Results of single-fibre pull-out tests reflect a combination of adhesive, cohesive and frictional phenomena that complicate micromechanical modelling and the relation to composite properties. SEM ...images of fracture surfaces detected cohesive fracture and unstable crack propagation during pull-out of well sized fibres out of both ductile and brittle matrices. New non-destructive methods have been used to characterize the physical properties of interphases. Atomic force microscopy in force modulation mode has visualized interphases of 1 to 3
μm thickness and gradients depending on the fibre–matrix model composite. The single fibre dynamic load test has been shown to be a feasible tool for determination of fibre–matrix adhesion or friction and ductility of matrix.
Abstract Decreased β-cell mass reflects a shift from quiescence/proliferation into apoptosis, it plays a crucial role in the pathophysiology of diabetes. A major attempt to restore β-cell mass and ...normoglycemia is to improve β-cell survival. Here we show that switching off the Fas pathway using Fas apoptotic inhibitory protein (Faim/TOSO), which regulates apoptosis upstream of caspase 8, blocked β-cell apoptosis and increased proliferation in human islets. TOSO was clearly expressed in pancreatic β-cells and down-regulated in T2DM. TOSO expression correlated with β-cell turnover; at conditions of improved survival, TOSO was induced. In contrast, TOSO downregulation induced β-cell apoptosis. Although TOSO overexpression resulted in a 3-fold induction of proliferation, proliferating β-cells showed a very limited capacity to undergo multiple rounds of replication. Our data suggest that TOSO is an important regulator of β-cell turnover and switches β-cell apoptosis into proliferation.
Gas–particle flows are present in many industrial applications such as polymerization, fluid catalytic cracking, chemical vapor deposition, combustion and drying. Particle–particle, particle–wall and ...gas–particle interactions cause electrostatic charge to form on particles. The motion of charged particles creates an electric field, affecting the hydrodynamics in reactors such as polymerization fluidized beds and fluid catalytic crackers (Hendrickson, 2006). In this work, a combined multi-fluid and electrostatic model previously developed in Rokkam et al. (2010) is used to simulate laboratory-scale experiments on electrostatics in gas–solid fluidized beds conducted by Sowinski et al. (2010). The fluidized-bed experiments were operated in two flow regimes, bubbling and slug flow. Charge-to-mass ratio (q/m) measured in the experiments was used as an input to the computational fluid dynamic (CFD) electrostatic model. Particle-phase segregation from CFD simulations with electrostatic forces compared well with experimental measurements and observations.
Mean volume fraction of wall particles in bubbling-bed simulations with refined grid (a) charged, (b) left wall near the distributor, (c) left wall near the distributor with different ranges. Display omitted
► A Faraday cup technique is used to study the electrostatics in fluidized-bed. ► The measured particle charge is used as an input to the multiphase CFD model. ► The CFD multiphase model predicted the segregation observed in experiments.
Sarcopenia has been identified as an independent risk factor for dysphagia. Dysphagia is one of the most important and prognostically relevant complications of acute stroke. The role of muscle ...atrophy as a contributing factor for the occurrence of poststroke dysphagia is yet unclear.
To assess whether there is a correlation between age and muscle volume and whether muscle volume is related to dysphagia in acute stroke patients.
This retrospective, single-center study included 73 patients with acute ischemic or hemorrhagic stroke who underwent computed tomography angiography on admission and an objective dysphagia assessment by Fiberoptic Endoscopic Evaluation of Swallowing within 72 hours from admission. With the help of semiautomated muscle segmentation and 3-dimensional reconstruction volumetry of the digastric, temporal, and geniohyoid muscles was performed. For further analysis, participants were first divided into 4 groups according to their age (<61 years, n = 12; 61-75 years, n = 16; 76-85 years, n = 28; ≥86 years, n = 17), secondly into 3 different groups according to their dysphagia severity using the Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS) (FEDSS 1 and 2, n = 25; FEDSS 3 and 4, n = 32; FEDSS 5 and 6, n = 16).
Correlation of muscle volumes with age and dysphagia severity.
Muscle volumes of single muscles (except for geniohyoid and the right digastric muscles) as well as the sum muscle volume were significantly and inversely related to dysphagia severity. We found a significant decline of muscle volume with advancing age for most muscle groups and, in particular, for the total muscle volume.
Apart from features being determined by the acute stroke itself (eg, site and size of stroke), also premorbid conditions, in particular age-related muscle atrophy, have an impact on the complex pathophysiology of swallowing disorders poststroke.
