Assessment of Tailor-Made HPMC-Based Matrix Minitablets Comprising a Weakly Basic Drug Compound

Tailor-made, pH-controlled matrix minitablets based on different HPMC types were developed comprising the weakly basic drug dipyridamole. The incorporation of pH modifiers, i.e., fumaric and succinic acid, enhanced the drug release at pH 6.8. Assessing the drug release, acid release, and the microenvironmental pH (pH_M) provided detailed understanding of pH-controlled mini-matrices.

The extent and duration of pH_M alteration was more pronounced in presence of fumaric acid. Minitablets based on the fast dissolving Methocel K100LV (≤ 100 cps) showed simultaneous release rates of dipyridamole and fumaric acid with a constant low average pH_M.     

Session and intersession experience related to treatment outcome in bulimia nervosa.

Treatment in bulimia nervosa is challenging, with rates of successful treatments for only about 50% of all patients. This study aimed to identify predictors of outcome through secondary analysis of data from a randomized clinical trial that compared inpatient and day hospital treatment for bulimia. Process measures included assessments of patients' in-session experiences, therapeutic alliance, and therapy-related intersession experiences (ISE). ISE measures were better predictors of outcome than pretreatment variables (e.g., social adjustment) or global therapeutic alliance. Outcome at 3 month follow-up was strongly related to the ISE dimension Recreating Therapeutic Dialogue with Negative Emotions, indicating a heightened risk of failure. Prediction of outcome by these variables showed a sensitivity of 0.86 and a specificity of 0.78, and 83% of patients could be correctly classified. These results show that certain aspects of ISE may serve as early and reliable indicators of long term treatment failure, prompting alternate treatment approaches and opening new directions of research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

State-of-the art comparability of corrected emission spectra. 1. Spectral correction with physical transfer standards and spectral fluorescence standards by expert laboratories

The development of fluorescence applications in the life and material sciences has proceeded largely without sufficient concern for the measurement uncertainties related to the characterization of fluorescence instruments. In this first part of a two-part series on the state-of-the-art comparability of corrected emission spectra, four National Metrology Institutes active in high-precision steady-state fluorometry performed a first comparison of fluorescence measurement capabilities by evaluating physical transfer standard (PTS)-based and reference material (RM)-based calibration methods. To identify achievable comparability and sources of error in instrument calibration, the emission spectra of three test dyes in the wavelength region from 300 to 770 nm were corrected and compared using both calibration methods. The results, obtained for typical spectrofluorometric (0°/90° transmitting) and colorimetric (45°/0° front-face) measurement geometries, demonstrated a comparability of corrected emission spectra within a relative standard uncertainty of 4.2% for PTS- and 2.4% for RM-based spectral correction when measurements and calibrations were performed under identical conditions. Moreover, the emission spectra of RMs F001 to F005, certified by BAM, Federal Institute for Materials Research and Testing, were confirmed. These RMs were subsequently used for the assessment of the comparability of RM-based corrected emission spectra of field laboratories using common commercial spectrofluorometers and routine measurement conditions in part 2 of this series (subsequent paper in this issue).     

State-of-the art comparability of corrected emission spectra. 2. Field laboratory assessment of calibration performance using spectral fluorescence standards

In the second part of this two-part series on the state-of-the-art comparability of corrected emission spectra, we have extended this assessment to the broader community of fluorescence spectroscopists by involving 12 field laboratories that were randomly selected on the basis of their fluorescence measuring equipment. These laboratories performed a reference material (RM)-based fluorometer calibration with commercially available spectral fluorescence standards following a standard operating procedure that involved routine measurement conditions and the data evaluation software LINKCORR developed and provided by the Federal Institute for Materials Research and Testing (BAM). This instrument-specific emission correction curve was subsequently used for the determination of the corrected emission spectra of three test dyes, X, QS, and Y, revealing an average accuracy of 6.8% for the corrected emission spectra. This compares well with the relative standard uncertainties of 4.2% for physical standard-based spectral corrections demonstrated in the first part of this study (previous paper in this issue) involving an international group of four expert laboratories. The excellent comparability of the measurements of the field laboratories also demonstrates the effectiveness of RM-based correction procedures.     

