Co-exposures of acid rain and ZnO nanoparticles accelerate decomposition of aquatic leaf litter.

The pattern of acid rain is dependent on the ratio of SO42- and NO3-, which change may affect the dissolution activity of dull heavy metals in the aquatic environment and further complicate the ongoing challenge of ecosystem stability and increase risks. In this study, we assessed the combined effects of acid rain (SO42-: NO3- was 2:1, 1:1, and 1:2) and ZnO nanoparticles (30 ng L-1) on plant litter decomposition through a microcosm experiment. The highest dissolution of ZnO nanoparticles was achieved when the SO42-: NO3- ratio was 1:2, and there were no significant differences among other treatments. The fungal biomass showed significant decreases under acute exposures but tended to be adaptive during chronic exposures. The co-exposure significantly stimulated the activities of leucine-aminopeptidase, glycine-aminopeptidase, polyphenol oxidase, and cellobiohydrolase. Besides, the fungal diversity and the relative abundance of some functional genera (e.g. Anguillospora) were enhanced when the SO42-: NO3- ratio was 1:2 and 2:1. In conclusion, the decomposition rate of plant litter was increased by 123-204% by co-exposures. Collectively, the findings underline the importance of considering environmental context to assess nanoparticle toxicity.

Comparison of Sleep Disturbances Between Older Nursing Home Residents in High- and Low-Altitude Areas.

BACKGROUND AND OBJECTIVE: This study compared sleep disturbances between older adults living in nursing home located in high- and low-altitude areas and explored the association between sleep disturbances and quality of life (QoL). METHOD: In total, 207 participants living in a high-altitude area and 437 participants in a low-altitude area were included. Sleep disturbances (ie, difficulty in initiating sleep, difficulty in maintaining sleep, and early morning awakening) were measured using standardized questions. The independent demographic and clinical correlates of sleep disturbances in high-altitude area were examined using multiple logistic regression analyses. Each type of sleep disturbance was entered as the dependent variable separately, while those with significant group differences in the univariate analyses (ie, male gender, married status, age and depressive symptoms) were entered as independent variables. RESULTS: The prevalence of any type of sleep disturbances in the whole sample was 26.09%, with 41.54% in the high-altitude area and 18.76% in the low-altitude area. Physical, psychological, social, and environmental QoL domains were negatively associated with sleep disturbances in high-altitude area. Multiple logistic regression analyses revealed that male gender and married status were less likely to have sleep disturbances, while those with more severe depressive symptoms were more likely to have sleep disturbances in high-altitude area. CONCLUSION: Sleep disturbance is common among older nursing home residents in high-altitude areas. Considering the negative impact of sleep disturbance on QoL, regular screening and treatment strategies need to be developed directly for this population.

Preparation of Bi2O3/Al Core-Shell Energetic Composite by Two-Step Ball Milling Method and Its Application in Solid Propellant.

In this article, Bi2O3/Al high-density energetic composites with a core-shell structure were prepared by a two-step ball milling method using a common planetary ball milling instrument, and their morphology, structure, and properties were characterized in detail. Through a reasonable ratio design and optimization of the ball milling conditions, the density of the Bi2O3/Al core-shell energetic composite is increased by about 11.3% compared to that of the physical mixed sample under the same conditions. The DSC (Differential Scanning Calorimetry) test also showed that the exothermic quantity of the thermite reaction of the energetic composite reached 2112.21 J/g, which is very close to the theoretical exothermic quantity. The effect of Bi2O3/Al core-shell energetic composite on the energy performance of insensitive HTPE propellant was further studied. The theoretical calculation results showed that replacing the partial Al with Bi2O3/Al core-shell energetic composite can make the density of propellant reach 2.056 g/cm3, and the density specific impulse reach 502.3 s·g/cm3, which is significantly higher than the density and density specific impulse of the conventional composite solid propellant. The thermal test showed that the explosive heat of the HTPE (Hydroxyl terminated polyether) propellant also increased with the increase of the content of Bi2O3/Al core-shell energetic composite.

[Influence of hydrogen sulfide on important organs in rats with severe burn].

