Summary
Background
Direct‐acting anti‐virals (DAAs) licensed to treat chronic HCV infection have revolutionised treatment algorithms by drastically mitigating side effects while enhancing efficacy ...relative to interferon‐based therapy.
Aim
To review adverse events (AEs) uniquely associated with DAA therapy across a broad spectrum of patient populations.
Methods
Searches of PubMed and FDA surveillance studies were undertaken to complete an exhaustive review. Search terms included ‘DAAs’, ‘safety’, and ‘tolerability’.
Results
While DAAs are remarkably well tolerated, they are accompanied by unique AEs. Simeprevir, an NS3/4A protease inhibitor, has been known, albeit infrequently, to cause mild hyperbilirubinemia and photosensitivity reactions; and paritaprevir boosted with ritonavir causes bilirubin and ALT elevations. Asunaprevir, another protease inhibitor, infrequently causes elevated transaminase levels. NS5A and NS5B inhibitors are well tolerated, although sofosbuvir is contraindicated in patients with severe renal impairment. Ribavirin co‐administered in certain treatment regimens has been associated with cough, rash and haemolytic anaemia.
Conclusions
With the impending reality of a more tolerable interferon‐sparing regimen, the future of DAA therapy offers shorter treatment duration, simplified disease management, and a patient‐centred regimen. With advantages come drawbacks, including development of resistance to therapy and accessibility to this expensive treatment. DAA therapy continues to advance at a brisk pace with a promising trend for higher tolerability, even in difficult‐to‐treat subgroups such as those with cirrhosis, nonresponders to prior therapy, and transplant recipients. Subgroup‐specific contraindications and safety‐related limitations are active areas of research. Concerted research efforts and continuing advances lend hope to the goal of rendering HCV a routinely curable disease.
We provide a simple proof of a Voronoi type identity using the Laplace transform for a class of arithmetical functions whose generating Dirichlet series satisfy a functional equation with gamma ...factors. As an application, we derivea Voronoi-type identity for Gaussian integers.
A
bstract
Heavy quarks placed within a hot QCD medium undergo Brownian motion, characterized by specific transport coefficients. Their determination can be simplified by expanding them in
T/M
, where
...T
is the temperature and
M
is a heavy quark mass. The leading term in the expansion originates from the colour-electric part of a Lorentz force, whereas the next-to-leading order involves the colour-magnetic part. We measure a colour-magnetic 2-point correlator in quenched QCD at
T
∼ (1
.
2
−
2
.
0)
T
c
. Employing multilevel techniques and non-perturbative renormalization, a good signal is obtained, and its continuum extrapolation can be estimated. Modelling the shape of the corresponding spectral function, we subsequently extract the momentum diffusion coefficient,
κ
. For charm (bottom) quarks, the magnetic contribution adds ∼ 30% (10%) to the electric one. The same increases apply also to the drag coefficient,
η
. As an aside, the colour-magnetic spectral function is computed at NLO.
The origin of dust in the early universe has been the subject of considerable debate. Core-collapse supernovae (ccSNe), which occur several million years after their massive progenitors form, could ...be a major source of that dust, as in the local universe several ccSNe have been observed to be copious dust producers. Here we report nine near-infrared (0.8-2.5 m) spectra, obtained with GNIRS on Gemini North, of the Type II-P supernova (SN) 2017eaw in NGC 6946, spanning the time interval 22-205 days after discovery. The spectra show the onset of CO formation and continuum emission at wavelengths greater than 2.1 m from newly formed hot dust, in addition to numerous lines of hydrogen and metals, which reveal the change in ionization as the density of much of the ejecta decreases. The observed CO masses estimated from a local thermodynamic equilibrium (LTE) model are typically 10−4 M during days 124-205, but could be an order of magnitude larger if non-LTE conditions are present in the emitting region. The timing of the appearance of CO is remarkably consistent with the chemically controlled dust models of Sarangi & Cherchneff.
The present study involved the assessment of potential generation of acid drainage from a coal mining area in India. Laboratory-based static and kinetic tests on overburden samples were conducted. ...Results of the static tests using acid base accounting indicate that all samples may be acid generators, and their generation capacity varied between likely, possible and low. To verify the acid generation potentiality of those samples showing a high acid drainage production in the static test, the kinetic test, using humidity cell, was conducted for a period of 15 weeks. The samples were leached with simulated rain water to mimic the chemical weathering under controlled laboratory conditions and imitate actual mine site leaching. Data obtained from chemical analysis of collected leachate were used to estimate production and reaction rates of acid generation and neutralizing capacity. Based on the kinetic test, it can be concluded that presently the neutralizing capacity of the samples is better than the oxidation capacity (acid generation). But due to the high weathering rate of carbonates, as reflected by the simulated leaching test, the neutralizing materials (carbonates) will eventually be exhausted earlier (since they showed dissolution rate) than the acid generation species (sulfates). Thus, acid drainage production is predicted from that point of time, when the neutralizing capacity has been exhausted for these mine sites.
