In vivo synthesis of monolysocardiolipin and cardiolipin by Acinetobacter baumannii phospholipase D and effect on cationic antimicrobial peptide resistance

Acinetobacter baumannii is an opportunistic pathogen, which has become a rising threat in healthcare facilities worldwide due to increasing antibiotic resistances and optimal adaptation to clinical environments and the human host. We reported in a former publication on the identification of three phopholipases of the phospholipase D (PLD) superfamily in A. baumannii ATCC 19606T acting in concerted manner as virulence factors in Galleria mellonella infection and lung epithelial cell invasion. This study focussed on the function of the three PLDs. A Δpld1-3 mutant was defect in biosynthesis of the phospholipids cardiolipin (CL) and monolysocardiolipin (MLCL), whereas the deletion of pld2 and pld3 abolished the production of MLCL. Complementation of the Δpld1-3 mutant with pld1 restored CL biosynthesis demonstrating that the PLD1 is implicated in CL biosynthesis. Complementation of the Δpld1-3 mutant with either pld2 or pld3 restored MLCL and CL production leading to the conclusion that PLD2 and PLD3 are implicated in CL and MLCL production. Mutant studies revealed that two catalytic motifs are essential for the PLD3-mediated biosynthesis of CL and MLCL. The Δpld1-3 mutant exhibited a decreased colistin and polymyxin B resistance indicating a role of CL in cationic antimicrobial peptides (CAMPs) resistance

Comprehensive CT Evaluation in Acute Ischemic Stroke: Impact on Diagnosis and Treatment Decisions

Background. With modern CT imaging a comprehensive overview of cerebral macro- and microcirculation can be obtained within minutes in acute ischemic stroke. This opens for patient stratification and individualized treatment. Methods. Four patients with acute ischemic stroke of different aetiologies and/or treatments were chosen for illustration of the comprehensive CT protocol and its value in subsequent treatment decisions. The patients were clinically evaluated according to the NIHSS-scale, examined with the comprehensive CT protocol including both CT angiography and CT perfusion, and followed up by MRI. Results. The comprehensive CT examination protocol increased the examination time but did not delay treatment initiation. In some cases CT angiography revealed the cause of stroke while CT perfusion located and graded the perfusion defect with reasonable accuracy, confirmed by follow-up MR-diffusion. In the presented cases findings of the comprehensive CT examination influenced the treatment strategy. Conclusions. The comprehensive CT examination is a fast and safe method allowing accurate diagnosis and making way for individualized treatment in acute ischemic stroke

Six iterative reconstruction algorithms in brain CT- A phantom study on image quality at different radiation doses.

OBJECTIVE: To evaluate the image quality produced by six different iterative reconstruction (IR) algorithms in four CT systems in the setting of brain CT, using different radiation dose levels and iterative image optimisation levels. METHODS: An image quality phantom, supplied with a bone mimicking annulus, was examined using four CT systems from different vendors and four radiation dose levels. Acquisitions were reconstructed using conventional filtered back-projection (FBP), three levels of statistical IR and, when available, a model-based IR algorithm. The evaluated image quality parameters were CT numbers, uniformity, noise, noise-power spectra, low-contrast resolution and spatial resolution. RESULTS: Compared with FBP, noise reduction was achieved by all six IR algorithms at all radiation dose levels, with further improvement seen at higher IR levels. Noise-power spectra revealed changes in noise distribution relative to the FBP for most statistical IR algorithms, especially the two model-based IR algorithms. Compared with FBP, variable degrees of improvements were seen in both objective and subjective low-contrast resolutions for all IR algorithms. Spatial resolution was improved with both model-based IR algorithms and one of the statistical IR algorithms. CONCLUSION: The four statistical IR algorithms evaluated in the study all improved the general image quality compared with FBP, with improvement seen for most or all evaluated quality criteria. Further improvement was achieved with one of the model-based IR algorithms. ADVANCES IN KNOWLEDGE: The six evaluated IR algorithms all improve the image quality in brain CT but show different strengths and weaknesses

Correlation between arterial blood volume obtained by arterial spin labelling and cerebral blood volume in intracranial tumours.

