Synovial chondromatosis is a benign condition characterised by the presence of small cartilaginous nodules in the joint; its aetiology is unknown. Only a few cases of temporomandibular chondromatosis ...are described in the literature. In some cases, the synovial chondromatosis can erode the adjacent bone structures, such as the glenoid fossa, middle cranial fossa, and internal carotid canal. In these cases, besides MRI, the gold standard to verify the erosion of the glenoid fossa is a computed tomography scan. The aim of this study is to report the use of MRI with PETRA (pointwise encoding time reduction with radial acquisition) sequences for the diagnosis and follow-up of temporomandibular joint chondromatosis with suspected erosion of the glenoid fossa.
Commissioning of the ALICE muon spectrometer trigger at LHC Ahn, S.; Arnaldi, R.; Baek, Y. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2012, Letnik:
661
Journal Article
Recenzirano
ALICE (a large ion collider experiment) is the LHC experiment dedicated to the study of ultra-relativistic heavy ion collisions. The ALICE muon spectrometer covers a large range in pseudo-rapidity ...and is designed to study quarkonia and heavy flavours decaying into (di-)muons. The high particle multiplicities environment in such collisions require a specific, fast and efficient trigger system, the muon trigger. It consists of four planes of RPC detectors, covering an area of 36
m
2 each, 21k front-end channels and a fast-decision electronics. The muon trigger is designed to reconstruct (muon) tracks and deliver a trigger signal each 25
ns (40
MHz) with a total latency of 800
ns. The hit position on the RPC is measured in two orthogonal directions with an accuracy of about 1
cm. The performance measured with the first p–p collisions at
(
s
)
=
900
GeV
carried out in December 2009 is reported.
We present preliminary NA50 results on J/$\psi$ and $\psi'$ production by 400 GeV/c incident protons on various targets. Production cross sections are determined for each p-target system. Their ...dependence on the target mass number A is studied using a Glauber model. The data obtained by experiment NA38 from S–U interactions at 200 GeV/nucleon incident momentum are also re-analysed which, together with our most recent 400 GeV and previous 450 GeV proton–nucleus results, lead to the J/$\psi$ absorption cross section in nuclear matter. We finally determine the expected 'normal' J/$\psi$ production in 158 GeV/nucleon Pb–Pb collisions as a function of centrality.
We report results on $\psi'$ production in Pb–Pb interactions at 158 GeV/c per nucleon incident momentum, from data collected by the NA50 experiment at CERN SPS. A comparison of proton- and ...sulfur-induced collisions shows a similar $\psi'$ production rate per nucleon–nucleon collision for S–U and Pb–Pb reactions, decreasing with increasing centrality and significantly lower than the rate measured from proton-induced reactions. This feature contrasts with J/$\psi$ production which exhibits a similar behaviour for reactions induced by protons and by sulfur nuclei and a significantly suppressed rate for Pb–Pb interactions.
Selected reaction monitoring (SRM) is a targeted mass spectrometry technique that is emerging in the field of proteomics as a complement to untargeted shotgun methods. SRM is particularly useful when ...predetermined sets of proteins, such as those constituting cellular networks or sets of candidate biomarkers, need to be measured across multiple samples in a consistent, reproducible and quantitatively precise manner. Here we describe how SRM is applied in proteomics, review recent advances, present selected applications and provide a perspective on the future of this powerful technology.
Abstract
Chemoproteomics is a key technology to characterize the mode of action of drugs, as it directly identifies the protein targets of bioactive compounds and aids in the development of optimized ...small-molecule compounds. Current approaches cannot identify the protein targets of a compound and also detect the interaction surfaces between ligands and protein targets without prior labeling or modification. To address this limitation, we here develop LiP-Quant, a drug target deconvolution pipeline based on limited proteolysis coupled with mass spectrometry that works across species, including in human cells. We use machine learning to discern features indicative of drug binding and integrate them into a single score to identify protein targets of small molecules and approximate their binding sites. We demonstrate drug target identification across compound classes, including drugs targeting kinases, phosphatases and membrane proteins. LiP-Quant estimates the half maximal effective concentration of compound binding sites in whole cell lysates, correctly discriminating drug binding to homologous proteins and identifying the so far unknown targets of a fungicide research compound.
•Mass spectrometry can probe structural properties of thousands of proteins in situ.•Methods may be based on several different principles.•These include limited proteolysis, stability profiling, ...cross-linking, or co-fractionation.•Structural changes, unfolding, aggregation, and molecular interactions can all be captured.•These readouts yield a systematic, in situ, dynamic view of protein structure.
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Mass spectrometry (MS)-based proteomics is moving beyond the simple generation of protein inventories of biological samples. The ability of MS to quantitatively probe complex protein mixtures is increasingly being used to study protein structural and biophysical properties at proteome-scale. MS provides a readout for proteome-wide structural alterations, folding and stability, aggregation, and molecular interactions, all in native-like conditions such as cell lysates or even intact cells. We provide an overview of methods that yield such proteome-wide structural information, covering cross-linking-MS, limited proteolysis-MS, co-fractionation-MS, hydroxyl radical footprinting-MS, thermal proteome profiling, and numerous approaches for monitoring molecular interactions at large scale. Methods to determine structural properties of the native proteome will drive structural systems biology.
Systems biology relies on data sets in which the same group of proteins is consistently identified and precisely quantified across multiple samples, a requirement that is only partially achieved by ...current proteomics approaches. Selected reaction monitoring (SRM)—also called multiple reaction monitoring—is emerging as a technology that ideally complements the discovery capabilities of shotgun strategies by its unique potential for reliable quantification of analytes of low abundance in complex mixtures. In an SRM experiment, a predefined precursor ion and one of its fragments are selected by the two mass filters of a triple quadrupole instrument and monitored over time for precise quantification. A series of transitions (precursor/fragment ion pairs) in combination with the retention time of the targeted peptide can constitute a definitive assay. Typically, a large number of peptides are quantified during a single LC‐MS experiment. This tutorial explains the application of SRM for quantitative proteomics, including the selection of proteotypic peptides and the optimization and validation of transitions. Furthermore, normalization and various factors affecting sensitivity and accuracy are discussed.
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