The Raman scattering spectra of polyoxyethyleneglycols were obtained vs. water solution concentration and temperature for two polymers (the molecular weight 1500 and 2000). On the basis of the ...characteristic frequency data of atomic group vibration in organic compounds, the characteristic bands observed in the Raman spectra for polyoxyethyleneglycols have been assigned. The temperature ranges of the phase transition and the changes in the order parameters for the first time on the basis of the Raman spectra have been estimated from the temperature dependence of the phonon band parameters. Moreover, the shape of the O–H band vs. water polymer solution concentration has been examined.
Dysphagia is a common complication of critical illness, and many known risk factors are also present in critically ill coronavirus disease 2019 victims.
To investigate dysphagia in patients with ...severe coronavirus disease 2019.
In this case series, we report results of dedicated evaluation of swallowing function in six consecutive, tracheotomized coronavirus disease 2019 patients after they had survived acute respiratory distress syndrome and were weaned from the respirator.
Dysphagia was assessed with flexible endoscopic evaluation of swallowing.
Three patients suffered from severe dysphagia and airway compromise precluding decannulation, whereas in the other, three swallowing was less critically impaired, and the tracheal cannula could be removed. Four patients presented with additional laryngeal dysfunctions not typically seen in acute respiratory distress syndrome survivors.
Dysphagia with impaired airway protection is a key feature in coronavirus disease 2019 acute respiratory distress syndrome survivors. Apart from critical illness polyneuropathy, coronavirus disease 2019-related involvement of the peripheral and central nervous system may contribute to swallowing impairment and laryngeal dysfunction.
The use of continuous in-line blood gas management (CILBGM) is steeped in controversy concerning its potential utility and impact on patient outcomes. The purpose of this study was to determine ...whether the use of CILBGM results in improved quality of patient care. Fifty-nine patients were enrolled in a Institutional Review Board-approved, prospective, randomized study. An in-line blood gas monitor (CDI 500) was placed into the arterial and venous lines for all patients. Blood gas monitoring in the control group was managed by intermittent sampling (every 20-30 min), while the treatment group was managed with continuous monitoring. There were no differences between groups in preoperative, surgical, anesthetic, or perfusion variables. The accuracy of the in-line monitor was comparable to laboratory analysis for arterial blood gas parameters (N = 160; pH bias = 0.00; PaCO2 bias = -1.1 mmHg; and PaO2 bias = 0.7 mmHg). There was less deviation from target values (pH = 7.40, PaCO2 = 40 mmHg, PaO2 = 150-200 mmHg) when in-line monitoring was used versus intermittent sampling (N = 784; pH deviation = 0.05 +/- 0.03 vs. 0.03 +/- 0.01, p < 0.0001; PaCO2 deviation = 4.0 +/- 2.9 mmHg vs. 2.0 +/- 0.9 mmHg, p < 0.0001; and PaO2 deviation = 22.7 +/- 16.9 mmHg vs. 11.7 +/- 8.3 mmHg, p < 0.0001). In conclusion, the results of part I of this study demonstrate that the use of CILBGM results in more accurate blood gas management during CPB.
The impact of blood gas management during cardiopulmonary bypass (CPB) on patient care has not been examined and remains controversial. The purpose of this study was to determine whether precise ...blood gas management during CPB influences patient outcome. Fifty-nine patients were enrolled in an Institutional Review Board-approved, prospective, randomized study. An in-line blood gas monitor (CDI 500) was placed into the arterial and venous lines for all patients. Blood gas monitoring in the control group was managed by intermittent sampling (every 20-30 min), while the treatment group was managed with continuous monitoring. Blood gas control and measured parameters were as follows: pH 7.40 +/- 0.05, PaCO2 40 +/- 5 mmHg, PaO2 200 +/- 50 mmHg. The treatment group had the CDI 500 guide clinical decisions. Compared to the control group, the treatment group consisted of significantly more diabetic (7% vs. 47%, p < or = 0.001), renal failure (3% vs. 13%, p < or = 0.01), and chronic obstructive pulmonary disease patients (7% vs. 20%, p < or = 0.01). Internal thoracic artery utilization was higher in treatment patients than control patients (67% vs. 95%, p < or = 0.02). No other differences existed in demographic, pharmacological, surgical, or anesthetic parameters. In the perioperative period, the control group required antiarrythmic support more frequently than the treatment group (10% vs. 0%, p < or = 0.05). Compared to the control group, the treatment group required antiarrythmic (18% vs. 10%, p < or = 0.05) and cardiac glycoside therapy (11% vs. 0%, p < or = 0.05) less frequently in the postoperative period. Although treatment patients required less intraoperative pacing and cardioversion and spent less time on mechanical ventilation, in the intensive care unit (ICU), and in the hospital than control patients, statistical significance was not achieved. In conclusion, the use of continuous, in-line blood gas monitoring resulted in improvement in a number of postoperative outcome variables, although ICU and hospital stay was not effected.
PDF
