116 research outputs found
Hard exclusive photoproduction of charmed mesons
{We investigate the photoproduction process within the handbag approach, which we assume
to be the dominant mechanism at energies well above the production threshold
and in the forward scattering hemisphere.Comment: proceedings of Photon 2013, May 20-24 2013, Paris, Franc
An Extremely Rare Congenital Muscle Bundle Crossing the Right Atrial Cavity
Muscle bundles in the right atrium are an extremely rare congenital anomaly. We report the case of a patient with 2 atrial septal defects and a large muscle bundle crossing the right atrium. Only 3 comparable cases have previously been published. (Level of Difficulty: Intermediate.)
A universal strategy for high-yield production of soluble and functional clostridial collagenases in E. coli
Clostridial collagenases are foe and friend: on the one hand, these enzymes enable host infiltration and colonization by pathogenic clostridia, and on the other hand, they are valuable biotechnological tools due to their capacity to degrade various types of collagen and gelatine. However, the demand for high-grade preparations exceeds supply due to their pathogenic origin and the intricate purification of homogeneous isoforms. We present the establishment of an Escherichia coli expression system for a variety of constructs of collagenase G (ColG) and H (ColH) from Clostridium histolyticum and collagenase T (ColT) from Clostridium tetani, mimicking the isoforms in vivo. Based on a setup of five different expression strains and two expression vectors, 12 different constructs were expressed, and a flexible purification platform was established, consisting of various orthogonal chromatography steps adaptable to the individual needs of the respective variant. This fast, cost-effective, and easy-to-establish platform enabled us to obtain at least 10Â mg of highly pure mono-isoformic protein per liter of culture, ideally suited for numerous sophisticated downstream applications. This production and purification platform paves the way for systematic screenings of recombinant collagenases to enlighten the biochemical function and to identify key residues and motifs in collagenolysis
Expression, regulation and function of phosphofructo-kinase/fructose-biphosphatases (PFKFBs) in glucocorticoid-induced apoptosis of acute lymphoblastic leukemia cells
<p>Abstract</p> <p>Background</p> <p>Glucocorticoids (GCs) cause apoptosis and cell cycle arrest in lymphoid cells and constitute a central component in the therapy of lymphoid malignancies, most notably childhood acute lymphoblastic leukemia (ALL). PFKFB2 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-2), a kinase controlling glucose metabolism, was identified by us previously as a GC response gene in expression profiling analyses performed in children with ALL during initial systemic GC mono-therapy. Since deregulation of glucose metabolism has been implicated in apoptosis induction, this gene and its relatives, PFKFB1, 3, and 4, were further analyzed.</p> <p>Methods</p> <p>Gene expression analyses of isolated lymphoblasts were performed on Affymetrix HGU133 Plus 2.0 microarrays. GCRMA normalized microarray data were analyzed using R-Bioconductor packages version 2.5. Functional gene analyses of <it>PFKFB2-15A </it>and <it>-15B </it>isoforms were performed by conditional gene over-expression experiments in the GC-sensitive T-ALL model CCRF-CEM.</p> <p>Results</p> <p>Expression analyses in additional ALL children, non-leukemic individuals and leukemic cell lines confirmed frequent <it>PFKFB2 </it>induction by GC in most systems sensitive to GC-induced apoptosis, particularly T-ALL cells. The 3 other family members, in contrast, were either absent or only weakly expressed (<it>PFKFB1 </it>and <it>4</it>) or not induced by GC (<it>PFKFB3</it>). Conditional PFKFB2 over-expression in the CCRF-CEM T-ALL <it>in vitro </it>model revealed that its 2 splice variants (PFKFB2-15A and PFKFB2-15B) had no detectable effect on cell survival. Moreover, neither PFKFB2 splice variant significantly affected sensitivity to, or kinetics of, GC-induced apoptosis.</p> <p>Conclusions</p> <p>Our data suggest that, at least in the model system investigated, PFKFB2 is not an essential upstream regulator of the anti-leukemic effects of GC.</p
Experimental delayed-choice entanglement swapping
Motivated by the question, which kind of physical interactions and processes
