Polymeric prosthesis having a phosphonylated surface

A process for phosphonylating the surface of an organic polymeric preform and the surface-phosphonylated preforms produced thereby are provided. Organic polymeric preforms made from various polymers including polyethylene, polyetheretherketone, polypropylene, polymethylmethacrylate, polyamides, and polyester, and formed into blocks, films, and fibers may have their surfaces phosphonylated according to the present inventive process. The process involves the use of a solvent that does not dissolve the organic polymeric preform but does dissolve a phosphorus halide such as phosphorus trichloride. The solvent chosen must also be nonreactive with the phosphorus halide. Such solvents available for use in the present process include the fully-halogenated liquid solvents such as carbon tetrachloride, carbon tetrabromide, and the like. The inventive process allows for surface phosphonylation of the organic polymeric preform such that up to about 30 percent, but preferably up to about 20 percent, of the reactive carbon sites in the polymer are phosphonylated. The inventive phosphonylated organic polymers are particularly useful as orthopedic implants because hydroxyapatite-like surfaces which can be subsequently created on the organic implants allow for co-crystallization of hydroxyapatite to form chemically-bound layers between prosthesis and bone tissue

GRAFT-VS.-HOST REACTION IN TISSUE CULTURE

The primary purpose of this study has been to validate the in vitro graft-vs.-host reaction as an experimental system. Time-dose studies have been presented for cells obtained from spleen, thymus, cortisone-treated thymus, inguinal lymph node, mesenteric lymph node, thoracic duct, and bone marrow cells. Both the degree of splenomegaly and the onset of spleen enlargement were found to be dependent on the number and source of cells tested. The effect of several immunosuppressive agents was examined. Amantadine was found to suppress completely the graft-vs.-host reaction in vitro when present at a concentration of 75 µg/ml. Pretreatment of effector cells with mitomycin C prevented their subsequent ability to cause a graft-vs.-host reaction. The effect of X irradiation on immunocompetence of spleen cells in vitro paralleled the known effect of irradiation on in vivo immunocompetence. Preimmunization did not increase the number or effectiveness of immunocompetent cells when measured under standard in vitro conditions. Preimmunization did, however, permit persistence of immunocompetence after immunosuppressive doses of X irradiation. Studies using congenic lines, moreover, indicated that the preimmunization effect could be demonstrated in strain combinations differing only in factors determined by the H-2 complex of genes. A weak graft-vs.-host reaction could be detected in strain combinations not involving differences at the H-2 locus. The potential of the in vitro graft-vs.-host reaction as a highly reproducible, quantifiable, internally controlled, and experimentally accessible system for study of such critical problems as cell differentiation and cell interactions is discussed

Spatiotemporal Characterization of Supercontinuum Extending from the Visible to the Mid-Infrared in Multimode Graded-Index Optical Fiber

We experimentally demonstrate that pumping a graded-index multimode fiber with sub-ns pulses from a microchip Nd:YAG laser leads to spectrally flat supercontinuum generation with a uniform bell-shaped spatial beam profile extending from the visible to the mid-infrared at 2500\,nm. We study the development of the supercontinuum along the multimode fiber by the cut-back method, which permits us to analyze the competition between the Kerr-induced geometric parametric instability and stimulated Raman scattering. We also performed a spectrally resolved temporal analysis of the supercontinuum emission.Comment: 5 pages 7 figure

Laparoscopic Hernia Repair in Infancy and Childhood; Evaluation of Two Different Techniques

Background/Purpose: There are many techniques available for laparoscopic hernia repair in infancy and childhood. The objective of this study is to compare two different laparoscopic techniques as regards operative time, recurrence rate, hydrocele formation and post operative cosmetic results. Materials & Methods: A prospective randomized controlled study was carried out in the Pediatric Surgery Unit of Al- Azhar University Hospitals, over three years period. ne-hundred and fifty patients with congenital inguinal hernia were randomized into two equals groups; (n = 75). Group A was subjected to purse-string suture around the internal inguinal ring (IIR) using two needle holders (TNH). Group B was subjected to laparoscopic hernia repair of inguinal hernia by Reverdin Needle (RN). Inclusion criteria included; bilateral inguinal hernia, recurrent hernia, hernia in obese child, incarcerated hernia and hernia on ipsilateral with questionable contralateral side. Exclusion criteria included; unilateral inguinal hernia, and hernia with undescended testicles. The main outcome measurements were; operative time, hospital stay, postoperative hydrocele formation, recurrence rate, and cosmetic results. Results: There were no significant differences as regard age, sex and mode of presentation between both groups. All cases were completed successfully without conversion. There were significant statistical differences in the operative time between the studied groups, while there were no significant statistical differences in the hospital stay, post operative hydrocele formation and recurrence rate. The cosmetic result is excellent in group B. Conclusion: Laparoscopic hernia repair by RN is an effective line of hernia repair in infancy and childhood. It resulted in marked reduction of operative time and excellent cosmetic results with low recurrence. Index Word: Laparoscopic, Reverdin Needle, Purse-string, Intracorporeal sutures

Study on Quality of Pair Distribution Function for Direct Space Approach of Structure Investigation

Study of the structure characteristics of solid materials is a key for development of technological applications. Potential of direct space approach for structure determination and refinement using powder X-ray diffraction data depend on the quality of pair distribution function (PDF) plot. So, the effect of data collection conditions and diffractogram characteristics on the quality of PDF plot has been investigated in detail. In addition, errors and possible tolerance have been estimated. Some parameters affect only either the X-ray diffractogram or PDF plots and others affect both. Considering the errors and tolerance, direct space approach can be confidently used for structure refinement, where the error did not exceed 10.0 % for inter-atomic radial distance longer than » 2.0 ? and 5.0 % for longer than » 4.0 ?, which is accepted for structure refinement. As tolerance is considered, every time the value of the lattice parameter is changed to smaller or larger than the correct value (+ 8.0 %), it comes back to the initial correct one. Although, advanced synchrotron radiation shows better data, conventional source can be used successfully for structure investigation applying direct space approach

Spatiotemporal Nonlinear Beam Shaping

International audienc

STAR-loc: Dataset for STereo And Range-based localization

This document contains a detailed description of the STAR-loc dataset. For a quick starting guide please refer to the associated Github repository (https://github.com/utiasASRL/starloc). The dataset consists of stereo camera data (rectified/raw images and inertial measurement unit measurements) and ultra-wideband (UWB) data (range measurements) collected on a sensor rig in a Vicon motion capture arena. The UWB anchors and visual landmarks (Apriltags) are of known position, so the dataset can be used for both localization and Simultaneous Localization and Mapping (SLAM).Comment: 15 pages, 15 figure