消像差光栅展宽器中色散量的矩阵分析

在ABCD矩阵基础上,通过引入角度色散项获得了可以方便描述色散系统的3×3阶矩阵方程.利用这种矩阵方程计算了消像差光栅展宽器中的二阶色散量,得到的结果与由常规积分法获得的结果相同,表明采用矩阵方程计算色散系统色散量具有简单方便,包含信息量大,可适用于任意结构色散系统等特点.     

导数恒基体强度同步荧光分析法同时测定光谱严重重叠的1-氯蒽和9-溴蒽

通过选择适合测定路径,应用恒基体强度同步及荧光法同时测定了两种光谱严重重叠的蒽衍生物1－氯蒽和9－溴蒽。混合物中1－氯蒽和9－溴蒽不必预分离就能直接同时测定。在混合物中1－氯蒽和9－溴蒽的回收率分别为83．5％－94．0％,90．0％－94．0％,检出限分别为0．69μg/L,10μg/L。     

基体辅助激光解吸电离飞行时间质谱用于人参皂甙Rg3的定量分析

考察了基体辅助激光解吸电离时间飞行质谱用于人参皂甙Rg3 定量分析时内标的选择。加入棉子糖作为内标时 ,Rg3 的定量标准曲线的回归系数R2 =0 .938,平均相对误差为 2 8 6 % ;加入性质相近的芦丁后 ,Rg3 的定量标准曲线的回归系数R2 =0 993,平均相对误差为 7 5 %。分辨率的提高以及采用Rg3 和内标物的质谱峰的相对面积来代表Rg3 的浓度可以使定量的重现性明显改善     

A Polymeric Extracellular Matrix Nanoremodeler for Activatable Cancer Photo-Immunotherapy

Cancer immunotherapy has shown tremendous potential to train the intrinsic immune system against malignancy in the clinic. However, the extracellular matrix (ECM) in tumor microenvironment is a formidable barrier that not only restricts the penetration of therapeutic drugs but also prevents the infiltration of antitumor immune cells. We herein report a semiconducting polymer-based ECM nanoremodeler (SPNcb) to combine photodynamic antitumor activity with cancer-specific inhibition of collagen-crosslinking enzymes (lysyl oxidase (LOX) family) for activatable cancer photo-immunotherapy. SPNcb is self-assembled from an amphiphilic semiconducting polymer conjugated with a LOX inhibitor (β-aminopropionitrile, BAPN) via a cancer biomarker (cathepsin B, CatB)-cleavable segment. BAPN can be exclusively activated to inhibit LOX activity in the presence of the tumor-overexpressed CatB, thus blocking collagen crosslinking and decreasing ECM stiffness. Such an ECM nanoremodeler synergizes immunogenic phototherapy and checkpoint blockade immunotherapy to improve the tumor infiltration of cytotoxic T cells, inhibiting tumor growth and metastasis.     

Excess energy and equation of state of fluids with hard-core potential models from a second-order Monte Carlo perturbation theory

Monte Carlo simulations in the NVT ensemble of the reference hard-sphere fluid have been performed to obtain the “exact” first- and second-order terms in the inverse temperature expansion of the free energy of fluids with hard-core potentials. The results have been used to obtain parametrizations of the free energy of fluids with Sutherland potentials with variable range as well as for a fluid with a hard-core Lennard–Jones potential. The results for the excess energy and the equation of state are compared with simulation data available in the literature for these fluids.     

Thermal stabilization of tellurium in mineral acids solutions: use of permanent modifiers for its determination in sulfur by GFAAS

The aim of this work is the study of the best conditions for thermal stabilization of tellurium in graphite furnaces under different experimental conditions, including highly concentrated nitric and hydrochloric acids solutions as those resulting of drastic dissolution procedures. The influence of different noble metals used as matrix modifiers in solution or as permanent layers on the graphite furnace will be assessed.Amongst the assayed matrix modifiers, iridium used as permanent has shown the best performance in high concentrations of mineral acids. The mass employed was 20 μg (for 1 ng of Te), with a maximal attainable pyrolysis temperature of 1400 °C without losses of the analyte or sensitivity (height, area and form of the atomization peak), being mo = 20 pg. Some speculations on the mechanisms of thermal stabilization of tellurium in graphite furnaces will be discussed.The potentiality of ETAAS for tellurium determination in technical grade sulfur will be evaluated. Results involving characteristics mass, limit of detection and percentage of recovery of tellurium in a mineralized sulfur sample will be compared with those obtained through a working curve in absence of interferences.     

