Ir Single Atoms Boost Metal-Oxygen Covalency on Selenide-Derived NiOOH for Direct Intramolecular Oxygen Coupling.

This investigation probes the intricate interplay of catalyst dynamics and reaction pathways during the oxygen evolution reaction (OER), highlighting the significance of atomic-level and local ligand structure insights in crafting highly active electrocatalysts. Leveraging a tailored ion exchange reaction followed by electrochemical dynamic reconstruction, we engineered a novel catalytic structure featuring single Ir atoms anchored to NiOOH (Ir1@NiOOH). This novel approach involved the strategic replacement of Fe with Ir, facilitating the transition of selenide precatalysts into active (oxy)hydroxides. This elemental substitution promoted an upward shift in the O 2p band and intensified the metal-oxygen covalency, thereby altering the OER mechanism toward enhanced activity. The shift from a single-metal site mechanism (SMSM) in NiOOH to a dual-metal-site mechanism (DMSM) in Ir1@NiOOH was substantiated by in situ differential electrochemical mass spectrometry (DEMS) and supported by theoretical insights. Remarkably, the Ir1@NiOOH electrode exhibited exceptional electrocatalytic performance, achieving overpotentials as low as 142 and 308 mV at current densities of 10 and 1000 mA cm-2, respectively, setting a new benchmark for the electrocatalysis of OER.

Efficient Acidic Photoelectrochemical Water Splitting Enabled by Ru Single Atoms Anchored on Hematite Photoanodes.

Photoelectrochemical (PEC) water splitting in acidic media holds promise as an efficient approach to renewable hydrogen production. However, the development of highly active and stable photoanodes under acidic conditions remains a significant challenge. Herein, we demonstrate the remarkable water oxidation performance of Ru single atom decorated hematite (Fe2O3) photoanodes, resulting in a high photocurrent of 1.42 mA cm-2 at 1.23 VRHE under acidic conditions. Comprehensive experimental and theoretical investigations shed light on the mechanisms underlying the superior activity of the Ru-decorated photoanode. The presence of single Ru atoms enhances the separation and transfer of photogenerated carriers, facilitating efficient water oxidation kinetics on the Fe2O3 surface. This is achieved by creating additional energy levels within the Fe2O3 bandgap and optimizing the free adsorption energy of intermediates. These modifications effectively lower the energy barrier of the rate-determining step for water splitting, thereby promoting efficient PEC hydrogen production.

Modulating the electronic structure of CoS2 by Sn doping boosting urea oxidation for efficient alkaline hydrogen production.

Urea electrocatalytic oxidation afforded by renewable energies is highly promising to replace the sluggish oxygen evolution reaction in water splitting for hydrogen production while realizing the treatment of urea-rich waste water. Therefore, the development of efficient and cost-effective catalysts for water splitting assisted by urea is highly desirable. Herein, Sn-doped CoS2 electrocatalysts were reported with the engineered electronic structure and the formation of Co-Sn dual active sites for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER), respectively. Consequently, the number of active sites and the intrinsic activity were enhanced simultaneously and the resultant electrodes exhibited outstanding electrocatalytic activity with a very low potential of 1.301 V at 10 mA·cm-2 for UOR and an overpotential of 132 mV at 10 mA·cm-2 for HER. Therefore, a two-electrode device was assembled by employing Sn(2)-CoS2/CC and Sn(5)-CoS2/CC and the constructed cell required only 1.45 V to approach a current density of 10 mA·cm-2 along with good durability for at least 95 h assisted by urea. More importantly, the assembled electrolyzer can be powered by commercial dry battery to generate numerous gas bubbles on the surface of the electrodes, demonstrating the high potential of the as-fabricated electrodes for applications in hydrogen production and pollutant treatment at a low-voltage electrical energy input.

PLA2 mediates the innate immune response in Asian corn borer, Ostrinia furnacalis.

The eicosanoid signaling pathway mediates insect immune reactions to a wide range of stimuli. This pathway begins with the biosynthesis of arachidonic acid (AA) from the hydrolysis of phospholipids catalyzed by phospholipase A2 (PLA2 ). We report here that the PLA2 inhibitor, dexamethasone (DEX), impaired the innate immune response including nodulation, encapsulation, and melanization in Ostrinia furnacalis larvae, while AA partially reversed these effects of DEX. We cloned a full-length complementary DNA encoding a PLA2 , designated as OfsPLA2 , from O. furnacalis. The open reading frame of OfsPLA2 encodes a 195-amino acid residue protein with a 22-residue signal peptide. Sequence alignment analyses indicated that O. furnacalis PLA2 might be a Group III secretory PLA2 . The highest transcript levels of OfsPLA2 were detected in the fat body, and its transcript levels increased dramatically after infection with Escherichia coli, Micrococcus luteus, or Beauveria bassiana. Recombinant OfsPLA2 significantly induced prophenoloxidase (PPO) activation in larval hemolymph in the presence of Ca2+ and encapsulation of agarose beads. Injection of recombinant OfsPLA2 into larvae resulted in increased transcript levels of attacin, defencin, and moricin-3 genes. Our results demonstrate the involvement of the eicosanoid signaling pathway in the innate immune response of O. furnacalis larvae and provide new information about the roles of O. furnacalis secretory PLA2 in activating PPO and antimicrobial peptide production.

