Two-dimensional numerical model for the analysis of macrosegregation during solidification

This paper presents a 2D extension of a one-dimensional model proposed initially for the analysis of macrosegregation of multicomponent alloys. Some simulations were carried out to compare the performance of an explicit/implicit time integration scheme for coupling thermal-solutal fields with a fully implicit one. Simulations carried out for the analysis of a two-dimensional solidification problem has fitted the unidirectional and two-dimensional experimental data very well.     

The Pro-Inflammatory Deletion Allele of the NF-κB1 Polymorphism Is Characterized by a Depletion of Subunit p50 in Sepsis

The functionally important NF-κB1 promoter polymorphism (−94ins/delATTG) significantly shapes inflammation and impacts the outcome of sepsis. However, exploratory studies elucidating the molecular link of this genotype-dependent pattern are lacking. Accordingly, we analyzed lipopolysaccharide-stimulated peripheral blood mononuclear cells from both healthy volunteers (n = 20) and septic patients (n = 10). All individuals were genotyped for the −94ins/delATTG NF-κB1 promoter polymorphism. We found a diminished nuclear activity of the NF-κB subunit p50 in ID/DD genotypes after 48 h of lipopolysaccharide stimulation compared to II genotypes (p = 0.025). This was associated with higher TNF-α (p = 0.005) and interleukin 6 concentrations (p = 0.014) and an increased production of mitochondrial radical oxygen species in ID/DD genotypes (p = 0.001). Although ID/DD genotypes showed enhanced activation of mitochondrial biogenesis, they still had a significantly diminished cellular ATP content (p = 0.046) and lower mtDNA copy numbers (p = 0.010) compared to II genotypes. Strikingly, these findings were mirrored in peripheral blood mononuclear cells taken from septic patients. Our results emphasize the crucial aspect of considering NF-κB subunits in sepsis. We showed here that the deletion allele of the NF-κB1 (−94ins/delATTG) polymorphism was associated with the lower nuclear activity of subunit p50, which, in turn, was associated with aggravated inflammation and mitochondrial dysfunction.     

A Swedish version of the Women's Health Questionnaire. A measure of postmenopausal complaints

We wanted to provide details on the psychometric documentation of the Swedish version of the Women's Health Questionnaire (WHQ), a patient based measure of postmenopausal complaints. The results of two clinical trials in Sweden in which the WHQ had been used as one out of several measurement tools were used to document the reliability, the validity and the responsiveness to change of the WHQ. More than 350 women suffering from postmenopausal complaints were included in the two trials. A factor analysis, using the baseline values of all women in each study, showed that the Swedish version of the WHQ was very close to the English original. The internal consistency reliability was excellent. The clinical validity was confirmed by a significant correlation between change in E2 levels and change in the WHQ during estrogen therapy. A high construct validity was established by the agreement between the WHQ and other quality of life scales. For use in clinical trials the WHQ was sensitive to treatment-induced changes, and added important information to the clinical effect variables.     

Rapid disappearance of zinc positive terminals in focal brain ischemia

The study was undertaken to determine if the levels of vesicular zinc in neuronal terminals would decrease in response to focal brain ischemia. The middle cerebral artery was occluded distal to the striatal branches in male spontaneously hypertensive rats. At 7, 15, 30, 45, 60, 90, 120 min; 3, 6, 12, 24, 48 h and 7 days later the animals were sacrificed and the brains were stained for zinc-sulfides, cell bodies and AChE-positive cholinergic fibers. The density of zinc positive terminals significantly decreased in the neocortical ischemic zone 7 min after middle cerebral artery occlusion (MCAO). In the neocortical layers II and III most zinc positive neuronal terminals disappeared at 7 min after MCAO whereas the zinc positive terminals in layers V and VI remained positive at least 2 h. Beginning at 1 h after MCAO and progressing to 24 h a significant decrease in the density of zinc positive terminals was observed in the dorsolateral striatum, and ventrobasal thalamic nucleus, both major projection areas of the sensorimotor cortex. The disappearance of zinc positive neuronal terminals in the ischemic neocortex and related areas, is most likely due to a neuronal release of vesicular zinc in response to hypoxia. The high extracellular concentration of zinc is thought to be both neuroprotective by blocking the NMDA receptor and neurotoxic by activating neuronal influx of Ca2+ through voltage gated calcium channels. It seems evident that the latter effect of zinc is contributing to the neuronal death in focal brain ischemia.     