OBJECTIVE: To investigate the changes in hydrogen sulfide (H2S) and cystathionine gamma-lyase (CSE) in rats with severe burn, and to analyze the effects on important organs. METHODS: One hundred and four healthy male SD rats were divided into normal control group (NC, n = 8), burn group (B, n = 48), and H2S intervention group (HI, n = 48) according to the random number table. SD rats in HI group were intraperitoneally injected with NaHS (56 micromol/kg) once a day for 5 days. Then rats in HI and B groups were subjected to 30% TBSA full-thickness burn. Blood sample as well as heart, liver, lung, kidney, and stomach tissue samples were harvested from rats in B group at post burn hour (PBH) 2, 6, 12, 24, 48, and 96 respectively for determination of serum content of H2S and CSE activity. Serum content of alanine transaminase (ALT), aspartate aminotransferase (AST), MB isoenzyme of creatine kinase (CK-MB), urea nitrogen (BUN), and creatinine (Cr) in HI and B groups were examined at each time point. Samples were harvested from above organs in each group for histomorphological observation. Above-mentioned indexes were also determined in NC group as control. Data were processed with SNK- q test, t test, correlation analysis (between serum content of H2S and CSE activities, biochemical indexes). RESULTS: Serum content of H2S and CSE activities of above organs (except for lung tissue at PBH 48, 96) in B group within PBH 96 were lower than those in NC group, reaching minimum values at PBH 6 or 12. Compared with those in NC group, serum contents of all biochemical indexes in B group were obviously increased within PBH 48, in which serum contents of BUN [(32.5 +/- 9.8) mmol/L] and Cr [(65 +/- 9) micromol/L] reached peak at PBH 6, and serum contents of ALT [(423 +/- 59) U/L], AST [(993 +/- 60) U/L], and CK-MB [(49 261 +/- 6637) U/L] peaked at PBH 12. Serum contents of all biochemical indexes in HI group at each time point were significantly decreased as compared with those in B group, but the same change tendencies were showed in both groups. Histomorphological observation showed that all the organs were severely injured in B group at PBH 24, whereas those in HI group were markedly ameliorated. Serum content of H2S in B group was respectively correlated with CSE activities of all organs (with r value from 0.639 to 0.894, P values all below 0.005) and serum contents of biochemical indexes (with r value from 0.301 to 0.585, P values all below 0.001). CONCLUSIONS: H2S/CSE system may take part in pathophysiological process in rats with severe burn. Exogenous H2S replacement therapy can protect important organs of rats with severe burn.

[The dynamic changing profiles of peripheral white blood cell telomere length in populations of different ages living at different altitude areas].

OBJECTIVE: To investigate the relationship between the length of telomere DNA and age at different altitude areas. METHODS: All 172 peripheral blood samples were randomly selected from healthy individuals of different ages from 25 to 65 years old. High altitude group (47 males, 48 females) living at an altitude of 4380 m (HA group), sea level group (39 males, 38 females) living at an altitude of 43 m (SL group). The terminal restriction fragment (TRF) length of telomere DNA was measured by Southern blotting analysis. The plasma levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were assayed. RESULTS: Average TRF lengths of males and females in HA groups were 10.45 +/- 1.35 and 10.50 +/- 1.45. Average TRF lengths of males and females in SL groups were 11.29 +/- 1.10 and 11.31 +/- 1.13. A negative correlation was shown between the average TRF length and age of males in two groups (P < 0.01). This was also the case for females. ANOVA test was used to analyze the difference between TRF length and gender at different ages (P < 0.001). It was shown that there was significant difference in TRF length between the male (25 years old and 55 years old) and female (25 years old and 55 years old) in two groups at different ages (P < 0.05). The plasma levels of SOD and MDA were significant different between HA groups and SL groups (25-44 years old groups/45-65 years old groups) (P < 0.05). CONCLUSION: Obviously shortening of telomere was observed by increasing of ages in high altitude groups. There was a negative correlation between the length of telomere DNA and ages. Telomere shortening became more obviously in high altitude group than in sea level group in keeping with the age increases.