uncovering the catalytic cycle of electrochemical and chemical oxygen reduction mediated by an iron porphyrin.

As one of the critical reactions in biotransformation and energy conversion processes, the oxygen reduction reaction (ORR) catalyzed by iron porphyrins has been widely explored by electrochemical, spectroscopic, and theoretical methods. However, experimental identification of all proposed intermediates of iron porphyrins in one catalytic cycle is rather challenging in the mechanistic studies of the ORR driven by electrochemical or chemical methods. Herein, we report the application of electrochemical mass spectrometry (EC-MS) and chemical reaction mass spectrometry (CR-MS) to uncover the catalytic cycle of electrochemical and chemical ORRs mediated by an iron porphyrin molecular catalyst.

Exogenous Melatonin Improves Drought Tolerance by Regulating the Antioxidant Defense System and Photosynthetic Efficiency in Fodder Soybean Seedings.

Fodder soybean ( L.) with high protein and yield is a popular forage grass in northeast China. Seasonal drought inhibits its growth and development during seedling stage.

Thermoresponsive dual-network chitosan-based hydrogels with demineralized bone matrix for controlled release of rhBMP9 in the treatment of femoral head osteonecrosis.

In an effort to mitigate or reverse the pathological progression of early-stage osteonecrosis of the femoral head (ONFH), this study employed a promising strategy that involves the sustained delivery of osteogenic factors to augment core decompression, facilitated by the use of composite hydrogels. Specifically, a hydrogel was synthesized by blending chitosan, Pluronic F-127, and tripolyphosphate, utilizing both ionic bonding and copolymer micelle cross-linking techniques. This hydrogel demonstrated exceptional biocompatibility, temperature responsiveness, pH-dependent biodegradation, and controlled release properties.

The steric hindrance effect of Co porphyrins promoting two-electron oxygen reduction reaction selectivity.

A new Co 5,10,15,20-tetrakis(2',6'-dipivaloyloxyphenyl)porphyrin (1) with eight ester groups in all and ' positions of phenyl groups was designed, which displayed significantly improved 2e oxygen reduction reaction (ORR) selectivity compared with a 5,10,15,20-tetrakis(-dipivaloyloxyphenyl) porphyrin (2) without large steric groups. This work is significant to reveal the steric hindrance effect of metal porphyrins on electrocatalytic ORR selectivity.

Electrocatalytic hydrogen evolution reaction with a Cu porphyrin bearing -CF substituents.

Cu tetrakis(trifluoromethyl)porphyrin (1) was synthesized and examined as an electrocatalyst for the hydrogen evolution reaction (HER). We showed that 1 is highly efficient for the electrocatalytic HER in acetonitrile with trifluoroacetic acid (TFA) and outperforms Cu tetrakis(pentafluorophenyl)porphyrin (2) by decreasing the onset overpotential by 220 mV. The / value ( is the catalytic peak current and is the non-catalytic peak current) with 1 is 97, while it is 53 with 2.

Revealing Significant Electronic Effects on the Oxygen Reduction Reaction with Iron Porphyrins.

Understanding electronic effects on catalysis from a mechanism point of view is of fundamental significance but is also challenging. We herein report on electronic effects on the oxygen reduction reaction (ORR) with Fe porphyrins. By using Fe tetraphenylporphyrin (TPP-Fe) and Fe tetra(pentafluorophenyl)porphyrin (TPFP-Fe), we showed their different electrochemical and chemical behaviors for ORR.

An Eu (III)-functionalized covalent organic framework fluorescent probe for specific detection of Flumequine based on pore restriction and antenna effect.

The overuse of quinolone antibiotics has led to a series of health and environmental issues. Herein, we combine the distinct luminescence properties of Eu with the unique structure of covalent organic frameworks (COFs) to develop a precise and sensitive fluorescent probe for detecting Flumequine (Flu) in water. Eu is thoroughly anchored into the channels of COFs as recognition sites, while the synthesized probe material still maintains its intact framework structure.

The biological functions and pathological mechanisms of CASK in various diseases.

