Analysis and simulations of vibrations of a beam with a slider

A model for vibrations of a beam with a slider is derived, analysed and numerically simulated. It describes a viscoelastic beam that is clamped at one end to a vibrating device, while the other end moves between two stops attached to a slider. The contact is described by the normal compliance or by the Signorini conditions. The existence of weak solutions is established using the theory of set-valued pseudomonotone operators. The model is discretized using fourth-order spatial discretization, the solutions are numerically simulated and their results presented. The dynamics of the vibrations are depicted and so are the noise characteristics of the system.     

Nucleation and growth of nickel by electrodeposition under galvanostatic conditions

The first stages of nickel electrodeposition on amorphous carbon and polycrystalline silver substrates have been studied under galvanostatic conditions. An island growth mode is observed on the two types of substrate. For equivalent conditions the cluster density is higher on silver substrates than on carbon substrates. Dissolution of some nickel clusters is observed a short time after the onset of electrolysis on carbon substrates. This is confirmed by the evolution of the current efficiency and the evolution of the metal surface cluster density as a function of the quantity of electricity.     

Ritualistic evocation of antiquated paradigms.

Comments on J. J. Magnavita's (see record 1993-42219-001) assertion that Freud's purported discovery of unconscious processes and psychic structures "laid the groundwork for the scientific investigation of emotional disorders and techniques for their amelioration." Freud fabricated an architectonic structure from hypothetical constructs that were developed over 150 yrs of psychophilosophical and clinical investigations of psychotherapy. The concepts popularized by Freud are often seen as increasingly antiquated or as impediments to a contemporary science of the mind. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrinsic, thermal and hygroscopic residual stresses in thin gas-barrier films on polymer substrates

Intrinsic, thermal, and hygroscopic contributions to the in-plane residual stress in silicon nitride films on polyimide substrates are identified, based on iso-hygric thermal ramps and isothermal relative humidity jumps, combined with non-linear elastic modeling of the resulting dynamics of film curvature. This approach enables the thermal and hygroscopic properties of thin nitride films to be determined and provides useful input for material and process control.     

Effect of cholesterol reduction by simvastatin on progression of coronary atherosclerosis: Design, baseline characteristics, and progress of the Multicenter Anti-Atheroma Study (MAAS)

The Multicenter Anti-Atheroma Study (MAAS) is a 2 + 2-year, placebo-controlled trial to evaluate the effect of simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme a (HMG-CoA) reductase inhibitor, on progression and regression of coronary atherosclerosis in patients with established coronary artery disease. This paper describes the aims, methodology, and baseline data. Patients with at least two coronary segments visibly involved with atherosclerosis, in whom an angiogram was carried out according to the standards required for quantitative analysis, were selected provided that the serum total cholesterol was between 5.5 and 8.0 mmol/L and fasting triglycerides were lower than 4 mmol/L. Between march 1988 and October 1989, 383 eligible patients of both sexes aged 30-67 years were randomized in 11 European clinics. Patients received either 20 mg oral simvastatin or placebo daily for 2 years in addition to dietary counseling. The primary outcome measures are the change in the mean absolute width and in the mean of the minimal width of segments analyzed quantitatively by coronary angiography performed before and after 2 and 4 years of trial medication. To this end, at least 5 coronary artery segments are analyzed in each angiogram using matched view. The 2-year analysis was completed on 89% of eligible patients in February 1992. The trial was initially designed with a 2-year treatment period. To allow for the possibility to extend this, the decision was taken to keep all patients on the original medication allocation until all 2-year angiograms had been analyzed. Based on a predefined decision rule, an independent committee then recommended extension of treatment with another 2 years, to be concluded by a third angiogram. Of the patients enrolled initially, 81% continued. Four-year follow-up will be completed late 1993 and final results are expected mid 1994.     

Development and pilot testing of the Neuromuscular Blockade Advisory System

The neuromuscular blocker advisory system (NMBAS) is a computer program developed to provide advisory guidance to anesthesiologists on the timing and dose of rocuronium to paralyze patients during surgery. It is believed that the use of such a system will administer the minimally effective amount of drug, maintaining the patient in a state of paralysis that is useful for surgery yet easily reversible. This will improve patient safety and result in more efficient care. In this paper we present the NMBAS, its basic methodology, and its development though a pilot study. Novel methods of handling neuromuscular response data are presented, including relaxation measurement and the enhanced-train-of-four sensing modality. New methods of handling nonlinearities at the neuromuscular junction to allow application of adaptive control techniques are presented. A novel form of modelling combining model swapping and RLSE adaptation to accommodate the patient variation seen with NMB drugs is introduced. A pilot study testing the NMBAS was undergone to prepare the NMBAS for application in a full clinical trial, in which patients undergoing prostate brachytherapy surgeries using rocuronium for intubation were admitted.     

Antioxidant enzyme activities in beef in relation to oxidation of lipid and myoglobin

Lipid- and oxy-free radical generation has been implicated in oxidative processes which occur during meat maturation but the importance of the antioxidant enzyme (AOE) activity in these processes is not known. It was shown that metmyoglobin (MetMb) % and lipofuscin content were higher in colour-unstable muscles such as psoas major (PM) and diaphragma (D) compared to longissimus lumborum (LL) and tensor fasciae latae (TFL). Although Superoxide dismutase (SOD) activity is higher post mortem in PM and D muscles than in LL and TFL muscles, catalase and glutathione peroxidase (GPx) activities were higher only in D muscle. The higher AOE activity in colour-unstable muscles such as PM and D was not sufficient to prevent increased formation of MetMb and lipofuscin in these muscles compared to LL and TFL muscles.     

A semi‐adaptive control approach to closed‐loop medication infusion

This paper presents a semi‐adaptive control approach to closed‐loop medication infusion problems. The rationale underlying this approach is to design a controller that can adapt model parameters with a large impact on the model's fidelity while fixing the remaining parameters at nominal values. In this paper, a control‐oriented model for this purpose is derived via system identification and sensitivity analysis of a low‐order model capturing the direct dose‐response relationship Using the model thus derived, a model‐reference adaptive controller and a composite adaptive controller are designed and compared with each other. In‐silico simulation results using remifentanil's effect on respiratory rate as an example indicate that both controllers can regulate the output at commanded set points. Copyright © 2016 John Wiley & Sons, Ltd.     

Extraction and characterization of highly purified collagen from bovine pericardium for potential bioengineering applications

Bovine pericardium is widely used as a raw material in bioengineering as a source of collagen, a fundamental structural molecule. The physical, chemical, and biocompatibility characteristics of these natural fibers enable their broad use in several areas of the health sciences. For these applications, it is important to obtain collagen of the highest possible purity. The lack of a method to produce these pure biocompatible materials using simple and economically feasible techniques presents a major challenge to their production on an industrial scale. This study aimed to extract, purify, and characterize the type I collagen protein originating from bovine pericardium, considered to be an abundant tissue resource. The pericardium tissue was collected from male animals at slaughter age. Pieces of bovine pericardium were enzymatically digested, followed by a novel protocol developed for protein purification using ion-exchange chromatography. The material was extensively characterized by electrophoresis, scanning electron microscopy, energy dispersive X-ray spectroscopy, and infrared spectroscopy. The results showed a purified material with morphological properties and chemical functionalities compatible with type I collagen and similar to a highly purified commercial collagen. Thus, an innovative and relatively simple processing method was developed to extract and purify type I collagen from bovine tissue with potential applications as a biomaterial for regenerative tissue engineering.