2,794 research outputs found
Innovative Concept Model Design for Linking Physicians to the System of Patient-Centered Care with Advancing Technologies in the World of Diabetes
This concept paper applies the concepts of complex sociotechnical engineering systems to the care and management of type 2 diabetes. It also includes an innovative design model that integrates the existing ecosystem of care and management of diabetes. This model could potentially improve quality of care, create transparency of information between patient and physician and decrease the overall cost of care of diabetes
Homogeneous Gold Catalysis through Relativistic Effects: Addition of Water to Propyne
In the catalytic addition of water to propyne the Au(III) catalyst is not
stable under non-relativistic conditions and dissociates into a Au(I) compound
and Cl2. This implies that one link in the chain of events in the catalytic
cycle is broken and relativity may well be seen as the reason why Au(III)
compounds are effective catalysts.Comment: 12 pages, 3 figures, 1 tabl
Prototype system development for wireless vehicle speed monitoring
Vehicle speed monitoring and management of the associated data in an intelligent and efficient way is an important issue in modern transportation system in order to reduce road accidents. The aim of this work is to develop an automatic wireless system for monitoring vehicle speed on the road, identify a speeding vehicle and imposing penalty for the speeding offenders. In this work, a prototype system has been developed in a laboratory environment to generate random speed data using a mechanical wheel, measure the speed data with a Shimmer wireless sensor and transfer the data wirelessly to a client computer for further analysis. Software has been developed using a Java based socket programming technique to monitor the vehicle speed in a server computer and to send the data associated with a speeding vehicle to a remotely placed client computer. The graphical user interface (GUI) can visually display the speed of a vehicle at any particular time. The functionality of the software has been tested by simulating different traffic scenarios with low and high speed limits (40 and 60 km/hr respectively). To do that a high or low speed limit can be set in the GUI. The mechanical wheel is run at different speeds and the GUI continuously displays the speed. If the vehicle speed is higher than the set speed limit for the road, the system automatically detects it and generates a report with the time of speeding, vehicle number, vehicle speed etc. to be saved in the client computer in order to take further necessary actions for the speeding offender
Experimental and Numerical Investigation of Therapeutic Ultrasound Angioplasty
Therapeutic ultrasound angioplasty is an emerging minimally invasive cardiovascular surgical procedure that involves the delivery of ultrasonic displacements to the distal-tip of small diameter wire waveguides. The ultrasonic distal-tip displacements affect atherosclerotic plaque and thrombus by direct contact ablation, pressure wave components and cavitation, in addition to an acoustic streaming event around the distal-tip. This study uses experimental and numerical methods to investigate ultrasonic displacements in wire waveguides and the effect the distal-tip displacements have on the surrounding fluid. An experimental therapeutic ultrasound wire waveguide apparatus is described that delivers displacements to the distal-tip of 1.0 mm and tapered 0.35 mm diameter nickel-titanium (NiTi) waveguides. The operating frequency of the apparatus has been experimentally determined to be 23.5 kHz and for the power settings tested delivers displacements of up to 85 µm peak-to-peak (p-p) to the distal-tip of 1.0 mm diameter waveguides. The apparatus has been shown to directly ablate calcified materials with a stiffer response when compared with atherosclerotic plaques and to generate cavitation and acoustic streaming. A coupled fluid-structure numerical model of the waveguide and fluid surrounding the distal-tip has been developed that predicts the waveguide displacements and stresses along the entire length of the wire waveguide. The structural results of the model have been validated against experimental measurements of the displacements of the waveguide with the inclusion of a constant damping value of 4.5%. The fluid results of the model predict the pressure amplitudes developed in the surrounding fluid and compare closely with values reported in literature. The model predicts the distal-tip displacements required to cause cavitation, a major disruptive event, and has been compared with experimental observations made with the ultrasonic wire waveguide apparatus. The waveguide numerical model will prove a valuable design tool in the further development and improvement of this emerging cardiovascular technology
Are non-diabetic women with abnormal glucose screening test at increased risk of pre-eclampsia, macrosomia and caesarian birth?
