35 research outputs found
Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTICâHF: baseline characteristics and comparison with contemporary clinical trials
Aims:
The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTICâHF) trial. Here we describe the baseline characteristics of participants in GALACTICâHF and how these compare with other contemporary trials.
Methods and Results:
Adults with established HFrEF, New York Heart Association functional class (NYHA)ââ„âII, EF â€35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokineticâguided dosing: 25, 37.5 or 50âmg bid). 8256 patients [male (79%), nonâwhite (22%), mean age 65âyears] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NTâproBNP 1971âpg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTICâHF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressureâ<â100âmmHg (n = 1127), estimated glomerular filtration rate <â30âmL/min/1.73 m2 (n = 528), and treated with sacubitrilâvalsartan at baseline (n = 1594).
Conclusions:
GALACTICâHF enrolled a wellâtreated, highârisk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
Acidic weathering of carbonate building stones: experimental assessment
Three types of carbonate rocks, travertine, limestone and marble have been studied to determine their selected technical parameters (water absorption, resistance to salt crystallization damage) and reaction to experimentally modelled acid rain weathering imitating the polluted urban atmospheric conditions. The acidic agents present in natural acid rain precipitation, H2SO4, HCl, HNO3, CH3COOH and mixture of all the acids, âAcid mixâ, were tested. The initial stages of acid weathering involve, apart from chemical dissolution, particularly intense physical detachment of rock particles (granular disintegration) significantly contributing to the total mass loss. Travertine was found to be most prone to salt crystallization damage and to acid weathering, and these features should be taken into account especially in external architectural usage of this stone in cold climate conditions and polluted urban atmosphere
Devonian deep-crustal metamorphism and exhumation in the Variscan Orogen: evidence from SHRIMP zircon ages from the HT-HP granulites and migmatites of the GĂłry Sowie (Polish Sudetes)
The high-temperature and high-pressure granulites in the internal zone of the Variscan belt are witnesses of deep crustal processes and subsequent exhumation of deeper lithospheric fragments. The GĂłry Sowie Block granulites in SW Poland and the surround
Palaeo- to mesoproterozoic inheritance and Ediacaran anatexis recorded in gneisses at the NE margin of the Bohemian Massif: SHRIMP zircon data from the Nowolesie gneiss, Fore-Sudetic Block (SW Poland)
Recent geochronological studies, including sensitive high mass-resolution ion microprobe (SHRIMP) zircon dating, have helped to differentiate into specific age groups the various gneisses that occur within the basement units of the central-European Variscides. The Fore-Sudetic Block basement unit, for example, has been divided into two major gneiss groups of Neoproterozoic and Cambrian/Ordovician age, respectively. These two gneiss groups have been assigned to different tectonic units, themselves separated by a major tectonic boundary that is interpreted to be the northern continuation of the Moldanubian (Lugodanubian) Thrust. This thrust divides the main tectonostratigraphic units of the Bohemian Massif: the Moldanubian and Saxo-Thuringian units to the west, and the Moravo-Silesian unit to the east. This paper interprets new SHRIMP zircon data from the Nowolesie gneiss at Skalice (sample S6) and integrates the results with data from the Strzelin gneiss at De{ogonek}bniki (sample S3), which is within the Strzelin Massif (E part of the Fore-Sudetic Block). Both the Nowolesie and Strzelin gneisses contain numerous inherited zircons within the age range of 1.5-2.0 Ga, indicating Meso- and Palaeoproterozoic sources for the zircons and suggesting that these zircons were recycled into younger units that subsequently underwent partial melting. The ages derived from samples S6 and S3, together with the absence of the Grenvillian ages (âŒ1.3-0.9 Ga), suggest a West-African and/or Amazonian cratonic crust as the source for both the Nowolesie and Strzelin gneiss protoliths. The main zircon populations from both gneisses fall into two similar age groups: 602 ± 7 Ma and 587 ± 4 Ma for the Nowolesie gneiss; 600 ± 7 Ma and 568 ± 7 Ma for the Strzelin gneiss. These sets of Ediacaran (late Neoproterozoic) dates possibly reflect anatexis of the gneiss protoliths during the Cadomian orogeny
A new ordinary chondrite L6, S1, W1: Northwest Africa 11779
