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- Adcox, K, et al.
(författare)
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PHENIX detector overview
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 469-479
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX detector is designed to perform a broad study of A-A, p-A, and p-p collisions to investigate nuclear matter under extreme conditions. A wide variety of probes, sensitive to all timescales, are used to study systematic variations with species and energy as well as to measure the spin structure of the nucleon. Designing for the needs of the heavy-ion and polarized-proton programs has produced a detector with unparalleled capabilities. PHENIX measures electron and muon pairs, photons, and hadrons with excellent energy and momentum resolution. The detector consists of a large number of subsystems that are discussed in other papers in this volume. The overall design parameters of the detector are presented. (C) 2002 Elsevier Science B.V. All rights reserved.
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5. |
- Adler, SS, et al.
(författare)
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PHENIX on-line systems
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 560-592
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX On-Line system takes signals from the Front End Modules (FEM) on each detector subsystem for the purpose of generating events for physics analysis. Processing of event data begins when the Data Collection Modules (DCM) receive data via fiber-optic links from the FEMs. The DCMs format and zero suppress the data and generate data packets. These packets go to the Event Builders (EvB) that assemble the events in final form. The Level-1 trigger (LVL1) generates a decision for each beam crossing and eliminates uninteresting events. The FEMs carry out all detector processing of the data so that it is delivered to the DCMs using a standard format. The FEMs also provide buffering for LVL1 trigger processing and DCM data collection. This is carried out using an architecture that is pipelined and deadtimeless. All of this is controlled by the Master Timing System (MTS) that distributes the RHIC clocks. A Level-2 trigger (LVL2) gives additional discrimination. A description of the components and operation of the PHENIX On-Line system is given and the solution to a number of electronic infrastructure problems are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
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- Murphy, M. P., et al.
(författare)
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Guidelines for measuring reactive oxygen species and oxidative damage in cells and in vivo
- 2022
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Ingår i: Nature Metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 4:6, s. 651-662
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Tidskriftsartikel (refereegranskat)abstract
- Multiple roles of reactive oxygen species (ROS) and their consequences for health and disease are emerging throughout biological sciences. This development has led researchers unfamiliar with the complexities of ROS and their reactions to employ commercial kits and probes to measure ROS and oxidative damage inappropriately, treating ROS (a generic abbreviation) as if it were a discrete molecular entity. Unfortunately, the application and interpretation of these measurements are fraught with challenges and limitations. This can lead to misleading claims entering the literature and impeding progress, despite a well-established body of knowledge on how best to assess individual ROS, their reactions, role as signalling molecules and the oxidative damage that they can cause. In this consensus statement we illuminate problems that can arise with many commonly used approaches for measurement of ROS and oxidative damage, and propose guidelines for best practice. We hope that these strategies will be useful to those who find their research requiring assessment of ROS, oxidative damage and redox signalling in cells and in vivo. Reactive oxygen species (ROS) have important roles in health and disease, but are chemically complex and difficult to measure accurately. This consensus statement proposes guidelines and best practices on the nomenclature and assessment of ROS, oxidative reactions and oxidative damage in cells, tissues and in vivo.
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8. |
- Moyroud, Edwige, et al.
(författare)
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Cuticle chemistry drives the development of diffraction gratings on the surface of Hibiscus trionum petals
- 2022
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 32:24, s. 5323-5334, 5323-5334.e1-e6
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Tidskriftsartikel (refereegranskat)abstract
- Plants combine both chemical and structural means to appear colorful. We now have an extensive understanding of the metabolic pathways used by flowering plants to synthesize pigments, but the mechanisms remain obscure whereby cells produce microscopic structures sufficiently regular to interfere with light and create an optical effect. Here, we combine transgenic approaches in a novel model system, Hibiscus trionum, with chemical analyses of the cuticle, both in transgenic lines and in different species of Hibiscus, to investigate the formation of a semi-ordered diffraction grating on the petal surface. We show that regulating both cuticle production and epidermal cell growth is insufficient to determine the type of cuticular pattern produced. Instead, the chemical composition of the cuticle plays a crucial role in restricting the formation of diffraction gratings to the pigmented region of the petal. This suggests that buckling, driven by spatiotemporal regulation of cuticle chemistry, could pattern the petal surface at the nanoscale.
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- Gruber, Jan, et al.