OBJECTIVE: To compare measurements of the arterial blood volume (aBV), a perfusion parameter calculated from arterial spin labelling (ASL), and cerebral blood volume (CBV), calculated from dynamic susceptibility contrast (DSC) MRI. In the clinic, CBV is used for grading of intracranial tumours. MATERIALS AND METHODS: Estimates of aBV from the model-free ASL technique quantitative STAR labelling of arterial regions (QUASAR) experiment and of DSC-CBV were obtained at 3T in ten patients with eleven tumours (three grade III gliomas, four glioblastomas and four meningiomas, two in one patient). Parametric values of aBV and CBV were determined in the tumour as well as in normal grey matter (GM), and tumour-to-GM aBV and CBV ratios were calculated. RESULTS: In a 4-pixel ROI representing maximal tumour values, the coefficient of determination R (2) was 0.61 for the comparison of ASL-based aBV tumour-to-GM ratios and DSC-MRI-based CBV tumour-to-GM ratios and 0.29 for the comparison of parametric values of ASL-aBV and DSC-CBV, under the assumption of proportionality. Both aBV and CBV showed a non-significant tendency to increase when going from grade III gliomas to glioblastomas to meningiomas. CONCLUSION: These results suggest that measurement of aBV is a potential tool for non-invasive assessment of blood volume in intracranial tumours

Investigating variation in Arabic intonation : : the case for a multi-level corpus approach

This paper provides a first description of the intonational patterns of San‘aani Arabic (SA, the dialect of Arabic spoken in the capital of Yemen) and a comparison of these patterns with those observed in Cairene Arabic (CA), revealing differences between the two varieties which mirror cross-linguistic prosodic variation. The SA analysis is based on qualitative transcription of portions of a multi-level corpus, including read speech sentences, a narrative retold from memory and a sociolinguistic data collection tool which yields free conversation data in the desired variety as well as information that can be used to confirm which variety is being used. The corpus design and methodology serve as a prototype for larger data collection to document intonational variation in Arabic

Printed Nanostructures for Organic Photovoltaic Cells and Solution‐Processed Polymer Light‐Emitting Diodes

We review the progress on printing‐based technologies for organic electronic devices, especially organic photovoltaic (OPV) cells and polymer light‐emitting diodes (PLEDs). First we discuss recent efforts to introduce interdigitated nanostructures on the order of tens of nanometers to the photoactive layers of OPV cells using nanoimprint lithography including a soft‐printing process developed in our research group that can easily produce sub‐20 nm scale organic semiconductor nanopillars. Second, we review solution‐processible printing technologies such as gravure printing, screen printing, blade coating, and slot–die coating for high‐throughput manufacturing of PLEDs.Illuminating results: This article reviews the progress on printing‐based technologies for organic electronic devices, especially organic photovoltaic (OPV) cells and polymer light‐emitting diodes (PLEDs), including solution‐processible printing technologies such as gravure printing, screen printing, blade coating, and slot–die coating for high‐throughput manufacturing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111088/1/340_ftp.pd

The Science of Pronominal Usage: He and It in Co-Reference to Inanimate Objects in Late Middle English Texts on Alchemy

This is the author's accepted manuscript. The published version can be found at http://dx.doi.org/10.1177/0075424210384225This article explores the variation between he and it in coreference to inanimate entities (such as mercury, sulfur, and salt). Using alchemical texts from the fifteenth century as material, the article demonstrates that there was much more variation in pronominal reference in this period than has previously been shown. Of the possible explanations suggested by previous research, the earlier grammatical gender system and transference from Latin do not seem to play a role, while pronoun clustering and pronominal reanalysis appear to influence the quantitative distribution. The scale of individuation used by Siemund and Stenroos to explain similar usage is shown not to be a straightforward predictor. Other factors such as personification and perceived similarities between animate and inanimate entities may affect the degree of perceived individuation. The choice of he over she seems to be influenced by pronominal reanalysis and straightforward personification in some cases. In other instances, it is speculated that the he usage reflects (stereotypical) gender conceptions in the Middle Ages