13 research outputs found
CO2 capture performance using biomass-templated cement-supported limestone pellets
Synthetic biomass-templated cement-supported CaO-based sorbents were produced by granulation
process for high-temperature post-combustion CO2 capture. Commercial flour was used as the biomass
and served as a templating agent. The investigation of porosity showed that the pellets with biomass or
cement resulted in enhancement of porosity. Four types of sorbents containing varying proportions of
biomass and cement were subject to 20 cycles in a TGA under different calcination conditions. After
first series of tests calcined at 850 °C in 100% N2, all composite sorbents clearly exhibited higher CO2
capture activity compared to untreated limestone with exception of sorbents doped by seawater. The
biomass-templated cement-supported pellets exhibited the highest CO2 capture level of 46.5% relative
to 20.8% for raw limestone after 20 cycles. However, the observed enhancement in performance was
substantially reduced under 950 °C calcination condition. Considering the fact that both sorbents
supported by cement exhibited relatively high conversion with a maximum value of 19.5%, cement
promoted sorbents appear to be better at resisting of harsh calcination conditions. Although flour as
biomass-templated material generated significantly enhancement in CO2 capture capacity, further
exploration must be carried out to find the way of maintaining outstanding performance for CaO-based
sorbents under severe reaction conditions
CO2 capture performance using biomass-templated cement-supported limestone pellets
Synthetic biomass-templated cement-supported CaO-based sorbents were produced by granulation process for high-temperature post-combustion CO2 capture. Commercial flour was used as the biomass and served as a templating agent. The investigation of porosity showed that the pellets with biomass or cement resulted in enhancement of porosity. Four types of sorbents containing varying proportions of biomass and cement were subject to 20 cycles in a TGA under different calcination conditions. After first series of tests calcined at 850 °C in 100% N2, all composite sorbents clearly exhibited higher CO2 capture activity compared to untreated limestone with exception of sorbents doped by seawater. The biomass-templated cement-supported pellets exhibited the highest CO2 capture level of 46.5% relative to 20.8% for raw limestone after 20 cycles. However, the observed enhancement in performance was substantially reduced under 950 °C calcination condition. Considering the fact that both sorbents supported by cement exhibited relatively high conversion with a maximum value of 19.5%, cement promoted sorbents appear to be better at resisting of harsh calcination conditions. Although flour as biomass-templated material generated significantly enhancement in CO2 capture capacity, further exploration must be carried out to find the way of maintaining outstanding performance for CaO-based sorbents under severe reaction conditions. Keywords: Calcium looping; CO2 capture; Granulation; Limestone; Biomass; Cemen
Afatinib Reverses EMT via Inhibiting CD44-Stat3 Axis to Promote Radiosensitivity in Nasopharyngeal Carcinoma
Background: Afatinib, a second-generation tyrosine kinase inhibitor (TKI), exerts its radiosensitive effects in nasopharyngeal carcinoma (NPC). However, the detailed mechanism of afatinib-mediated sensitivity to radiation is still obscure in NPC. Methods: Quantitative phosphorylated proteomics and bioinformatics analysis were performed to illustrate the global phosphoprotein changes. The activity of the CD44-Stat3 axis and Epithelial-Mesenchymal Transition (EMT)-linked markers were evaluated by Western blotting. Wound healing and transwell assays were used to determine the levels of cell migration upon afatinib combined IR treatment. Cell proliferation was tested by CCK-8 assay. A pharmacological agonist by IL-6 was applied to activate Stat3. The xenograft mouse model was treated with afatinib, radiation or a combination of afatinib and radiation to detect the radiosensitivity of afatinib in vivo. Results: In the present study, we discovered that afatinib triggered global protein phosphorylation alterations in NPC cells. Further, bioinformatics analysis indicated that afatinib inhibited the CD44-Stat3 signaling and subsequent EMT process. Moreover, functional assays demonstrated that afatinib combined radiation treatment remarkably impeded cell viability, migration, EMT process and CD44-Stat3 activity in vitro and in vivo. In addition, pharmacological stimulation of Stat3 rescued radiosensitivity and biological functions induced by afatinib in NPC cells. This suggested that afatinib reversed the EMT process by blocking the activity of the CD44-Stat3 axis. Conclusion: Collectively, this work identifies the molecular mechanism of afatinib as a radiation sensitizer, thus providing a potentially useful combination treatment and drug target for NPC radiosensitization. Our findings describe a new function of afatinib in radiosensitivity and cancer treatment
Harnessing instability for work hardening in multi-principal element alloys
