442 research outputs found
VICAR-DIGITAL image processing system
Computer program corrects various photometic, geometric and frequency response distortions in pictures. The program converts pictures to a number of elements, with each elements optical density quantized to a numerical value. The translated picture is recorded on magnetic tape in digital form for subsequent processing and enhancement by computer
Systems pharmacology approach for prediction of pulmonary and systemic pharmacokinetics and receptor occupancy of inhaled drugs
Pulmonary drug disposition after inhalation is complex involving mechanisms, such as regional drug deposition, dissolution, and mucociliary clearance. This study aimed to develop a systems pharmacology approach to mechanistically describe lung disposition in rats and thereby provide an integrated understanding of the system. When drug- and formulation-specific properties for the poorly soluble drug fluticasone propionate were fed into the model, it proved predictive of the pharmacokinetics and receptor occupancy after intravenous administration and nose-only inhalation. As the model clearly distinguishes among drug-specific, formulation-specific, and system-specific properties, it was possible to identify key determinants of pulmonary selectivity of receptor occupancy of inhaled drugs: slow particle dissolution and slow drug-receptor dissociation. Hence, it enables assessment of factors for lung targeting, including molecular properties, formulation, as well as the physiology of the animal species, thereby providing a general framework for rational drug design and facilitated translation of lung targeting from animal to man
Heat Treatment Process Energy Efficient Design and Optimisation
AbstractEnergy efficiency optimization ICT (Information and Communication Technology) solutions are currently being developed for energy saving in buildings and, to some ex-tent, also for the manufacturing domain. This paper describes an approach and ICT tool developed for manufacturing process energy efficiency optimization, in particular focused on the heat treatment process of steel casting parts. Traditionally this manufacturing process is designed based on experts experience selecting a predefined temperature-time curve provided customer specifications for the resulting steel parts. However this curve can actually be optimised in terms of energy consumption while keeping required mechanical properties. This improved design is what the tool here described provides, using knowledge based approach for process design and multivariate optimisation and simulation techniques for process optimisation
Human skeletal muscle plasmalemma alters its structure to change its Ca2+-handling following heavy-load resistance exercise
High-force eccentric exercise results in sustained increases in cytoplasmic Ca2+ levels ([Ca2+]cyto), which can cause damage to the muscle. Here we report that a heavy-load strength training bout greatly alters the structure of the membrane network inside the fibres, the tubular (t-) system, causing the loss of its predominantly transverse organization and an increase in vacuolation of its longitudinal tubules across adjacent sarcomeres. The transverse tubules and vacuoles displayed distinct Ca2+-handling properties. Both t-system components could take up Ca2+ from the cytoplasm but only transverse tubules supported store-operated Ca2+ entry. The retention of significant amounts of Ca2+ within vacuoles provides an effective mechanism to reduce the total content of Ca2+ within the fibre cytoplasm. We propose this ability can reduce or limit resistance exercise-induced, Ca2+-dependent damage to the fibre by the reduction of [Ca2+]cyto to help maintain fibre viability during the period associated with delayed onset muscle soreness
Balance in single-limb stance after surgically treated ankle fractures: a 14-month follow-up
BACKGROUND: The maintenance of postural control is fundamental for different types of physical activity. This can be measured by having subjects stand on one leg on a force plate. Many studies assessing standing balance have previously been carried out in patients with ankle ligament injuries but not in patients with ankle fractures. The aim of this study was to evaluate whether patients operated on because of an ankle fracture had impaired postural control compared to an uninjured age- and gender-matched control group. METHODS: Fifty-four individuals (patients) operated on because of an ankle fracture were examined 14 months postoperatively. Muscle strength, ankle mobility, and single-limb stance on a force-platform were measured. Average speed of centre of pressure movements and number of movements exceeding 10 mm from the mean value of centre of pressure were registered in the frontal and sagittal planes on a force-platform. Fifty-four age- and gender-matched uninjured individuals (controls) were examined in the single-limb stance test only. The paired Student t-test was used for comparisons between patients' injured and uninjured legs and between side-matched legs within the controls. The independent Student t-test was used for comparisons between patients and controls. The Chi-square test, and when applicable, Fisher's exact test were used for comparisons between groups. Multiple logistic regression was performed to identify factors associated with belonging to the group unable to complete the single-limb stance test on the force-platform. RESULTS: Fourteen of the 