457 research outputs found
A double continuum hydrological model for glacier applications
Peer reviewedPublisher PD
Adaptive mesh refinement versus subgrid friction interpolation in simulations of Antarctic ice dynamics
Geophysical Research Letters
Human and Viral microRNA Expression in Acute and Chronic HIV Infections
Human and viral microRNAs (miRNAs) are involved in the regulation of gene transcription, and the establishment of their profiles in acute (AHI) and chronic (CHI) HIV infections may shed light on the pathogenetic events related to different phases of HIV disease. Next-generation sequencing (NGS) of miRNA libraries was performed, and the reads were used to analyze miRNA differential expression in the plasma with AHI and CHI. Functional analysis was then undertaken to investigate the biological processes characterizing the two phases of HIV infection. Except for hsa-miR-122-5p, which was found in 3.39% AHI vs. 0.18% CHI, the most represented human miRNAs were similarly represented in AHI and CHI. However, when considering the overall detected miRNAs in AHI and CHI, 15 displayed differential expression (FDR p < 0.05). Functional analysis identified 163 target mRNAs involved in promoting angiogenesis activation in AHI versus CHI through the action of hsa-miR10b-5p, hsa-miR1290, hsa-miR1-3p, and hsa-miR296-5p. The viral miRNAs detected, all belonging to herpesviruses, accounted for only 0.014% of total reads. The present data suggest that AHI patients exhibit strong innate immune activation through the upregulation of hsa-miR-122-5p and early activation of angiogenesis. More specific investigations are needed to study the role of viral miRNAs in HIV pathogenesis
Phases of the two-band model of spinless fermions in one dimension
We study the two-band model of spinless fermions in one dimension for weak
repulsive interactions. In this case, the model is equivalent to the weakly
interacting spinless two-leg ladder. We obtain analytic expressions for the
superconducting pairing correlation function and the charge density correlation
function, which show, that a finite interchain hopping t_p results in dominant
superconductivity for repulsive interactions (for vanishing t_p, we recover
previous results). We furthermore find that the transition from the
superconducting phase to the usual one-dimensional (Luttinger) metal at large
doping occurs via a mixed phase, where superconducting pairs are formed in the
bonding band only. We give the phase diagram as a function of temperature and
doping.Comment: 10 pages, 2 figure
Generalization of the Luttinger Theorem for Fermionic Ladder Systems
We apply a generalized version of the Lieb-Schultz-Mattis Theorem to
fermionic ladder systems to show the existence of a low-lying excited state
(except for some special fillings). This can be regarded as a non-perturbative
proof for the conservation under interaction of the sum of the Fermi wave
vectors of the individual channels, corresponding to a generalized version of
the Luttinger Theorem to fermionic ladder systems. We conclude by noticing that
the Lieb-Schultz-Mattis Theorem is not applicable in this form to show the
existence of low-lying excitations in the limit that the number of legs goes to
infinity, e.g. in the limit of a 2D plane.Comment: RevTex, 4 pages with 4 eps figure
Characterization of chitin and chitosan derived from Hermetia illucens, a further step in a circular economy process
Due to their properties and applications, the growing demand for chitin and chitosan has stimulated the market to find more sustainable alternatives to the current commercial source (crustaceans). Bioconverter insects, such as Hermetia illucens, are the appropriate candidates, as chitin is a side stream of insect farms for feed applications. This is the first report on production and characterization of chitin and chitosan from different biomasses derived from H. illucens, valorizing the overproduced larvae in feed applications, the pupal exuviae and the dead adults. Pupal exuviae are the best biomass, both for chitin and chitosan yields and for their abundance and easy supply from insect farms. Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscope analysis revealed the similarity of insect-derived polymers to commercial ones in terms of purity and structural morphology, and therefore their suitability for industrial and biomedical applications. Its fibrillary nature makes H. illucens chitin suitable for producing fibrous manufacts after conversion to chitin nanofibrils, particularly adults-derived chitin, because of its high crystallinity. A great versatility emerged from the evaluation of the physicochemical properties of chitosan obtained from H. illucens, which presented a lower viscosity-average molecular weight and a high deacetylation degree, fostering its putative antimicrobial properties
Time spent with HIV-RNA †200 copies/ml in a cohort of people with HIV during the U=U era
Objective:
Zero risk of linked HIV transmission in sero-discordant couples when the HIV-infected partner had viral load (VL) <200 copies/mL (âU statusâ) was found in observational studies. We aimed at estimating the proportion of time in which âU statusâ was maintained and identifying factors associated with the risk of losing it. /
Design:
Observational cohort study. /
Methods:
We included participants in the ICONA cohort who had reached an established âU statusâ (VLâ€200 copies/mL for >6 months) as of December 2010. The outcome was the number of person-days of follow up (PDFU) above a VL>200 copies/ml, relative to the total number of PDFU observed. A logistic regression model was used to identify factors independently associated with the risk of losing âU statusâ. /
Results:
8,241 persons living with HIV were included in the analysis who contributed 12,670,888 PDFU. Of these, 1,648 (20%) were female, 768 (9%) were people who inject drugs (PWID), and 2,066 (25%) were foreing-born. The median of VL measurements was 9 (IQR: 4â15). Overall, only 3.1% of PDFU were observed when VL was >200 copies/mL. The proportion of PDFU with VL>200 cp/ml was higher than average in females (5.3%), unemployed (5.4%), PWID (4.7%), and in people with>3 previous virologic failures (6.3%). These variables were significant predictors of losing âU statusâ in the multivariable logistic regression. /
Conclusions:
Our results reinforce the validity of the U=U message in real-world setting. However, we identified subsets of our study population at higher risk of losing the âU statusâ for whom additional efforts are needed
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