Applied Mechanics and Materials Vols. 295-298

Abstract: AIM: To observe the effect of Sposknikovan on spleen in traumatized mice.METHODS: A total of 60 Kunming mice were randomly divided into three groups: normal group, model group and treatment group. Sposknikovan were administered once by intragastric administration (i.g.), lasting seven days. We stripped each group of mice, weighed spleen and calculated spleen index after an hour when the last administration, then stained by propidium iodide dye. We used FACSAria flow cytometry and ModFit software for cell cycle analysis of spleen cell proliferation index and the proportion of the spleen lymphocyte subsets.RESULTS: A total of 60 Kunming mice were analyzed. ① compared with control group, spleen index of model group decreased significantly, while treatment groups were higher than control and model group. ②Proliferation index of spleen cells in model group was lower than control group; treatment group could increase the proliferation index of mouse spleen cells. ③Compared with control group, the ratio of CD3+ CD4+ /CD3+CD8+ was decreased in model group. The ratio of CD3+CD4+/CD3+CD8+ in treatment group was increased compared with control and model group. CONCLUSION: Sposknikovan retrieved the ratio of CD3+CD4+/CD3+CD8+ and enhanced immune function of spleen in traumatized mice by promoting proliferation of lymphocytes in traumatized mice.

Abstract: The purpose of this study was to evaluate the effects of aqueous extract from Atractylodes macrocephala (AME) on the physical fatigue. A total of 48 mice were randomly divided into four groups of 12 mice each: control (C), low-dose AME-treated (LAT), middle-dose AME-treated (MAT) and high-dose AME-treated (HAT) groups. The mice in the treated groups received AME (50, 100 and 200 mg/kg, respectively) intragastrically (ig) and the mice in the control group received distilled water ig. After 30 days, a forced swimming test was performed and the biochemical parameters related to fatigue were examined. The results suggested that AME could extend the swimming time to exhaustion of the mice, as well as increase the liver and muscle glycogen contents, and decrease the blood lactate and blood urea nitrogen levels. These finding indicates that AME had anti-fatigue effects.

Abstract: Adsorption of metsulfuron-methyl by kaolinite, goethite，amorphous alumina and the effects of urea on the adsorption were examined with equilibrium adsorption method. Results indicated that the adsorption was in accordance with Langmuir equation, with the maximum absorbing capacities ranking as amorphous alumina (2150 g•g-1), goethite (729.4 g•g-1), kaolinite (529.1g•g-1). When urea was used in the adsorption system, the absorbing capacities of goethite and amorphous alumina to metsulfuron-methyl decreased whatever the addition order of urea and metsulfuron-methyl was. However, when urea was added before or simultaneously with metsulfuron-methyl in suspension of kaolinite, the adsorption quantity of metsulfuron-methyl was increased．

Abstract: To research influence of low light on macrophyte growth, seedlings of Vallisneria natans were transplanted into the waters with 5%, 1%, 0.5% and 0.1% full sunlights, respectively. The results show that germination rates are significantly inhibited with the experiment. In first 20 days leaf formation of new plants aren’t inhibited, and their leaf elongation are promoted. Since then, them of old plants and new plants are remarkably inhibited with the experiment. Though maximum photochemical quantum yield (Fv/Fm), relative electron transport rate (ETR) and non-photochemical quenching (NPQ) of old plants reduce significantly on low light conditions, but V. natans still hsa a certain degree of photoasynthetic capacity on the 80th day. Fresh weight ratio of roots and stems increase with decreasing light intensity. However, it exhibits an opposite trend for leaves. Thus, V. natans has a strong ability of low-light (≤1% full sunlight) tolerance.

Abstract: Biofouling organisms secrete adhesive polymers to settle themselves on man-made substrata in the marine environment. Mussels (Mytilus edulis) and diatom (Navicula sp.) are both major marine biofoulers. They attach tenaciously to a wide variety of submerged surfaces by virtue of byssus and extracellular polymer substances, respectively. The aim of this study is to evaluate the antifouling potential of the serine protease subtilisin on mussels and benthic diatoms. The effects of enzyme concentration, treatment duration and application time were tested on byssus deposition. The results showed that subtilisin effectively prevented the byssus formation. The reduction rate of byssal plaques was dependent on enzyme concentration and treatment duration. The byssal plaques of Mytilus edulis became progressively less sensitive to hydrolysis as they cured. Attached diatoms on polystyrene substrate were effectively removed by subtilisin.

