Sol-gel derived HA/TiO2 double coatings on Ti scaffolds for orthopaedic applications

Hydroxyapatite/titania (HA/TiO₂) double layers were coated onto Ti scaffolds throughout for orthopaedic applications by sol-gel method. Differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and X-ray diffractometry (XRD) were used for the characterisation of the phase transformations of the dried gels and coated surface structures. Scanning electron microscope (SEM) equipped with energy dispersive spectrometry (EDS) was used for the observation and evaluation of the morphology and phases of the surface layers and for the assessment of the in vitro tests. The in vitro assessments were performed by soaking the HA/TiO₂ double coated samples into the simulated body fluid (SBF) for various periods. The TiO₂ layer was coated by a dipping-coating method at a speed of 12 cm/min, followed by a heat treatment at 600 °C for 20 min. The HA layer was subsequently dipping-coated on the outer surface at the same speed and then heat-treated at difference temperatures. The results indicat that the HA phase begins to crystallize after a heat treatment at 560 °C. The crystallinity increases obviously at 760 °C. SEM observations find no delamination or crack at the interfaces of HA/TiO₂ and TiO₂/Ti. The HA/TiO₂ coated Ti scaffolds displays excellent bone-like apatite forming ability when it is soaked into SBF. Ti scaffolds after HA/TiO₂ double coatings can be anticipated as promising implant materials for orthopaedic applications

Sol-gel derived hydroxyapatite/titania biocoatings on titanium substrate

A simple sol–gel method was successfully developed for a hydroxyapatite (HA)/TiO₂ double layer deposition on a pure titanium substrate. Phase formation, surface morphology, and interfacial microstructure were investigated by differential scanning calorimetry analysis (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The TiO₂ layer was coated by a spin coating method at a speed of 1500 rpm for 15 s, followed by a heat treatment at 560 °C for 20 min. The HA film was subsequently spin coated on the outer surface at the same speed and then heat-treated at difference temperatures. Results indicated that the HA phase began to crystallize after a heat treatment at 580 °C; and the crystallinity increased obviously at a temperature of 780 °C. The HA film showed a porous structure and a thickness of 5–7 μm after the heat treatment at 780 °C. SEM observations revealed no delamination and crack at the interfaces of HA/TiO₂ and TiO₂/Ti. The HA film with a porous structure is expected to be more susceptible to the natural remodeling processes when it is implanted in a living body.

The effect of intra- versus post-interview feedback during simulated practice interviews about child abuse

Objective
This study compared the effectiveness of two types of instructor feedback (relative to no feedback) on investigative interviewers’ ability to adhere to open-ended questions in simulated practice interviews about child abuse.
Method
In one condition, feedback was provided at the end of each practice interview. In the other, the instructor stopped the interviewer at various stages during the practice interviews to provide feedback. The relative effect of these conditions was examined by measuring interviewers’ performance in a standardized mock interview paradigm immediately prior to, immediately after, and 12 weeks after the practice and feedback sessions.
Results
Prior to and 12 weeks after the practice sessions were administered, there was no significant difference in participants’ adherence to open-ended questions irrespective of the nature of the feedback, or whether feedback was received. At the immediate post-practice assessment interval, however, the participants who received feedback during the practice interviews performed better (M proportion of open-ended questions = .85, SD = .13) than the other participants (post-interview feedback M = .67, SD = .18, p < .001; no feedback M = .56, SD = .16, p < .001). This heightened use of open-ended questions was associated with a greater tendency among the interviewees to provide abuse-related details in response to open-ended questions (M = .91, SD = .11) compared to the other participants (post-interview feedback M = .77, SD = .15, p < .05; no feedback M = .69, SD = .16, p = .001).
Conclusions
Different types of feedback can be differentially effective in training child abuse investigators to adhere to open-ended questions. The benefits of any training program, however, are likely to be short-lived without ongoing practice.
Practice implications
A single study compared the relative effectiveness of two types of instructor feedback (relative to no feedback) on investigative interviewers’ ability to adhere to open-ended questions in simulated practice interviews about child abuse. This research is relevant to trainers of investigative interviewers because there is currently large variability in the type of feedback employed in training programs. This study is one of the first to empirically demonstrate that different types of feedback may be differentially effective in improving the performance of investigative interviewers.

Photo-catalysis of red wine stains using titanium dioxide sol-gel coatings on wool fabrics

This paper investigated the use of titanium dioxide sol-gel coatings to photo-catalyse red wine stains on wool fabrics. Coatings were produced by the hydrolysis and condensation of titanium butoxide (Ti(OC4H9)4) on the surface of wool fabrics after pad application. Coatings were partially converted to the anatase form of titanium dioxide by prolonged immersion in boiling water. The coating presence was confirmed using scanning electron microscopy, UVspectrophotometry and atomic force microscopy. Coated samples were measured for photo-catalytic activity by degrading red wine stains from the surface of the coated fabric. The level of photocatalysis was determined for each of the coating systems after 168 hours. Red wine stains were photo-catalysed and level of staining was reduced from the UV exposed surface of the coated wool fabric.

