一种车用单刀双掷开关的质检仪器研发

介绍了一种车用单刀双掷开关质量检测仪器的研发,包括检测系统的硬件设计、检测原理以及算法软件开发。首先,根据单刀双掷开关的工作原理及质量检测要求,开发了检测手指触觉压力的机械装置,以及控制开关通道切换的继电器控制电路;在此基础上,开发了相应的检测算法,可实现对开关切换状态、电压差以及手指触觉压力进行自动化的数据采集、分析、检测和判断,从而挑选出合格的开关;最后,设计了触屏人机交互界面,可实时显示产品检测的参数。该检测设备在某自动化生产线上经过近一年时间的检测验证,证明系统运行平稳,检测效果良好、误检率低,可以完全取代传统的人工检测方式,提高了开关的检测效率,降低了检测人员的工作量。     

False Results Caused by Solvent Impurity in Tetrahydrofuran for MALDI TOF MS Analysis of Amines

Tetrahydrofuran (THF) is one of the most frequently used solvents in the MALDI TOF MS analysis of synthetic compounds. However, it should be used with caution because a trace amount of 4-hydroxybutanal (HBA) might be generated and accumulated in THF during storage. Since only a tiny amount of analytes is required in MALDI MS measurements, a trace amount of HBA might have a significant effect on the MS results. It was found that HBA will quickly react with primary and secondary amino compounds, leading to false results about the sample composition with an extra series of ions with additional mass of 70 Da in between. The formation of HBA can be inhibited by butylated hydroxytoluene (BHT) antioxidant. Therefore, when THF is required as the solvent for sample preparation, it is strongly recommended to use a BHT-stabilized one, at least for the analysis of compounds with amino groups.

Hexicon 2: Automated Processing of Hydrogen-Deuterium Exchange Mass Spectrometry Data with Improved Deuteration Distribution Estimation

Hydrogen–deuterium exchange (HDX) experiments analyzed by mass spectrometry (MS) provide information about the dynamics and the solvent accessibility of protein backbone amide hydrogen atoms. Continuous improvement of MS instrumentation has contributed to the increasing popularity of this method; however, comprehensive automated data analysis is only beginning to mature. We present Hexicon 2, an automated pipeline for data analysis and visualization based on the previously published program Hexicon (Lou et al. 2010). Hexicon 2 employs the sensitive NITPICK peak detection algorithm of its predecessor in a divide-and-conquer strategy and adds new features, such as chromatogram alignment and improved peptide sequence assignment. The unique feature of deuteration distribution estimation was retained in Hexicon 2 and improved using an iterative deconvolution algorithm that is robust even to noisy data. In addition, Hexicon 2 provides a data browser that facilitates quality control and provides convenient access to common data visualization tasks. Analysis of a benchmark dataset demonstrates superior performance of Hexicon 2 compared with its predecessor in terms of deuteration centroid recovery and deuteration distribution estimation. Hexicon 2 greatly reduces data analysis time compared with manual analysis, whereas the increased number of peptides provides redundant coverage of the entire protein sequence. Hexicon 2 is a standalone application available free of charge under http://hx2.mpimf-heidelberg.mpg.de.

Dynamics simulation and reaction pathway analysis of characteristics of soot particles in ethylene oxidation at high temperature

Soot particles characteristics were investigated numerically for high temperature oxidation of C₂H₄/O₂/N₂ (C/O ratio of 2.2) in a closed jet-stirred/plug-flow reactor (JSR/PFR) system. Based on the growth mechanism of polycyclic aromatic hydrocarbons (PAHs), two mechanisms were used to explore the formation pathways of soot precursors and soot. Numerical results were compared with the experimental and reference data. The simulation results show that the value predicted for small molecule intermediates within A1 gives a strong regularity, consistent trend with reference data. However, with the hydrogen-abstraction-carbon-addition (HACA) growth mechanism, the predicted value for beyond-A1 PAH macromolecules and soot volume fraction are smaller than the experimental data. The results also show that the predicted soot volume fraction is in good agreement with experimental data when a combination of the HACA and PAHs condensation (HACA + PAH-PAH) growth mechanisms is used. Analyses of the A1 sensitivity and reaction pathway elucidated that A1 are mainly formed from C₂H₃, C₂H₂, C₃H₃, C₆H₅OH, A1C₂H and A1-. The reaction 2C₃H₃ → A1 is the dominant route of benzene formation. The prediction results and an analysis of the A3 reaction pathway indicate that the growth process from benzene to larger aromatic hydrocarbons (beyond two-ring polycyclic aromatic hydrocarbons [PAHs]) goes by two pathways, i.e., HACA combined with the PAH-PAH radical recombination and addition reaction growth mechanisms.     

Enzymatic Building-Block Synthesis for Solid-Phase Automated Glycan Assembly

Automated chemical oligosaccharide synthesis is an attractive concept that has been successfully applied to a large number of target structures, but requires excess quantities of suitably protected and activated building blocks. Herein we demonstrate the use of biocatalysis to supply such reagents for automated synthesis. By using the promiscuous NmLgtB-B β1-4 galactosyltransferase from Neisseria meningitidis we demonstrate fast and robust access to the LacNAc motif, common to many cell-surface glycans, starting from either lactose or sucrose as glycosyl donors. The enzymatic product was shown to be successfully incorporated as a complete unit into a tetrasaccharide target by automated assembly.     

