[Influence of paddy rice-upland crop rotation of cold-waterlogged paddy field on crops produc- tion and soil characteristics].

Two consecutive years (4-crop) experiments were conducted to study the influence of different paddy rice-upland crop rotation in cold-waterlogged paddy field on the growth of crops and soil characteristics. The result showed that compared with the rice-winter fallow (CK) pattern, the two-year average yield of paddy rice under four rotation modes, including rape-rice (R-R), spring corn-rice (C-R), Chinese milk vetch-rice (M-R) and bean-rice (B-R), were increased by 5.3%-26.7%, with significant difference observed in C-R and R-R patterns. Except for M-R pattern, the annual average total economic benefits were improved by 79.0%-392.4% in all rotation pattern compared with the CK, and the ration of output/input was enhanced by 0.06-0.72 unit, with the most significant effect found in the C-R pattern. Likewise, compared with the CK, the contents of chlorophyll and carotenoid, and net photosynthetic rate (Pn) of rice plant were all increased during the full-tillering stage of rice in all rotation patterns. The rusty lines and rusty spots of soils were more obvious compared with the CK during the rice harvest, particularly in R-R, C-R and B-R patterns. The ratio of water-stable soil macro aggregates of plough layer of soil (> 2 mm) decreased at different levels in all rotation patterns while the ratios of middle aggregate (0.25-2 mm, expect for M-R) and micro aggregate of soil (< 0.25 mm) were opposite. There was a decreasing trend for soil active reducing agents in all rotation patterns, whereas the available nutrient increased. The amounts of soil bacteria in C-R and B-R patterns, fungi in B-R rotation pattern, cellulose bacteria in R-R, C-R and B-R patterns and N-fixing bacteria in B-R pattern were improved by 285.7%-403.0%, 221.7%, 64.6-92.2% and 162.2%, respectively. Moreover, the differences in all microorganisms were significant. Thus, based on the experimental results of cold-waterlogged paddy field, it was concluded that changing from single cropping rice system to C-R, R-R and B-R rotation patterns had good effect in terms of improving total yield and economic benefits, and soil physical and chemical properties were improved.

Systematic review of high-dose and standard-dose chemotherapies in the treatment of primary well-differentiated osteosarcoma.

The objective of this study is to evaluate whether high-dose chemotherapy is more efficacious than standard-dose chemotherapy in the treatment of primary well-differentiated osteosarcoma. The Cochrane systematic evaluation method was adopted. A database search was conducted in MEDLINE, Embase, OVID, the Cochrane Central Register of Controlled Trials database and the Chinese Biomedical Literature CD-ROM Database. The quality of the included studies was jointly evaluated by two reviewers, and homogeneous studies were included for meta-analysis. A total of five studies were included in this meta-analysis, with 1,415 subjects with primary, nonmetastatic, well-differentiated osteosarcoma in the limbs. No statistically significant differences were found between the high-dose chemotherapy group and the low-dose group in 5-year event-free survival [RR 1.04, 95 %CI (0.95, 1.13)], 5-year overall survival [RR 1.02, 95 %CI (0.95, 1.10)], local recurrence rate [RR 0.90, 95 %CI (0.59, 1.39)], proportion of subjects with good histological response [RR 0.93, 95 %CI (0.81, 1.07)], or limb salvage rate [RR 0.97, 95 %CI (0.92, 1.02)]. A statistically significant difference was observed in the 5-year event-free survival between the subjects with good histological response to preoperative chemotherapy and the subjects with poor histological response [RR 1.55, 95 %CI (1.19, 2.00), P < 0.001]. High-dose chemotherapy did not show superior efficacy to low-dose chemotherapy in the treatment of primary well-differentiated osteosarcoma. Further high-quality randomized controlled trials are needed to provide additional reliable evidence for our observation.