Objective: To develop effective alternatives to natural enzymes, it is crucial to develop nanozymes that are economical, resource efficient, and environmentally conscious. Carbon nanomaterials that have enzyme-like activities have been extensively developed as substitutes for traditional enzymes. Methods: Carbide-derived carbons (CDCs) were directly synthesized via a one-step electrochemical method from a MAX precursor using an ammonium bifluoride electrolyte at ambient conditions. The CDCs were characterized by systematic techniques. Results: CDCs showed bienzyme-like activities similar to that of peroxidase and superoxide dismutase. We systematically studied the dependence of CDC enzyme-like activity on different electrolytes and electrolysis times to confirm activity dependence on CDC content. Additionally, the synthesis mechanism and CDC applicability were elaborated and demonstrated, respectively. Conclusion The demonstrated synthesis strategy eliminates tedious intercalation and delamination centrifugation steps and avoids using high concentrations of HF, high temperatures, and halogen gases. This study paves the way for designing two-dimensional material-based nanocatalysts for nanoenzyme and other applications.
Ammonium Compounds/chemical synthesis* ; Carbon/chemistry* ; Electrochemical Techniques ; Enzymes ; Fluorides/chemical synthesis* ; Humans ; Nanostructures ; Oxidation-Reduction

Brown algae are well known as a source of biologically active compounds, especially those having antioxidant activities, such as phlorotannins. In this study we examined the antioxidant activities of crude phlorotannins extracts (CPEs) obtained from Sargassum hemiphyllum (SH) and fractionated according to the molecular weights. When CPEs were administrated at a dose of 30 mg/kg to Kunming mice pre-treated with carbon tetrachloride (CCl4), the levels of oxidative stress indicators in the liver, kidney and brain were significantly reduced in vivo. All the components of various molecular weight fractions of CPEs exhibited greater scavenging capacities in clearing hydroxyl free radical and superoxide anion than the positive controls gallic acid, vitamin C and vitamin E. Particularly, the components greater than 30 kD obtained from ethyl acetate phase showed the highest antioxidant capacities. These results indicated that SH is a potential source for extracting phlorotannins, the algal antioxidant compounds.
Animals ; Antioxidants ; isolation & purification ; pharmacology ; Ascorbic Acid ; pharmacology ; Brain ; drug effects ; metabolism ; pathology ; Carbon Tetrachloride ; antagonists & inhibitors ; toxicity ; Carbon Tetrachloride Poisoning ; drug therapy ; metabolism ; pathology ; Chemical Fractionation ; methods ; Gallic Acid ; pharmacology ; Hydroxyl Radical ; antagonists & inhibitors ; metabolism ; Kidney ; drug effects ; metabolism ; pathology ; Liquid-Liquid Extraction ; methods ; Liver ; drug effects ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred Strains ; Oxidation-Reduction ; Oxidative Stress ; drug effects ; Phaeophyta ; chemistry ; Sargassum ; chemistry ; Superoxides ; antagonists & inhibitors ; metabolism ; Tannins ; isolation & purification ; pharmacology ; Vitamin E ; pharmacology

Non-steroidal anti-inflammatory drugs (NSAIDs) induce tissue damage and oxidative stress in animal models of stomach damage. In the present study, the protective effects of wheat peptides were evaluated in a NSAID-induced stomach damage model in rats. Different doses of wheat peptides or distilled water were administered daily by gavage for 30 days before the rat stomach damage model was established by administration of NSAIDs (aspirin and indomethacin) into the digestive tract twice. The treatment of wheat peptides decreased the NSAID-induced gastric epithelial cell degeneration and oxidative stress and NO levels in the rats. Wheat peptides significantly increased the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and decreased iNOS activity in stomach. The mRNA expression level of μ-opioid receptor was significantly decreased in wheat peptides-treated rats than that in in the control rats. The results suggest that NSAID drugs induced stomach damage in rats, wchih can be prevented by wheat peptides. The mechanisms for the protective effects were most likely through reducing NSAID-induced oxidative stress.
Animals ; Anti-Inflammatory Agents, Non-Steroidal ; adverse effects ; Antioxidants ; pharmacology ; Aspirin ; adverse effects ; Gastric Mucosa ; drug effects ; Gene Expression ; Glutathione Peroxidase ; drug effects ; Indomethacin ; adverse effects ; Male ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase ; chemical synthesis ; Oxidation-Reduction ; Oxidative Stress ; drug effects ; Plant Proteins ; pharmacology ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, Opioid, mu ; drug effects ; Stomach ; drug effects ; Superoxide Dismutase ; drug effects ; Triticum ; chemistry

