8 research outputs found
Different Crystallization Behaviors of Poly(vinylidene fluoride) Blended with or Coated with Cetyltrimethylammonium Bromide
Crystallization of poly(vinylidene fluoride) (PVDF) either
blended
with or coated with cetyltrimethylammonium bromide (CTAB) during isothermal
and nonisothermal processes has been studied, which reveals the influence
of the interaction way between PVDF and CTAB on the polymorphic behavior
of PVDF. The random dispersion of CTAB with limited content in the
blend sample leads to three different states of PVDF chains, i.e.,
intact chains and TGTG′ and TTT chain sequences induced by
the ion–dipole interaction. While the intact chains and TGTG′
sequences promote the crystallization of PVDF in the α-phase, the TTT chain sequences cause the crystallization
of PVDF in the γ-phase at high temperatures,
which endows a full transformation of α into γ′ at the later stage. On the other hand, for the
PVDF coated with CTAB, the ion–dipole interaction results in
the long TTT sequences, or even all-trans chain segments, at the interface
between PVDF and CTAB, which ensure the crystallization of PVDF directly
in the γ-phase at high temperatures but in
the β-phase during melt-quenching. This provides
a simple and effective method for fabricating high-crystallinity (e.g.,
47%) electroactive PVDF thin films with a preferential β-phase of ca. 95.3% and a small amount of γ-phase (around 4.7%)
Trehalose concentrations and related enzymatic activity of stains Z5 and SZ3-1.
<p>Yeast strains were harvested at the stationary phase and exposed to ethanol stress. Trehalose concentration (A) of strains Z5 (light gray) and SZ3-1 (gray) subjected to different ethanol stress (0%, 5%, 10%, and 15% (v/v) ethanol) was measured. Finally, we determined related enzymatic activities, namely, trehalose-P-synthase (B), acid trehalase (C), and neutral trehalase (D) under 0% ethanol and 10% ethanol conditions.</p
One-Step Fabrication of Robust, Nondrying, Elastic Gelatin Hydrogels with Self-Healing and Recycling Capabilities
Gelatin hydrogels, a kind of ideal biobased material
with excellent
biodegradability and biocompatibility, are weak and easy to dehydrate
in an ambient environment, which greatly hinders their practical application.
In this study, we have developed a simple strategy to fabricate robust,
nondrying, elastic gelatin hydrogels through introducing choline chloride
(ChCl) in hydrogel networks. Benefiting from the hydrated ions of
ChCl, the water content can be simply controlled by adjusting the
amount of ChCl; as a result, the mechanical strength of the gelatin
hydrogel can be regulated from 9.5 to 0.6 MPa through tuning the water
content as well as the tensile strain from 229 to 690%. Most importantly,
the water content of the hydrogels can be kept unchanged for at least
30 days, which resolves the prerequisite for the long-time use of
the hydrogels. Besides, the gelatin hydrogels exhibit good self-healing,
conductive, antifreezing, and recyclable properties. Combining with
the above excellent performance, the proposed hydrogels are successfully
applied as flexible sensors to monitor human movement. This study
demonstrates a novel strategy for the design of gelatin hydrogels
with high performance
Fatty acid compositions in plasma membrane and ergosterol content of strains Z5 and SZ3-1 cultivated in different conditions.
<p>Data are the mean values and standard deviation of three dependent experiments.</p>a<p>Fatty acids are denoted by the number of carbon atoms: number of unsaturated linkeages.</p>b<p>Unsaturation Index(Δ/mol) was calculated as: Δ/mol = [1×(% monoene)+2×(% diene)+3×(% triene)]/100.</p
The fermentation performance of strains Z5, Z5Δ<i>GPD2</i> and SZ3-1.
<p>The ethanol yield (A), glucose consumption (B), glycerol (filled symbols) and acetate (open symbols) production (C), and cell survival rate (D) of control strains Z5 (squares), Z5Δ<i>GPD2</i> (circles), and shuffled strain SZ3-1 (triangles) during fermentation were monitored and compared.</p
Relative expression level of six genes related to trehalose metabolism.
<p>Strains Z5 and SZ3-1 were grown in the absence (0%) or presence (10%) of ethanol. Gene expression of four cases were compared: strain Z5 grown in the presence and absence of ethanol (Z5 (10%)/Z5 (0%)); strain SZ3-1 grown in the presence and absence of ethanol (SZ3-1 (10%)/SZ3-1 (0%)); strain SZ3-1 and Z5 grown in absence of ethanol (SZ3-1(0%)/Z5(0%)); and strain SZ3-1 and Z5 grown in the presence of ethanol (SZ3-1 (10%)/Z5 (10%)).</p
Determination of ethanol stress tolerance of strains Z5, Z5Δ<i>GPD2</i> and SZ3-1.
<p>(A) Growth of strains Z5, Z5Δ<i>GPD2</i> and SZ3-1 on different concentration of ethanol. Cells were grown in the YPD liquid medium at 30°C overnight and 10-fold serial dilutions of each sample were spotted onto the YPD medium and the YPD medium containing 10%, 15%, 20% (v/v) ethanol. Stress tolerance was calculated as the percentage of biomass formation or viable cells in stressed culture compared with that in control culture. (B) Time course of extracellular nucleotide concentration in cell suspension of strains Z5 (filled symbols) and SZ3-1 (open symbols). Yeast cells were suspended in aqueous solution with 0% (triangles), 10% (squares), 15% (diamonds), and 20% (circles) (v/v) ethanol and incubated at 30°C. Concentration of nucleotide that leaked into the supernatant was measured every few hours.</p
Karyotype profiles of strains Z5 and SZ3-1 obtained by PFGE.
<p>Lanes M, Z5 and SZ3-1 respectively represent the chromosomal profiles of strains BY4743, Z5 and SZ3-1. Numbers corresponding to each band are designated in the left.</p