Abstract: 8 Cr(VI) removing strains were obtained from 24 Cr(VI) resistance bacteria isolates. 6 strains showed more than 50% removal rates for 50 mg/L of Cr(VI) and 5 strains exhibited more than 50% removal rates for 80 mg/L of Cr(VI). Strains n-1, n-6, n-9 and n-12 could remove Cr(VI) more efficient at lower Cr(VI) concentration, while strains n-7, z-2, z-3 and z-7 could remove Cr(VI) at higher concentration. In which, strain n-9 could complete remove Cr(VI) by cultured in TYG broth containing 50 mg/L Cr (VI) at 28°C for 3 days and remove 80.7% of it in 80 mg/L Cr (VI) . Further exploration indicated that strain n-9 could reduce Cr(VI) by endoenzyme related to NADPH, which was carried out by comparing the removal ability of living cells, culture supernatant, inactived cells, cell lysate solution and the effect of SDS, thermal treatment, as well as the oxidoreductase coenzyme NADPH.

Abstract: AIM: To investigate the mechanism of hyaluronic acid on rabbit chondrocyte apoptosis in vitro induced by NO. METHODS: We cultured rabbit chondrocytes as normal group and added SNP after cultured 24 h as model group. Treated group was added HA. We used cell culture experiment. We tested the activity of mitochondria though MTT. The flow cytometry detected mitochondrial membrane potential, the percentage of apoptosis and intracellular free calcium concentration.RESULTS: HA could elevate the active of chondrocyte mitochondria and MMP; it could decrease the rate of chondrocyte apoptosis and intracellular free calcium concentration.CONCLUSION: HA can inhibit the lowering of the MMP in chondrocyte, which has a stable role on MMP and inhibit apoptosis occurred. This effect may be related to inhibiting of intracellular calcium overload chondrocytes.

Abstract: In order to discuss the effects of nitrite on the density of hemocyte (DHC) and phenoloxidase (PO) activity in hemolymph of Charybdis japonica, the crabs were exposed to six nitrite-N groups (0, 2.0, 4.0, 6.0, 8.0 and 10.0 mg L-1 ambient nitrite-N concentrations). The DHC and PO activity was examined on days 1, 3, 5, 10 and 15 following the stress. Results showed that the two indexes appeared to have a decline trend after an initial ascent. After 1 day treatment, the DHC of five treatments were higher than that of the control group respectively, while the PO activity of 8.0 and 10.0 mg L-1 nitrite-N exposed group decreased compared with control. With time elapsed, the DHC of lower concentration nitrite-N exposed group increased faster, while the PO activity of higher concentration nitrite-N exposed group rised faster than other treatments. After 15-day stress, all parameters tested were lower than those of control group barring the DHC of 2.0 and 4.0 mg L-1 nitrite-N exposed group and the PO activity of 2.0, 4.0, and 6.0 mg L-1 nitrite-N exposed group.

Abstract: A new type of anion exchange resin was prepared from cassava stalk (CS) after reaction with epichlorohydrin and dimethylamine in the presence of pyridine and N,N-dimethylformamide. In order to obtain the optimal conditions for the preparation of cassava stalk anion exchanger (CS-AE), the single influential factor experiments were carried out, with nitrate removal efficiency as indicator. Factors like dosage of CS and catalyst, experimental temperatures were examined. The results indicated that the optimal synthesis reaction parameters of dosages were CS: pyridine: dimethylamine = 2 g: 30 ml: 35 ml. The optimal experimental temperature was 100 °C; the catalytic temperature was a key factor in the preparation of CS-AE.

Abstract: The reaction efficiency of rigid PU foam alcoholysis in different conditions is studied in this research. The 1,2-propanediol and DEA are respectively used as alcoholysis agent and catalyst in the experiment. The influence of 1,2- propanediol/rigid and DEA/rigid PU foam weight ratios on the decomposed product is examined, and the respective alcoholysis efficiencies are also investigated. According to the experiment, two weight ratios (i.e. 2:1 for 1,2-PDO/rigid PU foam, and 0.1:1 for DEA/rigid PU foam) can be identified to make the reaction more efficient with less 1,2-PDO and DEA inputs.