1,814 research outputs found
From Disordered Crystal to Glass: Exact Theory
We calculate thermodynamic properties of a disordered model insulator,
starting from the ideal simple-cubic lattice () and increasing the
disorder parameter to . As in earlier Einstein- and Debye-
approximations, there is a phase transition at . For the
low-T heat-capacity whereas for , . The van
Hove singularities disappear at {\em any finite }. For we discover
novel {\em fixed points} in the self-energy and spectral density of this model
glass.Comment: Submitted to Phys. Rev. Lett., 8 pages, 4 figure
Nutritional Evaluation and Optimisation in Neonates (NEON): a randomised double-blind controlled trial of amino-acid regimen and intravenous lipid composition in preterm parenteral nutrition
Magnetic Resonance Spectroscopy discriminates the response to microglial stimulation of wild type and Alzheimer's disease models.
Microglia activation has emerged as a potential key factor in the pathogenesis of Alzheimers disease. Metabolite levels assessed by magnetic resonance spectroscopy (MRS) are used as markers of neuroinflammation in neurodegenerative diseases, but how they relate to microglial activation in health and chronic disease is incompletely understood. Using MRS, we monitored the brain metabolic response to lipopolysaccharides (LPS)-induced microglia activation in vivo in a transgenic mouse model of Alzheimers disease (APP/PS1) and healthy controls (wild-type (WT) littermates) over 4 hours. We assessed reactive gliosis by immunohistochemistry and correlated metabolic and histological measures. In WT mice, LPS induced a microglial phenotype consistent with activation, associated with a sustained increase in macromolecule and lipid levels (ML9). This effect was not seen in APP/PS1 mice, where LPS did not lead to a microglial response measured by histology, but induced a late increase in the putative inflammation marker myoinositol (mI) and metabolic changes in total creatine and taurine previously reported to be associated with amyloid load. We argue that ML9 and mI distinguish the response of WT and APP/PS1 mice to immune mediators. Lipid and macromolecule levels may represent a biomarker of activation of healthy microglia, while mI may not be a glial marker
Lead and stable lead isotopes as tracers of soil pollution and human health risk assessment in former industrial cities of Hungary
The interaction of 11Li with 208Pb
Background: 11Li is one of the most studied halo nuclei. The fusion of 11Li
with 208Pb has been the subject of a number of theoretical studies with widely
differing predictions, ranging over four orders of magnitude, for the fusion
excitation function.
Purpose: To measure the excitation function for the 11Li + 208Pb reaction.
Methods: A stacked foil/degrader assembly of 208Pb targets was irradiated
with a 11Li beam producing center of target beam energies from above barrier to
near barrier energies (40 to 29 MeV). The intensity of the 11Li beam (chopped)
was 1250 p/s and the beam on-target time was 34 hours. The alpha-decay of the
stopped evaporation residues was detected in a alpha-detector array at each
beam energy in the beam-off period (the beam was on for <= 5 ns and then off
for 170 ns).
Results: The 215At evaporation residues were associated with the fusion of
11Li with 208Pb. The 213,214At evaporation residues were formed by the breakup
of 11Li into 9Li + 2n, with the 9Li fusing with 208Pb. The 214At evaporation
residue appears to result from a "quasi-breakup" process.
Conclusions: Most of 11Li + 208Pb interactions lead to breakup with a small
fraction (<= 11%) leading to complete fusion.Comment: 25 pages, 11 figure
One- and Two-Photon Stimulated Emission Depletion of a Sulfonyl-Containing Fluorene Derivative
One- and two-photon stimulated emission transitions were investigated by the fluorescence quenching of a sulfonyl-containing fluorene compound, 2,7-bis(4-(phenylsulfonyl)styryl)-9,9-didecyl-9H-fluorene (1), in solution at room temperature using a picosecond pump-probe technique. The nature of stimulated transitions under various fluorescence excitation and quenching conditions was analyzed theoretically, and good agreement with experimental data was demonstrated. Two-photon stimulated transitions S1f S0 were shown for 1 at λq) 1064 nm, representing the first report of two-photon stimulated emission depletion (STED) in a molecular system. The two-photon stimulated emission cross section, δ2PE(λq), of fluorene 1 was estimated to be ∼240-280 GM, suggesting that this compound may be a good candidate for use in two-photon STED microscopy. 1
Development of a core measurement set for research in degenerative cervical myelopathy: a study protocol (AO Spine RECODE-DCM CMS)
INTRODUCTION
Progress in degenerative cervical myelopathy (DCM) is hindered by inconsistent measurement and reporting. This impedes data aggregation and outcome comparison across studies. This limitation can be reversed by developing a core measurement set (CMS) for DCM research. Previously, the AO Spine Research Objectives and Common Data Elements for DCM (AO Spine RECODE-DCM) defined 'what' should be measured in DCM: the next step of this initiative is to determine 'how' to measure these features. This protocol outlines the steps necessary for the development of a CMS for DCM research and audit.
