Evaluation of in situ curable biodegradable polyurethanes containing zwitterion components

Porous polyurethane networks containing covalently attached zwitterionic compounds dihydroxypolycaprolactone phosphorylcholine and 1,2-dihydroxy-N,N-dimethylamino-propane sulfonate have been prepared and characterised. Three polymers were prepared by reacting methyl 2,6-diisocyanato hexanoate functionalised d-glucose as prepolymer A with either polycaprolactone triol alone or with addition of 10 mol% zwitterion as prepolymer B. All polymer compositions were mixed with 10 wt% hydrated gelatin beads. The cured polymers with the gelatin beads showed compression strengths that were still suitable for use in articular cartilage repair. The incorporation of zwitterions yielded more hydrophilic polymers that showed increased water absorption and increased porosity. After four months degradation in phosphate buffered saline, the polymers containing zwitterions had approximately 50% mass loss compared with 30% mass loss for that with polycaprolactone triol alone. All polymers were non-toxic in chondrocyte-based assays. Subcutaneous implantation of these polymers into rats confirmed that the polymers degraded slowly. Only a very mild inflammatory response was observed and the polymers were able to support new, well vascularised tissue formation.     

Current Progress and Future Directions for Tau-Based Fluid Biomarker Diagnostics in Alzheimer’s Disease

Despite continued efforts, there remain no disease-modifying drugs approved by the United States Food and Drug Administration (FDA) or European Medicines Agency (EMA) to combat the global epidemic of Alzheimer’s disease. Currently approved medicines are unable to delay disease progression and are limited to symptomatic treatment. It is well established that the pathophysiology of this disease remains clinically silent for decades prior to symptomatic clinical decline. Identifying those at risk of disease progression could allow for effective treatment whilst the therapeutic window remains open for preservation of quality of life. This review aims to evaluate critically the current advances in the interpretation of tau-based biomarkers and their use to provide insights into the onset and progression of Alzheimer’s disease, whilst highlighting important future directions for the field. This review emphasises the need for a more comprehensive analysis and interrogation of tau within biological fluids, to aid in obtaining a disease specific molecular signature for each stage of Alzheimer’s disease. Success in achieving this could provide essential utility for presymptomatic patient selection for clinical trials, monitoring disease progression, and evaluating disease modifying therapies.     

Dissolution Model for a Weak Carboxylic Acid

A chemical reaction, diffusion, and ionization model is presented for the dissolution of solid, weak acids in reactive media. The model assumes an equilibrium plane, which is located within the diffusion layer and in which ionization equilibrium is established. The model, which proposes that the aqueous diffusion layer is divided into three zones, is tested by use of experimental dissolution rates of p-aminobenzoic acid and is compared to a two-zone model.     

Use of tilmicosin in a severe outbreak of respiratory disease in weaned beef calves

In a liability lawsuit an expertise had to answer the question whether a mania in the course of an affective psychosis could have been caused by chronic mercury intoxication resulting from dental amalgam fillings. On the basis of current psychiatric and toxicological knowledge, such an association can be disproved. Mercury intake from amalgam fillings does not lead to toxic concentrations in organs or body fluids. Therefore physicians and dentists should avoid alarming patients and thus causing iatrogenic harm.     

Systemic sclerosis in DRw52-positive silica-exposed males: a case report

The excursion resistance between the canine flexor digitorum profundus tendon and A2 pulley was compared after pulley reconstruction using tendon grafts of either intrasynovial or extrasynovial origin at 10 days, 3 weeks, and 6 weeks after surgery. The changes over time in the underlying flexor digitorum profundus tendon after pulley reconstruction were also evaluated. The excursion resistance for both types of pulley reconstruction was significantly greater than that of the control group at all time periods. The excursion resistance of the extrasynovial tendon graft reconstruction was greater than that of intrasynovial pulley reconstruction at all time periods. In conclusion, pulley reconstruction with intrasynovial tendon grafts may facilitate tendon gliding after surgery.     

Individual differences in student cheating.

The incidence and causes of cheating were investigated using a questionnaire, consisting of 21 cheating behaviors, which was distributed to students at an English university. Respondents were asked to indicate, confidentially, which of the behaviors they had engaged in. Reported cheating was widespread and some types of cheating (e.g., on coursework) were more common than others. Reported cheating was more common in men than women; more common with less able students than more able ones; more common in younger students than mature ones; and more common in science and technology students than those in other disciplines. It is suggested that students' motivation, in particular whether they are studying to learn rather than simply to obtain good grades, is a major factor in explaining these differences. The results also indicate that cheating consists of a number of different types of behavior rather than being a unitary concept. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tests of a temporal theory of attentional binding.

Different features of stimuli present in the field of view appear to be registered in different cortical maps. How, then, are the features that come from the same object bound together rather than mistakenly assembled with features coming from other simultaneously present objects? One theory supposes that an attentional mechanism intercepts input coming from particular retinal locations at a way station prior to parsing of the features from the same object. Any enhancement (or facilitation) at that stage will cause all the features from that object to be modified simultaneously in the downstream registers. The imposed temporal synchronicity serves as the essential binding cue. Five experiments provided no support for the theory. There is no tendency for synchronicity of features to cause binding unless the features come from the same location. Location, rather than temporal synchronicity, appears to be the essential cue for binding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Word naming and memory load: Still searching for an individual differences explanation.

S. E. Bernstein and T. H. Carr (1996) and P. M. Pexman and S. J. Lupker (1995) suggested that classifiable individual differences in word-naming performance can account for the varied findings on the naming and memory load task (NMLT; K. R. Paap and R. W. Noel, 1991). Bernstein and Carr's technique of testing their explanation by using performance on part of the NMLT to classify participants is problematic, however. To remedy this, in the present study participants were classified on the basis of performance on a priori tasks: Participants completed a naming task, a naming task with low memory load, and the NMLT. Performance on the NMLT was not predicted by performance on either a priori task, thus providing no support for either Bernstein and Carr's or Pexman and Lupker's individual differences accounts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A tool for visualizing the execution of interactions on a loosely-coupled distributed system

The paper describes in detail the implementation of INMON, a prototype monitor for recording and displaying interaction networks. The interaction network is designed to show the interrelationships between significant events that occur during the processing of an interaction on a loosely-coupled distributed system. By being directed at analysing what happens in an interaction, this approach is fundamentally different from other graphical representations that show what happens during the execution of a single program on a distributed system. Examples are given of interaction networks recorded by INMON. The approach is based on very general models of a distributed system and of an interaction, and could be widely applied. We conclude by summarizing what is needed to provide facilities within any operating system for recording interaction networks.