Study on NO(2) absorption aimed at seeking a better NO(2) absorption chemical at pH 4.5 approximately 7.0 for application to existing wet flue gas desulfurization (FGD). The results from the double-stirred reactor indicated that ascorbic acid has very high absorption rate at this pH range. The rate constant of ascorbic acid reaction with NO(2) (0 approximately 1,000 x 10(-6) mol/mol) is about 3.54 x 10(6) mol/(Ls) at pH 5.4 approximately 6.5 at 55 degrees C.
Absorption ; Air Pollutants ; chemistry ; isolation & purification ; Ascorbic Acid ; chemistry ; Nitric Oxide ; chemistry ; isolation & purification

The pure titanium disks were divided into three groups and etched for 30 minutes with HNO3, hot H2SO4/H2O2 or hot H2SO4/HCl respectively. The treated disks were studied and analyzed with scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The disks etched with HNO3 had a smooth surface, while those etched with hot H2SO4/H2O2 or hot H2SO4/HCl had rough surfaces, and the surface etched with hot H2SO4/HCl had larger micropores. The XPS analysis demonstrated that the main elements of the surface in three groups were titanium, oxygen and carbon. The carbon concentration was the lowest on the surface etched with hot H2SO4/H2O2 and the highest on that etched with hot H2SO4/HCl. The substances were TiO2, Ti2O3, TiO and metal Ti on the surface etched with HNO3 or hot H2SO4/H2O2. Only TiO2 was detected on the surface etched with hot H2SO4/HCl.
Hydrochloric Acid ; Hydrogen Peroxide ; Metallurgy ; methods ; Nitric Acid ; Oxides ; Sulfuric Acids ; Surface Properties ; Titanium ; chemistry

OBJECTIVETo develop suitable methods for safety destruction of tetramethylene disulfotetramine (TETS) and the medical wastes polluted by TETS.

METHODSThe chemical stability of TETS was evaluated under the conditions of acid, alkali and high temperature. TETS was treated with sodium hydroxide, hydrochloric acid, sulfuric acid and nitric acid under various treatment conditions, i.e. concentration, temperature and time, followed by determining remaining TETS using gas chromatograms to estimating the degradation efficiency of TETS. TETS was put into ampoule and heated under the different conditions of temperature and time. After heat treatment, TETS residue was determined. For evaluating the absorption factor of active carbon to TETS in water and blood, active carbon was added into the water and blood with content of TETS, incubated at room temperature for 24 hours, and then determined the remaining TETS in water and blood.

RESULTSThe complete degradation of TETS was achieved by one of the following treatments: heating with 6.0 mol/L hydrochloric acid at 100 degrees C for half an hour, heating with 3.0 mol/L hydrochloric acid or 6.0 mol/L sodium hydroxide at 100 degrees C for 3 hours, mixing with concentrated sulfuric acid or nitric acid at room temperature for 24 hours, and dry heating at 300 degrees C for 4.5 hours. Active carbon showed a marked effectiveness in absorbing the TETS in blood and water, with the mean absorption efficiency of over 90%.

CONCLUSIONSThe results of this study suggest that TETS powder should be degraded by acid or alkali, and that the solid medical wastes polluted by TETS should be destroyed at high temperature. For the blood and water having contents of TETS, the active carbon should be used as to absorbing the TETS and then be destroyed at high temperature.

Bridged-Ring Compounds ; chemistry ; Capillary Electrochromatography ; Chromatography, Gas ; Hydrochloric Acid ; chemistry ; Medical Waste Disposal ; methods ; Nitric Acid ; chemistry ; Sodium Hydroxide ; chemistry ; Sulfuric Acids ; chemistry ; Temperature

To find novel antihepatitis drugs, a series of nitrate-oleanolic acid (OA) hybrids (10a, 10b, 11a-11e and 12a-12c) were designed and synthesized on the basis of previous studies using OA as lead compound, which is widely found in natural plants and liver-specific metabolism. In the present study, ten novel NO-releasing derivatives of OA were synthesized by connecting nitrate to the OA-3-OH through varying lengths of linkers containing antioxidants which were designed to increase the ability of these target compounds to scavenge free radicals. The structures of these objective compounds were determined by IR, MS, 1H NMR and elemental analysis. Their protective effects on anti-Fas mediated HepG2 cell apoptosis were in vitro evaluated by LDH assay. Compound 12a is the most potent inhibitor. Its effect on anti-Fas mediated HepG2 cell apoptosis and amount of NO-releasing in vitro are similar to those of positive control NCX-1000.
Antioxidants ; chemistry ; Apoptosis ; drug effects ; Hep G2 Cells ; Humans ; Nitrates ; chemical synthesis ; chemistry ; pharmacology ; Nitric Oxide ; metabolism ; Nitric Oxide Donors ; chemistry ; Oleanolic Acid ; chemical synthesis ; chemistry ; pharmacology ; Structure-Activity Relationship ; Ursodeoxycholic Acid ; analogs & derivatives ; pharmacology

