Boosting oxygen evolution reaction rates with mesoporous Fe-doped MoCo-phosphide nanosheets.

Transition metal-based catalysts are commonly used for water electrolysis and cost-effective hydrogen fuel production due to their exceptional electrochemical performance, particularly in enhancing the efficiency of the oxygen evolution reaction (OER) at the anode. In this study, a novel approach was developed for the preparation of catalysts with abundant active sites and defects. The MoCoFe-phosphide catalyst nanosheets were synthesized using a simple one-step hydrothermal reaction and chemical vapor deposition-based phosphorization. The resulting MoCoFe-phosphide catalyst nanosheets displayed excellent electrical conductivity and a high number of electrochemically active sites, leading to high electrocatalytic activities and efficient kinetics for the OER. The MoCoFe-phosphide catalyst nanosheets demonstrated remarkable catalytic activity, achieving a low overpotential of only 250 mV to achieve the OER at a current density of 10 mA cm-2. The catalyst also exhibited a low Tafel slope of 43.38 mV dec-1 and maintained high stability for OER in alkaline media, surpassing the performance of most other transition metal-based electrocatalysts. The outstanding OER performance can be attributed to the effects of Mo and Fe, which modulate the electronic properties and structures of CoP. The results showed a surface with abundant defects and active sites with a higher proportion of Co2+ active sites, a larger specific surface area, and improved interfacial charge transfer. X-ray photoelectron spectroscopy (XPS) analysis revealed that the catalyst's high activity originates from the presence of Mo6+/Mo4+ and Co2+/Co3+ redox couples, as well as the formation of active metal (oxy)hydroxide species on its surface.

Fructo-oligosaccharides supplementation enhances the growth of nursing dairy calves while stimulating the persistence of Bifidobacterium and hindgut microbiome's maturation.

The colonization and development of the gut microbiome in dairy calves play a crucial role in their overall health and future productivity. Despite the widely proposed benefits of inulin-related products on the host, there is insufficient information about how supplementing fructo-oligosaccharides (FOS) impacts the colonization and development of the gut microbiome in calves. In a randomized intervention trial involving newborn male Holstein dairy calves, we investigated the impact of FOS on the calf hindgut microbiome, short-chain fatty acids, growth performance, and the incidence of diarrhea. The daily administration of FOS exhibited a time-dependent increase in the average daily gain and the concentration of short-chain fatty acids. Concurrently, FOS delayed the natural decline of Bifidobacterium, promoting the maturation and stabilization of the hindgut microbiome. These findings not only contribute to a theoretical understanding of the judicious application of prebiotics but also hold significant practical implications for the design of early life dietary interventions in the rearing of dairy calves.

Sandwich-type electrochemical aptasensor for sensitive detection of myoglobin based on Pt@CuCo-oxide nanoparticles as a signal marker.

When an acute myocardial infarction (AMI) occurs, myoglobin (Mb) is the biomarker whose concentration firstly increases, and the high sensitive detection of Mb is critical for early diagnosis of AMI. Herein, a sandwich-type electrochemical aptasensor for the sensitive detection of Mb was constructed by using Pt@Cu1.33OCo0.83O as the signal marker. On one hand, nano-flower-like Cu1.33OCo0.83O was synthesized by hydrothermal method and Pt nanoparticles (Pt NPs) were loaded on its surface. Pt@Cu1.33OCo0.83O could immobilize aptamer 2 (Apt2) successfully by the Pt-S bond. And because of the synergistic effect between Pt and bimetallic oxide, Pt@Cu1.33OCo0.83O had an excellent catalytic effect on the signal source of hydrogen peroxide (H2O2) to amplify the current signal, which enhance the sensitivity of the aptasensor. On the other hand, the screen-printed gold electrode (SPGE) was used as the sensing base, which had good conductivity and ensured the immobilization of aptamer 1 (Apt1). The quantitative detection of Mb was achieved by specific recognition between Mb and Apt1, Apt2. As a result, the constructed electrochemical aptasensor had a good linear range (1-1500 ng/mL) with a low detection limit (LOD) of 0.128 ng/mL (S/N = 3), and a high sensitivity of 29.47 µA dec-1. The aptasensor also realized the detection of Mb in human serum samples with good accuracy, and the results were consistent with the hospital's biochemical indicators, which demonstrated the potential application of the prepared sensor in the clinical detection of Mb.

Surface Reconstruction Facilitated by Fluorine Migration and Bimetallic Center in NiCo Bimetallic Fluoride Toward Oxygen Evolution Reaction.

