Fabrication and characterization of poly(methyl methacrylate)/CaCu3Ti4O12 composites

Composites comprising Poly(Methyl Methacrylate) (PMMA) and CaCu₃Ti₄O₁₂ (CCTO) via melt mixing followed by hot pressing were fabricated. These were characterized using X‐ray diffraction, thermo gravimetric, scanning electron microscopy, and Impedance analyzer for their structural, morphology, and dielectric properties. Composites were found to have better thermal stability than that of pure PMMA. The composite, with 38 Vol % of CCTO (in PMMA), exhibited remarkably low dielectric loss at high frequencies and the low frequency relaxation is attributed to the space charge polarization/MWS effect. Theoretical models were employed to rationalize the dielectric behavior of these composites. At higher temperatures, the relaxation peak shifts to higher frequencies, due to the merging of both β and α relaxations into a single dielectric dispersion peak. The AC conductivity in the high frequency region was attributed to the electronic polarization. POLYM. ENG. SCI., 54:551–558, 2014. © 2013 Society of Plastics Engineers     

Impact of Spatially Heterogeneous Trop-2 Expression on Prognosis in Oral Squamous Cell Carcinoma

Oral cancer often presents with aggressive behavior and a high risk of recurrence and metastasis. For oral squamous cell carcinoma (OSCC), which is the most frequent histological subtype, therapy strategies include surgery, radiation therapy, chemotherapy, immune checkpoint inhibitors, and EGFR inhibitors. Recently, a Trop-2 antibody-drug conjugate (ADC) has been approved in the United States of America for the treatment of advanced triple-negative breast cancer. However, this ADC has also been tested in other solid tumors including head & neck squamous cell carcinoma. The prognostic impact of Trop-2 has already been reported for several cancers. We studied the prognostic influence of Trop-2 protein expression on OSCC patients’ survival. The cohort comprised n = 229 OSCC patients with available archived tumor tissue and corresponding non-neoplastic oral mucosa tissue. Using immunohistochemistry, we investigated Trop-2 expression in both the central and peripheral regions of each tumor and in corresponding non-neoplastic oral mucosa. In patients suffering from OSCC with combined high central and low peripheral Trop-2 expression, five-year overall survival (OS) was 41.2%, whereas 55.6% of OSCC patients who presented lower central and/or higher peripheral tumoral Trop-2 expression were alive after five years (p = 0.075). In multivariate Cox regression, the expression pattern of high central tumoral and lower peripheral Trop-2 expression was significantly correlated with impaired OS (HR = 1.802, 95%-CI: 1.134–2.864; p = 0.013) and recurrence-free survival (RFS) (HR = 1.633, 95%-CI: 1.042–2.560; p = 0.033), respectively, when adjusting for co-variables. Hence, Trop-2 may serve as an independent prognostic biomarker in OSCC. In subsequent studies, the pathophysiological meaning of downregulated Trop-2 expression in the OSCC periphery has to be analyzed.     

Modeling coagulation kinetics incorporating fractal theories: comparison with observed data

There are currently four possible approaches in modeling coagulation kinetics: the traditional Euclidean rectilinear; the Euclidean curvilinear; the fractal rectilinear; and the fractal curvilinear. The fractal model includes the Euclidean case as a subset. The primary purpose of this research is to investigate which of the rectilinear models among these best predicts the evolution of experimental observed particle size distribution (PSD). Using a fractal rectilinear model previously developed by the authors, model predictions were compared with a series of observed PSD data obtained from estuarine sediment particles in a 2m settling column, where the average velocity gradient (G) was 20 or 40s(-1). Nonlinear parameter estimation was performed to estimate two free parameters for the fractal model (the fractal dimension, DF, and the collision efficiency factor, a), and one free parameter (the collision efficiency factor, alpha) for the Euclidean model. Compared with the observed PSD, the simulation showed that the fractal rectilinear model was best, and that this model fit better for the larger size particles. The estimated DF was between 2.6 and 3.0. The research demonstrated that the alpha's have multiple values for the same observed data, depending on the coagulation model used. This finding is significant because a is currently used as a single value based on the conventional Euclidean rectilinear model.     

