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Background: Hydrogen sulfide (H2S), a novel gaseous mediator, has been recognized as an important neuromodulator and neuroprotective agent in the nervous system. The present study was undertaken to study the effects of exogenous H2S on ischemia/reperfusion (I/R) injury of spinal cord and the underlying mechanisms. Methods: The effects of exogenous H2S on I/R injury were examined by using assessment of hind motor function, spinal cord infarct zone by Triphenyltetrazolium chloride (TTC) staining. Autophagy was evaluated by expressions of Microtubule associated protein 1 light chain 3 (LC3) and Beclin-1 which were determined by using Quantitative Real-Time PCR and Western blotting, respectively. Results: Compared to I/R injury groups, H2S pretreatment had reduced spinal cord infarct zone, improved hind motor function in rats. Quantitative Real-Time PCR or Western blotting results showed that H2S pretreatment also downregulated miR-30c expression and upregulated Beclin-1 and LC3II expression in spinal cord. In vitro, miR-30c was showed to exert negative effect on Beclin-1 expression by targeting its 3'UTR in SY-SH-5Y cells treated with Oxygen, Glucose Deprivation (OGD). In rat model of I/R injury, pretreatment of pre-miR-30c or 3-MA (an inhibitor for autophagy) can abrogated spinal cord protective effect of H2S. Conclusion: H2S protects spinal cord and induces autophagy via miR-30c in a rat model of spinal cord hemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Climate change and prolong drought adversely affect the grassland ecosystem, is precarious environmental constraint restricting plant growth and productivity. An experiment was conducted to alleviate adverse impacts of drought on physiochemical and morphological attributes of Leymus chinensis (Trin.) Tzvelev using brassinosteroid (BR). Treatments comprised well watered control (soil water contents 80%-85%) including Control (T0) and Control+ BR (TB0), moderate drought stress (soil water contents 50%-55%) including (T1) and T1+ BR (TB1) and severe drought stress (soil water contents 30%-35%) including (T2) and T2+ BR (TB2), they were laid out in completely randomized design with five replicates. Drought stress significantly impaired growth, osmotic substances, photosynthetic rate, and other physiochemical process. Moreover, perturbation in recorded attributes was aggravated by increasing drought severity from moderate to severe. Nevertheless, BR application (0.1 mg L-1) improved plant weight (38.8%-46.2%), relative water content (23.4%-29.1%), chlorophyll a (16.6%-56.5%), chlorophyll b (8.5%-16.9%), carotenoids (29.1%-67.3%), soluble sugars (1.7%-29.4%), free amino acids (15.4%-19.4%), and proline content (45.2%-79.4%); while, lowered malondialdehyde (34.8%-45.4%) at each level of drought. Likewise, BR application enhanced net photosynthetic rate (69.8%-165.1%), transpiration rate (45.0%-146.9%), water utilization efficiency (9.3%-16.0%), carboxylation utilization efficiency (80%-250%), sunlight utilization efficiency (66.6%-158.8%) and improved chlorophyll fluorescence characteristics at each level of drought, as compared to untreated controls. The adverse implications on physiochemical and morphological attributes were aggravated with the enhancing severity of drought from control to severe drought. Yet, 0.1 mg L-1 exogenous BR improved morphological and physiochemical attributes remarkably over respective controls and hence can be used to improve growth of drought stressed L. chinensis. [ABSTRACT FROM AUTHOR]

In this paper, the k--ε renormalization group (RNG) turbulence model is used to simulate the flow and dispersion of pollutants emitted from a source at the top of a cubic building under neutral and stable atmospheric stratifications, the results of which were compared with corresponding wind tunnel experiment results. When atmosphere stratification is stable, the separation zones on the sides and at the top of a building are relatively smaller than those under neutral conditions, and the effect of the building in the horizontal direction is stronger than that in the vertical direction. The variation in turbulent kinetic energy under stable conditions is significantly lower than that under neutral conditions. The effect of atmospheric stratification on the turbulent kinetic energy becomes gradually more prominent with increased distance. When atmosphere conditions are stable, the vertical distribution of the plume is smaller than that of neutral conditions, but the lateral spread and near-ground concentration are slightly larger than those of neutral conditions, mainly because stable atmospheric stratification suppresses the vertical motions of airflow and increases the horizontal spread of the plume. [ABSTRACT FROM AUTHOR]