5 research outputs found
High-Efficiency All Polymer Solar Cell with a Low Voltage Loss of 0.56 V
Reducing voltage
loss, namely, <i>V</i><sub>loss</sub>, has been demonstrated
to be an effective way to improve the efficiencies of photovoltaic
devices, and power conversion efficiencies (PCEs) exceeding 10% have
been reported in non-fullerene based polymer solar cells (PSCs) with <i>V</i><sub>loss</sub> value lower than 0.6 V. However, for all
polymer solar cells (APSCs), the PCEs lag far behind the non-fullerene
PSCs with organic small molecular acceptors. And there have been no
successful examples of high-efficiency APSCs along with low <i>V</i><sub>loss</sub> values so far. Here, we reported APSCs
that demonstrated a high efficiency of 6.66% simultaneously with a
small voltage loss of 0.56 V by using a new polymer PBDT-DFQX1 as
donor and N2200 as acceptor. Notably, when PBDT-DFQX1 is combined
with a small molecular acceptor (SMA) O-IDTBR, the relative SMA based
PSC exhibited a higher PCE of 8.76% also with a low voltage loss of
0.56 V. These results indicated that PBDT-DFQX1 would be a promising
polymer donor material in photovoltaic device application, and the
strategy by minimizing the voltage loss to improve the photovoltaic
efficiencies is still valid for APSCs
Searching Missing Proteins Based on the Optimization of Membrane Protein Enrichment and Digestion Process
A membrane protein
enrichment method composed of ultracentrifugation
and detergent-based extraction was first developed based on MCF7 cell
line. Then, in-solution digestion with detergents and eFASP (enhanced
filter-aided sample preparation) with detergents were compared with
the time-consuming in-gel digestion method. Among the in-solution
digestion strategies, the eFASP combined with RapiGest identified
1125 membrane proteins. Similarly, the eFASP combined with sodium
deoxycholate identified 1069 membrane proteins; however, the in-gel
digestion characterized 1091 membrane proteins. Totally, with the
five digestion methods, 1390 membrane proteins were identified with
ā„1 unique peptides, among which 1345 membrane proteins contain
unique peptides ā„2. This is the biggest membrane protein data
set for MCF7 cell line and even breast cancer tissue samples. Interestingly,
we identified 13 unique peptides belonging to 8 missing proteins (MPs).
Finally, eight unique peptides were validated by synthesized peptides.
Two proteins were confirmed as MPs, and another two proteins were
candidate detections
iTRAQ-Based Membrane Proteomics Reveals Plasma Membrane Proteins Change During HepaRG Cell Differentiation
HepaRG cell, a stabilized bipotent
liver progenitor cell line,
exhibits hepatocyte functions only after differentiation. However,
the mechanism of transition from nondifferentiated to differentiated
states, accompanied by proliferation migration and differentiation,
remains poorly understood, particularly those proteins residing in
the plasma membrane. In this study, the membrane protein expression
change of HepaRG cell during differentiation were systematically analyzed
using an iTRAQ labeled quantitative membrane proteomics approach.
A total of 70 membrane proteins were identified to be differentially
expressed among 849 quantified membrane proteins. Function and disease
clustering analysis proved that 11 of these proteins are involved
in proliferation, migration, and differentiation. Two key factors
(MMP-14 and OCLN) were validated by qRT-PCR and Western blot. Blockade
of MMP-14 further demonstrated its important function during tumor
cell migration. The data sets have been uploaded to ProteomeXchange
with the identifier PXD004752
Quantitative Proteomics Reveals Membrane Protein-Mediated Hypersaline Sensitivity and Adaptation in Halophilic <i>Nocardiopsis xinjiangensis</i>
The
genus <i>Nocardiopsis</i> is one of the most dominant
Actinobacteria that survives in hypersaline environments. However,
the adaptation mechanisms for halophilism are still unclear. Here,
we performed isobaric tags for relative and absolute quantification
based quantitative proteomics to investigate the functions of the
membrane proteome after salt stress. A total of 683 membrane proteins
were identified and quantified, of which 126 membrane proteins displayed
salt-induced changes in abundance. Intriguingly, bioinformatics analyses
indicated that these differential proteins showed two expression patterns,
which were further validated by phenotypic changes and functional
differences. The majority of ABC transporters, secondary active transporters,
cell motility proteins, and signal transduction kinases were up-regulated
with increasing salt concentration, whereas cell differentiation,
small molecular transporter (ions and amino acids), and secondary
metabolism proteins were significantly up-regulated at optimum salinity,
but down-regulated or unchanged at higher salinity. The small molecule
transporters and cell differentiation-related proteins acted as sensing
proteins that played a more important biological role at optimum salinity.
However, the ABC transporters for compatible solutes, Na<sup>+</sup>-dependent transporters, and cell motility proteins acted as adaptive
proteins that actively counteracted higher salinity stress. Overall,
regulation of membrane proteins may provide a major protection strategy
against hyperosmotic stress
Special Enrichment Strategies Greatly Increase the Efficiency of Missing Proteins Identification from Regular Proteome Samples
As part of the Chromosome-Centric
Human Proteome Project (C-HPP)
mission, laboratories all over the world have tried to map the entire
missing proteins (MPs) since 2012. On the basis of the first and second
Chinese Chromosome Proteome Database (CCPD 1.0 and 2.0) studies, we
developed systematic enrichment strategies to identify MPs that fell
into four classes: (1) low molecular weight (LMW) proteins, (2) membrane
proteins, (3) proteins that contained various post-translational modifications
(PTMs), and (4) nucleic acid-associated proteins. Of 8845 proteins
identified in 7 data sets, 79 proteins were classified as MPs. Among
data sets derived from different enrichment strategies, data sets
for LMW and PTM yielded the most novel MPs. In addition, we found
that some MPs were identified in multiple-data sets, which implied
that tandem enrichments methods might improve the ability to identify
MPs. Moreover, low expression at the transcription level was the major
cause of the āmissingā of these MPs; however, MPs with
higher expression level also evaded identification, most likely due
to other characteristics such as LMW, high hydrophobicity and PTM.
By combining a stringent manual check of the MS<sub>2</sub> spectra
with peptides synthesis verification, we confirmed 30 MPs (neXtProt
PE2 ā¼ PE4) and 6 potential MPs (neXtProt PE5) with authentic
MS evidence. By integrating our large-scale data sets of CCPD 2.0,
the number of identified proteins has increased considerably beyond
simulation saturation. Here, we show that special enrichment strategies
can break through the data saturation bottleneck, which could increase
the efficiency of MP identification in future C-HPP studies. All 7
data sets have been uploaded to ProteomeXchange with the identifier
PXD002255