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The objective of this study is to explore the effect of soil moisture on the formation of storage roots in sweet potato and its relationship with the number and uniformity of storage roots. In this experiment, the sweet potato variety Yanshu 25 was used as the experimental material. We performed five soil relative water content levels with 50%±5% (W50), 60%±5% (W60), 70%±5% (W70), 80%±5% (W80), and 90%±5% (W90) at root branching stage. The effects of soil moisture on the content of carbohydrate and the activity of metabolic enzymes in the potential storage roots, as well as the number, uniformity and yield of storage roots at the harvest time were studied by a two-year field experiment. The results showed that the content of sucrose, glucose, and fructose and the activity of sucrose invertase in the potential storage roots of sweet potato in W70 treatment were significantly higher than those of other treatments during 10-35 days after planting. The activity of sucrose synthase and the content of starch in the potential storage roots of sweet potato in W70 treatment were significantly lower than those of other treatments at 10-25 days after planting, while the trend was opposite during 30-35 days after planting. Compared with other treatments, the number of storage roots per plant and the yield of storage root in W70 treatment increased by 14%-120% and 22%-122%, respectively. The variable coefficient of the single storage root weight decreased by 9%-34%. The soil relative water content of 70% at root branching stage of sweet potato was beneficial to the formation of storage roots, which increased the number of storage roots per plant, weight of the single storage root and yield of storage roots, and improved the commercial quality of storage roots at harvest time. [ABSTRACT FROM AUTHOR]

Two new 2H-pyranones and two new isocoumarin derivatives, maculanslines A-D (1–4), together with seven known compounds (5–11), were isolated from the plant pathogenic fungus Leptosphaena maculans. Their planar structures and absolute configuration were elucidated by comprehensive spectroscopic techniques including high-resolution electrospray ionization mass spectrum, 1D and 2D nuclear magnetic resonance, as well as electronic circular dichroism. All 11 compounds were tested for their inhibitory activity against α-glucosidase. Compound 1 showed moderate inhibitory activity against α-glucosidase with IC50 of 74.35 μM. [ABSTRACT FROM AUTHOR]

Three new cyathane diterpenoids, cyathin W (1), cyathin V (2), and cyathin T (3), were isolated from the solid culture ofCyathus africanus. The structures and configurations of these new compounds were elucidated on the basis of comprehensive spectroscopic analysis including 1D NMR, 2D NMR (HSQC, HMBC, NOESY), and HR-ESI-MS experiments. Compounds1and3showed moderate inhibition against nitric oxide production in lipopolysaccaride-activated macrophages with IC50value of 80.07 and 88.87 μM, respectively. In cytotoxicity assay, compound1showed weak cytotoxicity against K562 cell line with IC50value of 12.1 μM. [ABSTRACT FROM PUBLISHER]

In order to study the capacity of CO2 storage in coal bed and the displacement of methane CH4 in coal by CO2 injection, an experiment about the CO2 adsorption and coalbed methane ( CBM) replacement in coal under given pressure was carried out with coal specimens of large size (100 mm x100 mm x 200 mm) from the No. 3 coal seam, Qinshui Basin, China. Based on the experiment, the CO2 storage capacity difference between coal containing CH4 and coal without CH4 was contrastively analyzed. The experimental results demonstrate that, the storage of CO2 in the coal specimen can amount to 11. 03 L under the in-situ stress condition of the coal bed and injection pressure of 0. 5 MPa. CO2 permeability through the coal decreases with the increase of its adsorption amount during the experiment duration of 180 min. When the CO2 injection pressure increases to 1. 0 MPa from 0. 5 MPa under the same confining stresses, the CO2 storage amount in the coal increases by 93. 00%, the storage rate increases by 13. 50% and the amount of CH4 desorption increases by 18. 13%. It is found that the amount of CH4 desorption is larger than CO2 adsorption in the initial experimental stage. After that, the amount of CH4 desorption tends to be stable but far less than CO2 adsorption amount. Under the similar experimental condition, the CO2 storage capacity in coal containing CH4 is 59. 29% more than that of coal without CH4 and the storage rate in coal containing CH, increases by 12. 51% compared that in coal without CH4. [ABSTRACT FROM AUTHOR]

Six major rice varieties (Longdao 3, Kendao 12, Kongyu 131, Longdao 7, Longjing 16, and Songjing 6) in Heilongjiang Province were treated with low temperature 15 °C, 17 °C, and 19 °Cfor 2, 4, 6 and 8 days at booting stage, and the relationships between their empty grain rate per panicle and low temperature at booting stage were analyzed by using linear interpolation and linear regression methods. In the province, the critical temperature of sterile-type cool injury was 17 °C for sensitive varieties, and 16 °C for resistant varieties. The most sensitive period of rice to low temperature was 14-18 days before heading. At 15 °C for 8 days, the empty grain rate of Songjing 6 and Kendao 12 increased significantly, while that of Kongyu 131 increased less, suggesting that the cold tolerance of Songjing 6 and Kendao 12 was relatively weak, while Kongyu 131 was insensitive to low temperature. There was a significant correlation between the accumulated cool temperature and the empty grain rate of Kendao 12, Longjing 16, and Kongyu 131 (P<0.01). With the increase of accumulated cool temperature, the rice empty grain rate increased significantly, but the increment varied with rice variety. [ABSTRACT FROM AUTHOR]

