Effects of squeeze casting on the properties of Zn-Bi monotectic alloy

In composite production, the shortest route is via an in situ composite in which a melt dissociates simultaneously into two rather different solid phases. The monotectic alloys can be included in this group. The present work was aimed at extending our recent squeeze casting experience on the Zn-Bi monotectic alloy in order to increase its cast quality and mechanical properties. A squeeze casting unit was built, and its die and punch were machined. The molten monotectic alloy was squeezed in this unit under pressures up to 120 MPa in its freezing range until it solidified completely. It was found that an increase in squeeze casting pressure provided increases in density, tensile strength, and Vickers hardness, which resulted in decreases in chip length and electrical resistivity. Before the squeeze casting practice, the freezing characteristics of this monotectic were estimated using basic solidification principles.     

The outbreak of an epidemic of tick-borne encephalitis in Kielec province induced by milk ingestion

New liquid UHT milks supplemented with iron (0.9-1.4 mg/100 ml), vitamin C (1-7 mg/100 ml), lactose (2-4 g/100 ml) and linoleic acid (200-400 mg/100 ml), named growth milks, have recently become available to satisfy the specific nutritional needs of children aged 1-3 years. But the iron-vitamin C mixture could activate the lactose-induced Maillard reaction and tryptophan (Trp) oxidation in proteins. We have therefore examined the Amadori product and Trp concentrations of these milks. Forty-two commercial growth milks from five firms were analysed for the Maillard reaction and the soluble protein Trp content and compared with 64 UHT milks. The furosine concentration of total proteins was two to four times higher in 'growth' milks than in standard UHT milks, indicating a proportional loss of available lysine. The Trp fluorescence of undenatured proteins soluble at pH 4.6 was almost three times lower in 'growth' than in standard milks and Trp concentration 36% lower suggesting destruction of this oxidation-sensitive amino-acid. The mechanism of Trp destruction remains to be elucidated, and the roles of iron and Amadori products determined.     

Tetraparesis following dental extraction: case report and discussion of preventive measures for cervical spinal hyperextension injury

This concerns a patient with compression myelopathy following passive hyperextension of the cervical spine during a dental procedure. Although he had been asymptomatic prior to the procedure, subsequent cervical spinal imaging revealed advanced spondylosis and spinal stenosis. Spinal stenosis is often asymptomatic for a long time. However, when radiculomyelopathy occurs after minor trauma to the head or neck, the patient is often found to have spinal stenosis. Specifically, hyperextension of a cervical spine with spondylotic changes can lead to compression myelopathy. Acquired spinal stenosis correlates positively with aging. As the size of the elderly population continues to increase the prevalence of cervical spondylotic radiculo-myelopathy will likely increase as well. Since appropriate precautions against potential neurologic damage can be undertaken, we suggest radiographic screening for pre-existing spinal stenosis prior to a procedure requiring hyperextension of the neck. Preventive measures for individuals with asymptomatic spondylotic changes and education of all health-care professionals to avoid abrupt or prolonged hyperextension of the cervical spine is emphasized.     

Determination of land and ocean reflective, radiative, andbiophysical properties using multiangle imaging

Knowledge of the directional and hemispherical reflectance properties of natural surfaces, such as soils and vegetation canopies, is essential for classification studies and canopy model inversion. The Multi-angle Imaging SpectroRadiometer (MISR), an instrument to be launched in 1998 onboard the EOS-AM1 platform, will make global observations of the Earth's surface at 1.1-km spatial resolution, with the objective of determining the atmospherically corrected reflectance properties of most of the land surface and the tropical ocean. The algorithms to retrieve surface directional reflectances, albedos, and selected biophysical parameters using MISR data are described. Since part of the MISR data analyses includes an aerosol retrieval, it is assumed that the optical properties of the atmosphere (i.e. aerosol characteristics) have been determined well enough to accurately model the radiative transfer process. The core surface retrieval algorithms are tested on simulated MISR data, computed using realistic surface reflectance and aerosol models, and the sensitivity of the retrieved directional and hemispherical reflectances to aerosol type and column amount is illustrated. Included is a summary list of the MISR surface products     

Discrepancies between thyrotropin (TSH) measurement by four sensitive immunometric assays

A comparison of four different commercial immunometric thyrotropin (TSH) assays (Amerlite R TSH-30 Ultrasensitive assay from Kodak, BeriLux R hTSH from Behring Werke, Delfia R hTSH Ultra from Wallac and IMX R Ultrasensitive hTSH from Abbott) was made by measuring serum TSH in 81 consecutive patients referred to hospital for various reasons with a serum TSH less than 0.8 mlU/l in the IMX assay. The analytical and functional assay sensitivities of each of the assays were analysed. Even though three of the methods had a sensitivity corresponding to third generation assays, we could only demonstrate an overall agreement of serum TSH when comparing two of the kits. The measurements in Delfia Ultra and Berilux showed good agreement (P = 0.7, paired t-test and bias = 0.003 mIU/l), while the comparisons between the other assays showed different measurements (P < 0.00001, paired t-test and bias more than 0.07 mIU/l). Differences in the calibrators used in the assays might explain some of the discrepancy, although all methods were calibrated according to the same international standard. Also, differences in the specificity of the TSH monoclonal antibodies used in the assays might be an evident explanation and further studies of the specificity of the monoclonal antibodies are needed. An international collaborative study to clarify reasons for the differences between the TSH assays and to standardize the measurements is recommended.     

