金属钯/聚乙撑二氧噻吩-木质素磺酸钠复合材料的制备及电催化性能

以木质素磺酸钠(LGS)作为掺杂剂,三氯化铁和过硫酸铵为氧化剂及引发剂,利用氧化聚合法制备了聚乙撑二氧噻吩-木质素磺酸钠(PEDOT-LGS)复合聚合物,通过化学法沉积金属钯(Pd)粒子获得Pd/PEDOT-LGS复合聚合物功能材料。应用扫描电镜(SEM)、X射线衍射(XRD)、红外光谱(FT-IR)对材料的形貌及结构进行表征。结果显示,获得了分散均匀的Pd纳米粒子复合聚合物功能材料。采用循环伏安测试法(CV)和计时电流测试法(CA)研究该复合材料的电化学行为,结果表明,掺杂了LGS的载体材料PEDOT-LGS的导电性能得到明显改善;与Pd/PEDOT相比,Pd/PEDOT-LGS复合材料对甲醇的电催化氧化活性提高了2.4倍,此外新载体有效地提高了Pd纳米粒子对甲醇在碱性溶液中的电催化活性及催化剂的抗毒化性能。

Factors affecting directional migration of bone marrow mesenchymal stem cells to the injured spinal cord

Microtubule-associated protein 1B plays an important role in axon guidance and neuronal migration. In the present study, we sought to discover the mechanisms underlying microtu- bule-associated protein 1B mediation of axon guidance and neuronal migration. We exposed bone marrow mesenchymal stem cells to okadaic acid or N-acetyl-D-erythro-sphingosine （an inhibitor and stimulator, respectively, of protein phosphatase 2A） for 24 hours. The expression of the phosphorylated form of type I microtubule-associated protein 1B in the cells was greater after exposure to okadaic acid and lower after N-acetyl-D-erythro-sphingosine. We then injected the bone marrow mesenchymal stem cells through the ear vein into rabbit models of spinal cord contusion. The migration of bone marrow mesenchymal stem cells towards the injured spinal cord was poorer in cells exposed to okadaic acid- and N-acetyl-D-erythro-sphingosine than in non-treated bone marrow mesenchymal stem cells. Finally, we blocked phosphatidylinosi- tol 3-kinase （PI3K） and extracellular signal-regulated kinase 1/2 （ERK1/2） pathways in rabbit bone marrow mesenchymal stem cells using the inhibitors LY294002 and U0126, respectively. LY294002 resulted in an elevated expression of phosphorylated type I microtubule-associated protein 1B, whereas U0126 caused a reduction in expression. The present data indicate that PI3K and ERKI/2 in bone marrow mesenchymal stem cells modulate the phosphorylation of micro- tubule-associated protein 1B via a cross-signaling network, and affect the migratory efficiency of bone marrow mesenchymal stem cells towards injured spinal cord.

Simultaneously Enhanced Activity and Selectivity for C(sp^(3))-H Bond Oxidation Under Visible Light by Nitrogen Doping

Selective oxidation of saturated C(sp^(3))-H bonds in hydrocarbon to target chemicals under mild conditions remains a signifi-cant but challenging task because of the chemical inertness and high dissociation energy of C(sp^(3))-H bonds.Semiconductor photocatalysis can induce the generation of holes and oxidative radicals,off ering an alternative way toward selective oxidation of hydrocarbons under ambient conditions.Herein,we constructed N-doped TiO_(2) nanotubes(N-TNTs)that exhibited remark-able activity and selectivity for toluene oxidation under visible light,delivering the conversion of toluene and selectivity of benzaldehyde of 32% and>99%,respectively.Further mechanistic studies demonstrated that the incorporation of nitrogen induced the generation of N-doping level above the O 2p valance band,directly contributing to the visible-light response of TiO_(2).Furthermore,hydroxyl radicals generated by photogenerated holes at the orbit of O 2p were found to be unselective for the oxidation of toluene,aff ording both benzaldehyde and benzoic acid.The incorporation of nitrogen was able to inhibit the generation of hydroxyl radicals,terminating the formation of benzoic acid.