Divergent Total Synthesis of Euphoranginol C,Euphoranginone D,ent-Trachyloban-3β-ol,ent-Trachyloban-3-one,Excoecarin E,and ent-16α-Hydroxy-atisane-3-one

A divergent synthetic approach to biogenetically related diterpenoids such as ent-kauranes, ent-trachylobanes, ent-beyerane, and ent-atisane has been developed. The unified synthetic route involves the De Mayo reaction to rapidly generate the bicyclo[3.2.1]-octane moiety of ent-kaurane. The key reactions also include bioinspired nucleophilic cyclopropanation generating the [3.2.1.0^2,7]-tricyclic core of ent-trachylobane and regioselective cyclopropane fragmentation furnishing ent-beyerane and ent-atisane through the nucleophilic attack and protonation of the cyclopropane ring. This strategy enables the asymmetric total syntheses of six diterpenoids from the commercially available geraniol.     

Bioorthogonal Ligation and Cleavage by Reactions of Chloroquinoxalines with ortho-Dithiophenols

A bioorthogonal ligation and cleavage method via reactions of chloroquinoxalines (CQ) and ortho-dithiophenols (DT) is presented. Double nucleophilic substitutions of ortho-dithiophenols to chloroquinoxalines provide conjugates containing tetracyclic benzo[5,6][1,4]dithiino[2,3-b]quinoxaline with strong built-in fluorescence together with release of the other functional molecules. Three cleavable linkers were designed and successfully used in release of the molecules containing biotin from the protein conjugates. The CQ-DT bioorthogonal reactions can be applied for the bioorthogonal ligations, bioorthogonal cleavages, and trans-tagging of proteins, and show advantages of readily accessible unnatural orthogonal groups, appealing reaction kinetics (k₂≈1.3 m ⁻¹ s⁻¹), excellent biocompatibility of orthogonal groups, and high stability of conjugates. This complements previous bioorthogonal reactions and is a new route for protein-fishing applications and in-gel fluorescence analysis.     

Fabrication of Heterostructured Fe2TiO5–TiO2 Nanocages with Enhanced Photoelectrochemical Performance for Solar Energy Conversion

Photocatalysts with well‐designed compositions and structures are desirable for achieving highly efficient solar‐to‐chemical energy conversion. Heterostructured semiconductor photocatalysts with advanced hollow structures possess beneficial features for promoting the activity towards photocatalytic reactions. Here we develop a facile synthetic strategy for the fabrication of Fe₂TiO₅–TiO₂ nanocages (NCs) as anode materials in photoelectrochemical (PEC) water splitting cells. A hydrothermal reaction is performed to transform MIL‐125(Ti) nanodisks (NDs) to Ti–Fe–O NCs, which are further converted to Fe₂TiO₅–TiO₂ NCs through a post annealing process. Owing to the compositional and structural advantages, the heterostructured Fe₂TiO₅–TiO₂ NCs show enhanced performance for PEC water oxidation compared with TiO₂ NDs, Fe₂TiO₅ nanoparticles (NPs) and Fe₂TiO₅–TiO₂ NPs.     

On Symmetric Cayley Graphs of Valency Eleven

A Cayley graph Γ=Cay(G,S)is said to be normal if G is normal in Aut Γ.In this paper,we investigate the normality problem of the connected 11-valent symmetric Cayley graphs Γ of finite nonabelian simple groups G,where the vertex stabilizer Av is soluble for A=Aut Γ and v ∈ VΓ.We prove that either Γ is normal or G=A5,A10,A54,A274,A549 or A1099.Further,11-valent symmetric nonnormal Cayley graphs of A5,A54 and A274 are constructed.This provides some more examples of nonnormal 11-valent symmetric Cayley graphs of finite nonabelian simple groups after the first graph of this kind(of valency 11)was constructed by Fang,Ma and Wang in 2011.     

Quantification of Venetoclax for Therapeutic Drug Monitoring in Chinese Acute Myeloid Leukemia Patients by a Validated UPLC-MS/MS Method

Venetoclax has emerged as a breakthrough for treatment of leukemia with a wide interindividual variability in pharmacokinetics. Herein, a rapid, sensitive, and reliable UPLC-MS/MS method for quantification of venetoclax in plasma was developed and validated. The method was operated in the multiple-reaction monitoring (MRM) mode to detect venetoclax at m/z transition 868.5 > 321.0 and IS at 875.5 > 321.0, respectively. Protein precipitation prior to injection into the LC-MS/MS and the analyte was separated on an ACQUITY UPLC BEH C18 column by gradient elution with acetonitrile and 0.1% formic acid in water. Linear calibration curves were obtained in the range of 25–8000 ng/mL. The specificity, recovery, matrix effect, and stability also met the acceptance criteria of FDA guidance. The method was successfully applied to analyze plasma in acute myeloid leukemia (AML) patients. The peak plasma concentration (C_max) of venetoclax in Chinese AML patient was 2966.0 ± 1595.0 ng/mL while the trough concentration (C_min) was 1018.0 ± 729.4 ng/mL. Additionally, C_max and C_min showed a positive correlation with AST levels. Furthermore, C_max was significantly higher in the older patients. The present method can be applied for TDM of venetoclax in treatment of hematological cancers.