190 research outputs found
Aperistaltic effect of hyoscine N -butylbromide versus glucagon on the small bowel assessed by magnetic resonance imaging
The aim of this prospective study was to compare the intraindividual aperistaltic effect of 40mg hyoscine N-butylbromide (HBB/Buscopan) with that of 1mg glucagon on small bowel motility by using magnetic resonance imaging (MRI). Ten healthy volunteers underwent two separate 1.5-T MRI studies (HBB/glucagon) after a standardized oral preparation with an aqueous solution of Gd-DOTA and ispaghula (Metamucil). A 2D T1-w GRE sequence was acquired (TR 2.7ms/TE 1.3ms, temporal resolution 0.25s) before and after intravenous (i.v.) drug administration and motility was followed over 1h. On the resulting images the cross-sectional luminal diameters were assessed and plotted over time. Baseline motility frequency, onset of aperistalsis, duration of arrest, reappearance of motility and return to normal motility were analysed. Significant differences regarding reliability and duration of aperistalsis were observed. In the HBB group aperistalsis lasted a mean of 6.8 ± 5.3min compared with 18.3 ± 7min after glucagon (p < 0.0001). In 50% of cases HBB did not accomplish aperistalsis, whereas glucagon always succeeded (p = 0.05). There were no significant differences in terms of baseline and end frequencies for the onset of aperistalsis (22.2 ± 37.5s HBB/13.4 ± 9.2s glucagon, p = 0.1), nor for the return to normal motility. Arrest of small bowel motion is achieved more reliably and lasts significantly longer after i.v. administration of 1mg glucagon compared with 40mg HB
From regenerated wood pulp fibers to cationic cellulose: preparation, characterization and dyeing properties
The global demand for sustainable textile fibers is growing and has led to an increasing
research interest from both academia and industry to find effective solutions. In this research,
regenerated wood pulp fibers were functionalized with glycidyltrimethylammonium chloride (GTAC)
to produce modified regenerated cellulose with cationic pending groups for improved dye uptake.
The resultant cationic cellulose with a degree of substitution (DS) between 0.13 and 0.33 exhibited
distinct morphologies and contact angles with water ranging from 65.7◦
to 82.5◦
for the fibers with DS
values of 0.13 and 0.33, respectively. Furthermore, the thermal stability of the modified regenerated
cellulose fibers, albeit lower than the pristine ones, reached temperatures up to 220 ◦C. Additionally,
the modified fibers showed higher dye exhaustion and dye fixation values than the non-modified
ones, attaining maxima values of 89.3% ± 0.9% and 80.6% ± 1.3%, respectively, for the cationic fibers
with a DS of 0.13. These values of dye exhaustion and dye fixation are ca. 34% and 77% higher than
those obtained for the non-modified fibers. Overall, regenerated wood pulp cellulose fibers can be
used, after cationization, as textiles fiber with enhanced dye uptake performance that might offer
new options for dyeing treatments.publishe
Suction against resistance: a new breathing technique to significantly improve the blood flow ratio of the superior and inferior vena cava
Objectives: Optimal contrast within the pulmonary artery is achieved by the maximum amount of contrast-enhanced blood flowing through the superior vena cava (SVC), while minimum amounts of non-contrasted blood should originate from the inferior vena cava (IVC). This study aims to clarify whether "suction against resistance” might optimise this ratio. Methods: Phase-contrast pulse sequences on a 1.5T MRI magnet were used for flow quantification (mean flow (mL/s), stroke volume (Vol) in the SVC and IVC in volunteers. Different breathing manoeuvers were analysed repeatedly: free breathing; inspiration; expiration; suction against resistance, and Valsalva. To standardise breathing commands, volunteers performed suction and Valsalva manoeuvers with an MR-compatible manometer. Results: Suction against resistance was associated with a significant drop of the IVC/SVC flow quotient (1.63 [range 1.3-2.0] p 0.05). Conclusions: Suction against resistance caused a significant drop in the IVC/SVC quotient. Theoretically, this breathing manoeuver might significantly improve the enhancement characteristics of CT angiography. Key Points: • Suction provokes reduction in blood flow in the inferior vena cava. • Ratio between the inferior and superior vena cava blood flow diminished during suction. • Manometer used during breathing standardises MR phase-contrast blood flow measurements
The Nordic Corporate Governance Model
The Nordic Region is remarkable in many ways and has been the subject of increasing interest over the past years. The five countries of Denmark, Finland, Iceland, Norway and Sweden are culturally closely aligned and combine a well-functioning business sector and high GDP with an expansive welfare state and high taxes. What has been well less known outside the Nordic Region is the shared corporate governance model used by companies and for the first time a comprehensive study is available in English to explain this model.
