922 resultados para TRANSFORMER AT DEEP SATURATION


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PURPOSE Deep molecular response (MR(4.5)) defines a subgroup of patients with chronic myeloid leukemia (CML) who may stay in unmaintained remission after treatment discontinuation. It is unclear how many patients achieve MR(4.5) under different treatment modalities and whether MR(4.5) predicts survival. PATIENTS AND METHODS Patients from the randomized CML-Study IV were analyzed for confirmed MR(4.5) which was defined as ≥ 4.5 log reduction of BCR-ABL on the international scale (IS) and determined by reverse transcriptase polymerase chain reaction in two consecutive analyses. Landmark analyses were performed to assess the impact of MR(4.5) on survival. RESULTS Of 1,551 randomly assigned patients, 1,524 were assessable. After a median observation time of 67.5 months, 5-year overall survival (OS) was 90%, 5-year progression-free-survival was 87.5%, and 8-year OS was 86%. The cumulative incidence of MR(4.5) after 9 years was 70% (median, 4.9 years); confirmed MR(4.5) was 54%. MR(4.5) was reached more quickly with optimized high-dose imatinib than with imatinib 400 mg/day (P = .016). Independent of treatment approach, confirmed MR(4.5) at 4 years predicted significantly higher survival probabilities than 0.1% to 1% IS, which corresponds to complete cytogenetic remission (8-year OS, 92% v 83%; P = .047). High-dose imatinib and early major molecular remission predicted MR(4.5). No patient with confirmed MR(4.5) has experienced progression. CONCLUSION MR(4.5) is a new molecular predictor of long-term outcome, is reached by a majority of patients treated with imatinib, and is achieved more quickly with optimized high-dose imatinib, which may provide an improved therapeutic basis for treatment discontinuation in CML.

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Treatment of chronic myeloid leukemia (CML) with tyrosine kinase inhibitors has advanced to a stage where many patients achieve very low or undetectable levels of disease. Remarkably, some of these patients remain in sustained remission when treatment is withdrawn, suggesting that they may be at least operationally cured of their disease. Accurate definition of deep molecular responses (MRs) is therefore increasingly important for optimal patient management and comparison of independent data sets. We previously published proposals for broad standardized definitions of MR at different levels of sensitivity. Here we present detailed laboratory recommendations, developed as part of the European Treatment and Outcome Study for CML (EUTOS), to enable testing laboratories to score MR in a reproducible manner for CML patients expressing the most common BCR-ABL1 variants.Leukemia advance online publication, 27 February 2015; doi:10.1038/leu.2015.29.

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(31)P MRS magnetization transfer ((31)P-MT) experiments allow the estimation of exchange rates of biochemical reactions, such as the creatine kinase equilibrium and adenosine triphosphate (ATP) synthesis. Although various (31)P-MT methods have been successfully used on isolated organs or animals, their application on humans in clinical scanners poses specific challenges. This study compared two major (31)P-MT methods on a clinical MR system using heteronuclear surface coils. Although saturation transfer (ST) is the most commonly used (31)P-MT method, sequences such as inversion transfer (IT) with short pulses might be better suited for the specific hardware and software limitations of a clinical scanner. In addition, small NMR-undetectable metabolite pools can transfer MT to NMR-visible pools during long saturation pulses, which is prevented with short pulses. (31)P-MT sequences were adapted for limited pulse length, for heteronuclear transmit-receive surface coils with inhomogeneous B1 , for the need for volume selection and for the inherently low signal-to-noise ratio (SNR) on a clinical 3-T MR system. The ST and IT sequences were applied to skeletal muscle and liver in 10 healthy volunteers. Monte-Carlo simulations were used to evaluate the behavior of the IT measurements with increasing imperfections. In skeletal muscle of the thigh, ATP synthesis resulted in forward reaction constants (k) of 0.074 ± 0.022 s(-1) (ST) and 0.137 ± 0.042 s(-1) (IT), whereas the creatine kinase reaction yielded 0.459 ± 0.089 s(-1) (IT). In the liver, ATP synthesis resulted in k = 0.267 ± 0.106 s(-1) (ST), whereas the IT experiment yielded no consistent results. ST results were close to literature values; however, the IT results were either much larger than the corresponding ST values and/or were widely scattered. To summarize, ST and IT experiments can both be implemented on a clinical body scanner with heteronuclear transmit-receive surface coils; however, ST results are much more robust against experimental imperfections than the current implementation of IT.

