Ratiometric mode with dyads: a breakthrough in dynamic trapping and quantification for redox regulation in living cells

Redox-based post-translational modification of protein thiols has become an attractive strategy in cellular homeostasis and cell signaling.Due to the reductive end of the redox buffer network,the vicinal dithiol-containing proteins(VDPs)maintains an appropriate oxidation-reduction state of proteins through the reversible transformation from vicinal dithiols to disulfide,which is responsible for a variety of     

Metal-Organic Frameworks for Photocatalytic Water Splitting and CO2 Reduction

Photocatalytic water splitting and carbon dioxide (CO₂) reduction provide promising solutions to global energy and environmental issues. In recent years, metal-organic frameworks (MOFs), a class of crystalline porous solids featuring well-defined and tailorable structures as well as high surface areas, have captured great interest toward photocatalytic water splitting and CO₂ reduction. In this review, the semiconductor-like behavior of MOFs is first discussed. We then summarize the recent advances in photocatalytic water splitting and CO₂ reduction over MOF-based materials and focus on the unique advantage of MOFs for clarifying the structure-property relationship in photocatalysis. In addition, some representative characterization techniques have been presented to unveil the photocatalytic kinetics and reaction intermediates in MOF-based systems. Finally, the challenges, and perspectives for future directions are proposed.     

高效液相色谱-串联质谱法同时检测血液中3种季铵盐类肌松剂

维库溴铵、罗库溴铵和泮库溴铵是一类广泛使用的非去极化肌松剂,使用过程中引起过敏反应甚至死亡的情况时有发生,快速检测血液中该类肌松剂的浓度,可为临床早期诊断提供有价值的信息。该类肌松剂为强极性的季铵盐类化合物,在反相色谱柱上难以保留,主要采用离子对色谱法进行分离。采用离子对色谱法时,加入的离子对试剂有离子抑制作用,可降低质谱灵敏度,还会污染质谱系统。该文建立了高效液相色谱-串联质谱(HPLC-MS/MS)同时检测血液中3种季铵盐类肌松剂的检测方法。血液样品经稀释、高速离心后,上清液过Bond Elut AL-N固相萃取柱净化,用0.45 μm的微孔滤膜过滤后检测。采用ZIC-cHILIC色谱柱(50 mm×2.1 mm, 3.0 μm)分离,以乙腈和0.1%甲酸水溶液为流动相,梯度洗脱,在ESI⁺、多反应检测(MRM)模式下检测。3种季铵盐类肌松剂在血液中的基质效应为88.1%~95.4%,在各自范围内线性关系良好,相关系数(R²)均大于0.996,检出限为0.2~0.8 ng/mL,定量限为0.5~2.0 ng/mL,加标回收率为92.8%~110.6%,相对标准偏差(RSD)为3.2%~9.4%。该方法灵敏度高,准确性好,操作简便,可用于血液样品中维库溴铵、罗库溴铵和泮库溴铵的快速检测。     

四边固定载流矩形薄板的磁弹性稳定性分析

本文针对四边固定载流矩形薄板,利用Mathieu方程解的稳定性,研究其在电磁场与机械荷载共同作用下的磁弹性稳定性问题。首先在载流薄板的磁弹性非线性运动方程、物理方程、几何方程、洛仑兹力表达式及电动力学方程的基础上,导出了载流薄板在电磁场与机械荷载共同作用下的磁弹性动力稳定方程,然后应用Galer-kin方法将稳定方程整理为Mathieu方程的标准形式,并将薄板的动力稳定性问题归结为对Mathieu方程的求解。利用Mathieu方程的稳定解区域与非稳定解区域的分界,即方程系数λ和η的本征值关系,得出了磁弹性问题失稳临界状态的判别方程。通过具体算例,给出了四边固定载流矩形薄板的磁弹性动力失稳临界状态与相关参量之间的关系曲线,并对计算结果及其变化规律进行了分析讨论。     

白洋淀内水体的流动特征研究

研究了风对白洋淀内水体循环流动的影响，研究指出：(1)风应力可看作是水体循环 的主要驱动力. (2)在风应力的作用下，水体表层的流动主方向与风的方向一致，下层水体 的流动方向与表层方向相逆或近似相逆. (3)表层以下水体流动复杂，次表层水平流动有明 显的双涡结构. (4)淀底地形对水体垂向流动影响很大，垂向速度变化复杂，垂向上有双涡 流动现象. 从动力学角度研究了淀内水体流动的情况.     

THERMODYNAMIC AND PARTICLE-DYNAMIC STUDIES ON SYNTHESIS OF SILICA NANOPARTICLES USING MICROWAVE-INDUCED PLASMA CVD

1. Introduction1.1 Silica nanoparticles and synthesis methods Silica (SiO2) nanoparticles are widely used in industry asan active filler for polymer reinforcement, a rheologicaladditive in fluids, a free flow agent in powders, and anagent for chemical mechanical polishing during IC (inte-grated circuit) fabrication (Sniegowski & de Boer, 2000).Silica powder is also used for producing silicon carbide(Koc & Cattamanchi, 1998) or opaque silica aerosols (Leeet al., 1995). Many methods can …     

Silver(I)-mediated reaction of trimethylsilylated arylacetylenes with sulfonyl chlorides:Unexpected formation of vinvl sulfones

A novel reaction of trimethylsilylated arylacetylenes with sulfonyl chlorides was performed in the presence of silver nitrate or triflate.Conjugated vinyl sulfones as dramatic products were obtained in moderate yields and with Z-selectivity.A free radical mechanism has been proposed to account for the formation of the products.     

Photolyses of mammalian carboxy-hemoglobin studied by photoacoustic calorimetry

The enthalpy and conformational volume changes in the photolyses of carboxy-hemoglobin (HbCO) of human, bovine, pig, horse and rabbit are investigated by photoacoustic calorimetry. Considering the time scales of the exciting laser pulse and the receiving ultrasound transducers (PVDF films and PZT ceramics), as well as the reaction lifetimes in the photolysis processes of HbCO, the measured results are related to the geminate recombination and tertiary relaxation in photolyses of HbCO. Moreover, the quantum yields of the five mammals are also measured by laser pump-probe technique. The results show that the dynamic parameters, such as enthalpy and conformational volume changes, differ between the processes of the geminate recombination and tertiary relaxation. Also, the dynamic parameters differ among the five mammals although some of them may be consistent with each other.     

The sloshing of stratified liquid in a two-dimensional rectangular tank

The sloshing of inviscid liquid of stratified density in a rectangular tank is analyzed.As the flow is no longer irrotional,the governing equation is found to be quite different from the Laplace equation used for the liquid of constant density.In particular it contains terms of mixed temporal and spatial derivatives.The problem is solved based on the variable separation method and Laplace transform for the constant Vaisala-Brunt frequency.It is found that the stratification of density may have small effects...     

Generation of Bell states via Lyapunov control on a two-qubit system with an anisotropic XY Heisenberg interaction

We demonstrate that an arbitrary Bell state can be achieved in a two qubit anisotropic Heisenberg XY chain via Lyapunov control. During the whole process, we only need to apply an external field along a given direction to a single qubit. This control strategy is effective for all initial states in the four-dimensional Hilbert space where the target state is asymptotically stable. The effects of imperfections on the fidelity for the target state such as Gaussian leakage of local control and localized dephasi...