22 research outputs found
Facile Construction of Novel 3‑Dimensional Graphene/Amorphous Porous Carbon Hybrids with Enhanced Lithium Storage Properties
Presently,
porous materials have become essential to many technological
applications. In this account, 3-dimensional skeleton composite materials
consisting of a core–shell amorphous porous carbon/multilayer
graphene are synthesized by chemical vapor deposition on Ni foam using
a facile one-step growth method. The data suggest that these composites
have not only outstanding electrical and mechanical properties of
the multilayer graphene but also the mesoporous characteristics of
the amorphous carbon. Moreover, the composited carbon materials perfectly
inherit the macroporous structure of Ni foam, and the amorphous carbon
core in the skeleton serves as a cushion to buffer the volume variation
after the removal of Ni. The carbon composites reveal ultralow density
(4.45 mg cm<sup>–3</sup>) and high conductivity (45 S cm<sup>–1</sup>), essentially issued from the perfectly preserved
structural integrity of graphene. The novel carbon composites can
be used as anodes for lithium ion batteries. After these carbon composites
are incorporated with NaBiO<sub>3</sub>, superior electrochemical
activities above 2 V can be achieved with a discharge capacity of
∼300 mAh g<sup>–1</sup>
Few-Layer Antimonene: Anisotropic Expansion and Reversible Crystalline-Phase Evolution Enable Large-Capacity and Long-Life Na-Ion Batteries
Two-dimensional
(2D) antimonene is a promising anode material in
sodium-ion batteries (SIBs) because of its high theoretical capacity
of 660 mAh g<sup>–1</sup> and enlarged surface active sites.
However, its Na storage properties and sodiation/desodiation mechanism
have not been fully explored. Herein, we propose the sodiation/desodiation
reaction mechanism of 2D few-layer antimonene (FLA) based on results
acquired by <i>in situ</i> synchrotron X-ray diffraction, <i>ex situ</i> selected-area electron diffraction, and theoretical
simulations. Our study shows that the FLA undergoes anisotropic volume
expansion along the <i>a</i>/<i>b</i> plane and
exhibits reversible crystalline phase evolution (Sb ⇋ NaSb
⇋ Na<sub>3</sub>Sb) during cycling. Density-functional theory
calculations demonstrate that the FLA has a small Na-ion diffusion
barrier of 0.14 eV. The FLA delivers a larger capacity of 642 mAh
g<sup>–1</sup> at 0.1 C (1 C = 660 mA g<sup>–1</sup>) and a high rate capability of 429 mAh g<sup>–1</sup> at
5 C and maintains a stable capacity of 620 mA g<sup>–1</sup> at 0.5 C with 99.7% capacity retention from the 10th to the 150th
cycle. Considering the 660 mAh g<sup>–1</sup> theoretical capacity
of Sb, the electrochemical utilization of Sb atoms of FLA is as high
as 93.9% at a rate of 0.5 C for over 150 cycles, which is the highest
capacity and Sb utilization ratio reported so far. Our study discloses
the Na storage mechanism of 2D FLA, boosting promising applications
of 2D materials for advanced SIBs
Phase 1 Study in Malaria Naïve Adults of BSAM2/Alhydrogel®+CPG 7909, a Blood Stage Vaccine against <em>P. falciparum</em> Malaria
<div><p>A Phase 1 dose escalating study was conducted in malaria naïve adults to assess the safety, reactogenicity, and immunogenicity of the blood stage malaria vaccine BSAM2/Alhydrogel®+ CPG 7909. BSAM2 is a combination of the FVO and 3D7 alleles of recombinant AMA1 and MSP1<sub>42</sub>, with equal amounts by weight of each of the four proteins mixed, bound to Alhydrogel®, and administered with the adjuvant CPG 7909. Thirty (30) volunteers were enrolled in two dose groups, with 15 volunteers receiving up to three doses of 40 µg total protein at Days 0, 56, and 180, and 15 volunteers receiving up to three doses of 160 µg protein on the same schedule. Most related adverse events were mild or moderate, but 4 volunteers experienced severe systemic reactions and two were withdrawn from vaccinations due to adverse events. Geometric mean antibody levels after two vaccinations with the high dose formulation were 136 µg/ml for AMA1 and 78 µg/ml for MSP1<sub>42</sub>. Antibody responses were not significantly different in the high dose versus low dose groups and did not further increase after third vaccination. <em>In vitro</em> growth inhibition was demonstrated and was closely correlated with anti-AMA1 antibody responses. A Phase 1b trial in malaria-exposed adults is being conducted.</p> <h3>Trial Registration</h3><p>Clinicaltrials.gov <a href="http://clinicaltrials.gov/ct2/show/NCT00889616">NCT00889616</a></p> </div
<i>In Situ</i> Observation of Thermal Proton Transport through Graphene Layers
Protons can penetrate through single-layer
graphene, but thicker graphene layers (more than 2 layers), which
possess more compact electron density, are thought to be unfavorable
for penetration by protons at room temperature and elevated temperatures.
