Objective To investigate the antifatigue effect of hyperoxia solution and its mechanism. Methods Eighty soldiers were randomly divided into two groups: hyperoxic solution group and common balance salt solution group The exercise selected was 5000 meters constantly running. The soldiers of each group were respectively given hyperoxic solution or balanced salt solution 250ml thirty minutes before running; then each were respectively given orally 150ml hyperoxia solution or balanced salt solution at 2000 meters and 4000 meters, The soldiers were bled before running and after running immediately, and the contents of lactic acid and malondialdehyde,the general ability of antioxidation and the energy of adenosine triphosphate enzyme were determined instantly. Results The contents of lactic acid and malondialdehyde of hyperoxic solution group were significantly less than that of control group ( P

OBJECTIVE:To establish a method for the content determination of polymer in cefatrizine propylene glycol. METHODS:High performance sephadex gel chromatography was performed on the column of Sephadex G-10 with mobile phase A of 0.01 mol/L phosphate buffer [0.01 mol/L Disodium hydrogen phosphate solution-0.01 mol/L Sodium dihydrogen phosphate solution (61∶39,V/V)](pH7.0)and mobile phase B of water at a flow rate of 1.0 ml/min,the detection wavelength was 254 nm,column temperature was 30℃,and volume injection was 200μl. RESULTS:The linear range of polymer was 2.07-103.30 mg/ml(r=0.999 4);the limit of quantitation of 10.4 ng,limit of detection was 4.1 ng;RSDs of precision and reprodicibility tests were lower than 3%. CONCLUSIONS:The method is specific with high sensitivity and good reproducibility,and can be used for the content determination of polymer in active pharmacentical ingredient cefatrizine propylene glycol.

Currently, titanium alloys are widely used in the field of stomatology; however, owing to long-term exposure to a complex microbial environment, dental plaques easily form on the surface of the materials, affecting the use efficiency and the service life of the materials. The antibacterial titanium alloy is a new kind of titanium alloy with antimicrobials added through surface modification or overall modification. Based on the location of antibacterial agents in titanium alloy materials, antibacterial titanium alloys can be divided into coating and alloy types. The antibacterial effect of coated antibacterial titanium alloy is good, but the disadvantage is that most of the coatings are not wear-resistant. The widely-used antibacterial agent of the alloy type is metal elements, which can be evenly distributed in the alloy, and the antibacterial properties are stable and long-lasting. Based on whether antibacterial agents can be released, antibacterial titanium alloys can be further divided into active antibacterial and passive antibacterial types. Active antibacterial type titanium alloys can release loaded antibacterial agents, and the antibacterial effect is more obvious, but the release duration of antibacterial agents is relatively short. Passive antibacterial titanium alloys exhibit an antibacterial effect by contact sterilization or inhibition of bacterial adhesion instead of releasing antibacterial agents. The antibacterial titanium alloy can inhibit the adhesion of bacteria on the surface of the material and prolong the service life of oral orthodontic appliances, implants and titanium plates. Moreover, the mechanical properties of the titanium alloy after antibacterial modification are not significantly affected, and the addition of antibacterial agents such as hydroxyapatite can increase the osteogenic function of the material. Therefore, the alloy has good application prospects in the fields of dental implant, orthodontic treatment and oral and maxillofacial surgery. However, most of the current studies on antibacterial titanium alloys are in vitro experiments, and their long-term clinical effects and antibacterial mechanisms are still unclear and need further study.

The contractile force of hepatic stellate cells plays a very important role in liver damage, hepatitis and fibrosis. In this paper, a method based on polydimethylsiloxane (PDMS) thin micropillar arrays is proposed to measure the contractile force of human hepatic stellate cell line LX-2, which enables dynamic measurement of the subcellular distribution of force magnitude and direction. First, thin micropillar arrays on glass bottom dish were fabricated using two-step casting process in order to meet the working distance requirement of 100× objective lens. After hydrophilic treatment and protein imprint, cells were seeded on the micropillar arrays. LX-2 cells, which were quiesced by growth in serum-free medium, were activated by adding fetal bovine serum (FBS). The deflections of the micropillars were achieved by image processing technique, and then the contractile force of cells exerted on the micropillars was calculated according to mechanical simulation results, and was analyzed under both quiescent and activated conditions. The experimental results show that the average traction force of quiescent cells is about 20 nN, while the contractile force of activated cells increased to 110 nN upon adding FBS. This method can quantify the contractile force of LX-2 cell on subcellular scale in both quiescent and activated states, which may benefit pathology study and drug screen for chronic liver diseases resulted from liver fibrosis.
Cell Line ; Hepatic Stellate Cells ; cytology ; Humans ; Image Processing, Computer-Assisted ; Mechanical Phenomena