1,761 research outputs found
Osteosarcoma presentation stages at a tumour unit in South Africa
Background. Osteosarcoma is the most common malignant bonetumour found in children and adolescents. Changed treatment protocols have resulted in improved survival and the opportunity for limb salvage surgery. Despite these advances, the outcome is mainly determined by the stage of disease at presentation, making early referral to a tumour unit essential.Methods. Between July 2009 and October 2011, 25 consecutive patients were diagnosed with biopsy-confirmed osteosarcoma. Their records were reviewed and information extracted regarding clinical presentation, histological subtype and stage of disease.Results. Twenty-four patients met the inclusion and exclusion criteria. Conventional osteosarcoma was the most common histological diagnosis encountered; 16 out of 24 (66.7%) patients had metastases at presentation; 6 of the remaining had advanced local disease with very large tumours or pathological fractures that precluded limb salvage surgery.Conclusion. The great majority of patients referred to our tumour unit present with locally advanced or metastatic disease, which limits treatment options and adversely affects survival. Increased awareness, a high index of suspicion and appropriate early referral is crucial to enable limb salvage surgery and increase disease-free survival rates
A comparison between the effects of two cropping methods on the meat quality of impala (Aepyceros melampus)
Impala (Aepyceros melampus) constitute one of the most commercially important species in game farming in South Africa. The purpose of this study was to compare the effects of day and night cropping on the meat quality characteristics of impala. Emphasis was placed on the influence of the cropping method on muscle pH45 (45 minutes post mortem), pHu (ultimate pH), pH decline, and the related influence on drip loss, cooking loss, toughness and colour of the meat in the M. longissimus lumborum. Measurements taken from 16 animals cropped at night were compared to those taken from 24 animals cropped in daytime. A mean pH45 of 6.67 + 0.11 was recorded for the night cropped animals compared to a mean pH45 of 6.55 + 0.23 for the day cropped animals. A mean pHu of 5.39 + 0.08 for animals cropped at night was recorded compared to a mean pHu of 5.45 + 0.11 for the animals cropped in the day. Regression analysis showed the rate of pH decline to be slower in the night cropped animals compared to those cropped in the day. This persisted when the pH values were adjusted to correct for ambient temperature. The cooling rate of the M. longissimus lumborum was twice as fast in the night cropped group. Shear force values and drip losses respectively, for the night-cropped animals were 19.11 + 5.68 g/mm2 and 2.93 + 1.59%, whereas for the day cropped animals the values were 23.42 + 8.13 g/mm2 and 4.15 + 2.34%. The results of this study indicate that night-time cropping does have a beneficial effect on certain meat quality parameters.
Keywords: Meat quality, Impala, Cropping methods
South African Journal of Animal Science Vol.33(4) 2003: 233-24
Primary Production and Nutrient Content in Two Salt Marsh
Seasonal variation patterns of aboveground and belowground biomass, net primary production, and nutrient
accumulation were assessed in Atriplex portulacoides L. and Limoniastrum monopetalum (L.) Boiss. in Castro Marim salt marsh,
Portugal. Sampling was conducted for five periods during 2001–2002 (autumn, winter, spring, summer, and autumn). This
study indicates that both species have a clear seasonal variation pattern for both aboveground and belowground biomass.
Mean live biomass was 2516 g m22 yr21 for L. monopetalum and 598 g m22 yr21 for A. portulacoides. Peak living biomass, in
spring for both species, was three times greater in the former, 3502 g m22 yr21, than in the latter, 1077 g m22 yr21. For both
the Smalley (Groenendijk 1984) and Weigert and Evans (1964) methods, productivity of L. monopetalum (2917 and
3635 g m22 yr21, respectively) was greater than that of A. portulacoides (1002 and 1615 g m22 yr21, respectively). Belowground
biomass of L. monopetalum was 1.7 times greater than that of A. portulacoides. In spite of this, the root:shoot ratio for A.
portulacoides was greater throughout the year. This shows that A. portulacoides allocates more biomass to roots and L.
monopetalum to aerial components. Leaf area index was similar for both species, but specific leaf area of A. portulacoides was
twice that of L. monopetalum. The greatest nutrient contents were found in leaves. Leaf nitrogen content was maximum in
summer for both species (14.6 mg g21 for A. portulacoides and 15.5 mg g21 for L. monopetalum). Leaf phosphorus
concentration was minimum in summer (1.1 mg g21 in A. portulacoides and 1.2 mg g21 in L. monopetalum). Leaf potassium
contents in A. portulacoides were around three times greater than in L. monopetalum. Leaf calcium contents in L. monopetalum
were three times greater than in A. portulacoides. There was a pronounced seasonal variation of calcium content in the former,
while in the latter no clear variation was registered. Both species exhibited a decrease in magnesium leaf contents in the
summer period. Manganese content in L. monopetalum leaves was tenfold that in A. portulacoides. Seasonal patterns of nutrient
contents in A. portulacoides and L. monopetalum suggest that availability of these elements was not a limiting factor to biomass production
Left ventricular false aneurysm characterized by cardiovascular magnetic resonance and late enhancement technique
Left ventricular pseudoaneurysm is a rare
complication of myocardial infarction.
