Ingenane and jatrophane diterpenoids from Euphorbia kansui and their antiproliferative effects.

In this study, fourteen ingenane-type and nine jatrophane-type diterpenoids were isolated from Euphorbia kansui, including seven undescribed compounds. Kansuingenol A-C have the 6,7-vicinal diol moiety, and Kansuijatrophanol A and B possess the 11,12-vicinal diol moiety, both of which are rarely reported. 3,4-(Methylenedioxy) cinnamyl moiety was found for the first time in jatrophane-type diterpenoids, as shown in Kansuijatrophanol C and D. The absolute configurations of seven undescribed compounds have been analyzed and assigned by the modified Mosher's method, Mo2(OAc)4-induced circular dichroism (ICD) method, and CD exciton chirality method. All compounds were screened for their antiproliferative effects against HepG2, MCF-7 and DU145 cell lines. Regarding the HepG2 cells, Kansuijatrophanol C exhibited the most promising inhibition with the IC50 value of 9.47 ± 0.31 µM. Regarding the MCF-7 and DU145 cells, Kansuijatrophanol D exhibited the most promising inhibition with the IC50 values of 6.29 ± 0.18 and 4.19 ± 0.32 µM, respectively.

Carbon nanotube-based flexible electrothermal film heaters with a high heating rate.

High-performance, flexible film heaters with carbon nanotube transparent conducting films are easily fabricated by both a rod-coating method and a spraying method. The main conclusion we have reached is that the film demonstrates a heating rate of 6.1°C s-1 at 35 V and sheet resistance as low as 94.7 Ω sq-1 with 72.04% optical transmittance at a wavelength of 550 nm by the spraying method after a series of post-treatment processes with acid and distilled water. Then, we adopt a mathematical method of nonlinear fitting to simulate the collected experimental data and the functions effectively. Furthermore, through analysis of the formula, the correlation between temperature and time is well explained. Therefore, carbon nanotube-based, flexible, transparent heaters exhibit high electrothermal performance and are expected to find different applications, e.g. various functional devices such as heating materials, heatable smart windows or dining tables.

[Spatial distribution of soil total nitrogen in Liangshui National Nature Reserve based on local model].

Based on LiDAR data of Liangshui National Nature Reserve, digital elevation model (DEM) was constructed and both primary terrain attributes (slope, aspect, profile curvature, etc.) and secondary terrain attributes (wetness index, sediment transport index, relative stream power index, etc.) were extracted. According to the theory of soil formation, geographically weighted regression (GWR) was applied to predict soil total nitrogen (TN) of the area, and the predicted results were compared with those of three traditional interpolation methods including inverse distance weighting (IDW), ordinary Kriging (OK) and universal Kriging (UK). Results showed that the prediction accuracy of GWR (77.4%) was higher than that of other three interpolation methods and the accuracy of IDW (69.4%) was higher than that of OK (63.5%) and UK (60.6%). The average of TN predicted by GWR reached 4.82 g . kg-1 in the study area and TN tended to be higher in the region with higher elevation, bigger wetness index and stronger relative stream power index than in other areas. Further, TN also varied partly with various aspects and slopes. Thus, local model using terrain attributes as independent variables was effective in predicting soil attribute distribution.

[Ecological distribution and antimicrobial effects of soil actinomycetes in artificial vegetation systems in Shazhuyu of Qinghai, China].

In order to probe into the effects of artificial vegetation rehabilitation on soil actinomycetes, dilution plate and agar block methods were used to investigate the ecological distribution and antimicrobial effects of actinomycetes in sandy soil in Shazhuyu area of Qinghai after artificial vegetation restoration. The results showed that with the vegetation rehabilitation and the improvement of vegetation coverage on alpine sandy dry land, the quantity of soil actinomycetes increased significantly, being 145.4% higher in the grassland transferred from farmland than in sandy land. The quantity of soil Micromonospora in grassland transferred from farmland was about six times as much as that in sandy land. The average selection rate of antimicrobial actinomycetes was increased greatly, with the antimicrobial actinomycetes in the soil of grassland transferred from farmland, the antibacterial actinomycetes in the soil of natural grassland, and the pathogenic fungus resistant aetinomycetes in the soil of forestland being approximately 2, 3.2 and 1.5 times as much as those in the soil of sandy land, respectively. Vegetation coverage and soil nutrients had great influences on the quantities of actinomycetes and antimicrobial actinomycetes. The contents of soil organic matter and alkali-hydrolyzable nitrogen and the yield of fresh grasses had significant correlations with the quantities of actinomycetes (P < 0.01), and the content of soil organic matter and the yield of fresh grasses significantly correlated with the strain numbers of antimicrobial actinomycetes (P < 0.01). Furthermore, vegetation coverage and the contents of soil total nitrogen, total phosphorous, total potassium, total salt, and available potassium had significant correlations with the total quantities of actinomycetes, Streptomycetes, and Micromonospora (P < 0.05).

[Effects of microwave irradiation on isolation of soil actinomycetes].

