Characterization of the 3YSZ/CNT/HAP coating on the Ti6Al4V alloy by electrophoretic deposition.

In this article, the effects of the simultaneous addition of the 3 mol % yttria-stabilized zirconia (3YSZ) and carbon nanotubes (CNTs) reinforcements on different properties of the natural hydroxyapatite (HAP) coating were studied. The electrophoretic deposition (EPD) process was implemented to prepare thin coatings on the Ti6Al4V substrate. The coatings were then sintered at 1000 ° C under vacuum for 2 hr and the mechanical properties of them were studied by the nano-indentation method. The microsture and phase content of the coatings were investigated by the scanning electron microscope and X-ray diffraction methods, respectively. The electrochemical properties of the samples were studied by potentiodynamic polarization and electrochemical impedance spectroscopy. The biocompatibility of the coatings was evaluated by the MTT test under standard conditions. It was found that the proper voltage and duration for the deposition of the coatings were 20 V and 4 min, while the longer deposition time of up to 6 min. Was tolerable in the coatings containing 5 wt % of the CNTs. The hardness and Young's modulus of the coatings were improved significantly by the siumultaneous addition of 3YSZ and CNTs, but the effect of nanotubes was more prominent. It was also found that the composite coating had marginally lower biocompatibility, as compared to the natural HAP, which was probably due to their lower roughness. The corrosion resistance of the HAP was not affected by the presence of 3YSZ particles, while the addition of CNTs improved the corrosion resistance of the coatings.

A method to quantify crystallinity in amorphous metal alloys: A differential scanning calorimetry study.

We developed and describe a differential scanning calorimetry method for calculating the initial crystallinity, change of crystallinity and crystallinity percentage of amorphous metal alloys as a function of temperature. Using thermodynamic enthalpies of amorphous, crystalline and partially devitrified specimens, our methodology is capable of determining crystallinity percentages as low as a few percent. Moreover, the linear relationship between the set (pre-determined) and calculated crystallinities of experimental samples indicates that there is no need to prepare calibration samples before measuring the crystallinity percentage of target samples. This technique also eliminates the need for expensive in situ accessories, such as those required in electron microscopy. Thus, the technique is highly relevant as a primary technique for characterization of devitrification behavior in amorphous materials.

Deposition of Crystalline Hydroxyapatite Nanoparticles on Y-TZP Ceramic: A Potential Solution to Enhance Bonding Characteristics of Y-TZP Ceramics.

OBJECTIVES: Many advantages have been attributed to dental zirconia ceramics in terms of mechanical and physical properties; however, the bonding ability of this material to dental structure and/or veneering ceramics has always been a matter of concern. On the other hand, hydroxyapatite (HA) shows excellent biocompatibility and good bonding ability to tooth structure, with mechanically unstable and brittle characteristics, that make it clinically unacceptable for use in high stress bearing areas. The main purpose of this study was to introduce two simple yet practical methods to deposit the crystalline HA nanoparticles on zirconia ceramics. MATERIALS AND METHODS: zirconia blocks were treated with HA via two different deposition methods namely thermal coating and air abrasion. Specimens were analyzed by scanning electron microscopy, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). RESULTS: In both groups, the deposition techniques used were successfully accomplished, while the substrate showed no structural change. However, thermal coating group showed a uniform deposition of crystalline HA but in air abrasion method, there were dispersed thin islands of HA. CONCLUSIONS: Thermal coating method has the potential to significantly alter the surface characteristics of zirconia. The simple yet practical nature of the proposed method may be able to shift the bonding paradigm of dental zirconia ceramics. This latter subject needs to be addressed in future investigations.

Deposition of crystalline hydroxyapatite nano-particle on zirconia ceramic: a potential solution for the poor bonding characteristic of zirconia ceramics to resin cement.

The poor bonding strength of zirconia to different dental substrates is one of the challenging issues in restorative dentistry. Hydroxyapatite is an excellent biocompatible material with fine bonding properties. In this study, it was hypothesized that hydroxyapatite coating on zirconia would improve its bond strength. Forty-five zirconia blocks were prepared and randomly divided into three groups: hydroxyapatite coating, sandblasting, and no preparation (control). The blocks were bonded to cement and the micro-shear bond strength was measured following load application. The bond strength values were analyzed with the Kruskal-Wallis test in 3 groups and paired comparisons were made using the Mann-Whitney U test. The failure patterns of the specimens were studied by a stereomicroscope and a scanning electron microscope and then analyzed by the chi-square test (significance level = 0.05). Deposition of hydroxyapatite on the zirconia surface significantly improved its bond strength to the resin cement in comparison with the control specimens (p < 0.0001). Also, the bond strength was similar to the sandblasted group (p = 0.34). The sandblasted and control group only showed adhesive failure, but the hydroxyapatite coated group had mixed failures, indicating the better quality of bonding (p < 0.0001). As a final point, hydroxyapatite coating on the zirconia surface improved the bond strength quality and values.