This study aimed at elucidating the fractionation of Cd, Zn and Pb in mine tailings and evaluating the extraction selectivity of different extractants – and thus the efficiency of two sequential ...extraction procedures. For the purpose of figuring out the applicability of different sequential extraction procedures (SEP’s) in Cd, Zn and Pb fractionation in mine tailings, two SEP’s (i) modified BCR and (ii) Tessier’s scheme were applied to mine tailings (new as well as old). To compare the results obtained by two methods having different number of fractions (four and five respectively), the fractions were rearranged into four “equivalent fractions” defined as acid soluble, reducible, oxidisable and residual. Systematic variations in the “reducible” fraction, i.e. the content of metal in the reducible fractions obtained by Tessier’s procedure were, in general, higher than those obtained by BCR scheme. This may be attributed to stronger conditions used in Tessier’s scheme to extract this fraction. This shows that the fractions are only empirically (operationally) defined and are not totally exclusive to the specified mineral phase. Percentages of Cd, Zn and Pb extracted in the organic fraction by modified BCR scheme were always higher than those obtained by Tessier’s scheme. Based on the fractionation results by both the schemes, it appears that as compared to Cd and Zn, Pb has lower extraction yield in old tailings as compared to new tailings in organic/sulphides bound fraction. This can be explained by the formation of secondary Pb minerals of low solubility, formed by the oxidation of sulphides in old tailings as a result of weathering. Speciation data indicate that Cd has the greatest affinity in the acid soluble fraction, Pb is associated with the reducible fraction and Zn is incorporated into the residual fraction (crystalline silicate matrices) irrespective of the solid matrix type. The metal associations in the oxidizable fraction appear to be matrix specific, i.e., Zn dominates this fraction in new tailings and Pb in old tailings.
Abstract
We present near-IR (NIR) and optical observations of the Type Ic supernova (SN Ic) SN 2020oi in the galaxy M100 and the broad-lined SN Ic SN 2020bvc in UGC 9379, using Gemini, Las Cumbres ...Observatory, Southern Astrophysical Telescope, and other ground-based telescopes. The NIR spectrum of SN 2020oi at day 63 since the explosion shows strong CO emissions and a rising
K
-band continuum, which is the first unambiguous dust detection from an SN Ic. Non-LTE CO modeling shows that CO is still optically thick and that the lower limit to the CO mass is 10
−3
M
⊙
. The dust temperature is 810 K, and the dust mass is ∼10
−5
M
⊙
. We explore the possibilities that the dust is freshly formed in the ejecta, heated dust in the preexisting circumstellar medium, and an infrared echo. The light curves of SN 2020oi are consistent with a STELLA model with canonical explosion energy, 0.07
M
⊙
Ni mass, and 0.7
M
⊙
ejecta mass. A model of high explosion energy of 10
52
erg, 0.4
M
⊙
Ni mass, and 6.5
M
⊙
ejecta mass with the circumstellar matter reproduces the double-peaked light curves of SN 2020bvc. We observe temporal changes of absorption features of the IR Ca
ii
triplet, S
i
at 1.043
μ
m, and Fe
ii
at 5169 Å. The blueshifted lines indicate high velocities, up to 60,000 km s
−1
for SN 2020bvc and 20,000 km s
−1
for SN 2020oi, and the expansion velocity rapidly declines before the optical maximum. We present modeled spectral signatures and diagnostics of CO and SiO molecular bands between 1.4 and 10
μ
m.
A dusty rain falls on the nova V959 Monocerotis Evans, A; Banerjee, D P K; Varricatt, W P ...
Monthly notices of the Royal Astronomical Society,
05/2024, Volume:
531, Issue:
1
Journal Article
Peer reviewed
Open access
ABSTRACT We present archival and ground-based infrared observations of the γ-ray-emitting nova V959 Mon, covering the period 100–4205 d after the 2012 eruption. We use these data to determine that ...the secondary in the nova system is a G5 main sequence star. Data from the NEOWISE survey reveal a significant increase in the emission at 3.4 and 4.6 $\, \mu$m at late (≳600 d) times, which we interpret as emission by dust. Other interpretations are considered but cannot be reconciled with the data. The presence of such late dust emission, and in particular its variation with time, are unprecedented in the context of novae. The behaviour of the dust emission suggests a qualitative interpretation in which ejecta from the 2012 eruption encounter denser pre-eruption circumbinary material, giving rise to Rayleigh–Taylor instabilities that cause clumps of dust-bearing material to fall back towards the central binary, the dust undergoing destruction by chemisputtering as it does so. The observed rise in the dust temperature, the decline in the nova-dust distance, and in the dust mass are consistent with this interpretation. Not all novae are expected to show this behaviour, but inspection of resources such as NEOWISE might reveal other novae post-eruption that do.