Considering that high levels of nitric oxide (NO) exert anti-cancer effect and the derivatives of oleanolic acid (OA) have shown potent anti-cancer activity, new O-vinyl diazeniumdiolate-based NO releasing derivatives (5a-l, 11a-l) of OA were designed, synthesized, and biologically evaluated in the present study. These derivatives could release different amounts of NO in liver cells. Among them, 5d, 5i, 5j, 11g, 11h, and 11j released more NO in SMMC-7721 cells and displayed stronger proliferative inhibition against SMMC-7721 and HepG2 cells than OA and other tested compounds. The most active compound 5j showed almost 20-fold better solubility than OA in aqueous solution, released larger amounts of NO in liver cancer cells than that in normal ones, and exhibited potent anti-hepatocellular carcinoma activity but little effect on the normal liver cells. The inhibitory activity against the cancer cells was significantly diminished upon addition of an NO scavenger, suggesting that NO may contribute, at least in part, to the activity of 5j.
Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Apoptosis ; drug effects ; Azo Compounds ; chemistry ; Carcinoma, Hepatocellular ; drug therapy ; pathology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Drug Screening Assays, Antitumor ; Hep G2 Cells ; Hepatocytes ; drug effects ; metabolism ; pathology ; Humans ; Liver Neoplasms ; drug therapy ; pathology ; Nitric Oxide ; chemistry ; Nitric Oxide Donors ; chemical synthesis ; chemistry ; pharmacology ; Oleanolic Acid ; analogs & derivatives ; chemistry ; pharmacology

OBJECTIVE: To investigate the advantages of nitric acid digestion method and its differences with the traditional method. METHODS: Ethanol was used to fully fix the testing sample. About 80-100 g of the testing samples were cut into pieces and digested with nitric acid. It was then centrifuged and washed to remove organic components. Smears were prepared and examined under the light microscope. RESULTS: The diatom had been identified with clear striations, counted conveniently and classified easily. CONCLUSION The improved nitric acid digestion method is not only simple with a higher successful rate of detection, but also can prevent interference from contamination. It can improve the stability of the experimental results, avoid harm to human and environment, and provide higher safety in the course of experiment.
Autopsy ; Diatoms/isolation & purification* ; Drowning ; Forensic Pathology ; Humans ; Kidney/metabolism* ; Liver/metabolism* ; Lung/metabolism* ; Nitric Acid/chemistry* ; Postmortem Changes ; Tissue Fixation/methods*

OBJECTIVETo observe the influence of intra-articular injection of sodium hyaluronate (SH) on the expression of inducible nitric oxide synthase (iNOS) in the synovium and nitric oxide (NO) content in synovial fluid of rabbits with traumatic osteoarthritis (OA).

METHODSSixteen white rabbits underwent unilateral anterior cruciate ligament transection and were randomly divided into 2 groups 5 weeks after the operation. Rabbits in the experimental group received intra-articular injection of 0.3 ml of 1% SH, once a week for 5 weeks. Animals in the control group were treated under the same conditions using physiological saline. All the animals were sacrificed at the 10th week after surgery. The mRNA expression of iNOS in the synovium was analyzed using reverse transcription-polymerase chain reaction. The content of NO in the synovial fluid was assayed.

RESULTSThe level of iNOS expression of the synovium in the experimental group was lower than that in control group (0.47+/-0.09 vs. 0.65+/-0.12, t equal to 3.45, P less than 0.01). Compared with control group, the content of NO decreased significantly in synovial fluid of SH injection group (134.11 micromolar/L +/- 12.47 micromolar/L vs. 152.17 micromolar/L +/- 15.69 micromolar/L, t equal to 2.55, P less than 0.05).

CONCLUSIONSSH significantly decreases the content of NO in the synovial fluid of rabbits with traumatic OA. SH may exert the effect on synovial fluid NO level as a result of the suppression of iNOS expression in the synovium. It may be one of the mechanisms of the therapeutic effect of SH on early traumatic OA.