The Reduction of CS2N3 − Ion In Acidic Solution

Abstract

The electrochemical behaviour of 1, 2, 3, 4-thiatriazol-5-thiolate CS₂N₃ ^? ion in acidic solutions has been investigated. A cathodic wave has been detected, (E_1/2 =?1.05V versus S.C.E., M=1.0M (NaC10₄) and NaCS₂N₃ 1.00 × 10^?3M). The characteristics of this wave have been investigated by D.C., A.C. polarography and controlled potential electrolysis. A mechanism which involves the interaction of CS₂N₃ ^? with mercury and cyclic regeneration of mercury has been proposed. The reduction of CS₂N₃ ^? by amalgamated zinc has been also investigated and the results correlated with the pseudo-halide electrochemical reduction.     

基质固相分散-液相色谱串联质谱法同时检测鸡蛋中15种真菌毒素生物标志物

采用基质固相分散( Matrix solid phase dispersion, MSPD)技术,结合高效液相色谱-电喷雾离子化串联质谱联用技术( HPLC-ESI-MS/MS)分析,在多反应监测( MRM)模式下建立了鸡蛋中呕吐毒素、黄曲霉素、玉米赤霉烯酮等15种真菌毒素生物标志物的同时定量分析的方法。样品与吸附剂C18颗粒直接混合装柱,并用20 mL 1 mmol/L甲酸铵的乙腈/甲醇(1：1, V/V)溶液洗脱、吹干,萃取液经复溶、过滤后即可进行检测,整个分析过程无需复杂的净化、离心等步骤。本方法在0.2~100 ng/mL范围内具有良好的线性关系,相关系数R2逸0.9931,检出限在0.05~2.0μg/kg 之间,定量限在0.2~4.0μg/kg 之间,样品的提取回收率为61%~90%。     

Off-line hyphenation of boronate affinity monolith-based extraction with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for efficient analysis of glycoproteins/glycopeptides

Boronate affinity materials have attracted increasing attentions as sample enrichment platforms for glycoproteomic analysis in recent years. However, most of the boronate affinity materials that have already employed for proteomic analysis are suffering from apparent disadvantages, such as alkaline pH for binding, weak affinity, and relatively poor selectivity. Benzoboroxoles are a unique class of boronic acids which have showed excellent binding properties for the recognition of cis-diol-containing compounds. Recently, a 3-carboxy-benzoboroxole-functionalized monolithic column had been reported and it had exhibited the best selectivity and affinity as well as the lowest binding pH among all reported boronate affinity monolithic columns. In this study, an off-line hyphenation of this boronate affinity monolithic column-based extraction with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was developed and the powerfulness of this hyphenated approach in the analysis of glycoproteins and glycopeptides in complex samples was investigated. The approach was first applied to the analysis of glycopeptides in the tryptic digest of horseradish peroxidase (HRP). Totally 22 glycopeptides were identified. To the best of our knowledge, this is the best performance among all the boronic acid-functionalized materials. We further employed this approach to the analysis of intact proteins in human saliva. Totally 6 intact glycoproteins were successfully identified. As comparison, when the samples were analyzed without extraction, only a few glycopeptides were identified from the tryptic digest of HRP while no glycoproteins were found from the saliva samples.     

Matrix solid‐phase dispersion coupled with homogeneous ionic liquid microextraction for the determination of sulfonamides in animal tissues using high‐performance liquid chromatography

Matrix solid‐phase dispersion coupled with homogeneous ionic liquid microextraction was developed and applied to the extraction of some sulfonamides, including sulfamerazine, sulfamethazine, sulfathiazole, sulfachloropyridazine, sulfadoxine, sulfisoxazole, and sulfaphenazole, in animal tissues. High‐performance liquid chromatography was applied to the separation and determination of the target analytes. The solid sample was directly treated by matrix solid‐phase dispersion and the eluate obtained was treated by homogeneous ionic liquid microextraction. The ionic liquid was used as the extraction solvent in this method, which may result in the improvement of the recoveries of the target analytes. To avoid using organic solvent and reduce environmental pollution, water was used as the elution solvent of matrix solid‐phase dispersion. The effects of the experimental parameters on recoveries, including the type and volume of ionic liquid, type of dispersant, ratio of sample to dispersant, pH value of elution solvent, volume of elution solvent, amount of salt in eluate, amount of ion‐pairing agent (NH₄PF₆), and centrifuging time, were evaluated. When the present method was applied to the analysis of animal tissues, the recoveries of the analytes ranged from 85.4 to 118.0%, and the relative standard deviations were lower than 9.30%. The detection limits for the analytes were 4.3–13.4 μg/kg.