Experimental and stochastic analysis of lyophilisation.

The development of the freeze-drying processes through the use of a combination of targeted experiments and the application of multidimensional computational models is applied increasingly in pharmaceutical practice, especially for scale-up purposes. This study deals with the analysis of uncertainties in the data on material properties and model parameters, and their influence on the results delivered by advanced computational models of lyophilisation. As a means of uncertainty analysis, the Stochastic Collocation Method is applied, allowing the use of existing reliable deterministic models as black boxes in the stochastic computations. As a deterministic model, the lyophilisation model is used, based on the axisymmetric approximation of a vial, and the Boundary Element Method as a solver. Five parameters, covering material properties, process conditions and model constants, are selected for the sensitivity analysis simulation of the lyophilisation of an aqueous mannitol solution. The results show that during the initial stage of the primary drying heat transfer from the shelf is crucial, and that the uncertainties in the contact surface area and material properties of the vial play a more important role than the thermal properties of the drying material. When the temperature of the material reaches its distinct primary drying stage level the mass transfer through the porous cake becomes the most important, with great sensitivity to the Knudsen diffusivity in the porous cake. We observed uncertainties in the results for the primary drying time in the order of ±6%, and uncertainties in the results for temperatures of ±0.6°C in the frozen material and ±3°C in the porous cake. The uncertainty analysis proved to be a great help in determining the critical parameters in the heat and mass transfer during the important primary drying step, which led to a better definition of the numerical model for use in the context of design space determination.

Oral and Dental Examination Findings in European Polecats (Mustela putorius).

Dental and oral diseases in the domestic ferret have been reported, but comparison with their closest wild relative, the European polecat (Mustela putorius), is lacking. Dental and orofacial pathology was evaluated by means of visual examination and dental radiographical analysis of 234 museum skulls. Most of these (70.5%) originated from Austria and the remainder came from seven other European countries. Linguoverted mandibular second incisor teeth were noted in 77% of the skulls. There were 7,268 (91.4% of all potential) teeth available for examination. Few (0.3%) were presumed congenitally missing and 0.5% were presumed missing by acquired means. Supernumerary teeth were present in 2.6% of the skulls. Most (65.6%) of the maxillary first molar teeth were three rooted with the palatal root protruding into the orbit. Most (67.2%) of the mandibular first molar teeth were three rooted with the smaller third root being positioned in the furcation of the two larger roots. Thirty-one percent of the teeth were four rooted, with the smaller fourth root also being positioned in the furcation of the two largest roots. Attrition/abrasion was shown by 17.2% of the teeth in 47% of the skulls. Periodontitis was recognized in 57.6% of the teeth in 91.9% of the skulls and dental fractures were noted in 7.2% of the teeth in 62% of the skulls. Radiographical evidence of endodontic disease was found in 25% of the fractured teeth. Tooth resorption, in the form of external inflammatory resorption associated with endodontic disease, was found in 0.1% of teeth in 2.1% of skulls. Extrusion affected 44% of the canine teeth. Lesions consistent with infection by the helminth Troglotrema acutum were identified in 33.3% of the skulls. Oral and dental disease was significant and varied, often consistent with reports of the species domestic counterpart - the ferret. Comparison with other mustelids, notably the beech marten (Martes foina), showed both clear consistencies and discrepancies, dependent on the type of pathology.

Oral and dental diseases in a population of domestic ferrets (Mustela putorius furo).

OBJECTIVE: Domestic ferrets have been used for many purposes, but recently their popularity as companion animals has increased greatly. However, data on their oral and dental diseases are rare. The objective of this study was therefore to describe oral and dental diseases in a population of client-owned domestic ferrets. METHODS: In this cross-sectional clinical study, detailed oral and dental examination and full-mouth dental radiographs were performed in 57 client-owned ferrets. RESULTS: Variations in occlusion and number of roots per tooth were noted in comparison with previously published literature on ferrets. Periodontal disease, attrition/abrasion and dental fractures, especially of the canine teeth, were commonly observed. Periapical disease associated with dental fractures, malocclusion, tooth resorption and neoplasia was uncommon. CONCLUSION AND CLINICAL RELEVANCE: This study indicates that thorough oral and dental examination supported by dental radiography under general anaesthesia should be performed in domestic ferrets as a part of regular veterinary care.