Background: As a scaffold protein, calcium/calmodulin-dependent serine protein kinase (CASK) has been extensively studied in a variety of tissues throughout the body. The gene is ubiquitous in several tissues, such as the neurons, islets, heart, kidneys and sperm, and is mostly localised in the cytoplasm adjacent to the basement membrane. CASK binds to a variety of proteins through its domains to exerting its biological activity.

Astaxanthin reduces inflammation and promotes a chondrogenic phenotype by upregulating SIRT1 in osteoarthritis.

Objective: To investigate the effects of astaxanthin (AST) on mouse osteoarthritis (OA) and lipopolysaccharide (LPS)-induced ATDC5 cell damage and to explore whether SIRT1 protein plays a role.

Methods: In this study, some mouse OA models were constructed by anterior cruciate ligament transection (ACLT). Imaging, molecular biology and histopathology methods were used to study the effect of AST administration on traumatic OA in mice.

Covalent Tethering of Cobalt Porphyrins on Phenolic Resins for Electrocatalytic Oxygen Reduction and Evolution Reactions.

The front cover artwork is provided by Rui Cao's group at Shaanxi Normal University. The image shows the design of Co-porphyrin-engineered phenolic resins with intramolecular phenolic hydroxyl groups to facilitate proton and electron transfers for efficient oxygen electrocatalysis, which is bioinspired by cytochrome c oxidases, and shows the excellent performance of Zn-air batteries assembled with the hybrid material. Read the full text of the Research Article at 10.

Enhancing singlet oxygen production of dioxygen activation on the carbon-supported rare-earth oxide nanocluster and rare-earth single atom catalyst to remove antibiotics.

Singlet oxygen (O) is extensively employed in the fields of chemical, biomedical and environmental. However, it is still a challenge to produce high- concentration O by dioxygen activation. Herein, a system of carbon-supported rare-earth oxide nanocluster and single atom catalysts (named as REO/RE-C, RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y) with similar morphology, structure, and physicochemical characteristic are constructed to activate dissolved oxygen (DO) to enhance O production.

Covalent Tethering of Cobalt Porphyrins on Phenolic Resins for Electrocatalytic Oxygen Reduction and Evolution Reactions.

Using functionalized supporting materials for the immobilization of molecular catalysts is an appealing strategy to improve the efficiency of molecular electrocatalysis. Herein, we report the covalent tethering of cobalt porphyrins on phenolic resins (PR) for improved electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). A cobalt porphyrin bearing an alkyl bromide substituent was covalently tethered on phenolic resins, through the substitution reaction of alkyl bromides with phenolic hydroxyl groups, to afford molecule-engineered phenolic resins (Co-PR).

Switching Electrocatalytic Hydrogen Evolution Pathways through Electronic Tuning of Copper Porphyrins.

The electronic structure of metal complexes plays key roles in determining their catalytic features. However, controlling electronic structures to regulate reaction mechanisms is of fundamental interest but has been rarely presented. Herein, we report electronic tuning of Cu porphyrins to switch pathways of the hydrogen evolution reaction (HER).

Thiacalix[4]arene Etching of an Anisotropic CuH Intermediate for Accessing Robust Modularly Assembled Copper Nanoclusters.

Atom-precise metal nanoclusters (NCs) with large bulk (nuclearity >60) are important species for insight into the embryonic phase of metal nanoparticles and their top-down etching synthesis. Herein, we report a metastable rod-shaped 70-nuclei copper-hydride NC, [Cl@CuH(PhC≡C)(CFCOO)] (), with Cl as the template, in which the Cl@Cu kernel adopts a distinctive metal packing mode along the bipolar direction, and the protective ligand shell exhibits corresponding site differentiation. In terms of metal nuclearity, is the largest alkynyl-stabilized Cu-hydride cluster to date.

Adapting Synthetic Models of Heme/Cu Sites to Energy-Efficient Electrocatalytic Oxygen Reduction Reaction.

In nature, cytochrome c oxidases catalyze the 4e oxygen reduction reaction (ORR) at the heme/Cu site, in which Cu is used to assist O activation. Because of the thermodynamic barrier to generate Cu , synthetic Fe-porphyrin/Cu complexes usually show moderate electrocatalytic ORR activity. We herein report on a Co-corrole/Co complex 1-Co for energy-efficient electrocatalytic ORR.