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We report on the EPICA Dronning Maud Land (East Antarctica) deep drilling operation. Starting with the scientific questions that led to the outline of the EPICA project, we introduce the setting of sister drillings at NorthGRIP and EPICA Dome C within the European ice-coring community. The progress of the drilling operation is described within the context of three parallel, deep-drilling operations, the problems that occurred and the solutions we developed. Modified procedures are described, such as the monitoring of penetration rate via cable weight rather than motor torque, and modifications to the system (e.g. closing the openings at the lower end of the outer barrel to reduce the risk of immersing the drill in highly concentrated chip suspension). Parameters of the drilling (e.g. core-break force, cutter pitch, chips balance, liquid level, core production rate and piece number) are discussed. We also review the operational mode, particularly in the context of achieved core length and piece length, which have to be optimized for drilling efficiency and core quality respectively. We conclude with recommendations addressing the design of the chip-collection openings and strictly limiting the cable-load drop with respect to the load at the start of the run.

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The reconstruction of thermal histories of rocks (thermochronometry) is a fundamental tool both in Earth science and in geological exploration. However, few methods are currently capable of resolving the low-temperature thermal evolution of the upper ∼2 km of the Earth's crust. Here we introduce a new thermochronometer based on the infrared stimulated luminescence (IRSL) from feldspar, and validate the extrapolation of its response to artificial radiation and heat in the laboratory to natural environmental conditions. Specifically, we present a new detailed Na-feldspar IRSL thermochronology from a well-documented thermally-stable crustal environment at the German Continental Deep Drilling Program (KTB). There, the natural luminescence of Na-feldspar extracted from twelve borehole samples (0.1–2.3 km depth, corresponding to 10–70 °C) can be either (i) predicted within uncertainties from the current geothermal gradient, or (ii) inverted into a geothermal palaeogradient of 29 ± 2  °C km−1, integrating natural thermal conditions over the last ∼65 ka. The demonstrated ability to invert a depth–luminescence dataset into a meaningful geothermal palaeogradient opens new venues for reconstructing recent ambient temperatures of the shallow crust (<0.3 Ma, 40–70 °C range), or for studying equally recent and rapid transient cooling in active orogens (<0.3 Ma, >200 °C Ma−1 range). Although Na-feldspar IRSL is prone to field saturation in colder or slower environments, the method's primary relevance appears to be for borehole and tunnel studies, where it may offer remarkably recent (<0.3 Ma) information on the thermal structure and history of hydrothermal fields, nuclear waste repositories and hydrocarbon reservoirs.

