Determination of Young’s and shear moduli of common yew and Norway spruce by means of ultrasonic waves

Despite the exceptional position of yew among the gymnosperms concerning its elastomechanical properties, no reference values for its elastic constants apart from the longitudinal Young’s modulus have been available from literature so far. Hence, this study’s objective was to determine the Young’s moduli E _L, E _R and E _T and the shear moduli G _LR, G _LT and G _RT of yew wood. For that purpose, we measured the ultrasound velocities of longitudinal and transversal waves applied to small cubic specimens and derived the elastic constants from the results. The tests were carried out at varying wood moisture contents and were applied to spruce specimens as well in order to put the results into perspective. Results indicate that E _L is in the same order of magnitude for both species, which means that a high-density wood species like yew does not inevitably have to have a high longitudinal Young’s modulus. For the transverse Young’s moduli of yew, however, we obtained 1.5–2 times, for the shear moduli even 3–6 times higher values compared to spruce. The variation of moisture content primarily revealed differences between both species concerning the shear modulus of the RT plane. We concluded that anatomical features such as the microfibril angle, the high ray percentage and presumably the large amount of extractives must fulfil important functions for the extraordinary elastomechanical behaviour of yew wood which still has to be investigated in subsequent micromechanical studies.     

The effect of auto-vaccination therapy on the phenotypic variation of one clonal type of Staphylococcus aureus isolated from cows with mastitis

The aim of this study was to demonstrate the effect of auto-vaccine therapy on selected properties of Staphylococcus aureus strains, isolated from milk of cows with subclinical mastitis. The experiment was based on auto-vaccines which were prepared from S. aureus strains isolated from 16 cows. S. aureus strains isolated from cows on the 7th, 21st and 35th day following auto-vaccination, were analyzed phenotypically and genotypically. The isolated strains represented 17 biotypes all belonging to one clonal type. Increases of new biotypes of S. aureus were detected on the 35th day of therapy. Among 48 re-isolated strains, 18.75% (9/48) revealed single and 12.50% (6/48) multiple phenotypical changes. The present study demonstrated that during auto-vaccine therapy, S. aureus strains can change phenotypically, pointing out the necessity for using precise diagnostic methods, that would make possible a better assessment of the used therapy.     

Effect of meloxicam and carprofen on renal function when administered to healthy dogs prior to anesthesia and painful stimulation

OBJECTIVE: To determine whether administration of the nonsteroidal anti-inflammatory drugs meloxicam or carprofen to healthy dogs that were subsequently anesthetized and subjected to painful electrical stimulation has adverse effects on renal function as measured by glomerular filtration rate (GFR) and evaluation of serum concentrations of urea and creatinine. ANIMALS: 6 male and 6 female healthy young-adult Beagles. PROCEDURE: A study was conducted in accordance with a randomized crossover Latin-square design. One of 3 treatments (saline [0.9% NaCl] solution, 0.2 mg of meloxicam/kg, or 4.0 mg of carprofen/kg) was administered i.v. 1 hour before anesthesia was induced by use of drugs in accordance with a standard anesthetic protocol (butorphanol tartrate and acepromazine maleate as preanesthetic medications, ketamine hydrochloride and diazepam for induction, and maintenance with isoflurane). Anesthetized dogs were subjected to intermittent electrical stimulation for 30 minutes. Direct, mean arterial blood pressure; heart rate; and respiratory rate were monitored. End-tidal isoflurane concentration was maintained at 1.5 times the minimum alveolar concentration. The GFR, as measured by plasma clearance of 99mTc-diethylenetriaminepentaacetic acid, and serum concentrations of serum and creatinine were determined 24 hours after induction of anesthesia. RESULTS: Neither meloxicam nor carprofen significantly affected GFR or serum concentrations of urea and creatinine, compared with values for the saline treatment. CONCLUSIONS AND CLINICAL RELEVANCE: When administered 1 hour before onset of anesthesia and painful electrical stimulation, meloxicam or carprofen did not cause clinically important alterations of renal function in young healthy dogs.     

Analgesia and chemical restraint for the emergent patient.

This article discusses analgesia and chemical restraint for the emergency patient. As illness or injury affect all organ systems, specific recommendations and considerations of analgesic, anesthetic, and restraining regimens are presented. As animals of all ages, from neonates to geriatric and those that are pregnant or lactating,may require management of their illness or injury, recommendations for these patients are also presented.     

Photocatalytic degradation of pesticides and bio-molecules in water

Two approaches are suggested for the acceleration of the photocatalytic oxidation of organic contaminants of water: acceleration by oxidants and photo-enhancement by dyes. These processes were examined with several substances: two widely applied herbicides, bromacil (a uracil) and metribuzin (a triazine), and three proteins, studied as models of biocontaminated waters. The effects of oxygen and hydrogen peroxide indicated two different reaction patterns of photo-oxidation of the herbicides. With metribuzin, oxygen had a pronounced effect on the rate of photo-oxidation, while the influence of hydrogen peroxide was quite moderate; with bromacil, oxygen had a limited effect on the rate of photo-oxidation, which however was considerably enhanced by hydrogen peroxide. Acceleration of the photo-catalytic oxidation of colourless refractory contaminants by photo-excited dye was observed. Both UV and visible light were required for the enhanced decomposition. The mechanism of the reaction seems to involve a combination of oxidation by hydroxyl radicals, via the hole-electron semiconductor route, with subsequent oxidation of photo-intermediates by singlet oxygen formed by dye sensitization. The TiO2-photocatalyzed oxidation of proteins (albumin, ovalbumin and gamma-globulin) showed the susceptibility of proteins to photocleavage and of the amino acids to photocatalytic degradation. Tyrosine was the most sensitive, while the degradation of the aliphatic amino acids Gly and Asp was slow.     

Disseminated Intravascular Coagulation in Dogs: Review of the Literature

Diagnosis of Disseminated Intravascular coagulation (DIC) is controversial in both human and veterinary medicine. This article reviews the available literature in human and veterinary medicine regarding the etiology, pathophysiology, and diagnosis of DIC with emphasis on the diagnosis of DIC in dogs. Controversy surrounding the diagnosis of DIC arises from the complex nature of the disease itself, in addition to the absence of a consensus strategy for laboratory testing. The available literature indicates that dogs diagnosed with DIC possessed various hemostatic function testing abnormalities, typically possessed an underlying disease that predisposed to DIC, but may or may not have had clinically identifiable hemorrhage or thrombosis. Additionally, the hemostatic function testing utilized in diagnosis is not uniform. Generalizations about the usefulness of individual assays or diagnostic strategies cannot be formulated because of the marked diversity of the types of cases studied, as well as the small number of cases reported in the literature. (Vet Emerg & Crit Care, 1998; 8: 29–45)     

Three Species of Genus Pinus Suitable as Bioindicators of Polluted Environment

The long-term study objective was to determine the suitability of selected species of genus Pinus (Pinus sylvestris, Pinus nigra and Pinus mugo) for use as bioindicators of environmental pollution. In these experiments a new methodology of evaluation of mitotic abnormalities was established and its potential for common use tested. The study confirmed three species of genus Pinus as suitable bioindicators. The results also indicate that trees may show adaptive changes in response to severe pollution stress.