Impact of twice-a-day transcranial direct current stimulation intervention on cognitive function and motor cortex plasticity in patients with Alzheimer's disease

Background Non-invasive brain stimulation has improved cognitive functions in patients with Alzheimer's disease(AD),and some studies suggest a close relationship between cognition and plasticity.However,the clinical benefits of transcranial direct current stimulation(tDCS)in patients still need to be evaluated.Aims This study examined the role of tDCS in improving cognition and whether the improved cognition is related to altered cortical plasticity.Methods 124 patients with AD were randomly assigned to active tDCS(n=63)or sham tDCS(n=61).The tDCS was applied at the dorsolateral prefrontal cortex for 30 treatment sessions across 6 weeks(5 days per week,2 days off).The Mini-Mental State Examination and the Alzheimer's Disease Assessment Scale-Cognitive(ADAS-Cog)were used for cognition evaluation at baseline,week 2 and week 6.The cortical plasticity was represented by motor-evoked potential(MEP)measured with an electromyogram.Results The results showed thatmultiplecourses of active tDcS can improve the cognitive functions of patients with AD,especially in the memory domain(word recall,recall of test instructions and word recognition).In addition,the damaged MEP level was enhanced following active treatment.In the active tDCS group,the improvements in ADAS-Cog total and subitem(word recall and word recognition)scores were negatively correlated with the enhancement of MEP.Conclusions Our research indicates for the first time that twice-a-day tDS may improve the cognitive function of patients with AD.This study also suggests that cognitive dysfunction may be related to impaired cortical plasticity,which warrants mechanistic investigations of the relationship between cognition and plasticity in the future.

The relationship between soil,climate and forest development in the mid-mountain zone of the Sangong River watershed in the northern Tianshan Mountains,China

The mountainous forests in arid regions, being sensitive to climate change, are one of the key research topics related to the mechanism of interaction between climate and the terrestrial ecosystem. In this study, the spatial distribution of a mid-mountain forest and its environmental factors were investigated by using a combination of remote sensing technology, field survey, climate indices and soil nutrient analysis in the Sangong River watershed of the northern Tianshan Mountains. The forest （Picea schrenkiana） was distributed between 1,510 and 2,720 m asl. Tree height and diameter at breast height （DBH） exhibited a bi-modal pattern with increasing elevation, and rested at 2,450 and 2,250 m asl, respectively. The two maxima of DBH appeared at 2,000 and 2,550 m asl, and the taller trees were observed at 2,100 and 2,600 m asl. For the annual mean temperature, the difference was approximately 5.8℃ between the lowest and the highest limits of the forest, and the average decreasing rates per hundred meters were 0.4g℃ and 0.55℃ with increasing altitude between 1,500 and 2,000 m asl and above 2,000 m asl, respec- tively. The annual precipitation in the forest zone first increased and then decreased with the increase of altitude, and the maximum value was at 2,000 m asl. For per hundred meters, the annual precipitation increased with the rate of 31 mm between 1,500 and 2,000 m asl and decreased by 7.8 mm above 2,000 m asl. The SOM, TN and TP were high between 2,000 and 2,700 m asl and low at the lower and upper forest limits. The minimum CaCO3 con- centration, pH value and EC coincided with the maximum precipitation belt at 2,000 m asl. The SOM, TN and TP were high in the topsoil （0-10 cm） and differed significantly from the values observed in the deep soil layers （〉10 cm）. The soil nutrients exhibited spatial heterogeneity and higher aggregation in the topsoil. In conclusion, soil and climate are closely related to each other, working synergistically to determine the development and spatial distribution of the mid-mountain forest in the study area. The order of the importance of environmental factors to forest development in this study is as follows： soil nutrients〉precipitation〉elevation〉temperature.

2D Ca/Nb-based perovskite oxide with Ta doping as highly efficient H_(2)O_(2)synthesis catalyst

Perovskite oxides(POs)are emerging as a class of highly efficient catalysts for reducing oxygen to H_(2)O.Although a rich variety of POs-based catalysts have been developed by tuning the complex composition,a highly efficient PO catalyst that is able to alter the reaction pathway from a 4e−process to a 2e−process for H_(2)O_(2)production has rarely been achieved.We modified the structure and composition of a Ca-and Nb-based PO material by realizing a uniform two-dimensional(2D)morphology and varied Ta doping,resulting in the 2D Ca_(2)Nb_(3−x)Ta_(x)O_(10)−(x=0,0.5,1,and 1.5)monolayer catalysts.The obtained catalysts exhibit a dominant 2e−pathway and show exceptional H_(2)O_(2)production efficiency.The typical Ca_(2)Nb_(2.5)Ta_(0.5)O_(10)−nanoflakes showed an onset potential of 0.735 V vs.reversible hydrogen electrode(RHE),a remarkably high selectivity over 95%across a wide range of 0.3-0.7 V,an impressively high Faradaic efficiency of 94%,and a notable H_(2)O_(2)productivity of 1571 mmol·gcat^(−1)·h^(−1).These findings highlight the great potential of 2D perovskite oxide nanoflakes as advanced electrocatalysts for 2e−oxygen reduction reaction.

Approach and potential of replacing oil and natural gas with coal in China

China’s fossil energy is characterized by an abundance of coal and a relative lack of oil and natural gas.Developing a strategy in which coal can replace oil and natural gas is,therefore,a necessary and practical approach to easing the excessive external dependence on oil and natural gas.Based on the perspective of energy security,this paper proposes a technical framework for defining the substitution of oil and natural gas with coal in China.In this framework,three substitution classifications and 11 industrialized technical routes are reviewed.Then,three scenarios(namely,the cautious scenario,baseline scenario,and positive scenario)are developed to estimate the potential of this strategy for 2020 and 2030.The results indicate that oil and natural gas replaced by coal will reach 67 to 81 Mt and 8.7 to 14.3 Gm^3 in 2020 and reach 93 to 138 Mt and 32.3 to 47.3 Gm^3 in 2030,respectively.By implementing this strategy,China’s external dependence on oil,natural gas,and primary energy is expected to be curbed at approximately 70%,40%,and 20%by 2030,respectively.This paper also demonstrates how coal,as a substitute for oil and natural gas,can contribute to carbon and pollution reduction and economic cost savings.It suggests a new direction for the development of the global coal industry and provides a crucial reference for energy transformation in China and other countries with similar energy situations.

Effects of MOx(M=Mn,Cu,Sb,La)on V-Mo-Ce/Ti selective catalytic reduction catalysts

A series of MOx-V2O5-MoO3-CeO2/TiO2(M=Mn,Cu,Sb,and La) catalysts were prepared via an impregnation method.The physico-chemical properties of the catalysts were characterized and their NH3-SCR of NO performance was compared.The Mn-loaded catalyst(Mn5V1Mo3Ce7/Ti) exhibits a large number of acid sites of varying strength,and together with good reducibility of the catalyst,contributes to the optimal SCR performance.The sulphate species formed in the presence of SO2 significantly enhance the H2O and SO2 tolerance of Mn5V1Mo3Ce7/Ti.The Cu-loaded catalyst(Cu5V1Mo3Ce7/Ti)demonstrates potential in flue gas applications in the absence of SO2 at low temperatures because of the excellent redox ability observed and the high degree of weak acid sites.The Sb and La loaded catalysts(Sb5V1Mo3Ce7/Ti and La5V1Mo3Ce7/Ti),especially La5V1Mo3 Ce7/Ti,exhibit the largest number of acid sites and the lowest reducibility,and therefore,may be suitable for use in high temperature denitrification applications.