In the present study, a series of 13-β-elemene ester derivatives were designed and prepared, and their antioxidant activity was investigated in the H2O2-treated human umbilical vein endothelial cells (HUVECs). Among the test compounds, the dimer compounds 5v and 5w exhibited the most potent antioxidant activity with significant ROS suppression being observed. Both compounds markedly inhibited the H2O2-induced changes in various biochemical substances, such as superoxide dismutase (SOD), malonyldialdehyde (MDA), nitric oxide (NO), and lactic dehydrogenase (LDH), which were superior to that of the positive control vitamin E. Further more, they did not produce any obvious cytotoxicity, but increased the viability of HUVECs injured by H2O2 in a dose-dependent manner. Additionally, compound 5w, designed as a prodrug-like compound, showed improved stability relative to compound 4 in vitro.
Antioxidants ; chemical synthesis ; metabolism ; pharmacology ; Cells, Cultured ; Curcuma ; chemistry ; Drug Stability ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Endothelium, Vascular ; cytology ; drug effects ; metabolism ; Human Umbilical Vein Endothelial Cells ; drug effects ; Humans ; Hydrogen Peroxide ; metabolism ; Malondialdehyde ; metabolism ; Nitric Oxide ; metabolism ; Oxidation-Reduction ; Oxidative Stress ; drug effects ; Phthalic Acids ; chemical synthesis ; pharmacology ; Sesquiterpenes ; chemical synthesis ; pharmacology ; Succinates ; chemical synthesis ; pharmacology ; Superoxide Dismutase ; metabolism

Transforming technology for semi-synthesized isocorydione from the natural product ofisocorydine was studied. The factors affecting on the reaction yield were investigated. UV spectrophotometry was used to indicate the semi-synthesized yield of isocorydione. The optimum reaction conditions were determined as following: reacting for 12 h in the solution of sodium dihydrogen phosphate at pH 10, the temperature was 25 degrees C and the ratio of isocorydine to Fremy's radical was 1 : 2. Under the optimum conditions, the yield could reach up to 50.0%. The molecular structure of isocorydione was elucidated by X-ray single-crystal diffraction analysis for the first time.
Antineoplastic Agents, Phytogenic ; chemical synthesis ; chemistry ; isolation & purification ; Aporphines ; chemical synthesis ; chemistry ; isolation & purification ; Crystallography, X-Ray ; Hydrogen-Ion Concentration ; Molecular Structure ; Nitroso Compounds ; Oxidation-Reduction ; Papaveraceae ; chemistry ; Plants, Medicinal ; chemistry ; Spectrophotometry, Ultraviolet ; Temperature ; X-Ray Diffraction

In order to select better seeding sludge and promote start-up of Anammox reactors, we studied the start-up performances of three Anammox-EGSB bioreactors inoculated with anaerobic methanogenic sludge (AMS) (R1), Fresh Anammox sludge (FAS) (R2) and stored Anammox sludge (SAS) (R3), respectively. Results showed that these three seeding sludges could start up Anammox-EGSB bioreactors successfully, but the start-up progresses showed different characteristics. The start-up course of R1 could be divided into three phases including autolysis phase (15 d), lag phase (54 d) and activity elevation phase (40 d). However, the start-up courses of R2 and R3 only included lag phase (2 d and 12 d, respectively) and activity elevation phase (15 d and 57 d, respectively). Besides, the performance of R3 was better than that of R1, but worse than that of R2. Furthermore, bathing the Anammox sludge in the effluent of bioreactors was a convenient and effective way to keep the activity of the Anammox sludge. The ammonia removal efficiency, percentage of denitrification and the stoichiometric ratios of NH4(+)-Nr/NO2(-)-Nr and NO3(-)-Np/NH4(+)-Nr could serve as indicators to monitor the start-up of Anammox bioreactors.
Bacteria, Anaerobic ; metabolism ; Biodegradation, Environmental ; Bioreactors ; microbiology ; Nitrogen ; metabolism ; Oxidation-Reduction ; Quaternary Ammonium Compounds ; metabolism ; Sewage ; chemistry ; Water Pollutants, Chemical ; metabolism

We report a case of giant pancreatic pseudocyst after acute pancreatitis, successfully treated with saikokeishitokabushi. A 71-year-old man had been undergoing treatment in our hospital for cerebral infarction and diabetes. He was complicated with acute pancreatitis. He received conservative treatment, showing a tendency toward symptomatic improvement, although abdominal pain and anorexia subsequently developed. A giant pancreatic pseudocyst was identified on abdominal computed tomography. Therefore, we administered saikokeishitokabushi without changing the other oral medication. Many of his symptoms disappeared, and cyst reduction was noted. saikokeishitokabushi is generally prescribed for epigastric pain or anorexia after febrile illness. In this case, it is thought that saikokeishitokabushi exhibited an action leading to cyst reduction.
Acute pancreatitis ; Large ; Treated with ; Reduction (chemical) ; Pancreatic polypeptide, avian