Genotypic and climatic influences on the concentration and composition of flavonoids in kale (Brassica oleracea var. sabellica)

The aim of this study was to determine the composition and concentration of flavonoid aglycones in kale, the dependence on genotype and their interaction with decreasing temperature and global radiation. Eight kale cultivars, comprising hybrid and traditional, old cultivars, were grown in a field experiment and harvested four times at 4-week intervals. The traditional, old cultivars in particular contained high concentrations of flavonoids. In all of the investigated cultivars, kaempferol was the main flavonoid aglycone, followed by quercetin and isorhamnetin, which was quantified in six of the eight cultivars. Furthermore, in six of the eight cultivars, the total concentration of flavonoids remained unchanged with decreasing temperature and global radiation. The quercetin concentration increased in five of these six cultivars, whereas the kaempferol concentration decreased. Interestingly, the quercetin-to-kaempferol ratio increased in all of the investigated cultivars, despite the fact that the radiation level decreased, suggesting that the impact of the decline in temperature could be responsible for this effect.     

Substrate Templating upon Self‐Assembly of Hydrogen‐Bonded Molecular Networks on an Insulating Surface

Molecular self‐assembly on insulating surfaces, despite being highly relvant to many applications, generally suffers from the weak molecule–surface interactions present on dielectric surfaces, especially when benchmarked against metallic substrates. Therefore, to fully exploit the potential of molecular self‐assembly, increasing the influence of the substrate constitutes an essential prerequisite. Upon deposition of terephthalic acid and trimesic acid onto the natural cleavage plane of calcite, extended hydrogen‐bonded networks are formed, which wet the substrate. The observed structural complexity matches the variety realized on metal surfaces. A detailed analysis of the molecular structures observed on calcite reveals a significant influence of the underlying substrate, clearly indicating a substantial templating effect of the surface on the resulting molecular networks. This work demonstrates that choosing suitable molecule/substrate systems allows for tuning the balance between intermolecular and molecule–surface interactions even in the case of typically weakly interacting insulating surfaces. This study, thus, provides a strategy for deliberately exploiting substrate templating to increase the structural variety in molecular self‐assembly on a bulk insulator at room temperature.     

Preliminary studies on the effect of processing on the IgE reactivity of tomato products

Tomatoes and tomato products, obtained from a market, from companies or prepared in research laboratories, were tested in order to investigate how different processes could modulate the IgE reactivity of these products. The protein fraction of the samples was extracted by using a low‐temperature method in order to avoid degradation, and then separated on SDS PAGE to evaluate the protein profile. All the separated samples were blotted onto nitrocellulose membranes and then individually tested with pooled human sera that had been obtained from patients allergic to tomato, in order to evaluate the potential IgE binding of the protein bands. Heat treatments conventionally employed for the production of tomato‐based products were found to strongly degrade proteins thus dramatically reducing their IgE reactivity; characteristic protein profiles were found for specific processes such as hot and cold break. Ultra‐high‐pressure treatments were found to generally preserve the integrity of tomato proteins and this was reflected by the unaltered IgE reactivity observed. Copyright © 2007 Society of Chemical Industry     

Evaluation of the reliability of transport networks based on the stochastic flow of moving objects

In transport networks, human beings are moving objects whose moving direction is stochastic in emergency situations. Based on this idea, a new model—stochastic moving network (SMN) is proposed. It is different from binary-state networks and stochastic-flow networks. The flow of SMNs has multiple-saturated states, that correspond to different flow values in each arc. In this paper, we try to evaluate the system reliability, defined as the probability that the saturated flow of the network is not less than a given demand d. Based on this new model, we obtain the flow probability distribution of every arc by simulation. An algorithm based on the blocking cutset of the SMN is proposed to evaluate the network reliability. An example is used to show how to calculate the corresponding reliabilities for different given demands of the SMN. Simulation experiments of different size were made and the system reliability precision was calculated. The precision of simulation results also discussed.