Cardiovascular features in adolescents and adults with sickle cell anaemia

Fifty five sickle cell anaemia (SCA) patients at the Kenyatta National Hospital were studied with a view to elucidating their cardiovascular status. Their age range was 13 to 27 years (median 18.9 years). They comprised 27 males and 28 females and their mean haemoglobin concentration was 8.5 +/- 1.4 g/dl. Haemoglobin level of 8.0-9.9 g/dl seen in 30 patients was noted to confer the lowest incidence of exertional dyspnoea and palpitation. Similarly, patients with this haemoglobin level had the lowest mean heart rate. The mean blood pressure was 114.9 +/- 9.9 mmHg systolic and 64.6 +/- 10 mmHg diastolic. Blood pressures, ejection fraction (EF) and differential fibre shortening (%D) were found to be directly related to haemoglobin level, whereas cardio-thoracic index (CTI) and left ventricular dimensions were inversely related to haemoglobin level. Mean echocardiographic measurements were within normal limits and left ventricular functions were found to be normal in 80.9% of the patients indicating that the majority of SCA patients at the Kenyatta National Hospital have good cardiac function.     

Pressure measurement evaluation and accuracy validation: the Gabarith test

OBJECTIVE: The dynamic distortion introduced by manometric systems has been known for many years, with several methods developed to describe and quantify the degree of distortion. We developed the Gabarith as a technique to describe more accurately, and yet more simply, the dynamic accuracy of the chain of monitoring. SETTING: A pressure monitoring system transforms some input signal, i.e. the actual pressure waveform present in the artery, into some other shape of waveform, i.e. the waveform displayed on the patient monitor. This transformation is characterized by the transfer function of the total system. A complete technique to define the transfer function is to measure the response directly at many different frequencies and combine them to produce the dynamic response plot. METHOD: We described the dynamic response of a monitoring chain and we simplified the communication of this dynamic response to users by developing the Gabarith, as a tolerance envelope based on the frequency content of typical pressure waveforms. If a given monitoring chain's dynamic response (including a catheter, a pressure kit and a monitor) can be shown to fall within that tolerance envelope, the chain will provide adequate dynamic accuracy. CONCLUSION: "Gabarith tested" means that a pressure kit, in combination with a catheter and a monitor, has had its frequency response function measured and that the function falls within a tolerance band for dynamic accuracy. Passing a Gabarith means that a given level of accuracy will be reached when using the sets which have passed the corresponding test.     

Endoscopical management of ureteral trauma

Ureteric injuries are encountered with increasing frequency. Adequate definitions and etiologies are discussed. All treatment modalities are summarised with special attention for the use of JJ stents, the different endourological approaches and "urological pearls".     

Plant-to-Plant Variability in Root Metabolite Profiles of 19 Arabidopsis thaliana Accessions Is Substance-Class-Dependent

Natural variation of secondary metabolism between different accessions of Arabidopsis thaliana (A. thaliana) has been studied extensively. In this study, we extended the natural variation approach by including biological variability (plant-to-plant variability) and analysed root metabolic patterns as well as their variability between plants and naturally occurring accessions. To screen 19 accessions of A. thaliana, comprehensive non-targeted metabolite profiling of single plant root extracts was performed using ultra performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-QTOF-MS) and gas chromatography/electron ionization quadrupole mass spectrometry (GC/EI-QMS). Linear mixed models were applied to dissect the total observed variance. All metabolic profiles pointed towards a larger plant-to-plant variability than natural variation between accessions and variance of experimental batches. Ratios of plant-to-plant to total variability were high and distinct for certain secondary metabolites. None of the investigated accessions displayed a specifically high or low biological variability for these substance classes. This study provides recommendations for future natural variation analyses of glucosinolates, flavonoids, and phenylpropanoids and also reference data for additional substance classes.     

MIKE 3 versus HARTMANN apparatus: comparison of measured minimum ignition energy (MIE)

In this study, MIE values measured with two different explosion tubes, HARTMANN and MIKE 3, are compared. Generally, MIKE 3 apparatus provides MIE results, which are equal or lower to those measured with the HARTMANN apparatus; this is particularly true for the energy ranges between 1 and 10mJ and higher than 100mJ. Differences observed can modify samples classification according to their sensitivity to electrostatic ignition sources. Nevertheless, ignition of a dust cloud by an electrostatic discharge is complex, and implies a different mechanism from that occurring during MIE tests. Thus, it seems difficult to synchronise dust dispersion and spark triggering to obtain optimal concentration in the spark area. Moreover, spark characteristics such as duration or energy feeding rate of spark cannot reproduce exactly industrial-world ones. On this point, it is not possible to conclude if characteristics of MIKE 3 electric circuit, e.g., resistance and inductance, are more relevant than HARTMANN circuit ones.     

Strong morphological and crystallographic texture and resulting yield strength anisotropy in selective laser melted tantalum

Selective laser melting (SLM) makes use of a high energy density laser beam to melt successive layers of metallic powders in order to create functional parts. The energy density of the laser is high enough to melt refractory metals like Ta and produce mechanically sound parts. Furthermore, the localized heat input causes a strong directional cooling and solidification. Epitaxial growth due to partial remelting of the previous layer, competitive growth mechanism and a specific global direction of heat flow during SLM of Ta result in the formation of long columnar grains with a 〈1 1 1〉 preferential crystal orientation along the building direction. The microstructure was visualized using both optical and scanning electron microscopy equipped with electron backscattered diffraction and the global crystallographic texture was measured using X-ray diffraction. The thermal profile around the melt pool was modeled using a pragmatic model for SLM. Furthermore, rotation of the scanning direction between different layers was seen to promote the competitive growth. As a result, the texture strength increased to as large as 4.7 for rotating the scanning direction 90° every layer. By comparison of the yield strength measured by compression tests in different orientations and the averaged Taylor factor calculated using the viscoplastic self-consistent model, it was found that both the morphological and crystallographic texture observed in SLM Ta contribute to yield strength anisotropy.     

Ureteroscopic treatment of ureteric lithiasis. Analysis of 354 urs procedures in a community hospital

This article presents a career ladder for the reappointment and promotion of nontenured clinical faculty, based on Boyer's model of the scholarship of teaching, application, discovery, and integration and on his four principles and six standards. Titles, lengths of appointments, criteria, obligations, and professional development are defined for four levels of clinical faculty. Guide questions modeled on Boyer's dimensions of scholarship, principles, and standards that were used to guide the development of the career ladder are included.