Search

A closely packed hybrid electrocatalyst Pt1.5Ni1−x/Ni–N–C was engineered by a gas-promoted dealloying process, ensuring the relay catalysis of the reaction intermediates at Pt alloy and Ni single sites, thus achieving high performance in PEMFCs.

A precise modulation of heterogeneous catalysts in structural and surface properties promises the development of more sustainable advanced oxidation water purification technologies. However, while catalysts with superior decontamination activity and selectivity are already achievable, maintaining a long-term service life of such materials remains challenging. Here, we propose a crystallinity engineering strategy to break the activity–stability tradeoff of metal oxides in Fenton-like catalysis. The amorphous/crystalline cobalt-manganese spinel oxide (A/C-CoMnO x ) provided highly active, hydroxyl group-rich surface, with moderate peroxymonosulfate (PMS)-binding affinity and charge transfer energy and strong pollutant adsorption, to trigger concerted radical and nonradical reactions for efficient pollutant mineralization, thereby alleviating the catalyst passivation by oxidation intermediate accumulation. Meanwhile, the surface-confined reactions, benefited from the enhanced adsorption of pollutants at A/C interface, rendered the A/C-CoMnO x /PMS system ultrahigh PMS utilization efficiency (82.2%) and unprecedented decontamination activity (rate constant of 1.48 min −1 ) surpassing almost all the state-of-the-art heterogeneous Fenton-like catalysts. The superior cyclic stability and environmental robustness of the system for real water treatment was also demonstrated. Our work unveils a critical role of material crystallinity in modulating the Fenton-like catalytic activity and pathways of metal oxides, which fundamentally improves our understanding of the structure–activity–selectivity relationships of heterogeneous catalysts and may inspire material design for more sustainable water purification application and beyond.

Oil bodies (OBs) are a kind of natural and stable oil nucleate microcapsule in which the triglyceride matrix can be used as an appropriate carrier of hydrophobic molecules. Astaxanthin has high antioxidant properties but is extremely sensitive to oxidation, causing the loss of its bioactive properties.The purpose of this study was to clarify the effects of environmental factors (light, oxygen, temperature, and pH) on the physical and oxidative stability of astaxanthin microcapsules prepared with peanut oil bodies (POBs). After 14 days of storage, the retention rate of astaxanthin in peanut oil microcapsules (POMs) was significantly increased. The astaxanthin retention rate of POMs stored under light conditions was higher than under dark conditions. Similarly, the retention rate of astaxanthin in POMs was significantly increased during vacuum storage. The astaxanthin retention rate was also the highest when POMs were stored at 4 °C, whereas it was the lowest at pH 3.0.The experiment demonstrated that microcapsulation could improve the astaxanthin retention rate and storage stability, and recombinant OBs were potential ideal wall materials for astaxanthin embedding. © 2022 Society of Chemical Industry.

Lactobacillus plantarum 23-1 improved blood lipid level, liver oxidative stress injury, regulated the TLR4/NF-κB signaling pathway, enhanced intestinal barrier function, effectively alleviated intestinal inflammation and obesity symptoms of mice.

This study investigated the composition, antioxidant capacity, oxidative stability and physical stability of soybean oil body emulsions recovered from three high-protein and three high-oil genotype soybeans.

Developing highly stable and efficient catalysts toward oxygen reduction reaction is of great importance for the long-term operation in proton exchange membrane fuel cells but still challenging. Herein, we report a facile synthesis of two-dimensional coplanar Pt-carbon nanomeshes (NMs) that are composed of highly distorted Pt networks (neck width of 2.05 ± 0.72 nm) and carbon. X-ray absorption fine structure spectroscopy demonstrated metallic state of Pt in the coplanar Pt/C NMs. Fuel cell tests verified the excellent activity of the coplanar Pt/C NM catalyst with the peak power density of 1.21 W cm -2 and current density of 0.360 A cm -2 at 0.80 V in H 2 /O 2 cell. Moreover, the coplanar Pt/C NM electrocatalysts showed superior stability against aggregation with nanomesh structures preserved intact in a long-term operation over 30,000 cycles for electrode measurement, and the working voltage loss was negligible after 120 h in H 2 /O 2 single cell operation. Density functional theory analysis indicates the increased vacancy formation energy of Pt atoms for coplanar Pt/C NMs, restraining the tendency of Pt dissolution and aggregation.

Two-dimensional noble metal nanomaterials(2D NMNs) are widely used as electrocatalyst. In recent years, the researchers have focused on the synthesis of 2D NMNs at the atomic scale, and realize the improvement of electrocatalytic performance through further structural modification to reduce the usage of noble metals. Herein, we systematically introduce the synthesis methods of 2D NMNs categorized by element type. Subsequently, the catalytic applications toward a variety of electrocatalytic reactions are described in detail including the hydrogen evolution reaction(HER), oxygen reduction reaction(ORR), oxygen evolution reaction(OER) and CO2 reduction reaction (CO2RR). Finally, the potential opportunities and remaining challenges in this emerging research area are proposed.

