Characterization of stiffness degradation caused by fatigue damage in textile composites using circumferential plate acoustic waves

The aim of this paper is to show the possibility of fatigue damage characterization in GFRP-tube-like components by using circumferential plate waves. For that purpose, fatigue tests with different loading directions have been conducted and the stiffness degradation has been monitored. After a preset number of loading cycles, non-destructive ultrasonic tests using circumferential plate waves were performed. The correlation between damage induced amplitude changes of the plate waves and stiffness degradation in non-crimped fabric composites is discussed. The results indicate that the technique is applicable to fatigue damage assessment in complex-shaped components of composite materials and is relevant to a wide field of applications.     

Gold and thiol surface functionalized integrated optical Mach–Zehnder interferometer for sensing purposes

We demonstrate an integrated optical Mach–Zehnder interferometer for sensing purposes with a surface functionalized by thiols via an additional gold layer. Therefore, the oxidic silicon oxynitride waveguide surface was first covered by a thiol terminated silane self-assembled monolayer. An ultrathin gold layer was then deposited onto the “active” sulfur surface by OMCVD. This gold layer was finally functionalized by a biotinylated thiol in order to specifically bind streptavidin and a biotinylated antibody. Unspecific binding of streptavidin was tested also.     

Mechanisms of acute eosinophilic inflammation in a case of acute eosinophilic pneumonia in a 14-year-old girl

The alpha 1-, alpha 2-, alpha 3-, and alpha 4-tubulin genes have been mapped by in situ hybridization to the polytene chromosomes of five species representative of the Drosophila montium subgroup geographical distribution. A lambda phage clone containing alpha 1-tubulin specific sequences was isolated from a genomic DNA library of Drosophila auraria and its restriction endonuclease pattern is presented. Both well-characterized heterologous and homologous probes were used to assess orthogonality of gene members between species groups. The in situ hybridization pattern observed in all species studied is consistent with that of Drosophila melanogaster, since alpha 1-, alpha 2-, and alpha 3-tubulin genes are located on the same polytene arm, and the alpha 4-tubulin gene is found on a different arm. Cross-hybridization was observed among alpha 1-, alpha 2-, and alpha 3-tubulin specific sequences in all species studied, using either heterologous or homologous probes. However, unlike D. melanogaster, in all montium species studied, both alpha 1- and alpha 3-tubulin specific probes hybridize to the same polytene band, indicating a clustered organization of the above genes. The chromosomal organization of this gene family would suggest that taxa within the montium subgroup are closer to their common ancestors than are the taxa in the melanogaster species group. A mode of evolution for this gene family in Drosophila is proposed.     

Differential regulation of eosinophil adhesion and transmigration by pulmonary microvascular endothelial cells

In bronchial asthma, eosinophils (EOS) adhere to, and migrate across, the lung microvasculature to exert their effector functions in the airways. This study was conducted to determine the effect of cytokines on adhesion molecule expression on human pulmonary microvascular endothelial cells (HPMEC) and the influence of these molecules on EOS adhesion and transmigration in vitro. Unlike ICAM-1 expression (>80% positive cytokine-treated HPMEC by flow cytometry), VCAM-1 expression varied with the cytokine(s) pretreatment; the order of potency was: TNF-alpha + IL-4 (82.2 +/- 4.2% positive cells) > TNF-alpha (41.8 +/- 5.1%) > IL-1beta (20.8 +/- 4.7%). IL-4 alone had no effect on either ICAM-1 or VCAM-1 expression. EOS adhesion to cytokine-treated HPMEC followed the same order as that observed for VCAM-1 expression. Interestingly, EOS migration across cytokine-treated HPMEC varied inversely with VCAM-1 expression on, and EOS adhesion to, HPMEC; IL-1beta (21.2 +/- 1.4% migration) > TNF-alpha (12.6 +/- 2.6%) > TNF-alpha + IL-4 (9.1 +/- 2.0%). EOS adhesion was greatest with TNF-alpha + IL-4-treated HPMEC, was dependent on VCAM-1, and inhibited with anti-alpha4 integrin mAb (67.7 +/- 7.5% inhibition, p < 0.0005). In contrast, the highest EOS migration occurred across IL-1beta-treated HPMEC and was inhibited by anti-beta2 integrin mAb (40.4 +/- 2.5% inhibition, p < 0.005). Viable HPMEC were required for EOS migration but not adhesion. Our results suggest that EOS adhesion and transmigration are differentially regulated by VCAM-1 and ICAM-1 expression and the interaction of these adhesion proteins with their respective counterligands, i.e., alpha4 and beta2 integrins on EOS.     

