50 resultados para chambers

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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OBJECTIVE: Autopsy determination of fatal hemorrhage as the cause of death is often a difficult diagnosis in forensic medicine. No quantitative system for accurately measuring the blood volume in a corpse has been developed. MATERIALS AND METHODS: This article describes the measurement and evaluation of the cross-sectional areas of major blood vessels, of the diameter of the right pulmonary artery, of the volumes of thoracic aorta and spleen on MDCT, and of the volumes of heart chambers on MRI in 65 autopsy-verified cases of fatal hemorrhage or no fatal hemorrhage. RESULTS: Most cases with a cause of death of "fatal hemorrhage" had collapsed vessels. The finding of a collapsed superior vena cava, main pulmonary artery, or right pulmonary artery was 100% specific for fatal hemorrhage. The mean volumes of the thoracic aorta and of each of the heart chambers and the mean cross-sectional areas of all vessels except the inferior vena cava and abdominal aorta were significantly smaller in fatal hemorrhage than in no fatal hemorrhage. CONCLUSION: For the quantitative differentiation of fatal hemorrhage from other causes of death, we propose a three-step algorithm with measurements of the diameter of the right pulmonary artery, the cross-sectional area of the main pulmonary artery, and the volume of the right atrium (specificity, 100%; sensitivity, 95%). However, this algorithm must be corroborated in a prospective study, which would eliminate the limitations of this study. Quantitative postmortem cross-sectional imaging might become a reliable objective method to assess the question of fatal hemorrhage in forensic medicine.

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A number of liquid argon time projection chambers (LAr TPCs) are being built or are proposed for neutrino experiments on long- and short baseline beams. For these detectors, a distortion in the drift field due to geometrical or physics reasons can affect the reconstruction of the events. Depending on the TPC geometry and electric drift field intensity, this distortion could be of the same magnitude as the drift field itself. Recently, we presented a method to calibrate the drift field and correct for these possible distortions. While straight cosmic ray muon tracks could be used for calibration, multiple coulomb scattering and momentum uncertainties allow only a limited resolution. A UV laser instead can create straight ionization tracks in liquid argon, and allows one to map the drift field along different paths in the TPC inner volume. Here we present a UV laser feed-through design with a steerable UV mirror immersed in liquid argon that can point the laser beam at many locations through the TPC. The straight ionization paths are sensitive to drift field distortions, a fit of these distortion to the linear optical path allows to extract the drift field, by using these laser tracks along the whole TPC volume one can obtain a 3D drift field map. The UV laser feed-through assembly is a prototype of the system that will be used for the MicroBooNE experiment at the Fermi National Accelerator Laboratory (FNAL).

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The study focuses on gender norms and practices in Chinese Christian communities established by Jesuit missionary activity during the long seventeenth century. It analyzes how European and Chinese gender norms and practices affected each other in the context of the Sino-Western cultural contact initiated by the missionaries. The thesis consists of two parts. First, it analyzes the ways in which European Jesuits engaged with Chinese gender relations in the course of their mission in China. The study demonstrates that the Jesuits’ adoption of the Chinese scholar-gentry’s habitus entailed a partial adaptation to Confucian gender norms. The latter placed great emphasis on gender segregation and therefore discouraged direct communication between missionaries and Chinese women. This resulted in the emergence of organizational and devotional arrangements of Christian communities specific to China. Second, the study discusses Chinese Christian women's religious culture that emerged in the absence of a strong missionary presence among female devotees. It points out that Chinese Christian women created their own ritual culture and religious sociability in the domestic context, and that they actively took part in shaping Chinese Christianity as masters of domestic rituals.

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Segmented ionization chambers represent a good solution to monitor the position, the intensity and the shape of ion beams in hadrontherapy. Pixel and strip chambers have been developed for both passive scattering and active scanning dose delivery systems. In particular, strip chambers are optimal for pencil beam scanning, allowing for spatial and time resolutions below 0.1 mm and 1 ms, respectively. The MATRIX pixel and the Strip Accurate Monitor for Beam Applications (SAMBA) detectors are described in this paper together with the results of several beam tests and industrial developments based on these prototypes.