Vesicular neurotransmitter transporters (VNTs) mediate the selective uptake and enrichment of small-molecule neurotransmitters into synaptic vesicles (SVs) and are therefore a major determinant of the synaptic output of specific neurons. To identify novel VNTs expressed on SVs (thus identifying new neurotransmitters and/or neuromodulators), we conducted localization profiling of 361 solute carrier (SLC) transporters tagging with a fluorescent protein in neurons, which revealed 40 possible candidates through comparison with a known SV marker. We parallelly performed proteomics analysis of immunoisolated SVs and identified seven transporters in overlap. Ultrastructural analysis further supported that one of the transporters, SLC35D3, localized to SVs. Finally, by combining metabolite profiling with a radiolabeled substrate transport assay, we identified UDP-glucose as the principal substrate for SLC35D3. These results provide new insights into the functional role of SLC transporters in neurotransmission and improve our understanding of the molecular diversity of chemical transmitters.

Noble metal nanomaterials have been widely used as catalysts. Common techniques for the synthesis of noble metal often result in crystalline nanostructures. The synthesis of amorphous noble metal nanostructures remains a substantial challenge. We present a general route for preparing dozens of different amorphous noble metal nanosheets with thickness less than 10 nm by directly annealing the mixture of metal acetylacetonate and alkali salts. Tuning atom arrangement of the noble metals enables to optimize their catalytic properties. Amorphous Ir nanosheets exhibit a superior performance for oxygen evolution reaction under acidic media, achieving 2.5-fold, 17.6-fold improvement in mass activity (at 1.53 V vs. reversible hydrogen electrode) over crystalline Ir nanosheets and commercial IrO2 catalyst, respectively. In situ X-ray absorption fine structure spectra indicate the valance state of Ir increased to less than + 4 during the oxygen evolution reaction process and recover to its initial state after the reaction., While noble metal usage in catalysis is ubiquitous, the metals’ scarcity necessitates new materials designs for efficient utilization. Here, authors report a general strategy to prepare amorphous noble metal nanosheets and find the nanomaterials to act as efficient water-splitting electrocatalysts.

Lithium-sulfur batteries show great potential to achieve high-energy-density storage, but their long-term stability is still limited due to the shuttle effect caused by the dissolution of polysulfides into electrolyte. Herein, we report a strategy of significantly improving the polysulfides adsorption capability of cobaltous oxide by amorphization-induced surface electronic states modulation. The amorphous cobaltous oxide nanosheets as the cathode additives for lithium-sulfur batteries demonstrates the rate capability and cycling stability with an initial capacity of 1248.2 mAh g-1 at 1 C and a substantial capacity retention of 1037.3 mAh g-1 after 500 cycles. X-ray absorption spectroscopy analysis reveal that the coordination structures and symmetry of ligand field around Co atoms of cobaltous oxide nanosheets are notably changed after amorphization. Moreover, DFT studies further indicate that amorphization-induced re-distribution of d orbital makes more electrons occupy high energy level, thereby resulting in a high binding energy with polysulfides for favorable adsorption., Regulating the adsorption behaviour of the polysulfide species is the key to achieving highly stable Li-S batteries. Here, the authors show that amorphization-induced redistribution of d orbitals enable CoO to be a favourable candidate for polysulfide adsorption and conversion.

Vesicular neurotransmitter transporters (VNTs) mediate the selective uptake and enrichment of small molecule neurotransmitters into synaptic vesicles (SVs) and are therefore a major determinant of the synaptic output of specific neurons. To identify novel VNTs expressed on SVs (thus identifying new neurotransmitters and/or neuromodulators), we conducted localization profiling of 361 solute carrier (SLC) transporters tagging with a fluorescent protein in neurons, which revealed 40 possible candidates through comparison with a known SV marker. We parallelly performed proteomics analysis of immunoisolated SVs and identified 7 transporters in overlap. Ultrastructural analysis confirmed one of the transporters, SLC35D3, localized to SVs. Finally, by combining metabolite profiling with a radiolabeled substrate transport assay, we identified UDP-glucose as the principal substrate for SLC35D3. These results provide new insights into the functional role of SLC transporters in neurotransmission and improve our understanding of the molecular diversity of chemical transmitters.

