金属组学在急性心肌梗死早期诊断的应用

为探讨急性心肌梗死(AMI)患者血清中K⁺、Na⁺、Ca²⁺、Fe²⁺、Mg²⁺含量变化,并研究其与心肌梗死患者之间的关系。选取2022年5月至2023年2月收治的AMI患者37例,同时选取健康体检者35例作为对照组。依据入院时或体检时收集的抽血样本进行临床生化分析,比较两组间血清K⁺、Na⁺、Ca²⁺、Fe²⁺、Mg²⁺含量,采用判别方程、主成分分析法(PCA),判断分析哪种金属离子对于心肌梗死的诊断价值大。结果表明,AMI患者的血清中Ca²⁺和Fe²⁺含量低于健康对照组,差异具有统计学意义。基于血钙、铁水平两组具有显著性差异,以它们为基础进行判别分析,获得判别函数式。将血清中K⁺、Na⁺、Ca²⁺、Fe²⁺、Mg²⁺     

FTIR直接鉴别植物生药材

本文首次利用傅里叶变换红外光谱法的漫反射采样技术,快速、直接地测定了２５种常用植物生药材。结果表明：各种中药材由于其化学成分的不同使得每种药材都有自己独特的红外谱,据红外特征吸收均能达到分类鉴别、种类认定的目的。该方法具有快速、准确、制样简单不需对样品进行提取分离等特点。     

On-chip multiphoton Greenberger–Horne–Zeilinger state based on integrated frequency combs

One of the most important multipartite entangled states, Greenberger–Horne–Zeilinger state (GHZ), serves as a fundamental resource for quantum foundation test, quantum communication and quantum computation. To increase the number of entangled particles, significant experimental efforts should been invested due to the complexity of optical setup and the difficulty in maintaining the coherence condition for high-fidelity GHZ state. Here, we propose an ultra-integrated scalable on-chip GHZ state generation scheme based on frequency combs. By designing several microrings pumped by different lasers, multiple partially overlapped quantum frequency combs are generated to supply as the basis for on-chip polarization-encoded GHZ state with each qubit occupying a certain spectral mode. Both even and odd numbers of GHZ states can be engineered with constant small number of integrated components and easily scaled up on the same chip by only adjusting one of the pump wavelengths. In addition, we give the on-chip design of projection measurement for characterizing GHZ states and show the reconfigurability of the state. Our proposal is rather simple and feasible within the existing fabrication technologies and we believe it will boost the development of multiphoton technologies.     

Abundant Intramolecular Ring Rearrangements of 1-(N-Benzyloxycarbonylamino)arylmethylphosphonate Phenyl monoesters Under Electrospray Ionization Conditions

Abstract

The mass spectrometric behavior of 1-(N-benzyloxycarbonylamino)arylmethyl-phosphonate phenyl monoesters was investigated under positive ion electrospray ionization conditions. All nitrogen-protonated title compounds undergo four- and/or six-membered ring rearrangements to yield nitrogen-containing fragment ions by consecutive or simultaneous loss of a carbon dioxide and phenyl hydrogen phosphonate or phenyl benzylphosphonate or an arylmethylimine. All oxygen-protonated title compounds undergo four- to six-membered ring rearrangements to produce fragment ions by loss of a carbon dioxide plus an arylmethylimine, or phenyl benzylphosphonate, by consecutive or simultaneous loss of benzyl phenyl ether and isocyanic acid. The fragmentation is obviously different from the corresponding methyl and ethyl monoesters, which show a tendency to undergo intramolecular four-membered ring rearrangements only.

GRAPHICAL ABSTRACT      

高温熔融–电感耦合等离子体发射光谱法测定钼废渣中钼

通过优化高温熔融试剂和温度与分析谱线,建立了高温熔融-电感耦合等离子体发射光谱法快速测定钼废渣中钼含量的方法.准确称取0.10 g干燥钼废渣粉末,用2.5 g碳酸钠和1.0 g四硼酸钠混合熔剂于铂金坩埚中经920℃高温熔融15 min,以20 mL硝酸浸取并用水定容至200 mL.选择Mo 202.032 nm为分析谱...     

Ambient Preparation of Benzoxazine-based Phenolic Resins Enables Long-term Sustainable Photosynthesis of Hydrogen Peroxide

Rational design of polymer structures at the molecular level promotes the iteration of high-performance photocatalyst for sustainable photocatalytic hydrogen peroxide (H₂O₂) production from oxygen and water, which also lays the basis for revealing the reaction mechanism. Here we report a benzoxazine-based m-aminophenol-formaldehyde resin (APFac) polymerized at ambient conditions, exhibiting superior H₂O₂ yield and long-term stability to most polymeric photocatalysts. Benzoxazine structure was identified as the crucial photocatalytic active segment in APFac. Favorable adsorption of oxygen/intermediates on benzoxazine structure and commendable product selectivity accelerated the reaction kinetically in stepwise single-electron oxygen reduction reaction. The proposed benzoxazine-based phenolic resin provides the possibility of production in batches and industrial application, and sheds light on the de novo design and analysis of metal-free polymeric photocatalysts.     

