Automated carbohydrate profiling by capillary electrophoresis: a bioindustrial approach

Automated, high-resolution, quantitative, high-throughput analysis of mono- and oligosaccharides, produced by enzymatic digestion of cellohexaose (model substrate) and lignocellulosic biomass, is demonstrated using high-performance capillary electrophoresis in conjunction with a single-step fluorophore labeling strategy for sensitive laser-induced fluorescence detection. Unattended batch sample processing from 96-well plates enabled reliable industrial-scale carbohydrate analysis. Excellent resolution of mono- and oligosaccharides was achieved under suppressed electroosmotic flow conditions, using either covalently or dynamically coated fused-silica capillary columns. The proposed approach readily supports the demands of bioindustrial operation environments with respect to high-throughput carbohydrate profiling.     

JT-60U装置温度分布剖面不变性的实验研究

在一系列H模放电条件下，建立了一个旨在研究等离子体温度分布剖面不变性的数据库。介绍了数据库建立过程中要解决的关键问题和所用软件，对等离子体温度分布剖面不变性及芯部约束与边缘参数的关系进行了研究。     

Barkhausen effect in magnetic thin films: General behaviour and stationarity along the hysteresis loop

Several aspects of the Barkhausen effect can be investigated by using a measurement equipment that records the Barkhausen signal as a function of time in digital form on computer tape. Measurements on thin magnetic films containing a small number of domain walls are presented. The behaviour of the wall jumps during a reversal is investigated. During the steep part of the loop the stationarity of the signal is measured with the magnetic field as a parameter. The influence of the coercive fieldH _c and the thicknessd _m is considered and compared with results obtained by others on bulk samples.     

Immuno-column for on-line quantification of human serum IgG antibodies to Helicobacter pylori in human serum samples

This study report an human serum IgG antibodies to Helicobacter pylori quantitation procedure based on the multiple use of an immobilized H. pylori antigen on an immuno-column incorporated into an a flow-injection (FI) analytical system. The immuno-adsorbent column was prepared by packing 3-aminopropyl-modified controlled-pore glass (APCPG) covalently linking H. pylori antigens in a 3-cm of Teflon tubing (0.5 i.d.). Antibodies in the serum sample are allowed to react immunologically with the immobilized H. pylori antigen, and the bound antibodies are quantified by alkaline phosphatase (AP) enzyme-labeled second antibodies specific to human IgG. p-Aminophenyl phosphate (pAPP) was converted to p-aminophenol (pAP) by AP and an electroactive product was quantified on glassy carbon electrode (GCE) modified with multiwall carbon nanotubes (MWCNT) (GCE-CNTs) at 0.30 V. The total assay time was 25 min. The calculated detection limits for amperometric detection and the ELISA procedure are 0.62 and 1.8 UmL(-1), respectively. Reproducibility assays were made using repetitive standards of H. pylori-specific antibody and the intra- and inter-assay coefficients of variation were below 5%. The immuno-affinity method showed higher sensitivity and lower time-consumed, demonstrate its potential usefulness for early assessment of human serum immunoglobulin G (IgG) antibodies to H. pylori.     

High Ni2+-mobility in the Chevrel phase Ni2Mo6S8: a quasielastic neutron scattering study

A quasielastic neutron scattering study of Ni₂Mo₆S₈ has established relatively fast long-range motion of the intercalated Ni²⁺ ions, with a diffusion constantD=3×10^–9 cm² s^–1. A model with a jump distance of about 2.1 Å and an activation energy of 24 kJ/mol is favoured. A critical consideration of the information contained in fixed window measurements is given.     

Open‐tubular capillary electrochromatography for the simultaneous determination of cadmium and copper in plants

We discuss the separation and determination of cadmium and copper in plant samples such as Triticum durum (wheat) and Helianthus annuus (sunflower) using open tubular capillary electrochromatography with indirect detection. Before performing the analysis, the samples were digested by microwave‐assisted methods using HNO₃. Regarding the electrophoretic system, several experimental parameters were previously evaluated such as the capillary surface, mobile phase composition, buffer, pH, and voltage applied. The baseline resolution of the studied metals was obtained within 8 min by using a capillary immobilized with carboxylic multi‐walled carbon nanotubes and a background electrolyte composed of 6 mM imidazole, pH 4.0. The applied voltage and the temperature were set at 20 kV and 25°C, respectively. Precision, detection, and quantification limits, along with linearity were investigated. The limits of detection and quantification were 2.20 and 7.40 μg/kg, for Cu²? and 0.05 and 0.20 μg/kg in the case of Cd²?. A good linearity was achieved over a concentration working range of 7.5–100 and 0.2–25 μg/kg for Cu²? and Cd²? accordingly. Recovery data for validation studies were found in a range of 98.2–101.5% for both analytes.     

Large-scale carbohydrate analysis by capillary array electrophoresis: part 2. Data normalization and quantification

Automated 96-capillary array electrophoresis (CAE) methodology described in the first part of the present work offered large-scale high-performance profiling of oligo- and monosaccharides to fulfill the needs of bioindustrial laboratories. Sensitivity at low nanomolar concentration, good resolving power and reliability achieved in the experiments is invaluable for monitoring reaction products from enzymatic polysaccharide digestion with numerous applications in agricultural, chemical and food industries. In addition to optimization of mono- and oligosaccharide separations in CAE system and necessary operational protocol modifications, capillary-to-capillary and run-to-run variation in migration time and signal intensity necessitated development of data normalization tools. Internal fluorescent standards have been incorporated into the analysis aiding migration time normalization and CAE trace alignment. Data processing, visualization, and programming tools have been developed along with quantification approaches.     

Performance of slotted pores in particle manufacture using rotating membrane emulsification

This paper addresses the use of different slotted pores in rotating membrane emulsification technology.Pores of square and rectangular shapes were studied to understand the effect of aspect ratio (1-3.5) and their orientation on oil droplet formation.Increasing the membrane rotation speed decreased the droplet size,and the oil droplets produced were more uniform using slotted pores as compared to circular geometry.At a given rotation speed,the droplet size was mainly determined by the pore size and the fluid velocity of oil through the pore (pore fluid velocity).The ratio of droplet diameter to the equivalent diameter of the slotted pore increased with the pore fluid velocity.At a given pore fluid velocity and rotation speed,pore orientation significantly influences the droplet formation rate: horizontally disposed pores (with their longer side perpendicular to the membrane axis) generate droplets at double the rate of vertically disposed pores.This work indicates practical benefits in the use of slotted membranes over conventional methods.