Trehalose alleviates high-temperature stress in Pleurotus ostreatus by affecting central carbon metabolism.

BACKGROUND: Trehalose, an intracellular protective agent reported to mediate defense against many stresses, can alleviate high-temperature-induced damage in Pleurotus ostreatus. In this study, the mechanism by which trehalose relieves heat stress was explored by the addition of exogenous trehalose and the use of trehalose-6-phosphate synthase 1 (tps1) overexpression transformants. RESULTS: The results suggested that treatment with exogenous trehalose or overexpression of tps1 alleviated the accumulation of lactic acid under heat stress and downregulated the expression of the phosphofructokinase (pfk) and pyruvate kinase (pk) genes, suggesting an ameliorative effect of trehalose on the enhanced glycolysis in P. ostreatus under heat stress. However, the upregulation of hexokinase (hk) gene expression by trehalose indicated the involvement of the pentose phosphate pathway (PPP) in heat stress resistance. Moreover, treatment with exogenous trehalose or overexpression of tps1 increased the gene expression level and enzymatic activity of glucose-6-phosphate dehydrogenase (g6pdh) and increased the production of both the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH), confirming the effect of trehalose on alleviating oxidative damage by enhancing PPP in P. ostreatus under heat stress. Furthermore, treatment with exogenous trehalose or overexpression of tps1 ameliorated the decrease in the oxygen consumption rate (OCR) caused by heat stress, suggesting a relationship between trehalose and mitochondrial function under heat stress. CONCLUSIONS: Trehalose alleviates high-temperature stress in P. ostreatus by inhibiting glycolysis and stimulating PPP activity. This study may provide further insights into the heat stress defense mechanism of trehalose in edible fungi from the perspective of intracellular metabolism.

Using Monte Carlo simulation to assess uncertainty and variability of methamphetamine use and prevalence from wastewater analysis.

BACKGROUND: In recent years, methamphetamine (METH) has increased dramatically in China. However, little is known regarding the prevalence of METH use among the general population in China. METHODS: We provided a method to estimate the consumption and prevalence of METH in a city based on wastewater analysis. Monte Carlo simulations were employed to assess the uncertainty and variability of the consumption and prevalence rate in Beijing. RESULTS: METH consumption in Beijing based on Monte Carlo simulation varied between 1.3 and 5.2kg per day with a median of 2.6kg per day. In 2013, the 12-month prevalence of METH use was 0.58% (95% confidential interval 0.08-3.16) among the general population aged 15-64 years. A population-weight consumption map displayed the geographical differences in Beijing. CONCLUSIONS: The proposed method dramatically improved the accuracy and reliability and can be used as a useful complementary tool to official methodologies for drug use monitoring. This report describes the first comprehensive study concerning the prevalence of METH among the general population in mainland China.

[Study on the Emission Spectrum of Hydrogen Production with Microwave Discharge Plasma in Ethanol Solution].

Hydrogen is regarded as a kind of clean energy with high caloricity and non-pollution, which has been studied by many experts and scholars home and abroad. Microwave discharge plasma shows light future in the area of hydrogen production from ethanol solution, providing a new way to produce hydrogen. In order to further improve the technology and analyze the mechanism of hydrogen production with microwave discharge in liquid, emission spectrum of hydrogen production by microwave discharge plasma in ethanol solution was being studied. In this paper, plasma was generated on the top of electrode by 2.45 GHz microwave, and the spectral characteristics of hydrogen production from ethanol by microwave discharge in liquid were being studied using emission spectrometer. The results showed that a large number of H, O, OH, CH, C2 and other active particles could be produced in the process of hydrogen production from ethanol by microwave discharge in liquid. The emission spectrum intensity of OH, H, O radicals generated from ethanol is far more than that generated from pure water. Bond of O-H split by more high-energy particles from water molecule was more difficult than that from ethanol molecule, so in the process of hydrogen production by microwave discharge plasma in ethanol solution; the main source of hydrogen was the dehydrogenation and restructuring of ethanol molecules instead of water decomposition. Under the definite external pressure and temperature, the emission spectrum intensity of OH, H, O radicals increased with the increase of microwave power markedly, but the emission spectrum intensity of CH, C2 active particles had the tendency to decrease with the increase of microwave power. It indicated that the number of high energy electrons and active particles high energy electron energy increased as the increase of microwave power, so more CH, C2 active particles were split more thoroughly.