are needed for the production of quantum entanglement, Peres has put forward
the radical idea of delayed-choice entanglement swapping. There, entanglement
can be "produced a posteriori, after the entangled particles have been measured
and may no longer exist". In this work we report the first realization of
Peres' gedanken experiment. Using four photons, we can actively delay the
choice of measurement-implemented via a high-speed tunable bipartite state
analyzer and a quantum random number generator-on two of the photons into the
time-like future of the registration of the other two photons. This effectively
projects the two already registered photons onto one definite of two mutually
exclusive quantum states in which either the photons are entangled (quantum
correlations) or separable (classical correlations). This can also be viewed as
"quantum steering into the past"
Recovery of balance and walking in people with ataxia after acute cerebral stroke: study protocol for a prospective, monocentric, single-blinded, randomized controlled trial
IntroductionPosterior circulation stroke can lead to ataxia, manifesting in a loss of coordination and balance. Patients experience difficulty in activities of daily living and an increased risk of falling, both profoundly affecting quality of life. In individuals with neurodegenerative diseases, coordination exercises have been shown to lead to a reduction in ataxic symptoms. There is, however, limited evidence on the effect of physical therapy, specifically coordination exercises in patients with stroke-related ataxia. We therefore present a study protocol for a prospective trial.MethodsThe purpose of this trial is to investigate the effects of coordination exercises compared to standard physiotherapy on balance and walking in ataxic stroke patients. Therefore, a prospective, single-blinded randomized controlled trial is currently ongoing at the Clinical Department of Neurology, Medical University of Innsbruck, Austria, in collaboration with two local rehabilitation facilities in Austria, Hochzirl Hospital and the Clinic for Rehabilitation MĂĽnster. Balance is the primary outcome of the study as assessed using the Berg Balance Scale. Secondary outcomes are concerned with walking, risk and number of falls, independence in daily life, and quality of life, rated using appropriate scales and scores. Patients are allocated applying a 1:1 ratio and a stratified block randomization. In both groups recruited individuals undergo five 45-min treatment sessions per week, totaling 20 sessions of coordination exercises (IG) or standard physiotherapy (CG) over the course of 4 weeks. Data is collected at the baseline (T0), after the 4-week supervised practice (T1), and after another 8 weeks of independent home-based training (T2).DiscussionThis is the first randomized controlled trial investigating the effects of coordination exercises on balance and walking in people with stroke-related ataxia. As stroke guidelines emphasize the limited evidence of treatment for ataxic symptoms, this study aims to contribute further knowledge regarding tailored interventions for these patients.Clinical Trial RegistrationGerman Clinical Trials Registry (drks.de). Identifier: DRKS00020825
Proteomics of spatially identified tissues in whole organs
Spatial molecular profiling of complex tissues is essential to investigate cellular function in physiological and pathological states. However, methods for molecular analysis of biological specimens imaged in 3D as a whole are lacking. Here, we present DISCO-MS, a technology combining whole-organ imaging, deep learning-based image analysis, and ultra-high sensitivity mass spectrometry. DISCO-MS yielded qualitative and quantitative proteomics data indistinguishable from uncleared samples in both rodent and human tissues. Using DISCO-MS, we investigated microglia activation locally along axonal tracts after brain injury and revealed known and novel biomarkers. Furthermore, we identified initial individual amyloid-beta plaques in the brains of a young familial Alzheimer’s disease mouse model, characterized the core proteome of these aggregates, and highlighted their compositional heterogeneity. Thus, DISCO-MS enables quantitative, unbiased proteome analysis of target tissues following unbiased imaging of entire organs, providing new diagnostic and therapeutic opportunities for complex diseases, including neurodegeneration
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