Lipoxygenase Products in the Urine Correlate with Renal Function and Body Temperature but not with Acute Transplant Rejection

Acute transplant rejection is the leading cause of graft loss in the first months after kidney transplantation. Lipoxygenase products mediate pro- and anti-inflammatory actions and thus we aimed to correlate the histological reports of renal transplant biopsies with urinary lipoxygenase products concentrations to evaluate their role as a diagnostic marker. This study included a total of 34 kidney transplant recipients: 17 with an acute transplant rejection and 17 controls. LTE4, LTB4, 12-HETE and 15-HETE concentrations were measured by enzyme immunoassay. Urinary lipoxygenase product concentrations were not significantly changed during an acute allograft rejection. Nevertheless, LTB4 concentrations correlated significantly with the body temperature (P ≤ 0.05) 3 months after transplantation, and 12- and 15-HETE concentrations correlated significantly with renal function (P ≤ 0.05) 2 weeks after transplantation. In conclusion, our data show a correlation for LTB4 with the body temperature 3 months after transplantation and urinary 12- and 15-HETE concentrations correlate positively with elevated serum creatinine concentrations but do not predict acute allograft rejection.     

Cyclic Fatigue-Crack Propagation in Magnesia-Partially-Stabilized Zirconia Ceramics

The subcritical growth of fatigue cracks under (tension-tension) cyclic loading is demonstrated for ceramic materials, based on experiments using compact C(T) specimens of a MgO-partially-stabilized zirconia (PSZ), heat-treated to vary the fracture toughness K _c from ∼3 to 16 MPa·m^1/2 and tested in inert and moist environments. Analogous to behavior in metals, cyclic fatigue-crack rates (over the range 10⁻¹¹ to 10⁻⁵ m/cycle) are found to be a function of the stress-intensity range, environment, fracture toughness, and load ratio, and to show evidence of fatigue crack closure. Unlike toughness behavior, growth rates are not dependent on through0-thickness constraint. Under variable-amplitude cyclic loading, crack-growth rates show transient accelerations following low-high block overloads and transient retardations following high-low block overloads or single tensile overloads, again analogous to behavior commonly observed in ductile metals. Cyclic crack-growth rates are observed at stress intensities as low as 50% of K _c , and are typically some 7 orders of magnitude faster than corresponding stress-corrosion crack-growth rates under sustained-loading conditions. Possible mechanisms for cyclic crack advance in ceramic materials are examined, and the practical implications of such "ceramic fatigue" are briefly discussed.     

Komplikationen bei der Initiierung kationischer Polymerisationen mit Lewis-Säuren - Modellrechnungen an Antimon-(V)-halogeniden

Complications in the Initiation of Cationic Polymerizations by Lewis Acids - Model Calculations for Antimony(V)halogenids Quantum-chemical CNDO/2-calculations including geometry-optimization show that complex anions (X₅Sb-Z-SbY₅)⊖ are formed as a result of interaction between Lewis acids SbX₅ and anions SbY₅Z⊖ (X, Y, Z = F, Cl, Br). This interaction is very strong in the case of X, Z = F and Y = Br. When the complex anions decompose the simple anions with the greatest number of fluorine ligands are formed. The interaction between the two different Lewis acids SbX₅ and SbY₅ yields a random distribution of the ligands of both acids. During formation of the ions SbX₄⊕ and SbXY₅⊖ the anion with the greatest number of fluorine ligands is formed. The probability of the conversion Sb(V)-Sb(III) is higher for SbCl₅ than for SbCl₆⊖.     

Demosaicing algorithms for area- and line-scan cameras in print inspection

Most color image sensors use color filter arrays (CFA). With this sensor design the captured information at each sensor pixel position is restricted to a specific spectral portion (typically red, green and blue bands). To obtain the missing color responses at each pixel position, so-called CFA demosaicing algorithms are commonly used. We propose two new CFA demosaicing algorithms, which are well suited for industrial print inspection with respect to the requirements in accuracy and speed. As a main contribution, we introduce novel demosaicing algorithms for specific high-speed color digital time delay and integration (DTDI) CFA line-scan cameras. We compare the suggested CFA demosaicing algorithms to state-of-the art algorithms for area and line-scan camera operation modes. We show that the two new algorithms perform superior to conventional algorithms as indicated by reconstruction error.     

Evaluation of the effects of thermal treatments on color, polyphenol stability, enzyme activities and antioxidant capacities of innovative pasty celeriac (Apium graveolens L. var. rapaceum (Mill.) DC.) products

Initial heating was applied as the first processing step in the production of innovative pasty celeriac products. For this purpose, celeriac was converted into a paste and subsequently heated at 90 and 100 °C for 5–10 min. Alternatively, the fresh plant material was blanched prior to mincing. For the first time, phenolic compounds in celeriac were characterized by high-performance liquid chromatography coupled with mass spectrometry (LC–MSⁿ). Among the 14 phenolics detected, several caffeic, ferulic and quinic acid derivatives as well as malonylated and acetylated flavonoid derivatives were newly identified. Upon thermal treatment, the antioxidant capacities (TEAC assay) and the total phenolic contents remained virtually unchanged. The antioxidant capacities of heated samples determined by the FRAP assay were even higher than those of the unheated control. The contents of the main phenolic compound apiin decreased upon heat treatment, whereas the levels of the minor compounds malonylapiin A and B increased. Only by extended steam- and water-blanching at 100 °C, respectively, complete inactivation of peroxidase and polyphenol oxidase was achieved. The obtained celeriac products were characterized by their bright white color. Consequently, blanching is recommended as the initial operation in the processing of celeriac into novel pasty products.     