(författare)
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Allantoin in human plasma, serum, and nasal-lining fluids as a biomarker of oxidative stress : avoiding artifacts and establishing real in vivo concentrations.
- 2009
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Ingår i: Antioxidants and Redox Signaling. - 1523-0864 .- 1557-7716. ; 11:8, s. 1767-1776
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Tidskriftsartikel (refereegranskat)abstract
- Urate is the terminal product of purine metabolism in primates, including humans. Urate is also an efficient scavenger of oxidizing species and is thought to be an important antioxidant in human body fluids. Allantoin, the major oxidation product of urate, has been suggested as a candidate biomarker of oxidative stress because it is not produced metabolically. Although urate is converted to allantoin under strongly alkaline pH, such conditions have been used in the past to facilitate extraction of allantoin. We evolved a method for the determination of allantoin concentrations in human plasma and serum by gas chromatography-mass spectrometry without such artifact. With this method, we show that alkaline conditions do indeed cause breakdown of urate, leading to significant overestimation of allantoin concentration in human samples. By using our alternative method, serum samples from 98 volunteers were analyzed, and allantoin levels were found to be significantly lower than was previously reported. The in vivo utility and sensitivity of our method was further evaluated in human nasal-lining fluids. We were able to demonstrate an ozone-induced increase in allantoin, in the absence of increases in either ascorbate or glutathione oxidation products.
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- Rubertsson, Sten, et al.
(författare)
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The Study Protocol for the LINC (LUCAS in Cardiac Arrest) Study : a study comparing conventional adult out-of-hospital cardiopulmonary resuscitation with a concept with mechanical chest compressions and simultaneous defibrillation
- 2013
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Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. - : BioMed Central Ltd.. - 1757-7241. ; 21:5
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Tidskriftsartikel (refereegranskat)abstract
- Background The LUCAS™ device delivers mechanical chest compressions that have been shown in experimental studies to improve perfusion pressures to the brain and heart as well as augmenting cerebral blood flow and end tidal CO2, compared with results from standard manual cardiopulmonary resuscitation (CPR). Two randomised pilot studies in out-of-hospital cardiac arrest patients have not shown improved outcome when compared with manual CPR. There remains evidence from small case series that the device can be potentially beneficial compared with manual chest compressions in specific situations. This multicentre study is designed to evaluate the efficacy and safety of mechanical chest compressions with the LUCAS™ device whilst allowing defibrillation during on-going CPR, and comparing the results with those of conventional resuscitation. Methods/design This article describes the design and protocol of the LINC-study which is a randomised controlled multicentre study of 2500 out-of-hospital cardiac arrest patients. The study has been registered at ClinicalTrials.gov (http://clinicaltrials.gov/ct2/show/NCT00609778?term=LINC&rank=1 webcite). Results Primary endpoint is four-hour survival after successful restoration of spontaneous circulation. The safety aspect is being evaluated by post mortem examinations in 300 patients that may reflect injuries from CPR. Conclusion This large multicentre study will contribute to the evaluation of mechanical chest compression in CPR and specifically to the efficacy and safety of the LUCAS™ device when used in association with defibrillation during on-going CPR.
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- Karlsson, Pernilla C, et al.
(författare)
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Human fecal water inhibits COX-2 in colonic HT-29 cells : role of phenolic compounds
- 2005
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Ingår i: Journal of Nutrition. - : Elsevier BV. - 0022-3166 .- 1541-6100. ; 135:10, s. 2343-2349
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Tidskriftsartikel (refereegranskat)abstract
- The inducible enzyme cyclooxygenase-2 (COX-2) plays a major role in the regulation of inflammation and possibly in the development of colon cancer. The aim of the present study was to screen for COX-2 inhibitors in samples of fecal water (the aqueous phase of feces) and investigate whether phenolic compounds are responsible for any observed effects on COX-2. Volunteers (n = 20) were recruited and asked to supply a 24-h stool sample. Fecal water samples were prepared and analyzed by GC-MS for their content of phenolic compounds. These samples were also evaluated for their effects on COX-2 protein levels (Western blot) and prostaglandin (PG)E2 production in tumor necrosis-alpha-stimulated HT-29 cells and pure enzymatic activity in a COX-2-catalyzed prostaglandin biosynthesis in vitro assay. The major phenolic compounds identified were phenylpropionic acid, phenylacetic acid, cinnamic acid, and benzoic acid derivatives. Of 13 fecal water samples analyzed, 12 significantly decreased PGE2 production (range 5.4-39.7% inhibition, P-value < 0.05) compared with control cells and 13 of 14 samples analyzed decreased COX-2 protein levels in HT-29 cells (19-63% inhibition). Of the 20 fecal water samples, 2 also weakly inhibited enzymatic activity of purified COX-2 (22-24% inhibition). Three compounds identified in fecal water, 3-phenylpropionic acid, 3-hydroxyphenylacetic acid, and 3-(4-hydroxyphenyl)-propionic acid, decreased the protein level at 250 micromol/L (15-62% inhibition). This study shows for the first time that human fecal water contains components that can affect both the COX-2 protein level and enzymatic activity.