Oxygen evolution reaction (OER) is a critical anodic reaction of electrochemical water splitting, developing a high-efficiency electrocatalyst is essential. Transition metal-based catalysts are much more cost-effective if comparable activities can be achieved. Among them, fluorides are rarely reported due to their low aqueous stability of coordination and low electric conductivity. Herein, a NiCo bimetallic fluoride with good crystallinity is designed and constructed, and significantly enhanced catalytic activity and conductivity are observed. The inevitable oxidation of transition metal ions at high potential and the dissociation of F- are attributed to the low aqueous stability of coordination. The theoretical researches predicte that transition metal fluorides should have a strong tendency to electrochemical reconstruction. Therefore, based on the observations on their electrochemical behavior, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and bode plots, it is further demonstrated that surface reconstruction occurred during the electrochemical process, meanwhile a significant increase of electrochemically active area, which is created by F migration, are also directly observed. Additionally, DFT calculation results show that the electronic structure of the catalysts is modulated by the bimetallic centers, and this reconstruction helps optimizing the adsorption energy of oxygen-containing species and improves OER activity.

Alternative splicing and duplication of PI-like genes in maize.

Alternative splicing and duplication provide the possibility of functional divergence of MADS-box genes. Compared with its Arabidopsis counterpart PI gene, Zmm16 in maize recruits a new role in carpel abortion and floral asymmetry, whereas the other two duplicated genes, Zmm18/29, have not yet been attributed to any function in flower development as a typical B class gene does. Here, alternatively spliced transcripts of three PIL genes were analyzed, among which we described the candidate functional isoforms and analyzed the potential effects of alternative splicing (AS) on protein-protein interactions as well, then their phylogenetic relationships with orthologs in typical grasses were further analyzed. Furthermore, we compared the cis-acting elements specific for three maize PIL genes, especially the elements related to methyl jasmonate (MeJA) and gibberellic acid (GA), both hormones involved in the sex-determination process in maize. Together with the results from the co-expression networks during reproductive organ development, we speculated that, due to duplication and alternative splicing, Zmm18/29 may play a role in GA- and MeJA-related developmental process. These results provide novel clues for experimental validation of the evolutional meaning of maize PIL genes.

TRanscranial AlterNating current Stimulation FOR patients with Mild Alzheimer's Disease (TRANSFORM-AD study): Protocol for a randomized controlled clinical trial.

INTRODUCTION: Recently, transcranial alternating current stimulation (tACS), which can interact with ongoing neuronal activity, has emerged as a potentially effective and promising treatment for Alzheimer's disease (AD), and the 40 Hz gamma frequency was suggested as a suitable stimulation frequency for AD. METHODS: The TRANSFORM-AD study is a double-blind, randomized-controlled trial that will include 40 individuals with mild AD. Eligible patients need to have amyloid ß (Aß) loads examined by Pittsburgh compound B (PiB) positron emission tomography (PET) or decreased Aß level in cerebrospinal fluid. Participants will be randomized into either a 40 Hz tACS group or a sham stimulation group. Both groups will undergo 30 one-hour sessions across 3 weeks (21 days). The outcome measures will be assessed at baseline, at the end of the intervention, and 3 months after the first session. The primary outcome is global cognitive function, assessed by the 11-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-Cog), and the secondary outcomes include changes in other neuropsychological assessments and in PiB-PET, structural magnetic resonance imaging (MRI), resting electroencephalography (EEG), and simultaneous EEG-functional MRI (EEG-fMRI) results. RESULTS: The trial is currently ongoing, and it is anticipated that recruitment will be completed in June 2021. DISCUSSION: This trial will evaluate the efficacy and safety of 40 Hz tACS in patients with AD, and further explore the potential mechanisms by analyzing amyloid deposits using PiB-PET, brain volume and white matter integrity by structural MRI, and neural activity by EEG and EEG-fMRI.

Fast and efficient phosphate removal on lanthanum-chitosan composite synthesized by controlling the amount of cross-linking agent.

In the present study, non-crosslinked lanthanum-chitosan (La-CTS-0X) and crosslinked lanthanum-chitosan (La-CTS-1X/2X) composites were prepared as new complex biosorbents for effective phosphate removal from wastewater. Batch adsorption experiments were investigated by varying the influencing parameters, viz., pH, initial concentration of phosphate ions, contact time, temperature and co-existing anions. Experimental data were well fitted to the Langmuir isotherm model (R2 = 0.9998) as well as the pseudo-second-order model (R2 = 1.000), indicating that the phosphate adsorption process was homogeneous, mono-layered and chemisorption dominated. Besides, the maximum phosphate adsorption capacity for La-CTS-0X/1X/2X was 47.28, 57.84 and 31.01 mg g-1 at pH 6, respectively. Thermodynamic parameters including ΔH° (-43.7 kJ mol-1), ΔS° (-132 J mol-1 K-1) and ΔG° (-4.60 kJ mol-1) revealed that the essence of adsorption was spontaneous and exothermic. The regenerated materials could be repeatedly used for three cycles without obvious degradation of performance. Characterization of the adsorbent using FTIR, SEM, EDS and XPS techniques suggested that the possible adsorption mechanisms were electrostatic attraction as well as ligand exchange. More importantly, the La-CTS-1X had rapid removal rate for phosphate within 10 min and the remained P concentration met the permissible limit by the U.S. Environmental Protection Agency (EPA).