Model of Current Practice Regarding Prescriptions of Controlled Substances and the Perceived Benefits of E-Prescribing in an Academic Medical Center.

To review current practices regarding prescribing controlled substances at an academic medical center and describe possible advantages of electronic prescribing of controlled substances (EPCS). A 10-question multiple choice survey was sent electronically to all house staff at an academic medical center. Aggregated data was analyzed for trends. 193 surveys (18.8 %) were completed. Of all respondents, 46.6 % were not able to write their own prescriptions. 70.0 % have used another provider's prescription pad to write prescriptions. 53.4 % have had prescriptions rejected or not filled by a pharmacy for being written incorrectly. 59.6 % kept a patient as an inpatient for a longer period of time due to the inability to obtain a prescription, costing an estimated $3.28 million per year. 58.0 % needed to have a patient return to the hospital to pick up prescriptions for an estimated 1583 return trips to the hospital yearly. 35.1 % had a patient return to the emergency department due to uncontrolled pain, estimated at $139,000 in yearly emergency department patient charges. The authors' survey highlights some of the financial, legal, efficiency, and satisfaction disadvantages due to the inability to use EPCS. Implementing EPCS and making it ubiquitous may limit some inefficiencies in academic hospital systems.

Survival and quality of life in rheumatoid arthritis-associated interstitial lung disease after lung transplantation.

BACKGROUND: Patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD) have increased mortality with limited treatment options. We set out to examine post-transplant survival in RA-ILD patients compared with patients with idiopathic pulmonary fibrosis (IPF) and scleroderma-associated ILD (SSc-ILD). We also describe post-transplant quality of life (QoL) outcomes in RA-ILD. METHODS: A retrospective review was performed on lung transplantation (1989 to 2011) among patients with RA-ILD, IPF (group-matched for age and transplant year) and SSc-ILD. Cumulative survival after transplantation was estimated by the Kaplan-Meier method and compared between groups using the log-rank test. The 36-item Medical Outcomes Survey Short Form (SF-36) and the St. George's Respiratory Questionnaire (SGRQ) scores, before and after lung transplantation, were analyzed. RESULTS: Overall, 10 patients with RA-ILD, 53 with IPF and 17 with SSc-ILD underwent lung transplantation with ages (mean ± SD) of 59.4 ± 5.6, 61.0 ± 4.0 and 45.4 ± 12.7 years, respectively. Cumulative survival rates at 1-year post-transplant for the RA-ILD, IPF and SSc-ILD groups were 67%, 69% and 82%, respectively, and there was no significant difference among groups in age- and gender-adjusted analyses. Among the RA-ILD patients, mean SF-36 physical component summary scores improved from 22.4 ± 8.1 to 32.2 ± 12.9 (p = 0.1), SF-36 mental component summary scores improved from 44.7 ± 15.3 to 54.9 ± 4.8 (p = 0.19) and SGRQ total scores improved from 70.4 ± 16.1 to 36.0 ± 18.5 (p = 0.03). CONCLUSIONS: After lung transplantation, RA-ILD and IPF patients have similar survival rates. Further, in RA-ILD patients, lung transplantation appears to result in a significant improvement in QoL with regard to respiratory symptoms. These data suggest that lung transplantation should be considered in patients with end-stage RA-ILD.

Synthesis and anti-inflammatory effects of new piperazine and ethanolamine derivatives of H(1)-antihistaminic drugs.

In addition to their antihistamine effects, H1-receptor antagonists possess pharmacological properties that are not uniformly distributed among this class of drugs, such as anti-inflammatory, anti-allergic and antiplatelet activities. In this paper, Cyclizine (1-benzhydryl-4-methyl-piperazine, I), bromodiphenhydramine (2-[(4-bromophenyl)-phenylmethoxy]-N, N-dimethylethanamine, II) and some of their new piperazine and ethanolamine derivatives (III-VIII) inducing changes in substitution of phenyl and amine moieties were synthesized and their acute and chronic antiinflammatory effects were evaluated by standard pharmacological tests. The results showed that substitution of phenyl by tolyl, anisol and cumene groups in piperazine family could remarkably decrease acute inflammation in these new drugs. Also, substitution of dimethylamine by morpholine group could not decrease this inflammation in new synthesized ethanolamine family. But the results from the cotton pellet-induced granuloma formation in rats showed that none of drugs (I-VIII) were effective to reduce the chronic inflammation.

