A new and simple approach to geometrical factor of a parallel disk source and detector system

A new approach for calculating the average solid angle of a parallel disk source and detector system by a projection procedure is described. Comparison between calculation and two different methods is given.     

NaNO2-activated, iron-TEMPO catalyst system for aerobic alcohol oxidation under mild conditions

FeCl3-TEMPO-NaNO2 catalyses the selective and mild aerobic oxidation of a broad range of alcohols to the corresponding aldehydes and ketones.     

多氯联苯的正辛醇-空气分配系数与气相色谱保留参数的关联

通过对19种多氯联苯（PCBs）在DB-1,DB-5和DB-1701等3种色谱柱上的气相色谱（GC）保留参数A,B值与正辛醇-空气分配系数(Koa)的相关分析,发现GC保留参数A,B与Koa存在明显的线性关系。采用了逐步回归的方法,建立了保留参数A,B与Koa的二元回归方程,相关系数的平方达到了0.99以上,标准偏差小于0.11。此外,根据实验测定的153个PCBs的GC保留参数以及定量构效关系（QSAR）研究中的56个预测值,对剩余190种PCBs的Koa值进行了预测。     

五种不同类型土壤中有机化合物土壤吸附系数的预测

为了验证土壤柱液相色谱法测定农药的土壤吸附系数的普遍适用性和预测的准确性,采用了5种组成及性质差异较大、具有一定代表性的土壤样品,对在甲醇 水流动相条件下测定的保留因子与土壤吸附系数间的相关性进行了研究。结果表明,土壤柱液相色谱法是预测农药的土壤吸附系数的一种有效方法,适于多种类型土壤中农药土壤吸附系数的预测。     

Sine-azimuthal wavefront-modulated cosh-Gaussian beams with half-space amplitude modulation

Half-space amplitude modulation was introduced into the linearly polarized cosh-Gaussian beams with sine-azimuthal variation wavefront, and corresponding tunable focal patterns were investigated in detail. Simulation results show that focal pattern can be changed remarkably by the amplitude modulation. And under condition of different beam parameters and phase parameter that indicates the sine-azimuthal variation wavefront, the focal pattern evolution also differs considerably. Some novel focal shape may appear, including cross-shape, multiple-peak focal pattern, multiple intensity lines, wheel focal pattern, bell shape, and swallowtail focal spots. Symmetry of the whole focal pattern can be altered remarkably, the whole focal pattern evolves into uniaxial symmetry about perpendicular axes for odd and even phase parameter, respectively.     

Zirconia layer coated mesoporous silica microspheres as HILIC SPE materials for selective glycopeptide enrichment

Characterization of protein glycosylation requires highly specific methods for the enrichment of glycopeptides because of their sub-stoichiometric glycosylation-site occupancy. The hydrophilic affinity based strategy has attracted more attention, owing to its broad glycan specificity, good reproducibility, and compatibility with mass spectrometric (MS) analysis. Several polar matrices have emerged for hydrophilic interaction chromatography (HILIC) approaches, including sepharose, cellulose, ZIC-HILIC and titania. Here, we present the solid-phase extraction (SPE) utility of zirconia coated mesoporous silica (ZrO(2)/MPS) microspheres for glycopeptide isolation prior to MS analysis. The high specificity of this SPE approach was demonstrated by the enrichment of glycopeptides from the digests of model glycoproteins in HILIC mode. ZrO(2)/MPS microspheres show superior selectivity and glycosylation heterogeneity coverage for glycopeptide enrichment to conventional sepharose. Furthermore, digested mixtures of the phosphoprotein α-casein and IgG were also treated with ZrO(2)/MPS HILIC SPE materials, which exhibited that glycopeptides could be effectively enriched with interference from phosphorylated peptides.     

Enantiorecognition ability of peptoids with α-chiral, aromatic side chains

The enantiorecognition ability of oligomeric N-substituted glycines or "peptoids" with α-chiral, aromatic side chains was investigated by HPLC and (1)H NMR studies.     

Metabonomic Study of Lung Cancer and the Effects of Radiotherapy on Lung Cancer Patients: Analysis of Highly Polar Metabolites by Ultraperformance HILIC Coupled with Q-TOF MS

In this study, plasma samples were collected from 28 health volunteers and 66 lung cancer patients. Ultraperformance HILIC/Q-TOF MS-based metabonomic techniques were employed to compare the highly polar metabolites (HPMs) in the plasma of patients with lung cancer and those in the plasma of healthy volunteers. High separation efficiency and good repeatability of the HILIC/Q-TOF MS method were observed. Partial least squares discriminant analysis (PLS-DA) of the data from both ESI+ and ESI? mode revealed good classifications between the health volunteer and the lung cancer patients. This result showed that the HPMs from lung cancer patients and healthy controls were significantly different. The correct classification rate of models in both ion modes reached 100%, indicating that the metabonomics method established in this study could predict the plasma samples with high accuracy. Besides, we found 19 ions that show a significant difference in levels between lung cancer patients and healthy controls. Finally, we conducted a primary study of the effect of radiotherapy on HPMs in lung cancer patients. Clear differences among the HPMs of patients in different radiotherapy periods and significant changes in levels of the 19 ions after radiotherapy were noted. This demonstrated that radiotherapy influences the metabolism system of patients.