The introduction of oxygen vacancies (Ov) has been regarded as an effective method to enhance the catalytic performance of photoanodes in oxygen evolution reaction (OER). However, their stability ...under highly oxidizing environment is questionable but was rarely studied. Herein, NiFe‐metal–organic framework (NiFe‐MOFs) was conformally coated on oxygen‐vacancy‐rich BiVO4 (Ov‐BiVO4) as the protective layer and cocatalyst, forming a core–shell structure with caffeic acid as bridging agent. The as‐synthesized Ov‐BiVO4@NiFe‐MOFs exhibits enhanced stability and a remarkable photocurrent density of 5.3±0.15 mA cm−2 at 1.23 V (vs. RHE). The reduced coordination number of Ni(Fe)‐O and elevated valence state of Ni(Fe) in NiFe‐MOFs layer greatly bolster OER, and the shifting of oxygen evolution sites from Ov‐BiVO4 to NiFe‐MOFs promotes Ov stabilization. Ovs can be effectively preserved by the coating of a thin NiFe‐MOFs layer, leading to a photoanode of enhanced photocurrent and stability.
A core–shell Ov‐BiVO4@NiFe‐MOFs photoanode was constructed via a coordination‐assisted self‐assembly method. A NiFe‐MOFs thin layer acts as protective layer and cocatalyst to shift active sites from oxygen vacancies to NiFe‐MOFs, leading to improved stability and activity for OER. This molecular‐based approach tailors the coordination and electronic structure of active sites and provides mechanistic insights for rational design of photocatalysts.
The selectivity control of Pd nanoparticles (NPs) in the direct CO esterification with methyl nitrite toward dimethyl oxalate (DMO) or dimethyl carbonate (DMC) remains a grand challenge. Herein, Pd ...NPs are incorporated into isoreticular metal–organic frameworks (MOFs), namely UiO‐66‐X (X=‐H, ‐NO2, ‐NH2), affording Pd@UiO‐66‐X, which unexpectedly exhibit high selectivity (up to 99 %) to DMC and regulated activity in the direct CO esterification. In sharp contrast, the Pd NPs supported on the MOF, yielding Pd/UiO‐66, displays high selectivity (89 %) to DMO as always reported with Pd NPs. Both experimental and DFT calculation results prove that the Pd location relative to UiO‐66 gives rise to discriminated microenvironment of different amounts of interface between Zr‐oxo clusters and Pd NPs in Pd@UiO‐66 and Pd/UiO‐66, resulting in their distinctly different selectivity. This is an unprecedented finding on the production of DMC by Pd NPs, which was previously achieved by Pd(II) only, in the direct CO esterification.
Incorporating Pd nanoparticles into metal–organic frameworks (MOFs) exhibits high selectivity for dimethyl carbonate (DMC), while Pd nanoparticles on MOFs and other supports give high selectivity for dimethyl oxalate (DMO) in the direct CO esterification with methyl nitrite. The Lewis acid microenvironment surrounding Pd NPs is responsible for the reversed product selectivity.
The chemical microenvironment modulation of metal nanoparticles (NPs) holds promise for tackling the long‐lasting challenge of the trade‐off effect between activity and selectivity in catalysis. ...Herein, ultrafine PdCu2 NPs incorporated into covalent organic frameworks (COFs) with diverse groups on their pore walls have been fabricated for the semihydrogenation of alkynes. The Cu species, as the primary microenvironment of Pd active sites, greatly improves the selectivity. The functional groups as the secondary microenvironment around PdCu2 NPs effectively regulate the activity, in which PdCu2 NPs encapsulated in the COF bearing −CH3 groups exhibit the highest activity with >99 % conversion and 97 % selectivity. Both experimental and calculation results suggest that the functional group affects the electron‐donating ability of the COFs, which successively impacts the charge transfer between COFs and Pd sites, giving rise to a modulated Pd electronic state and excellent catalytic performance.
The PdCu2 nanoparticles are incorporated into isoreticular COFs, namely, MF−X (X=−CH3, −H, −CF3 and −CN), for the semihydrogenation of alkynes, where PdCu2@MF−CH3 exhibits the best catalytic performance. The dual modulation of the Pd microenvironment turns out to be crucial: the Cu species (primary microenvironment) improves the selectivity, while the engineered pore walls around PdCu2 sites (secondary microenvironment) optimize the activity.