Increased tumor necrosis factor-alpha (TNF-alpha) gene expression in parainfluenza type 1 (Sendai) virus-induced bronchiolar fibrosis

Increased airway resistance and airway hyperresponsiveness induced in rats by infection with parainfluenza type I (Sendai) virus is associated with bronchiolar fibrosis. To determine whether increased tumor necrosis factor (TNF)-alpha gene expression is an important regulatory event in virus-induced bronchiolar fibrosis, pulmonary TNF-alpha mRNA and protein expression was assessed in rat strains that are susceptible (Brown Norway; BN) and resistant (Fischer 344; F344) to virus-induced bronchiolar fibrosis. Virus-inoculated BN rats had increased TNF-alpha pulmonary mRNA levels (P < 0.05) and increased numbers of bronchiolar macrophages and fibroblasts expressing TNF-alpha protein compared with virus-inoculated F344 rats (P < 0.05). Virus inoculation also induced elevated TNF-alpha mRNA and protein levels (P < 0.05) in cultured rat alveolar macrophages (NR8383 cells). A 55-kd soluble TNF receptor-immunoglobulin G fusion protein (sTNFR-IgG) was used to inhibit TNF-alpha bioactivity in virus-inoculated BN rats. Treated rats had fewer proliferating bronchiolar fibroblasts, as detected by bromodeoxyuridine incorporation, compared with virus-inoculated control rats (P < 0.05). There was also increased mortality in p55sTNFR-IgG-treated virus-inoculated rats associated with increased viral replication and decreased numbers of macrophages and lymphocytes in bronchoalveolar lavage fluid (P < 0.05). The results of this study indicate that 1) Sendai virus can directly up-regulate TNF-alpha mRNA and protein expression in macrophages, 2) TNF-alpha is an important mediator of virus-induced bronchiolar fibrosis, and 3) TNF-alpha has a critical role in the termination of Sendai viral replication in the lung.     

Ca2+-independent activation of the endothelial nitric oxide synthase in response to tyrosine phosphatase inhibitors and fluid shear stress