Cloning and promoter activity analyses of the promoter of 2'-deoxymugineic acid (DMA) secretion channel gene YS3 in maize.

Iron (Fe) deficiency is a world-wide serious agricultural problem. Maize secretes 2'-deoxymugineic acid (DMA) to uptake and utilize Fe from the soil. In order to explore the gene expression patterns of the DMA secretion channel gene YS3, we cloned the 2813 bp YS3 promoter, and constructed the plant expression vector pCAMBIA-YS3GUS. The promoter contains a lot of TATA-boxes and CAAT-boxes, and cis-acting regulatory elements such as the light responsive elements and the hormone responsive elements. Arabidopsis was transformed via Agrobacterium tumefacients-mediated procedures to obtain the pYS3::GUS transgenic plants, which were confirmed by GUS staining. Then, the stained tissue was observed using paraffin section methods and the YS3 promoter activity was also analyzed. We found that the promoter could drive GUS gene expression specifically in the root epidermal cells. Mechanical damage could activate the promoter, and drive the GUS gene expression adjacent to the damage sites. Our results provide a molecular basis to understand the DMA secretion process in maize.

[Clinical features and management of complete heart block after transaortic extended septal myectomy in patients with hypertrophic obstructive cardiomyopathy].

OBJECTIVE: To analyze the clinical features, precaution and management of complete heart block (CHB) after transaortic extended septal myectomy operation (extended Morrow procedure) in patients with hypertrophic obstructive cardiomyopathy (HOCM). METHODS: From October 1996 to December 2011, 10[6 men; mean age (45.4 ± 15.8) years, range 13-60 years] out of 160 consecutive HOCM patients underwent extended Morrow procedure developed CHB postoperatively. Their clinical data were retrospectively analyzed. Baseline transthoracic echocardiography showed that the left ventricular outflow tract (LVOT) gradients was from 68 to 149 (105.1 ± 25.9) mm Hg (1 mm Hg = 0.133 kPa), ECG showed right bundle branch block in 5 patients and atrial fibrillation, atrial premature beats or ST-T segment changes in other 5 patients. Besides extended Morrow procedure, concomitant surgical procedures included mitral valve replacement (MVR) in 2 (2/10) and MVR plus coronary artery bypass grafting in another 2 (2/10) patients. Follow-up data were obtained by subsequent clinic visits in outpatient department and telephone interviews. RESULTS: The in-hospital mortality was 20% (these two patients died of low cardiac output syndrome and multiple organs failure). Four patients underwent MVR simultaneously survived the operation. Postoperative echocardiography demonstrated a reduced LVOT gradient[(13.6 ± 9.7) mm Hg, P < 0.001]. Permanent pacemakers were implanted in all 8 survived patients at 6 days to 7 months after operation. No other severe complications were observed. During follow-up [from 4 to 72 (19.4 ± 22.1) months], there was no death, 1 patient readmitted to our center at 71 months post operation to change the pacemaker because of low voltage of previously implanted pacemaker. Physical capacity and quality of life improved significantly post operation in these 8 patients. The NYHA functional class remained at I-II post operation and during follow up. CONCLUSIONS: CHB is a severe complication after extended Morrow procedure for patients with HOCM and timely permanent pacemaker implantation is mandatory for patients with post procedure CHB.

Intramammary expression and therapeutic effect of a human lysozyme-expressing vector for treating bovine mastitis.

To develop a gene therapy strategy for treating bovine mastitis, a new mammary-specific vector containing human lysozyme (hLYZ) cDNA and kanamycin resistance gene was constructed for intramammary expression and clinical studies. After one time acupuncture or intracisternal infusion of healthy cows with 400 microg of the p215C3LYZ vector, over 2.0 microg/ml of rhLYZ could be detected by enzymatic assay for about 3 weeks in the milk samples. Western blotting showed that rhLYZ secreted into milk samples from the vector-injected cows had molecular weight similar to that of the natural hLYZ in human colostrums. Twenty days after the primary injection, the quarters were re-injected with the same vector by quarter acupuncture and even higher concentrations of rhLYZ could be detected. Indirect competitive ELISA of milk samples showed that the vector injection did not induce detectable humoral immune response against hLYZ. Clinical studies showed that twice acupuncture of quarters with the p215C3LYZ vector had overt therapeutic effect on clinical and subclinical mastitis previously treated with antibiotics, including disappearance of clinical symptoms and relatively high microbiological cure rates. These data provide a solid rationale for using the vector to develop gene therapy for treating bovine mastitis.