Morella rubra, red bayberry, is an economically important fruit tree in south China. Here, we assembled the first high‐quality genome for both a female and a male individual of red bayberry. The ...genome size was 313‐Mb, and 90% sequences were assembled into eight pseudo chromosome molecules, with 32 493 predicted genes. By whole‐genome comparison between the female and male and association analysis with sequences of bulked and individual DNA samples from female and male, a 59‐Kb region determining female was identified and located on distal end of pseudochromosome 8, which contains abundant transposable element and seven putative genes, four of them are related to sex floral development. This 59‐Kb female‐specific region was likely to be derived from duplication and rearrangement of paralogous genes and retained non‐recombinant in the female‐specific region. Sex‐specific molecular markers developed from candidate genes co‐segregated with sex in a genetically diverse female and male germplasm. We propose sex determination follow the ZW model of female heterogamety. The genome sequence of red bayberry provides a valuable resource for plant sex chromosome evolution and also provides important insights for molecular biology, genetics and modern breeding in Myricaceae family.
The tensile properties at elevated temperature of nano-SiCp/Al2014 composites have been investigated. The nano-SiCp can remarkably improve the tensile strength at 493K of Al2014 alloy without ...sacrificing the ductility. The strengthening effect for the matrix alloy of 0.5vol% nano-particles is superior to that of 4vol% micron-particles.
Gallium‐based liquid metal alloys (LMAs) are extensively studied and used recently due to their excellent fluidity, high conductivity, and low evaporation pressure. Nonwettable and nonsticky liquid ...metal marbles (LMMs) are also developed to address the stickiness issue of oxidized LMAs in air. Current LMMs, however, lack acceptable controllability, shape stability, and robustness, greatly limiting their practical application. Here, a magnetically controllable liquid metal marble (MCLMM) that is noncorrosive and nonsticky, and exhibits good elasticity and mechanical robustness, is presented. The as‐obtained MCLMM consists of a soft liquid metal core coated with a mixture of ferronickel (FN) and polyethylene (PE) microparticles. This combined structure shows excellent magnetic controllability, good elasticity, and favorable mechanical robustness, as demonstrated by contact angle measurements, rolling angle measurements, corrosive testing, magnetically actuated locomotion, and impact and bounce tests. The MCLMM also possesses satisfying stability in air and stability against temperature changing. In addition, its capabilities are demonstrated as a robotic motor, controllable obstacle cleaner, and a flexible switch for circuits, which shows the potential for MCLMM applications in robotic locomotion and manipulation, electronic circuits, and beyond.
Wrapped in the mixture of microscale ferronickel (FN) and polyethylene (PE) particles, the Galinstan liquid metal marbles are given three main properties, which are magnetic controllability, high elasticity, and mechanically robustness. This combination of properties, which is important in practical use, is not simultaneously involved in previous studies.
Background
The C-reactive protein/albumin (CRP/Alb) ratio is associated with outcome in septic patients. However, as an inflammation-based score, its prognostic value for cancer has scarcely been ...investigated.
Methods
Between February 2010 and January 2015, we enrolled 386 patients with pancreatic ductal adenocarcinoma. Univariate and multivariate survival analysis between the groups were evaluated. Receiver operating characteristics curves were generated and areas under the curve (AUC) were compared to evaluate the discriminatory ability of the inflammation-based prognostic scoring systems, including CRP/Alb ratio, neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR) and modified Glasgow prognostic score (mGPS).
Results
The optimal cutoff level of the CRP/Alb ratio was defined as 0.180. The prognosis of patients with CRP/Alb ratio ≥0.180 was significantly worse than CRP/Alb ratio <0.180 in univariate analysis (
p
< 0.001). In multivariate analysis, the CRP/Alb ratio was still associated with overall survival (
p
< 0.001). In addition, the CRP/Alb ratio had significantly higher AUC values compared with PLR (6, 12, and 24 months:
p
< 0.001, 0.017, 0.012) and mGPS (6, 12, and 24 months:
p
= 0.002, 0.020, 0.046) and had similar AUC values to NLR (6, 12, and 24 months:
p
= 0.052, 0.139, 0.041).