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A constantly growing number of scooters produce an increasing amount of potentially harmful emissions. Due to their engine technology, two-stroke scooters emit huge amounts of adverse substances, which can induce adverse pulmonary and cardiovascular health effects. The aim of this study was to develop a system to expose a characterized triple cell coculture model of the human epithelial airway barrier, to freshly produced and characterized total scooter exhaust emissions. In exposure chambers, cell cultures were exposed for 1 and 2 h to 1:100 diluted exhaust emissions and in the reference chamber to filtered ambient air, both controlled at 5% CO(2), 85% relative humidity, and 37 degrees C. The postexposure time was 0-24 h. Cytotoxicity, used to validate the exposure system, was significantly increased in exposed cell cultures after 8 h postexposure time. (Pro-) inflammatory chemo- and cytokine concentrations in the medium of exposed cells were significantly higher at the 12 h postexposure time point. It was shown that the described exposure system (with 2 h exposure duration, 8 and 24 h postexposure time, dilution of 1:100, flow of 2 L/min as optimal exposure conditions) can be used to evaluate the toxic potential of total exhaust emissions.

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Despite evidence for the important role of oestrogens in the aetiology and pathophysiology of chronic immune/inflammatory diseases, the previous view of an unequivocal beneficial effect of oestrogens on RA compared with a detrimental effect on SLE has to be reconsidered. Likewise, the long-held belief that RA remits in the majority of pregnant patients has been challenged, and shows that only half of the patients experience significant improvement when objective disease activity measurements are applied. Pregnancies in patients with SLE are mostly successful when well planned and monitored interdisciplinarily, whereas a small proportion of women with APS still have adverse pregnancy outcomes in spite of the standard treatment. New prospective studies indicate better outcomes for pregnancies in women with rare diseases such as SSc and vasculitis. Fertility problems are not uncommon in patients with rheumatic disease and need to be considered in both genders. Necessary therapy, shortly before or during the pregnancy, demands taking into account the health of both mother and fetus. Long-term effects of drugs on offspring exposed in utero or during lactation is a new area under study as well as late effects of maternal rheumatic disease on children.

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A laboratory model system with the rosy apple aphid (Dysaphis plantaginea Pass.) on apple seedlings was developed to study the effects of homeopathic preparations on this apple pest. The assessment included the substance Lycopodium clavatum and a nosode of the rosy apple aphid. Each preparation was applied on the substrate surface as aqueous solution of granules (6c, 15c, or 30c). Controls were aqueous solutions of placebo granules or pure water. In eight independent, randomized, and blinded experiments under standardized conditions in growth chambers, the development of aphids on treated and untreated apple seedlings was observed over 17 days, each. Six experiments were determined to assess the effects of a strict therapeutic treatment; two experiments were designed to determine the effects of a combined preventative and therapeutic treatment. After application of the preparations, the number of juvenile offspring and the damage on apple seedlings were assessed after 7 and 17 days, respectively. In addition, after 17 days, the seedling weight was measured. In the final evaluation of the six strictly therapeutic trials after 17 days, the number of juvenile offspring was reduced after application of L. clavatum 15c (-17%, p = 0.002) and nosode 6c (-14%, p = 0.02) compared to the pure water control. No significant effects were observed for leaf damage or fresh weight for any application. In the two experiments with combined preventative and therapeutic treatment, no significant effects were observed in any measured parameter. Homeopathic remedies may be effective in plant-pest systems. The magnitude of observed effects seems to be larger than in models with healthy plants, which renders plant-pest systems promising candidates for homeopathic basic research. For successful application in agriculture, however, the effect is not yet sufficient. This calls for further optimization concerning homeopathic remedy selection, potency level, dosage, and application routes.

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During vertebrate development, the lung inaugurates as an endodermal bud from the primitive foregut. Dichotomous subdivision of the bud results in arborizing airways that form the prospective gas exchanging chambers, where a thin blood-gas barrier (BGB) is established. In the mammalian lung, this proceeds through conversion of type II cells to type I cells, thinning, and elongation of the cells as well as extrusion of the lamellar bodies. Subsequent diminution of interstitial tissue and apposition of capillaries to the alveolar epithelium establish a thin BGB. In the noncompliant avian lung, attenuation proceeds through cell-cutting processes that result in remarkable thinning of the epithelial layer. A host of morphoregulatory molecules, including transcription factors such as Nkx2.1, GATA, HNF-3, and WNT5a; signaling molecules including FGF, BMP-4, Shh, and TFG- β and extracellular proteins and their receptors have been implicated. During normal physiological function, the BGB may be remodeled in response to alterations in transmural pressures in both blood capillaries and airspaces. Such changes are mitigated through rapid expression of the relevant genes for extracellular matrix proteins and growth factors. While an appreciable amount of information regarding molecular control has been documented in the mammalian lung, very little is available on the avian lung.