Dilution plate- and agar block methods were employed to study the effects of microwave irradiation on the isolation of soil actinomycetes. The results showed that: 1) Microwave irradiation could significantly increase the total quantity of isolated actinomycetes. With the increasing duration of microwave irradiation, the total quantity of actinomycetes in soils with high organic matter content tended to increase first and decrease then. This quantity on GA and HA culture medium increased by 8.3%-92.6% and 24.4%-108.5% when the irradiation lasted 3-15 minutes, but decreased by 62.1%-78.8% and 41.4%-79.8%, respectively when the irradiation lasted 18-24 minutes, in comparison with that on the control medium. Microwave irradiation showed no remarkable effects on the total quantity of actinomycetes in the soils with low organic matter content. 2) Microwave irradiation also exerted remarkable effects on the number of actinomycetes species. With the increase of irradiation duration, the actinomycetes species number in soils with high organic matter content appeared to increase first and decrease then. When the irradiation lasted 3-24 minutes, the newly identified actinomycetes species on GA and HA culture medium, which included rare actinomycete genera such as Promicromonospora and Streptoverticillium, took up 62.5%-85.7% and 66.7%-83.3% of all the actinomycetes species respectively, and the genus Streptmycete also had obvious variation. Soils with low organic matter content showed the similar tendency. 3) Microwave irradiation could exert remarkable effects on the percentages of antimicrobial actinomycetes strains to all test actinomycete strains. When the microwave irradiation lasted 6, 9, and 15 minutes, the percentages of antimicrobial antinomycetes strains on the culture mediums increased by 66.7%, 66.7%, and 83.3%, and the newly identified antimicrobial antinomycetes strains made up 70.0%, 90.0%, and 81.8% of all the antimicrobial antinomycetes strains, respectively.

[Gene therapy for melanoma by bifidobacterium infantis-mediated transfer of CD and UPRT genes with 5-FC in vitro].

OBJECTIVE: This study was conducted by using Bifidobacterium Infantis as a delivery system to transport suicide gene CD and UPRT to tumors in an attempt to assess the UPRT-enhanced antitumor effect of CD/5-FC. METHODS: The recombinant plasmid pGEX-UPRT was constructed and transfered into Bifidobacterium Infantis by electroporation and then identified. The synergistic antitumor effect of coexpression CD and UPRT was determined by MTT method. And the morphologic changes of B16-F10 cells were observed. RESULTS: Recombinant Bifidobacterium Infantis could express UPRT correctly. The suvival rate of cells administrated CD+ UPRT and 5-FC was significantly lower than that of control (P<0.01), and the 5-FC sensitivity (IC50 = 0.015 micromol/mL) exhibited a 8. 5-fold increase when compared with that of cells administrated CD alone (IC50 = 0.127 micromol/mL). The cells treated with CD+UPRT were remarkably damaged morphologically, and the growth of cells was significantly inhibited as compared with that of other groups. CONCLUSION: Recombinant Bifidobacterium Infantis with UPRT gene can significantly enhance the killing effect of CD/5-FC suicide gene system on melanoma B16-F10 cells of mice.

[Antitumor efficacy of CD/5-FC suicide gene therapy system mediated by Bifidobacterium infantis against melanoma].

OBJECTIVE: To observe the antitumor efficacy of cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene therapy system mediated by Bifidobacterium infantis against melanoma in vitro and in vivo. METHODS: Bifidobacterium infantis transfected by CD gene was incubated with 5-FC in anaerobic condition. The supernatant of bacteria was collected and added to the melanoma B16-F10 cells for assessment of the killing effect of this suicide gene system. Mice were incubated with melanoma B16-F10 cells to establish animal models. Then the mice bearing melanoma were treated by a combination of Bifidobacterium infantis transfected by CD gene and 5-FC. Bifidobacterium infantis transfected by CD gene was injected into the tail vein of mice and 5-FC was given introperitoneally. RESULTS: (1) In vitro, the tumor cells in test groups appeared damaged with remarkable changes in morphology, and the cell growth was significantly inhibited as compared against those in the control group. (2) In animal experiment, after the mice melanoma model being treated with the recombined bacteria and 5-FC for 21 days, the tumor growth span was remarkably prolonged and the tumor volume was significantly inhibited when compared with control. The differences became more obvious with the passage of observation time. CONCLUSION: CD/5-FC suicide gene therapy system mediated by Bifidobacterium infantis was noted to have good antitumor effect on melanoma.

Antitumor effect of cytosine deaminase/5-fluorocytosine suicide gene therapy system mediated by Bifidobacterium infantis on melanoma.

AIM: To construct a Bifidobacterium infantis/CD targeting gene therapy system and observe the antitumor effect of cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene therapy system mediated by Bifidobacterium infantis on melanoma in vitro and in vivo. METHODS: A recombinant CD/pGEX-1LamdaT plasmid was transfected into Bifidobacterium infantis by electroporation. Bifidobacterium infantis transfected by recombinant CD/pGEX-1LamdaT plasmid was incubated with 5-FC anaerobically. Then the supernatant fluid was collected and added to melanoma B16-F10 cells to observe the killing effect for B16-F10 cells. Mice were inoculated with melanoma B16-F10 cells to establish animal models. The mice were then injected with 5-FC and Bifidobacterium infantis transfected by recombinant CD/pGEX-1LamdaT plasmid. RESULTS: Two segments of approximate 4.9 kb and 1.3 kb were extracted from the 6.2 kb recombinant plasmid, which were equal to the size of the pGEX-1LamdaT plasmid and CD gene, respectively. Sequencing results showed that the full length and sequence of nucleotide acid of the inserted gene in extracted recombinant plasmid was completely identical to the CD gene. In vitro, B16-F10 cells treated by supernatant fluid were remarkably damaged morphologically, and the cell growth was significantly inhibited. Experiments on the mice melanoma model showed that after treatment with a combination of transfected Bifidobacterium infantis and 5-FC, the tumor volume was significantly inhibited compared with controls. CONCLUSION: The foreign gene, CD gene, was correctly inserted into pGEX-1LambdaT plasmid and transferred into Bifidobacterium infantis. CD/5-FC suicide gene therapy system mediated by Bifidobacterium infantis demonstrated a good antitumor effect on melanoma in vitro and in vivo.