Reassessment of the environmental model of developmental polyphenism in spadefoot toad tadpoles.

Polyphenism is the expression of multiple, discrete phenotypes from one genotype, and understanding the environmental factors that trigger development of alternative phenotypes is a critical step toward understanding the evolution of polyphenism and its developmental control. While much is known about the ecology of the well-known carnivore/omnivore polyphenism in spadefoot toad tadpoles, the environmental cues for the development of the specialized carnivore phenotype are not completely clear. We examined 27 different experimental treatments in two spadefoot toad species and used over 1,000 tadpoles in an attempt to elucidate those cues. While only 44 carnivores developed in these treatments, they were concentrated at cooler water temperatures and a diet that included fairy shrimp. However, while a diet of fairy shrimp promoted carnivore development, it was not necessary for inducing carnivore development at lower and intermediate water temperatures. Evidence also suggested a role for social inhibition that limited the proportion of interacting tadpoles that become carnivores. Tadpoles of Spea multiplicata grew larger at cooler temperatures and larger when their diets included fairy shrimp, whereas tadpoles of S. bombifrons grew larger at warmer temperatures and when their diets did not include fairy shrimp. These results indicate that carnivore induction can occur through different cues and that our current model for carnivore development is too limited. Finally, we argue that the carnivore/omnivore spadefoot system is neither a polyphenism nor a polymorphism but is a continuously distributed plasticity.

Evaluating the cost-effectiveness of anterior uveitis investigation by Canadian ophthalmologists.

BACKGROUND: To evaluate the cost-effectiveness of anterior uveitis investigation by Canadian ophthalmologists and to assess the role of implementing national clinical guidelines for such investigation. METHODS: Based on data extracted from the Canadian National Uveitis Survey (CNUS, 2007 version), the cost of investigating a patient with anterior uveitis, according to current practice patterns of Canadian ophthalmologists, was determined and grouped across 4 clinical scenarios: (i) nongranulomatous anterior uveitis in an adult, (ii) granulomatous anterior uveitis in an adult, (iii) granulomatous anterior uveitis with suspected sarcoidosis in an adult or a child, and (iv) nongranulomatous anterior uveitis in a child. Similarly, the cost of investigating a patient with anterior uveitis as per published evidence-based guidelines was determined and compared with the current practice pattern using a cost-minimization model, sensitivity analyses, and Monte Carlo simulations. RESULTS: Ophthalmologists were found to consistently order more tests than recommended by evidence-based guidelines, across each of the scenarios studied (p < 0.05). Overall, complete blood count, erythrocyte sedimentation rate, C-reactive protein, antinuclear antibody, and rheumatoid factor were the most commonly ordered extraneous tests that were not included in the evidence-based guidelines for the routine investigation of anterior uveitis. Also, there were significant differences in the cost of investigating a patient with anterior uveitis when compared with those predicted by adhering to evidence-based clinical practice guidelines. Cost minimization and sensitivity analyses revealed that published guidelines imparted cost savings when compared with current practice patterns across the 4 clinical scenarios studied (p < 0.01). The maximum additional cost was associated with investigating nongranulomatous anterior uveitis in an adult, where a minimal additional cost of $75 per patient was spent. For granulomatous anterior uveitis in an adult, the additional cost was approximately $40, whereas the additional cost for investigating an adult or a child with suspected sarcoidosis was $36. Only $11 of additional cost was spent in the workup of a child with nongranulomatous anterior uveitis. When applied to the Canadian population, adherence to the Clinical Practice Guidelines recommended by the CNUS may result in cost savings of $600,000 per year to the Canadian health care system. INTERPRETATION: Adherence to the evidence-based Clinical Practice Guidelines recommended by the CNUS may result in significant cost savings, with virtually no loss of sensitivity in the routine investigation of anterior uveitis in Canada.

Knowledge and attitudes of young people in Guyana to HIV/AIDS.

HIV prevalence in Guyana is the third highest in the Caribbean which, in turn, is the second-most-affected region in the world. Over 2000 young people aged 12-20 years completed self-report questionnaires that examined their knowledge of HIV/AIDS, their attitudes to sexual behaviours and their intentions with regard to virginity and use of condoms. Nearly one-quarter of young people aged 12-14 were sexually active and this rose to over one-third for youths aged 15 years and over, but condoms were only used consistently by two in five of these persons. Attitudes and intentions towards sexual behaviour were significantly influenced by religious teaching as well as by gender and age. Hence, prevention strategies for the spread of HIV/AIDS should harness religious belief and practice, especially in societies such as Guyana where religious affiliation remains strong.