Impulse Correlation for Partially Filled Detonation Tubes

The effect of nozzles on the impulse obtained from a detonation tube of circular cross section has been the focus of many experimental and numerical studies. In these cases, the simplified detonation tube is closed at one end (forming the thrust surface) and open at the other end, enabling the attachment of an extension. A flowfield analysis of a detonation tube with an extension requires considering unsteady wave interactions making analytical and accurate numerical predictions difficult (especially in complicated extension geometries). To predict the impulse obtained from a detonation tube with an extension (considered a partially filled detonation tube), we utilize data from other researchers to generate a partial-fill correlation

The Characterization of Epstein-Barr Virus Infected B Cells in the Peripheral Blood of Pediatric Solid Organ Transplant Recipients with Elevated Viral Loads

Epstein-Barr virus (EBV) has infected 95% of the adult population. Yet, EBV stays as a harmless passenger in infected B-cells of nearly every host. EBV depends on a careful balance between the immune system and the virus that becomes evident when the host is immunocompromised. In such individuals, EBV can manifest as one of many associated malignancies. In children who have undergone solid organ transplantation, EBV-driven post-transplant lymphoproliferative disease (PTLD) can cause significant morbidity and mortality. We examined EBV-infected cells in non-diseased pediatric transplant recipients with elevated viral loads in their peripheral blood. Examination of high EBV genome copy cells in high load patients with a combined fluorescent in situ hybridization and immunofluorescence procedure demonstrated that the majority of high copy cells had no discernible expression of immunoglobulin on the surface (Ig-null cells). Such cells are lacking the crucial survival signal provided by an intact BCR and should not survive in the circulation. By flow cytometry, high load patients were shown to have the highest percentage of Ig-null cells in their peripheral blood; those with low viral loads and non-detectable viral loads had lower percentages. The phenotype of Ig-null cells was shown to differ from the resting memory B2 phenotype of normal latently infected B cells, with variable expression of CD20, CD40, and HLA Class I and II. Sorting Ig-null cells from the peripheral blood of high load carriers further demonstrated that in all patients examined, a large portion of the viral load was carried in the Ig-null compartment. Virus was also detected in the Ig-null, CD20- and HLA Class I- compartment, with a variable enrichment of the viral load in these compartments from patient to patient. Ig-null cells have been reported in the tumors of other EBV-associated malignancies, including PTLD, but never in the peripheral blood or in a non-disease state. This study has public health relevance because PTLD carries significant morbidity and mortality to transplant recipients; the presence in the blood of aberrant Ig-null cells which should have followed a program of apoptosis might be a risk factor for the development of PTLD or another EBV-associated disease

New multiplexing scheme for monitoring fiber optic Bragg grating sensors in the coherence domain

A new multiplexing scheme for monitoring fiber optic Bragg gratings in the coherence domain has been developed. Grating pairs with different grating distances are distributed along a fiber line, and interference between their reflections is monitored with a scanning Michelson interferometer. The Bragg wavelength of the individual sensor elements is determined from the interference signal frequency

Glutathione treatment protects the rat liver against injury after warm ischemia and Kupffer cell activation

Background/Aim: The generation of reactive oxygen species by activated Kupffer cells (KC) may contribute to reperfusion injury of the liver during liver transplantation or resection. The aim of our present studies was to investigate (1) prevention of hepatic reperfusion injury after warm ischemia by administration of the antioxidant glutathione (GSH) and (2) whether GSH confers protection through influences on KC toxicity. Methods: Isolated perfused rat livers were subjected to 1 h of warm ischemia followed by 90 min of reperfusion without (n = 5) or with GSH or catalase (n = 4-5 each). Selective KC activation by zymosan (150 mug/ml) in continuously perfused rat livers was used to investigate KC-related liver injury. Results: Postischemic infusion of 0.1, 0.5, 1.0 and 2.0 mM GSH, but not 0.05 mM GSH prevented reperfusion injury after warm ischemia as indicated by a marked reduction of sinusoidal LDH efflux by up to 83 +/- 13% (mean +/- SD; p < 0.05) and a concomitant significant improvement of postischemic bile flow by 58 +/- 27% (p < 0.05). A similar protection was conveyed by KC blockade with gadolinium chloride indicating prevention of KC-related reperfusion injury by postischemic GSH treatment. Postischemic treatment with catalase (150 U/ml) resulted in a reduction of LDH efflux by 40 +/- 9% (p < 0.05). Accordingly, catalase as well as GSH (0.1-2.0 mM) nearly completely prevented the increase in LDH efflux following selective :KC activation by zymosan in continously perfused rat livers. Conclusion: Postischemic administration of GSH protects the liver against reperfusion injury after warm ischemia. Detoxification of KC-derived hydrogen peroxide seem to be an important feature of the protective mechanisms. Copyright (C) 2002 S. Karger AG, Basel