In this work, we developed an <i>in situ</i> subsecond time-resolved
grazing-incidence X-ray diffraction technique, which fully realizes
the real-time observation of the thermal proton interaction with the
graphene layers at high temperature. By following the evolution of
interlayer structure during the protonation process, we demonstrated
that thermal protons can transport through multilayer graphene (more
than 8 layers) on nickel foil at 900 °C. In comparison, under
the same conditions, the multilayer graphenes are impermeable to argon,
nitrogen, helium, and their derived ions. Complementary <i>in
situ</i> transport measurements simultaneously verify the penetration
phenomenon at high temperature. Moreover, the direct transport of
protons through graphene is regarded as the dominant contribution
to the penetration phenomenon. The thermal activation, weak interlayer
interaction between layers, and the affinity of the nickel catalyst
may all contribute to the proton transport. We believe that this method
could become one of the established approaches for the characterization
of the ions intercalated with 2D materials <i>in situ</i> and in real-time
Antibody responses shown are the arithmetic mean of the FVO and 3D7 responses for each antigen for all volunteers who received all 3 vaccines and were not excluded per protocol (n = 23).
<p>Thicker lines show the geometric mean response; arrows indicate vaccinations. Mann-Whitney tests with Hodges-Lehmann confidence intervals were done to compare responses in low versus high dose groups and 2 weeks after 2<sup>nd</sup> and 3<sup>rd</sup> vaccinations (days 70 and 194); although the 160 µg group had slightly higher geometric means (AMA1 D70: Fold Change = 1.49 [95% CI 0.78, 2.92] p = 0.28; AMA1 D194: FC = 1.30 [0.68, 2.49] p = 0.61;MSP1 D70: FC = 1.18 [0.57,2.49] p = 0.70; MSP1 D 194: FC = 1.30 [0.85, 1.91]) p = 0.21; differences were not significant at the 0.05 level.</p
Characterization of MSP1<sub>42</sub>-FUP-EPA conjugates.
<p>Panel (A) Coomassie blue stained SDS-PAGE gel analysis of maleimide-EPA (lanes 1 and 5); monomeric MSP1<sub>42</sub>-FUP (lanes 2 and 6), un-purified conjugation mixture of MSP1<sub>42</sub>-FUP-EPA<sub>APA</sub> (lane 3), bulk purified MSP1<sub>42</sub>-FUP-EPA<sub>APA</sub> (lane 4); un-purified conjugation mixture of MSP1<sub>42</sub>-FUP-EPA<sub>PEO</sub> (lane 7) and bulk purified MSP1<sub>42</sub>-FUP-EPA<sub>PEO</sub> (lane 8). The asterisks indicate the conjugates with 3∶1 and 4∶1 ratio. Panel (B) SEC-HPLC-MALS analysis. Solid and dashed lines represent absorbance at 280 nm and molecular mass for MSP1<sub>42</sub>-FUP-EPA<sub>PEO</sub> and MSP1<sub>42</sub>-FUP-EPA<sub>APA</sub>, respectively. The capital letters A, B and C indicate the profile peaks of each conjugate.</p
Participants flow sheet.
<p>Thirty (30) participants were enrolled, 24 participants completed vaccinations, and 24 completed follow-up to Day 360.</p
Local (injection site pain, tenderness, erythema, swelling, induration) and related systemic adverse events after first, second and third vaccinations in the high dose group.
<p>The x-axis shows the number of participants experiencing adverse events, with the highest severity event for each participant after each vaccination shown. Other systemic adverse events in both high and low dose groups were: diarrhea (1 severe, 2 mild), abdominal pain, nausea, and cough (all mild or moderate).</p
In vitro growth inhibition of homologous 3D7 parasites as a function of specific antibody concentration is shown.
<p>Purified IgG from Day 70 samples (two weeks after the second vaccination) were used at a concentration of 10 mg/mL.</p
Correlation between average anti-AMA1 and -MSP1<sub>42</sub> antibody responses at Day 70 and Day 194 (two weeks after second and third vaccinations).
<p>Day 70: Spearman correlation, r = 0.60 [95% CI 0.23, 0.82]; Day 194: Spearman's correlation, r = 0.75 [0.50,0.89].</p