Experimental and numerical investigations of sedimentation of porous wastewater sludge flocs.

The paper studies the properties and sedimentation characteristics of sludge flocs, as they appear in biological wastewater treatment (BWT) plants. The flocs are described as porous and permeable bodies, with their properties defined based on conducted experimental study. The derivation is based on established geometrical properties, high-speed camera data on settling velocities and non-linear numerical model, linking settling velocity with physical properties of porous flocs. The numerical model for derivation is based on generalized Stokes model, with permeability of the floc described by the Brinkman model. As a result, correlation for flocs porosity is obtained as a function of floc diameter. This data is used in establishing a CFD numerical model of sedimentation of flocs in test conditions, as recorded during experimental investigation. The CFD model is based on Euler-Lagrange formulation, where the Lagrange formulation is chosen for computation of flocs trajectories during sedimentation. The results of numerical simulations are compared with experimental results and very good agreement is observed.

[Lipid infusion in multiple trauma intensive care patients in the early phase of treatment]. / Fettinfusion bei polytraumatisierten Intensivpatienten in der Frühphase der Behandlung.

OBJECTIVES: To study the metabolic effects of a high-dose fat infusion application in the early phase of total parenteral nutrition (TPN) after major trauma. DESIGN: Prospective study in male patients after major trauma. SETTING: Intensive care unit of the University Clinic. PATIENTS: 21 male, mechanically ventilated patients after major trauma. INTERVENTIONS: Infusion of Elolipid 20% (Fa. Leopold, Graz, Austria), starting on the 3rd day after ICU admission (0.075 g/kg body weight/h) in 8 h. The dose was increased on the 5th day (0.125 g/kg BW/h) and on the 7th day (0.15 g/kg BW/h). RESULTS: There was a pathologic rise in serum triglycerides on days 3, 5 and 7 during the infusion period. A serious diabetic metabolic state was shown on the 3rd day. No significant changes in urea production rate could be demonstrated after the high-dose fat infusion. CONCLUSIONS: The reason for the decreased fat elimination in patients after major trauma after high-dose fat infusion (8 h) remains unclear (fat clearance or fat oxidation failure). Therefore the fat infusion should be started after normalization of the blood glucose level. Thus the fat infusion should be given continuously over 24 h to avoid serious metabolic complications.

The role of the contralateral limb in below-knee amputee gait.

Very little quantitative biomechanical research has been carried out evaluating issues relevant to prosthetic management. The literature available suggests that amputees may demonstrate an asymmetrical gait pattern. Furthermore, studies suggest that the forces occurring during amputee gait may be unequally distributed between the contralateral and prosthetic lower limbs. This study investigates the role of the contralateral limb in amputee gait by determining lower limb joint reaction forces and symmetry of motion in an amputee and non-amputee population. Seven adult below-knee amputees and four non-amputees participated in the study. Testing involved collection of kinematic coordinate data employing a WATSMART video system and ground reaction force data using a Kistler force plate. The degree of lower limb symmetry was determined using bilateral angle-angle diagrams and a chain encoding technique. Ankle, knee and hip joint reaction forces were estimated in order to evaluate the forces acting across the joints of the amputee's contralateral limb. The amputees demonstrated a lesser degree of lower limb symmetry than the non-amputees. This asymmetrical movement was attributed to the inherent variability of the actions of the prosthetic lower limb. The forces acting across the joints of the contralateral limb were not significantly higher than that of the non-amputee. This suggests that, providing the adult amputee has a good prosthetic fit, there will not be increased forces across the joints of the contralateral limb and consequently no predisposition for the long-term wearer to develop premature degenerative arthritis.