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14. |
- Lundgren, Johan, et al.
(författare)
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Acidosis-induced ischemic brain damage: are free radicals involved?
- 1991
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - 1559-7016. ; 11:4, s. 587-596
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Tidskriftsartikel (refereegranskat)abstract
- Substantial evidence exists that reactive oxygen species participate in the pathogenesis of brain damage following both sustained and transient cerebral ischemia, adversely affecting the vascular endothelium and contributing to the formation of edema. One likely triggering event for free radical damage is delocalization of protein-bound iron. The binding capacity for some iron-binding proteins is highly pH sensitive and, consequently, the release of iron is enhanced by acidosis. In this study, we explored whether enhanced acidosis during ischemia triggers the production of reactive oxygen species. To that end, enhanced acidosis was produced by inducing ischemia in hyperglycemic rats, with normoglycemic ones serving as controls. Production of H2O2, estimated from the decrease in catalase activity after 3-amino-1,2,4-triazole (AT) administration, was measured in the cerebral cortex, caudoputamen, hippocampus, and substantia nigra (SN) after 15 min of ischemia followed by 5, 15, and 45 min of recovery, respectively (in substantia nigra after 45 min of recovery only). Free iron in cerebrospinal fluid (CSF) was measured after ischemia and 45 min of recovery. Levels of total glutathione (GSH + GSSH) in cortex and hippocampus, and levels of alpha-tocopherol in cortex, were also measured after 15 min of ischemia followed by 5, 15, and 45 min of recovery. The results confirm previous findings that brief ischemia in normoglycemic animals does not measurably increase H2O2 production in AT-injected animals. Ischemia under hyperglycemic conditions likewise failed to induce increased H2O2 production. No difference in free iron in CSF was observed between animals subjected to ischemia under hyper- and normoglycemic conditions. The moderate decrease in total glutathione or alpha-tocopherol levels did not differ between normo- and hyperglycemic animals in any brain region or at any recovery time. Thus, the results failed to give positive evidence for free radical damage following brief periods of ischemia complicated by excessive acidosis. However, it is possible that free radical production is localized to a small subcellular compartment within the tissue, thereby escaping detection. Also, the results do not exclude the possibility that free radicals are pathogenetically important after ischemia of longer duration.
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15. |
- While, Geoffrey M, et al.
(författare)
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Adaptive responses to cool climate promotes persistence of a non-native lizard.
- 2015
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Ingår i: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954. ; 282:1803
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Tidskriftsartikel (refereegranskat)abstract
- Successful establishment and range expansion of non-native species often require rapid accommodation of novel environments. Here, we use common-garden experiments to demonstrate parallel adaptive evolutionary response to a cool climate in populations of wall lizards (Podarcis muralis) introduced from southern Europe into England. Low soil temperatures in the introduced range delay hatching, which generates directional selection for a shorter incubation period. Non-native lizards from two separate lineages have responded to this selection by retaining their embryos for longer before oviposition-hence reducing the time needed to complete embryogenesis in the nest-and by an increased developmental rate at low temperatures. This divergence mirrors local adaptation across latitudes and altitudes within widely distributed species and suggests that evolutionary responses to climate can be very rapid. When extrapolated to soil temperatures encountered in nests within the introduced range, embryo retention and faster developmental rate result in one to several weeks earlier emergence compared with the ancestral state. We show that this difference translates into substantial survival benefits for offspring. This should promote short- and long-term persistence of non-native populations, and ultimately enable expansion into areas that would be unattainable with incubation duration representative of the native range.
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