•A simple experimental apparatus is configured for digital recording of spatial variation of temperature transients within a Thermal Energy Storage (TES) device using Phase Change Material (PCM) and ...on the surface of the containment apparatus.•Multi-Layer Perceptron (MLP) model is utilized for developing the artificial neural network (ANN) which is then used for enhancing the performance, reliability and accuracy of predictions for exploiting Cold Finger Techniques (CFT).•Using transient measurements from only three thermocouples, that were immersed in PCM at different levels, the ANN model can predict the progression of the melt front.•The ANN model accurately predicted 3-hours prior to reaching 90% melt fraction (to an accuracy of within 10-minutes).•Effect of different power input on the prediction accuracy was explored and the reliability of the ANN model was validated for different levels of noise (uncertainty) in the experimental data (that was used for training the MLP model).•The lowest error in the predicted results was observed for data sets that have lower noise and also have similar durations for complete melting.
Thermal Energy Storage (TES) platforms mitigate the paucity between peaks in consumption and supply, i.e., they absorb thermal energy during periods of excess supply and release thermal energy during periods of deficit. Phase change materials (PCMs) have attracted significant attention over recent years due to their efficacy in improving performance and reliability of TES platforms. High latent heat values accruing from the use of PCMs enable improved storage densities which in turn yield devices with compact form factors for TES applications. Typically, inorganic PCMs afford higher latent heat values than organic PCMs, yet often at the detriment of compromised reliability. A crucial issue with inorganic PCMs is the higher degree of supercooling (also known as “subcooling”) required to initiate nucleation (which degrades their reliability, net energy storage capacity, and power rating of the TES platform). “Cold Finger Technique (CFT)” can be used to mitigate these issues where a small portion of the total mass of PCM in the TES platform is left in solid state (in order to facilitate the spontaneous nucleation). Therefore, reliability issues are ameliorated by using CFT but at a marginal cost to the net storage capacity while power rating of the TES remains almost unaffected. In this study, machine learning (ML) techniques were leveraged to exploit the capability of CFT more effectively. Temperature transients from PCM melting experiments are used to investigate the capability of this deep learning technique (i.e., using multi-layer perceptron model or “MLP”) in order to predict the required time to reach the designated melt-fraction of the PCM. The results show that the Artificial Neural Network (ANN) model designed and implemented in this study is capable of predicting the time required to reach pre-designated value of melt-fraction with outstanding accuracy (e.g., 90% melt-fraction or 95% melt-fraction, that is specified by the user). The mean error of the predictions is calculated and is expected to be less than 10 min, especially for an interval of 30 min before the TES platform reaches the desired value of the melt fraction (i.e., 90% melt-fraction) for a total time spanning 2∼3 h. However, this approach is more susceptible to the fidelity of the data-set utilized for training the ANN (MLP) algorithm.
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Microplasticity at Room Temperature in α/β Titanium Alloys Hémery, S.; Villechaise, P.; Banerjee, D.
Metallurgical and materials transactions. A, Physical metallurgy and materials science,
10/2020, Volume:
51, Issue:
10
Journal Article
Peer reviewed
Open access
The current understanding of room temperature microplasticity in
α
/
β
titanium alloys is reviewed with a special emphasis on dual-phase engineering alloys. As the interplay between microstructure ...and deformation mechanisms governs both the microscale and macroscale mechanical response, a brief description of the main features of
α
/
β
microstructures is first provided. Elastic and plastic deformation in individual phases is then described. The complex interactions that govern the effect of grain boundaries, phase interfaces and microtexture on deformation behaviour are reviewed. Crystal plasticity simulations have evolved over the past decade as a key technique to obtain a mechanistic understanding of the deformation of Ti alloys. Micromechanical aspects are emphasized with a discussion of input parameters required to achieve realistic constitutive modeling. As microplasticity is especially relevant in cyclic loading such as experienced in-service by components, the current understanding of the relation of this regime with fatigue and dwell-fatigue behavior is briefly summarized in the final section.
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