Inhomogeneity of rolling texture in fcc metals

The cold rolling of metal sheets and strips results in the formation of an inhomogeneous texture. The type and sharpness of texture in layers and the degree of inhomogeneity depend on the friction between rolls and the material and the geometry of the rolling gap. Contrary to the opinion of several authors, it is shown that the inhomogeneity of texture appears not only in the case of small values of thel/h ratio (l/h characterizes the geometry of the rolling gap) but also in the case of large values whenl/h > 5. In the first case shear texture forms in the intermediate layers of the rolled sheet while in the second, in its outer layers. The results of experiments carried out on aluminum, silver and 70/30 brass clearly show that the sensitivity of metals and alloys to the formation of an inhomogeneous texture is caused by their flow characteristics: yield strength (Y) and the work hardening exponent (m). High values ofY andm will tend to hinder the shear deformation, and consequently they will hinder the occurrence of inhomogeneity.     

Concentrations of cadmium, lead and copper in atmospheric precipitation in Czechoslovakia.

The concentrations of Cd, Pb and Cu in wet and dry atmospheric precipitation were measured in 13 regions of Czechoslovakia. The Pb and Cd contents of rainwater were found to decrease with increasing rainfall intensity. The highest enrichment of Cd, Pb and Cu was observed in ice-accretion deposits; increasing amounts of metals were found at higher altitudes, i.e. 700-1000 m above sea level. The electrostatically separated fractions are rather high in Cu and Pb (approximately 90%), whereas Cd contributes less than 50%.     

Purification of the cardiac sarcoplasmic reticulum membrane protein phospholamban from recombinant Escherichia coli

Phospholamban (PLN) was expressed in Escherichia coli as a protein fusion with glutathione S-transferase (GST). GST-PLN was mostly present in the insoluble protein fraction and accounted for approximately 50% of total insoluble protein. Attempts to suppress inclusion body formation or to use GST as an affinity-purification tag failed. A successful purification method is based on preparative SDS/PAGE and electrodialysis. From 1 g cells we typically purified 13.5 mg fusion protein with a PLN content of 2.8 mg. We genetically inserted an enterokinase (EK) protease site just in front of the PLN sequence and demonstrated the proteolytical liberation of PLN from the carrier protein. The approach described represents a substantial advancement in PLN expression and purification.     

Salvage therapy of advanced squamous cell carcinoma of the mouth cavity and oropharynx. Results of interstitial high-dose-rate brachytherapy combined with ablative tumor surgery

PURPOSE: The clinical effect of high-dose-rate (HDR) interstitial brachytherapy combined with tumor resection was investigated in this retrospective study on patients with recurrent oral and oropharyngeal squamous cell carcinoma. PATIENTS AND METHODS: Oral and oropharyngeal squamous cell carcinoma in 38 patients were treated over a period of 7 years (1988-1994) by HDR interstitial brachytherapy using Gammamed 12i equipment. Pretreatment of patients in terms of irradiation and surgery differed (33 irradiated with a total dose between 60.0 and 75.6 Gy, including 8 patients with additional surgery; 1 patient with surgery alone, and 4 patients without any pretreatment). Indications for interstitial brachytherapy differed according to individual responses to treatment and medical histories. RESULTS: Interstitial brachytherapy was successful in the majority of patients, i.e. complete remission: 12, partial remission: 19, no change: 2, progression: 5. Local control and overall survival including patients with surgical treatment was 59% and 81% at 6 months and 47% and 49% after 12 months, respectively. CONCLUSION: Interstitial HDR brachytherapy with Iridium 192 is recommended in patients with local recurrences or second primary carcinomas after previous external radiotherapy in the head and neck region. Combination of interstitial brachytherapy and surgery is preferable for these patients.     

