The detection of fake-bad and fake-good responding on the Millon Clinical Multiaxial Inventory III.

The purpose of this study was to examine the effectiveness of the 3 Modifying Indices of the Millon Clinical Multiaxial Inventory III (MCMI—III) in the detection of fake-bad and fake-good responding. The sample consisted of 160 psychiatric outpatients. Paired t tests were performed to examine the effects of instructional set (faking vs standard instructions). As hypothesized, instructional set produced significant differences on Scale X, Scale Y, and Scale Z in both fake-bad and fake-good analyses. Single-scale cutoff scores were as effective as multiple-scale cutoffs. The overall rates of successful classification indicated moderate effectiveness and utility of the MCMI—III Modifying Indices in the detection of dissimulated responding. When base rates were varied to more closely approximate a general clinical population, overall classification accuracy increased, but identification of faking (positive predictive power) gradually eroded with declining base-rate estimates. At lower base rates of faking, MCMI—III standard cutoff points yielded a high number of false positives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Formation of antibiotic,biodegradable polymers by processing with Irgasan DP300R (triclosan) and its inclusion compound with β-cyclodextrin

The inclusion compound (IC) between the FDA-approved antibacterial Irgasan DP300 (Trichlosan), and β-cyclodextrin (CD) has been formed. When the Irgasan–β-CD–IC is embedded in biodegradeable/bioabsorbable films of poly(ϵ-caprolactone) (PCL) at low levels (a few wt %), they are rendered resistant to the growth of E. coli bacteria. When these same PCL films embedded with Irgasan–β-CD–IC are used as the adhesive for laminating cotton fabrics, we observe the resulting cotton laminates to also be resistant to the growth of E. coli bacteria. These results hold promise for the fabrication of bacteria-resistant polymer films and fibers, as well as antibacterial fabrics, by means of simple melt processing with Irgasan–β-CD–IC. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 300–309, 2001     

Structure of Liquid Al6Si2O13 (3:2 Mullite)

We report the first measurements of the structure factor, S ( Q ), and the pair distribution function, G ( r ), of Al₆Si₂O₁₃ (3:2 mullite) in the normal and supercooled liquid states in the temperature range 1776–2203 K. Measurements are obtained by synchrotron X-ray scattering on levitated, laser-heated liquid specimens. The S ( Q ) shows a prepeak at 2.0 Å⁻¹ followed by a main peak at 4.5 Å⁻¹ and a weak feature at 8 Å⁻¹. The G ( r ) shows a strong (Si,Al)–O correlation at 1.80 Å at high temperature that moves to 1.72 Å as the liquid is supercooled. The second and third nearest neighbor peaks at 3.0 and 4.25 Å sharpen with supercooling. The short-range structure of the high-temperature liquid is similar to the corresponding glasses produced by rapid quenching. Supercooling causes an increase in the concentration of tetrahedral Si⁴⁺ ions, which is manifested by the large shift in the first peak to lower ionic distance, r , values in G ( r ). The increase in tetrahedrally coordinated Si⁴⁺ ions is offset by an increase in octahedral Al³⁺ ions. The clustering of the SiO₄⁴⁻ tetrahedral units results in increased viscosity of the liquid at temperatures below the melting point, which is consistent with Al₆Si₂O₁₃ being a fragile liquid.     

Solid source MBE growth of InAsP/InP quantum wells

Strained InAsP multiquantum wells (MWQs) were grown on InP(100) substrates by solid source molecular beam epitaxy and were characterized to relate structural and optical quality to growth conditions. The multiquantum wells were grown using either dimer or tetramer arsenic (As₂ or As₄) over the substrate temperature range of 420–535°C. θ-2θ x-ray diffraction measurements showed only slight differences between arsenic compositions in the quantum wells grown with As₂ or As₄. 300K and 8K photoluminescence full width at half max (FWHM) decreased at higher growth temperatures regardless of the arsenic species used. The 8K photoluminescence FWHM and the surface roughness measured by atomic force microscopy are found to be less sensitive to substrate growth temperature for the multiquantum wells growth with As₂ as opposed to As₄.     

Controlled two-photon photodegradation of PEG hydrogels to study and manipulate subcellular interactions on soft materials

Cell adhesion and detachment to and from the extracellular matrix (ECM) are critical regulators of cell function and fate due to the exchange of mechanical signals between the cell and its microenvironment. To study this cell mechanobiology, researchers have developed several innovative methods to investigate cell adhesion in vitro; however, most of these culture platforms are unnaturally stiff or static. To better capture the soft, dynamic nature of the ECM, we present a PEG-based hydrogel in which the context and geometry of the extracellular space can be precisely controlled in situ via two-photon induced erosion. Here, we characterize the two-photon erosion process, demonstrate its efficacy in the presence of cells, and subsequently exploit it to induce subcellular detachment from soft hydrogels. A working space was established for a range of laser powers required to induce complete erosion of the gel, and these data are plotted with model predictions. From this working space, two-photon irradiation parameters were selected for complete erosion in the presence of cells. Micron-scale features were eroded on and within a gel to demonstrate the resolution of patterning with these irradiation conditions. Lastly, two-photon irradiation was used to erode the material at the cell-gel interface to remove cell adhesion sites selectively, and cell retraction was monitored to quantify the mesenchymal stem cell (MSC) response to subcellular detachment from soft materials.     

