UPLC-Q/TOF-MS coupled with multivariate analysis for comparative analysis of metabolomic in Dendrobium nobile from different growth altitudes

Dendrobium nobile alkaloids (DNLA) and glycosides are the main active components extracted from Dendrobium nobile Lindl. (D. nobile) used for thousands of years in China. The pharmacological effects of the above chemical components are significantly different. D. nobile is mainly grown at an altitude ranging from 230 to 800 m in Chishui City, Northwest Guizhou Province. However, it is unclear whether the metabolite in D. nobile is influenced by the planting altitude. Hence, to reveal the different metabolite in D. nobile cultivated at the altitude of 336 m, 528 m, and 692 m, ultra-high performance liquid chromatography with Q/TOF-MS couple with multivariate analysis were developed. Using the orthogonal partial least squares-discriminant analysis, 19 different metabolites were discovered and then tentatively assigned their structures as alkaloids and glycosides by comparing mass spectrometry data with in-house database and literature. Moreover, the result of semiquantitative analysis showed the content of dendrobine that was belonged to alkaloids significantly increased at the altitude of 692 m, whereas the content of glycosides demonstrated an accumulation trend at the altitude of 528 m. The results could provide valuable information for the optimal clinical drug therapeutics and provide a reference for quality control.     

Modified fully discretized projection method for the incompressible Navier–Stokes equations

The stability and convergence of a second-order fully discretized projection method for the incompressible Navier–Stokes equations is studied. In order to update the pressure field faster, modified fully discretized projection methods are proposed. It results in a nearly second-order method. This method sacrifices a little of accuracy, but it requires much less computations at each time step. It is very appropriate for actual computations. The comparison with other methods for the driven-cavity problem is presented.     

A transflective polymer-stabilised blue-phase liquid display with partitioned wall-shaped electrodes

A transflective polymer-stabilised blue-phase liquid crystal display (BP-LCD) with partitioned wall-shaped electrodes is proposed. The etched polymer layer contributes to balance the optical phase retardation between transmissive (T) and reflective (R) regions. The partitioned wall-shaped electrodes generate uniform and horizontal fields throughout the entire LC layer to induce isotropic-to-anisotropic transition in the blue-phase liquid crystal medium through Kerr effect. Consequently, the accumulated phase retardation along beam path is large, resulting in reasonable low operation voltage and high transmittance both in T and R regions. This approach enables the BP-LCD to be addressed by amorphous silicon thin-film transistors. Moreover, it exhibits wide viewing angle and a well-matched gamma curve.     

Blue-phase liquid crystal display with insulating protrusion

In order to lower the saturation voltage and enhance the transmittance of in-plane switching blue-phase liquid crystal display (IPS-BPLCD), IPS-BPLCD with insulating protrusion is proposed. The single-protrusion (only set on the top of pixel electrode) and double-protrusion (set on the top of pixel and common electrodes) structures are investigated in this work. The potential distribution changes when the protrusion is used. There is a thicker transverse electric field in BPLC range, because the stronger electric field at the edges of the electrodes is decentralised into BPLC range. As a result, the saturation voltage is reduced from 36.3 V to 28.9 V when the double-protrusion structure is used, and transmittance is increased by ~20%. The contrast ratio is larger than 1000:1 in 60° viewing cone using a half-wave biaxial film. Both single-protrusion and double-protrusion structures have the uniform gamma curves at large oblique viewing angles. Moreover, the off-axis image distortion index is 0.1590 at 60º polar angle when zigzag electrodes are used.     

Selection of phage-displayed antibodies with high affinity and specificity by electrophoresis in microfluidic devices

A method development aimed for high-throughput and automated antibody screening holds great potential for areas ranging from fundamental molecular interactions to the discovery of novel disease markers, therapeutic targets, and monoclonal antibody engineering. Surface display techniques enable efficient manipulation of large molecular libraries in small volumes. Specifically, phage display appeared as a powerful technology for selecting peptides and proteins with enhanced, target-specific binding affinities. Here, we present a phage-selection microfluidic device wherein electrophoresis was performed under two orthogonal electric fields through an agarose gel functionalized with the respective antigen. This microdevice was capable of screening and sorting in a single round high-affinity phage-displayed antibodies against virus glycoproteins, including human immunodeficiency virus-1 glycoprotein 120 or the Ebola virus glycoprotein (EBOV-GP). Phages were differentially and laterally swept depending on their antigen affinity; the high-affinity phages were recovered at channels proximal to the application site, whereas low-affinity phages migrated distal after electrophoresis. These experiments proved that the microfluidic device specifically designed for phage-selection is rapid, sensitive, and effective. Therefore, this is an efficient and cost-effective method that allowed highly controlled assay conditions for isolating and sorting high-affinity ligands displayed in phages.     

Stable Convergence of Multiple Wiener-Itô Integrals

We prove sufficient conditions ensuring that a sequence of multiple Wiener-Itô integrals (with respect to a general Gaussian process) converges stably to a mixture of normal distributions. Note that stable convergence is stronger than convergence in distribution. Our key tool is an asymptotic decomposition of contraction kernels, realized by means of increasing families of projection operators. We also use an infinite-dimensional Clark-Ocone formula, as well as a version of the correspondence between “abstract” and “concrete” filtered Wiener spaces, in a spirit similar to that of Üstünel and Zakai (J. Funct. Anal. 143, 10–32, [1997]).     

Sequences of ultrafast non-resonant multiphoton transitions in a three-electronic level molecule

Non-resonant multiphoton transitions between three electronic states of a molecular system are studied. Based on a projection operator formalism which is formulated in the framework of the so-called time-local as well as the time-nonlocal approach, time-dependent Schrödinger equations are obtained, which include effective couplings to the laser field. For both procedures a slowly varying amplitude approximation can be invoked. The resulting time-local equations are solved in a much more efficient way than the original effective Schrödinger equations. The validity of these approximations is verified numerically for a two-photon process. Furthermore, the effective Schrödinger equations are specified to sequences of two-photon and three-photon transitions. The derived equations are applied to a molecular system consisting of three electronic states with Morse-type potential energy curves. Using different laser pulse scenarios the conditions are discussed under which a sequence of two-photon and three-photon transitions can take place.     

NMR and chemometric methods: a powerful combination for characterization of Balsamic and Traditional Balsamic Vinegar of Modena

This work presents the capability of NMR spectroscopy combined with Chemometrics in predicting the ageing of Balsamic and Traditional Balsamic Vinegar of Modena. The need of an analytical method is an important requirement for both research oriented and commercial evaluation of these very valuable products. ¹H NMR spectroscopy, based on the advantage of rapid sample analysis without any manipulation or derivatization, is here proposed as a valid tool to describe Balsamic and Traditional Balsamic Vinegar of Modena. For this purpose, 72 reliable samples, were divided into three different groups according to their ageing process: young (<12 years), old (>12 and <25 years) and extra old (>25 years). Hierarchical Projection to Latent Structures Discriminant Analysis (PLS-DA) allowed us to characterize the ageing process. Variables showing the largest VIP (Variable Importance in the Projection) were extracted from PLS-DA model, thus shedding lights onto the role played by specific compounds in this complex ageing process. Two robust classification models, were built by PLS-DA and Naïve Bayes classifier and compared to prove the accuracy of the representation on both training and test sets. The predictions obtained for 41 “unknown” vinegar samples with these both methods gave more than 80% agreement among them.