Differentiation between true and false aneurysms,
although difficult, is crucial, because of the
different treatment options they entail.
We present a rare case of a giant pseudoaneurysm
of the left ventricle related with a previous
myocardial infarction. The present case highlights
the pivotal role of magnetic resonance imaging
for differential diagnosis between these entities
Left ventricular false aneurysm characterized by cardiovascular magnetic resonance and late enhancement technique
Left ventricular pseudoaneurysm is a rare
complication of myocardial infarction.
Differentiation between true and false aneurysms,
although difficult, is crucial, because of the
different treatment options they entail.
We present a rare case of a giant pseudoaneurysm
of the left ventricle related with a previous
myocardial infarction. The present case highlights
the pivotal role of magnetic resonance imaging
for differential diagnosis between these entities
25-state calculation for e(-)-Na-2 scattering
We use the Schwinger multichannel method with pseudopotentials to study low energy e(-)-Na-2 scattering. Our cross sections, for impact energies from 0 to 10 eV, include polarization effects and up to 25 open channels related to all electronic states lying below 3.5 eV. Our results predict prominent threshold effects due to a very intense coupling between the B(1)Pi(u) state and the elastic channel in an energy region where there is no experimental data. Our total 25-state cross sections are in very good agreement with available experimental data for energies below about 4 eV. [S0031-9007(98)07561-9].81183832383
Comparison Between Maximum Inspiratory Pressure Measured By A Digital Manometer And By An Electronic Inspiratory Muscle Training Device
Aims: To compare maximum inspiratory pressure (MIP) measured by a digital manometer and by an inspiratory muscle training (IMT) device and to evaluate hemodynamic changes after measurements. Methods: The sample included male and female individuals older than 18 years admitted to an intensive care unit who were hemodynamically stable, not being treated with vasoactive drugs or sedated, intubated or tracheostomized, and who were in the process of being weaned from mechanical ventilation. MIP was measured by both devices on three different occasions, with an occlusion time of 20 seconds and a 5-minute interval between measurements. The following parameters were assessed: respiratory rate, mean arterial pressure, and respiratory rate before and after each measurement by each device. The statistical analysis was made in the Statistical Analysis System and the R Project for Statistical Computing V. 3.1.2 softwares, using the ANOVA and the Wilcoxon tests. Results: Fifty-eight patients were included in the study. The mean value obtained for MIP was -46.22 centimeters of water (cmH(2)O) in the digital manometer and -13.15 cmH(2)O (p<0.001) in the IMT device. Heart rate showed a significant increase (p<0.0001) both before and after all measurements in both devices. Mean arterial pressure showed a statistically significant difference only before and after the first measurement by the digital manometer and before and after the second measurement by the IMT device (p<0.001). The respiratory rate oscillated significantly before and after the three measurements by both devices (p<0.0001). The hemodynamic parameters remained within reference values after MIP measurements. Conclusions: The digital manometer recorded a higher MIP than that measured by the IMT device. The hemodynamic parameter values oscillated in both devices, but they remained within the normal range and were not clinically significant.2
Comparison Between Maximum Inspiratory Pressure Measured By A Digital Manometer And By An Electronic Inspiratory Muscle Training Device
To compare maximum inspiratory pressure (MIP) measured by a digital manometer and by an inspiratory muscle training (IMT) device and to evaluate hemodynamic changes after measurements. Methods: The sample included male and female individuals older than 18 years admitted to an intensive care unit who were hemodynamically stable, not being treated with vasoactive drugs or sedated, intubated or tracheostomized, and who were in the process of being weaned from mechanical ventilation. MIP was measured by both devices on three different occasions, with an occlusion time of 20 seconds and a 5-minute interval between measurements. The following parameters were assessed: respiratory rate, mean arterial pressure, and respiratory rate before and after each measurement by each device. The statistical analysis was made in the Statistical Analysis System and the R Project for Statistical Computing V. 3.1.2 softwares, using the ANOVA and the Wilcoxon tests. Results: Fifty-eight patients were included in the study. The mean value obtained for MIP was -46.22 centimeters of water (cmH(2)O) in the digital manometer and -13.15 cmH(2)O (p<0.001) in the IMT device. Heart rate showed a significant increase (p<0.0001) both before and after all measurements in both devices. Mean arterial pressure showed a statistically significant difference only before and after the first measurement by the digital manometer and before and after the second measurement by the IMT device (p<0.001). The respiratory rate oscillated significantly before and after the three measurements by both devices (p<0.0001). The hemodynamic parameters remained within reference values after MIP measurements. Conclusions: The digital manometer recorded a higher MIP than that measured by the IMT device. The hemodynamic parameter values oscillated in both devices, but they remained within the normal range and were not clinically significant.2
Effect of band anisotropy on electronic structure of PbS, PbSe, and PbTe quantum dots
We have calculated the electronic structure of spherical PbS, PbSe, and PbTe quantum dots using a four-band envelope-function formalism that accounts for band anisotropy. By comparing our results with an analytical calculation that assumes a spherical approximation of the (k) over right arrow.(p) over right arrow Hamiltonian, we show that the effects of band anisotropy are more pronounced for the excited states and increase with the confinement. We also show how the same technique can be applied to ellipsoidal quantum dots.62117357736
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