The hydration of four sulfoaluminate cements have been studied: three sulfoaluminate systems, having different content of sulfate and silicate, and one blend Portland-CSA-calcium sulfate binder. ...Hydration was followed up to 90days by means of a combination of X-ray diffraction and solid state MAS-NMR; Differential scanning calorimetry and Scanning electron microscopy were also performed in order to help the interpretation of experimental data. High amount of amorphous phases were found in all the four systems: in low-sulfate cements, amorphous part is mainly ascribed to monosulfate and aluminium hydroxide, while strätlingite is observed if belite is present in the cement; in the blend system, C-S-H contributes to the amorphous phase beyond monosulfate.
Aims.
Very small asteroids (VSAs, objects with diameters smaller than about 150 m) can be spun up by the YORP effect to rotation periods as short as tens of seconds. This effect has been observed for ...many of them. It is also hypothesised, that in the same process their spin axes are asymptotically drawn to the position perpendicular to the orbital plane. So far this effect has been observed only for one VSA and needs further verification. For that, spin axes of several other VSAs should be determined by observing their brightness variations at many different positions on the sky.
Methods.
On 4 March 2021 at 9 UTC a 30-m in diameter near-Earth asteroid 2021 DW
1
passed the Earth at a distance of 570 000 km, reaching the maximum brightness of
V
= 14.6 mag. We observed it photometrically from 2 March, when it was visible at
V
= 16.5 mag, until 7 March (
V
= 18.2 mag). During that time 2021 DW
1
swept a 170° long arc in the northern sky, spanning solar phase angles in the range from 36° to 86°. This made it an excellent target for physical characterisation, including spin axis and shape derivation.
Results.
Convex inversion of the asteroid lightcurves gives a sidereal period of rotation
P
sid
= 0.013760 ± 0.000001 h, and two solutions for the spin axis ecliptic coordinates: (A)
λ
1
= 57° ± 10°,
β
1
= 29° ± 10° and (B)
λ
2
= 67° ± 10°,
β
2
= −40° ± 10°. The magnitude-phase curve can be fitted with a standard
H
,
G
function with
H
= 24.8 ± 0.5 mag and an assumed
G
= 0.24. The asteroid colour indices are
g
−
i
= 0.79 ± 0.01 mag, and
i
−
z
= 0.01 ± 0.02 mag which indicates an S taxonomic class, with an average geometric albedo
p
V
= 0.23 ± 0.02. The asteroid effective diameter, derived from
H
and
p
V
, is
D
eff
= 30 ± 10 m.
Conclusions.
It was found that the inclination of the spin axis of 2021 DW
1
is not perpendicular to the orbital plane (obliquity
ϵ
= 54° ± 10° or
ϵ
= 123° ± 10°). More spin axes of VSAs should be determined to check, if 2021 DW
1
is an exception or a typical case.
In vertebrates, the inner ear arises from the otic placode, a thickened swathe of ectoderm that invaginates to form the otic vesicle. We report that histone demethylase KDM4B is dynamically expressed ...during early stages of chick inner ear formation. A loss of KDM4B results in defective invagination and striking morphological changes in the otic epithelium, characterized by abnormal localization of adhesion and cytoskeletal molecules and reduced expression of several inner ear markers, including Dlx3. In vivo chromatin immunoprecipitation reveals direct and dynamic occupancy of KDM4B and its target, H3K9me3, at regulatory regions of the Dlx3 locus. Accordingly, coelectroporations of DLX3 or KDM4B encoding constructs, but not a catalytically dead mutant of KDM4B, rescue the ear invagination phenotype caused by KDM4B knockdown. Moreover, a loss of DLX3 phenocopies a loss of KDM4B. Collectively, our findings suggest that KDM4B play a critical role during inner ear invagination via modulating histone methylation of the direct target Dlx3.
2I/Borisov is the first interstellar comet discovered on 2019 August 30, and it soon showed a coma and a dust tail. This study reports the results of images obtained at the Telescopio Nazionale ...Galileo telescope, on La Palma-Canary Islands, in 2019 November and December. The images have been obtained with the R filter in order to apply our dust tail model. The model has been applied to the comet 67P/Churyumov-Gerasimenko and compared to the Rosetta dust measurements showing a very good agreement. It has been applied to the comet 2I/Borisov, using almost the same parameters, obtaining a dust environment similar to that of 67P/Churyumov-Gerasimenko, suggesting that the activity may be very similar. The dust tail analysis provided a dust-loss rate Qd 35 kg s−1 in 2019 November and Qd 30 kg s−1 in 2019 December.