Design of Hollow Nanoreactors for Size- and Shape-Selective Catalytic Semihydrogenation Driven by Molecular Recognition

Mimicking the structures and functions of cells to create artificial organelles has spurred the development of efficient strategies for production of hollow nanoreactors with biomimetic catalytic functions. However, such structure are challenging to fabricate and are thus rarely reported. We report the design of hollow nanoreactors with hollow multishelled structure (HoMS) and spatially loaded metal nanoparticles. Starting from a molecular-level design strategy, well-defined hollow multishelled structure phenolic resins (HoMS-PR) and carbon (HoMS-C) submicron particles were accurately constructed. HoMS-C serves as an excellent, versatile platform, owing to its tunable properties with tailored functional sites for achieving precise spatial location of metal nanoparticles, internally encapsulated (Pd@HoMS-C) or externally supported (Pd/HoMS-C). Impressively, the combination of the delicate nanoarchitecture and spatially loaded metal nanoparticles endow the pair of nanoreactors with size–shape-selective molecular recognition properties in catalytic semihydrogenation, including high activity and selectivity of Pd@HoMS-C for small aliphatic substrates and Pd/HoMS-C for large aromatic substrates. Theoretical calculations provide insight into the pair of nanoreactors with distinct behaviors due to the differences in energy barrier of substrate adsorption. This work provides guidance on the rational design and accurate construction of hollow nanoreactors with precisely located active sites and a finely modulated microenvironment by mimicking the functions of cells.     

Direct Visualization of Atomic Structure in Multivariate Metal-Organic Frameworks (MOFs) for Guiding Electrocatalysts Design

The direct utilization of metal–organic frameworks (MOFs) for electrocatalytic oxygen evolution reaction (OER) has attracted increasing interests. Herein, we employ the low-dose integrated differential phase contrast-scanning transmission electron microscopy (iDPC-STEM) technique to visualize the atomic structure of multivariate MOFs (MTV-MOFs) for guiding the structural design of bulk MOFs for efficient OER. The iDPC-STEM images revealed that incorporating Fe³⁺ or 2-aminoterephthalate (ATA) into Ni-BDC (BDC: benzenedicarboxylate) can introduce inhomogeneous lattice strain that weaken the coordination bonds, which can be selectively cleaved via a mild heat treatment to simultaneously generate coordinatively unsaturated metal sites, conductive Ni@C and hierarchical porous structure. Thus, excellent OER activity with current densities of 10 and 100 mA cm⁻² are achieved over the defective MOFs at small overpotentials of 286 mV and 365 mV, respectively, which is superior to the commercial RuO₂ catalyst and most of the bulk MOFs.     

基于单(6-巯基-6-去氧)-β-环糊精修饰金电极对L-半胱氨酸的快速灵敏检测

将单(6-巯基-6-去氧)-β-环糊精(HS-β-CD)通过金硫键自组装在金电极(GE)表面,构建了一种简单、快速、灵敏的超分子识别L-半胱氨酸(L-Cys)的电位型电化学传感器。通过循环伏安法和交流阻抗法研究了膜表面的电化学行为;通过扫描电子显微镜(SEM)和X射线光电子能谱(XPS)表征了电极表面的膜组装效果,其作用机制是固定在金电极表面的HS-β-CD空穴可通过分子间作用力吸附结合带负电的L-Cys,使电极表面的膜电位发生改变,导致对L-Cys的超分子选择性识别作用,从而实现对L-Cys的定量分析。在优化的实验条件下,该电极在pH=6. 0的磷酸盐缓冲溶液中对L-Cys有良好的电位响应性能,线性范围为1. 0×10^-7～1. 0×10^-4mol/L,斜率为(-65. 29±1. 0) mV/pc(25℃),检测下限达到6. 0×10^-8mol/L;电极响应速度快、稳定性和重现性好、抗干扰能力强。将该电极用于实际猪血清和猪尿液样品中L-Cys含量的测定,回收率为95. 0%～104. 7%,表明该新型电极在生命科学等...     

Theoretical calculational investigation on the regioselectivity of the ring opening of thiiranes with ammonia and amines

The course, especially the regioselectivity, of the nucleophilic ring opening of thiiranes with ammonia and amines was investigated with the density functional theory (DFT) calculation. In the ring-opening reaction, thiiranes could be attacked on either their less or more substituted carbon atoms. The analyses of the potential energy surfaces, the bond lengths, and charges of key species in both pathways indicate that alkyl-substituted thiiranes are attacked dominantly on their less substituted ring carbon atom, whereas arylthiiranes are on their more substituted one due to the existence of the p-π conjugative effect, which stabilizes the transition states generated in the reaction. Furthermore, the Lewis acid can modulate the regioselectivity. However, the steric hindrance of nucleophiles and solvents affect the regioselectivity slightly as they show similar influence on both pathways, despite the fact that they can put an impact on the energy. NBO and MO analyses also support the substituent-depended regioselectivity. This is the first DFT calculational investigation on the regioselective ring opening of thiiranes and provides a rational explanation for the experimental results. The theoretical investigation gives a general understanding and a rule for the rationale and prediction of the regioselectivity in the nucleophilic ring opening of thiiranes, even other three-membered heterocycles.