Chinese hamster V79 cell lines were constructed for stable expression of human cytochrome P450 1B1 (P450 1B1) in order to study its role in the metabolic activation of chemicals and toxicological consequences. The new V79 cell lines were applied to studies on DNA adduct formation of the polycyclic aromatic hydrocarbon (PAH) dibenzo[a,l]pyrene (DB[a,l]P). This compound has been found to be an environmental pollutant, and in rodent bioassays it is the most carcinogenic PAH yet discovered. Activation of DB[a,l]P in various metabolizing systems occurs via fjord region DB[a,l]P-11, 12-dihydrodiol 13,14-epoxides (DB[a,l]PDE): we found that DB[a,l]P is stereoselectively metabolized in human mammary carcinoma MCF-7 cells to the (-)-anti- and (+)-syn-DB[a,l]PDE which both bind extensively to cellular DNA. To follow up this study and to relate specific DNA adducts to activation by individual P450 isoforms, the newly established V79 cells stably expressing human P450 1B1 were compared with those expressing human P450 1A1. DNA adduct formation in both V79 cell lines differed distinctively after incubation with DB[a,l]P or its enantiomeric 11,12-dihydrodiols. Human P450 1A1 catalyzed the formation of DB[a,l]PDE-DNA adducts as well as several highly polar DNA adducts as yet unidentified. The proportion of these highly polar adducts to DB[a,l]PDE adducts was dependent upon both the concentration of DB[a,l]P and the time of exposure. In contrast, V79 cells stably expressing human P450 1B1 generated exclusively DB[a,l]PDE-DNA adducts. Differences in the total level of DNA binding were also observed. Exposure to 0.1 microM DB[a,l]P for 6 h caused a significantly higher level of DNA adducts in V79 cells stably expressing human P450 1B1 (370 pmol/mg of DNA) compared to those with human P450 1A1 (35 pmol/mg of DNA). A 4-fold higher extent of DNA binding was catalyzed by human P450 1B1 (506 pmol/mg of DNA) compared to human P450 1A1 (130 pmol/mg of DNA) 6 h after treatment with 0.05 microM (-)-(11R,12R)-dihydrodiol. In cells stably expressing human P450 1B1 the DNA adducts were derived exclusively from the (-)-anti-DB[a,l]PDE. These results indicate that human P450 1B1 and P450 1A1 differ in their regio- and stereochemical selectivity of activation of DB[a,l]P with P450 1B1 forming a higher proportion of the highly carcinogenic (-)-anti-(11R, 12S,13S,14R)-DB[a,l]PDE metabolite.     

Design parameters for fluoride multimode fibers

Numerical calculations of losses due to polymer coatings and macrobending have been made for step-index multimode fluoride fibers. To minimize such losses, fiber parameters must be chosen to give a large value for V, the normalized frequency. Due to the long propagation wavelength (2.5 μm) for fluoride fiber, the parameters needed are very different from those of silica fiber. Using the criterion that ⩾90% of the modes have losses ⩽0.01 dB/km, it was found that the cladding diameters need to be rather large compared to step-index silica fiber parameters. Although the mode distributions are unknown for fluoride fiber, using a theoretical Gaussian distribution, losses were calculated for the various fiber parameters     

The principal physician in emergency medicine

The implementation of an experienced pre-hospital care emergency physician as an on the-scene medical command officer (MCO) within the emergency medical service (EMS) is an essential prerequisite to guarantee qualified medical supervision during mass-casuality incidents (MCI). The MCO has four basic functions. Within the administration of the EMS system, he is responsible for the medical aspects of strategic planning for the MCI response. During the MCI the MCO is responsible for the overall assessment of the situation, triage, and supervision of medical treatment by physician and non-physician providers. Aside from extensive personal experience in pre-hospital care, the MCO needs special training to be qualified for this position. State EMS laws provide the legal basis for the MCO within the EMS system.     

Lacrimal duct surgery in childhood. Retrospective study at the Munster University Ophthalmology Clinic

Twenty-one consecutive laparoscopic cholecystectomies (LC) were compared with 29 consecutive open cholecystectomies (OC). Sickle-cell disease (SCD) was the most common reason for cholecystectomy in both groups. The average length of operative time for LC was significantly longer than that of OC (P=0.0149). In 1 patient there was conversion from LC to OC due to severe adhesions. Common bile duct (CBD) stones were diagnosed in 8 (27.6%) of the OC group; in 4 of them the diagnosis was made preoperatively by ultrasound, in 4 by intraoperative cholangiogram. All 8 patients required CBD exploration, and 2 had additional transduodenal sphincteroplasties. In the LC group 5 patients (23.8%) had CBD stones. All had (ERCP) endoscopic retrograde cholangiopancreatography sphincterotomy, and stone extraction followed by LC. ERCP is a necessary adjunct to treatment if LC is to be contemplated. Six patients in the OC group developed complications, while only 4 patients in the LC group developed minor complications. The length of hospitalization after LC was significantly shorter than after OC (P=0.0150). LC is the procedure of choice in the management of cholelithiasis in children, especially those with SCD.