Structural variants of biodegradable polyesterurethane in vivo evoke a cellular and angiogenic response that is dictated by architecture

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2008 Acta Materialia Inc.The aim of this study was to investigate an in vivo tissue response to a biodegradable polyesterurethane, specifically the cellular and angiogenic response evoked by varying implant architectures in a subcutaneous rabbit implant model. A synthetic biodegradable polyesterurethane was synthesized and processed into three different configurations: a non-porous film, a porous mesh and a porous membrane. Glutaraldehyde cross-linked bovine pericardium was used as a control. Sterile polyesterurethane and control samples were implanted subcutaneously in six rabbits (n = 12). The rabbits were killed at 21 and 63 days and the implant sites were sectioned and histologically stained using haemotoxylin and eosin (H&E), Masson’s trichrome, picosirius red and immunostain CD31. The tissue–implant interface thickness was measured from the H&E slides. Stereological techniques were used to quantify the tissue reaction at each time point that included volume fraction of inflammatory cells, fibroblasts, fibrocytes, collagen and the degree of vascularization. Stereological analysis inferred that porous scaffolds with regular topography are better tolerated in vivo compared to non-porous scaffolds, while increasing scaffold porosity promotes angiogenesis and cellular infiltration. The results suggest that this biodegradable polyesterurethane is better tolerated in vivo than the control and that structural variants of biodegradable polyesterurethane in vivo evoke a cellular and angiogenic response that is dictated by architecture.Irish Research Council for Science, Engineering and Technology: funded by the National Development Plan. Enterprise Ireland: Research Innovation Partnership

Intravenous Dezocine for Postoperative Pain: A Double‐Blind, Placebo‐Controlled Comparison With Morphine

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97255/1/j.1552-4604.1986.tb03523.x.pd

Dynamics of Passive-Scalar Turbulence

We present the first study of the dynamic scaling or multiscaling of passive-scalar and passive-vector turbulence. For the Kraichnan version of passive-scalar and passive-vector turbulence we show analytically, in both Eulerian and quasi-Lagrangian frameworks, that simple dynamic scaling is obtained but with different dynamic exponents. By developing the multifractal model we show that dynamic multiscaling occurs in passive-scalar turbulence only if the advecting velocity field is itself multifractal. We substantiate our results by detailed numerical simulations in shell models of passive-scalar advection.Comment: published versio

Edge wetting of an Ising three-dimensional system

The effect of edge on wetting and layering transitions of a three-dimensional spin-1/2 Ising model is investigated, in the presence of longitudinal and surface magnetic fields, using mean field (MF) theory and Monte Carlo (MC) simulations. For T=0, the ground state phase diagram shows that there exist only three allowed transitions, namely: surface and bulk transition, surface transition and bulk transition. However, there exist a surface intra-layering temperature $T_{L}^{s}$, above which the surface and the intra-layering surface transitions occur. While the bulk layering and intra-layering transitions appear above an other finite temperature $T_{L}^{b} (\ge T_{L}^{s})$. These surface and bulk intra-layering transitions are not seen in the perfect surfaces case. Numerical values of $T_{L}^{s}$ and $T_{L}^{b}$, computed by Monte Carlo method are found to be smaller than those obtained using mean field theory. However, the results predicted by the two methods become similar, and are exactly those given by the ground state phase diagram, for very low temperatures. On the other hand, the behavior of the local magnetizations as a function of the external magnetic field, shows that the transitions are of the first order type. $T_{L}^{s}$ and $T_{L}^{b}$ decrease when increasing the system size and/or the surface magnetic field. In particular, $T_{L}^{b}$ reaches the wetting temperature $T_{w}$ for sufficiently large system sizes.Comment: 11 Pages latex, 12 Figures P

Regional anaesthesia for outpatient surgery

Regional anaesthesia is an ideal anaesthetic technique for many outpatient surgery procedures. With proper preparation, selection and planning, regional anaesthesia will provide excellent operating conditions for the surgeon and a very satisfactory anaesthetic state for the patient in a cost-effective way. Its minimum effect on major organ functions, intense sensory blockade, low potential for postoperative side effects, and its ability to provide postoperative pain control, offers an excellent set up for these patients who will go home soon after the surgery.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31894/1/0000846.pd

Adverse drug reactions reporting among nursing staff and students: a validated questionnaire based knowledge, attitude and practice study

Background: Lack of knowledge regarding pharmacovigilance and adverse drug reaction (ADR) reporting among healthcare providers have been identified as major factors for under reporting of ADR in developing countries. Hence this study was planned to assess the knowledge and attitude of nursing faculty and students towards ADR reporting and also to determine the barriers to reporting ADR.Methods: A validated questionnaire based cross sectional study conducted among the nursing faculty and students in a tertiary health care center. Data was assessed by frequency, percentage, mean and standard deviation. Statistical analysis was performed by using SPSS version 22.Results: The composite score on knowledge on ADR reporting was found to be moderate among nursing staff, GNM and BSc nursing students. The knowledge on burden due to ADR was found to be poor among all the three categories. Around 70% of all the respondents were of the opinion that ADR reporting by one person can make a significant difference to the community. More than 80% of nursing staff and GNM students opined one should have a suspicion of possible ADR during treatment. Majority of the nursing staff were in favour of mandatory and voluntary ADR reporting in the hospital.Conclusions: The nurses were only moderately aware of pharmacovigilance and adverse drug reaction reporting. Though the attitude towards ADR reporting was adequate, our study has shown that the actual practice of ADR reporting is unsatisfactory. Hence, it is essential to include pharmacovigilance training in the undergraduate teaching programs of nurses to promote reporting of adverse reactions

Analyzing the effects of surface distribution of pores in cell electroporation for a cell membrane containing cholesterol

This paper presents a model and numerical analysis (simulations) of transmembrane potential induced in biological cell membrane under the influence of externally applied electric field (i.e., electroporation). This model differs from the established models of electroporation in two distinct ways. Firstly, it incorporates the presence of cholesterol (~20% mole-fraction) in biological membrane. Secondly, it considers the distribution of pores as a function of the variation of transmembrane potential from one region of the cell to another. Formulation is based on the role of membrane tension and electrical forces in the formation of pores in a cell membrane, which is considered as an infinitesimally thin insulator. The model has been used to explore the process of creation and evolution of pores and to determine the number and size of pores as a function of applied electric field (magnitude and duration). Results show that the presence of cholesterol enhances poration by changing the membrane tension. Analyses indicate that the number of pores and average pore radii differ significantly from one part of the cell to the other. While some regions of the cell membrane undergo rapid and dense poration, others remain unaffected. The method can be a useful tool for a more realistic prediction of pore formation in cells subjected to electroporation.Comment: 11 pages, 3 figures. v2: added new references, grammatical changes, corrected typo