On 2013 March 21, high-resolution slit spectrographs of the comet C/2011 L4 (Panstarrs), at a heliocentric distance r = 0.46 AU, were obtained at the Osservatorio Astronomico Campo dei Fiori, Italy. ...Emission lines of sodium were the strongest in the spectrum as is common in comets, but potassium lines were also detected. These have rarely been observed in comets since the apparition of the brightest comet C/1965 S1 (Ikeya-Seki). Lithium was not detected and stringent upper limits of its abundance compared to other alkali were derived. We obtain the abundance ratios Na/K = 54 + or - 14 and Na/Li > or = 810 super(3). In addition to Mercury's exosphere (Leblanc & Doressoundiram), we show that photoionization at the beginning of the alkali tails may increase the solar ratio Na/K = 15.5 (Asplund et al.) by a factor three, close to that required to match the observed value. In the same tail position, the Na/Li ratio increases only by a factor two, very far from the factor > or =8 required to match an original meteoritic ratio. We apply the same model to similar alkali data (Preston) of the comet C/1965 S1 (Ikeya-Seki) and obtain consistent results. An original solar Na/K ratio fits the observed value at the beginning of the alkali tails within the slit size, whereas Li is depleted by a factor > or =8.
One of the earliest manifestations of neural induction is onset of expression of the neural marker Sox2, mediated by the activation of the enhancers N1 and N2. By using loss and gain of function, we ...find that Sox2 expression requires the activity of JmjD2A and the Msk1 kinase, which can respectively demethylate the repressive H3K9me3 mark and phosphorylate the activating H3S10 (H3S10ph) mark. Bimolecular fluorescence complementation reveals that the adaptor protein 14-3-3, known to bind to H3S10ph, interacts with JMJD2A and may be involved in its recruitment to regulatory regions of the Sox2 gene. Chromatin immunoprecipitation reveals dynamic binding of JMJD2A to the Sox2 promoter and N-1 enhancer at the time of neural plate induction. Finally, we show a clear temporal antagonism on the occupancy of H3K9me3 and H3S10ph modifications at the promoter of the Sox2 locus before and after the neural plate induction. Taken together, our results propose a series of epigenetic events necessary for the early activation of the Sox2 gene in neural progenitor cells.
Ultrapotassic plutons from several domains of the Variscan orogenic belt have been in turn interpreted as syn- to post-orogenic due to their age spread, but assessment of their geodynamic setting and ...source regions is still open to interpretation. In the Svoge region (Bulgaria), at the southern margin of the Balkan orogen, peralkalic plutons are hosted within Ordovician pelites. The main intrusion, with lamproitic affinity, which hosts monzodiorite xenoliths and a polyphase syenite suite, was emplaced at a shallow level. 40Ar–39Ar dating by step-heating of amphibole and biotite yielded a Early Carboniferous intrusion age for the main body (337 ± 4 and 339.1 ± 1.6 Ma). The lamproite intrusion is silica-rich compared with bona fide lamproites and characterized by moderate LILE and LaN/YbN enrichments. Sr and Nd isotopic data (initial ϵNd in the range −4.87 to −5.88) suggest an origin in a depleted lithospheric mantle, possibly refertilized by eo-Variscan subduction. The high-K syn-tectonic plutonism in several zones of the Variscan orogen (Bohemian, Austro-Alpine, Vosges, French and Corsica domains) is consistent with a derivation of high-K magmatism from partial melting of metasomatized mantle following the subduction along the collision front between Gondwana and Laurasia.
Four different binders based on calcium sulfoaluminate cements have been submitted to accelerated chlorination through ionic exchange on hydrated pastes, in order to investigate their ability to ...chemically bind chloride ions that might reduce chloride penetration. The composition of hydrated cements before and after the treatment was evaluated by means of an X-Ray Diffraction–{sup 27}Al Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy combined study, allowing to take into account even partially amorphous phases and to make quantitative assumption on the relative abundance of the different aluminium-containing phases. It was found that low SO{sub 3} Sulfoaluminate–Portland ternary systems are the most effective in binding chloride ions and the active role played by different members of the AFm family in chloride uptake was confirmed. Moreover, a peculiar behavior related to the formation of Friedel's salt in different pH conditions was also established for the different cements.
