Stress injuries and autophagy in mouse hippocampus after chronic cold exposure.

Cold exposure is an external stress factor that causes skin frostbite as well as a variety of diseases. Estrogen might participate in neuroprotection after cold exposure, but its precise mechanism remains unclear. In this study, mice were exposed to 10°C for 7 days and 0-4°C for 30 days to induce a model of chronic cold exposure. Results showed that oxidative stress-related c-fos and cyclooxygenase 2 expressions, MAP1LC3-labeled autophagic cells, Iba1-labeled activated microglia, and interleukin-1ß-positive pyramidal cells were increased in the hippocampal CA1 area. Chronic cold exposure markedly elevated the levels of estrogen in the blood and the estrogen receptor, G protein-coupled receptor 30. These results indicate that neuroimmunoreactivity is involved in chronic cold exposure-induced pathological alterations, including oxidative stress, neuronal autophagy, and neuroimmunoreactivity. Moreover, estrogen exerts a neuroprotective effect on cold exposure.

[Application of non-nutritive sucking in preterm infants requiring mechanical ventilation].

OBJECTIVE: To study the role of non-nutritive sucking in preterm infants requiring mechanical ventilation therapy. METHODS: In a study of 68 preterm infants requiring mechanical ventilation, a randomly selected observation group of 35 infants was provided with non-nutritive sucking and a control group of 33 infants was not. The time to reach full enteral feeding, birth weight recovery time, body weight growth rate, hospitalization time, feeding tolerance and mechanical ventilation-related complications were compared between the two groups. RESULTS: The time to reach full enteral feeding and hospitalization time were shorter (P<0.01), the incidence of feeding intolerance was lower (P<0.05), and the body weight growth rate was higher (P<0.05) in the observation group than in the control group. There were no significant differences in the birth weight recovery time and the incidence of mechanical ventilation-related complications between the two groups. CONCLUSIONS: The use of non-nutritive sucking can increase growth rate, shorten hospitalization time and improve feeding tolerance in preterm infants requiring mechanical ventilation therapy. Moreover, it does not result in an increase in mechanical ventilation-related complications.

[Rainfall intensity effects on nutrients transport in surface runoff from farmlands in gentle slope hilly area of Taihu Lake Basin].

To investigate the effect of rainfall on agricultural nonpoint source pollution, watershed scale experiments were conducted to study the characteristics of nutrients in surface runoff under different rainfall intensities from farmlands in gentle slope hilly areas around Taihu Lake. Rainfall intensity significantly affected N and P concentrations in runoff. Rainfall intensity was positively related to TP, PO4(3-) -P and NH4+ -N event mean concentrations(EMC). However, this study have found the EMC of TN and NO3- -N to be positively related to rainfall intensity under light rain and negatively related to rainfall intensity under heavy rain. TN and TP site mean amounts (SMA) in runoff were positively related to rainfall intensity and were 1.91, 311.83, 127.65, 731.69 g/hm2 and 0.04, 7.77, 2.99, 32.02 g/hm2 with rainfall applied under light rain, moderate rain, heavy rain and rainstorm respectively. N in runoff was mainly NO3- -N and NH4+ -N and was primarily in dissolved form from Meilin soils. Dissolved P (DP) was the dominant form of TP under light rain, but particulate P (PP) mass loss increased with the increase of rainfall intensity and to be the dominant form when the rainfall intensity reaches rainstorm. Single relationships were used to describe the dependence of TN and TP mass losses in runoff on rainfall, maximum rainfall intensity, average rainfall intensity and rainfall duration respectively. The results showed a significant positive correlation between TN mass loss and rainfall, maximum rainfall intensity respectively (p < 0.01) and also TP mass loss and rainfall, maximum rainfall intensity respectively (p < 0.01).

[Suspension-sedimentation of sediment and release amount of internal load in Lake Taihu affected by wind].

The water quality in Meiliang Bay of the Taihu Lake was totally tested five times in the four seasons. The suspension samples were obtained by using a sediment trap. The sediment settling flux and resuspended flux were calculated according to the observation data by using Gansith formula, and the relationships between these fluxes and wind speeds were established. Seven experiments were conducted in Laboratory for hydrostatic settling behavior of suspended matter affected by different wind speeds in Lake Taihu. The hydrostatic settling fluxes of suspended matter were calculated and the relationships between the fluxes and suspended matter concentrations were established. Base on these works, the suspension-sedimentation process was decomposed and generalized according to the critical wind speed of 3.7 m/s. Daily sediment resuspended amount and settling amount of the year 2005 was calculated and annual average release amount of internal load in Lake Taihu was estimated using the wind data of nearly 10 years. The results indicate that daily release amount of internal load in Lake Taihu significantly influenced by wind and have the same trend of change with wind, while the release amount of different nutrients in the same condition are different. The Lake Taihu has an annual average release amount of internal load with COD 49,600 t, TN 7773.0 t and TP 275.5 t, of which summer has the markedly highest release amount than other seasons.