The sintering of supported metal nanoparticles is a major route to the deactivation of industrial heterogeneous catalysts, which largely increase the cost and decrease the productivity. Here, we discover that supported palladium/gold/platinum nanoparticles distributed at the interface of oxide supports and nitrogen-doped carbon shells would undergo an unexpected nitrogen-doped carbon atomization process against the sintering at high temperatures, during which the nanoparticles can be transformed into more active atomic species. The in situ transmission electron microscopy images reveal the abundant nitrogen defects in carbon shells provide atomic diffusion sites for the mobile atomistic palladium species detached from the palladium nanoparticles. More important, the catalytic activity of sintered and deactivated palladium catalyst can be recovered by this unique N-doped carbon atomization process. Our findings open up a window to preparation of sintering-resistant single atoms catalysts and regeneration of deactivated industrial catalysts., Sintering supported metal nanoparticles is the common route to the deactivation of industrial heterogeneous catalysts. Here, the authors report a carbon atomization process that allows one not only to redisperse metal nanoparticles, but also to recover deactivated catalysts.

Two soybean oil body (SOB) creams were recovered from soybean at pH 7 and pH 11, respectively, and dispersed in water to obtain a natural 5% o/w emulsion. The lipoxygenase (LOX) activity and oleosin hydrolysis behavior in two SOB emulsions, as affected by different washing times and thermal treatments (50–110 °C), were investigated. The SOB emulsions recovered under neutral conditions (pH 7) were accompanied by strong enzymatic degradation. The absence of LOX and oleosin hydrolase activities was observed in SOB emulsions recovered under alkaline conditions (pH 11). The oxidative and physical stabilities of two SOB emulsions were examined at 37 °C under 15-day storage. Thermal treatment significantly enhanced the oxidative stability of two SOB emulsions due to enzymatic inactivation or altered interfacial properties. Both SOB emulsions exhibited excellent coalescence resistance after the elimination of enzymatic degradation, but their oxidative stability was different. It was due to the modification of the SOB surface by exogenous proteins that accelerated its oxidation. The results of this study might help design highly stable products based on SOB to meet the demand of people for natural products.

The synergized optimization of water flux and salt rejection by blending with inorganic fillers has been achieved for the polyamide (PA) thin film nanocomposite (TFN) membrane. However, it is difficult to characterize its mass transport properties due to the very thin and heterogeneous PA film. In this work, we select cellulose triacetate (CTA) as the base to prepare hybrid films and their transport properties were studied according to solution-diffusion theory. A series of inorganic fillers, such as reduced graphene oxide (RGO), zeolites, ZIF-8, SiO2 and graphene oxide (GO) were incorporated. The SEM and EDX results indicate a less than 1 wt% filler content for a uniform dispersion. The blending of inorganic fillers leads to enhanced glass transition temperature (Tg) and density, little effect on the water transport property but dramatically decreased salt permeability values, which are nearly ten-fold of that of the CTA film. The blending of GO can densify and hydrophilize CTA simultaneously, which is most promising for a desalination application. The increased water uptake should contribute to its increased water permeability, while the decreased free volume size and FFV value and various interactions between the ions (Na+, Cl-) and GO sheets account for salt permeability decrease.

Background The temporal sequence between serum calcium and insulin resistance (IR) and their effects on hypertension are unclear. We studied the association between serum calcium and IR, with risk of hypertension events in a longitudinal cohort conducted in China. Methods and Results Data from 8653 subjects aged 20 to 74 years with an average follow‐up of 5.3 years were analyzed. Serum calcium, and fasting and 2‐hour serum glucose and insulin were measured at baseline and follow‐up. Cross‐lagged panel and mediation analysis were used to examine the temporal relationship between serum calcium and IR and its impact on hypertension incidence. The conjoint effects of serum calcium and IR at baseline on hypertension at follow‐up were observed ( P =0.029 for HOMA_IR [hepatic IR] and P =0.009 for Gutt index [peripheral IR]). The cross‐lagged path coefficient (β 2 ) from baseline serum calcium to follow‐up peripheral IR were significantly greater than path coefficient (β 1 ) from baseline peripheral insulin resistance to follow‐up serum calcium (β 2 =−0.354 versus β 1 =−0.005; P =0.027). However, no directional relationships were observed in the serum calcium↔hepatic IR analysis. The mediation effect of peripheral IR on the association of serum calcium at baseline with hypertension at follow‐up was estimated at 16.4% ( P Conclusions Our findings demonstrate that higher serum calcium levels probably precede peripheral IR, and this 1‐directional relation plays a role in the development of hypertension.

Heterogeneous noble-metal-based catalysis plays an essential role in the production of fine chemicals. Rh-based catalysts are one of the most active candidates for indole synthesis. However, it is still highly desired to develop heterogeneous Rh-based catalysts with high activity and selectivity. In this work, a general, facile wet-chemical method is reported to synthesize ultrathin amorphous/crystalline heterophase Rh and Rh-based bimetallic alloy nanosheets (NSs), including RhCu, RhZn, and RhRu. Impressively, the amorphous/crystalline heterophase Rh NSs exhibit enhanced catalytic activity toward the direct synthesis of indole compared to the crystalline counterpart. Importantly, the obtained amorphous/crystalline heterophase RhCu alloy NSs can further enhance the selectivity to indole of >99.9% and the conversion is 100%. This work demonstrates the importance of phase engineering and metal alloying in the rational design and synthesis of tandem heterogeneous catalysts toward fine chemical synthesis.