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Abstract Background: Aerosol therapy in preterm infants is challenging, as a very small proportion of the drug deposits in the lungs. Aim: Our aim was to compare efficiency of standard devices with newer, more efficient aerosol delivery devices. Methods: Using salbutamol as a drug marker, we studied two prototypes of the investigational eFlow(®) nebulizer for babies (PARI Pharma GmbH), a jet nebulizer (Intersurgical(®) Cirrus(®)), and a pressurized metered dose inhaler (pMDI; GSK) with a detergent-coated holding chamber (AeroChamber(®) MV) in the premature infant nose throat-model (PrINT-model) of a 32-week preterm infant (1,750 g). A filter or an impactor was placed below the infant model's "trachea" to capture the drug dose or particle size, respectively, that would have been deposited in the lung. Results: Lung dose (percentage of nominal dose) was 1.5%, 6.8%, and 18.0-20.6% for the jet nebulizer, pMDI-holding chamber, and investigational eFlow nebulizers, respectively (p<0.001). Jet nebulizer residue was 69.4% and 10.7-13.9% for the investigational eFlow nebulizers (p<0.001). Adding an elbow extension between the eFlow and the model significantly lowered lung dose (p<0.001). A breathing pattern with lower tidal volume decreased deposition in the PrINT-model and device residue (p<0.05), but did not decrease lung dose. Conclusions: In a model for infant aerosol inhalation, we confirmed low lung dose using jet nebulizers and pMDI-holding chambers, whereas newer, more specialized vibrating membrane devices, designed specifically for use in preterm infants, deliver up to 20 times more drug to the infant's lung.

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A 20-month old girl with severe pulmonary hypertension and cardiomegaly was admitted to the paediatric intensive care unit with right ventricular failure of unknown origin. Only after decompression of the heart chambers under extracorporeal membrane oxygenation (ECMO), did the pathognomonic membrane of Cor triatriatum become visible on echocardiography. The patient underwent successful surgical correction and subsequently cardiac function recovered completely. Cor triatriatum remains a rare congenital cardiac disorder with a variable presentation, often including recurrent respiratory infections before right-sided heart failure occurs. This case illustrates that ECMO can serve not only as a bridge to diagnosis, but can also facilitate correct diagnosis. Given the excellent outcome after surgical treatment, it is crucial that cardiologists rule out the possibility of cor triatriatum when assessing a child with unexplained pulmonary hypertension.

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Neutrophils are recruited to the site of parasite inoculation within a few hours of infection with the protozoan parasite Leishmania major. In C57BL/6 mice, which are resistant to infection, neutrophils are cleared from the site of s.c. infection within 3 days, whereas they persist for at least 10 days in susceptible BALB/c mice. In the present study, we investigated the role of macrophages (MPhi) in regulating neutrophil number. Inflammatory cells were recruited by i.p. injection of either 2% starch or L. major promastigotes. Neutrophils were isolated and cultured in the presence of increasing numbers of MPhi. Extent of neutrophil apoptosis positively correlated with the number of MPhi added. This process was strictly dependent on TNF because MPhi from TNF-deficient mice failed to induce neutrophil apoptosis. Assays using MPhi derived from membrane TNF knock-in mice or cultures in Transwell chambers revealed that contact with MPhi was necessary to induce neutrophil apoptosis, a process requiring expression of membrane TNF. L. major was shown to exacerbate MPhi-induced apoptosis of neutrophils, but BALB/c MPhi were not as potent as C57BL/6 MPhi in this induction. Our results emphasize the importance of MPhi-induced neutrophil apoptosis, and membrane TNF in the early control of inflammation.