Elderly rheumatoid arthritis patients on steroid treatment tolerate physical training without an increase in disease activity

The effects of physical training on elderly, fragile patients with rheumatoid arthritis (RA) who are on low-dose steroids were investigated. The controlled study included 24 patients who had been treated with low-dose steroids for 2 years. Each patient was assigned either to a treatment group receiving training or to an untrained control group. The training took place over a 3-month period and was based on a protocol using progressive interval training consisting of bicycle exercises, heel lifts, and step-climbing. The exercises were performed twice weekly for 45 minutes. Comparison of the two groups showed that disease activity did not increase in the trained group and that fewer, but not significantly fewer, swollen joints were observed in this group (p = 0.06). No significant changes were noticed in erythrocyte sedimentation rate, tender joints, or morning stiffness. The work capacity of the trained patients were doubled and the numbers of repetitions increased 76%. Individually adapted exercise programs can therefore be recommended for elderly rheumatoid arthritis patients on steroid treatment.     

Immunity and depression: insomnia, retardation, and reduction of natural killer cell activity

The contribution of chloride to the haemodynamic changes of salt-dependent deoxycorticosterone (DOC) hypertension was studied in young Wistar rats subjected to dietary loading with sodium chloride (NaCl) or sodium bicarbonate (NaHCO3). Mean arterial pressure (MAP), cardiac output, systemic resistance (TPR) and arterial rigidity (estimated from pulse pressure/stroke volume ratio, PP/SV) were determined in conscious chronically cannulated rats. DOC-induced increase of MAP and TPR appeared earlier in NaCl-loaded than in NaHCO3-loaded rats. After 4-6 weeks of hypertensive treatment MAP, TPR and PP/SV ratio were higher in DOC-treated rats fed NaCl diet than in those fed NaHCO3 diet. In contrast, after a long-term hypertensive regimen (lasting for 7-9 weeks) there was no significant difference in either MAP or TPR between rats loaded with NaCl or NaHCO3. On the other hand, DOC hypertension induced by a long-term feeding of NaHCO3 diet was not associated with an increase of arterial rigidity which was characteristic for DOC-NaCl hypertensive rats. Thus, a sufficiently long selective dietary sodium loading is capable to increase the systemic resistance but not to alter the arterial rigidity. This was also confirmed by a comparison of blood pressure-matched DOC hypertensive rats fed NaCl or NaHCO3 diets. These animals did not differ in the degree of systemic resistance elevation but the arterial rigidity was increased only in NaCl-loaded rats.     

A study of urinary dolichols as a biological marker for alcohol abuse. Report 2: Comparison of urinary dolichols/creatinine concentrations among non-drinkers, moderate-drinkers and heavy-drinkers

We report here the comparison of urinary dolichols/creatine (D/Cr) concentration ratios in male non-drinkers, moderate-drinkers and heavy drinkers at admission and during hospitalization, and also discuss its usefulness as a biological marker for alcohol abuse. Urine samples were collected from the following four experimental groups: non-(male and female) and moderate-drinker (male) volunteers, and alcoholic heavy-drinking patients (male) at admission for psychiatric treatment and after 9-15 days hospitalization (informed consent was obtained). Urinary dolichols were determined by high performance liquid chromatography after BondElutC18 (500 mg) extraction. Due to significant differences in urinary D/Cr concentrations between male and female groups in non-drinkers and because the heavy-drinkers available for this study were exclusively male, comparison of the value of urinary D/Cr concentration ratios was subsequently limited to male only. There were no statistical differences in urinary D/Cr concentrations in the male among non-drinkers, moderate-drinkers and heavy-drinkers at admission. The accuracy of urinary D/Cr as a biological marker for alcohol abuse, calculated using the mean +/- 2 s.d. in non- and moderate-drinkers as the normal range, is only 33.3% in heavy-drinkers at admission, while their value of gamma-GTP in serum was 88.3%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metabolism of tetramethrin isomers in rat: II. Identification and quantitation of metabolites

1. To examine the metabolic fate of (1RS, trans)- or (1RS, cis)-tetramethrin [3, 4, 5, 6-tetrahydrophthalimidomethyl (1RS, trans)- or (1RS, cis)-chrysanthemate], rat was administered a single oral dose of trans- or cis-[alcohol-14C]tetramethrin at dose levels of 2 or 250 mg/kg. 2. The radiocarbon was almost completely eliminated from rat within 7 days after administration in all groups. 14C-recoveries (expressed as percentages relative to the dosed 14C) in faeces and urine were 38-58 and 42-58% respectively in rat administrated trans-[alcohol-14C]tetramethrin, and in faeces and urine were 66-91 and 9-31% respectively in rat administered cis-[alcohol-14C]tetramethrin. 3. Fourteen metabolites found in excreta were purified by using several chromatographic techniques and identified by spectroanalyses (nmr and MS). Five sulphonate derivatives and three dicarboxylic acid derivatives were found. 4. The main metabolites were sulphonate derivatives in the faeces, and in the urine, alcohols, dicarboxylic acid and reduced metabolites derived from the 3,4,5,6-tetrahydrophthalimide moiety.