68 research outputs found
DataSheet_1_Impacts of morphological change and sea-level rise on stratification in the Pearl River Estuary.docx
The Pearl River Delta (PRD), where several megacities are located, has undergone drastic morphological changes caused by anthropogenic impact during the past few decades. In its main estuary, the water area has been reduced by 21% whilst the average water depth has increased by 2.24Â m from 1970s to 2010s. The mainly human-induced morphological change together with sea level rise has jointly led to a remarkable change in the water stratification. However, the spatial and temporal variability of stratification in the estuary and associated driving mechanisms remain less understood. In this study, stratification in the Pearl River Estuary (PRE) in response to morphological change and external forcing is investigated by 3-dimensional numerical modeling. Simulation results indicate that stratification in the PRE exhibits distinct spatial and temporal variabilities. At a tidal-to-monthly time scale, variation of stratification is mainly driven by advection and straining through tidal forcing. At a monthly-to-seasonal scale, monsoon-driven river runoff and associated plume and fronts dominate the variation of stratification. Human-induced morphological change leads to an enhancement of stratification by up to four times in the PRE. Compared to an overwhelming human impact in the past few decades, future sea level rise would further enhance stratification, but to a much lesser extent than past human impacts. In addition, stratification in different areas of the estuary also responds differently to the driving factors. The western shoal of the estuary is most sensitive to changes in morphology and sea level due to its shallowness, followed by the channels and other parts of the estuary, which are less sensitive.</p
The D<sup>14</sup>RMR<sup>17</sup> and Trp79 domains mediate the interaction between Vif and A3DE.
<p>HIV-1 Vif DR14/15 and W79 all showed reduced interaction with A3DE when compared to WT Vif. HEK293T cells were cotransfected with A3DE and a control vector, WT Vif, or one of the indicated Vif mutants. At 48 h post-transfection, cell lysates were prepared and immunoprecipitated with anti-myc antibody and agarose-conjugated protein A/G. Cell lysates (A) and the interaction of A3C with WT or mutant Vif molecules(B) were detected by immunoblotting with antibodies against A3DE-HA and Vif-myc.</p
The C-CCD of A3F behaves like the full-length A3F.
<p>(A) Alignment of A3C and the C-CCD of AF. (B) Alignment of A3C and the N-CCD of AF. (C) Interaction of A3F and A3F-C with HIV-1 Vif. HEK293T cells were cotransfected with HIV-1 Vif-myc plus control vector, full-length A3F-HA, or A3F-C-HA. The cells were treated with 10 µM MG132 12 h prior to harvesting., and A3F-HA proteins were immunoprecipitated from cell lysates with an anti-HA antibody conjugated to agarose beads. The interaction of A3F with HIV-1 Vif molecules was detected by immunoblotting with antibodies against A3F-HA and Vif antibody. (D) HIV-1 Vif induces the degradation of the C-CCD of A3F. HEK293T cells were transfected with an expression vector encoding the C-CCD of A3F plus a control vector, WT Vif, or one of the indicated Vif mutant expression vectors. A3F-C stability was assessed by immunoblotting with antibodies against V5, Vif-myc, and β-tubulin as a loading control.</p
Effect of mutations in HIV-1 Vif on Vif activity against A3C and A3G.
<p>(A) Vif DR14/15 and W79 are required for A3C degradation. HEK293T cells were cotransfected with A3C plus a control vector, WT Vif, or one of the indicated Vif mutant expression vectors. A3C stability was assessed by immunoblotting against A3C-HA, Vif-myc, and ribosomal p19 as a loading control. (B) Vif K22 and RH41/42 are required for A3G degradation. HEK293T cells were cotransfected with A3G plus a control vector, WT Vif, or one of the indicated Vif mutant expression vectors. A3G stability was assessed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003963#pone-0003963-g002" target="_blank">Fig. 2A</a>. (C) Mutation of Vif DR14/15 and W79 inhibits Vif function, resulting in the packaging of A3C into SIV virions. HEK293T cells were co-transfected with SIVagmTanΔVif, A3C plus a control vector, WT Vif, or one of the indicated Vif mutants. Virus was purified from the supernatant and evaluated for A3C packaging by immunoblotting with antibodies against A3C-HA and CAp27. (D) Mutation of Vif K22 and RH41/42 inhibits Vif function, resulting in the packaging of A3G into HIV-1 virions. HEK293T cells were co-transfected with NL4-3ΔVif and A3G plus a control vector, WT Vif, or one of the indicated Vif mutants. Virus was purified and evaluated by immunoblotting with antibodies against A3G-HA and CAp24.</p
The D<sup>14</sup>RMR<sup>17</sup> and Trp79 domains mediate the interaction between HIV-1 Vif and A3C.