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Radial artery (RA) bypass grafts can develop severe vasospasm. As histamine is known to induce vasospasm, its effect on RA was assessed compared with the classic bypass vessels internal mammary artery (MA) and saphenous vein (SV). The vessels were examined in organ chambers for isometric tension recording. Histamine induced contractions on baseline; the sensitivity was higher in RA and SV than MA. After precontraction with norepinephrine, histamine did not evoke relaxations of RA but induced relaxations of MA and less of SV at lower concentrations; it induced contractions at higher concentrations, reaching similar levels in all three vessels. Indomethacin did not affect the response of MA and RA but potentiated relaxations and reduced contractions of SV. Endothelium removal, N(omega)-nitro-L-arginine methyl ester (L-NAME), or the H2-receptor blocker cimetidine did not affect the response of RA, but inhibited relaxations and enhanced contractions in MA and inhibited relaxations in SV; in the latter, only L-NAME enhanced contractions. Real-time PCR detected much lower expression of endothelial H2-receptor in RA than MA or SV. Western blots revealed similar endothelial nitric oxide (NO) synthase expression in all three vessels. Relaxations to acetylcholine were identical in RA and MA. Thus histamine releases NO by activating the endothelial H2-receptor, the expression of which is much lower in RA than MA or SV. H2-receptor activation also releases prostaglandins in SV, partially antagonizing NO. The lack of histamine-induced NO production represents a possible mechanism of RA vasospasm.

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Today electronic portal imaging devices (EPID's) are used primarily to verify patient positioning. They have, however, also the potential as 2D-dosimeters and could be used as such for transit dosimetry or dose reconstruction. It has been proven that such devices, especially liquid filled ionization chambers, have a stable dose response relationship which can be described in terms of the physical properties of the EPID and the pulsed linac radiation. For absolute dosimetry however, an accurate method of calibration to an absolute dose is needed. In this work, we concentrate on calibration against dose in a homogeneous water phantom. Using a Monte Carlo model of the detector we calculated dose spread kernels in units of absolute dose per incident energy fluence and compared them to calculated dose spread kernels in water at different depths. The energy of the incident pencil beams varied between 0.5 and 18 MeV. At the depth of dose maximum in water for a 6 MV beam (1.5 cm) and for a 18 MV beam (3.0 cm) we observed large absolute differences between water and detector dose above an incident energy of 4 MeV but only small relative differences in the most frequent energy range of the beam energy spectra. It is shown that for a 6 MV beam the absolute reference dose measured at 1.5 cm water depth differs from the absolute detector dose by 3.8%. At depth 1.2 cm in water, however, the relative dose differences are almost constant between 2 and 6 MeV. The effects of changes in the energy spectrum of the beam on the dose responses in water and in the detector are also investigated. We show that differences larger than 2% can occur for different beam qualities of the incident photon beam behind water slabs of different thicknesses. It is therefore concluded that for high-precision dosimetry such effects have to be taken into account. Nevertheless, the precise information about the dose response of the detector provided in this Monte Carlo study forms the basis of extracting directly the basic radiometric quantities photon fluence and photon energy fluence from the detector's signal using a deconvolution algorithm. The results are therefore promising for future application in absolute transit dosimetry and absolute dose reconstruction.

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Type 1 diabetes is an immuno-inflammatory condition which increases the risk of cardiovascular disease, particularly in young adults. This study investigated whether vascular function is altered in mice prone to autoimmune diabetes and whether the nitric oxide (NO)-cyclic GMP axis is involved. Aortic rings suspended in organ chambers and precontracted with phenylephrine were exposed to cumulative concentrations of acetylcholine. To investigate the role of NO, some experiments were performed in the presence of either 1400W (N-(3-aminomethyl)benzyl-acetamidine hydrochloride), a selective inhibitor of the iNOS-isoform, L-NAME (N(G)-nitro-L-arginine methyl ester hydrochloride), an inhibitor of all three NOS-isoforms, or ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one), a selective inhibitor of guanylate cyclase. Moreover, contractility to phenylephrine, big endothelin-1, and endothelin-1 was assessed and histological analysis and iNOS immunohistochemistry were performed. Endothelium-dependent relaxation was reduced in prediabetic NOD mice (78+/-4 vs. 88+/-2%, respectively, P<0.05 vs. control) despite normal plasma glucose levels (n.s. vs. control). Preincubation with 1400W further attenuated responses in prediabetic (P<0.05 vs. untreated) but not in diabetic or in control mice. In contrast, basal NO bioactivity remained unaffected until the onset of diabetes in NOD mice. Contractile responses to big endothelin-1 and endothelin-1 were reduced in prediabetic animals (P<0.05 vs. control), whereas in diabetic mice only responses to big endothelin-1 were decreased (P<0.05 vs. control). These data demonstrate that endothelium-dependent and -independent vascular function in NOD mice is abnormal already in prediabetes in the absence of structural injury. Early proinflammatory activation due to iNOS in diabetes-prone NOD mice appears to be one of the mechanisms contributing to impaired vasoreactivity.