C:N:P stoichiometric characteristics of mosses in Picea crassifolia forest in Helan Mountains, Ningxia, China.

To explore the stoichiometric characteristics of C, N and P and adaptive mechanism of mosses in mountain forest ecosystems, we set up 15 plots along the altitude gradient in Picea crassifolia forest in Helan Mountains, Ningxia. We analyzed the C:N:P stoichiometry of moss aboveground tissues and its relationship with environmental factors. The results showed the mean values of C, N and P concentration in moss aboveground tissues were 336.67, 20.31 and 0.66 mg·g-1, respectively. The mean value of aboveground tissue N:P was 33.4, indicating that the growth of mosses was limited by P. The C concentration in the aboveground tissues of mosses was positively correlated with soil total nitrogen concentration and negatively correlated with soil total phosphorus concentration. The N concentration in aboveground tissues of mosses was significantly negatively correlated with soil organic carbon and soil total nitrogen concentrations. Results of redundancy analysis showed that the interpretation rate of environmental factors on the stoichiometry was 48.5%, with canopy closure, soil total nitrogen and soil total phosphorus as the main factors. Canopy closure was the main environmental factor affecting the growth of mosses in P. crassifolia forest in Helan Mountains. High canopy closure facilitated the growth of mosses.

Investigation of optimal gait speed for motor learning of walking using the vibro-tactile biofeedback system.

In stroke patients, sensory loss often reduces the sensation of ground contact, which impairs motor learning during rehabilitation. In our previous study, we proposed a vibro-tactile biofeedback system (which we called the perception-empathy biofeedback system) for gait rehabilitation. The results of our 9-week pilot clinical test suggested that patients who had reached the autonomous phase in gait learning had difficulty noticing the external vibratory feedback provided by the biofeedback system, leading to ineffective intervention. We considered the possibility that slower walking speed might return the patient to the association phase and allow patients to improve their gait according to the sensory feedback provided. Thus, in this research, a method based on reducing walking speed to guide patients' attention was derived. A pilot clinical trial shows that there is a statistically significant increase of ankle dorsiflexion in the initial contact phase and increase of ankle plantarflexion in the push-off phase after vibro-tactile biofeedback system intervention with speed reduction, compared to intervention without speed reduction. The results suggest that, by reducing their walking speed during intervention, patients return to the association phase and recognize external vibratory feedback, which may result in better intervention effects.Clinical Relevance-This study provides knowledge about the optimal walking speed when using vibro-tactile biofeedback for motor learning in stroke patients.

Antitumor activity of 3,5,4'-trimethoxystilbene in COLO 205 cells and xenografts in SCID mice.

Resveratrol (R-3), a trihydroxy trans-stilbene from grape, inhibits multistage carcinogenesis in animal models. Here we report that 3,5,4'-trimethoxystilbene (MR-3), the permethylated derivative of R-3 was more potent against the growth of human cancer cells (HT-29, PC-3, COLO 205) with estimated IC(50) values of 81.31,42.71, and 6.25 microM, respectively. We further observed that MR-3 induced apoptosis in COLO 205 cells through modulation of mitochondrial functions regulated by reactive oxygen species (ROS). ROS generation occurs in the early stages of MR-3-induced apoptosis, preceding cytochrome-c release, caspase activation, and DNA fragmentation. Significant therapeutic effects were demonstrated in vivo by treating severe combined immune deficiency (SCID) mice bearing COLO 205 tumor xenografts with MR-3 (50 mg/kg ip). Assays on DNA fragmentation and caspase activation were performed and demonstrated that apoptosis occurred in tumor tissues treated with MR-3. The appearance of apoptotic cells, as shown by Hematoxylin and Eosin (H&E) staining, and an increase in p21 and decrease in proliferating cell nuclear antigen (PCNA) protein by immuno-histochemistry were observed in tumor tissues under MR-3 treatment. Our study identifies the novel mechanisms of the antitumor effects of MR-3 and indicates that these results may have significant applications for cancer chemotherapy.