S-modified NiFe-phosphate hierarchical hollow microspheres for efficient industrial-level seawater electrolysis.

For sustained hydrogen generation from seawater electrolysis, an efficient and specialized catalyst must be designed to cope with the slow anode reaction and chloride ions (Cl-) corrosion. In this work, an S-modified NiFe-phosphate with hierarchical and hollow microspheres was grown on the NiFe foam skeleton (S-NiFe-Pi/NFF), acting as a bifunctional catalyst to enable industrial-scale seawater electrolysis. The introduction of S distorted the lattice of NiFe-phosphate and regulated the local electronic environment around Ni/Fe active metal, both of which enhanced the electrocatalytic activity. Additionally, the existence of phosphate groups repelled Cl- on the surface and enhanced corrosion resistance, enabling stable long-term operation in seawater. The double-electrode electrolyzer composed of the hollow-structured S-NiFe-Pi/NFF as both cathode and anode exhibited a potential of 1.68 V at 100 mA cm-2 for seawater electrolysis. Particularly, to achieve industrial requirements of 500 mA cm-2, it only required a low cell voltage of 1.8 V and demonstrated a consistent response over 100 h, which outperformed the pair of Pt/C || IrO2. This study provides a feasible idea for the preparation of electrocatalysts that are with both highly activity and corrosion resistance, which is crucial for the implementation of industrial-scale seawater electrolysis.

Novel angiotensin-converting enzyme and pancreatic lipase oligopeptide inhibitors from fermented rice bran.

This study determined the inhibitory activity of oligopeptides against angiotensin-converting enzyme (ACE) and pancreatic lipase through in vitro tests, molecular docking, and enzyme inhibition. The results showed that the IC50 of GLLGY, HWP, and VYGF for ACE inhibition was 1 mg/mL, and the IC50 of HWP for pancreatic lipase was 3.95 mg/mL. Molecular docking revealed that the binding energies between GLLGY, HWP, and VYGF and ACE were -9.0, -8.4, and -9.2 kcal/mol, respectively. The binding free energy between HWP and pancreatic lipase was -7.3 kcal/mol. GLLGY, HWP, and VYGF inhibited ACE compentitively. HWP inhibited pancreatic lipase through non-competition. in vitro simulated gastrointestinal digestion, the three oligopeptides still had inhibitory activity and low toxicity. The results revealed that the peptides GLLGY, HWP, and VYGF may be suitable candidates for further research on ACE inhibition, and HWP may be a suitable candidate for studying pancreatic lipase inhibition.

Fast and sensitive graphene oxide-DNAzyme-based biosensor for Vibrio alginolyticus detection.

DNAzymes have been widely and effectively used for the detection of pathogenic bacteria, which pose a serious public health threat. However, the rapid and cost-effective detection of such bacteria remains a major challenge. In this study, we successfully selected Vibrio alginolyticus-specific DNAzymes. The activity of the candidates was assessed via fluorescence intensity and gel electrophoresis. The DNAzyme DT1 had a detection limit of 31 CFU/ml for V. alginolyticus and exhibited high specificity. Graphene oxide (GO) was used to develop a DNAzyme-based fluorescent sensor for the detection of V. alginolyticus, which significantly improved detection performance and shortened the reaction time as little as 10 s. The proposed method was then validated using crab, shrimp, fish, clam, and oyster samples. This study thus provides a new method for the rapid and sensitive detection of V. alginolyticus.

Anti-Helicobacter pylori Activity of a Lactobacillus sp. PW-7 Exopolysaccharide.

Helicobacter pylori is a cause of gastric cancer. We extracted the exopolysaccharide (EPS) of Lactobacillus plajomi PW-7 for antibacterial activity versus H. pylori, elucidating its biological activity and structural characteristics. The minimum inhibitory concentration (MIC) of EPS against H. pylori was 50 mg/mL. Disruption of the cell membranes of pathogenic bacteria by EPS was indicated via the antibacterial mechanism test and confirmed through electron microscopy. EPS also has antioxidant capacity. The IC50 of EPS for 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical, superoxide anions, and hydroxyl radicals were 300 µg/mL, 180 µg/mL, and 10 mg/mL, respectively. The reducing power of EPS was 2 mg/mL, equivalent to 20 µg/mL of ascorbic acid. EPS is a heteropolysaccharide comprising six monosaccharides, with an approximate molecular weight of 2.33 × 104 Da. Xylose had a significant effect on H. pylori. EPS from L. plajomi PW-7 showed potential as an antibacterial compound and antioxidant, laying a foundation for the development of EPS-based foods.

Nickel Boride/Boron Carbide Particles Embedded in Boron-Doped Phenolic Resin-Derived Carbon Coating on Nickel Foam for Oxygen Evolution Catalysis in Water and Seawater Splitting.