METHODS AND ANALYSIS
The CMS will be developed in accordance with the guidance developed by the Core Outcome Measures in Effectiveness Trials and the Consensus-based Standards for the selection of health Measurement Instruments. The process involves five phases. In phase 1, the steering committee agreed on the constructs to be measured by sourcing consensus definitions from patients, professionals and the literature. In phases 2 and 3, systematic reviews were conducted to identify tools for each construct and aggregate their evidence. Constructs with and without tools were identified, and scoping reviews were conducted for constructs without tools. Evidence on measurement properties, as well as on timing of assessments, are currently being aggregated. These will be presented in phase 4: a consensus meeting where a multi-disciplinary panel of experts will select the instruments that will form the CMS. Following selection, guidance on the implementation of the CMS will be developed and disseminated (phase 5). A preliminary CMS review scheduled at 4 years from release.
ETHICS AND DISSEMINATION
Ethical approval was obtained from the University of Cambridge (HBREC2019.14). Dissemination strategies will include peer-reviewed scientific publications; conference presentations; podcasts; the identification of AO Spine RECODE-DCM ambassadors; and engagement with relevant journals, funders and the DCM community
Differential Regulation of the Melanoma Proteome by eIF4A1 and eIF4E.
Small molecules and antisense oligonucleotides that inhibit the translation initiation factors eIF4A1 and eIF4E have been explored as broad-based therapeutic agents for cancer treatment, based on the frequent upregulation of these two subunits of the eIF4F cap-binding complex in many cancer cells. Here, we provide support for these therapeutic approaches with mechanistic studies of eIF4F-driven tumor progression in a preclinical model of melanoma. Silencing eIF4A1 or eIF4E decreases melanoma proliferation and invasion. There were common effects on the level of cell-cycle proteins that could explain the antiproliferative effects in vitro Using clinical specimens, we correlate the common cell-cycle targets of eIF4A1 and eIF4E with patient survival. Finally, comparative proteomic and transcriptomic analyses reveal extensive mechanistic divergence in response to eIF4A1 or eIF4E silencing. Current models indicate that eIF4A1 and eIF4E function together through the 5'UTR to increase translation of oncogenes. In contrast, our data demonstrate that the common effects of eIF4A1 and eIF4E on translation are mediated by the coding region and 3'UTR. Moreover, their divergent effects occur through the 5'UTR. Overall, our work shows that it will be important to evaluate subunit-specific inhibitors of eIF4F in different disease contexts to fully understand their anticancer actions. Cancer Res; 77(3); 613-22. ©2016 AACR
Cholecystokinin in the central nervous system of the sea lamprey Petromyzon marinus: precursor identification and neuroanatomical relationships with other neuronal signalling systems
Cholecystokinin (CCK) is a neuropeptide that modulates processes such as digestion, satiety, and anxiety. CCK-type peptides have been characterized in jawed vertebrates and invertebrates, but little is known about CCK-type signalling in the most ancient group of vertebrates, the agnathans. Here, we have cloned and sequenced a cDNA encoding a sea lamprey (Petromyzon marinus L.) CCK-type precursor (PmCCK), which contains a CCK-type octapeptide sequence (PmCCK-8) that is highly similar to gnathostome CCKs. Using mRNA in situ hybridization, the distribution of PmCCK-expressing neurons was mapped in the CNS of P. marinus. This revealed PmCCK-expressing neurons in the hypothalamus, posterior tubercle, prethalamus, nucleus of the medial longitudinal fasciculus, midbrain tegmentum, isthmus, rhombencephalic reticular formation, and the putative nucleus of the solitary tract. Some PmCCK-expressing neuronal populations were only observed in adults, revealing important differences with larvae. We generated an antiserum to PmCCK-8 to enable immunohistochemical analysis of CCK expression, which revealed that GABA or glutamate, but not serotonin, tyrosine hydroxylase or neuropeptide Y, is co-expressed in some PmCCK-8-immunoreactive (ir) neurons. Importantly, this is the first demonstration of co-localization of GABA and CCK in neurons of a non-mammalian vertebrate. We also characterized extensive cholecystokinergic fibre systems of the CNS, including innervation of habenular subnuclei. A conspicuous PmCCK-8-ir tract ascending in the lateral rhombencephalon selectively innervates a glutamatergic population in the dorsal isthmic grey. Interestingly, this tract is reminiscent of the secondary gustatory/visceral tract of teleosts. In conclusion, this study provides important new information on the evolution of the cholecystokinergic system in vertebrates.</p
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