Electron self-energy and effective mass in a single heterostructure

In this paper, we investigate the electron self-energy and effective mass in a single heterostructure using Green-function method. Numerical calculations of the electron self-energy and effective mass for GaAs/AlAs heterostructure are performed. The results show that the self energy (effective mass) of electron, which incorporate the energy of electron coupling to interface-optical phonons and half three-dimension LO phonons, monotonically increase(decrease) from that of interface polaron to that of 3D bulk polaron with the increase of the distance between the position of the electron and interface.Comment: 10 pages, 2 figure

Phytoremediation : a sustainable remedial method for soil contaminated by vanadium

Vanadium amassing in the soil increased with its widespread usage in multi-field. Elevated soil vanadium confers adverse effects on living organisms involved in plants, animals, and microorganisms. Moreover, vanadium can enter the human body through the food chain and lead to potential health risks stemming from its toxicity and carcinogenicity. Therefore, the remediation of soil contaminated by vanadium is imperative. Phytoremediation, a clean phytotechnology, is gaining increasing grace in modern society that prefers spirit-enjoy persuing. However, due to the blemishes of the remediation plants per se, the remediation efficiency relying on plants alone is not attractive. Therefore, the strengthened screening of vanadium accumulator and hyperaccumulator plants should step forward. Simultaneously, it is necessary to improve phytoremediation efficiency by some complementary measures, such as inoculating plant growth-promoting bacteria, vanadium reducing bacteria, and the proper application of plant growth regulators. Overall, microbe-assisted and moderate usage of plant growth-promoting factors are promising for the phytoremediation of vanadium-contaminated soil

The impact on the soil microbial community and enzyme activity of two earthworm species during the bioremediation of pentachlorophenol-contaminated soils

The ecological effect of earthworms on the fate of soil pentachlorophenol (PCP) differs with species. This study addressed the roles and mechanisms by which two earthworm species (epigeic Eisenia fetida and endogeic Amynthas robustus E. Perrier) affect the soil microbial community and enzyme activity during the bioremediation of PCP-contaminated soils. A. robustus removed more soil PCP than did E. foetida. A. robustus improved nitrogen utilisation efficiency and soil oxidation more than did E. foetida, whereas the latter promoted the organic matter cycle in the soil. Both earthworm species significantly increased the amount of cultivable bacteria and actinomyces in soils, enhancing the utilisation rate of the carbon source (i.e. carbohydrates, carboxyl acids, and amino acids) and improving the richness and evenness of the soil microbial community. Additionally, earthworm treatment optimized the soil microbial community and increased the amount of the PCP-4-monooxygenase gene. Phylogenic classification revealed stimulation of indigenous PCP bacterial degraders, as assigned to the families Flavobacteriaceae, Pseudomonadaceae and Sphingobacteriacea, by both earthworms. A. robustus and E. foetida specifically promoted Comamonadaceae and Moraxellaceae PCP degraders, respectively

Enhancing pentachlorophenol degradation by vermicomposting associated bioremediation

Vermicomposting is an effective and environmentally friendly approach for soil organic contamination clean-up. This study investigated the roles and mechanisms of earthworm (Eisenia foetida) on soil pentachlorophenol (PCP) degradation with sterile and non-sterile soil-compost treatment. Limited soil PCP degradation was observed in the control and sterile compost treatments, whereas the synergetic effects of earthworm and compost contributed to the PCP biodegradation acceleration by significantly improving microbial biomass and activities. Sequence analysis and phylogentic classification of soil bacterial and fungal community structure after 42 days treatment identified the dominancy of indigenous bacterial families Pseudomonadaceae, Sphingobacteriaceae and Xanthomonadaceae, and fungal family Trichocomaceae, which were responsible for PCP biodegradation and stimulated by vermicomposting. Further investigation revealed the dominant roles of sterile compost during PCP biodegradation as the formation of humus-PCP in soil rather than neutralizing soil pH and increasing PCP availability. The mechanisms of vermicomposting include humus-PCP complex degradation, humus consumption and soil pH neutralization. This study provides a comprehensive understanding of the synergetic effect of vermicomposting on microbial community functions and PCP degradation enhancement in soils

Effect of three kinds of anaesthetic drugs on postoperative recovery, regulatory T cells and T lymphoid cells in elderly patients

Purpose: To investigate the effect of three anaesthetic drugs on postoperative recovery, regulatory T cells and T cell subset levels in elderly patients.Methods: The patients were randomly divided into groups A, B and C (42 patients per group). Group A received intravenous remifentanil, dexamethasone, dexmedetomidine and propofol, followed by continuous intraoperative inhalation of sevoflurane and continuous intravenous pumping of remifentanil. Group B was given intravenous propofol and midazolam, followed by continuous intraoperative inhalation of sevoflurane, while Group C received intravenous etomidate and rocuronium, with continuous intraoperative inhalation of sevoflurane. The preoperative or 24-h postoperative T regulatory cells (CD4+ CD25+) and T cell subsets (CD4+ and CD8+) were determined for each group.Results: MMSE scores in the three groups were lower than their pre-operation scores (p < 0.05). There were significant reductions in 24-h postoperative serum CD4+ CD25+ and CD4+ levels, with higher reductions in group B (p < 0.05). In contrast, CD8+ increased in all groups, but was lower in group B than in the other two groups (p < 0.05).Conclusion: These findings strongly suggest that propofol, midazolam and sevoflurane have rapid onset of action and recovery, which improves the comfort of patients while decreasing negative impact on the function of the immune system. Furthermore, these anaesthetic agents enhance the recovery of elderly patients.Keywords: Anaesthesia, Cognitive function, Regulatory T cells, T cell subset

1-(4-Methyl­phenyl­diazo­nium­yl)-2-naphtholate

In the title compound, C17H14N2O, the dihedral angle between the benzene ring and naphthalene ring system is 11.0 (3)°. The azo group adopts an anti configuration and an intra­molecular N—H⋯O hydrogen bond exists. Mol­ecules are packed by π–π inter­actions between adjacent mol­ecule (closest approach between centroids of benzene and naphthalene rings of 3.501 Å)