Facile Synthesis, Characterization, and Antimicrobial Activity of Cellulose-Chitosan-Hydroxyapatite Composite Material: A Potential Material for Bone Tissue Engineering

Hydroxyapatite (HAp) is often used as a bone-implant material because it is biocompatible and osteoconductive. However, HAp possesses poor rheological properties and it is inactive against disease-causing microbes. To improve these properties, we developed a green method to synthesize multifunctional composites containing: (1) cellulose (CEL) to impart mechanical strength; (2) chitosan (CS) to induce antibacterial activity thereby maintaining a microbe-free wound site; and (3) HAp. In this method, CS and CEL were co-dissolved in an ionic liquid (IL) and then regenerated from water. HAp was subsequently formed in situ by alternately soaking [CEL+CS] composites in aqueous solutions of CaCl2 and Na2HPO4. At least 88% of IL used was recovered for reuse by distilling the aqueous washings of [CEL+CS]. The composites were characterized using FTIR, XRD, and SEM. These composites retained the desirable properties of their constituents. For example, the tensile strength of the composites was enhanced 1.9 times by increasing CEL loading from 20% to 80%. Incorporating CS in the composites resulted in composites which inhibited the growth of both Gram positive (MRSA, S. aureus and VRE) and Gram negative (E. coli and P. aeruginosa) bacteria. These findings highlight the potential use of [CEL+CS+HAp] composites as scaffolds in bone tissue engineering

An analysis of third grade reading workbooks

Thesis (Ed. M.)--Boston University, 195

WHAT ARE YOU CRYING ABOUT? IT\u27S NOT YOUR REAL JOB!” EMOTIONAL LABOR AND COMMUNICATIVE SENSEMAKING IN RETAIL CUSTOMER SERVICE POSITIONS

Using Tracy and Trethewey‟s (2005) crystallized self metaphor as a framework through which to view organizational identity, the researcher bridges connections between emotional labor, job performance, meaning of work and communicative sensemaking within the organizational context of a grocery store. The purpose of this study is to seek the potential strategies that employees of this specific grocery store chain use to make communicative sense of their everyday realities in order to get through the day, especially with the great deal of emotional labor that takes place on the job. The researcher utilizes a combination of face-to-face interviews and participant observation to collect data for this study. Findings indicate that employees utilized multiple strategies to manage their emotionally laborious positions including venting, forming social relationships and pursuing interests outside of work, as well as resistance. Limitations of this project and directions for future research are discussed

How the Court Got It Wrong in Woodford v. NGO By Saying No to Simple Administrative Exhaustion Under the PLRA

Congress has estimated that the number of people who have been sexually assaulted in America\u27s prisons over the past twenty years tops one million. Some inmates are sexually assaulted by guards, and some by other inmates, facilitated by guards. The problem is so rampant that Congress enacted the Prison Rape Elimination Act of 2003. Though the State has a constitutional obligation to provide humane conditions of confinement, sometimes it fails. To receive compensation for or relief from such harm, a prisoner must conform to the guidelines provided in the Prison Litigation Reform Act of 1995 (PLRA), which requires an inmate to file a grievance for his injury with the very administration responsible for not providing humane conditions. Additionally, a prisoner who has just suffered the assault has a limited time in which to lodge his complaint, generally no more than fifteen days, and in nine states only between two and five days. A proper exhaustion requirement precludes an inmate from filing a lawsuit in federal court unless he has proceeded through each step of his prison\u27s grievance procedure while meeting all procedural requirements, including deadlines. On the other hand, simple exhaustion, or exhaustion simpliciter, permits an inmate to file a lawsuit as long as the administrative grievance procedure is no longer available, provided that he has not intentionally circumvented the administrative process

Teacher Perceptions of Parent Involvement in Literacy Education

Parent involvement appears to hold great potential for the improvement of literacy education. Without the coordination and support ofthe classroom teacher, however, the effects of such involvement may not be maximized. A question central to the development of parent involvement programs is, Do teachers recognize and support parent involvement as a significant component of children\u27s education? The purpose of this informal study was to describe perceptions of parent involvement in literacy education. Over sixty teachers from a cross section of schools in a Midwestern metropolitan area were interviewed in depth about their attitudes toward parent involvement in reading. A structured interview combining closed and open-ended questions was used to gather data. Results indicated that teacher perceptions of what constitutes parent involvement differed by grade level. Over 90 percent of the teachers recognized the importance of involving parents. Less than 5 percent, however, supported involving parents as partners. Teacher perceptions of the role of parents appeared to restrict involvement and limit dialogue

Quantitative electron energy-loss spectroscopy (EELS) analyses of lead zirconate titanate

Electron energy-loss spectroscopy (EELS) analyses have been performed on a sol–gel deposited lead zirconate titanate film, showing that EELS can be used for heavy as well as light element analysis. The elemental distributions within the sol–gel layers are profiled using the Pb N<sub>6,7</sub>-edges, Zr M-edges, Ti L-edges and O K-edge. A multiple linear least squares fitting procedure was used to extract the Zr signal which overlaps with the Pb signal. Excellent qualitative information has been obtained on the distribution of the four elements. The non-uniform and complementary distributions of Ti and Zr within each sol–gel deposited layer are observed. The metal:oxygen elemental ratios are quantified using experimental standards of PbTiO<sub>3</sub>, PbZrO<sub>3</sub>, ZrO<sub>2</sub> and TiO<sub>2</sub> to provide relevant cross-section ratios. The quantitative results obtained for Ti/O and Pb/O are very good but the Zr/O results are less accurate. Methods of further improving the results are discussed

A novel NGS library preparation method to characterize native termini of fragmented DNA.

Biological and chemical DNA fragmentation generates DNA molecules with a variety of termini, including blunt ends and single-stranded overhangs. We have developed a Next Generation Sequencing (NGS) assay, XACTLY, to interrogate the termini of fragmented DNA, information traditionally lost in standard NGS library preparation methods. Here we describe the XACTLY method, showcase its sensitivity and specificity, and demonstrate its utility in in vitro experiments. The XACTLY assay is able to report relative abundances of all lengths and types (5' and 3') of single-stranded overhangs, if present, on each DNA fragment with an overall accuracy between 80-90%. In addition, XACTLY retains the sequence of each native DNA molecule after fragmentation and can capture the genomic landscape of cleavage events at single nucleotide resolution. The XACTLY assay can be applied as a novel research and discovery tool for fragmentation analyses and in cell-free DNA