48 research outputs found
Effect of pruning-derived biochar on heavy metals removal and water dynamics
Biomass-derived biochar is considered as a promising
heavy metal adsorbent, due to abundance of polar functional
groups, such as carboxylic, hydroxyl, and amino
groups, which are available for heavy metal removal. The
aims of this study were to evaluate the effectiveness of an
orchard pruning-derived biochar in removing some heavy
metals (through the evaluation of isotherms) and to study
water dynamics at the solid-liquid interface as affected by
heavy metal adsorption (through an innovative nuclear magnetic
resonance (NMR) relaxometry approach). Both isotherms
and NMR spectra revealed that Pb and Cr showed a
good affinity for the biochar surface (Pb > Cr), while Cu was
less affine. Accordingly, higher amounts of Pb and Cr were
adsorbed by biochar as compared to those of Cu in the single
systems. In binary systems (i.e., when two metals were applied
simultaneously), Pb showed the highest inhibition of the
adsorption of the other two metals, whereas the opposite was
evidenced when Cu was used; the competitive adsorption was
also strongly influenced by the metal residence time on biochar
surface. In ternary systems (i.e., when all metals were
applied simultaneously), even in the presence of high amounts
of Pb and Cr, considerable adsorption of Cu occurred, indicating
that some biochar adsorption sites were highly specific
for a single metal
Identification and characterization of a novel non-structural protein of bluetongue virus
Bluetongue virus (BTV) is the causative agent of a major disease of livestock (bluetongue). For over two decades, it has been widely accepted that the 10 segments of the dsRNA genome of BTV encode for 7 structural and 3 non-structural proteins. The non-structural proteins (NS1, NS2, NS3/NS3a) play different key roles during the viral replication cycle. In this study we show that BTV expresses a fourth non-structural protein (that we designated NS4) encoded by an open reading frame in segment 9 overlapping the open reading frame encoding VP6. NS4 is 77–79 amino acid residues in length and highly conserved among several BTV serotypes/strains. NS4 was expressed early post-infection and localized in the nucleoli of BTV infected cells. By reverse genetics, we showed that NS4 is dispensable for BTV replication in vitro, both in mammalian and insect cells, and does not affect viral virulence in murine models of bluetongue infection. Interestingly, NS4 conferred a replication advantage to BTV-8, but not to BTV-1, in cells in an interferon (IFN)-induced antiviral state. However, the BTV-1 NS4 conferred a replication advantage both to a BTV-8 reassortant containing the entire segment 9 of BTV-1 and to a BTV-8 mutant with the NS4 identical to the homologous BTV-1 protein. Collectively, this study suggests that NS4 plays an important role in virus-host interaction and is one of the mechanisms played, at least by BTV-8, to counteract the antiviral response of the host. In addition, the distinct nucleolar localization of NS4, being expressed by a virus that replicates exclusively in the cytoplasm, offers new avenues to investigate the multiple roles played by the nucleolus in the biology of the cell
Prostatic sarcoma after treatment of rectal cancer
<p>Abstract</p> <p>Background</p> <p>The relationship between radiation exposure for treatment of cancer and occurrence of a second primary cancer at the irradiated site is well known. This phenomenon is however rare in prostate.</p> <p>Case presentation</p> <p>A 75-year-old farmer was treated for rectal cancer with preoperative 45 Gy of radiotherapy and abdominoperineal resection. Four years later he developed symptoms of bladder outlet obstruction and acute urinary retention. He underwent a transurethral resection of the prostate. Histological examination of the removed prostate tissue and immunohistochemistry revealed it to be a poorly differentiated sarcoma.</p> <p>Conclusion</p> <p>We believe this to be the first reported case of radiation-induced sarcoma following radiotherapy treatment for rectal cancer. Since radiotherapy plays a pivotal role in the contemporary treatment of rectal adenocarcinoma, it is relevant to be aware of the potential long-term carcinogenic complications of radiotherapy of the pelvis.</p
Information Transmission in Cercal Giant Interneurons Is Unaffected by Axonal Conduction Noise
What are the fundamental constraints on the precision and accuracy with which nervous systems can process information? One constraint must reflect the intrinsic “noisiness” of the mechanisms that transmit information between nerve cells. Most neurons transmit information through the probabilistic generation and propagation of spikes along axons, and recent modeling studies suggest that noise from spike propagation might pose a significant constraint on the rate at which information could be transmitted between neurons. However, the magnitude and functional significance of this noise source in actual cells remains poorly understood. We measured variability in conduction time along the axons of identified neurons in the cercal sensory system of the cricket Acheta domesticus, and used information theory to calculate the effects of this variability on sensory coding. We found that the variability in spike propagation speed is not large enough to constrain the accuracy of neural encoding in this system
Agrifood authentication and traceability by soil-based indicators.
Agrifood authentication and traceability by soil-based indicators
EFFECT OF METALS ON THE DYNAMICS OF WATER AT THE BIOCHAR SOLID-LIQUID INTERFACE
Previous studies revealed that water molecules are hooked to biochar surfaces through unconventional
hydrogen bonds (De Pasquale et al., 2012; Conte et al., 2013). Next question to answer is how metals can
affect water mobility as they are adsorbed on biochar surface. To this aim, an orchard pruning char
obtained by pyrolysis at 500°C was treated with solutions of Cu(II), Cr(VI) and Cu(II)+Cr(VI). Two different types of water can be recognized in BC.
Namely, a fast relaxing water (T1 = 99 ms) is
differentiated by a slow relaxing one (T
1= 233 ms). The
former is made by molecules interacting with biochar
surface through formation of the unconventional Hbonds previously identified (De Pasquale et al., 2012;
Conte et al., 2013). The latter is made by water
molecules freely slipping on the immobilized water layer.
After metal adsorption, no changes were observed in
MTBC relaxogram shapes as compared to BC relaxogram
(Fig. 1). Moreover, all the MTBC relaxograms were similar
to each other, regardless of the metal adsorbed on the
carbonaceous material. Nature of the metal appears not
to affect water dynamics on the porous material.
The shortening of the T
1values in MTBC as compared to
BC sample (from 99 to 42 ms, and from 23 to 95 ms,
respectively) has been interpreted by two different
molecular models. In the first case, a water layer may be immobilized on the metals directly adsorbed on
MTBC surface (Fig. 2A). Since metal-water interactionscan be stronger than those in the untreated BC, the
result is a shortening of the T1values from 99 to 40 ms. As a consequence, also the H-bonds between the
immobilized water and the freely moving one can be strengthened, thereby leading to shorter T
1 value. The second molecular model considers metal ions
bridging two water layers (Fig. 2B). The first water layer
is immobilized directly on the surface of the porous
material and it is bridged to the second water layer
through the metal cation.
Further investigations are needed in order to
differentiate among the different models accounting for
water dynamics on the surface of biochar treated with
metal cations