Disruption of p53 function in immortalized human cells does not affect survival or apoptosis after taxol or vincristine treatment

OBJECTIVE: We assessed the feasibility of contrast-enhanced color Doppler, power Doppler, and spectral duplex sonography for visualization and quantification of flow through transjugular intrahepatic portosystemic shunts (TIPS) in patients in whom the baseline sonographic evaluation was unsatisfactory. SUBJECTS AND METHODS: Thirty-three patients underwent color Doppler, power Doppler, and spectral duplex sonography after TIPS insertion or before TIPS revision (mean time interval +/- SD, 1 +/- 1 day). All sonograms were obtained before and after patients received echo-enhancing contrast material. Sonography was evaluated with regard to presence or absence of flow in the mid portion, portal segment, and hepatic segment of the shunt. The maximal peak velocity was measured in the mid portion of the shunt. For identifying and quantifying stenoses, the percentage of luminal diameter reduction was calculated at the tightest part of the shunt. Shunt angiography and measurements of portosystemic pressure gradients were independently evaluated and compared with the sonographic findings. RESULTS: Flow visualization on unenhanced color Doppler sonography was significantly improved through the use of power Doppler sonography and contrast-enhanced color Doppler and power Doppler sonography (p < .01). Between contrast-enhanced power Doppler and contrast-enhanced color Doppler sonography, a significant difference was found in the portal and hepatic segments (p < .05). All shunt stenoses (n = 8) and occlusions (n = 3) were revealed by power Doppler sonography, whereas color Doppler sonography failed to reveal six of eight stenoses. Compared with unenhanced sonography, the quality of spectral duplex sonography was improved in eight patients after contrast enhancement (p < .05). Maximal peak velocity ranged from 54 to 252 cm/sec (mean +/- SD, 132.7 +/- 52.1 cm/sec) in normal shunts and from 24.5 to 70.0 cm/sec (mean +/- SD, 45.0 +/- 18.9 cm/sec) in stenosed shunts. No correlation was found between maximal peak velocity and portosystemic pressure gradients (r = .28). CONCLUSION: Unenhanced power Doppler and contrast-enhanced color and power Doppler sonography can be helpful in the assessment of TIPS status in patients who previously underwent unsatisfactory sonography. These techniques may allow anatomic evaluation and quantification of shunt stenosis in most patients. Contrast enhancement may also considerably improve the quality of spectral duplex sonography.     

Toughening of nanoporous glasses using porogen residuals

Nanoporous glasses are inherently brittle materials that become increasingly fragile with increasing porosity. We show that remarkable increases in fracture energy can be obtained from remnants of the porogen molecules used to create the nanoscale pores. The interfacial fracture energy of approximately 2.6 J m(-2) for dense methylsilsesquioxane glass films is shown to increase by over one order of magnitude to >30 J m(-2) for glasses containing 50 vol.% porosity. The increased fracture resistance is related to a powerful molecular-bridging mechanism that was modelled using bridging mechanics. The study demonstrates that significant increases in interfacial fracture energy may be obtained using strategies involving controlled decomposition of the porogen molecule during processing of nanoporous glasses. The implications are important for a range of emerging optical, electronic and biological technologies that use nanoporous thin films, but are limited by the degradation of mechanical properties with increasing porosity.     

Evaluation of colour properties and chemical quality parameters of cactus juices

The chemical composition and visual appearance of cactus fruits from the genera Opuntia and Hylocereus were investigated. Colour properties were assessed in solutions with pH ranging from 1 to 8 and expressed as chroma, hue and colour shade. Between pH 3 and 7, all samples were stable as indicated by hue and chroma values. The colour shade of the red juice of Opuntia ficus-indica cv. 'Rossa' was in the range of red beet preparations hitherto most commonly used for colouring low-acid food commodities. Hylocereus was characterized by purplish hues, whereas the juice from O. ficus-indica cv. 'Gialla' displayed a yellow tonality. An improved spectrophotometric method for pigment quantification was proposed. Betacyanin contents were 525.3, 73.9 and 1.3 mg/l in juices from Hylocereus polyrhizus, Opuntia ficus-indica cv. 'Rossa' and O. ficus-indica cv. 'Gialla', whereas betaxanthins amounted to 48.3, 36.4 and 5.3 mg/l in O. ficus-indica cv. 'Gialla', O. ficus-indica cv. 'Rossa', and H. polyrhizus, respectively. Although the colourless fruits from O. ficus-indica cv. 'Bianca' and H. undatus could not be considered as a colour source, selected quality parameters were also investigated with respect to their nutritional value. To the best of our knowledge, this is the first report about the chemical quality parameters of H. polyrhizus and H. undatus.