Organochlorine pesticide, polychlorinated biphenyl and heavy metal concentrations in wolves (Canis lupus L. 1758) from north-west Russia.

The wolf Canis lupus is a major terrestrial predator in eastern Europe and, as a top carnivore, may be exposed to high concentrations of contaminants that are readily transferred through the food chain. Despite this, there are few published data on pollutant and pesticide levels in wolves. This study utilised tissues from animals legally killed by hunters for other reasons (animals were not killed for the purposes of this study) to carry out the only detailed investigation of contaminants in wolves in Europe and the first in animals from Eastern Europe. The livers of 58 wolves from the Tver and Smoliensk regions of northwest Russia (54 degrees N 31 degrees E to 57 degrees N 35 degrees E) were analysed for seven organochlorine pesticides, 24 PCB congeners, Aroclor 1254-matched summed PCBs (sigmaPCBs), total mercury, cadmium and lead. Cadmium, most of the organochlorine pesticides and many PCB congeners were not detectable in any of the wolves. Hexachlorobenzene, alpha-HCH, pp'DDE, PCB congeners 118, 138, 149 and 156 and lead were detected in up to 6% of livers. Dieldrin, PCB congeners 153, 170 and 180, sigmaPCBs and mercury were detected more frequently. Contaminant levels were generally low; maximum wet weight concentrations of any of the organochlorine pesticides, sigmaPCBs and mercury were less than 0.1, 1 and 0.25 microg g(-1), respectively. PCB congeners 153, 170 and 180 accounted for 41% of the sigmaPCBs. Dieldrin, sigmaPCBs and mercury concentrations did not vary significantly between males and females nor between adult and juvenile (< 12 months old) wolves apart from the sigmaPCB concentration, which was on average five times higher in adults than juveniles. Liver residues were generally below the level normally associated with adverse effects except for lead levels which exceeded the critical 5 microg g(-1) dry wt. concentration in three of the 58 animals examined.     

High-vacuum cryomicrotome with a single bellows input of the sample motion and cooling

A cryomicrotome based on a heated inlet of liquid nitrogen and complex (an 8-mm-amplitude reciprocating and circular rotary about the vertical axis) motion allows one to conduct all freeze-fracturing operations under visual control (the temperatures of the object and knife are −115°C and −180°C, respectively) and to obtain high-quality replicas of the studied biological sample in the operation chamber with a volume below 1.11 under an oil-free vacuum no worse than 10⁻⁵ Pa, created by a turbo-molecular pump.     

Organochlorine pesticide, polychlorinated biphenyl and heavy metal concentrations in wolves (Canis lupus L. 1758) from north-west Russia

The wolf Canis lupus is a major terrestrial predator in eastern Europe and, as a top carnivore, may be exposed to high concentrations of contaminants that are readily transferred through the food chain. Despite this, there are few published data on pollutant and pesticide levels in wolves. This study utilised tissues from animals legally killed by hunters for other reasons (animals were not killed for the purposes of this study) to carry out the only detailed investigation of contaminants in wolves in Europe and the first in animals from Eastern Europe. The livers of 58 wolves from the Tver and Smoliensk regions of northwest Russia (54°N 31°E to 57°N 35°E) were analysed for seven organochlorine pesticides, 24 PCB congeners, Aroclor 1254-matched summed PCBs (ΣPCBs), total mercury, cadmium and lead. Cadmium, most of the organochlorine pesticides and many PCB congeners were not detectable in any of the wolves. Hexachlorobenzene, alpha-HCH, pp′DDE, PCB congeners 118, 138, 149 and 156 and lead were detected in up to 6% of livers. Dieldrin, PCB congeners 153, 170 and 180, ΣPCBs and mercury were detected more frequently. Contaminant levels were generally low; maximum wet weight concentrations of any of the organochlorine pesticides, ΣPCBs and mercury were less than 0.1, 1 and 0.25 μg g⁻¹, respectively. PCB congeners 153, 170 and 180 accounted for 41% of the ΣPCBs. Dieldrin, ΣPCBs and mercury concentrations did not vary significantly between males and females nor between adult and juvenile (<12 months old) wolves apart from the ΣPCB concentration, which was on average five times higher in adults than juveniles. Liver residues were generally below the level normally associated with adverse effects except for lead levels which exceeded the critical 5 μg g⁻¹ dry wt. concentration in three of the 58 animals examined.     

Electrodeposited diamond coating with protection by diamond micron powder in a dressing tool. Part 2. Tool performance

The paper compares the results of tool life testing of dressing rollers with conventional electrodeposited diamond coating (EDC) and with protected EDC. The protection of EDC by diamond powder is demonstrated to extend the effective tool life (for the tools manufactured by the electroforming process) by 90% and the total tool life (i.e., till eventual failure of EDC) by 125%. The time history of the diamond grain depth in the bond has been theoretically clarified and this parameter has been found to be related to wear characteristics of the bond and diamond grains.     

Quasi-infeed dressing of abrasive wheels as express test method for diamond form dressing rollers. Part 1. Recording of dressing forces

A test procedure for complex-form rollers is put forward; it involves the so-called quasi-infeed dressing scheme that simulates the real infeed dressing. The procedure requires no specialized expensive equipment but can be implemented on universal equipment. The above-mentioned scheme has been substantiated for both the self-consistency of theoretical-experimental approaches to a study of infeed dressing as well as the efficiency of using abrasive material in simulation experiments.     

Benefits of a clinical pharmacokinetic service in optimising phenytoin use in the western Cape

OBJECTIVES: To study the benefits of a clinical pharmacokinetic service in optimising phenytoin use in the Western Cape. DESIGN: Assessment of the response to treatment was based on the number of seizures during the 3 months before entering the study (first baseline period), 3 months after entering the study (second baseline period) and 3 months before the termination of the study (test period). Patients kept a seizure diary throughout the study. The Michaelis-Menten model was used to calculate doses and predict steady-state serum concentrations. SETTING: Nine epilepsy clinics. SUBJECTS: One hundred and ninety-five (113 black and 82 coloured) compliant people with epilepsy receiving generic phenytoin monotherapy. OUTCOME MEASURES: Reduction in seizure frequency and adverse effects. RESULTS: A reduction in seizure frequency (64.8% compared with pre-optimisation) was experienced by 64.9% of patients. Mean seizure frequency was reduced from 3.39 to 1.18 per month. Reductions in seizure frequency of 100% and more than 50% were reported by 39.2% and 58.7% of patients, respectively. Adverse effects of phenytoin were reduced from 20.5% at the first visit to 3.2% at the last visit. CONCLUSION: The clinical pharmacokinetic dosing service for phenytoin applied in this study contributed significantly to the success of epilepsy management.     

The contribution of ion plasma sprayed coatings to performance of diamond dressing tools

The paper addresses the effect of ion plasma sprayed coatings on performance of diamond dressing tools under diamond abrasive machining conditions. The use of thick wear-resistant titanium nitride and carbide coatings with a compensating interlayer of a plastic metal (cobalt) is demonstrated to be a promising method for improving efficiency of dressing tools manufactured by electroplating and electroforming.     

Structural changes in 12Kh1MF pipe during creep tests

Conclusions Steel 12Kh1MF can be used at 585°C and a stress of 10 kg/mm² with up to 1.5% residual deformation.F. E. Dzerzhinskii Heat Engineering Scientific-Research Institute, Ural Branch. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No 7, pp. 6–9, July, 1976