一例非典型的快速进展性痴呆

目的:报道1例非典型的快速进展性痴呆患者,以提高临床医生对该病的认识。方法:对1例67岁男性患者的临床表现、体征、脑脊液、影像结果进行分析。结果:患者老年男性,隐袭起病,病情进行性加重,临床表现为走路不稳、性格改变,后期出现认知功能下降。颅脑MRI可见双侧基底节、丘脑、额顶叶皮层多发对称性异常信号;脑脊液14-3-3蛋白阳性。结论:结合患者临床表现、体征、脑脊液、颅脑MRI结果,考虑很可能的克雅病。克雅病临床表现复杂,容易漏诊,临床中应引起重视。

Regulation of Active Oxygen Species by Grain Boundaries to Optimize Reaction Paths toward Aerobic Oxidations

Aerobic oxidation by using molecular oxygen(O_(2))as the oxidant is highly attractive,in which activating O_(2)to reactive oxygen species(ROS)is a prerequisite.Although some progress has been achieved in regulating ROS by heterogeneous catalysts,the strategies to efficiently control ROS in aerobic oxidation are still urgently desired.Herein,grain boundaries(GBs)in metal oxides are discovered to be able to facilely regulate ROS.Impressively,MoO_(3)nanocrystals with high density of GBs(MoO_(3)-600)deliver a mass activity of 83 mmol g^(-1)h^(-1)in aerobic oxidation of benzyl alcohol,7 and 8 times as high as that of MoO_(3)nanoparticles without GBs and Pt/C,respectively.In addition,the selectivity of benzoic acid is 100%during whole reaction process over MoO_(3)-600.Mechanistic studies reveal that the oxygen atoms at GBs in MoO_(3)-600 are highly active to form·OH radicals with the generation of oxygen vacancies,while the oxygen vacancies are replenished by O_(2).The reaction path directly contributes to the excellent catalytic performance.

An Improved Method of the Energy Loss Calculation Considering the Volatility of Wind Power Generation

The energy loss of the power grid is one of the key factors affecting the economic operation of power systems. How to calculate the electric energy consumption accurately will have a great influence on the planning, operation and management of the power grid. Currently there is a mountain of theoretical methods to calculate the line loss of the power system. However, these methods have some limitation, such as less considering the volatility of wind power resources. This paper presents an improved method to calculate the energy loss of wind power generation, considering the fluctuations of wind power generation. First, data are collected to obtain the curve of the typical daily expected output of wind farms for one month. Second, the curve of the typical daily expected output are corrected by the average electricity and the shape factor to obtain the curve of the typical daily equivalent output of wind farms for one month. Finally, the power flow is calculated by using typical daily equivalent output curve to describe the energy loss for one month. The results in the 110 kV main network show that the method is feasible.

Astrocyte-derived exosome-transported GJA1-20k attenuates traumatic brain injury in rats

To the Editor:Traumatic brain injury(TBI)refers to brain tissue damage caused by trauma.TBI pathogenesis is complicated and the involved molecular targets are also not clear.Astrocytes proliferate and hypertrophy after brain injury.They have strong tolerance to hypoxia and ischemia to protect neurons in the acute phase of brain injury.

Au atoms doped in Ti_(3)C_(2)T_(x)MXene:Benefiting recovery of oxygen vacancies towards photocatalytic aerobic oxidation

Photocatalytic aerobic oxidation by using oxygen molecules(O_(2))as green and low-cost oxidants is of great attraction,where the introduction of irradiation has been proved as an efficient strategy to lower reaction temperature as well as promote catalytic performance.Moreover,the oxygen vacancies(OVs)of catalyst are highly active sites to adsorb and activate O_(2)during photocatalytic aerobic oxidation.However,OVs are easily blocked by oxygen atoms from active oxygen species during the catalytic process,leading to the deactivation of catalysis.Herein,a promising catalyst toward photocatalytic aerobic oxidation was successfully developed by recovering the OVs through doping Au atoms into Ti_(3)C_(2)T_(x)MXene(Au/Ti_(3)C_(2)T_(x)).Impressively,Au/Ti_(3)C_(2)T_(x)exhibited remarkable activity under full-spectrum irradiation towards photooxidation of methyl phenyl sulfide(MPS)and methylene blue(MB),attaining a conversion of>90%at room temperature.Moreover,Au/Ti_(3)C_(2)T_(x)also manifested remarkable stability by maintaining>95%initial activity after 10 successive reaction rounds.Further mechanistic studies indicated that the OVs of Au/Ti_(3)C_(2)T_(x)served as the active centers to efficiently adsorb and activate O_(2).More importantly,the doped Au atoms of Au/Ti_(3)C_(2)T_(x)were conducive to the recovery of OVs during photocatalytic process from the results of theoretical and experimental aspects.The recovered OVs of Au/Ti_(3)C_(2)T_(x)continuously and efficiently activated O_(2),directly contributing to the remarkable catalytic activity and stability.