54 patients (26%) did not manage to complete the single-limb stance test on the force-platform, whereas all controls managed this (p < 0.001). Age over 45 years was the only factor significantly associated with not managing the test. When not adjusted for age, decreased strength in the ankle plantar flexors and dorsiflexors was significantly associated with not managing the test. In the 40 patients who managed to complete the single-limb stance test no differences were found between the results of patients' injured leg and the side-matched leg of the controls regarding average speed and the number of centre of pressure movements. CONCLUSION: One in four patients operated on because of an ankle fracture had impaired postural control compared to an age- and gender-matched control group. Age over 45 years and decreased strength in the ankle plantar flexors and dorsiflexors were found to be associated with decreased balance performance. Further, longitudinal studies are required to evaluate whether muscle and balance training in the rehabilitation phase may improve postural control
Effect of carbohydrate-protein supplement timing on acute exercise-induced muscle damage
<p>Abstract</p> <p>Purpose</p> <p>To determine if timing of a supplement would have an effect on muscle damage, function and soreness.</p> <p>Methods</p> <p>Twenty-seven untrained men (21 ± 3 yrs) were given a supplement before or after exercise. Subjects were randomly assigned to a pre exercise (n = 9), received carbohydrate/protein drink before exercise and placebo after, a post exercise (n = 9), received placebo before exercise and carbohydrate/protein drink after, or a control group (n = 9), received placebo before and after exercise. Subjects performed 50 eccentric quadriceps contractions on an isokinetic dynamometer. Tests for creatine kinase (CK), maximal voluntary contraction (MVC) and muscle soreness were recorded before exercise and at six, 24, 48, 72, and 96 h post exercise. Repeated measures ANOVA were used to analyze data.</p> <p>Results</p> <p>There were no group by time interactions however, CK significantly increased for all groups when compared to pre exercise (101 ± 43 U/L) reaching a peak at 48 h (661 ± 1178 U/L). MVC was significantly reduced at 24 h by 31.4 ± 14.0%. Muscle soreness was also significantly increased from pre exercise peaking at 48 h.</p> <p>Conclusion</p> <p>Eccentric exercise caused significant muscle damage, loss of strength, and soreness; however timing of ingestion of carbohydrate/protein supplement had no effect.</p
Extramuscular myofascial force transmission alters substantially the acute effects of surgical aponeurotomy: assessment by finite element modeling
Effects of extramuscular myofascial force transmission on the acute effects of aponeurotomy were studied using finite element
modeling and implications of such effects on surgery were discussed. Aponeurotomized EDL muscle of the rat was modeled in
two conditions: (1) fully isolated (2) with intact extramuscular connections. The specific goal was to assess the alterations
in muscle length-force characteristics in relation to sarcomere length distributions and to investigate how the mechanical
mechanism of the intervention is affected if the muscle is not isolated. Major effects of extramuscular myofascial force transmission
were shown on muscle length-force characteristics. In contrast to the identical proximal and distal forces of the aponeurotomized
isolated muscle, substantial proximo-distal force differences were shown for aponeurotomized muscle with extramuscular connections
(for all muscle lengths F
dist > F
prox after distal muscle lengthening). Proximal optimal length did not change whereas distal optimal length was lower (by 0.5 mm).
The optimal forces of the aponeurotomized muscle with extramuscular connections exerted at both proximal and distal tendons
were lower than that of isolated muscle (by 15 and 7%, respectively). The length of the gap separating the two cut ends of
the intervened aponeurosis decreases substantially due to extramuscular myofascial force transmission. The amplitude of the
difference in gap length was muscle length dependent (maximally 11.6% of the gap length of the extramuscularly connected muscle).
Extramuscular myofascial force transmission has substantial effects on distributions of lengths of sarcomeres within the muscle
fiber populations distal and proximal to the location of intervention: (a) Within the distal population, the substantial sarcomere
shortening at the proximal ends of muscle fibers due to the intervention remained unaffected however, extramuscular myofascial
force transmission caused a more pronounced serial distribution towards the distal ends of muscle fibers. (b) In contrast,
extramuscular myofascial force transmission limits the serial distribution of sarcomere lengths shown for the aponeurotomized
isolated muscle in the proximal population. Fiber stress distributions showed that extramuscular myofascial force transmission
causes most sarcomeres within the aponeurotomized muscle to attain lengths favorable for higher force exertion. It is concluded
that acute effects of aponeurotomy on muscular mechanics are affected greatly by extramuscular myofascial force transmission.
Such effects have important implications for the outcome of surgery performed to improve impeded function since muscle in
vivo is not isolated both anatomically and mechanically
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