Construction and demolition waste (CDW) recycling is generally limited to the use of the coarser fraction as aggregate for new concrete. The recovery of fine aggregates requires a cleaning by ...removing the hydrated cement waste (HCW). In this paper, the possibility to use HCW extracted from CDW as alternative component for the production of new clinker is explored.
A pure HCW sample was prepared and used in partial replacement of natural materials in raw admixtures for new clinker production. At a replacement degree of 30%, a new Portland clinker containing almost 50% of C3S could be produced with a huge spare in the release of CO2 (about 1/3 less). At higher HCW dosage a non-Portland clinker containing almost 80% of C2S has been obtained: its use as supplementary cementing material in blended cements revealed satisfying long term performances.
Abstract
Background and purpose
Post-angiography renal replacement therapy (RRT) has shown protective effects from Ci-AKI (contrast induced acute kidney injury) in patients with pre-existing advanced ...renal disfunction. We analysed a series of 1095 continuative patients who undergone coronary or peripheral angiography in our center. In non-haemodialyzed patients with eGFR <20ml/min/1.73m2 or with poor renal reserve we performed an “early” RRT, starting during angiography procedure and applied for at least 6 h after procedure, thus diverging from previous literature data based only on post-procedure hours delayed RRT application. The RRT modality chosen was CVVHDF (continous veno-venous hemodiafiltration).
Methods
We considered following subjects variability: age, sex, weight, presence of hypertension, dyslipidaemia, diabetes, smoking habitude, left ventricular ejection fraction, amount of contrast media given and shock or infection occurrence during hospital stay. We evaluate statistic significative of serum creatine (SCr) variation in patients receiving RRT from pre-procedure time (T0), at 24h (T1), 48h (T2), 72h (T3) after procedure and at 3–8 weeks follow-up (T4). Quantitative data were compared with Student T test, qualitative data with Chi Square test, considering statistically significant p value <0.05 with two tails. Ci-AKI was defined as serum creatinine rise ≥0.3 mg/dL at 48h from contrast media administration, following KDIGO (kidney disease improving global outcomes) guidelines definition.
Results
26 patients received RRT. Medium SCr at T0 was 3.37 mg/dl and showed a significative reduction (see figure) at T1 (−0.88mg/dl = −20.6%, p=0.003) and T2 (−0.96mg/dl = −18.33%, p=0.029) and a trend towards reduction at T3 (−0.78mg/dl, p=0.174) and at T4 (−0.28mg/dl, p=0.568).
Between 26 pts, 6 pts (23%) developed Ci-AKI. Only contrast media amount significatively diverge between two groups (183 ml in the group with Ci-AKI vs 162 ml in pts with no Ci-AKI, p=0.03), showing also a trend towards significance for infection occurrence (83.3% pts Ci-AKI vs 40% pts no Ci-AKI, p=0.06) and shock onset (33.3%pts Ci-AKI vs 5% pts no Ci-AKI, p=0.06).
Average SCr diverge at T2 (3.18mg/dl Ci-AKI vs 2.04mg/dl no Ci-AKI, p=0.01) and at T3 (3.33mg/dl CI-AKI vs 2.31mg/dl no CI-AKI, p=0.06); we also found a trend towards progressive increase of SCr for Ci-AKI pts (T0-T1: +0.17mg/dl, p=ns; T0-T2: +0.41mg/dl, p=ns; T0-T3: +0.57mg/dl, p=ns; T0-T4: +1.35mg/dl, p=ns) and a significative reduction in SCr for no Ci-AKI pts (T0-T1: −1.23mg/dl = −29.32% p=0.001; T0-T2: −1.46mg/dl = −30.78%, p=0.01; T0-T4: −0.41mg/dl = −15.5%, p=0.05).
Conclusions
Early RRT with CVVHDF modality results effective in 77% of patients in avoiding Ci-AKI, with a significative SCr reduction at 24 and 48h. An increased amount of contrast media is significatively related to Ci-AKI incidence. Ci-AKI development could also possibly be related to shock and infection occurrence.
Figure 1
Funding Acknowledgement
Type of funding source: None
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