Animals ; Anterior Cruciate Ligament Injuries ; Hyaluronic Acid ; pharmacology ; therapeutic use ; Nitric Oxide ; analysis ; Nitric Oxide Synthase Type II ; analysis ; Osteoarthritis ; drug therapy ; etiology ; metabolism ; Rabbits ; Random Allocation ; Synovial Fluid ; chemistry ; Synovial Membrane ; enzymology

OBJECTIVETo study the effects of extracts of ginkgo biloba (EGB) on the levels of nitric oxide (NO) and apoptosis in the retina induced by glutamate by intravitreal injection in adult rabbit.

METHODThe model of apoptosis in retina induced by glutamate by intravitreal injection was established in adult rabbit and EGB was retrobulbarly injected. The levels of NO were measured by spectrophotometer. Retina DNA fragmentation was determined by agarose gel electrophoresis.

RESULTThe levels of NO in retina in experiment groups were significantly increased compared with controls, after treatment with high dosage of EGB, and levels of NO was decreased to normal. They were not decreased by injection of small dosage of EGB. DNA fragmentation of retina apoptosis was detected in experiment groups and small dosage EGB groups.

CONCLUSIONThe retina apoptosis was induced by glutamate by intravitreal injection in adult rabbit and was inhibited by EGB that may be through blocking the generation of NO free radicals.

Animals ; Apoptosis ; drug effects ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Ginkgo biloba ; chemistry ; Glutamic Acid ; Male ; Nitric Oxide ; metabolism ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry ; Rabbits ; Random Allocation ; Retina ; cytology ; metabolism

OBJECTIVETo explore the effects of paeoniflorin on antagonising the delayed neuronal death (DND) induced by cerebral ischemia,and the relation between DND, cerebral tissue energy metabolism, nitric oxide (NO) and nitric oxide synthase (NOS).

METHODIncomplete cerebral ischemia induced was induced by ligating bilateral arteries carotis communis for 20 min followed by reperfusion 48 h in rats. The indexes including Na(+)-K(+)-ATPase activity, lactic acid content, Ca(2+)-ATPase, Mg(2+)-ATPase activity, NO content and NOS activity were determined in fore brain cortex at 48 h after reperfusion.

RESULTNa(+)-K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase activity were lowered (P < 0.01), NO level was decreased (P < 0.01), NOS activity dropped (P < 0.01) in cerebral tissue at 48h after reperfusion, but lactic acid level had no change. Paeoniflorin could prevent reduction of Na(+)-K(+)-ATPase activity (P < 0.05, P < 0.01), increase NO level (P < 0.01), enhance NOS activity (P < 0.01) at 48h after reperfusion.

CONCLUSIONDND induced by ischemia may be concerned with energy metabolism disorder and decrease of NO formation. Paeoniflorin may play the role of antagonising cerebral ischemia by adjusting cerebral energy metabolism and nitric oxide formation.

Animals ; Benzoates ; isolation & purification ; pharmacology ; Brain ; metabolism ; Brain Ischemia ; complications ; Bridged-Ring Compounds ; isolation & purification ; pharmacology ; Ca(2+) Mg(2+)-ATPase ; metabolism ; Calcium-Transporting ATPases ; metabolism ; Energy Metabolism ; Female ; Gerbillinae ; Glucosides ; isolation & purification ; pharmacology ; Lactic Acid ; metabolism ; Male ; Monoterpenes ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Paeonia ; chemistry ; Plants, Medicinal ; chemistry ; Reperfusion Injury ; etiology ; metabolism ; Sodium-Potassium-Exchanging ATPase ; metabolism

OBJECTIVETo study and compare the changes of toxicity of Euphorbia pekinensis, E. kansui and E. ebracteolata before and after being prepared by vinegar.

METHODSmall intestinal accentuation of mice and peritoneal macrophage NO release experiments were assessed to investigate the changes of toxicity of the three Chinese Medicines of Euphorbia before and after being prepared.

RESULTE. pekinensis, E. kansui and E. ebracteolata and vinegar can obviously promot small intestinal accentuation and peritoneal macrophage NO release with the intensity of toxicity in the order of E. kansui > E. pekinensis > E. ebracteolata. After being prepared with vinegar, the toxicity of the three medicines decreased obviously compared to crude one.

CONCLUSIONE. pekinensis, E. kansui and E. ebracteolata can induce inflammation and accelerate enterokinesis. After being prepared with vinegar, the irritation on Euphorbia decreased obviously.

Acetic Acid ; chemistry ; Animals ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; toxicity ; Euphorbia ; chemistry ; toxicity ; Female ; Intestine, Small ; drug effects ; metabolism ; Macrophages, Peritoneal ; drug effects ; metabolism ; Male ; Medicine, Chinese Traditional ; Mice ; Mice, Inbred ICR ; Nitric Oxide ; analysis ; metabolism ; Plant Roots ; chemistry ; toxicity ; Toxicity Tests