The interaction of salinity stress and plant residue quality on C mineralization kinetics in soil is not well understood. A laboratory experiment was conducted to study the effects of salinity stress on C mineralization kinetics in a soil amended with alfalfa, wheat and corn residues. A factorial combination of two salinity levels (0.97 and 18.2 dS/m) and four levels of plant residues (control, alfalfa, wheat and corn) with three replications was performed. A first order kinetic model was used to describe the C mineralization and to calculate the potentially mineralizable C. The CO(2)-C evolved under non-saline condition, ranged from 814.6 to 4842.4 mg CO(2)-C/kg in control and alfalfa residue-amended soils, respectively. Salinization reduced the rates of CO(2) evolution by 18.7%, 6.2% and 5.2% in alfalfa, wheat and corn residue-amended soils, respectively. Potentially mineralizable C (C(0)) was reduced significantly in salinized alfalfa residue-treated soils whereas, no significant difference was observed for control treatments as well as wheat and corn residue-treated soils. We concluded that the response pattern of C mineralization to salinity stress depended on the plant residue quality and duration of incubation.
Carbon ; chemistry ; Carbon Dioxide ; chemistry ; Cellulose ; metabolism ; Ecosystem ; Kinetics ; Medicago sativa ; metabolism ; Models, Chemical ; Plants ; metabolism ; Salts ; chemistry ; pharmacology ; Soil ; Soil Pollutants ; Triticum ; metabolism ; Zea mays ; metabolism

PURPOSE: The purpose of this study was to investigate the activation of the respiratory centers during insufflation of the larynx with CO2 at different flow rates and concentrations. MATERIALS AND METHODS: The experiments were carried out in spontaneous air breathing rabbits, anesthetized with thiopental sodium (25mg kg(-1) i.v.). The larynx was separated from the oropharyngeal cavity and the trachea. The tidal volume (VT) and respiratory frequency (f min(-1)) were recorded from the lower tracheal cannula. The respiratory minute volume (VE) was calculated, the action potentials from the right phrenic nerve were recorded and the inspiratory (TI) and expiratory (TE) periods and the mean inspiratory flow rate (VT/TI) were calculated. The larynx was insufflated at flow rates of 500mL min(-1) and 750mL min(-1), with 7 and 12% CO2-Air by means of a respiratory pump. RESULTS: Insufflation of the larynx, with both gas mixtures, decreased the f and VT significantly. The TI and TE were found to increase significantly due to the decreasing in f. There was a significant decrease in VT/TI ratio. Following bilateral midcervical vagotomy, on the passing of both gas mixtures, significant decreases were observed in the VT, and the responses of f, TI and TE were abolished. After cutting the superior laryngeal nerve, the responses of the VT to both gas mixtures were abolished. CONCLUSION: In conclusion, the results of this study purpose that the stimulation of the laryngeal mechanoreceptors by the effect of hyper- capnia decreases the activation of the respiratory center
Air ; Animals ; Carbon Dioxide/chemistry/*pharmacology ; Female ; Laryngeal Nerves/drug effects/physiology ; Male ; Mechanoreceptors/drug effects/physiology ; Rabbits ; Reflex/*drug effects/physiology ; *Respiratory Mechanics/drug effects ; Tidal Volume

The tail suspension test (TST), forced swimming test (FST) and chronic unpredictable mild stress (CUMS) model were used to evaluate the anti-depressant effect of supercritical CO2 extract from Compound Chaigui Fang (FFCGF). A nuclear magnetic resonance (NMR)-based metabonomics combined with multivariate statistical analysis was performed to explore the mechanism of FFCGF. Rats were conducted by CUMS procedure for 28 days and drugs were administrated at the same time. The body weight, sucrose preference, crossings and rearings in open-field tests were evaluated and the urine was collected simultaneously. The metabonomic profiles of rats' urine were analyzed by NMR and potential biomarkers were searched by multivariate statistical analysis. The results showed that administration of FFCGF significantly decreasing the immobility time in FST and TST and improving rats' body weight, sucrose preference, crossings and rearings in CUMS, which were indication that the anti-depressant effect of FFCGF was abvious. Significant differences in the metabolic profile of the CUMS treated group and the control group were observed, which were consistent with the results of behavioral tests. Decreased levels of acetic acid, succinic acid, 2-oxidation glutaric acid and citric acid and increased glycine and pyruvic acid in urine were significantly affected by the CUMS procedure and the 6 biomarkers were reversed evidently after administration of FFCGF. These changes were suggestion that the anti-depressant mechanism of FFCGF was associated with energy metabolism, lipid metabolism and amino acid metabolism.
Animals ; Antidepressive Agents ; chemistry ; isolation & purification ; pharmacology ; therapeutic use ; Behavior, Animal ; drug effects ; Body Weight ; Carbon Dioxide ; chemistry ; Depression ; drug therapy ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; pharmacology ; therapeutic use ; Male ; Mice