Thermomechanical characterization of thermoset urethane shape‐memory polymer foams

The shape‐memory polymer performance of urethane foams compressed under a variety of conditions was characterized. The foams were water‐blown thermosets with a closed‐cell structure and ranged in density from about 0.25 to 0.75 g/cm³. Compressive deformations were carried out over a range of strain levels, temperatures, and lateral constraints. Recovery stresses measured between fixed platens were as high as 4 MPa. Recovery strains, measured against loads up to 0.13 MPa, demonstrated the effects of various parameters. The results suggest that compression near the foam glass‐transition temperature provided optimal performance. Foams with densities of about 0.5 g/cc and compressed 50% provided a useful balance (time, strain, and load) in the recovery performance. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Quantum dot/carrier-protein/haptens conjugate as a detection nanobioprobe for FRET-based immunoassay of small analytes with all-fiber microfluidic biosensing platform

This study demonstrates the use of carrier-protein/haptens conjugate (e.g., BSA/2,4-dichlorophenoxyacetic acid, 2,4-D-BSA) for biological modification of quantum dots (QDs) for the detection of small analytes. Bioconjugated QDs, which are used as a detection nanoimmunoprobe, were prepared through conjugating carboxyl QDs with 2,4-D-BSA conjugate. Based on the principle of quantum dot-fluorescence resonance energy transfer (QD-FRET), an all-fiber microfluidic biosensing platform has been developed for investigating FRET efficiency, immunoassay mechanism and format, and binding kinetics between QD immunoprobe and fluorescence labeled anti-2,4-D monoclonal antibody. The structure of multiplex-haptens/BSA conjugate coupling to QD greatly improves the FRET efficiency and the sensitivity of the nanosensor. With a competitive detection mode, samples containing different concentrations of 2,4-D were incubated with a given concentration of QD immunoprobe and fluorescence-labeled antibody, and then detected by the all-fiber microfluidic biosensing platform. A higher concentration of 2,4-D led to less fluorescence-labeled anti-2,4-D antibody bound to the QD immunoprobe surface and, thus, a lower fluorescence signal. The quantification of 2,4-D over concentration ranges from 0.5 nM to 3 μM with a detection limit determined as 0.5 nM. The performance of the nanosensor with spiked real water samples showed good recovery, precision, and accuracy, indicating that it was less suspectable to water matrix effects. With the use of different QD nanobioprobes modified by other carrier-protein/haptens conjugates, this biosensing protocol based on QD-FRET can be potentially applied for on-site, real-time, inexpensive, and easy-to-use monitoring of other trace analytes.     

REVERSE POTENTIAL PHENOMENA IN THE MEMBRANE-ELECTRODE (M-E) PROCESS

Conventional water treatment techniques typically suffer from severe limitations in selective removal and recovery of heavy metals from dilute solutions. For instance, treatment by pH control, chemical reduction, and chemical oxidation result in precipitation of heavy metaJs, which are subsequently landfilled. Ion exchange suffers from lack of selectivity in cation removal from multi-component mixtures, while electrochemical reduction has severe limitations in dilute solutions. In order to address the problem of selective heavy metal removal and recovery, development of the Membrane-Electrode (M-E) process was undertaken. The M-E process is a hybrid of electrochemical reduction and ion-exchange technologies and permits selective ion-exchange from dilute aqueous solutions.

High cation selectivities in the M-E process is due to controlled rate of ion-exchange. It has been discovered that cation exchange rates can be controlled by application of an electrical potential difference (pd), and that an inverse relationship exists between pd and the rate of ion-exchange. This behavior is termed as the “Reverse-Potential Phenomena”. Typically, the rate of ion-exchange in conventional ion-exchange processes is dependent upon the cation concentration in solution, and cation loading on the ion-exchange material; this rate cannot be controlled by external means.

Thus far, the M-E process has been effectively demonstrated for selective recovery of Pb²⁺ and Cu²⁺ ions from dilute aqueous binary and ternary cation solutions [,]. This paper focuses on the effect of Reverse-Potential phenomena on selectivity in the Cu²⁺ and Ni²⁺ binary solution mixture.     

Recovery of culturable Escherichia coli O157:H7 during operation of a liquid-based bioaerosol sampler

Collection fluids used in liquid-based bioaerosol samplers can influence the viability of microorganisms. In this study we determined the recovery efficiency of vegetative E. coli O157:H7 cells that were spiked into low viscosity evaporating collection fluids during operation of a BioSampler® for up to 90 min at room temperature. The collection fluids tested were deionized (DI) water, DI water with 0.1% (w/w) antifoam B (AFB), phosphate-buffered saline (PBS), and osmoprotectants consisting of peptone (with and without AFB) or betaine at .1% (w/w) in DI water. Using DI water, there was a rapid decline in the recovery of culturable E. coli, with only 11, 3, and 0% being recovered after 30, 60, and 90 min, respectively. Recoveries were substantially greater with use of PBS (53, 25, and 16%, respectively) but not as high as with use of the osmoprotectants or AFB. Peptone and AFB alone or together allowed for the greatest recovery of E. coli, with average values ranging from 87 to 98% at 90 min. Betaine was also determined to be an effective osmoprotectant for runtimes of 30 and 60 min, with respective E. coli recoveries of 101 and 77% from the impingers. The results from this study support the incorporation of peptone, AFB, and betaine in collection fluids for BioSampler runtimes from 30 to 90 min. Runtimes longer than the recommend 30 min with low viscosity collection fluids are sometimes necessary when the airborne concentration of a target microorganism is low and one is trying to increase the probability of detection.