Effects of a preventive cardiology curriculum on behavioral cardiovascular risk factors and knowledge of medical students

We evaluated a Preventive Cardiology Academic Award (PCAA) program designed to integrate preventive cardiology concepts into the medical school curriculum. Diet, preventive cardiology knowledge, preventive cardiology attitudes, exercise behavior, and body mass index were compared at entrance to medical school and during the graduation year. Complete data were available on 94 students (65 men and 29 women). Similar data from students who graduated in 1987, prior to the introduction of the PCAA curriculum, served as a control. Women showed a significant enhancement in attitude towards cardiovascular disease (CVD) prevention, while both men and women significantly increased their knowledge about CVD prevention. The frequency of planned physical activity decreased significantly in both sexes and men showed a significant increase in body mass index. Men significantly reduced total calories, percent of calories from fat and saturated fat and dietary cholesterol and increased fiber intake. In women, the only significant reduction was in total calories. In comparison to the control class that did not have the program, men receiving the PCAA curriculum reduced dietary cholesterol, dietary fat, saturated fat and monounsaturated fat. Changes in these dietary parameters were nonsignificant for women in comparison to the control class women. Additional analyses showed no systematic secular trends in dietary or other variables in classes entering from 1986 to 1990. We conclude that the PCAA curriculum changes have favorably affected the preventive cardiology knowledge, attitudes and diet of medical students.     

A study of the dynamics of a clapper-to-bell impact with the application of a simplified finite-element model

From an engineering point of view, church bells are structures that, during ringing, are exposed to severe loading conditions. They are damaged due to material wear, fatigue loading, material deficiencies, different clapper-to-bell layouts, ringing conditions, etc. To get an insight into the wear-related damage of bells, experimental investigations and numerical simulations of the local contact between the clapper and the bell were carried out as part of the activities of an EU-funded project called Maintenance and Protection of Bells. In order to make a full-scale comparison between the measured and simulated results a simplified model was set up. In this model the clapper was replaced by a cylinder with a rounded tip that was dropped against a block representing the bell wall. The aim of the simplified model was to study the impact phenomenon in a controlled way and to adapt the numerical model for simulating the local contact. In the article the synthesis of a finite-element model for simulating the cylinder-drop test is presented. The results of the finite-element simulations of repetitive cylinder drops are compared to the data that were measured in the laboratory. The effects of the cylinder material, the cylinder radius and the drop height of the cylinder on the local elastic–plastic behaviour of the cylinder and the block are also presented and discussed.     

The impact of etching during microfabrication on the microstructure and the electrical conductivity of gadolinia-doped ceria thin films

Gadolinia-doped ceria, Ce_0.8Gd_0.2O_1.9−x (CGO), thin films deposited by spray pyrolysis and annealed to different degree of crystallinity between 0% and 95% are exposed to different etchants and etching methods. The attack of the etchants on the CGO thin films is analyzed with respect to changes in microstructure and in-plane electrical conductivity. It is found that amorphous CGO films are dissolved in hydrochloric acid after elongated etching times. Hydrofluoric acid severely attacks CGO thin films after already short times of exposure (1 min), more intense the less crystalline the thin film is. Ar ion etching smoothens the surface of the CGO thin films without considerable removal of material. No microstructural attack of NaOH, CHF₃/O₂ and SF₆/Ar is found. The electrical conductivity is in general only affected when microstructural changes are severe. Therefore, it is concluded that CGO thin films can be well used as functional layers in micro-fabricated devices and that micro-fabrication is, with the exception of hydrofluoric, not harmful for the electrical properties of crystalline CGO thin films.     

Energy storage using weights hydraulically lifted above ground

Renewable energy sources constitute an ever-growing share of the total electrical market; but, the intermittency and instability issues make it difficult to dispatch these sources directly into the grid. Energy storage represents a promising solution to overcome this obstacle. Among energy storage solutions, pumped hydro energy storage is largely considered the most technologically and financially feasible, though having some drawbacks. In this paper, a new design is introduced to address the major challenges associated with the conventional pumped hydro energy storage. The proposed storage solution does not require tall water tank towers or long piping; rendering it more cost effective and implementable. It is also scalable to operate over a wide range of capacities depending on the electrical surpluses. Beyond this, the design provides a constant pressure and faster discharge, furnishing a quick response to instantaneous demand fluctuations.     

Electron microscopy of semithick sections: Advantages for biomedical research

Many transmission electron microscopes are available which can be used to examine biological material in 0.25–0.50-μm-thick sections. When compared to the traditional thin section, these “semithick” sections possess a number of inherent advantages: They can be screened for content with the phase contrast light microscope, they facilitate many types of studies requiring an analysis of serial sections, and they are frequently the optimum thickness for stereomicroscopy. Structures such as microtubule-associated components, as well as structural relationships between cellular constituents, may also be clearly visible in semithick sections which are not visible, or go unnoticed, in thin sections. Together these advantages enable an investigator to obtain a more complete three-dimensional picture of a cell or cell component in a significantly (i.e., up to 90%) shorter period of time than would be required if thin sections were used. Semithick sections may, therefore, make a study feasible which is not approachable, or which is approachable only with great difficulty, by conventional thin sectioning techniques.     

Deltarequirements – Auf den Spuren der Projektrealität

Ohne Zusammenfassung     

The calculation and analysis of the adiabatic temperature of solid combustion reactions

The adiabatic temperature (T_ad) presents a key parameter for the understanding of Solid Combustion Synthesis (SCS) reactions. Based on a generalized treatment of the underlying formalism, a microcomputer program for the calculation and analysis of adiabatic temperatures of SCS reactions is introduced, and representative types of SCS reactions are discussed. Examples include reactions with liquid formation and liquid-solid phase equilibria as well as complex combustion systems with additional inert diluents. The program ADIBAT is fully menu driven and provides graphic presentation of the the reaction temperature vs. the heat of reaction, phase equilibria information, and graphic presentation of the T_ad vs. the diluent concentration.