Behavioral analysis and nursing interventions for reducing disruptive behaviors of patients with dementia

In this study, two cases were used to examine the potential of behavioral analysis as an intervention to decrease disruptive behaviors of institutionalized individuals with dementia. Behavioral modeling was used to teach the principles of behavioral analysis. The nurses observed a behavior change plan implemented by the investigator, revised the plan based on behavioral analysis techniques, and subsequently implemented the revised behavioral strategies. The patients' disruptive behaviors decreased markedly when the behavioral intervention was implemented. Patients resumed disruptive behaviors when care was provided without the behavioral plan. The findings suggest the need to address interventions in nursing research, education, and practice that use behavioral analysis to reduce disruptive behaviors in individuals with dementia.     

Group I allergens of grass pollen as cell wall-loosening agents

Group I allergens are the major allergens of grass pollen, but their biological function is unknown. These proteins are shown here to be structurally related to expansins, which are able to induce extension (creep) of plant cell walls. Extracts of maize pollen possess potent expansin-like activity, as measured in wall extension and wall stress-relaxation assays. This activity is selective for grass cell walls and is, at least partly, due to the action of maize group I allergens. We propose that group I allergens facilitate invasion of the pollen tube into the maternal tissues by loosening the cell walls of the grass stigma and style. Additionally, the presence of related mRNAs in vegetative tissues of rice, Arabidopsis, and soybean implies that allergen homologs may function to loosen walls in growing vegetative tissues as well.     

Formal endoscopy training for senior and junior house staff

The upper endoscopic experience of junior and senior surgical residents was analyzed before (period 1) and after (period 2) creating a 2-month rotation with a dedicated surgical endoscopist. Three hundred sixty-two endoscopies were performed during the study period, with 295 (81%) being performed after formalizing training. A chi-square analysis was performed and found to be statistically significant for each group when compared to a control experience with colonoscopy. We conclude that a dedicated block of time and a committed surgical attending physician will have a significantly positive impact on resident caseload. Furthermore, the added benefits of being more closely involved with the patient rather than relying on another discipline will add to the resident's educational experience.     

Prolongation and optimization of Doppler enhancement with a microbubble US contrast agent by using continuous infusion: preliminary experience

The ptp gene of Acinetobacter johnsonii was previously reported to encode a low-molecular-mass protein, Ptp, whose amino acid sequence, predicted from the theoretical analysis of the nucleotide sequence of the gene, exhibits a high degree of similarity with those of different eukaryotic and prokaryotic phosphotyrosine-protein phophatases. We have now overexpressed the ptp gene in Escherichia coli cells, purified the Ptp protein to homogeneity by a single-step chromatographic procedure, and analysed its functional properties. We have shown that Ptp can catalyse the dephosphorylation of p-nitrophenyl phosphate and phosphotyrosine, but has no effect on phosphoserine or phosphothreonine. Its activity is blocked by ammonium molybdate and sodium orthovanadate, which are strong inhibitors of phosphotyrosine-protein phosphatases, as well as by N-ethylmaleimide and iodoacetic acid. Such specificity of Ptp for phosphotyrosine has been confirmed by the observation that it can dephosphorylate endogenous proteins phosphorylated on tyrosine, but not proteins modified on either serine or threonine. In addition, Ptp has been shown to quantitatively dephosphorylate two exogenous peptides, derived respectively from leech hirudin and human gastrin, previously phosphorylated on tyrosine. Moreover, site-directed mutagenesis experiments performed on Cys11 and Arg16, which are both present in the sequence motif (H/V)C(X5)R(S/T) typical of eukaryotic phosphotyrosine-protein phosphatases, have demonstrated that each amino acid residue is essential for the catalytic activity of Ptp. Taken together, these data provide evidence that Ptp is a member of the phosphotyrosine-protein phosphatase family. Furthermore, in search for the biological function of Ptp, we have found that it can specifically dephosphorylate an endogenous protein kinase, termed Ptk, which is known to autophosphorylate at multiple tyrosine residues in the inner membrane of Acinetobacter johnsonii cells. This represents the first identification of a protein substrate for a bacterial phosphotyrosine-protein phosphatase, and therefore constitutes a possible model for analysing the role of reversible phosphorylation on tyrosine in the regulation of microbial physiology.     