Potency comparison of peptidomimetic inhibitors against HIV-1 and HIV-2 proteinases: design of equipotent lead compounds

The results of investigation of haptoglobin (Hp) types in 596 donor blood samples in some towns of Ukraine (Dnepropetrovsk, Kharkov, Odessa, Kiev, Uzhgorod, Zhitomir) are presented. Three normal Hp types (Hp1-1, Hp2-1 and Hp2-2) have been found. The reliable interpopulation differences in the Hp types frequency were not found. On the whole the Hp types frequency in the type Hp1-1 comprised 12.7%. In the type Hp2-1-48.1% and in the type Hp2-2-36.5%. The frequency of the gene Hp1 is 0.38. The frequency of the Hp types and of the gene Hpl in Ukraine is similar to that in population of Eastern Europe and European Part of Russia.     

Uptake and metabolism of lipoproteins from patients with diabetes mellitus type II by glomerular epithelial cells

BACKGROUND: Recent studies suggest that dyslipidaemia accelerates the progression of diabetic nephropathy, but the various pathomechanisms underlying such abnormalities are not completely delineated. METHODS: We isolated, radiolabelled, and characterized very-low-density lipoproteins (VLDL) and low-density lipoproteins (LDL) from eight diabetic patients with moderate impairment of renal function and dyslipidaemia and studied their interaction with LDL receptors in human glomerular epithelial cells. RESULTS: While diabetic VLDL showed no compositional changes, LDL particles contained a higher proportion of triglycerides at the expense of cholesterol in comparison with healthy controls. Despite differences in composition, both VLDL and LDL from patients exhibited reduced receptor affinity and cellular uptake capacity by glomerular epithelial cells. Since LDL composition was altered intracellular cholesterol homeostasis was investigated. Due to reduced cholesterol content and lower uptake capacity, diabetic LDL were less effective in suppressing intracellular sterol synthesis and in activating acylcholesterol acyltransferase than LDL from controls. Electrophoretic mobility of apoB from diabetic patients was enhanced as compared to controls, most probably due to the higher degree of glycation (17 + 1.7 versus 11 + 1%, P < 0.05) but not to oxidation (TBARS 0.5 + 0.2 versus 0.2 + 0.1 mumol/1). Oxidized LDL was not taken up in significant amounts, indicating no scavenger receptor activity in glomerular epithelial cells. CONCLUSION: The receptor-specific uptake of diabetic VLDL and LDL by glomerular epithelial cells is impaired. Compositional changes of the LDL particle and glycation of the protein moiety may contribute to altered glomerular uptake. However, glycation of the protein moiety may be superior to compositional changes. Because glomerular structures like mesangial matrix and endothelial cells are known for preferential binding of modified lipoproteins, further studies are required to elucidate their potential role in the progression of diabetic glomerulosclerosis.     

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Condition-based tool management for small batch production

This paper presents a novel tool management concept for cutting processes which integrates tool relevant information, such as distribution data, tool orders, tool condition, and allocation data, within a centralized information cycle. The developed tool management approach uses decentralized identification and storage technologies, enabling an autonomous cooperation of tools and machine tools within a production. The first part of the paper is focused on the assessment of tool condition in a flexible job shop production. A tool wear monitoring system based on cutting force coefficients is developed and demonstrated by an exemplary milling operation. Thereby, it is shown that cutting force coefficients are suitable for wear monitoring and prediction, even for varying cutting conditions. For the online assessment of the current tool condition and for the prediction of residual tool life, an empirical tool wear model is demonstrated. This is applied to a novel condition-based tool management strategy which enables the optimum exploitation of the life time and performance of the cutting tool. The developed condition-based tool management concept is finally demonstrated by a software demonstrator.     

Automated three-dimensional US frame positioning computed from elevational speckle decorrelation

For ultrasonographic B-scan images collected by means of a handheld transducer moving in the elevational direction, frame spacings are computed with a speckle-decorrelation algorithm, without additional positioning hardware. Fully developed speckle volumes are automatically segmented and spacing computed from the decorrelation curves. Position accuracy is within 10% for phantoms and 15% for breast studies. The algorithm provides image-based registration, which allows accurate three-dimensional volume rendering.