Efficient polymeric adsorbents, including complexing membranes, attract increasing attention due to the global occurrence of micropollutants in water resources. Grafting polyhydroxy polymers onto a microporous membrane surface to prepare a complexing membrane for flow-through boron removal is also an emerging method. However, it remains a great challenge to develop efficient sorbents with both high capacity and high adsorption rate. In this work, hyperbranched polyols are grafted onto a polyacrylonitrile (PAN) membrane surface to prepare complexing membranes with high capacity and high adsorption rate, which utilize the structural characteristics of hyperbranched molecules to optimize the three-dimensional distribution of the chelating ligands. First, the PAN membrane was grafted with three hyperbranched polyethyleneimine (HPEI) macromolecules through a water mediated hydrolysis and amidation reaction in an autoclave followed by a ring opening reaction with glycidol. ATR-FTIR, XPS, FESEM and WCA methods were used to characterize the modified membranes. The results demonstrated that HPEI was successfully anchored onto the membrane surface and reacted with glycidol. Large quantities of hydroxyl groups were enriched on the surface of the membranes leading to rougher and superhydrophilic surfaces. The study on boron adsorption shows that the complexing membrane can absorb 3.2 mmol g−1 within only 4 min, which is superior to other reported sorbents. The adsorption isotherm can be described by the Langmuir model and the kinetic adsorption data fit very well with the pseudo-first-order expression. In addition, the boron adsorption can be completely regenerated for ten cycles of use by 15 min acid leaching without obvious degradation. The rapid boron removal and high regeneration are believed to benefit from the hyperbranched scaffold thanks to the high density and good accessibility of the ligands.

Summary The size and shape control of amorphous nanomaterials has long been a bottleneck restricting their further development. Here, we present a general approach to synthesize more than twenty kinds of amorphous metal oxide nanosheets. The amorphous state of the nanosheets is determined using aberration-corrected high-resolution transmission electron microscopy and X-ray diffraction. By using extended X-ray absorption fine structure analysis, we demonstrate that amorphous nanosheets have a larger interatomic distance and a looser packing characteristic compared with crystalline counterparts. The as-prepared amorphous FeOx nanosheets are used as sodium-ion batteries anode materials, exhibiting notable performance with a specific capacity of 263.4 mAh g−1 at 100 mA g−1 and long-term cyclic stability. Significantly, a reversible amorphous-crystalline-amorphous structure transformation phenomenon during the cycling test is observed at the atomic scale.

Most cells in the animal body are tailored to perform particular tasks, but stem cells have not yet made their choice. Instead, they have unlimited capacity to divide and, with the right signals, they can start to specialize to become a given type of cells. In the brain, this process starts with a stem cell dividing. One of the daughters will remain a stem cell, while the other, the neural progenitor, will differentiate to form a mature cell such as a neuron. Keeping this tight balance is crucial for the health of the organ: if the progenitor reverts back to being a stem cell, there will be a surplus of undifferentiated cells that can lead to a tumor. A one-way signal driven by the protein Notch partly controls the distinct fates of the two daughter cells. While the neural progenitor carries Notch at its surface, its neural stem cell sister has a Notch receptor on its membrane instead. This ensures that the Notch signaling goes in one direction, from the cell with Notch to the one sporting the receptor. When a stem cell divides, one daughter gets more of a protein called Numb than the other. Numb pulls Notch receptors away from the external membrane and into internal capsules called endosomes. This guarantees that only one of the siblings will be carrying the receptors at its surface. Yet, sometimes the Notch receptors can get activated in the endosomes, which may make neural progenitors revert to being stem cells. It is still unclear what tools the cells have to stop this abnormal activation. Here, Li et al. screened brain cells from fruit fly larvae to find out the genes that might play a role in suppressing the inappropriate Notch signaling. This highlighted a protein complex known as the retromer, which normally helps to transport proteins in the cell. Experiments showed that, in progenitors, the retromer physically interacts with Notch receptors and retrieves them from the endosomes back to the cell surface. If the retromer is inactive, the Notch receptors accumulate in the endosomes, where they can be switched on. It seems that, in fruit flies, the retromer acts as a bomb squad that recognizes and retrieves potentially harmful Notch receptors, thereby preventing brain tumor formation. Several retromer components are less present in patients with various cancers, including glioblastoma, an aggressive form of brain cancer. The results by Li et al. may therefore shed light on the link between the protein complex and the emergence of the disease in humans.