Recent studies showed that high biocompatibility and reduction of uremic toxin contributed to the improvement of freatment outcome in hemodialysis patients.Therefore, a high-flux membrane dialyzer, especially polysulfone (PS) membrane, was generally used in dialysis. However, it was suggested that the higher efficiency of reduction in uremic toxins might cause an increase in the albumin leakage through the dialyzer membrane during dialysis, resulting in a decrease in serum albumin concentration. In this study, we used two different dialyzer membranes with high biocompatibility, namely, ethylenevinylalcohol (EVAL) membrane and improved PS membrane with a very lower leakage of serum albumin. After using these two types of mambrane of six straight months, we examined the effect of each dialyzer membrane characteristic on the serum total protein and albumin concentration. The reduction rates of each uremic solute and serum total protein concentration were significantly higher. The serum albumin concentration and its rate of change with the passing of time tended to increase in the case of the PS membrane. But in the case of EVAL membrane, these values tended to decrease. These results suggested that the differences in the changes in the serum total protein and albumin concentration might result from the differences in the efficiency of the reduction of uremic toxins. Therefore, it is necessary to consider the usage of the dialyzer membrane with a higher reduction of uremic solutes and a lower leakage of serum albumin to add to the higher biocompatibility specially in hemodialysis patients with hypoproteinemia.
Membranes ; Concentration ; Reduction (chemical) ; Serum Albumin ; Hemodialysis

OBJECTIVETo investigate the variation of the corrosion resistance of micro-arc oxidation film on titanium by electrochemical methods in simulated body fluid.

METHODSMicro-arc oxidation film was formed on the titanium surface using micro-arc oxidation. The morphology was observed with scanning electron microscopy (SEM) and the phase composition was analyzed using X-ray diffraction (XRD). Polarization curves and electrochemical impedance spectroscopy (EIS) in simulated body fluid were examined with electrochemical methods.

RESULTSOn the titanium surface with micro-arc oxidation, the film consisted of many volcanic micropores. The film formed was a titanium dioxide (TiO(2)) with peaks for both anatase and rutile phases. In addition, hydroxylapatite was also observed. The self-corrosion potential and self-corrosion current density of titanium with micro-arc oxidation film were -0.255 V and 0.80 microA/cm(2) respectively, while those of untreated titanium were -0.358 V and 0.55 microA/cm(2). Electrochemical impedance spectroscopy confirmed the model of equivalent circuits reasonable.

CONCLUSIONSThe results of electrochemical examinations indicate that micro-arc oxidation film increases the corrosion resistance of titanium.

Corrosion ; Durapatite ; chemical synthesis ; Electrochemistry ; Oxidation-Reduction ; Titanium ; chemistry

OBJECTIVETo develop a coated electrode of immobilized denitrificants and to evaluate the performance of a bioelectrochemical reactor to enhance and control denitrification.

METHODSDenitrifying bacteria were developed by batch incubation and immobilized with polyvinyl alcohol (PVA) on the surface of activated carbon fiber (ACF) to make a coated electrode. Then the coated electrode (cathode) and graphite electrode (anode) were transferred to the reactor to reduce nitrate.

RESULTSAfter acclimated to the mixtrophic and autotrophic denitrification stages, the denitrifying bacteria could use hydrogen as an electron donor to reduce nitrate. When the initial nitrate concentration was 30.2 mg NO3- -N / L, the denitrification efficiency was 57.3% at an applied electric current of 15 mA and a hydraulic retention time (HRT) of 12 hours. Correspondingly, the current density was 0.083 mA/cm2. The nitrate removal rate of the reactor was 34.4 g NO3- -N/m3 x d, and the surface area loading was 1.34 g NO3- -N / m2 x d.

CONCLUSIONThe coated electrode may keep high quantity of biomass, thus achieving a high denitrification rate. Denitrification efficiencies are related to HRT, current density, oxidation reduction potential (ORP), dissolved oxygen (DO), pH value, and temperature.

Adsorption ; Bacteria ; metabolism ; Biodegradation, Environmental ; Bioreactors ; Carbon ; chemistry ; Electrodes ; Electrolysis ; Nitrates ; metabolism ; Oxidation-Reduction ; Oxygen ; Polyvinyl Alcohol ; Temperature ; Time Factors ; Water Pollutants, Chemical ; metabolism ; Water Purification ; methods