Based on the 1980-2005 observation data of ten-day soil humidity, monthly air temperature, and monthly precipitation during crop growth period (from May to September) from 16 agro-meteorological stations on Songnen Plain, the spatiotemporal variation of surface soil (0-30 cm) humidity and its responses to the air temperature and precipitation in study area were analyzed by using statistical method. The results showed that on Songnen Plain, the surface soil humidity during crop growth period in 1980-2005 had a decreasing trend, and tended to be aridified, especially in the west and south parts of the Plain. Before the 1990s, the surface soil on the Plain was relatively humid, but thereafter, the humidity kept decreasing, and partial dryness occurred. In the study period, the mean air temperature during crop growth period had a periodical increase before 1992, with a small fluctuation in a cycle of 6 years, but increased obviously after then. The precipitation during crop growth period had a larger inter-annual variation, with a cycle of 4-5 years. The surface soil humidity during crop growth period was significantly negatively correlated to air temperature and positively correlated to precipitation. Both air temperature and precipitation were the main climatic factors affecting the variation of surface soil humidity on Songnen Plain. [ABSTRACT FROM AUTHOR]

A new experimental equipment MCQ-II for supercritical CO2-ECBM recovery test with large size specimen was designed. The equipment can measure the specimen swelling during the supercritical CO2-ECBM recovery test. With the equipment, series of experiments for supercritical CO2 seepage and CH4 recovery with supercritical CO2 displacement were carried out. It is found that, under the conditions of 50 °C and constant volumetric stress, supercritical CO2 permeability is positively related to the infiltrating pressure, while it is negatively related to the confined volumetric stress. It turns out that supercritical CO2 permeability in the coal is higher than CO2 in general condition. The rise of volumetric stress and pore pressure will increase the supercritical CO2 adsorption. Under 48 MPa and 60 MPa volumetric stress, 10. 82 to 17. 52 and 16. 12 to 20. 40 units of carbon dioxide can be stored in per unit of coal, respectively. During the process of CH4 adsorption, CO2 adsorption and CH4 displacement by CO2, coal swelling volumetric percentage is recorded. In the experiment of CH4 displacement by supercritical CO2, more CH4 and CO2 were injected to specimen No. 1 (weakly caking coal) than specimen No. 2 (coking coal),but the replacement ratio of carbon dioxide to methane and the CO2 storage rate are almost equal, 4.01/4.16, 20.05%/20.09% Respectively. [ABSTRACT FROM AUTHOR]

Two new 2 H -pyranones and two new isocoumarin derivatives, maculanslines A-D ( 1-4 ), together with seven known compounds ( 5-11 ), were isolated from the plant pathogenic fungus Leptosphaena maculans . Their planar structures and absolute configuration were elucidated by comprehensive spectroscopic techniques including high-resolution electrospray ionization mass spectrum, 1D and 2D nuclear magnetic resonance, as well as electronic circular dichroism. All 11 compounds were tested for their inhibitory activity against α -glucosidase. Compound 1 showed moderate inhibitory activity against α -glucosidase with IC 50 of 74.35 μM.

Nine new isoprenylated depsides, sterenins E-M (1-9), as well as five known compounds (10-14), were isolated from the solid culture of Stereum hirsutum. The structures of the new compounds were elucidated by spectroscopic methods. Their inhibitory activities against yeast α-glucosidase were evaluated in vitro. Compounds 1-4 and 7-14 showed inhibitory activities with IC50 values of 7.62, 3.06, 6.03, 22.70, 36.64, 13.09, 27.52, 25.10, 12.32, 3.31, 23.82, and 14.17 µM, respectively. Compounds 5 and 6 showed no inhibitory activities with IC50 values higher than 50 µM. Therefore, the culture of S. hirsutum and its secondary metabolites could have a potential usage for the development of hypoglycemic drugs., (Georg Thieme Verlag KG Stuttgart · New York.)

Six major rice varieties (Longdao 3, Kendao 12, Kongyu 131, Longdao 7, Longjing 16, and Songjing 6) in Heilongjiang Province were treated with low temperature 15 degrees C, 17 degrees C, and 19 degrees C for 2, 4, 6 and 8 days at booting stage, and the relationships between their empty grain rate per panicle and low temperature at booting stage were analyzed by using linear interpolation and linear regression methods. In the province, the critical temperature of sterile-type cool injury was 17 degrees C for sensitive varieties, and 16 degrees C for resistant varieties. The most sensitive period of rice to low temperature was 14-18 days before heading. At 15 degrees C for 8 days, the empty grain rate of Songjing 6 and Kendao 12 increased significantly, while that of Kongyu 131 increased less, suggesting that the cold tolerance of Songjing 6 and Kendao 12 was relatively weak, while Kongyu 131 was insensitive to low temperature. There was a significant correlation between the accumulated cool temperature and the empty grain rate of Kendao 12, Longjing 16, and Kongyu 131 (P<0.01). With the increase of accumulated cool temperature, the rice empty grain rate increased significantly, but the increment varied with rice variety.

Based on the 1980-2005 observation data of ten-day soil humidity, monthly air temperature, and monthly precipitation during crop growth period (from May to September) from 16 agrometeorological stations on Songnen Plain, the spatiotemporal variation of surface soil (0-30 cm) humidity and its responses to the air temperature and precipitation in study area were analyzed by using statistical method. The results showed that on Songnen Plain, the surface soil humidity during crop growth period in 1980-2005 had a decreasing trend, and tended to be aridified, especially in the west and south parts of the Plain. Before the 1990s, the surface soil on the Plain was relatively humid, but thereafter, the humidity kept decreasing, and partial dryness occurred. In the study period, the mean air temperature during crop growth period had a periodical increase before 1992, with a small fluctuation in a cycle of 6 years, but increased obviously after then. The precipitation during crop growth period had a larger inter-annual variation, with a cycle of 4-5 years. The surface soil humidity during crop growth period was significantly negatively correlated to air temperature and positively correlated to precipitation. Both air temperature and precipitation were the main climatic factors affecting the variation of surface soil humidity on Songnen Plain.