Electrolysis of seawater can be a promising technology, but chloride ions in seawater can lead to adverse side reactions and the corrosion of electrodes. A new transition metal boride-based self-supported electrocatalyst was prepared for efficient seawater electrolysis by directly soaking nickel foam (NF) in a mixture of phenolic resin (PR) and boron carbide (B4 C), followed by an 800 °C annealing. During PR carbonization process, the reaction of B4 C and NF generated nickel boride (Nix B) with high catalytic activity, while PR-derived carbon coating was doped with boron atoms from B4 C (B-CPR ). The B-CPR coating fixed Nix B/B4 C particles in the frames and holes to improve the space utilization of NF. Meanwhile, the B-CPR coating effectively protected the catalyst from the corrosion by seawater and facilitates the transport of electrons. The optimal Nix B/B4 C/B-CPR /NF required 1.50 and 1.58 V to deliver 100 and 500 mA cm-2 , respectively, in alkaline natural seawater for the oxygen evolution reaction.

Alkalic dextranase produced by marine bacterium Cellulosimicrobium sp. PX02 and its application.

The enzyme dextranase is widely used in the sugar and food industries, as well as in the medical field. Most land-derived dextranases are produced by fungi and have the disadvantages of long production cycles, low tolerance to environmental conditions, and low safety. The use of marine bacteria to produce dextranases may overcome these problems. In this study, a dextranase-producing bacterium was isolated from the Rizhao seacoast of Shandong, China. The bacterium, denoted as PX02, was identified as Cellulosimicrobium sp. and its growing conditions and the production and properties of its dextranase were investigated. The dextranase had a molecular weight of approximately 40 kDa, maximum activity at 40°C and pH 7.5, with a stability range of up to 45°C and pH 7.0-9.0. High-performance liquid chromatography showed that the dextranase hydrolyzed dextranT20 to isomaltotriose, maltopentaose, and isomaltooligosaccharides. Hydrolysis by dextranase produced excellent antioxidant effects, suggesting its potential use in the health food industry. Investigation of the action of the dextranase on Streptococcus mutans biofilm and scanning electron microscopy showed that it to be effective both for removing and inhibiting the formation of biofilms, suggesting its potential application in the dental industry.

Detection of Vibrio vulnificus in Seafood With a DNAzyme-Based Biosensor.

Vibrio vulnificus is an important pathogenic bacterium that is often associated with seafood-borne illnesses. Therefore, to detect this pathogen in aquatic products, a DNAzyme-based fluorescent sensor was developed for the in vitro detection of V. vulnificus. After screening and mutation, a DNAzyme that we denominated "RFD-VV-M2" exhibited the highest activity, specificity, and sensitivity. The limit of detection was 2.2 × 103 CFU/ml, and results could be obtained within 5-10 min. Our findings suggested that the target of DNAzyme RFD-VV-M2 was a protein with a molecular weight between 50 and 100 kDa. The proposed biosensor exhibited an excellent capacity to detect marine products contaminated with V. vulnificus. Therefore, our study established a rapid, simple, sensitive, and highly specific detection method for V. vulnificus in aquatic products.

Rapid Detection of Helicobacter pylori by the Naked Eye Using DNA Aptamers.

Helicobacter pylori was first isolated from gastritis patients by Barry J. Marshall and J. Robin Warren in 1982, and more than 90% of duodenal ulcers and about 80% of gastric ulcers are caused by H. pylori infection. Most detection methods require sophisticated instruments and professional operators, making detection slow and expensive. Therefore, it is critical to develop a simple, fast, highly specific, and practical strategy for the detection of H. pylori. In this study, we used H. pylori as a target to select unique aptamers that can be used for the detection of H. pylori. In our study, we used random ssDNA as an initial library to screen nucleic acid aptamers for H. pylori. We used binding rate and the fluorescence intensity to identify candidate aptamers. One DNA aptamer, named HPA-2, was discovered through six rounds of positive selection and three rounds of negative selection, and it had the highest affinity constant of all aptamers tested (K d = 19.3 ± 3.2 nM). This aptamer could be used to detect H. pylori and showed no specificity for other bacteria. Moreover, we developed a new sensor to detect H. pylori with the naked eye for 5 min using illumination from a hand-held flashlight. Our study provides a framework for the development of other aptamer-based methods for the rapid detection of pathogenic bacteria.

Alterations of gut microbiota contribute to the progression of unruptured intracranial aneurysms.

Unruptured intracranial aneurysm (UIA) is a life-threatening cerebrovascular condition. Whether changes in gut microbial composition participate in the development of UIAs remains largely unknown. We perform a case-control metagenome-wide association study in two cohorts of Chinese UIA patients and control individuals and mice that receive fecal transplants from human donors. After fecal transplantation, the UIA microbiota is sufficient to induce UIAs in mice. We identify UIA-associated gut microbial species link to changes in circulating taurine. Specifically, the abundance of Hungatella hathewayi is markedly decreased and positively correlated with the circulating taurine concentration in both humans and mice. Consistently, gavage with H. hathewayi normalizes the taurine levels in serum and protects mice against the formation and rupture of intracranial aneurysms. Taurine supplementation also reverses the progression of intracranial aneurysms. Our findings provide insights into a potential role of H. hathewayi-associated taurine depletion as a key factor in the pathogenesis of UIAs.

A squaramide-based metal-organic framework as a luminescent sensor for the detection of lactose in aqueous solution and in milk.

A novel squaramide-containing metal-organic framework (MOF) has been designed and synthesized, which represents the first example of the luminescence selective detection of lactose over other monosaccharides and disaccharides. It was also used for the quantitative determination of lactose in milk.