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BACKGROUND Drug-eluting balloons (DEB) may reduce infrapopliteal restenosis and reintervention rates versus percutaneous transluminal angioplasty (PTA) and improve wound healing/limb preservation. OBJECTIVES The goal of this clinical trial was to assess the efficacy and safety of IN.PACT Amphirion drug-eluting balloons (IA-DEB) compared to PTA for infrapopliteal arterial revascularization in patients with critical limb ischemia (CLI). METHODS Within a prospective, multicenter, randomized, controlled trial with independent clinical event adjudication and angiographic and wound core laboratories 358 CLI patients were randomized 2:1 to IA-DEB or PTA. The 2 coprimary efficacy endpoints through 12 months were clinically driven target lesion revascularization (CD-TLR) and late lumen loss (LLL). The primary safety endpoint through 6 months was a composite of all-cause mortality, major amputation, and CD-TLR. RESULTS Clinical characteristics were similar between the 2 groups. Significant baseline differences between the IA-DEB and PTA arms included mean lesion length (10.2 cm vs. 12.9 cm; p = 0.002), impaired inflow (40.7% vs. 28.8%; p = 0.035), and previous target limb revascularization (32.2% vs. 21.8%; p = 0.047). Primary efficacy results of IA-DEB versus PTA were CD-TLR of 9.2% versus 13.1% (p = 0.291) and LLL of 0.61 ± 0.78 mm versus 0.62 ± 0.78 mm (p = 0.950). Primary safety endpoints were 17.7% versus 15.8% (p = 0.021) and met the noninferiority hypothesis. A safety signal driven by major amputations through 12 months was observed in the IA-DEB arm versus the PTA arm (8.8% vs. 3.6%; p = 0.080). CONCLUSIONS In patients with CLI, IA-DEB had comparable efficacy to PTA. While primary safety was met, there was a trend towards an increased major amputation rate through 12 months compared to PTA. (Study of IN.PACT Amphirion™ Drug Eluting Balloon vs. Standard PTA for the Treatment of Below the Knee Critical Limb Ischemia [INPACT-DEEP]; NCT00941733).

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Within the project “Tiefenschärfe – hochauflösende Vermes- sung Bodensee” a high-resolution seamless terrain model is created using airborne topobathymetric laserscanning and multibeam echosounder (MBES) techniques. The project visu- alizes the enormous wealth of features of underwater land- scapes of lakes. The combination of hydroacoustic (multibeam echosounder) and laser-optic (topobathymetric laserscan- ning) methods was used for the first time in a freshwater body of this size. Opportunities, limitations and restrictions of these high-resolution methods are presented.

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The deeply eroded West Gondwana Orogen is a major continental collision zone that exposes numerous occurrences of deeply subducted rocks, such as eclogites. The position of these eclogites marks the suture zone between colliding cratons, and the age of metamorphism constrains the transition from subduction-dominated tectonics to continental collision and mountain building. Here we investigate the metamorphic conditions and age of high-pressure and ultrahigh-pressure eclogites from Mali, Togo and NE-Brazil and demonstrate that continental subduction occurred within 20 million years over at least a 2,500-km-long section of the orogen during the Ediacaran. We consider this to be the earliest evidence of large-scale deep-continental subduction and consequent appearance of Himalayan-scale mountains in the geological record. The rise and subsequent erosion of such mountains in the Late Ediacaran is perfectly timed to deliver sediments and nutrients that are thought to have been necessary for the subsequent evolution of sustainable life on Earth.