The effect of using trained versus untrained adult respondents in simulated practice interviews about child abuse

Objective
A single study tested the hypothesis that simulated practice interviews for investigative interviewers of children are more effective when the role of the child respondent is played by trained actors (i.e., postgraduate psychology students) than untrained fellow participants (i.e., child protection workers).
Method
The interviewers included 50 child protection service workers. Each interviewer received instruction in the use of open-ended questions and then engaged in two simulated practice interviews. The role of the child respondent in the practice interviews was played by either a trained psychology student or an untrained fellow participant. The key outcome measure was the proportion of open-ended questions, which was assessed immediately prior to and after the practice sessions, as well as 12 weeks post-training.
Results
Interviewers who had practiced with trained actors had higher post-training performance (M = .83, SD = .12) compared to those who had practiced with untrained fellow participants (M = .73, SD = .13, p < .05), even at the 12-week follow up (M actors = .66, SD = .25; M untrained actors = .49, SD = .23, p < .05).
Conclusions
Training programs that make better use of practice opportunities (e.g., by using trained respondents) will be more effective in improving the performance of investigative interviewers.
Practice implications
A single study investigated the relative effectiveness of two simulated practice exercises for professionals who interview children about abuse. This research is relevant to professionals who design investigative interviewer training programs because it indicates that practical exercises, which are currently chosen on an ‘ad hoc’ or convenience basis, can vary markedly in their effectiveness in encouraging adherence to open questions.

Improving the competency of police officers in conducting investigative interviews with children

Despite the provision of 'best-practice' guidelines regarding conducting interviews with children, research indicates that most investigative interviews do not adhere to these guidelines. To date, there has been little discussion in the literature of the conditions that are needed to promote and sustain expertise in forensic interviewing. The current paper addresses this limitation by describing the main factors preventing the adoption of 'best-practice' interview guidelines. A description of these barriers (and the literature that supports them) forms the basis for the review component of this paper as well as the subsequent recommendations for change.

An examination of police officers' notes of interviews with alleged child abuse victims

This study provided a critical examination of handwritten records (notes) of interviews contained in a sample of 89 police case files about alleged child abuse. Some of the notes examined related to initial disclosure (complaint) interviews which were not electronically recorded and were meant to be recorded verbatim. Notes of electronically recorded interviews, which merely constituted a convenient summary of the case details, were also examined. Collectively, the analyses focused on the accessibility, completeness and accuracy of the notes, and the degree to which the interviewers' questions and witnesses' answers were differentiated. In relation to the disclosure interviews, a substantial proportion of these were not accessible. Of those where the notes were obtained, the detail recorded was not a complete record of conversation, and there was often poor delineation of questions and responses. Analysis of the electronically recorded interviews showed that these were not an entirely accurate summary of event details even though the note takers' sole task was to document the interview. The implications of these findings are discussed.

Professionals' perceptions of electronically recorded interviews with vulnerable witnesses

This study presents a qualitative evaluation of the Video and Audio Taped Evidence (VATE) process involving vulnerable witnesses, introduced by Victoria Police in 1996. Specifically, this study presents an analysis of individual in-depth interviews with a diverse group of 25 key Victorian stakeholders (police officers, prosecutors, solicitors, defence lawyers, and members of the judiciary). The aim of the interviews was to provide an overview of the stakeholders' perceptions of the VATE system, with particular focus on the usefulness of VATE interviews viewed or used in the stakeholders' practice. The findings revealed unanimous support for electronic recording of witness statements. However, the stakeholders also perceived that the effectiveness of the system was impeded by several factors. These include: (a) frequent absence within the interviews of a coherent account and detail needed to prove the various offences, (b) inability to scrutinise questions asked prior to the VATE interview, (c) lack of feedback regarding how well the VATE system is working, and (d) the recording medium itself which produced statements of poor sound and visual quality. Three broad recommendations arising from the interviews are discussed.

Bioactivating the surfaces of titanium by sol-gel process

In the present study, titanium (Ti) samples were surface-modified by titania (TiO₂), silica (SiO₂) and hydroxyapatite (HA) coatings using a sol-gel process. The bioactivity of the film-coated Ti samples was investigated by cell attachment and morphology study using human osteoblast-like SaOS-2 cells. Results of the cell attachment indicated that the densities of cell attachment on the surfaces of Ti samples were significantly increased by film coatings; the density of cell attachment on HA film-coated surface was higher than those on TiO₂ and SiO₂ film-coated surfaces. Cell morphology study showed that the cells attached, spread and grew well on the three kinds of film-coated surfaces. It can be concluded that the three kinds of film coatings can bioactivate the surfaces of Ti samples effectively. Overall, Ti sample with HA film-coated surface exhibited the best bioactivity.

Bioactive hydroxyapatite coating on titanium-niobium alloy through a sol-gel process

Hydroxyapatite (HA) was coated on the surface of a titanium-niobium (Ti-Nb) alloy by a sol-gel process. Triethyl phosphite and calcium nitrate were used as the phosphorus (P) and calcium (Ca) precursors respectively to prepare a Ca/P sol solution. The Ti-Nb alloy was dip-coated in the sol and heated at 600°C for 30 minutes. X-ray diffraction (XRD) analysis indicated the major phase constituent of the coating after heat treatment was HA. Scanning electron microscopy (SEM) observation showed that a few cracks were distributed on the HA coating. The in-vitro bioactivity of the HA coated Ti-Nb alloy was assessed using a cell culture of SaOS-2 osteoblast-like cells. The density of cell attachment was determined by MTT assay; the cell morphology was observed by SEM. Results indicated that the density of cell attachment on the surface of the Ti-Nb alloy was significantly increased by HA coating. Cell morphology observation showed that cells attached, spread and grew well on the HA coated surface. It can be concluded that the HA coating improved the in-vitro bioactivity of Ti-Nb alloy effectively.