Improving the effectiveness of computer-delivered personalized drinking feedback interventions for college students.

This study evaluated methods of enhancing college students' retention of information provided to them in a computer-delivered personalized drinking feedback intervention and whether enhanced retention reduced alcohol consumption during the two-week period following the intervention. Participants were 98 college students who reported at least one heavy drinking episode in the past two weeks. After participating in an online, personalized drinking feedback intervention, students were randomly assigned to one of three experimental conditions: 1) typical, in which they were simply sent home, 2) reading, in which they were asked to spend the next 20 minutes re-reading the feedback, and 3) recall, in which they were asked to spend the next 20 minutes writing down as much of the information from the feedback as they could remember. Two weeks following the intervention, participants completed a recall test and provided information on their alcohol use during the previous two weeks. Results indicated that participants in the reading and recall conditions retained more of the feedback information than did participants in the typical condition. In addition, participants in the reading and recall conditions reported reduced alcohol consumption in the two-week period following the intervention, compared to those in the typical condition. Information retention partially mediated the effects of the reading and recall conditions on drinking outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prevalence of Salmonella in two Botswana abattoir environments

A 1-year study was carried out to investigate the prevalence of Salmonella in two abattoir environments coded "A" and "B" in Gaborone, Botswana. The total number of environmental samples collected from abattoirs A and B was 250 and 300, respectively. The samples were taken from soils in the corrals, knife blades, saw blades, cattle-drinking water, cattle feces, and feed. Preenrichment, enrichment, and selective/differential media, which enabled the favorable growth of Salmonella, were used in the study. Salmonellae were present in all sampled environments. The most common serotypes found in the environment at abattoir A were E1, C1, C2, and B. Serotypes B, C1, C2, C3, and E1 were common in abattoir B. Antigenic characterization of the salmonellae isolates showed that Salmonella Anatum, Salmonella Azteca, Salmonella Saintpaul, Salmonella Cerro, and Salmonella Westhampton were predominant in abattoir A, whereas Salmonella Anatum, Salmonella Mbandaka, Salmonella Molade, Salmonella Reading, and Salmonella Oranienburg were dominant in abattoir B. Implementing hazard analysis critical control point principles in work procedures would definitely reduce the gross contamination taking place in abattoirs.     

Generative design in architecture using an expert system

The mathematician-architect Christopher Alexander has devised a theory of objective architectural design. He believes that all architectural forms can be described as interacting patterns, all possible relationships of which are governed by generative rules. These form a ‘pattern language’ capable of generating forms appropriate for a given environmental context. The complexity of interaction among these rules leads to difficulties in their representation by conventional methods. This paper presents a Prolog-based expert system which implements Alexander's design methodology to produce perspective views of partially and fully differentiated 3-dimensional architectural forms.     

"How much can we boost IQ and scholastic achievement": Addendum.

Responds to the critique by the Council for the Society for the Psychological Study of Social Issues (see record 1990-56779-001) of A. R. Jensen's article (see record 1969-09740-001) concerning the influence of heredity vs environment on IQ and scholastic achievement and suggests that the critique draws attention to Jensen's use of a social definition of race for the population tested for IQ. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The interaction of children's attribution and level of control over error correction in reading instruction.

32 learning disabled and slowly developing readers were assigned to reading instruction programs on context cue use differing only in extent of pupil control over determination of errors. Results indicate no main effect for experimental condition. However, a significant interaction was found between pretreatment Locus of Attribution (Intellectual Achievement Responsibility Scale) and Experimental Condition. Ss high in internal control benefited more under a condition in which they were encouraged to determine the correctness of their responses. Conversely, Ss low in internality benefited more from a condition in which the teacher determined the correctness of their responses. The results suggest that individual differences in locus of attribution may be important determinants of the extent to which learning-disabled and slow readers benefit from different approaches to reading instruction. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)