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Deep geological storage of radioactive waste foresees cementitious materials as reinforcement of tunnels and as backfill. Bentonite is proposed to enclose spent fuel canisters and as drift seals. Sand/bentonite (s/b) is foreseen as backfill material of access galleries or as drift seals. The emplacement of cementitious material next to clay material generates an enormous chemical gradient in pore-water composition that drives diffusive solute transport. Laboratory studies and reactive transport modeling predicted significant mineral alteration at and near interfaces, mainly resulting in a decrease of porosity in bentonite. The goal of this thesis was to characterize and quantify the cement/bentonite interactions both spatially and temporally in laboratory experiments. A newly developed mobile X-ray transparent core infiltration device was used to perform X-ray computed tomography (CT) scans without interruption of running experiments. CT scans allowed tracking the evolution of the reaction plume and changes in core volume/diameter/density during the experiments. In total 4 core infiltration experiments were carried out for this study with the compacted and saturated cores consisting of MX-80 bentonite and sand/MX-80 bentonite mixture (s/b; 65/35%). Two different high-pH cementitious pore-fluids were infiltrated: a young (early) ordinary Portland cement pore-fluid (APWOPC; K+–Na+–OH-; pH 13.4; ionic strength 0.28 mol/kg) and a young ‘low-pH’ ESDRED shotcrete pore-fluid (APWESDRED; Ca2+–Na+–K+–formate; pH 11.4; ionic strength 0.11 mol/kg). The experiments lasted between 1 and 2 years. In both bentonite experiments, the hydraulic conductivity was strongly reduced after switching to high-pH fluids, changing eventually from an advective to a diffusion-dominated transport regime. The reduction was mainly induced by mineral precipitation and possibly partly also by high ionic strength pore-fluids. Both bentonite cores showed a volume reduction and a resulting transient flow in which pore-water was squeezed out during high-pH infiltration. The outflow chemistry was characterized by a high ionic strength, while chloride in the initial pore water got replaced as main anionic charge carrier by sulfate, originating from gypsum dissolution. The chemistry of the high-pH fluids got strongly buffered by the bentonite, consuming hydroxide and in case of APWESDRED also formate. Hydroxide got consumed by mineral reactions (saponite and possibly talc and brucite precipitation), while formate being affected by bacterial degradation. Post-mortem analysis showed reaction zones near the inlet of the bentonite core, characterized by calcium and magnesium enrichment, consisting predominately of calcite and saponite, respectively. Silica got enriched in the outflow, indicating dissolution of silicate-minerals, identified as preferentially cristobalite. In s/b, infiltration of APWOPC reduced the hydraulic conductivity strongly, while APWESDRED infiltration had no effect. The reduction was mainly induced by mineral precipitation and probably partly also by high ionic strength pore-fluids. Not clear is why the observed mineral precipitates in the APWESDRED experiment had no effect on the fluid flow. Both s/b cores showed a volume expansion along with decreasing ionic strengths of the outflow, due to mineral reactions or in case of APWESDRED infiltration also mediated by microbiological activity, consuming hydroxide and formate, respectively. The chemistry of the high-pH fluids got strongly buffered by the s/b. In the case of APWESDRED infiltration, formate reached the outflow only for a short time, followed by enrichment in acetate, indicating most likely biological activity. This was in agreement to post-mortem analysis of the core, observing black spots on the inflow surface, while the sample had a rotten-egg smell indicative of some sulfate reduction. Post-mortem analysis showed further in both cores a Ca-enrichment in the first 10 mm of the core due to calcite precipitation. Mg-enrichment was only observed in the APWOPC experiment, originating from newly formed saponite. Silica got enriched in the outflow of both experiments, indicating dissolution of silicate-minerals, identified in the OPC experiment as cristobalite. The experiments attested an effective buffering capacity for bentonite and s/b, a progressing coupled hydraulic-chemical sealing process and also the preservation of the physical integrity of the interface region in this setup with a total pressure boundary condition on the core sample. No complete pore-clogging was observed but the hydraulic conductivity got rather strongly reduced in 3 experiments, explained by clogging of the intergranular porosity (macroporosity). Such a drop in hydraulic conductivity may impact the saturation time of the buffer in a nuclear waste repository, although the processes and geometry will be more complex in repository situation.

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The study of mass movements in lake sediments provides insights into past natural hazards at historic and prehistoric timescales. Sediments from the deep basin of Lake Geneva reveal a succession of six large-scale (volumes of 22 × 106 to 250 × 106 m3) mass-transport deposits, associated with five mass-movement events within 2600 years (4000 cal bp to 563 ad). The mass-transport deposits result from: (i) lateral slope failures (mass-transport deposit B at 3895 ± 225 cal bp and mass-transport deposits A and C at 3683 ± 128 cal bp); and (ii) Rhône delta collapses (mass-transport deposits D to G dated at 2650 ± 150 cal bp, 2185 ± 85 cal bp, 1920 ± 120 cal bp and 563 ad, respectively). Mass-transport deposits A and C were most probably triggered by an earthquake, whereas the Rhône delta collapses were likely to be due to sediment overload with a rockfall as the external trigger (mass-transport deposit G, the Tauredunum event in 563 ad known from historical records), an earthquake (mass-transport deposit E) or unknown external triggers (mass-transport deposits D and F). Independent of their origin and trigger mechanisms, numerical simulations show that all of these recorded mass-transport deposits are large enough to have generated at least metre-scale tsunamis during mass movement initiation. Since the Tauredunum event in 563 ad, two small-scale (volumes of 1 to 2 × 106 m3) mass-transport deposits (H and I) are present in the seismic record, both of which are associated with small lateral slope failures. Mass-transport deposits H and I might be related to earthquakes in Lausanne/Geneva (possibly) 1322 ad and Aigle 1584 ad, respectively. The sedimentary record of the deep basin of Lake Geneva, in combination with the historical record, show that during the past 3695 years, at least six tsunamis were generated by mass movements, indicating that the tsunami hazard in the Lake Geneva region should not be neglected, although such events are not frequent with a recurrence time of 0·0016 yr−1.

