An integrated microfabricated cell sorter

We have developed an integrated microfabricated cell sorter using multilayer soft lithography. This integrated cell sorter is incorporated with various microfluidic functionalities, including peristaltic pumps, dampers, switch valves, and input and output wells, to perform cell sorting in a coordinated and automated fashion. The active volume of an actuated valve on this integrated cell sorter can be as small as 1 pL, and the volume of optical interrogation is approximately 100 fL. Different algorithms of cell manipulation, including cell trapping, were implemented in these devices. We have also demonstrated sorting and recovery of Escherichia coli cells on the chip.     

Nine-analyte detection using an array-based biosensor

A fluorescence-based multianalyte immunosensor has been developed for simultaneous analysis of multiple samples. While the standard 6 x 6 format of the array sensor has been used to analyze six samples for six different analytes, this same format has the potential to allow a single sample to be tested for 36 different agents. The method described herein demonstrates proof of principle that the number of analytes detectable using a single array can be increased simply by using complementary mixtures of capture and tracer antibodies. Mixtures were optimized to allow detection of closely related analytes without significant cross-reactivity. Following this facile modification of patterning and assay procedures, the following nine targets could be detected in a single 3 x 3 array: Staphylococcal enterotoxin B, ricin, cholera toxin, Bacillus anthracis Sterne, Bacillus globigii, Francisella tularensis LVS, Yersiniapestis F1 antigen, MS2 coliphage, and Salmonella typhimurium. This work maximizes the efficiency and utility of the described array technology, increasing only reagent usage and cost; production and fabrication costs are not affected.     

Processing and characterisation of sol-gel glasses and powders in the system TeO2-TiO2

Sol-gel processing routes have been developed for the production of thin films and powders in the system TeO₂-TiO₂ from tellurium and titanium alkoxides. The structure and properties of the resultant materials have been characterised as a function of heat treatment temperature. Pure sol-gel derived TeO₂ thin films are difficult to prepare with good optical transparency due to the presence of organic impurities and/or a highly dispersed metallic tellurium phase when heated at temperatures up to approximately 340°C, with crystallisation to -TeO₂ occurring when the heat treatment temperature is further increased. Additions of TiO₂ were found to retard the crystallisation of the -TeO₂ but promote the formation of other TiO₂ or TiTe₃O₈ phases. However, an optimum composition in the range 0.9TeO₂ 0.1TiO₂ was identified, which allows optically transparent thin films to be prepared with high refractive index and offers the potential for practical device manufacture.     

Electrophoretic deposition of alkaline earth coatings from EDTA complexes

A novel process route combining electrophoretic deposition (EPD) and ethylene-diamine-tetra-acetic acid (EDTA) complexation has been developed and used to produce crack-free coatings of alkaline earth oxides with thickness up to 8 m after heat treatment at 700°C. Aqueous systems were found to be unsuitable for the EPD process due to their high conductivity and the effect of liberated gas evolved on the electrodes, and a non-aqueous based alternative formulation was developed based on methanol (solvent/carrier) and ethanediol (stabiliser) in conjunction with the EDTA complexes to allow the EPD process to be successfully used to deposit porous coatings. The coating process has been investigated by electrochemical impedance spectroscopy (EIS), and is thought to involve a combination of the migration of complexed ions in solution, their precipitation as charged colloidal particles in the vicinity of the anode, followed by their aggregation at, and adhesion to the anode surface. It is believed the process may have application for the low cost deposition of a wide range of porous coatings.     

Dynamics and control in component‐based agent models

Dynamics are an important aspect of agent models. Control of dynamics requires specific methods of specification that have their own specific semantics. This paper addresses specification and semantics of dynamics and control in component‐based agent models. Specification is based on a dedicated formal design specification language for agent models. Semantics of the dynamics are defined using temporal traces with composite states. It is shown in what manner control aspects can be specified, and what their semantics is in terms of the temporal traces. An agent model for controlled diagnostic reasoning processes is used to illustrate the approach. © 2002 Wiley Periodicals, Inc.     