Prognostic factors in patients with diffuse type gastric cancer (linitis plastica) after operative treatment

<p>Abstract</p> <p>Objective</p> <p>Treatment options for patients with diffuse type gastric cancer (linitis plastica) are discussed controversial. It is sometimes discussed that these patients should be treated primarily in palliative intention conservative without resection.</p> <p>Methods</p> <p>In a single-center analysis, we investigated 120 patients with diffuse type gastric cancer. All patients underwent a total gastrectomy, 45 patients even a multivisceral resection because of infiltrating growth, or metastases. Serum tumor marker CEA, CA 72-4, and CA 19-9 were recorded in all patients before surgery. An immunocytochemical detection of free peritoneal tumor cells (FPTC) using Ber-EP4 antibody was correlated with tumor stage and survival. Median follow-up time was 38 months.</p> <p>Results</p> <p>Complete resection rate was 31% (n = 37). 61% (n = 73) of all patients had already distant metastases at the time of surgery, 80% of them peritoneal carcinomatosis. Median survival for the whole group was 8 months, after complete resection 17 months. Lavage cytology, distant metastases, resection rate, and CA19-9 levels had significant influence on survival.</p> <p>Conclusion</p> <p>A significant survival advantage for patients with diffuse type gastric cancer can only be achived after complete resection. We could define a subset of patients with an extremely poor prognosis even after surgical resection. Meticulous preoperative staging, including a diagnostic laparoscopy to exclude peritoneal carcinomatosis and free peritoneal tumor cells before resection should be mandatory in these patients.</p

Application of synchrotron radiation for measurement of iron red-ox speciation in atmospherically processed aerosols

In this study, ambient atmospheric particulate matter samples were collected using a size-resolved impactor sampler from three urban sites. The purpose of this study is to gain a better understanding of transformations of aerosol-bound iron as it is processed in the atmosphere. Thus, the aerosol samples were artificially aged to represent long-term transport (10 to 40 days) or short-term transport (1 to 10 days) and were measured for iron at several time points. At each time point, iron was measured in each size fraction using three different techniques; 1) inductively coupled plasma-mass spectrometry (ICPMS) for total iron, 2) x-ray absorbance near edge structure (XANES) spectroscopy for the measurement of total Fe(II) and Fe(III), and 3) a wet-chemical method to measure soluble Fe(II) and Fe(III). Prior to aging, the XANES spectroscopy results show that a majority (&gt;60% for each size fraction) of the total iron in the PM is in the form of Fe(III). Fe(III) was shown to be a significant fraction of the soluble iron (sometimes &gt;50%), but the relative significance of Fe(III) was found to vary depending on the site. Overall, the total soluble iron depended on the sampling site, but values ranged from less than 1% up to about 20% of the total iron. Over the course of the 40 day aging period, we found moderate changes in the relative Fe(II)/Fe(III) content. A slight increase was noted in the coarse (&gt;2.5 &micro;m) fraction and a slight decrease in the 0.25 to 0.5 &micro;m fraction. The soluble fraction generally showed (excepting one day) a decrease of soluble Fe(II) prior to 10 days of aging, followed by a relatively constant concentration. In the short-term transport condition, we found that the sub-micron fraction of soluble Fe(II) spikes at 1 to 3 days of aging, then decreases to near the initial value at around 6 to 10 days. Very little change in soluble Fe(II) was observed in the super-micron fraction