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The asteroid 4 Vesta was recently found to have two large impact craters near its south pole, exposing subsurface material. Modelling suggested that surface material in the northern hemisphere of Vesta came from a depth of about 20 kilometres, whereas the exposed southern material comes from a depth of 60 to 100 kilometres. Large amounts of olivine from the mantle were not seen, suggesting that the outer 100 kilometres or so is mainly igneous crust. Here we analyse the data on Vesta and conclude that the crust–mantle boundary (or Moho) is deeper than 80 kilometres.

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PURPOSE In traumatic brain injury, diffusion-weighted and diffusion tensor imaging of the brain are essential techniques for determining the pathology sustained and the outcome. Postmortem cross-sectional imaging is an established adjunct to forensic autopsy in death investigation. The purpose of this prospective study was to evaluate postmortem diffusion tensor imaging in forensics for its feasibility, influencing factors and correlation to the cause of death compared with autopsy. METHODS Postmortem computed tomography, magnetic resonance imaging, and diffusion tensor imaging with fiber tracking were performed in 10 deceased subjects. The Likert scale grading of colored fractional anisotropy maps was correlated to the body temperature and intracranial pathology to assess the diagnostic feasibility of postmortem diffusion tensor imaging and fiber tracking. RESULTS Optimal fiber tracking (>15,000 fiber tracts) was achieved with a body temperature at 10°C. Likert scale grading showed no linear correlation (P > 0.7) to fiber tract counts. No statistically significant correlation between total fiber count and postmortem interval could be observed (P = 0.122). Postmortem diffusion tensor imaging and fiber tracking allowed for radiological diagnosis in cases with shearing injuries but was impaired in cases with pneumencephalon and intracerebral mass hemorrhage. CONCLUSIONS Postmortem diffusion tensor imaging with fiber tracking provides an exceptional in situ insight "deep into the fibers" of the brain with diagnostic benefit in traumatic brain injury and axonal injuries in the assessment of the underlying cause of death, considering influencing factors for optimal imaging technique.

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Navigation of deep space probes is most commonly operated using the spacecraft Doppler tracking technique. Orbital parameters are determined from a series of repeated measurements of the frequency shift of a microwave carrier over a given integration time. Currently, both ESA and NASA operate antennas at several sites around the world to ensure the tracking of deep space probes. Just a small number of software packages are nowadays used to process Doppler observations. The Astronomical Institute of the University of Bern (AIUB) has recently started the development of Doppler data processing capabilities within the Bernese GNSS Software. This software has been extensively used for Precise Orbit Determination of Earth orbiting satellites using GPS data collected by on-board receivers and for subsequent determination of the Earth gravity field. In this paper, we present the currently achieved status of the Doppler data modeling and orbit determination capabilities in the Bernese GNSS Software using GRAIL data. In particular we will focus on the implemented orbit determination procedure used for the combined analysis of Doppler and intersatellite Ka-band data. We show that even at this earlier stage of the development we can achieve an accuracy of few mHz on two-way S-band Doppler observation and of 2 µm/s on KBRR data from the GRAIL primary mission phase.