Based on petrological, mineralogical and geochemical research authors classified new meteorite Northwest Africa 11779 as the ordinary chondrite L6, S1, W1. Chemical composition of olivine crystals (Fa 24.9 mol.%) and of pyroxene crystals (Fs 19.4 mol.%) proved that this meteorite belongs to L chondrites. However, bulk chemical composition of NWA 11779 is not typical for L chondrites. Nevertheless, all analyzed elements (except Mo, Sn and Nb) are in abundances reported for L chondrites, some of elements have concentration closed to average abundances for L chondrites. The content of chosen, characteristic lithophile, siderophile and chalkophile elements in NWA 11779 chondrite is in most cases in accord with its typical abundance in L chondrites. Presence of poorly defined chondrules, secondary feldspar crystals larger than 50 ”m in size, absence of glass within chondrules, coarse recrystallized matrix (with olivine crystals of 0.5 mm in diameter and pyroxene crystals of 0.3 mm in diameter) as well as carbon content below 0.2 wt% proved that studied meteorite belongs to the petrologic type 6. The only difference from characteristic features of petrologic type 6 in case of NWA 11779 chondrite is presence of ca. 10% of monoclinic Ca-poor pyroxenes. Undulatory extinction by olivine and absence of other shock features in this chondrite allow to determine the shock level as S1. Weathering grade of NWA 11779 was identified as W1 based on weathering of only FeNi alloy grains. The outer part of metallic grains as well as contact zones of FeNi and FeS are changed due to weathering. Between 10 and 20% of FeNi alloy grains are oxidized to iron oxides and hydroxides. These secondary products of weathering replace outer zone of FeNi grains and fill the small cracks, creating a few thin veins
Klasyfikowanie chondrytĂłw zwyczajnych â kolejnoĆÄ prac, metody badaĆ, sprawy formalne i inne problemy
A new ordinary chondrite H5, S2, W1: Northwest Africa 11778
Based on petrological, mineralogical and geochemical analyses, the authors classified the new meteorite Northwest Africa 11778 as an ordinary chondrite H5, S2, W1. It is a single stone with mass 767.5 g and with well-preserved black fusion crust with brown shade (Fig. 1). This meteorite was found in Sahara Desert and it was purchased by Wroclaw University of Science and Technology, Faculty of Geoengineering, Mining and Geology from Moroccan dealer in Zagora in June 2013. The most characteristic component of analyzed chondrite are different types of chondrules (barred olivine â BO, porphyritic olivine â PO, granular olivine â GO, radial pyroxene â RP, porphyritic olivine-pyroxene â POP, cryptocrystalline â C) (Fig. 2), which constitute 75% of meteorite. Their size is in range 0.2â1.2 mm, with average chondrule size ca. 0.6 mm. Bigger porphyritic olivine chondrules with diameter up to 1.5 mm rarely occur. The chemical composition of olivine crystals (Fa 18 mol%) and pyroxene crystals (Fs 16.2 mol%) proves this meteorite to be an H chondrite (Tab. 1, Fig. 4â5, App. 1â2). The averaged concentration of major elements in the classified meteorite is comparable to their mean content in H chondrites (Fig. 8). The meteorite NWA 11778 contains only slightly less Mg and Al than average H chondrites (Tab. 2). Among the other analysed elements, values distinctly out of the range of typical concentrations for H chondrites are characteristic of Hg and Eu (lower concentration in the NWA 11778 meteorite) (Tab. 3, Fig. 8â9). The presence of chondrules with predominantly sharp boundaries (Fig. 2), secondary feldspar crystals with sizes of up to 50 mm, chiefly crystalline mesostasis and only secondarily â devitrified glass in chondrules, and transparent crystalline matrix (with olivine crystals up to 0.26 mm and pyroxenes up to 0.30 mm in size), as well as common occurrence of untwinned rhombic pyroxenes prove the classified meteorite to belong to petrological type 5. It is additionally confirmed by mean Ni content in troilite below 0.5 wt% (0.04 wt%) (Tab. 1, App. 4) and carbon content below 0.2 wt% (0.07 wt%) (Tab. 2). Undulatory extinction in some olivine and pyroxene crystals and the presence of irregular fractures in the NWA 11778 chondrite enables specifying its shock level as S2. The weathering grade adopted for the NWA 11778 chondrite was W1, as visible weathering changes cover only the marginal parts of FeNi alloy grains. As a result of the weathering of 10â20% of FeNi grains, iron oxides and hydroxides are formed. These secondary weathering Fe3+ compounds also fill cracks, forming veins running between chondrules within matrix (Fig. 3)
Acidic weathering of carbonate building stones: experimental assessment
Three types of carbonate rocks, travertine, limestone and marble have been studied to determine their selected technical parameters (water absorption, resistance to salt crystallization damage) and reaction to experimentally modelled acid rain weathering imitating the polluted urban atmospheric conditions. The acidic agents present in natural acid rain precipitation, H2SO4, HCl, HNO3, CH3COOH and mixture of all the acids, âAcid mixâ, were tested. The initial stages of acid weathering involve, apart from chemical dissolution, particularly intense physical detachment of rock particles (granular disintegration) significantly contributing to the total mass loss. Travertine was found to be most prone to salt crystallization damage and to acid weathering, and these features should be taken into account especially in external architectural usage of this stone in cold climate conditions and polluted urban atmosphere