OBJECTIVETo investigate the antimicrobial activity in vitro and chemical composition of essential oil from lavender extracted by supercritical CO2 extraction (SFE-CO2) process and hydrodistillation.

METHODThe antimicrobial activities against 4 bacteria and 4 fungi strains of these two oils were evaluated by using the agar disc diffusion and agar dilution method to determine the inhibition zone, minimal inhibitory concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC). A GC-MS method was established to determine the chemical components of essential oils.

RESULTThese two oils presented remarkable antimicrobiat activities against all tested strains in vitro. Compared with the hydrodistillation product, SFE-CO, oil showed better antimicrobial activity against either bacteria or fungi of which MIC values were 0.63-3.33 g x L(-1) and the MBC/MFC values were 1.04-5.00 g x L(-1). By GC-MS analysis, 34 and 29 compounds identified cover 95.51% and 98. 39% of total peak area of substances appeared. The main differences between SFE-CO2 oil and hydrodistillation oil were the amounts of linalyl acetate and 5-methyl-2-(1-methylethenyl)-4-hexen-1-ol acetate.

CONCLUSIONResults presented here may suggest that the essential oil of lavender extracted by SFE-CO2 possesses has better antimicrobial properties, and therefore it is a potential source of antimicrobial ingredients for pharmaceutical industry.

Bacteria ; drug effects ; Carbon Dioxide ; chemistry ; Chromatography, Supercritical Fluid ; methods ; Fungi ; drug effects ; Gas Chromatography-Mass Spectrometry ; methods ; Lavandula ; chemistry ; Microbial Sensitivity Tests ; Oils, Volatile ; analysis ; isolation & purification ; pharmacology

OBJECTIVETo investigate the effect of Qingikailing and Shengmai injection alone or combined on the acute lung injury (AL) induced by oleic acid in rabbits.

METHODThe rabbits were randomly divided into 11 groups: oleic acid group; control group; treatment groups including low, middle and high dosage groups of Qingkailing and Shengmai injection alone and combined, respectively. ALI model was established by iv oleic acid (0.05 mL x kg(-1)) in these groups, and then iv above drugs respectively,while in control group, the same volume of normal saline was given. The respiratory amplitude and rate were observed, and blood samples were taken from cervical artery for blood-gas analysis before and at 30, 60, 120 min after oleic acid or normal saline administration. At the end of experiment, the concentration of LDH, CAT and MDA in the lung tissue were measured and pathologic changes of lung tissue were observed microscopically.

RESULTCompared with oleic acid group, the respiratory amplitude markedly enhanced (P < 0.05) in the low and high dose groups of Qingkailing and Shengmai injection. PaO2 increased significantly (P < 0.05) in the low dose group of combined Qingkailing and Shengmai injection, PaCO2 decreased markedly (P < 0.05) in the low dose groups of Qingkailing and Shengmai injection alone and combined. The level of MDA significantly decreased (P < 0.05) in the each group of Qingkailing and Shengmai injection alone, the level of MDA significantly decreased (P < 0.05) and CAT increased (P < 0.05) in the low dose group of combined Qingkailing with Shengmai injection. The low dose group of combined Qingkailing and Shengmai injection can alleviate the pathological changes induced by oleic acid.

CONCLUSIONThe curative effect of the low dose group of combined Qingkailing with Shengmai injection for the ALI induced by oleic acid was better than Qingkailing and Shengmai injection alone at the same dosage.

Animals ; Carbon Dioxide ; blood ; Catalase ; blood ; Drug Combinations ; Drug Therapy, Combination ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Female ; L-Lactate Dehydrogenase ; metabolism ; Lung ; pathology ; Male ; Malondialdehyde ; blood ; Oleic Acid ; Oxygen ; blood ; Plants, Medicinal ; chemistry ; Rabbits ; Random Allocation ; Respiration ; drug effects ; Respiratory Distress Syndrome, Adult ; blood ; chemically induced ; pathology ; physiopathology