The strength-ductility trade-off has long been a Gordian knot in conventional metallic structural materials and it is no exception in multi-principal element alloys. In particular, at ultrahigh yield strengths, plastic instability, that is, necking, happens prematurely, because of which ductility almost entirely disappears. This is due to the growing difficulty in the production and accumulation of dislocations from the very beginning of tensile deformation that renders the conventional dislocation hardening insufficient. Here we propose that premature necking can be harnessed for work hardening in a VCoNi multi-principal element alloy. Luders banding as an initial tensile response induces the ongoing localized necking at the band front to produce both triaxial stress and strain gradient, which enables the rapid multiplication of dislocations. This leads to forest dislocation hardening, plus extra work hardening due to the interaction of dislocations with the local-chemical-order regions. The dual work hardening combines to restrain and stabilize the premature necking in reverse as well as to facilitate uniform deformation. Consequently, a superior strength-and-ductility synergy is achieved with a ductility of similar to 20% and yield strength of 2 GPa during room-temperature and cryogenic deformation. These findings offer an instability-control paradigm for synergistic work hardening to conquer the strength-ductility paradox at ultrahigh yield strengths
Performance characteristics of a new spherical metal mesh packing
Various tests and analysis on hydrodynamics and mass transfer properties show that, the newly invented spherical metal mesh packing (SMMP) has excellent properties from three aspects: (i) high void space (similar to 99%) and lower material cost; (ii) high mass transfer efficiency; (iii) easy installation, good liquid distribution, and prevention of wall flow. Moreover, SMMP is a type of isotropic spherical unit with numerous hollow holes, which realizes the regularization of random packing. The results indicate the potential of developing high-efficiency and energy-saving SMMP-based equipment. (C) 2013 Elsevier B.V. All rights reserved
DOT1L/H3K79me2 represses HIV-1 reactivation via recruiting DCAF1
Summary: DOT1L mediates the methylation of histone H3 at lysine 79 and, in turn, the transcriptional activation or repression in a context-dependent manner, yet the regulatory mechanisms and functions of DOT1L/H3K79me remain to be fully explored. Following peptide affinity purification and proteomic analysis, we identified that DCAF1—a component of the E3 ligase complex involved in HIV regulation—is associated with H3K79me2 and DOT1L. Interestingly, blocking the expression or catalytic activity of DOT1L or repressing the expression of DCAF1 significantly enhances the tumor necrosis factor alpha (TNF-α)/nuclear factor κB (NF-κB)-induced reactivation of the latent HIV-1 genome. Mechanistically, upon TNF-α/NF-κB activation, DCAF1 is recruited to the HIV-1 long terminal repeat (LTR) by DOT1L and H3K79me2. Recruited DCAF1 subsequently induces the ubiquitination of NF-κB and restricts its accumulation at the HIV-1 LTR. Altogether, our findings reveal a feedback modulation of HIV reactivation by DOT1L-mediated histone modification regulation and highlight the potential of targeting the DOT1L/DCAF1 axis as a therapeutic strategy for HIV treatment
Harnessing instability for work hardening in multi-principal element alloys
The strength-ductility trade-off has long been a Gordian knot in conventional metallic structural materials and it is no exception in multi-principal element alloys. In particular, at ultrahigh yield strengths, plastic instability, that is, necking, happens prematurely, because of which ductility almost entirely disappears. This is due to the growing difficulty in the production and accumulation of dislocations from the very beginning of tensile deformation that renders the conventional dislocation hardening insufficient. Here we propose that premature necking can be harnessed for work hardening in a VCoNi multi-principal element alloy. Luders banding as an initial tensile response induces the ongoing localized necking at the band front to produce both triaxial stress and strain gradient, which enables the rapid multiplication of dislocations. This leads to forest dislocation hardening, plus extra work hardening due to the interaction of dislocations with the local-chemical-order regions. The dual work hardening combines to restrain and stabilize the premature necking in reverse as well as to facilitate uniform deformation. Consequently, a superior strength-and-ductility synergy is achieved with a ductility of similar to 20% and yield strength of 2 GPa during room-temperature and cryogenic deformation. These findings offer an instability-control paradigm for synergistic work hardening to conquer the strength-ductility paradox at ultrahigh yield strengths
Enhanced Oxygen Evolution Reaction Performance on NiS<i><sub>x</sub></i>@Co<sub>3</sub>O<sub>4</sub>/Nickel Foam Electrocatalysts with Their Photothermal Property
Based on the principle of heterogeneous catalysis for
water electrolysis,
electrocatalysts with appropriate electronic structure and photothermal
property are expected to drive the oxygen evolution reaction effectively.
Herein, amorphous NiSx-coupled nanourchin-like
Co3O4 was prepared on nickel foam (NiSx@Co3O4/NF) and investigated
as a electrocatalyst for photothermal-assisted oxygen evolution reaction.
The experimental investigations and simulant calculations jointly
revealed NiSx@Co3O4/NF to be of suitable electronic structure and high near-infrared
photothermal conversion capability to achieve the oxygen evolution
reaction advantageously both in thermodynamics and in kinetics. Relative
to Co3O4/NF and NiSx/NF, better oxygen evolution reaction activity, kinetics, and stability
were achieved on NiSx@Co3O4/NF in 1.0 M KOH owing to the NiSx/Co3O4 synergetic effect. In addition, the
oxygen evolution reaction performance of NiSx@Co3O4/NF can be obviously enhanced under near-infrared
light irradiation, since NiSx@Co3O4 can absorb the near-infrared light to produce electric
and thermal field. For the photothermal-mediated oxygen evolution
reaction, the overpotential and Tafel slope of NiSx@Co3O4/NF at 50 mA cm–2 were reduced by 23 mV and 13 mV/dec, respectively. The present work
provides an inspiring reference to design and develop photothermal-assisted
water electrolysis using abundant solar energy