To determine, in non-diabetic women, the relationship of abnormal glucose screening test, with the incidence of pre-eclampsia, macrosomia and caesarian delivery, from 1988-92, 5646 consecutive women attending antenatal clinic were screened with a glucose challenge test (GCT) on their first visit (usually at 16-20 weeks); those with risk factors i.e., history of unexplained perinatal loss, macrosomia or family member with diabetes and an initial abnormal screening test were rescreened at 28-32 weeks, In 482 cases the GCT was abnormal (plasma glucose value was \u3e140 mg% 2 hours after 75g glucose challenge). Of these, 292 had one or more abnormal critical values at a 75g -3 hour oral glucose tolerance test (GTT) and they were treated to maintain euglycaemia. The rest (n=190) had no evidence of glucose intolerance with no abnormal values at the GTT. The subjects were divided into 3 groups based on GCT values; A, randomly selected subjects with a normal GCT (n=1000); B, those with abnormal GCT but normal GTT (n=190); and C, those with abnormal GTT (n=292). The variables studied were age, gravidity, parity, gestational age at delivery, pre-eclampsia, birth-weight and mode of delivery. The incidence of pre-eclampsia and caesarian birth varied, being the lowest in Group A (3.9% and 11.9% respectively) and then rising through group B (6.3% and 16.3% respectively) to the highest in Group C (12.6% and 26.0% respectively; test of linear trend, p\u3c0.05). For macrosomia, the incidence increased from Group A to B but there was a drop in Group C. The incidence of macrosomia was significantly higher for Group B as compared to A or C (9.5% and 3.3%,
Electrical performance of zinc oxide varistor using powders processed by different latex binders
The critical electrical parameters such as I-V characteristics, watt-loss and energy absorption
capability etc. are the determinants for performance evaluation of ZnO varistors. In this regard there are a large number of contributing variables. Selection of proper binder in the processing of electro-ceramic powder is also a crucial factor. It imparts green strength, enhances
compressibility and reduces density gradient within the green discs. Grain growth during sintering and subsequent microstructure of the varistor is also highly influenced by the binder system. It is envisaged that a disc with higher mechanical strength could be capable of withstanding more thermal stress due to temperature gradients. The energy absorption capability as well as high current performance can thus be enhanced. It was possible to generate varistor discs from the powder processed by the latex binder with better electrical performance than that of the powder processed with conventional binder of polyvinyl alcohol. Factorial analysis showed that the level of binder and solid concentration in the slurry had great influence on the
energy absorption capability of ZnO varistor
A Numerical Acoustic Fluid-structure Model of a Therapeutic Ultrasound Angioplasty Device
Ultrasonic angioplasty involves the use of ultrasonic vibrations delivered to the distal-tip of small diameter wire waveguides and is an emerging technology the may have potential use in the treatment of complicated atherosclerotic plaques during cardiovascular surgery. Complicated plaques, including chronic total occlusions and calcified lesions, seriously reduce success rates during standard intervention involving guidewire access, followed by balloon dilation or stent delivery. The large amplitude (0-150 μm) wire waveguide distal-tip displacements in the low-frequency ultrasonic (18-45 kHz) range have been shown to disrupt plaque material by direct contact ablation and cavitation, acoustic streaming and pressure wave components in adjacent fluid 1. The effects on this surrounding fluid are complex and are related to the distal-tip geometry, frequency of operation, vibration amplitude, as well as the operating environment, including, fluid properties and boundary conditions. While the majority of work to date on ultrasound angioplasty has focused on experimental and clinical studies 2, 3, further understanding of distal-tip effects is necessary. This work describes a numerical fluid-structure model of the wire waveguide distal-tip and is used to predict the pressures developed in the fluid region near the tip wall, the acoustic pressure field and, with the inclusion of appropriate threshold intensity, when cavitation will occur. The model has been validated against experimental acoustic pressure field results reported in the literature. The model can be further used to predict the effects of parameters such as distal-tip geometry, displacement amplitude and frequency of operation and will prove a valuable design aid in the choice of optimum powers to disrupt various biological materials
Fast upsetting of circular cylinders of aluminium metal matrix composites: experimental results and numerical analysis
Cylindrical specimens of Al/Cu and Al/Li metal matrix composite (MMC) were subjected to dynamic compression at room temperature using an experimental drop hammer. Force-time and displacement-time traces were recorded. The experimental results are compared with theoretical results obtained using finite-difference analysis proposed in a previous paper by the authors [1]. The computational results obtained for the force-time histories agree reasonably with the experimental observation. Effect of strain rate and thermal softening on the mechanical behaviour of Al/Cu MMC and Al/Li MMC were examined
Biomechanics of the infant foot during the transition to independent walking : a narrative review
Recognising structural and functional development of the paediatric foot is fundamental to ensuring a strong theoretical framework for health professionals and scientists. The transition of an infant from sitting to walking takes approximately 9 months and is when the structures and function of the foot must respond to the challenges of bearing load; becoming increasingly more essential for locomotion. Literature pertaining to the phase of development was searched. A narrative approach synthesised the information from papers written in English, with non-symptomatic infant participants up to the development stage of independent walking or two years of age. A range of literature was identified documenting morphological, physiological, neuromuscular and biomechanical aspects of the infant within this phase of development. The progression of variable gait to a regular pattern is documented within a range of studies focusing on neuromuscular control and ambulation development. However, methodological approaches may have compromised the external validity of such data. Additionally, limited consideration for the specific function and development of the foot is evident, despite its role as the primary site of weight bearing and interface with the floor. A lack of consideration of infants prior to ambulation (i.e. before cruising or walking) is also apparent which prevents a reference baseline being used effectively. This review also identifies future research priorities such that a comprehensive understanding of foot development from a non-weight bearing to a weight bearing structure during locomotor advancement can be gained
Frequency and type of toenail tumors in the dromedary camel
A total of 275 dromedary camels (16 males and 259 females) of local “Arabiyat” breed suffering from different types and degrees of severity of toenail tumors were surgically treated. Histopathological examination of the tissue samples removed from 50 tumor-like growths (2 males and 48 females) revealed three types of tumors; squamous cell carcinoma (70%), spiny keratoderma (22%) and fibroma (8%). An increased incidence of tumors was recorded in the medial when compared to the lateral toenails in both sexes. In females, the incidence in the medial toenails was 90/259 (34.75%) and 71/259 (27.41%) in the right and left forelimbs respectively when compared to the lateral toenails which was 25/259 (9.65%) and 5/259 (1.93%) for the respective right and left forelimbs. In the hind limbs, this ratio was 29/259 (11.20%) and 20/259 (7.72%) for right and left medial toenails respectively, whereas it was 17/259 (6.56%) and 2/259 (0.77%) for the right and left lateral toenails respectively. Similar to the observations in female camels, male camels also showed a higher incidence of these tumors in the medial when compared to the lateral toenails in both fore and hind limbs. Based on these findings, we conclude that in the dromedary camels, the medial toenails of the fore limbs are most commonly affected with tumors; with the most common tumor being the squamous cell carcinoma
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