[Study on the emission spectrum of microwave plasma in liquid].

After the technology of microwave discharge in liquid is realized for the first time in China, the basic physical phenomena and characteristic of microwave discharge in liquid is studied in order to lay a theoretical foundation of research on microwave discharge in liquid. In the present paper, the active particles generated by microwave discharge in liquid were detected using the emission spectrometer, and the statistical method of spectrum data of microwave discharge in liquid was also studied. The emission spectrometer and numerically controlled camera were used to detect synchronously the process of the initial discharge and stable discharge of microwave discharge in liquid. The results show that: the emission intensity of microwave plasma in liquid has a large fluctuation, and the spectrum intensity can be calculated using the average of 10 spectrum data points. The intensity of discharge is reflected by the plasma area in a certain extent, however, the variation gradient of the intensity of discharge is different from that of the plasma area. This is mainly because that, in the process of discharging, the discharge intensity is not only reflected by the plasma area, but also reflected by the brightness of the plasma.

[Genome-wide identification of exported proteins of the novel bacterium Phenylobacterium zucineum HLK1(T) using a consensus computational strategy].

OBJECTIVE: To predict the exported proteins of the novel bacterium Phenylobacterium zucineum HLK1(T) using genome-wide computational identification by searching the export signals including N-terminal signal peptides and alpha-transmembrane helices. METHODS: The computational identification of signal sequences was based on a consensus between multiple predictive tools, including SignalP V3.0, LipoP V1.0, Phobius and TMHMM 2.0. Type IV signal peptides and proteins exported via TAT machinery were searched manually based on the conservative motifs. All the predicted proteins were classified according to the Cluster of Orthologous Group (COG) standard. RESULT: In the total 3861 proteins encoded by P. zucineum HLK1(T) 1 378 (35.7%) were predicted to be exported proteins, most of which (totally 735, 19.0% of the proteome and 53.3% of all the exported proteins) were uncleavable transmembrane helices. In addition, 499 type I signal peptides (12.9%, 36.2%), 101 lipoproteins (2.6%, 7.3%) were also identified. Four Type IV signal peptides and 12 TAT proteins were detected as well. According to the COG classification standard, most of these exported proteins were P proteins related to inorganic ion transport and metabolism and S proteins whose functions were unknown. CONCLUSION: The genome of HLK1(T) coded various types of exported proteins which may play an important role in the interaction between P. zucineum and the host cell, and facilitate the strain to invade into the cell.

Expression changes of thrombospondin-1 and neuropeptide Y in myocardium of STZ-induced rats.

Diabetic cardiomyopathy was the most dangerous diabetic complication facing diabetics, with its exact mechanisms remaining obscure. Our study was conducted to investigate the expression of thrombospondin-1 (TSP-1) and neuropeptide Y (NPY) in myocardium of streptozotocin (STZ)-induced diabetic rats. We employed streptozotocin (STZ)-induced diabetic rats to study the alteration of the TSP-1 and NPY expression in the left ventricle myocardium in diabetic and normal group by immunohistochemistry and immunofluorescence. The data of weight, blood sugar and urine sugar indicated no significant difference between the two groups before the animal model was induced. Four weeks after the induction of diabetes the weight of the diabeteic animals was 189.1+/-18.4 g, plasma glucose was 23.7+/-3.25 mmol/L and urine glucose was (++) to (+++); whereas the weight of the control animals was 260.5+/-32.1 g, plasma glucose was 4.9+/-0.5 mmol/L and urine glucose undetectable (-). The differences between the control and the diabetes group were distinct. A significant increase of the TSP-1 and NPY expression was also observed in the diabetic rat's heart. The number of the NPY positive myocardium and the light density of the positive myocardium in the left ventricle of the diabetic model were 17.3+/-2.1 and 102.5+/-9.3/mm(2), respectively, which were considered as increased when compared with the control that were 10.1+/-2.6 and 61.2+/-6.7, respectively. Our results support the view that high glucose conditions can induce an increased synthesis of TSP-1 through the PKC-TGF-beta-TSP-1 pathway, which in turn facilitate TGF-beta activation. Additionally, the activation of PKC may further lead to the over-expression of NPY. This may be involved in diabetic cardiomyopathy.