Paclitaxel-Loaded Microparticles for Intratumoral Administration via the TMT Technique: Preparation,Characterization, and Preliminary Antitumoral Evaluation

In our pursuit to develop suitable therapeutic particulate systems for intratumoral delivery by the targeted multi-therapy (TMT) technique, we describe the preparation of paclitaxel-loaded poly(d,l-lactic-co-glycolic) acid (PLGA) microparticles (MPs) (drug loading 35–38%, wt/wt; size 0.7–5 μm). Magnetite (15%, wt/wt) was also incorporated in some preparations for a future magnetic resonance imaging (MRI)-guided delivery. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) experiments showed that paclitaxel was not encapsulated in its initial crystalline form. The paclitaxel in vitro release pattern showed a biphasic tendency with a burst effect followed by a sustained release (28% released amount after 1 month), which was accompanied with MP erosion and degradation signs as confirmed by scanning electronic microscopy (SEM) micrographs. The paclitaxel-loaded MPs demonstrated a dose-dependent antitumor effect on human uterine cancer cells, with an IC₅₀ value relatively close to that of commercial Taxol®. This paclitaxel delivery system represents a potent antiprofilerative and radiosensitizer agent for intratumoral administration via the TMT technique.     

Pulsed electrodeposition and characterization of molybdenum diselenide thin film

Molybdenum dichalcogenides are semiconductors with layered type structure, which can act as efficient electrodes in the realization of photoelectrochemical solar cells. The main advantage of this molybdenum diselenide (MoSe₂) semiconductor is the prevention of electrolyte corrosion because of the phototransitions involving non-bonding d-d orbital of the Mo atoms. Polycrystalline molybdenum diselenide thin films are prepared by pulsed electrodeposition on conducting glass and titanium substrates in galvanostatic mode from an ammoniacal solution of H₂MoO₄ and SeO₂. The growth kinetics of the film was studied and the deposition parameters such as electrolyte bath concentration, bath temperature, time of deposition, deposition current, pH of the electrolyte and duty cycle of the current are optimized. X-ray diffraction analysis of the as deposited and annealed films showed the presence of highly textured MoSe₂ films with polycrystalline nature. EDAX spectrum of the surface composition confirms the nearly stoichiometric MoSe₂ nature of the film. Surface morphology studies by scanning electron microscope (SEM) shows that the films are pinhole free and of device quality nature. The optical absorption spectra show an indirect band gap value of 1.16 eV. Conductivity measurements were carried out at different temperatures and electrical constants such as activation energy, trapped energy state and barrier height were calculated.     

The time course of spoken word learning and recognition: Studies with artificial lexicons.

The time course of spoken word recognition depends largely on the frequencies of a word and its competitors, or neighbors (similar-sounding words). However, variability in natural lexicons makes systematic analysis of frequency and neighbor similarity difficult. Artificial lexicons were used to achieve precise control over word frequency and phonological similarity. Eye tracking provided time course measures of lexical activation and competition (during spoken instructions to perform visually guided tasks) both during and after word learning, as a function of word frequency, neighbor type, and neighbor frequency. Apparent shifts from holistic to incremental competitor effects were observed in adults and neural network simulations, suggesting such shifts reflect general properties of learning rather than changes in the nature of lexical representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional plasticity: Conditions and effects of improving emotional competence in adulthood.

This study aimed to investigate (a) whether it is possible to increase emotional competence (EC) in adulthood; (b) whether this improvement results in better mental, physical, and social adjustment; (c) whether this improvement can be maintained 1 year later; and (d) whether these benefits are accompanied by a reduction in stress-hormone secretion (i.e., cortisol). One hundred and thirty-two participants were randomly assigned to an EC-enhancing intervention (in group format) or to a control group. Participants in the intervention group underwent a specifically designed 15-hr intervention targeting the 5 core emotional competencies, complemented with a 4-week e-mail follow-up. Results reveal that the level of emotional competencies increased significantly in the intervention group in contrast with the control group. This increase resulted in lower cortisol secretion, enhanced subjective and physical well-being, as well as improved quality of social and marital relationships in the intervention group. No significant change occurred in the control group. Peer reports on EC and quality of relationships confirmed these results. These data suggest that emotional competencies can be improved, with effective benefits on personal and interpersonal functioning lasting for at least 1 year. The theoretical implications of these results as well as their practical implications for the construction and the development of effective emotional competencies interventions are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Determination of the representativity between two multidimensional data sets by a comparison of their structure

An approach for the investigation and comparison of the data structure in the multidimensional space is proposed. It is based on three properties, namely, the direction of the data sets, the variance–covariance of the data points, and the location of the data sets' centroids. A number of tests have been studied and are presented. It is shown that the combined use of these parameters allows a satisfactory estimation of the representativity between two data sets. Simulated data, as well as real case studies are presented.     

Analyzing true change in longitudinal multitrait-multimethod studies: Application of a multimethod change model to depression and anxiety in children.

The authors show how structural equation modeling can be applied to analyze change in longitudinal multitrait-multimethod (MTMM) studies. For this purpose, an extension of latent difference models (McArdle, 1988; Steyer, Eid, & Schwenkmezger, 1997) to multiple constructs and multiple methods is presented. The model allows investigators to separate true change from measurement error and to analyze change simultaneously for different methods. The authors also show how Campbell and Fiske’s (1959) guidelines for analyzing convergent and discriminant validity can be applied to the measurement of latent change. The practical application of the multimethod change model is illustrated in a reanalysis of child depression and anxiety scores (N = 906 American children) that were assessed by self- and parent reports on three measurement occasions. The analyses revealed that (a) the convergent validity of change was low for both constructs and (b) sex was a significant predictor of self-reported, but not of parent reported, anxiety states. Finally, the authors discuss advantages and limitations and compare the model with other approaches for analyzing longitudinal MTMM data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of the temporal structure of spoken words on paired-associate learning.

In a series of experiments, participants learned to associate black-and-white shapes with nonsense spoken labels (e.g., “joop”). When tested on their recognition memory, participants falsely recognized as correct a shape paired with a label that began with the same sounds as the shape’s original label (onset-overlapping lure; e.g., joob) more often than a shape paired with a label that overlapped with the original label at offset (offset-overlapping lure; e.g., choop). Furthermore, the false-alarm rate was modulated by the phonetic distance between the sounds that distinguished the original label and the lures. Greater false-alarm rates to onset-overlapping labels were not predicted by explicit similarity ratings or by consonant identification and were not dependent upon label familiarity. The asymmetry at erroneously recognizing onset- versus offset-overlapping lures remained unchanged as the presentation of the shape at test was delayed in time, suggesting that response anticipation based on the first sounds of the spoken label did not contribute much to the false recognition of onset-overlapping lures. Thus, learning 2 words whose names differ in their last sounds appears to pose greater difficulty than learning 2 words whose names differ in their first sounds because, we argue, people are biased to give more importance to the early sounds of a name than to its last sounds when learning a novel label–referent association. (PsycINFO Database Record (c) 2010 APA, all rights reserved)