<p>Vif DR14/15 and W79 showed reduced interaction with A3C when compared to WT Vif. HEK293T cells were cotransfected with A3C and the control vector, HIV-1 Vif, or one of the indicated Vif mutants. At 48 h post-transfection, cell lysates were prepared and immunoprecipitated with anti-myc antibody and agarose-conjugated protein A/G. Cell lysate (A) and the interaction of A3C with WT or mutant Vif molecules(B) were detected by immunoblotting with antibodies against A3G-HA and Vif-myc.</p
Models of HIV-1 Vif mediated interaction and polyubiquitination of A3G (A) and A3F (B).
<p>(A) Two distinct domains of HIV-1 Vif (G-box and FG-box) mediate interaction with the amino-terminal domain of A3G. However, the carboxyl-terminal domain of A3G is also required for Vif-mediated polyubiquitination and degradation. (B) Three distinct domains of HIV-1 Vif (F1-box, F2-box, and FG-box) mediate interaction with the carboxyl-terminal domain of A3F. The carboxyl-terminal domain of A3F is sufficient for Vif-mediated A3F degradation.</p
Effect of mutations in HIV-1 Vif on Vif function.
<p>(A) Diagram of the functional domains of HIV-1 Vif. The BC-box structure mediates the interaction with ElonginB/C. A zinc-binding domain, Hx2YFxCFx4Φx2AΦx7-8Cx5H, is important for Cul5 selection. The N-terminal of Vif has been proposed to bind to APOBEC3 cytidine deaminases. (B) Effect of HIV-1 WT or mutant Vif proteins on the infectivity of SIVagmTan△Vif in the presence of A3C. SIV viruses were produced in HEK293T cells co-expressing A3C in the presence of HIV-1 WT or mutant Vif as indicated. Virus infectivity was assessed by Magi assay, with virus infectivity in the presence of WT Vif set to 100%. Error bars represent the standard deviations from triplicate wells. (C) Effect of HIV-1 WT or mutant Vif proteins on the infectivity of NL4-3△Vif in the presence of A3G. HIV viruses were produced in HEK293T cells co-expressing A3G in the presence of HIV-1 WT or mutant Vif as indicated. Virus infectivity was assessed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003963#pone-0003963-g001" target="_blank">Fig. 1B</a>.</p
Effect of mutation of HIV-1 Vif on its activity against A3DE.
<p>(A) Vif DR14/15 and W79 are required for A3DE degradation. HEK293T cells were cotransfected with A3DE plus a control vector, HIV-1 Vif, or one of the indicated Vif mutant expression vectors. A3DE stability was assessed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003963#pone-0003963-g002" target="_blank">Fig. 2A</a>. (B) Mutation of Vif DR14/15 and W79 inhibits Vif function, resulting in the packaging of A3DE into HIV-1 virions. HEK293T cells were co-transfected with NL4-3ΔVif and A3DE plus a control vector, WT Vif, or one of the indicated mutant expression vectors. Virus was purified and evaluated for A3DE packaging as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003963#pone-0003963-g002" target="_blank">Fig. 2D</a>. (C) Effect of WT or mutant Vif on the infectivity of NL4-3△Vif in the presence of A3DE. HIV viruses were produced in HEK293T cells coexpressing A3DE in the presence of WT or mutant Vif as indicated. Virus infectivity was assessed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003963#pone-0003963-g001" target="_blank">Fig. 1B</a>.</p
Effect of Vif mutants on A3G degradation and virion packaging.
<p>HEK293T cells were transfected with 0.5 µg NL4-3ΔVif plus 0.5 µg A3G in the presence of increasing doses of WT Vif or mutants as indicated. A3G stability was assessed by immunoblotting against A3G-HA, Vif-HA and tubulin as a loading control. A3G packaging was evaluated by immunoblotting against A3G-HA and CAp24 after viruses were isolated by ultracentrifugation from the supernatants of cell cultures.</p
Activating Montmorillonite for Light-Driven Hydrogen Evolution with the Coupling of Fe Species
Montmorillonite
(MMT), a layered hydrated aluminum silicate mineral,
emerges as a promising catalyst support due to its substantial specific
surface, ion storage capacity, thermal stability, and cost-effectiveness.
Despite the success of MMT-based photocatalysts in degrading compounds,
their potential for the photocatalytic hydrogen evolution reaction
(HER) is underexplored. Furthermore, the reliance on noble metals
and dye sensitization in MMT-based photocatalysts leads to elevated
costs. This study introduces an MMT-based photocatalyst modified with
Fe species (denoted as Fe@MMT) for photocatalytic HER without the
reliance on noble metals and dye sensitization. The incorporation
of Fe species has a dual impact, expanding the light harvesting region
of MMT and modulating the aluminum-silicate framework. Simultaneously,
it facilitates the exfoliation of individual sheets from stacked MMT
layers, generating abundant active sites and inner electronic fields
that can promote the separation of photoexcited electrons and enhance
the photon-to-electron conversion. In comparison to pristine MMT,
Fe@MMT exhibits a 43% reduction in the charge transfer resistance
in the dark and a 52% reduction under illumination. Additionally,
the majority carrier density within the space charge region increased
by 33%. Due to these advantages, the photocatalytic HER efficiency
over Fe@MMT was improved, approximately 2.9 times that of pristine
MMT
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