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The system of dynamic leaching was designed for samples of a coal gasification residual from a coalto-methanol plant in northwestern China in order to investigate the leaching behavior of four potentially hazardous elements – Hg, Cr, As, and Pb – in the coal gasification residual and investigate the impacts of the leaching time, size of the samples, and pH of the leaching solution on the leaching behavior of elements. The concentrations of elements in the leachate samples were all determined by inductively coupled plasma-mass atomic spectrometry (ICP-MS). The results showed that the leaching time, size of the samples, and pH of the leaching solution played an important role in affecting the leaching behavior of the selected elements from the coal residual samples. All trends were in decreasing order of significance as the leaching time went on and most leached concentrations reached the maximum at the initial stage of leaching experiments (from hours 0 to 4) accounting for 94.44%. The 80-mesh sample had the different leaching curve from the 10-mesh and 40-mesh samples for the same element because different forms of the heavy metals existed on the different-size samples.
To investigate how cognitive impairment is affected by the relief of bilateral carotid stenosis, chronic cerebral hypoperfusion was established through stenosis of the bilateral carotid common artery in adult Sprague-Dawley rats. Subsequently, the model rats received the intragastric placebo, donepezil (5 mg/kg), or surgery to relieve carotid stenosis after bilateral carotid common artery stenosis. After carotid stenosis was relieved, the cerebral blood flow values significantly increased, and P300 latency and escape latency in the Morris water-maze were significantly shortened. The concentrations of acetylcholine and norepinephrine in the dorsal hippocampus increased after carotid stenosis was relieved. Furthermore, P300 latency and escape latency were shortened in the relief-treated group compared to the drug-treated group, and acetylcholine levels in the relief-treated group were higher than the drug-treated group. No significant difference was found for the norepinephrine levels in the dorsal hippocampus between the relief-treated and drug-treated groups. Cognitive impairment can be significantly reduced by bilateral carotid stenosis relief, and the effect of relieving stenosis on cognitive dysfunction is superior to the effect of administering an acetylcholinesterase inhibitor.
In this study, the comparative effects of the two disturbances (aquaculture and water level fluctuations) on macroinvertebrate communities were explored in two waterbodies connected with the reservoir system of Three Gorges Reservoir (TGR) in China. One water body called Gaoyang Bay which suffered organic pollution from intensive aquaculture. Another named Hanfeng Lake, where the effects of water-level fluctuations are obvious. The results showed that aquaculture could significantly affect the chemical forms of nutrients, decrease the α-diversity and increase the β-diversity of macroinvertebrates although the communities in the treatment area in Gaoyang Bay were not fundamentally changed comparing to the control area in the same bay. The densities of macroinvertebrates in the treatment area were significantly lower than that of the control area. The composition of functional feeding groups in the treatment area was close to that in Hanfeng Lake, but obviously different from that in the control area in Gaoyang Bay and the collectors and predators dominated the communities in this control area with the highest percentages. Although water-level fluctuations had negative effects on the communities by decreasing the α-diversity and increasing the β-diversity, which were confirmed by the values of Simpson index, Shannon-Wiener index and Harrison's index in the control area of Gaoyang bay and Hanfeng Lake, the adverse effects were relative low compared to aquaculture. In the bays of TGR, the small-scale disturbance (aquaculture activities) had more significant negative effects compared to the big-scale disturbance (water-level fluctuations related to dam operation of TGR).
Coal gasification coarse cinder (CGCC) is the main waste in the coal gasification industry, containing low calorific value but high heavy metal residuals. To achieve environmental toxicity stabilization and waste recycling, we developed a manufacturing method of multiple-functional ceramsite from CGCC by pelletizing and sintering. By altering key parameters during the manufacturing process (including CGCC content, sintering temperature, and time), the physical properties and leaching toxicity of ceramsite were evaluated. Sintering temperature was identified with a significantly positive relationship with ceramsite’s compressive strength, whereas CGCC content was negatively correlated with water adsorption. The highest compressive strength (24.00 MPa) and relatively lower water absorption (21.36%) was achieved at 50% CGCC content and 1,150ºC sintering for 30 min. The toxicity tests showed acceptable leaching heavy metals with minimal environmental impact. Considering the energy conservation and the maximal recycling of CGCC, optimal ceramsite manufacturing is suggested as 50% CGCC content and 1,150ºC/10 min sintering temperature/time. Our results indicated that multiple-functional ceramsite manufacturing is a low-cost and environmentally friendly approach for CGCC recycling.
Angiopoietin-1 (Ang-1) belongs to a novel family of endothelial growth factors that function as ligands for an endothelialspecific receptor tyrosine kinase (Tie-2). The Ang-1/Tie-2 system may contribute to angiogenesis and vascular remodeling by mediating interactions of endothelial cells with smooth muscle cells and pericytes. The spatial distribution and temporal expression of Ang-1 and Tie-2 in the rat brain were studied following collagenase-induced intracerebral hemorrhage (ICH), by immunohistochemistry and reverse transcription-polymerase chain (RT-PCR) analysis, respectively. Immunohistochemical analysis revealed that some Ang-1 or Tie-2-positive dilated vessels resided around the hematoma and extended into the clot. RT-PCR analysis showed that Ang-1 and Tie-2 mRNA signal was detected at 2 days and persisted for 28 days after ICH. These findings suggest that ICH could lead to upregulation of Ang-1 and the receptor Tie-2 mRNA.
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