Conclusions
The current study demonstrated the CRP/Alb ratio may serve as a significant and promising inflammatory prognostic score in pancreatic cancer. An elevated CRP/Alb ratio is an independent factor for poor prognosis with the cutoff value of 0.180.
A novel Actinobacterium strain YIM 131861
T
, was isolated from lichen collected from the South Bank Forest of the Baltic Sea, Germany. It was Gram-stain-positive, strictly aerobic, catalase ...positive and oxidase negative, yellow pigmented. Cells were motile with a polar flagellum, irregular rod shaped and did not display spore formation. The strain grew at 15 − 30 °C (optimum 25 °C), at pH 6.0 − 10.0 (optimum pH 7.0) and in the presence of 0 − 1.5% (w/v) NaCl (optimum 1%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 131861
T
belonged to the genus
Glaciibacter
, and exhibited a high sequence similarity (96.4%) with
Glaciibacter superstes
NBRC 104264
T
. The genomic DNA G + C content of strain YIM 131861
T
was 68.2 mol%. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain YIM 131861
T
and
Glaciibacter superstes
NBRC 104264
T
were 73.2 and 19.9% based on the draft genome sequence. The cell-wall peptidoglycan type was B2
γ
and contained the 2, 4-diaminobutyric acid as the diagnostic amino acid. Whole cell sugars were galactose, rhamnose, ribose and glucose. It contained MK-12 and MK-13 as the predominant menaquinones. The major cellular fatty acids (> 10%) were identified as
anteiso
-C
15:0
,
iso
-C
16:0
and
anteiso
-C
17:0
. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and two unknown glycolipids. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain YIM 131861
T
should belong to the genus
Glaciibacter
and represents a novel species of the genus
Glaciibacter
, for which the name
Glaciibacter flavus
sp. nov. is proposed. The type strain is YIM 131861
T
(= CGMCC 1.16588
T
= NBRC 113572
T
).
Lithium‐sulfur batteries (LSBs) are still limited by the shuttle of lithium polysulfides (LiPS) and the slow Li−S reaction. Herein, we demonstrate that when using cobalt sulfide as a catalytic ...additive, an external magnetic field generated by a permanent magnet can significantly improve the LiPS adsorption ability and the Li−S reaction kinetics. More specifically, the results show both experimentally and theoretically how an electron spin polarization of Co ions reduces electron repulsion and enhances the degree of orbital hybridization, thus resulting in LSBs with unprecedented performance and stability. Under an external magnetic field, LSBs with 0.0084 % per cycle decay rate at 2 C during 8150 cycles are produced. Overall, this work not only demonstrates an effective strategy to promote LiPS adsorption and electrochemical conversion in LSBs at no additional energy cost but also enriches the application of the spin effect in the electrocatalysis fields.
Spin polarization in CoSx loaded on carbon nanofibers obtained by electrospinning method regulate LiPS conversion reaction. The external magnetic field induces electron spin polarization in CoSx, reducing electron repulsion, and enhancing the degree of 2p–3d orbital hybridization, thus accelerating the conversion ability of lithium polysulfides and enabling carbon nanofiber/CoSx/S cathodes with unprecedented performance and stability.
A novel class of crystalline porous materials has been developed utilizing multilevel dynamic linkages, including covalent B−O, dative B←N and hydrogen bonds. Typically, boronic acids undergo in situ ...condensation to afford B3O3‐based units, which further extend to molecular complexes or chains via B←N bonds. The obtained superstructures are subsequently interconnected via hydrogen bonds and π–π interactions, producing crystalline porous organic frameworks (CPOFs). The CPOFs display excellent solution processability, allowing dissolution and subsequent crystallization to their original structures, independent of recrystallization conditions, possibly due to the diverse bond energies of the involved interactions. Significantly, the CPOFs can be synthesized on a gram‐scale using cost‐effective monomers. In addition, the numerous acidic sites endow the CPOFs with high NH3 capacity, surpassing most porous organic materials and commercial materials.
A novel class of crystalline porous organic frameworks (CPOFs) are prepared based on covalent B−O, dative B←N and hydrogen bonds. Furthermore, gram‐scale production can be achieved at low cost, alongside excellent solution processibility, paving the way to diverse applications. Remarkably, the CPOFs exhibit exceptionally high NH3 uptake capacities, indicating their great potential toward NH3 capture.
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