Colorectal Carcinogenesis: A Cellular Response to Sustained Risk Environment

The current models for colorectal cancer (CRC) are essentially linear in nature with a sequential progression from adenoma through to carcinoma. However, these views of CRC development do not explain the full body of published knowledge and tend to discount environmental influences. This paper proposes that CRC is a cellular response to prolonged exposure to cytotoxic agents (e.g., free ammonia) as key events within a sustained high-risk colonic luminal environment. This environment is low in substrate for the colonocytes (short chain fatty acids, SCFA) and consequently of higher pH with higher levels of free ammonia and decreased mucosal oxygen supply as a result of lower visceral blood flow. All of these lead to greater and prolonged exposure of the colonic epithelium to a cytotoxic agent with diminished aerobic energy availability. Normal colonocytes faced with this unfavourable environment can transform into CRC cells for survival through epigenetic reprogramming to express genes which increase mobility to allow migration and proliferation. Recent data with high protein diets confirm that genetic damage can be increased, consistent with greater CRC risk. However, this damage can be reversed by increasing SCFA supply by feeding fermentable fibre as resistant starch or arabinoxylan. High protein, low carbohydrate diets have been shown to alter the colonic environment with lower butyrate levels and apparently greater mucosal exposure to ammonia, consistent with our hypothesis. Evidence is drawn from in vivo and in vitro genomic and biochemical studies to frame experiments to test this proposition.     

Friction Characteristics of Transition-Metal Disulfides and Diselenides

The disulfides and diselenides of the second and third row transition metals from Groups 4 through 7 have been studied for their ability to function as solid lubricants. These materials have similar layered crystal structures. This work has shown that only those with the MoS₂ type structure and a minimum value of the axial ratio of lattice parameters have inherent lubricating ability. The minimum axial ratios for low sliding friction have been experimentally established as 1.93 and 1.96, respectively, for second and third row transition metals. A rigid sphere atomic model shows that low friction sliding cannot take place unless the axial ratio exceeds 1.87.

Formation of binary solid solutions between the chalcogenides of Group 5, 6 and 7 transition metals shows that the MoS₂ type structure is stabilized at an average metal group number of 6, and that good lubricating properties are obtained when the axial ratio exceeds the minimum values previously stated.     

Effect of crosslinking on the mobility of PDMS filled with polysilicate nanoparticles: Positron lifetime, rheology and NMR relaxation studies

We study the effect of adding trimethylsilyl-treated polysilicate nanoparticles (Rg ∼ 2.2 nm) to crosslinked poly(dimethylsiloxane) (PDMS) elastomers above the entanglement molecular weight. The results are compared to un-crosslinked PDMS of a similar molecular weight, reported in previous studies and filled with the same polysilicate nanoparticles.Three techniques are used and compared to assess the enhancement or reduction in mobility with addition of filler: positron annihilation lifetime spectroscopy (PALS), rheology and nuclear magnetic resonance (NMR) spin-spin relaxation (T₂) measurements. PALS measurements do not show any clear effect of the filler on the mobility of the chains, as assessed by the size of free volume holes, but reveal a net increase in free volume with temperature increase (from 30 °C to 60 °C). A reduction in the dynamic shear storage modulus (measured at 1 rad s⁻¹) is observed in the filled network relative to the unfilled polymer (from 63 kPa without filler to 44 kPa with 40 w/w% filler), attributed primarily to a partial inhibition of the chemical crosslinking reaction by the particles. The NMR relaxation measurements, instead, show a reinforcement of the polymer network with increasing addition of polysilicate particles, as revealed by the faster T₂ decays at higher filler loadings, caused by increasing polymer bridging and particle flocculation. Similar trends are observed at higher temperatures (up to 80 °C), with a higher overall mobility. The apparent disagreement between rheology and NMR stems from the fact that rheology reflects bulk mobility and is primarily sensitive to chemical crosslinks in the network, while NMR probes segmental dynamics, which are affected by the presence of particles.In un-crosslinked PDMS instead, both rheology and NMR show an initial increase in mobility at low filler content, followed by reinforcement with further particle addition. These results strongly suggest that entanglements and filler-induced packing disruption, rather than free volume, play a major role in polymer dynamics.     

The use of block copolymer stabilizers for controlling dispersion stability

The role of block copolymers in stabilizing colloidal dispersions against flocculation or coalescence is discussed in terms of the detailed structure of the interface. Both particulate dispersions and liquid/liquid interfaces are used as examples. Two novel experimental methods are introduced, small-angle neutron scattering and neutron reflection. Comparison with the Scheutjens Fleer theory for block copolymers is also presented. Strategies for the optimum design of the stabilizing polymer are introduced.     

Software engineering and the law

For good or otherwise, the legal system has discovered the world of computers and its practitioners. Anyone opening a daily newspaper knows that litigation involving computers and software has exploded in recent years. On balance, the net effect of this attention might be positive because it gives practitioners an economic incentive to improve the way we work. Indeed, lawyers might well be the ones who provide the incentives for realistic contractual commitments, worst-case software engineering development practices, and a total organizational commitment to quality. Something similar happened to the US automobile industry, benefiting both car makers and the public