Response of soil stoichiometric characteristics to climatic factors in temperate steppe of Longzhong region, China.

We explored the relationship between climate factors (mean annual precipitation and mean annual temperature) and the contents and stoichiometry of soil carbon (C), nitrogen (N), and phosphorus (P) at different soil depths (0-5, 5-10, 10-20, 20-30, 30-50, 50-70, and 70-100 cm) temperate steppe of Longzhong. The results showed with the increases of soil depth, soil C, N contents, C:P, and N:P gradually decreased from 21.88 g·kg-1, 1.84 g·kg-1, 33.6 and 3.1 to 7.67 g·kg-1, 0.59 g·kg-1, 12.5 and 1.0, respectively. Soil C:N showed an increasing trend from 12.2 to 13.9, while soil P content remained stable with an average of 0.61 g·kg-1. Soil C, N, C:P, and N:P were significantly positively correlated with mean annual precipitation and negatively correlated with mean annual temperature. Soil P content and C:N were not correlated with mean annual precipita-tion and mean annual temperature. With the increases of soil depth, the total explanatory power of the changes in soil C, N and P contents by mean annual precipitation and mean annual temperature decreased and then increased, and that in soil C:P, N:P and C:N did not change significantly. The changes of soil C, N and P contents on the temperature steppe were mainly influenced by mean annual precipitation. The effects and relative contributions of mean annual precipitation and mean annual temperature on the variations of soil nutrient contents and stoichiometry of C, N and P differed at different soil depths.

A retrospective study of supplemental iron intake in singleton pregnancy women with risk of developing gestational diabetes mellitus.

This study investigated the effect of supplemental iron intake (SII) in early singleton pregnancy women with the risk of developing gestational diabetes mellitus (GDM) among Chinese population.This study included 259 singleton pregnancy participants. Of those, 135 women underwent SII and were assigned to an intervention group, while 124 participants received no SII and were assigned to a control group. The outcome measurements consisted of the number of patients with GDM development, the levels of hemoglobin (Hb) and ferritin, and the outcomes of infant at delivery.No significant difference in the number of patients with GDM development was found between 2 groups at delivery. However, when compared with control group, subjects in the intervention group showed greater efficacy in delivery mode choice of vaginal delivery (P = .04), and cesarean section (P = .01), as well as the birthweight of infants (P < .01). Moreover, Hb and ferritin levels were also significantly higher in the intervention group than those in the control group (P < .01).The results of this retrospective study showed that SII may not increase risk of developing GDM in singleton pregnancy women; and also may benefit both pregnancy women and infants among Chinese population.

Inhibitory effect of schisandrin B on gastric cancer cells in vitro.

AIM: To investigate the inhibitory effect and possible mechanism of action of schisandrin B in SC-B on gastric cancer cells in vitro. METHODS: SC-B consisted of schisandrin B, aloe-emodin, and Astragalus polysaccharides. Exponentially growing human gastric cancer SGC-7901 cells were divided into six treatment groups: (1) control group (RPMI 1640 medium); (2) negative control group (2% DMSO); (3) positive control group (50 mg/L 5-Fluorouracil, 5-FU); (4) low-dose group (LSC, final concentration of schisandrin B, 25 mg/L); (5) moderate-dose group (MSC, final concentration of schisandrin B, 50 mg/L); (6) high-dose group (HSC, final concentration of schisandrin B, 100 mg/L). Follow-up was done at 12-48 h. An MTT (Methylthiazolyldiphenyl-tetrazolium bromide) assay was used to examine the inhibitory effect of SC-B on gastric cancer cells. The mitosis index was assessed using an inverted microscope. Flow cytometry was used to visualize the cell cycle. An RT-PCR (Reverse transcription-Polymerase chain reaction) -based assay was used to detect mRNA expression for cyclin D1 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). RESULTS: The MTT assay showed that the number of living cells in the LSC, MSC and HSC groups was significantly smaller than that in the DMSO-treated group (P < 0.05) at 12-48 h. The inhibitory rate (IR) of the LSC group was 41.15% +/- 3.86%, 59.24% +/- 5.34% and 69.93% +/- 7.81% at 12, 24 and 48 h, respectively. The IR of the MSC group was 42.82% +/- 4.94%, 62.68% +/- 7.58% and 71.79% +/- 8.12% at 12, 24 and 48 h, respectively. The IR of the HSC group was 37.50% +/- 3.21%, 40.34% +/- 2.98% and 61.99% +/- 4.88% at 12, 24 and 48 h, respectively. These results suggested that a moderate dosage had the most obvious inhibitory efficacy at 48 h. Compared to the DMSO group, the mitosis index of the LSC, MSC, HSC groups was greatly decreased (P < 0.05) at all time points. Any dose of SC-B suppressed mitosis within 12-48 h. Compared to the DMSO group, the percentage of cells in the G0/G1 phase of the MSC group was greatly increased, and that of the S + G2M phase was greatly decreased, while the percentage of cell inhibition (PCI) in the MSC group was greatly increased (P < 0.05). This suggested that SC-B could exclusively arrest cells in the G0/G1 phase. Cyclin D1 mRNA expression was lower in the MSC group than that in the DMSO group (P < 0.05). CONCLUSION: SC-B can inhibit the proliferation and aberrant mitosis of human gastric cancer SCG-7901 cells in vitro. This inhibitory effect may be due to the down-regulation of cyclin D1 mRNA expression, which causes cell cycle arrest of gastric cancer cells.