Self-powered electronic paper with energy supplies and information inputs solely from mechanical motions

The electronic paper(E-paper)displays features such as flexibility,sunlight visibility,and low power consumption,which makes it ideal for Internet of Things(IoT)applications where the goal is to eliminate bulky power modules.Here,we report a unique self-powered E-paper(SPEP),where information inputs and energy supplies are all converted from mechanical motion by a triboelectric nanogenerator(TENG).The operation of an electrophoretic E-paper is first investigated,identifying the current density as a determinative parameter for driving pigment particle motion and color change.Electrical and optical responses of the E-paper driven by a slidingmode TENG are then found to be consistent with that under a current source mode.All-in-one monochromic and chromatic SPEPs integrated with a flexible transparent TENG are finally demonstrated,and a pixelated SPEP is discussed for future research.The sliding-driven mechanism of SPEP allows for a potential handwriting function,is free of an extra power supply,and promises undoubtedly a wide range of future applications.

Non-densely defined impulsive neutral stochastic functional differential equations driven by fBm in Hilbert space with infinite delay

We study a class of non-densely defined impulsive neutral stochastic functional differential equations driven by an independent cylindrical fractional Brownian motion （fBm） with Hurst parameter H ∈ （1/2, 1） in the Hilbert space. We prove the existence and uniqueness of the integral solution for this kind of equations with the coefficients satisfying some non-Lipschitz conditions. The results are obtained by using the method of successive approximation.

Dynamics of triboelectric nanogenerators: A review

Triboelectric nanogenerators(TENGs)represent a promising next‐generation renewable energy technology.TENGs have become increasingly popular for harvesting vibration energy in the environment due to their advantages of lightweight,broad range of material choices,low cost,and no pollution.However,issues such as input force irregularity,working bandwidth,efficiency calculation,and dynamic modeling hinder the use of TENGs in industrial or practical applications.In this paper,the modeling process of the dynamical system of a TENG is reviewed from the perspective of energy flow.In addition,this paper reviews the main contributions made in recent years to achieve optimized output based on springs,magnetic forces,and pendulums,and introduces different ways to increase the bandwidth of TENGs.Finally,the main problems of TENGs in the process of harvesting vibration energy are discussed.This review may serve as a practical reference for methods to convert irregular mechanical input sources into optimized output performance toward the commercialization of TENGs.

Insights into effects of thermotolerant nitrifying and sulfur-oxidizing inoculants on nitrogen-sulfur co-metabolism in sewage sludge composting

In this study,high temperature thermotolerant nitrifying bacteria(TNB)and high temperature thermotolerant sulfide oxidizing bacteria(TSOB)were obtained from compost samples and inoculated into sewage sludge(SS)compost.The effects of inoculation on physical and chemical parameters,ammonia and hydrogen sulfide release,nitrogen form and sulfur compound content change and physical-chemical properties during nitrogen and sulfur conversion were studied.The results showed that inoculation of TNB and TSOB increased the temperature,pH,OM degradation,C/N ratio and germination index(GI)of compost.Compared with the control treatment(CK),the addition of inoculants reduced the release of NH_(3) and H_(2)S,and transformed them into nitrogen and sulfur compounds,the hydrolysis of polymeric ferrous sulfate was promoted,resulting in relatively high content of sulfite and sulfate.At the same time,the physical and chemical properties of SS have a strong correlation with nitrogen and sulfur compounds.