The main part of the study is the condensed presentation of the Nordic CG model. It is based on four country reports covering the three EU Member States (DK, F, S) and one EEA Member State (N). Each country report has been drawn up by a team consisting of a legal expert and a corporate governance expert with practical experience. To ensure that the report reflects actual practices, each team was assisted by a reference group consisting of business practitioners with extensive experience from large-cap listed companies and connections to the national CG code committees. To provide an international aspect, the renowned American scholar Ronald J Gilson contributed a comment on the report’s findings in a separate chapter.
The key observation of the study is that the Nordic CG model allows the shareholder majority to effectively control and take long-term responsibility for the company that they own. The alleged risk of such a system – the potential that a shareholder majority misuses its power for its own benefit at the expense of minority shareholders – is effectively curbed through a well-developed system of minority protection. The result is a governance model that encourages strong shareholders to engage in the governance of the company in their own interest, while creating value for the company and all its shareholders
Phenotypic engineering by reprogramming gene transcription using novel artificial transcription factors in Escherichia coli
Now that many genomes have been sequenced and the products of newly identified genes have been annotated, the next goal is to engineer the desired phenotypes in organisms of interest. For the phenotypic engineering of microorganisms, we have developed novel artificial transcription factors (ATFs) capable of reprogramming innate gene expression circuits in Escherichia coli. These ATFs are composed of zinc finger (ZF) DNA-binding proteins, with distinct specificities, fused to an E. coli cyclic AMP receptor protein (CRP). By randomly assembling 40 different types of ZFs, we have constructed more than 6.4 × 104 ATFs that consist of 3 ZF DNA-binding domains and a CRP effector domain. Using these ATFs, we induced various phenotypic changes in E. coli and selected for industrially important traits, such as resistance to heat shock, osmotic pressure and cold shock. Genes associated with the heat-shock resistance phenotype were then characterized. These results and the general applicability of this platform clearly indicate that novel ATFs are powerful tools for the phenotypic engineering of microorganisms and can facilitate microbial functional genomic studies
Insula-specific responses induced by dental pain: a proton magnetic resonance spectroscopy study
OBJECTIVES: To evaluate whether induced dental pain leads to quantitative changes in brain metabolites within the left insular cortex after stimulation of the right maxillary canine and to examine whether these metabolic changes and the subjective pain intensity perception correlate.
METHODS: Ten male volunteers were included in the pain group and compared with a control group of 10 other healthy volunteers. The pain group received a total of 87-92 electrically induced pain stimuli over 15 min to the right maxillary canine tooth. Contemporaneously, they evaluated the subjective pain intensity of every stimulus using an analogue scale. Neurotransmitter changes within the left insular cortex were evaluated by MR spectroscopy.
RESULTS: Significant metabolic changes in glutamine (+55.1%), glutamine/glutamate (+16.4%) and myo-inositol (-9.7%) were documented during pain stimulation. Furthermore, there was a significant negative correlation between the subjective pain intensity perception and the metabolic levels of Glx, Gln, glutamate and N-acetyl aspartate.