Observation of rhombic facets on platinum wire after heating in air using scanning tunnelling microscopy

Evidence is provided for the formation of surface faceting due to heating in air at 1160 K. For the first time diamond-shaped facets with angles of 60 and 120° have been observed on the surface of a sample of ultrapure platinum wire in air using scanning tunnelling microscopy. The maximum extension of the facets is about 1000 Å.     

Counteraction of pitting in copper water pipes by bicarbonate dosing

Copper pipes are extensively used for tap water installations and generally perform well. Exceptionally, however, copper pipes are perforated due to pitting. Three main types of pitting (I, II and III) have been identified, but as for the causes and the mechanisms these have not yet been fully clarified. Through case studies, model experiments, thermodynamic calculations, and service tests, evidence has been obtained that waters having a pitting propensity for copper pipes can be made less corrosive by an increase of the HCO content. On water treatment the following water composition should be aimed at:

• – a pH value of at least 7
• – an HCO content of at least 70 mg/l, preferably 100 mg/l
• – as low SO content as possible, or at least lower than the HCO content (both in mg/l).

     

Infrared diffuser for application in transmission and reflection at 10.6 microm

A near-Lambertian diffuser for the infrared wavelength of 10.6 mum that operates in both the transmission mode and the reflection mode has been made. The diffuser is a porous sodium chloride window with the physical advantages and disadvantages of sodium chloride as an optical material. It is simple to manufacture because of the water solubility of the salt. The bidirectional scattering distribution function is nearly flat for all scattering and incidence angles. In addition, the diffuser effectively depolarizes the scattered radiation.     

Noncontact surface roughness measurement of engineering surfaces by total integrated infrared scattering

As precision engineering surfaces are gaining in importance in industry, so are the surface quality requirements. These surfaces have rms roughness typically ranging from some nanometers up to a few micrometers. Although numerous techniques exist for rough surface characterization, from traditional line-scanning stylus profilometers to modern three-dimensional (3-D) measurement instruments, there is a need for a fast, area-covering technique. An efficient method for the characterization of smooth surfaces is elastic light scattering. At visible wavelengths, the limits on roughness range and spatial frequency range make the method unsuitable for characterizing engineering surfaces. By increasing the wavelength of the incident light from the visible to the infrared, elastic light scattering turns out to be applicable for engineering surfaces. We have used total integrated scattering at 10.6 μm wavelength to measure rms roughness up to two micrometers. In this paper, the instrument design and properties are reviewed. We also present results from measurements on ground steel surfaces. Excellent correspondence with mechanical stylus measurements exists for surfaces with rms roughness in the range from 0.1–1.7 μm. The technique shows potential for rapid quality inspection of engineering surfaces.     

Characterization of in-vitro gel performance of novel MC with respect to the suitability for satiety applications

Rheological properties of aqueous solutions of a novel methyl cellulose has been compared to the performance of a conventional methyl cellulose. Gel formation of these materials is trigged only by increased temperatures. The low gelation temperature of the novel methyl cellulose enables this material to gel at body temperature. Compression measurements of the gels at various concentrations were performed and the investigated gel strength could be fitted according to an exponential equitation. The comparison to alginate as a known gel forming agent by acidification and known as satiety inducing agent showed comparable gel strength at 37 °C. Therefore, a potential of the novel methyl cellulose for human weight management applications has been identified. Gel formation in the human stomach could lead to a satiety effect.