10 research outputs found
Degradation Mechanism of Calcium Iridium Oxide for Oxygen Evolution Reaction in Acid
The development of active and acid-stable iridium-based
catalysts
is crucial to meet the requirements of proton exchange membrane technologies
for the sustainable production of hydrogen via water electrolysis.
However, long-term stability remains a critical challenge. In this
work, we focus on a Ca2IrO4 catalyst to develop
a holistic picture of catalyst electronic and geometric structure
evolution under various applied potentials by probing electrochemically
active surface area, metal dissolution, Ir valence, and surface morphology.
We observe an initial activity increase in parallel with increasing
capacitance and minor iridium dissolution. Extensive chronoamperometry
tests at oxidizing potentials lead to significant activity loss that
occurs simultaneously with a dramatic drop in capacitance and a change
in impedance. Using a combination of electrochemical and spectroscopic
tools, we provide fundamental insights to these material degradation
processes to enable future catalyst design with balanced activity
and long-term stability
Material Dynamics of Manganese-Based Oxychlorides for Oxygen Evolution Reaction in Acid
Earth-abundant
manganese-based oxides have emerged as promising
alternatives to noble-metal-based catalysts for the oxygen evolution
reaction (OER) in acidic conditions; however, their inferior activity
and stability present critical challenges for the sustainable production
of hydrogen via water electrolysis. Moving beyond oxides, heteroanionic
materials, which incorporate anions with lower electronegativity than
oxygen, have shown potential for improving the OER performance, but
a detailed understanding of the underlying mechanisms is lacking.
Here, we investigate manganese-based oxychlorides (Mn8O10Cl3 and FeMn7O10Cl3) that exhibit excellent activity and stability for acidic OER to
elucidate material property dynamics and correlate them with OER behaviors.
Our rigorous electrochemical stability testing reveals that the high
operating potential mitigates Mn dissolution over prolonged exposure
to the OER conditions. Through a combination of ex situ and in situ surface and bulk-sensitive X-ray spectroscopy
analyses, we observe a trade-off between increasing Mn valence and
maintaining structural integrity, which results in dynamic bond length
changes within the [MnCl6] octahedra during the activation
and degradation processes of these oxychloride catalysts. This study
provides insights into the fundamental relationships between the chemical,
electronic, and geometric properties of the catalysts and their electrocatalytic
outcomes
Albumin-Based Cyanine Crizotinib Conjugate Nanoparticles for NIR-II Imaging-Guided Synergistic Chemophototherapy
Colorectal
cancer (CRC) is presently the third deadliest cancer
in the world. This malignant cancer usually precedes the progression
of precancerous lesions, and it is challenging to distinguish its
nuanced morphological changes. Molecular-based near-infrared-II (NIR-II)
fluorescence imaging can effectively recognize lesion targets to improve
image contrast and increase early tumor detection compared with traditional
wide-light screening endoscopy. c-Met has been determined to be overexpressed
in advanced stages of CRC and is considered to be a potent tumor biomarker.
Herein, based on the well-targeted inhibitory effect of Crizotinib
on c-Met positive tumor cells, the dye IR808 was covalently combined
with the drug molecule Crizotinib, resulting in the synthesis of a
NIR fluorescent probe Crizotinib-IR808 targeting c-Met positive tumor
cells. Then, water-insoluble Crizotinib-IR808 was fabricated by using
bovine serum albumin (BSA) nanoparticles (NPs) with excellent biocompatibility
and biosafety. The prepared Crizotinib-IR808@BSA NPs showed tumor
targeting capability as well as use for noninvasive biomedical vascular
NIR-II imaging with intraoperative real-time NIR-II imaging to guide
tumor resection. Under 808 nm laser irradiation, Crizotinib-IR808@BSA
NPs exhibited synergistic chemophototherapy effects on tumors. In
conclusion, this innovative imaging-mediated multifunctional combination
therapy strategy with good c-Met targeting ability may provide a new
approach for colorectal cancer treatment
Additional file 1: of Effects of sang-qi granules on blood pressure and endothelial dysfunction in stage I or II hypertension: study protocol for a randomized double-blind double-simulation controlled trial
SPIRIT checklist
Additional file 3: of Effects of sang-qi granules on blood pressure and endothelial dysfunction in stage I or II hypertension: study protocol for a randomized double-blind double-simulation controlled trial
TCM Syndrome Integral Scale
Additional file 2: of Effects of sang-qi granules on blood pressure and endothelial dysfunction in stage I or II hypertension: study protocol for a randomized double-blind double-simulation controlled trial
Hypertension Symptom Scale
Topologically Controlled Syntheses of Unimolecular Oligo[<i>n</i>]catenanes
Catenanes are a well-known class of mechanically interlocked
molecules
that possess chain-like architectures and have been investigated for
decades as molecular machines and switches. However, the synthesis
of higher-order catenanes with multiple, linearly interlocked molecular
rings has been greatly impeded by the generation of unwanted oligomeric
byproducts and figure-of-eight topologies that compete with productive
ring closings. Here, we report two general strategies for the synthesis
of oligo[n]catenanes that rely on a molecular “zip-tie”
strategy, where the “zip-tie” is a central core macrocycle
precursor bearing two phenanthroline (phen) ligands to make odd-numbered
oligo[n]catenanes, or a preformed asymmetric iron(II)
complex consisting of two macrocycle precursors bearing phen and terpyridine
ligands to make even-numbered oligo[n]catenanes.