Amperometric sensing of ethylene oxide in the gas phase

The sensing device used is based on a porous Pt electrode, which is supported on an ion-exchange membrane and directly exposed to the gas phase. Under acid conditions, ethylene oxide was found to be oxidized on the platinum oxide surface at +550 mV vs MSE, thus enabling its monitoring via the measurement of the associated current. A detection limit of 15 ppb was obtained, based on a signal-to-noise ratio of three, and a linear dynamic range was found up to 100 ppm. The effects of mass transport, humidity, and oxygen on the cell response, as well as the cross sensitivity to other organic vapors and inorganic gases are discussed.     

Supplementation with isoflavonoid phytoestrogens does not alter serum lipid concentrations: a randomized controlled trial in humans

Isoflavonoids are a class of flavonoids that are derived in the human diet mainly from soybean-based foods. The major dietary isoflavonoids, genistein and daidzein, have estrogen-like activity and are classed as phytoestrogens. Because estrogens can lower serum LDL cholesterol and raise HDL cholesterol, the objective of this study was to determine if isoflavonoids could improve serum lipids in healthy subjects. Forty-six men and 13 postmenopausal women not receiving hormone replacement therapy completed a randomized, double-blind, placebo-controlled trial of two-way parallel design and 8 wk duration. One tablet containing 55 mg of isoflavonoids (predominantly in the form of genistein) or one placebo tablet was taken daily with the evening meal. Subjects maintained their usual diet and physical activity, which were unchanged throughout the intervention. Measurement of isoflavonoids and their metabolites in 24-h urine samples provided an assessment of compliance and of isoflavonoid metabolism. Serum total, LDL, HDL and HDL subclass cholesterol, triglycerides and lipoprotein (a) were assessed at baseline and during the last week of intervention. After adjustment for baseline values, no significant differences in postintervention serum lipid and lipoprotein (a) concentrations between groups were identified. Further adjustment for age, gender and weight change did not alter the results. In addition, changes in urinary isoflavonoids were not significantly correlated with changes in serum lipids and lipoprotein (a). Therefore, this study does not support the hypothesis that isoflavonoid phytoestrogens can improve the serum lipids, at least in subjects with average serum cholesterol concentrations.     

"Choice processing in emotionally difficult decisions": Correction.

Reports an error in the article "Choice Processing in Emotionally Difficult Decisions' by Mary Frances Luce, James R. Bettman, and John W. Payne (Journal of Experimental Psychology: Learning, Memory, and Cognition, 1997, Vol. 23, No. 2, pp. 384–405; see record 1997-03378-007). In Table 7 on page 396, the high conflict/low trade-off difficulty mean for the PATTERN variable was printed as -0.13, but the actual mean is 0.13. A portion of the original abstract follows: Extends the standard effort-accuracy approach to explaining task influences on decision processing by arguing that coping goals will interact with effort-minimization goals for negatively emotion-laden decision tasks. These coping goals may involve both a desire to process in a thorough, accurate manner and a desire to avoid particularly distressing aspects of processing. The authors hypothesized and found in 3 experiments that decision processing under increasing negative emotion both becomes more extensive and proceeds more by focusing on one attribute at a time. In particular, increased negative emotion leads to more attribute-based processing at the beginning of the decision process. The results are inconsistent with views that negative emotion acts only as an incentive or only as a source of decision complexity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Beam-quality changes generated by thermally-induced sphericalaberration in laser cavities

Thermally-induced spherical aberration in Nd:YAG rods is investigated. Attention is concentrated on the so-called “intensity moment formalism” to analyze the beam-quality parameter of the emitted laser beams. A number of resonance conditions that certain beam-shape parameters of any stable laser mode should fulfill are also derived, and a comparison with previously reported numerical results is presented     

Prototypic typology and the Borderline Personality Disorder.

Based on interview data from 76 18–45 yr old outpatients, the implications of a prototypic rather than a classical model of personality-disorder classification were demonstrated for DSM-III Axis II Borderline Personality Disorder (BPD). Heterogeneity of membership is described, and conditional probabilities are used to demonstrate the relative efficiency of single diagnostic criteria and combinations of criteria and the degree of overlap among BPD and other personality disorders. The conditional probability approach can be used to determine empirically the covariation of symptoms and to link the study of prototypicality to the individual patient rather than to the group. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)