Screen‐printed biosensor for allergens

Allergen levels in indoor environments, leading to many diseases, eg asthma, rhinitis and conjunctivitis, affect a large and increasing fraction of the population. A quite effective and inexpensive method of a rough but very rapid overall assessment of total allergen level in the environment has been developed. The method involved estimation of protein in allergen extracts by screen‐printed electrodes using two different techniques. The biosensor comprised a rhodinised carbon working electrode, a silver/silver chloride reference electrode and a carbon counter electrode. In the first method the enzyme protease reacted with allergen protein to release amino acid, which produced hydrogen peroxide in the presence of amino acid oxidase. This was detected amperometrically. The second method used potassium bromide as electrolyte and the electrode was subjected to dual potential. Bromine, released due to electrolysis at higher potential, was consumed by the allergen protein at lower potential. In the first method, a unique technique was used to microencapsulate the enzyme protease and immobilise it on the surface of the electrode by in‐situ polymerisation to avoid contact with the amino acid oxidase. A total of seven allergens were tested and the results gave a good correlation with the standard protein measurement method. Environmental specimens from indoors, schools and workplaces can be evaluated for the aeroallergens produced by dust mites, animal hairs, cockroach debris, pollens, etc as a means of determining the exposure risk. Copyright © 2005 Society of Chemical Industry     

Integrating heterogeneous distributed COTS discrete-event simulation packages: an emerging standards-based approach

This paper reports on the progress made toward the emergence of standards to support the integration of heterogeneous discrete-event simulations (DESs) created in specialist support tools called commercial-off-the-shelf (COTS) discrete-event simulation packages (CSPs). The general standard for heterogeneous integration in this area has been developed from research in distributed simulation and is the IEEE 1516 standard The High Level Architecture (HLA). However, the specific needs of heterogeneous CSP integration require that the HLA is augmented by additional complementary standards. These are the suite of CSP interoperability (CSPI) standards being developed under the Simulation Interoperability Standards Organization (SISO-http://www.sisostds.org) by the CSPI Product Development Group (CSPI-PDG). The suite consists of several interoperability reference models (IRMs) that outline different integration needs of CSPI, interoperability frameworks (IFs) that define the HLA-based solution to each IRM, appropriate data exchange representations to specify the data exchanged in an IF, and benchmarks termed CSP emulators (CSPEs). This paper contributes to the development of the Type I IF that is intended to represent the HLA-based solution to the problem outlined by the Type I IRM (asynchronous entity passing) by developing the entity transfer specification (ETS) data exchange representation. The use of the ETS in an illustrative case study implemented using a prototype CSPE is shown. This case study also allows us to highlight the importance of event granularity and lookahead in the performance and development of the Type I IF, and to discuss possible methods to automate the capture of appropriate values of lookahead.     

Freestanding Alumina Membrane by Double-Layer Anodization

A novel method has been developed for fabricating full or partial freestanding anodic alumina. In our method a sacrificial metal layer is introduced between an Al film and a Si₃N₄ substrate. A freestanding alumina film at wafer scale is successfully achieved by anodizing the double metal layer, during which the alumina is spontaneously stripped off the Si₃N₄ substrate due to the anodic oxidation of the sacrificial layer. The barrier oxide of the alumina film is effectively removed either by H₃PO₄ dissolution or by CF₄ reactive ion etching. The freestanding alumina film is utilized as a contact mask to transfer its nanoporous pattern to a Si substrate. By patterning the sacrificial metal layer with contact lithography, a partial freestanding alumina film is successfully achieved on the silicon chip, producing a unique micro/nanofluidic channel. Compared with previous techniques, the method reported here is advantageous for its simplicity and flexibility     

A Novel Inverse-Magnetostrictive Force Sensor

The change in magnetic permeability of a material under stress (inverse magnetostriction) offers the potential for a high-performance, low-cost force sensor capable of being used in harsh real-world environments. The existing force sensor technologies are limited in their use in commercial products by either cost issues or susceptibility to electromagnetic noise. Inverse Magnetostriction has been used to measure strain in controlled environments since its discovery by Joule in 1847, but not in practical applications due to a lack of data on how magnetic material properties change with environmental conditions such as temperature. Utilizing an innovative noise-reducing self-inductance design, this paper presents the basis for an inverse-magnetostrictive compressive load sensor. A lumped-parameter model for the change in sensor inductance under load, due to both mechanical and magnetic effects, is derived. The material properties of a magnetostrictive iron alloy are empirically determined over a broad range of loads and temperatures. The model and material properties are confirmed by testing a prototype force sensor. The prototype measures compressive forces from 100 to 25 000 N over a temperature range of 20 degC to 120 deg with a typical error of +/-2% (4% max). The sensor does experience significant thermal hysteresis for which the model does not currently account. This work was motivated by the need for a force sensor in an automobile electric brake system and used a single iron alloy (50% Ni), but the model and testing procedure provide a roadmap for future research to improve the performance and capabilities of such a sensor     

Turning software into a service

The software as a service model composes services dynamically, as needed, by binding several lower-level services-thus overcoming many limitations that constrain traditional software use, deployment, and evolution.     

