Physiological Roles of β-amyloid in Regulating Synaptic Function:Implications for AD Pathophysiology

The physiological functions of endogenous amyloid-β(Aβ),which plays important role in the pathology of Alzheimer's disease(AD),have not been paid enough attention.Here,we review the multiple physiological effects of Aβ,particularly in regulating synaptic transmission,and the possible mechanisms,in order to decipher the real characters of Aβunder both physiological and pathological conditions.Some worthy studies have shown that the deprivation of endogenous Aβgives rise to synaptic dysfunction and cognitive deficiency,while the moderate elevation of this peptide enhances long term potentiation and leads to neuronal hyperexcitability.In this review,we provide a new view for understanding the role of Aβin AD pathophysiology from the perspective of physiological meaning.

Biodegradation of typical azole fungicides in activated sludge under aerobic conditions

Widespread use of azole fungicides and low removal efficiency in wastewater treatment plants(WWTPs) have led to the elevated concentration of azole fungicides in receiving environment. However, there was limited research about the removal mechanism of azole fungicides in the biological treatment of WWTPs. Imidazole fungicide climbazole and triazole fungicide fluconazole were selected to investigate the biodegradation mechanism of azole fungicides in activated sludge under aerobic conditions. Climbazole was found to be adsorbed to solid sludge and resulted in quick biodegradation. The degradation of climbazole in the aerobic activated sludge system was fitted well by the first-order kinetic model with a half-life of 5.3 days, while fluconazole tended to stay in liquid and had only about 30% of loss within 77 days incubation. Ten biotransformation products of climbazole were identified by high resolution mass spectrometry using suspect and non-target screening method. But no biodegradation products of fluconazole were identified due to its limited removal. The possible biodegradation pathways for climbazole were proposed based on the products identification and pathway prediction system, and involves oxidative dehalogenation, side chain oxidation and azole ring loss. The findings from this study suggest that it should be a concern for the persistence of fluconazole in the environment.

一种超快的碲化法用于非常规相控碲化钯小纳米颗粒的合成

本研究发展了一种超快的碲化方法,可以在碳纳米管上快速制备非常规相控碲化钯小纳米颗粒.这种碲化方法只需要一台家用微波炉,整个过程非常快(60秒),简单,不含表面活性剂,可规模化生产.通过在相同条件下仅调整前驱体Te粉的使用量,可以精确调控合成小尺寸(约5.5 nm)、高产率(约90%)的六方结构PdTe/CNT和菱方结构Pd_(20)Te_7/CNT.其中,六方结构的PdTe/CNT在甘油氧化反应(GOR)和乙二醇氧化反应(EGOR)中表现出卓越的性能.具体来说,六方结构的PdTe/CNT在甘油氧化反应中,最高电流密度可达2.72 A mg_(Pd)^(-1),比菱方结构Pd_(20)Te_7/CNT的最高电流密度高1.9倍,比Pd/CNT最高电流密度高2.8倍,超过了目前文献中报道过的大多数催化剂.同时,六方结构的PdTe/CNT在乙二醇氧化反应中比活性达到3.65 A mg_(pd)^(-1),比菱方结构的Pd_(20)Te_7/CNT和Pd/CNT分别高2.1倍和3.9倍.我们希望这项工作可以为小尺寸非常规相控碲化物催化剂的制备提供新的碲化方法指导,并为相控材料的应用提供启发.

Large-scale estimates of gross primary production on the Qinghai-Tibet plateau based on remote sensing data

Vegetation gross primary production(GPP)is an important variable for the carbon cycle on the Qinghai-Tibetan Plateau(QTP).Based on the measurements from 12 eddy covariance flux sites,we validated a light use efficiency model(i.e.EC-LUE)to evaluate the spatial-temporal patterns of GPP and the effect of environmental variables on QTP.In general,EC-LUE model performed well in predicting GPP at different time scale over QTP.Annual GPP over the entire QTP ranged from 575 to 703 Tg C,and showed a significantly increasing trend from 1982 to 2013.However,there were large spatial heterogeneities in long-term trends of GPP.Throughout the entire QTP,air temperature increase had a greater influence than solar radiation and precipitation(PREC)changes on productivity.Moreover,our results highlight the large uncertainties of previous GPP estimates due to insufficient parameterization and validations.When compared with GPP estimates of the EC-LUE model,most Coupled Model Intercomparison Project(CMIP5)GPP products overestimate the magnitude and increasing trends of regional GPP,which potentially impact the feedback of ecosystems to regional climate changes.