CONCLUSION: The insular cortex is a metabolically active region in the processing of acute dental pain. Induced dental pain leads to quantitative changes in brain metabolites within the left insular cortex resulting in significant alterations in metabolites. Negative correlation between subjective pain intensity rating and specific metabolites could be observed
Ethanol-Mediated Regulation of Cytochrome P450 2A6 Expression in Monocytes: Role of Oxidative Stress-Mediated PKC/MEK/Nrf2 Pathway
Cytochrome P450 2A6 (CYP2A6) is known to metabolize nicotine, the major constituent of tobacco, leading to the production of toxic metabolites and induction of oxidative stress that result in liver damage and lung cancer. Recently, we have shown that CYP2A6 is induced by ethanol and metabolizes nicotine into cotinine and other metabolites leading to generation of reactive oxygen species (ROS) in U937 monocytes. However, the mechanism by which CYP2A6 is induced by ethanol is unknown. In this study, we have examined the role of the PKC/Nrf2 pathway (protein kinase C-mediated phosphorylation and translocation of nuclear erythroid 2-related factor 2 to the nucleus) in ethanol-mediated CYP2A6 induction. Our results showed that 100 mM ethanol significantly induced CYP2A6 mRNA and protein (∼150%) and increased ROS formation, and induction of gene expression and ROS were both completely blocked by treatment with either a CYP2E1 inhibitor (diallyl sulfide) or an antioxidant (vitamin C). The results suggest the role of oxidative stress in the regulation of CYP2A6 expression. Subsequently, we investigated the role of Nrf2 pathway in oxidative stress-mediated regulation of CYP2A6 expression in U937 monocytes. Our results showed that butylated hydroxyanisole, a stabilizer of nuclear Nrf2, increased CYP2A6 levels >200%. Staurosporine, an inhibitor of PKC, completely abolished ethanol-induced CYP2A6 expression. Furthermore, our results showed that a specific inhibitor of mitogen-activated protein kinase kinase (MEK) (U0126) completely abolished ethanol-mediated CYP2A6 induction and Nrf2 translocation. Overall, these results suggest that CYP2E1-mediated oxidative stress produced as a result of ethanol metabolism translocates Nrf2 into the nucleus through PKC/MEK pathway, resulting in the induction of CYP2A6 in monocytes. An increased level of CYP2A6 in monocytes is expected to further increase oxidative stress in smokers through CYP2A6-mediated nicotine metabolism. Thus, this study has clinical relevance because of the high incidence of alcohol use among smokers, especially in HIV-infected individuals
Late Pleistocene sediments, landforms and events in Scotland: a review of the terrestrial stratigraphic record
Lithostratigraphical studies coupled with the development of new dating methods has led to significant progress in understanding the Late Pleistocene terrestrial record in Scotland. Systematic analysis and re-evaluation of key localities have provided new insights into the complexity of the event stratigraphy in some regions and the timing of Late Pleistocene environmental changes, but few additional critical sites have been described in the past 25 years. The terrestrial stratigraphic record remains important for understanding the timing, sequence and patterns of glaciation and deglaciation during the last glacial/interglacial cycle. Former interpretations of ice-free areas in peripheral areas during the Last Glacial Maximum (LGM) are inconsistent with current stratigraphic and dating evidence. Significant challenges remain to determine events and patterns of glaciation during the Early and Middle Devensian, particularly in the context of offshore evidence and ice sheet modelling that indicate significant build-up of ice throughout much of the period. The terrestrial evidence broadly supports recent reconstructions of a highly dynamic and climate-sensitive British–Irish Ice Sheet (BIIS), which apparently reached its greatest thickness in Scotland between 30 and 27ka, before the global LGM. A thick (relative to topography) integrated ice sheet reaching the shelf edge with a simple ice-divide structure was replaced after the LGM by a much thinner one comprising multiple dispersion centres and a more complex flow structure
- …