the clinical course and outcomes.
Out of 1634 hospitalized COVID-19 patients, 473 (28.9%) had normal weight, 669 (40.9%) were overweight, and 492 (30.1%) were obese. Patients who were overweight or had obesity were younger, and there were more women in the obese group. Normal-weight patients more often had pre-existing conditions such as malignancy, or were organ recipients. During admission, patients who were overweight or had obesity had an increased probability of acute respiratory distress syndrome OR 1.70 (1.26-2.30) and 1.40 (1.01-1.96), respectively and acute kidney failure OR 2.29 (1.28-3.76) and 1.92 (1.06-3.48), respectively. Length of hospital stay was similar between groups. The overall in-hospital mortality rate was 27.7%, and multivariate logistic regression analyses showed that overweight and obesity were not associated with increased mortality compared to normal-weight patients.
In this study, overweight and obesity were associated with acute respiratory distress syndrome and acute kidney injury, but not with in-hospital mortality nor length of hospital stay.
Laboratory source X-ray scattering set-up has been used to determine the complete morphology and structure of an optically important composite thin film. Analysis of grazing incidence small angle ...X-ray scattering, X-ray reflectivity and powder diffraction data of Au/LiNbO3thin film prepared by sequential deposition of gold and lithium niobate on float glass substrate suggest that the Au-nanocrystallites are dispersed in amorphous medium, which although have average separation but do not have any long range periodicity other than growth or z-direction. The morphology of the nanocomposite thin film determined through X-ray scattering measurements agrees well with the measured optical absorption.
The influence of the pH value of an aqueous solution of P123 micelles on the growth and formation of gold nanoparticles (AuNPs), which is of immense importance for their controlled growth in a ...simple, single-step synthesis process, was investigated using time-evolution optical absorption spectroscopy, dynamic light scattering and transmission electron microscopy techniques. The sizes and structures of the AuNPs are found to be pH-dependent, even within the basic region, with a transition near pH 9.5, though the free P123 micelles remain almost unchanged. Below this pH value, the slow reduction rate of the gold ions creates a lower number of nucleation centers, which, through an autocatalytic thermodynamically controlled reduction (ATCR), initially formed chain-like aggregated small AuNPs (of different chain lengths) and subsequently, through further diffusion and coalescence, formed well-faceted near symmetrical large AuNPs of size >19 nm, the size of the free P123 micelles. Above this pH value, the fast reduction rate of the gold ions creates a large number of nucleation centers, the growth of which is restricted by the limited amount of available gold ions for the ATCR and also by the metal-polymer hydrophobic and polymer-water hydrophilic interactions. Accordingly, controlled growth of the majority of the centers takes place through ATCR, diffusion and early capping with near individual micelles to form isolated symmetric small AuNPs of size <19 nm, with a narrow size distribution, which are desirable for different applications and fundamental studies. However, a minority (but not insignificant amount) of the centers still remain in very small sizes and are trapped inside large micellar assemblies or even in the near atomic states, which limit the yield of the isolated small AuNPs.
The transition of the structure and size of AuNPs at a pH value around 9.5, from slowly grown, well-faceted, large (>19 nm), less uniform and near connected to fast grown, near symmetrical, small (<19 nm), more uniform and well-separated, is observed.
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