Creep in polyethylene and hydroxyapatite reinforced polyethylene composites

Isochronous stress-strain relationships and long term creep performance for unfilled and hydroxyapatite filled polyethylene composites have been studied. The tests were carried out in a buffered (pH=7.5) Ringer's solution at 37°C. It was observed that the inclusion of hydroxyapatite does not remove the non-linear viscoelasticity of polyethylene. The creep resistance is found to increase with increase in volume fraction of hydroxyapatite. The creep failure of composites at long times can occur due to debonding of the interface.     

The effects of chronic high dose androgen or estrogen treatment on the human prostate [corrected

Prostate development and disease are androgen dependent. However, the nature of hormonal effects on the prostate of healthy young men is not clear. We, therefore, measured prostate size in males chronically exposed to high doses of androgens (AS; habitual anabolic steroid abusers; n = 15) or estrogens (E; male to female transsexuals; n = 11) and compared the results with those in age-matched healthy eugonadal men without known prostate disorders. Prostate size was measured by planimetric ultrasound as cross-sectional areas and maximal dimensions in three orthogonal dimensions with a 7.5-megahertz B-mode sector scanner biplane in a transrectal transducer at 2.5 mm steps from the base to the apex of prostate. Total prostate volume (TPV) was reconstructed from planimetric sections, central prostate volume (CPV) was calculated by the ellipsoidal formula from the appropriate three maximum dimensions, and peripheral prostate volume was determined by the difference between TPV and CPV. Compared with age-matched controls, TPV was normal (-2%) in AS (P = 0.752) and reduced by 31% in E (P = 0.002), whereas CPV was increased by 20% in AS (P = 0.002) and reduced by 46% in E (P = 0.002), and the ratio of CPV/peripheral prostate volume was increased by 77% in AS (P < 0.001) and decreased by 33% in E (P = 0.047). Blood sex hormone-binding globulin was elevated by nearly 500% in E (P < 0.001), but was reduced by 47% in AS (P = 0.003). Prostate-specific antigen was normal (-6%) in AS (P = 0.799) and decreased by 86% in E (P = 0.002). Prostatic acid phosphatase was increased by 26% in AS (P = 0.007), but was unchanged (-28%) in E (P = 0.106). Total and free testosterone levels were reduced to castrate levels in E, whereas LH, FSH, and total testosterone levels were significantly reduced in AS. We conclude that in the human prostate of young men, CPV is more hormonally sensitive than TPV, and during high dose treatment, CPV is preferentially increased by chronic androgen treatment and decreased by chronic estrogen treatment. The reduction of TPV by estrogens was less than expected if solely attributable to inhibition of endogenous gonadotropin and testosterone secretion, suggesting that estrogens also have a positive effect on the normal human prostate. The reversibility and long term significance of androgen-induced stimulation of CPV and, in particular, its relationship to the onset and severity of benign prostatic hyperplasia remain to be clarified.     

Psychosocial characteristics of adolescents who refuse cancer treatment.

Examined psychosocial variables by comparing 10 13–17 yr old adolescents (and their mothers) who had refused cancer treatment with a group of 10 consenting adolescents who were matched on age and demographic and illness variables. Adolescents completed the State-Trait Anxiety Inventory for Children and measures of family characteristics, locus of control, religion, hopelessness, impact of event, and satisfaction with physician. Mothers completed the State-Trait Anxiety Inventory and measures of coping and religion. Adolescent refusers scored lower on state anxiety and subjective distress but scored higher on trait anxiety, religiosity, and external locus of control. Their mothers also scored higher than did the consenting-group mothers on religiosity and trait anxiety. It is suggested that refusers are prone to anxiety and cope with their present distress by maintaining the belief that their lives are determined by fate or religious convictions. An intervention approach that fosters mastery over the cancer experience is advocated. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correlates of improvement in multidisciplinary treatment of chronic pain.

Although multidisciplinary pain programs have been demonstrated to be effective, the processes of improvement have yet to be clarified. Cognitive-behavioral models posit that improvement is due, in part, to changes in patient pain beliefs and coping strategies. To test the relationships between treatment outcome and changes in beliefs and coping strategies, 94 chronic pain patients (aged 21–64 yrs) completed measures of physical and psychological functioning, health care utilization, pain beliefs, and use of pain coping strategies at admission and 3 to 6 mo after inpatient pain treatment. Improved functioning and decreased health care use were associated with changes in both beliefs and cognitive coping strategies. However, changes in some coping strategies, such as exercise and use of rest, were not associated with improvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Women Engineers: A Study of Educational Preparation and Professional Success

In an effort to better understand the educational experiences and professional issues facing women in these fields, a survey of women alumnae was conducted. Respondents seemed fairly pleased with the education they received and were heavily influenced by personal aspects of the campus. Relationships with faculty members were described as their most beneficial and detrimental experiences. They particularly liked opportunities to apply their technical knowledge but did not believe there were enough opportunities for application. The need for more female role models and importance of involvement in student organizations were cited by many of the respondents. Self-confidence and good communication skills were rated as the most important qualities for professional success and advancement. Alumnae have pursued training experiences since graduation, but would like to see more opportunities to enhance communication and personal management skills and apply theoretical knowledge built into the undergraduate experience. The findings are discussed in relationship to previous research studies and recommendations are made to improve the technically oriented college environment.