[Effect of lumbar dorsal muscle injuries on lumbar vertebral bone quality of rat]

Objective: To explored the effects of lumbar dorsal muscle damage on local lumbar vertebral bone quality. Methods: Thirty SD female rats, at age of 20 weeks, were randomly divided into three groups: control group, or say pseudo surgery group, an incision in the back were performed as CNT; bilateral erector spinal muscle group in which group bilateral lumbar erector spinal muscle were removed as RESM; castration group in which bilateral ovaries were resected as OVX.After three months, bone mineral density, microscopic CT and vertebral compression test were taken in lumbar vertebral (L4-6) in turn. Results: After three months bone mineral density in RESM group was obviously lower than the control group [(0.211±0.028) g/cm² vs(0.253±0.021) g/cm², P<0.01], however, there was no significant difference between OVX and RESM[(0.197±0.015) g/cm² vs(0.211±0.028) g/cm², P>0.05]. In microscopic CT three-dimensional reconstruction and bone histomorphometry analysis, compared with control group CNT , in the experimental groups OVX and RESM, bone trabecula of vertebral bodies were more sparse, the overall number and interconnection of trabecula were less.Especially in the OVX, osteoporotic trend of trabecular network trend is more obvious.In vertebral compression test, the maximum load, energy absorption, the maximum stress and elastic modulus in both OVX and RESM were significantly reduced (P<0.01). In the RESM the above four biomechanical parameters were significantly higher than those of OVX (P<0.05). Conclusion: Integrity and vigor of paravertebral muscles would be of great significance to maintain adjacent vertebral bone quality.Resection of lumbar dorsal muscles could lead to a significant decrease of local vertebral bone quality.Damage and atrophy of lumbar dorsal muscle could cause osteoporosis of vertebral bodies.

Comparative study on electrochemical 4-chlorophenol degradation in different diaphragm systems with combined reduction and oxidation properties

Two diaphragm electrolysis systems, two-electrode (anode-cathode) and three-electrode (cathode-anode-cathode), were compared for the electrochemical degradation of 4-chlorophenol. The performance of these systems was improved by feeding with hydrogen gas and then with air, in aid of the combined processes of reduction and oxidation. The 4-chlorophenol degradation, dechlorination, and total organic carbon removal were monitored to characterize the difference between the two systems. The results indicated that the three-electrode system exhibited higher degradation percentages for 4-chlorophenol compared with that of the two-electrode system. The dechlorination property of the three-electrode system was stronger than that of the two-electrode system. In addition, the total organic carbon removal percentage of the anodic compartment in the three-electrode system was higher than that of the two-electrode system. The three-electrode system showed excellent treatment properties for 4-chlorophenol.

Electrocatalytic degradation kinetic of 4-chlorophenol by the Pd/C gas-diffusion electrode system

A Pd/C gas-diffusion cathode which generated H2O2 through a two-electron reduction process of fed oxygen molecule was used to degrade 4-chlorophenol in an undivided electrolysis device. The kinetics of 4-chlorophenol degradation has been investigated by the electrochemical oxidation processes. By inspecting the relationship between the rate constants (k) and influencing factors, using first-order kinetics to describe the electrochemical oxidation process of 4-chlorophenol, a kinetic model of 4-chlorophenol degradation process was proposed to calculate the 4-chlorophenol effluent concentration: C = C0 exp( -3:76 × 10(-6) C(-0.5)0 J(2) M(-0.7) Q(0.17) Dt). It was found that the electrocatalytic degradation rate of 4-chlorophenol was affected by current density, electrode distance, air-feeding rate, electrolyte concentration and initial 4-chlorophenol concentration. The kinetics obtained from the experiments under corresponding electrochemical conditions could provide an accurate estimation of 4-chlorophenol effluent concentration and lead to better design of the electrochemical reactor.

Degradation of 4-chlorophenol by the anodic-cathodic cooperative effect with a Pd/MWNT gas-diffusion electrode

Pd/multi-walled carbon nanotubes (MWNTs) catalyst used for the gas-diffusion electrode was prepared by ethylene glycol (EG) reduction and characterized by the X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicated that Pd particles with an average size of 8.0 nm were highly dispersed in the MWNTs with amorphous structure. In a diaphragm electrolysis system with a Ti/RuO(2)/IrO(2) anode and the Pd/MWNT gas diffusion cathode, the degradation of 4-chlorophenol was performed by a combination of electrochemical reduction and oxidation. The combined process was in favor of improving 4-chlorophenol degradation efficiency. The optimum reaction conditions were as following: initial pH 7, aeration with hydrogen and air. Under the optimized electrolysis conditions the removal of 4-chlorophenol in the anodic and cathodic compartments were 98.5 and 90.5%, respectively. Additionally, based on the analysis of electrolysis intermediates using high performance liquid chromatography (HPLC) and ion chromatography (IC), the electrolysis degradation of 4-chlorophenol was proposed containing the intermediates, such as phenol, hydroquinone, benzoquinone, maleic acid, fumaric acid, succinic acid, malonic acid, oxalic acid, acetic acid and formic acid.

Degradation mechanism of 4-chlorophenol with electrogenerated hydrogen peroxide on a Pd/C gas-diffusion electrode

Using a self-made Pd/C gas-diffusion electrode as the cathode and a Ti/IrO2/RuO2 anode, the degradation of 4-chlorophenol has been investigated in an undivided electrolysis device by the electrochemical oxidation processes. The result indicated that the neutral aqueous solutions can accelerate 4-chlorophenol degradation during electrolysis. The removal efficiency of 4-chlorophenol and COD reached about 89.6% and 62.0% after 120 min electrolysis, respectively. It suggested that most of 4-chlorophenol was oxidised to intermediates using the Pd/C gas-diffusion electrode. Furthermore, the biodegradation ability of the solution was increased significantly during the electrolysis. The degradation of 4-chlorophenol was attributed to the cooperative oxidation processes including electrochemical oxidation at the anode and H2O2 and hydroxyl radical (HO·) produced by the reduction of oxygen at the cathode. Finally, main aromatic intermediates (e.g., hydroquinone and benzoquinone) and main aliphatic carboxylic intermediates (e.g., oxalic, malonic, maleic, succinic, fumaric, and dodecanoic acids) were identified by GC-MS. Moreover, a reaction scheme involving all these intermediates was proposed.