In either case, preformed macrocycles or [2]catenanes are threaded
onto the central “zip-tie” core using metal templation
prior to ring-closing metathesis (RCM) reactions that generate several
mechanical bonds in one pot. Using these synthetic strategies, a family
of well-defined linear oligo[n]catenanes were synthesized,
where n = 2, 3, 4, 5, or 6 interlocked molecular
rings, and n = 6 represents the highest number of
linearly interlocked rings reported to date for any isolated unimolecular oligo[n]catenane
DataSheet_1_High-throughput prediction and characterization of antimicrobial peptides from multi-omics datasets of Chinese tubular cone snail (Conus betulinus).docx
Individual cone snail (Conus sp.) contains thousands of bioactive peptides, but there are limited studies on its antimicrobial peptides (AMPs). Here, we investigated AMPs along with AMP-derived genes in the representative Chinese tubular cone snail (C. betulinus) by integration of our previously published multi-omics (genomics, transcriptomics, and peptidomics) data. We identified a total of 466 putative AMP-derived genes from the genome, and most of them were annotated as histones. While at the mRNA level, only 77 AMP-derived genes were confirmed with transcriptomic evidence, among them Ubiquicidin, cgUbiquitin, Ap, and VK10 were the most abundant transcripts in the venom gland. In addition, 30 AMPs were further validated by peptidomics data. After in silico analysis including 3D modeling, 11 putative AMPs were chemically synthesized for an in vitro assessment, and eight peptides were proved with good antifungal activity. In summary, this work systematically characterized the AMP repertoire in C. betulinus. This valuable genetic resource provides a solid foundation for in-depth therapeutic applications and drug development.</p
DataSheet1_Whole-Genome Sequencing of Sinocyclocheilus maitianheensis Reveals Phylogenetic Evolution and Immunological Variances in Various Sinocyclocheilus Fishes.docx
An adult Sinocyclocheilus maitianheensis, a surface-dwelling golden-line barbel fish, was collected from Maitian river (Kunming City, Yunnan Province, China) for whole-genome sequencing, assembly, and annotation. We obtained a genome assembly of 1.7 Gb with a scaffold N50 of 1.4 Mb and a contig N50 of 24.7 kb. A total of 39,977 protein-coding genes were annotated. Based on a comparative phylogenetic analysis of five Sinocyclocheilus species and other five representative vertebrates with published genome sequences, we found that S. maitianheensis is close to Sinocyclocheilus anophthalmus (a cave-restricted species with similar locality). Moreover, the assembled genomes of S. maitianheensis and other four Sinocyclocheilus counterparts were used for a fourfold degenerative third-codon transversion (4dTv) analysis. The recent whole-genome duplication (WGD) event was therefore estimated to occur about 18.1 million years ago. Our results also revealed a decreased tendency of copy number in many important genes related to immunity and apoptosis in cave-restricted Sinocyclocheilus species. In summary, we report the first genome assembly of S. maitianheensis, which provides a valuable genetic resource for comparative studies on cavefish biology, species protection, and practical aquaculture of this potentially economical fish.</p