HTD-TS: Weakly Supervised Hyperspectral Target Detection Based on Transformer via Spectral-Spatial Similarity.

As an advanced technique in remote sensing, hyperspectral target detection (HTD) is widely concerned in civilian and military applications. However, the limitation of prior and heterogeneous backgrounds makes HTD models sensitive to data corruption under various interference from the environment. In this article, a novel united HTD framework based on the concept of transformer is proposed to extract [HTD based on transformer via spectral-spatial similarity (HTD-TS3)] under weak supervision, which opens up more flexible ways to study HTD.

Enhanced selective separation of vanadium(V) and chromium(VI) using the CeO nanorod containing oxygen vacancies.

Adsorption of vanadium from wastewater defends the environment from toxic ions and contributes to recover the valuable metal. However, it is still challenging for the separation of vanadium (V) and chromium (Cr) because of their similar properties. Herein, a kind of CeO nanorod containing oxygen vacancies is facilely synthesized which displays ultra-high selectivity of V against various competitive ions (i.

Large-area Free-standing Metalloporphyrin-based Covalent Organic Framework Films by Liquid-air Interfacial Polymerization for Oxygen Electrocatalysis.

Synthesizing large-area free-standing covalent organic framework (COF) films is of vital importance for their applications but is still a big challenge. Herein, we reported the synthesis of large metalloporphyrin-based COF films and their applications for oxygen electrocatalysis. The reaction of meso-benzohydrazide-substituted metal porphyrins with tris-aldehyde linkers afforded free-standing COF films at the liquid-air interface.

Endo-TLIF versus MIS-TLIF in 1-segment lumbar spondylolisthesis: A prospective randomized pilot study.

Objective: To evaluate the curative efficacy by comparing perioperative characteristics and 1.5-year observational outcomes in 1-segment lumbar spondylolisthesis between traditional minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and optimized Endoscopic TLIF techniques.

Methods: The study was a single-center, randomized controlled trial comparing two different treatment approaches for 1-segment lumbar spondylolisthesis.

Deletion of p16 accelerates fracture healing in geriatric mice.

The biomarker p16 plays a role in aging and is upregulated in aged organs and cells, including bone marrow mesenchymal stem cells (BM-MSCs), which play a leading role in fracture healing. Several studies have reported delayed fracture healing in geriatric mice. However, the relationship between p16 expression and fracture healing in geriatric mice remains poorly understood.

[Comparison of two methods for preparing knee osteochondral injury models in mice].

Objective: To observe the effect of using tungsten drills to prepare mouse knee osteochondral injury model by comparing with the needle modeling method, in order to provide an appropriate animal modeling method for osteochondral injury research.

Methods: A total of 75 two-month-old male C57BL/6 mice were randomly divided into 3 groups ( =25). Mice in groups A and B were used to prepare the right knee osteochondral injury models by using needles and tungsten drills, respectively; group C was sham-operation group.

Study on preparation and performance of PEG-based polyurethane foams modified by the chitosan with different molecular weight.

A category of polyethylene glycol-polyurethane (PU) foams were prepared by chitosan (CS) with different molecular weight as chain extender. The activity group, CS grafting degree, crystallization behavior, morphology, thermal stability, mechanical properties, hydrophilicity, protein adsorption and degradation in vitro of PU-CS composite foams were investigated. The experimental results indicated that better group reactivity (-NH and -OH) in CS with low molecular weight led to the higher CS grafting degree (78.

Modulation of tumor cell migration, invasion and cell-matrix adhesion by human monopolar spindle-one-binder 2.

Human monopolar spindle-one-binder 2 (hMOB2) is a member of the hMOB family of proteins, and it has been reported to regulate the nuclear-Dbf2-related kinase (NDR) activation. However, the function of hMOB2 expression in tumor cell adhesion and motility has not been addressed. Herein, the lentiviral-mediated overexpression and the knockdown of hMOB2 in HepG2 and SMMC-7721 cells was established.